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1

A mineralogical model for density and elasticity of the Earth's A. S. Piazzoni  

E-Print Network [OSTI]

A mineralogical model for density and elasticity of the Earth's mantle A. S. Piazzoni Department fu, Germany [1] We present a thermodynamic model of high-pressure mineralogy that allows the evaluation: mantle mineralogy; Gibbs free energy minimization. Index Terms: 3612 Mineralogy and Petrology: Reactions

Steinle-Neumann, Gerd

2

Density functional theory and evolution algorithm calculations of elastic properties of AlON  

SciTech Connect (OSTI)

Different models for aluminum oxynitride (AlON) were calculated using density functional theory and optimized using an evolutionary algorithm. Evolutionary algorithm and density functional theory (DFT) calculations starting from several models of AlON with different Al or O vacancy locations and different positions for the N atoms relative to the vacancy were carried out. The results show that the constant anion model [McCauley et al., J. Eur. Ceram. Soc. 29(2), 223 (2009)] with a random distribution of N atoms not adjacent to the Al vacancy has the lowest energy configuration. The lowest energy structure is in a reasonable agreement with experimental X-ray diffraction spectra. The optimized structure of a 55 atom unit cell was used to construct 220 and 440 atom models for simulation cells using DFT with a Gaussian basis set. Cubic elastic constant predictions were found to approach the experimentally determined AlON single crystal elastic constants as the model size increased from 55 to 440 atoms. The pressure dependence of the elastic constants found from simulated stress-strain relations were in overall agreement with experimental measurements of polycrystalline and single crystal AlON. Calculated IR intensity and Raman spectra are compared with available experimental data.

Batyrev, I. G.; Taylor, D. E.; Gazonas, G. A.; McCauley, J. W. [U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States)

2014-01-14T23:59:59.000Z

3

Heterogeneous perturbation of fluid density and solid elastic strain in consolidating porous media  

E-Print Network [OSTI]

The occurrence of heterogeneous perturbations of fluid mass density and solid elastic strain of a porous continuum, as a consequence of its undrained response is a very important topic in theoretical and applied poromechanics. The classical Mandel--Cryer effect provides an explanation of fluid overpressure in the central region of a porous sample, immediately after the application of the loading. However this effect fades away when the fluid leaks out of the porous network. Here this problem is studied within the framework of a second gradient theory and a thorough description of the static and the dynamics of the phenomenon is given.

P. Artale Harris; E. N. M. Cirillo; G. Sciarra

2014-07-20T23:59:59.000Z

4

Topology of charge density and elastic properties of Ti3SiC2 polymorphs  

SciTech Connect (OSTI)

Using an all-electron, full potential first-principles method, we have investigated the topology of charge density and elastic properties of the two polymorphs, alpha and beta, of Ti3SiC2. The bonding effect was analyzed based on Bader's quantum theory of ''atoms in molecules'' (AIM). It was found that the Ti-Si bonding effect is significantly weaker in beta than in alpha, giving less stabilizing effect for beta. The Si-C bonds, which are absent in alpha, are formed in beta and provide additional stabilizing effect for beta. In contrast to conventional thinking, there is no direction interaction between Ti atoms in both alpha and beta. The calculated elastic properties are in good agreement with the experimental results, giving the bulk modulus of about 180 GPa and the Poisson's ratio of 0.2. The beta phase is generally softer than the alpha phase. As revealed by the direction dependent Young's modulus, there is only slight elastic anisotropy in Ti3SiC2. For alpha, Young's modulus is minimum in the c direction and maximum in the directions 42o from c. For beta, the maximum lies in the c direction, in part due to the formation of Si-C bonds in this direction.

Yu, Rong; Zhang, Xiao Feng; He, Lian Long; Ye, Heng Qiang

2004-06-24T23:59:59.000Z

5

Proton elastic scattering from tin isotopes at 295 MeV and systematic change of neutron density distributions  

E-Print Network [OSTI]

Cross sections and analyzing powers for proton elastic scattering from $^{116,118,120,122,124}$Sn at 295 MeV have been measured for a momentum transfer of up to about 3.5 fm$^{-1}$ to deduce systematic changes of the neutron density distribution. We tuned the relativistic Love-Franey interaction to explain the proton elastic scattering of a nucleus whose density distribution is well known. Then, we applied this interaction to deduce the neutron density distributions of tin isotopes. The result of our analysis shows the clear systematic behavior of a gradual increase in the neutron skin thickness of tin isotopes with mass number.

S. Terashima; H. Sakaguchi; H. Takeda; T. Ishikawa; M. Itoh; T. Kawabata; T. Murakami; M. Uchida; Y. Yasuda; M. Yosoi; J. Zenihiro; H. P. Yoshida; T. Noro; T. Ishida; S. Asaji; T. Yonemura

2008-02-02T23:59:59.000Z

6

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

E-Print Network [OSTI]

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

7

Weighted?density?functional theory calculation of elastic constants for face?centered?cubic and body?centered?cubic hard?sphere crystals  

E-Print Network [OSTI]

The isothermal elastic constants for the face?centered?cubic (fcc) and body?centered?cubic (bcc) hard?sphere crystal are calculated for a range of densities using the modified weighted?density functional of Denton and ...

Laird, Brian Bostian

1992-06-01T23:59:59.000Z

8

Elastic constants and Fermi surface topology change in Calaverite AuTe{sub 2}: A density functional study  

SciTech Connect (OSTI)

Structural, elastic, electronic and Fermi surface studies of AuTe{sub 2} have been carried out by means of first principles calculations based on density functional theory. The calculated ground state properties agree well with the experiment. Fermi surface and elastic constants are predicted for the first time and from the calculated elastic constants we find the compound to be mechanically stable satisfying the stability criteria of monoclinic structure. In addition, we also find the c-axis to be more compressible than the other two which is also speculated from the present work. The metallic behaviour of this compound is confirmed from the electronic band structure calculation as we find the bands to cross the Fermi level (E{sub F}). In addition, we also observe a FS topology change under pressure which is also explained in the present work.

Gudelli, Vijay Kumar, E-mail: kanchana@iith.ac.in; Kanchana, V., E-mail: kanchana@iith.ac.in [Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram-502205, Andhra Pradesh (India)

2014-04-24T23:59:59.000Z

9

Influence of the Target - Density Effects on Electron - Capture Processes  

SciTech Connect (OSTI)

The influence of the target density on the electron-capture (EC) processes in collisions of fast ions with atoms and molecules is considered. The partial EC cross sections {sigma}n on the principal quantum number n of the scattered projectile, as well as the total {sigma}tot values are calculated for highly charged ions interacting with gaseous and solid targets in the energy range of E = 100 keV/amu to 10 MeV/amu. It is shown that with the target density increasing, the population of the excited states of the scattered projectiles, formed via the EC channel, is suppressed due to projectile ionization by the target particles and, as a result, the effective EC cross sections drastically decrease.

Tolstikhina, I.Yu.; Shevelko, V.P. [P.N.Lebedev Physical Institute, 119991, Moscow (Russian Federation)

2004-12-01T23:59:59.000Z

10

Volunteer Potato Density Influences Critical Time of Weed Removal in Bulb Onion  

E-Print Network [OSTI]

Volunteer Potato Density Influences Critical Time of Weed Removal in Bulb Onion Martin M. Williams II, Corey V. Ransom, and W. Mack Thompson* Volunteer potato is highly competitive with onion and few control tactics are effective for removing this weed from an onion crop. Both volunteer potato density

Sims, Gerald K.

11

Influence of landscape elements on population densities and habitat use of three small-mammal species.  

SciTech Connect (OSTI)

Mabry, K.E., E.A. Dreelin, and G.W. Barrett. 2003. Influence of landscape elements on population densities and habitat use of three small-mammal species. J. Mammology. 84(1):20-25. Corridor effects on population densities and habitat use of 3 small mammal species were assessed in an experimentally fragmented landscape. Corridor presence did not have a statistically significant effect on population densities of cotton rats or cotton mice; however, a significant effect was observed for old-field mice. The results suggest that landscape fragmentation and habitat structure may have varying effects on population densities of different species.

Mabry, Karen, E.; Dreelin, Erin, A.; Barrett, Gary, W.

2003-01-01T23:59:59.000Z

12

Research of influence of temperature deformations of the big elastic elements on dynamics of a space vehicle  

E-Print Network [OSTI]

At this project considers the problem of analysis temperature deformation of elastic elements of the spacecraft. Spacecraft periodically appears in the earth's shadow on the sunny side when moving from the orbit. Abruptly changing the temperature field of large elastic elements can affect the dynamic characteristics of the spacecraft. This is important when dealing with the implementation of the gravity-sensitive processes on board.

A. V. Sedelnikov; M. I Kazarina

2010-07-23T23:59:59.000Z

13

Elastic constants and tensile properties of Al2OC by density functional calculations * X. F. Zhang,1, L. C. De Jonghe,1,2 and R. O. Ritchie1,2  

E-Print Network [OSTI]

Elastic constants and tensile properties of Al2OC by density functional calculations R. Yu,1, * X received 17 January 2007; published 26 March 2007 Al2OC is a compound that forms as a nanoscale grain properties of Al2OC are determined from first-principles calculations. The crystal structure of Al2OC

Ritchie, Robert

14

The influence of annual species composition and density on perennial seedling density in four plant communities in the Northern Mojave Desert  

SciTech Connect (OSTI)

According to the Nuclear Waste Policy Act of 1982 (as amended in 1987), the US Department of Energy (DOE) must study and characterize Yucca Mountain as a potential site for long-term underground storage of high-level nuclear waste. Part of the overall site characterization program is to monitor potential impacts on the biological resources at Yucca Mountain. A part of the biological monitoring program, assessed vegetation parameters included density of annual and perennial seedlings. This data was used to evaluate: (1) seed germination and seed survival; and (2) if annual plant species density and cover influence perennial seedling survival. Twelve permanent 200 {times} 200-m ,study plots were established in each of four vegetation associations present in the Yucca Mountain Project area. During the spring of 1992, 20 to 60, 1-m{sup 2} randomly-located quadrats per study plot were measured for perennial seedling density, annual species density, and annual species composition. Perennial seedlings found in 1992 were relocated in the spring of 1993, and survival determined. Cover was measure in the spring of 1992. Annual plant density and cover was greatest in the Larrea-Lycium-Grayia vegetation association, and lowest in the Larrea-Ambrosia vegetation association. Annual seedling density had a negative exponential relationship with perennial seedling density in 1992. However, non-linear regression analysis indicated that 1992 annual seedling density had a greater impact on survival of pernnial seedlings from 1992 to 1993.

Hall, P.F.; Angerer, J.P.; Ostler, W.K. [EG and G Energy Measurements, Inc., Las Vegas, NV (United States); Schultz, B.W. [Nevada Univ., Reno, NV (United States). Desert Research Inst.

1993-12-31T23:59:59.000Z

15

Beam energy distribution influences on density modulation efficiency in seeded free-electron lasers  

E-Print Network [OSTI]

The beam energy spread at the entrance of undulator system is of paramount importance for efficient density modulation in high-gain seeded free-electron lasers (FELs). In this paper, the dependences of high harmonic micro-bunching in the high-gain harmonic generation (HGHG), echo-enabled harmonic generation (EEHG) and phase-merging enhanced harmonic generation (PEHG) schemes on the electron energy spread distribution are studied. Theoretical investigations and multi-dimensional numerical simulations are applied to the cases of uniform and saddle beam energy distributions and compared to a traditional Gaussian distribution. It shows that the uniform and saddle electron energy distributions significantly enhance the performance of HGHG-FELs, while they almost have no influence on EEHG and PEHG schemes. A numerical example demonstrates that, with about 84keV RMS uniform and/or saddle slice energy spread, the 30th harmonic radiation can be directly generated by a single-stage seeding scheme for a soft x-ray FEL f...

Wang, Guanglei; Deng, Haixiao; Zhang, Weiqing; Wu, Guorong; Dai, Dongxu; Wang, Dong; Zhao, Zhentang; Yang, Xueming

2015-01-01T23:59:59.000Z

16

Evaluating systematic dependencies of type Ia supernovae : the influence of deflagration to detonation density.  

SciTech Connect (OSTI)

We explore the effects of the deflagration to detonation transition (DDT) density on the production of {sup 56}Ni in thermonuclear supernova (SN) explosions (Type Ia supernovae). Within the DDT paradigm, the transition density sets the amount of expansion during the deflagration phase of the explosion and therefore the amount of nuclear statistical equilibrium (NSE) material produced. We employ a theoretical framework for a well-controlled statistical study of two-dimensional simulations of thermonuclear SNe with randomized initial conditions that can, with a particular choice of transition density, produce a similar average and range of {sup 56}Ni masses to those inferred from observations. Within this framework, we utilize a more realistic 'simmered' white dwarf progenitor model with a flame model and energetics scheme to calculate the amount of {sup 56}Ni and NSE material synthesized for a suite of simulated explosions in which the transition density is varied in the range (1-3) x 10{sup 7} g cm{sup -3}. We find a quadratic dependence of the NSE yield on the log of the transition density, which is determined by the competition between plume rise and stellar expansion. By considering the effect of metallicity on the transition density, we find the NSE yield decreases by 0.055 {+-} 0.004 M {circle_dot} for a 1 Z {circle_dot} increase in metallicity evaluated about solar metallicity. For the same change in metallicity, this result translates to a 0.067 {+-} 0.004 M {circle_dot} decrease in the {sup 56}Ni yield, slightly stronger than that due to the variation in electron fraction from the initial composition. Observations testing the dependence of the yield on metallicity remain somewhat ambiguous, but the dependence we find is comparable to that inferred from some studies.

Jackson, A. P.; Calder, A. C.; Townsley, D. M.; Chamulak, D. A.; Brown, E. F.; Timmes, F. X. (Physics); (State Univ. of New York); (Univ. of Alabama); (Michigan State Univ.); (Arizona State Univ.); (Joint Inst. for Nuclear Astrophysics)

2010-09-01T23:59:59.000Z

17

EVALUATING SYSTEMATIC DEPENDENCIES OF TYPE Ia SUPERNOVAE: THE INFLUENCE OF DEFLAGRATION TO DETONATION DENSITY  

SciTech Connect (OSTI)

We explore the effects of the deflagration to detonation transition (DDT) density on the production of {sup 56}Ni in thermonuclear supernova (SN) explosions (Type Ia supernovae). Within the DDT paradigm, the transition density sets the amount of expansion during the deflagration phase of the explosion and therefore the amount of nuclear statistical equilibrium (NSE) material produced. We employ a theoretical framework for a well-controlled statistical study of two-dimensional simulations of thermonuclear SNe with randomized initial conditions that can, with a particular choice of transition density, produce a similar average and range of {sup 56}Ni masses to those inferred from observations. Within this framework, we utilize a more realistic 'simmered' white dwarf progenitor model with a flame model and energetics scheme to calculate the amount of {sup 56}Ni and NSE material synthesized for a suite of simulated explosions in which the transition density is varied in the range (1-3) x10{sup 7} g cm{sup -3}. We find a quadratic dependence of the NSE yield on the log of the transition density, which is determined by the competition between plume rise and stellar expansion. By considering the effect of metallicity on the transition density, we find the NSE yield decreases by 0.055 {+-} 0.004 M {sub sun} for a 1 Z{sub sun} increase in metallicity evaluated about solar metallicity. For the same change in metallicity, this result translates to a 0.067 {+-} 0.004 M{sub sun} decrease in the {sup 56}Ni yield, slightly stronger than that due to the variation in electron fraction from the initial composition. Observations testing the dependence of the yield on metallicity remain somewhat ambiguous, but the dependence we find is comparable to that inferred from some studies.

Jackson, Aaron P.; Calder, Alan C. [Department of Physics and Astronomy, State University of New York-Stony Brook, Stony Brook, NY (United States); Townsley, Dean M. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL (United States); Chamulak, David A. [Argonne National Laboratory, Argonne, IL (United States); Brown, Edward F.; Timmes, F. X. [Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States)

2010-09-01T23:59:59.000Z

18

The influence of calf density during weaning upon their performance and behavior  

E-Print Network [OSTI]

in the auction was due to farm of orig1n and preshipment treatment. Cole, NcLaren and Irwin (1979) report- ed that calves weaned 30 days pr1or to shipment and fed a 50%%d concentrate ration at the farm had significantly h1gher (P&. 05) average daily gains.... EXPERIMENTAL PROCEDURE It is hypothesized that decreasing the space allowance for calves dur 1ng weaning may influence the incidence of walking and bawl 1ng, which may in turn influence feed consumpt1on and weight gain. This hypothes1s was tested...

Richmond, Charles Edwin

1980-01-01T23:59:59.000Z

19

THE INFLUENCE OF NUMERICAL RESOLUTION ON CORONAL DENSITY IN HYDRODYNAMIC MODELS OF IMPULSIVE HEATING  

SciTech Connect (OSTI)

The effect of the numerical spatial resolution in models of the solar corona and corona/chromosphere interface is examined for impulsive heating over a range of magnitudes using one-dimensional hydrodynamic simulations. It is demonstrated that the principal effect of inadequate resolution is on the coronal density. An underresolved loop typically has a peak density of at least a factor of two lower than a resolved loop subject to the same heating, with larger discrepancies in the decay phase. The temperature for underresolved loops is also lower indicating that lack of resolution does not 'bottle up' the heat flux in the corona. Energy is conserved in the models to under 1% in all cases, indicating that this is not responsible for the low density. Instead, we argue that in underresolved loops the heat flux 'jumps across' the transition region to the dense chromosphere from which it is radiated rather than heating and ablating transition region plasma. This emphasizes the point that the interaction between corona and chromosphere occurs only through the medium of the transition region. Implications for three-dimensional magnetohydrodynamic coronal models are discussed.

Bradshaw, S. J. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Cargill, P. J., E-mail: stephen.bradshaw@rice.edu, E-mail: p.cargill@imperial.ac.uk [Space and Atmospheric Physics, Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)

2013-06-10T23:59:59.000Z

20

Identification of the true elastic modulus of high density polyethylene from tensile tests using an appropriate reduced model of the elastoviscoplastic behavior  

E-Print Network [OSTI]

The rheological parameters of materials are determined in the industry according to international standards established generally on the basis of widespread techniques and robust methods of estimation. Concerning solid polymers and the determination of Young's modulus in tensile tests, ISO 527-1 or ASTM D638 standards rely on protocols with poor scientific content: the determination of the slope of conventionally defined straight lines fitted to stress-strain curves in a given range of elongations. This paper describes the approach allowing for a correct measurement of the instantaneous elastic modulus of polymers in a tensile test. It is based on the use of an appropriate reduced model to describe the behavior of the material. The model comes a thermodynamical framework and allows to reproduce the behavior of an HDPE Polymer until large strains, covering the elastoviscoplastic and hardening regimes. Well-established principles of parameter estimation in engineering science are used to found the identificatio...

Blaise, A; Delobelle, Patrick; Meshaka, Yves; Cunat, C

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Influence of the Density Law on Various Fissile Single Unit and Array Storage Methods  

SciTech Connect (OSTI)

The advancement of computational technology has resulted in the wide-spread availability of powerful radiation transport Monte Carlo codes. Prevailing practices today rely heavily on Monte Carlo codes to provide the basis for assessing the reactivity of various fissile systems for nuclear criticality safety (NCS). In 1958, Weinberg and Wigner expressed their concerns on a 'deplorable trend in reactor design - the tendency to substitute a code for a theory'. Unfortunately, their concerns have largely become a reality in many modern NCS practices. lacking the time or information to understand the underlying neutron physics of the fissile system under consideration is indeed a deplorable trend. The purpose of this paper is to demonstrate that many features of criticality hand calculation methods are indeed based upon the fundamentals of the density law and that many correlations of important physics parameters can be more easily understood from such a perspective. Historically, the density law was recognized by many pioneers in the field, including during the Manhattan Project. However, it was by and large an 'oral tradition' in that bits and pieces of great physical insights of the pioneers were scattered in many earlier publications. This paper attempts to bring together some of the 'jewels' of the pioneers which might have been lost or forgotten.

Huang, S T

2011-03-02T23:59:59.000Z

22

Identification of the true elastic modulus of high density polyethylene from tensile tests using an appropriate reduced model of the elastoviscoplastic behavior  

E-Print Network [OSTI]

The rheological parameters of materials are determined in the industry according to international standards established generally on the basis of widespread techniques and robust methods of estimation. Concerning solid polymers and the determination of Young's modulus in tensile tests, ISO 527-1 or ASTM D638 standards rely on protocols with poor scientific content: the determination of the slope of conventionally defined straight lines fitted to stress-strain curves in a given range of elongations. This paper describes the approach allowing for a correct measurement of the instantaneous elastic modulus of polymers in a tensile test. It is based on the use of an appropriate reduced model to describe the behavior of the material. The model comes a thermodynamical framework and allows to reproduce the behavior of an HDPE Polymer until large strains, covering the elastoviscoplastic and hardening regimes. Well-established principles of parameter estimation in engineering science are used to found the identification procedure. It will be shown that three parameters only are necessary to model experimental tensile signals: the instantaneous ('Young's') modulus, the maximum relaxation time of a linear distribution (described with a universal shape) and a strain hardening modulus to describe the 'relaxed' state. The paper ends with an assessment of the methodology. Our results of instantaneous modulus measurements are compared with those obtained with other physical experiments operating at different temporal and length scales.

A. Blaise; Stéphane André; Patrick Delobelle; Yves Meshaka; C. Cunat

2012-06-19T23:59:59.000Z

23

Influence of microwave driver coupling design on plasma density at Testbench for Ion sources Plasma Studies, a 2.45 GHz Electron Cyclotron Resonance Plasma Reactor  

SciTech Connect (OSTI)

A comparative study of two microwave driver systems (preliminary and optimized) for a 2.45 GHz hydrogen Electron Cyclotron Resonance plasma generator has been conducted. The influence on plasma behavior and parameters of stationary electric field distribution in vacuum, i.e., just before breakdown, along all the microwave excitation system is analyzed. 3D simulations of resonant stationary electric field distributions, 2D simulations of external magnetic field mapping, experimental measurements of incoming and reflected power, and electron temperature and density along the plasma chamber axis have been carried out. By using these tools, an optimized set of plasma chamber and microwave coupler has been designed paying special attention to the optimization of stationary electric field value in the center of the plasma chamber. This system shows a strong stability on plasma behavior allowing a wider range of operational parameters and even sustaining low density plasma formation without external magnetic field. In addition, the optimized system shows the capability to produce values of plasma density four times higher than the preliminary as a consequence of a deeper penetration of the magnetic resonance surface in relative high electric field zone by keeping plasma stability. The increment of the amount of resonance surface embedded in the plasma under high electric field is suggested as a key factor.

Megía-Macías, A.; Vizcaíno-de-Julián, A. [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)] [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Cortázar, O. D., E-mail: dcortazar@essbilbao.org [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain)

2014-03-15T23:59:59.000Z

24

Elastic building blocks for confined sheets  

E-Print Network [OSTI]

We study the behavior of thin elastic sheets that are bent and strained under the influence of weak, smooth confinement. We show that the emerging shapes exhibit the coexistence of two types of domains that differ in their characteristic stress distributions and energies, and reflect different constraints. A focused-stress patch is subject to a geometric, piecewise-inextensibility constraint, whereas a diffuse-stress region is characterized by a mechanical constraint - the dominance of a single component of the stress tensor. We discuss the implications of our findings for the analysis of elastic sheets that are subject to various types of forcing.

Robert D. Schroll; Eleni Katifori; Benny Davidovitch

2010-12-17T23:59:59.000Z

25

Influence of the reactor wall composition on radicals' densities and total pressure in Cl{sub 2} inductively coupled plasmas: II. During silicon etching  

SciTech Connect (OSTI)

In an industrial inductively coupled plasma reactor dedicated to silicon etching in chlorine-based chemistry, the density of Cl{sub 2} molecules and the gas temperature are measured by means of laser absorption techniques, the density of SiCl{sub x} (x{<=}2) radicals by broadband absorption spectroscopy, the density of SiCl{sub 4} and ions by mass spectrometry, and the total gas pressure with a capacitance gauge. These measurements permit us to estimate the mole fractions of Cl, SiCl{sub 4}, and etch product radicals when etching a 200 mm diameter silicon wafer. The pure Cl{sub 2} plasma is operated in well prepared chamber wall coating with a thin film of SiOCl, AlF, CCl, or TiOCl. The impact of the chemical nature of the reactor wall's coatings on these mole fractions is studied systematically. We show that the reactor wall coatings have a huge influence on the radicals densities, but this is not only from the difference on Cl-Cl recombination coefficient on different surfaces. During silicon etching, SiCl{sub x} radicals sticking on the reactor walls are etched by Cl atoms and recycled into the plasma by forming volatile SiCl{sub 4}. Hence, the loss of Cl atoms in etching the wall deposited silicon is at least as important as their wall recombination in controlling the Cl atoms density. Furthermore, because SiCl{sub 4} is produced at high rate by both the wafer and reactor walls, it is the predominant etching product in the gas phase. However, the percentage of redeposited silicon that can be recycled into the plasma depends on the amount of oxygen present in the plasma: O atoms produced by etching the quartz roof window fix Si on the reactor walls by forming a SiOCl deposit. Hence, the higher the O density is, the lower the SiCl{sub 4} density will be, because silicon is pumped by the reactor walls and the SiOCl layer formed is not isotropically etched by chlorine. As a result, in the same pure Cl{sub 2} plasma at 20 mTorr, the SiCl{sub x} mole fraction can vary from 18% in a SiOCl-coated reactor, where the O density is the highest, to 62% in a carbon-coated reactor, where there is no O. In the latter case, most of the Cl mass injected in the reactor is stored in SiCl{sub 4} molecules, which results in a low silicon etch rate. In this condition, the Cl mass balance is verified within 10%, and from the silicon mass balance we concluded that SiCl{sub x} radicals have a high surface loss probability. The impact of the reactor wall coating on the etching process is thus important, but the mechanisms by which the walls control the plasma chemistry is much more complicated than a simple control through recombination reaction of halogen atoms on these surfaces.

Cunge, G.; Sadeghi, N.; Ramos, R. [Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (c/o CEA-LETI), 38054 Grenoble Cedex 9 (France); Laboratoire de Spectrometrie Physique (UMR 5588), Universite Joseph Fourier-Grenoble, and CNRS, BP 87, 38402 St. Martin d'Heres (France); Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (c/o CEA-LETI), 38054 Grenoble Cedex 9 (France)

2007-11-01T23:59:59.000Z

26

High elastic modulus polymer electrolytes  

DOE Patents [OSTI]

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

2013-10-22T23:59:59.000Z

27

Elastic properties of HMX.  

SciTech Connect (OSTI)

Atomistic molecular dynamics simulations have been used to calculate isothermal elastic properties for {beta}-, {alpha}-, and {delta}-HMX. The complete elastic tensor for each polymorph was determined at room temperature and pressure via analysis of microscopic strain fluctuations using formalism due to Rahman and Parrinello [J. Chem. Phys. 76,2662 (1982)]. Additionally, the isothermal compression curve was computed for {beta}-HMX for 0 {le} p {le} 10.6 GPa; the bulk modulus K and its pressure derivative K{prime} were obtained from two fitting forms employed previously in experimental studies of the {beta}-HMX equation of state. Overall, the results indicate good agreement between the bulk modulus predicted from the measured and calculated compression curves. The bulk modulus determined directly from the elastic tensor of {beta}-HMX is in significant disagreement with the compression curve-based results. The explanation for this discrepancy is an area of current research.

Sewell, T. D. (Thomas D.); Bedrov, D. (Dmitry); Menikoff, Ralph; Smith, G. D. (Grant D.)

2001-01-01T23:59:59.000Z

28

Elastic properties of superconducting MAX phases from first principles calculations  

E-Print Network [OSTI]

Using first-principles density functional calculations, a systematic study on the elastic properties for all known superconducting MAX phases (Nb2SC, Nb2SnC, Nb2AsC, Nb2InC, Mo2GaC and Ti2InC) was performed. As a result, the optimized lattice parameters, independent elastic constants, indicators of elastic anisotropy and brittle/ductile behavior as well as the so-called machinability indexis were calculated. We derived also bulk and shear moduli, Young's moduli, and Poisson's ratio for ideal polycrystalline MAX aggregates. The results obtained were discussed in comparison with available theoretical and experimental data and elastic parameters for other layered superconductors.

I. R. Shein; A. L. Ivanovskii

2010-06-03T23:59:59.000Z

29

Incremental elasticity for array databases  

E-Print Network [OSTI]

Relational databases benefit significantly from elasticity, whereby they execute on a set of changing hardware resources provisioned to match their storage and processing requirements. Such flexibility is especially ...

Duggan, Jennie

30

Transport and Induced Elastic Stress  

E-Print Network [OSTI]

Title: Variational Approach in Studying the Mixture of the Fluids: Transport and Induced Elastic Stress Abstract: From the energetic point of view, most ...

31

Nuclear isospin mixing and elastic parity-violating electron scattering  

E-Print Network [OSTI]

The influence of nuclear isospin mixing on parity-violating elastic electron scattering is studied for the even-even, N=Z nuclei 12C, 24Mg, 28Si, and 32S. Their ground-state wave functions have been obtained using a self-consistent axially-symmetric mean-field approximation with density-dependent effective two-body Skyrme interactions. Some differences from previous shell-model calculations appear for the isovector Coulomb form factors which play a role in determining the parity-violating asymmetry. To gain an understanding of how these differences arise, the results have been expanded in a spherical harmonic oscillator basis. Strangeness contributions to the asymmetry are also studied in concert with the isospin mixing contributions. Results are obtained within the distorted-wave Born approximation for comparison with potential future experimental studies of parity-violating electron scattering. To this end, for each nucleus the focus is placed on kinematic ranges where the signal (isospin-mixing effects on ...

Moreno, O; de Guerra, E Moya; Udias, J M; Donnelly, T W; Sick, I

2008-01-01T23:59:59.000Z

32

Elastic emission polishing  

SciTech Connect (OSTI)

Elastic emission polishing, also called elastic emission machining (EEM), is a process where a stream of abrasive slurry is used to remove material from a substrate and produce damage free surfaces with controlled surface form. It is a noncontacting method utilizing a thick elasto-hydrodynamic film formed between a soft rotating ball and the workpiece to control the flow of the abrasive. An apparatus was built in the Center, which consists of a stationary spindle, a two-axis table for the workpiece, and a pump to circulate the working fluid. The process is controlled by a programmable computer numerical controller (CNC), which presently can operate the spindle speed and movement of the workpiece in one axis only. This apparatus has been used to determine material removal rates on different material samples as a function of time, utilizing zirconium oxide (ZrO{sub 2}) particles suspended in distilled water as the working fluid. By continuing a study of removal rates the process should become predictable, and thus create a new, effective, yet simple tool for ultra-precision mechanical machining of surfaces.

Loewenthal, M.; Loseke, K.; Dow, T.A.; Scattergood, R.O.

1988-12-01T23:59:59.000Z

33

Elastic model of dry friction  

SciTech Connect (OSTI)

Friction of elastic bodies is connected with the passing through the metastable states that arise at the contact of surfaces rubbing against each other. Three models are considered that give rise to the metastable states. Friction forces and their dependence on the pressure are calculated. In Appendix A, the contact problem of elasticity theory is solved with adhesion taken into account.

Larkin, A. I.; Khmelnitskii, D. E., E-mail: dekl2@cam.ac.uk [Landau Institute for Theoretical Physics (Russian Federation)

2013-09-15T23:59:59.000Z

34

First-principles elastic properties of (alpha)-Pu  

SciTech Connect (OSTI)

Density-functional electronic structure calculations have been used to investigate the ambient pressure and low temperature elastic properties of the ground-state {alpha} phase of plutonium metal. The electronic structure and correlation effects are modeled within a fully relativistic anti-ferromagnetic treatment with a generalized gradient approximation for the electron exchange and correlation functionals. The 13 independent elastic constants, for the monoclinic {alpha}-Pu system, are calculated for the observed geometry. A comparison of the results with measured data from resonant ultrasound spectroscopy for a cast sample is made.

Soderlind, P; Klepeis, J E

2008-11-04T23:59:59.000Z

35

First-principles elastic properties of (alpha)-Pu  

SciTech Connect (OSTI)

Density-functional electronic-structure calculations have been used to investigate the ambient pressure and low temperature elastic properties of the ground-state {alpha} phase of plutonium metal. The electronic structure and correlation effects are modeled within a fully relativistic antiferromagnetic treatment with a generalized gradient approximation for the electron exchange and correlation functional. The 13 independent elastic constants, for the monoclinic {alpha}-Pu system, are calculated for the observed geometry. A comparison of the results with measured data from recent resonant ultrasound spectroscopy for a cast sample is made.

Soderlind, P; Klepeis, J

2009-02-18T23:59:59.000Z

36

Influences of short-duration grazing systems and stocking density on sediment production and infiltration rates on the rolling plains of Texas  

E-Print Network [OSTI]

density in the 42 cell SDG system was initially 11. 26 au ha ' and then reduced to 8. 10 au ha ' by June 1984. Stocking density in the MCG system was 0. 17 au ha'. Sampling Procedures The variables to be used in this study were selected on the basis... . 01 ?. 10 . 14 ~ ?. 09 -. 05 ?. 17 ** 20 se 43 4w 29 ?. 14 * 43 45 ?. 26 ** ?. 03 ?. 21 ** 18 44 ?. 08 19 24 ?. 12 32 ?. 46 ** 44 -. 48 ** 47 ?. 11 * ?. 05 ?. 11 " . 03 -. 03 . 01 ?. 07 . 08 39 -. 23 ** 17 39 ew 43...

Mings, Thomas Scott

2012-06-07T23:59:59.000Z

37

Statistical theory of elastic constants of cholesteric liquid crystals  

E-Print Network [OSTI]

A statistical theory of cholesteric liquid crystals composed of short rigid biaxial molecules is presented. It is derived in the thermodynamic limit at a small density and a small twist. The uniaxial (biaxial) cholesteric phase is regarded as a distorted form of the uniaxial (biaxial) nematic phase. The chirality of the interactions and the implementation of the inversion to the rotation matrix elements are discussed in detail. General microscopic expressions for the elastic constants are derived. The expressions involve the one-particle distribution function and the potential energy of two-body short-range interactions. It is shown that the elastic constants determine the twist of the phase. The stability condition for the cholesteric and nematic phases is presented. The theory is used to study unary and binary systems. The temperature and concentration dependence of the order parameters, the elastic constants and the twist of the phase are obtained. The possibility of phase separation is not investigated.

A. Kapanowski

2009-10-20T23:59:59.000Z

38

Stability of elastic grid shells  

E-Print Network [OSTI]

The elastic grid shell is a solution that combines double curvature and ease of mounting. This structural system, based on the deformation of an initially at grid without shear stiffness was invented more than fifty years ...

Mesnil, Romain, M. Eng. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

39

Influence of radiation therapy on the lung-tissue in breast cancer patients: CT-assessed density changes and associated symptoms  

SciTech Connect (OSTI)

The relative electron density of lung tissue was measured from computer tomography (CT) slices in 33 breast cancer patients treated by various techniques of adjuvant radiotherapy. The measurements were made before radiotherapy, 3 months and 9 months after completion of radiation therapy. The changes in lung densities at 3 months and 9 months were compared to radiation induced radiological (CT) findings. In addition, subjective symptoms such as cough and dyspnoea were assessed before and after radiotherapy. It was observed that the mean of the relative electron density of lung tissue varied from 0.25 when the whole lung was considered to 0.17 when only the anterior lateral quarter of the lung was taken into account. In patients with positive radiological (CT) findings the mean lung density of the anterior lateral quarter increased 2.1 times 3 months after radiotherapy and was still increased 1.6 times 6 months later. For those patients without findings, in the CT pictures the corresponding values were 1.2 and 1.1, respectively. The standard deviation of the pixel values within the anterior lateral quarter of the lung increased 3.8 times and 3.2 times at 3 months and 9 months, respectively, in the former group, as opposed to 1.2 and 1.1 in the latter group. Thirteen patients had an increase in either cough or dyspnoea as observed 3 months after completion of radiotherapy. In eleven patients these symptoms persisted 6 months later. No significant correlation was found between radiological findings and subjective symptoms. However, when three different treatment techniques were compared among 29 patients the highest rate of radiological findings was observed in patients in which the largest lung volumes received the target dose. A tendency towards an increased rate of subjective symptoms was also found in this group.

Rotstein, S.; Lax, I.; Svane, G. (Karolinska Hospital, Stockholm (Sweden))

1990-01-01T23:59:59.000Z

40

Influence of the reactor wall composition on radicals' densities and total pressure in Cl{sub 2} inductively coupled plasmas: I. Without silicon etching  

SciTech Connect (OSTI)

Laser absorption at 355 nm is used to monitor the time variations of the Cl{sub 2} density in high-density industrial inductively coupled plasma. This technique is combined with the measurement of the gas temperature from the Doppler width of the 811.5 nm line of argon, added as a trace gas and with the measurement of the total gas pressure with a Baratron gauge. These measurements permit to estimate the mole fractions of Cl{sub 2} and Cl species in Cl{sub 2} inductively coupled plasmas in a waferless reactor. The impact of the chemical nature of the reactor wall coatings on the Cl and Cl{sub 2} mole fractions is studied systematically. We show that under otherwise identical plasma conditions, the Cl mole fraction is completely different when the plasma is operated in SiOCl, AlF, CCl, or TiOCl coated reactors, because the homogeneous recombination probability of Cl atoms is strongly surface dependant. The Cl atom mole fraction reached at 100 W radiofrequency power in SiOCl coated reactor (80%) is much higher than that obtained at 900 W in a ''clean'' AlF reactor (40%). A simple zero-dimensional model permits to provide the recombination coefficient of Cl atoms, {gamma}{sub rec}: 0.005 on SiOCl film and about 0.3 on the other three coatings. It is proposed to get benefit of this very high sensitivity of Cl{sub 2} dissociation rate to the wall coating for the control of the chamber wall status from the Cl{sub 2} density measurements in standard conditions.

Cunge, G.; Sadeghi, N.; Ramos, R. [Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (c/o CEA-LETI), 38054 Grenoble Cedex 9 (France); Laboratoire de Spectrometrie Physique (UMR 5588), Universite Joseph Fourier-Grenoble, and CNRS, BP 87, 38402 St. Martin d'Heres (France); Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (c/o CEA-LETI), 38054 Grenoble Cedex 9 (France)

2007-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Influence of longitudinal isotope substitution on the thermal conductivity of carbon nanotubes: Results of nonequilibrium molecular dynamics and local density functional calculations  

SciTech Connect (OSTI)

We report reverse nonequilibrium molecular dynamics calculations of the thermal conductivity of isotope substituted (10,10) carbon nanotubes (CNTs) at 300 K. {sup 12}C and {sup 14}C isotopes both at 50% content were arranged either randomly, in bands running parallel to the main axis of the CNTs or in bands perpendicular to this axis. It is found that the systems with randomly distributed isotopes yield significantly reduced thermal conductivity. In contrast, the systems where the isotopes are organized in patterns parallel to the CNTs axis feature no reduction in thermal conductivity when compared with the pure {sup 14}C system. Moreover, a reduction of approximately 30% is observed in the system with the bands of isotopes running perpendicular to the CNT axis. The computation of phonon dispersion curves in the local density approximation and classical densities of vibrational states reveal that the phonon structure of carbon nanotubes is conserved in the isotope substituted systems with the ordered patterns, yielding high thermal conductivities in spite of the mass heterogeneity. In order to complement our conclusions on the {sup 12}C-{sup 14}C mixtures, we computed the thermal conductivity of systems where the {sup 14}C isotope was turned into pseudo-atoms of 20 and 40 atomic mass units.

Leroy, Frédéric, E-mail: f.leroy@theo.chemie.tu-darmstadt.de; Böhm, Michael C., E-mail: boehm@theo.chemie.tu-darmstadt.de [Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt (Germany); Schulte, Joachim [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany)] [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany); Balasubramanian, Ganesh [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)] [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)

2014-04-14T23:59:59.000Z

42

OFC/NFOEC '12 Summary --Elastic Networks  

E-Print Network [OSTI]

DWDMNetworks regarding CAPEX and Power Consumption Axel Klekamp ALU Traffic Engineering and Network Planning consumption and CAPEX for MLR and Elastic Networks. No. of transponders and fibers used is less in elastic

California at Davis, University of

43

The contact of elastic regular wavy surfaces revisited  

E-Print Network [OSTI]

We revisit the classic problem of an elastic solid with a two-dimensional wavy surface squeezed against an elastic flat half-space from infinitesimal to full contact. Through extensive numerical calculations and analytic derivations, we discover previously overlooked transition regimes. These are seen in particular in the evolution with applied load of the contact area and perimeter, the mean pressure and the probability density of contact pressure. These transitions are correlated with the contact area shape, which is affected by long range elastic interactions. Our analysis has implications for general random rough surfaces, as similar local transitions occur continuously at detached areas or coalescing contact zones. We show that the probability density of null contact pressures is non-zero at full contact. This might suggest revisiting the conditions necessary for applying Persson's model at partial contacts and guide the comparisons with numerical simulations. We also address the evaluation of the contact perimeter for discrete geometries and the applicability of Westergaard's solution for three-dimensional geometries.

Vladislav A. Yastrebov; Guillaume Anciaux Jean-Francois Molinari

2014-09-05T23:59:59.000Z

44

Elastic properties of Pu metal and Pu-Ga alloys  

SciTech Connect (OSTI)

We present elastic properties, theoretical and experimental, of Pu metal and Pu-Ga ({delta}) alloys together with ab initio equilibrium equation-of-state for these systems. For the theoretical treatment we employ density-functional theory in conjunction with spin-orbit coupling and orbital polarization for the metal and coherent-potential approximation for the alloys. Pu and Pu-Ga alloys are also investigated experimentally using resonant ultrasound spectroscopy. We show that orbital correlations become more important proceeding from {alpha} {yields} {beta} {yields} {gamma} plutonium, thus suggesting increasing f-electron correlation (localization). For the {delta}-Pu-Ga alloys we find a softening with larger Ga content, i.e., atomic volume, bulk modulus, and elastic constants, suggest a weakened chemical bonding with addition of Ga. Our measurements confirm qualitatively the theory but uncertainties remain when comparing the model with experiments.

Soderlind, P; Landa, A; Klepeis, J E; Suzuki, Y; Migliori, A

2010-01-05T23:59:59.000Z

45

QUANTITATIVE NON-DESTRUCTIVE EVALUATION (QNDE) OF THE ELASTIC MODULI OF POROUS TIAL ALLOYS  

SciTech Connect (OSTI)

The elastic moduli of {gamma}-TiA1 were studied in porous samples consolidated by various techniques e.g. cold isostatic pressing (CIP), pressure-less sintering, or hot isostatic pressing (HIP). Porosity linearly affects the dynamic elastic moduli of samples. The results indicate that the sound wave velocities and the elastic moduli affected by the processing route and depend not only on the attained density but also on the consolidation temperature. In this paper we show that there is linear correlation between the shear and the longitudinal sound velocities in porous TiA1. This opens the way to use a single sound velocity as a tool for quantitative non-destructive evaluation (QNDE) of porous TiA1 alloys. Here we demonstrate the applicability of an equation derived from the elastic theory and used previously for porous cubic metals.

