DESIGN AND VALIDATION OF A HIGH ENERGY DENSITY ELASTIC ACCUMULATOR USING POLYURETHANE
Barth, Eric J.
steels and titanium alloys have a gravimetric energy density of around 1-1.5 kJ/kg [1]. ConsequentlyDESIGN AND VALIDATION OF A HIGH ENERGY DENSITY ELASTIC ACCUMULATOR USING POLYURETHANE Alexander-35%. However, the relatively low gravimetric and volumetric energy densities of conventional HAs prohibit
A mineralogical model for density and elasticity of the Earth's A. S. Piazzoni
Steinle-Neumann, Gerd
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
Alkhazov, G. D.; Sarantsev, V. V., E-mail: saran@pnpi.spb.ru [Petersburg Nuclear Physics Institute NRC KI (Russian Federation)
2012-12-15T23:59:59.000Z
In order to clear up the sensitivity of the nucleus-nucleus scattering to the nuclear matter distributions in exotic halo nuclei, we have calculated differential cross sections for elastic scattering of the {sup 6}He and {sup 11}Li nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with different assumed nuclear density distributions in {sup 6}He and {sup 11}Li.
Topology of charge density and elastic properties of Ti3SiC2 polymorphs
Yu, Rong; Zhang, Xiao Feng; He, Lian Long; Ye, Heng Qiang
2004-06-24T23:59:59.000Z
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.
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
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.
Vel, Senthil
-rich, crustal rocks. We calculated the bulk elastic properties and resulting wave velocities for rock samplesThe influence of crenulation cleavage development on the bulk elastic and seismic properties of phyllosilicate-rich rocks Félice M.J. Naus-Thijssen a, , Andrew J. Goupee b , Scott E. Johnson a , Senthil S. Vel
Influence of the Target - Density Effects on Electron - Capture Processes
Tolstikhina, I.Yu.; Shevelko, V.P. [P.N.Lebedev Physical Institute, 119991, Moscow (Russian Federation)
2004-12-01T23:59:59.000Z
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.
Laird, Brian Bostian
1992-06-01T23:59:59.000Z
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 Ashcroft [Phys. Rev. A 3 9...
The Influence of Isotopic Mass, Edge Magnetic Shear and Input Power on High Density ELMy H-modes in JET
Volunteer Potato Density Influences Critical Time of Weed Removal in Bulb Onion
Sims, Gerald K.
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
A. V. Sedelnikov; M. I Kazarina
2010-07-23T23:59:59.000Z
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.
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
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.
Beam energy distribution influences on density modulation efficiency in seeded free-electron lasers
Wang, Guanglei; Deng, Haixiao; Zhang, Weiqing; Wu, Guorong; Dai, Dongxu; Wang, Dong; Zhao, Zhentang; Yang, Xueming
2015-01-01T23:59:59.000Z
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...
Sealey, Kathleen Sullivan
The influence of habitat selection and density on the population dynamics of stony coral species of Biology, University of Miami, Coral Gables, FL, 33124 USA *Corresponding author: K. Semon Phone: 1-305-284-3013, Fax: 1-305-284-3039, e-mail: ksemon@bio.miami.edu Abstract Although stony corals are most frequently
The influence of calf density during weaning upon their performance and behavior
Richmond, Charles Edwin
1980-01-01T23:59:59.000Z
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...
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
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, 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
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.
Elasticity driven self-organization of polarons
Maniadis, Panagiotis [Los Alamos National Laboratory; Lookman, Turab [Los Alamos National Laboratory; Bishop, Alan R [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
We use a strain description to couple long-range elastic fields adiabatically to electronic density to describe the behavior of a quantum particle in an elastic medium. We show that in this generalization of the Holstein polaron problem, a bound polaronic state results with strong long-range angular dependence in the elastic fields, but a localized electronic core. The deformation of the elastic fields creates an anisotropic, indirect interaction between polarons extending to large distances. For a given density of polarons, this interaction favors the formation of strings of polarons in preferred directions.
Ritchie, Robert
was approximated by an optimized model based on the wurtzite structure. The full set of single-crystal elastic properties of Al2OC, a wurtzite-type structure, and to ascertain if the properties of Al2OC conform to frac- ture mechanics expectations for the toughness of SiC ceram- ics. The wurtzite form of aluminum
Thomas L. Beck
2012-09-20T23:59:59.000Z
The surface or contact potential at the water liquid-vapor interface is discussed in relation to determinations of absolute ion hydration free energies and distributions of ions near the interface. It is shown that, rather than the surface potential itself, the net electrostatic potential at the center of an uncharged solute can aid both in relating differences between tabulations of hydration free energies and in explaining differing classical and quantum surface potential estimates. Quantum mechanical results are consistent with conclusions from classical simulations that there is a net driving force that enhances anion density at the surface relative to cations.
N. L. Calleya; S. R. Souza; B. V. Carlson; R. Donangelo; W. G. Lynch; M. B. Tsang; J. R. Winkelbauer
2014-08-28T23:59:59.000Z
The fragmentation of thermalized sources is studied using a version of the Statistical Multifragmentation Model which employs state densities that take the pairing gap in the nuclear levels into account. Attention is focused on the properties of the charge distributions observed in the breakup of the source. Since the microcanonical version of the model used in this study provides the primary fragment excitation energy distribution, one may correlate the reduction of the odd-even staggering in the charge distribution with the increasing occupation of high energy states. Thus, in the frame- work of this model, such staggering tends to disappear as a function of the total excitation energy of the source, although the energy per particle may be small for large systems. We also find that, although the deexcitation of the primary fragments should, in principle, blur these odd-even effects as the fragments follow their decay chains, the consistent treatment of pairing may significantly enhance these staggering effects on the final yields. In the framework of this model, we find that odd-even effects in the charge distributions should be observed in the fragmentation of relatively light systems at very low excitation energies. Our results also suggest that the odd-even staggering may provide useful information on the nuclear state density.
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
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.
Elastic building blocks for confined sheets
Robert D. Schroll; Eleni Katifori; Benny Davidovitch
2010-12-17T23:59:59.000Z
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.
Jiao, S. [Universite Francois Rabelais, Tours, Laboratoire de Microelectronique de Puissance, 16 rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); Centre de Recherche sur l'Hetero-Epitaxie et ses Applications CNRS-UPR10, rue Bernard Gregory, 06560 Valbonne (France); Zielinski, M.; Chassagne, T. [NOVASiC, Savoie Technolac, Arche Bat 4, BP 267, 73375 Le Bourget du Lac Cedex (France); Roy, S. [Saint Gobain recherche, 39 Quai Lucien Lefranc 93300 Aubervilliers cedex (France); Michaud, J. F.; Alquier, D. [Universite Francois Rabelais, Tours, Laboratoire de Microelectronique de Puissance, 16 rue Pierre et Marie Curie, BP 7155, 37071 Tours Cedex 2 (France); Portail, M. [Centre de Recherche sur l'Hetero-Epitaxie et ses Applications CNRS-UPR10, rue Bernard Gregory, 06560 Valbonne (France)
2010-11-01T23:59:59.000Z
In this work we investigated the influence of the Si substrate misorientation and 3C-SiC film thickness on the density of Anti-Phase Boundaries, in order to better understand the mechanism of antiphase domain annihilation. The two highlights in our work are the utilization of [001] orientated Si on-axis wafer with spherical dimples, which gave us access to a continuum of off-cut angles (0 deg. to {approx}11 deg.) and directions, and the deposition of elongated silicon islands on the surface of 3C-SiC epilayers, which improved the detection of APDs by analysis of Scanning Electron Microscopy images. We found that for a given layer thickness the relative surface occupation of one domain increases with the off-cut angle value, leading to single domain film up to a certain angle. This critical value is reduced as the film is thickened.
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
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.
High elastic modulus polymer electrolytes
Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel
2013-10-22T23:59:59.000Z
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.
Sewell, T. D. (Thomas D.); Bedrov, D. (Dmitry); Menikoff, Ralph; Smith, G. D. (Grant D.)
2001-01-01T23:59:59.000Z
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.
Sirajuddeen, M. Mohamed Sheik, E-mail: msheiksiraj@bsauniv.ac.in; Banu, I. B. Shameem [Department of Physics, B. S. Abdur Rahman University, Chennai-600 048 (India)
2014-05-15T23:59:59.000Z
Full Potential- Linear Augmented Plane Wave (FP-LAPW) method has been employed to study the electronic, magnetic, elastic and thermal properties of Fe-doped Zirconium nitride. In this work, Fe-atoms were doped into the super cell of ZrN in doping concentrations of 12.5%, 25% and 37.5% to replace Zr atoms. Electronic properties such as band structure and DOS were plotted and compared for the doped compounds. Charge density contours were plotted for all the doped compounds. The non-magnetic ZrN doped in different Fe concentrations were found to be ferromagnetic. Magnetic moments have been calculated and compared. Elastic properties have been studied and compared with electronic properties. Appearance of magnetic ordering and its influence with the elastic properties have been reported. Impact of 3d states of Fe in DOS plot on the elastic nature of the compounds has been highlighted. Thermal properties such as Debye temperature and molar heat capacities at low temperature have been determined. Debye temperature is found to decrease with higher doping concentrations. Molar heat capacities are found to increase with higher concentrations of Fe atoms.
Elastic properties of superconducting MAX phases from first principles calculations
I. R. Shein; A. L. Ivanovskii
2010-06-03T23:59:59.000Z
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.
Loewenthal, M.; Loseke, K.; Dow, T.A.; Scattergood, R.O.
1988-12-01T23:59:59.000Z
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.
First-principles elastic properties of (alpha)-Pu
Soderlind, P; Klepeis, J
2009-02-18T23:59:59.000Z
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.
First-principles elastic properties of (alpha)-Pu
Soderlind, P; Klepeis, J E
2008-11-04T23:59:59.000Z
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.
Stability of elastic grid shells
Mesnil, Romain, M. Eng. Massachusetts Institute of Technology
2013-01-01T23:59:59.000Z
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 ...
Rotstein, S.; Lax, I.; Svane, G. (Karolinska Hospital, Stockholm (Sweden))
1990-01-01T23:59:59.000Z
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.
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
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.
Quiñones-Galván, J. G.; Camps, Enrique [Departamento de Física, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, México D.F. C.P. 11801 (Mexico); Muhl, S. [Instituto de Investigaciones en Materiales, UNAM, México D.F. C.P. 04510 (Mexico); Flores, M. [Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara, Apdo. Postal 307, C.P. 45101 Zapopan, Jalisco (Mexico); Campos-González, E. [Departamento de Física, CINVESTAV-IPN, Apdo. Postal 14-740, México D.F. 07360 (Mexico)
2014-05-15T23:59:59.000Z
Incorporation of substitutional Al into the TiN lattice of the ternary alloy TiAlN results in a material with improved properties compared to TiN. In this work, TiAlN thin films were grown by the simultaneous ablation of Ti and Al targets in a nitrogen containing reactive atmosphere. The deposit was formed on silicon substrates at low deposition temperature (200?°C). The dependence of the Al content of the films was studied as a function of the ion density of the plasma produced by the laser ablation of the Al target. The plasma parameters were measured by means of a planar Langmuir probe and optical emission spectroscopy. The chemical composition of the films was measured by energy dispersive X-ray spectroscopy. The results showed a strong dependence of the amount of aluminum incorporated in the films with the plasma density. The structural characterization of the deposits was carried out by Raman spectroscopy, X-ray diffraction, and transmission electron microscopy, where the substitutional incorporation of the Al into the TiN was demonstrated.
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
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.
Comparison of elastic and inelastic analyses
Ammerman, D. J.; Heinstein, M. W.; Wellman, G. W.
1992-01-01T23:59:59.000Z
The use of inelastic analysis methods instead of the traditional elastic analysis methods in the design of radioactive material (RAM) transport packagings leads to a better understanding of the response of the package to mechanical loadings. Thus, better assessment of the containment, thermal protection, and shielding integrity of the package after a structural accident event can be made. A more accurate prediction of the package response can lead to enhanced safety and also allow for a more efficient use of materials, possibly leading to a package with higher capacity or lower weight This paper will discuss the advantages and disadvantages of using inelastic analysis in the design of RAM shipping packages. When using inelastic analysis the entire nonlinear response of the material must be known, including the effects of temperature changes and strain rate. There currently is not an acceptance criteria for this type of analysis that is approved by regulatory agencies. Inelastic analysis acceptance criteria based on failure stress, failure strain, or plastic energy density could be developed. For both elastic and inelastic analyses it is also important to include other sources of stress in the analyses, such as fabrication stresses, thermal stresses, stresses from bolt preloading, and contact stresses at material interfaces.
Thermal Fluctuations and Rubber Elasticity
Xiangjun Xing; Paul M. Goldbart; Leo Radzihovsky
2006-09-21T23:59:59.000Z
The effects of thermal elastic fluctuations in rubber materials are examined. It is shown that, due to an interplay with the incompressibility constraint, these fluctuations qualitatively modify the large-deformation stress-strain relation, compared to that of classical rubber elasticity. To leading order, this mechanism provides a simple and generic explanation for the peak structure of Mooney-Rivlin stress-strain relation, and shows a good agreement with experiments. It also leads to the prediction of a phonon correlation function that depends on the external deformation.
Thermoacoustic Tomography in Elastic Media
Justin Tittelfitz
2011-10-11T23:59:59.000Z
We investigate the problem of recovering the initial displacement f for a solution u of a linear, isotropic, non-homogeneous elastic wave equation, given measurements of u on [0,T] x \\partial \\Omega, where \\Omega\\subset\\R^3 is some bounded domain containing the support of f. For the acoustic wave equation, this problem is known as thermoacoustic tomography (TAT), and has been well-studied; for the elastic wave equation, the situation is somewhat more subtle, and we give sufficient conditions on the Lam\\'e parameters to ensure that recovery is possible.
OFC/NFOEC '12 Summary --Elastic Networks
California at Davis, University of
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
The contact of elastic regular wavy surfaces revisited
Vladislav A. Yastrebov; Guillaume Anciaux Jean-Francois Molinari
2014-09-05T23:59:59.000Z
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.
Transversely isotropic elasticity and poroelasticity arising from thin isotropic layers
Berryman, J.G.
1997-07-01T23:59:59.000Z
Since the classic work of Postma [1955] and Backus [1962], much has been learned about elastic constants in vertical transversely isotropic (VTI) media when the anisotropy is due to fine layering of isotropic elastic materials. However, new results are still being discovered. For example, the P-wave anisotropy parameter c{sub 11}/c{sub 33} lies in the range 1/4 {<=} c{sub 11}/c{sub 33} {<=} <{lambda}+2{mu}><1/({lambda}+2{mu})>, when the layers are themselves composed of isotropic elastic materials with Lame constants {lambda} and {mu} and the vertical average of the layers is symbolized by <{center_dot}>. The lower bound corrects a result of Postma. For porous layers, a connected solid frame forms the basis of the elastic behavior of a poroelastic medium in the presence of confining forces, while connected pores permit a percolating fluid (if present) to influence the mechanical response of the system from within. For isotropic and anisotropic poroelastic media, we establish general formulas for the behavior of transversely isotropic poroelasticity arising from laminations of isotropic components. The Backus averaging method is shown to provide elementary means of constructing general formulas. The results for confined fluids are then compared with the more general Gassmann [1951] formulas that must be satisfied by any anisotropic poroelastic medium and found to be in complete agreement. Such results are important for applications to oil exploration using AVO (amplitude versus offset) since the presence or absence of a fluid component, as well as the nature of the fluid, is the critical issue and the ways in which the fluid influences seismic reflection data still need to be better understood.
Elastic properties of Pu metal and Pu-Ga alloys
Soderlind, P; Landa, A; Klepeis, J E; Suzuki, Y; Migliori, A
2010-01-05T23:59:59.000Z
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.
Atomic picture of elastic deformation in a metallic glass
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Wang, X. D.; Aryal, S.; Zhong, C.; Ching, W. Y.; Sheng, H. W.; Zhang, H.; Zhang, D. X.; Cao, Q. P.; Jiang, J. Z.
2015-03-17T23:59:59.000Z
The tensile behavior of a Ni??Nb?? metallic glass (MG) has been studied by using ab initio density functional theory (DFT) calculation with a large cell containing 1024 atoms (614 Ni and 410 Nb). We provide insight into how a super elastic limit can be achieved in a MG. Spatially inhomogeneous responses of single atoms and also major polyhedra are found to change greatly with increasing external stress when the strain is over 2%, causing the intrinsically viscoelastic behavior. We uncover the origin of the observed super elastic strain limit under tension (including linear and viscoelastic strains) in small-sized MG samples,more »mainly caused by inhomogeneous distribution of excess volumes in the form of newly formed subatomic cavities.« less
Phase stability and elastic properties of Cr-V alloys
Gao, M. C.; Suzuki, Y.; Schweiger, H.; Do?an, Ö.N.; Hawk, J.; Widom M.
2013-02-20T23:59:59.000Z
V is the only element in the periodic table that forms a complete solid solution with Cr and thus is particularly important in alloying strategy to ductilize Cr. This study combines first-principles density functional theory calculations and experiments to investigate the phase stability and elastic properties of Cr–V binary alloys. The cluster expansion study reveals the formation of various ordered compounds at low temperatures that were not previously known. These compounds become unstable due to the configurational entropy of bcc solid solution as the temperature is increased. The elastic constants of ordered and disordered compounds are calculated at both T = 0 K and finite temperatures. The overall trends in elastic properties are in agreement with measurements using the resonant ultrasound spectroscopy method. The calculations predict that addition of V to Cr decreases both the bulk modulus and the shear modulus, and enhances the Poisson’s ratio, in agreement with experiments. Decrease in the bulk modulus is correlated to decrease in the valence electron density and increase in the lattice constant. An enhanced Poisson’s ratio for bcc Cr–V alloys (compared to pure Cr) is associated with an increased density of states at the Fermi level. Furthermore, the difference charge density in the bonding region in the (110) slip plane is highest for pure Cr and decreases gradually as V is added. The present calculation also predicts a negative Cauchy pressure for pure Cr, and it becomes positive upon alloying with V. The intrinsic ductilizing effect from V may contribute, at least partially, to the experimentally observed ductilizing phenomenon in the literature.
The elastic anisotropy of marble
Gebhard, Susan Nash
1982-01-01T23:59:59.000Z
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...
ELASTIC AND INELASTIC Y PRODUCTION BY MUONS
Loken, S.C.
2010-01-01T23:59:59.000Z
U.S. Department of Energy under Contract No. W-7405-ENG-48.under Contract No. W-7405-ENG-48. Ui-u ELASTIC AND INELASTIC
Random parking, Euclidean functionals, and rubber elasticity
Antoine Gloria; Mathew D. Penrose
2012-03-06T23:59:59.000Z
We study subadditive functions of the random parking model previously analyzed by the second author. In particular, we consider local functions $S$ of subsets of $\\mathbb{R}^d$ and of point sets that are (almost) subadditive in their first variable. Denoting by $\\xi$ the random parking measure in $\\mathbb{R}^d$, and by $\\xi^R$ the random parking measure in the cube $Q_R=(-R,R)^d$, we show, under some natural assumptions on $S$, that there exists a constant $\\bar{S}\\in \\mathbb{R}$ such that % $$ \\lim_{R\\to +\\infty} \\frac{S(Q_R,\\xi)}{|Q_R|}\\,=\\,\\lim_{R\\to +\\infty}\\frac{S(Q_R,\\xi^R)}{|Q_R|}\\,=\\,\\bar{S} $$ % almost surely. If $\\zeta \\mapsto S(Q_R,\\zeta)$ is the counting measure of $\\zeta$ in $Q_R$, then we retrieve the result by the second author on the existence of the jamming limit. The present work generalizes this result to a wide class of (almost) subadditive functions. In particular, classical Euclidean optimization problems as well as the discrete model for rubber previously studied by Alicandro, Cicalese, and the first author enter this class of functions. In the case of rubber elasticity, this yields an approximation result for the continuous energy density associated with the discrete model at the thermodynamic limit, as well as a generalization to stochastic networks generated on bounded sets.
Overall Dynamic Properties of 3-D periodic elastic composites
Ankit Srivastava; Sia Nemat-Nasser
2011-05-27T23:59:59.000Z
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.
Saleh, Tarik A. [Los Alamos National Laboratory; Farrow, Adam M. [Los Alamos National Laboratory; Freibert, Franz J. [Los Alamos National Laboratory
2012-06-06T23:59:59.000Z
Samples of {alpha} plutonium were fabricated at the Los Alamos National Laboratory's Plutonium Facility. Cylindrical samples were machined from cast pucks. Precision immersion density and resonant ultrasound spectroscopy (RUS) measurements were completed on 27 new samples, yielding elastic moduli measurements. Mechanical tests were performed in compression yielding stress-strain curves as a function of rate, temperature and phase.
Random Parking and Rubber Elasticity Mathew Penrose
Penrose, Mathew
Random Parking and Rubber Elasticity Mathew Penrose (University of Bath) Joint work with Antoine), Imperial January 2013 #12;Rubber Elasticity Let d, n N (e.g. d = n = 3). Suppose D Rd is a bounded domain. D represents a piece of rubber. Let L Rd be a locally finite point process. L D the locations
ROCK ELASTIC PROPERTIES: DEPENDENCE ON MICROSTRUCTURE
ROCK ELASTIC PROPERTIES: DEPENDENCE ON MICROSTRUCTURE James G. Berryman and Patricia A. Berge Lawrence Livermore National Laboratory P. O. Box 808 L202 Livermore, CA 945519900 #12; ROCK ELASTIC PROPERTIES: DEPENDENCE ON MICROSTRUCTURE James G. Berryman and Patricia A. Berge Lawrence Livermore National
Elastic–Plastic Spherical Contact Modeling Including Roughness Effects
Li, L.; Etsion, I.; Talke, F. E.
2010-01-01T23:59:59.000Z
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
Elastic continuum theory: Fully understanding of the twist-bend nematic phases
Giovanni Barbero; Luiz Roberto Evangelista; Michely Patrícia Rosseto; Rafael Soares Zola; Ioannis Lelidis
2015-03-30T23:59:59.000Z
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.
