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 ...
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.
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.
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].
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
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.
Elastic Wave Behavior Across Linear Slip Interfaces
Schoenberg, M.
Reflection and transmission coefficients for harmonic plane waves incident at arbitrary angles upon a plane linear slip interface are computed in terms of the.
Elastic interface acoustic waves in twinned crystals
Michel Destrade
2013-04-30
A new type of Interface Acoustic Waves (IAW) is presented, for single-crystal orthotropic twins bonded symmetrically along a plane containing only one common crystallographic axis. The effective boundary conditions show that the waves are linearly polarized at the interface, either transversally or longitudinally. Then the secular equation is obtained in full analytical form using new relationships for the displacement-traction quadrivector at the interface. For Gallium Arsenide and for Silicon, it is found that the IAWs with transverse (resp. longitudinal) polarization at the interface are of the Stoneley (resp. leaky) type.
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
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
Plane wave solution for elastic wave scattering by a heterogeneous ...
2004-05-28
tory ultrasonic transmission tests across a synthetic fracture with known, regular geometry, Myer et al. 19855 found good agreement between measured waves ...
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.
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.
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.
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.
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
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
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 ...
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
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.
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.
Coda wave interferometry and the equilibration of energy in elastic media Roel Snieder
Snieder, Roel
Coda wave interferometry and the equilibration of energy in elastic media Roel Snieder Department of Geophysics and Center for Wave Phenomena, Colorado School of Mines, Golden, Colorado 80401 Received 14 May 2002; published 21 October 2002 Multiple-scattered waves usually are not useful for creating
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.
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
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.
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
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
Elastic waves push organic fluids from reservoir rock Igor A. Beresnev,1
Beresnev, Igor
Elastic waves push organic fluids from reservoir rock Igor A. Beresnev,1 R. Dennis Vigil,2 Wenqing in a laboratory experiment, in which residual saturation is created in a glass micromodel, and mobilization waves push organic fluids from reservoir rock, Geophys. Res. Lett., 32, L13303, doi:10.1029/ 2005GL
Appelö, Daniel
; curvilinear grids ; finite differences; stability; energy estimate; seismic wave propagation 1 IntroductionA stable finite difference method for the elastic wave equation on complex geometries with free Institute of Technology, Pasadena, CA 91125, USA 2 Center for Applied and Scientific Computing, Lawrence
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
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.
Measurements of coupled Rayleigh wave propagation in an elastic plate
Illinois at Urbana-Champaign, University of
measurements, but did not widely report them. The longer service life of structures such as pipelines means, or if the damage were corrosion, then a surface wave would be more severely attenuated by the patch of corrosion
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
Gregor Tanner; Niels Sondergaard
2006-08-17
We derive a short wave length approximation of a boundary integral operator for two-dimensional isotropic and homogeneous elastic bodies of arbitrary shape. Trace formulae for elastodynamics can be deduced in this way from first principles starting directly from Navier-Cauchy's equation.
Wave propagation in anisotropic elastic materials and curvilinear
Office of Scientific and Technical Information (OSTI)
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Fourier analysis of wave turbulence in a thin elastic plate
Nicolas Mordant
2010-06-18
The spatio-temporal dynamics of the deformation of a vibrated plate is measured by a high speed Fourier transform profilometry technique. The space-time Fourier spectrum is analyzed. It displays a behavior consistent with the premises of the Weak Turbulence theory. A isotropic continuous spectrum of waves is excited with a non linear dispersion relation slightly shifted from the linear dispersion relation. The spectral width of the dispersion relation is also measured. The non linearity of this system is weak as expected from the theory. Finite size effects are discussed. Despite a qualitative agreement with the theory, a quantitative mismatch is observed which origin may be due to the dissipation that ultimately absorbs the energy flux of the Kolmogorov-Zakharov casade.
Semblat, Jean-François; Gandomzadeh, Ali
2010-01-01
The numerical analysis of elastic wave propagation in unbounded media may be difficult due to spurious waves reflected at the model artificial boundaries. This point is critical for the analysis of wave propagation in heterogeneous or layered solids. Various techniques such as Absorbing Boundary Conditions, infinite elements or Absorbing Boundary Layers (e.g. Perfectly Matched Layers) lead to an important reduction of such spurious reflections. In this paper, a simple absorbing layer method is proposed: it is based on a Rayleigh/Caughey damping formulation which is often already available in existing Finite Element softwares. The principle of the Caughey Absorbing Layer Method is first presented (including a rheological interpretation). The efficiency of the method is then shown through 1D Finite Element simulations considering homogeneous and heterogeneous damping in the absorbing layer. 2D models are considered afterwards to assess the efficiency of the absorbing layer method for various wave types and inci...
