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1

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

PubMed

We propose a novel method of calculation of free energy for coarse grained models of proteins by combining our newly developed multibody potentials with entropies computed from elastic network models of proteins. Multi-body potentials have been of much interest recently because they take into account three dimensional interactions related to residue packing and capture the cooperativity of these interactions in protein structures. Combining four-body non-sequential, four-body sequential and pairwise short range potentials with optimized weights for each term, our coarse-grained potential improved recognition of native structure among misfolded decoys, outperforming all other contact potentials for CASP8 decoy sets and performance comparable to the fully atomic empirical DFIRE potentials. By combing statistical contact potentials with entropies from elastic network models of the same structures we can compute free energy changes and improve coarse-grained modeling of protein structure and dynamics. The consideration of protein flexibility and dynamics should improve protein structure prediction and refinement of computational models. This work is the first to combine coarse-grained multibody potentials with an entropic model that takes into account contributions of the entire structure, investigating native-like decoy selection. PMID:21674234

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

2011-07-01

2

Notepad-like Triboelectric Generator for Efficiently Harvesting Low-Velocity Motion Energy by Interconversion between Kinetic Energy and Elastic Potential Energy.  

PubMed

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

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

2015-01-21

3

Potential Energy\\/Kinetic Energy  

Microsoft Academic Search

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

David Rogers

2004-01-01

4

Potential Energy  

NSDL National Science Digital Library

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

2010-01-01

5

Storage and utilization of elastic strain energy during jumping.  

PubMed

Based upon the optimal control solutions to a maximum-height countermovement jump (CMJ) and a maximum-height squat jump (SJ), this paper provides a quantitative description of how tendons and the elastic elements of muscle store and deliver energy during vertical jumping. After confirming the ability of the model to replicate the major features of each jump (i.e. muscle activation patterns, body-segmental motions, ground reaction forces, jump height, and total ground contact time), the time histories of the forces and shortening velocities of all the musculotendon actuators in the model were used to calculate the work done on the skeleton by tendons as well as the series-elastic elements, the parallel-elastic elements, and the contractile elements of muscle. We found that all the elastic tissues delivered nearly the same amount of energy to the skeleton during a CMJ and an SJ. The reason is twofold: first, nearly as much elastic strain energy was stored during the SJ as the CMJ; second, more stored elastic strain energy was lost as heat during the CMJ. There was also a difference in the way energy was stored during each jump. During the CMJ, strain energy stored in the elastic tissues came primarily from the gravitational potential energy of the skeleton as the more proximal extensor muscles were stretched during the downward phase of the jump. During the SJ, on the other hand, energy stored in the elastic tissues came primarily from the contractile elements as they did work to stretch the tendons and the series-elastic elements of the muscles. Increasing tendon compliance in the model led to an increase in elastic energy storage and utilization, but it also decreased the amount of energy delivered by the contractile elements to the skeleton. Jump height therefore remained almost the same for both jumps. These results suggest that elastic energy storage and utilization enhance jumping efficiency much more than overall jumping performance. PMID:8308046

Anderson, F C; Pandy, M G

1993-12-01

6

Universal formulae for the limiting elastic energy of membrane networks  

E-print Network

We provide universal formulae for the limiting stretching and bending energies of triangulated membrane networks endowed with nearest neighbor bond potentials and cosine-type dihedral angle potentials. The given formulae account for finite elasticity and solve some deficiencies of earlier results for Helfrich-type bending energies, due to shape-dependence and sensitivity to mesh distortion effects of the limiting elastic coefficients. We also provide the entire set of the elastic coefficients characterizing the limiting response of the examined networks, accounting for full bending-stretching coupling. We illustrate the effectiveness of the proposed formulae by way of example, on examining the special cases of cylindrical and spherical networks covered with equilateral triangles, and discussing possible strategies for the experimental characterization of selected elastic moduli.

Bernd Schmidt; Fernando Fraternali

2011-02-07

7

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

8

Elastic energy of a deformable earth - General expression  

NASA Astrophysics Data System (ADS)

The production of energy in the earth's elastic mantle as it is deformed by lunar and solar attraction is investigated analytically, extending and refining the results of Getino and Ferrandiz (1991). The derivation is given in detail, and it is shown that the energy expression obtained is valid for any order of the development in spherical harmonics of the perturbing tidal potential and independent of the earth model employed. As an example, the total elastic energy for Model 2 of Takeuchi (1950) is calculated as 5.813114 x 10 exp 49 in cgs units.

Getino, Juan

1992-03-01

9

Folding model study of the elastic $?+ ?$ scattering at low energies  

E-print Network

The folding model analysis of the elastic $\\alpha + \\alpha$ scattering at the incident energies below the reaction threshold of 34.7 MeV (in the lab system) has been done using the well-tested density dependent versions of the M3Y interaction and realistic choices for the $^4$He density. Because the absorption is negligible at the energies below the reaction threshold, we were able to probe the $\\alpha + \\alpha$ optical potential at low energies quite unambiguously and found that the $\\alpha + \\alpha$ overlap density used to construct the density dependence of the M3Y interaction is strongly distorted by the Pauli blocking. This result gives possible explanation of a long-standing inconsistency of the double-folding model in its study of the elastic $\\alpha + \\alpha$ and $\\alpha$-nucleus scattering at low energies using the same realistic density dependent M3Y interaction.

Ngo Hai Tan; Nguyen Hoang Phuc; Dao T. Khoa

2014-03-13

10

Optical Potentials for Elastic and Inelastic Scattering of Non-Electronic Projectiles from Electronic Targets  

NASA Astrophysics Data System (ADS)

The usual text book one-particle Green's function possesses a self-energy that is known to be an optical potential for elastic scattering. The introduction of an optical potential reduces the complex many-body scattering problem into a tractable one-body problem. In this work the definition of the Green's functions is extended. The defined inelastic functions are shown to possess self-energies that can be expressed in closed form in terms of the target states. It is proven that these self-energies are optical potentials for inelastic scattering. The properties of these potentials and working equations for the scattering wave functions are discussed.

Cederbaum, L. S.

1996-12-01

11

Elastically bounded flapping wing for energy harvesting  

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

12

Potential and kinetic energy  

NSDL National Science Digital Library

What is the difference between potential and kinetic energy? This informational piece, part of a series about the future of energy, introduces students to kinetic and potential energy. The law of conservation of energy is explained, using the example of turning natural gas into electricity. Definitions and examples of potential energy and kinetic energy are provided. Copyright 2005 Eisenhower National Clearinghouse

Iowa Public Television. Explore More Project

2004-01-01

13

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

14

An Expression for the Granular Elastic Energy  

E-print Network

Granular Solid Hydrodynamics (GSH) is a broad-ranged continual mechanical description of granular media capable of accounting for static stress distributions, yield phenomena, propagation and damping of elastic waves, the critical state, shear band, and fast dense flow. An important input of GSH is an expression for the elastic energy needed to deform the grains. The original expression, though useful and simple, has some draw-backs. Therefore, a slightly more complicated expression is proposed here that eliminates three of them: (1) The maximal angle at which an inclined layer of grains remains stable is increased from $26^\\circ$ to the more realistic value of $30^\\circ$. (2)Depending on direction and polarization, transverse elastic waves are known to propagate at slightly different velocities. The old expression neglects these differences, the new one successfully reproduces them. (3) Most importantly, the old expression contains only the Drucker-Prager yield surface. The new one contains in addition those named after Coulomb, Lade-Duncan and Matsuoka-Nakai -- realizing each, and interpolating between them, by shifting a single scalar parameter.

Yimin Jiang; Hepeng Zheng; Zheng Peng; Liping Fu; Shixiong Song; Qicheng Sun; Michael Mayer; Mario Liu

2012-06-13

15

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.

16

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

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

17

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

18

np elastic scattering analyzing power characteristics at intermediate energies  

SciTech Connect

Recent measurements of charge symmetry breaking in the {ital np} system at 477 MeV, and of {ital A}{sub 00{ital nn}} for {ital np} elastic scattering at 220, 325, and 425 MeV also yield accurate analyzing power data. These data allow the energy dependence of the analyzing power zero-crossing angle and the slope of the analyzing power at the zero-crossing angle to be determined. The incident neutron energies span a region where the zero-crossing angle is strongly energy dependent ({ital E}{sub {ital n}}{lt}250 MeV) to where it is almost independent of energy ({ital E}{sub {ital n}}{gt}350 MeV). The results are compared to current phase-shift analysis predictions, recently published data, and the predictions of the Bonn and Paris potentials.

Abegg, R.; Ahmad, M.; Bandyopadhyay, D.; Birchall, J.; Cairns, E.B.; Chantziantoniou, K.; Coombes, G.H.; Davis, C.A.; Davison, N.E.; Delheij, P.P.J.; Green, P.W.; Greeniaus, L.G.; Gubler, H.P.; Healey, D.C.; Lapointe, C.; Lee, W.P.; McDonald, W.J.; Miller, C.A.; Moss, G.A.; Page, S.A.; Plattner, G.R.; Poffenberger, P.R.; Ramsay, W.D.; Rodning, N.L.; Roy, G.; Soukup, J.; Svenne, J.P.; Tkachuk, R.R.; van Oers, W.T.H.; Wait, G.D.; Watson, J.W.; Ye, Y.; Zhang, Y.P. (TRIUMF, Vancouver, British Columbia, Canada V6T 2A3 (CA) University of Manitoba, Department of Physics, Winnipeg, Manitoba, Canada R3T 2N2 University of Alberta, Department of Physics, Edmonton, Alberta, Canada T6G 2N5 University of Basel, Institute of Physics, CH-4000 Basel, Switzerland Kent State University, Department of Physics, Kent, Ohio 44242)

1989-11-01

19

MATERIAL VOIDS IN ELASTIC SOLIDS WITH ANISOTROPIC SURFACE ENERGIES  

E-print Network

MATERIAL VOIDS IN ELASTIC SOLIDS WITH ANISOTROPIC SURFACE ENERGIES Irene Fonseca, Nicola Fusco energy for problems involving a material void in a linearly elastic solid. Using the calculus of variations it is shown that the qualitative features of the equilibrium shape of the void demonstrate

20

Lateral density variations in elastic Earth models from an extended minimum energy approach  

NASA Technical Reports Server (NTRS)

Kaula's minimum energy approach was extended to include the nonhydrostatic gravitational potential energy and the density perturbation field was obtained to degree and order eight. The depth profiles for the density perturbation show a stratification with density excesses and deficiencies alternating with depth. The addition of the gravitational potential energy in the minimization process does not change significantly the conclusions based on results for the minimum shear strain energy case, concerning the inability of the mantle to withstand the lateral loading elastically.

Sanchez, B. V.

1980-01-01

21

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

22

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

energy per unit volume when a body is strained is P. E.- Work stress . strain The moment acting upon a twisted rod nay be ob- tained by integrating, over the whole cross-section the moment acting upon a circular lamina. That is c* r * M - J 2 IT dr... * 2 W n ^ j r 9 T * I dr = -? • % nE4 - 4 - where 1 represents the length of the rod, 9 the angle through which one end is twisted from its original position, r the distance, from the center to any particular lamina, and R the radius of the rod...

Power, Archie Dayton

1912-06-01

23

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

24

Generalized available potential energy  

Microsoft Academic Search

The kinetic energy generation in either the dry or moist atmosphere may be estimated by the same relationships if we introduce\\u000a the new concept of generalized available potential energy. The largest magnitude of generalized available potential energy\\u000a and corresponding reference state of either dry or moist atmosphere are calculated in terms of the initial conditions and\\u000a entropy variation of the

Yong L. McHall

1990-01-01

25

{sup 6}He+{sup 12}C elastic scattering using a microscopic optical potential  

SciTech Connect

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

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)

2010-08-15

26

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

27

Elastic scattering of Li on Zn at near-barrier energies  

Microsoft Academic Search

Elastic-scattering angular distributions for the Li+Zn system were measured at eight beam energies from below to above the Coulomb barrier, 12.0{<=}E{sub lab}{<=}22.0 MeV. The experimental data were analyzed within the optical model to study the energy dependence of the interaction potential and to obtain total reaction cross sections. The results obtained using several optical model potentials show similar behavior. The

M. Zadro; P. Figuera; A. Di Pietro; M. Fisichella; C. Maiolino; D. Santonocito; F. Amorini; M. Lattuada; A. Musumarra; M. G. Pellegriti; F. Rizzo; V. Scuderi; D. Torresi; O. Goryunov; V. Ostashko; M. Papa

2009-01-01

28

Low-energy elastic electron interactions with pyrimidine  

SciTech Connect

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

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

2011-12-15

29

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

30

Do we understand elastic scattering up to LHC energies?  

SciTech Connect

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

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

2013-04-15

31

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

32

Elastic energy and tectonic surface movements on Mars  

Microsoft Academic Search

The results of detailed model calculations of the elastogravitational energy stored in the crust of Mars are presented. The quadrupolar elastic energy is found to be about 1.4 by 10 to the 30th power erg, while the average shear angle is approximately 0.00014. In the western hemisphere of Mars there is considerable correlation between the calculated higher-order maxima in the

D. Pines; J. Shaham; M. Cohen

1977-01-01

33

LABORATORY III POTENTIAL ENERGY  

E-print Network

of the system. · Be able to use forces and draw a free-body diagram for any system. · Be able to determine: sections 7.1-7.3. 1. Draw a picture of the situation at each of the three different times described in the problem. Label all relevant quantities on the diagram for each time. #12;PROBLEM #1: ELASTIC

Minnesota, University of

34

Elastic scattering of {sup 6}Li on {sup 64}Zn at near-barrier energies  

SciTech Connect

Elastic-scattering angular distributions for the {sup 6}Li+{sup 64}Zn system were measured at eight beam energies from below to above the Coulomb barrier, 12.0{<=}E{sub lab}{<=}22.0 MeV. The experimental data were analyzed within the optical model to study the energy dependence of the interaction potential and to obtain total reaction cross sections. The results obtained using several optical model potentials show similar behavior. The energy dependence of the strengths of the real and imaginary potentials suggests the presence of the breakup threshold anomaly. It is shown that the extracted energy dependence of the interaction potential at sub-barrier energies is very sensitive to possible experimental errors.

Zadro, M. [Rudjer Boskovic Institute, Bijenicka 54, HR-10000 Zagreb (Croatia); Figuera, P.; Pietro, A. Di; Fisichella, M.; Maiolino, C.; Santonocito, D. [INFN, Laboratori Nazionali del Sud, via S. Sofia 62, I-95123 Catania (Italy); Amorini, F.; Lattuada, M.; Musumarra, A.; Pellegriti, M. G.; Rizzo, F.; Scuderi, V.; Torresi, D. [INFN, Laboratori Nazionali del Sud, via S. Sofia 62, I-95123 Catania (Italy); Universita di Catania, via S. Sofia 64, I-95123 Catania (Italy); Goryunov, O.; Ostashko, V. [Kiev Institut for Nuclear Research, Kiev (Ukraine); Papa, M. [INFN, Sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy)

2009-12-15

35

Physics 321 Energy Conservation Potential Energy in  

E-print Network

Physics 321 Hour 7 Energy Conservation ­ Potential Energy in One Dimension Work-Energy Theorem = 1 work increases kinetic energy, negative work decreases kinetic energy Gravity Depending on initial is independent of path. If we know we also know . 1 2 y x Potential Energy If T is dependent only on the end

Hart, Gus

36

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

NASA Astrophysics Data System (ADS)

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

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

2010-07-01

37

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

38

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

39

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

40

Low Energy Experimental Elastic Cross Sections for Medical Physics Application  

NASA Astrophysics Data System (ADS)

Elastic cross sections for electron energies below 10 MeV are fundamental quantities needed in treatment planning systems used at hospitals and health facilities. To date, there is very little if not no data within that energy regime. In collaboration with the high current, high energy resolution continuous electron beam of the Department of Energy's Jefferson Lab accelerator, we have performed a first stage of dedicated experiments with energies of 100-150 keV to collect data for this type of reactions. The targets used were gold, copper and silver. A Mott scattering chamber was used to detect the outgoing electrons. We will present the first results of this program that aims at performing a wide range of measurements including the use of polarization data for spin studies.

Epps, Michael

2006-03-01

41

Failure of the Woods-Saxon nuclear potential to simultaneously reproduce precise fusion and elastic scattering measurements  

SciTech Connect

A precise fusion excitation function has been measured for the {sup 12}C+{sup 208}Pb reaction at energies around the barrier, allowing the fusion barrier distribution to be extracted. The fusion cross sections at high energies differ significantly from existing fusion data. Coupled reaction channels calculations have been carried out with the code FRESCO. A bare potential previously claimed to uniquely describe a wide range of {sup 12}C+{sup 208}Pb near-barrier reaction channels failed to reproduce the new fusion data. The nuclear potential diffuseness of 0.95 fm which fits the fusion excitation function over a broad energy range fails to reproduce the elastic scattering. A diffuseness of 0.55 fm reproduces the fusion barrier distribution and elastic scattering data, but significantly overpredicts the fusion cross sections at high energies. This may be due to physical processes not included in the calculations. To constrain calculations, it is desirable to have precisely measured fusion cross sections, especially at energies around the barrier.

Mukherjee, A.; Hinde, D. J.; Dasgupta, M.; Newton, J. O.; Butt, R. D. [Department of Nuclear Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Hagino, K. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

2007-04-15

42

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

43

Investigating Kinetic and Potential Energy  

NSDL National Science Digital Library

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

WGBH Educational Foundation

2007-04-19

44

Indirect evidence for elastic energy playing a role in limb recovery during toad hopping.  

PubMed

Elastic energy is critical for amplifying muscle power during the propulsive phase of anuran jumping. In this study, we use toads (Bufo marinus) to address whether elastic recoil is also involved after take-off to help flex the limbs before landing. The potential for such spring-like behaviour stems from the unusually flexed configuration of a toad's hindlimbs in a relaxed state. Manual extension of the knee beyond approximately 90° leads to the rapid development of passive tension in the limb as underlying elastic tissues become stretched. We hypothesized that during take-off, the knee regularly extends beyond this, allowing passive recoil to help drive limb flexion in mid-air. To test this, we used high-speed video and electromyography to record hindlimb kinematics and electrical activity in a hindlimb extensor (semimembranosus) and flexor (iliofibularis). We predicted that hops in which the knees extended further during take-off would require less knee flexor recruitment during recovery. Knees extended beyond 90° in over 80% of hops, and longer hops involved greater degrees of knee extension during take-off and more intense semimembranosus activity. However, knee flexion velocities during recovery were maintained despite a significant decrease in iliofibularis intensity in longer hops, results consistent with elastic recoil playing a role. PMID:25030045

Schnyer, Ariela; Gallardo, Mirialys; Cox, Suzanne; Gillis, Gary

2014-07-01

45

Elastic scattering of low-energy electrons by nitromethane  

SciTech Connect

In this work, we present integral, differential, and momentum transfer cross sections for elastic scattering of low-energy electrons by nitromethane, for energies up to 10 eV. We calculated the cross sections using the Schwinger multichannel method with pseudopotentials, in the static-exchange and in the static-exchange plus polarization approximations. The computed integral cross sections show a {pi}* shape resonance at 0.70 eV in the static-exchange-polarization approximation, which is in reasonable agreement with experimental data. We also found a {sigma}* shape resonance at 4.8 eV in the static-exchange-polarization approximation, which has not been previously characterized by the experiment. We also discuss how these resonances may play a role in the dissociation process of this molecule.

Lopes, A. R.; D'A Sanchez, S.; Bettega, M. H. F. [Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19044, 81531-990 Curitiba, Parana (Brazil)

2011-06-15

46

Proton-proton elastic scattering excitation functions at intermediate energies  

NASA Astrophysics Data System (ADS)

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

Rohdjess, H.

1998-05-01

47

Proton-proton elastic scattering excitation functions at intermediate energies  

SciTech Connect

Polarized and unpolarized proton-proton elastic scattering is investigated with the EDDA-experiment at the Cooler Synchrotron COSY at Juelich to significantly improve the world data base in the beam energy range 500-2500 MeV. Measurements during beam acceleration with thin internal targets and a large acceptance detector provide excitation functions over a broad angular and energy range with unprecedented internal consistency. Data taking with an unpolarized CH{sub 2} fiber target and an unpolarized beam have been completed and the derived differential cross sections are presented and compared to a recent phase shift analysis. With a polarized atomic beam target newly installed in COSY and a polarized COSY beam--currently under development--the measurements will be extended to analyzing powers and spin correlation parameters.

Rohdjess, H. [Institut fuer Strahlen- und Keruphysik. Universitaet Bonn, D-53115 Bonn (Germany)

1998-05-29

48

STATEWIDE ENERGY EFFICIENCY POTENTIAL ESTIMATES AND TARGETS  

E-print Network

Energy efficiency, energy savings, demand reduction, electricity consumption, natural gas consumption, electric peak demand reduction, energy efficiency potential estimates, energy efficiency targets, energyCALIFORNIA ENERGY COMMISSION STATEWIDE ENERGY EFFICIENCY POTENTIAL ESTIMATES AND TARGETS

49

Wind energy potential in Turkey  

Microsoft Academic Search

Lewis's methods are employed to evaluate the wind energy potentials of four selected locations, which have experienced relatively high wind velocities. In addition to Lewis's methods, the relations connecting the instantaneous and average wind powers, total and maximum wind energies for a given period of time are derived. Characteristics of wind energy, including rotor radius and tower height, are estimated

H. Külünk

1993-01-01

50

Chapter 20: Electric Potential and Electric Potential Energy  

E-print Network

. The change in potential energy is the charge times the potential difference (equation 20-2). The change in potential energy equals the gain in kinetic energy, which can then be used to find the speed. 1. Set the kinetic energy equal to the change in potential energy and solve for v: 21 2 2e V mv U e V v m = = = 2

Kioussis, Nicholas

51

Anchoring energy and orientational elasticity of a ferroelectric liquid crystal  

SciTech Connect

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

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

2012-06-15

52

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...

Blanchon, G; Arellano, H F; Mau, N Vinh

2014-01-01

53

The elastic modulus correction term in creep activation energies Applied to oxide dispersion strengthened superalloy  

NASA Technical Reports Server (NTRS)

The effect of elastic modulus and the temperature dependence of elastic modulus on creep activation energies for an oxide dispersion strengthened nickel-base superalloy are investigated. This superalloy is commercially known as Inconel Alloy MA 753, strengthened both by gamma-prime precipitates and by yttria particles. It is shown that at intermediate temperatures, say below 1500 F, where elastic modulus is weakly dependent on temperature, the modulus correction term to creep activation energy is small. Accordingly, modulus corrections are insignificant for the superalloy considered, which shows high apparent creep activation energies at this temperature. On the contrary, at very high temperatures, the elastic modulus correction term can be significant, thus reducing the creep activation energy to that of vacancy self-diffusion. In order to obtain high-temperature creep resistance, a high-value elastic modulus with a weak dependence on temperature is required.

Malu, M.; Tien, J. K.

1975-01-01

54

Elastic energy loss and longitudinal straggling of a hard jet  

SciTech Connect

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

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

2009-09-15

55

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

56

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

PubMed

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

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

2009-05-01

57

Regularization of hypersingular and nearly singular integrals in the potential theory and elasticity  

NASA Astrophysics Data System (ADS)

Both the hypersingular and nearly singular integrals, which appear in the hypersingular boundary integral equations and integral representations of the secondary fields, respectively, are regularized by the application of the superposition principle. Two kinds of the non-singular formulations, namely, those with the strongly singular and weakly singular kernels, are presented in this paper. The formulations are given in terms of the relevant boundary quantities and the collocation at element junctions is possible. Two- and three-dimensional problems are analyzed simultaneously in a unique way for either internal or external problems of the potential theory and elasticity.

Sladek, V.; Sladek, J.; Tanaka, M.

1993-05-01

58

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

2012-01-11

59

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

60

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

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

61

Systematic study of the ?-optical potential via elastic scattering near the Z=50 region for p-process nuclei  

NASA Astrophysics Data System (ADS)

Production of proton-rich nuclei beyond iron in stars proceeds via the p process, i.e., a sequence of photodisintegration reactions, (?,n), (?,p), and (?,?) on heavy nuclei at temperatures of 2-3×109 K. The involved reaction rates are typically calculated with the statistical Hauser-Feshbach (HF) model. However, the HF model performs poorly in calculating the critical (?,?) rates due to the uncertainty of the alpha optical potentials applied. To test the reliability of the HF calculations and provide a systematic understanding of the ? optical potential at energies of astrophysical interest, a series of precision ? scattering measurements were carried out at the Notre Dame FN Tandem Accelerator. Specifically, 106Cd, 118Sn, and 120,124,126,128,130Te were studied at energies both below and above the Coulomb barrier. A new parametrization of the ? optical potential was derived of the elastic scattering cross section data. The derived potential was applied for calculating the ?-induced reaction cross sections on these nuclei using the HF approach. The results were compared to the corresponding experimental values obtained from previous activation measurements on Cd, Sn, and Te isotopes.

Palumbo, A.; Tan, W. P.; Görres, J.; Best, A.; Couder, M.; Crowter, R.; deBoer, R. J.; Falahat, S.; LeBlanc, P. J.; Lee, H. Y.; O'Brien, S.; Strandberg, E.; Wiescher, M.; Greene, J. P.; Fülöp, Zs.; Kiss, G. G.; Somorjai, E.; Özkan, N.; Efe, G.; Güray, R. T.

2012-03-01

62

Performance of bistable piezoelectric cantilever vibration energy harvesters with an elastic support external magnet  

NASA Astrophysics Data System (ADS)

Based on the research results of conventional rigid support nonlinear energy harvesters, in this paper we conceive a kind of structure with an elastic support external magnet with the intent to keep the system in the state of bistable oscillation, even under low-intensity excitation conditions. It has been proved that elastic support systems have better power output performance than rigid support systems when excited at low-intensity vibrations. In addition, elastic support nonlinear energy harvesters do not need real-time adjustment of the magnet interval towards the variable-intensity random excitation source, consequently achieving maximum power output and sufficient electromechanical energy conversion of the system.