Fiber felts as low density structural materials
Milewski, J.V.; Newfield, S.E.
1981-01-01T23:59:59.000Z
Short fiber felts structures can be made which provide improvements in properties over foams. In applications where resistance to compression set or stress relaxation are important, bonded fiber felts excel due to the flexing of individual fibers within their elastic limit. Felts of stainless steel and polyester fibers were prepared by deposition from liquid slurries. Compressive properties were determined as a function of felt parent material, extent of bonding, felt density, and length-to-diameter (L/D) ratio of starting fibers.
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...
Molecular elasticity and the geometric phase
Joseph Samuel; Supurna Sinha
2003-01-23T23:59:59.000Z
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.
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
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.
Intraclass Price Elasticity & Electric Rate Design
Gresham, K. E.
1987-01-01T23:59:59.000Z
Electric rate design relies on cost incurrance for pricing and pricing structures. However, as utilities move into a marketing mode, rate design needs to respond more to customer reactions to pricing changes. Intraclass price elasticities aid rate...
Mechanical behavior of elastic rods under constraint
Miller, James Thomas, Ph. D. Massachusetts Institute of Technology
2014-01-01T23:59:59.000Z
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 ...
Coiling of elastic rods on rigid substrates
Khalid Jawed, Mohammad
We investigate the deployment of a thin elastic rod onto a rigid substrate and study the resulting coiling patterns. In our approach, we combine precision model experiments, scaling analyses, and computer simulations toward ...
Coiling of elastic rods on rigid substrates
Khalid Jawed, Mohammad
2014-01-01T23:59:59.000Z
We investigate the deployment of a thin elastic rod onto a rigid substrate and study the resulting coiling patterns. In our approach, we combine precision model experiments, scaling analyses, and computer simulations towards ...
Continuously-Variable Series-Elastic Actuator
Mooney, Luke M.
Actuator efficiency is an important factor in the design of powered leg prostheses, orthoses, exoskeletons, and legged robots. A continuously-variable series-elastic actuator (CV-SEA) is presented as an efficient actuator ...
Structural, elastic, electronic, magnetic and vibrational properties of CuCoMnGa under pressure
?yigör, Ahmet [Central Research and Practice Laboratory (AH?LAB), AhiEvran University, 40100 K?r?ehir (Turkey); U?ur, ?ule [Department of Physics, Faculty of Science, Gazi University, 06500 Ankara (Turkey)
2014-10-06T23:59:59.000Z
First principles calculations for the structural, electronic, elastic and phonon properties of the cubic quaternary heusler alloy CuCoMnGa on pressure have been reported by density functional theory (DFT) within generalized gradient approximation (GGA). The calculated values of the elastic constants were used for estimations of the Debye temperatures, the bulk modulus, the shear modulus, the young modulus E, the poisson's ratio ? and the B/G ratio. The elastic constants satisfy all of the mechanical stability criteria. The electronic structures of the ferromagnetic configuration for CuCoMnGa have a metallic character. The estimated magnetic moment per formula unit is 3.76 ?{sub B}. The phonon dispersion is studied using the supercell approach, and the stable nature at 0.2 GPa pressure is observed.
Strong coupling effects in near-barrier heavy-ion elastic scattering
N. Keeley; K. W. Kemper; K. Rusek
2014-09-25T23:59:59.000Z
Accurate elastic scattering angular distribution data measured at bombarding energies just above the Coulomb barrier have shapes that can markedly differ from or be the same as the expected classical Fresnel scattering pattern depending on the structure of the projectile, the target or both. Examples are given such as 18O + 184W and 16O + 148,152Sm where the expected rise above Rutherford scattering due to Coulomb-nuclear interference is damped by coupling to the target excited states, and the extreme case of 11Li scattering, where coupling to the 9Li + n + n continuum leads to an elastic scattering shape that cannot be reproduced by any standard optical model parameter set. The recent availability of high quality 6He, 11Li and 11Be data provides further examples of the influence that coupling effects can have on elastic scattering. Conditions for strong projectile-target coupling effects are presented with special emphasis on the importance of the beam-target charge combination being large enough to bring about the strong coupling effects. Several measurements are proposed that can lead to further understanding of strong coupling effects by both inelastic excitation and nucleon transfer on near-barrier elastic scattering. A final note on the anomalous nature of 8B elastic scattering is presented as it possesses a more or less normal Fresnel scattering shape whereas one would a priori not expect this due to the very low breakup threshold of 8B. The special nature of 11Li is presented as it is predicted that no matter how far above the Coulomb barrier the elastic scattering is measured, its shape will not appear as Fresnel like whereas the elastic scattering of all other loosely bound nuclei studied to date should eventually do so as the incident energy is increased, making both 8B and 11Li truly "exotic".
Intraclass Price Elasticity & Electric Rate Design
Gresham, K. E.
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...
DNA Twist Elasticity: Mechanics and Thermal Fluctuations
Supurna Sinha; Joseph Samuel
2010-11-30T23:59:59.000Z
The elastic properties of semiflexible polymers are of great importance in biology. There are experiments on biopolymers like double stranded DNA, which twist and stretch single molecules to probe their elastic properties. It is known that thermal fluctuations play an important role in determining molecular elastic properties, but a full theoretical treatment of the problem of twist elasticity of fluctuating ribbons using the simplest worm like chain model (WLC) remains elusive. In this paper, we approach this problem by taking first a mechanical approach and then incorporating thermal effects in a quadratic approximation applying the Gelfand-Yaglom (GY) method for computing fluctuation determinants. Our study interpolates between mechanics and statistical mechanics in a controlled way and shows how profoundly thermal fluctuations affect the elasticity of semiflexible polymers. The new results contained here are: 1) a detailed study of the minimum energy configurations with explicit expressions for their energy and writhe and plots of the extension versus Link for these configurations. 2) a study of fluctuations around the local minima of energy and approximate analytical formulae for the free energy of stretched twisted polymers derived by the Gelfand Yaglom method. We use insights derived from our mechanical approach to suggest calculational schemes that lead to an improved treatment of thermal fluctuations. From the derived formulae, predictions of the WLC model for molecular elasticity can be worked out for comparison against numerical simulations and experiments.
Effective medium theory of elastic waves in random networks of rods
J. I. Katz; J. J. Hoffman; M. S. Conradi; J. G. Miller
2012-06-13T23:59:59.000Z
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.
Optical theorem and elastic nucleon scattering
Milos V. Lokajicek; Vojtech Kundrat
2009-06-22T23:59:59.000Z
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.
Elasticity of Twist-Bend Nematic Phases
Epifanio G. Virga
2014-04-12T23:59:59.000Z
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.
Elastic and Proton Dynamics of the DNA
V. L. Golo
2008-03-28T23:59:59.000Z
The subject of this report is the dynamics of elastic system in conjunction with hydrogen bonds of the DNA. We draw attention to the draw-back of the familiar rod model of the DNA, and make a case of constructing models that could accommodate the intrinsic structure of the DNA. In this respect studying the interplay among the elastic system and the protons of the DNA, is of interest, for it could accommodate the inter-strand as well as the tunneling modes of protons. Following this direction, we come to the conclusion that the elastic-proton dynamics may have a bearing on biophysics of the DNA. The phenomenon of point mutations is discussed within this framework.
Paris-Sud XI, Université de
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
Phenomenological explanation of elastic anomalies in superlattices
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
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.
First principle study of elastic and thermodynamic properties of FeB{sub 4} under high pressure
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
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.
THE RESPONSE OF SOLIDS TO ELASTIC/ PLASTIC INDENTATION
Chiang, S.S.
2013-01-01T23:59:59.000Z
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,
Interaction of gravitational waves with an elastic solid medium
B. Carter
2001-02-28T23:59:59.000Z
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.
Nonaffine rubber elasticity for stiff polymer networks
C. Heussinger; B. Schaefer; E. Frey
2007-11-26T23:59:59.000Z
We present a theory for the elasticity of cross-linked stiff polymer networks. Stiff polymers, unlike their flexible counterparts, are highly anisotropic elastic objects. Similar to mechanical beams stiff polymers easily deform in bending, while they are much stiffer with respect to tensile forces (``stretching''). Unlike in previous approaches, where network elasticity is derived from the stretching mode, our theory properly accounts for the soft bending response. A self-consistent effective medium approach is used to calculate the macroscopic elastic moduli starting from a microscopic characterization of the deformation field in terms of ``floppy modes'' -- low-energy bending excitations that retain a high degree of non-affinity. The length-scale characterizing the emergent non-affinity is given by the ``fiber length'' $l_f$, defined as the scale over which the polymers remain straight. The calculated scaling properties for the shear modulus are in excellent agreement with the results of recent simulations obtained in two-dimensional model networks. Furthermore, our theory can be applied to rationalize bulk rheological data in reconstituted actin networks.
The elasticity of -helices Seungho Choe
Sun, Sean
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
Anisotropic thermo-elasticity in 2D -- Part II: Applications
Jens Wirth
2007-11-15T23:59:59.000Z
In this note we present concrete applications of the general treatment of anisotropic thermo-elasticity developed in Part I.
Eric DeGiuli; Adrien Laversanne-Finot; Gustavo Düring; Edan Lerner; Matthieu Wyart
2014-02-22T23:59:59.000Z
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 $\
Pavel Galich; Stephan Rudykh
2014-12-31T23:59:59.000Z
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.
Measurements of elastic modulus using laser-induced surface waves
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
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.
Packing of elastic wires in flexible shells
Vetter, Roman; Herrmann, Hans J
2015-01-01T23:59:59.000Z
The packing problem of long thin filaments that are injected into confined spaces is of fundamental interest for physicists, biologists and materials engineers alike. How linear threads pack and coil is well known only for the ideal case of rigid containers, however. Here, we force long elastic rods into flexible spatial confinement borne by an elastic shell to examine under which conditions recently acquired knowledge on wire packing in rigid spheres breaks down. We find that unlike in rigid cavities, friction plays a key role by giving rise to the emergence of two distinct packing patterns. At low friction, the wire densely coils into an ordered toroidal bundle with semi-ellipsoidal cross section, while at high friction, it packs into a highly disordered, self-similar structure. These two morphologies are shown to be separated by a continuous phase transition.
Packing of elastic wires in flexible shells
Roman Vetter; Falk K. Wittel; Hans J. Herrmann
2015-04-03T23:59:59.000Z
The packing problem of long thin filaments that are injected into confined spaces is of fundamental interest for physicists, biologists and materials engineers alike. How linear threads pack and coil is well known only for the ideal case of rigid containers, however. Here, we force long elastic rods into flexible spatial confinement borne by an elastic shell to examine under which conditions recently acquired knowledge on wire packing in rigid spheres breaks down. We find that unlike in rigid cavities, friction plays a key role by giving rise to the emergence of two distinct packing patterns. At low friction, the wire densely coils into an ordered toroidal bundle with semi-ellipsoidal cross section, while at high friction, it packs into a highly disordered, self-similar structure. These two morphologies are shown to be separated by a continuous phase transition.
Elastic electron scattering from formic acid
Trevisan, Cynthia S.; Orel, Ann E.; Rescigno, Thomas N.
2006-07-31T23:59:59.000Z
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.
U?ur, ?ule [Central Research and Practice Laboratory (AH?LAB), Ahi Evran University, 40100 K?r?ehir (Turkey); ?yigör, Ahmet [Department of Physics, Faculty of Science, Gazi University, 06500 Ankara (Turkey)
2014-10-06T23:59:59.000Z
The electronic, elastic and dynamical properties of the quaternary alloy FeNiMnAl have been investigated using a pseudopotential plane wave method within the generalized gradient approximation (GGA). We determined the lattice parameters and the bulk modulus B. In addition, the elastic properties such as elastic constans (C{sub 11}, C{sub 12} and C{sub 44}), the shear modulus G, the young modulus E, the poisson's ratio ? and the B/G ratio are also given. The FeNiMnAl Heusler alloy exhibit a ferromagnetic half-metallic behavior with the total magnetic moment of 4.02 ?{sub B}. The phonon dispersion of FeNiMnAl has been performed using the density functional theory and the direct method with 2×2×2 supercell.
Environmental bias and elastic curves on surfaces
Jemal Guven; Dulce María Valencia; Pablo Vázquez-Montejo
2014-08-15T23:59:59.000Z
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.
Preferred orientation and elastic anisotropy in shales.
Lonardelli, I.; Wenk, H.-R.; Ren, Y.; Univ. of California at Berkeley
2007-03-01T23:59:59.000Z
Anisotropy in shales is becoming an important issue in exploration and reservoir geophysics. In this study, the crystallographic preferred orientation of clay platelets that contributes to elastic anisotropy was determined quantitatively by hard monochromatic X-ray synchrotron diffraction in two different shales from drillholes off the coast of Nigeria. To analyze complicated diffraction images with five different phases (illite/smectite, kaolinite, quartz, siderite, feldspar) and many overlapping peaks, we applied a methodology based on the crystallographic Rietveld method. The goal was to describe the intrinsic physical properties of the sample (phase composition, crystallographic preferred orientation, crystal structure, and microstructure) and compute macroscopic elastic properties by averaging single crystal properties over the orientation distribution for each phase. Our results show that elastic anisotropy resulting from crystallographic preferred orientation of the clay particles can be determined quantitatively. This provides a possible way to compare measured seismic anisotropy and texture-derived anisotropy and to estimate the contribution of the low-aspect ratio pores aligned with bedding.
The elastic properties of beta-eucryptite in the glassy and microcracked crystalline states
Shyam, Amit [ORNL; Lara-Curzio, Edgar [ORNL; Muth, Joseph T. [Purdue University
2012-01-01T23:59:59.000Z
Amorphous and crystalline {beta}-eucryptite (LiAlSiO{sub 4}) specimens were prepared with controlled grain sizes and varying levels of microcracking, and their elastic moduli were determined using resonant ultrasound spectroscopy. It was found that the relationship between Young's modulus, Poisson's ratio and degree of microcracking in these materials can be described well with fracture-mechanics-based models. It was also found that if glassy {beta}-eucryptite is considered to be a microcracked medium in which broken Si-O bonds, with respect to the crystalline material, constitute microcracks, then its elastic properties can be described equally well by these models. Such considerations are explained by noting the differences in atomic bond density among the different states of the material and by accounting for differences in strain energy release rate measurements on glass and ceramic specimens.
Pair densities in density functional theory
Chen, Huajie
2015-01-01T23:59:59.000Z
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...
Yaws, C.L.; Yang, H.C.; Hopper, J.R.; Cawley, W.A. (Lamar Univ., Beaumont, TX (US))
1991-01-01T23:59:59.000Z
Saturated liquid densities for organic chemicals are given as functions of temperature using a modified Rackett equation.
Dynamics of Bianchi type I elastic spacetimes
Simone Calogero; J. Mark Heinzle
2007-06-26T23:59:59.000Z
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.
Lessons from LHC elastic and diffractive data
A. D. Martin; V. A. Khoze; M. G. Ryskin
2014-10-13T23:59:59.000Z
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.
Elastic and diffractive scattering at D0
Edwards, Tamsin; /Manchester U.
2004-04-01T23:59:59.000Z
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.
The effect of elastic strain on M-center distribution in LiF
Wolny, Richard Frank
1962-01-01T23:59:59.000Z
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...
Motivation Elastic Net Computation Elastic-Net and algorithms for computing the
Recht, Ben
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
New Atomic Force Microscope Spectroscopy Probes Local Elasticity...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Materials Characterization New Atomic Force Microscope Spectroscopy Probes Local Elasticity March 04, 2015 Shown is a contact resonance frequency image after nano-oxidation of a...
anisotropic elastic constants: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
under scale factors rescalings. Davi C. Rodrigues 2007-08-08 17 UltrasonicsBaron Propagation of elastic waves in an anisotropic functionally graded hollow cylinder in...
anomalous elastic behavior: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
of symmetry and relevance, we introduce a minimal Landau-Ginzburg-Wilson elastic energy for nematic elastomers. Performing a diagrammatic low temperature expansion, we...
Failure Stress and Apparent Elastic Modulus of Diesel Particulate...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
test specimen geometries and test methods for brittle materials are adapted to DPF architecture to evaluate failure initiation stress and apparent elastic modulus of the ceramics....
Chang Q. Sun
2015-02-26T23:59:59.000Z
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.
Elastic properties of the degenerate f.c.c. crystal of polydisperse soft dimers at zero temperature
J. W. Narojczyk; K. W. Wojciechowski
2015-04-12T23:59:59.000Z
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.
Elastic properties of the degenerate f.c.c. crystal of polydisperse soft dimers at zero temperature
Narojczyk, J W
2015-01-01T23:59:59.000Z
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.
Stoica, Grigoreta M [ORNL; Stoica, Alexandru Dan [ORNL; Miller, Michael K [ORNL; Ma, Dong [ORNL
2014-01-01T23:59:59.000Z
Nanostructured ferritic alloys (NFA) are a new class of ultrafine-grained oxide dispersion-strengthened steels, promising for service in extreme environments of high temperature and high irradiation in the next-generation of nuclear reactors. This is owing to the remarkable stability of their complex microstructures containing a high density of Y-Ti-O nanoclusters within grains and along the grain boundaries. While nanoclusters have been recognized to be the primary contributor to the exceptional resistance to irradiation and high-temperature creep, very little is known about the mechanical roles of the polycrystalline grains that constitute the bulk ferritic matrix. Here we report the mesoscale characterization of anisotropic responses of the ultrafine NFA grains to tensile stresses at various temperatures using the state-of-the-art in situ neutron diffraction. We show the first experimental determination of temperature-dependent single-crystal elastic constants for the NFA, and reveal a strong temperature-dependent elastic anisotropy due to a sharp decrease in the shear stiffness constant [c'=(c_11-c_12)/2] when a critical temperature ( T_c ) is approached, indicative of elastic softening and instability of the ferritic matrix. We also show, from anisotropy-induced intergranular strain/stress accumulations, that a common dislocation slip mechanism operates at the onset of yielding for low temperatures, while there is a deformation crossover from low-temperature lattice hardening to high temperature lattice softening in response to extensive plastic deformation.
Propagation of elastic waves through a lattice of cylindrical cavities
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
Net Balanced Floorplanning Based on Elastic Energy Model
Nannarelli, Alberto
Net Balanced Floorplanning Based on Elastic Energy Model Wei Liu and Alberto Nannarelli Dept variations can introduce extra signal skew, it is desirable to have floorplans with balanced net delays based on the elastic energy model. The B*-tree, which is based on an ordered binary tree, is used
Rubber Elasticity: Solution of the James-Guth Model
B. E. Eichinger
2015-03-21T23:59:59.000Z
The solution of the many-body statistical mechanical theory of elasticity formulated by James and Guth in the 1940s is presented. The remarkable aspect of the solution is that it gives an elastic free energy that is essentially equivalent to that developed by Flory over a period of several decades.
Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities
Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities by Adam C. Baylin-Stern B.A. & Sc in the estimation of ESUBs from CIMS. Keywords: Elasticity of substitution; hybrid energy-economy model; translog-Stern Degree: Project No.: Master of Resource Management 535 Title of Thesis: Hybrid Simulation Modeling
Elastic nucleon scattering at small angles at LHC energies
S. V. Goloskokov; S. P. Kuleshov; O. V. Selyugin
1997-07-02T23:59:59.000Z
Predictions of the elastic proton-proton cross sections at energies of LHC are calculate on the base of the high energy dynamical model. The growth of $ds/dt$ at fixed transfer momenta are shown. The form of eikonal of elastic hadron scattering at super high energies is discussed.
CAPITAL FOR ENERGY AND INTER-FUEL ELASTICITIES OF SUBSTITUTION
substitution elasticity and inter-fuel substitution elasticities, determine how much a change in the price the standard econometric approach, grounded in behaviorally realistic historical statistics, and linear in the case of switching from oil to natural gas and natural gas to electricity. It was also found that all
Nitrogen Contamination in Elastic Neutron Scattering Songxue Chi,ab
Lynn, Jeffrey W.
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
Modeling Elastic Properties in Finite-Element Analysis: How Much
Modeling Elastic Properties in Finite- Element Analysis: How Much Precision Is Needed to Produce analysis was investigated using a finite-element model of a Macaca fascicularis skull. Four finite-element realistically using the orthotropic elastic properties employed in analysis 4. Results suggest that finite-element
Impact of Acid Additives on Elastic Modulus of Viscoelastic Surfactants
Khan, Waqar Ahmad
2012-02-14T23:59:59.000Z
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...
Relativistic elasticity of rigid rods and strings
Jose Natario
2014-09-30T23:59:59.000Z
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.
Elastic Metal Alloy Refrigerants: Thermoelastic Cooling
None
2010-10-01T23:59:59.000Z
BEETIT Project: UMD is developing an energy-efficient cooling system that eliminates the need for synthetic refrigerants that harm the environment. More than 90% of the cooling and refrigeration systems in the U.S. today use vapor compression systems which rely on liquid to vapor phase transformation of synthetic refrigerants to absorb or release heat. Thermoelastic cooling systems, however, use a solid-state material—an elastic shape memory metal alloy—as a refrigerant and a solid to solid phase transformation to absorb or release heat. UMD is developing and testing shape memory alloys and a cooling device that alternately absorbs or creates heat in much the same way as a vapor compression system, but with significantly less energy and a smaller operational footprint.
Phonons and elasticity in critically coordinated lattices
T C Lubensky; C L Kane; Xiaoming Mao; A Souslov; Kai Sun
2015-03-04T23:59:59.000Z
Much of our understanding of vibrational excitations and elasticity is based upon analysis of frames consisting of sites connected by bonds occupied by central-force springs, the stability of which depends on the average number of neighbors per site $z$. When $zzero energy and the number, $N_S$, of states of self stress, in which springs can be under positive or negative tension while forces on sites remain zero, it explores the properties of periodic square, kagome, and related lattices for which $z=z_c$ and the relation between states of self stress and zero modes in periodic lattices to the surface zero modes of finite free lattices (with free boundary conditions). It shows how modifications to the periodic kagome lattice can eliminate all but trivial translational zero modes and create topologically distinct classes, analogous to those of topological insulators, with protected zero modes at free boundaries and at interfaces between different topological classes.