Tang, Wei
1996-01-01
The critically refracted longitudinal (LCR) wave ultrasonic technique has been used to investigate a typical turbine disk material in the elastic-plastic region. Both applied tensile stress and residual strain effects are ...
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
Making and Propagating Elastic Waves: Overview of the new wave propagation code WPP
McCandless, K P; Petersson, N A; Nilsson, S; Rodgers, A; Sjogreen, B; Blair, S C
2006-05-09
We are developing a new parallel 3D wave propagation code at LLNL called WPP (Wave Propagation Program). WPP is being designed to incorporate the latest developments in embedded boundary and mesh refinement technology for finite difference methods, as well as having an efficient portable implementation to run on the latest supercomputers at LLNL. We are currently exploring seismic wave applications, including a recent effort to compute ground motions for the 1906 Great San Francisco Earthquake. This paper will briefly describe the wave propagation problem, features of our numerical method to model it, implementation of the wave propagation code, and results from the 1906 Great San Francisco Earthquake simulation.
The explicit secular equation for surface acoustic waves in monoclinic elastic crystals
Michel Destrade
2013-05-30
The secular equation for surface acoustic waves propagating on a monoclinic elastic half-space is derived in a direct manner, using the method of first integrals. Although the motion is at first assumed to correspond to generalized plane strain, the analysis shows that only two components of the mechanical displacement and of the tractions on planes parallel to the free surface are nonzero. Using the Stroh formalism, a system of two second order differential equations is found for the remaining tractions. The secular equation is then obtained as a quartic for the squared wave speed. This explicit equation is consistent with that found in the orthorhombic case. The speed of subsonic surface waves is then computed for twelve specific monoclinic crystals.
Influence of surface waves on measured and modeled irradiance profiles
Boss, Emmanuel S.
Influence of surface waves on measured and modeled irradiance profiles J. Ronald V. Zaneveld-parallel assumption. We show that the Gershun equation is valid if the irradiance is averaged over a sufficiently in which horizontal gradients of irradiance in the presence of waves are much larger than vertical
Dimitrova, Zlatinka I
2015-01-01
We investigate flow of incompressible fluid in a cylindrical tube with elastic walls. The radius of the tube may change along its length. The discussed problem is connected to the blood flow in large human arteries and especially to nonlinear wave propagation due to the pulsations of the heart. The long-wave approximation for modeling of waves in blood is applied. The obtained model Korteweg-deVries equation possessing a variable coefficient is reduced to a nonlinear dynamical system of 3 first order differential equations. The low probability of arising of a solitary wave is shown. Periodic wave solutions of the model system of equations are studied and it is shown that the waves that are consequence of the irregular heart pulsations may be modeled by a sequence of parts of such periodic wave solutions.
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.
Yamashita, Teruo
Generation of microcracks by dynamic shear rupture and its effects on rupture growth and elastic propagating earthquake faults generate a large number of tensile microcracks in their vicinity, which waves will also be affected by the generation of microcracks. We numerically study how such tensile
Snieder, Roel
Interferometry by deconvolution: Part 2 -- Theory for elastic waves and application to drill-point boundary condition imposed by the deconvolution process. In seismic-while-drilling SWD practice, the goal is to determine the subsurface impulse re- sponse from drill-bit noise records. Most SWD technologies rely
J. Lundin; M. Marklund; E. Lundstrom; G. Brodin; J. Collier; R. Bingham; J. T. Mendonca; P. Norreys
2006-10-10
We derive expressions for the coupling coefficients for electromagnetic four-wave mixing in the non-linear quantum vacuum. An experimental setup for detection of elastic photon-photon scattering is suggested, where three incoming laser pulses collide and generate a fourth wave with a new frequency and direction of propagation. An expression for the number of scattered photons is derived and, using beam parameters for the Astra Gemini system at the Rutherford Appleton Laboratory, it is found that the signal can reach detectable levels. Problems with shot-to-shot reproducibility are reviewed, and the magnitude of the noise arising from competing scattering processes is estimated. It is found that detection of elastic photon-photon scattering may for the first time be achieved.
