Measurements of fuel and shell areal densities of OMEGA capsule implosions using elastically., Opt. Commun. 133, 495 1997 . Simultaneous measurements of elastically scattered protons, i.e., ``knock in diameter and with CD shells of 20 m thickness, were filled to about 15 atm and irradiated with 23 kJ of UV
DESIGN AND VALIDATION OF A HIGH ENERGY DENSITY ELASTIC ACCUMULATOR USING POLYURETHANE
Barth, Eric J.
DESIGN 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 them from being used in HRB is their low gravimetric energy density. Using linear analysis, spring
Yield stress and elasticity influence on surface tension measurements
Loren Jørgensen; Marie Le Merrer; Hélène Delanoë-Ayari; Catherine Barentin
2015-06-04
We have performed surface tension measurements on carbopol gels of different concentrations and yield stresses. Our setup, based on the force exerted by a capillary bridge on two parallel plates, allows to measure an effective surface tension of the complex fluid and to investigate the influence of flow history. More precisely the effective surface tension measured after stretching the bridge is always higher than after compressing it. The difference between the two values is due to the existence of a yield stress in the fluid. The experimental observations are successfully reproduced with a simple elasto-plastic model. The shape of successive stretching-compression cycles can be described by taking into account the yield stress and the elasticity of the gel. We show that the surface tension $\\gamma_{LV}$ of yield stress fluids is the mean of the effective surface tension values only if the elastic modulus is high compared to the yield stress. This work highlights that thermodynamical quantities measurements are challenged by the fluid out-of-equilibrium state implied by jamming, even at small scales where the shape of the bridge is driven by surface energy. Therefore setups allowing deformation in opposite directions are relevant for measurements on yield stress fluids.
Estimating the effect of Earth elasticity and variable water density on tsunami speeds
Tsai, Victor C.
Estimating the effect of Earth elasticity and variable water density on tsunami speeds Victor C; revised 25 December 2012; accepted 7 January 2013; published 13 February 2013. [1] The speed of tsunami comparisons of tsunami arrival times from the 11 March 2011 tsunami suggest, however, that the standard
Elastic models of the glass transition applied to a liquid with density anomalies
M. Pica Ciamarra; Peter Sollich
2015-08-19
Elastic models of the glass transition relate the relaxation dynamics and the elastic properties of structural glasses. They are based on the assumption that the relaxation dynamics occurs through activated events in the energy landscape whose energy scale is set by the elasticity of the material. Here we investigate whether such elastic models describe the relaxation dynamics of systems of particles interacting via a purely repulsive harmonic potential, focusing on a volume fraction and temperature range that is characterized by entropy--driven water--like density anomalies. We do find clear correlations between relaxation time and diffusivity on the one hand, and plateau shear modulus and Debye--Waller factor on the other, thus supporting the validity of elastic models of the glass transition. However, we also show that the plateau shear modulus is not related to the features of the underlying energy landscape of the system, at variance with recent results for power--law potentials. This challenges the common potential energy landscape interpretation of elastic models.
A reactive BGK-type model: influence of elastic collisions and chemical interactions
Ceragioli, Francesca
, Portugal Abstract. A BGK-type model for a reactive multicomponent gas undergoing chemical bimolecularA reactive BGK-type model: influence of elastic collisions and chemical interactions R. Monaco£ , M, as well as on common mean velocity and tempera- ture, is investigated with respect to chemical equilibrium
Quasi-static analysis of elastic behavior for some systems having higher fracture densities.
Berryman, J.G.
2010-01-01
J. Microcracks, and the static and dynamic elastic constantsQuasi-static analysis of elastic behavior for some systemssemi-analytical estimates of quasi-static elastic moduli for
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
2008-02-02
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.
SOIL MICROBIOLOGY Resource Amendments Influence Density and Competitive
Thomas, David D.
SOIL MICROBIOLOGY Resource Amendments Influence Density and Competitive Phenotypes of Streptomyces in Soil Daniel Schlatter & Alfred Fubuh & Kun Xiao & Dan Hernandez & Sarah Hobbie & Linda Kinkel Received Media, LLC 2008 Abstract Carbon from plant rhizospheres is a source of energy for soil microbial
Chung, Le Xuan; Khoa, Dao T; Egelhof, Peter
2015-01-01
The Glauber model analysis of the elastic $^{6,8}$He+$p$ scattering data at energies around 700 MeV/nucleon, measured in two separate experiments at GSI-Darmstadt, has been done using several phenomenological parametrizations of the nuclear matter density. By taking into account the new data points measured at the high momentum transfer, the nuclear matter radii of $^{6,8}$He were accurately determined from the Glauber model analysis of the data, with the spin-orbital interaction explicitly taken into account. The well-known geometry for the core and dineutron halo has been used with the new parametrizations of the $^{6}$He density to extract the detailed information on the structure of $^{6}$He in terms of the core and dineutron halo radii. An enhanced sensitivity of the data measured at the high momentum transfer to the core part of the $^{6,8}$He densities has been found.
Elastic and plastic properties of soils influencing the design of rigid pavements
Khuri, Fuad I.
1954-01-01
This analytical model predicts the stress concentration around an elastic, spherical particle in an elastic-plastic metal matrix using strain gradient plasticity theory and a finite unit cell. The model reduces to the special case with a spherical...
Stachiv, I., E-mail: stachiv@fzu.cz [Institute of Physics, Czech Academy of Sciences, Prague (Czech Republic); Advanced Manufacturing Institute with High-Tech Innovations, National Chung Cheng University, Chiayi County, Taiwan (China); Zapomel, J. [Institute of Thermomechanics, Czech Academy of Sciences, Prague (Czech Republic); Chen, Y.-L. [Institute of Physics, Academia Sinica, Taipei, Taiwan (China); Department of Physics, National Taiwan University, Taipei, Taiwan (China); Department of Chemical Engineering, National Tsing-Hua University, Hsinchu, Taiwan (China)
2014-03-28
Thin films are widely used in microelectronics, optics, filters, and various sensing devices. We propose a method to simultaneously determine the elastic modulus and density or thickness of ultrathin films deposited on various substrate materials. This methodology utilizes measurement of the resonant frequencies of the micro-/nanoresonator under intentionally applied axial tension and, consequently, the beam to string transition. Elastic modulus and density/thickness of thin film are obtained from the ratio between the resonant frequencies of the nanoresonator with and without applied axial force.
Vapor-like liquid coexistence densities affect the extension of the critical point's influence zone
Rivera, Jose Luis; Guerra-Gonzalez, Roberto
2015-01-01
The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone range covers up to hundreds of degrees below the critical temperature. Here we show that for a simple molecular potential of ethane, the critical influence zone covers a wide zone of tens of degrees (below the critical temperature) down to a transition temperature, at which the apparent critical influence zone vanishes and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, the experimentally observed wide extension of the critical influence zone is due to a vapor-like effect ...
Ion Density Deviations in Polyelectrolyte Microcapsules: Influence on Biosensors
Qiyun Tang; Alan R. Denton
2014-10-24
Polyelectrolyte microcapsules loaded with fluorescent dyes have been proposed as biosensors to monitor local pH and ionic strength for diagnostic purposes. In the case of charged microcapsules, however, the local electric field can cause deviations of ion densities inside the cavities, potentially resulting in misdiagnosis of some diseases. Using nonlinear Poisson-Boltzmann theory, we systematically investigate these deviations induced by charged microcapsules. Our results show that the microcapsule charge density, as well as the capsule and salt concentrations, contribute to deviations of local ion concentrations and pH. Our findings are relevant for applications of polyelectrolyte microcapsules with encapsulated ion-sensitive dyes as biosensors.
Influence of density dependent symmetry energy on Elliptical flow
Karan Singh Vinayak; Suneel Kumar
2011-09-18
The effect of density dependent symmetry energy on elliptical flow is studied using isospin-dependent quantum molecular dynamics model(IQMD). We have used the reduced isospin- dependent cross-section with hard(H) equation of state to study the sensitivity of elliptical flow towards symmetry energy in the energy range of 50 - 1000 MeV/nucleon. The elliptical flow becomes zero at a particular energy termed as transition energy. A systematic effort has been made to pin down the transition energy for the density dependent symmetry energy.
Vapor-like liquid coexistence densities affect the extension of the critical point's influence zone
Jose Luis Rivera; Homero Nicanor-Guzman; Roberto Guerra-Gonzalez
2015-04-16
The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone range covers up to hundreds of degrees below the critical temperature. Here we show that for a simple molecular potential of ethane, the critical influence zone covers a wide zone of tens of degrees (below the critical temperature) down to a transition temperature, at which the apparent critical influence zone vanishes and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, the experimentally observed wide extension of the critical influence zone is due to a vapor-like effect due to low bulk liquid phase densities.
Upchurch, Gary - Department of Biology, Texas State University
of weather events can also positively influence recruitment by enhancing food supplies available in a vacuum. Inverse relations between recruitment and female density are ubiquitous among ungulates
U?ur, Gökay; Candan, Abdullah
2014-10-06
First-principle calculations of structural, electronic, elastic and phonon properties of SnMg{sub 2}O{sub 4}, SnZn{sub 2}O{sub 4} and SnCd{sub 2}O{sub 4} compounds are presented, using the pseudo-potential plane waves approach based on density functional theory (DFT) within the generalized gradient approximation (GGA). The computed ground state structural parameters, i.e. lattice constants, internal free parameter and bulk modulus are in good agreement with the available theoretical results. Our calculated elastic constants are indicative of stability of SnX{sub 2}O{sub 4} (X=Mg, Zn, Cd) compounds in the spinel structure. The partial density of states (PDOS) of these compounds is in good agreement with the earlier ab-initio calculations. The phonon dispersion relations were calculated using the direct method. Phonon dispersion results indicate that SnZn{sub 2}O{sub 4} is dynamically stable, while SnMg{sub 2}O{sub 4} and SnCd{sub 2}O{sub 4} are unstable.
Kaur, Gurpreet; Jhingan, A; Sugathan, P; Hagino, K
2015-01-01
We discuss the role of channel coupling in the surface properties of an inter-nuclear potential for heavy-ion reactions. To this end, we analyze the experimental quasi-elastic cross sections for the $^{12}$C + $^{105,106}$Pd and $^{13}$C + $^{105,106}$Pd systems using the coupled-channels approach by including the vibrational excitations in the target nuclei. While earlier studies have reported a negligible influence of vibrational excitation on the surface diffuseness parameter for spherical systems, we find a significant effect for the C+Pd systems. Our systematic study also reveals influence of transfer couplings on the surface diffuseness parameter.
Moix, Jeremy M.
An exact method to compute the entire equilibrium-reduced density matrix for systems characterized by a system-bath Hamiltonian is presented. The approach is based upon a stochastic unraveling of the influence functional ...
Lewis, Caroline A Ms.
2012-01-01
INFLUENCE OF CURRENT ON THE ADHESIVE POTENTIAL, DENSITY ANDeffects of current on the adhesive potential were observed,adhesiveness To estimate the adhesive force of the anemones,
Research Associate School of Renewable Natural Resources Louisiana State University Agricultural Center-formaldehyde (PF) resin as binder. The effects of fines level and density on the panel properties were studied, including effective modulus (EM), linear expansion (LE), and swelling stresses using single-layer data
Influence of defects on the charge density wave of ([SnSe]1+?)1(VSe2)1 ferecrystals
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Falmbigl, Matthias; Putzky, Daniel; Ditto, Jeffrey; Esters, Marco; Bauers, Sage R.; Ronning, Filip; Johnson, David C.
2015-07-14
A series of ferecrystalline compounds ([SnSe]1+?)1(VSe2)1 with varying Sn/V ratios were synthesized using the modulated elemental reactant technique. Temperature-dependent specific heat data reveal a phase transition at 102 K, where the heat capacity changes abruptly. An abrupt increase in electrical resistivity occurs at the same temperature, correlated with an abrupt increase in the Hall coefficient. Combined with the magnitude and nature of the specific heat discontinuity, this suggests that the transition is similar to the charge density wave transitions in transition metal dichalcogenides. An ordered intergrowth was formed over a surprisingly wide compositional range of Sn/V ratios of 0.89 ?more »1 + ? ? 1.37. X-ray diffraction and transmission electron microscopy reveal the formation of various volume defects in the compounds in response to the nonstoichiometry. The electrical resistivity and Hall coefficient data of samples with different Sn/V ratios show systematic variation in the carrier concentration with the Sn/V ratio. There is no significant change in the onset temperature of the charge density wave transition, only a variation in the carrier densities before and after the transition. Given the sensitivity of the charge density wave transitions of transition metal dichalcogenides to variations in composition, it is very surprising that the charge density wave transition observed at 102 K for ([SnSe]1.15)1(VSe2)1 is barely influenced by the nonstoichiometry and structural defects. As a result, this might be a consequence of the two-dimensional nature of the structurally independent VSe2 layers.« less
Blaise, A; Delobelle, Patrick; Meshaka, Yves; Cunat, C
2012-01-01
The rheological parameters of materials are determined in the industry according to international standards established generally on the basis of widespread techniques and robust methods of estimation. Concerning solid polymers and the determination of Young's modulus in tensile tests, ISO 527-1 or ASTM D638 standards rely on protocols with poor scientific content: the determination of the slope of conventionally defined straight lines fitted to stress-strain curves in a given range of elongations. This paper describes the approach allowing for a correct measurement of the instantaneous elastic modulus of polymers in a tensile test. It is based on the use of an appropriate reduced model to describe the behavior of the material. The model comes a thermodynamical framework and allows to reproduce the behavior of an HDPE Polymer until large strains, covering the elastoviscoplastic and hardening regimes. Well-established principles of parameter estimation in engineering science are used to found the identificatio...
Influence of the Density Law on Various Fissile Single Unit and Array Storage Methods
Huang, S T
2011-03-02
The advancement of computational technology has resulted in the wide-spread availability of powerful radiation transport Monte Carlo codes. Prevailing practices today rely heavily on Monte Carlo codes to provide the basis for assessing the reactivity of various fissile systems for nuclear criticality safety (NCS). In 1958, Weinberg and Wigner expressed their concerns on a 'deplorable trend in reactor design - the tendency to substitute a code for a theory'. Unfortunately, their concerns have largely become a reality in many modern NCS practices. lacking the time or information to understand the underlying neutron physics of the fissile system under consideration is indeed a deplorable trend. The purpose of this paper is to demonstrate that many features of criticality hand calculation methods are indeed based upon the fundamentals of the density law and that many correlations of important physics parameters can be more easily understood from such a perspective. Historically, the density law was recognized by many pioneers in the field, including during the Manhattan Project. However, it was by and large an 'oral tradition' in that bits and pieces of great physical insights of the pioneers were scattered in many earlier publications. This paper attempts to bring together some of the 'jewels' of the pioneers which might have been lost or forgotten.
Li, Neng; Mo, Yuxiang; Ching, Wai-Yim
2013-11-14
In this work, we assess a full spectrum of properties (chemical bonding, charge distribution, spin ordering, optical, and elastic properties) of Cr{sub 2}AC (A?=?Al, Ge) and their hypothetical nitride counterparts Cr{sub 2}AN (A?=?Al, Ge) based on density functional theory calculations. The calculated total energy values indicate that a variety of spin ordering of these four compounds depending on interlayer-interactions between M-A and M-X within the sublattice, which is supported by bonding analysis. MAX phase materials are discovered to possess exotic magnetic properties which indicates that these materials could serve as promising candidates for novel layered magnetic materials for various electronic and spintronic applications. Further analysis of optical properties for two polarization vectors of Cr{sub 2}AX shows that the reflectivity is high in the visible-ultraviolet region up to ?15?eV suggesting Cr{sub 2}AX as a promising candidate for use as a coating material. The elastic coefficients (C{sub ij}) and bulk mechanical properties [bulk modulus (K), shear modulus (G), Young's modulus (E), Poisson's ratio (?), and Pugh ratio (G/K)] of these four Cr{sub 2}AX compounds are also calculated and analyzed, which pave the way to predict or design new MAX phases that are less brittle or tougher by having a lower G/K value or higher ?.
The influence of dynamical friction on the collapse of spherical density pertubation
A. Del Popolo; M. Gambera; V. Antonuccio-Delogu
1996-10-24
We solve numerically the equations of motion for the collapse of a shell of baryonic matter falling into the central regions of a cluster of galaxies, taking into account of the presence of the substructure inducing dynamical friction. The evolution of the expansion parameter a(t) of the perturbation is calculated in spherical systems. The effect of dynamical friction is to reduce the binding radius and the total mass accreted by the central regions. Using a peak density profile given by Bardeen et al. (1986) we show how the binding radius of the perturbation is modified by dinamical friction. We show how dynamical friction modifies the collapse parameter of the perturbation slowing down the collapse.
Carbon Density and Anthropogenic Land Use Influences on Net Land-Use Change Emissions
Smith, Steven J.; Rothwell, Andrew J.
2013-10-08
We examine historical and future land-use emissions using a simple mechanistic carbon-cycle model with regional and ecosystem specific parameterizations. Our central estimate of net terrestrial land-use change emissions, exclusive of climate feedbacks, is 250 GtC over the last three hundred years. This estimate is most sensitive to assumptions for preindustrial forest and soil carbon densities. We also find that estimates are sensitive to the treatment of crop and pasture lands. These sensitivities also translate into differences in future terrestrial uptake in the RCP4.5 land-use scenario. This estimate of future uptake is lower than the native values from the GCAM integrated assessment model result due to lower net reforestation in the RCP4.5 gridded land-use data product
A. Blaise; Stéphane André; Patrick Delobelle; Yves Meshaka; C. Cunat
2012-06-19
The rheological parameters of materials are determined in the industry according to international standards established generally on the basis of widespread techniques and robust methods of estimation. Concerning solid polymers and the determination of Young's modulus in tensile tests, ISO 527-1 or ASTM D638 standards rely on protocols with poor scientific content: the determination of the slope of conventionally defined straight lines fitted to stress-strain curves in a given range of elongations. This paper describes the approach allowing for a correct measurement of the instantaneous elastic modulus of polymers in a tensile test. It is based on the use of an appropriate reduced model to describe the behavior of the material. The model comes a thermodynamical framework and allows to reproduce the behavior of an HDPE Polymer until large strains, covering the elastoviscoplastic and hardening regimes. Well-established principles of parameter estimation in engineering science are used to found the identification procedure. It will be shown that three parameters only are necessary to model experimental tensile signals: the instantaneous ('Young's') modulus, the maximum relaxation time of a linear distribution (described with a universal shape) and a strain hardening modulus to describe the 'relaxed' state. The paper ends with an assessment of the methodology. Our results of instantaneous modulus measurements are compared with those obtained with other physical experiments operating at different temporal and length scales.
Samuel A. Isaacson; Carolyn A. Larabell; Mark A. Le Gros; David M. McQueen; Charles S. Peskin
2013-08-19
In this work we examine how volume exclusion caused by regions of high chromatin density might influence the time required for proteins to find specific DNA binding sites. The spatial variation of chromatin density within mouse olfactory sensory neurons is determined from soft X-ray tomography reconstructions of five nuclei. We show that there is a division of the nuclear space into regions of low-density euchromatin and high-density heterochromatin. Volume exclusion experienced by a diffusing protein caused by this varying density of chromatin is modeled by a repulsive potential. The value of the potential at a given point in space is chosen to be proportional to the density of chromatin at that location. The constant of proportionality, called the volume exclusivity, provides a model parameter that determines the strength of volume exclusion. Numerical simulations demonstrate that the mean time for a protein to locate a binding site localized in euchromatin is minimized for a finite, non-zero volume exclusivity. For binding sites in heterochromatin, the mean time is minimized when the volume exclusivity is zero (the protein experiences no volume exclusion). An analytical theory is developed to explain these results. The theory suggests that for binding sites in euchromatin there is an optimal level of volume exclusivity that balances a reduction in the volume searched in finding the binding site, with the height of effective potential barriers the protein must cross during the search process.
Mayrhofer, P. H.; Music, D.; Schneider, J. M.
2006-11-01
Ti{sub 1-x}Al{sub x}N films and/or their alloys are employed in many industrial applications due to their excellent mechanical and thermal properties. Synthesized by plasma-assisted vapor deposition, Ti{sub 1-x}Al{sub x}N is reported to crystallize in the cubic NaCl (c) structure for AlN mole fractions below 0.4-0.91, whereas at larger Al contents the hexagonal ZnS-wurtzite (w) structure is observed. Here we use ab initio calculations to analyze the effect of composition and Al distribution on the metal sublattice on phase stability, structure, and elastic properties of c-Ti{sub 1-x}Al{sub x}N and w-Ti{sub 1-x}Al{sub x}N. We show that the phase stability of supersaturated c-Ti{sub 1-x}Al{sub x}N not only depends on the chemical composition but also on the Al distribution of the metal sublattice. An increase of the metastable solubility limit of AlN in c-Ti{sub 1-x}Al{sub x}N from 0.64 to 0.74 is obtained by decreasing the number of Ti-Al bonds. This can be understood by considering the Al distribution induced changes of the electronic structure, bond energy, and configurational entropy. This may in part explain the large variation of the metastable solubility limit reported in the literature.
U. S. Schwarz; S. A. Safran
2002-01-08
Biological cells in soft materials can be modeled as anisotropic force contraction dipoles. The corresponding elastic interaction potentials are long-ranged ($\\sim 1/r^3$ with distance $r$) and depend sensitively on elastic constants, geometry and cellular orientations. On elastic substrates, the elastic interaction is similar to that of electric quadrupoles in two dimensions and for dense systems leads to aggregation with herringbone order on a cellular scale. Free and clamped surfaces of samples of finite size introduce attractive and repulsive corrections, respectively, which vary on the macroscopic scale. Our theory predicts cell reorientation on stretched elastic substrates.
Liu, Jie
excitation power density on the efficiency of intrinsic defect emission in ZnO powders was characterized. This material system is potentially useful as an ultraviolet-photoexcited, white light phosphor under low-power.1063/1.2753540 Since the introduction of nitride-based white light emit- ting diodes LEDs in the mid-1990s, much
Opazo, A; Bustamante, G; Labbé, R
2015-01-01
We report experimental results for fluctuations of injected power in confined von K\\'arm\\'an swirling flows with constant external torque applied to the stirrers. Two experiments were performed at nearly equal Reynolds numbers in geometrically similar experimental setups, using air in one of them and water in the other. We found that the probability density function of power fluctuations is strongly asymmetric in air, while in water it is closer to a Gaussian, showing that the effect that a big change on the fluid density has on the flow-stirrer interaction is not reflected merely by a change in the amplitude of stirrers' response. In the case of water, with a density roughly 830 times greater than air density, the forcing exerted by the flow on the stirrers is stronger, so that they follow more closely the locally averaged rotation of the flow. When the fluid is air, the forcing is much weaker, resulting not only in a smaller stirrer response to the torque exerted by the flow, but also in power fluctuations ...
N. L. Calleya; S. R. Souza; B. V. Carlson; R. Donangelo; W. G. Lynch; M. B. Tsang; J. R. Winkelbauer
2014-08-28
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)
2014-03-15
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
2010-12-17
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.
Elasticity of Stiff Polymer Networks
Jan Wilhelm; Erwin Frey
2003-03-27
We study the elasticity of a two-dimensional random network of rigid rods (``Mikado model''). The essential features incorporated into the model are the anisotropic elasticity of the rods and the random geometry of the network. We show that there are three distinct scaling regimes, characterized by two distinct length scales on the elastic backbone. In addition to a critical rigidiy percolation region and a homogeneously elastic regime we find a novel intermediate scaling regime, where elasticity is dominated by bending deformations.
High elastic modulus polymer electrolytes
Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel
2013-10-22
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.
Martin, F.; Jaouen, C.; Pacaud, J.; Abadias, G.; Djemia, Ph.; Ganot, F.
2005-01-15
The interdependence between the microstructure of sputter-deposited Ni(111)/Mo(110) superlattices and their elastic behavior is investigated as a function of the bilayer period ({lambda}). Brillouin light scattering measurements show that a drastic softening of the effective shear modulus occurs with decreasing {lambda}, until {lambda}=2 nm where it reaches -62%. Ion irradiation is here used to trigger stress relaxation and to induce, in a controlled way, interdiffusion and structural changes allowing us thus to investigate their influence on the elastic anomaly. At a very low irradiation dose (0.1 displacements per atom), the relief of the lattice expansion and associated compressive stresses does not induce any change of the elastic response, which indicates that the elastic behavior of the as-grown multilayers is not correlated with the presence of elastic strains. Furthermore, a detailed x-ray diffraction analysis shows that the unstrained lattice parameter of Mo layers exhibit a linear dependence with the interface density, while the Ni unstrained lattice parameter remains nearly unchanged in the same {lambda} range. This effect can be attributed to an interfacial mixing of a constant Ni amount ({approx}1.5 monolayers) into the Mo layers, as a consequence of a dynamic segregation of Ni atoms during growth. Thus, the formation of interfacial metastable and supersaturated solid solutions, structurally and mechanically unstable, appears as the origin of the huge elastic softening observed in this system. At high ion fluences, when the mixing process becomes dominant, the present study also provides experimental data on phase transformation in 'driven' alloys, by addressing the issue of the stability of out-of-equilibrium structures under irradiation.
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)
2014-05-15
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.