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

2014-09-01

63

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

64

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

E-print Network

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

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

2014-05-26

65

Available equivalent potential energy in moist atmospheres  

Microsoft Academic Search

Summary The equivalent potential energy of the moist atmosphere is defined as the sum of its total potential energy and latent heat. The available equivalent potential energy is the amount of equivalent potential energy available for conversion into kinetic energy. For the isolated moist atmospheres, we may find the equivalent lowest state which is the limit of the states attained

Y. L. McHall

1991-01-01

66

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

67

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

68

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

69

Phase-shift analysis of low-energy $?^{\\pm}p$ elastic-scattering data  

E-print Network

Using electromagnetic corrections previously calculated by means of a potential model, we have made a phase-shift analysis of the $\\pi^\\pm p$ elastic-scattering data up to a pion laboratory kinetic energy of 100 MeV. The hadronic interaction was assumed to be isospin invariant. We found that it was possible to obtain self-consistent databases by removing very few measurements. A pion-nucleon model was fitted to the elastic-scattering database obtained after the removal of the outliers. The model-parameter values showed an impressive stability when the database was subjected to different criteria for the rejection of experiments. Our result for the pseudovector $\\pi N N$ coupling constant (in the standard form) is $0.0733 \\pm 0.0014$. The six hadronic phase shifts up to 100 MeV are given in tabulated form. We also give the values of the s-wave scattering lengths and the p-wave scattering volumes. Big differences in the s-wave part of the interaction were observed when comparing our hadronic phase shifts with those of the current GWU solution. We demonstrate that the hadronic phase shifts obtained from the analysis of the elastic-scattering data cannot reproduce the measurements of the $\\pi^- p$ charge-exchange reaction, thus corroborating past evidence that the hadronic interaction violates isospin invariance. Assuming the validity of the result obtained within the framework of chiral perturbation theory, that the mass difference between the $u$- and the $d$-quark has only a very small effect on the isospin invariance of the purely hadronic interaction, the isospin-invariance violation revealed by the data must arise from the fact that we are dealing with a hadronic interaction which still contains residual effects of electromagnetic origin.

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

2006-07-07

70

Elastic energy in microscopically phase-separated swollen polymer networks  

Microsoft Academic Search

The paper analyzes a microscopic regime of strain, different from the one conventionally considered, that presumably takes place in swollen polymers showing strong microscopic phase separation, such as ion-exchange resins in water. Such systems show linear dependence of the elastic pressure on swelling in contrast to the Flory–Rehner theory and its modifications. The present work proposes a simple model that

Viatcheslav Freger

2002-01-01

71

Neuromechanics of elastic energy storage and recovery during ballistic  

E-print Network

physiologists typically study the behavior of muscle under a limited set of conditions, such as isometric a wide range of conditions, particularly those in which muscles develop force against a resisting force, and shorten when the resisting force is reduced. Using this technique, we developed an elastic recoil model

Valero-Cuevas, Francisco

72

Elastic energy of a deformable earth: General expression  

Microsoft Academic Search

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

Juan Getino; Facultad Ciencias

1992-01-01

73

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

74

Improved global /?-optical model potentials at low energies  

NASA Astrophysics Data System (ADS)

Many nuclear astrophysics applications involve radiative /?-particle captures, /? decays and /?-particle transfer reactions. Theoretical estimates of the corresponding reaction rates within the framework of the statistical model of Hauser-Feshbach remain highly uncertain due to the poor knowledge of the /?-nucleus optical model potential, especially at low energies far below the Coulomb barrier. In the present paper we propose a new global /?-optical potential that takes into account the strong energy dependence and nuclear structure effects that characterize the /?-nucleus interaction. The real part of the potential is calculated using a double-folding procedure over the M3Y effective nucleon-nucleon interaction. A Woods-Saxon potential is used for the imaginary potential where now a new parameterization is introduced to describe its energy dependence. The influence of purely volume absorption or volume plus surface absorption on the description of the experimental data is investigated. Finally, the dispersive relation is applied to relate the real and imaginary parts of the optical model potential and reduce the ambiguities in deriving the potential from experimental data. The three potentials considered are able to reproduce well the bulk of experimental data on (/?,?), (/?,n), (/?,p) and (n,?) reactions as well as the existing elastic scattering data at energies of relevance to astrophysical applications. However, when considering reaction rates on experimentally unexplored targets, deviations within a factor of 10 are found. These uncertainties are principally due to the difficulty in constraining the diffuseness of the imaginary potential from analyses of existing experimental data.

Demetriou, P.; Grama, C.; Goriely, S.

2002-08-01

75

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

NASA Technical Reports Server (NTRS)

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

Li, Rongshun; Chudnovsky, A.

1993-01-01

76

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

77

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

Microsoft Academic Search

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

P. Demetriou; M. Axiotis

2007-01-01

78

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

SciTech Connect

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

Kawano, Toshihiko [Los Alamos National Laboratory

2010-12-07

79

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

80

Simultaneous analysis of elastic scattering and transfer/breakup channels for the 6He + 208Pb reaction at energies near the Coulomb barrier  

NASA Astrophysics Data System (ADS)

The elastic and ?-production channels for the He6+Pb208 reaction are investigated at energies around the Coulomb barrier ( E=14, 16, 18, 22, and 27 MeV). The effect of the two-neutron transfer channels on the elastic scattering has been studied within the Coupled-Reaction-Channels (CRC) method. We find that the explicit inclusion of these channels allows a simultaneous description of the elastic data and the inclusive ? cross sections at backward angles. Three-body Continuum-Discretized Coupled-Channels (CDCC) calculations are found to reproduce the elastic data, but not the transfer/breakup data. The trivial local polarization potential (TLP) derived from the CRC and CDCC calculations are found to explain the features found in previous phenomenological optical model calculations for this system.

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

2010-10-01

81

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

E-print Network

Interaction potential for silicon carbide: A molecular dynamics study of elastic constants and vibrational density of states for crystalline and amorphous silicon carbide Priya Vashishta,a Rajiv K. Kalia Silicon carbide SiC has been proposed for a wide range of technological applications

Southern California, University of

82

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

83

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

84

Unified interatomic potential and energy barrier distributions for amorphous oxides  

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

85

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

86

Damped oscillations in the energy autocorrelation functions of the 58 Ni+ 46 Ti elastic and 58 Ni+ 62 Ni elastic and inelastic scattering cross sections  

Microsoft Academic Search

Structures of non-statistical character, recently observed in 58Ni+46Ti elastic and 58Ni+62Ni elastic and inelasti excitation functions, produce damped oscillations in the cross section energy autocorrelation functions. The analysis of these damped oscillations in terms of S-matrix spin and parity decoherence indicates, as a possible interpretation, damping of the coherent rotational motion of the intermediate dinuclear system formed in the reaction.

S. Y. Kun; U. Abbondanno; M. Bruno; N. Cindro; M. D'Agostino; P. M. Milazzo; R. A. Ricci; T. Ritz; B. A. Robson; W. Scheid; A. V. Vagov; G. Vannini; L. Vannucci

1997-01-01

87

Elastic constants of defected and amorphous silicon with the environment-dependent interatomic potential  

E-print Network

Elastic constants of defected and amorphous silicon with the environment-dependent interatomic of a wide range of models of defected crystalline and amorphous silicon are calculated, using) Defects have independent effects on the elastic constants of silicon up to (at least) a defect

Bazant, Martin Z.

88

Renewable Energy Potential for Brownfield Redevelopment Strategies  

E-print Network

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

89

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

90

H-He elastic scattering at low energies: Contribution of nonzero partial waves  

SciTech Connect

The present study reports the nonzero partial wave elastic cross sections together with s-wave results for the scattering of an antihydrogen atom off a gaseous helium target at thermal energies (up to 10{sup -2} a.u.). We have used a nonadiabatic atomic orbital method having different basis sets to investigate the system. The consideration of all the significant partial waves (up to J=24) reduces the oscillatory nature present in the individual partial wave cross section. The added elastic cross section is almost constant up to 10{sup -7} a.u. and then decreases steadily and very slowly with increasing energy.

Sinha, Prabal K.; Ghosh, A.S. [Department of Physics, Bangabasi College, 19, Raj Kumar Chakravorty Sarani, Kolkata 700 009 (India); Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032 (India)

2005-01-01

91

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

92

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

93

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

2014-11-18

94

Spin correlation parameter and analyzing power in n - p elastic scattering at intermediate energies  

SciTech Connect

In order to improve existing {ital I}=0 phase shift solutions, the spin correlation parameter {ital A}{sub {ital NN}} and the analyzing powers {ital A}{sub 0{ital N}} and {ital A}{sub {ital N}0} have been measured in {ital n}-{ital p} elastic scattering over an angular range of 50{degree}--150{degree} (c.m.) at three neutron energies (220, 325, and 425 MeV) to an absolute accuracy of {plus minus}0.03. The data have a profound effect on various phase parameters, particularly the {sup 1}P{sub 1}, {sup 3}D{sub 2}, and {epsilon}{sub 1} phase parameters which in some cases change by almost a degree. With the exception of the highest energy, the data support the predictions of the latest version of the Bonn potential. Also, the analyzing power data ({ital A}{sub 0{ital N}} and {ital A}{sub {ital N}0}) measured at 477 MeV in a different experiment over a limited angular range (60{degree}--80{degree} (c.m.)) are reported here.

Bandyopadhyay, D. (Department of Physics, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 (CA)); Abegg, R. (TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3); Ahmad, M. (Department of Physics, University of Alberta, Edmonton, Alberta, Canada); Birchall, J.; Chantziantoniou, K.; Davis, C.A.; Davison, N.E.; Delheij, P.P.J.; Green, P.W.; Greeniaus, L.G.; Healey, D.C.; Lapointe, C.; McDonald, W.J.; Miller, C.A.; Moss, G.A.; Page, S.A.; Ramsay, W.D.; Rodning, N.L.; Roy, G.; van Oers, W.T.H.; Wait, G.D.; Watson, J.W.; Ye, Y.

1989-12-01

95

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

NASA Astrophysics Data System (ADS)

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

Luddy, Richard Joseph

96

Energy dependence of nucleon-nucleon potentials  

E-print Network

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

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

2008-12-03

97

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

98

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

99

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

E-print Network

DESIGN AND VALIDATION OF A HIGH ENERGY DENSITY ELASTIC ACCUMULATOR USING POLYURETHANE Alexander storage density values are among the highest of any material, polyurethane was the elastomer chosen as the constituent material. Using a curable type of polyurethane, an -prototype is currently being manufactured

Barth, Eric J.

100

Wind energy potential for Oman  

Microsoft Academic Search

The wind power potential was summarized using data from thirteen weather stations. The overall long term average wind speed for Oman is a moderate 3.67(s.d.=2.13)m\\/s yielding a potential power of 30.30 W. Wind speeds at four stations, Thumrait, Sur, Masirah and Marmul, are appreciably higher than the national average and hence these stations have a great potential for wind power

A. S. S Dorvlo; D. B Ampratwum

2002-01-01

101

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

102

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

SciTech Connect

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

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

1984-01-01

103

Three Nucleon Force Effects in Intermediate Energy Deuteron Analyzing Powers for dp Elastic Scattering  

E-print Network

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

K. Sekiguchi; H. Okamura; N. Sakamoto; H. Suzuki; M. Dozono; Y. Maeda; T. Saito; S. Sakaguchi; H. Sakai; M. Sasano; Y. Shimizu; T. Wakasa; K. Yako; H. Wita?a; W. Glöckle; J. Golak; H. Kamada; A. Nogga

2011-06-01

104

Urban form and renewable energy potential  

Microsoft Academic Search

Urban form, i.e., the layout, density, shape and orientation of buildings within the street grid of a city, affects greatly the potential of using renewable energy sources such as sun and wind for electricity production and climatisation of buildings. This paper outlines the framework of the European research Project PRECis (assessing the Potential for Renewable Energy in Cities) and, in

M. Grosso

1998-01-01

105

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

106

Peculiarities of elastic scattering of intermediate-energy electrons related to their capture at quasi-stationary levels of an atom in a continuous spectrum  

NASA Astrophysics Data System (ADS)

A theoretical model of electron scattering on an atom is constructed to study elastic atomic scattering of intermediate-energy electrons. The proposed model is based upon the combined Mensing potential with two spheres of atomic electrons, which admits analytical solutions of the radial Schröbinger equation. A procedure for matching the parameters of this scatterer to an approximate electrostatic potential of an atom in the form of a screened Coulomb potential has been determined. The screening radius of the latter potential has been calculated proceeding from the properties corresponding to the Thomas-Fermi method. A model of a scatterer determined according to the aforementioned procedure can be used to calculate the energy dependence of the cross section of elastic electron scattering on some atoms with s, p, and d shells representing elements neighboring zirconium. The main result is the establishment of factors responsible for the appearance of maxima on the energy dependences of the cross section of elastic electron scattering. These maxima are related to the resonant trapping of impinging electrons by quasi-stationary levels in a continuous spectrum.

Libenson, B. N.

2014-05-01

107

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

108

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

109

Wind energy potential of Algeria  

Microsoft Academic Search

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

N. Kasbadji Merzouk

2000-01-01

110

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

111

California offshore wind energy potential  

Microsoft Academic Search

This study combines multi-year mesoscale modeling results, validated using offshore buoys with high-resolution bathymetry to create a wind energy resource assessment for offshore California (CA). The siting of an offshore wind farm is limited by water depth, with shallow water being generally preferable economically. Acceptable depths for offshore wind farms are divided into three categories: ?20m depth for monopile turbine

Michael J. Dvorak; Cristina L. Archer; Mark Z. Jacobson

2010-01-01

112

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

113

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

114

Adhesion Energy of Receptor-Mediated Interaction Measured by Elastic Deformation  

Microsoft Academic Search

We investigated the role of receptor binding affinity in surface adhesion. A sensitive technique was developed to measure the surface energy of receptor-mediated adhesion. The experimental system involved a functionalized elastic agarose bead resting on a functionalized glass coverslip. Attractive intersurface forces pulled the two surfaces together, deforming the bead to produce an enlarged contact area. The Johnson-Kendall-Roberts (JKR) model

Vincent T. Moy; Yuekan Jiao; Thomas Hillmann; Horst Lehmann; Takeshi Sano

1999-01-01

115

On dual energy theorems for a class of elastic-plastic problems due to G. Maier  

NASA Astrophysics Data System (ADS)

I NANEARLIER work by A.R.S. Ponter and J.R. Martin (1972), dual energy principles were derived for general inelastic time-independent materials from a consistent definition of a deformation theory. In the present paper it is shown that dual theorems derived by G. Maier (1969) for a class of linearly work-hardening elastic-plastic materials may be derived from this earlier work.

Martin, J. B.; Ponter, A. R. S.

1972-10-01

116

Industrial Energy Conservation Potentials in North Carolina  

E-print Network

INDUSTRIAL ENERGY CONSERVATION POTENTIALS IN NORTH CAROLINA MONJED G. BARAKAT Chief Engineer Energy Analysis and Diagnostic Center North Carolina A & T State University HARMOHINDAR SINGH Associate Professor Architectural Engineering...; however, this luxury is not always affordable by the small and medium size manufacturers. The U.S. Department of Energy is helping these smaller companies by supporting Energy Analysis and Diagnostic Centers (EADC) at 13 universities throughout...

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

117

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

118

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

119

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

120

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

121

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

PubMed

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

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

2013-07-21

122

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

123

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

PubMed Central

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

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

2011-01-01

124

Interacting elastic lattice polymers: A study of the free energy of globular rings  

NASA Astrophysics Data System (ADS)

We introduce and implement a Monte Carlo scheme to study the equilibrium statistics of polymers in the globular phase. It is based on a model of "interacting elastic lattice polymers" and allows a sufficiently good sampling of long and compact configurations, an essential prerequisite to study the scaling behavior of free energies. By simulating interacting self-avoiding rings at several temperatures in the collapsed phase, we estimate both the bulk and the surface free energy. Moreover from the corresponding estimate of the entropic exponent ? -2 we provide evidence that, unlike for swollen and ?-point rings, the hyperscaling relation is not satisfied for globular rings.

Baiesi, M.; Orlandini, E.

2014-06-01

125

A new measurement of the overline?ee - elastic cross section at very low energy  

NASA Astrophysics Data System (ADS)

We have built a low background detector, a time projection chamber surrounded by an active anti-Compton, to measure the overline?ee - elastic cross section down to the antineutrino energy of 900 keV. With our detector, running at 18 m from the core of a nuclear reactor in Bugey, we could detect reactor antineutrinos by measuring both the energy and the direction of the recoiling electrons. We report here on a first analysis of the data using an automatic scanning procedure. The results we obtain are 1.5 ? higher than the ones predicted by the standard model.

Amsler, C.; Avenier, M.; Broggini, C.; Busto, J.; Cerna, C.; Daraktchieva, Z.; Gervasio, G.; Jeanneret, P.; Jonkmans, G.; Koang, D. H.; Lamblin, J.; Lebrun, D.; Link, O.; Ould-Saada, F.; Puglierin, G.; Stutz, A.; Tadsen, A.; Vuilleumier, J. L.

2002-10-01

126

Wind energy potential in Aden-Yemen  

Microsoft Academic Search

The wind energy resource is very large and widely distributed throughout the world as well as in Yemen. Aden possesses a very good potential of wind energy. In this article a number of years data on wind speed in Aden has been studied and presented. A statistical analysis was carried out from which the annual wind speed was found to

Abdulla H. Algifri

1998-01-01

127

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

128

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

129

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

NASA Astrophysics Data System (ADS)

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

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

2007-11-01

130

Measurement of the elastic, total and diffraction cross sections at tevatron energies  

NASA Astrophysics Data System (ADS)

The CDF collaboration has measured the differential elastic cross section d-sigma(sub el)/dt, the single diffraction dissociation double differential cross section d(sup 2)-sigma(sub sd)/dM(sup 2)dt and the total inelastic cross section for antiproton-proton collisions at center of mass energies radical s = 546 and 1800 GeV. Data for this measurement have been collected in short dedicated runs during the 1988-1989 data taking period of CDF. The elastic scattering slope is 15.28 +/- 0.58 (16.98 +/- 0.25) GeV(exp -2) at square root of s = 546 (1800) GeV. Using the luminosity independent method (1 + rho(exp 2)) sigma(sub T) is measured to be 62.64 +/- 0.95 (81.83 +/ 2.29) mb at square root of s = 546 (1800) GeV. Assuming rho = 0.15 the elastic, total, and single diffraction cross sections are sigma(sub el) = 12.87 +/- 0.30, sigma(sub T) = 61.26 +/- 0.93, and sigma(sub sd) = 7.89 +/- 0.33 mb (sigma(sub el) = 19.70 +/- 0.85, sigma(sub T) = 80.03 +/- 2.24, and sigma(sub sd) = 9.46 +/- 0.44 mb) at square root of s = 546 (1800) GeV.

Belforte, S.

1993-11-01

131

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

Microsoft Academic Search

First-principles study of the structural, elastic, magnetic and electronic properties of the cubic perovskite SrFeO3 and BaFeO3 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 SrFeO3 is in good agreement with the available theoretical results. The independent elastic constants Cij, bulk modulus B and

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

2010-01-01

132

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

133

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

2014-10-01

134

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

135

Recto Running Head 1 Available Potential Energy and Exergy in  

E-print Network

Internal Energy · KE: Kinetic Energy · GPE: Gravitational Potential Energy · IE: Internal energy · AMOC: The difference in potential energy between the actual state and Lorenz's reference state. · Available PotentialRecto Running Head 1 Available Potential Energy and Exergy in Stratified Fluids R´emi Tailleux

Tailleux, Remi

136

The wind energy potential of Malaysia  

Microsoft Academic Search

Wind data collected at ten stations in Malaysia were analysed for wind energy potential. The data were collected over a ten-year period (1982–1991). The results were presented as a Weibull distribution and analysis indicated that the station at Mersing has the greatest potential, with a mean power density of 85.61 W\\/m2 at 10 m above sea level.

K. Sopian; M. Y. Hj. Othman; A. Wirsat

1995-01-01

137

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

138

Complete set of deuteron analyzing powers for dp elastic scattering at intermediate energies  

NASA Astrophysics Data System (ADS)

With the aim of clarifying roles of the 3NFs in nuclei experimental programs with polarized deuterons beams at intermediate energies are in progress at RIKEN RI Beam Factory. As the first step, we have measured a complete set of deuteron analyzing powers ( iT 11, T 20, T 21, T 22) in deuteron-proton elastic scattering at 250 and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon-nucleon forces together with the Tucson-Melbourne'99, and UrbanaIX three nucleon forces.

Sekiguchi, K.; Okamura, H.; Wada, Y.; Miyazaki, J.; Taguchi, T.; Gebauer, U.; Dozono, M.; Kawase, S.; Kubota, Y.; Lee, C. S.; Maeda, Y.; Mashiko, T.; Miki, K.; Sakaguchi, S.; Sakai, H.; Sakamoto, N.; Sasano, M.; Shimizu, Y.; Takahashi, K.; Tang, R.; Uesaka, T.; Wakasa, T.; Yako, K.

2014-01-01

139

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

SciTech Connect

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

Jozef Dudek, Robert Edwards, Christopher Thomas

2013-02-01

140

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

141

Gurson-type elastic-plastic damage model based on strain-rate plastic potential  

NASA Astrophysics Data System (ADS)

Ductile damage is generally described by stress-space analytical potentials. In this contribution, it is shown that strain rate potentials, which are exact conjugate of the stress-based potentials, can be equally used to describe the dilatational response of porous metals. This framework is particularly appropriate for porous materials with matrix described by complex yield criteria for which a closed-form expression of the stress-based potential is not available. Illustration of the new approach is done for porous metals containing randomly distributed spherical voids in a von Mises elasto-plastic matrix. Furthermore, a general time integration algorithm for simulation of the mechanical response using this new formulation is developed and implemented in Abaqus/Standard. The proposed model and algorithm are validated with respect to the Abaqus built-in GTN model, which is based on a stress potential, through the simulation of a tensile test on a round bar.

Balan, Tudor; Cazacu, Oana

2013-12-01

142

Potential energy for slantwise parcel motion  

Microsoft Academic Search

Two formulations for the potential energy for slantwise motion are compared: one which applies strictly only to two-dimensional flows (SCAPE) and a three-dimensional formulation based on a Bernoulli equation. The two formulations share an identical contribution from the vertically integrated buoyancy anomaly and a contribution from different Coriolis terms. The latter arise from the neglect of (different) components of the

S. L. Gray; A. J. Thorpe

2000-01-01

143

The wind energy potential of western Greece  

Microsoft Academic Search

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

B. D. Katsoulis; D. A. Metaxas

1992-01-01

144

Assessment of wind energy potential in Croatia  

Microsoft Academic Search

In this work, the eolian potential of Croatia (one of the Yugoslav republics) is investigated on the basis of 32 anemograph stations. Mean hourly values were used for calculation of Weibull's distribution parameter c and k, and mean annual and seasonal wind power densities. The vertical extrapolation of wind speeds was based on Justus expression. Mean annual wind energies were

D. Poje; B. Cividini

1988-01-01

145

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

146

The synergy between protein positioning and DNA elasticity: energy minimization of protein-decorated DNA minicircles  

E-print Network

The binding of proteins onto DNA contributes to the shaping and packaging of genome as well as to the expression of specific genetic messages. With a view to understanding the interplay between the presence of proteins and the deformation of DNA involved in such processes, we developed a new method to minimize the elastic energy of DNA fragments at the mesoscale level. Our method makes it possible to obtain the optimal pathways of protein-decorated DNA molecules for which the terminal base pairs are spatially constrained. We focus in this work on the deformations induced by selected architectural proteins on circular DNA. We report the energy landscapes of DNA minicircles subjected to different levels of torsional stress and containing one or two proteins as functions of the chain length and spacing between the proteins. Our results reveal cooperation between the elasticity of the double helix and the structural distortions of DNA induced by bound proteins. We find that the imposed mechanical stress influence...

Clauvelin, Nicolas

2014-01-01

147

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

E-print Network

. The Hypersingular Boundary Element Method (HBEM) has diverse important applications in areas such as fracture element formulation. The present work presents a coupling of Hypersingular Boundary Integral Equations reserved. Keywords: Boundary element method; Boundary mode method; Hypersingular integrals; Potential

Paulino, Glaucio H.

148

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

149

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

150

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

151

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

152

Surface tension, surface energy, and chemical potential due to their difference.  

PubMed

It is well-known that surface tension and surface energy are distinct quantities for solids. Each can be regarded as a thermodynamic property related first by Shuttleworth. Mullins and others have suggested that the difference between surface tension and surface energy cannot be sustained and that the two will approach each other over time. In this work we show that in a single-component system where changes in elastic energy can be neglected, the chemical potential difference between the surface and bulk is proportional to the difference between surface tension and surface energy. By further assuming that mass transfer is driven by this chemical potential difference, we establish a model for the kinetics by which mass transfer removes the difference between surface tension and surface energy. PMID:23926928

Hui, C-Y; Jagota, A

2013-09-10

153

20Ne+20Ne elastic scattering in the ? +16O model of 20Ne  

NASA Astrophysics Data System (ADS)

A folding potential for elastic 20Ne + 20Ne scattering is constructed based on the ? {{+}16}O model of 20Ne nucleus. The elastic scattering angular distributions at energies of 62.1–74.5 MeV can be reasonably described. Linear expressions of energy-dependent of the renormalization factor N and the central imaginary depth W0 are obtained from the analyzes of the elastic angular distributions. The excitation function for the elastic 20Ne + 20Ne scattering at ? =90{}^\\circ in the energy region of Ec.m. ? 30–38 MeV can be well reproduced by the linear energy-dependent potential.