Influence of frozen capillary waves on contact mechanics
B. N. J. Persson
2005-12-23
Free surfaces of liquids exhibit thermally excited (capillary) surface waves. We show that the surface roughness which results from capillary waves when a glassy material is cooled below the glass transition temperature can have a large influence on the contact mechanics between the solids. The theory suggest a new explanation for puzzling experimental results [L. Bureau, T. Baumberger and C. Caroli, arXiv:cond-mat/0510232] about the dependence of the frictional shear stress on the load for contact between a glassy polymer lens and flat substrates. It also lend support for a recently developed contact mechanics theory.
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...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gao, Kai; Fu, Shubin; Gibson, Richard L.; Chung, Eric T.; Efendiev, Yalchin
2015-04-14
It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both the boundaries and interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale mediummore »property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and discontinuous Galerkin formulation of the multiscale method, both of which have pros and cons. Applications of the multiscale method to three heterogeneous models show that our multiscale method can effectively model the elastic wave propagation in anisotropic media with a significant reduction in the degrees of freedom in the modeling system.« less
Gao, Kai; Gibson, Richard L; Chung, Eric T; Efendiev, Yalchin
2014-01-01
It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both boundaries and the interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale medium property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and di...
Control influence on the electromagnetic generator pre-design for a wave energy converter
Paris-Sud XI, Université de
461 1 Control influence on the electromagnetic generator pre-design for a wave energy converter M of an electromagnetic generator for wave energy recovery. We will start by describing the wave energy converter (WEC of the study problem. Keywords: optimization, control, design methodology, direct drive generator, wave energy
Long waves in water over a visco-elastic muddy seabed
Garnier, Erell-Isis
2011-01-01
The propagation of surface waves over a flat muddy seabed are studied. Mud is first considered as a Newtonian fluid. Water and mud equations are derived in order to obtain governing equation for surface and interface waves. ...
Investigation of elastic wave transmission in a metaconcrete Stephanie J. Mitchell a
Ortiz, Michael
of modified concrete, termed metaconcrete, has been shown to exhibit trapping of wave energy and a reduction and therefore reduce stress within the mortar phase of the composite material. The transmission of wave energy of measuring the absorption of wave energy as an applied forcing of known frequency travels through
Determination of third order elastic constants in a complex solid applying coda wave interferometry
material, concrete. Concrete, a structurally heterogeneous and volumetrically mechanically damaged material nonequilibrium class3 or also the nonlinear mesoscopic class,4 and an extreme example is concrete. It is highly complex both chemically and mechani- cally, is porous and permeable, heterogeneous, and highly elastically
Influence of control strategy on the global efficiency of a Direct Wave Energy Converter with
Paris-Sud XI, Université de
Influence of control strategy on the global efficiency of a Direct Wave Energy Converter, France Abstract--The choice of control strategy for Direct Wave Energy Converters (DWEC) is often a simple loss model in order to design a better control strategy. Keywords--Wave energy conversion; Point
Multiscale Method for Elastic Wave Propagation in the Heterogeneous, Anisotropic Media
Gao, Kai
2014-08-05
Seismic wave simulation in realistic Earth media with full wavefield methods is a fundamental task in geophysical studies. Conventional approaches such as the finite-difference method and the finite-element method solve ...
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.