Yeheskel, O. [NRCN, PO Box 9001, Beer Sheva, 84190 (Israel)

2008-02-28T23:59:59.000Z

46

The elastic anisotropy of marble  

E-Print Network [OSTI]

on acoustic anisotropy in marble has been shown to be negligable in four naturally-deformed samples. Compressional-wave velocities in each of the samples were calculated from the single crystal elastic constants of calcite and the orien- tat1ons... thanks to my husband, Fred Tubb, for his patience and support. This research was supported by the National Science Foundation under grant OCN 7817919 and Office of Naval Research contract N-00014- 80-0-0013. To my mother and father, for al1...

Gebhard, Susan Nash

1982-01-01T23:59:59.000Z

47

Final Report Port and Modal Elasticity Study  

E-Print Network [OSTI]

1 Final Report Port and Modal Elasticity Study Prepared for Southern California Association................................................................................................. 23 Financing Transportation Infrastructure for Port Access ..................................................................................... 27 Comparison of West Coast Port Facilities

California at Berkeley, University of

48

Overall Dynamic Properties of 3-D periodic elastic composites  

E-Print Network [OSTI]

A method for the homogenization of 3-D periodic elastic composites is presented. It allows for the evaluation of the averaged overall frequency dependent dynamic material constitutive tensors relating the averaged dynamic ?eld variable tensors of velocity, strain, stress, and linear momentum. The formulation is based on micromechanical modeling of a representative unit cell of a composite proposed by Nemat-Nasser & Hori (1993), Nemat-Nasser et. al. (1982) and Mura (1987) and is the 3-D generalization of the 1-D elastodynamic homogenization scheme presented by Nemat-Nasser & Srivastava (2011). We show that for 3-D periodic composites the overall compliance (stiffness) tensor is hermitian, irrespective of whether the corresponding unit cell is geometrically or materially symmetric.Overall mass density is shown to be a tensor and, like the overall compliance tensor, always hermitian. The average strain and linear momentum tensors are, however, coupled and the coupling tensors are shown to be each others' hermitian transpose. Finally we present a numerical example of a 3-D periodic composite composed of elastic cubes periodically distributed in an elastic matrix. The presented results corroborate the predictions of the theoretical treatment.

Ankit Srivastava; Sia Nemat-Nasser

2011-05-27T23:59:59.000Z

49

Utility of Hyaluronan Oligomers and Transforming Growth Factor-Beta1 Factors for Elastic Matrix Regeneration by Aneurysmal Rat Aortic Smooth Muscle Cells  

E-Print Network [OSTI]

The progression of aortic aneurysms (AAs) is typically associated with an activated smooth muscle cell (SMC) phenotype, diminished density of mature medial elastic fibers, and an elevated presence of matrix-degrading ...

Kothapalli, Chandrasekhar R.

50

Elastic continuum theory: Fully understanding of the twist-bend nematic phases  

E-Print Network [OSTI]

The twist-bend nematic phase, $N_{\\rm TB}$, may be viewed as a heliconical molecular arrangement in which the director $\\bf n$ precesses uniformly about an extra director field, $\\bf t$. It corresponds to a nematic ground state exhibiting nanoscale periodic modulation. To demonstrate the stability of this phase from the elastic point of view, a natural extension of the Frank elastic energy density is proposed. The elastic energy density is built in terms of the elements of symmetry of the new phase in which intervene the components of these director fields together with the usual Cartesian tensors. It is shown that the ground state corresponds to a deformed state for which $K_{22} > K_{33}$. When the elastic free energy is interpreted in analogy with the Landau theory, it is demonstrated the existence of a second order phase transition between the usual and the twist-bend nematic phase, driven by a new elastic parameter playing a role similar to the one of the main dielectric anisotropy of classical nematics and being closely related to the bulk compression modulus representing the pseudo-layers of twist-bend nematic phases. A phase transition and the value of the nanoscale pitch are predicted in accordance to experimental results.

Giovanni Barbero; Luiz Roberto Evangelista; Michely Patrícia Rosseto; Rafael Soares Zola; Ioannis Lelidis

2015-03-30T23:59:59.000Z

51

Elastic–Plastic Spherical Contact Modeling Including Roughness Effects  

E-Print Network [OSTI]

A multilevel model for elastic–plastic contact between ajunction growth of an elastic–plastic spherical contact. J.nite element based elastic–plastic model for the contact of

Li, L.; Etsion, I.; Talke, F. E.

2010-01-01T23:59:59.000Z

52

Single chain elasticity and thermoelasticity of polyethylene  

E-Print Network [OSTI]

Single-chain elasticity of polyethylene at $\\theta$ point up to 90% of stretching with respect to its contour length is computed by Monte-Carlo simulation of an atomistic model in continuous space. The elasticity law together with the free-energy and the internal energy variations with stretching are found to be very well represented by the wormlike chain model up to 65% of the chain elongation, provided the persistence length is treated as a temperature dependent parameter. Beyond this value of elongation simple ideal chain models are not able to describe the Monte Carlo data in a thermodynamic consistent way. This study reinforces the use of the wormlike chain model to interpret experimental data on the elasticity of synthetic polymers in the finite extensibility regime, provided the chain is not yet in its fully stretched regime. Specific solvent effects on the elasticity law and the partition between energetic and entropic contributions to single chain elasticity are investigated.

John T. Titantah; Carlo Pierleoni; Jean-Paul Ryckaert

2002-09-05T23:59:59.000Z

53

Hydrogen Species Motion in Piezoelectrics: A Quasi-Elastic Neutron...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Species Motion in Piezoelectrics: A Quasi-Elastic Neutron Scattering Study. Hydrogen Species Motion in Piezoelectrics: A Quasi-Elastic Neutron Scattering Study. Abstract: Hydrogen...

54

Defect-induced incompatability of elastic strains: dislocations within the Landau theory of martensitic phase transformations  

SciTech Connect (OSTI)

In dislocation-free martensites the components of the elastic strain tensor are constrained by the Saint-Venant compatibility condition which guarantees continuity of the body during external loading. However, in dislocated materials the plastic part of the distortion tensor introduces a displacement mismatch that is removed by elastic relaxation. The elastic strains are then no longer compatible in the sense of the Saint-Venant law and the ensuing incompatibility tensor is shown to be proportional to the gradients of the Nye dislocation density tensor. We demonstrate that the presence of this incompatibility gives rise to an additional long-range contribution in the inhomogeneous part of the Landau energy functional and to the corresponding stress fields. Competition among the local and long-range interactions results in frustration in the evolving order parameter (elastic) texture. We show how the Peach-Koehler forces and stress fields for any distribution of dislocations in arbitrarily anisotropic media can be calculated and employed in a Fokker-Planck dynamics for the dislocation density. This approach represents a self-consistent scheme that yields the evolutions of both the order parameter field and the continuous dislocation density. We illustrate our method by studying the effects of dislocations on microstructure, particularly twinned domain walls, in an Fe-Pd alloy undergoing a martensitic transformation.

Groger, Roman1 [Los Alamos National Laboratory; Lockman, Turab [Los Alamos National Laboratory; Saxena, Avadh [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

55

Molecular elasticity and the geometric phase  

E-Print Network [OSTI]

We present a method for solving the Worm Like Chain (WLC) model for twisting semiflexible polymers to any desired accuracy. We show that the WLC free energy is a periodic function of the applied twist with period 4 pi. We develop an analogy between WLC elasticity and the geometric phase of a spin half system. These analogies are used to predict elastic properties of twist-storing polymers. We graphically display the elastic response of a single molecule to an applied torque. This study is relevant to mechanical properties of biopolymers like DNA.

Joseph Samuel; Supurna Sinha

2003-01-23T23:59:59.000Z

56

The work function of elastic solids  

E-Print Network [OSTI]

In solid phase the pressure correlates to the elastic related volume change while the temperature to the thermal related volume change. These volume changes are not compatible with the exception of constant volume condition when the expanded volume converts completely compressed volume. Separating the thermal and elastic related volume changes the work functions for each of the thermodynamic conditions are derived. Based on theoretical consideration it is suggested that the thermal related volume change do not result mechanical work. Homogeneous model, both the system and the surrounding have the same phase, can completely explain the lack of the thermal related work and provide a self-consistent thermodynamic description for the elastic solids.

Jozsef Garai; Alexandre Laugier

2005-11-02T23:59:59.000Z

57

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

SciTech Connect (OSTI)

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)

2014-01-28T23:59:59.000Z

58

Mechanical behavior of elastic rods under constraint  

E-Print Network [OSTI]

We present the results of an experimental investigation of the mechanics of thin elastic rods under a variety of loading conditions. Four scenarios are explored, with increasing complexity: i) the shape of a naturally ...

Miller, James Thomas, Ph. D. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

59

Conservation of Momentum: Fluids and Elastic Solids  

E-Print Network [OSTI]

Chapter 6 Conservation of Momentum: Fluids and Elastic Solids The description of the motion.2) (see A.11). By conservation of mass, the rate of change of the total mass in A does not change

Chicone, Carmen

60

Elastic moduli of nickel and iron aluminides  

E-Print Network [OSTI]

ELASTIC MODULI OF NICKEL AND IRON ALUMINIDES A Thesis by SREEDHAR MAN JIGANI Submitted to the Oifice of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1993... Major Subject: Mechanical Engineering ELASTIC MODULI OF NICKEL AND IRON ALUMINIDES A Thesis by SREEDHAR MAN JIGANI Submitted to Texas AkM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved...

Manjigani, Sreedhar

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Intraclass Price Elasticity & Electric Rate Design  

E-Print Network [OSTI]

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... industries are already affecting electric utilities. Cogeneration is one example of competition which effects electric utilities. Utilities now have a competing source of generation which often causes load and revenue losses. Competition has specifically...

Gresham, K. E.

62

Effective medium theory of elastic waves in random networks of rods  

E-Print Network [OSTI]

We formulate an effective medium (mean field) theory of a material consisting of randomly distributed nodes connected by straight slender rods, hinged at the nodes. Defining novel wavelength-dependent effective elastic moduli, we calculate both the static moduli and the dispersion relations of ultrasonic longitudinal and transverse elastic waves. At finite wave vector $k$ the waves are dispersive, with phase and group velocities decreasing with increasing wave vector. These results are directly applicable to networks with empty pore space. They also describe the solid matrix in two-component (Biot) theories of fluid-filled porous media. We suggest the possibility of low density materials with higher ratios of stiffness and strength to density than those of foams, aerogels or trabecular bone.

J. I. Katz; J. J. Hoffman; M. S. Conradi; J. G. Miller

2012-06-13T23:59:59.000Z

63

Comparison of Precision Orbit Derived Density Estimates for CHAMP and GRACE Satellites  

E-Print Network [OSTI]

. These density variations are the result of many factors; however, the Sun is the main driver in upper atmospheric density changes. The Sun influences the densities in Earth's atmosphere through solar heating of the atmosphere, as well as through geomagnetic...

Fattig, Eric

2011-04-21T23:59:59.000Z

64

Stochastic reduced-order model for an automotive vehicle in presence of numerous local elastic modes in the low-  

E-Print Network [OSTI]

Stochastic reduced-order model for an automotive vehicle in presence of numerous local elastic a high modal density in the low-frequency range, such as an automotive vehicle. This type of structure is applied on a complex computational model of an automotive vehicle. 1 INTRODUCTION This work is performed

Paris-Sud XI, Université de

65

Optical theorem and elastic nucleon scattering  

E-Print Network [OSTI]

In the theoretical analysis of high-energy elastic nucleon scattering one starts commonly from the description based on the validity of optical theorem, which allows to derive the value of total cross section directly from the experimentally measured t-dependence of elastic differential cross section. It may be shown, however, that this theorem has been derived on the basis of one assumption that might be regarded perhaps as acceptable for long-range (e.g., Coulomb) forces but must be denoted as quite unacceptable for finite-range hadron forces. Consequently, the conclusions leading to the increase of total cross section with energy at higher collision energies must be newly analyzed. The necessity of new analysis concerns also the derivation of elastic scattering t-dependence at very low transverse momenta from measured data.

Milos V. Lokajicek; Vojtech Kundrat

2009-06-22T23:59:59.000Z

66

Elasticity of Twist-Bend Nematic Phases  

E-Print Network [OSTI]

The ground state of twist-bend nematic liquid crystals is a heliconical molecular arrangement in which the nematic director precesses uniformly about an axis, making a fixed angle with it. Both precession senses are allowed in the ground state of these phases. When one of the two \\emph{helicities} is prescribed, a single helical nematic phase emerges. A quadratic elastic theory is proposed here for each of these phases which features the same elastic constants as the classical theory of the nematic phase, requiring all of them to be positive. To describe the helix axis, it introduces an extra director field which becomes redundant for ordinary nematics. Putting together helical nematics with opposite helicities, we reconstruct a twist-bend nematic, for which the quadratic elastic energies of the two helical variants are combined in a non-convex energy.

Epifanio G. Virga

2014-04-12T23:59:59.000Z

67

Phenomenological explanation of elastic anomalies in superlattices  

SciTech Connect (OSTI)

The experimental fact that measured elastic and structural properties of superlattices are strongly correlated can be understood on the basis of a simple model based on the packing of hard spheres. The model is consistent with features of many models that have been proposed to explain the supermodulus effect; but contrary to previous explanations, it allows predictions for a given pair of constitutents to be made. For an arbitrary pair of elements, it predicts the existence or non-existence of an elastic anomaly, and a rough estimate of its magnitude.

Grimsditch, M.; Fullerton, E.E. [Argonne National Lab., IL (United States); Schuller, I.K. [California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics

1993-06-01T23:59:59.000Z

68

First principle study of elastic and thermodynamic properties of FeB{sub 4} under high pressure  

SciTech Connect (OSTI)

The elastic properties, elastic anisotropy, and thermodynamic properties of the lately synthesized orthorhombic FeB{sub 4} at high pressures are investigated using first-principles density functional calculations. The calculated equilibrium parameters are in good agreement with the available experimental and theoretical data. The obtained normalized volume dependence of high pressure is consistent with the previous experimental data investigated using high-pressure synchrotron x-ray diffraction. The complete elastic tensors and crystal anisotropies of the FeB{sub 4} are also determined in the pressure range of 0–100?GPa. By the elastic stability criteria and vibrational frequencies, it is predicted that the orthorhombic FeB{sub 4} is stable up to 100 GPa. In addition, the calculated B/G ratio reveals that FeB{sub 4} possesses brittle nature in the range of pressure from 0 to 100?GPa. The calculated elastic anisotropic factors suggest that FeB{sub 4} is elastically anisotropic. By using quasi-harmonic Debye model, the compressibility, bulk modulus, the coefficient of thermal expansion, the heat capacity, and the Grüneisen parameter of FeB{sub 4} are successfully obtained in the present work.

Zhang, Xinyu, E-mail: xyzhang@ysu.edu.cn, E-mail: jiaqianqin@gmail.com, E-mail: riping@ysu.edu.cn; Ning, Jinliang; Sun, Xiaowei; Li, Xinting; Ma, Mingzhen; Liu, Riping, E-mail: xyzhang@ysu.edu.cn, E-mail: jiaqianqin@gmail.com, E-mail: riping@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Qin, Jiaqian, E-mail: xyzhang@ysu.edu.cn, E-mail: jiaqianqin@gmail.com, E-mail: riping@ysu.edu.cn [Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok 10330 (Thailand); State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

2013-11-14T23:59:59.000Z

69

THE RESPONSE OF SOLIDS TO ELASTIC/ PLASTIC INDENTATION  

E-Print Network [OSTI]

OF SOLIDS TO ELASTIC/PLASTIC INDENTATION S.S. Chiang, D.B.134. Table I Normalized Plastic Zone Size (B) and Materialken from the elastic/plastic boundary, surface intersection,

Chiang, S.S.

2013-01-01T23:59:59.000Z

70

Interaction of gravitational waves with an elastic solid medium  

E-Print Network [OSTI]

Contents. 1. Introduction. 2. Kinematics of a Material Medium: Material Representation. 3. Kinematics of a Material Medium: Convected Differentials. 4. Kinematics of a Perfect Elastic Medium. 5. Small Gravitational Perturbations of an Elastic Medium.

B. Carter

2001-02-28T23:59:59.000Z

71

Conservation of Momentum: Fluids and Elastic Solids  

E-Print Network [OSTI]

Chapter 3 Conservation of Momentum: Fluids and Elastic Solids The description of the motion, t) dx = (A,t) t(x, t) + div(u)(x, t) dx (3.2) (see A.11). By conservation of mass, the rate is conserved by the fluid motion. A differential equation for the velocity field u is obtained from the equa

Chicone, Carmen

72

The elasticity of -helices Seungho Choe  

E-Print Network [OSTI]

The elasticity of -helices Seungho Choe Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218 Sean X. Suna Department of Mechanical Engineering and Whitaker chemical energy into mechanical work. Binding of nucleotides such as ATP generates a local- ized force

Sun, Sean

73

Effects of coordination and pressure on sound attenuation, boson peak and elasticity in amorphous solids  

E-Print Network [OSTI]

Connectedness and applied stress strongly affect elasticity in solids. In various amorphous solids, mechanical stability can be lost either by reducing connectedness or by increasing pressure. We present an effective medium theory of elasticity that extends previous approaches by incorporating the effect of compression, of amplitude $e$, allowing one to describe quantitative features of sound propagation, transport, the boson peak, and elastic moduli near the elastic instability occurring at a compression $e_c$. The theory disentangles several frequencies characterizing the vibrational spectrum: the onset frequency $\\omega_0\\sim \\sqrt{e_c-e}$ where strongly-scattered modes appear in the vibrational spectrum, the pressure-independent frequency $\\omega_*$ where the density of states displays a plateau, the boson peak frequency $\\omega_{BP}$, and the Ioffe-Regel frequency $\\omega_{IR}$ where scattering length and wavelength become equal. We predict that sound attenuation crosses over from $\\omega^4$ to $\\omega^2$ behaviour at $\\omega_0$. We predict that a frequency-dependent length scale $l_s(\\omega)$ and speed of sound $\

Eric DeGiuli; Adrien Laversanne-Finot; Gustavo Düring; Edan Lerner; Matthieu Wyart

2014-02-22T23:59:59.000Z

74

TOPOLOGICAL DERIVATIVE FOR THE INVERSE SCATTERING OF ELASTIC WAVES  

E-Print Network [OSTI]

TOPOLOGICAL DERIVATIVE FOR THE INVERSE SCATTERING OF ELASTIC WAVES by B. B. GUZINA (Department December 2002. Revise 20 May 2003] Summary To establish an alternative analytical framework for the elastic-wave. For a comprehensive solution to three-dimensional inverse scattering problems involving elastic waves, the proposed

Guzina, Bojan

75

Measurements of elastic modulus using laser-induced surface waves  

SciTech Connect (OSTI)

In general, the mechanical testing methods that are utilized for alloys and polymers, e.g., dogbone, rheovibron, etc., are not applicable to thin film structures. We wish to report noncontacting measurements of the surface acoustic wave (SAW) velocity and the elastic modulus applicable to thin films of moderate thickness. An accompanying paper extends this technique to smaller film dimensions. A 15 ns pulsed YAG laser was used as the energy source to thermoelastically excite surface waves. The propagation of the waves was then observed by a second, independent He-Ne laser at a distance from the excitation spot. using the knife edge/beam deflection technique. A cylindrical lens was used to reduce the energy loading of the YAG laser on the sample to avoid damaging the surface of the specimen. The Rayleigh wave velocity is calculated from measurements of the arrival time of the surface wave as a function of distance from the ND:YAG laser spot. The shear modulus, G, can be determined from the measured speed of the surface waves, V, the specimen density, p, and Poisson`s ratio, v, according to the following relationship: V = R(v){sm_bullet}(G/p){sup {1/2}} where R(v), expressed as (0.862 + 1.14v)/(l + v), is the ratio of the Rayleigh wave velocity to the shear wave velocity and ranges from 0.86 to 0.95 Table below lists the measured surface wave velocities and the calculated shear modulus for our experimental results and the published values. Excellent agreement is observed. The depth of the SAW is approximately equal to the SAW wavelength which is approximately the laser spot size. Typically 30 {mu}m spot sizes can be readily achieved. In conclusion, SAW velocities and the modulus of elasticity of various materials have been measured. We have demonstrated that this non-contacting method can be used to characterize moderately thin films.

Chang, D.J.; Amimoto, S.T.; Gross, R.W.F. [Aerospace Corporation, Los Angeles, CA (United States); Glenn, T. [Massachusetts Institute of Technology, Cambridge, MA (United States)

1995-12-31T23:59:59.000Z

76

Explicit dispersion relations for elastic waves in extremely deformed soft matter with application to nearly incompressible and auxetic materials  

E-Print Network [OSTI]

We analyze the propagation of elastic waves in soft materials subjected to finite deformations. We derive explicit dispersion relations, and apply these results to study elastic wave propagation in (i) nearly incompressible materials such as biological tissues and polymers, and (ii) negative Poisson's ratio or auxetic materials. We find that for nearly incompressible materials transverse wave velocities exhibit strong dependence on direction of propagation and initial strain state, whereas the longitudinal component is not affected significantly until extreme levels of deformations are attained. For highly compressible materials, we show that both pressure and shear wave velocities depend strongly on initial deformation and direction of propagation. When compression is applied, longitudinal wave velocity decreases in positive bulk modulus materials, and increases for negative bulk modulus materials; this is regardless the direction of wave prorogation. We demonstrate that finite deformations influence elastic wave propagation through combinations of induced effective compressibility and stiffness.

Pavel Galich; Stephan Rudykh

2014-12-31T23:59:59.000Z

77

Elastic electron scattering from formic acid  

SciTech Connect (OSTI)

Following our earlier study on the dynamics of low energy electron attachment to formic acid, we report the results of elastic low-energy electron collisions with formic acid. Momentum transfer and angular differential cross sections were obtained by performing fixed-nuclei calculations employing the complex Kohn variational method. We make a brief description of the technique used to account for the polar nature of this polyatomic target and compare our results with available experimental data.

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

2006-07-31T23:59:59.000Z

78

Subsonic Free Surface Waves in Linear Elasticity  

E-Print Network [OSTI]

For general anisotropic linear elastic solids with smooth boundaries, Rayleigh-type surface waves are studied. Using spectral factorizations of matrix polynomials, a self-contained exposition of the case of a homogeneous half-space is given first. The main result is about inhomogeneous anisotropic bodies with curved surfaces. The existence of subsonic free surface waves is shown by giving ray series asymptotic expansions, including formulas for the transport equation.

Sönke Hansen

2014-05-09T23:59:59.000Z

79

Pionic atoms and low energy elastic scattering  

SciTech Connect (OSTI)

A fit to pionic atom data is used to determine four of the parameters of the low energy pion-nucleus optical potential, while the other parameters are taken from theory. The resulting potential is used to predict elastic scattering from 30 --50 MeV pions. The effects of extrapolating the parameters to 50 MeV with a simple energy dependence are examined.

Stricker, K.; Carr, J.A.; McManus, H.

1980-11-01T23:59:59.000Z

80

Pair densities in density functional theory  

E-Print Network [OSTI]

The exact interaction energy of a many-electron system is determined by the electron pair density, which is not well-approximated in standard Kohn-Sham density functional models. Here we study the (complicated but well-defined) exact universal map from density to pair density. We show that many common functionals, including the most basic version of the LDA (Dirac exchange with no correlation contribution), arise from particular approximations of this map. We develop an algorithm to compute the map numerically, and apply it to one-parameter families {a*rho(a*x)} of one-dimensional homogeneous and inhomogeneous single-particle densities. We observe that the pair density develops remarkable multiscale patterns which strongly depend on both the particle number and the "width" 1/a of the single-particle density. The simulation results are confirmed by rigorous asymptotic results in the limiting regimes a>>1 and a<<1. For one-dimensional homogeneous systems, we show that the whole spectrum of patterns is rep...

Chen, Huajie

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

ELEMENTARY APPROACH TO SELF-ASSEMBLY AND ELASTIC PROPERTIES OF RANDOM COPOLYMERS  

SciTech Connect (OSTI)

The authors have mapped the physics of a system of random copolymers onto a time-dependent density functional-type field theory using techniques of functional integration. Time in the theory is merely a label for the location of a given monomer along the extent of a flexible chain. We derive heuristically within this approach a non-local constraint which prevents segments on chains in the system from straying too far from each other, and leads to self-assembly. The structure factor is then computed in a straightforward fashion. The long wave-length limit of the structure factor is used to obtain the elastic modulus of the network. It is shown that there is a surprising competition between the degree of micro-phase separation and the elastic moduli of the system.

S. M. CHITANVIS

2000-10-01T23:59:59.000Z

82

Environmental bias and elastic curves on surfaces  

E-Print Network [OSTI]

The behavior of an elastic curve bound to a surface will reflect the geometry of its environment. This may occur in an obvious way: the curve may deform freely along directions tangent to the surface, but not along the surface normal. However, even if the energy itself is symmetric in the curve's geodesic and normal curvatures, which control these modes, very distinct roles are played by the two. If the elastic curve binds preferentially on one side, or is itself assembled on the surface, not only would one expect the bending moduli associated with the two modes to differ, binding along specific directions, reflected in spontaneous values of these curvatures, may be favored. The shape equations describing the equilibrium states of a surface curve described by an elastic energy accommodating environmental factors will be identified by adapting the method of Lagrange multipliers to the Darboux frame associated with the curve. The forces transmitted to the surface along the surface normal will be determined. Features associated with a number of different energies, both of physical relevance and of mathematical interest, are described. The conservation laws associated with trajectories on surface geometries exhibiting continuous symmetries are also examined.

Jemal Guven; Dulce María Valencia; Pablo Vázquez-Montejo

2014-08-15T23:59:59.000Z

83

Density of Spray-Formed Materials  

SciTech Connect (OSTI)

Spray Forming is an advanced materials processing technology that transforms molten metal into a near-net-shape solid by depositing atomized droplets onto a substrate. Depending on the application, the spray-formed material may be used in the as-deposited condition or it may undergo post-deposition processing. Regardless, the density of the as-deposited material is an important issue. Porosity is detrimental because it can significantly reduce strength, toughness, hardness and other properties. While it is not feasible to achieve fully-dense material in the as-deposited state, density greater than 99% of theoretical density is possible if the atomization and impact conditions are optimized. Thermal conditions at the deposit surface and droplet impact angle are key processing parameters that influence the density of the material. This paper examines the factors that contribute to porosity formation during spray forming and illustrates that very high as-deposited density is achieved by optimizing processing parameters.

Kevin M. McHugh; Volker Uhlenwinkel; Nils Ellendr

2008-06-01T23:59:59.000Z

84

Equation for liquid density  

SciTech Connect (OSTI)

Saturated liquid densities for organic chemicals are given as functions of temperature using a modified Rackett equation.

Yaws, C.L.; Yang, H.C.; Hopper, J.R.; Cawley, W.A. (Lamar Univ., Beaumont, TX (US))

1991-01-01T23:59:59.000Z

85

Elastic properties of the degenerate f.c.c. crystal of polydisperse soft dimers at zero temperature  

E-Print Network [OSTI]

Elastic properties of soft, three-dimensional dimers, interacting through site-site n-inverse-power potential, are determined by computer simulations at zero temperature. The degenerate crystal of dimers exhibiting (Gaussian) size distribution of atomic diameters - i.e. size polydispersity - is studied at the molecular number density $1/\\sqrt{2}$; the distance between centers of atoms forming dimers is considered as a length unit. It is shown that, at the fixed number density of the dimers, increasing polydispersity causes, typically, an increase of pressure, elastic constants and Poisson's ratio; the latter is positive in most direction. A direction is found, however, in which the size polydispersity causes substantial decrease of Poisson's ratio, down to negative values for large $n$. Thus, the system is partially auxetic for large polydispersity and large n.

J. W. Narojczyk; K. W. Wojciechowski

2015-04-12T23:59:59.000Z

86

Study of structural, electronic and elastic properties of RPd{sub 3} (R = Lu and Sc) compounds  

SciTech Connect (OSTI)

The structural, electronic and elastic properties of nonmagnetic RPd{sub 3} (R = Lu and Sc) compounds, which crystallize in AuCu{sub 3}-type structure, are studied using first principles density functional theory based on full potential linearized augmented plane wave (FP-LAPW) method. The calculations are carried out within the PBE-GGA and WC-GGA for the exchange correlation potential. Our calculated ground state properties such as lattice constant (a0), bulk modulus (B) and its pressure derivative (B’) are in good agreement with the experimental results. We first time predict the elastic constants for these compounds using different approximations of GGA. These RPd{sup 3} compounds are found to be ductile in nature in accordance with Pugh’s criteria. The computed electronic band structures and density of states show metallic character of these compounds.

Thakur, Veena, E-mail: gita-pagare@yahoo.co.in; Pagare, Gitanjali, E-mail: gita-pagare@yahoo.co.in; Chouhan, S. S., E-mail: gita-pagare@yahoo.co.in [Department of Physics, Government M. L. B. Girls P. G. Autonomous College, Bhopal-462002 (India); Sanyal, S. P. [Department of Physics, Barkatullah University, Bhopal-462026 (India)

2014-04-24T23:59:59.000Z

87

Lessons from LHC elastic and diffractive data  

E-Print Network [OSTI]

In the light of LHC data, we discuss the global description of all high energy elastic and diffractive data, using a one-pomeron model, but including multi-pomeron interactions. The LHC data indicate the need of a $k_t(s)$ behaviour, where $k_t$ is the gluon transverse momentum along the partonic ladder structure which describes the pomeron. We also discuss tensions in the data, as well as the $t$ dependence of the slope of $d\\sigma_{el}/dt$ in the small $t$ domain.

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

2014-10-13T23:59:59.000Z

88

Elastic and diffractive scattering at D0  

SciTech Connect (OSTI)

The first search for diffractively produced Z bosons in the muon decay channel is presented, using a data set collected by the D0 detector at the Fermilab Tevatron at {radical}s = 1.96 TeV between April and September 2003, corresponding to an integrated luminosity of approximately 110 pb{sup -1}. The first dN/d|t| distribution for proton-antiproton elastic scattering at this c.o.m. energy is also presented, using data collected by the D0 Forward Proton Detector between January and May 2002. The measured slope is reproduced by theoretical predictions.

Edwards, Tamsin; /Manchester U.

2004-04-01T23:59:59.000Z

89

Dynamics of Bianchi type I elastic spacetimes  

E-Print Network [OSTI]

We study the global dynamical behavior of spatially homogeneous solutions of the Einstein equations in Bianchi type I symmetry, where we use non-tilted elastic matter as an anisotropic matter model that naturally generalizes perfect fluids. Based on our dynamical systems formulation of the equations we are able to prove that (i) toward the future all solutions isotropize; (ii) toward the initial singularity all solutions display oscillatory behavior; solutions do not converge to Kasner solutions but oscillate between different Kasner states. This behavior is associated with energy condition violation as the singularity is approached.

Simone Calogero; J. Mark Heinzle

2007-06-26T23:59:59.000Z

90

Deriving Atmospheric Density Estimates Using Satellite Precision Orbit Ephemerides  

E-Print Network [OSTI]

Model regardless of solar and geomagnetic activity levels. The POE density estimates were obtained with the desired accuracy for a ±10% variation in the ballistic coefficient used to initialize the process. Fit span length showed little influence...

Hiatt, Andrew Timothy

2009-01-01T23:59:59.000Z

91

Motivation Elastic Net Computation Elastic-Net and algorithms for computing the  

E-Print Network [OSTI]

Solution Lemma Given data set (y, X) and (1, 2), define an artificial data set (y, X) by X (n+p)Ã?p = (1 + 2 compute the elastic-net estimator ^(enet), and then we construct the adaptive weights by ^wj = (|^j

Recht, Ben

92

Failure Stress and Apparent Elastic Modulus of Diesel Particulate...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

and Apparent Elastic Modulus of Diesel Particulate Filter Ceramics Three established mechanical test specimen geometries and test methods for brittle materials are adapted to DPF...

93

Water skin anomalies: density, elasticity, hydrophobicity, thermal stability, interface repulsivity, etc  

E-Print Network [OSTI]

Molecular undercoordination induced O:H-O bond relaxation and dual polarization dictates the supersolid behavior of water skins interacting with other substances such as flowing in nanochannels, dancing of water droplets, floating of insects. The BOLS-NEP notion unifies the Wenzel-Cassie-Baxter models and explains controllable transition between hydrophobicity and hydrophilicity.

Chang Q. Sun

2015-02-26T23:59:59.000Z

94

The effect of elastic strain on M-center distribution in LiF  

E-Print Network [OSTI]

of lithium fluoride, illustrating the Seitz and Knox models of the M-center 3 2. A two dimensional lattice of lithium fluoride, illustrating the F and P -centers. 2 4 3. Prism sub]ected to torque about z-axis 4. Cross-section of a rectangular crystal... was to determine the influence of elastic strain on the production of M-centers in crystals of lithium fluoride. g secondary objective was to observe whether the amount of time that a crystal was strained had any effect on the M-center distribution. Data...

Wolny, Richard Frank

1962-01-01T23:59:59.000Z

95

Agriculture, Ecosystems and Environment 87 (2001) 93109 Comparing pocket gopher (Thomomys bottae) density  

E-Print Network [OSTI]

in Yolo County, California, as well as the distributionofspecialstatus rare in the valley portion of Yolo County. Gopher control failed to influence density to the magnitude; Yolo County; California 1. Introduction The density of pocket gophers (Thomomys bottae) affects

Zhang, Minghua

96

Net Balanced Floorplanning Based on Elastic Energy Model  

E-Print Network [OSTI]

Net Balanced Floorplanning Based on Elastic Energy Model Wei Liu and Alberto Nannarelli Dept variations can introduce extra signal skew, it is desirable to have floorplans with balanced net delays based on the elastic energy model. The B*-tree, which is based on an ordered binary tree, is used

Nannarelli, Alberto

97

Impact of Acid Additives on Elastic Modulus of Viscoelastic Surfactants  

E-Print Network [OSTI]

In live acid solutions at concentrations of HCl namely 15-20 wt% HCl, elastic modulus remained quite low as compared to 10-12 wt% HCl concentrations. At 10 wt% HCl concentration, elastic modulus was 3.4 Pa observed whereas at 20 wt% HCl...

Khan, Waqar Ahmad

2012-02-14T23:59:59.000Z

98

Soft Autonomous Materials --Using Active Elasticity and Embedded Distributed  

E-Print Network [OSTI]

Soft Autonomous Materials -- Using Active Elasticity and Embedded Distributed Computation Nikolaus and demonstrate shape changing, and autonomous, sensor-based locomotion using distributed control. We show elasticity in their designs [23]. Here we show soft robots that can autonomously undergo shape-change and gen

Liang, Haiyi

99

Nitrogen Contamination in Elastic Neutron Scattering Songxue Chi,ab  

E-Print Network [OSTI]

Nitrogen Contamination in Elastic Neutron Scattering Songxue Chi,ab Jeffrey W. Lynn,a* Ying Chen a neutron scattering measurement is a contribution to the background, especially in inelastic measurements of having N2 in the sample environment system during elastic neutron scattering measurements on a single

Lynn, Jeffrey W.

100

Elasticity solutions for plane anisotropic functionally graded beams  

E-Print Network [OSTI]

Elasticity solutions for plane anisotropic functionally graded beams H.J. Ding a , D.J. Huang a This paper considers the plane stress problem of generally anisotropic beams with elastic compliance of anisotropic functionally graded plane beams, with the integral constants completely determined from boundary

Wang, Ji

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Propagation of elastic waves through a lattice of cylindrical cavities  

E-Print Network [OSTI]

Propagation of elastic waves through a lattice of cylindrical cavities By S. Guo & P. Mc asymptotic homogenization to obtain low-frequency approximations to elastic wave propagation through periodic follows that of McIver (2007) who investigates acoustic-wave propagation through a lattice of rigid

102

Density-dependent covariant energy density functionals  

SciTech Connect (OSTI)

Relativistic nuclear energy density functionals are applied to the description of a variety of nuclear structure phenomena at and away fromstability line. Isoscalar monopole, isovector dipole and isoscalar quadrupole giant resonances are calculated using fully self-consistent relativistic quasiparticle randomphase approximation, based on the relativistic Hartree-Bogoliubovmodel. The impact of pairing correlations on the fission barriers in heavy and superheavy nuclei is examined. The role of pion in constructing desnity functionals is also investigated.

Lalazissis, G. A. [Physics Department, Aristotle University of Thessaloniki, GR-54124 (Greece)

2012-10-20T23:59:59.000Z

103

On the grade consistent theories of micromorphic elastic solids  

SciTech Connect (OSTI)

For the investigation of specific nonlocal phenomena the second-order displacement gradient has been added to the independent constitutive variables used in the classical theories of elastic solids. In this paper we outline the hystorical development of the subject and present a nonlinear grade consistent theory of micromorphic elastic solids in which the independent constitutive variables are the deformation gradient, the second-order displacement gradient, microdeformation tensor, and microdeformation gradient. Then, we present the linearized theory and establish a uniqueness result with no definiteness assumption on the elastic coefficients. The theory is used to obtain the basic eqations of a grade consistent theory of microstretch elastic bodies. The field equations for an isotropic and homogeneous elastic body are presented. A counterpart of the Cauchy-Kowalevski-Somigliana solution of the classical elastodynamics is established.

Iesan, D. [Department of Mathematics, 'Al.I. Cuza' University, and 'O. Mayer' Institute of Mathematics, Romanian Academy, 700506 Iasi (Romania)

2011-02-10T23:59:59.000Z

104

Peeling from a patterned thin elastic film  

E-Print Network [OSTI]

Inspired by the observation that many naturally occurring adhesives arise as textured thin films, we consider the displacement controlled peeling of a flexible plate from an incision-patterned thin adhesive elastic layer. We find that crack initiation from an incision on the film occurs at a load much higher than that required to propagate it on a smooth adhesive surface; multiple incisions thus cause the crack to propagate intermittently. Microscopically, this mode of crack initiation and propagation in geometrically confined thin adhesive films is related to the nucleation of cavitation bubbles behind the incision which must grow and coalesce before a viable crack propagates. Our theoretical analysis allows us to rationalize these experimental observations qualitatively and quantitatively and suggests a simple design criterion for increasing the interfacial fracture toughness of adhesive films.

A. Ghatak; L. Mahadevan; J. Y. Chung; M. K. Chaudhury; V. Shenoy

2004-04-29T23:59:59.000Z

105

Relativistic elasticity of rigid rods and strings  

E-Print Network [OSTI]

We show that the equation of motion for a rigid one-dimensional elastic body (i.e. a rod or string whose speed of sound is equal to the speed of light) in a two-dimensional spacetime is simply the wave equation. We then solve this equation in a few simple examples: a rigid rod colliding with an unmovable wall, a rigid rod being pushed by a constant force, a rigid string whose endpoints are simultaneously set in motion (seen as a special case of Bell's spaceships paradox), and a radial rigid string that has partially crossed the event horizon of a Schwarzschild black hole while still being held from the outside.

Jose Natario

2014-09-30T23:59:59.000Z

106

Nonlinear Elasticity of Flow-Stabilized Solids  

E-Print Network [OSTI]

Thermal fluctuations, geometric exclusion, and external driving all govern the mechanical response of dense particulate suspensions. Here, we measure the stress-strain response of quasi-two-dimensional flow-stabilized microsphere heaps in a regime in which all three effects are present using a microfluidic device. We observe that the elastic modulus and the mean interparticle separation of the heaps are tunable via the confining stress provided by the fluid flow. Furthermore, the measured stress-strain curves exhibit a universal nonlinear shape which can be predicted from a thermal van der Waals equation of state with excluded volume. This analysis indicates that many-body interactions contribute a significant fraction of the stress supported by the heap.

Carlos P. Ortiz; Karen E. Daniels; Robert Riehn

2014-07-20T23:59:59.000Z

107

Enhanced Elasticity and Soft Glassy Rheology of a Smectic in a Random Porous Environment  

E-Print Network [OSTI]

We report studies of the frequency dependent shear modulus, $G^*(\\omega)=G'(\\omega)+iG''(\\omega)$, of the liquid crystal octylcyanobiphenyl (8CB) confined in a colloidal aerosil gel. With the onset of smectic order, $G'$ grows approximately linearly with decreasing temperature, reaching values that exceed by more than three orders of magnitude the values for pure 8CB. The modulus at low temperatures possesses a power-law component, $G^*(\\omega) \\sim \\omega^\\alpha$, with exponent $\\alpha$ that approaches zero with increasing gel density. The amplitude of $G'$ and its variation with temperature and gel density indicate that the low temperature response is dominated by a dense population of defects in the smectic. In contrast, when the 8CB is isotropic or nematic, the modulus is controlled by the elastic behavior of the colloidal gel.

Ranjini Bandyopadhyay; Dennis Liang; Ralph H. Colby; James L. Harden; Robert L. Leheny

2005-02-18T23:59:59.000Z

108

Pump and probe waves in dynamic acousto-elasticity: Comprehensive description and comparison with nonlinear elastic theories  

E-Print Network [OSTI]

- static stress).1 For isotropic materials, the speed of sound change with stress levels allows onePump and probe waves in dynamic acousto-elasticity: Comprehensive description and comparison with nonlinear elastic theories J. Rivie`re,1,a) G. Renaud,2 R. A. Guyer,1,b) and P. A. Johnson1 1 Earth

109

Three-dimensional iso-geometric solutions to general boundary value problems of Toupin's gradient elasticity theory at finite strains  

E-Print Network [OSTI]

We present, to the best of our knowledge, the first complete three-dimensional numerical solutions to a broad range of boundary value problems for a general theory of finite strain gradient elasticity. We have chosen for our work, Toupin's theory [Arch. Rat. Mech. Anal., 11(1), 385-414, 1962]-one of the more general formulations of strain gradient elasticity. Our framework has three crucial ingredients: The first is iso-geometric analysis [Hughes et al., Comp. Meth. App. Mech. Engrg., 194(39-41), 4135-4195, 2005], which we have adopted for its straightforward and robust representation of C1-continuity. The second is a weak treatment of the higher-order Dirichlet boundary conditions in the formulation, which control the development of strain gradients in the solution. The third ingredient is algorithmic (automatic) differentiation, which eliminates the need for linearization "by hand" of the rather complicated geometric and material nonlinearities in gradient elasticity at finite strains. We present a number of numerical solutions to demonstrate that the framework is applicable to arbitrary boundary value problems in three dimensions. We discuss size effects, the role of higher-order boundary conditions, and perhaps most importantly, the relevance of the framework to problems with elastic free energy density functions that are non-convex in strain space.

Shiva Rudraraju; Anton van der Ven; Krishna Garikipati

2014-06-11T23:59:59.000Z

110

E-Print Network 3.0 - aero-elasticity rotor aerodynamics Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: HVDC 12;Rotor aero-elastics and structural dynamics 12;Aerodynamics for wind turbines Flow over... and components Rotor aero-elastics and structural dynamics Grid...

111

E-Print Network 3.0 - active site elasticity Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

; Engineering ; Materials Science 54 Analysis of the elastic behaviour of silica aerogels taken as a percolating system Summary: 289 Analysis of the elastic behaviour of...

112

Mechanical and Elastic Property Evaluation of n- and p-type Skutterudi...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Mechanical and Elastic Property Evaluation of n- and p-type Skutterudites Mechanical and Elastic Property Evaluation of n- and p-type Skutterudites This talk discusses the...