McBride, Carl; Noya, Eva G; Vega, Carlos; 10.1039/C2CP42393F
2012-01-01
The melting point of ice Ih, as well as the temperature of maximum density (TMD) in the liquid phase, has been computed using the path integral Monte Carlo method. Two new models are introduced; TIP4PQ_D2O and TIP4PQ_T2O which are specifically designed to study D2O and T2O respectively. We have also used these models to study the "competing quantum effects" proposal of Habershon, Markland and Manolopoulos; the TIP4PQ/2005, TIP4PQ/2005 (D2O) and TIP4PQ/2005 (T2O) models are able to study the isotopic substitution of hydrogen for deuterium or tritium whilst constraining the geometry, while the TIP4PQ_D2O and TIP4PQ_T2O models, where the O-H bond lengths are progressively shortened, permit the study of the influence of geometry (and thus dipole moment) on the isotopic effects. For TIP4PQ_D2O - TIP4PQ/2005 we found a melting point shift of 4.9 K (experimentally the value is 3.68K) and a TMD shift of 6K (experimentally 7.2K). For TIP4PQ_T2O - TIP4PQ/2005 we found a melting point shift of 5.2 K (experimentally the ...
Elastic monopoles and external torques in nematic liquid crystal colloids
O. M. Tovkach; S. B. Chernyshuk; B. I. Lev
2013-11-19
Up to now it is commonly believed that a colloidal particle suspended in a nematic liquid crystal never produces elastic monopoles because this violates the mechanical equilibrium condition. And the only way to obtain deformations of director field falling off with distance as r^{-1} is to exert an external torque \\Gamma_{ext} on the colloid \\cite{de_Gennes}. In this paper we demonstrate that this statement is not quite correct and elastic monopoles, as well as dipoles and quadrupoles, can be induced without any external influence just by the particle itself. A behavior of a spherical colloidal particle with asymmetric anchoring strength distribution is considered theoretically. It is demonstrated that such a particle when suspended in a nematic host can produce director deformations decreasing as $r^{-1}$, i.e. elastic monopoles, by itself without any external influence.
Loewenthal, M.; Loseke, K.; Dow, T.A.; Scattergood, R.O.
1988-12-01
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.
Initial Stress Symmetry and Applications in Elasticity
Artur L. Gower; Pasquale Ciarletta; Michel Destrade
2015-06-16
An initial stress within a solid can arise to support external loads or from processes such as thermal expansion in inert matter or growth and remodelling in living materials. For this reason it is useful to develop a mechanical framework of initially stressed solids irrespective of how this stress formed. An ideal way to do this is to write the free energy density $\\Psi= \\Psi(\\boldsymbol F, \\boldsymbol {\\tau})$ in terms of initial stress $\\boldsymbol \\tau$ and the elastic deformation gradient $\\boldsymbol F$. In this paper we present a new constitutive condition for initially stressed materials, which we call the initial stress symmetry (ISS). We focus on two consequences of this symmetry. First we examine how ISS restricts the free energy density $\\Psi = \\Psi (\\boldsymbol F, \\boldsymbol \\tau) $ and present two examples of $\\Psi (\\boldsymbol F, \\boldsymbol \\tau)$ that satisfy ISS. Second we show that the initial stress can be derived from the Cauchy stress and the elastic deformation gradient. To illustrate we take an example from biomechanics and calculate the optimal Cauchy stress within an artery subjected to internal pressure. We then use ISS to derive the optimal target residual stress for the material to achieve after remodelling.
Unbiased Volumetric Registration via Nonlinear Elastic Regularization
Ferguson, Thomas S.
Unbiased Volumetric Registration via Nonlinear Elastic Regularization Igor Yanovsky1 , Carole Le elasticity method was tested using volumetric serial magnetic resonance images and shown to have some
First-principles elastic properties of (alpha)-Pu
Soderlind, P; Klepeis, J E
2008-11-04
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.
Baik, Mu-Hyun
Contribution from the Department of Chemistry, UniVersity of North Carolina, Chapel Hill, North Carolina 27599 in dimethylformamide solution. In all cases, the computed reaction energy profiles are in fair agreement for comparison that is not complicated by the major structural change that influences the COT energy profile
Statistical theory of elastic constants of cholesteric liquid crystals
A. Kapanowski
2009-10-20
A statistical theory of cholesteric liquid crystals composed of short rigid biaxial molecules is presented. It is derived in the thermodynamic limit at a small density and a small twist. The uniaxial (biaxial) cholesteric phase is regarded as a distorted form of the uniaxial (biaxial) nematic phase. The chirality of the interactions and the implementation of the inversion to the rotation matrix elements are discussed in detail. General microscopic expressions for the elastic constants are derived. The expressions involve the one-particle distribution function and the potential energy of two-body short-range interactions. It is shown that the elastic constants determine the twist of the phase. The stability condition for the cholesteric and nematic phases is presented. The theory is used to study unary and binary systems. The temperature and concentration dependence of the order parameters, the elastic constants and the twist of the phase are obtained. The possibility of phase separation is not investigated.
Rotstein, S.; Lax, I.; Svane, G. )
1990-01-01
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.
Philippe, M. P.; Ainslie, M. D.; Wéra, L.; Fagnard, J.-F.; Dennis, A. R.; Shi, Y.-H.; Cardwell, D. A.; Vanderheyden, B.; Vanderbemden, P.
2015-07-14
applications [13]. Large grain, bulk superconductors are often used in applications that incorporate ferromagnetic materials, such as in motors and generators [14, 15]. Ferromagnets can also increase the force in levitation systems [16, 17] and close... = 1.4 T). To achieve full penetration of the superconductor, a magnetizing induction of 15 T is applied. As can be seen, the remanent magnetic flux density is approximately ten times higher, with maximum values on the order of 3 teslas...
Stability of elastic grid shells
Mesnil, Romain, M. Eng. Massachusetts Institute of Technology
2013-01-01
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 ...
Comparison of elastic and inelastic analyses
Ammerman, D. J.; Heinstein, M. W.; Wellman, G. W.
1992-01-01
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.
Thermoacoustic Tomography in Elastic Media
Justin Tittelfitz
2011-10-11
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
Elastic Analogies Gordon C. Everstine
Everstine, Gordon C.
the coupling of an elastic structure with an acoustic field is the motivation for solving wave, Helmholtz) Poisson's equation: 2 + g = 0 (3) wave equation: 2 = Â¨/c2 (4) heat equation: k 2 + q = c (5) telegraph-harmonic form of the wave equation. That is, for time-harmonic motion, = 0 cos(t), and the wave equation
Elastic properties of Pu metal and Pu-Ga alloys
Soderlind, P; Landa, A; Klepeis, J E; Suzuki, Y; Migliori, A
2010-01-05
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.
2015-03-17
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.
2013-02-20
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.
Transversely isotropic elasticity and poroelasticity arising from thin isotropic layers
Berryman, J.G.
1997-07-01
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.
Third- and fourth-order constants of incompressible soft solids and the acousto-elastic effect
Michel Destrade; Michael D. Gilchrist; G. Saccomandi
2013-01-29
Acousto-elasticity is concerned with the propagation of small-amplitude waves in deformed solids. Results previously established for the incremental elastodynamics of exact non-linear elasticity are useful for the determination of third- and fourth-order elastic constants, especially in the case of incompressible isotropic soft solids, where the expressions are particularly simple. Specifically, it is simply a matter of expanding the expression for $\\rho v^2$, where $\\rho$ is the mass density and v the wave speed, in terms of the elongation $e$ of a block subject to a uniaxial tension. The analysis shows that in the resulting expression: $\\rho v^2 = a + be + ce^2$, say, $a$ depends linearly on $\\mu$; $b$ on $\\mu$ and $A$; and $c$ on $\\mu$, $A$, and $D$, the respective second-, third, and fourth-order constants of incompressible elasticity, for bulk shear waves and for surface waves.
Cooperative Gating and Spatial Organization of Membrane Proteins through Elastic Interactions
Tristan Ursell; Kerwyn Huang; Eric Peterson; Rob Phillips
2007-02-14
Biological membranes are elastic media in which the presence of a transmembrane protein leads to local bilayer deformation. The energetics of deformation allow two membrane proteins in close proximity to influence each other's equilibrium conformation via their local deformations, and spatially organize the proteins based on their geometry. We use the mechanosensitive channel of large conductance (MscL) as a case study to examine the implications of bilayer-mediated elastic interactions on protein conformational statistics and clustering. The deformations around MscL cost energy on the order of 10 kT and extend ~3nm from the protein edge, as such elastic forces induce cooperative gating and we propose experiments to measure these effects. Additionally, since elastic interactions are coupled to protein conformation, we find that conformational changes can severely alter the average separation between two proteins. This has important implications for how conformational changes organize membrane proteins into functional groups within membranes.
Muscle performance during frog jumping: influence of elasticity on
Azizi, Manny
such as long hindlimbs, a stout vertebral column and a relatively small body size are considered-B204, Providence, RI 02912, USA A fundamental feature of vertebrate muscle is that maximal force can all vertebrate skeletal muscles, are governed in their mechan- ical function by well-known contractile
Random parking, Euclidean functionals, and rubber elasticity
Antoine Gloria; Mathew D. Penrose
2012-03-06
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.
On stress-dependent elastic moduli and wave speeds
Michel Destrade; Ray W. Ogden
2013-02-19
On the basis of the general nonlinear theory of a hyperelastic material with initial stress, initially without consideration of the origin of the initial stress, we determine explicit expressions for the stress-dependent tensor of incremental elastic moduli. In considering three special cases of initial stress within the general framework, namely hydrostatic stress, uniaxial stress and planar shear stress, we then elucidate in general form the dependence of various elastic moduli on the initial stress. In each case the effect of initial stress on the wave speed of homogeneous plane waves is studied and it is shown how various special theories from the earlier literature fit within the general framework. We then consider the situation in which the initial stress is a pre-stress associated with a finite deformation and, in particular, we discuss the specialization to the second-order theory of elasticity and highlight connections between several classical approaches to the topic, again with special reference to the influence of higher-order terms on the speed of homogeneous plane waves. Some discrepancies arising in the earlier literature are noted.
Shapes of sedimenting soft elastic capsules in a viscous fluid
Horst-Holger Boltz; Jan Kierfeld
2015-09-08
Soft elastic capsules which are driven through a viscous fluid undergo shape deformation coupled to their motion. We introduce an iterative solution scheme which couples hydrodynamic boundary integral methods and elastic shape equations to find the stationary axisymmetric shape and the velocity of an elastic capsule moving in a viscous fluid at low Reynolds numbers. We use this approach to systematically study dynamical shape transitions of capsules with Hookean stretching and bending energies and spherical rest shape sedimenting under the influence of gravity or centrifugal forces. We find three types of possible axisymmetric stationary shapes for sedimenting capsules with fixed volume: a pseudospherical state, a pear-shaped state, and buckled shapes. Capsule shapes are controlled by two dimensionless parameters, the F\\"oppl-von-K\\'arm\\'an number characterizing the elastic properties and a Bond number characterizing the driving force. For increasing gravitational force the spherical shape transforms into a pear shape. For very large bending rigidity (very small F\\"oppl-von-K\\'arm\\'an number) this transition is discontinuous with shape hysteresis. The corresponding transition line terminates, however, in a critical point, such that the discontinuous transition is not present at typical F\\"oppl-von-K\\'arm\\'an numbers of synthetic capsules. In an additional bifurcation, buckled shapes occur upon increasing the gravitational force. This type of instability should be observable for generic synthetic capsules. All shape bifurcations can be resolved in the force-velocity relation of sedimenting capsules, where up to three capsule shapes with different velocities can occur for the same driving force. All three types of possible axisymmetric stationary shapes are stable with respect to rotation during sedimentation.
Decoupled elastic prestack depth migration Alexander Druzhinin*
Edinburgh, University of
Decoupled elastic prestack depth migration $ Alexander Druzhinin* British Geological Survey of the formula for common-shot or common-receiver amplitude-preserving elastic prestack depth migration (Pre to enhance strongly polarized wave modes prior to prestack depth migration (PreSDM) (e.g. Dillon et al., 1988
Elastic–Plastic Spherical Contact Modeling Including Roughness Effects
Li, L.; Etsion, I.; Talke, F. E.
2010-01-01
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
Single chain elasticity and thermoelasticity of polyethylene
John T. Titantah; Carlo Pierleoni; Jean-Paul Ryckaert
2002-09-05
Single-chain elasticity of polyethylene at $\\theta$ point up to 90% of stretching with respect to its contour length is computed by Monte-Carlo simulation of an atomistic model in continuous space. The elasticity law together with the free-energy and the internal energy variations with stretching are found to be very well represented by the wormlike chain model up to 65% of the chain elongation, provided the persistence length is treated as a temperature dependent parameter. Beyond this value of elongation simple ideal chain models are not able to describe the Monte Carlo data in a thermodynamic consistent way. This study reinforces the use of the wormlike chain model to interpret experimental data on the elasticity of synthetic polymers in the finite extensibility regime, provided the chain is not yet in its fully stretched regime. Specific solvent effects on the elasticity law and the partition between energetic and entropic contributions to single chain elasticity are investigated.
Nonlinear Elasticity in Biological Gels
Cornelis Storm; Jennifer J. Pastore; Fred C. MacKintosh; Tom C. Lubensky; Paul A. Janmey
2004-06-01
Unlike most synthetic materials, biological materials often stiffen as they are deformed. This nonlinear elastic response, critical for the physiological function of some tissues, has been documented since at least the 19th century, but the molecular structure and the design principles responsible for it are unknown. Current models for this response require geometrically complex ordered structures unique to each material. In this Article we show that a much simpler molecular theory accounts for strain stiffening in a wide range of molecularly distinct biopolymer gels formed from purified cytoskeletal and extracellular proteins. This theory shows that systems of semi-flexible chains such as filamentous proteins arranged in an open crosslinked meshwork invariably stiffen at low strains without the need for a specific architecture or multiple elements with different intrinsic stiffnesses.
Doster, Wolfgang
Elastic Incoherent Neutron Scattering, operating by varying instrumental energy resolution, Principles, Simulations and Experiments of the Resolution Elastic Neutron Scattering (RENS) by Magazu a different name "RENS" (resolution dependent elastic neutron scattering) [1-5]. Our ERS papers, first
Failure Stress and Apparent Elastic Modulus of Diesel Particulate...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Failure Stress and Apparent Elastic Modulus of Diesel Particulate Filter Ceramics Failure Stress and Apparent Elastic Modulus of Diesel Particulate Filter Ceramics Three...
High elastic modulus polymer electrolytes suitable for preventing...
Office of Scientific and Technical Information (OSTI)
High elastic modulus polymer electrolytes suitable for preventing thermal runaway in lithium batteries Citation Details In-Document Search Title: High elastic modulus polymer...
Polycrystalline gamma plutonium's elastic moduli versus temperature
Migliori, Albert; Betts, J; Trugman, A; Mielke, C H; Mitchell, J N; Ramos, M; Stroe, I
2009-01-01
Resonant ultrasound spectroscopy was used to measure the elastic properties of pure polycrystalline {sup 239}Pu in the {gamma} phase. Shear and longitudinal elastic moduli were measured simultaneously and the bulk modulus was computed from them. A smooth, linear, and large decrease of all elastic moduli with increasing temperature was observed. They calculated the Poisson ratio and found that it increases from 0.242 at 519 K to 0.252 at 571 K. These measurements on extremely well characterized pure Pu are in agreement with other reported results where overlap occurs.
Structural, elastic, electronic, magnetic and vibrational properties of CuCoMnGa under pressure
?yigör, Ahmet; U?ur, ?ule
2014-10-06
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.
Deep--elastic scattering and asymptotics
S. M. Troshin; N. E. Tyurin
2012-01-20
Deep--elastic scattering and its role in discrimination of the possible absorptive and reflective asymptotic scattering mechanisms are discussed with emphasis on the difference in the experimental signatures related to production processes.
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 ...
Coiling of elastic rods on rigid substrates
Khalid Jawed, Mohammad
2014-01-01
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 ...
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 ...
Mechanical behavior of elastic rods under constraint
Miller, James Thomas, Ph. D. Massachusetts Institute of Technology
2014-01-01
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 ...
Elastic moduli of nickel and iron aluminides
Manjigani, Sreedhar
1993-01-01
A research program has been completed on the dynamic elastic modulus measurements for several nickel and iron aluminide based intermetallics. The PUCOT (piezoelectric ultrasonic composite oscillator technique) was used for this purpose. Stress...
Intraclass Price Elasticity & Electric Rate Design
Gresham, K. E.
1987-01-01
beyond this becomes more elastic as usage increases. In the book "Innovative Electric, Rates," John Chamberlin and Charles Dickson utilize an economic model to test conservation programs. This model utilizes intrac1ass price elasticities and has a.... Utilities must rely on customer data and intuition to estimate customer response to rate changes. These methods have several downfalls. First, the customer data may not reflect customer behavior in an economic downturn. Second, the data may not exactly...
Strong coupling effects in near-barrier heavy-ion elastic scattering
N. Keeley; K. W. Kemper; K. Rusek
2014-09-25
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".
Effective medium theory of elastic waves in random networks of rods
J. I. Katz; J. J. Hoffman; M. S. Conradi; J. G. Miller
2012-06-13
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.
Third- and fourth-order elasticity of biological soft tissues
Michel Destrade; Michael D. Gilchrist; Raymond W. Ogden
2013-01-24
In the theory of weakly non-linear elasticity, Hamilton et al. [J. Acoust. Soc. Am. \\textbf{116} (2004) 41] identified $W = \\mu I_2 + (A/3)I_3 + D I_2^2$ as the fourth-order expansion of the strain-energy density for incompressible isotropic solids. Subsequently, much effort focused on theoretical and experimental developments linked to this expression in order to inform the modeling of gels and soft biological tissues. However, while many soft tissues can be treated as incompressible, they are not in general isotropic, and their anisotropy is associated with the presence of oriented collagen fiber bundles. Here the expansion of $W$ is carried up to fourth-order in the case where there exists one family of parallel fibers in the tissue. The results are then applied to acoustoelasticity, with a view to determining the second- and third-order nonlinear constants by employing small-amplitude transverse waves propagating in a deformed soft tissue.
Folding model calculations for 6He+12C Elastic Scattering
Awad A. Ibraheem
2015-11-02
In the framework of the double folding model, we used the {\\alpha}+2n and di-triton configurations for the nuclear matter density of the 6He nucleus to generate the real part of the optical potential for the system 6He+12C. As an alternative, we also use the high energy approximation to generate the optical potential for the same system. The derived potentials are employed to analyze the elastic scattering differential cross section at energies of 38.3, 41.6 and 82.3 MeV/nucleon. For the imaginary part of the potential we adopt the squared Woods-Saxon form. The obtained results are compared with the corresponding measured data as well as with available results in literature. The calculated total reaction cross sections are investigated and compared with the optical limit Glauber model description.
Folding model calculations for 6He+12C Elastic Scattering
Ibraheem, Awad A
2015-01-01
In the framework of the double folding model, we used the {\\alpha}+2n and di-triton configurations for the nuclear matter density of the 6He nucleus to generate the real part of the optical potential for the system 6He+12C. As an alternative, we also use the high energy approximation to generate the optical potential for the same system. The derived potentials are employed to analyze the elastic scattering differential cross section at energies of 38.3, 41.6 and 82.3 MeV/nucleon. For the imaginary part of the potential we adopt the squared Woods-Saxon form. The obtained results are compared with the corresponding measured data as well as with available results in literature. The calculated total reaction cross sections are investigated and compared with the optical limit Glauber model description.
Peeling, Healing, and Bursting in a Lubricated Elastic Sheet A. E. Hosoi1,* and L. Mahadevan2,
Mahadevan, L.
gap thick- ness), density s,Young's modulus E, Poisson ratio , and bending stiffness B Eb3=121 ÿ 2 of the sheet, we derive an evolution equation for its motion, accounting for the effects of elastic bending, paper, and textiles [5] and in small scale biological and microelectrome- chanical systems (MEMS) [6
Elastic and Proton Dynamics of the DNA
V. L. Golo
2008-03-28
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.
Optical theorem and elastic nucleon scattering
Milos V. Lokajicek; Vojtech Kundrat
2009-06-22
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.
Yin, Xi
2011-01-01
the elastic and plastic properties of the softer material Eof the elastic and plastic properties of the soft surfaceon the elastic and plastic properties of the soft surface (
Song, Zhichao
2012-01-01
substrate elastic-plastic properties also play an importantof elastic-plastic material properties. The indentationand elastic-plastic materials properties by curve fitting
Elastic swimmer on a free surface
Ramananarivo, Sophie; Godoy-Diana, Ramiro
2013-01-01
We present in this fluid dynamics video a novel experimental setup with self-propelled swimmers on a free surface. The swimmers, modeled as flexible thin filaments, are subjected to external electromagnetic forcing driving a propagating elastic wave that gives rise to self- propulsion. The fluid-structure interaction problem of these passive anguilliform swimmers is analyzed in: S. Ramananarivo, R. Godoy-Diana, and B. Thiria. Passive elastic mechanism to mimic fish-muscles action in anguilliform swimming. J. R. Soc. Interface, 10, 20130667 (2013). DOI:10.1098/rsif.2013.0667
Interaction of gravitational waves with an elastic solid medium
B. Carter
2001-02-28
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.
THE RESPONSE OF SOLIDS TO ELASTIC/ PLASTIC INDENTATION
Chiang, S.S.
2013-01-01
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,
Charting the complete elastic properties of inorganic crystalline compounds
de Jong, Maarten
The elastic constant tensor of an inorganic compound provides a complete description of the response of the material to external stresses in the elastic limit. It thus provides fundamental insight into the nature of the ...
Quasi-elastic Neutrino Scattering - an Overview
Jan T. Sobczyk
2011-08-02
A non-technical overview of charge current quasi-elastic neutrino interaction is presented. Many body computations of multinucleon ejection which is proposed to explain recent large axial mass measurements are discussed. A few comments on recent experimental results reported at NuInt11 workshop are included.
Chiral dynamics and peripheral transverse densities
Granados, Carlos G.; Weiss, Christian
2014-01-01
In the partonic (or light-front) description of relativistic systems the electromagnetic form factors are expressed in terms of frame-independent charge and magnetization densities in transverse space. This formulation allows one to identify the chiral components of nucleon structure as the peripheral densities at transverse distances b = O(M{sub {pi}}{sup -1}) and compute them in a parametrically controlled manner. A dispersion relation connects the large-distance behavior of the transverse charge and magnetization densities to the spectral functions of the Dirac and Pauli form factors near the two--pion threshold at timelike t = 4 M{ sub {pi}}{sup 2}, which can be computed in relativistic chiral effective field theory. Using the leading-order approximation we (a) derive the asymptotic behavior (Yukawa tail) of the isovector transverse densities in the "chiral" region b = O(M{sub {pi}}{sup -1}) and the "molecular" region b = O(M{sub N}{sup 2}/M{sub {pi}}{sup 3}); (b) perform the heavy-baryon expansion of the transverse densities; (c) explain the relative magnitude of the peripheral charge and magnetization densities in a simple mechanical picture; (d) include Delta isobar intermediate states and study the peripheral transverse densities in the large-N{ sub c} limit of QCD; (e) quantify the region of transverse distances where the chiral components of the densities are numerically dominant; (f) calculate the chiral divergences of the b{sup 2}-weighted moments of the isovector transverse densities (charge and anomalous magnetic radii) in the limit M{sub {pi}} -> 0 and determine their spatial support. Our approach provides a concise formulation of the spatial structure of the nucleon's chiral component and offers new insights into basic properties of the chiral expansion. It relates the information extracted from low-t elastic form factors to the generalized parton distributions probed in peripheral high-energy scattering processes.
On the Rheology of Cold Drawing. I. Elastic Materials*
On the Rheology of Cold Drawing. I. Elastic Materials* BERNARD D. COLEMAN and DANIEL C. NEWMAN effects and, therefore, can be treated by use of constitutive assumptions appropriate to elastic materials constitutive equation for incompressible,three-dimensional,elastic materials is explored in detail and is found
Peeling, healing and bursting in a lubricated elastic sheet
Hosoi, Anette "Peko"
Peeling, healing and bursting in a lubricated elastic sheet A. E. Hosoi and L. Mahadevan August 10 in a lubricated elastic sheet A. E. Hosoi1, and L. Mahadevan2, 1 Hatsopoulos Microfluids Laboratory, Department 02138, USA (Dated: August 6, 2004) We consider the dynamics of an elastic sheet lubricated by the flow
Energy scaling laws for conically constrained thin elastic Jeremy Brandman
Energy scaling laws for conically constrained thin elastic sheets Jeremy Brandman , Robert V. Kohn Classification: 74B20, 74K20 Keywords: d-cone, thin elastic sheets, energy scaling laws 1 Introduction 1 consistent with a conical deformation? In particular: Â What is the elastic energy scaling law
Zhou, Songsheng
2012-02-14
- the adhesive contact mechanics, surface elasticity and strain gradient elasticity - are employed to study the mechanical behaviors of a semi-infinite solid induced by the boundary forces. A unified treatment of axisymmetric adhesive contact problems...
Jose Manuel Romero-Enrique; Chi-Tuong Pham; Pedro Patricio
2010-06-23
We characterize the elastic contribution to the surface free energy of a nematic in presence of a sawtooth substrate. Our findings are based on numerical minimization of the Landau-de Gennes model and analytical calculations on the Frank-Oseen theory. The nucleation of disclination lines (characterized by non-half-integer winding numbers) in the wedges and apexes of the substrate induces a leading order proportional to qlnq to the elastic contribution to the surface free energy density, q being the wavenumber associated with the substrate periodicity.
He, Yayun; Wang, Xin-Nian; Zhu, Yan
2015-01-01
A Linear Boltzmann Transport model within the perturbative QCD is developed for the study of parton propagation inside the quark-gluon plasma. Both leading partons and thermal recoil partons are tracked so that one can also study jet-induced medium excitations. In this study, we implement the complete set of elastic parton scattering processes and investigate elastic parton energy loss, transverse momentum broadening and their nontrivial energy and length dependence. We further investigate medium modifications of the jet shape and fragmentation functions of reconstructed jets. Contributions from thermal recoil partons are found to have significant influences on jet shape, fragmentation functions and angular distribution of reconstructed jets.