Density-dependent covariant energy density functionals
Lalazissis, G. A. [Physics Department, Aristotle University of Thessaloniki, GR-54124 (Greece)
2012-10-20T23:59:59.000Z
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.
- 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
in the Earth. In the laboratory, the disturbance that induces elastic changes is a low-frequency wave sandstone as a function of the applied low-frequency (LF) axial strain (varied from 10À7 to 10À5 the wave speed is measured as a function of the applied static load. Dynamic acousto-elasticity uses low-frequency
Huang, Jianbin
Thermo-responsive viscoelastic wormlike micelle to elastic hydrogel transition in dual report a thermo-responsive phase transition from a viscoelastic wormlike micelle solution to an elastic
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...
Enhanced Elasticity and Soft Glassy Rheology of a Smectic in a Random Porous Environment
Ranjini Bandyopadhyay; Dennis Liang; Ralph H. Colby; James L. Harden; Robert L. Leheny
2005-02-18T23:59:59.000Z
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.
Thore, A., E-mail: andth@ifm.liu.se; Dahlqvist, M., E-mail: madah@ifm.liu.se, E-mail: bjoal@ifm.liu.se, E-mail: johro@ifm.liu.se; Alling, B., E-mail: madah@ifm.liu.se, E-mail: bjoal@ifm.liu.se, E-mail: johro@ifm.liu.se; Rosén, J., E-mail: madah@ifm.liu.se, E-mail: bjoal@ifm.liu.se, E-mail: johro@ifm.liu.se [Thin Film Physics Division, Department of Physics, Chemistry, and Biology, Linköping University, SE-581 83 Linköping (Sweden)
2014-09-14T23:59:59.000Z
In this paper, we report the by first-principles predicted properties of the recently discovered magnetic MAX phase Mn?GaC. The electronic band structure and vibrational dispersion relation, as well as the electronic and vibrational density of states, have been calculated. The band structure close to the Fermi level indicates anisotropy with respect to electrical conductivity, while the distribution of the electronic and vibrational states for both Mn and Ga depend on the chosen relative orientation of the Mn spins across the Ga sheets in the Mn–Ga–Mn trilayers. In addition, the elastic properties have been calculated, and from the five elastic constants, the Voigt bulk modulus is determined to be 157?GPa, the Voigt shear modulus 93?GPa, and the Young's modulus 233?GPa. Furthermore, Mn?GaC is found relatively elastically isotropic, with a compression anisotropy factor of 0.97, and shear anisotropy factors of 0.9 and 1, respectively. The Poisson's ratio is 0.25. Evaluated elastic properties are compared to theoretical and experimental results for M?AC phases where M?=?Ti, V, Cr, Zr, Nb, Ta, and A?=?Al, S, Ge, In, Sn.
Shiva Rudraraju; Anton van der Ven; Krishna Garikipati
2014-06-11T23:59:59.000Z
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.
The influence of ambient medium density on laser ablation processes
Kilgo, M.M. III
1995-11-01T23:59:59.000Z
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.
Elastic properties of gamma-Pu by resonant ultrasound spectroscopy
Migliori, Albert [Los Alamos National Laboratory; Betts, J [Los Alamos National Laboratory; Trugman, A [Los Alamos National Laboratory; Mielke, C H [Los Alamos National Laboratory; Mitchell, J N [Los Alamos National Laboratory; Ramos, M [Los Alamos National Laboratory; Stroe, I [WORXESTER, MA
2009-01-01T23:59:59.000Z
Despite intense experimental and theoretical work on Pu, there is still little understanding of the strange properties of this metal. We used resonant ultrasound spectroscopy method to investigate the elastic properties of pure polycrystalline Pu at high temperatures. Shear and longitudinal elastic moduli of the {gamma}-phase of Pu were determined simultaneously and the bulk modulus was computed from them. A smooth linear and large decrease of all elastic moduli with increasing temperature was observed. We calculated the Poisson ratio and found that it increases from 0.242 at 519K to 0.252 at 571K.
Effect of elasticity of wall on diffusion in nano channel
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
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.
Elastic Z^0 production at HERA
Luca Stanco
2014-10-13T23:59:59.000Z
The production of $Z^{0}$ bosons in the reaction $eparrow eZ^{0}p^{(*)}$, 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 $Z^{0}$ was measured in the hadronic decay mode. The elasticity of the events was ensured by a cut on $\\eta_{{\\rm max}} 3.0$, where $\\eta_{{\\rm max}}$ is the maximum pseudorapidity of energy deposits in the calorimeter defined with respect to the proton beam direction. A signal was observed at the $Z^{0}$ mass. The cross section of the reaction $ep arrow eZ^{0}p^{(*)}$ was measured to be $\\sigma (ep arrow eZ^{0}p^{(*)}) = {\\rm 0.13 \\pm{0.06} ({\\rm stat.}) \\pm{0.01} ({\\rm syst.})}\\, {\\rm pb}$, in agreement with the Standard Model prediction of $0.16\\, {\\rm pb}$. This is the first measurement of $Z^{0}$ production in $ep$ collisions. In this paper we report the already published ZEUS result by adding the sensitivities of the most recent similar results from CMS and ATLAS.
Nuclear level density as a tool for probing the inelastic scattering of 6He
Bora Canbula; Halil Babacan
2014-10-23T23:59:59.000Z
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.
Determination of Elastic Twist in Horizontal Axis Wind Turbines (HAWTs)
Stoddard, F.; Nelson, V.; Starcher, K.; Andrews, B.
2006-06-01T23:59:59.000Z
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.
Finite Difference Elastic Wave Modeling Including Surface Topography
Al Muhaidib, Abdulaziz
2011-01-01T23:59:59.000Z
Surface topography and the weathered zone (i.e., heterogeneity near the earth’s surface) have great effects on elastic wave propagation. Both surface waves and body waves are contaminated by scattering and conversion by ...
Kinematic quantities of finite elastic and plastic deformation
T. Fülöp; P. Ván
2012-03-05T23:59:59.000Z
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.
Instrumentation for multiaxial mechanical testing of inhomogeneous elastic membranes
Herrmann, Ariel Marc
2006-01-01T23:59:59.000Z
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 ...
Acoustic modes in metallic nanoparticles: Atomistic versus elasticity modeling
Combe, Nicolas; Saviot, Lucien [CNRS, CEMES (Centre d'Elaboration des Materiaux et d'Etudes Structurales), BP 94347, 29 Rue J. Marvig, F-31055 Toulouse, France and Universite de Toulouse, UPS, F-31055 Toulouse (France); Institut Carnot de Bourgogne, UMR 5209 CNRS - Universite de Bourgogne, 9 Avenue A. Savary, BP 47870, F-21078 Dijon Cedex (France)
2009-07-15T23:59:59.000Z
The validity of the linear elasticity theory is examined at the nanometer scale by investigating the vibrational properties of silver and gold nanoparticles whose diameters range from about 1.5-4 nm. Comparing the vibration modes calculated by elasticity theory and atomistic simulation based on the embedded-atom method, we first show that the anisotropy of the stiffness tensor in elastic calculation is essential to ensure a good agreement between elastic and atomistic models. Second, we illustrate the reduction in the number of vibration modes due to the diminution of the number of atoms when reducing the nanoparticles size. Finally, we exhibit a breakdown of the frequency-spectra scaling of the vibration modes and attribute it to surface effects. Some critical sizes under which such effects are expected, depending on the material and the considered vibration modes, are given.
Actin network architecture and elasticity in lamellipodia of melanoma cells
Schmidt, Volker
Actin network architecture and elasticity in lamellipodia of melanoma cells Frank Fleischer1 melanoma cells. This method is based on fitting multi-layer geometrical statistical models to electron
Exploiting Covariate Similarity in Sparse Regression via the Pairwise Elastic Net
Low, Steven H.
. 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
Exploiting Covariate Similarity in Sparse Regression via the Pairwise Elastic Net
Blei, David M.
, 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
Strange Quark Contribution to the Nucleon Spin from Electroweak Elastic Scattering Data
S. F. Pate; J. P. Schaub; D. P. Trujillo
2012-08-29T23:59:59.000Z
The total contribution of strange quarks to the intrinsic spin of the nucleon can be determined from a measurement of the strange-quark contribution to the nucleon's elastic axial form factor. We have studied the strangeness contribution to the elastic vector and axial form factors of the nucleon, using elastic electroweak scattering data. Specifically, we combine elastic $\
Elastic energy of proteins and the stages of protein folding
Lei, Jinzhi
2010-01-01T23:59:59.000Z
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^{\
J. R. Stone
2013-02-11T23:59:59.000Z
The microscopic composition and properties of matter at super-saturation densities have been the subject of intense investigation for decades. The scarcity of experimental and observational data has lead to the necessary reliance on theoretical models. However, there remains great uncertainty in these models, which, of necessity, have to go beyond the over-simple assumption that high density matter consists only of nucleons and leptons. Heavy strange baryons, mesons and quark matter in different forms and phases have to be included to fulfil basic requirements of fundamental laws of physics. In this review the latest developments in construction of the Equation of State (EoS) of high-density matter at zero and finite temperature assuming different composition of the matter are surveyed. Critical comparison of model EoS with available observational data on neutron stars, including gravitational masses, radii and cooling patterns is presented. The effect of changing rotational frequency on the composition of neutron stars during their lifetime is demonstrated. Compatibility of EoS of high-density, low temperature compact objects and low density, high temperature matter created in heavy-ion collisions is discussed.
Density Matrix Topological Insulators
A. Rivas; O. Viyuela; M. A. Martin-Delgado
2013-10-31T23:59:59.000Z
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.
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
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.
Nucleon and $?$ elastic and transition form factors
Jorge Segovia; Ian C. Cloet; Craig D. Roberts; Sebastian M. Schmidt
2014-09-03T23:59:59.000Z
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.
Measurement of the antineutrino neutral-current elastic differential cross section
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aguilar-Arevalo, A. ?A.; Brown, B. ?C.; Bugel, L.; Cheng, G.; Church, E. ?D.; Conrad, J. ?M.; Dharmapalan, R.; Djurcic, Z.; Finley, D. ?A.; Ford, R.; Garcia, F. ?G.; Garvey, G. ?T.; Grange, J.; Huelsnitz, W.; Ignarra, C.; Imlay, R.; Johnson, R. ?A.; Karagiorgi, G.; Katori, T.; Kobilarcik, T.; Louis, W. ?C.; Mariani, C.; Marsh, W.; Mills, G. ?B.; Mirabal, J.; Moore, C. ?D.; Mousseau, J.; Nienaber, P.; Osmanov, B.; Pavlovic, Z.; Perevalov, D.; Polly, C. ?C.; Ray, H.; Roe, B. ?P.; Russell, A. ?D.; Shaevitz, M. ?H.; Spitz, J.; Stancu, I.; Tayloe, R.; Van de Water, R. ?G.; Wascko, M. ?O.; White, D. ?H.; Wickremasinghe, D. ?A.; Zeller, G. ?P.; Zimmerman, E. ?D.
2015-01-01T23:59:59.000Z
We report the measurement of the flux-averaged antineutrino neutral current elastic scattering cross section (d??-barN??-barN/dQ2) on CH2 by the MiniBooNE experiment using the largest sample of antineutrino neutral current elastic candidate events ever collected. The ratio of the antineutrino to neutrino neutral current elastic scattering cross sections and a ratio of the antineutrino neutral current elastic to antineutrino charged current quasi elastic cross sections are also presented.
Multiple density layered insulator
Alger, Terry W. (Tracy, CA)
1994-01-01T23:59:59.000Z
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.
Multiple density layered insulator
Alger, T.W.
1994-09-06T23:59:59.000Z
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.
Vranjes, J
2015-01-01T23:59:59.000Z
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 ...
Stages of destruction and elastic compression of granular nanoporous carbon medium at high pressures
I. M. Neklyudov; O. P. Ledenyov; N. B. Bobrova; A. A. Chupikov
2015-05-14T23:59:59.000Z
The granular nanoporous carbon medium, made of the cylindrical coal granules of the adsorbent of SKT 3, at an influence by the high pressures from 1MPa to 3GPa has been researched. The eight consecutive stages of the materials specific volume change, which is characterized by a certain dependence of the volume change on the pressure change, have been registered. It is shown that there is a linear dependence on the double log log plot of the materials specific volume change on the pressure for an every stage of considered process. The two stages are clearly distinguished such as a stage of materials mechanical destruction, and a stage of elastic compression of material without the disintegration of structure at a nanscale. The hysteresis dependence of the materials specific volume change on the pressure change at the pressure decrease is observed. The small disperse coal dust particles jettisoning between the high pressure cell and the base plate was observed, resulting in the elastic stress reduction in relation to the small disperse coal dust particles volume. The obtained research data can be used to improve the designs of air filters for the radioactive chemical elements absorption at the NPP with the aims to protect the environment.
Beyond mean-field study of elastic and inelastic electron scattering off nuclei
J. M. Yao; M. Bender; P. -H. Heenen
2015-01-21T23:59:59.000Z
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....
Mode III interfacial crack in the presence of couple stress elastic materials
Andrea Piccolroaz; Gennady Mishuris; Enrico Radi
2011-04-02T23:59:59.000Z
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.
Nonlinear elastic polymers in random flow
M. Martins Afonso; D. Vincenzi
2005-08-09T23:59:59.000Z
Polymer stretching in random smooth flows is investigated within the framework of the FENE dumbbell model. The advecting flow is Gaussian and short-correlated in time. The stationary probability density function of polymer extension is derived exactly. The characteristic time needed for the system to attain the stationary regime is computed as a function of the Weissenberg number and the maximum length of polymers. The transient relaxation to the stationary regime is predicted to be exceptionally slow in the proximity of the coil-stretch transition.
Price-elastic demand in deregulated electricity markets
Siddiqui, Afzal S.
2003-05-01T23:59:59.000Z
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.
Determination of elastic properties of a film-substrate system by using the neural networks
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
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.
Mullin, Scott; Panday, Ashoutosh; Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel
2014-04-22T23:59:59.000Z
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.
Finite-difference schemes for elastic waves based on the integration approach
Zahradnik, J. (Charles Univ., Prague (Czech Republic). Faculty of Mathematics and Physics); O'Leary, P. (Univ. of Wyoming, Laramie, WY (United States). Dept. of Mathematics); Sochacki, J. (James Madison Univ., Harrisonburg, VA (United States). Dept. of Mathematics)
1994-06-01T23:59:59.000Z
The authors present a second order explicit finite-difference scheme for elastic waves in 2-D nonhomogeneous media. These schemes are based on integrating the equations of motion and the stress-free surface conditions across the discontinuities before discretizing them on a grid. As an alternative for the free-surface treatment, a scheme using zero density above the surface is suggested. This scheme is first order and is shown to be a natural consequence of the integrated equations of motion and is called a vacuum formalism. These schemes remove instabilities encountered in earlier integration schemes. The consistency study reveals a close link between the vacuum formalism and the integrated/discretized stress-free condition, giving priority to the vacuum formalism when a material discontinuity reaches the free surface. The two presented free-surface treatments coincide in the sense of the limit (grid size [yields] 0) for lateral homogeneity at or near the free surface.
Elastic and plastic properties of soils influencing the design of rigid pavements
Khuri, Fuad I.
1954-01-01T23:59:59.000Z
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
Elastic and plastic properties of soils influencing the design of rigid pavements
Khuri, Fuad I.
1954-01-01T23:59:59.000Z
s ............................................................................... 1 3 3 3 7 8 11 11 12 16 19 26 33 33 47 55 EX III. DETERMINATION OF THE PERTINENT STRESS-STRAIN CHARACTERISTICS OF THE S O I L .................................................. 82 A . P repara tion of S a m p l e... s .................................................................82 B. Unconfined C om press ion T e s t s .................................................. 85 C. Var ied Latera l P r e s su r e T r iax ia l T e s t s ............................. 88 D. Repetitive Load T riax ia l T e...
Elastic breakup cross sections of well-bound nucleons
K. Wimmer; D. Bazin; A. Gade; J. A. Tostevin; T. Baugher; Z. Chajecki; D. Coupland; M. A. Famiano; T. K. Ghosh; G. F. Grinyer M. E. Howard; M. Kilburn; W. G. Lynch; B. Manning; K. Meierbachtol; P. Quarterman; A. Ratkiewicz; A. Sanetullaev; R. H. Showalter; S. R. Stroberg; M. B. Tsang; D. Weisshaar; J. Winkelbauer; R. Winkler; M. Youngs
2014-12-07T23:59:59.000Z
The 9Be(28Mg,27Na) one-proton removal reaction with a large proton separation energy of Sp(28Mg)=16.79 MeV is studied at intermediate beam energy. Coincidences of the bound 27Na residues with protons and other light charged particles are measured. These data are analyzed to determine the percentage contributions to the proton removal cross section from the elastic and inelastic nucleon removal mechanisms. These deduced contributions are compared with the eikonal reaction model predictions and with the previously measured data for reactions involving the re- moval of more weakly-bound protons from lighter nuclei. The role of transitions of the proton between different bound single-particle configurations upon the elastic breakup cross section is also quantified in this well-bound case. The measured and calculated elastic breakup fractions are found to be in good agreement.
Temperature relationship of the elastic constants of vanadium
Belousov, O.K.
1987-09-01T23:59:59.000Z
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
Biaxial Deformations of Rubber: Entanglements or Elastic Fluctuations?
Xiangjun Xing
2010-11-01T23:59:59.000Z
The classical theory of rubber elasticity fails in the regime of large deformation. The un- derlying physical mechanism has been under debate for long time. In this work, we test the recently proposed mechanism of thermal elastic fluctuations by Xing, Goldbart and Radzi- hovsky1 against the biaxial stress-strain data of three distinct polymer networks with very different network structures, synthesized by Urayama2 and Kawabata3 respectively. We find that both the two parameters version and the one-parameter version of the XGR theory provide satisfactory description of the elasticity in whole deformation range. For comparison, we also fit the same sets of data using the slip-link model by Edwards and Vilgis with four parameters. The fitting qualities of two theories are found to be comparable.
Spatial Distributions of Local Elastic Moduli Near the Jamming Transition
Hideyuki Mizuno; Leonardo E. Silbert; Matthias Sperl
2015-04-10T23:59:59.000Z
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.
Impedance of rigid bodies in one-dimensional elastic collisions
Santos, Janilo; Nelson, Osman Rosso
2012-01-01T23:59:59.000Z
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.
Meisam Asgari; Aisa Biria
2015-02-17T23:59:59.000Z
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.
Khare, Sanjay V.
elastic constants. Ó 2014 Elsevier Ltd. All rights reserved. Keywords: CZTS; CZTSe; Density functional-effective replacements materials. Recent demonstration of around 10% efficient, solar cells with Cu2ZnSnS4 (CZTS) and Cu2, 2010). CZTS and CZTSe have been investigated both experi- mentally and theoretically. Todorov et al
Low-energy elastic electron interactions with pyrimidine
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
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.
Accurate hydrogen depth profiling by reflection elastic recoil detection analysis
Verda, R. D. (Raymond D.); Tesmer, Joseph R.; Nastasi, Michael Anthony,; Bower, R. W. (Robert W.)
2001-01-01T23:59:59.000Z
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.
Elastic anisotropy in multifilament Nb3Sn superconducting wires
Scheuerlein, C; Alknes, P; Arnau, G; Bjoerstad, R; Bordini, B
2015-01-01T23:59:59.000Z
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.
High Energy Density Capacitors
None
2010-07-01T23:59:59.000Z
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.
Influence of interstitial Mn on magnetism in room-temperature ferromagnet Mn(1+delta)Sb
Taylor, Alice E [ORNL; Berlijn, Tom [ORNL; Hahn, Steven E [ORNL; May, Andrew F [ORNL; Williams, Travis J [ORNL; Poudel, Lekhanath N [ORNL; Calder, Stuart A [ORNL; Fishman, Randy Scott [ORNL; Stone, Matthew B [ORNL; Aczel, Adam A [ORNL; Cao, Huibo [ORNL; Lumsden, Mark D [ORNL; Christianson, Andrew D [ORNL
2015-01-01T23:59:59.000Z
We report elastic and inelastic neutron scattering measurements of the high-TC ferromagnet Mn(1+delta)Sb. Measurements were performed on a large, TC = 434 K, single crystal with interstitial Mn content of delta=0.13. The neutron diffraction results reveal that the interstitial Mn has a magnetic moment, and that it is aligned antiparallel to the main Mn moment. We perform density functional theory calculations including the interstitial Mn, and find the interstitial to be magnetic in agreement with the diffraction data. The inelastic neutron scattering measurements reveal two features in the magnetic dynamics: i) a spin-wave-like dispersion emanating from ferromagnetic Bragg positions (H K 2n), and ii) a broad, non-dispersive signal centered at forbidden Bragg positions (H K 2n+1). The inelastic spectrum cannot be modeled by simple linear spin-wave theory calculations, and appears to be significantly altered by the presence of the interstitial Mn ions. The results show that the influence of the int
The full weak charge density distribution of 48Ca from parity violating electron scattering
Lin, Z
2015-01-01T23:59:59.000Z
Background: The ground state neutron density of a medium mass nucleus contains fundamental nuclear structure information and is at present relatively poorly known. Purpose: We explore if parity violating elastic electron scattering can provide a feasible and model independent way to determine not just the neutron radius but the full radial shape of the neutron density $\\rho_n(r)$ and the weak charge density $\\rho_W(r)$ of a nucleus. Methods: We expand the weak charge density of $^{48}$Ca in a model independent Fourier Bessel series and calculate the statistical errors in the individual coefficients that might be obtainable in a model parity violating electron scattering experiment. Results: We find that it is feasible to determine roughly six Fourier Bessel coefficients of the weak charge density of 48Ca within a reasonable amount of beam time. However, it would likely be much harder to determine the full weak density of a significantly heavier nucleus such as 208Pb. Conclusions: Parity violating elastic elec...