113

The influence of ambient medium density on laser ablation processes  

SciTech Connect (OSTI)

Interest in high flux transport processes has grown in recent years along with the ability and need to manipulate systems with microscopic length and time scales. These systems present unique engineering challenges. Because the time and length scales associated with these problems are very small, assumptions of local equilibrium, physical and mathematical smoothness of boundaries and the unambiguous definition of thermodynamic fields can not be automatically made, even though they may ultimately be acceptable. Furthermore, the observations are made on macroscopic or integrated scales. The large difference in scales between the temporal evolution of the process and the observation requires careful consideration of the claims made regarding the system`s microscopic, temporal behavior. In particular, consistency of a proposed model with observed results does not guarantee uniqueness, or predictive accuracy for the model. For these reasons, microscale heat transfer systems demand a careful consideration of the framework within which the experimentation and analysis are conducted.

Kilgo, M.M. III

1995-11-01T23:59:59.000Z

114

INFLUENCE OF ELEVATED OZONE AND CARBON DIOXIDE ON INSECT DENSITIES.  

SciTech Connect (OSTI)

The combustion of fossil fuels is profoundly altering the chemical composition of the atmosphere. Beginning with the Industrial Revolution, the concentration of carbon dioxide in the atmosphere has increased from approximately 280 to 370 {micro}l l{sup -1} in 2004, and it is expected to exceed 550 {micro}l l{sup -1} by 2050. Tropospheric ozone has risen even more rapidly than CO{sub 2} and average summer concentrations in the Northern Hemisphere are expected to continue to increase by 0.5-2.5% per year over the next 30 years. Although elevated CO{sub 2} stimulates photosynthesis and productivity of terrestrial ecosystems, ozone (O{sub 3}) is deleterious. In addition to directly affecting the physiology and productivity of crops, increased concentrations of tropospheric CO{sub 2} and O{sub 3} are predicted to lower the nutritional quality of leaves, which has the potential to increase herbivory as insects eat more to meet their nutritional demands. We tested the hypothesis that changes in tropospheric chemistry affect the relationship between plants and insect herbivores by changing leaf quality. The susceptibility to herbivory of soybean grown in elevated CO{sub 2} or O{sub 3} was examined using free air gas concentration enrichment (SoyFACE). FACE technology has the advantage that plants are cultivated under realistic field conditions with no unwanted alteration of microclimate or artificial constraints on the insect community.

DELUCIA, E.; DERMODY, O.; O'NEILL, B.; ALDEA, M.; HAMILTON, J.; ZANGERL, A.; ROGER, A.; BERENBAUM, M.

2005-01-05T23:59:59.000Z

115

Effect of elasticity of wall on diffusion in nano channel  

SciTech Connect (OSTI)

Confining walls of nano channel are taken to be elastic to study their effect on the diffusion coefficient of fluid flowing through the channel. The wall is elastic to the extent that it responses to molecular pressure exerted by fluid. The model to study diffusion is based on microscopic considerations. Results obtained for fluid confining to 20 atomic diameter width contrasted with results obtained by considering rigid and smooth wall. The effect of roughness of wall on diffusion can be compensated by the elastic property of wall.

Tankeshwar, K., E-mail: tankesh@pu.ac.in [Computer Centre, Panjab University Chandigarh,- 160014 (India); Srivastava, Sunita [Department of Physics, Panjab University, Chandigarh 160014 (India)

2014-04-24T23:59:59.000Z

116

Nuclear level density as a tool for probing the inelastic scattering of 6He  

E-Print Network [OSTI]

The cross sections are calculated for the both elastic and inelastic scattering of 6He from 12C and 4He. A phenomenological optical potential is used to describe the elastic scattering. 4He is taken as spherical and inelastic couplings to the first excited states of 6He and 12C are described with collective rotational model and coupled-channels method. Deformation lengths for 6He and 12C are determined from semi-classical nuclear level density model by using Laplace-like formula for the nuclear level density parameter. The comparison of the predicted and the measured cross sections are presented to test the applicability of nuclear level density model to the light exotic nuclei reactions. Good agreement is achieved between the predicted and measured cross sections.

Bora Canbula; Halil Babacan

2014-10-23T23:59:59.000Z

117

Degenerate weakly nonlinear elastic plane waves  

E-Print Network [OSTI]

Weakly nonlinear plane waves are considered in hyperelastic crystals. Evolution equations are derived at a quadratically nonlinear level for the amplitudes of quasi-longitudinal and quasi-transverse waves propagating in arbitrary anisotropic media. The form of the equations obtained depends upon the direction of propagation relative to the crystal axes. A single equation is found for all propagation directions for quasi-longitudinal waves, but a pair of coupled equations occurs for quasi-transverse waves propagating along directions of degeneracy, or acoustic axes. The coupled equations involve four material parameters but they simplify if the wave propagates along an axis of material symmetry. Thus, only two parameters arise for propagation along an axis of two-fold symmetry, and one for a three-fold axis. The transverse wave equations decouple if the axis is four-fold or higher. In the absence of a symmetry axis it is possible that the evolution equations of the quasi-transverse waves decouple if the third order elastic moduli satisfy a certain identity. The theoretical results are illustrated with explicit examples.

W?odzimierz Doma?ski; Andrew N. Norris

2008-12-18T23:59:59.000Z

118

Atomistic force field for alumina fit to density functional theory  

SciTech Connect (OSTI)

We present a force field for bulk alumina (Al{sub 2}O{sub 3}), which has been parametrized by fitting the energies, forces, and stresses of a large database of reference configurations to those calculated with density functional theory (DFT). We use a functional form that is simpler and computationally more efficient than some existing models of alumina parametrized by a similar technique. Nevertheless, we demonstrate an accuracy of our potential that is comparable to those existing models and to DFT. We present calculations of crystal structures and energies, elastic constants, phonon spectra, thermal expansion, and point defect formation energies.

Sarsam, Joanne [Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom) [Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom); Thomas Young Centre, Imperial College London, London SW7 2AZ (United Kingdom); Finnis, Michael W.; Tangney, Paul, E-mail: p.tangney@imperial.ac.uk [Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom) [Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom); Thomas Young Centre, Imperial College London, London SW7 2AZ (United Kingdom); Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom)

2013-11-28T23:59:59.000Z

119

Direct Measurement of the Surface Tension of a Soft Elastic Hydrogel: Exploration of Elasto-Capillary Instability in Adhesion  

E-Print Network [OSTI]

An adhesively stressed thin film of a soft hydrogel confined between two rigid flat substrates auto-roughens with its dominant wavelength exhibiting pronounced dependence on the film thickness (H). A linear stability analysis confirmed that this long wavelength instability (~7H) is due to an elasto-capillary effect, the implementation of which required direct measurements of the surface tension and the elasticity of the gel. The surface tension of the gel was estimated from the fundamental spherical harmonic of a hemispherical cap of the gel that was excited by an external noise. The shear modulus of the gel was determined from its resonant shear mode in a confined geometry. During the course of this study, it was found that a high density steel ball submerges itself inside the gel by balancing its excess weight with the accumulated strain induced elastic force that allows another estimation of its elastic modulus. The large ratio (1.8 mm) of the surface tension to its elasticity ascertains the role of elasto-capillarity in the adhesion induced pattern formation with such gels. Experimental results are in accord with a linear stability analysis that predicts that the rescaled wavelength is linear with H, which modifies the conventional stress to pull-off a rigid flat object from a very soft film by a multiplicative factor. The analysis also suggests some new results related to the role of the finite dilation of a material in interfacial pattern formation that may have non-trivial consequences in the adhesive delamination of very thin and/or soft elastic films via self-generated cracks.

Aditi Chakrabarti; Manoj K. Chaudhury

2014-01-28T23:59:59.000Z

120

Preconditioning for the mixed formulation of linear plane elasticity  

E-Print Network [OSTI]

. An overlapping Schwarz preconditioner and a multigrid preconditioner for the discrete system are developed and analyzed. We start by introducing the mixed formulation (stress-displacement formulation) for the linear plane elasticity problem and its discretization...

Wang, Yanqiu

2005-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Addiction to car use and dynamic elasticity measures in France  

E-Print Network [OSTI]

mileage travelled by French households with their personal cars, defining their automobility. To feature-price and income elasticities of household automobility, for both the short and the long runs. Keywords

Boyer, Edmond

122

Kinematic quantities of finite elastic and plastic deformation  

E-Print Network [OSTI]

Kinematic quantities for finite elastic and plastic deformations are defined via an approach that does not rely on auxiliary elements like reference frame and reference configuration, and that gives account of the inertial-noninertial aspects explicitly. These features are achieved by working on Galilean spacetime directly. The quantity expressing elastic deformations is introduced according to its expected role: to measure how different the current metric is from the relaxed/stressless metric. Further, the plastic kinematic quantity is the change rate of the stressless metric. The properties of both are analyzed, and their relationship to frequently used elastic and plastic kinematic quantities is discussed. One important result is that no objective elastic or plastic quantities can be defined from deformation gradient.

T. Fülöp; P. Ván

2012-03-05T23:59:59.000Z

123

Instrumentation for multiaxial mechanical testing of inhomogeneous elastic membranes  

E-Print Network [OSTI]

This thesis presents the design, development, and construction of an instrument for biaxial mechanical testing of inhomogeneous elastic membranes. The instrument incorporates an arrangement of linear motion stages for ...

Herrmann, Ariel Marc

2006-01-01T23:59:59.000Z

124

Elastic constants of single crystal Hastelloy X at elevated temperatures  

SciTech Connect (OSTI)

An acoustic time of flight technique is described in detail for measuring the elastic constants of cubic single crystals that allows for the constants to be determined at elevated temperature. Although the overall technique is not new, various aspects of the present work may prove extremely useful to others interested in finding these values, especially for aerospace materials applications. Elastic constants were determined for the nickel based alloy, Hastelloy X from room temperature to 1,000 C. Accurate elastic constants were needed as part of an effort to predict both polycrystal mechanical properties and the nature of grain induced heterogeneous mechanical response. The increased accuracy of the acoustically determined constants resulted in up to a 15% change in the predicted stresses in individual grains. These results indicate that the use of elastic single crystal constants of pure nickel as an approximation for the constants of gas turbine single crystal alloys, which is often done today, is inaccurate.

Canistraro, H.A. [Univ. of Hartford, CT (United States). Dept. of Mechanical and Audio Engineering Technology; Jordan, E.H.; Shi Shixiang [Univ. of Connecticut, Storrs, CT (United States); Favrow, L.H.; Reed, F.A. [United Technologies Research Center, East Hartford, CT (United States)

1998-07-01T23:59:59.000Z

125

Between Architecture and Science: Elasticity and Networks | ornl...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Between Architecture and Science: Elasticity and Networks Feb 09 2015 11:00 AM - 12:00 PM Jenny Sabin, Cornell University, Ithaca, New York Environmental Sciences Division Seminar...

126

Determination of Elastic Twist in Horizontal Axis Wind Turbines (HAWTs)  

SciTech Connect (OSTI)

This report presents the results of a project at the Alternative Energy Institute (AEI) which measured and calculated the elastic twist of three representative composite horizontal-axis blades: Carter 300, Gougeon ESI 54, and UTRC 8 kW.

Stoddard, F.; Nelson, V.; Starcher, K.; Andrews, B.

2006-06-01T23:59:59.000Z

127

Density Matrix Topological Insulators  

E-Print Network [OSTI]

Thermal noise can destroy topological insulators (TI). However we demonstrate how TIs can be made stable in dissipative systems. To that aim, we introduce the notion of band Liouvillian as the dissipative counterpart of band Hamiltonian, and show a method to evaluate the topological order of its steady state. This is based on a generalization of the Chern number valid for general mixed states (referred to as density matrix Chern value), which witnesses topological order in a system coupled to external noise. Additionally, we study its relation with the electrical conductivity at finite temperature, which is not a topological property. Nonetheless, the density matrix Chern value represents the part of the conductivity which is topological due to the presence of quantum mixed edge states at finite temperature. To make our formalism concrete, we apply these concepts to the two-dimensional Haldane model in the presence of thermal dissipation, but our results hold for arbitrary dimensions and density matrices.

A. Rivas; O. Viyuela; M. A. Martin-Delgado

2013-10-31T23:59:59.000Z

128

Elastic energy of proteins and the stages of protein folding  

E-Print Network [OSTI]

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

2010-01-01T23:59:59.000Z

129

Exploiting Covariate Similarity in Sparse Regression via the Pairwise Elastic Net  

E-Print Network [OSTI]

, the Elastic Net can yield a sparse esti- mate with more than n non-zero weights (Efron et al., 2004). One canExploiting Covariate Similarity in Sparse Regression via the Pairwise Elastic Net Alexander Lorbert- tion called the Pairwise Elastic Net is pro- posed. Like the Elastic Net, it simultane- ously performs

Blei, David M.

130

Exploiting Covariate Similarity in Sparse Regression via the Pairwise Elastic Net  

E-Print Network [OSTI]

. Furthermore, un- like the Lasso, the Elastic Net can yield a sparse esti- mate with more than n non-zero477 Exploiting Covariate Similarity in Sparse Regression via the Pairwise Elastic Net Alexander to regression regulariza- tion called the Pairwise Elastic Net is pro- posed. Like the Elastic Net, it simultane

Low, Steven H.

131

Density Functional Theory for Superconductors  

E-Print Network [OSTI]

Density Functional Theory for Superconductors LATHIOTAKIS, A. MARQUES, 1,2,3 LU DERS, L. FAST, 2004 words: theory superconductors; density functional theory; critical temperature; exchange matter physics theoretical chemistry is density functional theory (DFT). foundations were established mid

Gross, E.K.U.

132

The influence of ankle-foot orthosis stiffness on walking performance in individuals with lower-limb impairments  

E-Print Network [OSTI]

The influence of ankle-foot orthosis stiffness on walking performance in individuals with lower sintering Stiffness Background: Passive-dynamic ankle-foot orthoses utilize stiffness to improve gait performance through elastic energy storage and return. However, the influence of ankle-foot orthosis stiffness

133

The influence of ankle-foot orthosis stiffness on walking performance in individuals with lower-limb impairments  

E-Print Network [OSTI]

The influence of ankle-foot orthosis stiffness on walking performance in individuals with lower-dynamic ankle-foot orthoses utilize stiffness to improve gait performance through elastic energy storage and return. However, the influence of ankle-foot orthosis stiffness on gait performance has not been

134

Nucleon and $?$ elastic and transition form factors  

E-Print Network [OSTI]

We compute nucleon and Delta elastic and transition form factors, and compare predictions made using a framework built upon a Faddeev equation kernel and interaction vertices that possess QCD-like momentum dependence with results obtained using a vector-vector contact-interaction. The comparison emphasises that experiment is sensitive to the momentum dependence of the running couplings and masses in the strong interaction sector of the Standard Model and highlights that the key to describing hadron properties is a veracious expression of dynamical chiral symmetry breaking in the bound-state problem. Amongst the results we describe, the following are of particular interest: $G_E^p(Q^2)/G_M^p(Q^2)$ possesses a zero at $Q^2=9.5GeV^2$; any change in the interaction which shifts a zero in the proton ratio to larger $Q^2$ relocates a zero in $G_E^n(Q^2)/G_M^n(Q^2)$ to smaller $Q^2$; and there is likely a value of momentum transfer above which $G_E^n>G_E^p$. Regarding the $\\Delta(1232)$-baryon, we find that, inter alia: the electric monopole form factor exhibits a zero; the electric quadrupole form factor is negative, large in magnitude, and sensitive to the nature and strength of correlations in the $\\Delta(1232)$ Faddeev amplitude; and the magnetic octupole form factor is negative so long as rest-frame P- and D-wave correlations are included. In connection with the N-to-Delta transition, the momentum-dependence of the magnetic transition form factor, $G_M^\\ast$, matches that of $G_M^n$ once the momentum transfer is high enough to pierce the meson-cloud; and the electric quadrupole ratio is a keen measure of diquark and orbital angular momentum correlations.

Jorge Segovia; Ian C. Cloet; Craig D. Roberts; Sebastian M. Schmidt

2014-09-03T23:59:59.000Z

135

Multiple density layered insulator  

DOE Patents [OSTI]

A multiple density layered insulator for use with a laser is disclosed which provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation. 4 figs.

Alger, T.W.

1994-09-06T23:59:59.000Z

136

Multiple density layered insulator  

DOE Patents [OSTI]

A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

Alger, Terry W. (Tracy, CA)

1994-01-01T23:59:59.000Z

137

Energy in density gradient  

E-Print Network [OSTI]

Inhomogeneous plasmas and fluids contain energy stored in inhomogeneity and they naturally tend to relax into lower energy states by developing instabilities or by diffusion. But the actual amount of energy in such inhomogeneities has remained unknown. In the present work the amount of energy stored in a density gradient is calculated for several specific density profiles in a cylindric configuration. This is of practical importance for drift wave instability in various plasmas, and in particular in its application in models dealing with the heating of solar corona because the instability is accompanied with stochastic heating, so the energy contained in inhomogeneity is effectively transformed into heat. It is shown that even for a rather moderate increase of the density at the axis in magnetic structures in the corona by a factor 1.5 or 3, the amount of excess energy per unit volume stored in such a density gradient becomes several orders of magnitude greater than the amount of total energy losses per unit ...

Vranjes, J

2015-01-01T23:59:59.000Z

138

Beyond mean-field study of elastic and inelastic electron scattering off nuclei  

E-Print Network [OSTI]

Electron scattering provides a powerful tool to determine charge distributions and transition densities of nuclei. This tool will soon be available for short-lived neutron-rich nuclei. [Purpose] Beyond mean-field methods have been successfully applied to the study of excitation spectra of nuclei in the whole nuclear chart. These methods permit to determine energies and transition probabilities starting from an effective in-medium nucleon-nucleon interaction but without other phenomenological ingredients. Such a method has recently been extended to calculate the charge density of nuclei deformed at the mean-field level of approximation [J. M. Yao et al., Phys. Rev. C86, 014310 (2012)]. The aim of this work is to further extend the method to the determination of transition densities between low-lying excited states. [Method] The starting point of our method is a set of Hartree-Fock-Bogoliubov wave functions generated with a constraint on the axial quadrupole moment and using a Skyrme energy density functional. Correlations beyond the mean field are introduced by projecting mean-field wave functions on angular-momentum and particle number and by mixing the symmetry restored wave functions.[Results] We give in this paper detailed formulae derived for the calculation of densities and form factors. These formulae are rather easy to obtain when both initial and final states are $0^+$ states but are far from being trivial when one of the states has a finite $J$-value. Illustrative applications to $^{24}$Mg and to the even-mass $^{58-68}$Ni have permitted to analyse the main features of our method, in particular the effect of deformation on densities and form factors. An illustration calculation of both elastic and inelastic scattering form factors is presented....

J. M. Yao; M. Bender; P. -H. Heenen

2015-01-21T23:59:59.000Z

139

Calculations of single crystal elastic constants for yttria partially stabilised zirconia from powder diffraction data  

SciTech Connect (OSTI)

Yttria Stabilised Zirconia (YSZ) is a tough, phase-transforming ceramic that finds use in a wide range of commercial applications from dental prostheses to thermal barrier coatings. Micromechanical modelling of phase transformation can deliver reliable predictions in terms of the influence of temperature and stress. However, models must rely on the accurate knowledge of single crystal elastic stiffness constants. Some techniques for elastic stiffness determination are well-established. The most popular of these involve exploiting frequency shifts and phase velocities of acoustic waves. However, the application of these techniques to YSZ can be problematic due to the micro-twinning observed in larger crystals. Here, we propose an alternative approach based on selective elastic strain sampling (e.g., by diffraction) of grain ensembles sharing certain orientation, and the prediction of the same quantities by polycrystalline modelling, for example, the Reuss or Voigt average. The inverse problem arises consisting of adjusting the single crystal stiffness matrix to match the polycrystal predictions to observations. In the present model-matching study, we sought to determine the single crystal stiffness matrix of tetragonal YSZ using the results of time-of-flight neutron diffraction obtained from an in situ compression experiment and Finite Element modelling of the deformation of polycrystalline tetragonal YSZ. The best match between the model predictions and observations was obtained for the optimized stiffness values of C11?=?451, C33?=?302, C44?=?39, C66?=?82, C12?=?240, and C13?=?50 (units: GPa). Considering the significant amount of scatter in the published literature data, our result appears reasonably consistent.

Lunt, A. J. G., E-mail: alexander.lunt@eng.ox.ac.uk; Xie, M. Y.; Baimpas, N.; Korsunsky, A. M. [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom); Zhang, S. Y.; Kabra, S.; Kelleher, J. [ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell, Oxford OX11 0QX (United Kingdom); Neo, T. K. [Specialist Dental Group, Mount Elizabeth Orchard, 3 Mount Elizabeth, #08-03/08-08/08-10, Singapore 228510 (Singapore)

2014-08-07T23:59:59.000Z

140

10.1177/0092070304267108 ARTICLEJOURNAL OF THE ACADEMY OF MARKETING SCIENCE WINTER 2005Fibich et al. / PRICE ELASTICITY OF DEMAND The Dynamics of Price Elasticity  

E-Print Network [OSTI]

. / PRICE ELASTICITY OF DEMAND The Dynamics of Price Elasticity of Demand in the Presence of Reference Price derive an expression for the price elasticity of demand in the presence of reference price effects. The effectof reference price is most noticeable immediately after a price change, before consumers have had

Fibich, Gadi

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Gedanken densities and exact constraints in density functional theory  

SciTech Connect (OSTI)

Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherical two-electron gedanken density in which the dimensionless density gradient can be an arbitrary positive constant wherever the density is non-zero. The Lieb-Oxford lower bound on the exchange energy can be satisfied within a generalized gradient approximation (GGA) by bounding its enhancement factor or simplest GGA exchange-energy density. This enhancement-factor bound is well known to be sufficient, but our gedanken density shows that it is also necessary. The conventional exact exchange-energy density satisfies no such local bound, but energy densities are not unique, and the simplest GGA exchange-energy density is not an approximation to it. We further derive a strongly and optimally tightened bound on the exchange enhancement factor of a two-electron density, which is satisfied by the local density approximation but is violated by all published GGA's or meta-GGA’s. Finally, some consequences of the non-uniform density-scaling behavior for the asymptotics of the exchange enhancement factor of a GGA or meta-GGA are given.

Perdew, John P. [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States) [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 (United States); Ruzsinszky, Adrienn; Sun, Jianwei [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States)] [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Burke, Kieron [Department of Chemistry and Department of Physics, University of California, Irvine, California 92697 (United States)] [Department of Chemistry and Department of Physics, University of California, Irvine, California 92697 (United States)

2014-05-14T23:59:59.000Z

142

Price-elastic demand in deregulated electricity markets  

SciTech Connect (OSTI)

The degree to which any deregulated market functions efficiently often depends on the ability of market agents to respond quickly to fluctuating conditions. Many restructured electricity markets, however, experience high prices caused by supply shortages and little demand-side response. We examine the implications for market operations when a risk-averse retailer's end-use consumers are allowed to perceive real-time variations in the electricity spot price. Using a market-equilibrium model, we find that price elasticity both increases the retailers revenue risk exposure and decreases the spot price. Since the latter induces the retailer to reduce forward electricity purchases, while the former has the opposite effect, the overall impact of price responsive demand on the relative magnitudes of its risk exposure and end-user price elasticity. Nevertheless, price elasticity decreases cumulative electricity consumption. By extending the analysis to allow for early settlement of demand, we find that forward stage end-user price responsiveness decreases the electricity forward price relative to the case with price-elastic demand only in real time. Moreover, we find that only if forward stage end-user demand is price elastic will the equilibrium electricity forward price be reduced.

Siddiqui, Afzal S.

2003-05-01T23:59:59.000Z

143

High elastic modulus polymer electrolytes suitable for preventing thermal runaway in lithium batteries  

DOE Patents [OSTI]

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. In another aspect, the electrolyte exhibits a conductivity drop when the temperature of electrolyte increases over a threshold temperature, thereby providing a shutoff mechanism for preventing thermal runaway in lithium battery cells.

Mullin, Scott; Panday, Ashoutosh; Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel

2014-04-22T23:59:59.000Z

144

Determination of elastic properties of a film-substrate system by using the neural networks  

SciTech Connect (OSTI)

An inverse method based on artificial neural network (ANN) is presented to determine the elastic properties of films from laser-genrated surface waves. The surface displacement responses are used as the inputs for the ANN model; the outputs of the ANN are the Young's modulus, density, Poisson's ratio, and thickness of the film. The finite element method is used to calculate the surface displacement responses in a film-substrate system. Levenberg Marquardt algorithm is used as numerical optimization to speed up the training process for the ANN model. In this method, the materials parameters are not recovered from the dispersion curves but rather directly from the transient surface displacement. We have also found that this procedure is very efficient for determining the materials parameters of layered systems.

Xu Baiqiang; Shen Zhonghua; Ni Xiaowu; Wang Jijun; Guan Jianfei; Lu Jian [Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094 (China); Faculty of Science, Jiangsu University, Zhenjiang 212013 (China); Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094 (China); Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094 (China); Faculty of Science, Jiangsu University, Zhenjiang 212013 (China); Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094 (China)

2004-12-20T23:59:59.000Z

145

Mode III interfacial crack in the presence of couple stress elastic materials  

E-Print Network [OSTI]

In this paper we are concerned with the problem of a crack lying at the interface between dissimilar materials with microstructure undergoing antiplane deformations. The micropolar behaviour of the materials is described by the theory of couple stress elasticity developed by Koiter (1964). This constitutive model includes the characteristic lengths in bending and torsion and thus it is able to account for the underlying microstructure of the two materials. We perform an asymptotic analysis to investigate the behaviour of the solution near the crack tip. It turns out that the stress singularity at the crack tip is strongly influenced by the microstructural parameters and it may or may not show oscillatory behaviour depending on the ratio between the characteristic lengths.

Andrea Piccolroaz; Gennady Mishuris; Enrico Radi

2011-04-02T23:59:59.000Z

146

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

E-Print Network [OSTI]

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

Meisam Asgari; Aisa Biria

2015-02-17T23:59:59.000Z

147

Spatial Distributions of Local Elastic Moduli Near the Jamming Transition  

E-Print Network [OSTI]

Recent progress in studies of the nanoscale mechanical responses in amorphous solids has highlighted a strong degree of heterogeneity in the elastic moduli of thermal glassy systems. In this contribution, using computer simulations, we study the elastic heterogeneities in athermal amorphous solids, composed of isotropic, static, sphere packings near the jamming transition. We employ techniques based on linear response theory which avoid the need to invoke any explicit deformation. Not only do we validate these procedures by reproducing established scaling laws for the global elastic moduli, but our technique reveals new power-law behaviors in the spatial fluctuations of the local moduli. The local moduli are randomly distributed in space, and are described by Gaussian probability distributions all the way down to the transition point. However, the moduli fluctuations grow as the jamming threshold is approached, through which we are able to identify a characteristic length scale, associated with the shear modulus heterogeneities.

Hideyuki Mizuno; Leonardo E. Silbert; Matthias Sperl

2015-04-10T23:59:59.000Z

148

Temperature relationship of the elastic constants of vanadium  

SciTech Connect (OSTI)

Information on the elastic constants of vanadium and their temperature relationship is limited and ambiguous. This article gives the values of these characteristics for VEL-2 electron beam remelted vanadium with a purity of about 99.8%. The elastic properties were measured in heating from 20 to 1600/sup 0/C in a vacuum. The relationship of the modulus of elasticity to temperature has two almost linear portions in the 20-300 and 300-1350/sup 0/C ranges and then a more intense reduction in it is observed. The shear modulus drops sharply starting with 800/sup 0/C and decreases to G = 36 kN/mm/sup 2/ at 1600/sup 0/C. Poisson's ratio has values close to 0.3. Its most significant increase starts with 1400/sup 0/C.e

Belousov, O.K.

1987-09-01T23:59:59.000Z

149

Impedance of rigid bodies in one-dimensional elastic collisions  

E-Print Network [OSTI]

In this work we study the problem of one-dimensional elastic collisions of billiard balls, considered as rigid bodies, in a framework very different from the classical one presented in text books. Implementing the notion of impedance matching as a way to understand eficiency of energy transmission in elastic collisions, we find a solution which frames the problem in terms of this conception. We show that the mass of the ball can be seen as a measure of its impedance and verify that the problem of maximum energy transfer in elastic collisions can be thought of as a problem of impedance matching between different media. This approach extends the concept of impedance, usually associated with oscillatory systems, to system of rigid bodies.

Santos, Janilo; Nelson, Osman Rosso

2012-01-01T23:59:59.000Z

150

Elastic and plastic properties of soils influencing the design of rigid pavements  

E-Print Network [OSTI]

B 1 ?? i t i J *>. . i - i ~ i ' - o D? e? .u c f.M fC L )^ - ; 4 '6 . CBBTB ? 3 1 J >4 * ' ? z . d . 4... s ? ? -W flj ? ? f t 3 f t ? c g ? S

Khuri, Fuad I.

1954-01-01T23:59:59.000Z

151

High Energy Density Capacitors  

SciTech Connect (OSTI)

BEEST Project: Recapping is developing a capacitor that could rival the energy storage potential and price of today’s best EV batteries. When power is needed, the capacitor rapidly releases its stored energy, similar to lightning being discharged from a cloud. Capacitors are an ideal substitute for batteries if their energy storage capacity can be improved. Recapping is addressing storage capacity by experimenting with the material that separates the positive and negative electrodes of its capacitors. These separators could significantly improve the energy density of electrochemical devices.

None

2010-07-01T23:59:59.000Z

152

Accurate hydrogen depth profiling by reflection elastic recoil detection analysis  

SciTech Connect (OSTI)

A technique to convert reflection elastic recoil detection analysis spectra to depth profiles, the channel-depth conversion, was introduced by Verda, et al [1]. But the channel-depth conversion does not correct for energy spread, the unwanted broadening in the energy of the spectra, which can lead to errors in depth profiling. A work in progress introduces a technique that corrects for energy spread in elastic recoil detection analysis spectra, the energy spread correction [2]. Together, the energy spread correction and the channel-depth conversion comprise an accurate and convenient hydrogen depth profiling method.

Verda, R. D. (Raymond D.); Tesmer, Joseph R.; Nastasi, Michael Anthony,; Bower, R. W. (Robert W.)

2001-01-01T23:59:59.000Z

153

Elastic anisotropy in multifilament Nb3Sn superconducting wires  

E-Print Network [OSTI]

The elastic anisotropy caused by the texture in the Nb3Sn filaments of PIT and RRP wires has been calculated by averaging the estimates of Voigt and Reuss, using published Nb3Sn single crystal elastic constants and the Nb3Sn grain orientation distribution determined in both wire types by Electron Backscatter Diffraction. At ambient temperature the calculated Nb3Sn E-moduli in axial direction in the PIT and the RRP wire are 130 GPa and 140 GPa, respectively. The calculated E-moduli are compared with tensile test results obtained for the corresponding wires and extracted filament bundles.

Scheuerlein, C; Alknes, P; Arnau, G; Bjoerstad, R; Bordini, B

2015-01-01T23:59:59.000Z

154

Low-energy elastic electron interactions with pyrimidine  

SciTech Connect (OSTI)

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)

2011-12-15T23:59:59.000Z

155

Gluon density in nuclei  

SciTech Connect (OSTI)

In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.

Ayala, A.L. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica][Pelotas Univ., RS (Brazil). Inst. de Fisica e Matematica; Ducati, M.B.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Levin, E.M. [Fermi National Accelerator Lab., Batavia, IL (United States)][Nuclear Physics Inst., St. Petersburg (Russian Federation)

1996-10-01T23:59:59.000Z

156

Low density microcellular foams  

DOE Patents [OSTI]

Disclosed is a process of producing microcellular from which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 .mu.m is produced. Also disclosed are the foams produced by the process.

LeMay, James D. (Castro Valley, CA)

1992-01-01T23:59:59.000Z

157

Low density microcellular foams  

DOE Patents [OSTI]

Disclosed is a process of producing microcellular foam which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 [mu]m is produced. Also disclosed are the foams produced by the process. 8 figures.

LeMay, J.D.

1991-11-19T23:59:59.000Z

158

Low density microcellular foams  

DOE Patents [OSTI]

Disclosed is a process of producing microcellular foam which comprises the steps of: (a) selecting a multifunctional epoxy oligomer resin; (b) mixing said epoxy resin with a non-reactive diluent to form a resin-diluent mixture; (c) forming a diluent containing cross-linked epoxy gel from said resin-diluent mixture; (d) replacing said diluent with a solvent therefore; (e) replacing said solvent with liquid carbon dioxide; and (f) vaporizing off said liquid carbon dioxide under supercritical conditions, whereby a foam having a density in the range of 35-150 mg/cc and cell diameters less than about 1 .mu.m is produced. Also disclosed are the foams produced by the process.

LeMay, James D. (Castro Valley, CA)

1991-01-01T23:59:59.000Z

159

Density constrained TDHF  

E-Print Network [OSTI]

In this manuscript we provide an outline of the numerical methods used in implementing the density constrained time-dependent Hartree-Fock (DC-TDHF) method and provide a few examples of its application to nuclear fusion. In this approach, dynamic microscopic calculations are carried out on a three-dimensional lattice and there are no adjustable parameters, the only input is the Skyrme effective NN interaction. After a review of the DC-TDHF theory and the numerical methods, we present results for heavy-ion potentials $V(R)$, coordinate-dependent mass parameters $M(R)$, and precompound excitation energies $E^{*}(R)$ for a variety of heavy-ion reactions. Using fusion barrier penetrabilities, we calculate total fusion cross sections $\\sigma(E_\\mathrm{c.m.})$ for reactions between both stable and neutron-rich nuclei. We also determine capture cross sections for hot fusion reactions leading to the formation of superheavy elements.

Oberacker, V E

2015-01-01T23:59:59.000Z

160

Nuclear Energy Density Optimization  

E-Print Network [OSTI]

We carry out state-of-the-art optimization of a nuclear energy density of Skyrme type in the framework of the Hartree-Fock-Bogoliubov (HFB) theory. The particle-hole and particle-particle channels are optimized simultaneously, and the experimental data set includes both spherical and deformed nuclei. The new model-based, derivative-free optimization algorithm used in this work has been found to be significantly better than standard optimization methods in terms of reliability, speed, accuracy, and precision. The resulting parameter set UNEDFpre results in good agreement with experimental masses, radii, and deformations and seems to be free of finite-size instabilities. An estimate of the reliability of the obtained parameterization is given, based on standard statistical methods. We discuss new physics insights offered by the advanced covariance analysis.

M. Kortelainen; T. Lesinski; J. Moré; W. Nazarewicz; J. Sarich; N. Schunck; M. V. Stoitsov; S. Wild

2010-05-27T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


161

SIMULATION TECHNIQUES IN HYPERSONIC LOW-DENSITY AEROTHERMODYNAMICS  

E-Print Network [OSTI]

SIMULATION TECHNIQUES IN HYPERSONIC LOW-DENSITY AEROTHERMODYNAMICS V. V. Riabov Rivier University, 420 South Main Street, Nashua, NH 03060, USA, vriabov@rivier.edu Hypersonic rarefied flows near-8] and hypersonic flights. The direct simulation Monte- Carlo (DSMC) method [9] is used to study the influence

Riabov, Vladimir V.

162

Elastic scattering at CERN collider energies and the Chou-Yang model  

SciTech Connect (OSTI)

The p-barp elastic scattering at ..sqrt..s-bar = 546 and 630 GeV is analyzed in the Chou-Yang model with Martin's real part in the elastic amplitude.

Bellandi F , J.; Brunetto, S.Q.; Covolan, R.J.M.; Menon, M.J.; Pimentel, B.M.; Padua, A.B.

1987-05-01T23:59:59.000Z

163

Analysis of Automobile Travel Demand Elasticities with Respect to Travel Cost  

E-Print Network [OSTI]

Analysis of Automobile Travel Demand Elasticities with Respect to Travel Cost Oak Ridge National relationships between automobile travel demand and cost to analyze the elasticities of the demand for personal

164

RIS-M-2586 ELASTIC-PLASTIC FRACTURE MECHANICS ANALYSIS OF A CT-SPECIMEN  

E-Print Network [OSTI]

RISÃ?-M-2586 ELASTIC-PLASTIC FRACTURE MECHANICS ANALYSIS OF A CT-SPECIMEN - A TWO-DIMENSIONAL APPROACH Gunner C. Larsen Abstract. This report documents the results obtained from an elastic-plastic

165

Elastic-plastic analysis of the transition divertor joint for high performance divertor target plate  

E-Print Network [OSTI]

locations of principal plastic strains in 3D warm and coldthe ARIES Team “Elastic-Plastic analysis of the transitionSAN DIEGO Elastic-Plastic Analysis of the Transition

Navaei, Dara

2011-01-01T23:59:59.000Z

166

E-Print Network 3.0 - anomalous quasi-elastic electron Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sample search results for: anomalous quasi-elastic electron Page: << < 1 2 3 4 5 > >> 1 Neutron scattering study of the quasi-elastic spectral width in CeMg, CeMg3 and NdMg3...

167

E-Print Network 3.0 - anisotropic elastic constants Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

"Extreme Poisson's Ratios and Related Elastic Crystal... , "Effect of Wave Action on a Pipe Buried in an Elastic Seabed," 1982, PhD. Bahir H. Eldiwany, "Shape... for Pressurized...

168

Drop Formation and Breakup of Low Viscosity Elastic Fluids: Effects of Molecular Weight and Concentration  

E-Print Network [OSTI]

The dynamics of drop formation and pinch-off have been investigated for a series of low viscosity elastic fluids possessing similar shear viscosities, but differing substantially in elastic properties. On initial approach ...

Tirtaatmadja, Viyada

2007-01-23T23:59:59.000Z

169

E-Print Network 3.0 - anomalous elastic softening Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ELASTIC ANOMALIES IN INTERMEDIATE VALENT TmxSe AND TmSel-yTey M. Celio, R. Monnier and P. Wachter Abstract... and the elastic constant c12 becomes negative. The first order...

170

Efficient control of series elastic actuators through the exploitation of resonant modes  

E-Print Network [OSTI]

This thesis explores the efficiency potential inherent to series elastic actuators during oscillatory tasks. Series elastic actuators have a spring intentionally placed at the actuator output that provides good force ...

Albert, Kevin B. (Kevin Bjorn)

2007-01-01T23:59:59.000Z

171

Bending Elasticity of Anti-Parallel b-Sheets Seungho Choe and Sean X. Sun  

E-Print Network [OSTI]

fluctuations of the structure at room temperature. By matching the probability distributions of elastic strainsBending Elasticity of Anti-Parallel b-Sheets Seungho Choe and Sean X. Sun Department of Mechanical

Sun, Sean

172

Density Functional Theory for Superconductors  

E-Print Network [OSTI]

Density Functional Theory for Superconductors N. N. LATHIOTAKIS,1,2 M. A. L. MARQUES,1,2,3 M. LU; density functional theory; critical temperature; exchange and correlation; phonon and theoretical chemistry is density functional theory (DFT). Its foundations were established in the mid-1960s

Gross, E.K.U.

173

Production of Z0 bosons in elastic and quasi-elastic ep collisions at HERA  

E-Print Network [OSTI]

The production of Z0 bosons in the reaction ep -> eZ0p*, where p* stands for a proton or a low-mass nucleon resonance, has been studied in ep collisions at HERA using the ZEUS detector. The analysis is based on a data sample collected between 1996 and 2007, amounting to 496 pb-1 of integrated luminosity. The Z0 was measured in the hadronic decay mode. The elasticity of the events was ensured by a cut on eta_max energy deposits in the calorimeter defined with respect to the proton beam direction. A signal was observed at the Z0 mass. The cross section of the reaction ep -> eZ0p* was measured to be sigma(ep -> eZ0p*) = 0.13 +/- 0.06 (stat.) +/- 0.01 (syst.) pb, in agreement with the Standard Model prediction of 0.16 pb. This is the first measurement of Z0 production in ep collisions.