Yang, Yongxu; Zhang, Xinrui; Li, Qingrun

2015-01-01

154

Analysis of the Effect of Fiber Orientation on the Elastic Field in a Stiffened Orthotropic Panel under Uniform Tension using Displacement Potential Approach  

Microsoft Academic Search

The effect of fiber orientation on the stresses and displacements at different sections of a stiffened panel of orthotropic composite material under a uniform tension is analyzed. The supporting edge of the panel is rigidly fixed and two opposing edges are stiffened. The mixed boundary value plane stress elasticity problem is formulated in terms of a single displacement potential function

S. K. D. Nath; A. M. Afsar

2009-01-01

155

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

156

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

157

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

PubMed

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 Bu, Au, and Bg 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. PMID:24832266

Barbosa, Alessandra Souza; Bettega, Márcio H F

2014-05-14

158

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

NASA Astrophysics Data System (ADS)

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 Bu, Au, and Bg 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.

2014-05-01

159

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

160

The scattering of low energy helium ions and atoms from a copper single crystal. Elastic and inelastic effects  

Microsoft Academic Search

The scattering of 4–10 keV Helium ions from a copper surface can be described reasonably well with elastic, single collisions, even for fairly small scattering angles. However, in a more refined analysis of the experimental results, deviations from this behaviour are observed. Measurements of the energy and the width (FWHM) of the surface peak have been performed. The general behaviour

L. K. Verhey; B. Poelsema; A. L. Boers

1976-01-01

161

Decreased elastic energy storage, not increased material stiffness, characterizes central artery dysfunction in fibulin-5 deficiency independent of sex.  

PubMed

Central artery stiffness has emerged over the past 15 years as a clinically significant indicator of cardiovascular function and initiator of disease. Loss of elastic fiber integrity is one of the primary contributors to increased arterial stiffening in aging, hypertension, and related conditions. Elastic fibers consist of an elastin core and multiple glycoproteins; hence defects in any of these constituents can adversely affect arterial wall mechanics. In this paper, we focus on mechanical consequences of the loss of fibulin-5, an elastin-associated glycoprotein involved in elastogenesis. Specifically, we compared the biaxial mechanical properties of five central arteries-the ascending thoracic aorta, descending thoracic aorta, suprarenal abdominal aorta, infrarenal abdominal aorta, and common carotid artery-from male and female wild-type and fibulin-5 deficient mice. Results revealed that, independent of sex, all five regions in the fibulin-5 deficient mice manifested a marked increase in structural stiffness but also a marked decrease in elastic energy storage and typically an increase in energy dissipation, with all differences being most dramatic in the ascending and abdominal aortas. Given that the primary function of large arteries is to store elastic energy during systole and to use this energy during diastole to work on the blood, fibulin-5 deficiency results in a widespread diminishment of central artery function that can have significant effects on hemodynamics and cardiac function. PMID:25532020

Ferruzzi, J; Bersi, M R; Uman, S; Yanagisawa, H; Humphrey, J D

2015-03-01

162

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

163

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

164

Potential energy surfaces for vibrating hexatomic molecules  

NASA Astrophysics Data System (ADS)

Extension of empirical methods enables potential energy model construction for a vibrating hexatomic molecule. Application of these methods yields a model potential energy function that describes intramolecular vibrational dynamics and spectra of glyoxal, (CHO)2. A functional form is chosen that aids in model development and promotes transferability. It features a simple, modular design, and consists of Morse interactions applied between all atomic pairs. The Morse recipe assists in model development by naturally defining efficient basis functions for representing vibrational states. Solution of a series of sub-problems provides model parameter value estimates by nonlinear least- squares fits to spectroscopic data. Model development proceeds in both rectilinear normal and curvilinear local coordinate sets, letting efficiency determine which circumstance favors one set over the other. For example, the uncoupled harmonic oscillator sub-problem is solved in normal coordinates, while the hindered rotational sub- problem with limited coupling is solved in curvilinear coordinates. Definitive model evaluation is achieved by solving variationally for the energy levels and states of the full vibrational Schrödinger equation, composed of the exact kinetic energy operator and the model potential function. In normal coordinates, both operator and basis are readily defined. In curvilinear coordinates, however, the complex analytic form of the J = 0 kinetic energy operator is derived. Due to careful coordinate selection, terms in the model describing hindered rotational motion separate out, thus promoting development of an excellent contracted basis set. The contracted basis is expanded in terms of Mathieu functions, which are found to provide a rapidly convergent basis for any general one-dimensional hindering problem. Imposing symmetry on the functions further improves the basis. The full vibrational analysis reveals that the Morse functional form is capable of describing stretch, bend, and, surprisingly, torsion motions. The model reproduces structural and spectroscopic data with reasonable accuracy. Although the full calculation is set up and solved far more easily in normal coordinates, large- amplitude states converge slowly and localized states are described poorly. Dramatically improved rates of convergence result when using curvilinear coordinates due to coordinate and basis customization.

Rempe, Susan Lynne Beamis

165

Intermixing in heteroepitaxial islands: fast, self-consistent calculation of the concentration profile minimizing the elastic energy  

NASA Astrophysics Data System (ADS)

We present a novel computational method for finding the concentration profile which minimizes the elastic energy stored in heteroepitaxial islands. Based on a suitable combination of continuum elasticity theory and configurational Monte Carlo, we show that such profiles can be readily found by a simple, yet fully self-consistent, iterative procedure. We apply the method to SiGe/Si islands, considering realistic three-dimensional shapes (pyramids, domes and barns), finding strongly non-uniform distributions of Si and Ge atoms, in qualitative agreement with several experiments. Moreover, our simulated selective-etching profiles display, in some cases, a remarkable resemblance to the experimental ones, opening intriguing questions on the interplay between kinetic, entropic and elastic effects.

Gatti, R.; Uhlík, F.; Montalenti, F.

2008-08-01

166

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

167

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

168

Energy potential of leafy spurge (Euphorbia esula)  

SciTech Connect

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

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

1985-01-01

169

Kinetic and potential energy in the first law of thermodynamics  

Microsoft Academic Search

Kinetic and potential energy are included in the first law of thermodynamics in quite a contradictory way. Whereas in thermodynamics\\u000a the total energy is understood as the sum of internal, kinetic and potential energy, the total energy in continuum mechanics\\u000a incorporates only internal and kinetic energy, the potential energy being part of the work. The Gibbs ' fundamental equation\\u000a is

K. Stephan

1975-01-01

170

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

171

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

172

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

173

Induced Seismicity Potential of Energy Technologies  

NASA Astrophysics Data System (ADS)

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

Hitzman, Murray

2013-03-01

174

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

175

Shallow and diffuse spin-orbit potential for proton elastic scattering from neutron-rich helium isotopes at 71 MeV/nucleon  

E-print Network

Vector analyzing powers for proton elastic scattering from 8He at 71 MeV/nucleon have been measured using a solid polarized proton target operated in a low magnetic field of 0.1 T. The spin-orbit potential obtained from a phenomenological optical model analysis is found to be significantly shallower and more diffuse than the global systematics of stable nuclei, which is an indication that the spin-orbit potential is modified for scattering involving neutron-rich nuclei. A close similarity between the matter radius and the root-mean-square radius of the spin-orbit potential is also identified.

S. Sakaguchi; T. Uesaka; N. Aoi; Y. Ichikawa; K. Itoh; M. Itoh; T. Kawabata; T. Kawahara; Y. Kondo; H. Kuboki; T. Nakamura; T. Nakao; Y. Nakayama; H. Sakai; Y. Sasamoto; K. Sekiguchi; T. Shimamura; Y. Shimizu; T. Wakui

2013-02-18

176

Shallow and diffuse spin-orbit potential for proton elastic scattering from neutron-rich helium isotopes at 71 MeV/nucleon  

E-print Network

Vector analyzing powers for proton elastic scattering from 8He at 71 MeV/nucleon have been measured using a solid polarized proton target operated in a low magnetic field of 0.1 T. The spin-orbit potential obtained from a phenomenological optical model analysis is found to be significantly shallower and more diffuse than the global systematics of stable nuclei, which is an indication that the spin-orbit potential is modified for scattering involving neutron-rich nuclei. A close similarity between the matter radius and the root-mean-square radius of the spin-orbit potential is also identified.

Sakaguchi, S; Aoi, N; Ichikawa, Y; Itoh, K; Itoh, M; Kawabata, T; Kawahara, T; Kondo, Y; Kuboki, H; Nakamura, T; Nakao, T; Nakayama, Y; Sakai, H; Sasamoto, Y; Sekiguchi, K; Shimamura, T; Shimizu, Y; Wakui, T

2013-01-01

177

Elastic Scattering of Protons and Pions from Polarized HELIUM-3 at Intermediate Energies  

NASA Astrophysics Data System (ADS)

A novel cryogenic technique has been used to produce polarized ^3He targets with a relative density of up to p = 12 atmospheres (or ~ 3 times 10^ {20} ^3He atoms/cm ^3; p = 1 atmosphere corresponds to 760 Torr or 101.3 kPa pressure at 273 K). In these targets the ^3He nuclei are polarized by spin exchange collisions with optically pumped rubidium atoms. From transmission measurements at wavelengths of 790-800 nm, pressure shifts, linewidths and lineshape asymmetries for the Rb 5S_{1/2} to 5P_{1/2} D1 transition have been determined. The Rb spin destruction rate was found to exhibit a quadratic increase versus ^3 He pressure: this might indicate the importance of Rb-^3He-^3He collision processes. The transmission results for circularly polarized light are well described by a model which predicts the dependence of the average Rb polarization on Rb density, ^3He pressure, light intensity and cell geometry. The Rb - ^3 He spin exchange cross section, < sigma_{Se^nu}> = 6.1 times 10^ {-20} cm^3s ^{-1}, was found to be independent of ^3He pressure up to p = 12.1 atmospheres. Maximum ^3He polarizations of up to 70% were achieved with cells of 35 cm ^3 volume containing ^3He at p = 7-10 atmospheres. This target has been used to measure cross sections and spin observables in elastic scattering of both pions and protons from polarized ^3He. Angular distributions of cross sections and the spin observables A_{OOON}, A_ {OONO}, and A_{OONN } have been measured for the elastic scattering of polarized protons from polarized ^3He at incident proton energies of 200, 290, 400 and 500 MeV. Measurements were made at 12 angles in the range 24^ circ-73^circ for most of the energies. The results are compared to two nonrelativistic microscopic momentum space optical model calculations. One calculation utilizes the Distorted Wave Impulse Approximation (DWIA) formalism whereas the second uses the Distorted Wave Born Approximation (DWBA). The overall agreement with the data is poor. For the target related spin observables (A_{OOON} and A_{OONN} the DWBA calculation represents a significant improvement over the DWIA model but the observables are poorly described whereas the beam related asymmetry (A_{OONO }) is well described. The measurement of elastic scattering of 100 MeV pi^+ from a polarized ^3He target is, together with recent measurements on the spin-1/2 nuclei ^{13}C and ^{15}N, the world's database for pion scattering from polarized spin-1/2 complex nuclei (A > 2). Measurements have been made at lab angles of 60^circ, 80^circ and 100^ circ, with the largest value A_ {y} = 0.89 +/- 0.12 occurring at 80^circ near a cross section minimum. This asymmetry is the largest observed to date in pion scattering from a spin-1 over 2 nucleus. The A_{y } data are qualitatively reproduced by a schematic model. However agreement with the data is significantly improved when realistic three-body Faddeev wave functions and a full nonlocal DWIA reaction model is used.

Larson, Bart William

178

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

179

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

180

Thermophotovoltaic energy conversion: Technology and market potential  

SciTech Connect

This report contains material displayed on poster panels during the Conference. The purpose of the contribution was to present a summary of the business overview of thermophotovoltaic generation of electricity and its market potential. The market analysis has shown that the TPV market, while currently still in an early nucleation phase, is evolving into a range of small niche markets out of which larger-size opportunities can emerge. Early commercial applications on yachts and recreational vehicles which require a quiet and emission-free compact electrical generator fit the current TPV technology and economics. Follow-on residential applications are attractive since they can combine generation of electricity with space and hot water heating in a co-generation system. Development of future markets in transportation, both private and communal or industrial, will be driven by legislation requiring emission-free vehicles, and by a reduction in TPV systems cost. As a result of {open_quote}{open_quote}moving down the learning curve,{close_quote}{close_quote} growing power and consumer markets are predicted to come into reach of TPV systems, a development favored by high overall energy conversion efficiency due to high radiation energy density and to high electric conversion efficiency available with photovoltaic cells. {copyright} {ital 1996 American Institute of Physics.}

Ostrowski, L.J.; Pernisz, U.C. [Dow Corning Corporation, Midland, Michigan 48686 (United States); Fraas, L.M. [JX Crystals, Incorporated, Issaquah, Washington 98027 (United States)

1996-02-01

181

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

182

Energy conservation potential in Taiwanese textile industry  

Microsoft Academic Search

Since Taiwan lacks sufficient self-produced energy, increasing energy efficiency and energy savings are essential aspects of Taiwan’s energy policy. This work summarizes the energy savings implemented by 303 firms in Taiwan’s textile industry from the on-line Energy Declaration System in 2008. It was found that the total implemented energy savings amounted to 46,074ton of oil equivalent (TOE). The energy saving

Gui-Bing Hong; Te-Li Su; Jenq-Daw Lee; Tsung-Chi Hsu; Hua-Wei Chen

2010-01-01

183

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

184

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...

185

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

186

Biomass energy in China and its potential Li Jingjing  

E-print Network

energy Coal 25,128 56.9 Crude oil 8,852 20.0 Natural gas 938 2.1 Large-scale hydro power 2,587 5Biomass energy in China and its potential Li Jingjing Asia Alternative Energy Program, Energy.R.China Zhuang Xing Center for Renewable Energy Development, Energy Research Institute, State Development

187

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

SciTech Connect

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

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

2010-09-27

188

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

189

Complete Set of Deuteron Analyzing Powers for dp Elastic Scattering at Intermediate Energies and Three Nucleon Forces  

NASA Astrophysics Data System (ADS)

Experimental programs with polarized deuterons beams at intermediate energies are in progress at RIKEN RI Beam Factory. We have measured a complete set of deuteron analyzing powers in deuteron-proton elastic scattering at 250 and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon-nucleon forces together with the Tucson-Melbourne'99, and UrbanaIX three nucleon forces.

Sekiguchi, K.; Okamura, H.; Wada, Y.; Miyazaki, J.; Taguchi, T.; Gebauer, U.; Dozono, M.; Kawase, S.; Kubota, Y.; Lee, C. S.; Maeda, Y.; Mashiko, T.; Miki, K.; Sakaguchi, S.; Sakai, H.; Sakamoto, N.; Sasano, M.; Shimizu, Y.; Takahashi, K.; Tang, R.; Uesaka, T.; Wakasa, T.; Yako, K.

2014-03-01

190

Grain-boundary free energy in an assembly of elastic disks  

NASA Astrophysics Data System (ADS)

Grain-boundary free energy is estimated as a function of misoriention for symmetric tilt boundaries in an assembly of nearly hard disks. Fluctuating cell theory is used to accomplish this since the most common techniques for calculating interfacial free energy cannot be applied to such assemblies. The results are analogous to those obtained using a Leonard-Jones potential, but in this case the interfacial energy is dominated by an entropic contribution. Disk assemblies colorized with free and specific volume elucidate differences between these two characteristics of boundary structure. Profiles are also provided of the Helmholtz and Gibbs free energies as a function of distance from the grain boundaries. Low angle grain boundaries are shown to follow the classical relationship between dislocation orientation/spacing and misorientation angle.

Lusk, Mark T.; Beale, Paul D.

2004-02-01

191

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

192

Momentum-space calculation of electron—CO elastic collision  

NASA Astrophysics Data System (ADS)

We report a momentum-space study on low-energy electron-CO collisions. Elastic differential cross sections (DCS) are obtained using a static-exchange-optical (SEO) model for the incident energies of 2, 3, 5, and 10 eV. Polarization effect of higher reaction channels, including the ionization continuum, on the elastic collision is represented by an ab initio equivalent-local optical potential. The cross sections are compared with experimental measurements and other theoretical results.

Wang, Yuan-Cheng; Ma, Jia; Zhou, Ya-Jun

2013-02-01

193

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

194

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

195

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

196

On the failure of hyperbolicity in elasticity  

Microsoft Academic Search

The failure of hyperbolicity leading to the instability as an ill-posedness of the Cauchy problem is investigated for elasticity. The criteria for that instability are derived in terms of the potential energy as a function of the strain invariants. The theory is illustrated by examples.

Michail Zak

1982-01-01

197

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

198

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

199

A snapshot of geothermal energy potential and utilization in Turkey  

Microsoft Academic Search

Turkey is one of the countries with significant potential in geothermal energy. It is estimated that if Turkey utilizes all of her geothermal potential, she can meet 14% of her total energy need (heat and electricity) from geothermal sources. Therefore, today geothermal energy is an attractive option in Turkey to replace fossil fuels. Besides, increase in negative effects of fossil

Erkan Erdogdu

2009-01-01

200

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

201

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

202

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

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 (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

203

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

204

Absolute elastic differential electron scattering cross sections in the intermediate energy region. III - SF6 and UF6  

NASA Technical Reports Server (NTRS)

A recently developed technique has been used to measure the ratios of elastic differential electron scattering cross sections (DCS) for SF6 and UF6 to those of He at electron impact energies of 5, 10, 15, 20, 30, 40, 50, 60, and 75 eV and at scattering angles of 20 to 135 deg. In order to obtain the absolute values of DCS from these ratios, He DCS of McConkey and Preston have been employed in the 20 to 90 deg range. At angles in the 90 to 135 deg range the recently determined cross sections of Srivastava and Trajmar have been utilized. From these DCS, elastic integral and momentum transfer cross sections have been obtained.

Srivastava, S. K.; Trajmar, S.; Chutjian, A.; Williams, W.

1976-01-01

205

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

Microsoft Academic Search

Originally Einstein proposed the the mass-energy equivalence at low speeds as E=mc^2 + 1\\/2 mv^2. However, a mass may also be rotating and vibrating as well as moving linearly. Although small, these kinetic energies must be included in formulating a true mathematical statement of the mass-energy equivalence. Also, gravitational, electromagneic and magnetic potential energies must be included in the mass-energy

Stewart Brekke

2010-01-01

206

Solar energy in California industry - Applications, characteristics and potential  

Microsoft Academic Search

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

R. H. Barbieri; D. S. Pivirotto

1978-01-01

207

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

208

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

209

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

210

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

PHYSICAL REVIEW C 81, 044612 (2010) Elastic and inelastic scattering of 240-MeV 6Li ions from 40Ca and 48Ca and tests of a systematic optical potential Krishichayan, X. Chen,* Y.-W. Lui, J. Button, and D. H. Youngblood Cyclotron Institute, Texas... MAYA at the Grand Accelerateur National D?Ions Lourds (GANIL) [8]. Chen et al. [9] have explored the possibilities of using 6Li in giant resonances studies and have shown that the inelastic scattering of 6Li excites the ISGMR strongly. For 6Li...

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

2010-01-01

211

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

212

General Potential-Energy Function for Exchange Reactions  

Microsoft Academic Search

A general potential-energy function for linear triatomic systems has been developed for use in connection with reaction kinetics calculations. The function is a generalization of the Morse function with a sufficient number of adjustable parameters to permit arbitrary fixing of the location and curvatures of the saddle point of the potential energy surface. The function reduces, of course, to the

Frederick T. Wall; Richard N. Porter

1962-01-01

213

Assessing the wind energy potential projects in Algeria  

Microsoft Academic Search

A research program is under way in the SONELGAZ R&D Office with the aim of studying the potential of wind energy in Algeria. This paper presents an analysis of recently collected hourly wind data over a period of almost 5 years between 2002 and 2006, from four selected sites as well as preliminary evaluation of the wind energy potential. The

Y. Himri; S. Himri; A. Boudghene Stambouli

2009-01-01

214

An Analysis of the Wind Energy Potential of Elazig, Turkey  

Microsoft Academic Search

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

E. Kavak Akpinar; S. Akpinar

2004-01-01

215

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

216

Energy Stored in a Capacitor What is the potential energy, U, of a  

E-print Network

Energy Stored in a Capacitor What is the potential energy, U, of a charged capacitor? Think of U energy by discharging capacitor VqWU == #12;Energy Stored in a Capacitor Charge capacitor by transferring takes positive work to charge capacitor #12;Energy Stored in a Capacitor At given instance potential

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

217

Elastic properties of graphene-graphane nanoribbons  

NASA Astrophysics Data System (ADS)

The results of theoretical investigation of the atomic structure, deformations, and elastic properties of graphene-graphane nanoribbons (GGN) are represented here. To study the properties of GGN we applied the empirical method based on the bond-order potential developed by Brenner and the tight-binding method. We calculated the Young's pseudo-modulus of GGN and the strain energy of GGN subject to axial tension and compression. The curve of the strain energy collapse occurs at the axial compression of 0.03-0.04. Plane atomic network subject to axial compression becomes wave-like. This is a so-called phase transition. Elasticity of armchair-graphene nanoribbons is greater than elasticity of armchair nanotubes and graphane nanoribbons with the same width and length.

Glukhova, O. E.; Saliy, I. N.; Zhnichkov, R. Y.; Khvatov, I. A.; Kolesnikova, A. S.; Slepchenkov, M. M.

2010-11-01

218

Complete Set of Deuteron Analyzing Powers for dp Elastic Scattering at Intermediate Energies and Three Nucleon Forces  

NASA Astrophysics Data System (ADS)

With the aim of clarifying roles of the 3NFs in nuclei experimental programs with polarized deuterons beams at intermediate energies are in progress at RIKEN RI Beam Factory. As the first step, we have measured a complete set of deuteron analyzing powers in deuteron-proton elastic scattering at 250 and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon-nucleon forces together with the Tucson-Melbourne'99, and UrbanaIX three nucleon forces.

Sekiguchi, K.; Okamura, H.; Wada, Y.; Miyazaki, J.; Taguchi, T.; Gebauer, U.; Dozono, M.; Kawase, S.; Kubota, Y.; Lee, C. S.; Maeda, Y.; Mashiko, T.; Miki, K.; Sakaguchi, S.; Sakai, H.; Sakamoto, N.; Sasano, M.; Shimizu, Y.; Takahashi, K.; Tang, R.; Uesaka, T.; Wakasa, T.; Yako, K.

219

Complete Set of Deuteron Analyzing Powers for dp Elastic Scattering at Intermediate Energies and Three Nucleon Forces  

NASA Astrophysics Data System (ADS)

With the aim of clarifying roles of the 3NFs in nuclei experimental programs with the polarized deuteron beam at intermediate energies are in progress at RIKEN RI Beam Factory. As the first step, we have measured a complete set of deuteron analyzing powers in deuteron-proton elastic scattering at 250 and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon-nucleon forces together with the Tucson-Melbourne'99, and UrbanaIX three nucleon forces.

Sekiguchi, K.; Okamura, H.; Wada, Y.; Miyazaki, J.; Taguchi, T.; Gebauer, U.; Dozono, M.; Kawase, S.; Kubota, Y.; Lee, C. S.; Maeda, Y.; Mashiko, T.; Miki, K.; Sakaguchi, S.; Sakai, H.; Sakamoto, N.; Sasano, M.; Shimizu, Y.; Takahashi, K.; Tang, R.; Uesaka, T.; Wakasa, T.; Yako, K.

2014-08-01

220

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

SciTech Connect

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

Hiester, T.R.

1980-06-01

221

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

222

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

NASA Astrophysics Data System (ADS)

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

Assadi, Abbas; Farshi, Behrooz

2011-03-01

223

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

224

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

225

Magic mass ratios of complete energy-momentum transfer in one-dimensional elastic three-body collisions  

NASA Astrophysics Data System (ADS)

We consider the one-dimensional scattering of two identical blocks of mass M that exchange energy and momentum via elastic collisions with an intermediary ball of mass m = ? M . Initially, one block is incident upon the ball with the other block at rest. For ? < 1 , the three objects will make multiple collisions with one another. In our analysis, we construct a Euclidean vector V n whose components are proportional to the velocities of the objects. Energy-momentum conservation then requires a covariant recurrence relation for V n that transforms like a pure rotation in three dimensions. The analytic solutions of the terminal velocities result in a remarkable prediction for values of ?, in cases where the initial energy and momentum of the incident block are completely transferred to the scattered block. We call these values for ? "magic mass ratios."

Ee, June-Haak; Lee, Jungil

2015-02-01

226

Rapid Hydrogel Microactuator Using Elastic Instability  

NASA Astrophysics Data System (ADS)

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

Lee, Howon; Xia, Chunguang; Fang, Nicholas

2009-03-01

227

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

228

Exotic energy R&D has potential  

Microsoft Academic Search

The paper examines the use of wave power or ocean gradient differential as one aspect of energy production along with the farming of biomass as a feedstock for methane production. Attention is given to various cost estimates for projects such as the conversion of kelp to methane that will hopefully result in a reasonable yield. The design features of a

J. T. Miskell

1980-01-01

229

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

NASA Astrophysics Data System (ADS)

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

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

2005-04-01

230

Periodic discrete energy for long-range potentials  

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

231

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

2014-03-28

232

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

233

Brittle fracture in a periodic structure with internal potential energy.  

PubMed

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

Mishuris, Gennady S; Slepyan, Leonid I

2014-05-01

234

The black disk and the dip in the differential elastic cross section at asymptotic energy  

E-print Network

We test the validity of the black disk limit in elastic scattering by studying the evolution of the dip in the scaling variable $\\tau=-t_{D}\\sigma^{tot}$, where $t_{D}$ is the transverse momentum squared at the dip and $\\sigma_{tot}$ the total cross section. As $s\\rightarrow \\infty $ and $-t_{D} \\rightarrow 0 $, $\\tau$ may consistently be approaching the black disc value, $\\tau \\xrightarrow[ \\sqrt{s}\\rightarrow \\infty ]{} \\tau_{BD}=35.92$ GeV$^{2}$ mb.