Yayun He; Tan Luo; Xin-Nian Wang; Yan Zhu
2015-05-21
A Linear Boltzmann Transport model within perturbative QCD is developed for the study of parton propagation inside the quark-gluon plasma. Both leading partons and thermal recoil partons are tracked so that one can also study jet-induced medium excitations. In this study, we implement the complete set of elastic parton scattering processes and investigate elastic parton energy loss, transverse momentum broadening and their nontrivial energy and length dependence. We further investigate medium modifications of the jet shape and fragmentation functions of reconstructed jets. Contributions from thermal recoil partons are found to have significant influences on jet shape, fragmentation functions and angular distribution of reconstructed jets.
Laboratory Density Functionals
B. G. Giraud
2007-07-26
We compare several definitions of the density of a self-bound system, such as a nucleus, in relation with its center-of-mass zero-point motion. A trivial deconvolution relates the internal density to the density defined in the laboratory frame. This result is useful for the practical definition of density functionals.
Periodic homogenization and material symmetry in linear elasticity
Mariya Ptashnyk; Brian Seguin
2015-05-07
Here homogenization theory is used to establish a connection between the symmetries of a periodic elastic structure associated with the microscopic properties of an elastic material and the material symmetries of the effective, macroscopic elasticity tensor. Previous results of this type exist but here more general symmetries on the microscale are considered. Using an explicit example, we show that it is possible for a material to be fully anisotropic on the microscale and yet have a nontrivial material symmetry group on the macroscale. Another example demonstrates that not all material symmetries of the macroscopic elastic tensor are generated by symmetries of the periodic elastic structure.
Hall viscosity from elastic gauge fields in Dirac crystals
Cortijo, Alberto; Landsteiner, Karl; Vozmediano, María A H
2015-01-01
The combination of Dirac physics and elasticity has been explored at length in graphene where the so--called "elastic gauge fields" have given rise to an entire new field of research and applications: Straintronics. The fact that these elastic fields couple to fermions as the electromagnetic field, implies that many electromagnetic responses will have elastic counterparts not explored before. In this work we will first show that the presence of elastic gauge fields will be the rule rather than the exception in most of the topologically non--trivial materials in two and three dimensions. In particular we will extract the elastic gauge fields associated to the recently observed Weyl semimetals, the "three dimensional graphene". As it is known, quantum electrodynamics suffers from the chiral anomaly whose consequences have been recently explored in matter systems. We will show that, associated to the physics of the anomalies, and as a counterpart of the Hall conductivity, elastic materials will have a Hall visco...
U?ur, ?ule; ?yigör, Ahmet
2014-10-06
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.
Relativistic Elasticity of Stationary Fluid Branes
Jay Armas; Niels A. Obers
2012-10-18
Fluid mechanics can be formulated on dynamical surfaces of arbitrary co-dimension embedded in a background space-time. This has been the main object of study of the blackfold approach in which the emphasis has primarily been on stationary fluid configurations. Motivated by this approach we show under certain conditions that a given stationary fluid configuration living on a dynamical surface of vanishing thickness and satisfying locally the first law of thermodynamics will behave like an elastic brane when the surface is subject to small deformations. These results, which are independent of the number of space-time dimensions and of the fluid arising from a gravitational dual, reveal the (electro)elastic character of (charged) black branes when considering extrinsic perturbations.
Relativistic Elasticity of Stationary Fluid Branes
Armas, Jay
2012-01-01
Fluid mechanics can be formulated on dynamical surfaces of arbitrary co-dimension embedded in a background space-time. This has been the main object of study of the blackfold approach in which the emphasis has primarily been on stationary fluid configurations. Motivated by this approach we show under certain conditions that a given stationary fluid configuration living on a dynamical surface of vanishing thickness and satisfying locally the first law of thermodynamics will behave like an elastic brane when the surface is subject to small deformations. These results, which are independent of the number of space-time dimensions and of the fluid arising from a gravitational dual, reveal the (electro)elastic character of (charged) black branes when considering extrinsic perturbations.
Packing of elastic wires in flexible shells
Vetter, Roman; Herrmann, Hans J
2015-01-01
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
2015-04-03
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.
Pavel Galich; Stephan Rudykh
2014-12-31
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.
Taylor, DeCarlos E., E-mail: decarlos.e.taylor.civ@mail.mil [U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States)
2014-08-07
The elastic constants of the ? and ? polymorphs of cyclotrimethylene trinitramine (RDX) have been computed using dispersion corrected density functional theory (DFT). The DFT results validate the values obtained in several experiments using ultrasonic and impulsive stimulated thermal scattering techniques and disagree with those obtained using Brillouin scattering which, in general, exceed the other experimental and theoretical results. Compressibility diagrams at zero pressure are presented for the ab, ac, and bc crystallographic planes, and the anisotropic linear compressibility within the ac plane of ?-RDX at 0?GPa, observed using ultrasonic and impulsive stimulated thermal scattering measurements, is verified using DFT. The pressure dependence of the elastic constants of ?-RDX (0–4?GPa) and ?-RDX (4–8?GPa) is also presented.
ELEMENTARY APPROACH TO SELF-ASSEMBLY AND ELASTIC PROPERTIES OF RANDOM COPOLYMERS
S. M. CHITANVIS
2000-10-01
The authors have mapped the physics of a system of random copolymers onto a time-dependent density functional-type field theory using techniques of functional integration. Time in the theory is merely a label for the location of a given monomer along the extent of a flexible chain. We derive heuristically within this approach a non-local constraint which prevents segments on chains in the system from straying too far from each other, and leads to self-assembly. The structure factor is then computed in a straightforward fashion. The long wave-length limit of the structure factor is used to obtain the elastic modulus of the network. It is shown that there is a surprising competition between the degree of micro-phase separation and the elastic moduli of the system.
Low-frequency elastic waves alter pore-scale colloid mobilization
Beckham, Richard Edward; Abdel-fattah, Amr I; Roberts, Peter M; Ibrahim, Reem; Tarimala, Sownitri
2009-01-01
Naturally occurring seismic events and artificially generated low-frequency elastic waves have been observed to alter the production rates of oil and water wells, sometimes increasing and sometimes decreasing production, and to influence the turbidity of water wells. TEe decreases in production are of particular concern - especially when artificially generated elastic waves are applied as a method for enhanced oil recovery. The exact conditions that result in a decrease in production remain unknown. While the underlying environment is certainly complex, the observed increase in water well turbidity after seismic events suggests the existence of a mechanism that can affect both the subsurface flow paths and mobilization of in-situ colloidal particles. This paper explores the macroscopic and microscopic effects of elastic wave stimulations on the release of colloidal particles and investigates the microscopic mechanism of particle release during stimulation. Experiments on a column packed with 1-mm borosilicate beads loaded with polystyrene microspheres demonstrate that low-frequency elastic wave stimulations enhance the mobilization of captured microspheres. Increasing the intensity of the stimulations increases the number of microspheres released and can also result in cyclical variations in effluent microsphere concentration during and after stimulations. Under a prolonged period of stimulation, the cyclical effluent variations coincided with fluctuations in the column pressure data. This behavior can be attributed to flow pathways fouling and/or rearrangements of the beads in the column. Optical microscopy observations of the beads during low frequency oscillations reveal that the individual beads rotate, thereby rubbing against each other and scraping off portions of the adsorbed microspheres. These results support the theory that mechanical interactions between soil grains are important mechanisms in flow path alteration and the mobilization of naturally occurring colloidal particles during elastic wave stimulation. These results also point to both continuous and discrete, en masse releases of colloidal particles.
Environmental bias and elastic curves on surfaces
Jemal Guven; Dulce María Valencia; Pablo Vázquez-Montejo
2014-08-15
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.
An Expression for the Granular Elastic Energy
Yimin Jiang; Hepeng Zheng; Zheng Peng; Liping Fu; Shixiong Song; Qicheng Sun; Michael Mayer; Mario Liu
2012-06-13
Granular Solid Hydrodynamics (GSH) is a broad-ranged continual mechanical description of granular media capable of accounting for static stress distributions, yield phenomena, propagation and damping of elastic waves, the critical state, shear band, and fast dense flow. An important input of GSH is an expression for the elastic energy needed to deform the grains. The original expression, though useful and simple, has some draw-backs. Therefore, a slightly more complicated expression is proposed here that eliminates three of them: (1) The maximal angle at which an inclined layer of grains remains stable is increased from $26^\\circ$ to the more realistic value of $30^\\circ$. (2)Depending on direction and polarization, transverse elastic waves are known to propagate at slightly different velocities. The old expression neglects these differences, the new one successfully reproduces them. (3) Most importantly, the old expression contains only the Drucker-Prager yield surface. The new one contains in addition those named after Coulomb, Lade-Duncan and Matsuoka-Nakai -- realizing each, and interpolating between them, by shifting a single scalar parameter.
Ion Density Deviations in Semipermeable Ionic Microcapsules
Qiyun Tang; Alan R. Denton
2015-07-07
By implementing the nonlinear Poisson-Boltzmann theory in a cell model, we theoretically investigate the influence of polyelectrolye gel permeability on ion densities and pH deviations inside the cavities of ionic microcapsules. Our calculations show that variations in permeability of a charged capsule shell cause a redistribution of ion densities within the capsule, which ultimately affects the pH deviation and Donnan potential induced by the electric field of the shell. We find that semipermeable capsules can induce larger pH deviations inside their cavities that can permeable capsules. Furthermore, with increasing capsule charge, the influence of permeability on pH deviations progressively increases. Our theory, while providing a self-consistent method for modeling the influence of permeability on fundamental properties of ionic microgels, makes predictions of practical significance for the design of microcapsules loaded with fluorescent dyes, which can serve as biosensors for diagnostic purposes.
Complete wetting of elastically responsive substrates
N. R. Bernardino; S. Dietrich
2012-02-07
We analyze theoretically complete wetting of a substrate supporting an array of parallel, vertical plates which can tilt elastically. The adsorbed liquid tilts the plates, inducing clustering, and thus modifies the substrate geometry. In turn, this change in geometry alters the wetting properties of the substrate and, consequently, the adsorption of liquid. This geometry-wetting feedback loop leads to stepped adsorption isotherms with each step corresponding to an abrupt change in the substrate geometry. We discuss how this can be used for constructing substrates with tunable wetting and adsorption properties.
Elastic properties of the degenerate f.c.c. crystal of polydisperse soft dimers at zero temperature
Narojczyk, J W
2015-01-01
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
J. W. Narojczyk; K. W. Wojciechowski
2015-04-12
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.
NEAR-FIELD IMAGING OF BIPERIODIC SURFACES FOR ELASTIC ...
2015-06-16
scattering problem for elastic wave scattering by biperiodic surfaces in three ...... we obtained power series expansions for both the scalar and vector potential ...
Numerical simulations for width fluctuations in compound elastic...
Office of Scientific and Technical Information (OSTI)
simulations for width fluctuations in compound elastic and inelastic scattering at low energies Citation Details In-Document Search Title: Numerical simulations for width...
Elastic properties of saturated porous rocks with aligned fractures
2003-12-02
Elastic properties of fluid saturated porous media with aligned fractures can be studied using the ...... that are in hydraulic equilibrium with the fractures, the.
Observation of elastic collisions between lithium atoms and calcium ions
Haze, Shinsuke; Fujinaga, Munekazu; Mukaiyama, Takashi
2013-01-01
We observed elastic collisions between laser-cooled fermionic lithium atoms and calcium ions at the energy range from 100 mK to 3 K. Lithium atoms in an optical-dipole trap were transported to the center of the ion trap using an optical tweezer technique, and a spatial overlap of the atoms and ions was realized in order to observe the atom-ion interactions. The elastic scattering rate was determined from the decay of atoms due to elastic collisions with ions. The collision-energy dependence of the elastic scattering cross-section was consistent with semi-classical collision theory.
Studying conformally flat spacetimes with an elastic stress energy tensor using 1+3 formalism
I. Brito; M. P. Machado Ramos
2015-01-12
Conformally flat spacetimes with an elastic stress energy tensor given by a diagonal trace-free anisotropic pressure tensor are investigated using 1+3 formalism. We show how the null tetrad Ricci components are related to the pressure components and energy density. The 1+3 Bianchi and Jacobi identities and Einstein field equations are written for this particular case. In general the commutators must be considered since they supply potentially new information on higher order derivatives of the 1+3 quantities. We solve the system for the non rotating case which consist of ODEs of a spatial coordinate.
Elastic Refresh: Techniques to Mitigate Refresh Penalties in High Density Memory
John, Lizy Kurian
-processor SRAM memory). In the server space, JEDEC- standardized DDR3 DRAMs are currently prevalent, and DDR4 frequencies for DDR, DDR2, DDR3, and DDR4 are 200400 MHz, 4001066 MHz, 8001600 MHz, and 16003200 MHz
Chang Q. Sun
2015-02-26
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.
Development of configurational forces during the injection of an elastic rod
F. Bosi; D. Misseroni; F. Dal Corso; D. Bigoni
2015-09-18
When an inextensible elastic rod is 'injected' through a sliding sleeve against a fixed constraint, configurational forces are developed, deeply influencing the mechanical response. This effect, which is a consequence of the change in length of the portion of the rod included between the sliding sleeve and the fixed constraint, is theoretically demonstrated (via integration of the elastica) and experimentally validated on a proof-of-concept structure (displaying an interesting force reversal in the load/deflection diagram), to provide conclusive evidence to mechanical phenomena relevant in several technologies, including guide wire for artery catheterization, or wellbore insertion of a steel pipe.
The effect of elastic strain on M-center distribution in LiF
Wolny, Richard Frank
1962-01-01
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...
Stoica, Grigoreta M [ORNL; Stoica, Alexandru Dan [ORNL; Miller, Michael K [ORNL; Ma, Dong [ORNL
2014-01-01
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.
Achieving large linear elasticity and high strength in bulk nanocompsite via synergistic effect
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Hao, Shijie; Cui, Lishan; Guo, Fangmin; Liu, Yinong; Shi, Xiaobin; Jiang, Daqiang; Brown, Dennis E.; Ren, Yang
2015-03-09
Elastic strain in bulk metallic materials is usually limited to only a fraction of 1%. Developing bulk metallic materials showing large linear elasticity and high strength has proven to be difficult. Here, based on the synergistic effect between nanowires and orientated martensite NiTi shape memory alloy, we developed an in-situ Nb nanowires -orientated martensitic NiTi matrix composite showing an ultra-large linear elastic strain of 4% and an ultrahigh yield strength of 1.8 GPa. This material also has a high mechanical energy storage efficiency of 96% and a high energy storage density of 36 J/cm³ that is almost one order ofmore »larger than that of spring steel. It is demonstrated that the synergistic effect allows the exceptional mechanical properties of nanowires to be harvested at macro scale and the mechanical properties of matrix to be greatly improved, resulting in these superior properties. This study provides new avenues for developing advanced composites with superior properties by using effective synergistic effect between components.« less
Achieving large linear elasticity and high strength in bulk nanocompsite via synergistic effect
Hao, Shijie; Cui, Lishan; Guo, Fangmin; Liu, Yinong; Shi, Xiaobin; Jiang, Daqiang; Brown, Dennis E.; Ren, Yang
2015-03-09
Elastic strain in bulk metallic materials is usually limited to only a fraction of 1%. Developing bulk metallic materials showing large linear elasticity and high strength has proven to be difficult. Here, based on the synergistic effect between nanowires and orientated martensite NiTi shape memory alloy, we developed an in-situ Nb nanowires -orientated martensitic NiTi matrix composite showing an ultra-large linear elastic strain of 4% and an ultrahigh yield strength of 1.8 GPa. This material also has a high mechanical energy storage efficiency of 96% and a high energy storage density of 36 J/cm³ that is almost one order of larger than that of spring steel. It is demonstrated that the synergistic effect allows the exceptional mechanical properties of nanowires to be harvested at macro scale and the mechanical properties of matrix to be greatly improved, resulting in these superior properties. This study provides new avenues for developing advanced composites with superior properties by using effective synergistic effect between components.
Pandech, Narasak; Limpijumnong, Sukit; Sarasamak, Kanoknan
2015-05-07
The mechanical properties of perovskite oxides depend on two metal oxide lattices that are intercalated. This provides an opportunity for separate tuning of hardness, Poisson's ratio (transverse expansion in response to the compression), and shear strength. The elastic constants of series of perovskite oxides were studied by first principles approach. Both A-site and B-site cations were systematically varied in order to see their effects on the elastic parameters. To study the effects of A-site cations, we studied the elastic properties of perovskite ATiO{sub 3} for A being Be, Mg, Ca, Sr, or Ba, one at a time. Similarly, for B-site cations, we studied the elastic properties of PbBO{sub 3} for B being Ti, Zr, or Hf, one at a time. The density functional first principles calculations with local density approximation (LDA) and generalized gradient approximation (GGA) were employed. It is found that the maximum C{sub 11} elastic constant is achieved when the atomic size of the cations at A-site and B-site are comparable. We also found that C{sub 12} elastic constant is sensitive to B-site cations while C{sub 44} elastic constant is more sensitive to A-site cations. Details and explanations for such dependencies are discussed.
Density Functional Theory investigations of titanium gamma-surfaces and stacking faults
Benoit, Magali; Morillo, Joseph
2015-01-01
Properties of hcp-Ti such as elastic constants, stacking faults and gamma-surfaces are computed using Density Functional Theory (DFT) and two central force Embedded Atom interaction Models (EAM). The results are compared to previously published calculations and to predicting models. Their implications on the plastic properties of hcp-Ti are discussed.
Effect of Green Density on the Thermomechanical Properties of a Ceramic During Sintering
Messing, Gary L.
Effect of Green Density on the Thermomechanical Properties of a Ceramic During Sintering Sam E the sintering process. I. Introduction AMAJOR challenge during the manufacture of ceramics is the elimination ceramics can be treated as viscoelastic solids.3 Typ- ically, densifying ceramic compacts exhibit elastic
Visualization of electronic density
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Grosso, Bastien; Cooper, Valentino R.; Pine, Polina; Hashibon, Adham; Yaish, Yuval; Adler, Joan
2015-04-22
An atom’s volume depends on its electronic density. Although this density can only be evaluated exactly for hydrogen-like atoms, there are many excellent numerical algorithms and packages to calculate it for other materials. 3D visualization of charge density is challenging, especially when several molecular/atomic levels are intertwined in space. We explore several approaches to 3D charge density visualization, including the extension of an anaglyphic stereo visualization application based on the AViz package to larger structures such as nanotubes. We will describe motivations and potential applications of these tools for answering interesting questions about nanotube properties.
Turbulent density fluctuations in the solar wind
Ingale, Madhusudan
2015-01-01
Treatments of the radio scattering due to density turbulence in the solar wind typically employ asymptotic approximations to the phase structure function. We use a general structure function (GSF) that straddles the asymptotic limits and quantify the relative error introduced by the approximations. We show that the regimes where GSF predictions are accurate than those of its asymptotic approximations is not only of practical relevance, but are where inner scale effects influence the estimate of the scatter-broadening. Thus we propose that GSF should henceforth be used for scatter broadening calculations and estimates of quantities characterizing density turbulence in the solar corona and solar wind. In the next part of this thesis we use measurements of density turbulence in the solar wind from previously publish observations of radio wave scattering and interplanetary scintillations. Density fluctuations are inferred using the GSF for radio scattering data and existing analysis methods for IPS. Assuming that...
Noncontacting benchtop measurements of the elastic properties of shales
Boise State University
Noncontacting benchtop measurements of the elastic properties of shales Thomas E. Blum1 , Ludmila the elastic anisotropy of horizontal shale cores. Whereas conventional transducer data contained an ambigu shales were almost surely exaggerated by delamination of clay platelets and microfracturing, but provided
Elastic nucleon scattering at small angles at LHC energies
S. V. Goloskokov; S. P. Kuleshov; O. V. Selyugin
1997-07-02
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.
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
Static self-gravitating elastic bodies in Einstein gravity
Lars Andersson; Robert Beig; Bernd Schmidt
2009-01-12
We prove that given a stress-free elastic body there exists, for sufficiently small values of the gravitational constant, a unique static solution of the Einstein equations coupled to the equations of relativistic elasticity. The solution constructed is a small deformation of the relaxed configuration. This result yields the first proof of existence of static solutions of the Einstein equations without symmetries.
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
Towards Elastic Transactional Cloud Storage with Range Query Support
Ooi, Beng Chin
storage that can elastically scale on- demand with minimal startup cost. In this paper, we propose ecStore an elastic cloud storage sys- tem that supports automated data partitioning and replication, load balancing with a replication layer in the middle and a transaction management layer on top. ecStore pro- vides adaptive read
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
WHIRLING OF A CANTILEVER ELASTIC SHAFT SUBJECTED TO EXTERNAL PRESSURE
Newland, David E.
11 WHIRLING OF A CANTILEVER ELASTIC SHAFT SUBJECTED TO EXTERNAL PRESSURE D. E. Newland* This paper is a theoretical study of the whirling of a cantilever elastic shaft subjected to external pressure. The whirling speeds are shown to depend on the variation of pressure and area along the shaft and the lowest whirling
Elastic and Conductive Properties of Plasma-Sprayed Ceramic Coatings
Sevostianov, Igor
Elastic and Conductive Properties of Plasma-Sprayed Ceramic Coatings in Relation and conductive properties of plasma-sprayed ceramic coatings in terms of relevant microstructural parameters sprayed 1. Introduction The present review discusses the elastic stiffness of plasma-sprayed ceramic
Density-dependent covariant energy density functionals
Lalazissis, G. A.
2012-10-20
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.
Lula, J.W.
1982-01-01
A formulation for low density syntactic foam desiccant, using a polyimide resin binder, glass microbubble filler, and molecular sieve desiccant powder has been developed. The formulation may be modified easily to meet specific part requirements such as density and desired moisture pickup. Some parts can be molded to size.
Elastic wave-turbulence and intermittency
Chibbaro, Sergio
2015-01-01
Weak Wave Turbulence is a powerful theory to predict statistical observables of diverse relevant physical phenomena, such as ocean waves, magnetohydrodynamics and nonlinear optics. The theory is based upon an asymptotic closure permitted in the limit of small nonlinearity. Here, we explore the possible deviations from this mean-field framework, in terms of anomalous scaling, focusing on the case of elastic plates. We establish the picture of the possible behaviors at varying the extent of nonlinearity, and we show that the mean-field theory is appropriate when all excited scales remain dominated by linear dynamics. The other picture is non-trivial and our results suggest that, when large scales contain much energy, the cascade sustains extreme events at small scales and the system displays intermittency.
Elastic interactions between 2D geometric defects
Michael Moshe; Eran Sharon; Raz Kupferman
2015-10-13
In this paper, we introduce a methodology applicable to a wide range of localized two-dimensional sources of stress. This methodology is based on a geometric formulation of elasticity. Localized sources of stress are viewed as singular defects---point charges of the curvature associated with a reference metric. The stress field in the presence of defects can be solved using a scalar stress function that generalizes the classical Airy stress function to the case of materials with nontrivial geometry. This approach allows the calculation of interaction energies between various types of defects. We apply our methodology to two physical systems: shear-induced failure of amorphous materials and the mechanical interaction between contracting cells.
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
Screening effects on the elastic nucleon-nucleon cross section in relativistic nuclear matter
J. Diaz Alonso; L. Mornas
1997-11-18
We investigate the screening effects on the nucleon-nucleon elastic cross section inside nuclear matter at zero and finite temperature. The N-N interaction is described phenomenologically via meson exchanges ($\\sigma$, $\\pi$ and $\\omega$) in the framework of a relativistic lagrangian model. The expressions for the in-medium meson propagators, which take into account the effects of matter polarization and renormalized vacuum polarization, are used in the calculation of the various meson contributions to the total cross section in the one-boson exchange approximation. The final expressions allow a satisfactory fit of the Coulomb substracted proton-proton cross section data in vacuum. At finite density or temperature the cross section is reduced as compared to the vacuum values and compatible with the existing experimental constraints. At high density the $p$-$p$ differential cross section gets increasingly forward and backward peaked. The $\\sigma$-$\\omega$ mixing plays a key role in the understanding of the results.
Evidence of a Shift in the Short-Run Price Elasticity of Gasoline Demand
Hughes, Jonathan; Knittel, Christopher R; Sperling, Dan
2007-01-01
Basic Model TABLE 3 Price and Income Elasticities – BasicSpecifications TABLE 8 Price and Income Elasticities –constant 2000 dollars Table 7 Price Income Interaction Model
Mechanical and Elastic Property Evaluation of n- and p-type Skutterudi...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
and Elastic Property Evaluation of n- and p-type Skutterudites This talk discusses the mechanical and elastic properties of skutterudites and the steps used to obtain them -...
Krishichayan; Chen, X.; Lui, Y.-W.; Tokimoto, Y.; Button, J.; Youngblood, D. H. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States)
2010-01-15
Elastic and inelastic scattering of 240-MeV {sup 6}Li particles from {sup 58}Ni and {sup 90}Zr were measured with the multipole-dipole-multipole spectrometer from 4 deg. <={theta}{sub c.m.}<=43 deg. The elastic scattering data were fitted with the double-folding model using the density-dependent M3Y NN effective interaction and with a phenomenological Woods-Saxon potential. B(E2) and B(E3) values obtained for low-lying 2{sup +} and 3{sup -} states with the double-folding calculations agreed with the adopted values.