ZEUS collaboration; H. Abramowicz; I. Abt; L. Adamczyk; M. Adamus; R. Aggarwal; S. Antonelli; P. Antonioli; A. Antonov; M. Arneodo; O. Arslan; V. Aushev; Y. Aushev; O. Bachynska; A. Bamberger; A. N. Barakbaev; G. Barbagli; G. Bari; F. Barreiro; N. Bartosik; D. Bartsch; M. Basile; O. Behnke; J. Behr; U. Behrens; L. Bellagamba; A. Bertolin; S. Bhadra; M. Bindi; C. Blohm; V. Bokhonov; T. Bo?d; K. Bondarenko; E. G. Boos; K. Borras; D. Boscherini; D. Bot; I. Brock; E. Brownson; R. Brugnera; N. Brümmer; A. Bruni; G. Bruni; B. Brzozowska; P. J. Bussey; B. Bylsma; A. Caldwell; M. Capua; R. Carlin; C. D. Catterall; S. Chekanov; J. Chwastowski; J. Ciborowski; R. Ciesielski; L. Cifarelli; F. Cindolo; A. Contin; A. M. Cooper-Sarkar; N. Coppola; M. Corradi; F. Corriveau; M. Costa; G. D'Agostini; F. Dal Corso; J. del Peso; R. K. Dementiev; S. De Pasquale; M. Derrick; R. C. E. Devenish; D. Dobur; B. A. Dolgoshein; G. Dolinska; A. T. Doyle; V. Drugakov; L. S. Durkin; S. Dusini; Y. Eisenberg; P. F. Ermolov; A. Eskreys; S. Fang; S. Fazio; J. Ferrando; M. I. Ferrero; J. Figiel; B. Foster; G. Gach; A. Galas; E. Gallo; A. Garfagnini; A. Geiser; I. Gialas; A. Gizhko; L. K. Gladilin; D. Gladkov; C. Glasman; O. Gogota; Yu. A. Golubkov; P. Göttlicher; I. Grabowska-Bo?d; J. Grebenyuk; I. Gregor; G. Grigorescu; G. Grzelak; O. Gueta; M. Guzik; C. Gwenlan; T. Haas; W. Hain; R. Hamatsu; J. C. Hart; H. Hartmann; G. Hartner; E. Hilger; D. Hochman; R. Hori; A. Hüttmann; Z. A. Ibrahim; Y. Iga; R. Ingbir; M. Ishitsuka; H. -P. Jakob; F. Januschek; T. W. Jones; M. Jüngst; I. Kadenko; B. Kahle; S. Kananov; T. Kanno; U. Karshon; F. Karstens; I. I. Katkov; M. Kaur; P. Kaur; A. Keramidas; L. A. Khein; J. Y. Kim; D. Kisielewska; S. Kitamura; R. Klanner; U. Klein; E. Koffeman; N. Kondrashova; O. Kononenko; P. Kooijman; Ie. Korol; I. A. Korzhavina; A. Kota?ski; U. Kötz; H. Kowalski; O. Kuprash; M. Kuze; A. Lee; B. B. Levchenko; A. Levy; V. Libov; S. Limentani; T. Y. Ling; M. Lisovyi; E. Lobodzinska; W. Lohmann; B. Löhr; E. Lohrmann; K. R. Long; A. Longhin; D. Lontkovskyi; O. Yu. Lukina; J. Maeda; S. Magill; I. Makarenko; J. Malka; R. Mankel; A. Margotti; G. Marini; J. F. Martin; A. Mastroberardino; M. C. K. Mattingly; I. -A. Melzer-Pellmann; S. Mergelmeyer; S. Miglioranzi; F. Mohamad Idris; V. Monaco; A. Montanari; J. D. Morris; K. Mujkic; B. Musgrave; K. Nagano; T. Namsoo; R. Nania; A. Nigro; Y. Ning; T. Nobe; D. Notz; R. J. Nowak; A. E. Nuncio-Quiroz; B. Y. Oh; N. Okazaki; K. Olkiewicz; Yu. Onishchuk; K. Papageorgiu; A. Parenti; E. Paul; J. M. Pawlak; B. Pawlik; P. G. Pelfer; A. Pellegrino; W. Perla?ski; H. Perrey; K. Piotrzkowski; P. Pluci?ski; N. S. Pokrovskiy; A. Polini; A. S. Proskuryakov; M. Przybycie?; A. Raval; D. D. Reeder; B. Reisert; Z. Ren; J. Repond; Y. D. Ri; A. Robertson; P. Roloff; I. Rubinsky; M. Ruspa; R. Sacchi; U. Samson; G. Sartorelli; A. A. Savin; D. H. Saxon; M. Schioppa; S. Schlenstedt; P. Schleper; W. B. Schmidke; U. Schneekloth; V. Schönberg; T. Schörner-Sadenius; J. Schwartz; F. Sciulli; L. M. Shcheglova; R. Shehzadi; S. Shimizu; I. Singh; I. O. Skillicorn; W. S?omi?ski; W. H. Smith; V. Sola; A. Solano; D. Son; V. Sosnovtsev; A. Spiridonov; H. Stadie; L. Stanco; N. Stefaniuk; A. Stern; T. P. Stewart; A. Stifutkin; P. Stopa; S. Suchkov; G. Susinno; L. Suszycki; J. Sztuk-Dambietz; D. Szuba; J. Szuba; A. D. Tapper; E. Tassi; J. Terrón; T. Theedt; H. Tiecke; K. Tokushuku; J. Tomaszewska; V. Trusov; T. Tsurugai; M. Turcato; O. Turkot; T. Tymieniecka; M. Vázquez; A. Verbytskyi; O. Viazlo; N. N. Vlasov; R. Walczak; W. A. T. Wan Abdullah; J. J. Whitmore; K. Wichmann; L. Wiggers; M. Wing; M. Wlasenko; G. Wolf; H. Wolfe; K. Wrona; A. G. Yagües-Molina; S. Yamada; Y. Yamazaki; R. Yoshida; C. Youngman; O. Zabiegalov; A. F. ?arnecki; L. Zawiejski; O. Zenaiev; W. Zeuner; B. O. Zhautykov; N. Zhmak; A. Zichichi; Z. Zolkapli; D. S. Zotkin

2012-10-19T23:59:59.000Z

174

Preconditioned Conjugate Gradient Methods for Three Dimensional Linear Elasticity  

E-Print Network [OSTI]

Preconditioned Conjugate Gradient Methods for Three Dimensional Linear Elasticity by John Kenneth. A brief review is also made of stopping criteria for conjugate gradient solvers. One method based and tested with poor results. iv #12;Contents 1 Introduction 1 1.1 Preconditioned Conjugate Gradient Methods

Waterloo, University of

175

Neutron-deuteron elastic scattering and three-nucleon force  

E-Print Network [OSTI]

The differential cross section for neutron-deuteron elastic scattering was measured at six angles over the center-of-mass angular range 65? - 1300? and incident neutron energies 140 - 240 MeV at the LANSCE/WNR facility of ...

Chtangeev, Maxim B

2005-01-01T23:59:59.000Z

176

Elastic membranes of close-packed nanoparticle arrays  

E-Print Network [OSTI]

,11 or comprising interpenetrating organic/inorganic networks12 , show enhanced strength and robustness that allow of the ligands or further embedding in polymer. To characterize the membranes we measured elastic properties properties9 . Thin- film membranes, with nanoparticles sandwiched into the centre of polymer multilayers10

Jaeger, Heinrich M.

177

Transient accumulation of elastic energy in proton translocating ATP synthase  

E-Print Network [OSTI]

Hypothesis Transient accumulation of elastic energy in proton translocating ATP synthase Dmitry A 12 March 1999 Abstract ATP synthase is conceived as a rotatory engine with two reversible drives that the hydrolysis of three molecules of ATP in FI drives the shaft over a full circle in three steps of 120³ each

Steinhoff, Heinz-Jürgen

178

np elastic spin transfer measurements at 788 MeV  

E-Print Network [OSTI]

We have measured the spin-transfer parameters K(LL), K(SL), K(LS), and K(SS) at 788 MeV from 47-degrees to 177-degrees c.m., and also uncovered a 10-16 % normalization discrepancy which affects all previous np elastic spin data from LAMPF. Results...

McNaughton, M. W.; Koch, K.; Supek, I.; Tanaka, N.; McNaughton, K. H.; Riley, P. J.; Ambrose, DA; Johnson, J. D.; Smith, A.; Glass, G.; Hiebert, John C.; Northcliffe, L. C.; Simon, A. J.; Adams, D. L.; Ransome, R. D.; Clayton, D. B.; Spinka, H. M.; Jepperson, R. H.; Tripard, G. E.

1991-01-01T23:59:59.000Z

179

Elastic modulus of viral nanotubes Zhibin Ge,2  

E-Print Network [OSTI]

TMV nano- tubes. The initial elastic response of TMV nanotubes can be described by finite. INTRODUCTION Tobacco mosaic virus TMV is a hollow tubular structure formed by the self-assembly of 2130 nano- particles because it combines high sensitivity in applying and measuring forces and high

Wu, Shin-Tson

180

Buckling-induced encapsulation of structured elastic shells under pressure  

E-Print Network [OSTI]

functional origami-like structures at the nano- and microscales (1­3), including encapsulation using hollow for dynamic actuation using a swelling-induced elastic instability (16). There are a few existing hollow shell example of a hollow shell structure satisfying geometric compatibility for gating holes. It enables

Reis, Pedro Miguel

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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Elasticity-aware Virtual Machine Placement for Cloud Datacenters  

E-Print Network [OSTI]

Elasticity-aware Virtual Machine Placement for Cloud Datacenters Kangkang Li, Jie Wu, and Adam computing, the cloud datacenter suffers from both limited resources and the variation of users' requests in datacenters, satisfying the VMs' requested resources of users is the primary objective, neglecting future

Wu, Jie

182

analysis elastic recoil: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

analysis elastic recoil First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Optimal foil shape for neutron...

183

Love wave propagation in layered magneto-electro-elastic structures  

E-Print Network [OSTI]

Love wave propagation in layered magneto-electro-elastic structures with initial stress J. Du, X that the initial stress has an important effect on the Love wave propagation in layered piezomagnetic at their interface. He concluded that shear surface waves propagate in the layer and attenuate along the thickness

Wang, Ji

184

Port and Modal Elasticity Study Robert C. Leachman  

E-Print Network [OSTI]

1 Port and Modal Elasticity Study Robert C. Leachman Dept. of Industrial Engineering and Operations is described. Imports are allocated to alternative ports and logistics channels so as to minimize total containers via truck or rail, and trans-loading in the hinterlands of the ports of entry from marine

California at Berkeley, University of

185

First-principles study of structural, electronic, vibrational, dielectric and elastic properties of tetragonal Ba{sub 2}YTaO{sub 6}  

SciTech Connect (OSTI)

We report first-principles study of structural, electronic, vibrational, dielectric, and elastic properties of Ba{sub 2}YTaO{sub 6}, a pinning material in high temperature superconductors (HTS), by using density functional theory. By using different exchange-correlation potentials, the accuracy of the calculated lattice constants of Ba{sub 2}YTaO{sub 6} has been achieved with GGA-RPBE, since many important physical quantities crucially depend on change in volume. We have calculated the electronic band structure dispersion, total and partial density of states to study the band gap origin and found that Ba{sub 2}YTaO{sub 6} is an insulator with a direct band gap of 3.50?eV. From Mulliken population and charge density studies, we conclude that Ba{sub 2}YTaO{sub 6} have a mixed ionic-covalent character. Moreover, the vibrational properties, born effective charges, and the dielectric permittivity tensor have been calculated using linear response method. Vibrational spectrum determined through our calculations agrees well with the observed Raman spectrum, and allows assignment of symmetry labels to modes. We perform a detailed analysis of the contribution of the various infrared-active modes to the static dielectric constant to explain its anisotropy, while electronic dielectric tensor of Ba{sub 2}YTaO{sub 6} is nearly isotropic, and found that static dielectric constant is in good agreement with experimental value. The six independent elastic constants were calculated and found that tetragonal Ba{sub 2}YTaO{sub 6} is mechanically stable. Other elastic properties, including bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and elastic anisotropy ratios are also investigated and found that Poisson's ratio and Young's modulus of Ba{sub 2}YTaO{sub 6} are similar to that of other pinning materials in HTS.

Ganeshraj, C.; Santhosh, P. N., E-mail: santhosh@physics.iitm.ac.in [Low Temperature Physics Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu (India)

2014-10-14T23:59:59.000Z

186

Elastic nucleon-nucleus scattering as a direct probe of correlations beyond the independent-particle model  

E-Print Network [OSTI]

Employing a recently-developed dispersive optical model (DOM) which allows a complete description of experimental data both above (up to 200 MeV) and below the Fermi energy in $^{40}$Ca, we demonstrate that elastic nucleon-nucleus scattering data constrain the spectral strength in the continuum of orbits that are nominally bound in the independent-particle model. In the energy domain between 0 and 200 MeV, the integrated strength or depletion number is highly sensitive to the separation of the IPM orbit to the scattering continuum. This sensitivity is determined by the influence of the surface-absorption properties of the DOM self-energy. For an ab initio calculation employing the self-energy of the charge-dependent Bonn (CDBonn) interaction which only includes the effect of short-range correlations, no such sensitivity is obtained and a depletion of 4% is predicted between 0 and 200 MeV irrespective of the orbit. The ab initio spectral strength generated with the CDBonn interaction approaches the empirical DOM spectral strength at 200 MeV. Both spectral distributions allow for an additional 3-5% of the strength at even higher energies which is associated with the influence of short-range correlations. We suggest that the non-local form of the DOM allows for an analysis of elastic-nucleon-scattering data that directly determines the depletion of bound orbits. While obviously relevant for the analysis of elastic nucleon scattering on stable targets, this conclusion holds equally well for experiments involving rare isotopes in inverse kinematics as well as experiments with electrons on atoms or molecules.

H. Dussan; M. H. Mahzoon; R. J. Charity; W. H. Dickhoff; A. Polls

2014-10-09T23:59:59.000Z

187

Method of determining elastic and plastic mechanical properties of ceramic materials using spherical indenters  

DOE Patents [OSTI]

The invention pertains a method of determining elastic and plastic mechanical properties of ceramics, intermetallics, metals, plastics and other hard, brittle materials which fracture prior to plastically deforming when loads are applied. Elastic and plastic mechanical properties of ceramic materials are determined using spherical indenters. The method is most useful for measuring and calculating the plastic and elastic deformation of hard, brittle materials with low values of elastic modulus to hardness.

Adler, Thomas A. (Corvallis, OR)

1996-01-01T23:59:59.000Z

188

Dynamics of structures coupled with elastic media -a review of numerical models and methods  

E-Print Network [OSTI]

), the structure's environment is restricted here to a large and possibly unbounded visco-elastic medium. Under in the field of structure-environment interaction problems, in which the environment is an elastic body and vibration emitted by transportation systems and wave diffraction by obstacles in an elastic medium

Paris-Sud XI, Université de

189

Price elasticity reconsidered: Panel estimation of an agricultural water demand function  

E-Print Network [OSTI]

Price elasticity reconsidered: Panel estimation of an agricultural water demand function Karina, this paper estimates the price elasticity of irrigation water demand. Price elasticity is decomposed into the direct effect of water management and the indirect effect of water price on choice of output

Sadoulet, Elisabeth

190

ON THE DERIVATION OF NONLINEAR SHELL MODELS FROM THREE-DIMENSIONAL ELASTICITY  

E-Print Network [OSTI]

, 74G10, 74G65. Key words and phrases. Elasticity, shells, energy minimization, Koiter. hal-00392028ON THE DERIVATION OF NONLINEAR SHELL MODELS FROM THREE-DIMENSIONAL ELASTICITY Cristinel Mardare. A nonlinearly elastic shell is modeled either by the nonlinear three- dimensional shell model or by a nonlinear

191

Elasticity of hydrous wadsleyite to 12 GPa: Implications for Earth's transition zone  

E-Print Network [OSTI]

on elasticity of hydrous olivine polymorphs is necessary to model seismic wave speeds for potential hydrousElasticity of hydrous wadsleyite to 12 GPa: Implications for Earth's transition zone Z. Mao,1 S. D regions of the mantle. Here we report single-crystal elastic properties of wadsleyite, b-Mg2SiO4, with 0

Duffy, Thomas S.

192

High-throughput generation of hydrogel microbeads with varying elasticity for cell encapsulation  

E-Print Network [OSTI]

High-throughput generation of hydrogel microbeads with varying elasticity for cell encapsulation a microfluidic approach for high-throughput generation of 3D microenvironments with different elasticity for studies of cell fate. The generation of agarose microgels with different elastic moduli was achieved by (i

Zandstra, Peter W.

193

Elastic properties of transparent nano-polycrystalline diamond measured by GHz-ultrasonic interferometry and resonant  

E-Print Network [OSTI]

Elastic properties of transparent nano-polycrystalline diamond measured by GHz-ultrasonic interferometry Sphere resonance Nano-polycrystalline diamond NPD Elastic properties Superhard materials a b s t r a c t The sound velocities and elastic moduli of transparent nano-polycrystalline diamond (NPD) have

Jacobsen, Steven D.

194

Super-Elastic and Plastic Shock Waves Generated by Lasers N.A. Inogamov a,1  

E-Print Network [OSTI]

Super-Elastic and Plastic Shock Waves Generated by Lasers N.A. Inogamov a,1 , V.V. Zhakhovsky b,3 fortov@ihed.ras.ru, i oleynik@usf.edu Keywords: Femtosecond laser-matter interactions, elastic-plastic there is an elastic shock wave (SW), which propagates before the strong plastic shock with plastic pressures of up

Fominov, Yakov

195

FINITE-ELEMENT FORMULATIONS FOR PROBLEMS OF LARGE ELASTIC-PLASTIC DEFORMATION  

E-Print Network [OSTI]

FINITE-ELEMENT FORMULATIONS FOR PROBLEMS OF LARGE ELASTIC-PLASTIC DEFORMATION R. M. MCM~EKING and J elastic-plastic flow.The method is based on Hill's variational principle for incremental deformations in a manner which allows any conventions finite element program, for "small strain" elastic-plastic analysis

196

PLASTIC VERSUS ELASTIC DEFORMATION EFFECTS ON MAGNETIC BARKHAUSEN NOISE IN STEEL  

E-Print Network [OSTI]

PLASTIC VERSUS ELASTIC DEFORMATION EFFECTS ON MAGNETIC BARKHAUSEN NOISE IN STEEL C.-G. STEFANITA, D) AbstractÐA study was performed to dierentiate the eects of elastic and plastic deformation on magnetic samples subjected to varying degrees of uniaxial elastic and plastic deformation up to H40% strain

Clapham, Lynann

197

THE ELASTIC-PLASTIC MECHANICS OF CRACK EXTENSION James R. Rice*  

E-Print Network [OSTI]

THE ELASTIC-PLASTIC MECHANICS OF CRACK EXTENSION James R. Rice* ABSTRACT This paper briefly reviews progres~in the elastic plastic analysisof crack extension. Analytical results for plane strain and plane stress deformation fields are noted, and elastic-plastic fracture instability as well as transitional

198

A CAVITATION TRACKING METHOD FOR ELASTIC-PLASTIC FLOW IN SOLIDS  

E-Print Network [OSTI]

A CAVITATION TRACKING METHOD FOR ELASTIC-PLASTIC FLOW IN SOLIDS Keh-Ming Shyue Department tracking approach for the numerical simulation of one-dimensional elastic- plastic flow in solids, and the von Mises condition for the elastic-plastic phase change. To characterize the cavitation

Shyue, Keh-Ming

199

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

E-Print Network [OSTI]

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

Udgaonkar, Jayant B.

200

Porous Elasticity: Lectures on the elasticity of porous materials as an application of the theory of mixtures  

E-Print Network [OSTI]

of classical porous media models. Chapter 2 introduces the essentials of the theory of mixtures. Chapters 3,4 and 5 exploit the theory of mixtures to formulate various models of porous elastic materials. Chapter 6 is concerned with establishing connections...

Bowen, Ray M.

2014-01-22T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

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

E-Print Network [OSTI]

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

2015-02-09T23:59:59.000Z

202

Structural and elastic properties of a confined 2D colloidal solid: a molecular dynamics study  

E-Print Network [OSTI]

We implement molecular dynamics simulations in canonical ensemble to study the effect of confinement on a $2d$ crystal of point particles interacting with an inverse power law potential proportional to $r^{-12}$ in a narrow channel. This system can describe colloidal particles at the air-water interface. It is shown that the system characteristics depend sensitively on the boundary conditions at the two {\\it walls} providing the confinement. The walls exert perpendicular forces on their adjacent particles. The potential between walls and particles varies as the inverse power of ten. Structural quantities such as density profile, structure factor and orientational order parameter are computed. It is shown that orientational order persists near the walls even at temperatures where the system in the bulk is in fluid state. The dependence of elastic constants, stress tensor elements, shear and bulk modulii on density as well as the channel width is discussed. Moreover, the effect of channel incommensurability with the triangular lattice structure is discussed. It is shown that incommensurability notably affects the system properties. We compare our findings to those obtained by Monte Carlo simulations and also to the case with the periodic boundary condition along the channel width. .

M. Ebrahim Foulaadvand; Neda Ojaghlou

2014-09-27T23:59:59.000Z

203

A novel method to determine the elastic modulus of thin films using a travelling interference pattern  

SciTech Connect (OSTI)

Recently picosecond techniques have been used to generate surface acoustic waves (SAW) with wavelengths of a few microns. Previously generation of short SAW wavelengths required a laser pulse duration shorter than the transit time of the acoustic wave as it traverses the spatial pattern produced by the laser and a thermal relaxation time much faster than the acoustic time constant. In this paper we wish to report an investigation using spatially and temporally modulated light beams using long lasers pulses as a means to generate short acoustic wavelengths. Such a method may be useful in measuring the elastic modulus of thin films. The experiment that is being conducted utilizes two laser beams, one at frequency, vo, and the other at a shifted frequency, vo-v{prime}, to form a traveling interference pattern. The method of generating these frequencies will be described. By adjusting the angle between the two laser beams, the surface wave speed of an arbitrary material used for a thin film can be selectively matched. Using a YAG laser at 1064 rim to create the moving gratings, surface acoustic wavelengths of 1-3 microns may be generated in a variety of materials. The penetration depth of the acoustic wave is approximately the wavelength itself, thus, this method is well suited for characterizing thin films. For multiple thin film layers of different materials, SAW can be selectively produced in any layer of interest provided the top layers are transparent enough to allow the laser energy to be deposited on the intended layer. The presence of these modulated surface waves is detected by a He-Ne laser using light scattering. From the measured surface acoustic wave velocity, Poisson`s ratio, and the specimen density, the elastic modulus may be calculated. Measurements in progress will be reported for a variety of materials.

Amimoto, S.T.; Chang, D.J. [Aerospace Corporation, Los Angeles, CA (United States)

1995-12-31T23:59:59.000Z

204

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

SciTech Connect (OSTI)

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

Donegan, Sean; Rolett, Anthony

2013-12-31T23:59:59.000Z

205

Probing the density dependence of symmetry energy at subsaturation density with HICs  

E-Print Network [OSTI]

The reaction mechanism of the central collisions and peripheral collisions for $^{112,124}Sn+^{112,124}Sn$ at $E/A=50MeV$ is investigated within the framework of the Improved Quantum Molecular Dynamics model. The results show that multifragmentation process is an important mechanism at this energy region, and the influence of the cluster emission on the double n/p ratios and the isospin transport ratio are important. Furthermore, three observables, double n/p ratios, isospin diffusion and the rapidity distribution of the ratio $R_{7}$ for $^{112,124}Sn+^{112,124}Sn$ at E/A=50MeV are analyzed with the Improved Quantum Molecular Dynamics model. The results show that these three observables are sensitive to the density dependence of the symmetry energy. By comparing the calculation results to the data, the consistent constraint on the density dependence of the symmetry energy from these three observables is obtained.

Zhang, Yingxun; Li, Zhuxia; Danielewicz, P; Lynch, W G; Lu, Xiaohua

2009-01-01T23:59:59.000Z

206

Probing the density dependence of symmetry energy at subsaturation density with HICs  

E-Print Network [OSTI]

The reaction mechanism of the central collisions and peripheral collisions for $^{112,124}Sn+^{112,124}Sn$ at $E/A=50MeV$ is investigated within the framework of the Improved Quantum Molecular Dynamics model. The results show that multifragmentation process is an important mechanism at this energy region, and the influence of the cluster emission on the double n/p ratios and the isospin transport ratio are important. Furthermore, three observables, double n/p ratios, isospin diffusion and the rapidity distribution of the ratio $R_{7}$ for $^{112,124}Sn+^{112,124}Sn$ at E/A=50MeV are analyzed with the Improved Quantum Molecular Dynamics model. The results show that these three observables are sensitive to the density dependence of the symmetry energy. By comparing the calculation results to the data, the consistent constraint on the density dependence of the symmetry energy from these three observables is obtained.

Yingxun Zhang; M. B. Tsang; Zhuxia Li; P. Danielewicz; W. G. Lynch; Xiaohua Lu

2009-11-09T23:59:59.000Z

207

Canonical density matrix perturbation theory  

E-Print Network [OSTI]

Density matrix perturbation theory [Niklasson and Challacombe, Phys. Rev. Lett. 92, 193001 (2004)] is generalized to canonical (NVT) free energy ensembles in tight-binding, Hartree-Fock or Kohn-Sham density functional theory. The canonical density matrix perturbation theory can be used to calculate temperature dependent response properties from the coupled perturbed self-consistent field equations as in density functional perturbation theory. The method is well suited to take advantage of sparse matrix algebra to achieve linear scaling complexity in the computational cost as a function of system size for sufficiently large non-metallic materials and metals at high temperatures.

Niklasson, Anders M N; Rubensson, Emanuel H; Rudberg, Elias

2015-01-01T23:59:59.000Z

208

Generation of Gaussian Density Fields  

E-Print Network [OSTI]

This document describes analytical and numerical techniques for the generation of Gaussian density fields, which represent cosmological density perturbations. The mathematical techniques involved in the generation of density harmonics in k-space, the filtering of the density fields, and the normalization of the power spectrum to the measured temperature fluctuations of the Cosmic Microwave Background, are presented in details. These techniques are well-known amongst experts, but the current literature lacks a formal description. I hope that this technical report will prove useful to new researchers moving into this field, sparing them the task of reinventing the wheel.

Hugo Martel

2005-07-15T23:59:59.000Z

209

Surface tension and contact with soft elastic solids  

E-Print Network [OSTI]

Johnson-Kendall-Robert (JKR) theory is the basis of modern contact mechanics. It describes how two deformable objects adhere together, driven by adhesion energy and opposed by elasticity. However, it does not include solid surface tension, which also opposes adhesion by acting to flatten the surface of soft solids. We tested JKR theory to see if solid surface tension affects indentation behaviour. Using confocal microscopy, we characterised the indentation of glass particles into soft, silicone substrates. While JKR theory held for particles larger than a critical, elastocapillary lengthscale, it failed for smaller particles. Instead, adhesion of small particles mimicked the adsorption of particles at a fluid interface, with a size-independent contact angle between the undeformed surface and the particle given by a generalised version of Young's law. A simple theory quantitatively captures this behaviour, and explains how solid surface tension dominates elasticity for small-scale indentation of soft materials.

Robert W. Style; Callen Hyland; Rostislav Boltyanskiy; John S. Wettlaufer; Eric R. Dufresne

2013-10-11T23:59:59.000Z

210

Heat transfer between elastic solids with randomly rough surfaces  

E-Print Network [OSTI]

We study the heat transfer between elastic solids with randomly rough surfaces. We include both the heat transfer from the area of real contact, and the heat transfer between the surfaces in the noncontact regions. We apply a recently developed contact mechanics theory, which accounts for the hierarchical nature of the contact between solids with roughness on many different length scales. For elastic contact, at the highest (atomic) resolution the area of real contact typically consists of atomic (nanometer) sized regions, and we discuss the implications of this for the heat transfer. For solids with very smooth surfaces, as is typical in many modern engineering applications, the interfacial separation in the non-contact regions will be very small, and for this case we show the importance of the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies.

B. N. J. Persson; B. Lorenz; A. I. Volokitin

2009-08-27T23:59:59.000Z

211

Acoustic excitations and elastic heterogeneities in disordered solids  

E-Print Network [OSTI]

In the recent years, much attention has been devoted to the inhomogeneous nature of the mechanical response at the nano-scale in disordered solids. Clearly, the elastic heterogeneities that have been characterized in this context are expected to strongly impact the nature of the sound waves which, in contrast to the case of perfect crystals, cannot be completely rationalized in terms of phonons. Building on previous work on a toy model showing an amorphisation transition [Mizuno H, Mossa S, Barrat JL (2013) EPL {\\bf 104}:56001], we investigate the relationship between sound waves and elastic heterogeneities in a unified framework, by continuously interpolating from the perfect crystal, through increasingly defective phases, to fully developed glasses. We provide strong evidence of a direct correlation between sound waves features and the extent of the heterogeneous mechanical response at the nano-scale.

Hideyuki Mizuno; Stefano Mossa; Jean-Louis Barrat

2014-03-26T23:59:59.000Z

212

Density Functional Theory (DFT) Simulated Annealing (SA)  

E-Print Network [OSTI]

. . . . . . . . 9 2009 #12;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory) % Lattice-Boltzmann (LBM) #12;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory (DFT;! " # $ % & - " # $ %' ! " # # $ % & # ( # " ) Density Functional Theory (DFT) Simulated Annealing (SA) Monte Carlo &$ ' ' (GCMC

213

Rayleigh scattering and nonlinear inversion of elastic waves  

SciTech Connect (OSTI)

Rayleigh scattering of elastic waves by an inclusion is investigated and the limitations determined. In the near field of the inhomogeneity, the scattered waves are up to a factor of 300 stronger than in the far field, excluding the application of the far field Rayleigh approximation for this range. The investigation of the relative error as a function of parameter perturbation shows a range of applicability broader than previously assumed, with errors of 37% and 17% for perturbations of {minus}100% and +100%, respectively. The validity range for the Rayleigh limit is controlled by large inequalities, and therefore, the exact limit is determined as a function of various parameter configurations, resulting in surprisingly high values of up to k{sub p}R = 0.9. The nonlinear scattering problem can be solved by inverting for equivalent source terms (moments) of the scatterer, before the elastic parameters are determined. The nonlinear dependence between the moments and the elastic parameters reveals a strong asymmetry around the origin, which will produce different results for weak scattering approximations depending on the sign of the anomaly. Numerical modeling of cross hole situations shows that near field terms are important to yield correct estimates of the inhomogeneities in the vicinity of the receivers, while a few well positioned sources and receivers considerably increase the angular coverage, and thus the model resolution of the inversion parameters. The pattern of scattered energy by an inhomogeneity is complicated and varies depending on the object, the wavelength of the incident wave, and the elastic parameters involved. Therefore, it is necessary to investigate the direction of scattered amplitudes to determine the best survey geometry.

Gritto, R.

1995-12-01T23:59:59.000Z

214

Polarization effects in elastic proton-electron scattering  

SciTech Connect (OSTI)

The experimental observables for the elastic reaction induced by protons scattering from electrons are calculated in the Born approximation. The differential cross section and polarization observables have been derived assuming one-photon exchange. Numerical estimates are given for spin correlation coefficients, polarization transfer coefficients, and depolarization coefficients in a wide kinematical range. Specific attention is given to the kinematical conditions; that is, to the specific range of incident energy and transferred momentum.

Gakh, G. I. [National Science Centre 'Kharkov Institute of Physics and Technology,' 61108 Akademicheskaya 1, Kharkov (Ukraine); Dbeyssi, A.; Marchand, D.; Tomasi-Gustafsson, E. [CNRS/IN2P3, Institut de Physique Nucleaire, UMR 8608, F-91405 Orsay (France); Bytev, V. V. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

2011-07-15T23:59:59.000Z

215

Elastic Coulomb-levitation: why is ice so slippery?  

E-Print Network [OSTI]

The elastic, less dense, polarized, and thermally stable supersolid skin lubricates ice. Molecular undercoordination shortens the H-O bond and lengthens the O:H nonbond through O-O repulsion, which is associated with low-frequency and high-magnitude of O:H vibration and a dual O-O polarization. The softer O:H springs attached with stronger molecular dipoles provide forces levitating objects sliding on ice, like Maglev or Hovercraft.

Chang Q. Sun

2015-02-14T23:59:59.000Z

216

Microscopic analysis of $^{10,11}$Be elastic scattering on protons and nuclei and breakup processes of $^{11}$Be within the $^{10}$Be+$n$ cluster model  

E-Print Network [OSTI]

The density distributions of $^{10}$Be and $^{11}$Be nuclei obtained within the quantum Monte Carlo (QMC) model and the generator coordinate method (GCM) are used to calculate the microscopic optical potentials (OPs) and cross sections of elastic scattering of these nuclei on protons and $^{12}$C at energies $Ewell known energy dependence of the volume integrals is used as a physical constraint to resolve the ambiguities of the parameter values. The role of the spin-orbit potential and the surface contribution to the OP is studied for an adequate description of available experimental elastic scattering cross section data. Also, the cluster model, in which $^{11}$Be consists of a $n$-halo and the $^{10}$Be core, is adopted. Within the latter, the breakup cross sections of $^{11}$Be nucleus on $^{9}$Be, $^{93}$Nb, $^{181}$Ta, and $^{238}$U targets and momentum distributions of $^{10}$Be fragments are calculated and compared with the existing experimental data.

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

2015-02-23T23:59:59.000Z

217

Quantization of Perturbations in an Inflating Elastic Solid  

E-Print Network [OSTI]

A sufficiently rigid relativistic elastic solid can be stable for negative pressure values and thus is capable of driving a stage of accelerated expansion. If a relativistic elastic solid drove an inflationary stage in the early Universe, quantum mechanically excited perturbations would arise in the medium. We quantize the linear scalar and tensor perturbations and investigate the observational consequences of having such an inflationary period. We find that slowly varying sound speeds of the perturbations and a slowing varying equation of state of the solid can produce a slightly red-tilted scalar power spectrum that agrees with current observational data. Even in the absence of nonadiabatic pressures, perturbations evolve on superhorizon scales, due to the shear stresses within the solid. As such, the spectra of perturbations are in general sensitive to the details of the end of inflation and we characterize this dependence. Interestingly, we uncover here accelerating solutions for elastic solids with (1 + P/\\rho) significantly greater than 0 that nevertheless have nearly scale-invariant scalar and tensor spectra. Beyond theoretical interest, this may allow for the possibility of viable inflationary phenomenology relatively far from the de Sitter regime.

Michael Sitwell; Kris Sigurdson

2014-07-01T23:59:59.000Z

218

Production and perception of vowels: does the density of the system play a role?  

E-Print Network [OSTI]

Production and perception of vowels: does the density of the system play a role? Christine Meunier system seems to influence vowel perception but not vowel production. 1. INTRODUCTION Each language has with a dense vocalic system? Moreover, is the phonetic production of a vowel affected by the density

Paris-Sud XI, Université de

219

Transverse Beam Spin Asymmetries at Backward Angles in Elastic Electron-Proton and Quasi-elastic Electron-Deuteron Scattering  

E-Print Network [OSTI]

We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (piN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasi-static deuterium approximation, and is also in agreement with theory.

The G0 Collaboration; D. Androi?; D. S. Armstrong; J. Arvieux; S. L. Bailey; D. H. Beck; E. J. Beise; J. Benesch; F. Benmokhtar; L. Bimbot; J. Birchall; P. Bosted; H. Breuer; C. L. Capuano; Y. -C. Chao; A. Coppens; C. A. Davis; C. Ellis; G. Flores; G. Franklin; C. Furget; D. Gaskell; M. T. W. Gericke; J. Grames; G. Guillard; J. Hansknecht; T. Horn; M. K. Jones; P. M. King; W. Korsch; S. Kox; L. Lee; J. Liu; A. Lung; J. Mammei; J. W. Martin; R. D. McKeown; A. Micherdzinska; M. Mihovilovic; H. Mkrtchyan; M. Muether; S. A. Page; V. Papavassiliou; S. F. Pate; 10 S. K. Phillips; P. Pillot; M. L. Pitt; M. Poelker; B. Quinn; W. D. Ramsay; J. -S. Real; J. Roche; P. Roos; J. Schaub; T. Seva; N. Simicevic; G. R. Smith; D. T. Spayde; M. Stutzman; R. Suleiman; V. Tadevosyan; W. T. H. van Oers; M. Versteegen; E. Voutier; W. Vulcan; S. P. Wells; S. E. Williamson; S. A. Wood; B. Pasquini; M. Vanderhaeghen

2011-06-16T23:59:59.000Z

220

Detecting Density Variations and Nanovoids  

SciTech Connect (OSTI)

A combination of simulated and experimental data has been used to investigate the size range of nanovoids that can be detected in atom probe tomography data. Simulated atom probe tomography data have revealed that nanovoids as small as 1 nm in diameter can be detected in atom probe tomography data with the use of iso-density surfaces. Iso-density surfaces may be used to quantify the size, morphology and number density of nanovoids and other variations in density in atom probe tomography data. Experimental data from an aluminum-yttrium-iron metallic glass ribbon have revealed the effectiveness of this approach. Combining iso-density surfaces with atom maps also permits the segregation of solute to the nanovoids to be investigated. Field ion microscopy and thin section atom maps have also been used to detect pores and larger voids.

Miller, Michael K [ORNL; Longstreth-Spoor, L. [Washington University, St. Louis; Kelton, K. F. [Washington University, St. Louis

2011-01-01T23:59:59.000Z

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221

Energy density fluctuations in early universe  

SciTech Connect (OSTI)

The primordial nucleosinthesys of the element can be influenced by the transitions of phase that take place after the Big Bang, such as the QCD transition. In order to study the effect of this phase transition, in this work we compute the time evolution of thermodynamical quantities of the early universe, focusing on temperature and energy density fluctuations, by solving the relevant equations of motion using as input the lattice QCD equation of state to describe the strongly interacting matter in the early universe plasma. We also study the effect of a primordial strong magnetic field by means of a phenomenological equation of state. Our results show that small inhomogeneities of strongly interacting matter in the early Universe are moderately damped during the crossover.

Guardo, G. L.; Ruggieri, M. [Department of Physics and Astronomy, University of Catania, Catania (Italy); Greco, V. [Department of Physics and Astronomy, University of Catania, Catania, Italy and INFN - Laboratori Nazionali del Sud, Catania (Italy)

2014-05-09T23:59:59.000Z

222

Density and pair-density scaling for deriving the Euler equation in density-functional and pair-density-functional theory  

SciTech Connect (OSTI)

A link between density and pair density functional theories is presented. Density and pair density scaling are used to derive the Euler equation in both theories. Density scaling provides a constructive way of obtaining approximations for the Pauli potential. The Pauli potential (energy) of the density functional theory is expressed as the difference of the scaled and original exchange-correlation potentials (energies).

Nagy, A. [Department of Theoretical Physics, University of Debrecen, H-4010 Debrecen (Hungary)

2011-09-15T23:59:59.000Z

223

Phenomenological Relativistic Energy Density Functionals  

SciTech Connect (OSTI)

The framework of relativistic nuclear energy density functionals is applied to the description of a variety of nuclear structure phenomena, not only in spherical and deformed nuclei along the valley of beta-stability, but also in exotic systems with extreme isospin values and close to the particle drip-lines. Dynamical aspects of exotic nuclear structure is explored using the fully consistent quasiparticle random-phase approximation based on the relativistic Hartree-Bogoliubov model. Recent applications of energy density functionals with explicit density dependence of the meson-nucleon couplings are presented.

Lalazissis, G. A.; Kartzikos, S. [Physics Department, Aristotle University of Thessaloniki (Greece); Niksic, T.; Paar, N.; Vretenar, D. [Physics Department, University of Zagreb (Croatia); Ring, P. [Physics Department, TU Muenchen, Garching (Germany)

2009-08-26T23:59:59.000Z

224

Longitudinal density monitor for the LHC  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The longitudinal density monitor (LDM) is primarily intended for the measurement of the particle population in nominally empty rf buckets. These so-called satellite or ghost bunches can cause problems for machine protection as well as influencing the luminosity calibration of the LHC. The high dynamic range of the system allows measurement of ghost bunches with as little as 0.01% of the main bunch population at the same time as characterization of the main bunches. The LDM is a single-photon counting system using visible synchrotron light. The photon detector is a silicon avalanche photodiode operated in Geiger mode, which allows the longitudinal distribution of the LHC beams to be measured with a resolution of 90 ps. Results from the LDM are presented, including a proposed method for constructing a 3-dimensional beam density map by scanning the LDM sensor in the transverse plane. In addition, we present a scheme to improve the sensitivity of the system by using an optical switching technique.

Jeff, A.; Andersen, M.; Boccardi, A.; Bozyigit, S.; Bravin, E.; Lefevre, T.; Rabiller, A.; Roncarolo, F.; Welsch, C. P.; Fisher, A. S.

2012-03-01T23:59:59.000Z

225

Determination of elastic properties of a MnO{sub 2} coating by surface acoustic wave velocity dispersion analysis  

SciTech Connect (OSTI)

MnO{sub 2} is a material of interest in the development of high energy-density batteries, specifically as a coating material for internal 3D structures, thus ensuring rapid energy deployment. Its electrochemical properties have been mapped extensively, but there are, to the best of the authors' knowledge, no records of the elastic properties of thin film MnO{sub 2}. Impulsive stimulated thermal scattering (ISTS), also known as the heterodyne diffraction or transient grating technique, was used to determine the Young's modulus (E) and porosity (?) of a 500?nm thick MnO{sub 2} coating on a Si(001) substrate. ISTS is an all optical method that is able to excite and detect surface acoustic waves (SAWs) on opaque samples. From the measured SAW velocity dispersion, the Young's modulus and porosity were determined to be E?=?25?±?1?GPa and ?=42±1%, respectively. These values were confirmed by independent techniques and determined by a most-squares analysis of the carefully fitted SAW velocity dispersion. This study demonstrates the ability of the presented technique to determine the elastic parameters of a thin, porous film on an anisotropic substrate.

Sermeus, J.; Glorieux, C., E-mail: christ.glorieux@fys.kuleuven.be [Laboratory for Acoustics and Thermal Physics, KU Leuven, University of Leuven, Celestijnenlaan 200D, B-3001 Heverlee (Belgium); Sinha, R.; Vereecken, P. M. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Center for Surface Chemistry and Catalysis, KU Leuven, University of Leuven, Kasteelpark Arenberg 23, B-3001 Leuven (Belgium); Vanstreels, K. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)

2014-07-14T23:59:59.000Z

226

Elastically Cooperative Activated Barrier Hopping Theory of Relaxation in Viscous Fluids. I. General Formulation and Application to Hard Sphere Fluids  

E-Print Network [OSTI]

We generalize the force-level Nonlinear Langevin Equation theory of single particle hopping to include collective effects associated with long range elastic distortion of the liquid. The activated alpha relaxation event is of a mixed spatial character, involving two distinct, but inter-related, local and collective barriers. There are no divergences at volume fractions below jamming or temperatures above zero Kelvin. The ideas are first developed and implemented analytically and numerically in the context of hard sphere fluids. In an intermediate volume fraction crossover regime, the local cage process is dominant in a manner consistent with an apparent Arrhenius behavior. The super-Arrhenius collective barrier is more strongly dependent on volume fraction, dominates the highly viscous regime, and is well described by a nonsingular law below jamming. The increase of the collective barrier is determined by the amplitude of thermal density fluctuations, shear modulus or transient localization length, and a growing microscopic jump length. Alpha relaxation time calculations are in good agreement with recent experiments and simulations on dense fluids and suspensions of hard spheres. Comparisons of the theory with elastic models and entropy crisis ideas are explored. The present work provides a foundation for constructing a quasi-universal, fit-parameter-free theory for relaxation in thermal molecular liquids over 14 orders of magnitude in time.

Stephen Mirigian; Kenneth S. Schweizer

2014-02-20T23:59:59.000Z

227

Influence of the SiO{sub 2} interlayer thickness on the density and polarity of charges in Si/SiO{sub 2}/Al{sub 2}O{sub 3} stacks as studied by optical second-harmonic generation  

SciTech Connect (OSTI)

By accurately tuning the SiO{sub 2} interlayer thickness the density and polarity of charges in Si/SiO{sub 2}/Al{sub 2}O{sub 3} stacks can be controlled. We report on the number density, polarity, and physical location of charges present in the stacks as studied by optical second-harmonic generation (SHG). Depending on the SiO{sub 2} interlayer thickness (1–150?nm) the effective charge density in the Si/SiO{sub 2}/Al{sub 2}O{sub 3} stacks ranges from 10{sup 13} to 10{sup 11}?cm{sup ?2} for both n- and p-type silicon. The polarity of the charges switches from negative to positive around a SiO{sub 2} interlayer thickness of 5–10?nm at which point the effective charge density in the stacks is negligible. This switch in polarity is apparent from spectroscopic, time-dependent, and azimuthal SHG measurements. The observed trends in charge density and polarity can be explained by tunneling of electrons into defect states at the SiO{sub 2}/Al{sub 2}O{sub 3} interface as well as the presence of fixed and bulk charges at the Si/SiO{sub 2} interface and in the SiO{sub 2}, respectively. This charge mechanism appears to hold generally for Si/SiO{sub 2}/Al{sub 2}O{sub 3} stacks as similar results were observed for SiO{sub 2} films prepared by various techniques.

Terlinden, N. M.; Dingemans, G.; Vandalon, V.; Bosch, R. H. E. C.; Kessels, W. M. M., E-mail: w.m.m.kessels@tue.nl [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2014-01-21T23:59:59.000Z

228

Energy Dependence of the NN t-matrix in the Optical Potential for Elastic Nucleon-Nucleus Scattering  

E-Print Network [OSTI]

The influence of the energy dependence of the free NN t-matrix on the optical potential of nucleon-nucleus elastic scattering is investigated within the context of a full-folding model based on the impulse approximation. The treatment of the pole structure of the NN t-matrix, which has to be taken into account when integrating to negative energies is described in detail. We calculate proton-nucleus elastic scattering observables for $^{16}$O, $^{40}$Ca, and $^{208}$Pb between 65 and 200 MeV laboratory energy and study the effect of the energy dependence of the NN t-matrix. We compare this result with experiment and with calculations where the center-of-mass energy of the NN t-matrix is fixed at half the projectile energy. It is found that around 200 MeV the fixed energy approximation is a very good representation of the full calculation, however deviations occur when going to lower energies (65 MeV).