I. Bautista; J. Dias de Deus

2012-12-08

235

New approach to calculating the potential energy of colliding nuclei  

NASA Astrophysics Data System (ADS)

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.; Kosenko, G. I.

2014-12-01

236

Absolute differential cross sections for the elastic scattering of electrons from atomic hydrogen at low incident energies  

NASA Astrophysics Data System (ADS)

Absolute differential cross sections for electrons elastically scattered from atomic hydrogen have been measured at low incident energies. The measurements were facilitated by the moveable nozzle source recently developed in our lab. Data taken at the incident energies of 20 eV, 40 eV, and 100 eV, and spanning the angular range of 10^rc to 120^rc will be presented. The results will be compared to the earlier measurements of Williams(Joseph Callaway and J. F. Williams, Phys. Rev. A) 12, 2312 (1975), J. F. Williams, J. Phys. B 8, 2191 (1975) and Shyn(T. W. Shyn and S. Y. Cho, Phys. Rev. A) 40, 1315 (1989), T. W. Shyn and Alan Grafe, Phys. Rev. A 46, 2949 (1992), and the theoretical calculations of Bray(Igor Bray, Phys. Rev. A) 46, 6995 (1992). Funded by the National Science Foundation under Grant # NSF-RUI-PHY-0096808.

James, Kenneth; Leonard, Linda; Proctor, Stephanie; Childers, J. G.; Khakoo, Murtadha A.

2003-05-01

237

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

238

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

239

Energy Savings Potential of Process Control Valve Replacement  

E-print Network

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

Holzenthal, L. Jr.

240

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

241

Wind energy potential assessment at four typical locations in Ethiopia  

Microsoft Academic Search

The wind energy potential at four different sites in Ethiopia – Addis Ababa (09:02N, 38:42E), Mekele (13:33N, 39:30E), Nazret (08:32N, 39:22E), and Debrezeit (8:44N, 39:02E) – has been investigated by compiling data from different sources and analyzing it using a software tool. The results relating to wind energy potential are given in terms of the monthly average wind speed, wind

Getachew Bekele; Björn Palm

2009-01-01

242

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

243

Wind energy potential in Antakya and ?skenderun regions, Turkey  

Microsoft Academic Search

The aim of this study is to establish the potential and the feasibility basis for the wind energy resources in some locations of East Mediterranean region of Turkey and provide suitable data for evaluating the potential wind power. For this purpose, hourly wind data, which were observed between the years 1997 and 2001 at the meteorological stations of Antakya and

M. Bilgili; B. ?ahin; A. Kahraman

2004-01-01

244

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

245

Investigating energy-saving potentials in the cloud.  

PubMed

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

246

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

247

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

248

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

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

249

DoD energy vulnerabilities: potential problems and observations  

SciTech Connect

The Department of Defense is almost entirely dependent on civilian energy supplies to meet its needs in both peacetime and periods of heightened conflict. There are a number of potential vulnerabilities to the continual and timely supply of energy to both the civilian and military sectors. These include denial of the energy resources themselves, disruption of critical transportation networks, destruction of storage facilities, and interruption of electrical power. This report briefly reviews the present situation for provision of energy from the civilian sector to the military. General vulnerabilities of the existing energy supply system are identified, along with the potential for armed aggression (including terrorist and sabotage activities) against the energy network. Conclusions and some tentative observations are made as to a proper response to the existing vulnerabilities.

Freiwald, D A; Berger, M E; Roach, J F

1982-08-01

250

Acousto-optically generated potential energy landscapes: potential mapping using colloids under flow.  

PubMed

Optical potential energy landscapes created using acousto-optical deflectors are characterized via solvent-driven colloidal particles. The full potential energy of both single optical traps and complex landscapes composed of multiple overlapping traps are determined using a simple force balance argument. The potential of a single trap is shown to be well described by a Gaussian trap with stiffness found to be consistent with those obtained by a thermal equilibrium method. We also obtain directly the depth of the well, which (as with stiffness) varies with laser power. Finally, various complex systems ranging from double-well potentials to random landscapes are generated from individually controlled optical traps. Predictions of these landscapes as a sum of single Gaussian wells are shown to be a good description of experimental results, offering the potential for fully controlled design of optical landscapes, constructed from single optical traps. PMID:23263108

Juniper, Michael P N; Besseling, Rut; Aarts, Dirk G A L; Dullens, Roel P A

2012-12-17

251

Target element dependence in the elastic and inelastic energy loss of fast heavy ions  

NASA Astrophysics Data System (ADS)

The target atomic number dependence of elastic and inelastic stopping power has been investigated by using theoretical stopping power formulations from literature. The stopping powers for target elements with atomic numbers from 3 to 92 are calculated on the basis of the model of Montenegro et al. and the nuclear stopping power is calculated using the formulation of Wilson et al.. The target atomic number dependence of the electronic and nuclear stopping power is examined for some light and heavy projectiles by comparing the stopping powers for all considered targets. It is observed that there is a strong target atomic number oscillation for helium, nickel and silver ions in nuclear and electronic stopping as a result of varying densities of neighboring elements. We have also determined the target materials, which apply a maximum total stopping force for some incident ions.

Kabadayi, Önder; Gümü?, Hasan; Ça?atay Tufan, M.

2007-03-01

252

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

E-print Network

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

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

2012-05-09

253

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

NASA Astrophysics Data System (ADS)

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

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

2000-01-01

254

Calculations of potential energy surfaces using Monte Carlo configuration interaction  

NASA Astrophysics Data System (ADS)

We apply the method of Monte Carlo configuration interaction (MCCI) to calculate ground-state potential energy curves for a range of small molecules and compare the results with full configuration interaction. We show that the MCCI potential energy curve can be calculated to relatively good accuracy, as quantified using the non-parallelity error, using only a very small fraction of the full configuration interaction space. In most cases the potential curve is of better accuracy than its constituent single-point energies. We finally test the MCCI program on systems with basis sets beyond full configuration interaction: a lattice of 50 hydrogen atoms and ethylene. The results for ethylene agree fairly well with other computational work while for the lattice of 50 hydrogens we find that the fraction of the full configuration interaction space we were able to consider appears to be too small as, although some qualitative features are reproduced, the potential curve is less accurate.

Coe, Jeremy P.; Taylor, Daniel J.; Paterson, Martin J.

2012-11-01

255

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

256

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

257

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

258

Saint Paul Energy Park: the potential for district heating  

SciTech Connect

The results of ANL's study of the energy and economic aspects of using district heating in the St. Paul Energy Park are summarized. The Energy Park is a 6 million ft/sup 2/ residential, commercial office, and light industrial complex to be built in the midway area of St. Paul, Minnesota. Space heating and cooling design loads for the park were calculated assuming that the ASHRAE's 90-75 energy-conserving construction standards would be used in constructing the park's buildings. Based in part on this assumption, ANL estimated the costs and energy use characteristics of six possible energy system options for supplying Energy Park's space heating, space cooling, and domestic hot water heating needs. The results indicate that in today's economy, a central heating and cooling plant with natural gas boilers and electrically driven centrifugal chillers with thermal storage has good potential for energy and economic savings and clearly merits further consideration.

Lee, C.; Kron, R.; Davis, H.

1980-03-01

259

Free energy and direct photon emission at finite chemical potential  

NASA Astrophysics Data System (ADS)

We investigate the evolution of free energy and direct photon production from quark-gluon plasma (QGP) considering finite chemical potential. The evolution of QGP formation at the chemical potential is done through finite value of quark mass. The evolution rate is found to be decreasing with chemical potential. We further study the direct photon emission from the fireball of such QGP and found the result to be increasing function of chemical potential in all the channels of photon production. It also shows enhancement of photon emission in comparison to the other theoretical calculation of direct photon productions.

Somorendro Singh, S.

2014-08-01

260

Energy potential of municipal solid waste is limited  

SciTech Connect

Energy recovery from municipal solid waste has the potential for making only a limited contribution to the nation`s overall energy production. Although the current contribution of waste-derived energy production is less than one-half of 1 percent of the nation`s total energy Supply, DOE has set a goal for energy from waste at 2 percent of the total supply by 2010. The industry`s estimates show a smaller role for waste as an energy source in the future. The energy potential from waste is limited not only by the volume and energy content of the waste itself, but also by the factors affecting the use of waste disposal options, including public opposition and the availability of financing. Energy production from waste combustors and from landfill gases generates pollutants, although these are reduced through current regulations that require the use of emissions control technology and define operational criteria for the facilities. Although DOE estimates that one-third of the energy available from waste is available in the form of energy savings through the recycling of materials, the Department`s research in this area is ongoing.

NONE

1994-09-01

261

Elastic $?$-transfer in the elastic scattering of $^{\\bf 16}$O$+^{\\bf 12}$C  

E-print Network

The elastic scattering $^{16}$O$+^{12}$C angular distributions at $^{16}$O bombarding energies of 100.0, 115.9 and 124.0 MeV and their optical model description including the $\\alpha$-particle exchange contribution calculated in the Coupled Reaction Channel approach are presented. The angular distributions show not only the usual diffraction pattern but also, at larger angles, intermediate structure of refractive origin on which finer oscillations are superimposed. The large angle features can be consistently described including explicitly the elastic $\\alpha$-transfer process and using a refractive optical potential with a deep real part and a weakly absorptive imaginary part.

S. Szilner; W. von Oertzen; Z. Basrak; F. Haas; M. Milin

2002-02-14

262

Monte Carlo simulation of radiative energy transfer in continuous elastic random media-three-component envelopes and numerical validation  

NASA Astrophysics Data System (ADS)

We present Monte Carlo solutions of the 3-D radiative transfer (RT) equations for energy transport in elastic media with randomly fluctuating velocity and density. It includes mode conversions from P- to S-wave energy and vice versa and considers angular-dependent scattering patterns following from the Born approximation. Synthesis of the space-time distribution of seismic energy emitted from point sources with arbitrary radiation patterns can be achieved. The method offers a unique way to model complete mean square envelopes of high-frequency wavefields in the presence of random heterogeneity starting from the first P-wave onset until the late S-wave coda. Validation of the method is achieved through a comparison of mean square envelopes from an isotropic P-wave radiation point source with full 3-D wavefield simulations for the whole envelope shape and with the analytical Markov approximation for small lapse times. RT yields accurate envelope shapes even for parameter ranges where strong and direction-dependent scattering occurs. Peak amplitudes, envelope broadening and coda decay at long lapse times are correctly modelled. A breakdown of RT with Born scattering coefficients only occurs in the vicinity of a point source: waveform modelling shows that even for a pure compressional source, some per cent of shear wave energy are generated by near-source scattering that are not explained within the framework of Born approximation.

Przybilla, Jens; Korn, Michael

2008-05-01

263

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

264

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

265

Elastic relaxations and interactions on metallic vicinal surfaces: Testing the dipole model  

NASA Astrophysics Data System (ADS)

We have studied, by quenched molecular dynamics using a second-moment approximation (SMA) potential, the atomic relaxations and step interaction energies on Ni, Cu, Pt, and Au vicinal surfaces for which steps run along the [11¯0] direction. The results have been compared to anisotropic linear elasticity calculations (ALE). We show that steps are well described with a model of lines of force dipoles buried under the surface. The elastic interaction energies between steps obtained by SMA and ALE are in good agreement. This demonstrates that the elastic step interaction energy can be determined from the measurement of the atomic relaxations.

Prévot, G.; Croset, B.

2006-12-01

266

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

267

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

NASA Astrophysics Data System (ADS)

We report absolute differential cross sections (DCSs) for elastic electron scattering from GeF4. The incident electron energy range was 3-200 eV, while the scattered electron angular range was typically 15°-150°. In addition, corresponding independent atom model (IAM) calculations, within the screened additivity rule (SCAR) formulation, were also performed. Those results, particularly for electron energies above about 10 eV, were found to be in good quantitative agreement with the present experimental data. Furthermore, we compare our GeF4 elastic DCSs to similar data for scattering from CF4 and SiF4. All these three species possess Td symmetry, and at each specific energy considered above about 50 eV their DCSs are observed to be almost identical. These indistinguishable features suggest that high-energy elastic scattering from these targets is virtually dominated by the atomic-F species of the molecules. Finally, estimates for the measured GeF4 elastic integral cross sections are derived and compared to our IAM-SCAR computations and with independent total cross section values.

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

2012-04-01

268

Potential energy production from algae on marginal land in China.  

PubMed

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

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

2012-04-01

269

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

270

Warm Body Temperature Facilitates Energy Efficient Cortical Action Potentials  

PubMed Central

The energy efficiency of neural signal transmission is important not only as a limiting factor in brain architecture, but it also influences the interpretation of functional brain imaging signals. Action potential generation in mammalian, versus invertebrate, axons is remarkably energy efficient. Here we demonstrate that this increase in energy efficiency is due largely to a warmer body temperature. Increases in temperature result in an exponential increase in energy efficiency for single action potentials by increasing the rate of Na+ channel inactivation, resulting in a marked reduction in overlap of the inward Na+, and outward K+, currents and a shortening of action potential duration. This increase in single spike efficiency is, however, counterbalanced by a temperature-dependent decrease in the amplitude and duration of the spike afterhyperpolarization, resulting in a nonlinear increase in the spike firing rate, particularly at temperatures above approximately 35°C. Interestingly, the total energy cost, as measured by the multiplication of total Na+ entry per spike and average firing rate in response to a constant input, reaches a global minimum between 37–42°C. Our results indicate that increases in temperature result in an unexpected increase in energy efficiency, especially near normal body temperature, thus allowing the brain to utilize an energy efficient neural code. PMID:22511855

Yu, Yuguo; Hill, Adam P.; McCormick, David A.

2012-01-01

271

Elastic and inelastic collision of low energy proton scattering from rare gas solids  

Microsoft Academic Search

We have carried out the systematic measurements of energy spectrum for low energy (50–500eV) proton scattering from rare gas solids of Ar, Kr and Xe. The observed energy spectra showed a multiple peak structure. The multiple peaks have been ascribed to the multiple inter-band electronic excitations, from valence to conduction band of the rare gas solid. In addition, each peak

Masahiko Kato; Ryutaro Souda

2007-01-01

272

Curvature of the universe and the dark energy potential  

E-print Network

The flatness of an accelerating universe model (characterized by a dark energy scalar field $\\chi$) is mimicked from a curved model that is filled with, apart from the cold dark matter component, a quintessencelike scalar field $Q$. In this process, we characterize the original scalar potential $V(Q)$ and the mimicked scalar potential $V(\\chi)$ associated to the scalar fields $Q$ and $\\chi$, respectively. The parameters of the original model are fixed through the mimicked quantities that we relate to the present astronomical data, such that the equation state parameter $w_{_{\\chi}}$ and the dark energy density parameter $\\Omega_{\\chi}$.

Sergio del Campo

2002-11-20

273

Finding reaction paths using the potential energy as reaction coordinate.  

PubMed

The intrinsic reaction coordinate curve (IRC), normally proposed as a representation of a reaction path, is parametrized as a function of the potential energy rather than the arc-length. This change in the parametrization of the curve implies that the values of the energy of the potential energy surface points, where the IRC curve is located, play the role of reaction coordinate. We use Caratheodory's relation to derive in a rigorous manner the proposed parametrization of the IRC path. Since this Caratheodory's relation is the basis of the theory of calculus of variations, then this fact permits to reformulate the IRC model from this mathematical theory. In this mathematical theory, the character of the variational solution (either maximum or minimum) is given through the Weierstrass E-function. As proposed by Crehuet and Bofill [J. Chem. Phys. 122, 234105 (2005)], we use the minimization of the Weierstrass E-function, as a function of the potential energy, to locate an IRC path between two minima from an arbitrary curve on the potential energy surface, and then join these two minima. We also prove, from the analysis of the Weierstrass E-function, the mathematical bases for the algorithms proposed to locate the IRC path. The proposed algorithm is applied to a set of examples. Finally, the algorithm is used to locate a discontinuous, or broken, IRC path, namely, when the path connects two first order saddle points through a valley-ridged inflection point. PMID:18345872

Aguilar-Mogas, Antoni; Giménez, Xavier; Bofill, Josep Maria

2008-03-14

274

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

275

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 - have been 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. An awareness of probable shortages of strategic materials has been maintained in these suggested programs.

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

1976-01-01

276

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

277

Potential energy changes and the Boussinesq approximation in stratified fluids  

Microsoft Academic Search

The evolution of the potential energy of an ideal binary fluid mixture that is initially stably stratified is re-examined. The initial stable stratification evolves to a state of uniform density under the influence of molecular diffusion. We derive the appropriate governing equations using either a mass-averaged or a volume-averaged definition of velocity, and develop an energy budget describing the changes

K. Seshadri; J. W. Rottman; K. K. Nomura; D. D. Stretch

2002-01-01

278

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

279

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

PubMed Central

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. PMID:17259270

Wang, Wangchen; Yang, Lin; Huang, Huey W.

2007-01-01

280

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

281

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

282

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

283

Ab initio potential energy surfaces for NH,,3 -...NH,,3 -  

E-print Network

Conversely, direct methods such as Stark deceleration14 and buffer gas cooling15 employ a scheme in which pre-space density. At present, direct-cooling methods for NH are limited to temperatures of a few hundredAb initio potential energy surfaces for NH,,3 - ...­NH,,3 - ... with analytical long range Liesbeth

284

Solar Energy Potential of Clusters on Sloped Terrains  

Microsoft Academic Search

Rapid worldwide urbanizations are demanding more land for construction and many cities surrounded by hills have started to expand onto neighbouring slopes. Whilst building on flat terrains is well investigated and documented, there is sill limited published research on the potential of energy conscious building on sloped terrain. The present study is part of a long-term research project which aims

PATRICIA VELOSO DA VEIGA; MOHAMED GADI

285

A highly accurate potential energy curve for the mercury dimer.  

PubMed

The potential energy curve of the electronic ground state of the mercury dimer based on CCSD(T) calculations at the complete basis set (CBS) limit, including corrections for the full triples DeltaT and explicit spin-orbit (SO) interactions at the CCSD(T) level of theory, is presented. In the far long-range part, the potential energy curve is complemented by symmetry-adapted perturbation theory calculations. Potential curves of an analytically simple, extended Lennard-Jones form are obtained from very accurate fits to the CBS/CCSD(T)+SO and CBS/CCSD(T)+SO+DeltaT data. The Hg(2) potential curves yield dissociation energies of D(e)=424/392 cm(-1) and equilibrium distances of r(e)=3.650/3.679 A at the CBS/CCSD(T)+SO and CBS/CCSD(T)+SO+DeltaT levels of theory, respectively. By including perturbative quadruple corrections in our coupled-cluster calculations and corrections from correlating the 4f-core, we arrive at a final dissociation energy of D(e)=405 cm(-1), in excellent agreement with the experimentally estimated value of 407 cm(-1) by Greif and Hensel. In addition, the rotational and vibrational spectroscopic constants as well as the second virial coefficient B(T) in dependence of the temperature T are calculated and validated against available experimental and theoretical data. PMID:20331291

Pahl, Elke; Figgen, Detlev; Thierfelder, Christian; Peterson, Kirk A; Calvo, Florent; Schwerdtfeger, Peter

2010-03-21

286

Biomass energy: the scale of the potential resource  

E-print Network

substantial use of fossil fuels, but it also has the potential to threaten conservation areas, pollute water is large in absolute terms, but it is not enough to replace more than a few percent of current fossil fuel to heighten energy secur- ity in regions without abundant fossil fuel reserves, to increase supplies of liquid

287

A formula for the static potential energy in quantum gravity  

Microsoft Academic Search

We give a general expression for the static potential energy of the gravitational interaction of two massive particles, in terms of an invariant vacuum expectation value of the quantized gravitational field. This formula holds for functional integral formulations of euclidean quantum gravity, regularized to avoid conformal instability. It could be regarded as the analogue of the Wilson loop for gauge

Giovanni Modanese

1993-01-01

288

Use and potential of geothermal energy in Belgium  

Microsoft Academic Search

Our basic knowledge of the geothermal potential in Belgium derives from existing geological reconnaissance surveys. As a result of the energy arises in the 1970s and early 1980s, efforts were made by public organisations such as the Belgian National Geological Survey and the Directorate-General for Science, Research and Development of the European Community to acquire further fundamental knowledge in the

Arne Berckmans; Noël Vandenberghe

1998-01-01

289

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.

290

Free energy versus internal energy potential for heavy quark systems at finite temperature  

NASA Astrophysics Data System (ADS)

The strength of the J / ? wave function at origin | ? (0) | is calculated by using the finite temperature QCD sum rule with the gluon condensates determined from the lattice QCD. The result is compared with that from a potential model based on the static free or internal energy obtained from lattice calculations. We find that the | ? (0) | decreases with temperature around the deconfinement transition temperature both in the QCD sum rule and in the potential model with the free energy potential. Our result thus suggests that the free energy potential from lattice calculations is appropriate for describing the properties of charmonia at finite temperature.

Song, Taesoo; Lee, Su Houng; Morita, Kenji; Ko, Che Ming

2014-11-01

291

Surface excitations in surface electron spectroscopies studied by reflection electron energy-loss spectroscopy and elastic peak electron spectroscopy.  

PubMed

Surface excitations, in addition to bulk excitation, undergone by signal electrons in surface electron spectroscopies, such as Auger electron spectroscopy, and X-ray photoelectron spectroscopy, play an important role in the formation of electron spectra. Those inelastic scattering processes not only induce decay in the peak intensity, but also form background appearing in the lower kinetic energy side of relevant peaks. Information on surface excitation is essential in addition to bulk excitations for the quantification of material surfaces by surface electron spectroscopies, and extensive studies have been devoted to it. In this report, we introduce the basics of the study of surface excitations by reflection electron energy loss spectroscopy (REELS) and elastic peak electron spectroscopy (EPES). The application of several approaches within the schemes of EPES analysis and REELS analysis to the experimental determination of inelastic scattering parameters, such as the surface excitation parameter (SEP), differential SEP (DSEP), inelastic mean free path (IMFP), and dielectric function, are also introduced. Information useful to calculate the values of the IMFP and SEP using predictive equations is provided in Supporting Information as well. PMID:20145317

Nagatomi, Takaharu; Tanuma, Shigeo

2010-01-01

292

Spin-asymmetry in elastic scattering of low-energy electrons from ultrathin Au films on W(110)  

NASA Astrophysics Data System (ADS)

We present joint experimental and theoretical results on the elastic scattering of spin-polarized electrons from an epitaxial Au film on a W(110) substrate in the energy range from 8 eV to 27 eV. A time-of-flight technique with a position-sensitive detector is applied to measure secondary emission spectra for spin-up and spin-down primary electrons in a specular geometry. The spin-asymmetry of coherently scattered electrons is obtained by selecting the diffraction spot on the detector. Regions of large asymmetries - with a maximum of about -60 % - are identified for electron energies of about 14 eV. Relativistic multiple-scattering calculations produce spin-orbit-induced asymmetries which are in agreement with their experimental counterparts. They further reveal that large asymmetries are associated with high intensities. This offers the possibility of an efficient new spin polarimeter with a figure of merit of about 1.5 · 10 -2.

Samarin, S. N.; Williams, J. F.; Artamonov, O. M.; Henk, J.; Feder, R.

2010-10-01

293

Analytical potential energy functions for some interhalogen diatomic electronic states  

NASA Astrophysics Data System (ADS)

The studies of vibrational energies and analytical potential energy functions (APEFs) have been carried out for four interhalogen diatomic electronic states B(3?0 +) and A(3?1) of ClF, A'(3?2u) of Cl2, and the ground state X1? g+ of Br2 by using an improved variational algebraic energy-consistent method (VAECM(4)). The full vibrational energies, the vibrational spectroscopic constants, the force constants fn, and the expansion coefficients an of the ECM (energy-consistent method) potential are tabulated. The VAECM(4) APEF with adjustable variational parameter ? for each electronic state is determined, and is shown to be in excellent agreement with available experimental data and has no any artificial barrier in all the calculation ranges that may appear in some other analytical potentials. Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2014-50639-7

Fan, Qunchao; Fan, Zhixiang; Nie, Yanping; Sun, Weiguo; Zhang, Yi; Feng, Hao

2015-01-01

294

N2(+) bound quartet and sextet state potential energy curves  

NASA Technical Reports Server (NTRS)

The N2(+) potential energies have been determined from a complete active space self-consistent field calculation with active 2s and 2p electrons. A (6s 4p 3d 1f) Gaussian basis set was used together with additional higher angular momentum and diffuse functions. The calculated potential energy curves for the states 4Sigma(mu)(+), 4Pi(g), and 6Sigma(g)(+), for which there are no spectroscopic observations, are presented. The corresponding spectroscopic constants have been determined from a polynomial curve fit to the computed energies near the well minima and are shown. The 6Sigma(g)(+) state is found to be significantly bound, with a minimum at 1.72 A.

Partridge, H.; Bauschlicher, C. W., Jr.; Stallcop, J. R.

1985-01-01

295

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

296

Protein dynamics in solution and powder measured by incoherent elastic neutron scattering: the influence of Q-range and energy resolution.  