Kuryliuk, V. V., E-mail: kuryluk@univ.kiev.ua; Korotchenkov, O. A., E-mail: olegk@univ.kiev.ua [Kyiv National University, Physics Faculty (Ukraine)
2013-08-15T23:59:59.000Z
Within the elastic continuum model, with the use of the finite-element method, the stress-strain state of silicon-germanium heterostructures with semispherical germanium islands grown on an oxidized silicon surface is calculated. It is shown that as the density of islands is increased to limiting values, in the SiGe structure with open quantum dots the value and spatial distribution of the elastic-strain fields significantly change. The results of theoretical calculation allow the heterostructure portions with the maximum variation in the stress-strain state to be determined. The position of such a portions can be controlled by changing the density of islands.
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
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.
Bending Elasticity of Anti-Parallel b-Sheets Seungho Choe and Sean X. Sun
Sun, Sean
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
RIS-M-2586 ELASTIC-PLASTIC FRACTURE MECHANICS ANALYSIS OF A CT-SPECIMEN
RISØ-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
Elastic-plastic analysis of the transition divertor joint for high performance divertor target plate
Navaei, Dara
2011-01-01T23:59:59.000Z
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
Tirtaatmadja, Viyada
2007-01-23T23:59:59.000Z
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 ...
Efficient control of series elastic actuators through the exploitation of resonant modes
Albert, Kevin B. (Kevin Bjorn)
2007-01-01T23:59:59.000Z
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 ...
Boyer, Edmond
-bounded positive-definite matrix-valued random fields in the context of mesoscale modeling of heterogeneous elastic; Heterogeneous materials; Apparent elasticity tensor; Mesoscale modeling; Random field; Non-Gaussian. $ J
Elastic scattering at CERN collider energies and the Chou-Yang model
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
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.
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...
Analysis of Automobile Travel Demand Elasticities with Respect to Travel Cost
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
H. Dussan; M. H. Mahzoon; R. J. Charity; W. H. Dickhoff; A. Polls
2014-10-09T23:59:59.000Z
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.
Elastic modulus of viral nanotubes Zhibin Ge,2
Wu, Shin-Tson
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
Buckling-induced encapsulation of structured elastic shells under pressure
Reis, Pedro Miguel
functional origami-like structures at the nano- and microscales (1Â3), 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
Revenue Management for Cognitive Spectrum Underlay Networks: An Interference Elasticity
Huang, Jianwei
to the large body of work on uplink power control with pricing for CDMA networks (e.g., [5][10] and a recent a total received interference power constraint at the primary user's receiver. The transmission power1 Revenue Management for Cognitive Spectrum Underlay Networks: An Interference Elasticity
Addiction to car use and dynamic elasticity measures in France
Boyer, Edmond
1 Addiction to car use and dynamic elasticity measures in France Roger Collet* Matthieu de: Transportation, Car use, Consumption, Addiction, Panel, GMM. JEL Classification: C23, D12. * Corresponding author-le-Grand Cedex, France. Tel: +33(1) 45 92 55 73. E-mail: rcollet@inrets.fr. ** Université Paris-Est. Institut
Love wave propagation in layered magneto-electro-elastic structures
Wang, Ji
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
Two typical processes ... Isentropic("mechanical" reversible, elastic)
Kostic, Milivoje M.
is coupled and accompanied with energy conversions and dissipation to heat/thermal energy ... Carnot cycle12/28/2011 1 Two typical processes ... · Isentropic("mechanical" reversible, elastic) where useful provides for de-coupling of thermal energy from other types and, YES!, for reversible heat transfer
VISUALIZATION OF ELASTIC BODY DYNAMICS FOR AUTOMOTIVE ENGINE SIMULATIONS
drives, hydraulic systems and gas flow in combustion chambers. It also includes AVL Excite, a soft- ware-body system: linear elastic bod- ies (crankshaft, conrod, etc) connected by joints (bear- ings, dampers, etc a brief overview of the typical workflow of a user working with Excite be- fore the 3D view
Generalised elastic nets Miguel A. Carreira-Perpi~nan
Carreira-PerpiÃ±Ã¡n, Miguel Ã.
for combinatorial optimisation and has been applied, among other problems, to biological modelling. It has an energy the elastic net model to an arbitrary quadratic tension term, e.g. derived from a discretised differential, and show that the model is sensitive to the choice of finite difference scheme that represents
Preconditioned Conjugate Gradient Methods for Three Dimensional Linear Elasticity
Waterloo, University of
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
RESEARCH ARTICLE Bubble growth in visco-elastic magma: implications
Lyakhovsky, Vladimir
RESEARCH ARTICLE Bubble growth in visco-elastic magma: implications to magma fragmentation modulus, bubble growth is slow and follows an exponential law in a viscous growth regime, while for low friction and the Mohr-Coulomb failure theory, and a strain related one based on fibre elongation
MEASUREMENTS OF THE DEUTERON ELASTIC STRUCTURE FUNCTION AQ2
's continuous electron beam with energies from 3.2 to 4.4 GeV, and currents from 5 to 120 A. The beam current. CHUDAKOVa Thomas Je erson National Accelerator Facility, Newport News, Va, US The deuteron elastic structure of the experimental areas Hall A of the Thomas Je erson National Accelerator Facility JLab, using the Jlab
Neutron-deuteron elastic scattering and three-nucleon force
Chtangeev, Maxim B
2005-01-01T23:59:59.000Z
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 ...
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...
ELASTIC ROCK PROPERTIES OF TIGHT GAS SANDSTONES FOR RESERVOIR CHARACTERIZATION
to successfully produce low permeability gas reservoirs. My study links rock physics to well log and seismic data shales to reservoir sandstones. Typically, the presence of gas-saturated sandstones lowers the Vp/Vs evenELASTIC ROCK PROPERTIES OF TIGHT GAS SANDSTONES FOR RESERVOIR CHARACTERIZATION AT RULISON FIELD
Adler, Thomas A. (Corvallis, OR)
1996-01-01T23:59:59.000Z
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.
Low density microcellular foams
LeMay, James D. (Castro Valley, CA)
1991-01-01T23:59:59.000Z
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.
Low density microcellular foams
LeMay, James D. (Castro Valley, CA)
1992-01-01T23:59:59.000Z
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.
Oberacker, V E
2015-01-01T23:59:59.000Z
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.
Low density microcellular foams
LeMay, J.D.
1991-11-19T23:59:59.000Z
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.
Nuclear Energy Density Optimization
M. Kortelainen; T. Lesinski; J. Moré; W. Nazarewicz; J. Sarich; N. Schunck; M. V. Stoitsov; S. Wild
2010-05-27T23:59:59.000Z
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.
Low density microcellular foams
Aubert, James H. (Albuquerque, NM); Clough, Roger L. (Albuquerque, NM); Curro, John G. (Placitas, NM); Quintana, Carlos A. (Albuquerque, NM); Russick, Edward M. (Albuquerque, NM); Shaw, Montgomery T. (Mansfield Center, CT)
1987-01-01T23:59:59.000Z
Low density, microporous polymer foams are provided by a process which comprises forming a solution of polymer and a suitable solvent followed by rapid cooling of the solution to form a phase-separated system and freeze the phase-separated system. The phase-separated system comprises a polymer phase and a solvent phase, each of which is substantially continuous within the other. The morphology of the polymer phase prior to and subsequent to freezing determine the morphology of the resultant foam. Both isotropic and anisotropic foams can be produced. If isotropic foams are produced, the polymer and solvent are tailored such that the solution spontaneously phase-separates prior to the point at which any component freezes. The morphology of the resultant polymer phase determines the morphology of the resultant foam and the morphology of the polymer phase is retained by cooling the system at a rate sufficient to freeze one or both components of the system before a change in morphology can occur. Anisotropic foams are produced by forming a solution of polymer and solvent that will not phase separate prior to freezing of one or both components of the solution. In such a process, the solvent typically freezes before phase separation occurs. The morphology of the resultant frozen two-phase system determines the morphology of the resultant foam. The process involves subjecting the solution to essentially one-dimensional cooling. Means for subjecting such a solvent to one-dimensional cooling are also provided. Foams having a density of less than 0.1 g/cc and a uniform cell size of less than 10 .mu.m and a volume such that the foams have a length greater than 1 cm are provided.
Low density microcellular foams
Aubert, J.H.; Clough, R.L.; Curro, J.G.; Quintana, C.A.; Russick, E.M.; Shaw, M.T.
1985-10-02T23:59:59.000Z
Low density, microporous polymer foams are provided by a process which comprises forming a solution of polymer and a suitable solvent followed by rapid cooling of the solution to form a phase-separated system and freeze the phase-separated system. The phase-separated system comprises a polymer phase and a solvent phase, each of which is substantially continuous within the other. The morphology of the polymer phase prior to and subsequent to freezing determine the morphology of the resultant foam. Both isotropic and anisotropic foams can be produced. If isotropic foams are produced, the polymer and solvent are tailored such that the solution spontaneously phase-separates prior to the point at which any component freezes. The morphology of the resultant polymer phase determines the morphology of the reusltant foam and the morphology of the polymer phase is retained by cooling the system at a rate sufficient to freeze one or both components of the system before a change in morphology can occur. Anisotropic foams are produced by forming a solution of polymer and solvent that will not phase separate prior to freezing of one or both components of the solution. In such a process, the solvent typically freezes before phase separation occurs. The morphology of the resultant frozen two-phase system determines the morphology of the resultant foam. The process involves subjecting the solution to essentially one-dimensional cooling. Foams having a density of less than 0.1 g/cc and a uniform cell size of less than 10 ..mu..m and a volume such that the foams have a length greater than 1 cm are provided.
LETTER doi:10.1038/nature12267 Elastic energy storage in the shoulder and the
Udgaonkar, Jayant B.
#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
Elasticity measurements on minerals: a review ROSS J. ANGEL1,*, JENNIFER M. JACKSON2
Jackson, Jennifer M.
Elasticity measurements on minerals: a review ROSS J. ANGEL1,*, JENNIFER M. JACKSON2 , HANS J 91125, USA 3 Deutsches Geoforschungszentrum, 14473 Potsdam, Germany Abstract: The elasticity of minerals in the experimental methods used to determine the elastic properties of minerals. Not only have new techniques become
ON THE DERIVATION OF NONLINEAR SHELL MODELS FROM THREE-DIMENSIONAL ELASTICITY
, 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
Elasticity of hydrous wadsleyite to 12 GPa: Implications for Earth's transition zone
Duffy, Thomas S.
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
High-throughput generation of hydrogel microbeads with varying elasticity for cell encapsulation
Zandstra, Peter W.
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
Jacobsen, Steven D.
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
THE ELASTIC-PLASTIC MECHANICS OF CRACK EXTENSION James R. Rice*
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
Super-Elastic and Plastic Shock Waves Generated by Lasers N.A. Inogamov a,1
Fominov, Yakov
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
FINITE-ELEMENT FORMULATIONS FOR PROBLEMS OF LARGE ELASTIC-PLASTIC DEFORMATION
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
PLASTIC VERSUS ELASTIC DEFORMATION EFFECTS ON MAGNETIC BARKHAUSEN NOISE IN STEEL
Clapham, Lynann
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
Dynamics of structures coupled with elastic media -a review of numerical models and methods
Paris-Sud XI, UniversitÃ© de
), 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
ARTICLE IN PRESS 1 Effects of testing methods and conditions on the elastic
Al-Shayea, Naser Abdul-Rahman
on the elastic 2 properties of limestone rock 3 Naser A. Al-Shayea* 4 Department of Civil Engineering, King Fahd. The objective is to compare elastic properties (elastic modulus and Poisson's ratio) for 12 limestone rockfundamental mechanical properties of rock materials 34required for the analysis and design of engineering 35
Bowen, Ray M.
2014-01-22T23:59:59.000Z
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...
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
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.
Elastic free-energy of wormlike micellar chains: theory and suggested experiments
Meisam Asgari
2015-02-09T23:59:59.000Z
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.
Structural and elastic properties of a confined 2D colloidal solid: a molecular dynamics study
M. Ebrahim Foulaadvand; Neda Ojaghlou
2014-09-27T23:59:59.000Z
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. .
Measurement of the antineutrino neutral-current elastic differential cross section
Aguilar-Arevalo, A. ?A.; Brown, B. ?C.; Bugel, L.; Cheng, G.; Church, E. ?D.; Conrad, J. ?M.; Dharmapalan, R.; Djurcic, Z.; Finley, D. ?A.; Ford, R.; Garcia, F. ?G.; Garvey, G. ?T.; Grange, J.; Huelsnitz, W.; Ignarra, C.; Imlay, R.; Johnson, R. ?A.; Karagiorgi, G.; Katori, T.; Kobilarcik, T.; Louis, W. ?C.; Mariani, C.; Marsh, W.; Mills, G. ?B.; Mirabal, J.; Moore, C. ?D.; Mousseau, J.; Nienaber, P.; Osmanov, B.; Pavlovic, Z.; Perevalov, D.; Polly, C. ?C.; Ray, H.; Roe, B. ?P.; Russell, A. ?D.; Shaevitz, M. ?H.; Spitz, J.; Stancu, I.; Tayloe, R.; Van de Water, R. ?G.; Wascko, M. ?O.; White, D. ?H.; Wickremasinghe, D. ?A.; Zeller, G. ?P.; Zimmerman, E. ?D.
2015-01-01T23:59:59.000Z
We report the measurement of the flux-averaged antineutrino neutral current elastic scattering cross section (d?_{?-barN??-barN}/dQ^{2}) on CH_{2} by the MiniBooNE experiment using the largest sample of antineutrino neutral current elastic candidate events ever collected. The ratio of the antineutrino to neutrino neutral current elastic scattering cross sections and a ratio of the antineutrino neutral current elastic to antineutrino charged current quasi elastic cross sections are also presented.
Nonlinear elasticity of composite networks of stiff biopolymers with flexible linkers
C. P. Broedersz; C. Storm; F. C. MacKintosh
2008-10-19T23:59:59.000Z
Motivated by recent experiments showing nonlinear elasticity of in vitro networks of the biopolymer actin cross-linked with filamin, we present an effective medium theory of flexibly cross-linked stiff polymer networks. We model such networks by randomly oriented elastic rods connected by flexible connectors to a surrounding elastic continuum, which self-consistently represents the behavior of the rest of the network. This model yields a crossover from a linear elastic regime to a highly nonlinear elastic regime that stiffens in a way quantitatively consistent with experiment.
Amimoto, S.T.; Chang, D.J. [Aerospace Corporation, Los Angeles, CA (United States)
1995-12-31T23:59:59.000Z
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.
Spectral Modeling of Residual Stress and Stored Elastic Strain Energy in Thermal Barrier Coatings
Donegan, Sean; Rolett, Anthony
2013-12-31T23:59:59.000Z
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.
Rate-dependent elastic hysteresis during the peeling of Pressure Sensitive Adhesives
Richard Villey; Costantino Creton; Pierre-Philippe Cortet; Marie-Julie Dalbe; Thomas Jet; Baudouin Saintyves; Stéphane Santucci; Loïc Vanel; David Yarusso; Matteo Ciccotti
2015-05-20T23:59:59.000Z
The modelling of the adherence energy during peeling of Pressure Sensitive Adhesives (PSA) has received much attention since the 1950's, uncovering several factors that aim at explaining their high adherence on most substrates, such as the softness and strong viscoelastic behaviour of the adhesive, the low thickness of the adhesive layer and its confinement by a rigid backing. The more recent investigation of adhesives by probe-tack methods also revealed the importance of cavitation and stringing mechanisms during debonding, underlining the influence of large deformations and of the related non-linear response of the material, which also intervenes during peeling. Although a global modelling of the complex coupling of all these ingredients remains a formidable issue, we report here some key experiments and modelling arguments that should constitute an important step forward. We first measure a non-trivial dependence of the adherence energy on the loading geometry, namely through the influence of the peeling angle, which is found to be separable from the peeling velocity dependence. This is the first time to our knowledge that such adherence energy dependence on the peeling angle is systematically investigated and unambiguously demonstrated. Secondly, we reveal an independent strong influence of the large strain rheology of the adhesives on the adherence energy. We complete both measurements with a microscopic investigation of the debonding region. We discuss existing modellings in light of these measurements and of recent soft material mechanics arguments, to show that the adherence energy during peeling of PSA should not be associated to the propagation of an interfacial stress singularity. The relevant deformation mechanisms are actually located over the whole adhesive thickness, and the adherence energy during peeling of PSA should rather be associated to the energy loss by viscous friction and by rate-dependent elastic hysteresis.
Acoustic excitations and elastic heterogeneities in disordered solids
Hideyuki Mizuno; Stefano Mossa; Jean-Louis Barrat
2014-03-26T23:59:59.000Z
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.
Flow of Navier-Stokes Fluids in Cylindrical Elastic Tubes
Sochi, Taha
2013-01-01T23:59:59.000Z
Analytical expressions correlating the volumetric flow rate to the inlet and outlet pressures are derived for the time-independent flow of Newtonian fluids in cylindrically-shaped elastic tubes using a one-dimensional Navier-Stokes flow model with two pressure-area constitutive relations. These expressions for elastic tubes are the equivalent of Poiseuille and Poiseuille-type expressions for rigid tubes which were previously derived for the flow of Newtonian and non-Newtonian fluids under various flow conditions. Formulae and procedures for identifying the pressure field and tube geometric profile are also presented. The results are validated by a finite element method implementation. Sensible trends in the analytical and numerical results are observed and documented.
Heat transfer between elastic solids with randomly rough surfaces
B. N. J. Persson; B. Lorenz; A. I. Volokitin
2009-08-27T23:59:59.000Z
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.
Surface tension and contact with soft elastic solids
Robert W. Style; Callen Hyland; Rostislav Boltyanskiy; John S. Wettlaufer; Eric R. Dufresne
2013-10-11T23:59:59.000Z
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.
Elastic Coulomb-levitation: why is ice so slippery?
Chang Q. Sun
2015-02-14T23:59:59.000Z
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.
Rayleigh scattering and nonlinear inversion of elastic waves
Gritto, R.
1995-12-01T23:59:59.000Z
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.
Surface effects in the crystallization process of elastic flexible polymers
Stefan Schnabel; Thomas Vogel; Michael Bachmann; Wolfhard Janke
2010-02-10T23:59:59.000Z
Investigating thermodynamic properties of liquid-solid transitions of flexible homopolymers with elastic bonds by means of multicanonical Monte Carlo simulations, we find crystalline conformations that resemble ground-state structures of Lennard-Jones clusters. This allows us to set up a structural classification scheme for finite-length flexible polymers and their freezing mechanism in analogy to atomic cluster formation. Crystals of polymers with "magic length" turn out to be perfectly icosahedral.
Relativistic models for quasi-elastic neutrino scattering
M. C. Martinez; P. Lava; N. Jachowicz; J. Ryckebusch; K. Vantournhout; J. M. Udias
2006-02-17T23:59:59.000Z
We present quasi-elastic neutrino-nucleus cross sections in the energy range from 150 MeV up to 5 GeV for the target nuclei 12C and 56Fe. A relativistic description of the nuclear dynamics and the neutrino-nucleus coupling is adopted. For the treatment of final-state interactions (FSI) we rely on two frameworks succesfully applied to exclusive electron-nucleus scattering: a relativistic optical potential and a relativistic multiple-scattering Glauber approximation. At lower energies, the optical-potential approach is considered to be the optimum choice, whereas at high energies a Glauber approach is more natural. Comparing the results of both calculations, it is found that the Glauber approach yields valid results down to the remarkably small nucleon kinetic energies of 200 MeV. We argue that the nuclear transparencies extracted from A(e,e'p) measurements can be used to obtain realistic estimates of the effect of FSI mechanisms on quasi-elastic neutrino-nucleus cross sections. We present two independent relativistic plane-wave impulse approximation (RPWIA) calculations of quasi-elastic neutrino-nucleus cross sections. They agree at the percent level, showing the reliability of the numerical techniques adopted and providing benchmark RPWIA results.
Studying the Proton "Radius" Puzzle with ?p Elastic Scattering
R. Gilman; E. J. Downie; G. Ron; A. Afanasev; J. Arrington; O. Ates; F. Benmokhtar; J. Bernauer; E. Brash; W. J. Briscoe; K. Deiters; J. Diefenbach; C. Djalali; B. Dongwi; L. El Fassi; S. Gilad; K. Gnanvo; R. Gothe; D. Higinbotham; R. Holt; Y. Ilieva; H. Jiang; M. Kohl; G. Kumbartzki; J. Lichtenstadt; A. Liyanage; N. Liyanage; M. Meziane; Z. -E. Meziani; D. G. Middleton; P. Monaghan; K. E. Myers; C. Perdrisat; E. Piasetzsky; V. Punjabi; R. Ransome; D. Reggiani; P. Reimer; A. Richter; A. Sarty; E. Schulte; Y. Shamai; N. Sparveris; S. Strauch; V. Sulkosky; A. S. Tadepalli; M. Taragin; L. Weinstein
2013-07-29T23:59:59.000Z
The Proton Radius Puzzle is the inconsistency between the proton radius determined from muonic hydrogen and the proton radius determined from atomic hydrogen level transitions and ep elastic scattering. No generally accepted resolution to the Puzzle has been found. Possible solutions generally fall into one of three categories: the two radii are different due to novel beyond-standard-model physics, the two radii are different due to novel aspects of nucleon structure, and the two radii are the same, but there are underestimated uncertainties or other issues in the ep experiments. The MUon proton Scattering Experiment (MUSE) at the Paul Scherrer Institut is a simultaneous measurement of \\mu^+ p and e^+ p elastic scattering, as well as \\mu^- p and e^- p elastic scattering, which will allow a determination of the consistency of the \\mu p and the ep interactions. The differences between + and - charge scattering are sensitive to two-photon exchange effects, higher-order corrections to the scattering process. The slopes of the cross sections as Q^2 -> 0 determine the proton "radius". We plan to measure relative cross sections at a typical level of a few tenths of a percent, which should allow the proton radius to be determined at the level of ~0.01 fm, similar to previous ep measurements. The measurements will test several possible explanations of the proton radius puzzle, including some models of beyond-standard-model physics, some models of novel hadronic physics, and some issues in the radius extraction from scattering data.