Ch. Elster; S. P. Weppner

1997-08-07T23:59:59.000Z

229

Elastic contribution to interaction of vortices in uniaxial superconductors  

SciTech Connect (OSTI)

The stress caused by vortices in tetragonal superconductors contributes to the intervortex interaction which depends on vortex orientation within the crystal, on elastic moduli, and is attractive within certain angular regions even in fields along the c crystal axis. For sufficiently strong stress dependence of the critical temperature, this contribution may result in distortions of the hexagonal vortex lattice for H||c. In small fields it leads to formation of a square vortex lattice with a fixed H independent spacing. This should be seen in the magnetization M(H) as a discontinuous jump of magnetization at the transition from the Meissner to mixed states.

Kogan, Vladimir [Ames Laboratory, DOE; Department of Physics, Iowa State University, Ames, Iowa

2013-10-24T23:59:59.000Z

230

An analytically solvable eigenvalue problem for the linear elasticity equations.  

SciTech Connect (OSTI)

Analytic solutions are useful for code verification. Structural vibration codes approximate solutions to the eigenvalue problem for the linear elasticity equations (Navier's equations). Unfortunately the verification method of 'manufactured solutions' does not apply to vibration problems. Verification books (for example [2]) tabulate a few of the lowest modes, but are not useful for computations of large numbers of modes. A closed form solution is presented here for all the eigenvalues and eigenfunctions for a cuboid solid with isotropic material properties. The boundary conditions correspond physically to a greased wall.

Day, David Minot; Romero, Louis Anthony

2004-07-01T23:59:59.000Z

231

Dirt Softens Soap: Anomalous Elasticity of Disordered Smectics  

E-Print Network [OSTI]

We show that a smectic in a disordered medium (e.g., aerogel) exhibits anomalous elasticity, with the compression modulus B(k) vanishing and the bend modulus K(k) diverging as k --> 0. In addition, the effective disorder develops long ranged correlations. These divergences are much stronger than those driven by thermal fluctuations in pure smectics, and are controlled by a zero temperature glassy fixed point, which we study in an $\\epsilon=5-d$ expansion. We discuss the experimental implications of these theoretical predictions.

Leo Radzihovsky; John Toner

1997-08-01T23:59:59.000Z

232

Current density partitioning in time-dependent current density functional theory  

SciTech Connect (OSTI)

We adapt time-dependent current density functional theory to allow for a fragment-based solution of the many-electron problem of molecules in the presence of time-dependent electric and magnetic fields. Regarding a molecule as a set of non-interacting subsystems that individually evolve under the influence of an auxiliary external electromagnetic vector-scalar potential pair, the partition 4-potential, we show that there are one-to-one mappings between this auxiliary potential, a sharply-defined set of fragment current densities, and the total current density of the system. The partition electromagnetic (EM) 4-potential is expressed in terms of the real EM 4-potential of the system and a gluing EM 4-potential that accounts for exchange-correlation effects and mutual interaction forces between fragments that are required to yield the correct electron dynamics. We prove the zero-force theorem for the fragmented system, establish a variational formulation in terms of action functionals, and provide a simple illustration for a charged particle in a ring.

Mosquera, Martín A. [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States)] [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States); Wasserman, Adam, E-mail: awasser@purdue.edu [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States) [Department of Chemistry, Purdue University, West Lafayette, Indiana 47907 (United States); Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States)

2014-05-14T23:59:59.000Z

233

Seismology of adolescent neutron stars: Accounting for thermal effects and crust elasticity  

E-Print Network [OSTI]

We study the oscillations of relativistic stars, incorporating key physics associated with internal composition, thermal gradients and crust elasticity. Our aim is to develop a formalism which is able to account for the state-of-the-art understanding of the complex physics associated with these systems. As a first step, we build models using a modern equation of state including composition gradients and density discontinuities associated with internal phase-transitions (like the crust-core transition and the point where muons first appear in the core). In order to understand the nature of the oscillation spectrum, we carry out cooling simulations to provide realistic snapshots of the temperature distribution in the interior as the star evolves through adolescence. The associated thermal pressure is incorporated in the perturbation analysis, and we discuss the presence of $g$-modes arising as a result of thermal effects. We also consider interface modes due to phase-transitions and the gradual formation of the star's crust and the emergence of a set of shear modes.

C. J. Krüger; W. C. G. Ho; N. Andersson

2014-08-20T23:59:59.000Z

234

E-Print Network 3.0 - approximately constrained elastic Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Programming for Autonomous Robots (SIMPAR 2010), Summary: Rob Series Elastic Robot Arm for Simulation and Control Thomas Lens, Jurgen Kunz, and Oskar von Stryk......

235

Tailoring Structure Property Relationships and Elastic Phenomenon in Native and Polymer Reinforced Silica Aerogels.  

E-Print Network [OSTI]

?? The focus of this work was to study the effects of flexible silica backbones on elastic properties of silica aerogels. Two routes were examined.… (more)

Randall, Jason P.

2010-01-01T23:59:59.000Z

236

Elastic Properties of Rolled Uranium -- 10 wt.% Molybdenum Nuclear Fuel Foils  

SciTech Connect (OSTI)

In situ neutron diffraction data was collected during elastic loading of rolled foils of uranium-10 wt.% molybdenum bonded to a thin layer of zirconium. Lattice parameters were ascertained from the diffraction patterns to determine the elastic strain and, subsequently, the elastic moduli and Poisson’s ratio in the rolling and transverse directions. The foil was found to be elastically isotropic in the rolling plane with an effective modulus of 86 + / - 3 GPa and a Poisson’s ratio 0.39 + / - 0.04.

D. W. Brown; D. J. Alexander; K. D. Clarke; B. Clausen; M. A. Okuniewski; T. A. Sisneros

2013-11-01T23:59:59.000Z

237

Goddard rattler-jamming mechanism for quantifying pressure dependence of elastic moduli of grain packs  

E-Print Network [OSTI]

Elastic properties of unconsolidated porous reservoirs.Seismic velocities of unconsolidated sands. Part 1. PressureP = P c ? P f . Unconsolidated sediments have distinct

Pride, Steven R.; Berryman, James G.

2009-01-01T23:59:59.000Z

238

Goddard rattler-jamming mechanism for quantifying pressure dependence of elastic moduli of grain packs  

E-Print Network [OSTI]

Elastic properties of unconsolidated porous reservoirs. Geo-and Berryman 1 Introduction Unconsolidated sediments form ansociety. Furthermore, unconsolidated ocean-bottom sediments

Pride, Steven R.

2009-01-01T23:59:59.000Z

239

Evidence of a Shift in the Short-Run Price Elasticity of Gasoline Demand  

E-Print Network [OSTI]

An Empirical-Analysis of Gasoline Demand in Denmark UsingT. (1991). "Analyzing Gasoline Demand Elasticities: AConsumer Adjustment to a Gasoline Tax." The Review of

Hughes, Jonathan; Knittel, Christopher R; Sperling, Dan

2007-01-01T23:59:59.000Z

240

E-Print Network 3.0 - angle elastic scattering Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Physics and Astronomy, Texas A&M University - Commerce Collection: Physics 17 Subcritical scattering from buried elastic shells Irena Lucifredi and Henrik Schmidt Summary:...

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

E-Print Network 3.0 - aging elastic material Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

a Summary: were water quenched. Aging treatments were carried out in a nitridenitrate salt bath. Elastic spring... ). It was also found that aging at lower temperatures after...

242

E-Print Network 3.0 - assess liver elasticity Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

fibrotic murine liver Stephanie L. Barnes Summary: modalities for possible elastogra- phy assessment. Given that the gel modulus is being used as the elastic... reference for...

243

Estimating Energy Efficiency Technology Adoption Curve Elasticity with Respect to Government and Utility Deployment Program Indicators  

E-Print Network [OSTI]

Energy Efficiency Technology Adoption Curve Elasticity withEnvironmental Energy Technologies Division Ernest OrlandoEnergy, Building Technologies Office under Contract no. DE-

Van Buskirk, Robert

2014-01-01T23:59:59.000Z

244

Effects of gaps in adhesives that bond elastically deformed panels to parabolic, cylindrical substructures  

SciTech Connect (OSTI)

In previous studies of the mechanical behavior of line focusing solar collectors, the reflective surface panel was modeled as a thin, initially flat, elastic plate that underwent large displacements to attain the shape of a prescribed parabolic cylinder. Attention was focused upon the stresses that developed in an adhesive layer which bonded the deformed panel to a rigid, parabolic substructure. Among the myriad possible collector designs, some possess longitudinally oriented, hollow ribs or corrugations in the substructure which interrupt the transverse continuity of the bond line between the deformed panel and the substructure. Thus, finite gaps in the adhesive are present which create regions where the panel surface becomes intermittently supported. The presence of these gaps perturbs the otherwise smooth distribution of adhesive contact stresses and it is the analytical modeling of this behavior that is the subject of the present report. In particular, attention is devoted to gaps which overlap with the edge effect zone - a region near the rim or vertex of the deformed panel where, in the absence of uniform edge loads necessary to maintain a true parabolic shape, high stresses and associated deformations occur. Significant influences of the gap size and position in the edge effect zone are demonstrated and discussed.

Wilson, R.K.; Reuter, R.C. Jr.

1982-03-01T23:59:59.000Z

245

First principle study of elastic and thermodynamic properties of ZrZn{sub 2} and HfZn{sub 2} under high pressure  

SciTech Connect (OSTI)

A comprehensive investigation of the structural, elastic, and thermodynamic properties for Laves-phases ZrZn{sub 2} and HfZn{sub 2} are conducted using density functional total energy calculations combined with the quasi-harmonic Debye model. The optimized lattice parameters of ZrZn{sub 2} and HfZn{sub 2} compare well with available experimental values. We estimated the mechanical behaviors of both compounds under compression, including mechanical stability, Young's modulus, Poisson's ratio, ductility, and anisotropy. Additionally, the thermodynamic properties as a function of pressure and temperature are analyzed and found to be in good agreement with the corresponding experimental data.

Sun, Na; Zhang, Xinyu, E-mail: jiaqianqin@gmail.com; Ning, Jinliang; Zhang, Suhong; Liang, Shunxing; Ma, Mingzhen; Liu, Riping [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Qin, Jiaqian, E-mail: jiaqianqin@gmail.com [Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok 10330 (Thailand)

2014-02-28T23:59:59.000Z

246

Electric field Induced Patterns in Soft Visco-elastic films: From Long Waves of Viscous Liquids to Short Waves of Elastic Solids  

E-Print Network [OSTI]

We show that the electric field driven surface instability of visco-elastic films has two distinct regimes: (1) The visco-elastic films behaving like a liquid display long wavelengths governed by applied voltage and surface tension, independent of its elastic storage and viscous loss moduli, and (2) the films behaving like a solid require a threshold voltage for the instability whose wavelength always scales as ~ 4 x film thickness, independent of its surface tension, applied voltage, loss and storage moduli. Wavelength in a narrow transition zone between these regimes depends on the storage modulus.

N. Arun; Ashutosh Sharma; Partho S. G. Pattader; Indrani Banerjee; Hemant M. Dixit; K. S. Narayan

2009-06-02T23:59:59.000Z

247

Effect of oxygen incorporation on the structure and elasticity of Ti-Al-O-N coatings synthesized by cathodic arc and high power pulsed magnetron sputtering  

SciTech Connect (OSTI)

Ti-Al-O-N coatings were synthesized by cathodic arc and high power pulsed magnetron sputtering. The chemical composition of the coatings was determined by means of elastic recoil detection analysis and energy dispersive X-ray spectroscopy. The effect of oxygen incorporation on the stress-free lattice parameters and Young's moduli of Ti-Al-O-N coatings was investigated by X-ray diffraction and nanoindentation, respectively. As nitrogen is substituted by oxygen, implications for the charge balance may be expected. A reduction in equilibrium volume with increasing O concentration is identified by X-ray diffraction and density functional theory calculations of Ti-Al-O-N supercells reveal the concomitant formation of metal vacancies. Hence, the oxygen incorporation-induced formation of metal vacancies enables charge balancing. Furthermore, nanoindentation experiments reveal a decrease in elastic modulus with increasing O concentration. Based on ab initio data, two causes can be identified for this: First, the metal vacancy-induced reduction in elasticity; and second, the formation of, compared to the corresponding metal nitride bonds, relatively weak Ti-O and Al-O bonds.

Hans, M., E-mail: hans@mch.rwth-aachen.de; Baben, M. to; Music, D.; Ebenhöch, J.; Schneider, J. M. [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Primetzhofer, D. [Department of Physics and Astronomy, Uppsala University, Lägerhyddsvägen 1, S-75120 Uppsala (Sweden); Kurapov, D.; Arndt, M.; Rudigier, H. [Oerlikon Balzers Coating AG, Iramali 18, LI-9496 Balzers, Principality of Liechtenstein (Liechtenstein)

2014-09-07T23:59:59.000Z

248

Radial elasticity of multi-walled boron nitride nanotubes  

SciTech Connect (OSTI)

We investigated the radial mechanical properties of multi-walled boron nitride nanotubes (MW-BNNTs) using atomic force microscopy. The employed MW-BNNTs were synthesized using pressurized vapor/condenser (PVC) methods and were dispersed in aqueous solution using ultrasonication methods with the aid of ionic surfactants. Our nanomechanical measurements reveal the elastic deformational behaviors of individual BNNTs with two to four tube walls in their transverse directions. Their effective radial elastic moduli were obtained through interpreting their measured radial deformation profiles using Hertzian contact mechanics models. Our results capture the dependences of the effective radial moduli of MW-BNNTs on both the tube outer diameter and the number of tube layers. The effective radial moduli of double-walled BNNTs are found to be several-fold higher than those of single-walled BNNTs within the same diameter range. Our work contributes directly to a complete understanding of the fundamental structural and mechanical properties of BNNTs and the pursuits of their novel structural and electronics applications.

Michael W. Smith, Cheol Park, Meng Zheng, Changhong Ke ,In-Tae Bae, Kevin Jordan

2012-02-01T23:59:59.000Z

249

Transport of organelles by elastically coupled motor proteins  

E-Print Network [OSTI]

Motor-driven intracellular transport is a complex phenomenon where multiple motor proteins attached to a cargo are simultaneously engaged in pulling activity, often leading to tug-of-war and bidirectional motion. However, most mathematical and computational models ignore the details of the motor-cargo interaction. A few papers have studied more realistic models of cargo transport by including elastic motor-cargo coupling, but either restricts the number of motors and/or uses purely phenomenological forms for energy-dependent hopping rates. Here, we study a generic Model In which N motors are elastically coupled to a cargo, which itself is subject to thermal noise in the cytoplasm and an additional external applied force. The motor-hopping rates are chosen to satisfy detailed balance with respect to the energy of stretching. The master equation is converted to a linear Fokker-Planck equation (LFPE), which yields the average positions of the cargo and motors, as well as their fluctuations and correlation functions. We apply this formalism to two specific forms of the hopping rates. Analytical results are obtained for mean cargo velocity, diffusion coefficient and the average force experienced by each motor for arbitrary N, and compared with numerical simulations. The expansion procedure also allows us to quantify load-sharing features among the cargo-bound motors. In general, we observe significant deviations between analytical predictions based on LFPE and the corresponding numerical results, which suggests a prominent role for higher order corrections.

Deepak Bhat; Manoj Gopalakrishnan

2014-12-17T23:59:59.000Z

250

The Elastic Basis for the Shape of Borrelia burgdorferi  

E-Print Network [OSTI]

ABSTRACT The mechanisms that determine bacterial shape are in many ways poorly understood. A prime example is the Lyme disease spirochete, Borrelia burgdorferi (B. burgdorferi), which mechanically couples its motility organelles, helical flagella, to its rod-shaped cell body, producing a striking flat-wave morphology. A mathematical model is developed here that accounts for the elastic coupling of the flagella to the cell cylinder and shows that the flat-wave morphology is in fact a natural consequence of the geometrical and material properties of the components. Observations of purified periplasmic flagella show two flagellar conformations. The mathematical model suggests that the larger waveform flagellum is the more relevant for determining the shape of B. burgdorferi. Optical trapping experiments were used to measure directly the mechanical properties of these spirochetes. These results imply relative stiffnesses of the two components, which confirm the predictions of the model and show that the morphology of B. burgdorferi is completely determined by the elastic properties of the flagella and cell body. This approach is applicable to a variety of other structures in which the shape of the composite system is markedly different from that of the individual components, such as coiled-coil domains in proteins and the eukaryotic axoneme.

Christopher Dombrowski; Wanxi Kan; Md. Abdul Motaleb; Nyles W. Charon; Raymond E. Goldstein; Charles W. Wolgemuth

2009-01-01T23:59:59.000Z

251

Connecting local active forces to macroscopic stress in elastic media  

E-Print Network [OSTI]

In contrast with ordinary materials, living matter drives its own motion by generating active, out-of-equilibrium internal stresses. These stresses typically originate from localized active elements embedded in an elastic medium, such as molecular motors inside the cell or contractile cells in a tissue. While many large-scale phenomenological theories of such active media have been developed, a systematic understanding of the emergence of stress from the local force-generating elements is lacking. In this paper, we present a rigorous theoretical framework to study this relationship. We show that the medium's macroscopic active stress tensor is equal to the active elements' force dipole tensor per unit volume in both continuum and discrete linear homogeneous media of arbitrary geometries. This relationship is conserved on average in the presence of disorder, but can be violated in nonlinear elastic media. Such effects can lead to either a reinforcement or an attenuation of the active stresses, giving us a glimpse of the ways in which nature might harness microscopic forces to create active materials.

Pierre Ronceray; Martin Lenz

2014-11-12T23:59:59.000Z

252

Stationary self-focusing of intense laser beam in cold quantum plasma using ramp density profile  

SciTech Connect (OSTI)

By using a transient density profile, we have demonstrated stationary self-focusing of an electromagnetic Gaussian beam in cold quantum plasma. The paper is devoted to the prospects of using upward increasing ramp density profile of an inhomogeneous nonlinear medium with quantum effects in self-focusing mechanism of high intense laser beam. We have found that the upward ramp density profile in addition to quantum effects causes much higher oscillation and better focusing of laser beam in cold quantum plasma in comparison to that in the classical relativistic case. Our computational results reveal the importance and influence of formation of electron density profiles in enhancing laser self-focusing.

Habibi, M. [Department of Physics, Shirvan Branch, Islamic Azad University, Shirvan (Iran, Islamic Republic of); Ghamari, F. [Department of Physics, Khorramabad Branch, Islamic Azad University, Khorramabad (Iran, Islamic Republic of)

2012-10-15T23:59:59.000Z

253

Kaon condensation in neutron stars and high density behaviour of nuclear symmetry energy  

E-Print Network [OSTI]

We study the influence of a high density behaviour of the nuclear symmetry energy on a kaon condensation in neutron stars. We find that the symmetry energy typical for several realistic nuclear potentials, which decreases at high densities, inhibits kaon condensation for weaker kaon-nucleon couplings. There exists a threshold coupling above which the kaon condensate forms at densities exceeding some critical value. This is in contrast to the case of rising symmetry energy, as e.g. for relativistic mean field models, when the kaon condensate can form for any coupling at a sufficiently high density. Properties of the condensate are also different in both cases.

S. Kubis; M. Kutschera

1999-07-24T23:59:59.000Z

254

A common supersolid low-density skin sliperizing ice and toughening water surface  

E-Print Network [OSTI]

Skins of water and ice share the same attribute of supersolidity characterized by the identical H-O vibration frequency of 3450 cm-1. Molecular undercoordination and inter-electron-pair repulsion shortens the H-O bond and lengthen the O:H nonbond, leading to a dual process of nonbonding electron polarization. This relaxation-polarization process enhances the dipole moment, elasticity,viscosity, thermal stability of these skins with 25% density loss, which is responsible for the hydrophobicity and toughness of water skin and for the slippery of ice.

Xi Zhang; Yongli Huang; Zengsheng Ma; Yichun Zhou; Weitao Zheng; Ji Zhou; Chang Q. Sun

2014-08-15T23:59:59.000Z

255

Intercrystalline density on nanocrystalline nickel  

SciTech Connect (OSTI)

Most methods currently available for the synthesis of nanostructured materials result in considerable residual porosity. Studies concerned with the novel structures and properties of these materials are thus compromised by the intrinsically high levels of porosity. As recently shown by Kristic et al., porosity can have a significant effect on fundamental materials properties such as Young`s modulus. One of the most promising techniques for the production of fully dense nanocrystalline materials is electrodeposition. In the present work, the residual porosity and density of nanostructured nickel produced by the electrodeposition method is assessed and discussed in light of the intrinsic intercrystalline density of nickel.

Haasz, T.R.; Aust, K.T. [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science] [Univ. of Toronto, Ontario (Canada). Dept. of Metallurgy and Materials Science; Palumbo, G. [Ontario Hydro Research Div., Toronto, Ontario (Canada)] [Ontario Hydro Research Div., Toronto, Ontario (Canada); El-Sherik, A.M.; Erb, U. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering] [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Materials and Metallurgical Engineering

1995-02-01T23:59:59.000Z

256

Time Dependent Density Functional Theory An introduction  

E-Print Network [OSTI]

Time Dependent Density Functional Theory An introduction Francesco Sottile LSI, Ecole Polytechnique (ETSF) Time Dependent Density Functional Theory Palaiseau, 7 February 2012 1 / 32 #12;Outline 1 Frontiers 4 Perspectives and Resources Francesco Sottile (ETSF) Time Dependent Density Functional Theory

Botti, Silvana

257

Time Dependent Density Functional Theory An Introduction  

E-Print Network [OSTI]

Time Dependent Density Functional Theory An Introduction Francesco Sottile Laboratoire des Solides) Belfast, 29 Jun 2007 Time Dependent Density Functional Theory Francesco Sottile #12;Intro Formalism Dependent Density Functional Theory Francesco Sottile #12;Intro Formalism Results Resources Outline 1

Botti, Silvana

258

Statistical density modification using local pattern matching  

DOE Patents [OSTI]

A computer implemented method modifies an experimental electron density map. A set of selected known experimental and model electron density maps is provided and standard templates of electron density are created from the selected experimental and model electron density maps by clustering and averaging values of electron density in a spherical region about each point in a grid that defines each selected known experimental and model electron density maps. Histograms are also created from the selected experimental and model electron density maps that relate the value of electron density at the center of each of the spherical regions to a correlation coefficient of a density surrounding each corresponding grid point in each one of the standard templates. The standard templates and the histograms are applied to grid points on the experimental electron density map to form new estimates of electron density at each grid point in the experimental electron density map.

Terwilliger, Thomas C.

2007-01-23T23:59:59.000Z

259

On the Symmetry of Energy Minimising Deformations in Nonlinear Elasticity II: Compressible Materials  

E-Print Network [OSTI]

On the Symmetry of Energy Minimising Deformations in Nonlinear Elasticity II: Compressible that has less elastic energy than the given deformation, provided that the stored-energy function, of radius R > 0, centred at the origin into another such sphere Sr = urad (SR) A that encloses the same

Sivaloganathan, J.

260

Elastic uplift in southeast Greenland due to rapid ice mass loss Shfaqat A. Khan,1  

E-Print Network [OSTI]

Elastic uplift in southeast Greenland due to rapid ice mass loss Shfaqat A. Khan,1 John Wahr,2] The rapid unloading of ice from the southeastern sector of the Greenland ice sheet between 2001 and 2006), Elastic uplift in southeast Greenland due to rapid ice mass loss, Geophys. Res. Lett., 34, L21701, doi:10

Larson, Kristine

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

FIRST-ORDER SYSTEM LEAST SQUARES (FOSLS) FOR GEOMETRICALLY NONLINEAR ELASTICITY  

E-Print Network [OSTI]

and a consti- tutive equation. The equilibrium equation and associated boundary conditions relate a balance of nonlinearity into the equations of elasticity. The constitutive equation, or material law as it is sometimes-squares (FOSLS) method to approximate the solution to the equations of geometrically nonlinear elasticity in two

McCormick, Steve

262

SHELL THEORIES ARISING AS LOW ENERGY -LIMIT OF 3D NONLINEAR ELASTICITY  

E-Print Network [OSTI]

SHELL THEORIES ARISING AS LOW ENERGY -LIMIT OF 3D NONLINEAR ELASTICITY MARTA LEWICKA, MARIA to minimizers of suitable lower dimensional limit energies. In this paper we discuss shell theories arising of -limit) of the 3d nonlinear elasticity for thin shells around an arbitrary smooth 2d surface

Lewicka, Marta

263

SHELL THEORIES ARISING AS LOW ENERGY -LIMIT OF 3D NONLINEAR ELASTICITY  

E-Print Network [OSTI]

SHELL THEORIES ARISING AS LOW ENERGY -LIMIT OF 3D NONLINEAR ELASTICITY By Marta Lewicka Maria that the elastic energy of defor- mations scales like h4, h being the thickness of a shell, we derive a limiting dimensional limit energies. In this paper we discuss shell theories arising as -limits of higher scalings

264

Materials Science and Engineering A297 (2001) 235243 Plasma-sprayed ceramic coatings: anisotropic elastic and  

E-Print Network [OSTI]

anisotropic elastic stiffnesses and thermal conductivities of the plasma sprayed ceramic coatingMaterials Science and Engineering A297 (2001) 235­243 Plasma-sprayed ceramic coatings: anisotropic are derived. © 2001 Elsevier Science S.A. All rights reserved. Keywords: Thermal spray; Elastic properties

Sevostianov, Igor

265

Mechanically equivalent elastic-plastic deformations and the problem of plastic spin David J. Steigmann1  

E-Print Network [OSTI]

Mechanically equivalent elastic-plastic deformations and the problem of plastic spin David J author to receive correspondence (steigman@me.berkeley.edu) Abstract: The problem of plastic spin is phrased in terms of a notion of mechanical equivalence among local relaxed configurations of an elastic/plastic

Paris-Sud XI, Université de

266

Elastic-Plastic Models for Stable Crack Growtht *James R. Rice  

E-Print Network [OSTI]

Elastic-Plastic Models for Stable Crack Growtht by *James R. Rice Mareh 1973 'PCAbh ~ ~ e c.\\. (n do not fully recover their strain upon unloading. The idealized non-linear elastic (left) and rigid-plastic,. there is ~ strain concentration created at the cut-ahead tip in the rigid-plastic material and the deformation field

267

Phenomenological study of parabolic and spherical indentation of elastic-ideally plastic material  

E-Print Network [OSTI]

Phenomenological study of parabolic and spherical indentation of elastic-ideally plastic material O ideally plastic materials was carried out by using precise results of finite elements calculations behaviour is found. Two elastic-plastic regimes and two plastic regimes are observed for materials of very

Paris-Sud XI, Université de

268

Wood elastic characterization from a single sample by resonant ultrasound spectroscopy  

E-Print Network [OSTI]

Wood elastic characterization from a single sample by resonant ultrasound spectroscopy R. Longoa materials such as wood using only one sample. To do so, two complementary methods are used. First, the wood: Resonant ultrasound spectroscopy, spherical and cubic samples, wood, elastic constants 1. Introduction Wood

Paris-Sud XI, Université de

269

Analysis of the elastic behaviour of silica aerogels taken as a percolating system  

E-Print Network [OSTI]

289 Analysis of the elastic behaviour of silica aerogels taken as a percolating system T. Woignier of silica aerogels are performed using the three points flexural technique. The elastic behaviour is studied measurement - for silica aerogels. These highly porous materials are obtained from a sol-gel process. Solvent

Paris-Sud XI, Université de

270

ON QUASI-ELASTIC SCATTERING OF SLOW NEUTRONS IN MOLECULAR LIQUIDS  

E-Print Network [OSTI]

L-317 ON QUASI-ELASTIC SCATTERING OF SLOW NEUTRONS IN MOLECULAR LIQUIDS M. UTSURO Research Reactor de neutrons avec élargissement par rotation moléculaire dans le liquide sont étudiés dans le cadre du du benzène liquide. Abstract. 2014 The rotational broadened quasi-elastic scattering spectrum

Boyer, Edmond

271

Plane wave solution for elastic wave scattering by a heterogeneous fracture  

E-Print Network [OSTI]

Plane wave solution for elastic wave scattering by a heterogeneous fracture Seiji Nakagawa,a) Kurt for computing the three-dimensional scattering of propagating elastic waves by a planar fracture with heterogeneous fracture compliance distribution is presented. This method is based upon the spatial Fourier

Santos, Juan

272

Relativistic impulse-approximation calculation of p-bar-nucleus elastic scattering  

SciTech Connect (OSTI)

The first calculations of p-bar-nucleus elastic scattering using the relativistic impulse approximation are presented and compared with the recent 46.8-MeV p-bar-/sup 12/C elastic scattering data. The calculated cross sections agree well with the data. The differences between relativistic and nonrelativistic impulse approximation calculations using the same input are small.

Clark, B.C.; Hama, S.; McNeil, J.A.; Mercer, R.L.; Ray, L.; Serot, B.D.; Sparrow, D.A.; Stricker-Bauer, K.

1984-10-08T23:59:59.000Z

273

Journal of Sound and Vibration 298 (2006) 108131 Elastic wave radiation from a high frequency  

E-Print Network [OSTI]

JOURNAL OF SOUND AND VIBRATION Journal of Sound and Vibration 298 (2006) 108­131 Elastic wave. Introduction Problems concerning the propagation, refraction and diffraction of waves are the subject method to detect defects is to analyse the scattering of the elastic waves generated by ultrasonic

Abrahams, I. David

274

PHYSICAL REVIEW E 84, 061906 (2011) Mechanics of soft composites of rods in elastic gels  

E-Print Network [OSTI]

PHYSICAL REVIEW E 84, 061906 (2011) Mechanics of soft composites of rods in elastic gels Moumita of composites consisting of randomly distributed stiff fibers embedded in an elastic matrix in two and three of the compressibility of the composite relative to its shear compliance as a result of the addition of stiff rodlike

MacKintosh, F.C.

275

ANALYSIS OF ANISOTROPY IN ELASTIC CONSTANTS OF SiCp/2124 Al METAL MATRIX COMPOSITES  

E-Print Network [OSTI]

ANALYSIS OF ANISOTROPY IN ELASTIC CONSTANTS OF SiCp/2124 Al METAL MATRIX COMPOSITES H.K. Jung* , Y; Metal matrix composite; Elastic constants; Aspect ratio; Anisotropy 1. Introduction Metal matrix composites (MMCs) are becoming attractive materials for advanced aerospace structures because

Hong, Soon Hyung

276

NONLINEAR ELASTIC WAVE NDE II. NONLINEAR WAVE MODULATION SPECTROSCOPY AND NONLINEAR TIME  

E-Print Network [OSTI]

NONLINEAR ELASTIC WAVE NDE II. NONLINEAR WAVE MODULATION SPECTROSCOPY AND NONLINEAR TIME REVERSED. This paper presents the second part of the review of Nonlinear Elastic Wave Spectroscopy (NEWS) in NDE, and describe two different methods of nonlinear NDE that provide not only damage detection but location as well

277

Elastic displacements and step interactions on metallic surfaces: GIXD and ab initio study of Au(332)  

E-Print Network [OSTI]

-range displacement fields generated by atomic relaxations at the steps.10 It is generally assumed that the most authors have come up with elastic models to describe step-step interactions.10,11,12,13,14 In generalElastic displacements and step interactions on metallic surfaces: GIXD and ab initio study of Au

Paris-Sud XI, Université de

278

THESIS FOR THE DEGREE OF LICENTIATE OF PHILOSOPHY Model Adaptivity in Elasticity  

E-Print Network [OSTI]

THESIS FOR THE DEGREE OF LICENTIATE OF PHILOSOPHY Model Adaptivity in Elasticity DAVID HEINTZ, Sweden 2008 #12;Model Adaptivity in Elasticity DAVID HEINTZ © DAVID HEINTZ, 2008 Thesis for Licentiate List of Appended Papers The licentiate thesis consists of an introductory text to subjects and methods

Patriksson, Michael

279

Trends in elasticity and electronic structure of transition-metal nitrides and carbides from first principles  

E-Print Network [OSTI]

Trends in elasticity and electronic structure of transition-metal nitrides and carbides from first 2005 The elastic properties of selected transition-metal TM nitrides and carbides in B1 structure the transition-metal nitrides and carbides remain unclear and a challenge for engineering hard materials

Wu, Zhigang

280

Continued Fraction Absorbing Boundary Conditions for Transient Elastic Wave Propagation Modeling  

E-Print Network [OSTI]

Continued Fraction Absorbing Boundary Conditions for Transient Elastic Wave Propagation Modeling Md of the truncated exterior. Development of an accurate ABC for transient elastic wave propagation problems are obtained by factoring the wave equation into outward and inward propagating operators and permitting only

Guddati, Murthy N.

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Effective elastic thickness of South America and its implications for intracontinental deformation  

E-Print Network [OSTI]

Effective elastic thickness of South America and its implications for intracontinental deformation. Within cratonic South America, Te variations are observed at regional scale: relatively lower Te occurs.y. Components: 13,516 words, 8 figures. Keywords: elastic thickness; South America; lithospheric structure

Watts, A. B. "Tony"

282

A maximum entropy-least squares estimator for elastic origin-destination trip matrix estimation  

E-Print Network [OSTI]

A maximum entropy-least squares estimator for elastic origin- destination trip matrix estimation propose a combined maximum entropy-least squares (ME-LS) estimator, by which O- D flows are distributed-destination trip table; elastic demand; maximum entropy; least squares; subnetwork analysis; convex combination

Kockelman, Kara M.

283

Open problems in nuclear density functional theory  

E-Print Network [OSTI]

This note describes five subjects of some interest for the density functional theory in nuclear physics. These are, respectively, i) the need for concave functionals, ii) the nature of the Kohn-Sham potential for the radial density theory, iii) a proper implementation of a density functional for an "intrinsic" rotational density, iv) the possible existence of a potential driving the square root of the density, and v) the existence of many models where a density functional can be explicitly constructed.

B. G. Giraud

2009-11-30T23:59:59.000Z

284

Transformations for densities Linear transformations  

E-Print Network [OSTI]

' & $ % Lecture 28 Transformations for densities Linear transformations 1-1 differentiable functions General transformations Expectation of a function 1 #12;' & $ % Transformations for discrete transformation of a U[0, 1] · Take X U[0, 1], so that fX(x) = 1 0 0 and set Y

Adler, Robert J.

285

Flavor decomposition of the elastic nucleon electromagnetic form factors  

SciTech Connect (OSTI)

The u- and d-quark contributions to the elastic nucleon electromagnetic form factors have been determined using experimental data on GEn , GMn , GpE , and GpM . Such a flavor separation of the form factors became possible up to 3.4 GeV2 with recent data on GEn from Hall A at JLab. At a negative four-momentum transfer squared Q2 above 1 GeV2, for both the u- and d-quark components, the ratio of the Pauli form factor to the Dirac form factor, F2/F1, was found to be almost constant, and for each of F2 and F1 individually, the d-quark component drops continuously with increasing Q2.

C.D. Cates, C.W. Jager, S. Riordan, B. Wojtsekhowski

2011-06-01T23:59:59.000Z

286

Critical confinement and elastic instability in thin solid films  

E-Print Network [OSTI]

When a flexible plate is peeled off a thin and soft elastic film bonded to a rigid support, uniformly spaced fingering patterns develop along their line of contact. While, the wavelength of these patterns depends only on the thickness of the film, their amplitude varies with all material and geometric properties of the film and that of the adhering plate. Here we have analyzed this instability by the regular perturbation technique to obtain the excess deformations of the film over and above the base quantities. Furthermore, by calculating the excess energy of the system we have shown that these excess deformations, associated with the instability, occur for films which are critically confined. We have presented two different experiments for controlling the degree of confinement: by pre-stretching the film and by adjusting the contact width between the film and the plate.

Animangsu Ghatak; Manoj K. Chaudhury

2007-01-11T23:59:59.000Z

287

Elastic Hadron Scattering on Li Isotopes at Intermediate Energies  

SciTech Connect (OSTI)

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

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

2005-01-01T23:59:59.000Z

288

Asymptotic behavior of an elastic satellite with internal friction  

E-Print Network [OSTI]

We study the dynamics of an elastic body whose shape and position evolve due to the gravitational forces exerted by a pointlike planet. The main result is that, if all the deformations of the satellite dissipate some energy, then under a suitable nondegeneracy condition there are only three possible outcomes for the dynamics: (i) the orbit of the satellite is unbounded, (ii) the satellite falls on the planet, (iii) the satellite is captured in synchronous resonance i.e. its orbit is asymptotic to a motion in which the barycenter moves on a circular orbit, and the satellite moves rigidly, always showing the same face to the planet. The result is obtained by making use of LaSalle's invariance principle and by a careful kinematic analysis showing that energy stops dissipating only on synchronous orbits. We also use in quite an extensive way the fact that conservative elastodynamics is a Hamiltonian system invariant under the action of the rotation group.

Emanuele Haus; Dario Bambusi

2012-12-04T23:59:59.000Z

289

Hadronic uncertainties in the elastic scattering of supersymmetric dark matter  

SciTech Connect (OSTI)

We review the uncertainties in the spin-independent and spin-dependent elastic scattering cross sections of supersymmetric dark matter particles on protons and neutrons. We propagate the uncertainties in quark masses and hadronic matrix elements that are related to the {pi}-nucleon {sigma} term and the spin content of the nucleon. By far the largest single uncertainty is that in spin-independent scattering induced by our ignorance of the matrix elements linked to the {pi}-nucleon {sigma} term, which affects the ratio of cross sections on proton and neutron targets as well as their absolute values. This uncertainty is already impacting the interpretations of experimental searches for cold dark matter. We plead for an experimental campaign to determine better the {pi}-nucleon {sigma} term. Uncertainties in the spin content of the proton affect significantly, but less strongly, the calculation of rates used in indirect searches.

Ellis, John [TH Division, Physics Department, CERN, 1211 Geneva 23 (Switzerland); Olive, Keith A.; Savage, Christopher [William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

2008-03-15T23:59:59.000Z

290

Overall Dynamic Constitutive Relations of Micro-structured Elastic Composites  

E-Print Network [OSTI]

A method for homogenization of a heterogeneous (finite or periodic) elastic composite is presented. It allows direct, consistent, and accurate evaluation of the averaged overall frequency-dependent dynamic material constitutive relations. It is shown that when the spatial variation of the field variables is restricted by a Bloch-form (Floquet-form) periodicity, then these relations together with the overall conservation and kinematical equations accurately yield the displacement or stress modeshapes and, necessarily, the dispersion relations. It also gives as a matter of course point-wise solution of the elasto-dynamic field equations, to any desired degree of accuracy. The resulting overall dynamic constitutive relations however, are general and need not be restricted by the Bloch-form periodicity. The formulation is based on micro-mechanical modeling of a representative unit cell of the composite proposed by Nemat-Nasser and coworkers; see, e.g., [1] and [2].

Sia Nemat-Nasser; Ankit Srivastava

2011-05-25T23:59:59.000Z

291

Measurement of Muon Neutrino Quasi-Elastic Scattering on Carbon  

E-Print Network [OSTI]

The observation of neutrino oscillations is clear evidence for physics beyond the standard model. To make precise measurements of this phenomenon, neutrino oscillation experiments, including MiniBooNE, require an accurate description of neutrino charged current quasi-elastic (CCQE) cross sections to predict signal samples. Using a high-statistics sample of muon neutrino CCQE events, MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments, accurately characterizes the CCQE events observed in a carbon-based detector. The extracted parameters include an effective axial mass, M_A^eff = 1.23+/-0.20 GeV, that describes the four-momentum dependence of the axial-vector form factor of the nucleon; and a Pauli-suppression parameter, kappa = 1.019+/-0.011. Such a modified Fermi gas model may also be used by future accelerator-based experiments measuring neutrino oscillations on nuclear targets.

MiniBooNE collaboration

2007-06-07T23:59:59.000Z

292

Noise-assisted Thouless pump in elastically deformable molecular junctions  

E-Print Network [OSTI]

We study a Thouless pump realized with an elastically \\textit{deformable quantum dot} whose center of mass follows a non-linear stochastic dynamics. The interplay of noise, non-linear effects, dissipation and interaction with an external time-dependent driving on the pumped charge is fully analyzed. The results show that the quantum pumping mechanism not only is not destroyed by the force fluctuations, but it becomes stronger when the forcing signal frequency is tuned close to the resonance of the vibrational mode. The robustness of the quantum pump with temperature is also investigated and an exponential decay of the pumped charge is found when the coupling to the vibrational mode is present. Implications of our results for nano-electromechanical systems are also discussed.

C. A. Perroni; F. Romeo; A. Nocera; V. Marigliano Ramaglia; R. Citro; V. Cataudella

2014-04-16T23:59:59.000Z

293

Elastic anomalies associated with transformation sequences in perovskites: II. The strontium zirconatetitanate Sr(Zr,Ti)O  

E-Print Network [OSTI]

Elastic anomalies associated with transformation sequences in perovskites: II. The strontium.1088/0953-8984/21/1/015902 Elastic anomalies associated with transformation sequences in perovskites: II. The strontium zirconate

Cambridge, University of

294

aggregatibacter actinomycetemcomitansarcb influences: Topics...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

was compared with that of control Paris-Sud XI, Universit de 393 INFLUENCE OF CARBON AEROGEL TEXTURE ON PEMFC PERFORMANCES Computer Technologies and Information Sciences...

295

Experimental results on pp forward elastic scattering and the possibility of universal shrinkage of the hadronic diffraction cone  

E-Print Network [OSTI]

Experimental results on pp forward elastic scattering and the possibility of universal shrinkage of the hadronic diffraction cone

Burq, J P; Chevallier, M; Denisov, A S; Ekelöf, T J C; Fay, F; Grafström, P; Gustafsson, L; Hagberg, E; Ille, B; Kashchuk, A P; Kulikov, A V; Lambert, M; Martin, J P; Maury, S; Querrou, M; Schegelsky, V A; Tkach, I I; Verbeken, M; Vorobyov, A A

1982-01-01T23:59:59.000Z

296

Anisotropic Motion and Molecular Dynamics of Cholesterol, Lanosterol, and Ergosterol in Lecithin Bilayers Studied by Quasi-elastic Neutron Scattering  

E-Print Network [OSTI]

Bilayers Studied by Quasi-elastic Neutron Scattering Emil Endress, Helmut Heller,§ He´le`ne CasaltaVised Manuscript ReceiVed June 27, 2002 ABSTRACT: Quasi-elastic neutron scattering (QENS) was employed to study of motion within the bilayer on the molecular dynamics time scale. In a recent quasi-elastic neutron

Brown, Michael F.

297

Jacek Dobaczewski Density functional theory and energy  

E-Print Network [OSTI]

Jacek Dobaczewski Density functional theory and energy density functionals in nuclear physics Jacek Functional #12;Jacek Dobaczewski Mean-Field Theory Density Functional Theory · mean-field one? Density Functional Theory: A variational method that uses observables as variational parameters. #12;Jacek

Dobaczewski, Jacek

298

Density Functional Theory (DFT) Rob Parrish  

E-Print Network [OSTI]

Density Functional Theory (DFT) Rob Parrish robparrish@gmail.com 1 #12;Agenda · The mechanism Easy to do this Why? Because of Hermitian Operators: Kinetic Energy Density: #12;Density Functional The density completely defines the observable state of the system: The way in which it does so (the functional

Sherrill, David

299

A current density distribution tool  

E-Print Network [OSTI]

. I. INTRODUCTION Current density distribution is an important consideration for those involved in electrochemical systems and electroplating in particular. In the printed wiring board (PWB) business, great emphasis is placed on the study of current... exist. Numerical techniques on the other hand, are usually easy to implement and are easily applicable to microcomputers. Their disadvantage as with any approximation technique is that the exactness of the results with This document follows the style...