Hall viscosity from elastic gauge fields in Dirac crystals
Alberto Cortijo; Yago Ferreirós; Karl Landsteiner; María A. H. Vozmediano
2015-06-16
The combination of Dirac physics and elasticity has been explored at length in graphene where the so--called "elastic gauge fields" have given rise to an entire new field of research and applications: Straintronics. The fact that these elastic fields couple to fermions as the electromagnetic field, implies that many electromagnetic responses will have elastic counterparts not explored before. In this work we will first show that the presence of elastic gauge fields will be the rule rather than the exception in most of the topologically non--trivial materials in two and three dimensions. In particular we will extract the elastic gauge fields associated to the recently observed Weyl semimetals, the "three dimensional graphene". As it is known, quantum electrodynamics suffers from the chiral anomaly whose consequences have been recently explored in matter systems. We will show that, associated to the physics of the anomalies, and as a counterpart of the Hall conductivity, elastic materials will have a Hall viscosity in two and three dimensions with a coefficient orders of magnitude bigger than the previously studied response. The magnitude and generality of the new effect will greatly improve the chances for the experimental observation of this topological, non dissipative response.
The influence of ambient medium density on laser ablation processes
Kilgo, M.M. III
1995-11-01
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.
Accurate neutralino relic density
Paolo Gondolo; Joakim Edsjo
1998-04-30
We enlarge our set of supersymmetric models and update accelerator constraints in our precise calculation of the relic density of the lightest neutralino, which includes relativistic Boltzmann averaging, subthreshold and resonant annihilations, and coannihilation processes among charginos and neutralinos.
Bulk elastic fingering instability in Hele-Shaw cells
Baudouin Saintyves; Olivier Dauchot; Elisabeth Bouchaud
2013-08-17
We demonstrate experimentally the existence of a purely elastic fingering instability which arises when air penetrates into an elastomer confined in a Hele-Shaw cell. Fingers appear sequentially and propagate within the bulk of the material as soon as a critical strain, independent of the elastic modulus, is exceeded. Their width depends non-linearly on the distance between the confining glass plates. A key element in the driving force of the instability is the adhesion of layers of gels to the plates, which results in a considerable expense of elastic energy during the growth of the air bubble.
Elastic properties of gamma-Pu by resonant ultrasound spectroscopy
Migliori, Albert; Betts, J; Trugman, A; Mielke, C H; Mitchell, J N; Ramos, M; Stroe, I
2009-01-01
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.
Passive tomography for elastic waves in solids
Mikael Carmona; Olivier Michel; Jean-Louis Lacoume; Nathalie Sprynski; Barbara Nicolas
2011-03-24
In this paper we derive relations between the cross-correlation of ambient noises recorded at two different points and the Green's function of the elastic waves in a medium with viscous damping. The Green's function allows to estimate physical parameters such as speeds or distances. Furthermore, this work is extended by introducing the Green's correlation function proposed by J-L. Lacoume in [Lacoume07]. Some recent works proved the possible reconstruction of the Green's function for scalar waves from the cross-correlation function of ambient noise. In this work, we consider vector waves propagating in a three dimensional solid medium. Two approaches are developed. Firstly, we extend theoretical derivations proposed by Y. Colin de Verdi`ere in [ColinDeVerdiere09], relating cross-correlation of scalar waves to 1D Green's function using linear operator theory. The second approach recasts the three dimensional problem in the framework of Fourier theory. This allows to improve physical understanding of the underlying physical processes as outlined in [Lacoume07].
Bayesian prediction of modulus of elasticity of self consolidated concrete
Bhattacharjee, Chandan
2009-05-15
Current models of the modulus of elasticity, E , of concrete recommended by the American Concrete Institute (ACI) and the American Association of State Highway and Transportation Officials (AASHTO) are derived only for normally vibrated concrete...
Applications of the thermodynamics of elastic, crystalline materials
Si, Xiuhua
2006-10-30
The thermodynamic behaviors of multicomponent, elastic, crystalline solids under stress and electro-magnetic fields are developed, including the extension of EulerÃ¢Â?Â?s equation, Gibbs equation, Gibbs-Duhem equation, the conditions to be expected...
Kinematic quantities of finite elastic and plastic deformation
T. Fülöp; P. Ván
2012-03-05
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.
Finite Difference Elastic Wave Modeling Including Surface Topography
Al Muhaidib, Abdulaziz
2011-01-01
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 ...
Preconditioning for the mixed formulation of linear plane elasticity
Wang, Yanqiu
2005-11-01
In this dissertation, we study the mixed ?nite element method for the linear plane elasticity problem and iterative solvers for the resulting discrete system. We use the Arnold-Winther Element in the mixed ?nite element discretization...
Instrumentation for multiaxial mechanical testing of inhomogeneous elastic membranes
Herrmann, Ariel Marc
2006-01-01
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 ...
Elastic wave propagation in an irregularly layered medium Rossana Vaia
Komatitsch, Dimitri
Sismologie (URA 195), Institut de Physique du Globe de Paris, 4, Place Jussieu, 75252 -Paris Cedex 05, France by basin-induced surface waves (Kawase [1]). Analytical solutions of elastic wave propagation problems
Elastic energy of proteins and the stages of protein folding
Lei, Jinzhi
2010-01-01
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^{\
The influence of energy storage and return foot stiffness on walking mechanics and muscle activity feet have been developed to minimize these asymmetries by utilizing elastic energy storage and return the influence of foot stiffness on kinematics, kinetics, muscle activity, prosthetic energy storage and return
Bowen, Ray M.
2014-01-22
This work was originally planned as a textbook exploiting the structure of the Theory of Mixtures as the basis for the study of porous elasticity. The decision to write this book was made approximately thirty years ago! ...
Grover, William H.
We have used a microfluidic mass sensor to measure the density of single living cells. By weighing each cell in two fluids of different densities, our technique measures the single-cell mass, volume, and density of ...
High Energy Density Laboratory Plasmas
High Energy Density Laboratory Plasmas General Plasma Science Developing founda/ons and advancing fundamental understanding #12;The High Energy Density developing innovative techniques to study the properties of instabilities in magnetized-high-energy-density
Nucleon and $?$ elastic and transition form factors
Jorge Segovia; Ian C. Cloet; Craig D. Roberts; Sebastian M. Schmidt
2014-09-03
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.; et al
2015-01-08
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.
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.
2015-01-01
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.
Lunt, A. J. G. Xie, M. Y.; Baimpas, N.; Korsunsky, A. M.; Zhang, S. Y.; Kabra, S.; Kelleher, J.; Neo, T. K.
2014-08-07
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.
Multiple density layered insulator
Alger, Terry W. (Tracy, CA)
1994-01-01
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.
Granular mixtures modeled as elastic hard spheres subject to a drag force
Francisco Vega Reyes; Vicente Garzo; Andres Santos
2007-04-24
Granular gaseous mixtures under rapid flow conditions are usually modeled by a multicomponent system of smooth inelastic hard spheres with constant coefficients of normal restitution. In the low density regime an adequate framework is provided by the set of coupled inelastic Boltzmann equations. Due to the intricacy of the inelastic Boltzmann collision operator, in this paper we propose a simpler model of elastic hard spheres subject to the action of an effective drag force, which mimics the effect of dissipation present in the original granular gas. The Navier--Stokes transport coefficients for a binary mixture are obtained from the model by application of the Chapman--Enskog method. The three coefficients associated with the mass flux are the same as those obtained from the inelastic Boltzmann equation, while the remaining four transport coefficients show a general good agreement, especially in the case of the thermal conductivity. Finally, the approximate decomposition of the inelastic Boltzmann collision operator is exploited to construct a model kinetic equation for granular mixtures as a direct extension of a known kinetic model for elastic collisions.
Flow of the Viscous-Elastic Liquid in the Non- Homogeneous Tube
V. Yu. Babanly
2009-06-17
A problem on propagation of waves in deformable shells with flowing liquid is very urgent in connection with wide use of liquid transportation systems in living organisms and technology. It is necessary to consider shell motion equations for influence of moving liquid in cavity on the dynamics of a shell by solving such kind problems. Nowadays a totality of such problems is a widely developed field of hydrodynamics. However, a number of peculiarities connected with taking into account viscous-elastic properties of the liquid and inhomogeneity of the shell material generates considerable mathematical difficulties connected with integration of boundary value problems with variable coefficients. In the paper we consider wave flow of the liquid enclosed in deformable tube. The used mathematical model is described by the equation of motion of incompressible viscous elastic liquid combined with equation of continuity and dynamics equation for a tube inhomogeneous in length. It is accepted that the tube is cylindric, semi-infinite and rigidly fastened to the environment. At the infinity the tube is homogeneous. As a final result, the problem is reduced to the solution of Volterra type integral equation that is solved by sequential approximations method. Pulsating pressure is given at the end of the tube to determine the desired hydrodynamic functions.}
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
2015-05-14
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.
Nonlinear elastic polymers in random flow
M. Martins Afonso; D. Vincenzi
2005-08-09
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.
Gedanken densities and exact constraints in density functional theory
Perdew, John P.; Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 ; Ruzsinszky, Adrienn; Sun, Jianwei; Burke, Kieron
2014-05-14
Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherical two-electron gedanken density in which the dimensionless density gradient can be an arbitrary positive constant wherever the density is non-zero. The Lieb-Oxford lower bound on the exchange energy can be satisfied within a generalized gradient approximation (GGA) by bounding its enhancement factor or simplest GGA exchange-energy density. This enhancement-factor bound is well known to be sufficient, but our gedanken density shows that it is also necessary. The conventional exact exchange-energy density satisfies no such local bound, but energy densities are not unique, and the simplest GGA exchange-energy density is not an approximation to it. We further derive a strongly and optimally tightened bound on the exchange enhancement factor of a two-electron density, which is satisfied by the local density approximation but is violated by all published GGA's or meta-GGA’s. Finally, some consequences of the non-uniform density-scaling behavior for the asymptotics of the exchange enhancement factor of a GGA or meta-GGA are given.
Hydrogen, Deuterium and Tritium in Palladium: An Elastic Constants Study
Bach, H.T.; Schwarz, R.B.; Tuggle, D.G.
2005-07-15
We have used resonant ultrasound spectroscopy to measure the three independent elastic constants of Pd-H, Pd-D, and Pd-T single crystal at 300K as a function of hydrogen, deuterium, and tritium concentration, respectively. The addition of interstitial H (D, or T) atoms, located at (0,1/2,0) in the fcc Pd lattice, affects all three elastic constants C', C{sub 44}, and B. In the mixed ({alpha}+{beta}) phase, and with increasing H isotope, the shear modulus C' shows an abnormal softening whereas C{sub 44} and B do not. This is explained in terms of Zener-type an elastic relaxations affecting the shape of the hydride phases in the coherent({alpha}+{beta}) two-phase mixture In the single {beta}-phase, C' shows a strong isotope dependence whereas C{sub 44} and B show none. This behavior is explained in terms of differences in the excitation of optical phonons. In Pd-T, {sup 3}He is produced by the radioactive decay of tritium. We have measured in situ the swelling and the change in the elastic constants in Pd-T as a function of aging time. Aging ({sup 3}He formation) affects all three elastic constants. These measurements are being used to understand the early stages of {sup 3}H-{sup 3}He cluster formation in aged Pd-T crystal.
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)
1994-06-01
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.
Mullin, Scott; Panday, Ashoutosh; Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel
2014-04-22
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.
N. Mulakaluri; B. N. J. Persson
2011-12-22
The adhesive contact between elastic solids with randomly rough, self affine fractal surfaces is studied by molecular dynamics (MD) simulations. The interfacial binding energy obtained from the simulations of nominally flat and curved surfaces is compared with the predictions of the contact mechanics theory by Persson. Theoretical and simulation results agree rather well, and most of the differences observed can be attributed to finite size effects and to the long-range nature of the interaction between the atoms in the block and the substrate in the MD model, as compared to the analytical theory which is for an infinite system with interfacial contact interaction. For curved surfaces (JKR-type of problem) the effective interfacial energy exhibit a weak hysteresis which may be due to the influence of local irreversible detachment processes in the vicinity of the opening crack tip during pull-off.
Hörandel, Jörg R.
: www-ik.fzk.de/joerg on leave of absence c now at University Leeds, LS2 9JT Leeds, United King- dom §on from 385 mbarn to 364 mbarn at 106 GeV. The modified version of QGSJET 01 is labeled model 3
The full weak charge density distribution of 48Ca from parity violating electron scattering
Lin, Z
2015-01-01
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...
Tearing of thin sheets: Cracks interacting through an elastic ridge
Fabian Brau
2014-12-17
We study the interaction between two cracks propagating quasistatically during the tearing of a thin brittle sheet. We show that the cracks attract each other following a path described by a power law resulting from the competition between elastic and fracture energies. The power law exponent (8/11) is in close agreement with experiments. We also show that a second (asymptotic) regime, with an exponent of 9/8, emerges for small distances between the two crack tips due to the finite transverse curvature of the elastic ridge joining them.
High Energy Density Capacitors
2010-07-01
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
2015-01-01
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
Tirtaatmadja, Viyada
2007-01-23
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 ...
An Analysis of the Price Elasticity of Demand for Household Appliances
Dale, Larry
2008-01-01
D. and R. Rao. Effect of Price on the Demand for Durables:1997 Tellis, G. The Price Elasticity of Selective Demand: A1997 4 G. Tellis. "The Price Elasticity of Selective Demand:
Limitations of Preisach Theory: Elastic aftereffect, congruence, and end point memory
of the hysteresis in rocks that can be found is shown by Adams and Coker [1906]. Elastic after of the Preisach model, a hysteretic rock ``domain'' or elastic unit opens at one stress and closes at another
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
Efficient control of series elastic actuators through the exploitation of resonant modes
Albert, Kevin B. (Kevin Bjorn)
2007-01-01
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 ...
Elastic-plastic analysis of the transition divertor joint for high performance divertor target plate
Navaei, Dara
2011-01-01
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
An Asymptotic Numerical Method for Inverse Elastic Shape Design Changxi Zheng
Grinspun, Eitan
]: Computational Geom- etry and Object Modeling--Physically based modeling; Keywords: elastic fabrication, 3D printing, finite element methods, nonlinear optimization Links: DL PDF VIDEO CODE 1 Introduction Elastic
Song, Zhichao
2012-01-01
Greenwood, J.A. , 1997. Adhesion of elastic spheres. Proc.to the Maugis model of adhesion between elastic spheres. J.determination of interfacial adhesion properties by wedge
Elasticity-aware Virtual Machine Placement for Cloud Datacenters
Wu, Jie
Elasticity-aware Virtual Machine Placement for Cloud Datacenters Kangkang Li, Jie Wu, and Adam computing, the cloud datacenter suffers from both limited resources and the variation of users' requests in datacenters, satisfying the VMs' requested resources of users is the primary objective, neglecting future
Wrinkling of Pressurized Elastic Shells Dominic Vella,1
Vaziri, Ashkan
the formation of localized structures formed by the point loading of an internally pressurized elastic shell that pressurized shells are subject to a wrinkling instability. We study wrinkling in depth, presenting scaling-pong player knows, objects with an intrinsic curvature suffer a surprising mode of instability in which
Dynamic Simulations of Elastic Rods for Medical Applications
Nuti, Sravani
2014-12-05
This study deals with a detailed development of a computational model based on the Cosserat rod theory to describe the motion of elastic filaments such as threads and hair. The need for a simulation software for the act of suturing has motivated...
CAPITAL FOR ENERGY AND INTER-FUEL ELASTICITIES OF SUBSTITUTION
CAPITAL FOR ENERGY AND INTER- FUEL ELASTICITIES OF SUBSTITUTION FROM A TECHNOLOGY SIMULATION MODEL: Christopher G.F. Bataille Energy Research Group School of Resource and Environmental Management Simon Fraser to make a cost comparison of potential greenhouse gas (GHG) abatement policies. Our primary tools
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.
1991-01-01
We have measured the spin-transfer parameters K(LL), K(SL), K(LS), and K(SS) at 788 MeV from 47-degrees to 177-degrees c.m., and also uncovered a 10-16 % normalization discrepancy which affects all previous np elastic spin data from LAMPF. Results...
Time Delay Plot for Pion-Nucleon Elastic Scattering
Mohamed E. Kelabi
2012-01-14
We evaluated the time delay plot in the established region of the Delta(1232) resonance through the use of elastic scattering phase shift analysis of the partial wave amplitude P33. The pole position and width of the Delta(1232) resonance were obtained and found in agreement with earlier calculations.
SYMMETRIC NON-CONFORMING MIXED FINITE ELEMENTS FOR LINEAR ELASTICITY
GuzmÃ¡n, Johnny
. However, stress elements are difficult to design due to two requirements. First, due to conservation finite elements satisfying both these requirements have been designed in [1, 8, 4, 3]. But the mainSYMMETRIC NON-CONFORMING MIXED FINITE ELEMENTS FOR LINEAR ELASTICITY J. GOPALAKRISHNAN AND J. GUZM
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
Negative Poisson's Ratio Behavior Induced by an Elastic Instability
Reis, Pedro Miguel
for the development of a new class of materials which take advantage of such behavior. Here we exploit elastic. Reis, Stephen Willshaw, and Tom Mullin When materials are compressed along a particular axis transverse and longitudinal strains. The majority of materials are characterized by a positive Poisson
Neutron-deuteron elastic scattering and three-nucleon force
Chtangeev, Maxim B
2005-01-01
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 ...
Elastic effects in the foaming of thermoplastics Celeste Sagui,1
Grant, Martin
. Inside an extruder, the foams are pre- pared by dissolving a small molecular species, such as CO2 , whichElastic effects in the foaming of thermoplastics Celeste Sagui,1 Luc Piche´,1,2 Abdelhadi Sahnoune1063-651X 98 16109-3 PACS number s : 83.80.Bp, 61.25.Hq, 82.70.Rr Polymeric foams have gained
Hybrid Simulation Modeling to Estimate U.S. Energy Elasticities
to Estimate U.S. Energy Elasticities Examining Committee: Chair: Jacob Fox Master of Resource Management energy efficiency index (AEEI) parameters. The ability of economies to reduce greenhouse gas emissions to calculate price- independent changes in energy-efficiency in the form of the AEEI, by comparing energy
Experimental investigations of elastic tail propulsion at low Reynolds number
Lauga, Eric
of such a propulsive mechanism. A robotic swimmer is constructed and both tail shape and propulsive force are measured in a viscous fluid, generating traveling waves along the filament that produce a propulsive force see also RefsExperimental investigations of elastic tail propulsion at low Reynolds number Tony S. Yu, Eric
Nacre: An orthotropic and bimodular elastic material K. Bertoldi a
Bigoni, Davide
in Table 1), it is dif- ficult to understand how a composite with a highly compli- ant organic matrix may: Mother-of-pearl; Biological composites; Masonry; Homogenization theory; Elasticity 1. Introduction of Currey [7,8]. The fact that these mechanical characteristics remain unchallenged by the cur- rent ceramic
Measuring luminosity at LHCb using elastic diphoton dimuon production
Dermot Moran
2011-01-25
We report on an indirect method being used to measure luminosity at LHCb. It involves recording the event rate of elastic diphoton dimuon production. Preliminary MC studies suggest that with 1 fb^{-1} of data this method could provide a luminosity measurement with a precision of better than 2%
Introduction Result Bibliography Accepted Elasticity in Local Arithmetic
Ponomarenko, Vadim
Introduction Result Bibliography Accepted Elasticity in Local Arithmetic Congruence Monoids Vadim, 2014 http://www-rohan.sdsu.edu/~vadim/ accepted-talk.pdf #12;Introduction Result Bibliography Shameless one property, in the one class not yet understood, called "local". gcd(a, b) = p i.e. a = p, b = pn
Sound radiation from a line forced perforated elastic sandwich panel
Sidorov, Nikita
Sound radiation from a line forced perforated elastic sandwich panel I. David Abrahams Department by altering the interior geometry, and perforations can be added to one or both sides. With perforations399 1990 devised an effective boundary condition for a perforated sandwich plate structure, valid
Anisotropic elasticity in confocal studies of colloidal crystals
Schindler, M
2011-01-01
We consider the theory of fluctuations of a colloidal solid observed in a confocal slice. For a cubic crystal we study the evolution of the projected elastic properties as a function of the anisotropy of the crystal using numerical methods based on the fast Fourier transform. In certain situations of high symmetry we find exact analytic results for the projected fluctuations.
V. E. Oberacker; A. S. Umar
2015-02-13
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.
Nuclear Energy Density Optimization
M. Kortelainen; T. Lesinski; J. Moré; W. Nazarewicz; J. Sarich; N. Schunck; M. V. Stoitsov; S. Wild
2010-05-27
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.
Oberacker, V E
2015-01-01
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, James D. (Castro Valley, CA)
1991-01-01
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)
1992-01-01
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.
Low density microcellular foams
LeMay, J.D.
1991-11-19
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.
Low density microcellular foams
Aubert, J.H.; Clough, R.L.; Curro, J.G.; Quintana, C.A.; Russick, E.M.; Shaw, M.T.
1985-10-02
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.
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)
1987-01-01
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.
Adler, Thomas A. (Corvallis, OR)
1996-01-01
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.
Progress in an experiment to measure elastic nu. mu. e. -->. nu. mu. e scattering
Abe, K.; Ahrens, L.A.; Amako, K.
1983-01-01
The experimental setup and preliminary results of nu..mu.. + e elastic scattering measurements are described. (WHK)
California at Santa Cruz, University of
behave when subjected to external influences. External influences which a#ect the properties concentrate upon the macroscopic properties rather than the microscopic properties of the material. We treat a linear elastic material. In contrast, a plastic material is one which deforms under applied forces
California at Santa Cruz, University of
behave when subjected to external influences. External influences which affect the properties concentrate upon the macroscopic properties rather than the microscopic properties of the material. We treat a linear elastic material. In contrast, a plastic material is one which deforms under applied forces
Elastic-Wavefield Seismic Stratigraphy: A New Seismic Imaging Technology
Bob A. Hardage; Milo M. Backus; Michael V. DeAngelo; Sergey Fomel; Khaled Fouad; Robert J. Graebner; Paul E. Murray; Randy Remington; Diana Sava
2006-07-31
The purpose of our research has been to develop and demonstrate a seismic technology that will provide the oil and gas industry a better methodology for understanding reservoir and seal architectures and for improving interpretations of hydrocarbon systems. Our research goal was to expand the valuable science of seismic stratigraphy beyond the constraints of compressional (P-P) seismic data by using all modes (P-P, P-SV, SH-SH, SV-SV, SV-P) of a seismic elastic wavefield to define depositional sequences and facies. Our objective was to demonstrate that one or more modes of an elastic wavefield may image stratal surfaces across some stratigraphic intervals that are not seen by companion wave modes and thus provide different, but equally valid, information regarding depositional sequences and sedimentary facies within that interval. We use the term elastic wavefield stratigraphy to describe the methodology we use to integrate seismic sequences and seismic facies from all modes of an elastic wavefield into a seismic interpretation. We interpreted both onshore and marine multicomponent seismic surveys to select the data examples that we use to document the principles of elastic wavefield stratigraphy. We have also used examples from published papers that illustrate some concepts better than did the multicomponent seismic data that were available for our analysis. In each interpretation study, we used rock physics modeling to explain how and why certain geological conditions caused differences in P and S reflectivities that resulted in P-wave seismic sequences and facies being different from depth-equivalent S-wave sequences and facies across the targets we studied.
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, Salt Lake City, UT 84112, USA Abstract We consider protective structures with elastic-plastic links: Protective structure, Elastic-plastic material, Necking, Bistability, Partial damage, Collision, Waves
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 tracking approach for the numerical simulation of one-dimensional elastic- plastic flow in solids, and the von Mises condition for the elastic-plastic phase change. To characterize the cavitation
Elastic parabolic equation solutions for underwater acoustic problems using seismic sources
between elastic and acoustic waves, current elastic parabolic equation solutions must be modified to allowElastic parabolic equation solutions for underwater acoustic problems using seismic sources Scott D acoustic field is consistent with benchmark solu- tions. A shear wave self-starter is implemented and shown
FOURTH-ORDER ELASTIC CONSTANTS: GENERAL METHOD FOR DETERMINATION AND APPLICATIONS X. Markenscoff
Paris-Sud XI, Université de
FOURTH-ORDER ELASTIC CONSTANTS: GENERAL METHOD FOR DETERMINATION AND APPLICATIONS X. Markenscoff.- A list of the independent fourth-order elastic constants (FOEC's) and the interpenden- cies among the non. The fourth-order elastic constants are related to the second-derivatives of the wave velocity with respect
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
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
Grant, Martin
Modeling elastic and plastic deformations in nonequilibrium processing using phase field crystals K November 2004) A continuum field theory approach is presented for modeling elastic and plastic deformation the construction of a phase field model for the dynamics of crystal growth that includes elastic and plastic
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
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 away the elastic wave, instead of overrun it. Prior to that, people thought that the generated together there is an elastic shock wave (SW), which propagates before the strong plastic shock with plastic pressures of up
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
Elastic-wave identification of penetrable obstacles using shape-material sensitivity framework
Guzina, Bojan
Elastic-wave identification of penetrable obstacles using shape-material sensitivity framework Marc a c t This study deals with elastic-wave identification of discrete heterogeneities (inclusions Elsevier Inc. All rights reserved. 1. Introduction Elastic-wave sensing of penetrable (i.e. deformable
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
Structural and elastic properties of a confined 2D colloidal solid: a molecular dynamics study
M. Ebrahim Foulaadvand; Neda Ojaghlou
2014-09-27
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. .