Jirsa, Viktor
. Surface and guided waves are significant information source in non-destructive testing and evaluation As a non-destructive, non-invasive and non-ionizing evaluation technique for heterogeneous media, the non-destructive characterization of FGM structures became a key issue: first, to better understand
THE INFLUENCE OF WAVES ON THE OFFSHORE WIND Bernhard Lange, Jrgen Hjstrup*
Heinemann, Detlev
THE INFLUENCE OF WAVES ON THE OFFSHORE WIND RESOURCE Bernhard Lange, Jørgen Højstrup* Risø National and waves and thus in air-sea interaction in general. For predicting the offshore wind climate'8&7,21 The favourable wind resource at offshore compared to land sites is caused by the very low surface roughness
Influence of Nonlinear Irregular Waves on the Fatigue Loads of an Offshore Wind Turbine
Papalambros, Panos
Influence of Nonlinear Irregular Waves on the Fatigue Loads of an Offshore Wind Turbine Michiel B-mail: michiel van.der.meulen@siemens.com Abstract. In order to make offshore wind power a cost effective load calculations by using a more advanced model for wave kinematics. As offshore wind turbines
Influence of HSX Geometry on Drift Waves Tariq Rafiq and C.C. Hegna
Hudson, Stuart
Influence of HSX Geometry on Drift Waves Tariq Rafiq and C.C. Hegna US/Japan meeting 2006 #12 and Magnetic Geometry #12;The Equilibrium The VMEC code is used to generate equilibrium data for the nested electron drift wave model, numerical method and numerical results #12;The eigenvalue equation: Using
Unravelling the influence of water depth and wave energy on the facies diversity of shelf carbonates
Purkis, Sam
Unravelling the influence of water depth and wave energy on the facies diversity of shelf their production is tied to light and wave energy, carbonate sediments are most effectively produced in shallow energy regime to be reliable indicators of facies type when considered in isolation. Consid- ered
Peculiarities in the energy transfer by waves on strained strings
Butikov, Eugene
Peculiarities in the energy transfer by waves on strained strings Eugene I. Butikov St. Petersburg of elastic potential energy associated with waves in a stretched string is discussed. The influence of nonlinear coupling between transverse and longitudinal waves on the density of energy is investigated
Petersson, A
2009-01-29
The LDRD project 'A New Method for Wave Propagation in Elastic Media' developed several improvements to the traditional finite difference technique for seismic wave propagation, including a summation-by-parts discretization which is provably stable for arbitrary heterogeneous materials, an accurate treatment of non-planar topography, local mesh refinement, and stable outflow boundary conditions. This project also implemented these techniques in a parallel open source computer code called WPP, and participated in several seismic modeling efforts to simulate ground motion due to earthquakes in Northern California. This research has been documented in six individual publications which are summarized in this report. Of these publications, four are published refereed journal articles, one is an accepted refereed journal article which has not yet been published, and one is a non-refereed software manual. The report concludes with a discussion of future research directions and exit plan.
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.
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
Naoto Yokoyama; Masanori Takaoka
2014-12-09
A single-wavenumber representation of nonlinear energy spectrum, i.e., stretching energy spectrum is found in elastic-wave turbulence governed by the F\\"oppl-von K\\'arm\\'an (FvK) equation. The representation enables energy decomposition analysis in the wavenumber space, and analytical expressions of detailed energy budget in the nonlinear interactions are obtained for the first time in wave turbulence systems. We numerically solved the FvK equation and observed the following facts. Kinetic and bending energies are comparable with each other at large wavenumbers as the weak turbulence theory suggests. On the other hand, the stretching energy is larger than the bending energy at small wavenumbers, i.e., the nonlinearity is relatively strong. The strong correlation between a mode $a_{\\bm{k}}$ and its companion mode $a_{-\\bm{k}}$ is observed at the small wavenumbers. Energy transfer shows that the energy is input into the wave field through stretching-energy transfer at the small wavenumbers, and dissipated through the quartic part of kinetic-energy transfer at the large wavenumbers. A total-energy flux consistent with the energy conservation is calculated directly by using the analytical expression of the total-energy transfer, and the forward energy cascade is observed clearly.
A. N. Norris; A. L. Shuvalov; A. A. Kutsenko
2013-03-20
The matrix sign function is shown to provide a simple and direct method to derive some fundamental results in the theory of surface waves in anisotropic materials. It is used to establish a shortcut to the basic formulas of the Barnett-Lothe integral formalism and to obtain an explicit solution of the algebraic matrix Riccati equation for the surface impedance. The matrix sign function allows the Barnett-Lothe formalism to be readily generalized for the problem of finding the surface wave speed in a periodically inhomogeneous half-space with material properties that are independent of depth. No partial wave solutions need to be found; the surface wave dispersion equation is formulated instead in terms of blocks of the matrix sign function of i times the Stroh matrix.
Sidler, Rolf, E-mail: rsidler@gmail.com [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland)] [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland); Carcione, José M. [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Borgo Grotta Gigante 42c, 34010 Sgonico, Trieste (Italy)] [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Borgo Grotta Gigante 42c, 34010 Sgonico, Trieste (Italy); Holliger, Klaus [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland)] [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland)
2013-02-15
We present a novel numerical approach for the comprehensive, flexible, and accurate simulation of poro-elastic wave propagation in 2D polar coordinates. An important application of this method and its extensions will be the modeling of complex seismic wave phenomena in fluid-filled boreholes, which represents a major, and as of yet largely unresolved, computational problem in exploration geophysics. In view of this, we consider a numerical mesh, which can be arbitrarily heterogeneous, consisting of two or more concentric rings representing the fluid in the center and the surrounding porous medium. The spatial discretization is based on a Chebyshev expansion in the radial direction and a Fourier expansion in the azimuthal direction and a Runge–Kutta integration scheme for the time evolution. A domain decomposition method is used to match the fluid–solid boundary conditions based on the method of characteristics. This multi-domain approach allows for significant reductions of the number of grid points in the azimuthal direction for the inner grid domain and thus for corresponding increases of the time step and enhancements of computational efficiency. The viability and accuracy of the proposed method has been rigorously tested and verified through comparisons with analytical solutions as well as with the results obtained with a corresponding, previously published, and independently benchmarked solution for 2D Cartesian coordinates. Finally, the proposed numerical solution also satisfies the reciprocity theorem, which indicates that the inherent singularity associated with the origin of the polar coordinate system is adequately handled.