Quantization of Perturbations in an Inflating Elastic Solid
Michael Sitwell; Kris Sigurdson
2014-07-01T23:59:59.000Z
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.
'Elastic' fluctuation-induced effects in smectic wetting films
Pikina, E. S., E-mail: elena@ogri.r [Russian Academy of Sciences, Oil and Gas Research Institute (Russian Federation)
2009-11-15T23:59:59.000Z
The Li-Kardar field theory approach is generalized to wetting smectic films and the 'elastic' fluctuation-induced interaction is obtained between the external flat bounding surface and distorted IA (isotropic liquid-smectic A) interface acting as an 'internal' (bulk) boundary of the wetting smectic film under the assumption that the IA interface is essentially 'softer' than the surface smectic layer. This field theory approach allows calculating the fluctuation-induced corrections in Hamiltonians of the so-called 'correlated' liquids confined by two surfaces, in the case where one of the bounding surfaces is 'rough' and with different types of surface smectic layer anchoring. We obtain that in practice, the account of thermal displacements of the smectic layers in a wetting smectic film reduces to the addition of two contributions to the IA interface Hamiltonian. The first, so-called local contribution describes the long-range thermal 'elastic' repulsion of the fluctuating IA interface from the flat bounding surface. The second, so-called nonlocal contribution is connected with the occurrence of an 'elastic' fluctuation-induced correction to the stiffness of the IA interface. An analytic expression for this correction is obtained.
Comparison of finite-difference and ray-theory seismograms in the elastic SEG/EAGE Salt Model,
Cerveny, Vlastislav
Comparison of finite-difference and ray-theory seismograms in the elastic SEG/EAGE Salt Model, shot-difference seismograms for a selected shot and two receiver configurations com- puted in the elastic SEG/EAGE Salt Model-waves and converted S-waves in the smoothed elastic SEG/EAGE Salt Model are computed. Keywords Elastic velocity model
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
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.
Nuclear Energy Density Functionals: What do we really know?
Bulgac, Aurel; Jin, Shi
2015-01-01T23:59:59.000Z
We present the simplest nuclear energy density functional (NEDF) to date, determined by only 4 significant phenomenological parameters, yet capable of fitting measured nuclear masses with better accuracy than the Bethe-Weizs\\"acker mass formula, while also describing density structures (charge radii, neutron skins etc.) and time-dependent phenomena (induced fission, giant resonances, low energy nuclear collisions, etc.). The 4 significant parameters are necessary to describe bulk nuclear properties (binding energies and charge radii); an additional 2 to 3 parameters have little influence on the bulk nuclear properties, but allow independent control of the density dependence of the symmetry energy and isovector excitations, in particular the Thomas-Reiche-Kuhn sum rule. This Hohenberg-Kohn-style of density functional theory successfully realizes Weizs\\"acker's ideas and provides a computationally tractable model for a variety of static nuclear properties and dynamics, from finite nuclei to neutron stars, where...
Generation of Gaussian Density Fields
Hugo Martel
2005-07-15T23:59:59.000Z
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.
Minimization of Fractional Power Densities
Minimization of Fractional Power Densities. Robert Hardt, Rice University. Abstract: A k dimensional rectifiable current is given by an oriented k dimensional
Canonical density matrix perturbation theory
Niklasson, Anders M N; Rubensson, Emanuel H; Rudberg, Elias
2015-01-01T23:59:59.000Z
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.
Constraining the gravitational wave energy density of the Universe using Earth's ring
Coughlin, Michael
2014-01-01T23:59:59.000Z
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 o...
Detecting Density Variations and Nanovoids
Miller, Michael K [ORNL; Longstreth-Spoor, L. [Washington University, St. Louis; Kelton, K. F. [Washington University, St. Louis
2011-01-01T23:59:59.000Z
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.
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
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.
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
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.
Longitudinal density monitor for the LHC
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
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
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.
Application of elastic-plastic fracture mechanics to marine structures
Pathi, Amarkumar
1991-01-01T23:59:59.000Z
, as it was not possible to measure yield strength directly from the high rate tensile tests: Cryc(dynamic) ~ CTTa(dynacaic) Cryc(ciaiic) CTTc(cCaiic) (IV. 8) The basic algorithm for predicting CTOD consists of integrating (IV. 9) where B is the crack front length... OF SCIENCE May 1991 Major Subject: Mechanical Engineering APPLICATION OF ELASTIC-PLASTIC FRACTURE MECHANICS TO MARINE STRUCTURES A Thesis by AMARI&UMAR PATEII Approved as to style and content by: Ted L. Anderson (C 'r of Commi e) Ravind ona ember...
np elastic spin transfer measurements at 788 MeV
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
PHYSICAL REVIEW C VOLUME 44, NUMBER 6 DECEMBER 1991 ARTICLES np elastic spin transfer measurements at 788 MeV M. W. McNaughton, K. Koch, I. Supek, and N. Tanaka Los Alamos National Laboratory, Los Alamos, New Mexico 87545 K. H. McNaughton, P. J... radius of about 3 rnm and centered on the 25-cm-thick liquid-deuterium (LD2) neutron-production target. B. Neutron beam magnets (LBBM6,7). The neutrons passed through the fringe fields of these magnets and were precessed about 50' from L spin. A...
Nonlinear elastic free energies and gradient Young-Gibbs measures
Roman Kotecký; Stephan Luckhaus
2012-06-26T23:59:59.000Z
We investigate, in a fairly general setting, the limit of large volume equilibrium Gibbs measures for elasticity type Hamiltonians with clamped boundary conditions. The existence of a quasiconvex free energy, forming the large deviations rate functional, is shown using a new interpolation lemma for partition functions. The local behaviour of the Gibbs measures can be parametrized by Young measures on the space of gradient Gibbs measures. In view of unboundedness of the state space, the crucial tool here is an exponential tightness estimate that holds for a vast class of potentials and the construction of suitable compact sets of gradient Gibbs measures.
Elastic Moduli Inheritance and Weakest Link in Bulk Metallic Glasses
Stoica, Alexandru Dan [ORNL; Wang, Xun-Li [ORNL; Lu, Z.P. [University of Science and Technology, Beijing; Clausen, Bjorn [Los Alamos National Laboratory (LANL); Brown, Donald [Los Alamos National Laboratory (LANL)
2012-01-01T23:59:59.000Z
We show that a variety of bulk metallic glasses (BMGs) inherit their Young s modulus and shear modulus from the solvent components. This is attributed to preferential straining of locally solvent-rich configurations among tightly bonded atomic clusters, which constitute the weakest link in an amorphous structure. This aspect of inhomogeneous deformation, also revealed by our in-situ neutron diffraction studies of an elastically deformed BMG, suggests a scenario of rubber-like viscoelasticity owing to a hierarchy of atomic bonds in BMGs.
Elastic contribution to interaction of vortices in uniaxial superconductors
Kogan, Vladimir [Ames Laboratory, DOE; Department of Physics, Iowa State University, Ames, Iowa
2013-10-24T23:59:59.000Z
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.
Spherical Wave Propagation in a Nonlinear Elastic Medium
Korneev, Valeri A.
2009-07-01T23:59:59.000Z
Nonlinear propagation of spherical waves generated by a point-pressure source is considered for the cases of monochromatic and impulse primary waveforms. The nonlinear five-constant elastic theory advanced by Murnaghan is used where general equations of motion are put in the form of vector operators, which are independent of the coordinate system choice. The ratio of the nonlinear field component to the primary wave in the far field is proportional to ln(r) where r is a propagation distance. Near-field components of the primary field do not contribute to the far field of nonlinear component.
Quasi-Elastic Scattering Measurements Morgan Wascko Imperial College London
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah47,193.70COMMUNITY AEROSOL:QuantumAprilElastic Scattering
Wilson, R.K.; Reuter, R.C. Jr.
1982-03-01T23:59:59.000Z
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.
Phenomenological Relativistic Energy Density Functionals
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
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.
Elastic Properties of Rolled Uranium -- 10 wt.% Molybdenum Nuclear Fuel Foils
D. W. Brown; D. J. Alexander; K. D. Clarke; B. Clausen; M. A. Okuniewski; T. A. Sisneros
2013-11-01T23:59:59.000Z
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.
Elastic constants determined by nanoindentation for p-type thermoelectric half-Heusler
Gahlawat, S.; Wheeler, L.; White, K. W., E-mail: zren@uh.edu, E-mail: kwwhite@uh.edu [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204 (United States); He, R.; Chen, S.; Ren, Z. F., E-mail: zren@uh.edu, E-mail: kwwhite@uh.edu [Department of Physics and TcSUH, University of Houston, Houston, Texas 77204 (United States)
2014-08-28T23:59:59.000Z
This paper presents a study of the elastic properties of the p-type thermoelectric half-Heusler material, Hf{sub 0.44}Zr{sub 0.44}Ti{sub 0.12}CoSb{sub 0.8}Sn{sub 0.2}, using nanoindentation. Large grain-sized polycrystalline specimens were fabricated for these measurements, providing sufficient indentation targets within single grains. Electron Backscatter Diffraction methods indexed the target grains for the correlation needed for our elastic analysis of individual single crystals for this cubic thermoelectric material. Elastic properties, including the Zener ratio and the Poisson ratio, obtained from the elasticity tensor are also reported.
Elastic Constants of Ni-Mn-Ga Magnetic Shape Memory Alloys
Stipcich, M. [Universitat de Barcelona; Manosa, L. [Universitat de Barcelona; Planes, A. [Universitat de Barcelona; Morin, M. [INSA de Lyon; Zarestky, Jerel L [ORNL; Lograsso, Tom [Ames Laboratory; Stassis, C. [Ames Laboratory
2004-01-01T23:59:59.000Z
We have measured the adiabatic second order elastic constants of two Ni-Mn-Ga magnetic shape memory crystals with different martensitic transition temperatures, using ultrasonic methods. The temperature dependence of the elastic constants has been followed across the ferromagnetic transition and down to the martensitic transition temperature. Within experimental errors no noticeable change in any of the elastic constants has been observed at the Curie point. The temperature dependence of the shear elastic constant C' has been found to be very different for the two alloys. Such a different behavior is in agreement with recent theoretical predictions for systems undergoing multi-stage structural transitions.
A Numerical Algorithm for Single Phase Fluid Flow in Elastic Porous Media
Ewing, Richard E.
, petroleum, and environmental engineering for several decades. While considering the impact of the rock algorithm. KEYWORDS: geomechanics, uid ow, elastic deformation, porous media 1 Introduction Mechanical
Seismology of adolescent neutron stars: Accounting for thermal effects and crust elasticity
C. J. Krüger; W. C. G. Ho; N. Andersson
2014-08-20T23:59:59.000Z
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.
Low density metal hydride foams
Maienschein, Jon L. (Oakland, CA); Barry, Patrick E. (Pleasant Hill, CA)
1991-01-01T23:59:59.000Z
Disclosed is a low density foam having a porosity of from 0 to 98% and a density less than about 0.67 gm/cc, prepared by heating a mixture of powered lithium hydride and beryllium hydride in an inert atmosphere at a temperature ranging from about 455 to about 490 K for a period of time sufficient to cause foaming of said mixture, and cooling the foam thus produced. Also disclosed is the process of making the foam.
Maximum-likelihood density modification
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2000-08-01T23:59:59.000Z
A likelihood-based density modification approach is developed that can incorporate expected electron-density information from a wide variety of sources. A likelihood-based approach to density modification is developed that can be applied to a wide variety of cases where some information about the electron density at various points in the unit cell is available. The key to the approach consists of developing likelihood functions that represent the probability that a particular value of electron density is consistent with prior expectations for the electron density at that point in the unit cell. These likelihood functions are then combined with likelihood functions based on experimental observations and with others containing any prior knowledge about structure factors to form a combined likelihood function for each structure factor. A simple and general approach to maximizing the combined likelihood function is developed. It is found that this likelihood-based approach yields greater phase improvement in model and real test cases than either conventional solvent flattening and histogram matching or a recent reciprocal-space solvent-flattening procedure [Terwilliger (1999 ?), Acta Cryst. D55, 1863–1871].
Elastic Compton Scattering from the Nucleon and Deuteron
Robert P. Hildebrandt
2005-12-20T23:59:59.000Z
Goal of this work is the consistent description of elastic Compton scattering from the single nucleon and the deuteron. The theoretical framework chosen is Chiral Perturbation Theory, which is the low-energy formulation of Quantum Chromodynamics, where we extend the spectrum of active degrees of freedom from only pions and nucleons to also the Delta(1232) resonance. In the deuteron sector, we treat the nucleon-nucleon interaction non-perturbatively. Besides the Compton cross sections, our main concern is with the nucleon polarizabilities, which are a useful tool to describe the reaction of the internal nucleonic degrees of freeedom to the external electromagnetic field. Experimentally, only a few nucleon polarizabilities are known. Especially our present knowledge of the neutron polarizabilities is not satisfying. The reason why it is so difficult to determine these quantities experimentally is the finite lifetime of the free neutron. Therefore, we want to contribute to the ongoing discussion of the neutron polarizabilities by fitting the average over proton and neutron polarizabilities to the elastic deuteron Compton-scattering data. Similarly, we determine the proton polarizabilities from fits to the single-proton Compton data. We finally combine both results in order to identify the neutron polarizabilities.
Transport of organelles by elastically coupled motor proteins
Deepak Bhat; Manoj Gopalakrishnan
2014-12-17T23:59:59.000Z
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.
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
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.
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
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.
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...
A common supersolid low-density skin sliperizing ice and toughening water surface
Xi Zhang; Yongli Huang; Zengsheng Ma; Yichun Zhou; Weitao Zheng; Ji Zhou; Chang Q. Sun
2014-08-15T23:59:59.000Z
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.
Stationary self-focusing of intense laser beam in cold quantum plasma using ramp density profile
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
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.
PHYSICAL REVIEW E 84, 061906 (2011) Mechanics of soft composites of rods in elastic gels
MacKintosh, F.C.
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
ANALYSIS OF ANISOTROPY IN ELASTIC CONSTANTS OF SiCp/2124 Al METAL MATRIX COMPOSITES
Hong, Soon Hyung
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
THESIS FOR THE DEGREE OF LICENTIATE OF PHILOSOPHY Model Adaptivity in Elasticity
Patriksson, Michael
THESIS FOR THE DEGREE OF LICENTIATE OF PHILOSOPHY Model Adaptivity in Elasticity DAVID HEINTZ, Sweden 2008 #12;Model Adaptivity in Elasticity DAVID HEINTZ Â© DAVID HEINTZ, 2008 Thesis for Licentiate List of Appended Papers The licentiate thesis consists of an introductory text to subjects and methods
Flow of Volatile-Free and Volatile-Rich Basaltic Magmas through Elastic-Walled Dikes
Al Hanbali, Ahmad
averaged in "one-dimensional" flow tube. #12;Questions: · Can we obtain a simple 1D symmetric model) · Anisotropy 1 in horizontal and vertical rock stress #12;Elastic flow equations · Continuity equation t(m bFlow of Volatile-Free and Volatile-Rich Basaltic Magmas through Elastic-Walled Dikes O. Bokhove
Journal of Sound and Vibration 298 (2006) 108131 Elastic wave radiation from a high frequency
Abrahams, I. David
JOURNAL OF SOUND AND VIBRATION Journal of Sound and Vibration 298 (2006) 108Â131 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
Continued Fraction Absorbing Boundary Conditions for Transient Elastic Wave Propagation Modeling
Guddati, Murthy N.
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
SHELL THEORIES ARISING AS LOW ENERGY -LIMIT OF 3D NONLINEAR ELASTICITY
Lewicka, Marta
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
SHELL THEORIES ARISING AS LOW ENERGY -LIMIT OF 3D NONLINEAR ELASTICITY
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
Thermo-visco-elasticity with rate-independent plasticity in isotropic materials undergoing
Bartels, Soeren
Thermo-visco-elasticity with rate-independent plasticity in isotropic materials undergoing thermal effects. Numerical discretization of the thermo- dynamically consistent model is proposed by implicit time. These "thermo-elastic" stresses may trigger activated inelastic processes, typically slip plastic- ity or even
Paris-Sud XI, Université de
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
Phenomenological study of parabolic and spherical indentation of elastic-ideally plastic material
Paris-Sud XI, Université de
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
Elastic-Plastic Models for Stable Crack Growtht *James R. Rice
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
Effect of elastic strain energy on self-organized pattern formation
Pan, Ernie
Effect of elastic strain energy on self-organized pattern formation E Pan1*, R Zhu1 , and P W Chung2 1 Department of Civil Engineering, University of Akron, Akron, Ohio, USA 2 US Army Research in the calculation of the binding energy among atoms. The elastic strain energy is accurately evaluated
A nonlocal problem arising in the study of magneto-elastic interactions
Shafrir, Itai
the exchange energy Eex, the elastic energy Eel and the elastic-magnetic energy Eem. Let v be the displacement(m) + Eem(m, v) + Eel(v) We neglect here other contributions to the free energy due, for example
A New Attempt to Reconcile the Statistical and Phenomenological Theories of Rubber Elasticity
Fleming, Paul D. "Dan"
A New Attempt to Reconcile the Statistical and Phenomenological Theories of Rubber Elasticity O. H theories of rubber elasticity are re- viewed briefly. Combining recent concepts proposed by Yeoh and Gent, a new theory is proposed. The proposed constitutive model for rubber vulcanizates invokes two mech
Thermal Fluctuations and Rubber Elasticity Xiangjun Xing,1,* Paul M. Goldbart,2
Goldbart, Paul M.
Thermal Fluctuations and Rubber Elasticity Xiangjun Xing,1,* Paul M. Goldbart,2 and Leo Radzihovsky, compared to that of classical rubber elasticity. To leading order, this mechanism provides a simple on the external deformation. DOI: 10.1103/PhysRevLett.98.075502 PACS numbers: 62.20.Dc, 61.41.+e The term rubber
CONSTRUCTING AN ELASTIC TOUCH PANEL WITH EMBEDDED IR-LEDS USING SILICONE RUBBER
Tanaka, Jiro
CONSTRUCTING AN ELASTIC TOUCH PANEL WITH EMBEDDED IR-LEDS USING SILICONE RUBBER Yuichiro Sakamoto a technique for the construction of an elastic touch panel using silicone rubber. The technique is similar is made of transparent silicone rubber rather than acrylic. Moreover, we embedded infrared LEDs within
COMPARISON OF ELASTIC OF POROUS CORDIERITE BY FLEXURE AND DYNAMIC TEST METHODS
Stafford, Randall [Cummins, Inc] [Cummins, Inc; Golovin, K. B. [Cummins, Inc] [Cummins, Inc; Dickinson, A. [Cummins, Inc] [Cummins, Inc; Watkins, Thomas R [ORNL] [ORNL; Shyam, Amit [ORNL] [ORNL; Lara-Curzio, Edgar [ORNL] [ORNL
2012-01-01T23:59:59.000Z
Previous work showed differences in apparent elastic modulus between mechanical flexure testing and resonance methods. Flexure tests have been conducted using non-contact optical systems to directly measure deflection for calculation of elastic modulus. Dynamic test methods for elastic modulus measurement were conducted on the same material for comparison. The results show significant difference in the apparent elastic modulus for static flexure versus dynamic methods. The significance of the difference in apparent elastic modulus on thermal stress and the hypotheses for these differences will be discussed. Dynamic measurement (resonance) and static measurement (mechanical) produce different values for elastic modulus of porous cordierite ceramic. The elastic modulus from resonance is a measure of the material response at very low strain which is different from the material response in a mechanical test with relatively large strain. The apparent elastic moduli for dynamic versus static test methods in this study are different by a factor of two. This result has significant impact on calculated stress and life in an aftertreatment component.
Sevostianov, Igor
Elsevier B.V. All rights reserved. Keywords: Polymer matrix composites; Short-fiber composite; ElasticConnection between elastic moduli and thermal conductivities of anisotropic short fiber reinforced form 29 May 2003 Abstract Cross-property connections for two phase composites derived recently
Elastic uplift in southeast Greenland due to rapid ice mass loss Shfaqat A. Khan,1
Larson, Kristine
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
Elastic parabolic equation solutions for underwater acoustic problems using seismic sources
. Franka) Department of Mathematics, Marist College, 3399 North Road, Poughkeepsie, New York 12601 Robert I that it may be necessary to account for elastic bottom interactions. In order to study energy conversion elastic energy is converted to acoustic energy at the ocean-bottom interface. These waves enter
FIRST-ORDER SYSTEM LEAST SQUARES (FOSLS) FOR GEOMETRICALLY NONLINEAR ELASTICITY
McCormick, Steve
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
Swigon, David
DNA stretching modeled at the base pair level: Overtwisting and shear instability in elastic Accepted 28 October 2011 Available online 12 November 2011 Keywords: DNA mechanics Overstretching Discrete elastic model Simplex algorithm Bifurcations a b s t r a c t Stretching experiments on single DNA
ON QUASI-ELASTIC SCATTERING OF SLOW NEUTRONS IN MOLECULAR LIQUIDS
Boyer, Edmond
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
Elastic Lennard-Jones polymers meet clusters: Differences and similarities Stefan Schnabel,1,a
Bachmann, Michael
Elastic Lennard-Jones polymers meet clusters: Differences and similarities Stefan Schnabel,1,a of elastic flexible off-lattice polymers with Lennard-Jones monomer-monomer interaction and anharmonic and nonicosahedral low-energy polymer morphologies. © 2009 American Institute of Physics. doi:10.1063/1.3223720 I
Geophysical Prospecting, 2004, 52, 183195 Effective elastic properties of randomly fractured soils
Santos, Juan
relationships be- tween pore structure and elastic properties of porous rocks is an ongoing problem and fluids, and how they control rock properties is cru- cial to a better understanding of acousticGeophysical Prospecting, 2004, 52, 183195 Effective elastic properties of randomly fractured soils
A Performance and Cost Analysis of the Amazon Elastic Compute Cloud (EC2) Cluster Compute Instance
Bjørnstad, Ottar Nordal
A Performance and Cost Analysis of the Amazon Elastic Compute Cloud (EC2) Cluster Compute Instance the availability of Elastic Compute Cloud (EC2) Cluster Compute Instances specifically designed for high compute power available on demand the question arises if cloud computing with using and Amazon EC2 HPC
Lutchen, Kenneth
Lung and alveolar wall elastic and hysteretic behavior in rats: effects of in vivo elastase P. Ingenito, and Be´la Suki. Lung and alveolar wall elastic and hysteretic behavior in rats: effects behavior of the alveolar walls and the macroscopic mechanical properties of the whole lung in an in vivo
Analysis of the elastic behaviour of silica aerogels taken as a percolating system
Paris-Sud XI, UniversitÃ© de
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
A CAVITATION TRACKING METHOD FOR ELASTIC-PLASTIC FLOW IN SOLIDS
Shyue, Keh-Ming
A CAVITATION TRACKING METHOD FOR ELASTIC-PLASTIC FLOW IN SOLIDS Keh-Ming Shyue Department with cavitation. The algorithm uses a simplified model system where the behavior of the materials is modeled, and the von Mises condition for the elastic-plastic phase change. To characterize the cavitation
RESEARCH NOTE: DEFLECTION EQUATION FOR THE BUCKLING OF AN ELASTIC COLUMN
Newland, David E.