Elastic free-energy of wormlike micellar chains: theory and suggested experiments
Meisam Asgari
2015-02-09
The extensive application of surfactants motivates comprehensive and predictive theoretical studies that improve our understanding of the behaviour of these complex systems. In this study, an expression for the elastic free-energy density of a wormlike micellar chain is derived taking into account interactions between its constituent molecules. The resulting expression incorporates the sum of a quadratic term in the curvature and a quadratic term in the torsion of the centerline of wormlike micelle and thus resembles free-energy density functions for polymer chains and DNA available in the literature. The derived model is applied on a wormlike micelle in the shape of a circular arc, open or closed. A detailed application of the derived model on wormlike micelles of toroidal shape, along with employing necessary statistical-thermodynamical concepts of self-assembly, is performed, and the results are found to be consistent with the ones available in the literature. Steps towards obtaining the material parameters through experiments are suggested and discussed.
High Energy Density Microwaves
Phillips, R.M. [Stanford Linear Accelerator Center, Stanford, CA 94309 (United States)
1999-04-01
These proceedings represent papers presented at the RF98 Workshop entitled `High Energy Density Microwaves` held in California in October, 1998. The topics discussed were predominantly accelerator{minus}related. The Workshop dealt, for the most part, with the generation and control of electron beams, the amplification of RF signals, the design of mode converters, and the effect of very high RF field gradients. This Workshop was designed to address the concerns of the microwave tube industry worldwide, the plasma physicists who deal with very high beam currents and gigawatts of RF power, and researchers in accelerator centers around the world. Papers were presented on multibeam klystrons, gyrotron development, plasmas in microwave tubes, RF breakdown, and alternatives to conventional linear coliders at 1 TeV and above. The Workshop was partially sponsored by the US Department of Energy. There were 46 papers presented at the conference,out of which 19 have been abstracted for the Energy,Science and Technology database.(AIP)
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.
2015-01-01
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.
Spectral Modeling of Residual Stress and Stored Elastic Strain Energy in Thermal Barrier Coatings
Donegan, Sean; Rolett, Anthony
2013-12-31
Solutions to the thermoelastic problem are important for characterizing the response under temperature change of refractory systems. This work extends a spectral fast Fourier transform (FFT) technique to analyze the thermoelastic behavior of thermal barrier coatings (TBCs), with the intent of probing the local origins of failure in TBCs. The thermoelastic FFT (teFFT) approach allows for the characterization of local thermal residual stress and strain fields, which constitute the origins of failure in TBC systems. A technique based on statistical extreme value theory known as peaks-over-threshold (POT) is developed to quantify the extreme values ("hot spots") of stored elastic strain energy (i.e., elastic energy density, or EED). The resolution dependence of the teFFT method is assessed through a sensitivity study of the extreme values in EED. The sensitivity study is performed both for the local (point-by-point) #12;eld distributions as well as the grain scale #12;eld distributions. A convergence behavior to a particular distribution shape is demonstrated for the local #12;elds. The grain scale fields are shown to exhibit a possible convergence to a maximum level of EED. To apply the teFFT method to TBC systems, 3D synthetic microstructures are created to approximate actual TBC microstructures. The morphology of the grains in each constituent layer as well as the texture is controlled. A variety of TBC materials, including industry standard materials and potential future materials, are analyzed using the teFFT. The resulting hot spots are quantified using the POT approach. A correlation between hot spots in EED and interface rumpling between constituent layers is demonstrated, particularly for the interface between the bond coat (BC) and the thermally grown oxide (TGO) layer.
Deformable elastic network refinement for low-resolution macromolecular crystallography
Schröder, Gunnar F.; Levitt, Michael; Brunger, Axel T.
2014-09-01
An overview of applications of the deformable elastic network (DEN) refinement method is presented together with recommendations for its optimal usage. Crystals of membrane proteins and protein complexes often diffract to low resolution owing to their intrinsic molecular flexibility, heterogeneity or the mosaic spread of micro-domains. At low resolution, the building and refinement of atomic models is a more challenging task. The deformable elastic network (DEN) refinement method developed previously has been instrumental in the determinion of several structures at low resolution. Here, DEN refinement is reviewed, recommendations for its optimal usage are provided and its limitations are discussed. Representative examples of the application of DEN refinement to challenging cases of refinement at low resolution are presented. These cases include soluble as well as membrane proteins determined at limiting resolutions ranging from 3 to 7 Å. Potential extensions of the DEN refinement technique and future perspectives for the interpretation of low-resolution crystal structures are also discussed.
Electromagnetic prompt response in an elastic wave cavity
A. M. Martínez-Argüello; M. Martínez-Mares; M. Cobián-Suárez; G. Báez; R. A. Méndez-Sánchez
2015-02-11
A rapid, or prompt response, of an electromagnetic nature, is found in an elastic wave scattering experiment. The experiment is performed with torsional elastic waves in a quasi-one-dimensional cavity with one port, formed by a notch grooved at a certain distance from the free end of a beam. The stationary patterns are diminished using a passive vibration isolation system at the other end of the beam. The measurement of the resonances is performed with non-contact electromagnetic-acoustic transducers outside the cavity. In the Argand plane, each resonance describes a circle over a base impedance curve which comes from the electromagnetic components of the equipment. A model, based on a variation of Poisson's kernel is developed. Excellent agreement between theory and experiment is obtained.
Elastic enhancement factor as a quantum chaos probe
Kharkov, Yaroslav A
2012-01-01
Recent development of the resonance scattering theory with a transient from the regular to chaotic internal dynamics inspires renewed interest to the problem of the elastic enhancement phenomenon. We reexamine the question what the experimentally observed value of the elastic enhancement factor can tell us about the character of dynamics of the intermediate system. Noting first a remarkable connection of this factor with the time delays variance in the case of the standard Gaussian ensembles we then prove the universal nature of such a relation. This reduces our problem to that of calculation of the Dyson's binary form factor in the whole transition region. By the example of systems with no time-reversal symmetry we then demonstrate that the enhancement can serve as a measure of the degree of internal chaos.
Elastic enhancement factor as a quantum chaos probe
Yaroslav A. Kharkov; Valentin V. Sokolov
2012-12-30
Recent development of the resonance scattering theory with a transient from the regular to chaotic internal dynamics inspires renewed interest to the problem of the elastic enhancement phenomenon. We reexamine the question what the experimentally observed value of the elastic enhancement factor can tell us about the character of dynamics of the intermediate system. Noting first a remarkable connection of this factor with the time delays variance in the case of the standard Gaussian ensembles we then prove the universal nature of such a relation. This reduces our problem to that of calculation of the Dyson's binary form factor in the whole transition region. By the example of systems with no time-reversal symmetry we then demonstrate that the enhancement can serve as a measure of the degree of internal chaos.
Elasticity and Glocality: Initiation of Embryonic Inversion in ${\\it Volvox}$
Pierre A. Haas; Raymond E. Goldstein
2015-07-06
Elastic objects across a wide range of scales deform under local changes of their intrinsic properties, yet the shapes are ${\\it glocal}$, set by a complicated balance between local properties and global geometric constraints. Here, we explore this interplay during the inversion process of the green alga ${\\it Volvox}$, whose embryos must turn themselves inside out to complete their development. This process has recently been shown [S. H\\"ohn ${\\it et~al}.$, ${\\it Phys. Rev. Lett.}$ $\\textbf{114}$, 178101 (2015)] to be well described by the deformations of an elastic shell under local variations of its intrinsic curvatures and stretches, although the detailed mechanics of the process have remained unclear. Through a combination of asymptotic analysis and numerical studies of the bifurcation behavior, we illustrate how appropriate local deformations can overcome global constraints to initiate inversion.
Heat transfer between elastic solids with randomly rough surfaces
B. N. J. Persson; B. Lorenz; A. I. Volokitin
2009-08-27
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.
Derivation of the Camassa-Holm equations for elastic waves
H. A. Erbay; S. Erbay; A. Erkip
2015-02-10
In this paper we provide a formal derivation of both the Camassa-Holm equation and the fractional Camassa-Holm equation for the propagation of small-but-finite amplitude long waves in a nonlocally and nonlinearly elastic medium. We first show that the equation of motion for the nonlocally and nonlinearly elastic medium reduces to the improved Boussinesq equation for a particular choice of the kernel function appearing in the integral-type constitutive relation. We then derive the Camassa-Holm equation from the improved Boussinesq equation using an asymptotic expansion valid as nonlinearity and dispersion parameters tend to zero independently. Our approach follows mainly the standard techniques used widely in the literature to derive the Camassa-Holm equation for shallow water waves. The case where the Fourier transform of the kernel function has fractional powers is also considered and the fractional Camassa-Holm equation is derived using the asymptotic expansion technique.
General elastic interaction in nematic liquid crystals colloids
S. B. Chernyshuk; B. I. Lev
2009-07-29
The new free energy functional that describes general elastic interaction between colloidal particles and nematic liquid crystal has been proposed. It generalizes results of the paper \\cite{lupe} on the case of arbitrary orientation of colloidal particles and is valid for arbitrary surface anchoring strength. Formal analogies and differences between electric particles and colloidal particles in LC are found. It is first time shown that spur of the quadrupole moment tensor is different from zero $Sp\\hat{Q}_{\\mu}\
Broader source: Energy.gov [DOE]
This scenario provides the planning instructions, guidance, and evaluation forms necessary to conduct an exercise involving a highway shipment of a soil moisture/density gauge (Class 7 -...
Nuclear Level Density: Shell Model vs Mean Field
Sen'kov, Roman
2015-01-01
The knowledge of the nuclear level density is necessary for understanding various reactions including those in the stellar environment. Usually the combinatorics of Fermi-gas plus pairing is used for finding the level density. Recently a practical algorithm avoiding diagonalization of huge matrices was developed for calculating the density of many-body nuclear energy levels with certain quantum numbers for a full shell-model Hamiltonian. The underlying physics is that of quantum chaos and intrinsic thermalization in a closed system of interacting particles. We briefly explain this algorithm and, when possible, demonstrate the agreement of the results with those derived from exact diagonalization. The resulting level density is much smoother than that coming from the conventional mean-field combinatorics. We study the role of various components of residual interactions in the process of thermalization, stressing the influence of incoherent collision-like processes. The shell-model results for the traditionally...
Nuclear Energy Density Functionals: What do we really know?
Bulgac, Aurel; Jin, Shi
2015-01-01
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...
Krishichayan,; Chen, X.; Lui, Y.-W.; Button, J.; Youngblood, D. H. [Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States)
2010-04-15
Elastic and inelastic scattering of 240-MeV {sup 6}Li particles from {sup 40}Ca and {sup 48}Ca were measured with the multipole-dipole-multipole spectrometer from 4 deg. <=theta{sub c.m.}<=40 deg. Optical potential parameters were obtained by fitting the elastic-scattering data with the double-folding model using the density-dependent M3Y NN effective interaction and B(E2) and B(E3) values obtained for low-lying 2{sup +} and 3{sup -} states agreed with the adopted values. The results are compared with those obtained using potentials derived from the systematics of potentials previously obtained for {sup 24}Mg, {sup 28}Si, {sup 58}Ni, and {sup 90}Zr. Cross sections for excitation of giant resonances were also calculated with the potentials obtained.
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
2013-07-29
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.
'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)
2009-11-15
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.
Capillary adhesion between elastic solids with randomly rough surfaces
B. N. J. Persson
2008-05-06
I study how the contact area and the work of adhesion, between two elastic solids with randomly rough surfaces, depend on the relative humidity. The surfaces are assumed to be hydrophilic, and capillary bridges form at the interface between the solids. For elastically hard solids with relative smooth surfaces, the area of real contact and therefore also the sliding friction, are maximal when there is just enough liquid to fill out the interfacial space between the solids, which typically occurs for $d_{\\rm K} \\approx 3 h_{\\rm rms}$, where $d_{\\rm K}$ is the height of the capillary bridge and $h_{\\rm rms}$ the root-mean-square roughness of the (combined) surface roughness profile. For elastically soft solids, the area of real contact is maximal for very low humidity (i.e., small $d_{\\rm K}$), where the capillary bridges are able to pull the solids into nearly complete contact. In both case, the work of adhesion is maximal (and equal to $2\\gamma {\\rm cos}\\theta$, where $\\gamma$ is the liquid surface tension and $\\theta$ the liquid-solid contact angle) when $d_{\\rm K} >> h_{\\rm rms}$, corresponding to high relative humidity.
Stability boundaries for wrinkling in highly stretched elastic sheets
Qingdu Li; Timothy J. Healey
2015-09-14
We determine stability boundaries for the wrinkling of highly uni-directionally stretched, finely thin, rectangular elastic sheets. For a given fine thickness and length, a stability boundary here is a curve in the parameter plane, aspect ratio vs. the macroscopic strain; the values on one side of the boundary are associated with a flat, unwrinkled state, while wrinkled configurations correspond to all values on the other. In our recent work we demonstrated the importance of finite elasticity in the membrane part of such a model in order to capture the correct phenomena. Here we present and compare results for four distinct models:(i) the popular F\\"oppl-von K\\'arm\\'an plate model (FvK), (ii) a correction of the latter, used in our earlier work, in which the approximate 2D F\\"oppl strain tensor is replaced by the exact Green strain tensor, (iii) and (iv): effective 2D finite-elasticity membrane models based on 3D incompressible neo-Hookean and Mooney-Rivlin materials, respectively. In particular, (iii) and (iv) are superior models for elastomers. The 2D nonlinear, hyperelastic models (ii)-(iv) all incorporate the same quadratic bending energy used in FvK. Our results illuminate serious shortcomings of the latter in this problem, while also pointing to inaccuracies of model (ii), in spite of yielding the correct qualitative phenomena in our earlier work. In each of these, the shortcoming is a due to a deficiency of the membrane part of the model.
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
2015-05-20
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.
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
The G0 Collaboration; D. Androi?; D. S. Armstrong; J. Arvieux; S. L. Bailey; D. H. Beck; E. J. Beise; J. Benesch; F. Benmokhtar; L. Bimbot; J. Birchall; P. Bosted; H. Breuer; C. L. Capuano; Y. -C. Chao; A. Coppens; C. A. Davis; C. Ellis; G. Flores; G. Franklin; C. Furget; D. Gaskell; M. T. W. Gericke; J. Grames; G. Guillard; J. Hansknecht; T. Horn; M. K. Jones; P. M. King; W. Korsch; S. Kox; L. Lee; J. Liu; A. Lung; J. Mammei; J. W. Martin; R. D. McKeown; A. Micherdzinska; M. Mihovilovic; H. Mkrtchyan; M. Muether; S. A. Page; V. Papavassiliou; S. F. Pate; 10 S. K. Phillips; P. Pillot; M. L. Pitt; M. Poelker; B. Quinn; W. D. Ramsay; J. -S. Real; J. Roche; P. Roos; J. Schaub; T. Seva; N. Simicevic; G. R. Smith; D. T. Spayde; M. Stutzman; R. Suleiman; V. Tadevosyan; W. T. H. van Oers; M. Versteegen; E. Voutier; W. Vulcan; S. P. Wells; S. E. Williamson; S. A. Wood; B. Pasquini; M. Vanderhaeghen
2011-06-16
We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (piN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasi-static deuterium approximation, and is also in agreement with theory.
Magnetic confinement of a high-density cylindrical plasma Eduardo Ahedoa)
Carlos III de Madrid, Universidad
collisional plasma column, confined by an axial magnetic field and a cylindrical vessel, is studiedMagnetic confinement of a high-density cylindrical plasma Eduardo Ahedoa) E. T. S. Ingenieros the independent influence of the applied magnetic field and the plasma density on the plasma response. The strong
Constraining the gravitational wave energy density of the Universe using Earth's ring
Coughlin, Michael
2014-01-01
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...
Phenomenological Relativistic Energy Density Functionals
Lalazissis, G. A.; Kartzikos, S.; Niksic, T.; Paar, N.; Vretenar, D.; Ring, P.
2009-08-26
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.
Zinin, Pavel V.; Burgess, Katherine; Jia, Ruth; Sharma, Shiv; Ming, Li-Chung; Liu, Yongsheng; Ciston, Jim; Hong, Shiming
2014-10-07
Dense BC{sub x} phases with high boron concentration are predicted to be metastable, superhard, and conductors or superconductors depending on boron concentration. However, up to this point, diamond-like boron rich carbides BC{sub x} (dl-BC{sub x}) phases have been thought obtainable only through high pressure and high temperature treatment, necessitating small specimen volume. Here, we use electron energy loss spectroscopy combined with transmission electron microscopy, Raman spectroscopy, surface Brillouin scattering, laser ultrasonics (LU) technique, and analysis of elastic properties to demonstrate that low pressure synthesis (chemical vapor deposition) of BC{sub x} phases may also lead to the creation of diamond-like boron rich carbides. The elastic properties of the dl-BC{sub x} phases depend on the carbon sp²versus sp³ content, which decreases with increasing boron concentration, while the boron bonds determine the shape of the Raman spectra of the dl-BC{sub x} after high pressure-high temperature treatment. Using the estimation of the density value based on the sp³ fraction, the shear modulus ? of dl-BC?, containing 10% carbon atoms with sp³ bonds, and dl-B?C?, containing 38% carbon atoms with sp³ bonds, were found to be ? = 19.3 GPa and ? = 170 GPa, respectively. The presented experimental data also imply that boron atoms lead to a creation of sp³ bonds during the deposition processes.
Sermeus, J.; Glorieux, C.; Sinha, R.; Vereecken, P. M.; Vanstreels, K.
2014-07-14
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.
Luther-Emery Phase and Atomic-Density Waves in a Trapped Fermion Gas
Gao Xianlong; Rizzi, M.; Polini, Marco; Tosi, M. P.; Fazio, Rosario; Campo, V. L. Jr.; Capelle, K.
2007-01-19
The Luther-Emery liquid is a state of matter that is predicted to occur in one-dimensional systems of interacting fermions and is characterized by a gapless charge spectrum and a gapped spin spectrum. In this Letter we discuss a realization of the Luther-Emery phase in a trapped cold-atom gas. We study by means of the density-matrix renormalization-group technique a two-component atomic Fermi gas with attractive interactions subject to parabolic trapping inside an optical lattice. We demonstrate how this system exhibits compound phases characterized by the coexistence of spin pairing and atomic-density waves. A smooth crossover occurs with increasing magnitude of the atom-atom attraction to a state in which tightly bound spin-singlet dimers occupy the center of the trap. The existence of atomic-density waves could be detected in the elastic contribution to the light-scattering diffraction pattern.
Integral identities for a semi-infinite interfacial crack in 2D and 3D elasticity
Piccolroaz, Andrea
2011-01-01
The paper is concerned with the problem of a semi-infinite crack at the interface between two dissimilar elastic half-spaces, loaded by a general asymmetrical system of forces distributed along the crack faces. On the basis of the weight function approach and the fundamental reciprocal identity (Betti formula), we formulate the elasticity problem in terms of singular integral equations relating the applied loading and the resulting crack opening. Such formulation is fundamental in the theory of elasticity and extensively used to solve several problems in linear elastic fracture mechanics (for instance various classic crack problems in homogeneous and heterogeneous media). This formulation is also crucial in important recent multiphysics applications, where the elastic problem is coupled with other concurrent physical phenomena. A paradigmatic example is hydraulic fracturing, where the elasticity equations are coupled with fluid dynamics.
Integral identities for a semi-infinite interfacial crack in 2D and 3D elasticity
Andrea Piccolroaz; Gennady Mishuris
2012-06-06
The paper is concerned with the problem of a semi-infinite crack at the interface between two dissimilar elastic half-spaces, loaded by a general asymmetrical system of forces distributed along the crack faces. On the basis of the weight function approach and the fundamental reciprocal identity (Betti formula), we formulate the elasticity problem in terms of singular integral equations relating the applied loading and the resulting crack opening. Such formulation is fundamental in the theory of elasticity and extensively used to solve several problems in linear elastic fracture mechanics (for instance various classic crack problems in homogeneous and heterogeneous media). This formulation is also crucial in important recent multiphysics applications, where the elastic problem is coupled with other concurrent physical phenomena. A paradigmatic example is hydraulic fracturing, where the elasticity equations are coupled with fluid dynamics.
Energy Dependence of the NN t-matrix in the Optical Potential for Elastic Nucleon-Nucleus Scattering
Ch. Elster; S. P. Weppner
1997-08-07
The influence of the energy dependence of the free NN t-matrix on the optical potential of nucleon-nucleus elastic scattering is investigated within the context of a full-folding model based on the impulse approximation. The treatment of the pole structure of the NN t-matrix, which has to be taken into account when integrating to negative energies is described in detail. We calculate proton-nucleus elastic scattering observables for $^{16}$O, $^{40}$Ca, and $^{208}$Pb between 65 and 200 MeV laboratory energy and study the effect of the energy dependence of the NN t-matrix. We compare this result with experiment and with calculations where the center-of-mass energy of the NN t-matrix is fixed at half the projectile energy. It is found that around 200 MeV the fixed energy approximation is a very good representation of the full calculation, however deviations occur when going to lower energies (65 MeV).
Dirt Softens Soap: Anomalous Elasticity of Disordered Smectics
Leo Radzihovsky; John Toner
1997-08-01
We show that a smectic in a disordered medium (e.g., aerogel) exhibits anomalous elasticity, with the compression modulus B(k) vanishing and the bend modulus K(k) diverging as k --> 0. In addition, the effective disorder develops long ranged correlations. These divergences are much stronger than those driven by thermal fluctuations in pure smectics, and are controlled by a zero temperature glassy fixed point, which we study in an $\\epsilon=5-d$ expansion. We discuss the experimental implications of these theoretical predictions.
Elastic moderation of intrinsically applied tension in lipid membranes
Michael A. Lomholt; Bastien Loubet; John H. Ipsen
2010-10-20
Tension in lipid membranes is often controlled externally, by pulling on the boundary of the membrane or changing osmotic pressure across a curved membrane. But modifications of the tension can also be induced in an internal fashion, for instance as a byproduct of changing a membranes electric potential or, as observed experimentally, by activity of membrane proteins. Here we develop a theory which demonstrate how such internal contributions to the tension are moderated through elastic stretching of the membrane when the membrane is initially in a low tension floppy state.
Anomalous dynamics of an elastic membrane in an active fluid
S. A. Mallory; C. Valeriani; A. Cacciuto
2015-05-06
Using numerical simulations, we characterized the behavior of an elastic membrane immersed in an active fluid. Our findings reveal a nontrivial folding and re-expansion of the membrane that is controlled by the interplay of its resistance to bending and the self-propulsion strength of the active components in solution. We show how flexible membranes tend to collapse into multi-folded states, whereas stiff membranes oscillates between an extended configuration and a singly folded state. This study provides a simple example of how to exploit the random motion of active particles to perform mechanical work at the micro-scale.
Snap buckling of a confined thin elastic sheet
Gaetano Napoli; Stefano S. Turzi
2015-04-20
A growing or compressed thin elastic sheet adhered to a rigid substrate can exhibit a buckling instability, forming an inward hump. Our study shows that the strip morphology depends on the delicate balance between the compression energy and the bending energy. We find that this instability is a first order phase transition between the adhered solution and the buckled solution whose main control parameter is related to the sheet stretchability. In the nearly- unstretchable regime we provide an analytic expression for the critical threshold. Compressibility is the key assumption which allows us to resolve the apparent paradox of an unbounded pressure exerted on the external wall by a confined flexible loop.
Vortex-type elastic structured media and dynamic shielding
Michele Brun; Ian S. Jones; Alexander B. Movchan
2012-01-27
The paper addresses a novel model of metamaterial structure. A system of spinners has been embedded into a two-dimensional periodic lattice system. The equations of motion of spinners are used to derive the expression for the chiral term in the equations describing the dynamics of the lattice. Dispersion of elastic waves is shown to possess innovative filtering and polarization properties induced by the vortextype nature of the structured media. The related homogenised effective behavior is obtained analytically and it has been implemented to build a shielding cloak around an obstacle. Analytical work is accompanied by numerical illustrations.
Spherical Wave Propagation in a Nonlinear Elastic Medium
Korneev, Valeri A.
2009-07-01
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.
Strain fluctuations and elastic moduli in disordered solids
Daniel M. Sussman; Samuel S. Schoenholz; Ye Xu; Tim Still; A. G. Yodh; Andrea J. Liu
2015-08-24
Recently there has been a surge in interest in using video-microscopy techniques to infer the local mechanical properties of disordered solids. One common approach is to minimize the difference between particle vibrational displacements in a local coarse-graining volume and the displacements that would result from a best-fit affine deformation. Effective moduli are then be inferred under the assumption that the components of this best-fit affine deformation tensor have a Boltzmann distribution. In this paper, we combine theoretical arguments with experimental and simulation data to demonstrate that the above does not reveal information about the true elastic moduli of jammed packings and colloidal glasses.
Fluid driven fingering instability of a confined elastic meniscus
Biggins, John S.; Wei, Z.; Mahadevan, L.
2015-04-15
1 > a) and shear modulus µ. Since adhesion is maintained, an in-plane p-1 John S Biggins1, Z Wei2,L Mahadevan2,3 (a) r2r1 elastic layer fluid a z rigid plate (c) (b) (d) afluid elasticlayer Fig. 1: (a) Top-view of the experiment used... -11) numerically to find the fingering threshold and mode without further approximation (see Appendix) but the algebra is cum- bersome. However, the expressions simplify in the limit of thin layers, a #28; r1, a case of much interest. As in the Cartesian geometry...