Pettit, J. R. [Rolls-Royce Nuclear, PO BOX 2000, Derby, UK, DE21 7XX and Research Centre for NDE, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Walker, A. [Rolls-Royce Nuclear, PO BOX 2000, Derby DE21 7XX (United Kingdom); Lowe, M. J. S. [Research Centre for NDE, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)
2014-02-18
Defects which posses rough surfaces greatly affect ultrasonic wave scattering behaviour, often reducing the magnitude of reflected signals. Ultrasonic inspections rely upon this response for detecting and sizing flaws. For safety critical components reliable characterisation is crucial. Therefore, providing an accurate means to predict reductions in signal amplitude is essential. An extension of Kirchhoff theory has formed the basis for the UK power industry inspection justifications. However, it is widely recognised that these predictions are pessimistic owing to analytical approximations. A numerical full field modelling approach does not fall victim to such limitations. Here, a Finite Element model is used to aid in setting a non-conservative reporting threshold during the inspection of a large pressure vessel forging that might contain embedded rough defects. The ultrasonic response from multiple rough surfaces defined by the same statistical class is calculated for normal incident compression waves. The approach is validated by comparing coherent scattering with predictions made by Kirchhoff theory. At lower levels of roughness excellent agreement is observed, whilst higher values confirm the pessimism of Kirchhoff theory. Furthermore, the mean amplitude in the specular direction is calculated. This represents the information obtained during an inspection, indicating that reductions due to increasing roughness are significantly less than the coherent component currently being used.
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.
Pascal, Remy Claude Rene
2012-11-29
Accurate predictions of the annual energy yield from wave energy converters are essential to the development of the wave industry. The current method based on power matrices uses only a small part of the data available ...
Stress Wave Source Characterization: Impact, Fracture, and Sliding Friction
McLaskey, Gregory Christofer
2011-01-01
717-725. Graff, K. (1975). Wave Motion in Elastic Solids (and deterioration on stress wave velocities in concrete,Greenspan, M. (1981) Surface-wave displacement: absolute
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 ...
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
Paris-Sud XI, UniversitÃ© de
and the surrounding soft tissues are attenuating media, which might affect the radiofrequency signals measured systems and media, 43.20.Mv Waveguides, wave propagation in tubes and ducts, 43.20.Px Transient radiation and scattering, 43.40.Rj Radiation from vibrating structures into fluid media, 43.35.Pt Surface waves in solids
Wave propagation in a solar quiet region and the influence of the magnetic canopy
Kontogiannis, Ioannis; Tziotziou, Kostas
2015-01-01
Aims. We seek indications or evidence of transmission/conversion of magnetoacoustic waves at the magnetic canopy, as a result of its impact on the properties of the wave field of the photosphere and chromosphere. Methods. We use cross-wavelet analysis to measure phase differences between intensity and Doppler signal oscillations in the Halpha, CaII H, and G-band.We use the height of the magnetic canopy to create appropriate masks to separate internetwork (IN) and magnetic canopy regions. We study wave propagation and differences between these two regions. Results. The magnetic canopy affects wave propagation by lowering the phase differences of progressive waves and allowing the propagation of waves with frequencies lower than the acoustic cut-off. We also find indications in the Doppler signals of Halpha of a response to the acoustic waves at the IN, observed in the CaII H line. This response is affected by the presence of the magnetic canopy. Conclusions. Phase difference analysis indicates the existence of...