13 RESEARCH NOTE: DEFLECTION EQUATION FOR THE BUCKLING OF AN ELASTIC COLUMN SUBJECTED TO SURFACE. Introduction THE EFFECT of pressure on the buckling of elastic columns has been studied for at least the last to axial load and lateral pressure. Other authors have considered the theoretical aspects (Handelman (4
A maximum entropy-least squares estimator for elastic origin-destination trip matrix estimation
Kockelman, Kara M.
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
The Role of Architecture in the Elastic Response of Semiflexible Polymer and Fiber Networks
Claus Heussinger; Erwin Frey
2007-01-18T23:59:59.000Z
We study the elasticity of cross-linked networks of thermally fluctuating stiff polymers. As compared to their purely mechanical counterparts, it is shown that these thermal networks have a qualitatively different elastic response. By accounting for the entropic origin of the single-polymer elasticity, the networks acquire a strong susceptibility to polydispersity and structural randomness that is completely absent in athermal models. In extensive numerical studies we systematically vary the architecture of the networks and identify a wealth of phenomena that clearly show the strong dependence of the emergent macroscopic moduli on the underlying mesoscopic network structure. In particular, we highlight the importance of the full polymer length that to a large extent controls the elastic response of the network, surprisingly, even in parameter regions where it does not enter the macroscopic moduli explicitly. We provide theoretical scaling arguments to relate the observed macroscopic elasticity to the physical mechanisms on the microscopic and the mesoscopic scale.
Intercrystalline density on nanocrystalline 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
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.
Mao, Chunliu
2012-02-14T23:59:59.000Z
The adhesive contact problems of a conical frustum punch indenting a transversely isotropic elastic half space and an orthotropic elastic half space are analytically studied in this thesis work. To solve the problem involving a transversely...
Overall Dynamic Constitutive Relations of Micro-structured Elastic Composites
Sia Nemat-Nasser; Ankit Srivastava
2011-05-25T23:59:59.000Z
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].
Complex Rheology of Nematogenic Fluid; Connection to Elastic Turbulence
Rituparno Mandal; Buddhapriya Chakrabarti; Debarshini Chakraborti; Chandan Dasgupta
2014-06-10T23:59:59.000Z
We numerically analyse the full non-linear hydrodynamic equations of a sheared nematic fluid under shear stress and strain rate controlled situations incorporating spatial heterogeneity in the gradient direction. For a certain range of imposed stress and strain rates, this extended dynamical system shows signatures of spatio-temporal chaos and transient shear banding. In the chaotic regime the power spectra of the order parameter stress and the total injected power shows power law behavior and the total injected power shows a non-Gaussian, skewed probability distribution, which bear striking resemblance to elastic turbulence phenomena observed in polymer solutions. The scaling behavior is independent of the choice of shear rate/stress control method.
Weak and strong wave turbulence spectra for elastic thin plate
Naoto Yokoyama; Masanori Takaoka
2013-02-15T23:59:59.000Z
Variety of statistically steady energy spectra in elastic wave turbulence have been reported in numerical simulations, experiments, and theoretical studies. Focusing on the energy levels of the system, we have performed direct numerical simulations according to the F\\"{o}ppl--von K\\'{a}rm\\'{a}n equation, and successfully reproduced the variability of the energy spectra by changing the magnitude of external force systematically. When the total energies in wave fields are small, the energy spectra are close to a statistically steady solution of the kinetic equation in the weak turbulence theory. On the other hand, in large-energy wave fields, another self-similar spectrum is found. Coexistence of the weakly nonlinear spectrum in large wavenumbers and the strongly nonlinear spectrum in small wavenumbers are also found in moderate energy wave fields.
Asymptotic behavior of an elastic satellite with internal friction
Emanuele Haus; Dario Bambusi
2012-12-04T23:59:59.000Z
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.
Elastic scattering of Beryllium isotopes near the Coulomb barrier
Di Pietro, A.; Figuera, P. [INFN-Laboratori Nazionali del Sud, Catania (Italy); Amorini, F.; Fisichella, M.; Lattuada, M.; Musumarra, A.; Pellegriti, M. G.; Randisi, G.; Rizzo, F.; Santonocito, D.; Scalia, G.; Scuderi, V.; Strano, E.; Torresi, D. [Dipartimento di Fisica ed Astronomia Universita di Catania, Catania (Italy); INFN-Laboratori Nazionali del Sud, Catania (Italy); Papa, M. [INFN-Sezione di Catania, Catania (Italy); Acosta, L.; Martel, I.; Perez-Bernal, F. [Departamento de Fisica Aplicada Universidad de Huelva, Huelva (Spain); Borge, M. J. G.; Tengblad, O. [Instituto de Estructura de la Materia CSIC, Madrid (Spain)
2011-10-28T23:59:59.000Z
In this contribution, results of experiments performed with the three Beryllium isotopes {sup 9,10,11}Be on a medium mass {sup 64}Zn target, at a center of mass energy of {approx_equal}1.4 the Coulomb barrier, will be discussed. Elastic scattering angular distributions have been measured for the {sup 9,10}Be reactions. In the {sup 11}Be case the quasielastic scattering angular distribution was obtained. In the halo nucleus case, the angular distribution exhibit a non-Fresnel-type pattern with a strong damping of the Coulomb-nuclear interference peak. Moreover, it is found that the total reaction cross-section for the halo nucleus induced collision is more than double the ones extracted in the collisions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the {sup 11}Be case could be attributed to transfer and/or break-up events.
Elastic Hadron Scattering on Li Isotopes at Intermediate Energies
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
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.
Noise-assisted Thouless pump in elastically deformable molecular junctions
C. A. Perroni; F. Romeo; A. Nocera; V. Marigliano Ramaglia; R. Citro; V. Cataudella
2014-04-16T23:59:59.000Z
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.
Flavor decomposition of the elastic nucleon electromagnetic form factors
C.D. Cates, C.W. Jager, S. Riordan, B. Wojtsekhowski
2011-06-01T23:59:59.000Z
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.
Bifurcations in the optimal elastic foundation for a buckling column
Rayneau-Kirkhope, Daniel; Ding, K; Mao, Yong
2010-01-01T23:59:59.000Z
We investigate the buckling under compression of a slender beam with a distributed lateral elastic support, for which there is an associated cost. For a given cost, we study the optimal choice of support to protect against Euler buckling. We show that with only weak lateral support, the optimum distribution is a delta-function at the centre of the beam. When more support is allowed, we find numerically that the optimal distribution undergoes a series of bifurcations. We obtain analytical expressions for the buckling load around the first bifurcation point and corresponding expansions for the optimal position of support. Our theoretical predictions, including the critical exponent of the bifurcation, are confirmed by computer simulations.
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
Experimental results on pp forward elastic scattering and the possibility of universal shrinkage of the hadronic diffraction cone
Statistical density modification using local pattern matching
Terwilliger, Thomas C.
2007-01-23T23:59:59.000Z
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.
Boyer, Edmond
Trade performances and the estimation of price-elasticities: Quality matters+ By Matthieu Crozet : Traditional trade models ignoring the dimension of product quality generally lead to excessively low trade price elasticities. In this paper, we show that higher estimated trade price elasticities, more
Brown, Michael F.
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
Jackson, Jennifer M.
2005-01-01T23:59:59.000Z
for determining the elastic moduli at high temperatures, using both electric resistive heating (to 1800 K) and CO2 by Elsevier Ltd. Keywords: Spectroscopy; Mechanical properties; High-temperature elasticity measurements by Brillouin scattering 1. Introduction Knowledge of the high-temperature elastic properties is fundamental
Fujiwara, Y., E-mail: s1220908@u.tsukuba.ac.jp; Nakamiya, A.; Sakakita, H. [Department of Engineering Mechanics and Energy, University of Tsukuba, Ibaraki (Japan) [Department of Engineering Mechanics and Energy, University of Tsukuba, Ibaraki (Japan); Innovative Plasma Technologies Group, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki (Japan); Hirano, Y. [Innovative Plasma Technologies Group, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki (Japan) [Innovative Plasma Technologies Group, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki (Japan); Laboratory of Physics, College of Science and Technologies, Nihon University, Tokyo (Japan); Kiyama, S.; Koguchi, H. [Innovative Plasma Technologies Group, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki (Japan)] [Innovative Plasma Technologies Group, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki (Japan)
2014-02-15T23:59:59.000Z
The self-focusing phenomenon has been observed in a high current density and low energy ion beam. In order to study the mechanism of this phenomenon, a special designed double probe to measure the electron density and temperature is installed into the chamber where the high current density ion beam is injected. Electron density profile is successfully measured without the influence of the ion beam components. Estimated electron temperature and density are ?0.9 eV and ?8 × 10{sup 8} cm{sup ?3} at the center of ion beam cross section, respectively. It was found that a large amount of electrons are spontaneously accumulated in the ion beam line in the case of self-forcing state.
Balanced homodyne detectors and Casimir energy densities
P. Marecki
2008-03-22T23:59:59.000Z
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.
Extending the Place Glacier mass-balance record to AD 1585, using tree rings and wood density
Smith, Dan
Extending the Place Glacier mass-balance record to AD 1585, using tree rings and wood density Lisa August 2011 Keywords: Dendroclimatology Glacier mass balance Tree rings Wood density Place Glacier Recognizing that climate influences both annual tree-ring growth and glacier mass balance, changes in the mass
A current density distribution tool
Jagush, Frederic A.
1989-01-01T23:59:59.000Z
. 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...
Updated Axion CDM energy density
Ji-Haeng Huh
2008-10-08T23:59:59.000Z
We update cosmological bound on axion model. The contribution from the anharmonic effect and the newly introduced initial overshoot correction are considered. We present an explicit formula for the axion relic density in terms of the QCD scale Lambda_{QCD}, the current quark masses m_q's and the Peccei-Quinn scale F_a, including firstly introduced 1.85 factor which is from the initial overshoot.
Jakub P?kalski; Alina Ciach; Noé G. Almarza
2014-11-14T23:59:59.000Z
The impact of confinement on self-assembly of particles interacting with short-range attraction and long-range repulsion (SALR) potential is studied for thermodynamic states corresponding to local ordering of clusters or layers in the bulk. Exact and asymptotic expressions for the local density and for the effective potential between the confining surfaces are obtained for a one-dimensional lattice model introduced in [J. P\\k{e}kalski et al. $J. Chem. Phys.$ ${\\bf 140}$, 144903 (2013)].The simple asymptotic formulas are shown to be in good quantitative agreement with exact results for slits containing at least 5 layers. We observe that the incommensurability of the system size and the average distance between the clusters or layers in the bulk leads to structural deformations that are different for different values of the chemical potential $\\mu$. The change of the type of defects is reflected in the dependence of density on $\\mu$ that has a shape characteristic for phase transitions. Our results may help to avoid misinterpretation of the change of the type of defects as a phase transition in simulations of inhomogeneous systems. Finally, we show that a system confined by soft elastic walls may exhibit bistability such that two system sizes that differ approximately by the average distance between the clusters or layers are almost equally probable. This may happen when the equilibrium separation between the soft boundaries of an empty slit corresponds to the largest stress in the confined self-assembling system.
Covariance Matrix of a Double-Differential Doppler-broadened Elastic Scattering Cross Section
Arbanas, Goran [ORNL; Becker, B. [Rensselaer Polytechnic Institute (RPI); Dagan, R [Institut fur Neutronenphysik und Reaktortechnik; Dunn, Michael E [ORNL; Larson, Nancy M [ORNL; Leal, Luiz C [ORNL; Williams, Mark L [ORNL
2012-01-01T23:59:59.000Z
Legendre moments of a double-differential Doppler-broadened elastic neutron scattering cross section on {sup 238}U are computed near the 6.67 eV resonance at temperature T = 10{sup 3} K up to angular order 14. A covariance matrix of these Legendre moments is computed as a functional of the covariance matrix of the elastic scattering cross section. A variance of double-differential Doppler-broadened elastic scattering cross section is computed from the covariance of Legendre moments.
Constraining the gravitational wave energy density of the Universe using Earth's ring
Michael Coughlin; Jan Harms
2014-06-04T23:59:59.000Z
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.
Density gradients and absorption effects in gas-filled magnetic axion helioscopes
Creswick, R. J.; Avignone, F. T. III [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina, 29208 (United States); Nussinov, S [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina, 29208 (United States); Department of Physics, Tel Aviv University, Tel Aviv, Israel 69978 (Israel)
2008-07-01T23:59:59.000Z
The effects of absorption in the gas, and of density variations on the sensitivity of gas-filled solar-axion helioscopes, are theoretically investigated. It is concluded that the 10-meter long CAST helioscope, the most sensitive experiment to date, is near the limit of sensitivity in axion mass. Increasing the length, gas density, or tilt angle all have negative influences and will not improve the sensitivity.
Density Gradient and Absorption Effects in Gas-Filled Magnetic Axion Helioscopes
R. J. Creswick; S. Nussinov; F. T. Avignone III
2008-05-14T23:59:59.000Z
The effects of absorption in the gas, and of density variations on the sensitivity of gas-filled solar-axion helioscopes are theoretically investigated. It is concluded that the 10-meter long CAST helioscope, the most sensitive experiment to date is near the limit of sensitivity in axion mass. Increasing the length, gas density, or tilt angle all have negative influences, and will not improve the sensitivity.
Probability distribution 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
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.
Jobs masonry in LHCb with elastic Grid Jobs
Stagni, F
2015-01-01T23:59:59.000Z
In any distributed computing infrastructure, a job is normally forbidden to run for an indefinite amount of time. This limitation is implemented using different technologies, the most common one being the CPU time limit implemented by batch queues. It is therefore important to have a good estimate of how much CPU work a job will require: otherwise, it might be killed by the batch system, or by whatever system is controlling the jobs' execution. In many modern interwares, the jobs are actually executed by pilot jobs, that can use the whole available time in running multiple consecutive jobs. If at some point the available time in a pilot is too short for the execution of any job, it should be released, while it could have been used efficiently by a shorter job. Within LHCbDIRAC, the LHCb extension of the DIRAC interware, we developed a simple way to fully exploit computing capabilities available to a pilot, even for resources with limited time capabilities, by adding elasticity to production MonteCarlo (MC) si...
Benchmark calculations for elastic fermion-dimer scattering
Shahin Bour; H. -W. Hammer; Dean Lee; Ulf-G. Meißner
2012-06-08T23:59:59.000Z
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.
Double porosity modeling in elastic wave propagation for reservoir characterization
Berryman, J. G., LLNL
1998-06-01T23:59:59.000Z
Phenomenological equations for the poroelastic behavior of a double porosity medium have been formulated and the coefficients in these linear equations identified. The generalization from a single porosity model increases the number of independent coefficients from three to six for an isotropic applied stress. In a quasistatic analysis, the physical interpretations are based upon considerations of extremes in both spatial and temporal scales. The limit of very short times is the one most relevant for wave propagation, and in this case both matrix porosity and fractures behave in an undrained fashion. For the very long times more relevant for reservoir drawdown,the double porosity medium behaves as an equivalent single porosity medium At the macroscopic spatial level, the pertinent parameters (such as the total compressibility) may be determined by appropriate field tests. At the mesoscopic scale pertinent parameters of the rock matrix can be determined directly through laboratory measurements on core, and the compressibility can be measured for a single fracture. We show explicitly how to generalize the quasistatic results to incorporate wave propagation effects and how effects that are usually attributed to squirt flow under partially saturated conditions can be explained alternatively in terms of the double-porosity model. The result is therefore a theory that generalizes, but is completely consistent with, Biot`s theory of poroelasticity and is valid for analysis of elastic wave data from highly fractured reservoirs.
Synthesis, Crystal Structure, and Elastic Properties of Novel Tungsten Nitrides
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
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.
Small angle elastic scattering of protons off of spinless nuclei
Ling, A.G.
1988-07-01T23:59:59.000Z
Elastic differential cross sections and analyzing powers for 800 MeV protons incident on /sup 12/C, /sup 40/Ca, and /sup 208/Pb in the momentum transfer range 20 MeV/c < q < 130 MeV/c have been measured. The data was taken with the High Resolution Spectrometer (HRS) at the Los Alamos Meson Physics Facility. Special delay-line drift chambers with dead regions for the beam to pass through them were used to obtain the data. Through the interference of the Coulomb and nuclear contributions to the differential cross section in the small angle region, the ratio of the real to imaginary part of the forward nuclear amplitude ..cap alpha../sub n/(0) = Ref/sub n/(0)/Imf/sub n/(0) is extracted. The importance of knowing this quantity at lower energies in order to study the differences between relativistic and non-relativistic scattering theories is discussed. 130 refs., 60 figs., 12 tabs.
Influence of Nanoclay on Properties of HDPE/Wood Composites
Influence of Nanoclay on Properties of HDPE/Wood Composites Yong Lei,1 Qinglin Wu,1 Craig M Agricultural Center, Baton Rouge, Louisiana 70803 2 Performance Engineered Composites, USDA Forest ServiceScience (www.interscience.wiley.com). ABSTRACT: Composites based on high density polyeth- ylene (HDPE), pine
Esmen, Ekrem Alp, 1977-
2004-01-01T23:59:59.000Z
Three-dimensional mixed-mode linear elastic fracture mechanics analysis is presented using domain interaction integrals. An out-of-plane sinusoidal crack was analyzed using a commercially available finite element package ...
Numerical modeling of elastic wave scattering by near-surface heterogeneities
Al Muhaidib, Abdulaziz
2013-01-01T23:59:59.000Z
A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated ...
Physica D xxx (2003) xxxxxx Dynamic supercoiling bifurcations of growing elastic filaments
Wolgemuth, Charles
2003-01-01T23:59:59.000Z
Physica D xxx (2003) xxxxxx Dynamic supercoiling bifurcations of growing elastic filaments Charles xxx (2003) xxxxxx essentially unchanging as the three-dimensional form develops, and the properties
Design, prototyping and preliminary testing of an elastic-powered climbing exoskeleton
Briner, Hazel (Hazel Linn)
2011-01-01T23:59:59.000Z
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 ...
A coupled theory for diffusion of hydrogen and large elastic-plastic deformations of metals
Di Leo, Claudio V
2012-01-01T23:59:59.000Z
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 ...
Faghih, Ali
2011-01-01T23:59:59.000Z
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 ...
Bonet, J.
We present an implicit a-posteriori finite element procedure to compute bounds for functional outputs of finite element solutions in large strain elasticity. The method proposed relies on the existence of a potential energy ...
Multiscale Method for Elastic Wave Propagation in the Heterogeneous, Anisotropic Media
Gao, Kai
2014-08-05T23:59:59.000Z
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...
Geophysical Prospecting 31,265-292, 1983. REFLECTION OF ELASTIC WAVES FROM
Santos, Juan
Geophysical Prospecting 31,265-292, 1983. REFLECTION OF ELASTIC WAVES FROM PERIODICALLY STRATIFIED from Periodically Stratified Media with Interfacial Slip, Geophysical Prospecting 31 phase propagation in some other direction. INTRODUCTION Geophysical media often exhibit anisotropic
Williams, Michael Eric
2009-05-15T23:59:59.000Z
In thiswork we present the development of a method for the prediciton of finite temperature elastic and thermodynamic properties of cubic, non-magnetic unary and binary metals from first principles calculations. Vibrational, electronic...
Lawrence, Shawn A. (Shawn Adam), 1975-
2003-01-01T23:59:59.000Z
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 ...
Parton-Parton Elastic Scattering and Rapidity Gaps at Tevatron Energies
Vittorio Del Duca; Wai-Keung Tang
1993-08-02T23:59:59.000Z
The theory of the perturbative pomeron, due to Lipatov and collaborators, is used to compute the probability of observing parton-parton elastic scattering and rapidity gaps between jets in hadron collisions at Tevatron energies.
Parton-Parton Elastic Scattering and Rapidity Gaps at SSC and LHC Energies
Vittorio Del Duca
1993-08-02T23:59:59.000Z
The theory of the perturbative pomeron, due to Lipatov and collaborators, is used to compute the probability of observing parton-parton elastic scattering and rapidity gaps between jets in hadron collisions at SSC and LHC energies.
Finite element analysis of elastic interaction of two en echelon overlapping faults
Leem, Junghun
1995-01-01T23:59:59.000Z
The primary objective is the analysis of the elastic stress fields and prediction of incipient secondary faulting associated with the interaction of two overlapping, en echelon faults with a sense of stepover opposite to the sense of shear...
Affine maps of density matrices
Thomas F. Jordan
2004-11-21T23:59:59.000Z
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.