Elastic octopoles and colloidal structures in nematic liquid crystals
S. B. Chernyshuk; O. M. Tovkach; B. I. Lev
2013-05-14
We propose a simple theoretical model which explains a formation of dipolar 2D and 3D colloidal structures in nematic liquid crystal. Colloidal particles are treated as effective hard spheres interacting via their elastic dipole, quadrupole and octopole moments. It is shown that octopole moment plays an important role in the formation of 2D and 3D nematic colloidal crystals. We generalize this assumption on the case of the external electric field and theoretically explain a giant electrostriction effect in 3D crystals observed recently [A. Nych et al., Nature Communications \\textbf{4}, 1489 (2013)].
Quasi-Elastic Scattering Measurements Morgan Wascko Imperial College London
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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High elastic modulus polymer electrolytes (Patent) | SciTech Connect
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High elastic modulus polymer electrolytes suitable for preventing thermal
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Elasticity of Pu -a window into fundamental understanding and aging
Office of Scientific and Technical Information (OSTI)
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Elasticity of Pu -a window into fundamental understanding and aging
Office of Scientific and Technical Information (OSTI)
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Low density carbonized composite foams
Kong, Fung-Ming (Pleasanton, CA)
1991-01-01
A carbonized composite foam having a density less than about 50 mg/cm.sup.3 and individual cell sizes no greater than about 1 .mu.m in diameter is described, and the process of making it.
Neutralino relic density including coannihilations
Paolo Gondolo; Joakim Edsjo
1997-11-25
We give an overview of our precise calculation of the relic density of the lightest neutralino, in which we included relativistic Boltzmann averaging, subthreshold and resonant annihilations, and coannihilation processes with charginos and neutralinos.
Low density metal hydride foams
Maienschein, Jon L. (Oakland, CA); Barry, Patrick E. (Pleasant Hill, CA)
1991-01-01
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.
Evidence of a Shift in the Short-Run Price Elasticity of Gasoline Demand
Hughes, Jonathan; Knittel, Christopher R; Sperling, Dan
2007-01-01
An Empirical-Analysis of Gasoline Demand in Denmark UsingT. (1991). "Analyzing Gasoline Demand Elasticities: AConsumer Adjustment to a Gasoline Tax." The Review of
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
2004-01-01
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.
Market Share Elasticities for Fuel and Technology Choice in Home Heating and Cooling
Wood, D.J.
2010-01-01
Data. Both fuel prices and capital costs are taken for the2 Price, Income, and Capital Cost Elasticities for Marketby operating and capital costs (or which are otherwise
A Numerical Algorithm for Single Phase Fluid Flow in Elastic Porous Media
Ewing, Richard E.
algorithm. KEYWORDS: geomechanics, uid ow, elastic deformation, porous media 1 Introduction Mechanical, petroleum, and environmental engineering for several decades. While considering the impact of the rock
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)
2000-08-01
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].
Hans, M. Baben, M. to; Music, D.; Ebenhöch, J.; Schneider, J. M.; Primetzhofer, D.; Kurapov, D.; Arndt, M.; Rudigier, H.
2014-09-07
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.
Oscillatory elastic instabilities in an extensional viscoelastic flow
Atul Varshney; Eldad Afik; Yoav Kaplan; Victor Steinberg
2015-10-01
Dilute polymer solutions are known to exhibit purely elastic instabilities even when the fluid inertia is negligible. Here we report the quantitative evidence of two consecutive oscillatory elastic instabilities in an elongation flow of a dilute polymer solution as realized in a T-junction geometry with a long recirculating cavity. The main result reported here is the observation and characterization of the first transition as a forward Hopf bifurcation resulted in a uniformly oscillating state due to breaking of time translational invariance. This unexpected finding is in contrast with previous experiments and numerical simulations performed in similar ranges of the $Wi$ and $Re$ numbers, where the forward fork-bifurcation into a steady asymmetric flow due to the broken spatial inversion symmetry was reported. We discuss the plausible discrepancy between our findings and previous studies that could be attributed to the long recirculating cavity, where the length of the recirculating cavity plays a crucial role in the breaking of time translational invariance instead of the spatial inversion. The second transition is manifested via time aperiodic transverse fluctuations of the interface between the dyed and undyed fluid streams at the channel junction and advected downstream by the mean flow. Both instabilities are characterized by fluid discharge-rate and simultaneous imaging of the interface between the dyed and undyed fluid streams in the outflow channel.
Parity Violation in Forward Angle Elastic Electron-Proton Scattering
Grady Wilson Miller, IV
2001-01-01
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton at Jefferson Laboratory. The kinematic point ({theta}_lab = 12.3 deg. and (Q^2) = 0.48 (GeV/c)^2) is chosen to provide sensitivity to the strange electric form factor G^s_E. A 3.36 GeV beam of longitudinally polarized electrons was scattered from protons in a liquid hydrogen target. The scattered flux was detected by a pair of spectrometers which focussed the elastically-scattered electrons onto total-absorption detectors. The detector signals were integrated and digitized by a custom data acquisition system. A feedback system reduced systematic errors by controlling helicity-correlated beam intensity differences at the sub-ppm (part per million) level. The experimental result, A = 14.5 +/- 2.0 (stat) +/- 1.1 (syst) ppm, is consistent with the electroweak Standard Model with no additional contributions from strange quarks. In particular, the measurement implies G^S_E + 0.39 G^s_M = 0.023 +/- 0.040 +/- 0.026 ({delta}G^n_E), where the last uncertainty is due to the estimated uncertainty in the neutron electric form factor G^n_E . This result represents the first experimental constraint of the strange electric form factor.
Transport of organelles by elastically coupled motor proteins
Deepak Bhat; Manoj Gopalakrishnan
2014-12-17
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.
Thermodynamics of the low density excluded volume hadron gas
Zalewski, Kacper
2015-01-01
We discuss the influence of the excluded volume of hadrons on macroscopic variables and thermal parameters of the hadron gas at finite temperature and chemical potential in the low density approximation. Based solely on elementary thermodynamics we show that when the excluded volume grows at constant temperature, pressure, and number of particles, the overall volume increases just as much as the excluded volume, while the entropy and energy remain unchanged. The growth of the chemical potentials is equal to the work needed to create the respective excluded volumes. Consequently, the bulk density functions of a gas with excluded volume are expressed by the corresponding variables in a system of point particles with the shifted chemical potentials. Our results are fully consistent with the previous findings obtained upon applications of more advanced methods of statistical physics. A validity limit for the low density approximation is derived and discussed in the context of the hadron gas created in heavy ion c...
Thermodynamics of the low density excluded volume hadron gas
Kacper Zalewski; Krzysztof Redlich
2015-07-20
We discuss the influence of the excluded volume of hadrons on macroscopic variables and thermal parameters of the hadron gas at finite temperature and chemical potential in the low density approximation. Based solely on elementary thermodynamics we show that when the excluded volume grows at constant temperature, pressure, and number of particles, the overall volume increases just as much as the excluded volume, while the entropy and energy remain unchanged. The growth of the chemical potentials is equal to the work needed to create the respective excluded volumes. Consequently, the bulk density functions of a gas with excluded volume are expressed by the corresponding variables in a system of point particles with the shifted chemical potentials. Our results are fully consistent with the previous findings obtained upon applications of more advanced methods of statistical physics. A validity limit for the low density approximation is derived and discussed in the context of the hadron gas created in heavy ion collisions.
Magnetic confinement of a high-density cylindrical plasma
Ahedo, Eduardo [E. T. S. Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Madrid 28040 (Spain)
2011-10-15
The stationary structure of a weakly collisional plasma column, confined by an axial magnetic field and a cylindrical vessel, is studied for the high-density case, when the diamagnetic azimuthal current is large enough to demagnetize partially the plasma. The plasma response is characterized mainly by two dimensionless parameters: the ratios of the electron gyroradius and the electron skin-depth to the plasma radius, and each of them measures the independent influence of the applied magnetic field and the plasma density on the plasma response. The strong magnetic confinement regime, characterized by very small wall losses, is limited to the small gyroradius and large skin-depth ranges. In the high-density case, when the electron skin-depth is smaller than the electron gyroradius, the skin-depth turns out to be the magnetic screening length, so that the bulk of the plasma behaves as unmagnetized.
Comparison of transition densities in the DDHMS model of pre-equilibrium emission
Brito, L.; Carlson, B. V.
2014-11-11
The DDHMS (double differential hybrid Monte Carlo simulation) model treats nucleon-induced pre-equilibrium reactions as a series of particle-particle and particle-hole interactions in the space of energy and angle. This work compares spectra obtained within the model using diferent approximations to the density of accessible states. The calculations are performed with the EMPIRE reaction model code, a modular system containing several nuclear reaction models that permits a fairly complete descritpion of the reaction, from elastic scattering and absorption through the pre-equilbrium stage to the final decay by statistical emission.
Stationary self-focusing of intense laser beam in cold quantum plasma using ramp density profile
Habibi, M.; Ghamari, F.
2012-10-15
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.
Jacek Dobaczewski Density functional theory and energy
Dobaczewski, Jacek
Jacek Dobaczewski Density functional theory and energy density functionals in nuclear physics Jacek UNEDFCollaboration,http://unedf.org/ Universal Nuclear Energy Density FunctionalUniversal Nuclear Energy Density in Poland per voivodship Energy density functional 245 647 Price voivodship functional 654 763 295 580
M. M. Islam; R. J. Luddy
2013-10-28
We study high energy $\\small{\\rm{pp}}$ and $\\small{\\rm{\\bar {p}p}}$ elastic scattering in the TeV region based on an effective field theory model of the proton. We phenomenologically investigate the main processes underlying elastic scattering and quantitatively describe the measured elastic d$\\small{\\sigma}$/dt at energies 7.0 TeV (LHC $\\small{\\rm{pp}}$), 1.96 TeV (Tevatron $\\small{\\rm{\\bar {p}p}}$), and 0.630 TeV (SPS $\\small{\\rm{\\bar {p}p}}$). Finally, we give our prediction for $\\small{\\rm{pp}}$ elastic d$\\small{\\sigma}$/dt at 14 TeV that will be measured by the TOTEM Collaboration.
Light-front representation of chiral dynamics in peripheral transverse densities
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Granados, Carlos G.; Weiss, Christian
2015-07-31
The nucleon's electromagnetic form factors are expressed in terms of the transverse densities of charge and magnetization at fixed light-front time. At peripheral transverse distances b = O(M_pi^{-1}) the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). We represent the leading-order chiral EFT results for the peripheral transverse densities as overlap integrals of chiral light-front wave functions, describing the transition of the initial nucleon to soft pion-nucleon intermediate states and back. The new representation (a) explains the parametric order of the peripheral transverse densities; (b) establishes an inequality between the spin-independentmore »and -dependent densities; (c) exposes the role of pion orbital angular momentum in chiral dynamics; (d) reveals a large left-right asymmetry of the current in a transversely polarized nucleon and suggests a simple interpretation. The light-front representation enables a first-quantized, quantum-mechanical view of chiral dynamics that is fully relativistic and exactly equivalent to the second-quantized, field-theoretical formulation. It relates the charge and magnetization densities measured in low-energy elastic scattering to the generalized parton distributions probed in peripheral high-energy scattering processes. The method can be applied to nucleon form factors of other operators, e.g. the energy-momentum tensor.« less
Light-front representation of chiral dynamics in peripheral transverse densities
C. Granados; C. Weiss
2015-03-16
The nucleon's electromagnetic form factors are expressed in terms of the transverse densities of charge and magnetization at fixed light-front time. At peripheral transverse distances $b = O(M_\\pi^{-1})$ the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). We represent the leading-order chiral EFT results for the peripheral transverse densities as overlap integrals of chiral light-front wave functions, describing the transition of the initial nucleon to soft pion-nucleon intermediate states and back. The new representation (a) explains the parametric order of the peripheral transverse densities; (b) establishes an inequality between the spin-independent and -dependent densities; (c) exposes the role of pion orbital angular momentum in chiral dynamics; (d) reveals a large left-right asymmetry of the current in a transversely polarized nucleon and suggests a simple interpretation. The light-front representation enables a first-quantized, quantum-mechanical view of chiral dynamics that is fully relativistic and exactly equivalent to the second-quantized, field-theoretical formulation. It relates the charge and magnetization densities measured in low-energy elastic scattering to the generalized parton distributions probed in peripheral high-energy scattering processes. The method can be applied to nucleon form factors of other operators, e.g. the energy-momentum tensor.
High-density fluid compositions
Sanders, D.C.
1981-09-29
Clear, high-density fluids suitable for use as well completion, packing, and perforation media comprise aqueous solutions of zinc bromide and calcium bromide having densities lying in the range of about 14.5 up to about 18.0 pounds per gallon and measured PH's lying in the range of about 3.5 up to about 6.0. Optionally, such fluids may also comprise calcium chloride and/or a soluble film-forming amine-based corrosion inhibitor. Such fluids under conditions of ordinary use exhibit low corrosion rates and have crystallization points lying well below the range of temperatures under which they are used.
Matrix Fourier transform in dynamic theory of elasticity of piecewise homogeneous medium
O. Yaremko.; E. Mogileva
2013-09-24
The analytical solving dynamic problems of elasticity theory for piecewise homogeneous half-space is found. The explicit construction of direct and inverse Fourier's vector transform with discontinuous coefficients is presented. The technique of applying Fourier's vector transform with discontinuous coefficients for solving problems of mathematical physics in the heterogeneous environments is developed on an example of the dynamic problems of the elasticity theory.
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
Gasoline price volatility and the elasticity of demand for gasoline1 C.-Y. Cynthia Lina
Lin, C.-Y. Cynthia
- 1 - Gasoline price volatility and the elasticity of demand for gasoline1 C.-Y. Cynthia Lina, California Abstract We examine how gasoline price volatility impacts consumers' price elasticity of demand for gasoline. Results show that volatility in prices decreases consumer demand for gasoline in the intermediate
Alencar, Adriano Mesquita
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
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 caused an elastic uplift of $35 mm at a GPS site in Kulusuk. Most of the uplift results from ice dynamic digital elevation models, contributes about $16 mm of the observed uplift, with an additional $5 mm from
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
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
Revealing highly complex elastic nonlinear (anelastic) behavior of Earth materials applying a new nonlinear (anelastic) behavior of Earth materials applying a new probe: Dynamic acoustoelastic testing, J nonlinear acoustics has led to the development of refined experimental method to measure material elastic
Modal analysis of Lamb wave generation in elastic plates by liquid wedge transducers
Paris 7 - Denis Diderot, Université
Modal analysis of Lamb wave generation in elastic plates by liquid wedge transducers X. Jia Groupe by a variety of methods. For signal processing applications, Lamb waves are generated by using interdigital is presented to describe the excitation of Lamb waves in an elastic plate using a liquid wedge transducer
Estimating the Price Elasticity of Residential Water Demand: The Case of Phoenix, Arizona
Article Estimating the Price Elasticity of Residential Water Demand: The Case of Phoenix, Arizona elasticity of residential water demand in Phoenix, Arizona, which is likely to be strongly impacted to such changes requires understanding the responsiveness of water demand to price changes. We estimate the price
Principles of Software-defined Elastic Systems for Big Data Analytics
Dustdar, Schahram
Principles of Software-defined Elastic Systems for Big Data Analytics Hong-Linh Truong, Schahram}@dsg.tuwien.ac.at Abstract Techniques for big data analytics should support principles of elasticity that are inherent characteristics of big data described through the "four V's of volume, variety, velocity and veracity" [1] have
Future Measurements of the Nucleon Elastic Electromagnetic Form Factors at Jefferson Lab
Gilfoyle, Jerry
Future Measurements of the Nucleon Elastic Electromagnetic Form Factors at Jefferson Lab G.P.Gilfoyle Future Form Factor Measurements p. 1/3 #12;Scientific Motivation Nucleon elastic electromagnetic form violation experiments. G.P.Gilfoyle Future Form Factor Measurements p. 2/3 #12;Scientific Motivation
CONVERGENCE OF NUMERICAL APPROXIMATIONS TO A PHASE FIELD BENDING ELASTICITY MODEL OF
CONVERGENCE OF NUMERICAL APPROXIMATIONS TO A PHASE FIELD BENDING ELASTICITY MODEL OF MEMBRANE, Number 1, Pages 1Â18 CONVERGENCE OF NUMERICAL APPROXIMATIONS TO A PHASE FIELD BENDING ELASTICITY MODEL OF MEMBRANE DEFORMATIONS QIANG DU AND XIAOQIANG WANG This paper is dedicated to Prof.Max Gunzburger
Laboratory measurements of low-and high-frequency elastic moduli in Fontainebleau sandstone
Fortin, Jérôme
Laboratory measurements of low- and high-frequency elastic moduli in Fontainebleau sandstone-saturated sam- ples were much more compliant at low frequencies than at high frequencies. The measured bulk- quency dependent, the elastic behavior observed in the laboratory at "high-frequencies" (MHz) does not
Minimal energy for elastic inclusions By Hans Knupfer and Robert V. Kohn
the emergence of the new phase, the interfacial energy provides an energy barrier for the creation and growthMinimal energy for elastic inclusions By Hans Kn¨upfer and Robert V. Kohn Courant Institute, New problem with a nonlocal term represent- ing elastic energy. More precisely, our aim is to analyse
Learning Price-Elasticity of Smart Consumers in Power Distribution Systems
Gómez, Vicenç
rely on consumers and/or loads responding to exogenous signals, typically in the form of energy pricingLearning Price-Elasticity of Smart Consumers in Power Distribution Systems Vicenc¸ G´omez1, Michael for estimating the price elasticity of many customers comprising a distribution system. We utilize a sparse
Elastic Lennard-Jones polymers meet clusters: Differences and similarities Stefan Schnabel,1,a
Janke, Wolfhard
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
Locally corrected semi-Lagrangian methods for Stokes flow with moving elastic interfaces
Locally corrected semi-Lagrangian methods for Stokes flow with moving elastic interfaces J. Thomas interfaces that respond elastically to stretching. The interface is moved by semi- Lagrangian contouring: a distance function is introduced on a tree of cells near the interface, transported by a semi
Inclusions on Fluid Membranes Anchored to Elastic Media M. S. Turner*#
Sens, Pierre
, Rockefeller University, New York, New York 10021 USA; and § Institut Charles Sadron, 67083 Strasbourg, France elastic medium. We use this as a simple model for the plasma membrane of a cell. The atomic force, caveolae, and similar membrane invaginations. The breakdown of linear elastic response, as observed by AFM
Time Dependent Density Functional Theory An introduction
Botti, Silvana
Time Dependent Density Functional Theory An introduction Francesco Sottile LSI, Ecole Polytechnique (ETSF) Time Dependent Density Functional Theory Palaiseau, 7 February 2012 1 / 32 #12;Outline 1 Frontiers 4 Perspectives and Resources Francesco Sottile (ETSF) Time Dependent Density Functional Theory
Statistical density modification using local pattern matching
Terwilliger, Thomas C.
2007-01-23
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.
Daniel, L., E-mail: laurent.daniel@u-psud.fr [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); LGEP (CNRS UMR8507, SUPELEC, UPMC, Univ Paris-Sud), 91192 Gif sur Yvette cedex (France); Hall, D. A.; Withers, P. J. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Webber, K. G. [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); King, A. [European Synchrotron Radiation Facility (ESRF), 6 rue J. Horowitz, 38043 Grenoble (France); Synchrotron SOLEIL, BP 48, 91192 Gif sur Yvette cedex (France)
2014-05-07
High energy x-ray diffraction measurements of lattice strains were performed on a rhombohedral Lead Zirconate Titanate ceramic (PZT 55-45) under combinations of applied electric field and compressive stress. These measurements allow the construction of blocking stress curves for different sets of crystallographic orientations which reflect the single crystal elastic anisotropy. A micro-mechanical interpretation of the results is then proposed. Assuming cubic symmetry for the crystalline elastic stiffness tensor and isotropy for the macroscopic elastic properties, the elastic properties of the single crystal are extracted from the measured data. An anisotropy ratio close to 0.3 is found (compared to 1 for isotropic materials). The high level of anisotropy found in this work suggests that crystalline elastic anisotropy should not be neglected in the modelling of ferroelectric materials.
The Role of Architecture in the Elastic Response of Semiflexible Polymer and Fiber Networks
Claus Heussinger; Erwin Frey
2007-01-18
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.
Elastic Fidelity: Trading-off Computational Accuracy for Energy Reduction
Roy, Sourya; Faisal, S M; Liu, Ke; Hardavellas, Nikos; Parthasarathy, Srinivasan
2011-01-01
Power dissipation and energy consumption have become one of the most important problems in the design of processors today. This is especially true in power-constrained environments, such as embedded and mobile computing. While lowering the operational voltage can reduce power consumption, there are limits imposed at design time, beyond which hardware components experience faulty operation. Moreover, the decrease in feature size has led to higher susceptibility to process variations, leading to reliability issues and lowering yield. However, not all computations and all data in a workload need to maintain 100% fidelity. In this paper, we explore the idea of employing functional or storage units that let go the conservative guardbands imposed on the design to guarantee reliable execution. Rather, these units exhibit Elastic Fidelity, by judiciously lowering the voltage to trade-off reliable execution for power consumption based on the error guarantees required by the executing code. By estimating the accuracy r...
NN inversion potentials intermediate energy proton-nucleus elastic scattering
Arellano, H.F.; Brieva, F.A.; Love, W.G.; Geramb, H.V. von
1995-10-01
Recently developed nucleon-nucleon interactions using the quantum inverse scattering method shed new fight on the off-shell properties of the internucleon effective force for nucleon-nucleus scattering. Calculations of proton elastic scattering from {sup 40}Ca and {sup 208}Pb in the 500 MeV region show that variations in off-shell contributions are determined to a great extent by the accuracy with which the nucleon-nucleon phase shifts are reproduced. The study is based on the full-folding approach to the nucleon-nucleus optical potential which allows a deep understanding of the interplay between on- and off-shell effects in nucleon scattering. Results and the promising extension offered by the inversion potentials beyond the range of validity of the low-energy internucleon forces will be discussed.
Flavor decomposition of the elastic nucleon electromagnetic form factors
C.D. Cates, C.W. Jager, S. Riordan, B. Wojtsekhowski
2011-06-01
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.
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)
2011-10-28
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.
Extracting forward strong amplitudes from elastic differential cross sections
Chen, C M; Johnson, M B; Johnson, Mikkel B.
2001-01-01
The feasibility of a model-independent extraction of the forward strong amplitude from elastic nuclear cross section data in the Coulomb-nuclear interference region is assessed for $\\pi$ and $K^+$ scattering at intermediate energies. Theoretically-generated "data" are analyzed to provide criteria for optimally designing experiments to measure these amplitudes, whose energy dependence (particularly that of the real parts) is needed for disentangling various sources of medium modifications of the projectile-nucleon interaction. The issues considered include determining the angular region over which to make the measurements, the role of the most forward angles measured, and the effects of statistical and systematic errors. We find that there is a region near the forward direction where Coulomb-nuclear interference allows reliable extraction of the strong forward amplitude for both pions and the $K^+$ from .3 to 1 GeV/c.
Extracting forward strong amplitudes from elastic differential cross sections
C. M. Chen; D. J. Ernst; Mikkel B. Johnson
2001-07-11
The feasibility of a model-independent extraction of the forward strong amplitude from elastic nuclear cross section data in the Coulomb-nuclear interference region is assessed for $\\pi$ and $K^+$ scattering at intermediate energies. Theoretically-generated "data" are analyzed to provide criteria for optimally designing experiments to measure these amplitudes, whose energy dependence (particularly that of the real parts) is needed for disentangling various sources of medium modifications of the projectile-nucleon interaction. The issues considered include determining the angular region over which to make the measurements, the role of the most forward angles measured, and the effects of statistical and systematic errors. We find that there is a region near the forward direction where Coulomb-nuclear interference allows reliable extraction of the strong forward amplitude for both pions and the $K^+$ from .3 to 1 GeV/c.
Mao, Chunliu
2012-02-14
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...
About density functional theory interpretation
Kirill Koshelev
2015-05-28
Two forms of relativistic density functional are derived from Dirac equation. Based on their structure analysis model of split electron is proposed. In this model electric charge and mass of electron behave like two point-like particles. It is shown that two electrons obeying this model cannot occupy the same quantum state. Empirical verification of the model is discussed.
Longitudinal polarized parton densities updated
Leader, Elliot; Sidorov, Aleksander V.; Stamenov, Dimiter B. [Imperial College, Prince Consort Road, London SW7 2BW (United Kingdom); Bogoliubov Theoretical Laboratory Joint Institute for Nuclear Research 141980 Dubna (Russian Federation); Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences Blvd. Tsarigradsko Chaussee 72, Sofia 1784 (Bulgaria)
2006-02-01
We have reanalyzed the world data on inclusive polarized DIS, in both NLO and LO QCD, including the new HERMES and COMPASS data. The updated NLO polarized densities are given in both the MS and JET schemes. The impact of the new data on the results is discussed.
Fujiwara, Y. Nakamiya, A.; Sakakita, H.; Innovative Plasma Technologies Group, National Institute of Advanced Industrial Science and Technology , Ibaraki ; Hirano, Y.; Laboratory of Physics, College of Science and Technologies, Nihon University, Tokyo ; Kiyama, S.; Koguchi, H.
2014-02-15
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.
The Elasticity of Demand for Gasoline in China1 C.-Y. Cynthia Lin, Jieyin (Jean) Zeng
Lin, C.-Y. Cynthia
The Elasticity of Demand for Gasoline in China1 C.-Y. Cynthia Lin, Jieyin (Jean) Zeng Department the price and income elasticities of demand for gasoline in China. Our estimates of the intermediate-run price elasticity of gasoline demand range between -0.497 and -0.196, and our estimates
Beckermann, Christoph
and distortions in steel casting are particularly sensitive to the elastic modulus of the sand mold. The objective1 Measurement of Elastic Modulus of PUNB Bonded Sand as a Function of Temperature J. Thole and C Measurements of the elastic modulus of PUNB bonded silica sand are performed using a three-point bend test from
Jackson, Jennifer M.