Jagush, Frederic A.

1989-01-01T23:59:59.000Z

300

Balanced homodyne detectors and Casimir energy densities  

E-Print Network [OSTI]

We recall and generalize the analysis of the output of the so-called balanced homodyne detectors. The most important feature of these detectors is their ability to quantify the vacuum fluctuations of the electric field, that is expectation values of products of (quantum-) electric-field operators. More precisely, the output of BHDs provides information on the one- and two-point functions of arbitrary states of quantum fields. We generalize the analysis of the response of BHDs to the case of quantum fields under influence of static external conditions such as cavities or polarizable media. By recalling the expressions for two-point functions of quantum fields in Casimir geometries we show, that a rich, position- and frequency-dependent pattern of BHD responses is predicted for ground states. This points to a potentially new characterization of quantum fields in Casimir setups which would not only complement the current global methods (Casimir forces), but also improve understanding of sub-vacuum energy densities present in some regions in these geometries.

P. Marecki

2008-03-22T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Constraining the gravitational wave energy density of the Universe using Earth's ring  

E-Print Network [OSTI]

The search for gravitational waves is one of today's major scientific endeavors. A gravitational wave can interact with matter by exciting vibrations of elastic bodies. Earth itself is a large elastic body whose so-called normal-mode oscillations ring up when a gravitational wave passes. Therefore, precise measurement of vibration amplitudes can be used to search for the elusive gravitational-wave signals. Earth's free oscillations that can be observed after high-magnitude earthquakes have been studied extensively with gravimeters and low-frequency seismometers over many decades leading to invaluable insight into Earth's structure. Making use of our detailed understanding of Earth's normal modes, numerical models are employed for the first time to accurately calculate Earth's gravitational-wave response, and thereby turn a network of sensors that so far has served to improve our understanding of Earth, into an astrophysical observatory exploring our Universe. In this article, we constrain the energy density of gravitational waves to values in the range 0.035 - 0.15 normalized by the critical energy density of the Universe at frequencies between 0.3mHz and 5mHz, using 10 years of data from the gravimeter network of the Global Geodynamics Project that continuously monitors Earth's oscillations. This work is the first step towards a systematic investigation of the sensitivity of gravimeter networks to gravitational waves. Further advance in gravimeter technology could improve sensitivity of these networks and possibly lead to gravitational-wave detection.

Michael Coughlin; Jan Harms

2014-06-04T23:59:59.000Z

302

Influence of Microstructure on Residual Thermal Stresses in TiCxN1-x and -Al2O3 Coatings on WC-Co Tool Inserts  

E-Print Network [OSTI]

Influence of Microstructure on Residual Thermal Stresses in TiCxN1-x and -Al2O3 Coatings on WC deposited coatings on four tool inserts have been comprehensively characterized using electron backscatter the residual thermal strains in the coatings. The results indicate that the thermal strains and stored elastic

Rohrer, Gregory S.

303

Probability distribution of the vacuum energy density  

SciTech Connect (OSTI)

As the vacuum state of a quantum field is not an eigenstate of the Hamiltonian density, the vacuum energy density can be represented as a random variable. We present an analytical calculation of the probability distribution of the vacuum energy density for real and complex massless scalar fields in Minkowski space. The obtained probability distributions are broad and the vacuum expectation value of the Hamiltonian density is not fully representative of the vacuum energy density.

Duplancic, Goran; Stefancic, Hrvoje [Theoretical Physics Division, Rudjer Boskovic Institute, P.O. Box 180, HR-10002 Zagreb (Croatia); Glavan, Drazen [Department of Physics, Faculty of Science, University of Zagreb, P.O. Box 331, HR-10002 Zagreb (Croatia)

2010-12-15T23:59:59.000Z

304

Nonlinear Relaxation Dynamics in Elastic Networks and Design Principles of Molecular Machines  

E-Print Network [OSTI]

Analyzing nonlinear conformational relaxation dynamics in elastic networks corresponding to two classical motor proteins, we find that they respond by well-defined internal mechanical motions to various initial deformations and that these motions are robust against external perturbations. We show that this behavior is not characteristic for random elastic networks. However, special network architectures with such properties can be designed by evolutionary optimization methods. Using them, an example of an artificial elastic network, operating as a cyclic machine powered by ligand binding, is constructed.

Yuichi Togashi; Alexander S. Mikhailov

2007-05-17T23:59:59.000Z

305

Subcritical finite-amplitude solutions in plane Couette flow of visco-elastic fluids  

E-Print Network [OSTI]

Plane Couette flow of visco-elastic fluids is shown to exhibit a purely elastic subcritical instability in spite of being linearly stable. The mechanism of this instability is proposed and the nonlinear stability analysis of plane Couette flow of the Upper-Convected Maxwell fluid is presented. It is found that above the critical Weissenberg number, a small finite-size perturbation is sufficient to create a secondary flow, and the threshold value for the amplitude of the perturbation decreases as the Weissenberg number increases. The results suggest a scenario for weakly turbulent visco-elastic flow which is similar to the one for Newtonian fluids as a function of Reynolds number.

Alexander N. Morozov; Wim van Saarloos

2004-11-10T23:59:59.000Z

306

Density functional theory of electrowetting  

E-Print Network [OSTI]

The phenomenon of electrowetting, i.e., the dependence of the macroscopic contact angle of a fluid on the electrostatic potential of the substrate, is analyzed in terms of the density functional theory of wetting. It is shown that electrowetting is not an electrocapillarity effect, i.e., it cannot be consistently understood in terms of the variation of the substrate-fluid interfacial tension with the electrostatic substrate potential, but it is related to the depth of the effective interface potential. The key feature, which has been overlooked so far and which occurs naturally in the density functional approach is the structural change of a fluid if it is brought into contact with another fluid. These structural changes occur in the present context as the formation of finite films of one fluid phase in between the substrate and the bulk of the other fluid phase. The non-vanishing Donnan potentials (Galvani potential differences) across such film-bulk fluid interfaces, which generically occur due to an unequal partitioning of ions as a result of differences of solubility contrasts, lead to correction terms in the electrowetting equation, which become relevant for sufficiently small substrate potentials. Whereas the present density functional approach confirms the commonly used electrocapillarity-based electrowetting equation as a good approximation for the cases of metallic electrodes or electrodes coated with a hydrophobic dielectric in contact with an electrolyte solution and an ion-free oil, a significantly reduced tendency for electrowetting is predicted for electrodes coated with a dielectric which is hydrophilic or which is in contact with two immiscible electrolyte solutions.

Markus Bier; Ingrid Ibagon

2014-02-10T23:59:59.000Z

307

Affine maps of density matrices  

E-Print Network [OSTI]

For quantum systems described by finite matrices, linear and affine maps of matrices are shown to provide equivalent descriptions of evolution of density matrices for a subsystem caused by unitary Hamiltonian evolution in a larger system; an affine map can be replaced by a linear map, and a linear map can be replaced by an affine map. There may be significant advantage in using an affine map. The linear map is generally not completely positive, but the linear part of an equivalent affine map can be chosen to be completely positive and related in the simplest possible way to the unitary Hamiltonian evolution in the larger system.

Thomas F. Jordan

2004-11-21T23:59:59.000Z

308

Exponential decay in one-dimensional porous-thermo-elasticity  

E-Print Network [OSTI]

is the equilibrated stress, g is the equilibrated body force and q is the heat flux. The variables u" (BFM2003- 00309) of the Spanish Ministry of Science and Technology. Keywords: porous energy density is a positive definite form. Thus, the constitutive coefficients satisfy the conditions: µ

Politècnica de Catalunya, Universitat

309

Fluids, elasticity, matter Newtonian mechanics of deformable media  

E-Print Network [OSTI]

: p = 5 atm T = -56°C demo: geyser & collapsing tank ideal gas · Atoms and molecules are small, hard contains a thick layer of oil (shown in green) of density 2 floating on water (shown in blue), which has is the distance d between the top of the wood cube (after it has come to rest) and the interface between oil

Winokur, Michael

310

Combining Density Functional Theory and Density Matrix Functional Theory Daniel R. Rohr1  

E-Print Network [OSTI]

Combining Density Functional Theory and Density Matrix Functional Theory Daniel R. Rohr1 , Julien and CNRS, 4 place Jussieu, 75252 Paris, France We combine density-functional theory with density cleavage is an ubiquitous process for chemistry. Density-matrix functional theory (DMFT) (see, e.g., Refs

Paris-Sud XI, Université de

311

Synthesis, Crystal Structure, and Elastic Properties of Novel Tungsten Nitrides  

SciTech Connect (OSTI)

Among transition metal nitrides, tungsten nitrides possess unique and/or superior chemical, mechanical, and thermal properties. Preparation of these nitrides, however, is challenging because the incorporation of nitrogen into tungsten lattice is thermodynamically unfavorable at atmospheric pressure. To date, most materials in the W-N system are in the form of thin films produced by nonequilibrium processes and are often poorly crystallized, which severely limits their use in diverse technological applications. Here we report synthesis of tungsten nitrides through new approaches involving solid-state ion exchange and nitrogen degassing under pressure. We unveil a number of novel nitrides including hexagonal and rhombohedral W{sub 2}N{sub 3}. The final products are phase-pure and well-crystallized in bulk forms. For hexagonal W{sub 2}N{sub 3}, hexagonal WN, and cubic W3N4, they exhibit elastic properties rivaling or even exceeding cubic-BN. All four nitrides are prepared at a moderate pressure of 5 GPa, the lowest among high-pressure synthesis of transition metal nitrides, making it practically feasible for massive and industrial-scale production.

Wang, Shanmin; Yu, Xiaohui; Lin, Zhijun; Zhang, Ruifeng; He, Duanwei; Qin, Jiaqian; Zhu, Jinlong; Han, Jiantao; Wang, Lin; Mao, Ho-kwang; Zhang, Jianzhong; Zhao, Yusheng (UNLV); (Ehime U); (CIW); (Sichuan U.); (LANL)

2012-12-13T23:59:59.000Z

312

Benchmark calculations for elastic fermion-dimer scattering  

E-Print Network [OSTI]

We present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit. For the continuum calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to determine the scattering length and effective range parameter to high precision. For the lattice calculation we use the finite-volume method of L\\"uscher. We take into account topological finite-volume corrections to the dimer binding energy which depend on the momentum of the dimer. After subtracting these effects, we find from the lattice calculation kappa a_fd = 1.174(9) and kappa r_fd = -0.029(13). These results agree well with the continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained from the STM equation. We discuss applications to cold atomic Fermi gases, deuteron-neutron scattering in the spin-quartet channel, and lattice calculations of scattering for nuclei and hadronic molecules at finite volume.

Shahin Bour; H. -W. Hammer; Dean Lee; Ulf-G. Meißner

2012-06-08T23:59:59.000Z

313

On oscillator-bath system: Exact propagator, Reduced density matrix and Green's function  

E-Print Network [OSTI]

The exact form of quantum propagator of a quantum oscillator interacting with a bosonic bath consisting of $N$ distinguished quantum oscillators with different frequencies is obtained in the Heisenberg picture. Reduced density matrix for oscillator is obtained. The kernel or Green's function connecting the initial density matrix of the oscillator to the density matrix in an arbitrary time is obtained and its connection to Feynman-Vernon influence functional is discussed. Weak coupling regime and squared mean values for position, momentum and energy of the oscillator are obtained in equilibrium.

A. Refaei; F. Kheirandish

2014-07-27T23:59:59.000Z

314

High density behaviour of nuclear symmetry energy  

E-Print Network [OSTI]

Role of the isospin asymmetry in nuclei and neutron stars, with an emphasis on the density dependence of the nuclear symmetry energy, is discussed. The symmetry energy is obtained using the isoscalar as well as isovector components of the density dependent M3Y effective interaction. The constants of density dependence of the effective interaction are obtained by reproducing the saturation energy per nucleon and the saturation density of spin and isospin symmetric cold infinite nuclear matter. Implications for the density dependence of the symmetry energy in case of a neutron star are discussed, and also possible constraints on the density dependence obtained from finite nuclei are compared.

D. N. Basu; Tapan Mukhopadhyay

2006-12-27T23:59:59.000Z

315

Test method Evaluating the influence of contacting fluids on polyethylene  

E-Print Network [OSTI]

Test method Evaluating the influence of contacting fluids on polyethylene using acoustic emissions emissions Polyethylene Penetrant Toluene Aqueous detergent a b s t r a c t Identifying microstructural) on the structure of a semi-crystalline polymer (high density polyethylene, HDPE) over different periods of exposure

Thompson, Michael

316

Kinematically consistent, elastic block model for the eastern Mediterranean constrained by GPS measurements  

E-Print Network [OSTI]

I use a Global Positioning System (GPS) velocity field to constrain block models of the eastern Mediterranean and surrounding regions that account for the angular velocities of constituent blocks and elastic strain ...

Lawrence, Shawn A. (Shawn Adam), 1975-

2003-01-01T23:59:59.000Z

317

Design, prototyping and preliminary testing of an elastic-powered climbing exoskeleton  

E-Print Network [OSTI]

Human powered elastic mechanisms can be used to reduce work requirements of muscles, by storing and releasing energy to more evenly distribute work load. An exoskeleton was designed to delay human fatigue during rock ...

Briner, Hazel (Hazel Linn)

2011-01-01T23:59:59.000Z

318

UPWIND, Aerodynamics and aero-elasticity Rotor aerodynamics in atmospheric shear flow  

E-Print Network [OSTI]

UPWIND, Aerodynamics and aero-elasticity Rotor aerodynamics in atmospheric shear flow Niels N codes for wind turbines utilize aerodynamics based on BEM methods, see [1, 2]. For modern large scale

319

Multiscale Method for Elastic Wave Propagation in the Heterogeneous, Anisotropic Media  

E-Print Network [OSTI]

FEM) for elastic wave propagation in heterogeneous, anisotropic media in both continuous Galerkin (CG) and discontinuous Galerkin (DG) formulations. The advantage of the multiscale basis functions is they are model-dependent, unlike the predefined polynomial basis...

Gao, Kai

2014-08-05T23:59:59.000Z

320

E-Print Network 3.0 - angle quasi-elastic scattering Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Force Academy, University of New South Wales Collection: Physics ; Materials Science 2 Neutron scattering study of the quasi-elastic spectral width in CeMg, CeMg3 and NdMg3...

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

A coupled theory for diffusion of hydrogen and large elastic-plastic deformations of metals  

E-Print Network [OSTI]

A thermodynamically-consistent coupled-theory which accounts for diffusion of hydrogen, trapping of hydrogen, diffusion of heat, and large elastic-plastic deformations of metals is developed. Our theoretical framework ...

Di Leo, Claudio V

2012-01-01T23:59:59.000Z

322

Stochastic dynamic optimization of consumption and the induced price elasticity of demand in smart grids  

E-Print Network [OSTI]

This thesis presents a mathematical model of consumer behavior in response to stochastically-varying electricity prices, and a characterization of price-elasticity of demand created by optimal utilization of storage and ...

Faghih, Ali

2011-01-01T23:59:59.000Z

323

Elastic scattering and total reaction cross section of {sup 6}He+{sup 120}Sn  

SciTech Connect (OSTI)

The elastic scattering of {sup 6}He on {sup 120}Sn has been measured at four energies above the Coulomb barrier using the {sup 6}He beam produced at the RIBRAS (Radioactive Ion Beams in Brasil) facility. The elastic angular distributions have been analyzed with the optical model and three- and four-body continuum-discretized coupled-channels calculations. The total reaction cross sections have been derived and compared with other systems of similar masses.

Faria, P. N. de; Lichtenthaeler, R.; Pires, K. C. C.; Lepine-Szily, A.; Guimaraes, V.; Mendes, D. R. Jr.; Barioni, A.; Morcelle, V.; Morais, M. C.; Camargo, O. Jr.; Alcantara Nunez, J. [Instituto de Fisica-Universidade de Sao Paulo, C. P. 66318, 05389-970 Sao Paulo, SP (Brazil); Moro, A. M. [Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Arazi, A. [Laboratorio Tandar, Comision Nacional de Energia Atomica, Av. del Libertador 8250, 1429 Buenos Aires (Argentina); Rodriguez-Gallardo, M. [Departamento de FAMN, Universidad de Sevilla, Apartado 1065, E-41080 Sevilla (Spain); Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid (Spain); Assuncao, M. [Universidade Federal de Sao Paulo, Campus Diadema, 09941-510 Sao Paulo, SP (Brazil)

2010-04-15T23:59:59.000Z

324

Shell theories arising as low energy ?-limit of 3d nonlinear elasticity  

E-Print Network [OSTI]

We discuss the limiting behavior (using the notion of \\Gamma-limit) of the 3d nonlinear elasticity for thin shells around an arbitrary smooth 2d surface. In particular, under the assumption that the elastic energy of deformations scales like h^4 (where h is the thickness of a shell), we derive a limiting theory which is a generalization of the von K\\'arm\\'an theory for plates.

Marta Lewicka; Maria Giovanna Mora; Mohammad Reza Pakzad

2008-03-04T23:59:59.000Z

325

Modeling the elastic and plastic response of single crystals and polycrystalline aggregates  

E-Print Network [OSTI]

MODELING THE ELASTIC AND PLASTIC RESPONSE OF SINGLE CRYSTALS AND POLYCRYSTALLINE AGGREGATES A Thesis by PARAG VILAS PATWARDHAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 2003 Major Subject: Mechanical Engineering MODELING THE ELASTIC AND PLASTIC RESPONSE OF SINGLE CRYSTALS AND POLYCRYSTALLINE AGGREGATES A Thesis by PARAG VILAS...

Patwardhan, Parag Vilas

2005-02-17T23:59:59.000Z

326

Measurement of the elastic scattering cross section of neutrons from argon and neon  

E-Print Network [OSTI]

Background: The most significant source of background in direct dark matter searches are neutrons that scatter elastically from nuclei in the detector's sensitive volume. Experimental data for the elastic scattering cross section of neutrons from argon and neon, which are target materials of interest to the dark matter community, were previously unavailable. Purpose: Measure the differential cross section for elastic scattering of neutrons from argon and neon in the energy range relevant to backgrounds from (alpha,n) reactions in direct dark matter searches. Method: Cross-section data were taken at the Triangle Universities Nuclear Laboratory (TUNL) using the neutron time-of-flight technique. These data were fit using the spherical optical model. Results: The differential cross section for elastic scatting of neutrons from neon at 5.0 and 8.0 MeV and argon at 6.0 MeV was measured. Optical-model parameters for the elastic scattering reactions were determined from the best fit to these data. The total elastic scattering cross section for neon was found to differ by 6% at 5.0 MeV and 13% at 8.0 MeV from global optical-model predictions. Compared to a local optical-model for 40Ar, the elastic scattering cross section was found to differ from the data by 8% at 6.0 MeV. Conclusions: These new data are important for improving Monte-Carlo simulations and background estimates for direct dark matter searches and for benchmarking optical models of neutron elastic scattering from these nuclei.

S. MacMullin; M. Kidd; R. Henning; W. Tornow; C. R. Howell; M. Brown

2012-12-12T23:59:59.000Z

327

Frame Indifferent Formulation of Maxwell's Elastic Fluid and the Rational Continuum Mechanics of the Electromagnetic Field  

E-Print Network [OSTI]

We show that the linearized equations of the incompressible elastic medium admit a `Maxwell form' in which the shear component of the stress vector plays the role of the electric field, and the vorticity plays the role of the magnetic field. Conversely, the set of dynamic Maxwell equations are strict mathematical corollaries from the governing equations of the incompressible elastic medium. This suggests that the nature of `electromagnetic field' may actually be related to an elastic continuous medium. The analogy is complete if the medium is assumed to behave as fluid in shear motions, while it may still behave as elastic solid under compressional motions. Then the governing equations of the elastic fluid are re-derived in the Eulerian frame by replacing the partial time derivatives by the properly invariant (frame indifferent) time rates. The `Maxwell from' of the frame indifferent formulation gives the frame indifferent system that is to replace the Maxwell system. This new system comprises terms already present in the classical Maxwell equations, alongside terms that are the progenitors of the Biot--Savart, Oersted--Ampere's, and Lorentz--force laws. Thus a frame indifferent (truly covariant) formulation of electromagnetism is achieved from a single postulate that the electromagnetic field is a kind of elastic (partly liquid partly solid) continuum.

Christo I. Christov

2011-03-06T23:59:59.000Z

328

Risk Bounds for Mixture Density Estimation  

E-Print Network [OSTI]

In this paper we focus on the problem of estimating a bounded density using a finite combination of densities from a given class. We consider the Maximum Likelihood Procedure (MLE) and the greedy procedure described by ...

Rakhlin, Alexander

2004-01-27T23:59:59.000Z

329

Quantum critical benchmark for density functional theory  

E-Print Network [OSTI]

Two electrons at the threshold of ionization represent a severe test case for electronic structure theory. A pseudospectral method yields a very accurate density of the two-electron ion with nuclear charge close to the critical value. Highly accurate energy components and potentials of Kohn-Sham density functional theory are given, as well as a useful parametrization of the critical density. The challenges for density functional approximations and the strength of correlation are also discussed.

Paul E. Grabowski; Kieron Burke

2014-08-09T23:59:59.000Z

330

Oxides having high energy densities  

DOE Patents [OSTI]

Certain disclosed embodiments generally relate to oxide materials having relatively high energy and/or power densities. Various aspects of the embodiments are directed to oxide materials having a structure B.sub.i(M.sub.jY.sub.k)O.sub.2, for example, a structure Li.sub.j(Ni.sub.jY.sub.k)O.sub.2 such as Li(Ni.sub.0.5Mn.sub.0.5)O.sub.2. In this structure, Y represents one or more atoms, each independently selected from the group consisting of alkaline earth metals, transition metals, Group 14 elements, Group 15, or Group 16 elements. In some embodiments, such an oxide material may have an O3 crystal structure, and/or a layered structure such that the oxide comprises a plurality of first, repeating atomic planes comprising Li, and a plurality of second, repeating atomic planes comprising Ni and/or Y.

Ceder, Gerbrand; Kang, Kisuk

2013-09-10T23:59:59.000Z

331

RESEARCH PAPER Effects of Structural Refuge and Density on Foraging Behaviour  

E-Print Network [OSTI]

empirical studies in this general area have helped shape our current understanding of the starvation-0310.2011.01927.x Abstract Theoretical models of prey behaviour predict that food-limited prey engage in risk be influenced by factors including prey density and structural cover, such that the pre- sumed role of prey

332

Generalized dynamical density functional theory for classical fluids and the significance of inertia and hydrodynamic interactions  

E-Print Network [OSTI]

We study the dynamics of a colloidal fluid including inertia and hydrodynamic interactions, two effects which strongly influence the non-equilibrium properties of the system. We derive a general dynamical density functional theory (DDFT) which shows very good agreement with full Langevin dynamics. In suitable limits, we recover existing DDFTs and a Navier-Stokes-like equation with additional non-local terms.

Benjamin D. Goddard; Andreas Nold; Nikos Savva; Grigorios A. Pavliotis; Serafim Kalliadasis

2012-08-08T23:59:59.000Z

333

The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers  

E-Print Network [OSTI]

The optically thin critical densities and the effective excitation densities to produce a 1 K km/s (or 0.818 Jy km/s $(\\frac{\

Shirley, Yancy L

2015-01-01T23:59:59.000Z

334

Density Functional Theory Models for Radiation Damage  

E-Print Network [OSTI]

Density Functional Theory Models for Radiation Damage S.L. Dudarev EURATOM/CCFE Fusion Association, DFT Abstract Density functional theory models developed over the past decade provide unique phenomena. Density functional theory models have effectively created a new paradigm for the scientific

335

Time Dependent Density Functional Theory An introduction  

E-Print Network [OSTI]

Time Dependent Density Functional Theory An introduction Francesco Sottile LSI, Ecole Polytechnique) Time Dependent Density Functional Theory Palaiseau, 26 May 2014 1 / 62 #12;Outline 1 Introduction: why and Resources Francesco Sottile (ETSF) Time Dependent Density Functional Theory Palaiseau, 26 May 2014 2 / 62

Botti, Silvana

336

DENSITY FUNCTIONAL THEORY OF FIELD THEORETICAL SYSTEMS  

E-Print Network [OSTI]

DENSITY FUNCTIONAL THEORY OF FIELD THEORETICAL SYSTEMS E. Engel Inst. fur Theor. Physik background of relativistic density functional theory is emphasized and its consequences for relativistic Kohn-Sham equations are shown. The local density approximation for the exchange energy functional is reviewed

Engel, Eberhard

337

Density functional theory George F. Bertsch  

E-Print Network [OSTI]

Density functional theory George F. Bertsch #3; Institute for Nuclear Theory and Department of Physics University of Tsukuba Tsukuba 305-8577 Japan Abstract Density functional theory is a remarkably Time-dependent density functional theory: the equations 34 A Optical properties

Bertsch George F.

338

DENSITY FUNCTIONAL THEORY, THE MODERN TREATMENT OF  

E-Print Network [OSTI]

DENSITY FUNCTIONAL THEORY, THE MODERN TREATMENT OF ELECTRON CORRELATIONS E.K.U. Gross and Stefan The basic idea of density functional theory is to describe a many-electron system exclusively and completely-consistent scheme, known as the Kohn-Sham scheme [2], is the heart of modern density functional theory

Gross, E.K.U.

339

Constitutive relationships for elastic deformation of clay rock: Data Analysis  

SciTech Connect (OSTI)

Geological repositories have been considered a feasible option worldwide for storing high-level nuclear waste. Clay rock is one of the rock types under consideration for such purposes, because of its favorable features to prevent radionuclide transport from the repository. Coupled hydromechanical processes have an important impact on the performance of a clay repository, and establishing constitutive relationships for modeling such processes are essential. In this study, we propose several constitutive relationships for elastic deformation in indurated clay rocks based on three recently developed concepts. First, when applying Hooke's law in clay rocks, true strain (rock volume change divided by the current rock volume), rather than engineering strain (rock volume change divided by unstressed rock volume), should be used, except when the degree of deformation is very small. In the latter case, the two strains will be practically identical. Second, because of its inherent heterogeneity, clay rock can be divided into two parts, a hard part and a soft part, with the hard part subject to a relatively small degree of deformation compared with the soft part. Third, for swelling rock like clay, effective stress needs to be generalized to include an additional term resulting from the swelling process. To evaluate our theoretical development, we analyze uniaxial test data for core samples of Opalinus clay and laboratory measurements of single fractures within macro-cracked Callovo-Oxfordian argillite samples subject to both confinement and water reduced swelling. The results from this evaluation indicate that our constitutive relationships can adequately represent the data and explain the related observations.

Liu, H.H.; Rutqvist, J.; Birkholzer, J.T.

2011-04-15T23:59:59.000Z

340

Aerodynamic Focusing Of High-Density Aerosols  

SciTech Connect (OSTI)

High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1#22; m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.

Ruiz, D. E.; Fisch, Nathaniel

2014-02-24T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

KH Computational Physics-2009 Density Functional Theory (DFT) Density Functional Theory  

E-Print Network [OSTI]

KH Computational Physics- 2009 Density Functional Theory (DFT) Density Functional Theory of interacting particles. Kristjan Haule, 2009 ­2­ #12;KH Computational Physics- 2009 Density Functional Theory functional of n. Kristjan Haule, 2009 ­3­ #12;KH Computational Physics- 2009 Density Functional Theory (DFT

Haule, Kristjan

342

Density-functional theory of nonuniform classical liquids: An extended modified weighted-density approximation  

E-Print Network [OSTI]

Density-functional theory of nonuniform classical liquids: An extended modified weighted-density the approximationstreat long-rangeand short-rangepotentials. I. INTRODUCTION The density-functional theory of nonuniform of density- functional theory to the problem of freezing of classical liquids,4 and in particular

Likos, Christos N.

343

Population Density Population density (persons per square kilometer) layers, for 1990  

E-Print Network [OSTI]

Population Density Africa Population density (persons per square kilometer) layers, for 1990 the 12 population density classes. Source information: http://sedac.ciesin.columbia.edu/gpw/. ´ Robinson://sedac.ciesin.columbia.edu/place/ Publish Date: 03/13/07 0 1,000 km Population Density 2000 0 Persons \\ Sq.Km 0-2 Persons \\ Sq.Km 2

Columbia University

344

Dot Density Maps Dot density maps, or dot maps, portray the geographic distribution of discrete phenomena  

E-Print Network [OSTI]

Dot Density Maps Dot density maps, or dot maps, portray the geographic distribution of discrete for representing geographic patterns. Dot density maps are particularly useful for understanding global distribution of the mapped phenomenon and comparing relative densities of different regions on the map. Dot

Klippel, Alexander

345

Non-axisymmetric wind-accretion simulations. II. Density gradients  

E-Print Network [OSTI]

The hydrodynamics of a variant of classical Bondi-Hoyle-Lyttleton accretion is investigated: a totally absorbing sphere moves at various Mach numbers (3 and 10) relative to a medium, which is taken to be an ideal gas having a density gradient (of 3%, 20% or 100% over one accretion radius) perpendicular to the relative motion. Similarly to the 3D models published previously, both with velocity gradients and without, the models with a density gradient presented here exhibit non-stationary flow patterns, although the Mach cone remains fairly stable. The accretion rates of mass, linear and angular momenta do not fluctuate as strongly as published previously for 2D models. No obvious trend of the dependency of mass accretion rate fluctuations on the density gradient can be discerned. The average specific angular momentum accreted is roughly between zero and 70% of the total angular momentum available in the accretion cylinder in the cases where the average is prograde. Due to the large fluctuations during accretion, the average angular momentum of some models is retrograde by up to 25%. Small gradients hardly influence the average accretion rates as compared to accretion from a homogeneous medium, while very large ones succeed to dominate and form an accretion flow in which the sense of rotation is not inverted.

M. Ruffert

1999-03-19T23:59:59.000Z

346

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

E-Print Network [OSTI]

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

Richard D. Saam

2007-01-09T23:59:59.000Z

347

Elasticity, strength, and toughness of single crystal silicon carbide, ultrananocrystalline diamond, and hydrogen-free tetrahedral amorphous  

E-Print Network [OSTI]

Elasticity, strength, and toughness of single crystal silicon carbide, ultrananocrystalline diamond carbide 3C-SiC , ultrananocrystalline diamond, and hydrogen-free tetrahedral amorphous carbon

Espinosa, Horacio D.

348

THE RESPONSE OF SOLIDS TO ELASTIC/PLASTIC INDENTATION AND THE APPLICATION OF INDENTATION TO ADHESION MEASUREMENTS  

E-Print Network [OSTI]

676. Table I. Normalized Plastic Zone Size (B) and Material·• • Initial - - Elastic/ plastic bounda ---- Cavi in rfaceCTIONAL VIEW XBLSOI Fig. I-9 Plastic Boundary solu/ Initial

Chiang, Shu-Sheng

2013-01-01T23:59:59.000Z

349

Revisit of the relationship between the elastic properties and sound velocities at high pressures  

SciTech Connect (OSTI)

The second-order elastic constants and stress-strain coefficients are defined, respectively, as the second derivatives of the total energy and the first derivative of the stress with respect to strain. Since the Lagrangian and infinitesimal strain are commonly used in the two definitions above, the second-order elastic constants and stress-strain coefficients are separated into two categories, respectively. In general, any of the four physical quantities is employed to characterize the elastic properties of materials without differentiation. Nevertheless, differences may exist among them at non-zero pressures, especially high pressures. Having explored the confusing issue systemically in the present work, we find that the four quantities are indeed different from each other at high pressures and these differences depend on the initial stress applied on materials. Moreover, the various relations between the four quantities depicting elastic properties of materials and high-pressure sound velocities are also derived from the elastic wave equations. As examples, we calculated the high-pressure sound velocities of cubic tantalum and hexagonal rhenium using these nexus. The excellent agreement of our results with available experimental data suggests the general applicability of the relations.

Wang, Chenju; Yan, Xiaozhen [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, PO Box 919-102, Mianyang, Sichuan 621900 (China); Institute of Atomic and Molecular Sciences, Sichuan University, Chengdu 610065 (China); Xiang, Shikai, E-mail: skxiang@caep.ac.cn; Chen, Haiyan [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, PO Box 919-102, Mianyang, Sichuan 621900 (China); Gu, Jianbing; Yu, Yin [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, PO Box 919-102, Mianyang, Sichuan 621900 (China); College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Kuang, Xiaoyu [Institute of Atomic and Molecular Sciences, Sichuan University, Chengdu 610065 (China); International Centre for Materials Physics, Academia Sinica, Shenyang 110016 (China)

2014-09-14T23:59:59.000Z

350

Elastomeric optical fiber sensors and method for detecting and measuring events occurring in elastic materials  

DOE Patents [OSTI]

Fiber optic sensing means for the detection and measurement of events such as dynamic loadings imposed upon elastic materials including cementitious materials, elastomers, and animal body components and/or the attrition of such elastic materials are provided. One or more optical fibers each having a deformable core and cladding formed of an elastomeric material such as silicone rubber are embedded in the elastic material. Changes in light transmission through any of the optical fibers due the deformation of the optical fiber by the application of dynamic loads such as compression, tension, or bending loadings imposed on the elastic material or by the attrition of the elastic material such as by cracking, deterioration, aggregate break-up, and muscle, tendon, or organ atrophy provide a measurement of the dynamic loadings and attrition. The fiber optic sensors can be embedded in elastomers subject to dynamic loadings and attrition such as commonly used automobiles and in shoes for determining the amount and frequency of the dynamic loadings and the extent of attrition. The fiber optic sensors are also useable in cementitious material for determining the maturation thereof.

Muhs, Jeffrey D. (Lenoir City, TN); Capps, Gary J. (Knoxville, TN); Smith, David B. (Oak Ridge, TN); White, Clifford P. (Knoxville, TN)

1994-01-01T23:59:59.000Z

351

Quartz resonator fluid density and viscosity monitor  

DOE Patents [OSTI]

A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

Martin, Stephen J. (Albuquerque, NM); Wiczer, James J. (Albuquerque, NM); Cernosek, Richard W. (Albuquerque, NM); Frye, Gregory C. (Cedar Crest, NM); Gebert, Charles T. (Albuquerque, NM); Casaus, Leonard (Bernalillo, NM); Mitchell, Mary A. (Tijeras, NM)

1998-01-01T23:59:59.000Z

352

Considering Air Density in Wind Power Production  

E-Print Network [OSTI]

In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

Farkas, Zénó

2011-01-01T23:59:59.000Z

353

Considering Air Density in Wind Power Production  

E-Print Network [OSTI]

In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.

Zénó Farkas

2011-03-11T23:59:59.000Z

354

Method of synthesizing a low density material  

DOE Patents [OSTI]

A novel method of synthesizing a polymeric material of low density of the order of 50mg/cc or less. Such a low density material has applications in many areas including laser target fabrication. The method comprises preparing a polymer blend of two incompatible polymers as a major and a minor phase by mixing them and extruding the mixture, and then selectively extracting the major component, to yield a fine, low density structure.

Lorensen, L.E.; Monaco, S.B.

1987-02-27T23:59:59.000Z

355

Betatron radiation from density tailored plasmas  

E-Print Network [OSTI]

Betatron radiation from density tailored plasmas K. Tathe resulting betatron radiation spectrum can therefore bepro?le, the betatron radiation emitted by theses electrons

Ta Phuoc, Kim

2010-01-01T23:59:59.000Z

356

Some challenges for Nuclear Density Functional Theory  

E-Print Network [OSTI]

We discuss some of the challenges that the DFT community faces in its quest for the truly universal energy density functional applicable over the entire nuclear chart.

T. Duguet; K. Bennaceur; T. Lesinski; J. Meyer

2006-06-20T23:59:59.000Z

357

3-D capacitance density imaging system  

DOE Patents [OSTI]

A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved. 7 figs.

Fasching, G.E.

1988-03-18T23:59:59.000Z

358

Isospin coupling-channel decomposition of nuclear symmetry energy in covariant density functional theory  

E-Print Network [OSTI]

The isospin coupling-channel decomposition of the potential energy density functional is carried out within the covariant density functional theory, and their isospin and density dependence in particular the influence on the symmetry energy is studied. It is found that both isospin-singlet and isospin-triplet components of the potential energy play the dominant role in deciding the symmetry energy, especially when the Fock diagram is introduced. The results illustrate a quite different mechanism to the origin of the symmetry energy from the microscopic Brueckner-Hartree-Fock theory, and demonstrate the importance of the Fork diagram in the CDF theory, especially from the isoscalar mesons, in the isospin properties of the in-medium nuclear force at high density.

Qian Zhao; Bao Yuan Sun; Wen Hui Long

2014-11-23T23:59:59.000Z

359

A non-linear elastic constitutive framework for replicating plastic deformation in solids.  

SciTech Connect (OSTI)

Ductile metals and other materials typically deform plastically under large applied loads; a behavior most often modeled using plastic deformation constitutive models. However, it is possible to capture some of the key behaviors of plastic deformation using only the framework for nonlinear elastic mechanics. In this paper, we develop a phenomenological, hysteretic, nonlinear elastic constitutive model that captures many of the features expected of a plastic deformation model. This model is based on calculating a secant modulus directly from a material's stress-strain curve. Scalar stress and strain values are obtained in three dimensions by using the von Mises invariants. Hysteresis is incorporated by tracking an additional history variable and assuming an elastic unloading response. This model is demonstrated in both single- and multi-element simulations under varying strain conditions.

Roberts, Scott Alan; Schunk, Peter Randall

2014-02-01T23:59:59.000Z

360

Phased array compaction cell for measurement of the transversely isotropic elastic properties of compacting sediments  

SciTech Connect (OSTI)

Sediments undergoing compaction typically exhibit transversely isotropic (TI) elastic properties. We present a new experimental apparatus, the phased array compaction cell, for measuring the TI elastic properties of clay-rich sediments during compaction. This apparatus uses matched sets of P- and S-wave ultrasonic transducers located along the sides of the sample and an ultrasonic P-wave phased array source, together with a miniature P-wave receiver on the top and bottom ends of the sample. The phased array measurements are used to form plane P-waves that provide estimates of the phase velocities over a range of angles. From these measurements, the five TI elastic constants can be recovered as the sediment is compacted, without the need for sample unloading, recoring, or reorienting. This paper provides descriptions of the apparatus, the data processing, and an application demonstrating recovery of the evolving TI properties of a compacting marine sediment sample.

Nihei, K.T.; Nakagawa, S.; Reverdy, F.; Meyer, L.R.; Duranti, L.; Ball, G.

2010-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

An elastic, plastic, viscous model for slow shear of a liquid foam  

E-Print Network [OSTI]

We suggest a scalar model for deformation and flow of an amorphous material such as a foam or an emulsion. To describe elastic, plastic and viscous behaviours, we use three scalar variables: elastic deformation, plastic deformation rate and total deformation rate; and three material specific parameters: shear modulus, yield deformation and viscosity. We obtain equations valid for different types of deformations and flows slower than the relaxation rate towards mechanical equilibrium. In particular, they are valid both in transient or steady flow regimes, even at large elastic deformation. We discuss why viscosity can be relevant even in this slow shear (often called "quasi-static") limit. Predictions of the storage and loss moduli agree with the experimental literature, and explain with simple arguments the non-linear large amplitude trends.

Philippe Marmottant; François Graner

2007-07-06T23:59:59.000Z

362

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

SciTech Connect (OSTI)

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

2010-12-07T23:59:59.000Z

363

Elastic Properties and Internal Friction of Two Magnesium Alloys at Elevated Temperatures  

SciTech Connect (OSTI)

The elastic properties and internal friction of two magnesium alloys were studied from 25 C to 450 C using Resonant Ultrasound Spectroscopy (RUS). The Young's moduli decrease with increasing temperature. At 200 C, a change in the temperature dependence of the elastic constants is observed. The internal friction increases significantly with increasing temperature above 200 C. The observed changes in the temperature dependence of the elastic constants and the internal friction are the result of anelastic relaxation by grain boundary sliding at elevated temperatures. Elastic properties govern the behavior of a materials subjected to stress over a region of strain where the material behaves elastically. The elastic properties, including the Young's modulus (E), shear modulus (G), bulk modulus (B), and Poisson's ratio (?), are of significant interest to many design and engineering applications. The choice of the most appropriate material for a particular application at elevated temperatures therefore requires knowledge of its elastic properties as a function of temperature. In addition, mechanical vibration can cause significant damage in the automotive, aerospace, and architectural industries and thus, the ability of a material to dissipate elastic strain energy in materials, known as damping or internal friction, is also important property. Internal friction can be the result of a wide range of physical mechanisms, and depends on the material, temperature, and frequency of the loading. When utilized effectively in engineering applications, the damping capacity of a material can remove undesirable noise and vibration as heat to the surroundings. The elastic properties of materials can be determined by static or dynamic methods. Resonant Ultrasound Spectroscopy (RUS), used in this study, is a unique and sophisticated non-destructive dynamic technique for determining the complete elastic tensor of a solid by measuring the resonant spectrum of mechanical resonance for a sample of known geometry, dimensions, and mass. In addition, RUS allows determination of internal friction, or damping, at different frequencies and temperatures. Polycrystalline pure magnesium (Mg) exhibits excellent high damping properties. However, the poor mechanical properties limit the applications of pure Mg. Although alloying can improve the mechanical properties of Mg, the damping properties are reduced with additions of alloying elements. Therefore, it becomes necessary to study and develop Mg-alloys with simultaneous high damping capacity and improved mechanical properties. Moreover, studies involving the high temperature dynamic elastic properties of Mg alloys are limited. In this study, the elastic properties and internal friction of two magnesium alloys were studied at elevated temperatures using RUS. The effect of alloy composition and grain size was investigated. The wrought magnesium alloys AZ31 and ZK60 were employed. Table 1 gives the nominal chemical compositions of these two alloys. The ZK60 alloy is a commercial extruded plate with a T5 temper, i.e. solution-treated at 535 C for two hours, quenched in hot water, and aged at 185 C for 24 hours. The AZ31 alloy is a commercial rolled plate with a H24 temper, i.e. strain hardened and partially annealed.

Freels, M.; Liaw, P. K.; Garlea, E.; Morrell, J. S.; Radiovic, M.

2011-06-01T23:59:59.000Z

364

Postbuckling behaviors of nanorods including the effects of nonlocal elasticity theory and surface stress  

SciTech Connect (OSTI)

This paper is concerned with postbuckling behaviors of nanorods subjected to an end concentrated load. One end of the nanorod is clamped while the other end is fixed to a support that can slide in the slot. The governing equation is developed from static equilibrium and geometrical conditions by using the exact curvature corresponding to the elastica theory. The nonlocal elasticity, the effect of surface stress, and their combined effects are taken into account in Euler–Bernoulli beam theory. Differential equations in this problem can be solved numerically by using the shooting-optimization technique for the postbuckling loads and the buckled configurations. The results show that nanorods with the nonlocal elasticity effect undergo increasingly large deformation while the effect of surface stress in combination with nonlocal elasticity decreases the deflection of nanorods under the same postbuckling load.