PubMed

Incoherent elastic neutron scattering (IENS) has been widely used to measure intramolecular atomic mean square displacements (MSDs) of proteins in powder and in solution. The instrumental energy resolution and the wave vector transfer (Q-range) determine, respectively, the time and length scales of observable motions. In order to investigate contributions of diffusive motions to MSDs measured by this method, we calculated the elastic intensity for several simple scattering functions. We showed that continuous translational diffusion contributes to MSDs in a Q-range where the energy width of the scattering function is of the order of the instrumental energy resolution. We discuss the choice of instruments adapted to focus on intramolecular motions in the presence of solvent or global macromolecular diffusion. The concepts developed are applied to interpret experimental data from H(2)O- and D(2)O-hydrated proteins. Finally, analogies between the Gaussian approximation in IENS and the Guinier approximation in small-angle scattering are discussed. PMID:15378211

Gabel, Frank

2005-02-01

297

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

298

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

299

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

Microsoft Academic Search

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

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

2000-01-01

300

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

E-print Network

and CaO targets of about 0.5 mg/cm' were used and different targets were always cross-checked against a CaO standard. Absolute normaliza- tions were also checked by comparing forward angle, low-energy a scattering with the Ruther- ford formula...

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

1972-01-01

301

Technical Potential of Solar Energy to Address Energy Poverty and Avoid GHG Emissions in Africa  

SciTech Connect

This analysis explores the technical potential of photovoltaics (PV) or concentrating solar power (CSP) to address energy poverty in Africa through a geographic information system (GIS) screening of solar resource data developed by the U.S. Department of Energy's National Renewable Energy Laboratory (NREL).

Cowlin, S. C.; Heimiller, D.; Bilello, D.; Renne, D.

2008-01-01

302

An energy-saving oil drilling rig for recovering potential energy and decreasing motor power  

Microsoft Academic Search

An energy-saving oil drilling rig is researched. A large accumulator is adopted in this rig to store the energy of the motor during the auxiliary time of lifting the drill stem and the potential energy of the drill stem when lowered. The equipped power of this rig decreases remarkably compared with the conventional drilling rig, and this rig can also

Lujun Zhang

2011-01-01

303

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

PubMed

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

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

2013-09-01

304

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

305

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

306

Analysis of energy dissipation in an elastic moving string with a viscous damper at one end  

NASA Astrophysics Data System (ADS)

In this paper transverse vibration of an axially moving viscoelastic string with a viscous damper at one end is investigated analytically. The string is assumed to be travelling with constant velocity and the length of string is constant or time varying. The linear and nonlinear mathematical models are derived using the Lagrangian function and implemented using a finite element method. The method considers a time varying state space function applied to the linear model, the Newmark-Beta method is used to solve the response for the nonlinear problem numerically. The case of energy dissipated by a viscoelastic damper at one end of the string for different axial string velocities is considered. When a disturbance arrives at the boundary an exact value for the damper which provides maximum energy dissipation is investigated. Finally, numerical simulations are presented to establish the feasibility of the method.

Chen, E. W.; Ferguson, N. S.

2014-04-01

307

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

Microsoft Academic Search

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

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

2000-01-01

308

From Static Potentials to High-Energy Scattering  

E-print Network

We develop a loop-loop correlation model for a unified description of static color dipole potentials, confining QCD strings, and hadronic high-energy reactions with special emphasis on saturation effects manifesting S-matrix unitarity at ultra-high energies. The model combines perturbative gluon exchange with the non-perturbative stochastic vacuum model which describes color confinement via flux-tube formation of color fields. We compute the chromo-field distributions of static color dipoles in various SU(N_c) representations and find Casimir scaling in agreement with recent lattice QCD results. We investigate the energy stored in the confining string and use low-energy theorems to show consistency with the static quark-antiquark potential. We generalize Meggiolaro's analytic continuation from parton-parton to dipole-dipole scattering and obtain a Euclidean approach to high-energy scattering that allows us in principle to calculate S-matrix elements in lattice QCD. In this approach we compute high-energy dipole-dipole scattering with the Euclidean loop-loop correlation model. Together with a universal energy dependence and reaction-specific wave functions, the result forms the basis for a unified description of proton-proton, pion-proton, kaon-proton, photon-proton, and photon-photon reactions in good agreement with experimental data for cross sections, slope parameters, and structure functions. The obtained impact parameter profiles for proton-proton and longitudinal photon-proton reactions and the impact parameter dependent gluon distribution of the proton xG(x,Q^2,b) show saturation at ultra-high energies in accordance with unitarity constraints.

Frank Daniel Steffen

2003-01-13

309

Residential energy efficiency: Progress since 1973 and future potential  

NASA Astrophysics Data System (ADS)

Today's 85 million U.S. homes use 100 billion of fuel and electricity (1150/home). If their energy intensity (resource energy/ft2) were still frozen at 1973 levels, they would use 18% more. With well-insulated houses, need for space heat is vanishing. Superinsulated Saskatchewan homes spend annually only 270 for space heat, 150 for water heat, and 400 for appliances, yet they cost only 2000±1000 more than conventional new homes. The concept of Cost of Conserved Energy (CCE) is used to rank conservation technologies for existing and new homes and appliances, and to develop supply curves of conserved energy and a least cost scenario. Calculations are calibrated with the BECA and other data bases. By limiting investments in efficiency to those whose CCE is less than current fuel and electricity prices, the potential residential plus commercial energy use in 2000 AD drops to half of that estimated by DOE, and the number of power plants needed drops by 200. For the whole buildings sector, potential savings by 2000 are 8 Mbod (worth 50B/year), at an average CCE of 10/barrel.

Rosenfeld, Arthur H.

1985-11-01

310

Using peat for energy: Potential environmental restraints. Overview  

NASA Astrophysics Data System (ADS)

Serious consideration is being given to using peat as an energy resource in Minnesota, North Carolina, Florida, and some New England States. Potential environmental constraints for using peat as an energy resource are associated with disruption of important regional wetland ecosystems. Mining peatlands may significantly modify ground and surface water hydrology, degrade water quality in downstream receiving systems, contribute to the deterioration of local air quality, disrupt or eliminate plant and animal populations having specialized requirements and limited distributions, and destroy unique wetland ecosystems representing important scientific and educational resources. Careful selection of peatlands to be developed and application of appropriate mitigation and monitoring programs will be necessary to offset these impacts.

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

311

PBS Learning Media: Investigating Kinetic and Potential Energy  

NSDL National Science Digital Library

In this 3-5 day multimedia module, students explore concepts of kinetic, potential, and total energy within different types of systems. Watch a video of engineers who recreate a medieval trebuchet (using only 14th century technology) and an animation of energy transformation in a roller coaster. Play with a digital mass-and-spring model and a projectile simulator. Finally, students will use computational reasoning in a hands-on golf ball activity. This lesson was designed to engage multiple sensory paths and styles of learning through video, interactive simulation, animations, lab activities, and informative text.

2013-06-06

312

Quintom dark energy models with nearly flat potentials  

SciTech Connect

We examine quintom dark energy models, produced by the combined consideration of a canonical and a phantom field, with nearly flat potentials and dark energy equation-of-state parameter w{sub DE} close to -1. We find that all such models converge to a single expression for w{sub DE}(z), depending only on the initial field values and their derivatives. We show that this quintom paradigm allows for a description of the transition through -1 in the near cosmological past. In addition, we provide the necessary conditions for the determination of the direction of the -1 crossing.

Setare, M. R.; Saridakis, E. N. [Department of Science, Payame Noor University, Bijar (Iran, Islamic Republic of); Department of Physics, University of Athens, GR-15771 Athens (Greece)

2009-02-15

313

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

314

Preliminary evaluation of wind energy potential, Cook Inlet Area, Alaska  

NASA Astrophysics Data System (ADS)

Likely candidate regions for windpower utilization were analyzed in blocks of 25 to 100 square miles each. A monitoring system was developed to quantify the energy potential of each area. Screening factors included match between time of occurrance of wind power and load; access to adequate transmission and distribution systems; hazards at the site; environmental considerations of the site; and public acceptance of wind turbines at the site.

Hiester, T. R.

1980-06-01

315

Low Frequency Vibrational Spectra and Potential Energy Surface for Phthalan  

Microsoft Academic Search

The far-infrared and low-frequency Raman spectra of phthalan have been recorded and the ring-puckering and ring-flapping (butterfly) vibrations, which have fundemental frequencies of 31 and 216 cm -1, respectively, have been examined in detail. These two vibrations are strongly coupled, and this interaction results in complex spectra with numerous sum, difference and hot band series. A two-dimensional potential energy surface

Timothy Klots; Sachie Sakurai; Niklas Meinander; Jaan Laane

1996-01-01

316

Topographies and dynamics on multidimensional potential energy surfaces  

Microsoft Academic Search

The stochastic master equation is a valuable tool for elucidating potential energy surface (PES) details that govern structural relaxation in clusters, bulk systems, and protein folding. This work develops a comprehensive framework for studying non-equilibrium relaxation dynamics using the master equation. Since our master equations depend upon accurate partition function models for use in Rice-Ramsperger-Kassel-Marcus (RRK(M) transition state theory, this

Keith Douglas Ball

1998-01-01

317

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

318

Spectroscopic Properties and Potential Energy Curves of SnF +  

NASA Astrophysics Data System (ADS)

Spectroscopic properties and potential energy curves of several electronic states of SnF + are computed using the complete active space self-consistent field (CASSCF) followed by first- and second-order configuration interaction (FOCI, SOCI) methods that include up to 1.6 million configurations. Spin-orbit effects were incorporated using the relativistic configuration interaction (RCI) method. Spectroscopic properties of several excited electronic states of SnF + are reported, none of which is observed at present.

Balasubramanian, K.; Xu, H.

1995-06-01

319

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

320

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

321

Elastic O16+Ne20 scattering from a folding model analysis  

NASA Astrophysics Data System (ADS)

A folding potential for elastic 16O+20Ne scattering is constructed based on the four-?-particle model for the O16 nucleus and the ?+16O model for the Ne20 nucleus. The elastic scattering angular distributions of the 16O+20Ne system in the energy range of Ec.m.=24.5-35.5 MeV are calculated by use of the ?-folding potential obtained. The calculations show that the experimental data can be reasonably well described. The surface term in the imaginary potential has a significant effect on the calculations of the cross section at large angles for the energies considered.

Yang, Yong-Xu; Li, Qing-Run

2011-07-01

322

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

NASA Astrophysics Data System (ADS)

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

Robin, Ivan-Christophe; André, Régis; Bougerol, Catherine; Aichele, Thomas; Tatarenko, Serge

2006-06-01

323

Determination of nonlinear electromechanical energy conversion and the field-dependent elastic modulus of Pb(Mg1\\/3Nb2\\/3 )O3-based electrostrictors  

Microsoft Academic Search

Energy conversion efficiency is a critical parameter for all electromechanical materials. Although excellent techniques are available for linear materials, nonlinearities complicate the determination of conversion efficiency in electrostrictive Pb(Mg1\\/3Nb2\\/3 )O3 (PMN). The field dependence of the elastic modulus presents additional problems. A technique combining pulse-echo ultrasound has been developed to approximate the change in the Young's modulus with applied field.

Sean P. Leary; Steven M. Pilgrim

1999-01-01

324

Measurement of the asymmetry parameter A in pi-p elastic and charge-exchange scattering at pion energies Tpi=98, 238, 292, and 310 MeV  

Microsoft Academic Search

The asymmetry parameter A in pi-p elastic scattering at incident pion laboratory kinetic energies Tpi of 98, 238, and 2922 MeV and in pi-p charge-exchange scattering pi-p-->pi0n at Tpi=238, 292, and 310 MeV have been measured over a wide range of scattering angles (typically from about 60° to 130° c.m.) with a polarized proton target. The data have been used

J. C. Alder; C. Joseph; J. P. Perroud; M. T. Tran; G. H. Eaton; R. Frosch; H. Hirschmann; S. Mango; J. W. McCulloch; P. Shrager; G. Strassner; P. Truöl; P. Weymuth; P. Wiederkehr

1983-01-01

325

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

326

The effect of the new nucleon-nucleus elastic scattering data in LAHET{trademark} Version 2.8 on neutron displacement cross section calculations  

SciTech Connect

The latest release of the medium-energy Monte Carlo transport code LAHET includes a new nucleon-nucleus elastic scattering treatment based on a global medium-energy phenomenological optical-model potential. Implementation of this new model in LAHET allows nuclear elastic scattering for neutrons with energies greater than 15 MeV and for protons with energies greater than 50 MeV. Previous investigations on the impact of the new elastic scattering data revealed that the addition of the proton elastic scattering channel can lead to a significant increase in the calculated damage energy under certain conditions. The authors report here results on the impact of the new elastic scattering data on calculated displacement cross sections in various elements for neutrons with energies in the range 16 to 3,160 MeV. Calculated displacement cross sections at 20 MeV in low-mass materials are in better agreement with SPECTER-calculated cross sections.

Pitcher, E.J.; Ferguson, P.D.; Russell, G.J.; Prael, R.E.; Madland, D.G.; Court, J.D.; Daemen, L.L. [Los Alamos National Lab., NM (United States); Wechsler, M.S. [North Carolina State Univ., Raleigh, NC (United States)

1997-10-01

327

GIS Assessment of Wind Energy Potential in California and Florida  

NASA Astrophysics Data System (ADS)

Energy efficiency coupled with renewable energy technologies can provide most of the U.S. carbon emissions reductions needed to contain atmospheric carbon concentrations at 450-500 parts per million, considered by many to be a tipping point in mitigating climate change. Among the leaders in the alternative energy sector is wind power, which is now one of the largest sources of new power generation in the U.S. creating jobs and revenue for rural communities while powering our economy with an emissions-free source of energy. In 2006, wind turbines capable of generating more than 2,400 megawatts of electricity were installed in the U.S. and by 2007 this number had risen to 3,000 megawatts. The U.S. generated 31 billion kilowatt-hours of wind power in 2007, which is enough electricity to power the equivalent of nearly 3 million average homes. It is estimated that generating the same amount of electricity would require burning 16 million tons of coal or 50 million barrels of oil. This study examines the wind power potential of sites near populated areas in Florida and California to determine the practicability of installing wind turbines at these locations. A GIS was developed in order to conduct a spatial analysis of these sites based on mean annual wind speed measured in meters per second and wind power density ratings measured in watts per square meter. The analysis indicates that coastal areas of Cocoa Beach, Key West, Hollywood, and West Palm Beach, respectively, possess the greatest potential for wind energy in Florida with mean annual wind speeds of 4.9 m/s and average wind power density ratings of 171 w/m2 peaking at Cocoa Beach followed by wind speeds of 4.64 m/s and wind power ratings of 115 w/m2 at Key West. California wind energy potential is even greater than that of Florida with Fairfield exhibiting mean annual wind speeds of 5.9 m/s and average wind power density ratings of 327 w/m2 followed by the Mojave and Palmdale areas with mean annual wind speeds of 5.0 m/s and 4.6 m/s, respectively. Wind power density ratings for Mojave are 240 w/m2 and 153 w/m2 at Palmdale. These results help confirm that wind energy continues to offer a clean, cost-effective, inexhaustible, and readily available means of helping to curb global warming while answering the increasing demand for electricity.

Snow, R. K.; Snow, M. M.

2008-05-01

328

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

329

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

330

Desalination of water by reverse osmosis using gravitational potential energy and wind energy  

Microsoft Academic Search

This paper proposes an alternative configuration to conventional reverse osmosis (RO) desalination systems by incorporating the use of gravitational potential energy. The proposal suggests a model that can be viewed as the energy station of a RO desalination plant. Conventionally, RO plants use a high-pressure pump, powered by electricity or fossil fuel. The function of the pump is to send

E. A. F. A. Fadigas; J. R. Dias

2009-01-01

331

Solar energy and urban morphology: Scenarios for increasing the renewable energy potential of neighbourhoods in London  

E-print Network

the consumption and the generation of resources need to be assessed. In terms of urban environmental sustainability, the potential to generate renewable energy within the city boundaries is a research topic of growing interest, being solar energy one of the main...

Sarralde, Juan José; Quinn, David James; Wiesmann, Daniel; Steemers, Koen

2014-07-07

332

Very High Energy Blazars and the Potential for Cosmological Insight  

NASA Astrophysics Data System (ADS)

Gamma-ray blazars are among the most extreme astrophysical sources, harboring phenomena far more energetic than those attainable by terrestrial accelerators. These galaxies are understood to be active galactic nuclei that are powered by accretion onto supermassive black holes and have relativistic jets pointed along the Earth line of sight. The emission displayed is variable at all wavelengths and timescales probed thus far, necessitating contemporaneous broadband observations to disentangle the details of the emission processes within the relativistic jets. The very high energy (VHE; E> 100 GeV) photons emitted by these sources are detectable with ground based imaging atmospheric Cherenkov telescopes such as VERITAS. As these photons propagate extragalactic distances, the interaction with the diffuse starlight that pervades the entire Universe results in a distance and energy dependent gamma-ray opacity, offering a unique method for probing photon densities on cosmological scales. These galaxies have also been postulated to be potential sources of ultra-high-energy cosmic rays, a theory which can be examined through the deep gamma-ray observations of sources which probe moderate gamma-ray opacities. Within this talk, I will highlight ongoing research regarding the broadband emission from VERITAS-observed VHE blazars, as well as the potential to use them for cosmological insight.

Furniss, Amy

2014-08-01

333

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

334

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

335

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

336

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

337

Quasi-Elastic Transfer Reactions in SULFUR-32 + MOLYBDENUM-92,98,100 and NIOBIUM-93 Systems at Energies Near the Coulomb Barrier.  

NASA Astrophysics Data System (ADS)

Angular distributions of the few-nucleon transfer reactions in ^{32}S + ^{92,98,100}Mo and ^{93}Nb were measured at laboratory energies of 109, 116, and 125 MeV. Beams of ^ {32}S were accelerated by the Stony Brook tandem-linac accelerator. The charge of the projectile -like transfer products was identified by E - Delta E gas telescopes. The mass identification was achieved by measuring the energy and time-of-flight, using Si surface barrier detectors, where the linac RF signals provided master time references. The timing width of the beam was between 150 and 200 ps. Up to three nucleons pickup and four nucleons stripping were observed. The pickup channels are primarily neutron pickup and the stripping channels are dominated by proton stripping which agrees with the Q-matching condition predictions. The elastic scattering data were fitted by the optical model to obtain optical model potential parameters. The transfer angular distributions are bell-shaped. The peak of the angular distribution shifts toward 180 ^circ, in the center-of-mass frame, as energies approach the Coulomb barrier. Distorted-wave Born approximation calculations were performed to compare with the one- and two-nucleon transfer data. Good agreement was seen, particularly at energies below the barrier. The one-nucleon transfer cross sections are among 60 to 70% of the total transfer cross sections. The sum of the total transfer and fusion cross sections made up the total reaction cross sections. Large transfer cross sections were measured in ^{98,100 }Mo and ^{93}Nb targets while small transfer cross sections were measured in ^{92}Mo target, particularly at energies near the barrier. This is consistent with the large sub-barrier fusion enhancement observed in ^{32}S + ^{98,100 }Mo, ^{93}Nb but no enhancement in ^{32}S + ^{92}Mo. The transfer probability for one- and two-nucleon transfer was compared with the DWBA predictions at large reaction distances, d_0 >= 1.6 fm. The transfer probability for one-nucleon transfer is in good agreement with the DWBA calculations. The two -proton transfer probability shows anomalous slope at energies slightly above the barrier. However, there is no slope anomaly for two-proton stripping at energies below the barrier. A sharp change in the slope behaviour for two -proton transfer was observed right at the barrier. For two-neutron transfer, there is no slope anomaly at energies above the barrier which agrees with the neutron transfer systematics. A simple model studied suggests that at these energies, the transfer mechanism should be dominated by the semiclassical picture. The slope anomaly for two-proton transfer at energies above the barrier may be due to the influence of diffractive processes.

Liang, Junjien Felix

338

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

339

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

340

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

341

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

342

Potential energy curves and collision integrals of air components  

NASA Technical Reports Server (NTRS)

Collision integrals are fundamental quantities required to determine the transport properties of the environment surrounding aerospace vehicles in the upper atmosphere. These collision integrals can be determined as a function of temperature from the potential energy curves describing the atomic and molecular collisions. Ab initio calculations provide a practical method of computing the required interaction potentials. In this work we will discuss recent advances with an emphasis on the accuracy that is obtainable. Results for interactions, e.g. N+N, N+O, O+O, and H+N2 will be reviewed and their application to the determination of transport properties, such as diffusion and viscosity coefficients, will be examined.

Partridge, Harry; Stallcop, James R.; Levin, Eugene; Langhoff, Stephen R. (Technical Monitor)

1995-01-01

343

High elastic modulus polymer electrolytes  

DOEpatents

A polymer that combines high ionic conductivity with the structural properties required for Li electrode stability is useful as a solid phase electrolyte for high energy density, high cycle life batteries that do not suffer from failures due to side reactions and dendrite growth on the Li electrodes, and other potential applications. The polymer electrolyte includes a linear block copolymer having a conductive linear polymer block with a molecular weight of at least 5000 Daltons, a structural linear polymer block with an elastic modulus in excess of 1.times.10.sup.7 Pa and an ionic conductivity of at least 1.times.10.sup.-5 Scm.sup.-1. The electrolyte is made under dry conditions to achieve the noted characteristics.

Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel

2013-10-22

344

Modeling diatomic potential energy curves through the generalized exponential function  

NASA Astrophysics Data System (ADS)

In the present work, an alternative family of analytical potential energy curves (PECs) has been developed for diatomic systems. These kinds of functions, that are based on q-exponential, are used here to generalize the usual Bond Order (BO) and Rydberg analytical PECs of diatomic molecular systems. The diatomic systems H2+ and Li 2 have been examined by means of this alternative approach. In particular, the computed vibrational spectra and spectroscopic constants were found to be in good agreement with the available experimental data.

Esteves, C. S.; de Oliveira, H. C. B.; Ribeiro, L.; Gargano, R.; Mundim, K. C.

2006-08-01

345

Embedded atom potentials in fcc and bcc metals  

Microsoft Academic Search

A new embedded atom potential has been proposed in this paper. The potential is expressed by simple functions and is applicable to the molecular dynamics simulations of large atomic systems. The potential parameters are determined from the experimental data using the cohesive energy, Born stability, elastic constants, C11,C12 and C44, the formation energy of a vacancy. In case of fcc

Masao Doyama; Y. Kogure

1999-01-01

346

Visualization of the energy flow for guided forward and backward waves in and around a fluid-loaded elastic cylindrical shell via the Poynting vector field  

NASA Astrophysics Data System (ADS)

Color-coded and vector-arrow grid representations of the Poynting vector field are used to show the energy flow in and around a fluid-loaded elastic cylindrical shell for both forward- and backward-propagating waves. The present work uses a method adapted from a simpler technique due to Kaduchak and Marston [G. Kaduchak and P. L. Marston, ``Traveling-wave decomposition of surface displacements associated with scattering by a cylindrical shell: Numerical evaluation displaying guided forward and backward wave properties,'' J. Acoust. Soc. Am. 98, 3501-3507 (1995)] to isolate unidirectional energy flows.

Dean, Cleon E.; Braselton, James P.

2001-05-01

347

Potential for energy savings in old and new auto engines  

NASA Astrophysics Data System (ADS)

This paper disucsses the potential for energy savings in the transportation sector through the use of both improved and entirely new automotive engines. Although spark-ignition and diesel internal combustion engines will remain the dominant choices for passenger-car use throughout the rest of this century, improved versions of these engines (lean-burn, low-friction spark-ignition and adiabatic, low-friction diesel engines) could, in the long term, provide a 20-30 percent improvement in fuel economy over what is currently available. The use of new materials, and modifications to both vehicle structure and vehicle transmissions may yield further improvements. Over a longer time frame, the introduction of the high-temperature gas-turbine engine and the use of new synfuels may provide further opportunities for energy conservation.

Reitz, John R.

1985-11-01

348

Stabilized quasi-Newton optimization of noisy potential energy surfaces.  

PubMed

Optimizations of atomic positions belong to the most commonly performed tasks in electronic structure calculations. Many simulations like global minimum searches or characterizations of chemical reactions require performing hundreds or thousands of minimizations or saddle computations. To automatize these tasks, optimization algorithms must not only be efficient but also very reliable. Unfortunately, computational noise in forces and energies is inherent to electronic structure codes. This computational noise poses a severe problem to the stability of efficient optimization methods like the limited-memory Broyden-Fletcher-Goldfarb-Shanno algorithm. We here present a technique that allows obtaining significant curvature information of noisy potential energy surfaces. We use this technique to construct both, a stabilized quasi-Newton minimization method and a stabilized quasi-Newton saddle finding approach. We demonstrate with the help of benchmarks that both the minimizer and the saddle finding approach are superior to comparable existing methods. PMID:25612694

Schaefer, Bastian; Alireza Ghasemi, S; Roy, Shantanu; Goedecker, Stefan

2015-01-21

349

Stabilized quasi-Newton optimization of noisy potential energy surfaces  

NASA Astrophysics Data System (ADS)

Optimizations of atomic positions belong to the most commonly performed tasks in electronic structure calculations. Many simulations like global minimum searches or characterizations of chemical reactions require performing hundreds or thousands of minimizations or saddle computations. To automatize these tasks, optimization algorithms must not only be efficient but also very reliable. Unfortunately, computational noise in forces and energies is inherent to electronic structure codes. This computational noise poses a severe problem to the stability of efficient optimization methods like the limited-memory Broyden-Fletcher-Goldfarb-Shanno algorithm. We here present a technique that allows obtaining significant curvature information of noisy potential energy surfaces. We use this technique to construct both, a stabilized quasi-Newton minimization method and a stabilized quasi-Newton saddle finding approach. We demonstrate with the help of benchmarks that both the minimizer and the saddle finding approach are superior to comparable existing methods.