Rock Density | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f < RAPIDâ€Ž |Rippey Jump to: navigation, searchRobbinsDensity At
Shell theories arising as low energy ?-limit of 3d nonlinear elasticity
Marta Lewicka; Maria Giovanna Mora; Mohammad Reza Pakzad
2008-03-04T23:59:59.000Z
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.
Does DOF Separation on Elastic Devices Improve User 3D Steering Task Performance?
Casiez, Géry
Does DOF Separation on Elastic Devices Improve User 3D Steering Task Performance? G´ery CasiezHaptic in a 3D steering task. Unlike other devices intended to interact in 3D with one end-effector, the Digi the manipulation of a stylus or thimble, and the SpaceMouse [2] is an elastic device to rate control objects in 3D
Elastic scattering and total reaction cross section of {sup 6}He+{sup 120}Sn
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
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.
Measurement of the elastic scattering cross section of neutrons from argon and neon
S. MacMullin; M. Kidd; R. Henning; W. Tornow; C. R. Howell; M. Brown
2012-12-12T23:59:59.000Z
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.
On oscillator-bath system: Exact propagator, Reduced density matrix and Green's function
A. Refaei; F. Kheirandish
2014-07-27T23:59:59.000Z
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.
High density behaviour of nuclear symmetry energy
D. N. Basu; Tapan Mukhopadhyay
2006-12-27T23:59:59.000Z
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.
2012 Jonathan G. Lange IMPROVING LITHIUM-ION BATTERY POWER AND ENERGY DENSITIES USING
Braun, Paul
1 ©2012 Jonathan G. Lange #12;1 IMPROVING LITHIUM-ION BATTERY POWER AND ENERGY DENSITIES USING ABSTRACT Lithium-ion batteries are commonly used as energy storage devices in a variety of applications. The cathode architectures and materials have a large influence on the performance of lithium-ion batteries
The effect of agrochemicals on indicator bacteria densities in outdoor mesocosmsemi_2287 3150..3158
Rohr, Jason
The effect of agrochemicals on indicator bacteria densities in outdoor mesocosmsemi_2287 3150, including patho- gens. Agrochemicals may influence the survival of these microorganisms in water bodies were used to investigate the response of Escherichia coli and enterococci to agrochemicals. Replicate
Detection of screw threads in computed tomography 3D density fields
Kosarevsky, Sergey
2013-01-01T23:59:59.000Z
In this paper, a new method is proposed to automatically detect screw threads in 3D density fields obtained from computed tomography measurement devices. The described method can be used to automate many operations during screw thread inspection process and drastically reduce operator's influence on the measurement process resulting in lower measurement times and increased repeatability.
Oxides having high energy densities
Ceder, Gerbrand; Kang, Kisuk
2013-09-10T23:59:59.000Z
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.
Failure Stress and Apparent Elastic Modulus of Diesel Particulate Filter
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport in RepresentativeDepartmentEnergy Factors Affecting PMUNuclear Cooperation
Yield Strength as a Function of Dislocation Density
Collins, Gary S.
-displacement graphs as well as obvious excursions and yield points ·These perfect indents give a guideline for what a micro-hardness indenter, which uses a square pyramidal indenter tip. 10 m Procedures and Methods Before/23/2, using known elastic modulus to find tip radius. E* is the elastic modulus, R is the indenter tip radius
Quantum critical benchmark for density functional theory
Paul E. Grabowski; Kieron Burke
2014-08-09T23:59:59.000Z
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.
Lipoprotein subclass analysis by immunospecific density
Lester, Sandy Marie
2009-05-15T23:59:59.000Z
to obtain a lipoprotein density profile in the absence and presence of apo C-1. Density Lipoprotein Profiling (DLP) gives relevant information of lipoproteins, such as density and subclass characterization, and is a novel approach to purify apo C-1-enriched...
Ultimate Energy Densities for Electromagnetic Pulses
Mankei Tsang
2008-03-06T23:59:59.000Z
The ultimate electric and magnetic energy densities that can be attained by bandlimited electromagnetic pulses in free space are calculated using an ab initio quantized treatment, and the quantum states of electromagnetic fields that achieve the ultimate energy densities are derived. The ultimate energy densities also provide an experimentally accessible metric for the degree of localization of polychromatic photons.
Jacek Dobaczewski Density functional theory and energy
Dobaczewski, Jacek
in Poland per voivodship Energy density functional 245 647 Price voivodship functional 654 763 295 580Jacek Dobaczewski Density functional theory and energy density functionals in nuclear physics Jacek://www.fuw.edu.pl/~dobaczew/Stellenbosch/dobaczewski_lecture.pdf Home page: http://www.fuw.edu.pl/~dobaczew/ #12;Jacek Dobaczewski Nuclear Structure Energy scales
Shirley, Yancy L
2015-01-01T23:59:59.000Z
The optically thin critical densities and the effective excitation densities to produce a 1 K km/s (or 0.818 Jy km/s $(\\frac{\
Aerodynamic Focusing Of High-Density Aerosols
Ruiz, D. E.; Fisch, Nathaniel
2014-02-24T23:59:59.000Z
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.
Statistical density modification using local pattern matching
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2003-10-01T23:59:59.000Z
Statistical density modification can make use of local patterns of density found in protein structures to improve crystallographic phases. A method for improving crystallographic phases is presented that is based on the preferential occurrence of certain local patterns of electron density in macromolecular electron-density maps. The method focuses on the relationship between the value of electron density at a point in the map and the pattern of density surrounding this point. Patterns of density that can be superimposed by rotation about the central point are considered equivalent. Standard templates are created from experimental or model electron-density maps by clustering and averaging local patterns of electron density. The clustering is based on correlation coefficients after rotation to maximize the correlation. Experimental or model maps are also used to create histograms relating the value of electron density at the central point to the correlation coefficient of the density surrounding this point with each member of the set of standard patterns. These histograms are then used to estimate the electron density at each point in a new experimental electron-density map using the pattern of electron density at points surrounding that point and the correlation coefficient of this density to each of the set of standard templates, again after rotation to maximize the correlation. The method is strengthened by excluding any information from the point in question from both the templates and the local pattern of density in the calculation. A function based on the origin of the Patterson function is used to remove information about the electron density at the point in question from nearby electron density. This allows an estimation of the electron density at each point in a map, using only information from other points in the process. The resulting estimates of electron density are shown to have errors that are nearly independent of the errors in the original map using model data and templates calculated at a resolution of 2.6 Å. Owing to this independence of errors, information from the new map can be combined in a simple fashion with information from the original map to create an improved map. An iterative phase-improvement process using this approach and other applications of the image-reconstruction method are described and applied to experimental data at resolutions ranging from 2.4 to 2.8 Å.
Revisit of the relationship between the elastic properties and sound velocities at high pressures
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
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.
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
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.
EFFECTIVE POROSITY IMPLIES EFFECTIVE BULK DENSITY IN SORBING SOLUTE TRANSPORT
Flach, G.
2012-02-27T23:59:59.000Z
The concept of an effective porosity is widely used in solute transport modeling to account for the presence of a fraction of the medium that effectively does not influence solute migration, apart from taking up space. This non-participating volume or ineffective porosity plays the same role as the gas phase in single-phase liquid unsaturated transport: it increases pore velocity, which is useful towards reproducing observed solute travel times. The prevalent use of the effective porosity concept is reflected by its prominent inclusion in popular texts, e.g., de Marsily (1986), Fetter (1988, 1993) and Zheng and Bennett (2002). The purpose of this commentary is to point out that proper application of the concept for sorbing solutes requires more than simply reducing porosity while leaving other material properties unchanged. More specifically, effective porosity implies the corresponding need for an effective bulk density in a conventional single-porosity model. The reason is that the designated non-participating volume is composed of both solid and fluid phases, both of which must be neglected for consistency. Said another way, if solute does not enter the ineffective porosity then it also cannot contact the adjoining solid. Conceptually neglecting the fluid portion of the non-participating volume leads to a lower (effective) porosity. Likewise, discarding the solid portion of the non-participating volume inherently leads to a lower or effective bulk density. In the author's experience, practitioners virtually never adjust bulk density when adopting the effective porosity approach.
Effects of pulse duration and areal density on ultrathin foil acceleration
Zhang Xiaomei; Shen Baifei; Ji Liangliang; Wang Fengchao; Wen Meng; Wang Wenpeng; Xu Jiancai; Yu Yahong [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)
2010-06-15T23:59:59.000Z
The influence of laser pulse duration and areal density of target in the interaction of a circularly polarized pulse with an ultrathin overdense foil is investigated. One-dimensional particle-in-cell simulation shows that with an appropriate laser-pulse rising front, the light pressure acceleration regime is effective even though the thin foil is transparent. As the laser intensity evolves, three stages in the acceleration process can be identified: at first the total reflection of the laser pulse, followed by partial reflection, and then near total reflection again due to the Doppler effect. The influences of the rising front of laser pulse and areal density of the ultrathin foil are investigated. It is found that an optimal laser pulse rising front exists for obtaining high (saturation) ion energy with the same laser energy within a short time. An optimal areal density also exists for obtaining the highest energy. For the same laser pulse, a higher areal density or a higher density with same areal density is more appropriate for obtaining a stationary state for making light pressure acceleration mechanism more effective.
Richard D. Saam
2007-01-09T23:59:59.000Z
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.
A non-linear elastic constitutive framework for replicating plastic deformation in solids.
Roberts, Scott Alan; Schunk, Peter Randall
2014-02-01T23:59:59.000Z
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.
Modeling and Application of Series Elastic Actuators for Force Control Multi Legged Robots
S, Arumugom; V, Ponselvan
2009-01-01T23:59:59.000Z
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...
Aidun, J.B.; Addessio, F.L.
1995-11-01T23:59:59.000Z
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.
Elastic Cross Sections for Electron Collisions with Molecules Relevant to Plasma Processing
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
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.
An elastic, plastic, viscous model for slow shear of a liquid foam
Philippe Marmottant; François Graner
2007-07-06T23:59:59.000Z
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.
Elastic properties of sulphur and selenium doped ternary PbTe alloys by first principles
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
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.
Squeeze flow of potato starch gel: effect of loading history on visco-elastic properties
Moutushi Dutta Choudhury; Shantanu Das; Sujata Tarafdar
2015-03-25T23:59:59.000Z
In this work gelatinized potato starch is shown to retain the memory of past loading history. It exhibits a visco-elastic response which does not depend solely on instantaneous conditions. A simple squeeze flow experiment is performed, where loading is done in two steps with a time lag $\\tau \\sim$ seconds between the steps. The effect on the strain, of varying $\\tau$ is reproduced by a three element visco-elastic solid model. Non-linearity is introduced through a generalized calculus approach by incorporating a non-integer order time derivative in the viscosity equation. A strain hardening proportional to the time lag between the two loading steps is also incorporated. This model reproduces the three salient features observed in the experiment, namely - the memory effect, slight initial oscillations in the strain as well as the long-time solid-like response. Dynamic visco-elasticity of the sample is also reported.
Discrete-time Lyapunov design for neuroadaptive control of elastic-joint robots
Macnab, C.J.B.; D'Eleuterio, G.M.T.
2000-05-01T23:59:59.000Z
A neural-network controller operating in discrete time is shown to result in stable trajectory tracking for rigid and elastic-joint robots. The technique assumes continuous-time state feedback. The proof of stability uses discrete-time Lyapunov functions. For the elastic-joint case, a discrete-time version of the adaptive backstepping technique is used. The result is that the neural network can be run at a very slow control rate, suitable for online calculations. The neural network used is referred to as the CMAC-RBF Associative Memory (CRAM), a modification of Albus's Cerebellar Model Arithmetic Computer (CMAC) algorithm using radial basis functions (RBFs). Simulation results are provided for a two-link planar elastic-joint robot and show that performance can be improved by using a larger network at a slower control rate.
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
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}.
Quartz resonator fluid density and viscosity monitor
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
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.
Observation of Narrow Structures in the P-P Elastic Analyzing Power
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
PHYSICAL REVIEW C VOLUME 42, NUMBER 2 AUGUST 1990 Observation of narrow structures in the p-p elastic analyzing power H. Shimizu, * H. Y. Yoshida, and H. Ohnuma Department of Physics, Tokyo Institute of Techno1ogy, Tokyo 152, Japan Y. Kobayashi... cross section, made at LAMPF utilizing a "white ' source of incident neutrons; of the p-p elastic differential cross section, made at Laboratoire National Saturne, Centre d'Etudes Nucleaires de Saclay (LNS), with a hydrogen-gas-jet target...
Elastic and Inelastic Scattering of Alpha-Particles and Protons from Sm-144
Barker, J. H.; Hiebert, John C.
1971-01-01T23:59:59.000Z
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...
On the origin of elastic strain limit of bulk metallic glasses
Ding, J., E-mail: ding@jhu.edu; Ma, E., E-mail: ema@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Cheng, Y. Q. [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
2014-01-06T23:59:59.000Z
All bulk metallic glasses exhibit a large and almost universal elastic strain limit. Here, we show that the magnitude of the yield strain of the glass state can be quantitatively derived from a characteristic property of the flow state typical in running shear bands (the root cause of yielding). The strain in the shear flow is mostly plastic, but associated with it there is an effective elastic atomic strain. The latter is almost identical for very different model systems in our molecular dynamics simulations, such that the corresponding yield strain is universal at any given homologous temperature.
Aditi Chakrabarti; Manoj K. Chaudhury
2014-01-28T23:59:59.000Z
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.
Method of synthesizing a low density material
Lorensen, L.E.; Monaco, S.B.
1987-02-27T23:59:59.000Z
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.
Some recent efforts toward high density implosions
McClellan, G.E.
1980-12-04T23:59:59.000Z
Some recent Livermore efforts towards achieving high-density implosions are presented. The implosion dynamics necessary to compress DT fuel to 10 to 100 times liquid density are discussed. Methods of diagnosing the maximum DT density for a specific design are presented along with results to date. The dynamics of the double-shelled target with an exploding outer shell are described, and some preliminary experimental results are presented.
Considering Air Density in Wind Power Production
Zénó Farkas
2011-03-11T23:59:59.000Z
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.
Considering Air Density in Wind Power Production
Farkas, Zénó
2011-01-01T23:59:59.000Z
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.
Observation of finite-wavelength screening in high-energy-density matter
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chapman, D. A.; Vorberger, J.; Fletcher, L. B.; Baggott, R. A.; Divol, L.; Döppner, T.; Falcone, R. W.; Glenzer, S. H.; Gregori, G.; Guymer, T. M.; et al
2015-04-23T23:59:59.000Z
A key component for the description of charged particle systems is the screening of the Coulomb interaction between charge carriers. First investigated in the 1920s by Debye and Hückel for electrolytes, charge screening is important for determining the structural and transport properties of matter as diverse as astrophysical and laboratory plasmas, nuclear matter such as quark-gluon plasmas, electrons in solids, planetary cores and charged macromolecules. For systems with negligible dynamics, screening is still mostly described using a Debye–Hückel-type approach. Here, we report the novel observation of a significant departure from the Debye–Hückel-type model in high-energy-density matter by probing laser-driven, shock-compressedmore »plastic with high-energy X-rays. We use spectrally resolved X-ray scattering in a geometry that enables direct investigation of the screening cloud, and demonstrate that the observed elastic scattering amplitude is only well described within a more general approach.« less
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
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.
The Influence of Thermal Convection on Density Segregation in a Vibrated Binary Granular System
Al Hanbali, Ahmad
of this work strongly imply the possibility that, for an adequately fluidised granular bed, the degree^ole of diffusive behaviour in the segregation of a gran- ular bed in the convective regime. The results on the fluctuation of particle velocities about a mean value [53]. For a granular bed excited by, for instance
A beautiful day in the neighborhood : the influence of neighborhood density on speech production
Freedman, Skott Elliot
2009-01-01T23:59:59.000Z
disability ( for example, dyslexia)? YES NO If yes, pleasedisability (for example, dyslexia)? YES NO If yes, please
Influence of ambient gas on the temperature and density of laser produced carbon plasma
Harilal, S. S.
; 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
Qian Zhao; Bao Yuan Sun; Wen Hui Long
2014-11-23T23:59:59.000Z
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.
On the Extensive Air Shower density spectrum
Aleksander Zawadzki; Tadeusz Wibig; Jerzy Gawin
1998-07-29T23:59:59.000Z
In search for new methods of determining the primary energy spectrum of Cosmic Rays, the attention was paid to the density spectrum measurement. New methods available at present warrant an accurateness of conclusions derived from the density spectrum measurements. The general statement about the change of the spectral index of the charged particle density spectrum is confirmed very clearly. Results concerning the shower size and primary energy spectra are also presented and discussed. Interesting future prospects for applications of the density spectrum method are proposed.
Lipoprotein subclass analysis by immunospecific density
Lester, Sandy Marie
2009-05-15T23:59:59.000Z
] 6 Table 1: Composition of Human Serum Lipoproteins Component Chylomicrons VLDL IDL LDL HDL Phospholipids (Weight %) 6-9 16-20 20-24 24-30 24-30 Free Cholesterol (Weight %) 1-3 4-8 8-9 9-12 2-5 Cholesteryl Esters (Weight %) 3-6 9... lipase; IDL, intermediate-density lipoprotein; LCAT, lecithin-cholesterol acyltransferase; LDL, low-density lipoprotein; LDL-R, low-density lipoprotein receptor; LDL-RRP, low-density lipoprotein receptor-related protein; Lyso PC...
3-D capacitance density imaging system
Fasching, G.E.
1988-03-18T23:59:59.000Z
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.
Effect of Elastic Stress on Phase Separation in Fe-20%Cr-6%Al-0.5%Ti ODS alloy
Cambridge, University of
Effect of Elastic Stress on Phase Separation in Fe- 20%Cr-6%Al-0.5%Ti ODS alloy C. Capdevila1, M. K Aldazabal from CEIT; and Monica Campos from Carlos III University (UC3) for their help with ODS for nuclear applications Acknowledgements Effect of Elastic Stress on Phase Separation in Fe-Cr-Al-Ti ODS alloy by C
Pseudo-elastic deformation behavior in a Ti/Mo-based alloy , M. Aindow a,*, S.P. Alpay a
Alpay, S. Pamir
, and are increasingly finding applications in aerospace, oil well systems and automotive parts [1]. Alloys in the metaPseudo-elastic deformation behavior in a Ti/Mo-based alloy T. Zhou a , M. Aindow a,*, S.P. Alpay 2003 Abstract It is shown that the pseudo-elastic response in a series of TiMoVNbAl alloys with 8
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
Ostoja-Starzewski, Martin
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
Lopez-Pamies, Oscar
To appear in the International Journal of Fracture Cavitation in Rubber: An Elastic Instability that cavitation in rubber -- that is, the sudden growth of inherent defects in rubber into large enclosed cavities far exceed the elastic limit of the rubber, which therefore ought to inelastically deform
Cross sections for neutron-deuteron elastic scattering in the energy range 135–250 MeV
Ertan, E.
We report new measurements of the neutron-deuteron elastic scattering cross section at energies from 135 to 250 MeV and center-of-mass angles from 80[degrees] to 130[degrees]. Cross sections for neutron-proton elastic ...
Johnson, P.A.; McCall, K.R.; Meegan, G.D. Jr. [Los Alamos National Lab., NM (United States)
1993-11-01T23:59:59.000Z
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.
Henri PoincarÃ© -Nancy-UniversitÃ©, UniversitÃ©
Energy change due to the appearance of cavities in elastic solids Tomasz Lewi#19;nski a;#3; and Jan of Technology. Al. Armii Ludowej 16, 00-637 Warsaw. Poland b Institute Elie Cartan. University of Nancy 1. BP of assessing an increment of strain energy due to the appearance of small cavities in elastic solids
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...
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
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.
Critical behaviour in the elastic response of hydrogels
M. Dennison; M. Jaspers; P. H. J. Kouwer; C. Storm; A. E. Rowan; F. C. MacKintosh
2014-07-01T23:59:59.000Z
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.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Li, Xiao -Hua; Guo, Wen -Jun; Li, Bao -An; Chen, Lie -Wen; Fattoyev, Farrukh J.; Newton, William G.
2015-04-01T23:59:59.000Z
The neutron–proton effective mass splitting in asymmetric nucleonic matter of isospin asymmetry ? and normal density is found to be m*n-p?(m*n – m*p)/m = (0.41 ± 0.15)? from analyzing globally 1088 sets of reaction and angular differential cross sections of proton elastic scattering on 130 targets with beam energies from 0.783 MeV to 200 MeV, and 1161 sets of data of neutron elastic scattering on 104 targets with beam energies from 0.05 MeV to 200 MeV within an isospin dependent non-relativistic optical potential model. It sets a useful reference for testing model predictions on the momentum dependence of the nucleonmore »isovector potential necessary for understanding novel structures and reactions of rare isotopes.« less
High density laser-driven target
Lindl, John D. (San Ramon, CA)
1981-01-01T23:59:59.000Z
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.
Molecular dynamics simulations of the elastic properties of polymer/carbon nanotube composites
Elliott, James
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
Jang, Jae-il [Hanyang University, Korea; Bei, Hongbin [ORNL; Becher, Paul F [ORNL; Pharr, George M [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)
2012-01-01T23:59:59.000Z
The elastic-to-plastic transition in single crystal a-silicon nitride was experimentally characterized through a series of nanoindentation experiments using a spherical indenter. The experimental results provide a quantitative description of the critical shear strengths for the transition, as well as estimates of the shear modulus and nanohardness of the material.
Nuclear elastic scattering effects on fusion product transport in the FRM
DeVeaux, J.C.; Greenspan, E.; Miley, G.H.
1981-01-01T23:59:59.000Z
Large energy transfer (LET) events such as nuclear elastic scatterng (NES) are shown to have significant effects on fusion product transport in the field-reversed mirror. The method used and preliminary results obtained from the study on NES effects on f/sub p/ orbits are described. (MOW)
Paris-Sud XI, UniversitÃ© de
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 StÂ¨aubli CS8 controller provides the actual joint
Experimental testing of the variable rotated elastic parabolic Harry J. Simpsona)
of polyvinyl chloride (PVC) demonstrated the necessity of accounting for elasticity in the bottom PVC slabs joined at an angle to create a waveguide with variable bottom slope. Acoustic trans. The PVC slabs were oriented to produce three different simulated waveguides: flat bot- tom followed
Pressure-Induced Magnetization in FeO: Evidence from Elasticity and Mossbauer Spectroscopy
Jacobsen, Steven D.