Thongyothee, Chawis, E-mail: chawist@hotmail.com; Chucheepsakul, Somchai [Department of Civil Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140 (Thailand)

2013-12-28T23:59:59.000Z

365

Elastic properties of sulphur and selenium doped ternary PbTe alloys by first principles  

SciTech Connect (OSTI)

Lead telluride (PbTe) is an established thermoelectric material which can be alloyed with sulphur and selenium to further enhance the thermoelectric properties. Here, a first principles study of ternary alloys PbS{sub x}Te{sub (1?x)} and PbSe{sub x}Te{sub (1?x)} (0?x?1) based on the Virtual Crystal Approximation (VCA) is presented for different ratios of the isoelectronic atoms in each series. Equilibrium lattice parameters and elastic constants have been calculated and compared with the reported data. Anisotropy parameter calculated from the stiffness constants showed a slight improvement in anisotropy of elastic properties of the alloys over undoped PbTe. Furthermore, the alloys satisfied the predicted stability criteria from the elastic constants, showing stable structures, which agreed with the previously reported experimental results.

Bali, Ashoka, E-mail: rcmallik@physics.iisc.ernet.in; Chetty, Raju, E-mail: rcmallik@physics.iisc.ernet.in; Mallik, Ramesh Chandra, E-mail: rcmallik@physics.iisc.ernet.in [Thermoelectric Materials and Devices Laboratory, Department of Physics, Indian Institute of Science, Bangalore-560012 (India)

2014-04-24T23:59:59.000Z

366

Modeling and Application of Series Elastic Actuators for Force Control Multi Legged Robots  

E-Print Network [OSTI]

Series Elastic Actuators provide many benefits in force control of robots in unconstrained environments. These benefits include high force fidelity, extremely low impedance, low friction, and good force control bandwidth. Series Elastic Actuators employ a novel mechanical design architecture which goes against the common machine design principal of "stiffer is better". A compliant element is placed between the gear train and driven load to intentionally reduce the stiffness of the actuator. A position sensor measures the deflection, and the force output is accurately calculated using Hooke's Law (F=Kx). A control loop then servos the actuator to the desired output force. The resulting actuator has inherent shock tolerance, high force fidelity and extremely low impedance. These characteristics are desirable in many applications including legged robots, exoskeletons for human performance amplification, robotic arms, haptic interfaces, and adaptive suspensions. We describe several variations of Series Elastic Ac...

S, Arumugom; V, Ponselvan

2009-01-01T23:59:59.000Z

367

An elastic-perfectly plastic flow model for finite element analysis of perforated materials  

SciTech Connect (OSTI)

This paper describes the formulation of an elastic-perfectly plastic flow theory applicable to equivalent solid [EQS] modeling of perforated materials. An equilateral triangular array of circular penetrations is considered. The usual assumptions regarding geometry and loading conditions applicable to the development of elastic constants for EQS modeling of perforated plates are considered to apply here. An elastic-perfectly plastic [EPP] EQS model is developed for a collapse surface that includes fourth-order stress terms. The fourth order yield function has been shown to be appropriate for plates with a triangular array of circular holes. A complete flow model is formulated using the consistent tangent modulus approach based on the fourth order yield function.

Jones, D.P.; Gordon, J.L.; Hutula, D.N.; Banas, D.; Newman, J.B.

1999-02-01T23:59:59.000Z

368

A cell model for homogenization of fiber-reinforced composites: General theory and nonlinear elasticity effects  

SciTech Connect (OSTI)

The theoretical basis of the homogenization technique developed by Aboudi is presented and assessed. Given the constitutive relations of the constituents, this technique provides an equivalent, homogeneous, constitutive model of unidirectional, continuous-fiber-reinforced composites. The expressions that comprise the first-order version of the technique are given special attention as this treatment has considerable practical value. Nonlinear elasticity effects are added to it. This extension increases the accuracy of numerical simulations of high strain-rate loadings. It is particularly important for any dynamic loading in which shock waves might be produced, including crash safety, armor, and munitions applications. Examples illustrate that elastic nonlinearity can make substantial contributions at strains of only a few per cent. These contributions are greatest during post-yield inelastic deformation. The micromechanics-based homogenization technique is shown to facilitate use of an efficient approximate treatment of elastic nonlinearity in composites with isotropic matrix materials.

Aidun, J.B.; Addessio, F.L.

1995-11-01T23:59:59.000Z

369

Elastic Cross Sections for Electron Collisions with Molecules Relevant to Plasma Processing  

SciTech Connect (OSTI)

Absolute electron-impact cross sections for molecular targets, including their radicals, are important in developing plasma reactors and testing various plasma processing gases. Low-energy electron collision data for these gases are sparse and only the limited cross section data are available. In this report, elastic cross sections for electron-polyatomic molecule collisions are compiled and reviewed for 17 molecules relevant to plasma processing. Elastic cross sections are essential for the absolute scale conversion of inelastic cross sections, as well as for testing computational methods. Data are collected and reviewed for elastic differential, integral, and momentum transfer cross sections and, for each molecule, the recommended values of the cross section are presented. The literature has been surveyed through early 2010.

Yoon, J.-S.; Song, M.-Y.; Kato, H.; Hoshino, M.; Tanaka, H.; Brunger, M. J.; Buckman, S. J.; Cho, H. [National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Department of Material and Life Sciences, Sophia University, Tokyo 102-8554 (Japan); ARC Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001 (Australia); ARC Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia); Physics Department, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

2010-09-15T23:59:59.000Z

370

Global SAXS Data Analysis for Multilamellar Vesicles: Evolution of the Scattering Density Profile (SDP) Model  

SciTech Connect (OSTI)

The highly successful scattering density profile (SDP) model, used to jointly analyze small-angle X-ray and neutron scattering data from unilamellar vesicles, has been adapted for use with data from fully hydrated, liquid crystalline multilamellar vesicles (MLVs). Using a genetic algorithm, this new method is capable of providing high-resolution structural information, as well as determining bilayer elastic bending fluctuations from standalone X-ray data. Structural parameters such as bilayer thickness and area per lipid were determined for a series of saturated and unsaturated lipids, as well as binary mixtures with cholesterol. The results are in good agreement with previously reported SDP data, which used both neutron and X-ray data. The inclusion of deuterated and non-deuterated MLV neutron data in the analysis improved the lipid backbone information but did not improve, within experimental error, the structural data regarding bilayer thickness and area per lipid.

Heftberger, Peter [University of Graz, Institute of Molecular Biosciences, Austria] [University of Graz, Institute of Molecular Biosciences, Austria; Kollmitzer, Benjamin [University of Graz, Institute of Molecular Biosciences, Austria] [University of Graz, Institute of Molecular Biosciences, Austria; Heberle, Frederick A [ORNL] [ORNL; Pan, Jianjun [ORNL] [ORNL; Rappolt, Michael [University of Leeds, UK] [University of Leeds, UK; Amenitsch, Heinz [Graz University of Technology] [Graz University of Technology; Kucerka, Norbert [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,] [Atomic Energy of Canada Limited (AECL), Canadian Neutron Beam Centre (CNBC) and Comenius University,; Katsaras, John [ORNL] [ORNL; Pabst, georg [University of Graz, Institute of Molecular Biosciences, Austria] [University of Graz, Institute of Molecular Biosciences, Austria

2014-01-01T23:59:59.000Z

371

aerial density profiles: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

present an analytic approach to predict gas density and temperature profiles in dark matter haloes. We assume that the gas density profile traces the dark matter density profile...

372

Scaling analysis of bio-molecular dynamics derived from elastic incoherent neutron scattering experiments  

SciTech Connect (OSTI)

Numerous neutron scattering studies of bio-molecular dynamics employ a qualitative analysis of elastic scattering data and atomic mean square displacements. We provide a new quantitative approach showing that the intensity at zero energy exchange can be a rich source of information of bio-structural fluctuations on a pico- to nano-second time scale. Elastic intensity scans performed either as a function of the temperature (back-scattering) and/or by varying the instrumental resolution (time of flight spectroscopy) yield the activation parameters of molecular motions and the approximate structural correlation function in the time domain. The two methods are unified by a scaling function, which depends on the ratio of correlation time and instrumental resolution time. The elastic scattering concept is illustrated with a dynamic characterization of alanine-dipeptide, protein hydration water, and water-coupled protein motions of lysozyme, per-deuterated c-phycocyanin (CPC) and hydrated myoglobin. The complete elastic scattering function versus temperature, momentum exchange, and instrumental resolution is analyzed instead of focusing on a single cross-over temperature of mean square displacements at the apparent onset temperature of an-harmonic motions. Our method predicts the protein dynamical transition (PDT) at T{sub d} from the collective (?) structural relaxation rates of the solvation shell as input. By contrast, the secondary (?) relaxation enhances the amplitude of fast local motions in the vicinity of the glass temperature T{sub g}. The PDT is specified by step function in the elastic intensity leading from elastic to viscoelastic dynamic behavior at a transition temperature T{sub d}.

Doster, W. [Physik-Department, Technische Universität München, D-85748 Garching (Germany)] [Physik-Department, Technische Universität München, D-85748 Garching (Germany); Nakagawa, H. [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany) [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany); Japan Atomic Energy Agency, Quantum Beam Science Directorate, Tokai, Ibaraki 319-1195 (Japan); Appavou, M. S. [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)] [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)

2013-07-28T23:59:59.000Z

373

Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering  

SciTech Connect (OSTI)

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q{sup 2}=0.15, 0.25 (GeV/c){sup 2}. The results are inconsistent with calculations solely using the elastic nucleon intermediate state and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A{sub n} provides a direct probe of the imaginary component of the 2{gamma} exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

Armstrong, D. S.; Averett, T.; Bailey, S. L.; Finn, J. M.; Griffioen, K. A.; Moffit, B.; Phillips, S. K.; Secrest, J.; Sulkosky, V. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187 (United States); Arvieux, J.; Bimbot, L.; Guler, H.; Lenoble, J.; Marchand, D.; Morlet, M.; Ong, S.; Van de Wiele, J. [Institut de Physique Nucleaire d'Orsay, CNRS/IN2P3, Universite Paris Sud, Orsay (France); Asaturyan, R.; Mkrtchyan, H.; Stepanyan, S. [Yerevan Physics Institute, Yerevan 375036 (Armenia)] (and others)

2007-08-31T23:59:59.000Z

374

Extension of Coupled-Modes Method to Waveguides with Elastic Bottom  

SciTech Connect (OSTI)

In this paper, the coupled-modes method of acoustic propagation is extended to waveguides with smoothly varying fluid-elastic interfaces. To formulate the problem without recourse to the SH wave component from the ground up, we employ the {l_brace}u{sub z},u{sub v{r_brace}}-formulation developed in seismology. The result is remarkably different from that for fluid-fluid interfaces; the boundary conditions imposed at fluid-elastic interfaces give rise to terms including unknown boundary values so that the differential system obtained is not closed. To make the system closed, additional compatibility and constraining conditions have to be imposed.

Wang Ning; Wang Haozhong; Gao Dazhi [Department of Physics, Ocean University of China, 238 Songling Rd. Qingdao (China)

2010-09-06T23:59:59.000Z

375

Observation of Narrow Structures in the P-P Elastic Analyzing Power  

E-Print Network [OSTI]

of the analyzing power A~ in proton-proton elastic scattering has been measured in small steps using an internal target during polarized beam acceleration from 1 to 3 GeV/c. The momentum bin size ranges from 5 to 18 MeV/c. The relative uncertainty of ?t... intercepting the proton beam dur- ing its acceleration; and of the p-p elastic analyzing power, also made at LNS but with the distribution of in- cident proton energies generated through energy loss of the primary beam traversing a thick target. (In...

Shimizu, H.; Yoshida, H. Y.; Ohnuma, H.; Kobayashi, Y.; Kobayashi, K.; Nakagawa, T.; Holt, J. A.; Glass, G.; Hiebert, John C.; Kenefick, R. A.; Nath, S.; Northcliffe, L. C.; Simon, A.; Hirmatsu, S.; Mori, Y.; Sato, H.; Takagi, A.; Toyana, T.; Ueno, A.; Imai, K.

1990-01-01T23:59:59.000Z

376

Application Of Elastic Perfectly Plastic Cyclic Analysis To Assessment Of Creep Strain  

SciTech Connect (OSTI)

A cyclic elastic-perfectly plastic analysis method is proposed which provides a conservative estimate to cyclic creep strain accumulation within the ratchet boundary. The method is to check for ratcheting based on an elastic-perfectly material with a temperature-dependent pseudo yield stress defined by temperature, time and stress to give 1% creep strain. It does not require stress classification and is also applicable to a full range of temperature above and below the creep regime. This simplified method could be used as a rapid screening calculation, with full time-dependent creep analysis used if necessary.

Carter, Peter [Stress Engineering Services Inc.] [Stress Engineering Services Inc.; Jetter, Robert I [Consultant] [Consultant; Sham, Sam [ORNL] [ORNL

2012-01-01T23:59:59.000Z

377

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

E-Print Network [OSTI]

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 $^{16}$O+$^{120}$Sn,$^{144}$Sm,$^{208}$Pb systems at energies near and below the corresponding Coulomb 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 literature for the nuclear potential diffuseness derived from both methods.

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

2014-06-05T23:59:59.000Z

378

Comparison of temperature and humidity profiles with elastic-backscatter lidar data  

SciTech Connect (OSTI)

This contribution analyzes elastic-backscatter lidar data and temperature and humidity profiles from radiosondes acquired in Barcelona in July 1992. Elastic-backscatter lidar data reveal the distribution of aerosols within the volume of atmosphere scanned. By comparing this information with temperature and humidity profiles of the atmosphere at a similar time, we are able to asses de relationship among aerosol distribution and atmospheric stability or water content, respectively. Comparisons have shown how lidar`s revealed layers of aerosols correspond to atmospheric layers with different stability condition and water content.

Soriano, C. [Universidad Politecnica de Cataluna, Barcelona (Spain)]|[Los Alamos National Lab., NM (United States); Buttler, W.T. [Los Alamos National Lab., NM (United States); Baldasano, J.M. [Universidad Politecnica de Cataluna, Barcelona (Spain)

1995-04-01T23:59:59.000Z

379

Elastic and Inelastic Scattering of Alpha-Particles and Protons from Sm-144  

E-Print Network [OSTI]

PH YSICA L REVIEW C VOLUME 4, NUMB ER 6 DECEMBER 1971 Elastic and Inelastic Scattering of o. Particles and Protons from Sm~ J. H. Barker* and J. C. Hiebert Texas ARM University, College Station, Texas 77843 (Received 14 June 1971) Differential... cross sections for the elastic scattering and inelastic scattering to the low-ly- ing states in Sm have been measured using 50-MeV e-particle and 30-MeV proton beams from the Texas ASM variable-energy cyclotron. Spin and parity assignments are checked...

Barker, J. H.; Hiebert, John C.

1971-01-01T23:59:59.000Z

380

Surface Folding Induced Attraction and Motion of Particles in a Soft Elastic Gel: Cooperative Effects of Surface Tension, Elasticity and Gravity  

E-Print Network [OSTI]

We report, for the first time, some experimental observations regarding a new type of long range interaction between rigid particles that prevails when they are suspended in an soft elastic gel. A denser particle submerges itself to a considerable depth inside the gel and becomes buoyant by balancing its weight against the elastic force exerted by the surrounding medium. By virtue of a large elastic-capillary length, the surface of the gel wraps around the particle and closes to create a line singularity connecting the particle to the free surface of the gel. Substantial amount of tensile strain is thus developed in the gel network parallel to the free surface that penetrates to a significant depth inside the gel. The field of this tensile strain is rather long range owing to a large correlation length and strong enough to pull two submerged particles into contact. The particles move towards each other with an effective force following an inverse linear distance law. When more monomers or dimers of the particles are released inside the gel, they orient rather freely inside the capsules they are in, and attract each other to form close packed clusters. Eventually, these clusters themselves interact and coalesce. This is an emergent phenomenon in which the gravity, the capillarity and the elasticity work in tandem to create a long range interaction. We also present the results of a related experiment, in which a particle suspended inside a thickness graded gel moves accompanied by the continuous folding and the relaxation of the surface of the gel.

Aditi Chakrabarti; Manoj K. Chaudhury

2014-01-28T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

A beautiful day in the neighborhood : the influence of neighborhood density on speech production  

E-Print Network [OSTI]

disability ( for example, dyslexia)? YES NO If yes, pleasedisability (for example, dyslexia)? YES NO If yes, please

Freedman, Skott Elliot

2009-01-01T23:59:59.000Z

382

Influence of ambient gas on the temperature and density of laser produced carbon plasma  

E-Print Network [OSTI]

; accepted for publication 11 November 1997 The effect of ambient gas on the dynamics of the plasma generated In moderate or high pressures, a blast wave model is found to describe accurately the plume propagation the maximum plume length with considerable accuracy.7,13 In this letter we report the effect of ambient

Harilal, S. S.

383

Influence of board density, mat construction, and chip type on performance of  

E-Print Network [OSTI]

of the cypress family (Cup- ressaceae) native to poor or limestone soils of eastern North America (Wittwer 1985 of this study was to investigate mechanical and physical performances of particleboard made from low

384

High density laser-driven target  

DOE Patents [OSTI]

A high density target for implosion by laser energy composed of a central quantity of fuel surrounded by a high-Z pusher shell with a low-Z ablator-pusher shell spaced therefrom forming a region filled with low-density material.

Lindl, John D. (San Ramon, CA)

1981-01-01T23:59:59.000Z

385

Density Estimation Trees in High Energy Physics  

E-Print Network [OSTI]

Density Estimation Trees can play an important role in exploratory data analysis for multidimensional, multi-modal data models of large samples. I briefly discuss the algorithm, a self-optimization technique based on kernel density estimation, and some applications in High Energy Physics.

Anderlini, Lucio

2015-01-01T23:59:59.000Z

386

Density functional theory for carbon dioxide crystal  

SciTech Connect (OSTI)

We present a density functional approach to describe the solid?liquid phase transition, interfacial and crystal structure, and properties of polyatomic CO{sub 2}. Unlike previous phase field crystal model or density functional theory, which are derived from the second order direct correlation function, the present density functional approach is based on the fundamental measure theory for hard-sphere repulsion in solid. More importantly, the contributions of enthalpic interactions due to the dispersive attractions and of entropic interactions arising from the molecular architecture are integrated in the density functional model. Using the theoretical model, the predicted liquid and solid densities of CO{sub 2} at equilibrium triple point are in good agreement with the experimental values. Based on the structure of crystal-liquid interfaces in different planes, the corresponding interfacial tensions are predicted. Their respective accuracies need to be tested.

Chang, Yiwen; Mi, Jianguo, E-mail: mijg@mail.buct.edu.cn; Zhong, Chongli [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

2014-05-28T23:59:59.000Z

387

Neutral depletion and the helicon density limit  

SciTech Connect (OSTI)

It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup ?3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 ?s. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States)

2013-12-15T23:59:59.000Z

388

How to Calculate Molecular Column Density  

E-Print Network [OSTI]

The calculation of the molecular column density from molecular spectral (rotational or ro-vibrational) transition measurements is one of the most basic quantities derived from molecular spectroscopy. Starting from first principles where we describe the basic physics behind the radiative and collisional excitation of molecules and the radiative transfer of their emission, we derive a general expression for the molecular column density. As the calculation of the molecular column density involves a knowledge of the molecular energy level degeneracies, rotational partition functions, dipole moment matrix elements, and line strengths, we include generalized derivations of these molecule-specific quantities. Given that approximations to the column density equation are often useful, we explore the optically thin, optically thick, and low-frequency limits to our derived general molecular column density relation. We also evaluate the limitations of the common assumption that the molecular excitation temperature is con...

Mangum, Jeffrey G

2015-01-01T23:59:59.000Z

389

Characteristics of sound propagation in shallow water over an elastic seabed with a thin cap-rock layer  

E-Print Network [OSTI]

Characteristics of sound propagation in shallow water over an elastic seabed with a thin cap over a lay- ered elastic seabed with a shear wave speed comparable to but lower than the water-column sound speed. A theoretical analysis and numerical modeling show that, in such environments, low attenua

390

NUCLEARENGINEERINGAND DESIGN17 (1971) 64.-75. NORTH-HOLLANDPUBLISHINGCOMPANY PROGRESS IN THREE-DIMENSIONAL ELASTIC-PLASTIC STRESS  

E-Print Network [OSTI]

-DIMENSIONAL ELASTIC-PLASTIC STRESS ANALYSIS FOR FRACTURE MECHANICS * N. LEVY, P.V. MARCAL and J.R. RICE Division summarizesprogressin the development of finite element methods for three-dimensionalelastic- plastic stressanalysisin methods for three-dimensional elastic-plastic stress analysis in fracture mechanics, as a part

391

Elastic-Plastic-Brittle Transitions and Avalanches in Disordered Media Sohan Kale and Martin Ostoja-Starzewski*  

E-Print Network [OSTI]

Elastic-Plastic-Brittle Transitions and Avalanches in Disordered Media Sohan Kale and Martin Ostoja to simulate elastic-plastic-brittle transitions in a disordered medium is presented. The model is based, and the fracture surfaces. The model demonstrates a plastic strain avalanche behavior for perfectly plastic as well

Ostoja-Starzewski, Martin

392

Experimental and theoretical studies of spectral alteration in ultrasonic waves resulting from nonlinear elastic response in rock  

SciTech Connect (OSTI)

Experiments in rock show a large nonlinear elastic wave response, far greater than that of gases, liquids and most other solids. The large response is attributed to structural defects in rock including microcracks and grain boundaries. In the earth, a large nonlinear response may be responsible for significant spectral alteration at amplitudes and distances currently considered to be well within the linear elastic regime.

Johnson, P.A.; McCall, K.R.; Meegan, G.D. Jr. [Los Alamos National Lab., NM (United States)

1993-11-01T23:59:59.000Z

393

Measurement of Elastic Modulus of PUNB Bonded Sand as a Function of Temperature J. Thole and C. Beckermann  

E-Print Network [OSTI]

. Beckermann Dept. of Mechanical and Industrial Engineering, University of Iowa, Iowa City, Iowa 52242 Abstract Measurements of the elastic modulus of PUNB bonded silica sand are performed using a three-point bend test from for the elastic modulus at room temperature is obtained when measured under compressive, tensile or bending

Beckermann, Christoph

394

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

E-Print Network [OSTI]

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

Ertan, E.

395

Control of non-linear elasticity in F-actin networks with microtubules Yi-Chia Lin,a  

E-Print Network [OSTI]

of micro- tubules to F-actin networks confers a local compressibility.25 An increased degree of controlControl of non-linear elasticity in F-actin networks with microtubules Yi-Chia Lin,a Gijsje H DOI: 10.1039/c0sm00478b We measure the elastic properties of composite cytoskeletal networks

MacKintosh, F.C.

396

Ions in solution: Density corrected density functional theory (DC-DFT)  

SciTech Connect (OSTI)

Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes of density functional theory calculations are significantly improved by using densities more accurate than the self-consistent densities. We discuss how to identify such cases, and how DC-DFT applies more generally. To illustrate, we calculate potential energy surfaces of HO·Cl{sup ?} and HO·H{sub 2}O complexes using various common approximate functionals, with and without this density correction. Commonly used approximations yield wrongly shaped surfaces and/or incorrect minima when calculated self consistently, while yielding almost identical shapes and minima when density corrected. This improvement is retained even in the presence of implicit solvent.

Kim, Min-Cheol; Sim, Eunji, E-mail: esim@yonsei.ac.kr [Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 120-749 (Korea, Republic of)] [Department of Chemistry and Institute of Nano-Bio Molecular Assemblies, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Burke, Kieron [Department of Chemistry, University of California, Irvine, California 92697 (United States)] [Department of Chemistry, University of California, Irvine, California 92697 (United States)

2014-05-14T23:59:59.000Z

397

High pressure elastic properties of minerals from ab initio simulations: The case of pyrope, grossular and andradite silicate garnets  

SciTech Connect (OSTI)

A computational strategy is devised for the accurate ab initio simulation of elastic properties of crystalline materials under pressure. The proposed scheme, based on the evaluation of the analytical stress tensor and on the automated computation of pressure-dependent elastic stiffness constants, is implemented in the CRYSTAL solid state quantum-chemical program. Elastic constants and related properties (bulk, shear and Young moduli, directional seismic wave velocities, elastic anisotropy index, Poisson's ratio, etc.) can be computed for crystals of any space group of symmetry. We apply such a technique to the study of high-pressure elastic properties of three silicate garnet end-members (namely, pyrope, grossular, and andradite) which are of great geophysical interest, being among the most important rock-forming minerals. The reliability of this theoretical approach is proved by comparing with available experimental measurements. The description of high-pressure properties provided by several equations of state is also critically discussed.

Erba, A., E-mail: alessandro.erba@unito.it; Mahmoud, A.; Dovesi, R. [Dipartimento di Chimica and Centre of Excellence NIS (Nanostructured Interfaces and Surfaces), Università di Torino, via Giuria 5, IT-10125 Torino (Italy)] [Dipartimento di Chimica and Centre of Excellence NIS (Nanostructured Interfaces and Surfaces), Università di Torino, via Giuria 5, IT-10125 Torino (Italy); Belmonte, D. [DISTAV, Università di Genova, Corso Europa 26, 16132 Genoa (Italy)] [DISTAV, Università di Genova, Corso Europa 26, 16132 Genoa (Italy)

2014-03-28T23:59:59.000Z

398

Critical behaviour in the elastic response of hydrogels  

E-Print Network [OSTI]

Highly responsive, or 'smart' materials are abundant in Nature; individual cells, for instance, can adapt their mechanical properties to the local surroundings through small changes in their internal structure. An effective method to enhance the responsiveness of synthetic materials is to operate near a critical point, where small variations lead to large changes in material properties. Recent theories have suggested that fibre/polymer networks can show critical behaviour near and below the point of marginal connectivity that separates rigid and floppy states [1-4]. To date, however, experimental evidence for criticality in such networks has been lacking. Here, we demonstrate critical behaviour in the stress response of synthetic hydrogels at low concentrations of order 0.1% volume fraction. We show, using computer simulations, that the observed response to stress can be understood by considering the influence of a zero-temperature critical point, i.e. the Maxwell isostatic point [5], together with the intrinsically nonlinear stretch response of semi-flexible polymer strands in the gel.

M. Dennison; M. Jaspers; P. H. J. Kouwer; C. Storm; A. E. Rowan; F. C. MacKintosh

2014-07-01T23:59:59.000Z

399

Wood density measurement protocol J Chave Page 1 Measuring wood density for tropical forest trees  

E-Print Network [OSTI]

Wood density measurement protocol ­ J Chave Page 1 Measuring wood density for tropical forest trees Diversité Biologique Université Paul Sabatier 31000 Toulouse, France 1. Introduction Wood is a biological, that transport the sap along the stem and they are filled by water. The density of tree wood is an interesting

Chave, Jérôme

400

Testing the kinetic energy functional: Kinetic energy density as a density functional  

E-Print Network [OSTI]

is to the exchange-correlation energy as a functional of the density. A large part of the total energy, the kinetic contexts. For finite systems these forms integrate to the same global ki- netic energy, but they differTesting the kinetic energy functional: Kinetic energy density as a density functional Eunji Sim

Burke, Kieron

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Yield Strength as a Function of Dislocation Density  

E-Print Network [OSTI]

this ·Elastic load-unload curve for Iron sample is plotted and curve-fitted to Hertzian model P=4/3E*R1, and is depth. ·This radius value is then used with the elastic load-unload curve of brass to solve for its and calculated yield stress are plotted and a curve fit is applied using the Hall-Petch equation to give

Collins, Gary S.

402

Implementation of a parallel conjugate gradient method for simulation of elastic light scattering  

E-Print Network [OSTI]

1 Implementation of a parallel conjugate gradient method for simulation of elastic light scattering solved with (preconditioned) conjugate gradient methods. For realistic problems the size of the matrix gradient method for this type of problems, with emphasis on coarse grain distributed memory implementations

403

Minimal energy for elastic inclusions By Hans Knupfer and Robert V. Kohn  

E-Print Network [OSTI]

Minimal energy for elastic inclusions By Hans Kn¨upfer and Robert V. Kohn Courant Institute, New York University Mercer Street 251, New York, NY 10012, USA We consider a variant of the isoperimetric the emergence of the new phase, the interfacial energy provides an energy barrier for the creation and growth

404

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

E-Print Network [OSTI]

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

Snieder, Roel

405

Elastic properties of carbon nanotubes under hydrostatic pressure S. Reich and C. Thomsen  

E-Print Network [OSTI]

.g., in composite nanotube materials, and to gain a better understanding of this one-dimensional carbon basedElastic properties of carbon nanotubes under hydrostatic pressure S. Reich and C. Thomsen Institut. Ordejo´n Institut de Cie`ncia de Materials de Barcelona (CSIC), Campus de la U.A.B. E-08193 Bellaterra

Nabben, Reinhard

406

Microscopic optical potentials of the nucleon-nucleus elastic scattering at medium energies  

E-Print Network [OSTI]

Microscopic optical potentials of the nucleon-nucleus elastic scattering at medium energies R interpreted in terms of the phenomenological optical model potential [1]. At medium and high energies of the optical model approach at medium energies has also some theoretical founda- tions. At a sufficiently large

Paris-Sud XI, Université de

407

Description of the dip in meson-proton elastic scattering by the Chou-Yang model  

SciTech Connect (OSTI)

We show it is possible to reproduce the correct localization of the dip and bump structure in the meson-proton elastic scattering by using the Chou-Yang model with a modification which consists in expressing the eikonal in momentum-transfer space as the product of the form factors times a function that carries zero.

Bellandi F., J.; Covolan, R.J.M.; Menon, M.J.; Pimentel, B.M.

1988-01-01T23:59:59.000Z

408

Ratcheting-induced wrinkling of an elastic film on a metal layer under cyclic temperatures  

E-Print Network [OSTI]

Ratcheting-induced wrinkling of an elastic film on a metal layer under cyclic temperatures S.H. Im­metal interface, which bias the plastic flow of the metal. Consequently, the metal ratchets, namely, accumulates of the film grows. The model reveals an analogy between ratcheting and creep. Analytical solutions

Huang, Rui

409

High precision measurement of the proton elastic form factor ratio at low Q²  

E-Print Network [OSTI]

Experiment E08-007 measured the proton elastic form factor ratio [mu]GE/GM in the range of Q2 = 0.3-0.7(GeV/c)2 by recoil polarimetry. Data were taken in 2008 at the Thomas Jefferson National Accelerator Facility in Virginia, ...

Zhan, Xiaohui

2010-01-01T23:59:59.000Z

410

An annual quasidifference approach to water price elasticity David R. Bell1  

E-Print Network [OSTI]

, industrial, and heavy commercial water usage, residential/urban water use is more likely to occur in settingsAn annual quasidifference approach to water price elasticity David R. Bell1 and Ronald C. Griffin1] The preferred price specification for retail water demand estimation has not been fully settled by prior

Griffin, Ronald

411

Elastic uplift in southeast Greenland due to rapid ice mass loss  

E-Print Network [OSTI]

[1] The rapid unloading of ice from the southeastern sector of the Greenland ice sheet between 2001 and 2006 caused an elastic uplift of ?35 mm at a GPS site in Kulusuk. Most of the uplift results from ice dynamic-induced volume losses on two nearby...

Khan, Shfaqat A.; Wahr, John; Stearns, Leigh; Hamilton, Gordon; van Dam, Tonie; Larson, Kristine M.; Francis, Olivier

2007-11-01T23:59:59.000Z

412

Wilhelmy plate artifacts in elastic monolayers T. A. Witten,a  

E-Print Network [OSTI]

are in the radial and azimuthal directions, so that r =0. This equation expresses the balance of radial forces that rr is uniform, as expected. In an extremely anisotropic material for which =0, Eq. 1 implies that rr that it retains the symmetry of the boundaries. We also suppose that the elasticity of the material is isotropic

Lee, Ka Yee C.

413

Experimental testing of the variable rotated elastic parabolic Harry J. Simpsona)  

E-Print Network [OSTI]

Experimental testing of the variable rotated elastic parabolic equation Harry J. Simpsona) Physical Street, Golden, Colorado 80401 Raymond J. Soukup Acoustics Division Code 7144, Naval Research Laboratory and the ability of the model to produce benchmark-quality agreement with experimental data [J. M. Collis et al., J

414

Elastic response of a carbon nanotube fiber reinforced polymeric composite: A numerical and experimental study  

E-Print Network [OSTI]

Elastic response of a carbon nanotube fiber reinforced polymeric composite: A numerical. The carbon nanotubes increase the effective diameter of the fiber and provide a larger interface area clay, fibers like carbon nanotube and carbon nanofiber, or particulates like sil- ica or expanded

Qian, Dong

415

Absolute angle-differential elastic cross sections for electron collisions with diacetylene  

SciTech Connect (OSTI)

We report measured and calculated differential elastic cross sections for collisions of low-energy electrons with diacetylene (1,3-butadiyne). A generally satisfactory agreement between theory and experiment has been found. The calculated cross sections provide interesting insight into the underlying resonant structure.

Allan, M.; Winstead, C.; McKoy, V. [Department of Chemistry, University of Fribourg, chemin du Musee 9, CH-1700 Fribourg (Switzerland); A. A. Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States)

2011-06-15T23:59:59.000Z

416

A Radiation Condition for Layered Elastic Media ANDREW I. MADYAROV and BOJAN B. GUZINAj  

E-Print Network [OSTI]

A Radiation Condition for Layered Elastic Media ANDREW I. MADYAROV and BOJAN B. GUZINAj Department. This study aims to establish a generalized radiation condition for time-harmonic elastodynamic states.g. Rayleigh, Love and Stoneley) waves comprising the far-field patterns, the radiation condition is formulated

Guzina, Bojan

417

A molecular dynamics simulation study of elastic properties of HMX Thomas D. Sewell and Ralph Menikoff  

E-Print Network [OSTI]

is compared to one based on a fit to sound speed data yielding reasonably good agreement. The bulk modulus fitting form. ISLS sound speed measurements provide a more-or-less direct path to the isentropic elastic for comparison to sound speed measurements generally requires extrapolation of the EOS fit to zero pressure

Utah, University of

418

Two parabolic equations for propagation in layered poro-elastic media  

E-Print Network [OSTI]

Two parabolic equations for propagation in layered poro-elastic media Adam M. Metzlera) Applied Space Center, Mississippi 39529 Jon M. Collis Colorado School of Mines, Golden, Colorado 80401 (Received.40.Fz, 43.30.Ma [TFD] Pages: 246­256 I. INTRODUCTION The parabolic equation method is accurate

419

Elastic properties and pressure-induced phase transitions of single-walled carbon nanotubes  

E-Print Network [OSTI]

Elastic properties and pressure-induced phase transitions of single-walled carbon nanotubes S-walled carbon nanotubes under hydrostatic pressure by first-princi- ples calculations. The circular tubes of carbon nanotubes has been studied with a variety of experimental techniques. Most of these studies seemed

Nabben, Reinhard

420

np-elastic analyzing power A(N0) at 485 and 788 MeV  

E-Print Network [OSTI]

Measurements are reported for the np-elastic analyzing power from 30 degrees to 128 degrees c.m., at 485 and 788 MeV, with a typical precision of 0.005 and absolute accuracy of 2%. Results strengthen the isospin-0 phase-shift analysis, and clarify...

McNaughton, M. W.; McNaughton, K. H.; Glass, G.; Riley, P. J.; Auer, KH; Davis, CA; Gulmez, E.; Hiebert, John C.; Jeppersen, R. H.; Ransome, R. D.; Spinka, H.; Sum, V.; Supek, I.; Tripard, G. E.; Woolverton, H.

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Silver Surfer: A System to Compare Isometric and Elastic Board Interfaces for Locomotion in VR  

E-Print Network [OSTI]

Silver Surfer: A System to Compare Isometric and Elastic Board Interfaces for Locomotion in VR Jia travel in virtual environments. We also demonstrate the setup of a complete virtual reality system aimed Surf Simulator. Because it is hard for people to yaw a board when standing on it, most board interfaces

Lindeman, Robert W.

422

Swept Blade Aero-Elastic Model for a Small Wind Turbine (Presentation)  

SciTech Connect (OSTI)

A preprocessor for analyzing preswept wind turbines using the in-house aero-elastic tool coupled with a multibody dynamic simulator was developed. A baseline 10-kW small wind turbine with straight blades and various configurations that featured bend-torsion coupling via blade-tip sweep were investigated to study their impact on ultimate loads and fatigue damage equivalent loads.

Damiani, R.; Lee, S.; Larwood, S.

2014-07-01T23:59:59.000Z

423

Formal Modeling and Evaluation of Stateful Service-based Business Process Elasticity in the  

E-Print Network [OSTI]

Formal Modeling and Evaluation of Stateful Service-based Business Process Elasticity in the Cloud Based on the pay-as-you-go business principle, the Cloud computing is a new model for provisioning are being increasingly used for deploy- ing and executing business processes and particularly Service

Paris-Sud XI, Université de

424

OC3 -- Benchmark Exercise of Aero-Elastic Offshore Wind Turbine Codes: Preprint  

SciTech Connect (OSTI)

This paper introduces the work content and status of the first international investigation and verification of aero-elastic codes for offshore wind turbines as performed by the "Offshore Code Comparison Collaboration" (OC3) within the "IEA Wind Annex XXIII -- Subtask 2".

Passon, P.; Kuhn, M.; Butterfield, S.; Jonkman, J.; Camp, T.; Larsen, T. J.

2007-08-01T23:59:59.000Z

425

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

E-Print Network [OSTI]

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

426

The time reversed elastic nonlinearity diagnostic applied to evaluation of diffusion bonds  

E-Print Network [OSTI]

The time reversed elastic nonlinearity diagnostic applied to evaluation of diffusion bonds T. J based nondestructive evaluation techniques has begun. Here, diffusion bonded metal disks containing and impulse responses to perform TR experiments in thin h 5 mm, d 5 cm diffusion bonded disks, in order

427

Determination of third order elastic constants in a complex solid applying coda wave interferometry  

E-Print Network [OSTI]

material, concrete. Concrete, a structurally heterogeneous and volumetrically mechanically damaged material nonequilibrium class3 or also the nonlinear mesoscopic class,4 and an extreme example is concrete. It is highly complex both chemically and mechani- cally, is porous and permeable, heterogeneous, and highly elastically

428

Real-Time Load Elasticity Tracking and Pricing for Electric Vehicle Charging  

E-Print Network [OSTI]

owners may also benefit from lower energy cost in the face of spiking gasoline prices. Although1 Real-Time Load Elasticity Tracking and Pricing for Electric Vehicle Charging Nasim Yahya Soltani price intelligently for individual customers to elicit desirable load curves. In this context

Giannakis, Georgios

429

Drainage fracture networks in elastic solids with internal fluid gen-Maya Kobchenko1  

E-Print Network [OSTI]

epl draft Drainage fracture networks in elastic solids with internal fluid gen- eration Maya layer to fracture. The gas produced is drained on short length scales by diffusion and on long length scales by flow in a fracture network, which has topological properties that are intermediate between

Galland, Olivier

430

A nonlinear elastic deformable template for soft structure segmentation. Application to the heart  

E-Print Network [OSTI]

A nonlinear elastic deformable template for soft structure segmentation. Application to the heart of the heart's anatomy and motion from temporal image sequences, more precisely Magnetic Resonance Imaging (MRI) sequences. Currently, a clinical examination results in a stack of slices covering the whole heart

Rouchdy, Youssef

431

Effects of nanoscale thickness and elastic nonlinearity on measured mechanical properties of polymeric films  

E-Print Network [OSTI]

of polymeric films B. Oommen, K.J. Van Vliet Department of Materials Science and Engineering, Massachusetts the mechanical properties of nanoscale, compliant material volumes such as polymeric films and bio materials of semi-infinite thickness fails to accurately predict the nominal elastic modulus E for polymeric

Van Vliet, Krystyn J.

432

Simplest piston problem. I. Elastic collisions Pablo I. Hurtado 1,2, * and S. Redner 3,+  

E-Print Network [OSTI]

Simplest piston problem. I. Elastic collisions Pablo I. Hurtado 1,2, * and S. Redner 3,+ 1 light particles are separated by a heavy ``piston.'' The piston undergoes surprisingly complex motion that is oscillatory at short time scales but seemingly chaotic at longer scales. The piston also makes long

Redner, Sidney

433

Simplest piston problem. I. Elastic collisions Pablo I. Hurtado1,2,  

E-Print Network [OSTI]

Simplest piston problem. I. Elastic collisions Pablo I. Hurtado1,2, * and S. Redner3, 1 Institute light particles are separated by a heavy "piston." The piston undergoes surprisingly complex motion that is oscillatory at short time scales but seemingly chaotic at longer scales. The piston also makes long

Redner, Sidney

434

Temperature dependent elastic constants and ultimate strength of graphene and graphyne  

E-Print Network [OSTI]

Temperature dependent elastic constants and ultimate strength of graphene and graphyne Tianjiao strength of graphene and graphyne Tianjiao Shao,1,2 Bin Wen,1,a) Roderick Melnik,3,4 Shan Yao,2 Yoshiyuki strength of graphene and graphyne. For the linear thermal expan- sion coefficient, both graphene

Melnik, Roderick

435

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

E-Print Network [OSTI]

An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel been used to convert wind flow energy into mechanical vibration, which is then transformed-scale renewable energy generating systems such as wind turbines, thermal generators, and solar panels, energy

Stanford University

436

SURFACE ELASTICITY MODELS FOR STATIC AND DYNAMIC RESPONSE OF NANOSCALE BEAMS  

E-Print Network [OSTI]

SURFACE ELASTICITY MODELS FOR STATIC AND DYNAMIC RESPONSE OF NANOSCALE BEAMS by Chang Liu B) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) February 2010 © Chang Liu, 2010 #12;ii Abstract Nanoscale beam of nanoscale beams. The objective is to provide NEMS designers with an efficient set of tools that can predict

Phani, A. Srikantha

437

Molecular dynamics simulations of the elastic properties of polymer/carbon nanotube composites  

E-Print Network [OSTI]

Molecular dynamics simulations of the elastic properties of polymer/carbon nanotube composites Yue composite. However, improvements in properties are by no means guaranteed, and the results are often in the composite. In this paper, we present classical molecular dynamics (MD) simulations of model polymer

Elliott, James

438

Steady-State Propagation of a Mode II Crack in Couple Stress Elasticity  

E-Print Network [OSTI]

The present work deals with the problem of a semi-infinite crack steadily propagating in an elastic body subject to plane-strain shear loading. It is assumed that the mechanical response of the body is governed by the theory of couple-stress elasticity including also micro-rotational inertial effects. This theory introduces characteristic material lengths in order to describe the pertinent scale effects that emerge from the underlying microstructure and has proved to be very effective for modeling complex microstructured materials. It is assumed that the crack propagates at a constant sub-Rayleigh speed. An exact full field solution is then obtained based on integral transforms and the Wiener-Hopf technique. Numerical results are presented illustrating the dependence of the stress intensity factor and the energy release rate upon the propagation velocity and the characteristic material lengths in couple-stress elasticity. The present analysis confirms and extends previous results within the context of couple-stress elasticity concerning stationary cracks by including inertial and micro-inertial effects.