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
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
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
Wang, J.; Zhang, X., E-mail: zhangxm@ecust.edu.cn; Yu, L.; Zhao, X. [East China University of Science and Technology, Department of Physics (China)
2014-12-15
In tokamaks, fusion generated ? particles may absorb lower hybrid (LH) wave energy, thus reducing the LH current drive efficiency. The absorption coefficient ?{sub ?} of LH waves due to ? particles changing with some typical parameters is calculated in this paper. Results show that ?{sub ?} increases with the parallel refraction index n{sub ?}, while decreases with the frequency of LH waves ? over a wide range. Higher background plasma temperature and toroidal magnetic field will increase the absorption. The absorption coefficient ?{sub ?} increases with n{sub e} when n{sub e} ? 8 × 10{sup 19} m{sup ?3}, while decreases with n{sub e} when n{sub e} becomes larger, and there is a peak value of ?{sub ?} when n{sub e} ? 8 × 10{sup 19} m{sup ?1} for the ITER-like scenario. The influence of spectral broadening in parametric decay instabilities on the absorption coefficient is evaluated. The value of ?{sub ?} with n{sub ?} being 2.5 is almost two times larger than that with n{sub ?} being 2.0 and is even lager in the case of 2.9, which will obviously increase the absorption of the LH power by alpha particles.
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
Influence of grain size, shape and compaction on georadar waves: example of an Aeolian dune
Guillemoteau, Julien; Dujardin, Jean-Rémi; 10.1111/j.1365-246X.2012.05577.x
2012-01-01
Many Ground Penetrating Radar (GPR) profiles acquired in dry aeolian environment have shown good reflectivity inside present-day dunes. We show that the origin of this reflectivity is related to changes in grain size distribution, packing and/or grain shape in a sandy material. We integrate these three parameters into analytical models for bulk permittivity in order to predict the reflections and the velocity of GPR waves. We consider two GPR cross-sections acquired over Aeolian dunes in the Chadian desert. The 2D migration of GPR data suggests that dunes contain different kinds of bounding surfaces. We discuss and model three kinds of reflections using reasonable geological hypothesis about Aeolian sedimentation processes. The propagation and the reflection of radar waves are calculated using the 1D wavelet modelling method in spectral domain. The results of the forward modelling are in good accordance with real observed data.
Winey, J. M.; Gupta, Y. M.
2014-07-21
Understanding and modeling the response of hcp metals to high stress impulsive loading is challenging because the lower crystal symmetry, compared to cubic metals, results in a significantly more complex material response. To gain insight into the inelastic deformation of hcp metals subjected to high dynamic stresses, shock wave compression of single crystals provides a useful approach because different inelastic deformation mechanisms can be examined selectively by shock compression along different crystal orientations. As a representative example, we report, here, on wave propagation simulations for beryllium (Be) single crystals shocked along the c-axis, a-axis, and several low-symmetry directions to peak stresses reaching 7?GPa. The simulations utilized a time-dependent, anisotropic material model that incorporated dislocation dynamics, deformation twinning, and shear cracking based descriptions of inelastic deformation. The simulation results showed good overall agreement with measured wave profiles for all the different crystal orientations examined [Pope and Johnson, J. Appl. Phys. 46, 720 (1975)], including features arising from wave mode coupling due to the highly anisotropic inelastic response of Be. This good agreement demonstrates that the measured profiles can be understood in terms of dislocation slip along basal, prismatic, and pyramidal planes, together with deformation twinning along (101{sup ¯}2) planes. Our results show that the response of shocked Be single crystals involves the simultaneous operation of multiple, distinct inelastic deformation mechanisms for all orientations except the c-axis. For shocked c-axis Be, the measured wave profiles do not provide good discrimination between pyramidal slip and other inelastic deformation mechanisms, such as shear cracking. The findings presented here provide insight into the complex inelastic deformation response of shocked Be single crystals and are expected to be useful for other hcp crystals. More broadly, the present work demonstrates the potential of shock wave propagation along low-symmetry directions to examine, and discriminate between, different inelastic deformation mechanisms in crystalline solids.
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.
Xiao Renzhen; Zhang Xiaowei; Zhang Ligang; Li Xiaoze; Zhang Lijun [National Key Laboratory of Science and Technology on High Power Microwave, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)
2012-07-15
In this paper, we analyze the factors that affect the microwave pulse duration in a klystron-like relativistic backward wave oscillator (RBWO), including the diode voltage, the guiding magnetic field, the electron beam collector, the extraction cavity, and the gap between the electron beam and the slow wave structure (SWS). The results show that the microwave pulse duration increases with the diode voltage until breakdown occurs on the surface of the extraction cavity. The pulse duration at low guiding magnetic field is generally 5-10 ns smaller than that at high magnetic field due to the asymmetric electron emission and the larger energy spread of the electron beam. The electron beam collector can affect the microwave pulse duration significantly because of the anode plasma generated by bombardment of the electron beam on the collector surface. The introduction of the extraction cavity only slightly changes the pulse duration. The decrease of the gap between the electron beam and the SWS can increase the microwave pulse duration greatly.