Schaefer, Bastian; Alireza Ghasemi, S.; Roy, Shantanu; Goedecker, Stefan

2015-01-01

350

Domestic refrigeration appliances in Poland: Potential for improving energy efficiency  

SciTech Connect

This report is based on information collected from the main Polish manufacturer of refrigeration appliances. We describe their production facilities, and show that the energy consumption of their models for domestic sale is substantially higher than the average for similar models made in W. Europe. Lack of data and uncertainty about future production costs in Poland limits our evaluation of the cost-effective potential to increase energy efficiency, but it appears likely that considerable improvement would be economic from a societal perspective. Many design options are likely to have a simple payback of less than five years. We found that the production facilities are in need of substantial modernization in order to produce higher quality and more efficient appliances. We discuss policy options that could help to build a market for more efficient appliances in Poland and thereby encourage investment to produce such equipment.

Meyers, S.; Schipper, L. [Lawrence Berkeley Lab., CA (United States); Lebot, B. [Agence de l`Environnement and de la Maitrise de l`Energie, 6 - Sophia Antipolis (France)

1993-08-01

351

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

352

The Nonlinear Spring and Energy Conservation.  

ERIC Educational Resources Information Center

Describes an air track experiment demonstrating the transfer of mechanical energy from elastic potential to kinetic. Discusses four methods for calculating energy stored in the spring. Included are pictures, typical data, and graphs. (YP)

Sherfinski, John

1989-01-01

353

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

354

The mechanics of elastic loading and recoil in anuran jumping.  

PubMed

Many animals use catapult mechanisms to produce extremely rapid movements for escape or prey capture, resulting in power outputs far beyond the limits of muscle. In these catapults, muscle contraction loads elastic structures, which then recoil to release the stored energy extremely rapidly. Many arthropods employ anatomical 'catch mechanisms' to lock the joint in place during the loading period, which can then be released to allow joint motion via elastic recoil. Jumping vertebrates lack a clear anatomical catch, yet face the same requirement to load the elastic structure prior to movement. There are several potential mechanisms to allow loading of vertebrate elastic structures, including the gravitational load of the body, a variable mechanical advantage, and moments generated by the musculature of proximal joints. To test these hypothesized mechanisms, we collected simultaneous 3D kinematics via X-ray Reconstruction of Moving Morphology (XROMM) and single-foot forces during the jumps of three Rana pipiens. We calculated joint mechanical advantage, moment and power using inverse dynamics at the ankle, knee, hip and ilio-sacral joints. We found that the increasing proximal joint moments early in the jump allowed for high ankle muscle forces and elastic pre-loading, and the subsequent reduction in these moments allowed the ankle to extend using elastic recoil. Mechanical advantage also changed throughout the jump, with the muscle contracting against a poor mechanical advantage early in the jump during loading and a higher mechanical advantage late in the jump during recoil. These 'dynamic catch mechanisms' serve to resist joint motion during elastic loading, then allow it during elastic recoil, functioning as a catch mechanism based on the balance and orientation of forces throughout the limb rather than an anatomical catch. PMID:25520385

Astley, Henry C; Roberts, Thomas J

2014-12-15

355

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

356

Structures and potential energy surface of faujasitic zeolite/water  

NASA Astrophysics Data System (ADS)

The structures and the potential energy surface of the system faujasitic zeolite/water have been investigated by Hartree-Fock, second-order Moller-Plesset (MP2) and by the density functional theory (DFT) calculations, using five basis sets 6-31G(d), 6-31G(d,p), 6-311G(d), 6-311G(d,p) and 6-311 + G(d,p). The DFT calculations employ the Becke-3-Lee-Yang-Parr (B3LYP) and Becke-Lee-Yang-Parr (BLYP) density functional, and, for comparisons, the local density approximation with the Vosko-Wilk-Nusair (VWN) functional. The B3LYP approach is found to yield better agreement with the corresponding experimental results than the VWM and BLYP functionals. The B3LYP amd MP2 levels of theory yield basically the same results. Results of B3LYP with a 6-311 + G(3df,2p) basis set are also very close to those of the very accurate coupled pair functional (CPF) method. Also proton affinities (PA) computed by B3LYP reproduce the corresponding CPF and G1 results very well. The predicted PA of faujasitic catalyst is estimated to be 294 ± 3 kcal/mol, which is in the range of the experimentally determined value of 291-300 kcal/mol. The interaction of faujasite catalyst with water has revealed that the structures can be stabilized by the formation of two hydrogen bonds with water molecules adsorbed at the bridging hydroxyl groups which can act either as a proton acceptor or as a proton donor. Comparison of the faujasite complexes with silanol and hydrogen halides has demonstrated that the faujasitic zeolite is a strong acid. The potential energy surfaces of faujasite zeolite/water has been investigated and analytical interaction potentials have been derived.

Limtrakul, Jumras; Treesukol, Piti; Ebner, Christoph; Sansone, Roland; Probst, Michael

1997-02-01

357

Potential energy surface and rovibrational energy levels of the H2-CS van der Waals complex.  

PubMed

Owing to its large dipole, astrophysicists use carbon monosulfide (CS) as a tracer of molecular gas in the interstellar medium, often in regions where H(2) is the most abundant collider. Predictions of the rovibrational energy levels of the weakly bound complex CS-H(2) (not yet observed) and also of rate coefficients for rotational transitions of CS in collision with H(2) should help to interpret the observed spectra. This paper deals with the first goal, i.e., the calculation of the rovibrational energy levels. A new four-dimensional intermolecular potential energy surface for the H(2)-CS complex is presented. Ab initio potential energy calculations were carried out at the coupled-cluster level with single and double excitations and a perturbative treatment of triple excitations, using a quadruple-zeta basis set and midbond functions. The potential energy surface was obtained by an analytic fit of the ab initio data. The equilibrium structure of the H(2)-CS complex is found to be linear with the carbon pointing toward H(2) at the intermolecular separation of 8.6 a(o). The corresponding well depth is -173 cm(-1). The potential was used to calculate the rovibrational energy levels of the para-H(2)-CS and ortho-H(2)-CS complexes. The present work provides the first theoretical predictions of these levels. The calculated dissociation energies are found to be 35.9 cm(-1) and 49.9 cm(-1), respectively, for the para and ortho complexes. The second virial coefficient for the H(2)-CS pair has also been calculated for a large range of temperature. These results could be used to assign future experimental spectra and to check the accuracy of the potential energy surface. PMID:23267480

Denis-Alpizar, Otoniel; Stoecklin, Thierry; Halvick, Philippe; Dubernet, Marie-Lise; Marinakis, Sarantos

2012-12-21

358

Potential energy surface and rovibrational energy levels of the H2-CS van der Waals complex  

NASA Astrophysics Data System (ADS)

Owing to its large dipole, astrophysicists use carbon monosulfide (CS) as a tracer of molecular gas in the interstellar medium, often in regions where H2 is the most abundant collider. Predictions of the rovibrational energy levels of the weakly bound complex CS-H2 (not yet observed) and also of rate coefficients for rotational transitions of CS in collision with H2 should help to interpret the observed spectra. This paper deals with the first goal, i.e., the calculation of the rovibrational energy levels. A new four-dimensional intermolecular potential energy surface for the H2-CS complex is presented. Ab initio potential energy calculations were carried out at the coupled-cluster level with single and double excitations and a perturbative treatment of triple excitations, using a quadruple-zeta basis set and midbond functions. The potential energy surface was obtained by an analytic fit of the ab initio data. The equilibrium structure of the H2-CS complex is found to be linear with the carbon pointing toward H2 at the intermolecular separation of 8.6 ao. The corresponding well depth is -173 cm-1. The potential was used to calculate the rovibrational energy levels of the para-H2-CS and ortho-H2-CS complexes. The present work provides the first theoretical predictions of these levels. The calculated dissociation energies are found to be 35.9 cm-1 and 49.9 cm-1, respectively, for the para and ortho complexes. The second virial coefficient for the H2-CS pair has also been calculated for a large range of temperature. These results could be used to assign future experimental spectra and to check the accuracy of the potential energy surface.

Denis-Alpizar, Otoniel; Stoecklin, Thierry; Halvick, Philippe; Dubernet, Marie-Lise; Marinakis, Sarantos

2012-12-01

359

Investigation of wind characteristics and wind energy potential in Kirklareli, Turkey  

Microsoft Academic Search

Utilization of wind energy as an energy source has been growing rapidly in the whole world due to environmental pollution, consumption of the limited fossil fuels and global warming. Although Turkey has fairly high wind energy potential, exploitation of the wind energy is still in the crawling level. In the current study, wind characteristics and wind energy potential of K?rklareli

Murat Gökçek; Ahmet Bayülken; ?ükrü Bekdemir

2007-01-01

360

Elasticity of Fractal Inspired Interconnects.  

PubMed

The use of fractal-inspired geometric designs in electrical interconnects represents an important approach to simultaneously achieve large stretchability and high aerial coverage of active devices for stretchable electronics. The elastic stiffness of fractal interconnects is determined analytically in this paper. Specifically, the elastic energy and the tensile stiffness for an order n fractal interconnect of arbitrary shape are obtained, and are verified by the finite element analysis and experiments. PMID:25183293

Su, Yewang; Wang, Shuodao; Huang, YongAn; Luan, Haiwen; Dong, Wentao; Fan, Jonathan A; Yang, Qinglin; Rogers, John A; Huang, Yonggang

2014-09-01

361

Cadmium tolerance and accumulation in eight potential energy crops.  

PubMed

The production of energy crops that can be used for biodiesel production is a sustainable approach for the removal of metal pollutants by phytoremediation. This study investigated the cadmium (Cd) accumulation and tolerance of eight potential energy crops. After growth for 28 days in substrates containing 0, 50, 100 or 200 mg Cd x kg(-1), seedlings were evaluated for growth parameters, chlorophyll content, chlorophyll fluorescence parameters and Cd accumulation. All eight crops were moderately tolerant to Cd toxicity, with four [i.e., hemp (Cannabis sativa), flax (Linum usitatissimum), castor (Ricinus communis) and peanut (Arachis hypogaea)] being more tolerant than the others. Three of these crops (hemp, flax and peanut) had higher Cd accumulation capacities. The roots of peanut and hemp had high bioconcentration factors (BCF>1000), while flax shoots accumulated a higher concentration of Cd (>100 mg/kg). These results demonstrate that it is possible to grow energy crops on Cd-contaminated soil. Hemp, flax and peanut are excellent candidates for phytoremediation. PMID:19393309

Shi, Gangrong; Cai, Qingsheng

2009-01-01

362

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 equation agrees with the usual expression for the energy of a radial density distribution. The second degree terms give a maximum nonhydrostatic energy in the mantle and crust of -2.77 x 10 to the twenty-ninth power ergs, an order of magnitude. 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 twentieth power poises is found by assuming the total geothermal flux is due to viscous dissipation. If the nonequilibrium figure is dynamically maintained by the earth acting as a heat engine at one per cent efficiency, then the viscosity is ten to the twenty second power poises, a number preferred by some as the viscosity of the mantle.

Rubincam, D. P.

1977-01-01

363

Molecular spinless energies of the modified Rosen-Morse potential energy model in higher spatial dimensions  

NASA Astrophysics Data System (ADS)

We solve the Klein-Gordon equation with the modified Rosen-Morse potential energy model in D spatial dimensions. The bound state energy equation has been obtained by using the supersymmetric WKB approximation approach. We find that the inter-dimensional degeneracy symmetry exists for the molecular system represented by the modified Rosen-Morse potential. For fixed vibrational and rotational quantum numbers, the relativistic energies for the 61?u state of the 7Li2 molecule and the X3? state of the SiC radical increase as D increases. We observe that the behavior of the relativistic vibrational energies in higher dimensions remains similar to that of the three-dimensional system.

Jia, Chun-Sheng; Dai, Jian-Wei; Zhang, Lie-Hui; Liu, Jian-Yi; Zhang, Guang-Dong

2015-01-01

364

Energy conservation potential of the US Department of Energy interim commercial building standards  

SciTech Connect

This report describes a project conducted to demonstrate the whole-building energy conservation potential achievable from full implementation of the US Department of Energy (DOE) Interim Energy Conservation Performance Standards for New Commercial and Multi-Family High Rise Residential Buildings. DOE`s development and implementation of energy performance standards for commercial buildings were established by the Energy Conservation Standards for New Buildings Act of 1976, as amended, Public Law (PL) 94-385, 42 USC 6831 et seq., hereinafter referred to as the Act. In accordance with the Act, DOE was to establish performance standards for both federal and private sector buildings ``to achieve the maximum practicable improvements in energy efficiency and use of non-depletable resources for all new buildings``.

Hadley, D.L.; Halverson, M.A.

1993-12-01

365

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

366

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

367

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

368

Spectroscopic constants and potential energy curves for OsH  

NASA Astrophysics Data System (ADS)

Complete active space (CASSCF) followed by first-order configuration interaction (FOCI) and second-order CI (SOCI) are carried out on 21 low-lying electronic states of OsH. Spin-orbit effects are investigated using the relativistic CI (RCI) methodology. The ground state of OsH is found to be 4? symmetry with R e = 1.606 Å, ?e = 2138 cm -1, De = 2.317 eV, and ?e = -1.651 D in the absence of spin-orbit interactions, while the ground state is found to be a strong mixture of 4?( {5}/{2}) and 4?( {5}/{2}) including spin-orbit coupling. Potential energy surfaces for 21 low-lying electronic states are reported. Allowed electronic transitions from the ground X4? and some other low-lying states are predicted. The nature and bonding of the low-lying electronic states are analyzed through Mulliken populations.

Benavides-Garcia, M.; Balasubramanian, K.

1991-11-01

369

Spectroscopic Constants and Potential Energy Curves of PbI  

NASA Astrophysics Data System (ADS)

The spectroscopic constants and potential energy curves of the PbI diatomic were computed using complete active space SCF (CASSCF) followed by first-order CI (FOCI) and second-order CI (SOCI) calculations which included 607 000 configurations. Spin-orbit coupling was studied using the relativistic CI (RCI) method. The spectroscopic properties of the 2? 1/2 state are Re = 2.885 Å, ? e, = 153 cm -1, and De = 2.54(eV), while for the 2? 3/2 state the corresponding values are Re = 2.859 Å, ? e = 162 cm -1, and Te = 8255 cm -1. Our computed constants are in good agreement with experiment for the observed states. We also computed the properties and curves for several excited states which are yet to be observed.

Benavidesgarcia, M.; Balasubramanian, K.

1993-10-01

370

A new local theory of available potential energy for quantifying energy pathways in the oceans  

NASA Astrophysics Data System (ADS)

Lorenz's theory of available potential energy (APE) has recently received much attention in the context of ocean energetics, for it is increasingly realized to be a key tool for clarifying the relative importance of the surface buoyancy fluxes in powering the ocean circulation, a controversial issue over the past 15 years or so. So far, however, most recent approaches have been restricted to global APE budgets, often for idealized equations of state, which is arguably of limited interest to understand the precise nature of the energy pathways in the oceans. Here, we will present a local extension of the theory of available potential energy, which is developed for the primitive equations that form the basis of most current general ocean circulation models, and which is valid for an arbitrary nonlinear equation of state. Another advantage of the new theory is that it does not require the reference state underlying Lorenz's APE theory to be necessarily the state of minimum potential energy obtained in an adiabatic re-arrangement of the fluid parcels, and hence does not suffer from traditional difficulties pertaining to how to do the sorting of the fluid parcels. The main result of this work is the ability in some instances to link local conversion of APE into kinetic energy directly to the local production of APE by surface fluxes. The framework is also shown to be useful to provide an energy-based characterization of oceanic water masses.

Tailleux, Remi

2013-04-01

371

Top-down free-energy minimization on protein potential energy landscapes  

Microsoft Academic Search

The hierarchical properties of potential energy landscapes have been used to gain insight into thermodynamic and kinetic properties of protein ensembles. It also may be possible to use them to direct computational searches for thermodynamically stable macroscopic states, i.e., computational protein folding. To this end, we have developed a top-down search procedure in which conformation space is recursively dissected according

Bruce W. Church; David Shalloway

2001-01-01

372

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

373

Elastic cross sections in an RSIIp scenario  

NASA Astrophysics Data System (ADS)

The elastic differential cross section is calculated at low energies (below 100 MeV) for the elements 3He, 20Ne, 40Ar, 14N, 12C, and for the 208Pb using a finite electromagnetic potential, which is obtained by considering a Randall–Sundrum II scenario modified by the inclusion of p compact extra-dimensions. The length scale is adjusted in the potential to compare with known experimental data and to set bounds for the parameter of the model. The effective four-dimensional (4D) electromagnetic potential is produced by a point charge, as seen from the three-brane that contains it, in uniform motion in an RSIIp scenario.

Arceo, R.; Pedraza, Omar; González-Espinosa, E.; Escalera Santos, G. J.; Díaz-Hernández, O.

2015-01-01

374

Material and energy recovery in integrated waste management systems: the potential for energy recovery.  

PubMed

This article is part of a set of six coordinated papers reporting the main findings of a research project carried out by five Italian universities on "Material and energy recovery in Integrated Waste Management Systems (IWMS)". An overview of the project and a summary of the most relevant results can be found in the introductory article of the series. This paper describes the work related to the evaluation of mass and energy balances, which has consisted of three major efforts (i) development of a model for quantifying the energy content and the elemental compositions of the waste streams appearing in a IWMS; (ii) upgrade of an earlier model to predict the performances of Waste-to-Energy (WtE) plants; (iii) evaluation of mass and energy balances of all the scenarios and the recovery paths considered in the project. Results show that not only the amount of material available for energy recovery is significantly higher than the Unsorted Residual Waste (URW) left after Separate Collection (SC), because selection and recycling generate significant amounts of residues, but its heating value is higher than that of the original, gross waste. Therefore, the energy potential of what is left after recycling is always higher than the complement to 100% of the Source Separation Level (SSL). Also, increasing SSL has marginal effects on the potential for energy recovery: nearly doubling SSL (from 35% to 65%) reduces the energy potential only by one fourth. Consequently, even at high SSL energy recovery is a fundamental step of a sustainable waste management system. Variations of SSL do bring about variations of the composition, heating value and moisture content of the material fed to WtE plants, but these variations (i) are smaller than one can expect; (ii) have marginal effects on the performances of the WtE plant. These considerations suggest that the mere value of SSL is not a good indicator of the quality of the waste management system, nor of its energy and environmental outcome. Given the well-known dependence of the efficiency of steam power plants with their power output, the efficiency of energy recovery crucially depends on the size of the IWMS served by the WtE plant. A fivefold increase of the amount of gross waste handled in the IWMS (from 150,000 to 750,000 tons per year of gross waste) allows increasing the electric efficiencies of the WtE plant by about 6-7 percentage points (from 21-23% to 28.5% circa). PMID:21689919

Consonni, Stefano; Viganò, Federico

2011-01-01

375

IRETHERM: The geothermal energy potential of Irish radiothermal granites  

NASA Astrophysics Data System (ADS)

The IRETHERM project is developing a strategic understanding of Ireland's deep geothermal energy potential through integrated modelling of new and existing geophysical and geological data. One aspect of IRETHERM's research focuses on Ireland's radiothermal granites, where increased concentrations of radioelements provide elevated heat-production (HP), surface heat-flow (SHF) and subsurface temperatures. An understanding of the contribution of granites to the thermal field of Ireland is important to assessing the geothermal energy potential of this low-enthalpy setting. This study focuses on the Galway granite in western Ireland, and the Leinster and the buried Kentstown granites in eastern Ireland. Shallow (<250 m) boreholes were drilled into the exposed Caledonian Leinster and Galway granites as part of a 1980's geothermal project. These studies yielded HP = 2-3 ?Wm-3 and HF = 80 mWm-2 at the Sally Gap borehole in the Northern Units of the Leinster granite, to the SW of Dublin. In the Galway granite batholith, on the west coast of Ireland, the Costelloe-Murvey granite returned HP = 7 ?Wm-3 and HF = 77 mWm-2, measured at the Rossaveal borehole. The buried Kentstown granite, 35 km NW of Dublin, has an associated negative Bouguer anomaly and was intersected by two mineral exploration boreholes at depths of 660 m and 490 m. Heat production is measured at 2.4 ?Wm-3 in core samples taken from the weathered top 30 m of the granite. The core of this study consists of a program of magnetotelluric (MT) and audio-magnetotelluric (AMT) data acquisition across the three granite bodies, over three fieldwork seasons. MT and AMT data were collected at 59 locations along two profiles over the Leinster granite. Preliminary results show that the northern units of the Leinster granite (40 km SW of Dublin) extend to depths of 2-5 km. Preliminary results from the southern profile suggest a greater thickness of granite to a depth of 6-9 km beneath the Tullow pluton, 75 km SW of Dublin. Over the Galway granite, MT and AMT data have been collected at a total of 75 sites (33 consist of only AMT data acquisition, with both MT and AMT recorded at the remaining 42). Preliminary results show a deep resistor extending to depths of 15-20 km beneath the central block, with the resistive upper layer extending to depths of 3.5-7 km west of the Shannawona fault, a major structure that cuts the batholith. MT and AMT data acquired along a profile at 22 locations over the Kentstown granite suggests that this buried granite is at a depth of 400 m beneath the centre of the gravity anomaly. The MT and AMT data will be integrated with gravity and seismic refraction data (in the case of the Leinster granite) to identify deeply penetrating faults, which may provide conduits for hydrothermal fluids, and to produce a robust estimation of the volumetric extent of the granites, which is crucial in defining their geothermal energy potential. Thermal conductivity and geochemical data will be incorporated to constrain the heat contribution of granites to the Irish crust.

Farrell, Thomas; Jones, Alan; Muller, Mark; Feely, Martin; Brock, Andrew; Long, Mike; Waters, Tim

2014-05-01

376

Exploring the local elastic properties of bilayer membranes using molecular dynamics simulations.  

PubMed

Membrane mechanical elastic properties regulate a variety of cellular processes involving local membrane deformation, such as ion channel function and vesicle fusion. In this work, we used molecular dynamics simulations to estimate the local elastic properties of a membrane. For this, we calculated the energy needed to extract a DOPE lipid molecule, modified with a linker chain, from a POPC bilayer membrane using the umbrella sampling technique. Although the extraction energy entails several contributions related not only to elastic deformation but also to solvation, careful analysis of the potential of mean force (PMF) allowed us to dissect the elastic contribution. With this information, we calculated an effective linear spring constant of 44 ± 4 kJ·nm(-2)·mol(-1) for the DOPC membrane, in agreement with experimental estimates. The membrane deformation profile was determined independently during the stretching process in molecular detail, allowing us to fit this profile to a previously proposed continuum elastic model. Through this approach, we calculated an effective membrane spring constant of 42 kJ·nm(-2)·mol(-1), which is in good agreement with the PMF calculation. Furthermore, the solvation energy we derived from the data is shown to match the solvation energy estimated from critical micelle formation constants. This methodology can be used to determine how changes in lipid composition or the presence of membrane modifiers can affect the elastic properties of a membrane at a local level. PMID:25325715

Pieffet, Gilles; Botero, Alonso; Peters, Günther H; Forero-Shelton, Manu; Leidy, Chad

2014-11-13

377

Material and energy recovery in integrated waste management systems: The potential for energy recovery  

SciTech Connect

Highlights: > The amount of waste available for energy recovery is significantly higher than the Unsorted Residual Waste (URW). > Its energy potential is always higher than the complement to 100% of the Source Separation Level (SSL). > Increasing SSL has marginal effects on the potential for energy recovery. > Variations in the composition of the waste fed to WtE plants affect only marginally their performances. > A large WtE plant with a treatment capacity some times higher than a small plant achieves electric efficiency appreciably higher. - Abstract: This article is part of a set of six coordinated papers reporting the main findings of a research project carried out by five Italian universities on 'Material and energy recovery in Integrated Waste Management Systems (IWMS)'. An overview of the project and a summary of the most relevant results can be found in the introductory article of the series. This paper describes the work related to the evaluation of mass and energy balances, which has consisted of three major efforts (i) development of a model for quantifying the energy content and the elemental compositions of the waste streams appearing in a IWMS; (ii) upgrade of an earlier model to predict the performances of Waste-to-Energy (WtE) plants; (iii) evaluation of mass and energy balances of all the scenarios and the recovery paths considered in the project. Results show that not only the amount of material available for energy recovery is significantly higher than the Unsorted Residual Waste (URW) left after Separate Collection (SC), because selection and recycling generate significant amounts of residues, but its heating value is higher than that of the original, gross waste. Therefore, the energy potential of what is left after recycling is always higher than the complement to 100% of the Source Separation Level (SSL). Also, increasing SSL has marginal effects on the potential for energy recovery: nearly doubling SSL (from 35% to 65%) reduces the energy potential only by one fourth. Consequently, even at high SSL energy recovery is a fundamental step of a sustainable waste management system. Variations of SSL do bring about variations of the composition, heating value and moisture content of the material fed to WtE plants, but these variations (i) are smaller than one can expect; (ii) have marginal effects on the performances of the WtE plant. These considerations suggest that the mere value of SSL is not a good indicator of the quality of the waste management system, nor of its energy and environmental outcome. Given the well-known dependence of the efficiency of steam power plants with their power output, the efficiency of energy recovery crucially depends on the size of the IWMS served by the WtE plant. A fivefold increase of the amount of gross waste handled in the IWMS (from 150,000 to 750,000 tons per year of gross waste) allows increasing the electric efficiencies of the WtE plant by about 6-7 percentage points (from 21-23% to 28.5% circa).