P. A. Gourgiotis; A. Piccolroaz

2014-05-13T23:59:59.000Z

439

Improving the Dynamic Accuracy of Elastic Industrial Robot Joint by Algebraic Identification Approach  

E-Print Network [OSTI]

Improving the Dynamic Accuracy of Elastic Industrial Robot Joint by Algebraic Identification, robots are finding their way to realize continuous operations and especially machining applications like (DOF) industrial robot with revolute joints. The St¨aubli CS8 controller provides the actual joint

Paris-Sud XI, Université de

440

Coupling Elastic Solids with SPH Fluids Nadir Akinci Jens Cornelis Gizem Akinci Matthias Teschner  

E-Print Network [OSTI]

. In the remainder of this section, we discuss the existing works about solid boundary handling in SPH (Sec. 1 these issues, for handling solid boundaries in SPH, most of the existing works rely on boundary particles, eCoupling Elastic Solids with SPH Fluids Nadir Akinci Jens Cornelis Gizem Akinci Matthias Teschner

Teschner, Matthias

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Fractal Shear Bands at Elastic-Plastic Transitions in Random Mohr-Coulomb Materials  

E-Print Network [OSTI]

Fractal Shear Bands at Elastic-Plastic Transitions in Random Mohr-Coulomb Materials J. Li, A.M.ASCE1 ; and M. Ostoja-Starzewski, M.ASCE2 Abstract: This paper studies fractal patterns forming of plastic grains (i.e., a shear-band system) is always a monotonically growing fractal under increasing

Ostoja-Starzewski, Martin

442

Physically Accurate Haptic Rendering of Elastic Object for a Haptic Glove  

E-Print Network [OSTI]

Physically Accurate Haptic Rendering of Elastic Object for a Haptic Glove Chan-Su Lee Abstract for Rutgers Master II and how to take advantage of its features in the modeled haptic rendering. Finally, we the force fast. 1.2 Modeling for Haptic Rendering Haptic rendering is the process of computing

Lee, Chan-Su

443

A framework for the construction of state surfaces of unsaturated soils in the elastic domain  

E-Print Network [OSTI]

. Introduction [2] Many geotechnical problems concern coupling be- tween the mechanical behavior of a soil of the important subjects of soil mechanics which still presents some unknown and poorly understood aspectsA framework for the construction of state surfaces of unsaturated soils in the elastic domain P

Paris-Sud XI, Université de

444

Coating Flows of Non-Newtonian Fluids: Weakly and Strongly Elastic Limits  

E-Print Network [OSTI]

Coating Flows of Non-Newtonian Fluids: Weakly and Strongly Elastic Limits J. Ashmore(1,a), A.Q. Shen(1,b), H.P. Kavehpour(2,c), H.A. Stone(1) & G.H. McKinley(2) 1: Division of Engineering and Applied of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (a): Current address: TIAX

445

Pumping fluids in microfluidic systems using the elastic deformation of poly(dimethylsiloxane){  

E-Print Network [OSTI]

Pumping fluids in microfluidic systems using the elastic deformation of polyth October 2007 DOI: 10.1039/b714664g This paper demonstrates a methodology for storing and pumping. Introduction This note describes a technique for storing and pumping fluids in microfluidic devices fabricated

Prentiss, Mara

446

Some aspects of thermal and elastic properties of thallium R. Ramji Rao and A. Rajput  

E-Print Network [OSTI]

Department of Physics Indian Institute of Technology Madras, 600036, India (Reçu le 19 juillet 1979, révisé lattice heat capacity, third-order elastic (TOE) constants and thermal expansion. The calculated TOE-packed structure at room temperature and atmospheric pressure. At about 510 K it transforms to body centered cubic

Boyer, Edmond

447

EUROMECH Young Scientist Prize Paper "Cavitation in rubber: The role of elasticity"  

E-Print Network [OSTI]

EUROMECH Young Scientist Prize Paper "Cavitation in rubber: The role of elasticity" AUTHOR won suddenly "appear" in the interior of rubber. This phenomenon has come to be popularly known as cavitation and describe cavitation in rubber, Gent and Lindley [2] proposed to consider the initiation of cavitation

Lopez-Pamies, Oscar

448

Laser Excitation of a Fracture Source for Elastic Waves Thomas E. Blum* and Kasper van Wijk  

E-Print Network [OSTI]

Laser Excitation of a Fracture Source for Elastic Waves Thomas E. Blum* and Kasper van Wijk a transparent sample by focusing laser light directly onto this fracture. The associated displacement field, measured by a laser interferometer, has pronounced waves that are diffracted at the fracture tips. We

Snieder, Roel

449

Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media  

E-Print Network [OSTI]

Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media Q.-A. Ta numerical experiments that were performed on wave propagation in a randomly generated anisotropic used for the propagation of waves in geophysical media are not compatible with the surface recordings

Boyer, Edmond

450

Journal of Mining Science, Vol. 45, No. 5, 2009 MODELING THE ELASTIC WAVE PROPAGATION  

E-Print Network [OSTI]

427 Journal of Mining Science, Vol. 45, No. 5, 2009 MODELING THE ELASTIC WAVE PROPAGATION UDC 622.7 + 622 The wave propagation analysis revealed that the low-frequency pendulum wave propagating in a 2D block medium with periodic structure due to the action of local impulse has a two-wave

Alexandrov, Victor

451

Modeling a swimming fish with an initial-boundary value problem: unsteady maneuvers of an elastic  

E-Print Network [OSTI]

Modeling a swimming fish with an initial-boundary value problem: unsteady maneuvers of an elastic In order to model unsteady maneuvers in swimming fish, we develop an initial-boundary value problem for a fourth-order hyperbolic partial differential equation in which the fish's body is treated as an inhomo

Smith, Marc L.

452

Subcritical scattering from buried elastic shells Irena Lucifredi and Henrik Schmidt  

E-Print Network [OSTI]

Subcritical scattering from buried elastic shells Irena Lucifredi and Henrik Schmidt Department the detection and classification of buried objects using low frequency, subcritical sonar an interesting the range coverage of such a sonar to be limited to about twice the ocean depth. With subcritical

Schmidt, Henrik

453

SUBCRITICAL INSTABILITIES IN PLANE COUETTE FLOW OF VISCO-ELASTIC FLUIDS  

E-Print Network [OSTI]

SUBCRITICAL INSTABILITIES IN PLANE COUETTE FLOW OF VISCO-ELASTIC FLUIDS Alexander N. Morozov of an eigenfunction of the linearized equations of motion becomes subcritically unstable, and the threshold value, subcritical instabilities, amplitude equation Introduction In the last decades, stability of flows of polymers

van Saarloos, Wim

454

Implicit Rate-Type Models for Elastic Bodies: Development, Integration, Linearization and Application  

E-Print Network [OSTI]

much richer class of models than traditional elasticity wherein the Helmholtz potential is utilized, and the relationship between the stress and stretch is governed by a tensor-valued rate equation. For the special case of an isotropic body, we obtain a...

Bridges, Ronald 1980-

2011-08-02T23:59:59.000Z

455

Ab-initio elastic and thermodynamic properties of high-temperature cubic intermetallics at finite temperatures  

E-Print Network [OSTI]

elasticity. The model is first developed for FCC aluminum and BCC tungsten which demonstrate the validity of the model as well as some of the limitations arising from the approximations made such as the effects of intrinsic anharmonicity. The same procedure...

Williams, Michael Eric

2009-05-15T23:59:59.000Z

456

Periodic subsystem density-functional theory  

SciTech Connect (OSTI)

By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.

Genova, Alessandro; Pavanello, Michele, E-mail: m.pavanello@rutgers.edu [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); Ceresoli, Davide [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); CNR-ISTM, Institute of Molecular Sciences and Technologies, Milano (Italy)

2014-11-07T23:59:59.000Z

457

Density Prediction of Uranium-6 Niobium Ingots  

SciTech Connect (OSTI)

The densities of uranium-6 niobium (U-Nb) alloys have been compiled from a variety of literature sources such as Y-12 and Rocky Flats datasheets. We also took advantage of the 42 well-pedigreed, homogeneous baseline U-Nb alloys produced under the Enhanced Surveillance Program for density measurements. Even though U-Nb alloys undergo two-phase transitions as the Nb content varies from 0 wt. % to 8 wt %, the theoretical and measured densities vary linearly with Nb content. Therefore, the effect of Nb content on the density was modeled with a linear regression. From this linear regression, a homogeneous ingot of U-6 wt.% Nb would have a density of 17.382 {+-} 0.040 g/cc (95% CI). However, ingots produced at Y-12 are not homogeneous with respect to the Nb content. Therefore, using the 95% confidence intervals, the density of a Y-12 produced ingot would vary from 17.310 {+-} 0.043 g/cc at the center to 17.432 {+-} 0.039 g/cc at the edge. Ingots with larger Nb inhomogeneities will also have larger variances in the density.

D.F.Teter; P.K. Tubesing; D.J.Thoma; E.J.Peterson

2003-04-15T23:59:59.000Z

458

Low density, resorcinol-formaldehyde aerogels  

DOE Patents [OSTI]

The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer ''clusters''. The covalent crosslinking of these ''clusters'' produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density less than or equal to100 mg/cc; cell size less than or equal to0.1 microns). The aerogels are transparent,dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 A/degree/. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron. 1 fig., 1 tab.

Pekala, R.W.

1988-05-26T23:59:59.000Z

459

Low density, resorcinol-formaldehyde aerogels  

DOE Patents [OSTI]

The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "Clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density.ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100.circle.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

Pekala, Richard W. (Pleasant Hill, CA)

1991-01-01T23:59:59.000Z

460

Low density, resorcinol-formaldehyde aerogels  

SciTech Connect (OSTI)

The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density .ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 .ANG.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

Pekala, Richard W. (Pleasant Hill, CA)

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "density influences elastic" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Low density, resorcinol-formaldehyde aerogels  

DOE Patents [OSTI]

The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer clusters. The covalent crosslinking of these clusters produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density [<=]100 mg/cc; cell size [<=]0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 [angstrom]. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

Pekala, R.W.

1989-10-10T23:59:59.000Z

462

The temperature dependence of equilibrium plasma density  

E-Print Network [OSTI]

Temperature dependence of an electron-nuclear plasma equilibrium density is considered basing on known approaches, which are given in (1)(2). It is shown that at a very high temperature, which is characteristic for a star interior, the equilibrium plasma density is almost constant and equals approximately to $10^{25}$ particles per $cm^3$. At a relatively low temperature, which is characteristic for star surface, the equilibrium plasma density is in several orders lower and depends on temperature as $T^{3/2}$.

B. V. Vasiliev

2002-03-17T23:59:59.000Z

463

Instabilities in the Nuclear Energy Density Functional  

E-Print Network [OSTI]

In the field of Energy Density Functionals (EDF) used in nuclear structure and dynamics, one of the unsolved issues is the stability of the functional. Numerical issues aside, some EDFs are unstable with respect to particular perturbations of the nuclear ground-state density. The aim of this contribution is to raise questions about the origin and nature of these instabilities, the techniques used to diagnose and prevent them, and the domain of density functions in which one should expect a nuclear EDF to be stable.

M. Kortelainen; T. Lesinski

2010-02-05T23:59:59.000Z

464

Shock compression of low-density foams  

SciTech Connect (OSTI)

Shock compression of very low density micro-cellular materials allows entirely new regimes of hot fluid states to be investigated experimentally. Using a two-stage light-gas gun to generate strong shocks, temperatures of several eV are readily achieved at densities of roughly 0.5--1 g/cm{sup 3} in large, uniform volumes. The conditions in these hot, expanded fluids are readily found using the Hugoniot jump conditions. We will briefly describe the basic methodology for sample preparation and experimental measurement of shock velocities. We present data for several materials over a range of initial densities. This paper will explore the applications of these methods for investigations of equations of state and phase diagrams, spectroscopy, and plasma physics. Finally, we discus the need for future work on these and related low-density materials.

Holmes, N.C.

1993-07-01T23:59:59.000Z

465

Breast Density and Cancer | GE Global Research  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Breast Cancer Awareness Series: Understanding Breast Density Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in...

466

Magnetic fields and density functional theory  

SciTech Connect (OSTI)

A major focus of this dissertation is the development of functionals for the magnetic susceptibility and the chemical shielding within the context of magnetic field density functional theory (BDFT). These functionals depend on the electron density in the absence of the field, which is unlike any other treatment of these responses. There have been several advances made within this theory. The first of which is the development of local density functionals for chemical shieldings and magnetic susceptibilities. There are the first such functionals ever proposed. These parameters have been studied by constructing functionals for the current density and then using the Biot-Savart equations to obtain the responses. In order to examine the advantages and disadvantages of the local functionals, they were tested numerically on some small molecules.

Salsbury Jr., Freddie

1999-02-01T23:59:59.000Z

467

Separation of carbon nanotubes in density gradients  

DOE Patents [OSTI]

The separation of single-walled carbon nanotubes (SWNTs), by chirality and/or diameter, using centrifugation of compositions of SWNTs in and surface active components in density gradient media.

Hersam, Mark C. (Evanston, IL); Stupp, Samuel I. (Chicago, IL); Arnold, Michael S. (Northbrook, IL)

2012-02-07T23:59:59.000Z

468

Density controlled carbon nanotube array electrodes  

DOE Patents [OSTI]

CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.

Ren, Zhifeng F. (Newton, MA); Tu, Yi (Belmont, MA)

2008-12-16T23:59:59.000Z

469

Separation of carbon nanotubes in density gradients  

DOE Patents [OSTI]

The separation of single-walled carbon nanotubes (SWNTs), by chirality and/or diameter, using centrifugation of compositions of SWNTs in and surface active components in density gradient media.

Hersam, Mark C. (Evanston, IL); Stupp, Samuel I. (Chicago, IL); Arnold, Michael S. (Northbrook, IL)

2010-02-16T23:59:59.000Z

470

Inverse diffusion from knowledge of power densities  

E-Print Network [OSTI]

This paper concerns the reconstruction of a diffusion coefficient in an elliptic equation from knowledge of several power densities. The power density is the product of the diffusion coefficient with the square of the modulus of the gradient of the elliptic solution. The derivation of such internal functionals comes from perturbing the medium of interest by acoustic (plane) waves, which results in small changes in the diffusion coefficient. After appropriate asymptotic expansions and (Fourier) transformation, this allow us to construct the power density of the equation point-wise inside the domain. Such a setting finds applications in ultrasound modulated electrical impedance tomography and ultrasound modulated optical tomography. We show that the diffusion coefficient can be uniquely and stably reconstructed from knowledge of a sufficient large number of power densities. Explicit expressions for the reconstruction of the diffusion coefficient are also provided. Such results hold for a large class of boundary...

Bal, Guillaume; Monard, Francois; Triki, Faouzi

2011-01-01T23:59:59.000Z

471

High density effective theory on the lattice  

E-Print Network [OSTI]

Long-range interactions in finite density QCD necessitate a non-perturbative approach in order to reliably map out the key features and spectrum of the QCD phase diagram. However, the complex nature of the fermion determinant in this sector prohibits the use of established Monte Carlo techniques that utilize importance sampling. Whilst significant progress has been made in the low density, high temperature region, this remains a considerable challenge at mid to high density. At large chemical potential, QCD can be approximated using high density effective theory which is free from the sign problem at leading order. We investigate the implementation of this theory on the lattice in conjunction with existing re-weighting techniques.

A. Dougall

2007-10-08T23:59:59.000Z

472

QCD Level Density from Maximum Entropy Method  

E-Print Network [OSTI]

We propose a method to calculate the QCD level density directly from the thermodynamic quantities obtained by lattice QCD simulations with the use of the maximum entropy method (MEM). Understanding QCD thermodynamics from QCD spectral properties has its own importance. Also it has a close connection to phenomenological analyses of the lattice data as well as experimental data on the basis of hadronic resonances. Our feasibility study shows that the MEM can provide a useful tool to study QCD level density.

Shinji Ejiri; Tetsuo Hatsuda

2005-09-24T23:59:59.000Z

473

Density of vacuum energy for multidimensional model of Kazner with scalar field and cosmological birth of particles  

E-Print Network [OSTI]

In the work's considered density of vacuum energy and dynamic of scalar field in multidimensional theory with cosmological constant. Using method of N.N.Bogolubov coefficients, was gotten expression for influence of anisotropic metric to vacuum energy. Obtained the effective mass of massles scalar field, that depends on cosmological constant, and some general theoretical results concerning arising of particles in the model.

Sergey Yakovlev

2011-12-22T23:59:59.000Z

474

Elastic properties, sp{sup 3} fraction, and Raman scattering in low and high pressure synthesized diamond-like boron rich carbides  

SciTech Connect (OSTI)

Dense BC{sub x} phases with high boron concentration are predicted to be metastable, superhard, and conductors or superconductors depending on boron concentration. However, up to this point, diamond-like boron rich carbides BC{sub x} (dl-BC{sub x}) phases have been thought obtainable only through high pressure and high temperature treatment, necessitating small specimen volume. Here, we use electron energy loss spectroscopy combined with transmission electron microscopy, Raman spectroscopy, surface Brillouin scattering, laser ultrasonics (LU) technique, and analysis of elastic properties to demonstrate that low pressure synthesis (chemical vapor deposition) of BC{sub x} phases may also lead to the creation of diamond-like boron rich carbides. The elastic properties of the dl-BC{sub x} phases depend on the carbon sp{sup 2} versus sp{sup 3} content, which decreases with increasing boron concentration, while the boron bonds determine the shape of the Raman spectra of the dl-BC{sub x} after high pressure-high temperature treatment. Using the estimation of the density value based on the sp{sup 3} fraction, the shear modulus ? of dl-BC{sub 4}, containing 10% carbon atoms with sp{sup 3} bonds, and dl-B{sub 3}C{sub 2}, containing 38% carbon atoms with sp{sup 3} bonds, were found to be ??=?19.3?GPa and ??=?170?GPa, respectively. The presented experimental data also imply that boron atoms lead to a creation of sp{sup 3} bonds during the deposition processes.

Zinin, Pavel V.; Burgess, Katherine; Jia, Ruth; Sharma, Shiv; Ming, Li-Chung [Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96822 (United States); Liu, Yongsheng [Science and Technology on Thermostructure Composite Materials Laboratory, Northwestern Polytechnical University, Xi'an Shanxi (China); Ciston, Jim [National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Hong, Shiming [Laboratory of High Pressure Physics, Southwest Jiaotong University, Chengdu, Sichuan (China)

2014-10-07T23:59:59.000Z

475

Nuclear energy density optimization: Shell structure  

E-Print Network [OSTI]

Nuclear density functional theory is the only microscopical theory that can be applied throughout the entire nuclear landscape. Its key ingredient is the energy density functional. In this work, we propose a new parameterization UNEDF2 of the Skyrme energy density functional. The functional optimization is carried out using the POUNDerS optimization algorithm within the framework of the Skyrme Hartree-Fock-Bogoliubov theory. Compared to the previous parameterization UNEDF1, restrictions on the tensor term of the energy density have been lifted, yielding a very general form of the energy density functional up to second order in derivatives of the one-body density matrix. In order to impose constraints on all the parameters of the functional, selected data on single-particle splittings in spherical doubly-magic nuclei have been included into the experimental dataset. The agreement with both bulk and spectroscopic nuclear properties achieved by the resulting UNEDF2 parameterization is comparable with UNEDF1. While there is a small improvement on single-particle spectra and binding energies of closed shell nuclei, the reproduction of fission barriers and fission isomer excitation energies has degraded. As compared to previous UNEDF parameterizations, the parameter confidence interval for UNEDF2 is narrower. In particular, our results overlap well with those obtained in previous systematic studies of the spin-orbit and tensor terms. UNEDF2 can be viewed as an all-around Skyrme EDF that performs reasonably well for both global nuclear properties and shell structure. However, after adding new data aiming to better constrain the nuclear functional, its quality has improved only marginally. These results suggest that the standard Skyrme energy density has reached its limits and significant changes to the form of the functional are needed.

M. Kortelainen; J. McDonnell; W. Nazarewicz; E. Olsen; P. -G. Reinhard; J. Sarich; N. Schunck; S. M. Wild; D. Davesne; J. Erler; A. Pastore

2014-04-28T23:59:59.000Z

476

A Bayesian Probability Calculus for Density Matrices  

E-Print Network [OSTI]

One of the main concepts in quantum physics is a density matrix, which is a symmetric positive definite matrix of trace one. Finite probability distributions are a special case where the density matrix is restricted to be diagonal. Density matrices are mixtures of dyads, where a dyad has the form uu' for any any unit column vector u. These unit vectors are the elementary events of the generalized probability space. Perhaps the simplest case to see that something unusual is going on is the case of uniform density matrix, i.e. 1/n times identity. This matrix assigns probability 1/n to every unit vector, but of course there are infinitely many of them. The new normalization rule thus says that sum of probabilities over any orthonormal basis of directions is one. We develop a probability calculus based on these more general distributions that includes definitions of joints, conditionals and formulas that relate these, i.e. analogs of the theorem of total probability, various Bayes rules for the calculation of posterior density matrices, etc. The resulting calculus parallels the familiar 'classical' probability calculus and always retains the latter as a special case when all matrices are diagonal. Whereas the classical Bayesian methods maintain uncertainty about which model is 'best', the generalization maintains uncertainty about which unit direction has the largest variance. Surprisingly the bounds also generalize: as in the classical setting we bound the negative log likelihood of the data by the negative log likelihood of the MAP estimator.

Manfred K. Warmuth; Dima Kuzmin

2014-08-09T23:59:59.000Z

477

Orbital-optimized density cumulant functional theory  

SciTech Connect (OSTI)

In density cumulant functional theory (DCFT) the electronic energy is evaluated from the one-particle density matrix and two-particle density cumulant, circumventing the computation of the wavefunction. To achieve this, the one-particle density matrix is decomposed exactly into the mean-field (idempotent) and correlation components. While the latter can be entirely derived from the density cumulant, the former must be obtained by choosing a specific set of orbitals. In the original DCFT formulation [W. Kutzelnigg, J. Chem. Phys. 125, 171101 (2006)] the orbitals were determined by diagonalizing the effective Fock operator, which introduces partial orbital relaxation. Here we present a new orbital-optimized formulation of DCFT where the energy is variationally minimized with respect to orbital rotations. This introduces important energy contributions and significantly improves the description of the dynamic correlation. In addition, it greatly simplifies the computation of analytic gradients, for which expressions are also presented. We offer a perturbative analysis of the new orbital stationarity conditions and benchmark their performance for a variety of chemical systems.

Sokolov, Alexander Yu., E-mail: asokolov@uga.edu; Schaefer, Henry F. [Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602 (United States)] [Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602 (United States)

2013-11-28T23:59:59.000Z

478

Tracing spiral density waves in M81  

E-Print Network [OSTI]

We use SPITZER IRAC 3.6 and 4.5micron near infrared data from the Spitzer Infrared Nearby Galaxies Survey (SINGS), optical B, V and I and 2MASS Ks band data to produce mass surface density maps of M81. The IRAC 3.6 and 4.5micron data, whilst dominated by emission from old stellar populations, is corrected for small-scale contamination by young stars and PAH emission. The I band data are used to produce a mass surface density map by a B-V colour-correction, following the method of Bell and de Jong. We fit a bulge and exponential disc to each mass map, and subtract these components to reveal the non-axisymmetric mass surface density. From the residual mass maps we are able to extract the amplitude and phase of the density wave, using azimuthal profiles. The response of the gas is observed via dust emission in the 8micron IRAC band, allowing a comparison between the phase of the stellar density wave and gas shock. The relationship between this angular offset and radius suggests that the spiral structure is reasonably long lived and allows the position of corotation to be determined.

S. Kendall; R. C. Kennicutt; C. Clarke; M. D. Thornley

2008-04-15T23:59:59.000Z

479

ORBITAL-FREE KINETIC-ENERGY DENSITY FUNCTIONAL THEORY  

E-Print Network [OSTI]

Chapter 5 ORBITAL-FREE KINETIC-ENERGY DENSITY FUNCTIONAL THEORY Yan Alexander Wang and Emily A Theory (DFT), there was the Thomas-Fermi (TF) model, which uses the electron density ¢¡ r£ (a function-dependent DFT Density-Functional Theory DI density-independent DM1 first-order reduced density matrix EDF energy

Wang, Yan Alexander

480

Measurement of the two-photon exchange contribution in elastic $ep$ scattering at VEPP-3  

E-Print Network [OSTI]

We report on the status of the Novosibirsk experiment on a precision measurement of the ratio $R$ of the elastic $e^+ p$ and $e^- p$ scattering cross sections. Such measurements determine the two-photon exchange effect in elastic electron-proton scattering. The experiment is conducted at the VEPP-3 storage ring using a hydrogen internal gas target. The ratio $R$ is measured with a beam energy of 1.6 GeV (electron/positron scattering angles are $\\theta = 55 \\div 75^{\\circ}$ and $\\theta = 15 \\div 25^{\\circ}$) and 1 GeV ($\\theta = 65 \\div 105^{\\circ}$). We briefly describe the experimental method, paying special attention to the radiative corrections. Some preliminary results are presented.

A. V. Gramolin; J. Arrington; L. M. Barkov; V. F. Dmitriev; V. V. Gauzshtein; R. A. Golovin; R. J. Holt; V. V. Kaminsky; B. A. Lazarenko; S. I. Mishnev; N. Yu. Muchnoi; V. V. Neufeld; D. M. Nikolenko; I. A. Rachek; R. Sh. Sadykov; Yu. V. Shestakov; V. N. Stibunov; D. K. Toporkov; H. de Vries; S. A. Zevakov; V. N. Zhilich

2011-12-22T23:59:59.000Z

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481

An In-vacuum Diffractometer for Resonant elastic Soft X-ray Scattering  

SciTech Connect (OSTI)

We describe the design, construction, and performance of a 4-circle in-vacuum diffractometer for resonant elastic soft x-ray scattering. The diffractometer, installed on the resonant elastic and inelastic x-ray scattering beamline at the Canadian Light Source, includes 9 in-vacuum motions driven by in-vacuum stepper motors and operates in ultra-high vacuum at base pressure of 2 x 10{sup -10} Torr. Cooling to a base temperature of 18 K is provided with a closed-cycle cryostat. The diffractometer includes a choice of 3 photon detectors: a photodiode, a channeltron, and a 2D sensitive channelplate detector. Along with variable slit and filter options, these detectors are suitable for studying a wide range of phenomena having both weak and strong diffraction signals. Example measurements of diffraction and reflectivity in Nd-doped (La,Sr){sub 2}CuO{sub 4} and thin film (Ga,Mn)As are shown.

D Hawthorn; F He; L Venema; H Davis; A Achkar; J Zhang; R Sutarto; H Wadati; A Radi; et al.

2011-12-31T23:59:59.000Z

482

Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering  

SciTech Connect (OSTI)

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely-polarized 3 GeV electrons from unpolarized protons at Q^2 values of 0.15 and 0.25 (GeV/c)^2 with results of A_n = -4.06 +- 0.99(stat) +- 0.63(syst) and A_n = -4.82 +- 1.87(stat) +- 0.98(syst) ppm. These results are inconsistent with calculations solely using the elastic nucleon intermediate state, and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A_n provides a direct probe of the imaginary component of the two-photon exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

David Armstrong; Francois Arvieux; Razmik Asaturyan; Todd Averett; Stephanie Bailey; Guillaume Batigne; Douglas Beck; Elizabeth Beise; Jay Benesch; Louis Bimbot; James Birchall; Angela Biselli; Peter Bosted; Elodie Boukobza; Herbert Breuer; Roger Carlini; Robert Carr; Nicholas Chant; Yu-Chiu Chao; Swapan Chattopadhyay; Russell Clark; Silviu Covrig; Anthony Cowley; Daniel Dale; Charles Davis; Willie Falk; John Finn; Tony Forest; Gregg Franklin; Christophe Furget; David Gaskell; Joseph Grames; Keith Griffioen; Klaus Grimm; Benoit Guillon; Hayko Guler; Lars Hannelius; Richard HASTY; Alice Hawthorne Allen; Tanja Horn; Kathleen Johnston; Mark Jones; Peter Kammel; Reza Kazimi; Paul King; Ameya Kolarkar; Elie Korkmaz; Wolfgang Korsch; Serge Kox; Joachim Kuhn; Jeff Lachniet; Lawrence Lee; Jason Lenoble; Eric Liatard; Jianglai Liu; Berenice Loupias; Allison Lung; Dominique Marchand; Jeffery Martin; Kenneth McFarlane; David McKee; Robert McKeown; Fernand Merchez; Hamlet Mkrtchyan; Bryan Moffit; M. Morlet; Itaru Nakagawa; Kazutaka Nakahara; Retief Neveling; Silvia Niccolai; S. Ong; Shelley Page; Vassilios Papavassiliou; Stephen Pate; Sarah Phillips; Mark Pitt; Benard Poelker; Tracy Porcelli; Gilles Quemener; Brian Quinn; William Ramsay; Aamer Rauf; Jean-Sebastien Real; Julie Roche; Philip Roos; Gary Rutledge; Jeffery Secrest; Neven Simicevic; Gregory Smith; Damon Spayde; Samuel Stepanyan; Marcy Stutzman; Vince Sulkosky; Vincent Sulkosky; Vince Sulkosky; Vincent Sulkosky; Vardan Tadevosyan; Raphael Tieulent; Jacques Van de Wiele; Willem van Oers; Eric Voutier; William Vulcan; Glen Warren; Steven Wells; Steven Williamson; Stephen Wood; Chen Yan; Junho Yun; Valdis Zeps

2007-08-01T23:59:59.000Z

483

Mechanism of elastic and inelastic proton scattering on a {sup 15}C nucleus in diffraction theory  

SciTech Connect (OSTI)

The amplitudes for elastic and inelastic proton scattering on the neutron-rich nucleus {sup 15}C (to its J{sup {pi}} = 5/2{sup +} level in the latter case) in inverse kinematics were calculated within Glauber diffraction theory. First- and second-order terms were taken into account in the multiple-scattering operator. The {sup 15}C wave function in the multiparticle shell model was used. This made it possible to calculate not only respective differential cross sections but also the contribution of proton scattering on nucleons occurring in different shells. The differential cross sections for elastic and inelastic scattering were calculated at the energies of 0.2, 0.6, and 1 GeV per nucleon.

Ibraeva, E. T., E-mail: ibr@inp.kz [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Zhusupov, M. A. [Al-Farabi Kazakh National University (Kazakhstan); Imambekov, O. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan)

2012-11-15T23:59:59.000Z

484

Structure of light neutron-rich nuclei and mechanism of elastic proton scattering  

SciTech Connect (OSTI)

Differential cross sections for elastic p{sup 6}He, p{sup 8}Li, and p{sup 9}Li scattering at two energies of 70 and 700 MeV per nucleon were calculated within the Glauber theory of multiple diffractive scattering. Threeparticle wave functions ({alpha}-n-n for {sup 6}He, {alpha}-t-n for {sup 8}Li, and {sup 7}Li-n-n for {sup 9}Li) were used for realistic potentials of intercluster interactions. The sensitivity of elastic scattering to proton-nucleus interaction and to the structure of nuclei was explored. In particular, the dependence of the differential cross section on the contribution of higher order collisions, on scattering on the core and peripheral nucleons, and on the contribution of small wave-function components and their asymptotic behavior was determined. A comparison with available experimental data and with the results of calculations within different formalisms was performed.

Ibraeva, E. T., E-mail: ibr@inp.kz [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Zhusupov, M. A. [Al-Farabi Kazakh National University (Kazakhstan); Imambekov, O. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan)

2011-11-15T23:59:59.000Z

485

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

SciTech Connect (OSTI)

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

2008-07-15T23:59:59.000Z

486

Irreducible decompositions of the elasticity tensor under the linear and orthogonal groups and their physical consequences  

E-Print Network [OSTI]

We study properties of the fourth rank elasticity tensor C within linear elasticity theory. First C is irreducibly decomposed under the linear group into a "Cauchy piece" S (with 15 independent components) and a "non-Cauchy piece" A (with 6 independent components). Subsequently, we turn to the physically relevant orthogonal group, thereby using the metric. We find the finer decomposition of S into pieces with 9+5+1 and of A into those with 5+1 independent components. Some reducible decompositions, discussed earlier by numerous authors, are shown to be inconsistent. --- Several physical consequences are discussed. The Cauchy relations are shown to correspond to A=0. Longitudinal and transverse sound waves are basically related by S and A, respectively.

Yakov Itin; Friedrich W. Hehl

2014-11-19T23:59:59.000Z

487

Optimal Three-Material Wheel Assemblage of Conducting and Elastic Composites  

E-Print Network [OSTI]

We describe a new type of three material microstructures which we call wheel assemblages, that correspond to extremal conductivity and extremal bulk modulus for a composite made of two materials and an ideal material. The exact lower bounds for effective conductivity and matching laminates was found in (Cherkaev, 2009) and for anisotropic composites, in (Cherkaev, Zhang, 2011). Here, we show different optimal structures that generalize the classical Hashin-Shtrikman coated spheres (circles). They consist of circular inclusions which contain a solid central circle (hub) and radial spikes in a surrounding annulus, and (for larger volume fractions of the best material) an annulus filled with it. The same wheel assemblages are optimal for the pair of dual problems of minimal conductivity (resistivity) of a composite made from two materials and an ideal conductor (insulator), in the problem of maximal effective bulk modulus of elastic composites made from two linear elastic material and void, and the dual minimum problem.

Andrej Cherkaev

2011-05-22T23:59:59.000Z

488

Frequency-dependent attenuation and elasticity in unconsolidated earth materials: effect of damping  

E-Print Network [OSTI]

We use the Discrete Element Method (DEM) to understand the underlying attenuation mechanism in granular media, with special applicability to the measurements of the so-called effective mass developed earlier. We consider that the particles interact via Hertz-Mindlin elastic contact forces and that the damping is describable as a force proportional to the velocity difference of contacting grains. We determine the behavior of the complex-valued normal mode frequencies using 1) DEM, 2) direct diagonalization of the relevant matrix, and 3) a numerical search for the zeros of the relevant determinant. All three methods are in strong agreement with each other. The real and the imaginary parts of each normal mode frequency characterize the elastic and the dissipative properties, respectively, of the granular medium. We demonstrate that, as the interparticle damping, $\\xi$, increases, the normal modes exhibit nearly circular trajectories in the complex frequency plane and that for a given value of $\\xi$ they all lie ...

Hu, Yanqing; Valenza, John J; Johnson, David L

2014-01-01T23:59:59.000Z

489

A Predictive Theory for Elastic Scattering and Recoil of Protons from $^4$He  

E-Print Network [OSTI]

Low-energy cross sections for elastic scattering and recoil of protons from $^4$He nuclei (also known as $\\alpha$ particles) are calculated directly by solving the Schr\\"odinger equation for five nucleons interacting through accurate two- and three-nucleon forces derived within the framework of chiral effective field theory. Precise knowledge of these processes at various proton backscattering/recoil angles and energies is needed for the ion-beam analysis of numerous materials, from the surface layers of solids, to thin films, to fusion-reactor materials. Indeed, the same elastic scattering process, in two different kinematic configurations, can be used to probe concentrations and depth profiles of either hydrogen or helium. We compare our results to available experimental data and show that direct calculations with modern nuclear potentials can help to resolve remaining inconsistencies among different data sets and can be used to predict these cross sections when measurements are not available.

Guillaume Hupin; Sofia Quaglioni; Petr Navrátil

2014-09-02T23:59:59.000Z

490

Dynamics of Enzyme Digestion of a Single Elastic Fiber Under Tension: An Anisotropic Diffusion Model  

E-Print Network [OSTI]

We study the enzymatic degradation of an elastic fiber under tension using an an isotropic random-walk model, coupled with binding-unbinding reactions that weaken the fiber. The fiber is represented by a chain of elastic springs in series, surrounded by two layers of sites along which enzyme molecules can diffuse. Through numerical simulations we show that the fiber stiffness decreases exponentially with two distinct regimes. The time constant associated with the first regime decreases with increasing applied force, which is in agreement with published experimental data. In addition, a simple mean field calculation allows us to partition the time constant into geometrical, chemical and externally controllable factors, which is corroborated by the simulations.

Ascânio D. Araújo; Arnab Majumdar; Harikrishnan Parame swaran; Béla Suki

2009-10-07T23:59:59.000Z

491

Maximum-Entropy Meshfree Method for Compressible and Near-Incompressible Elasticity  

SciTech Connect (OSTI)

Numerical integration errors and volumetric locking in the near-incompressible limit are two outstanding issues in Galerkin-based meshfree computations. In this paper, we present a modified Gaussian integration scheme on background cells for meshfree methods that alleviates errors in numerical integration and ensures patch test satisfaction to machine precision. Secondly, a locking-free small-strain elasticity formulation for meshfree methods is proposed, which draws on developments in assumed strain methods and nodal integration techniques. In this study, maximum-entropy basis functions are used; however, the generality of our approach permits the use of any meshfree approximation. Various benchmark problems in two-dimensional compressible and near-incompressible small strain elasticity are presented to demonstrate the accuracy and optimal convergence in the energy norm of the maximum-entropy meshfree formulation.

Ortiz, A; Puso, M A; Sukumar, N

2009-09-04T23:59:59.000Z

492

High power density solid oxide fuel cells  

DOE Patents [OSTI]

A method for producing ultra-high power density solid oxide fuel cells (SOFCs). The method involves the formation of a multilayer structure cells wherein a buffer layer of doped-ceria is deposited intermediate a zirconia electrolyte and a cobalt iron based electrode using a colloidal spray deposition (CSD) technique. For example, a cobalt iron based cathode composed of (La,Sr)(Co,Fe)O (LSCF) may be deposited on a zirconia electrolyte via a buffer layer of doped-ceria deposited by the CSD technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2 at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes a 2-3 times increased in power density over conventionally produced SOFCs.

Pham, Ai Quoc; Glass, Robert S.

2004-10-12T23:59:59.000Z

493

Statistical approach to nuclear level density  

SciTech Connect (OSTI)

We discuss the level density in a finite many-body system with strong interaction between the constituents. Our primary object of applications is the atomic nucleus but the same techniques can be applied to other mesoscopic systems. We calculate and compare nuclear level densities for given quantum numbers obtained by different methods, such as nuclear shell model (the most successful microscopic approach), our main instrument - moments method (statistical approach), and Fermi-gas model; the calculation with the moments method can use any shell-model Hamiltonian excluding the spurious states of the center-of-mass motion. Our goal is to investigate statistical properties of nuclear level density, define its phenomenological parameters, and offer an affordable and reliable way of calculation.

Sen'kov, R. A.; Horoi, M. [Department of Physics, Central Michigan University, Mount Pleasant, MI 48859 (United States); Zelevinsky, V. G. [Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States)

2014-10-15T23:59:59.000Z

494

Neutron Matter from Low to High Density  

E-Print Network [OSTI]

Neutron matter is an intriguing nuclear system with multiple connections to other areas of physics. Considerable progress has been made over the last two decades in exploring the properties of pure neutron fluids. Here we begin by reviewing work done to explore the behavior of very low density neutron matter, which forms a strongly paired superfluid and is thus similar to cold Fermi atoms, though at energy scales differing by many orders of magnitude. We then increase the density, discussing work that ties the study of neutron matter with the determination of the properties of neutron-rich nuclei and neutron-star crusts. After this, we review the impact neutron matter at even higher densities has on the mass-radius relation of neutron stars, thereby making contact with astrophysical observations.

Gandolfi, Stefano; Carlson, J

2015-01-01T23:59:59.000Z

495

Fabrication of low density ceramic material  

DOE Patents [OSTI]

A precursor mixture and a method of making a low-density ceramic structural material are disclosed. The precursor mixture includes hollow microballoons, typically made of glass, together with a cementing agent capable of being cured by microwave irradiation. A preferred cementing agent is liquid hydrated potassium silicate, which is mixed with the glass microballoons to form a slurry. Upon irradiation the potassium silicate is dehydrated to form a solid porous matrix in which the microballoons are evenly distributed. Ground glass or other filling agents may be included in the slurry to enhance the properties of the final product. Low-density structural ceramics having densities on the order of 0.1 to 0.3 are obtained.

Meek, T.T.; Blake, R.D.; Sheinberg, H.

1985-01-01T23:59:59.000Z

496

A 3D Orthotropic Strain-Rate Dependent Elastic Damage Material Model.  

SciTech Connect (OSTI)

A three dimensional orthotropic elastic constitutive model with continuum damage and cohesive based fracture is implemented for a general polymer matrix composite lamina. The formulation assumes the possibility of distributed (continuum) damage followed b y localized damage. The current damage activation functions are simply partially interactive quadratic strain criteria . However, the code structure allows for changes in the functions without extraordinary effort. The material model formulation, implementation, characterization and use cases are presented.

English, Shawn Allen

2014-09-01T23:59:59.000Z

497

A study of Poisson's ratio and the elastic and plastic properties of Ottawa sand  

E-Print Network [OSTI]

in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Mayq 1957 Ma)or Sub)acts Civil Engineering A STUDY OF POISSON'S RATIO AND THE ELASTIC AND PLASTIC PROPERTIES OF OTTAWA SAND A Thesis ROSERT RENT WZmne Captain, Corps...' IHTRODUCTIOS Engineering achievements have paced the rise oi civilization through the ages. Today the cries for greater strength, capacity and economy are heard with ever increasing frequency. Transportation and defense requirements have never lagged...

Werner, Robert Rehm

1957-01-01T23:59:59.000Z

498

Study of the dp-elastic scattering at 2 GeV  

E-Print Network [OSTI]

The results on the measurements of dp-elastic scattering cross section at the energy 2 GeV at Internal Target Station at the Nuclotron JINR are reported. The data were obtained for the angular range of 70-107 deg. in the c.m.s. by using CH2 and C targets. The results are compared with the existing data and with the theoretical calculations based on the relativistic multiple scattering theory.

Terekhin, A A; Isupov, A Yu; Khrenov, A N; Kurilkin, A K; Kurilkin, P K; Ladygin, V P; Ladygina, N B; Piyadin, S M; Reznikov, S G; Vnukov, I E

2015-01-01T23:59:59.000Z

499

Elastic proton scattering on tritium below the n-$^{3}{He}$ threshold  

E-Print Network [OSTI]

Elastic proton scattering on ${}^{3}{H}$ nucleus is studied inbetween p-% ${}^{3}{H}$ and n-${}^{3}{He}$ thresholds, in the energy region where $\\alpha$-particles first excited state is inbeded in the continuum. For this aim Faddeev-Yakubovski equations are solved in configuration space, fully considering effects due to the isospin breaking as well as rigorously treating Coulomb interaction. Different realistic nuclear Hamiltonians are tested, elucidating open problems in nuclear interaction description.

Rimantas Lazauskas

2009-03-27T23:59:59.000Z

500

Note and calculations concerning elastic dilatancy in 2D glass-glass liquid foams  

E-Print Network [OSTI]

When deformed, liquid foams tend to raise their liquid contents like immersed granular materials, a phenomenon called dilatancy. We have aready described a geometrical interpretation of elastic dilatancy in 3D foams and in very dry foams squeezed between two solid plates (2D GG foams). Here, we complement this work in the regime of less dry 2D GG foams. In particular, we highlight the relatively strong dilatancy effects expected in the regime where we have predicted rapid Plateau border variations.

François Molino; Pierre Rognon; Cyprien Gay

2010-10-30T23:59:59.000Z