Seismic waves in rocks with fluids and fractures
Berryman, J.G.
2007-05-14
Seismic wave propagation through the earth is often stronglyaffected by the presence of fractures. When these fractures are filledwith fluids (oil, gas, water, CO2, etc.), the type and state of the fluid(liquid or gas) can make a large difference in the response of theseismic waves. This paper summarizes recent work on methods ofdeconstructing the effects of fractures, and any fluids within thesefractures, on seismic wave propagation as observed in reflection seismicdata. One method explored here is Thomsen's weak anisotropy approximationfor wave moveout (since fractures often induce elastic anisotropy due tononuniform crack-orientation statistics). Another method makes use ofsome very convenient fracture parameters introduced previously thatpermit a relatively simple deconstruction of the elastic and wavepropagation behavior in terms of a small number of fracture parameters(whenever this is appropriate, as is certainly the case for small crackdensities). Then, the quantitative effects of fluids on thesecrack-influence parameters are shown to be directly related to Skempton scoefficient B of undrained poroelasticity (where B typically ranges from0 to 1). In particular, the rigorous result obtained for the low crackdensity limit is that the crack-influence parameters are multiplied by afactor (1 ? B) for undrained systems. It is also shown how fractureanisotropy affects Rayleigh wave speed, and how measured Rayleigh wavespeeds can be used to infer shear wave speed of the fractured medium.Higher crack density results are also presented by incorporating recentsimulation data on such cracked systems.
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.
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
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.
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
INVERSE OBSTACLE SCATTERING FOR ELASTIC WAVES 1 ...
2015-03-04
scientific areas such as seismic tomography, non-destructive testing, and ...... This observation motivates us to design an explicit formula to reconstruct the ...
E. B. Herbold; V. F. Nesterenko; C. Daraio
2005-12-22
Strongly nonlinear phononic crystals were assembled from stainless steel spheres. Single solitary waves and splitting of an initial pulse into a train of solitary waves were investigated in different viscous media using motor oil and non-aqueous glycerol to introduce a controlled viscous dissipation. Experimental results indicate that the presence of a viscous fluid dramatically altered the splitting of the initial pulse into a train of solitary waves. Numerical simulations qualitatively describe the observed phenomena only when a dissipative term based on the relative velocity between particles is introduced.
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.
Distributed Computation of Wave Propagation Models Using PVM R. E. Ewing D. Mitchum and P. O'Leary
Ewing, Richard E.
will be the acoustic and elastic wave equations. The acoustic wave equation is used to simulate presÂ sure changes the propagation of seismic waves in the earth. The equations used to model seismic wave propagaÂ tion and the elastic wave equation is used to simulate particle displacement. We present results for largeÂscale two
A high-order discontinuous Galerkin method for wave propagation...
Office of Scientific and Technical Information (OSTI)
A high-order discontinuous Galerkin method for wave propagation through coupled elastic-acoustic media Citation Details In-Document Search Title: A high-order discontinuous...
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.
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.
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.}
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.
Smith-Konter, Bridget
by rapid release is called elastic rebound. Energy, friction and waves. At first the rock does not move, so the energy is stored in the elastic cord. The more the elastic cord is stretched, the more energy is stored friction that is resisting motion of the rock. The energy that was slowly stored up within the elastic cord
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.
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
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.
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
Long wave expansions for water waves over random topography
Craig, Walter
Long wave expansions for water waves over random topography Anne de Bouard1 , Walter Craig2 interacting with the random bottom. We show that the resulting influence of the random topography is expressed numbers: 76B15, 35Q53, 76M50, 60F17 Keywords :Water waves, random topography, long wave asymptotics #12
1.138J / 2.062J Wave Propagation, Fall 2000
Mei, Chiang C.
Linearized theory of wave phenomena in applied mechanics. Examples are chosen from elasticity, acoustics, geophysics, hydrodynamics and other subjects. Basic concepts. One dimensional examples. Characteristics, dispersion ...
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.
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.
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.
Mazur, V. A. Chuiko, D. A.