2005-01-01
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
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
Density Functional Theory (DFT) Rob Parrish
Sherrill, David
· References 2 #12;Wavefunction Approach 3 Hydrogen 421 Wavefunction at Density Isosurface. Really hard to find Easy to do this Why? Because of Hermitian Operators: Kinetic Energy Density: #12;Density Functional Approach 4 Hydrogen 421 Density (Why is it grayscale?) A bit less obvious Probably easier to find
Updated Axion CDM energy density
Ji-Haeng Huh
2008-10-08
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.
Constraining the gravitational wave energy density of the Universe using Earth's ring
Michael Coughlin; Jan Harms
2014-06-04
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.
Balanced homodyne detectors and Casimir energy densities
P. Marecki
2008-03-22
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.
Density variations and anomalies in palladium compacts
Back, D.; Jones, T.; Ransick, M.; Walburg, T.; Werkmeister, D.
1992-05-14
Low-density compacts of palladium powder have relative densities of about 30{plus minus}10% TD. The variations in density are of concern for operations such as chemical/hydrogen pump systems because heat, mass, and momentum transport properties can be affected. Variations in density result from the inherent nature and interacting forces of UASA compaction of powder in cylinders. In addition to these expected variations, discontinuous density anomalies, such as cracks or high density ridges, are also found. An anomaly of particular concern was found to resemble a steer's head.'' it is a symmetrical region of low density located at or near the center of a compact. Typically, this region is surrounded by a band of high density, compacted palladium that sometimes exceeds the density of the surrounding compact matrix by a factor of three. This report examines these density variations and anomalies both theoretically and empirically.
Density variations and anomalies in palladium compacts
Back, D.; Jones, T.; Ransick, M.; Walburg, T.; Werkmeister, D.
1992-05-14
Low-density compacts of palladium powder have relative densities of about 30{plus_minus}10% TD. The variations in density are of concern for operations such as chemical/hydrogen pump systems because heat, mass, and momentum transport properties can be affected. Variations in density result from the inherent nature and interacting forces of UASA compaction of powder in cylinders. In addition to these expected variations, discontinuous density anomalies, such as cracks or high density ridges, are also found. An anomaly of particular concern was found to resemble a ``steer`s head.`` it is a symmetrical region of low density located at or near the center of a compact. Typically, this region is surrounded by a band of high density, compacted palladium that sometimes exceeds the density of the surrounding compact matrix by a factor of three. This report examines these density variations and anomalies both theoretically and empirically.
Probability distribution of the vacuum energy density
Duplancic, Goran; Stefancic, Hrvoje; Glavan, Drazen
2010-12-15
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.
Density functional theory of freezing: Analysis of crystal density
Laird, Brian Bostian; McCoy, John D.; Haymet, A. D. J.
1987-09-01
the natural variables are temperature, chemical potential, and volume. The pressures are set equal by varying the liquid density until the grand thermodynamic potential, flO = - pV /kT, of the solid phase equals that of the liquid phase. It should... with temperature T, volume V, and chemical potential J.L. The particles interact via a potential energy U(rl, ... ,rn ) and feel an external single particle potential ifJ (r). Defining a dimen sionless single particle effective potential by u (r) = pJ.L - pif...
elastic wave propagation in media with parallel fractures and ...
M . SCHOENBERG2 and J . DOUMA
2002-02-14
A model of parallel slip interfaces simulates the behaviour of a fracture system composed of large, closely .... Note that when the ith constituent layer is isotropic, c44i = c66i = pi, clli = c,,~ = ,Ii + 2pi and .... Thus (14) becomes. Define the .... system's characteristic properties, such as crack size, crack density or the contents of.
Elastic Neutron Scattering at 96 MeV
Hildebrand, A.; Blomgren, J.; Atac, A.; Bergenwall, B.; Johansson, C.; Klug, J.; Mermod, P.; Nilsson, L.; Pomp, S.; Esterlund, M.; Dangtip, S.; Tippawan, U.; Phansuke, P.; Jonsson, O.; Renberg, P.-U.; Prokofiev, A.; Nadel-Turonski, P.; Elmgren, K.; Olsson, N.; Blideanu, V.
2005-05-24
A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20 - 180-MeV neutron beam line of The Svedberg Laboratory, Uppsala. Elastic neutron scattering from 12C, 16O, 56Fe, 89Y, and 208Pb has been studied at 96 MeV in the 10-70 deg. interval. The results from 12C and 208Pb have recently been published,6 while the data from 16O, 56Fe, and 89Y are under analysis. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated normalization uncertainty, 3%, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic theory. Applications for these measurements are nuclear-waste incineration, single-event upsets in electronics, and fast-neutron therapy.
Double porosity modeling in elastic wave propagation for reservoir characterization
Berryman, J. G., LLNL
1998-06-01
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.
Benchmark calculations for elastic fermion-dimer scattering
Shahin Bour; H. -W. Hammer; Dean Lee; Ulf-G. Meißner
2012-06-08
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.
Small angle elastic scattering of protons off of spinless nuclei
Ling, A.G.
1988-07-01
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.
Turbulence elasticity—A new mechanism for transport barrier dynamics
Guo, Z. B.; Diamond, P. H.; Kosuga, Y.; Gürcan, Ö. D.
2014-09-15
We present a new, unified model of transport barrier formation in “elastic” drift wave-zonal flow (DW-ZF) turbulence. A new physical quantity—the delay time (i.e., the mixing time for the DW turbulence)—is demonstrated to parameterize each stage of the transport barrier formation. Quantitative predictions for the onset of limit-cycle-oscillation (LCO) among DW and ZF intensities (also denoted as I-mode) and I-mode to high-confinement mode (H-mode) transition are also given. The LCO occurs when the ZF shearing rate (|?v?{sub ZF}{sup ?}|) enters the regime ??{sub k}<|?V?{sub ZF}{sup ?}|?{sub cr}{sup ?1}, where the mean E?×?B shear flow driven by ion pressure “locks” the DW-ZF system to the H-mode by reducing the delay time below the threshold value.
Test method Evaluating the influence of contacting fluids on polyethylene
Thompson, Michael
Test method Evaluating the influence of contacting fluids on polyethylene using acoustic emissions emissions Polyethylene Penetrant Toluene Aqueous detergent a b s t r a c t Identifying microstructural) on the structure of a semi-crystalline polymer (high density polyethylene, HDPE) over different periods of exposure
Rock Density | Open Energy Information
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Nuclear Level Density: Shell Model vs Mean Field
Roman Sen'kov; Vladimir Zelevinsky
2015-08-15
The knowledge of the nuclear level density is necessary for understanding various reactions including those in the stellar environment. Usually the combinatorics of Fermi-gas plus pairing is used for finding the level density. Recently a practical algorithm avoiding diagonalization of huge matrices was developed for calculating the density of many-body nuclear energy levels with certain quantum numbers for a full shell-model Hamiltonian. The underlying physics is that of quantum chaos and intrinsic thermalization in a closed system of interacting particles. We briefly explain this algorithm and, when possible, demonstrate the agreement of the results with those derived from exact diagonalization. The resulting level density is much smoother than that coming from the conventional mean-field combinatorics. We study the role of various components of residual interactions in the process of thermalization, stressing the influence of incoherent collision-like processes. The shell-model results for the traditionally used parameters are also compared with standard phenomenological approaches.
Modeling the elastic and plastic response of single crystals and polycrystalline aggregates
Patwardhan, Parag Vilas
2005-02-17
Understanding the elastic-plastic response of polycrystalline materials is an extremely difficult task. A polycrystalline material consists of a large number of crystals having different orientations. On its own, each ...
An Analysis of the Price Elasticity of Demand for Household Appliances
Dale, Larry
2008-01-01
and Appliance Price………………………………6 LIST OF TABLES Table 1.1estimates in this table. 7 Average brand price elasticityTable 2.2 Appliance Refrigerators Clothes Washers Dishwashers Economic Variables Price
Krauklis wave in a stack of alternating fluid-elastic layers
Korneev, V.A.
2013-01-01
of Stoneley guided wave reflection and scattering at theH. B. Helle, 1993, Slow wave in oil-saturated layer: 55thmodeling of elastic wave dispersion and attenuation in
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
Aranibar Fernandez, Alvaro A
2015-01-05
Organic Content (TOC), fluid saturation, volumetric concentrations of mineral constituents, and elastic properties facilitated identification of different rock classes, using an unsupervised artificial neural network. A good rock classification technique...
Numerical modeling of elastic wave scattering by near-surface heterogeneities
Al Muhaidib, Abdulaziz
2013-01-01
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 ...
Curvature Condensation and Bifurcation in an Elastic Shell Moumita Das,1
Kudrolli, Arshad
ordered and partially ordered bulk condensed matter systems such as crystals, liquid crystals, and various context of an everyday example, a thin mylar sheet is bent into a half- cylindrical elastic shell
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 ...
Digital instability of a confined elastic meniscus John S. Bigginsa,b
Mahadevan, L.
failure of the glue joint via cavitation (68). Though these modes of failure have been well documented is an elastic analog of a well- studied classical hydrodynamic free-surface instability associated
Parton-Parton Elastic Scattering and Rapidity Gaps at Tevatron Energies
Vittorio Del Duca; Wai-Keung Tang
1993-08-02
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
1993-08-02
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.
A coupled theory for diffusion of hydrogen and large elastic-plastic deformations of metals
Di Leo, Claudio V
2012-01-01
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 ...
A method for measuring non-linear elastic properties of thermal barrier coatings
Johnson, C.A.; Ruud, J.A.; Kaya, A.C.; deLorenzi, H.G.
1995-06-01
Accurate characterization of the elastic properties of thermal barrier coatings (TBC`s) is important for failure prediction. Thermally sprayed coatings often exhibit anisotropic and nonlinear elastic properties due to the coating microstructure that results from the thermal spray process. A method was developed for determining the elastic behavior of TBC`s on substrates by measuring the in-plane modulus as a function of residual coating stress. The in-plane modulus was determined by resonant frequency measurement, and the residual stress was measured from the substrate curvature. The residual stress was varied both by increasing the temperature of the TBC and substrate and by applying compressive plastic strain to the metal substrate. The stress-strain behavior of the TBC was derived from the data for modulus versus residual stress, and significant nonlinear elastic behavior was observed.
Design, prototyping and preliminary testing of an elastic-powered climbing exoskeleton
Briner, Hazel (Hazel Linn)
2011-01-01
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 ...
Fast proton hopping detection in ice I{sub h} by quasi-elastic...
Office of Scientific and Technical Information (OSTI)
Journal Article: Fast proton hopping detection in ice Isub h by quasi-elastic neutron scattering. Citation Details In-Document Search Title: Fast proton hopping detection in ice...
Chu, Shih-I; Dalgarno, A.
1975-08-01
The effective close-coupling method of Rabitz is tested and used to calculate the angular distributions of the elastic and inelastic scattering of molecular hydrogen in collision with atomic hydrogen when rotational transitions may occur...
Lawrence, Shawn A. (Shawn Adam), 1975-
2003-01-01
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 ...
Finite element analysis of elastic interaction of two en echelon overlapping faults
Leem, Junghun
1995-01-01
on the faults. Attention is focuses on the role of variable fault spacing and overlap for constant far-field compressive principal stresses. The linear elastic, isotropic, plane strain, finite element analyses are obtained. The basic modeling approach...
Faghih, Ali
2011-01-01
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 ...
Elastic laboratory measurements and modeling of saturated basalts Ludmila Adam,1,2
Boise State University
the elastic behavior of basalt is important to seismically monitor volcanoes, subsea basalts, and carbon. Monitor- ing fluid substitution in basalts with seismic waves can be extended to volcanoes and subsea
Shyam, Amit; Lara-Curzio, Edgar
2009-01-01
Mechanical properties of plasma sprayed ceramic coatings are extremely important to engine design. However, the determination of these properties is often difficult because of the unique and complicated microstructure of the coatings. In this presentation the determination of the elastic constants of plasma sprayed Yttria stabilized Zirconia thermal barrier coatings using resonant ultrasound spectroscopy will be described along with an analysis that enables the determination of the elastic constants as a function of temperature and coating direction. In this work, results on the following issues will be discussed: 1) the elastic anisotropy of thermal barrier coatings, which is associated with coating failure modes; 2) sintering effects on coating compliance comparing with thermal behavior, which is important to coating performance on engineering structures, such as turbine engines; 3) coating elastic modulus at high temperatures close to the service condition, which provides insights of coating mechanical behavior in both fundamental and practical studies.
Failure Stress and Apparent Elastic Modulus of Diesel Particulate Filter Ceramics
Broader source: Energy.gov [DOE]
Three established mechanical 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.
Paris 7 - Denis Diderot, Université
interest but also of practical impor- tance in many fields, including soil mechanics and geophys- ics. Unlike consolidated porous materials such as sedimen- tary rocks, soils, and sintered bead packs, dry inhomogeneous force network 16 . The mechanical properties of such materials depend strongly on both
Measurements of the Deuteron Elastic Structure Function A(Q{sup 2}) at Jefferson Lab
Gerassimos Petratos
1999-06-01
Measurements of the deuteron elastic structure function A(Q{sup 2}) for 0.7 {le} Q{sup 2} {le} 6.0 (GeV/c){sup 2} are reported. The experiment performed elastic electron-deuteron scattering in coincidence, using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models based on the impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark dimensional scaling and perturbative quantum chromodynamics.
Christo I. Christov
2011-03-06
We show that the linearized equations of the incompressible elastic medium admit a `Maxwell form' in which the shear component of the stress vector plays the role of the electric field, and the vorticity plays the role of the magnetic field. Conversely, the set of dynamic Maxwell equations are strict mathematical corollaries from the governing equations of the incompressible elastic medium. This suggests that the nature of `electromagnetic field' may actually be related to an elastic continuous medium. The analogy is complete if the medium is assumed to behave as fluid in shear motions, while it may still behave as elastic solid under compressional motions. Then the governing equations of the elastic fluid are re-derived in the Eulerian frame by replacing the partial time derivatives by the properly invariant (frame indifferent) time rates. The `Maxwell from' of the frame indifferent formulation gives the frame indifferent system that is to replace the Maxwell system. This new system comprises terms already present in the classical Maxwell equations, alongside terms that are the progenitors of the Biot--Savart, Oersted--Ampere's, and Lorentz--force laws. Thus a frame indifferent (truly covariant) formulation of electromagnetism is achieved from a single postulate that the electromagnetic field is a kind of elastic (partly liquid partly solid) continuum.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gao, Kai; Chung, Eric T.; Gibson, Richard L.; Fu, Shubin; Efendiev, Yalchin
2015-06-05
The development of reliable methods for upscaling fine scale models of elastic media has long been an important topic for rock physics and applied seismology. Several effective medium theories have been developed to provide elastic parameters for materials such as finely layered media or randomly oriented or aligned fractures. In such cases, the analytic solutions for upscaled properties can be used for accurate prediction of wave propagation. However, such theories cannot be applied directly to homogenize elastic media with more complex, arbitrary spatial heterogeneity. We therefore propose a numerical homogenization algorithm based on multiscale finite element methods for simulating elasticmore »wave propagation in heterogeneous, anisotropic elastic media. Specifically, our method used multiscale basis functions obtained from a local linear elasticity problem with appropriately defined boundary conditions. Homogenized, effective medium parameters were then computed using these basis functions, and the approach applied a numerical discretization that is similar to the rotated staggered-grid finite difference scheme. Comparisons of the results from our method and from conventional, analytical approaches for finely layered media showed that the homogenization reliably estimated elastic parameters for this simple geometry. Additional tests examined anisotropic models with arbitrary spatial heterogeneity where the average size of the heterogeneities ranged from several centimeters to several meters, and the ratio between the dominant wavelength and the average size of the arbitrary heterogeneities ranged from 10 to 100. Comparisons to finite-difference simulations proved that the numerical homogenization was equally accurate for these complex cases.« less
The QBO's influence on lightning production and deep convection in the tropics
Hernandez, Celina Anne
2009-05-15
. THE QBO?S INFLUENCE ON LIGHTING PRODUCTION IN THE TROPICS ................................................................................................................ 10 3.1 Africa... lightning flash densities observed over land (Fig.8). Therefore, this analysis focuses on four land regions: Africa, India, Maritime continent/Australia, and South America. 3.1 Africa West minus east flash density anomalies for DJF (Fig. 9a) show...
DENSITY OF STATES CALCULATIONS FOR CARBON
Adler, Joan
DENSITY OF STATES CALCULATIONS FOR CARBON ALLOTROPES AND MIXTURES EDUARDO WARSZAWSKI #12;#12;DENSITY OF STATES CALCULATIONS FOR CARBON ALLOTROPES AND MIXTURES Research Thesis Submitted in Partial;#12;Contents Abstract xiii 1 Introduction 1 1.1 Carbon allotropes
Low density expansion for Lyapunov exponents
Hermann Schulz-Baldes
2006-07-12
In some quasi-one-dimensional weakly disordered media, impurities are large and rare rather than small and dense. For an Anderson model with a low density of strong impurities, a perturbation theory in the impurity density is developed for the Lyapunov exponent and the density of states. The Lyapunov exponent grows linearly with the density. Anomalies of the Kappus-Wegner type appear for all rational quasi-momenta even in lowest order perturbation theory.
Oxides having high energy densities
Ceder, Gerbrand; Kang, Kisuk
2013-09-10
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.
Sotnikov, V.; Kim, T.; Lundberg, J.; Paraschiv, I.; Mehlhorn, T. A.
2014-05-15
The presence of plasma turbulence can strongly influence propagation properties of electromagnetic signals used for surveillance and communication. In particular, we are interested in the generation of low frequency plasma density irregularities in the form of coherent vortex structures. Interchange or flute type density irregularities in magnetized plasma are associated with Rayleigh-Taylor type instability. These types of density irregularities play an important role in refraction and scattering of high frequency electromagnetic signals propagating in the earth ionosphere, in high energy density physics, and in many other applications. We will discuss scattering of high frequency electromagnetic waves on low frequency density irregularities due to the presence of vortex density structures associated with interchange instability. We will also present particle-in-cell simulation results of electromagnetic scattering on vortex type density structures using the large scale plasma code LSP and compare them with analytical results.
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
Low-Density Attack Revisited Tetsuya Izu
International Association for Cryptologic Research (IACR)
Low-Density Attack Revisited Tetsuya Izu Jun Kogure Takeshi Koshiba Takeshi Shimoyama Secure The low-density attack proposed by Lagarias and Odlyzko is a powerful algorithm against the subset sum, densities of the subset sum problems should be higher than 0.9408... in order to avoid the low
Ultimate Energy Densities for Electromagnetic Pulses
Mankei Tsang
2008-03-06
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.
Cerveny, Vlastislav
Matrix Pseudospectral Method for Elastic Tides Modeling of Planetary BodiesMatrix Pseudospectral with continuous model parameters that makes the matrix of the algebraic system almost block diagonal (the ABD matrix). An advantage of preserving 2nd -order equations is that a half-size algebraic system
Branch xylem density variations across the Amazon Basin
2009-01-01
increase wood density in Eucalyptus grandis seedlings? ,Changes in wood density of Eucalyptus camaldulensis due to
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)
2003-10-01
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.
Aerodynamic Focusing Of High-Density Aerosols
Ruiz, D. E.; Fisch, Nathaniel
2014-02-24
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.
Energy density bounds for black strings
Shinya Tomizawa
2005-06-07
The conserved charge called Y-ADM mass density associated with asymptotically translational Killing-Yano tensor gives us an appropriate physical meaning about the energy density of $p$ brane spacetimes or black strings. We investigated the positivity of energy density in black string spacetimes, using the spinorial technique introduced by Witten. Recently, the positivity of Y-ADM mass density in p brane spacetimes was discussed. In this paper, we will extend this discussion to the transversely asymptotically flat black string spacetimes containing an apparent horizon. We will give the sufficient conditions for the Y-ADM mass density to become positive in such spacetimes.
Zhang, Shuai; Liu, Tao; Stackhouse, Stephen; Militzer, Burkhard
2015-01-01
Fe and Al are two of the most important rock-forming elements other than Mg, Si, and O. Their presence in the lower mantle's most abundant minerals, MgSiO_3 bridgmanite, MgSiO_3 post-perovskite and MgO periclase, alters their elastic properties. However, knowledge on the thermoelasticity of Fe- and Al-bearing MgSiO_3 bridgmanite, and post-perovskite is scarce. In this study, we perform ab initio molecular dynamics to calculate the elastic and seismic properties of pure, Fe^{3+}- and Fe^{2+}-, and Al^{3+}-bearing MgSiO_3 perovskite and post-perovskite, over a wide range of pressures, temperatures, and Fe/Al compositions. Our results show that a mineral assemblage resembling pyrolite fits a 1D seismological model well, down to, at least, a few hundred kilometers above the core-mantle boundary, i.e. the top of the D'' region. In D'', a similar composition is still an excellent fit to the average velocities and fairly approximate to the density. We also implement polycrystal plasticity with a geodynamic model to ...
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)
2010-06-15
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.
EFFECTIVE POROSITY IMPLIES EFFECTIVE BULK DENSITY IN SORBING SOLUTE TRANSPORT
Flach, G.
2012-02-27
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.
Richard D. Saam
2007-01-09
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.
Chiang, Shu-Sheng
2013-01-01
676. Table I. Normalized Plastic Zone Size (B) and Material·• • Initial - - Elastic/ plastic bounda ---- Cavi in rfaceCTIONAL VIEW XBLSOI Fig. I-9 Plastic Boundary solu/ Initial
Stanley J. Brodsky; Michael Rijssenbeek
2005-11-15
Summary of the XIth International Conference on Elastic and Diffractive Scattering in Chateau de Blois, France, May 15 - 20, 2005, summarizing both theoretical and experimental presentations and discussions.
Muhs, Jeffrey D. (Lenoir City, TN); Capps, Gary J. (Knoxville, TN); Smith, David B. (Oak Ridge, TN); White, Clifford P. (Knoxville, TN)
1994-01-01
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.
Cubic Single Crystal Representations in Classical and Size-dependent Couple Stress Elasticity
Dipanshu Bansal; Gary F. Dargush; Amjad J. Aref; Ali R. Hadjesfandiari
2015-09-27
Beginning with Cosserat theory in the early 20th century, there have been several different formulations for size-dependent elastic response. In this paper, we concentrate on the application of classical Cauchy theory and the recent parsimonious consistent couple stress theory to model a homogeneous linear elastic solid, exemplified by a pure single crystal with cubic structure. The focus is on an examination of elastodynamic response based upon wave velocities from ultrasonic excitation and phonon dispersion curves, along with adiabatic bulk moduli measurements. In particular, we consider in detail elastic parameter estimation within classical elasticity and consistent couple stress theory for four different cubic single crystals (NaCl, KCl, Cu, CuZn). The classical theory requires the estimation of three independent material parameters, while only one additional parameter relating skew-symmetric mean curvature to skew-symmetric couple-stress is needed for the size-dependent consistent couple stress theory. This additional parameter can be defined for cubic crystals in terms of a material length scale, which is found to be on the order of tens of microns for the four materials studied here. Furthermore, a detailed statistical investigation provides strong to very strong evidence that couple stress theory is superior to classical Cauchy elasticity for representing the wave velocities and adiabatic bulk moduli for all four single crystals.
The Quantum Energy Density: Improved E
Krogel, Jaron; Yu, Min; Kim, Jeongnim; Ceperley, David M.
2013-01-01
We establish a physically meaningful representation of a quantum energy density for use in Quantum Monte Carlo calculations. The energy density operator, dened in terms of Hamiltonian components and density operators, returns the correct Hamiltonian when integrated over a volume containing a cluster of particles. This property is demonstrated for a helium-neon \\gas," showing that atomic energies obtained from the energy density correspond to eigenvalues of isolated systems. The formation energies of defects or interfaces are typically calculated as total energy dierences. Using a model of delta-doped silicon (where dopant atoms form a thin plane) we show how interfacial energies can be calculated more eciently with the energy density, since the region of interest is small. We also demonstrate how the energy density correctly transitions to the bulk limit away from the interface where the correct energy is obtainable from a separate total energy calculation.
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)
2014-04-24
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
2015-03-25
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.
A non-linear elastic constitutive framework for replicating plastic deformation in solids.
Roberts, Scott Alan; Schunk, Peter Randall
2014-02-01
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.
An elastic, plastic, viscous model for slow shear of a liquid foam
Philippe Marmottant; François Graner
2007-07-06
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 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.
2010-09-15
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.
New pure shear acoustic surface waves guided by cuts in magneto-electro-elastic materials
Arman Melkumyan
2006-07-12
It is shown that new pure shear acoustic surface waves with five different velocities can be guided by stress free plane cuts with different magneto-electrical properties in magneto-electro-elastic materials. The possibility for the surface waves to be guided by a cut in pairs, which is reported in this paper, is new in magneto-electro-elastic materials and has no counterpart in piezoelectric materials. The five velocities of propagation of the surface waves are obtained in explicit forms. It is shown that the possibility for the surface waves to be guided in pairs disappears and the number of surface waves decreases from 5 to 1 if the magneto-electro-elastic material is changed to a piezoelectric material.
Discrete-time Lyapunov design for neuroadaptive control of elastic-joint robots
Macnab, C.J.B.; D'Eleuterio, G.M.T.
2000-05-01
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.