Consonni, Stefano [Department of Energy, Politecnico di Milano, Via Lambruschini 4, 20156 Milan (Italy); LEAP - Laboratorio Energia Ambiente Piacenza, Via Bixio 27, 29100 Piacenza (Italy); Vigano, Federico, E-mail: federico.vigano@polimi.it [Department of Energy, Politecnico di Milano, Via Lambruschini 4, 20156 Milan (Italy); LEAP -Laboratorio Energia Ambiente Piacenza, Via Bixio 27, 29100 Piacenza (Italy)

2011-09-15

378

Calculation of free-energy differences and potentials of mean force by a multi-energy gap method  

E-print Network

Calculation of free-energy differences and potentials of mean force by a multi-energy gap method the convergence of free-energy calculations. It introduces a bias factor in Monte Carlo simulations or.e., the difference in energy function between two states, and is therefore specifically designed for calculating free-energy

Weston, Ken

379

Flapping states of an elastically anchored plate in a uniform flow with applications to energy harvesting by fluid-structure interaction  

NASA Astrophysics Data System (ADS)

Linear stability analysis of an elastically anchored flat plate in a uniform flow is investigated both analytically and numerically. The analytical formulation explicitly takes into account the effect of the wake on the plate by means of Theodorsen's theory. Three different parameters non-trivially rule the observed dynamics: mass density ratio between plate and fluid, spring elastic constant, and distance between the plate center of mass and the spring anchor point on the plate. We found relationships between these parameters which rule the transition between stable equilibrium and fluttering. The shape of the resulting marginal curve has been successfully verified by high Reynolds number numerical simulations. Finally, the limiting case corresponding to a simply supported rigid rod is also analyzed and the resulting flapping instability traced back to a simple resonance condition. Our findings are of interest in applications related to energy harvesting by fluid-structure interaction, a problem that has recently attracted a great deal of attention. The main aim in that context is to identify the optimal physical/geometrical system configuration leading to large sustained motion, which is the source of energy one aims to extract.

Orchini, A.; Mazzino, A.; Guerrero, J.; Festa, R.; Boragno, C.

2013-09-01

380

Intraclass Price Elasticity & Electric Rate Design  

E-print Network

INTRACLASS PRICE ELASTICITY &ELECTRIC RATE DESIGN KEVIN E. GRESHAM Senior Research Analyst Houston Lighting & Power Company Houston, Texas ABSTRACT PRICE ELASTICITY Electric ~ate design relies on cost incur rance for pricing and pricing... 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...

Gresham, K. E.

381

Energy storage in carbon nanotube super-springs  

E-print Network

A new technology is proposed for lightweight, high density energy storage. The objective of this thesis is to study the potential of storing energy in the elastic deformation of carbon nanotubes (CNTs). Prior experimental ...

Hill, Frances Ann

2008-01-01

382

On the potential energy in an electrostatically bound two-body system  

E-print Network

The potential energy problem in an electrostatically bound two-body system is studied in the framework of a recently proposed impact model of the electrostatic force and in analogy to the potential energy in a gravitationally bound system. The physical processes are described that result in the variation of the potential energy as a function of the distance between the charged bodies. The energy is extracted from distributions of hypothetical interaction entities modified by the charged bodies.

Wilhelm, K

2015-01-01

383

On the potential energy in an electrostatically bound two-body system  

E-print Network

The potential energy problem in an electrostatically bound two-body system is studied in the framework of a recently proposed impact model of the electrostatic force and in analogy to the potential energy in a gravitationally bound system. The physical processes are described that result in the variation of the potential energy as a function of the distance between the charged bodies. The energy is extracted from distributions of hypothetical interaction entities modified by the charged bodies.

K. Wilhelm; B. N. Dwivedi

2014-08-30

384

The potential of energy farming in the southeastern California desert  

NASA Astrophysics Data System (ADS)

The use of energy forms to provide future sources of energy for California is considered. Marginal desert lands in southeastern California are proposed for the siting of energy farms using acacia, eucalyptus, euphorbia, guayule, jojoba, mesquite, or tamarisk.

Lew, V.

1980-04-01

385

(Molecular understanding of mutagenicity using potential energy methods)  

SciTech Connect

The objective of our work has been, for many year, to elucidate on a molecular level at atomic resolution the structures of DNAs modified by highly mutagenic polycyclic aromatic amines and hydrocarbons, and their less mutagenic chemically related analogs and unmodified DNAs, as controls. The ultimate purpose of this undertaking is to obtain an understanding of the relationship DNA structures and mutagenicity. Our methods for elucidating structures are computational, but we keep in close contact with experimental developments, and have, very recently, been able to incorporate the first experimental information from NMR studies by other workers in our calculations. The specific computational methods we employ are minimized potential energy calculations using the torsion angle space program DUPLEX, developed and written by Dr. Brain Hingerty to yield static views. Molecular dynamics simulations of the important static structures with full solvation and salt are carried out with the program AMBER; this yields mobile views in a milieu that best mimics the natural environment of the cell. In addition, we have been developing new strategies for searching conformation space and building DNA duplexes from favored subunit structures. 30 refs., 12 figs.

Broyde, S.

1990-01-01

386

Molecular understanding of mutagenicity using potential energy methods  

SciTech Connect

Our objective, has been to elucidate on a molecular level, at atomic resolution, the structures of DNAs modified by 2-aminofluorene and its N-acetyl derivative, 2-acetylaminofluorene (AAF). The underlying hypothesis is that DNA replicates with reduced fidelity when its normal right-handed B-structure is altered, and one result is a higher mutation rate. This change in structure may occur normally at a low incidence, for example by the formation of hairpin loops in appropriate sequences, but it may be enhanced greatly after covalent modification by a mutagenic substance. We use computational methods and have been able to incorporate the first data from NMR studies in our calculations. Computational approaches are important because x-ray and spectroscopic studies have not succeeded in producing atomic resolution views of mutagen and carcinogen-oligonucleotide adducts. The specific methods that we employ are minimized potential energy calculations using the torsion angle space molecular mechanics program DUPLEX to yield static views. Molecular dynamics simulations, with full solvent and salt, of the important static structures are carried out with the program AMBER; this yields mobile views in a medium that mimics the natural aqueous environment of the cell as well as can be done with current available computing resources.

Broyde, S.; Shapiro, R.

1992-07-01

387

Relationship of the Williams-Poulios and Manning-Rosen Potential Energy Models for Diatomic Molecules  

NASA Astrophysics Data System (ADS)

By employing the dissociation energy and the equilibrium bond length for a diatomic molecule as explicit parameters, we generate an improved form of the Williams-Poulios potential energy model. It is found that the negative Williams-Poulios potential model is equivalent to the Manning-Rosen potential model for diatomic molecules. We observe that the Manning-Rosen potential is superior to the Morse potential in reproducing the interaction potential energy curves for the {{a}3 ?u+} state of the 6Li2 molecule and the {{X}1 sum+} state of the SiF+ molecule.

Jia, Chun-Sheng; Liang, Guang-Chuan; Peng, Xiao-Long; Tang, Hong-Ming; Zhang, Lie-Hui

2014-06-01

388

Potential Ambient Energy-Harvesting Sources and Techniques  

ERIC Educational Resources Information Center

Ambient energy harvesting is also known as energy scavenging or power harvesting, and it is the process where energy is obtained from the environment. A variety of techniques are available for energy scavenging, including solar and wind powers, ocean waves, piezoelectricity, thermoelectricity, and physical motions. For example, some systems…

Yildiz, Faruk

2009-01-01

389

Biomass and biogas energy in Thailand: Potential, opportunity and barriers  

Microsoft Academic Search

Biomass has been traditional energy source in rural Thailand for decades. Country modernization, instead of reducing the biomass energy consumption, has continuously increased its utilization for both households and production of modern energy. While the GDP\\/capita was triple during 1980–1996, the biomass energy consumption increased by 68%, and expected to be higher as signaled by the increasing number of new

S. Prasertsan; B. Sajjakulnukit

2006-01-01

390

History and potential of renewable energy development in New Zealand  

Microsoft Academic Search

Many years before greenhouse gas emission reduction became a major driver for renewable energy development, New Zealand was an early adopter of several alternative energy technologies, particularly hydroelectricity and geothermal energy. It has achieved a level of 60% of total electricity generation from such sources, and is now pursuing a target of 95% of electricity generation from renewable energy, to

Geoff Kelly

2011-01-01

391

Analysis of {{\\pi }^{+/- }}-nucleus elastic and inelastic scattering using the single folding {\\boldsymbol{ \\alpha }} -cluster model  

NASA Astrophysics Data System (ADS)

An analysis of {{? }+/- }-nucleus elastic and inelastic scattering has been performed using local semi-microscopic optical potentials constructed in the framework of the single folding approach. The folding calculations are carried out based upon the ?-cluster structure of the target nuclei with two different phenomenological forms of the pion–alpha effective interaction. The derived potentials have been employed to extract the angular distributions of elastic and inelastic scattering cross sections through a broad energy range, 100–766 MeV, where 39 sets of data have been successfully described. The corresponding reaction and total cross sections have also been extracted.

El-Azab Farid, M.; Ebrahim, A. A.

2015-01-01

392

Elastic ?+Ne20 scattering in the ?+O16 model of Ne20  

NASA Astrophysics Data System (ADS)

A folding potential for the elastic ?+Ne20 scattering is constructed based on the ?+O16 structure model of the Ne20 nucleus. The elastic scattering angular distributions of the ?+Ne20 system at incident energies E?=31.1, 54.1, and 104.0 MeV have been calculated by using the folding potential. The experimental angular distributions and the anomalous large angle scattering (ALAS) features can be satisfactorily described. The anomaly of the ?+Ne20 system is clearly reconfirmed in the present folding model analysis and should be further systematically investigated.

Yang, Yong-Xu; Tan, Hai-Lan; Li, Qing-Run

2010-08-01

393

Theoretical investigations of BBS (singlet)?BSB (triplet) transformation on a potential energy surface obtained from neural network fitting  

NASA Astrophysics Data System (ADS)

B2S, the simplest BnSm cluster, has been shown to exhibit an interesting ground-state structure. B3LYP/6-311G (d,p) calculations suggest that its most stable configuration is singlet linear B-B-S. When promoted to the excited triplet state, B2S adopts the B-S-B configuration (C2v point group). To characterize its structural transformation, the lowest energy at each configuration is selected, and the neural network surface is developed with symmetry exchange incorporated. The triplet potential energy is found to be 0.48 eV above the ground state. Subsequently, the nudged-elastic-band method is employed to locate the BBS?BSB transition state. It is found that the barrier height is 1.35 eV above the equilibrium singlet BBS energy (0.88 eV for the reverse reaction). In addition, quasiclassical molecular dynamics with different vibrational excitations shows that the reaction is accelerated when the bending vibrational mode of BBS is excited, while the activation of BBS stretching modes causes a negative effect.

Nguyen-Truong, Hieu T.; Thi, Cao Minh; Le, Hung M.

2013-11-01

394

Marine renewable energy: potential benefits to biodiversity? An urgent call for research  

E-print Network

Marine renewable energy: potential benefits to biodiversity? An urgent call for research Richard 1 Centre for Ecology and Conservation and Peninsula Research Institute for Marine Renewable Energy. Concerns over the potential impacts on biodiversity of marine renewable energy installations (MREI) include

Exeter, University of

395

Relationship between the electronic potential energy of a crystal and X-ray scattering  

Microsoft Academic Search

Some simple but approximate relationships arc shown to yield the total deformation potential energy of a crystal from a summation of the structure factors and their squares. By application of the virial theorem this deformation potential should be consistent with similar kinetic energy differences obtained from integration of the Compton profiles in addition to being consistent with the cohesive energy

R. J. Weiss

1978-01-01

396

A Cumulus Parameterization Based on the Generalized Convective Available Potential Energy  

Microsoft Academic Search

This paper reports tests of a cumulus parameterization in which the reference state associated with the generalized convective available potential energy (GCAPE) is chosen as the end-state of the convective adjustment. The GCAPE is defined as the enthalpy difference between the given state and the reference state and represents the total potential energy available for conversion into convective kinetic energy

Junyi Wang; David A. Randall

1996-01-01

397

Boussinesq and Anelastic Approximations Revisited: Potential Energy Release during Thermobaric Instability  

Microsoft Academic Search

Expressions are derived for the potential energy of a fluid whose density depends on three variables: temperature, pressure, and salinity. The thermal expansion coefficient is a function of depth, and the application is to thermobaric convection in the oceans. Energy conservation, with conversion between kinetic and potential energies during adiabatic, inviscid motion, exists for the Boussinesq and anelastic approximations but

Andrew P. Ingersoll

2005-01-01

398

By-products: oil sorbents as a potential energy source.  

PubMed

The present study investigated the utilization of an industrial by-product, lignite fly ash, in oil pollution treatment, with the further potential profit of energy production. The properties of lignite fly ash, such as fine particle size, porosity, hydrophobic character, combined with the properties, such as high porosity and low specific gravity, of an agricultural by-product, namely sawdust, resulted in an effective oil-sorbent material. The materials were mixed either in the dry state or in aqueous solution. The oil sorption behaviour of the fly ash-sawdust mixtures was investigated in both marine and dry environments. Mixtures containing fly ash and 15-25% w/w sawdust performed better than each material alone when added to oil spills in a marine environment, as they formed a cohesive semi-solid phase, adsorbing almost no water, floating on the water surface and allowing total oil removal. For the clean-up of an oil spill 0.5 mm thick with surface area 1000 m(2), 225-255 kg of lignite fly ash can be utilized with the addition of 15-25% w/w sawdust. Fly ash-sawdust mixtures have also proved efficient for oil spill clean-up on land, since their oil sorption capacity in dry conditions was at least 0.6-1.4 g oil g(-1) mixture. The higher calorific value of the resultant oil-fly ash-sawdust mixtures increased up to that of bituminous coal and oil and exceeded that of lignite, thereby encouraging their utilization as alternative fuels especially in the cement industry, suggesting that the remaining ash can contribute in clinker production. PMID:23179513

Karakasi, Olga K; Moutsatsou, Angeliki

2013-04-01

399

A satellite investigation of energy flux and inferred potential drop in auroral electron energy spectra  

NASA Technical Reports Server (NTRS)

Because predicted relationship (epsilon directly varies with V squared) between auroral electron energy flux (epsilon) and the inferred acceleration potential drop (V) for accelerated Maxwellian distributions was favorably tested by other using sounding rocket data for the limiting case of eVE 1 (where Ec is the characteristic energy of the accelerated Maxwellian distribution) and for a single inverted-V observed by the Injun 5 satellite, data from Atmosphere D were used to extend these studies over the range .2 eV/Ec 5 and for a wide range of latitudes and local times on both the nightside and the dayside. Results show good agreement with the full accelerated Maxwellian model. An analytical approximation to the electron energy flux was derived which better describes the data over the range .2 eV/Ec approximated 3. Analyses of individual energy spectra at small and large pitch angles through well-defined inverted-V structures suggest that the altitude of the inferred potential drop maximizes near the center of the inverted-V's.

Meniett, J. D.; Burch, J. L.

1981-01-01

400

Possible hyperdeformed band in Ar36 observed in C12+Mg24 elastic scattering  

NASA Astrophysics Data System (ADS)

Fifteen strongly oscillating angular distributions of the elastic scattering of C12+Mg24 at energies around the Coulomb barrier (Ec.m.=10.67-16.00 MeV) are reproduced by adding five Breit-Wigner resonance terms to the l=2,4,6,7, and 8 elastic S matrix. The nonresonant, background elastic scattering S matrix Sl0 is calculated using the São Paulo potential. The J=2,4,6,7, and 8 ? molecular resonances fit well into a rotational molecular band, together with other higher lying resonances observed in the O16+Ne20 elastic scattering. We propose that the presently observed, largely deformed molecular band corresponds to the hyperdeformed band, which has been found previously in ?-cluster calculations, as well as in a new Nilsson model calculation. Systematic study of its possible clusterizations predicts the preference of the C12+Mg24 and O16+Ne20 molecular structure, in accordance with our present results.

Sciani, Wagner; Otani, Yul; Lépine-Szily, Alinka; Benjamim, Elisangela A.; Chamon, Luiz Carlos; Filho, Rubens Lichtenthäler; Darai, Judit; Cseh, József

2009-09-01

401

Vibration of an elastic tensegrity structure  

Microsoft Academic Search

The dynamic behavior of a simple elastic tensegrity structure is examined, in order to validate observations that the natural damping of the elastic elements in such a structure is poorly mobilized, due to the natural flexibility of the equilibrium position of the structure. It is confirmed, analytically and numerically, that the energy decay of such a system is slower than

Irving J Oppenheim; William O Williams

2001-01-01

402

Near-Barrier Elastic Scattering of Weakly Bound Nuclei and the Threshold Anomaly  

NASA Astrophysics Data System (ADS)

It is pointed out that the usual threshold anomaly, found operative in the energy behavior of the imaginary and real parts of the optical potential representing the elastic scattering of tightly bound nuclei at near- and below-barrier energies, suffers a drastic qualitative change in the case of the elastic scattering of weakly bound projectile nuclei. Owing to the strong coupling to the breakup channel even at sub-barrier energies, the imaginary potential strength seems to increase as the energy is lowered down to below the natural, barrier, threshold, accompanied by a decrease in the real potential strength. This feature is consistent with the dispersion relation. It also clearly indicates the effective increase of the barrier height. The systems 9Be, 16O + 64Zn and 6,7Li + 138Ba are analyzed to illustrate this new phenomenon.

Hussein, M. S.; Chamon, L. C.; Gomes, P. R. S.

2005-10-01

403

A comprehensive and comparative study of elastic electron scattering from OCS and CS2 in the energy region from 1.2 to 200 eV  

NASA Astrophysics Data System (ADS)

We report absolute differential cross sections (DCSs) for elastic electron scattering from OCS (carbonyl sulphide) and CS2 (carbon disulphide) in the impact energy range of 1.2-200 eV and for scattering angles from 10° to 150°. Above 10 eV, the angular distributions are found to agree quite well with our present calculations using two semi-phenomenological theoretical approaches. One employs the independent-atom model with the screening-corrected additivity rule (IAM-SCAR), while the other uses the continuum-multiple-scattering method in conjunction with a parameter-free exchange-polarization approximation. Since OCS is a polar molecule, further dipole-induced rotational excitation cross sections have been calculated in the framework of the first Born approximation and incoherently added to the IAM-SCAR results. In comparison with the calculated DCS for the S atom, atomic-like behavior for the angular distributions in both the OCS and CS2 scattering systems is observed. Integrated elastic cross sections are obtained by extrapolating the experimental measurements, with the aid of the theoretical calculations, for those scattering angles below 10° and above 150°. These values are then compared with the available total cross sections.

Murai, H.; Ishijima, Y.; Mitsumura, T.; Sakamoto, Y.; Kato, H.; Hoshino, M.; Blanco, F.; García, G.; Limão-Vieira, P.; Brunger, M. J.; Buckman, S. J.; Tanaka, H.

2013-02-01

404

Elastic constants of sodium from molecular dynamics  

NASA Astrophysics Data System (ADS)

We have performed molecular-dynamics calculations of the adiabatic elastic constants of sodium at three different temperatures, T=198, 299, and 349 K. Our method uses fluctuation formulas appropriate for the microcanonical ensemble which contain the elastic constants. In the simulation we have used a first-principles potential to model the interaction between the sodium atoms. The results, including the shear modulus C44, show good agreement with experiment at all three temperatures. We have analyzed the contributions to the elastic constants from different types of terms appearing in the fluctuation formula and compared these contributions to other model-potential calculations. The volume dependence in the potential has considerable effect on the values of elastic constants. In comparison to some earlier calculations which employed pair potentials with no volume dependence, the fluctuation contributions to elastic constants C11 and C44 are noticeably large (20% of the value of the elastic constants in some cases). We find that the elastic constants do not change by much for the different potential-cutoff ranges employed: 17.85, 23.27, and 27.70 bohrs.

Çagin, Tahir; Ray, John R.

1988-01-01

405

Brownian motor with competing spatial and temporal asymmetry of potential energy.  

PubMed

A Brownian motor is considered which operates due to asymmetric dichotomic fluctuations of the spatially periodic asymmetric potential energy. As shown, the motion direction and stopping points of this motor are dictated by the competition between the spatial and temporal asymmetry of the potential energy (or solely by temporal asymmetry in the case that the potential energy sign fluctuates). For an asymmetric sawtooth potential, the Brownian-particle average velocity is calculated numerically as a function of certain parameters of the model, whereas the low-frequency and low-energy approximations allow the corresponding analytical relationships to be derived for an arbitrarily shaped potential profile. It is shown that temporal asymmetry is not necessary for stopping point occurrence provided that the potential profile fluctuates not only in amplitude but in shape as well. This inference is illustrated by photoinduced fluctuations of the potential energy for a number of substituted arylpyrene molecules on a substrate with symmetrically distributed charge density. PMID:21728503

Rozenbaum, V M; Korochkova, T Ye; Chernova, A A; Dekhtyar, M L

2011-05-01

406

Disagreement between capture probabilities extracted from capture and quasi-elastic backscattering excitation functions  

NASA Astrophysics Data System (ADS)

Experimental quasi-elastic backscattering and capture (fusion) excitation functions are usually used to extract the s -wave capture probabilities for the heavy-ion reactions. We investigated the 16O + 120Sn , 144Sm , 208Pb systems at energies near and below the corresponding interaction barriers and concluded that the probabilities extracted from quasi-elastic data are much larger than the ones extracted from fusion excitation functions at sub and deep-sub barrier energies. This seems to be a reasonable explanation for the known disagreement observed in the literature for the nuclear potential diffuseness derived from both methods.

Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.; Gomes, R. P. S.

2014-12-01

407

A potential enstrophy and energy conserving scheme for the shallow water equations  

NASA Technical Reports Server (NTRS)

To improve the simulation of nonlinear aspects of the flow over steep topography, a potential enstrophy and energy conserving scheme for the shallow water equations is derived. It is pointed out that a family of schemes can conserve total energy for general flow and potential enstrophy for flow with no mass flux divergence. The newly derived scheme is a unique member of this family, that conserves both potential enstrophy and energy for general flow. Comparison by means of numerical experiment with a scheme that conserves (potential) enstrophy for purely horizontal nondivergent flow demonstrated the considerable superiority of the newly derived potential enstrophy and energy conserving scheme, not only in suppressing a spurious energy cascade but also in determining the overall flow regime. The potential enstrophy and energy conserving scheme for a spherical grid is also presented.

Arakawa, A.; Lamb, V. R.

1981-01-01

408

Energy eigenvalues of spherical symmetric potentials with relativistic corrections: analytic results  

NASA Astrophysics Data System (ADS)

Based on the investigation of the asymptotic behaviour of the polarization loop function for charged n scalar particles in an external gauge field, we determine the interaction Hamiltonian including the relativistic corrections. The energy eigenvalues of spherical symmetric potentials for two-particle bound state systems with relativistic corrections are analytically derived. The energy spectra of linear and funnel potentials with orbital and radial excitations are determined. The energy spectrum of a superposition of Coulomb and Yukawa potentials is also determined. Our result shows that the energy spectrum with the relativistic corrections for the linear, harmonic oscillator and funnel potentials is smaller than the upper boundaries for the energy spectrum established in the framework of the spinless Salpeter equation for the orbital and radial excited states. The relativistic corrections to the energy spectrum of a superposition of the attractive Coulomb potential and the Yukawa (exponentially screened Coulomb) potentials are very small.

Dineykhan, M.; Zhaugasheva, S. A.; Toinbaeva, N. Sh

2010-01-01

409

Solar energy potential atlas for planning energy system off-grid electrification in the Republic of Djibouti  

E-print Network

1 Solar energy potential atlas for planning energy system off-grid electrification in the Republic solar resource can therefore be an interesting mean to produce energy where it is consumed. The aimWh/m². Furthermore, the solar radiation reaching Djibouti corresponded to 20 000 times the total yearly energy

Boyer, Edmond

410

A model for a constrained, finitely deforming, elastic solid with rotation gradient dependent strain energy, and its specialization to von Kármán plates and beams  

NASA Astrophysics Data System (ADS)

The aim of this paper is to develop the governing equations for a fully constrained finitely deforming hyperelastic Cosserat continuum where the directors are constrained to rotate with the body rotation. This is the generalization of small deformation couple stress theories and would be useful for developing mathematical models for an elastic material with embedded stiff short fibers or inclusions (e.g., materials with carbon nanotubes or nematic elastomers, cellular materials with oriented hard phases, open cell foams, and other similar materials), that account for certain longer range interactions. The theory is developed as a limiting case of a regular Cosserat elastic material where the directors are allowed to rotate freely by considering the case of a high "rotational mismatch energy". The theory is developed using the formalism of Lagrangian mechanics, with the static case being based on Castigliano's first theorem. By considering the stretch U and the rotation R as additional independent variables and using the polar decomposition theorem as an additional constraint equation, we obtain the governing and as well as the boundary conditions for finite deformations. The resulting equations are further specialized for plane strain and axisymmetric finite deformations, deformations of beams and plates with small strain and moderate rotation, and for small deformation theories. We also show that the boundary conditions for this theory involve "surface tension" like terms due to the higher gradients in the strain energy function. For beams and plates, the rotational gradient dependent strain energy does not require additional variables (unlike Cosserat theories) and additional differential equations; nor do they raise the order of the differential equations, thus allowing us to include a material length scale dependent response at no extra "computational cost" even for finite deformation beam/plate theories

Srinivasa, A. R.; Reddy, J. N.

2013-03-01

411

Wind energy potential mapping in Karnataka, India, using GIS  

Microsoft Academic Search

Increasing negative effects of fossil fuel combustion on the environment in addition to limited stock have forced many countries to explore and change to environmentally friendly alternatives that are renewable to sustain the increasing energy demand. Changing to renewable sources and implementation of effective conservation measures would ensure sustainability. Currently, wind energy is one of the fastest developing renewable energy

T. V. Ramachandra; B. V. Shruthi

2005-01-01

412

On the regional wind energy potential of Turkey  

Microsoft Academic Search

Continuous uses of fossil fuels are bound to pollute the atmosphere and consequently unwanted greenhouse and climate change effects will come to dominate every part of the earth. It is, therefore, advised to exploit clean energy resources, and for many nations in the world to try to assess their environmentally friendly, clean energy resources such as wind energy. Hence, it

Ahmet Öztopal; Ahmet D ?ahin; Nezihe Akgün; Zekai ?en

2000-01-01

413

Development of the Potential Energy Savings Estimation (PESE) Toolkit  

E-print Network

the corresponding energy conservation measures (ECMs) in the early phase of an EBCx project or energy retrofit project. Using the tool requires limited information about the building and the built-in HVAC system type, as well as sorted bin weather and energy...