Pressure-Induced Magnetization in FeO: Evidence from Elasticity and Mo¨ssbauer Spectroscopy of a magnetic ordering transition is observed by high-pressure Mo¨ssbauer spectroscopy and neutron powder that a unique combination of Mo¨ssbauer spectroscopy (MS), neutron powder diffrac- tion, and GHz
Fractal Shear Bands at Elastic-Plastic Transitions in Random Mohr-Coulomb Materials
Ostoja-Starzewski, Martin
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
Luo, Haoxiang
An efficient immersed boundary-lattice Boltzmann method for the hydrodynamic interaction of elastic flapping in the Kármán gait and the entrainment regions near a cylinder is studied to model fish swimming in these regions. Significant drag reduction is found for the filament, and the result is consistent
Short communication Determination of local and global elastic moduli of valve interstitial
Sun, Yu
guidelines for AFM measurement of cells grown on soft substrates are not well established. In this study of which are accounted for in the Hertz model. The results of this study provide practical guidelines indented either with tips mounted with a microsphere to yield a single (global) value for cell elasticity
Physically Accurate Haptic Rendering of Elastic Object for a Haptic Glove
Lee, Chan-Su
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
Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media
Boyer, Edmond
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
Journal of Mining Science, Vol. 45, No. 5, 2009 MODELING THE ELASTIC WAVE PROPAGATION
Alexandrov, Victor
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
Learning Price-Elasticity of Smart Consumers in Power Distribution Systems
Gómez, Vicenç
--Demand Response is an emerging technology which will transform the power grid of tomorrow. It is revolutionaryLearning Price-Elasticity of Smart Consumers in Power Distribution Systems Vicenc¸ G´omez1, Michael, not only because it will enable peak load shaving and will add resources to manage large distribution
Modeling a swimming fish with an initial-boundary value problem: unsteady maneuvers of an elastic
Smith, Marc L.
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
Doctoral Defense "Carbon Dioxide Capture on Elastic Layered Metal-Organic
Kamat, Vineet R.
Doctoral Defense "Carbon Dioxide Capture on Elastic Layered Metal-Organic Framework Adsorbents requires drastic modifications to the current energy infrastructure. Thus, carbon capture and sequestration for use as carbon capture adsorbents. Ideal adsorbed solution theory (IAST) estimates of CO2 selectivity
Nonlinear Elasticity, Proteinquakes and the Energy Landscapes of Functional Transitions in Proteins
Blanco, Philip R.
Nonlinear Elasticity, Proteinquakes and the Energy Landscapes of Functional Transitions in Proteins. By generalizing the energy landscape theory of protein folding for biological functional events, we have developed becomes too high during the transition. (A) (B) (A) The residue strain energy as the structure is deformed
Journal of Elasticity 66: 6392, 2002. 2002 Kluwer Academic Publishers. Printed in the Netherlands.
Shu, Yi-Chung
on the morphology of a stressed solid. Recent experiment [15, 44, 60] has observed a 3D morphology for a strainedJournal of Elasticity 66: 63Â92, 2002. Â© 2002 Kluwer Academic Publishers. Printed techniques, we derive a rigorous relaxation formula based on the energy approach in the case of slightly
Elastic scattering of {sup 6}He and {sup 7}Be on a {sup 9}Be target
Pires, K. C. C.; Lichtenthaeler, R. [Depto de Fisica Nuclear, Universidade de Sao Paulo, C.P. 66318, 05389-970, Sao Paulo (Brazil); Mukha, I.; Moro, A. M. [Depto de FAMN, Facultad de Fisica, Universidad de Sevilla, E-41080 Sevilla (Spain); Gomez-Camacho, J. [Depto de FAMN, Facultad de Fisica, Universidad de Sevilla, E-41080 Sevilla (Spain); Centro Nacional de Aceleradores, E-41092 Sevilla (Spain)
2010-04-26T23:59:59.000Z
The elastic scattering data for the {sup 6}He+{sup 9}Be and {sup 7}Be+{sup 9}Be reactions, measured at E{sub lab} = 16.2 MeV and E{sub lab} = 23.7 MeV respectively, are presented and analyzed using the optical model and coupled-channels formalisms.
Ghoniem, Nasr M.
Multipole representation of the elastic field of dislocation ensembles Zhiqiang Wang and Nasr Laboratory, Los Alamos, New Mexico 87545, USA Received 23 December 2003; published 7 May 2004 A multipole forces by a factor of 100, with an error of less than 0.4%. The multipole expansion reveals a physical
POSTURE MATCHING AND ELASTIC REGISTRATION OF A MOUSE ATLAS TO SURFACE TOPOGRAPHY RANGE DATA
Leahy, Richard M.
POSTURE MATCHING AND ELASTIC REGISTRATION OF A MOUSE ATLAS TO SURFACE TOPOGRAPHY RANGE DATA A. A-imaged mouse based only on the atlas data and the measured surface topography of the i is required for quan- titative bioluminescence or fluorescence tomography. How- ever, only surface range data
An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel
Stanford University
An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel been used to convert wind flow energy into mechanical vibration, which is then transformed-scale renewable energy generating systems such as wind turbines, thermal generators, and solar panels, energy
On Some Models in Linear Thermo-Elasticity with Rational Material Laws
Santwana Mukhopadhyay; Rainer Picard; Sascha Trostorff; Marcus Waurick
2014-09-03T23:59:59.000Z
We shall consider some common models in linear thermo-elasticity within a common structural framework. Due to the flexibility of the structural perspective we will obtain well-posedness results for a large class of generalized models allowing for more general material properties such as anisotropies, inhomogeneities, etc.
Utah, University of
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
High precision measurement of the proton elastic form factor ratio at low Q²
Zhan, Xiaohui
2010-01-01T23:59:59.000Z
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, ...
Characterization of surface and nonlinear elasticity in wurtzite ZnO nanowires J. Yvonnet,1, a)
Paris-Sud XI, UniversitÃ© de
Characterization of surface and nonlinear elasticity in wurtzite ZnO nanowires J. Yvonnet,1, a) AÂ25 . Several first-principles studies have been conducted on wurtzite ZnO surfaces26Â32 . Marana et al.33 have effects and their relation to size-dependent effective properties of ZnO wurtzite nanowires, by means
Formal Modeling and Evaluation of Stateful Service-based Business Process Elasticity in the
Paris-Sud XI, UniversitÃ© de
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
OC3 -- Benchmark Exercise of Aero-Elastic Offshore Wind Turbine Codes: Preprint
Passon, P.; Kuhn, M.; Butterfield, S.; Jonkman, J.; Camp, T.; Larsen, T. J.
2007-08-01T23:59:59.000Z
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".
Geophysical Prospecting 36,571-590,1988 ELASTIC WAVE PROPAGATION IN MEDIA WITH
Santos, Juan
Geophysical Prospecting 36,571-590,1988 ELASTIC WAVE PROPAGATION IN MEDIA WITH PARALLEL FRACTURES propagation in media with parallel frac- tures and aligned cracks. Geophysical Prospecting 36,571-590. A model,CT 06877-4108, USA. Institute for Earth Sciences, Department of Geophysics, PB 80021, 3508 TA Utrecht
Circumferential creeping waves around a fluid-filled cylindrical cavity in an elastic medium
Nagy, Peter B.
of fluid fuel trapped in these rather small approximately 67 mm in diameter holes would strongly affectCircumferential creeping waves around a fluid-filled cylindrical cavity in an elastic medium Waled The dispersion behavior of circumferential creeping waves around a fluid-filled cylindrical cavity in an infinite
Implementation of a parallel conjugate gradient method for simulation of elastic light scattering
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
Energy Use in the Australian Manufacturing Industry: An Analysis of Energy Demand Elasticity
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
Papadopouli, Maria
Optimal Provisioning of Elastic Service Availability Dahai Xu Ying Li Mung Chiang A. Robert University, NJ 08544, USA Abstract-- Service availability is one of the most closely scruti- nized metrics higher service availability at the cost of higher operational expense. It is important to cost
The waves of damage in elastic-plastic lattices with waiting links: design and simulation
Cherkaev, Andrej
The waves of damage in elastic-plastic lattices with waiting links: design and simulation A damage (a neck) in an element, initiating the damage instead in another sequen- tial element. A wave of "partial damage" propagates through the chain, as all the links develop necks but do not fail. When
EUROMECH Young Scientist Prize Paper "Cavitation in rubber: The role of elasticity"
Lopez-Pamies, Oscar
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. It corresponds, at heart, to nothing more than to the growth of defects inherent in rubber. Such defects can
RANDOM PARKING, EUCLIDEAN FUNCTIONALS, AND RUBBER ELASTICITY ANTOINE GLORIA AND MATHEW D. PENROSE
Boyer, Edmond
RANDOM PARKING, EUCLIDEAN FUNCTIONALS, AND RUBBER ELASTICITY ANTOINE GLORIA AND MATHEW D. PENROSE. In particular, classical Euclidean optimization problems as well as the discrete model for rubber previously studied by Alicandro, Cicalese, and the first author enter this class of functions. In the case of rubber
On the physical basis for the nematic rubber elastic free energy
J. S. Biggins; M. Warner
2009-10-20T23:59:59.000Z
We discuss why it is physical to keep terms in the nematic rubber elastic free energy that reflect the order parameter dependence of the natural size of the network polymers. We address a point of difficulty in some mathematical approaches to this problem.
Minimal energy for elastic inclusions By Hans Knupfer and Robert V. Kohn
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
Elastic properties of carbon nanotubes under hydrostatic pressure S. Reich and C. Thomsen
Nabben, Reinhard
.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. OrdejoÂ´n Institut de Cie`ncia de Materials de Barcelona (CSIC), Campus de la U.A.B. E-08193 Bellaterra
Description of the dip in meson-proton elastic scattering by the Chou-Yang model
Bellandi F., J.; Covolan, R.J.M.; Menon, M.J.; Pimentel, B.M.
1988-01-01T23:59:59.000Z
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.
A nonlinear elastic deformable template for soft structure segmentation. Application to the heart
Rouchdy, Youssef
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
Ratcheting-induced wrinkling of an elastic film on a metal layer under cyclic temperatures
Huang, Rui
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
Proton structure from multiparticle contribution to elastic pp-scattering at 7 TeV
Heller, Barbara
Proton structure from multiparticle contribution to elastic pp-scattering at 7 TeV I.M. Dremin Lebedev Physical Institute, Moscow 119991, Russia The parton content of protons gets strong peripheral protons. The very first analyses [1, 2, 3] have lead to extremely interesting conclusions about
Elastic uplift in southeast Greenland due to rapid ice mass loss
Khan, Shfaqat A.; Wahr, John; Stearns, Leigh; Hamilton, Gordon; van Dam, Tonie; Larson, Kristine M.; Francis, Olivier
2007-11-01T23:59:59.000Z
[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...
Two parabolic equations for propagation in layered poro-elastic media
Rensselaer Polytechnic Institute, Troy, New York 12180 Michael D. Collins Naval Research Laboratory, Stennis and efficient for ocean acoustic propagation when outgoing energy domi- nates backscattered.1 In many shallow new parabolic equation formulations are derived for layered poro-elastic media. An earlier formulation
Wilhelmy plate artifacts in elastic monolayers T. A. Witten,a
Lee, Ka Yee C.
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
Beck, A.
We have measured the beam-normal single-spin asymmetry A[subscript n] in the elastic scattering of 1–3 GeV transversely polarized electrons from [superscript 1]H and for the first time from [superscript 4]He, [superscript ...
Viscosity and elastic constants of amorphous Si and Ge Ann Witwow@ and Frans Spaepen
Spaepen, Frans A.
Viscosity and elastic constants of amorphous Si and Ge Ann Witwow@ and Frans Spaepen Division expansion. Viscous flow was measured by stress relaxation and was found to be Newtonian. The viscosity of the viscosity of sputter-deposited samples as a function of stress (to establish the Newtonian charac- ter
650 IEEE ELECTRON DEVICE LETTERS, VOL. 27, NO. 8, AUGUST 2006 Fully Elastic Interconnects interconnects are re- quired for electronic skin. To date, the resistance of such thin-film interconnects has by only 60%, which is in close agreement with purely geometric deformation. Index Terms
The time reversed elastic nonlinearity diagnostic applied to evaluation of diffusion bonds
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
Absolute angle-differential elastic cross sections for electron collisions with diacetylene
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
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.
Elastic and Viscoelastic Properties of Non-bulk Polymer Interphases in Nanotube-reinforced Polymers
Fisher, Frank
Elastic and Viscoelastic Properties of Non-bulk Polymer Interphases in Nanotube-reinforced Polymers polymer composite materials with outstanding mechanical, electrical, and thermal properties. A hurdle to nanoscale interactions between the embedded NTs and adjacent polymer chains. This interphase region
Pumping fluids in microfluidic systems using the elastic deformation of poly(dimethylsiloxane){
Prentiss, Mara
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
Determination of third order elastic constants in a complex solid applying coda wave interferometry
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
Real-Time Load Elasticity Tracking and Pricing for Electric Vehicle Charging
Giannakis, Georgios
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
Dynamic measurements of the nonlinear elastic parameter A in rock under varying conditions
saturation. INDEX TERMS: 5102 Physical Properties of Rocks: Acoustic properties; 5112 Physical Properties of Rocks: Microstructure; 5199 Physical Properties of Rocks: General or miscellaneous; 9810 GeneralDynamic measurements of the nonlinear elastic parameter A in rock under varying conditions Paul A
Swept Blade Aero-Elastic Model for a Small Wind Turbine (Presentation)
Damiani, R.; Lee, S.; Larwood, S.
2014-07-01T23:59:59.000Z
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.
Cross section in deuteron-proton elastic scattering at 1.25 GeV/u
HADES Collaboration; P. K. Kurilkin; G. Agakishiev; A. Balanda; D. Belver; A. Belyaev; A. Blanco; M. Böhmer; J. L. Boyard; P. Cabanelas; E. Castro; S. Chernenko; J. Díaz; A. Dybczak; E. Epple; L. Fabbietti; O. Fateev; P. Finocchiaro; P. Fonte; J. Friese; I. Fröhlich; T. Galatyuk; J. A. Garzón; A. Gil; M. Golubeva; D. González-Díaz; F. Guber; T. Hennino; R. Holzmann; P. Huck; A. Ierusalimov; I. Iori; A. Ivashkin; M. Jurkovic; B. Kämpfer; T. Karavicheva; I. Koenig; W. Koenig; B. W. Kolb; A. Kopp; G. Korcyl; G. K. Kornakov; R. Kotte; A. Kozuch; A. Krása; F. Krizek; R. Krücken; H. Kuc; W. Kühn; A. Kugler; A. Kurepin; A. Kurilkin; P. Khlitz; V. Ladygin; J. Lamas-Valverde; S. Lang; K. Lapidus; T. Liu; L. Lopes; M. Lorenz; L. Maier; A. Mangiarotti; J. Markert; V. Metag; B. Michalska; J. Michel; C. Müntz; L. Naumann; Y. C. Pachmayer; M. Palka; Y. Parpottas; V. Pechenov; O. Pechenova; J. Pietraszko; W. Przygoda; B. Ramstein; A. Reshetin; J. Roskoss; A. Rustamov; A. Sadovsky; P. Salabura; A. Schmah; J. Siebenson; Yu. G. Sobolev; S. Spataro; H. Ströbele; J. Stroth; C. Sturm; M. Sudol; A. Tarantola; K. Teilab; P. Tlusty; M. Traxler; R. Trebacz; H. Tsertos; T. Vasiliev; V. Wagner; M. Weber; J. Wüstenfeld; S. Yurevich; Y. Zanevsky
2011-02-18T23:59:59.000Z
First results of the differential cross section in dp elastic scattering at 1.25 GeV/u measured with the HADES over a large angular range are reported. The obtained data corresponds to large transverse momenta, where a high sensitivity to the two-nucleon and three-nucleon short-range correlations is expected.
The Stumbling Block in Lung Repair of Emphysema: Elastic Fiber Assembly
Mecham, Robert
The Stumbling Block in Lung Repair of Emphysema: Elastic Fiber Assembly Adrian Shifren and Robert P properties of the lung are largely determined by the connective tissue networks laid down during development. The macromolecules most important for lung mechanics and structural integrity are collagen, elastin
Asymptotic perturbative QCD in elastic scattering, color transparency and A sub NN
Botts, J. (Department of Physics, FM-15, University of Washington, Seattle, Washington (USA))
1991-04-20T23:59:59.000Z
The effective transverse size of hadrons in leading perturbative contributions to elastic wide angle hadron-hadron scattering is discussed. The leading perturbative contribution to {ital A}{sub {ital NN}}, the spin asymmetry, at {pi}/2 scattering angle is evaluated as a function of the center of mass energy.
Characterization of in situ elastic properties of gas hydrate-bearing sediments on the Blake Ridge
Guerin, Gilles
17 Chapter 2: Characterization of in situ elastic properties of gas hydrate-bearing sediments acquired in gas-hydrate bearing sediments on the Blake Ridge to characterize the very distinct seismic with free gas. Between these two depths, gas hydrate and free gas seem to coexist. Within the Gas Hydrate
Factors influencing quantitative liquid (scanning) transmission...
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Factors influencing quantitative liquid (scanning) transmission electron microscopy. Factors influencing quantitative liquid (scanning) transmission electron microscopy. Abstract:...
Neutral depletion and the helicon density limit
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
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.
Density functional theory for carbon dioxide crystal
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
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.
Sayag, Roiy
using elastic models included only the floating shelves, clamped at a fixed GL over a stiff bed (stiff-fixed the dynamics of ice, bed, and ocean in a new elastic model for the tidal-timescale migration of grounding lines with fixed grounding lines were found to be inconsistent, suggesting an elasticity of ice that varies
Density Prediction of Uranium-6 Niobium Ingots
D.F.Teter; P.K. Tubesing; D.J.Thoma; E.J.Peterson
2003-04-15T23:59:59.000Z
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.
Periodic subsystem density-functional theory
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
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.
Instabilities in the Nuclear Energy Density Functional
M. Kortelainen; T. Lesinski
2010-02-05T23:59:59.000Z
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.
The temperature dependence of equilibrium plasma density
B. V. Vasiliev
2002-03-17T23:59:59.000Z
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 $T^{3/2}$.
Low density, resorcinol-formaldehyde aerogels
Pekala, R.W.
1988-05-26T23:59:59.000Z
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.
Low density, resorcinol-formaldehyde aerogels
Pekala, R.W.
1989-10-10T23:59:59.000Z
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.
Low density, resorcinol-formaldehyde aerogels
Pekala, Richard W. (Pleasant Hill, CA)
1989-01-01T23:59:59.000Z
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.
Low density, resorcinol-formaldehyde aerogels
Pekala, Richard W. (Pleasant Hill, CA)
1991-01-01T23:59:59.000Z
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.
Surface density profiles of collisionless disc merger remnants
Thorsten Naab; Ignacio Trujillo
2006-03-01T23:59:59.000Z
We present a detailed surface density analysis of a large sample of simulated collisionless mergers of disc galaxies with bulges (mass ratios 1:1, 2:1, 3:1, 4:1, and 6:1) and without bulges (mass ratios 1:1 and 3:1). They were classified, according to their bulge--to--total ($B/T$) ratio, either as a one-component system or as a two-component systems. In general projection effects change the classification of a remnant. Only merger remnants of discs with bulges show properties similar to observed early--type galaxies. Their B/T ratios are in the range $0.2influence on the distributions of $B/T$, effective radius and S\\'ersic index $n$. For all one-component projections ($\\approx 60%$ of all projections) the S\\'ersic index distribution peaks at $3
Alpha track density using a semiconductor detector
Hamilton, Ian Scott
1993-01-01T23:59:59.000Z
of factors including variation in the initial dielectric thickness, and other undefined parameters. In addition, the resultant radon concentration reading is dependent upon the calibration factor used to interpret the track density reading. Obtaining...
Breast Density and Cancer | GE Global Research
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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...
Magnetic fields and density functional theory
Salsbury Jr., Freddie
1999-02-01T23:59:59.000Z
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.
Density controlled carbon nanotube array electrodes
Ren, Zhifeng F. (Newton, MA); Tu, Yi (Belmont, MA)
2008-12-16T23:59:59.000Z
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.
Inverse diffusion from knowledge of power densities
Bal, Guillaume; Monard, Francois; Triki, Faouzi
2011-01-01T23:59:59.000Z
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...
High density load bearing insulation peg
Nowobilski, J.J.; Owens, W.J.
1985-01-29T23:59:59.000Z
A high density peg is disclosed which can support a large load and exhibits excellent thermal resistance produced by a method wherein the peg is made in compliance with specified conditions of time, temperature and pressure. 4 figs.
Tweedie Family Densities: Methods of Evaluation
Smyth, Gordon K.
of Queensland, St Lucia, Q 4072, Australia. 2 University of Southern Queensland, Toowoomba, Q 4350, Australia. Tweedie family densities are characterised by power variance functions of the form V[µ] = µp , where p
Shock compression of low-density foams
Holmes, N.C.
1993-07-01T23:59:59.000Z
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.
QCD Level Density from Maximum Entropy Method
Shinji Ejiri; Tetsuo Hatsuda
2005-09-24T23:59:59.000Z
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.
Chevalier, Luc; 10.1002/pen.10948
2010-01-01T23:59:59.000Z
We present an experimental approach to discriminate hyper-elastic models describing the mechanical behavior of rubber-like materials. An evaluation of the displacement field obtained by digital image correlation allows us to evaluate the heterogeneous strain field observed during these tests. We focus on the particular case of hyper-elastic models to simulate the behavior of some rubber-like materials. Assuming incompressibility of the material, the hyper-elastic potential is determined from tension and compression tests. A biaxial loading condition is obtained in a multiaxial testing machine and model predictions are compared with experimental results.