Room-temperature elastic constants of Sc and ScD[sub 0. 18
Leisure, R.G. ); Schwarz, R.B.; Migliori, A.; Lei, M. )
1993-07-01
The complete set of elastic constants for Sc and ScD[sub 0.18] has been measured at room temperature. The results show that the addition of hydrogen to this rare-earth metal has a qualitatively different effect than the addition of hydrogen to transition metals such as palladium, vanadium, niobium, and tantalum. In the case of Sc all five elastic constants increase with the addition of hydrogen. The bulk modulus for ScD[sub 0.18] is 9.5% higher than that for Sc. The Debye temperature computed from the room-temperature elastic constants is 355 K for Sc and 371 K for ScD[sub 0.18].
Considering Air Density in Wind Power Production
Zénó Farkas
2011-03-11
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.
Method of synthesizing a low density material
Lorensen, L.E.; Monaco, S.B.
1987-02-27
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.
Considering Air Density in Wind Power Production
Farkas, Zénó
2011-01-01
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
2015-04-23
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
2014-01-01
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.
3-D capacitance density imaging system
Fasching, G.E.
1988-03-18
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.
Mini-review of Electron Density Visualization
Adler, Joan; Adler, Omri; Kreif, Meytal; Cohen, Or; Grosso, Bastien; Hashibon, Adham; Cooper, Valentino R
2015-01-01
We describe both educational and research oriented examples of electronic density visualization with AViz. Several detailed cases are presented and the procedures for their preparation are described.
Chiral dynamics and peripheral transverse densities Granados...
Office of Scientific and Technical Information (OSTI)
dynamics and peripheral transverse densities Granados, Carlos G. Uppsala University (Sweden); Weiss, Christian JLAB, Newport News, VA (United States) 72 PHYSICS OF ELEMENTARY...
Uncertainty Quantification for Nuclear Density Functional Theory...
Office of Scientific and Technical Information (OSTI)
Uncertainty Quantification for Nuclear Density Functional Theory and Information Content of New Measurements Citation Details In-Document Search Title: Uncertainty Quantification...
Uncertainty Quantification for Nuclear Density Functional Theory...
Office of Scientific and Technical Information (OSTI)
Uncertainty Quantification for Nuclear Density Functional Theory and Information Content of New Measurements Citation Details In-Document Search This content will become publicly...
Building a Universal Nuclear Energy Density Functional
Bertulani, Carlos A.
2014-09-10
This grant had two components: Density functional theory and pairing and Nuclear reactions. This final report summarizes the activities for this SciDAC-2 project.
Qian Zhao; Bao Yuan Sun; Wen Hui Long
2014-11-23
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.
Quasi-Elastic Charge-Exchange in Nh-2-]Pnn at 794 Mev
Bonner, BE; Simmons, J. E.; Wallace, J. M.; Evans, M. L.; Glass, G.; Hiebert, John C.; Jain, M.; Northcliffe, L. C.; Bjork, C. W.; Riley, P. J.; Cassapakis, C. G.
1978-01-01
UOLUME 17, NUMBER 2 FEBRUARY 1978 Quasielastic charge exchange in n28 -+ pnn at 794 Mev~ 9. E. Bonner, J. E. Simmons, and J. M. Wallace Los Alamos Scientific Laboratory, University of California, Los A/amos, Ne~ Mexico 87545 M. I . Evans, f G. Glass... CEX. Quoted errors are de- rived from statistical errors only. Parameter d'0/fit= & e~& + &2e~2 Quas ielastic Elastic Present expt. Saclay (814 MeV) Elastic Los Alamos (800 MeV) (7 ( f3( A2 Pp do./rA (t=0) (=A)+ Ap) 12.87 + 0.22 123,4 +5...
A beautiful day in the neighborhood : the influence of neighborhood density on speech production
Freedman, Skott Elliot
2009-01-01
Disorders by Skott Elliot Freedman Committee in charge:Chair Professor Sonja Pruitt Skott Elliot Freedman, 2009 AllThe Dissertation of Skott Elliot Freedman is approved, and
Influence of increased gas density on hydrodynamics of bubble-column reactors
Krishna, R.; Swart, J.W.A. de; Hennephof, D.E.; Ellenberger, J.; Hoefsloot, H.C.J. (Univ. of Amsterdam (Netherlands). Dept. of Chemical Engineering)
1994-01-01
A mechanistic background to the understanding of the hydrodynamics of high-pressure bubble column reactors in both the homogeneous and heterogeneous flow regimes is discussed. An important parameter determining the stability of homogeneous bubbly flow in a bubble column is shown to be the Richardson-Zaki exponent in the bubble swarm velocity relationship V[sub swarm] = [upsilon][sub [infinity
A beautiful day in the neighborhood : the influence of neighborhood density on speech production
Freedman, Skott Elliot
2009-01-01
children’s speech production. Journal of Child Language, 31,J.A. (2009). Bilingual production as a function of lexicaleffects on children's production accuracy and fluency in
First-principles study of the structural and elastic properties of Cr{sub 2}AlX (X=N, C) compounds
Cui Shouxin; Wei Dongqing; Hu Haiquan; Feng Wenxia; Gong Zizheng
2012-07-15
The structural, electronic and elastic properties of Cr{sub 2}AlX, with X=N, C, have been investigated at the density functional theory level by applying a plane-wave pseudopotential approach. The band structure and density of states reveal the metallic features of Cr{sub 2}AlX. The total and projected density of states indicate that the bonding is achieved through a hybridization of Cr 3d states with Al and X-atom p states. The Cr 3d-X2p bonds are lower in energy and are stiffer than Cr 3d-Al 3p bonds. The charge density distributions indicate that there exist soft Cr-Al and relatively strong Cr-X covalent bonds, which might be responsible for their hardness. The elastic constants were obtained in the pressure range 0-100 GPa, and satisfy the stability conditions for hexagonal crystal, which indicates that these two compounds are stable in the pressure regime studied. By analyzing bulk modulus to shear modulus ratio and Cauchy pressure, Cr{sub 2}AlC is predicted to be brittleness and Cr{sub 2}AlN is ductile. The Debye temperature was obtained from the average sound velocity. - Graphical abstract: The heterogeneity of chemical bonds in Cr{sub 2}AlX (X=N, C) is observed: soft Cr-Al and relatively strong Cr-X covalent bonds might be contributed to their hardness. Highlights: Black-Right-Pointing-Pointer Cr 3d-X2p (X=N, C) bonds are lower in energy and stiffer than Cr 3d-Al 3p bonds for Cr{sub 2}AlX. Black-Right-Pointing-Pointer The hardness of Cr{sub 2}AlX might be ascribed to soft Cr-Al and relatively strong Cr-X covalent bonds. Black-Right-Pointing-Pointer The predicted brittleness of Cr{sub 2}AlC and ductility of Cr{sub 2}AlN originated from their novel structure.
: Proof of concept and physical limits to the data storage density F. E. Rougieux and D. Macdonald in multicrystalline silicon wafers for solar cells J. Appl. Phys. 102, 054506 (2007); 10.1063/1.2776003 Influence to the data storage density F. E. Rougieux and D. Macdonald Research School of Engineering, College
Effects of residual stress on the thin-film elastic moduli calculated from surface acoustic wave stress affects the values of thin-film elastic moduli determined from surface acoustic wave spectroscopy surface acoustic wave measurements may be analyzed to obtain additional information about the mechanical
Zhu, Dakai
-oriented functionality (e.g., cap- turing photos in unmanned aerial vehicles) [1]. Note that, in general, the flight-criticalTechnical Report: CS-TR-2013-010, UTSA Scheduling Algorithms for Elastic Mixed-Criticality Tasks--The Elastic Mixed-Criticality (E-MC) task model and an Early-Release EDF (ER-EDF) scheduling algorithm have
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 ...
Mueser, Martin
or numerically at a moderate amount of computing effort. While solving numerically the full elastic or plastoElastic contact between self-affine surfaces: Comparison of numerical stress and contact Department of Applied Mathematics, University of Western Ontario, London, ON, Canada N6A 5B7 and 3 Department
Weimer, Westley
faster response time and improved cost efficiency. In this paper, we introduce LCA, a resource managementComprehensive Elastic Resource Management to Ensure Predictable Performance for Scientific satisfaction rates. To solve these problems, we designed an end-to-end elastic resource management system
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.
2015-04-01
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
Time Dependent Density Functional Theory An Introduction
Botti, Silvana
Time Dependent Density Functional Theory An Introduction Francesco Sottile Laboratoire des Solides) Belfast, 29 Jun 2007 Time Dependent Density Functional Theory Francesco Sottile #12;Intro Formalism Linear Response Formalism 3 TDDFT in practice: The ALDA: Achievements and Shortcomings 4 Resources Time
Enhancing critical current density of cuprate superconductors
Chaudhari, Praveen
2015-06-16
The present invention concerns the enhancement of critical current densities in cuprate superconductors. Such enhancement of critical current densities include using wave function symmetry and restricting movement of Abrikosov (A) vortices, Josephson (J) vortices, or Abrikosov-Josephson (A-J) vortices by using the half integer vortices associated with d-wave symmetry present in the grain boundary.
Neutral depletion and the helicon density limit
Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E.
2013-12-15
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 Zhong, Chongli
2014-05-28
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.
Effects of anharmonic vibration on large-angle quasi-elastic scattering of 16O+144Sm
Muhammad Zamrun F.; K. Hagino
2007-10-15
We study the effects of double octupole and quadrupole phonon excitations in the 144Sm nucleus on quasi-elastic 16O+144Sm scattering at backward angles. To this end, we use the coupled-channels framework, taking into account explicitly the anharmonicities of the vibrations. We use the same coupling scheme as that previously employed to explain the experimental data of sub-barrier fusion cross sections for the same system. We show that the experimental data for the quasi-elastic cross sections are well reproduced in this way, although the quasi-elastic barrier distribution has a distinct high energy peak which is somewhat smeared in the experimental barrier distribution. We also discuss the effects of proton transfer on the quasi-elastic barrier distribution. Our study indicates that the fusion and quasi-elastic barrier distributions for this system cannot be accounted for simultaneously with the standard coupled-channels approach.
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)
2014-03-28
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.
Ions in solution: Density corrected density functional theory (DC-DFT)
Kim, Min-Cheol; Sim, Eunji; Burke, Kieron
2014-05-14
Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes of density functional theory calculations are significantly improved by using densities more accurate than the self-consistent densities. We discuss how to identify such cases, and how DC-DFT applies more generally. To illustrate, we calculate potential energy surfaces of HO·Cl{sup ?} and HO·H{sub 2}O complexes using various common approximate functionals, with and without this density correction. Commonly used approximations yield wrongly shaped surfaces and/or incorrect minima when calculated self consistently, while yielding almost identical shapes and minima when density corrected. This improvement is retained even in the presence of implicit solvent.
McKittrick, Joanna
Elastic moduli of untreated, demineralized and deproteinized cortical bone: Validation online 15 November 2011 Keywords: Cortical bone Elastic moduli Multi-scale modeling Demineralization include completely demineralized and deproteinized bones as well as untreated bone samples. Porosity
np-elastic analyzing power A(N0) at 485 and 788 MeV
McNaughton, M. W.; McNaughton, K. H.; Glass, G.; Riley, P. J.; Auer, KH; Davis, CA; Gulmez, E.; Hiebert, John C.; Jeppersen, R. H.; Ransome, R. D.; Spinka, H.; Sum, V.; Supek, I.; Tripard, G. E.; Woolverton, H.
1996-01-01
Measurements are reported for the np-elastic analyzing power from 30 degrees to 128 degrees c.m., at 485 and 788 MeV, with a typical precision of 0.005 and absolute accuracy of 2%. Results strengthen the isospin-0 phase-shift analysis, and clarify...
Adaptive Energy Saving Scheme for Downlink Elastic Traffic in Wireless Networks
Bahk, Saewoong
Adaptive Energy Saving Scheme for Downlink Elastic Traffic in Wireless Networks Jongwook Lee, we propose several adaptive energy saving schemes that consider throughput and energy saving simultaneously. The proposed schemes are designed for an efficient tradeoff between throughput and energy saving
techniques to minimize the work needed before deactivation or activation of servers. Analysis of real-world the members and companies of the PDL Consortium (including Actifio, APC, EMC, Emulex, Facebook, Fusion activities, elasticity is useful for reducing energy usage, allowing temporarily unneeded storage components
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
Proton form factors and two-photon exchange contribution to elastic electron-proton scattering
Proton form factors and two-photon exchange contribution to elastic electron-proton scattering A. V Perspectives of High Energy Physics" Alexander Gramolin (Budker INP) Proton form factors and 2-exchange. . . September 4, 2010 1 / 18 #12;Proton electromagnetic form factors The proton's electric GE (Q2 ) and magnetic
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 ...
Extremely fast prey capture in pipefish is powered by elastic recoil
Lauder, George V.
of the post-cranial muscles before prey capture is initiated. Next, an abrupt elastic recoil generates high-speed dorsal rotation of the head and snout, rapidly bringing the mouth close to the prey, thus enabling Syngnathus leptorhynchus, as well as electromyography of the muscle responsible for head rotation (the
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 of polymer/CNT composites was initially reported by Ajayan et al. [3]. In their research, multi-wall carbon 20 June 2006 Abstract Carbon nanotubes (CNTs) are promising additives to polymeric materials due
Laser Excitation of a Fracture Source for Elastic Waves Thomas E. Blum* and Kasper van Wijk
Snieder, Roel
Laser Excitation of a Fracture Source for Elastic Waves Thomas E. Blum* and Kasper van Wijk a transparent sample by focusing laser light directly onto this fracture. The associated displacement field, measured by a laser interferometer, has pronounced waves that are diffracted at the fracture tips. We
Kostelec, Peter J.
Registration We have developed a multiscale algorithm for elastic (or molded) alignment of images results of this molding technique on a variety of images, and conclude with some closing remarks about'', by a grant from DODAMRD, DAMD179616119, and in part by ARPA as administered by the AFOSR under contract
Crustal subsidence due to the Hlsln reservoir: predicting the elastic Earth response
Grapenthin, Ronni
Crustal subsidence due to the Hálslón reservoir: predicting the elastic Earth response Ronni. Later, a viscoelastic response due to stress relaxation will result in further subsidence. We present to the actual subsidence after filling of the reservoir will e.g. allow a determination of the effective Young
POSTURE MATCHING AND ELASTIC REGISTRATION OF A MOUSE ATLAS TO SURFACE TOPOGRAPHY RANGE DATA
Leahy, Richard M.
-imaged mouse based only on the atlas data and the measured surface topography of the iPOSTURE MATCHING AND ELASTIC REGISTRATION OF A MOUSE ATLAS TO SURFACE TOPOGRAPHY RANGE DATA A. A Laboratory of Neuro Imaging, UCLA School of Medicine, Los Angeles, CA 90095, USA, 2 Department of Biomedical
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
High precision measurement of the proton elastic form factor ratio at low Q²
Zhan, Xiaohui
2010-01-01
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, ...
An archive for quasi-elastic electron-nucleus scattering data
O. Benhar; D. Day; I. Sick
2006-03-30
In connection with a review article on inclusive quasi-elastic electron-nucleus scattering submitted to Reviews of Modern Physics, we have collected as many cross sections as possible, and placed them in an web-archive. This brief note is intended to alert potential users of these data to this resource.
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
2007-11-01
[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...
Z. C. Tu; L. Q. Ge; J. B. Li; Z. C. Ou-Yang
2005-08-18
The entropy of a polymer confined in a curved surface and the elastic free energy of a membrane consisting of polymers are obtained by scaling analysis. It is found that the elastic free energy of the membrane has the form of the in-plane strain energy plus Helfrich's curvature energy [Z. Naturforsch. C \\textbf{28}, 693 (1973)]. The elastic constants in the free energy are obtained by discussing two simplified models: one is the polymer membrane without in-plane strains and asymmetry between its two sides, which is the counterpart of quantum mechanics in curved surface [Jensen and Koppe, Ann. Phys. \\textbf{63}, 586 (1971)]; another is the planar rubber membrane with homogeneous in-plane strains. The equations to describe equilibrium shape and in-plane strains of the polymer vesicles by osmotic pressure are derived by taking the first order variation of the total free energy containing the elastic free energy, the surface tension energy and the term induced by osmotic pressure. The critical pressure, above which spherical polymer vesicle will lose its stability, is obtained by taking the second order variation of the total free energy. It is found that the in-plane mode also plays important role in the critical pressure because it couples with the out-of-plane mode. Theoretical results reveal that polymer vesicles possess the mechanical properties intermediate between fluid membranes and solid shells.
The structure of the nucleon Elastic and deep inelastic scattering from nucleons, 19561973
Murayama, Hitoshi
, scattering of electrons by protons and neutrons is open to direct interpretation. For the scattering8 The structure of the nucleon Elastic and deep inelastic scattering from nucleons, 19561973 Hadronic scattering experiments produced extensive and rich data revealing reso- nances and regularities
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 Professor, Civil & Environmental Engineering The steady rising level of atmospheric carbon dioxide resulting to the economy that is heavily relied on fossil fuels. Although the transition of the existing carbon
Swept Blade Aero-Elastic Model for a Small Wind Turbine (Presentation)
Damiani, R.; Lee, S.; Larwood, S.
2014-07-01
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.
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
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
On The Semi-Supervised Joint Trained Elastic Net October 19, 2012
Culp, Mark
net (supervised enet henceforth) is a popular and computationally efficient approach for performing regression setting. Semi-supervised regression, currently unrelated to the supervised enet, uses data-supervised regression with the supervised enet. The supervised elastic net and other approaches like it rely
Price elasticity reconsidered: Panel estimation of an agricultural water demand function
Sadoulet, Elisabeth
Price elasticity reconsidered: Panel estimation of an agricultural water demand function Karina: Panel estimation of an agricultural water demand function, Water Resour. Res., 42, W09411, doi:10 to the data improvements, we use a novel approach to estimate land allocation (defined as the joint choice
Elastic scattering of the proton drip-line nucleus F-17
Blackmon, JC; Carstoiu, F.; Trache, L.; Bardayan, DW; Brune, CR; Gagliardi, Carl A.; Greife, U.; Gross, CJ; Jewett, CC; Kozub, R. L.; Lewis, TA; Liang, JF; Moazen, BH; Mukhamedzhanov, AM; Nesaraja, CD; Nunes, FM; Parker, PD; Sahin, L.; Scott, JP; Shapira, D.; Smith, MS; Thomas, JS; Tribble, Robert E.
2005-01-01
-elastic scattering on a heavy target has been measured by Liang et al. [12,13] and by Romoli et al. [14] at near-barrier energies. Not much information about the nuclear part has been extracted from these studies because the interaction is strongly dominated...
Nonlinear elasticity of the sliding columnar phase C. S. O'Hern* and T. C. Lubensky
O'Hern, Corey S.
positional correlations between lattices in neighboring layers and a vanishing shear modulus for sliding fluctuations of the columns and has three important elastic constants: the compression, rotation, and bending lattices 2 . Two recent theoretical papers 4,5 have pointed out that weakly coupled 2D smectic lattices
ELASTIC PROPERTIES OF NACRE ARAGONITE TABLETS F. Barthelat and H.D. Espinosa
Espinosa, Horacio D.
mechanical tests at the macroscale, using tensile [2,3], three-point bending [3,4], four-point bending load-deflection analysis method [9] only a single isotropic elastic modulus (99.5 GPa) could 68, Paper 187, 2003. #12;Figure 1: Schematic of the microstructure of nacre from Red Abalone
PHYSICAL REVIEW E 84, 031924 (2011) Fluid transport by active elastic membranes
Lauga, Eric
2011-01-01
PHYSICAL REVIEW E 84, 031924 (2011) Fluid transport by active elastic membranes Arthur A. Evans1, if the membrane is anchored, its deformation will lead to fluid transport. Past work in this area focused. In each case, we asymptotically calculate the membrane shape and the fluid transport velocities for small
Measurements of the Differential Cross Sections for the Elastic n-3 H Scattering
.1 MeV by Using an Inertial Confinement Fusion Facility J. A. Frenje, C. K. Li, F. H. Seguin, D. T elastically scattered 3H and 2H ions from a deuterium-tritium gas-filled inertial confinement fusion capsule-ion reactions to constrain models of inertial confinement fusion (ICF) ex- periments involving deuterium
Mega Data Center for Elastic Internet Applications Hangwei Qian Michael Rabinovich
Rabinovich, Michael "Misha"
1 Mega Data Center for Elastic Internet Applications Hangwei Qian Michael Rabinovich VMWare Case data center. Our architecture includes a scalable load-balancing fabric and provides effective knobs Modern cloud providers are building data centers with hundreds of thousands of servers, knowns as mega
Cascading elastic perturbation in Japan due to the 2012 Mw 8.6 Indian Ocean Earthquake
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Delorey, A. A.; Johnson, P. A.; Chao, K.; Obara, K.
2015-10-02
Since the discovery of extensive earthquake triggering occurring in response to the 1992 Mw 7.3 Landers earthquake, it is now well established that seismic waves from earthquakes can trigger other earthquakes, tremor, slow slip, and pore pressure changes. Our contention is that earthquake triggering is one manifestation of a more widespread elastic disturbance that reveals information about Earth’s stress state. Earth’s stress state is central to our understanding of both natural and anthropogenic-induced crustal processes. Here we present that seismic waves from distant earthquakes may perturb stresses and frictional properties on faults and elastic moduli of the crust in cascadingmore »fashion. Transient dynamic stresses place crustal material into a metastable state during which material recovers through a process termed slow dynamics. This observation of widespread, dynamically induced elastic perturbation, including systematic migration of offshore seismicity, strain transients, and velocity transients, presents a new characterization of Earth’s elastic system that will advance our understanding of plate tectonics, seismicity, and seismic hazards.« less
North Caspian Basin: 2D elastic modeling for seismic imaging of salt and subsalt
Bailey, Zhanar Alpysbaevna
2006-04-12
. The two central tools for investigation of these imaging challenges were the construction of a geological model of the NCB and the use of an accurate elastic wave-propagation technique to analyze the capability of seismic to illuminate the geological...
IEEE INFOCOM 2001 Behavior of TCP-like elastic traffic at a buffered
Schwefel, Hans-Peter
IEEE INFOCOM 2001 Behavior of TCP-like elastic traffic at a buffered bottleneck router Hans by a stochastic process. The essential behavior of TCP-like flow-control mechanisms is captured in the analytic to existing congestion, the throttling mechanism is only activated when the buffer-occupancy at the bottleneck
Permeability and elastic properties of cracked glass under pressure A. OugierSimonin,1
Fortin, Jérôme
for independent controls of the confining pressure, the axial stress, and pore pressure. We produced cracks with identified average aspect ratio and crack aperture, (2) a very small permeability which decreases as a power behavior of a cracked elastic brittle solid is reversible and independent of the fluid nature. Two
Acoustic Measurements of the Elastic Properties and Quality of Plutonium and Uranium Based Oxide ranged from depleted uranium oxide to mixtures of plutonium and depleted uranium oxide (MOX) and mixed.8Pu0.2 92 121 152.6 63.3 281Plutonium Futures -- The Science 2010, September 19-23, 2010, Keystone, CO
A statistical approach to close packing of elastic rods and to DNA packaging in viral capsids
Adda-Bedia, Mokhtar
a statistical minimal model based on Edwards' theory to study the conformations of the rod. This approach provA statistical approach to close packing of elastic rods and to DNA packaging in viral capsids E, France Communicated by Sam Edwards, University of Cambridge, Cambridge, United Kingdom, October 13, 2006
Future Measurements of the Nucleon Elastic Electromagnetic Form Factors at Jefferson Lab
Gilfoyle, Jerry
Future Measurements of the Nucleon Elastic Electromagnetic Form Factors at Jefferson Lab G, Hadron2014 Future Form Factor Measurements at JLab 1 / 26 #12;Scientific Motivation - What We Hope the hadronic picture to QCD. Jerry Gilfoyle, Hadron2014 Future Form Factor Measurements at JLab 2 / 26 #12
Macromolecules 1994,27,981-988 981 Bending and Twisting Elasticity of DNA
Siggia, Eric
to bending persistence, persistence of internal twisting degrees of f r e e d ~ m . ~ ~ ~In this paper, weMacromolecules 1994,27,981-988 981 Bending and Twisting Elasticity of DNA J. F.Marko' and E to the independentbendingandtorsionalenergiesincorporatedin previoustheories,apreviouslyunknowncoupling between twist and bend. If the backbone is given
Elastic stability of DNA configurations. I. General theory Irwin Tobias,1,
s : 87.10. e, 46.70.Hg, 02.40. k, 46.32. x I. INTRODUCTION In this paper we derive various necessary, , is determined by C and accounts for the elastic bending energy and the possible presence of long range forces long range forces are absent, reduces to the bending energy, B , which is determined by the curva- ture
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
perovskite phase suggests slow longitudinal elastic-wave velocities propagating along the
Hansell, Dennis
perovskite phase suggests slow longitudinal elastic-wave velocities propagating along the [010] direction. In addition, it is also inferred that the post-perovskite phase forms a platy crystal habit) observed in the D region (1, 2) is possibly caused by the preferred orientation of the post-perovskite
Coating Flows of Non-Newtonian Fluids: Weakly and Strongly Elastic Limits
is on viscoelastic effects on single roll coating at low dimensionless speeds, although the analytical results weCoating Flows of Non-Newtonian Fluids: Weakly and Strongly Elastic Limits J. Ashmore(1,a), A February 2007 Abstract. We present an asymptotic analysis of the thickness of the liquid film that coats
Drainage fracture networks in elastic solids with internal fluid gen-Maya Kobchenko1
Galland, Olivier
epl draft Drainage fracture networks in elastic solids with internal fluid gen- eration Maya layer to fracture. The gas produced is drained on short length scales by diffusion and on long length scales by flow in a fracture network, which has topological properties that are intermediate between