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

414

Technical and Economic Potentials of Renewable Energy Development in Thailand  

Microsoft Academic Search

Energy consumption of Thailand has been continually increasing whereas the government policy to import those conventional energy seems to be limited. To sustainably overcome this problem, the development of renewable energy projects are important keys. Among them, bio- fuels projects seem to be the most promising one because of abundant reserves available in the domestic. There have been two groups

Watchara Permchart; Somporn Tanatvanit

415

Using cell potential energy to model the dynamics of adhesive biological cells  

NASA Astrophysics Data System (ADS)

Developing a continuous mathematical model of a physical phenomenon which is based on a discrete model of the same system is not straightforward. Yet such a process is useful in illustrating the link between the individual behavior of the elements comprising a system and its macroscopic behavior. Collections of biological cells can exhibit phenomena such as pattern formation, aggregation, and invasion, and mathematics has proven useful in elucidating the underlying dynamics of these phenomena. The continuous models formulated are frequently of reaction-diffusion form, and central to their application is a knowledge of the diffusion coefficient of a collection of the elements comprising the system. Cohen and Murray [J. Math Biol. 12, 237 (1981)] developed a means of deriving this quantity which has since been largely neglected by model developers, and which is based on a knowledge of the potential energy associated with the mutual interaction between the cells. In this work, we begin by deriving the energy of interaction of biological cells modeled as adhesive, deformable spheres. In so doing, we are able to quantify the equilibrium density of a biological cell aggregate, and also obtain a quantitative estimate of the diffusion coefficient of a collection of cells modeled in this way. In so doing, we are able to use experimental data from single-cell studies of the adhesiveness and cell membrane elasticity of a biological cell to derive the diffusion coefficient of a cell mass composed of a collection of identical cells. This allows us to better inform the parameter values used in reaction-diffusion models of biological systems. We go on to apply this technique to a particular situation: modeling the dynamics of a collection of biological cells which experience strong cell-cell adhesion. In so doing, we derive a nonlinear fourth-order partial differential equation to model this system. We conclude by discussing the practical utility of this work in illuminating the link between the microscopic behavior of individual biological cells and the macroscopic behavior of the aggregate to which they give rise, and also by giving some insights into how the modeling of cell-cell adhesion may be treated mathematically.

Turner, Stephen

2005-04-01

416

Constraints on the total and kinetic energy of ground states in a class of potential models  

NASA Astrophysics Data System (ADS)

It is shown that the ground state energy in a central potential is a concave (convex) function of angular momentum l when this potential is a concave (convex) function of r2. A result stronger than concavity is obtained when the Laplacian of the potential is negative. New bounds in the kinetic energy of these states are derived in terms of energy differences and for s states in terms of the wave function at the origin. These bounds can be used to give good estimates of the ground state energies for power law potentials.

Common, A. K.; Martin, A.

1989-03-01

417

Methodology for the Determination of Potential Energy Savings in Commercial Buildings  

E-print Network

This paper describes a methodology to determine potential energy savings of buildings with limited information. This methodology is based upon the simplified energy analysis procedure of heating, ventilation and air condition (HVAC) systems...

Baltazar-Cervantes, J. C.; Claridge, D. E.

2007-01-01

418

Nuclear rainbow in elastic scattering of {sup 9}Be nuclei  

SciTech Connect

A systematic investigation of the elastic scattering of the {sup 9}Be nucleus, which is among themost loosely bound stable nuclei was performed.Differential cross sections for elastic {sup 9}Be + {sup 16}O scattering were measured at a c.m. energy of 47.5 MeV (beam of 132-MeV {sup 16}O nuclei). Available data at different energy values and data for neighboring nuclei were included in our analysis. As a result, the very fact of rainbow scattering was reliably established for the first time in systems involving {sup 9}Be. In addition, the analysis in question made it possible to identify Airy minima and to determine unambiguously the nucleus-nucleus potential with a high probability.

Glukhov, Yu. A., E-mail: gloukhov@inbox.ru; Ogloblin, A. A.; Artemov, K. P.; Rudakov, V. P. [Russian Research Center Kurchatov Institute (Russian Federation)

2010-01-15

419

Potential of energy farming in the southeastern California desert  

SciTech Connect

The California Energy Commission is currently analyzing the use of energy farms to provide future sources of energy for California. Energy farms can be defined as growing plants and converting them to various forms of energy. The use of marginal desert lands in southeastern California for the siting of energy farms using acacia, Eucalyptus, euphorbia, quayule, jojoba, mesquite, or tamarisk is considered. Two hypothetical scenarios using either rainfall, or rainfall and groundwater as water sources were described to determine the maximum amount of energy produced from estimated amounts of suitable land in this area. Considering both scenarios, the maximum range of energy produced is .03 to 0.4 Quads. It is recommended that (1) genetic research be continued to increase biomass yields of these and other candidate plants grown in the desert; and (2) small test plots be established at varying desert locations to collect yield growth, and survival data. Once this information is known, the identification of the best plant(s) to use for energy farming in the California desert area will be known, as well as the cost and quantity of energy produced.

Lew, V.

1980-04-01

420

Vibrations of Tetrahedral Pentatomic Molecules. Part I. Potential Energy. Part II. Kinetic Energy and Normal Frequencies of Vibration  

Microsoft Academic Search

Part I. It is shown that the most general potential energy function consistent with tetrahedral symmetry involves five force constants, also that with a suitable choice of variables this expression may be written in a quite simple form convenient for the discussion of different types of vibration. Special cases of potential energy such as the \\

Jenny E. Rosenthal

1934-01-01

421

Influences of the surface elastic energy term K13 on the critical fields of liquid crystal cells and experimental measurement of K13  

NASA Astrophysics Data System (ADS)

Based on the modified formula of Rapini-Papoular, the equation and boundary condition of the director of weak anchoring nematic liquid crystal (NLC) cell have been obtained in the case of existence of the surface elastic energy term K13. The influences of K13 on the threshold field and the saturation field have been studied in detail with the methods of analytical derivation and numerical calculation. A new method of checking whether K13 exists or not is given in theory. Combining with the previous work, we also propose an experimental plan to measure the value of K13 with a wedge-shaped planar-aligned weak anchoring NLC cell. The numerical experiments are carried out to verify the feasibility of our method.

Guan, Rong-Hua; Wang, Chui-Ru; Yu, Hui; Kang, Wen-Xiu; Huai, Jun-Xia; Yang, Guo-Chen

2005-02-01

422

Phase-field study the effects of elastic strain energy on the occupation probability of Cr atom in Ni-Al-Cr alloy  

NASA Astrophysics Data System (ADS)

The occupation probability (OP) of Cr atom at ? sublattices and ? sublattices of DO22-Ni3Cr and L12-Ni3Al in Ni-Al-Cr alloy was studied by using phase-field microelasticity model. The elastic strain energy (ESE) arised by a coherent misfit has little effect on the precipitation sequence of alloy while it changes the behavior of the temporal evolution OP of Cr atom in DO22 and L12 phases. With the ESE increasing, the OP of Cr atom at both ? sublattices and ? sublattices in DO22 phase increases, the OP of Cr atom at ? sublattices in L12 phase decreases, and the OP of Cr atom at ? sublattices in L12 phase increases. Eventually, the ESE leads to directional coarsening of coherent microstructure.

Lu, Yanli; Jia, Dewei; Hu, Tingting; Chen, Zheng; Zhang, Liuchao

2014-02-01

423

FORTRAN 4 programs for the extraction of potential well parameters from the energy dependence of total elastic scattering cross sections  

NASA Technical Reports Server (NTRS)

An attempt has been made to keep the programs as subroutine oriented as possible. Usually only the main programs are directly concerned with the problem of total cross sections. In particular the subroutines POLFIT, BILINR, GASS59/MAXLIK, SYMOR, MATIN, STUDNT, DNTERP, DIFTAB, FORDIF, EPSALG, REGFAL and ADSIMP are completely general, and are concerned only with the problems of numerical analysis and statistics. Each subroutine is independently documented.

Labudde, R. A.

1972-01-01

424

Cancellation of Kinetic and Potential Energy in Atoms, Molecules, and Solids  

Microsoft Academic Search

In the energy levels of valence electrons in atoms, molecules, solids, and liquids, there is a contribution from the large negative potential energy inside the core of the atom and the large positive kinetic energy which the electron has there. Phillips and Kleinman have shown how the kinetic energy can be represented by a repulsive pseudopotential which cancels most of

Morrel H. Cohen; V. Heine

1961-01-01

425

The analysis of wind data and wind energy potential in Kutahya, Turkey  

Microsoft Academic Search

The wind energy is one of the most significant and rapidly developing renewable energy sources in the world and it provides a clean energy resource, which is a promising alternative in the short term in Turkey. The wind energy potential in various parts of Turkey is becoming economical due to reductions in the wind turbine costs, and in fossil fuel

Ramazan Kose; M. Arif Ozgur; Oguzhan Erbas; Abtullah Tugcu

2004-01-01

426

The potential for dynamic distribution systems to create a new energy marketplace  

E-print Network

July 2014 The potential for dynamic distribution systems to create a new energy marketplace be the technology basis to create a new electrical energy marketplace in which electric power is generated with a marketplace that enables energy transactions, such as payments passing between buyers and sellers of energy

Van Veen, Barry D.

427

{sup 7,9,10}Be elastic scattering and total reaction cross sections on a {sup 12}C target  

SciTech Connect

Elastic scattering angular distributions for {sup 7}Be, {sup 9}Be, and {sup 10}Be isotopes on {sup 12}C target were measured at laboratory energies of 18.8, 26.0, and 23.2 MeV, respectively. The analysis was performed in terms of optical model potentials using Woods-Saxon and double-folding form factors. Also, continuum discretized coupled-channels calculations were performed for {sup 7}Be and {sup 9}Be + {sup 12}C systems to infer the role of breakup in the elastic scattering. For the {sup 10}Be + {sup 12}C system, bound states coupled-channels calculations were considered. Moreover, total reaction cross sections were deduced from the elastic scattering analysis and compared with published data on other weakly and tightly bound projectiles elastically scattered on the {sup 12}C target, as a function of energy.

Zamora, J. C.; Guimaraes, V.; Barioni, A.; Lepine-Szily, A.; Lichtenthaeler, R.; Faria, P. N. de; Mendes, D. R. Jr.; Gasques, L. R.; Scarduelli, V.; Pires, K. C. C.; Morcelle, V.; Leistenschneider, E.; Condori, R. P.; Zagatto, V. A.; Morais, M. C.; Crema, E. [Instituto de Fisica, Universidade de Sao Paulo, P.O. Box 66318, 05389-970 Sao Paulo, SP (Brazil); Shorto, J. M. B. [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN, Sao Paulo, SP (Brazil)

2011-09-15

428

Higher-order elastics and elastic hulls  

NASA Astrophysics Data System (ADS)

By higher-order elastics we mean solutions of the problem to minimize integrals of quadratic forms of curvatures of multidimensional curves. Differential equations of second-order elastics (minimizing a quadratic form of the curvature and torsion of the curve) are obtained. Surfaces minimizing integrals of the squared Gaussian curvature are found.

Osipov, Yu. S.; Zelikin, M. I.

2012-04-01

429

Computing Ligand Field Potentials and Relative Energies of d Orbitals  

ERIC Educational Resources Information Center

Presents a method for calculating the relative energies of d orbitals in various geometric configurations having coordination numbers 1 to 12. Discusses the changes in orbital degeneracies and energies due to symmetry differences. Shows that the addivity principle of Dq values gives results identical to the complete perturbation treatment. Also…

Krishnamurthy, R.; Schaap, Ward B.

1969-01-01

430

Potential prediction needs in support of energy systems  

NASA Technical Reports Server (NTRS)

The relationship between emerging energy systems and the natural environment is discussed, including selected examples to show that energy systems are tied to global solar terrestrial processess. The interdependence of resources, technology, and environmental impact is considered in terms of needed geophysical, atmospheric, and solar terrestrial data inputs. The need for long term basic research on the solar terrestrial system is emphasized.

Blake, R. L.

1979-01-01

431

Structural, elastic, and thermal properties of cementite (Fe3C) calculated using a modified embedded atom method  

NASA Astrophysics Data System (ADS)

Structural, elastic, and thermal properties of cementite (Fe3C) were studied using a modified embedded atom method (MEAM) potential for iron-carbon (Fe-C) alloys. Previously developed Fe and C single-element potentials were used to develop a Fe-C alloy MEAM potential, using a statistics-based optimization scheme to reproduce structural and elastic properties of cementite, the interstitial energies of C in bcc Fe, and heat of formation of Fe-C alloys in L12 and B1 structures. The stability of cementite was investigated by molecular dynamics simulations at high temperatures. The nine single-crystal elastic constants for cementite were obtained by computing total energies for strained cells. Polycrystalline elastic moduli for cementite were calculated from the single-crystal elastic constants of cementite. The formation energies of (001), (010), and (100) surfaces of cementite were also calculated. The melting temperature and the variation of specific heat and volume with respect to temperature were investigated by performing a two-phase (solid/liquid) molecular dynamics simulation of cementite. The predictions of the potential are in good agreement with first-principles calculations and experiments.

Liyanage, Laalitha S. I.; Kim, Seong-Gon; Houze, Jeff; Kim, Sungho; Tschopp, Mark A.; Baskes, M. I.; Horstemeyer, M. F.

2014-03-01

432

Positron interactions with water–total elastic, total inelastic, and elastic differential cross section measurements  

SciTech Connect

Utilising a high-resolution, trap-based positron beam, we have measured both elastic and inelastic scattering of positrons from water vapour. The measurements comprise differential elastic, total elastic, and total inelastic (not including positronium formation) absolute cross sections. The energy range investigated is from 1 eV to 60 eV. Comparison with theory is made with both R-Matrix and distorted wave calculations, and with our own application of the Independent Atom Model for positron interactions.

Tattersall, Wade [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia) [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Chiari, Luca [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia)] [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Machacek, J. R.; Anderson, Emma; Sullivan, James P. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)] [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); White, Ron D. [Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia)] [Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Brunger, M. J. [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia) [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Buckman, Stephen J. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia) [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Garcia, Gustavo [Instituto de F?sica Fundamental, Consejo Superior de Investigationes Cient?ficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain)] [Instituto de F?sica Fundamental, Consejo Superior de Investigationes Cient?ficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain); Blanco, Francisco [Departamento de F?sica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain)] [Departamento de F?sica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

2014-01-28

433

Consequences of Converting Graded to Action Potentials upon Neural Information Coding and Energy Efficiency  

PubMed Central

Information is encoded in neural circuits using both graded and action potentials, converting between them within single neurons and successive processing layers. This conversion is accompanied by information loss and a drop in energy efficiency. We investigate the biophysical causes of this loss of information and efficiency by comparing spiking neuron models, containing stochastic voltage-gated Na+ and K+ channels, with generator potential and graded potential models lacking voltage-gated Na+ channels. We identify three causes of information loss in the generator potential that are the by-product of action potential generation: (1) the voltage-gated Na+ channels necessary for action potential generation increase intrinsic noise and (2) introduce non-linearities, and (3) the finite duration of the action potential creates a ‘footprint’ in the generator potential that obscures incoming signals. These three processes reduce information rates by ?50% in generator potentials, to ?3 times that of spike trains. Both generator potentials and graded potentials consume almost an order of magnitude less energy per second than spike trains. Because of the lower information rates of generator potentials they are substantially less energy efficient than graded potentials. However, both are an order of magnitude more efficient than spike trains due to the higher energy costs and low information content of spikes, emphasizing that there is a two-fold cost of converting analogue to digital; information loss and cost inflation. PMID:24465197

Sengupta, Biswa; Laughlin, Simon Barry; Niven, Jeremy Edward

2014-01-01

434

Elastic modulus mapping of atomically thin film based Lithium Ion Battery electrodes Lithium Ion Batteries (LIB) are one of the most promising class of next generation energy storage devices,  

E-print Network

Elastic modulus mapping of atomically thin film based Lithium Ion Battery electrodes Lithium Ion Batteries (LIB) are one of the most promising class of next generation energy storage devices, which can within composite electrode materials to mitigate detrimental effects of expansion and contraction during

435

Mechanics of Elastic Solids  

NSDL National Science Digital Library

After conducting the associated activity, students are introduced to the material behavior of elastic solids. Engineering stress and strain are defined and their importance in designing devices and systems is explained. How engineers measure, calculate and interpret properties of elastic materials is addressed. Students calculate stress, strain and modulus of elasticity, and learn about the typical engineering stress-strain diagram (graph) of an elastic material.

Integrated Teaching And Learning Program

436

Exploring potential mechanisms responsible for observed changes of ultrasonic backscattered energy with temperature variations  

E-print Network

Exploring potential mechanisms responsible for observed changes of ultrasonic backscattered energy on probability variation of backscatter data Med. Phys. 39, 2369 (2012); 10.1118/1.3700235 Ultrasonic backscatter.1121/1.3460109 #12;Exploring potential mechanisms responsible for observed changes of ultrasonic backscattered energy

Illinois at Urbana-Champaign, University of

437

Critical insight into the influence of the potential energy surface on fission dynamics  

Microsoft Academic Search

The present work is dedicated to a careful investigation of the influence of the potential energy surface on the fission process. The time evolution of nuclei at high excitation energy and angular momentum is studied by means of three-dimensional Langevin calculations performed for two different parametrizations of the macroscopic potential: the Finite Range Liquid Drop Model (FRLDM) and the Lublin-Strasbourg

K. Mazurek; C. Schmitt; J. P. Wieleczko; P. N. Nadtochy; G. Ademard

2011-01-01

438

Concerning analytical derivatives of kinetic and potential energies in the Hartree-Fock theory  

Microsoft Academic Search

Two analytical procedures for obtaining the derivatives of the kinetic and potential energies in the Hartree–Fock theory are presented. They are the derivation from direct differentiation of the expectation values of the kinetic and potential energies, and that from the virial theorem. Since the molecular orbital wave function in the linear combination of atomic orbitals, in which the scale factor

Hiroaki Tokiwa; Hiroshi Ichikawa; Yoshihiro Osamura

1992-01-01

439

Hamilton's principle: Why is the integrated difference of the kinetic and potential energy minimized?  

Microsoft Academic Search

Why is the integrated difference of the kinetic and potential energies the quantity to be minimized in Hamilton's principle? I use simple arguments to convert the problem of finding the path of a particle connecting two points to that of finding the minimum potential energy of a string. The mapping implies that the configuration of a nonstretchable string of variable

Alberto G. Rojo

2005-01-01

440

A survey on the assessment of wind energy potential in Greece  

Microsoft Academic Search

In the present paper a statistical study of the available wind data for Greece is carried out to assess its wind energy potential. It is essential to establish the available wind energy for any given region in order to assess the relative potential at different sites. The applicability of the Weibull distribution is examined and tables and plots of Weibull

B. D. Katsoulis

1993-01-01

441

Elastic-plastic transition in iron: Structural and thermodynamic features  

NASA Astrophysics Data System (ADS)

The structural and thermodynamic features of the elastic-plastic transition in armco iron and its plastic deformation are studied. Energy storage in iron is shown to have a nonlinear character and be accompanied by wavelike heat dissipation. To describe the energy balance in the plastically deformed metal, a theoretical model is proposed based on a statistical description of the evolution of an ensemble of typical mesodefects (microshears). Moreover, a procedure is developed to experimentally determine the dependence of the potential of the medium on the mesodefect density using infrared scanning data.

Plekhov, O. A.; Naimark, O. B.; Saintier, N.; Palin-Luc, T.

2009-08-01

442

An Integrated Assessment of China’s Wind Energy Potential  

E-print Network

Computable general equilibrium (CGE) models seeking to evaluate the impacts of electricity policy face difficulties incorporating detail on the variable nature of renewable energy resources. To improve the accuracy of ...

Zhang, D.

443

Energy Use Reduction Potential in the Beet Sugar Industry  

E-print Network

Process energy use data are presented for most of the forty operating beet sugar factories in the United States. Sixty percent of the processing capacity is in states that actively pursue cogeneration projects. Most of the present factories...

Barron, T. S.; Heist, J. A.

1984-01-01

444

The economic potential of producing energy from agricultural biomass  

E-print Network

activities which produce ethanol and biomass electricity. The forced supply of new biomass crops, along with corn, involves several levels of energy production. This forced supply was based on projected ethanol demands and land capability for biomass...

Jerko, Christine

1996-01-01

445

Energy conservation potential of Portland cement particle size distribution control  

SciTech Connect

The main objective of Phase 3 is to develop practical economic methods of controlling the particles size distribution of portland cements using existing or modified mill circuits with the principal aim of reducing electrical energy requirements for cement manufacturing.

Tresouthick, S.W.; Weiss, S.J.

1986-01-01

446

Assessing the potential of renewable energy sources in Turkey  

Microsoft Academic Search

To meet Turkey’s growing energy demand, the installed electric power capacity of 27.8 GW in 2001 has to be doubled by 2010 and increased fourfold by 2020. The difference between Turkey’s total primary energy supply (TPES) of from its own sources and total final consumption (TFC) is projected grow from 1 quad (1.06–2.06) in 1999 to 5.71 quads (2.79–8.5) in

F Evrendilek; C Ertekin

2003-01-01

447

Phenomenological approach to the problem of the K13 surfacelike elastic term in the free energy of a nematic liquid crystal  

NASA Astrophysics Data System (ADS)

We consider the mathematical foundations of continuum theories of nematic liquid crystals of the Frank-Oseen form which include, in addition, the surfacelike K13 term. Such theories present problems because (i) the free-energy functional F2, quadratic in the director derivatives, is unbounded from below and hence possesses no minima unless K13 is strictly zero; and (ii) microscopic theories indicate that in the general case K13 does not vanish. The continuum theory presupposes the existence of weak director deformations. This is not consistent with the idea, proposed by Oldano and Barbero, that there should be strong subsurface director deformations, which are shown in the present paper to be a formal consequence of (i). Instead we propose a resolution of the K13 problem which is consistent with weak director distortions alone. The resolution involves a formal consideration of all the terms in the total free energy containing high-order derivatives, the infinite sum of which, R?, bounds the total free energy F2+R? from below. A consequence of this resolution is that the Euler-Lagrange equations which follow from a naive consideration of the Oseen-Frank free-energy functional F2, and which appear to give rise to a nonminimal family thereof, in fact give rise to a minimal family of director distributions of the total free energy F2+R?. Moreover, no specific information on higher-order elastic terms enters the theory. The theory further allows consideration of the derivative-dependent terms in the anchoring energy. Each such derivative is shown to be proportional to a small parameter. As a result, all derivative-dependent anchoring terms are much smaller than the usual Rapini-Popoular term.

Pergamenshchik, V. M.

1993-08-01

448

The vibrational energies of ozone up to the dissociation threshold: Dynamics calculations on an accurate potential energy surface  

E-print Network

The vibrational energies of ozone up to the dissociation threshold: Dynamics calculations present an ab initio potential energy surface for the ground electronic state of ozone. It is global, i. All bound states of nonrotating ozone up to more than 99% of the dissociation energy are calculated

Farantos, Stavros C.

449

High-energy behavior of the nuclear symmetry potential in asymmetric nuclear matter  

E-print Network

Using the relativistic impulse approximation with empirical NN scattering amplitude and the nuclear scalar and vector densities from the relativistic mean-field theory, we evaluate the Dirac optical potential for neutrons and protons in asymmetric nuclear matter. From the resulting Schr\\"{o}% dinger-equivalent potential, the high energy behavior of the nuclear symmetry potential is studied. We find that the symmetry potential at fixed baryon density is essentially constant once the nucleon kinetic energy is greater than about 500 MeV. Moreover, for such high energy nucleon, the symmetry potential is slightly negative below a baryon density of about $% \\rho =0.22$ fm$^{-3}$ and then increases almost linearly to positive values at high densities. Our results thus provide an important constraint on the energy and density dependence of nuclear symmetry potential in asymmetric nuclear matter.

Lie-Wen Chen; Che Ming Ko; Bao-An Li

2005-12-07

450

Comparison of 120Sn(6He,6He)120Sn and 120Sn(alpha,alpha)120Sn elastic scattering and signatures of the 6He neutron halo in the optical potential  

E-print Network

Cross sections of $^{120}$Sn($\\alpha$,$\\alpha$)$^{120}$Sn elastic scattering have been extracted from the $\\alpha$ particle beam contamination of a recent $^{120}$Sn($^6$He,$^6$He)$^{120}$Sn experiment. Both reactions are analyzed using systematic double folding potentials in the real part and smoothly varying Woods-Saxon potentials in the imaginary part. The potential extracted from the $^{120}$Sn($^6$He,$^6$He)$^{120}$Sn data may be used as the basis for the construction of a simple global $^6$He optical potential. The comparison of the $^6$He and $\\alpha$ data shows that the halo nature of the $^6$He nucleus leads to a clear signature in the reflexion coefficients $\\eta_L$: the relevant angular momenta $L$ with $\\eta_L \\gg 0$ and $\\eta_L \\ll 1$ are shifted to larger $L$ with a broader distribution. This signature is not present in the $\\alpha$ scattering data and can thus be used as a new criterion for the definition of a halo nucleus.

P. Mohr; P. N. de Faria; R. Lichtenthäler; K. C. C. Pires; V. Guimarães; A. Lépine-Szily; D. R. Mendes Junior; A. Arazi; A. Barioni; V. Morcelle; M. C. Morais