2013-12-15
The coefficient of reflection of a fast magnetosonic wave incident on the magnetosphere from the solar wind is studied analytically in the framework of a plane-stratified model of the medium with allowance for the transverse inhomogeneity of the magnetosphere and a jump of the plasma parameters at the magnetopause. Three factors decisively affecting the properties of reflection are taken into account: the shear flow of the solar wind plasma relative to the magnetosphere; the presence of a magnetospheric magnetohydrodynamic waveguide caused by the transverse plasma inhomogeneity; and the presence of an Alfvén resonance deep in the magnetosphere, where the oscillation energy dissipates. If the solar wind velocity exceeds the wave phase velocity along the magnetopause, then the wave energy in the solar wind is negative and such a wave experiences overreflection. In the opposite case, the wave energy is positive and the wave is reflected only partially. The wave reflection has a pronounced resonant character: the reflection coefficient has deep narrow minima or high narrow maxima at the eigenfrequencies of the magnetospheric waveguide. For other frequencies, the reflection coefficient only slightly differs from unity. The wave energy influx into the magnetosphere is positive for waves with both positive and negative energies. For waves with a negative energy, this is a consequence of their overreflection, because the flux of negative energy carried away by the reflected wave exceeds the incident flux of negative energy.
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.
Wave Motion 52 (2015) 151159 Contents lists available at ScienceDirect
Snieder, Roel
2015-01-01
, or compress, elastic wave energy, or to improve the quality of the reconstruction of the source signal focusing. The desire to enhance the TR process to focus wave energy has led researchers to develop
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
LONG WAVE EXPANSIONS FOR WATER WAVES OVER RANDOM TOPOGRAPHY
LONG WAVE EXPANSIONS FOR WATER WAVES OVER RANDOM TOPOGRAPHY ANNE DE BOUARD 1 , WALTER CRAIG 2 with the ran dom bottom. We show that the resulting influence of the random topography is expressed in terms of bottom topography a#ects the equations describing the limit of solutions in the long wave regime. We
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 ...
Gustafsson, Torgny
2011 Waves - 1 STANDING WAVES ON A STRING The objectives of the experiment are: · To show that standing waves can be set up on a string. · To determine the velocity of a standing wave. · To understand of waves. A #12;2011 Waves - 2 A standing wave is caused by superposing two similar (same frequency
Pack, Julie Diane
2009-05-15
Objectives were to determine: 1) whether estradiol benzoate (EB) provides a superior alternative to GnRH for synchronizing emergence, growth and maturation of a new follicular wave for fixed timed AI (TAI) in Bos ...
Capillary wave turbulence on a spherical fluid surface in low gravity
Falcon, Eric
.epljournal.org #12;Europhysics Letters (EPL) has a new online home at www.epljournal.org Take a look for the latest. The surface wave amplitude displays power law spectrum over two decades in frequency, corresponding´en waves in solar wind [3], plasmas [4], surface waves on elastic plates [5], and spin waves in solids
WAVE SPEEDS FOR AN ELASTOPLASTIC MODEL FOR TWODIMENSIONAL DEFORMATIONS WITH A NONASSOCIATIVE FLOW of variables, the character istic speeds of plane wave solutions of the system are computed. For both plastic and elastic deformations, there are two nonzero wave speeds, referred to as fast and slow waves. It is shown
Wave Motion 49 (2012) 765781 Contents lists available at SciVerse ScienceDirect
Guzina, Bojan
2012-01-01
Wave Motion 49 (2012) 765781 Contents lists available at SciVerse ScienceDirect Wave Motion scattering of elastic waves [1] is a long-standing problem in mechanics whose applications extend to a wide: huinayuan@mail.tsinghua.edu.cn (H. Yuan), guzina@wave.ce.umn.edu (B.B. Guzina). 0165-2125/$ see front
Konofagou, Elisa E.
Electromechanical wave imaging for noninvasive mapping of the 3D electrical activation sequence Echocardiography Elasticity imaging Electromechanical Ischemia Myocardial Radio-frequency Stiffness Strain of the myocardium. Electromechanical Wave Imaging (EWI) is an ultrasound-based technique that utilizes
van Manen, Dirk-Jan
2006-01-01
In exploration seismics and non-destructive evaluation, acoustic, elastic and electro-magnetic waves sensitive to inhomogeneities in the medium under investigation are used to probe its interior. Waves multiply scattered ...
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
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.
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
Nonlinear Hysteretic Torsional Waves
J. Cabaret; P. Béquin; G. Theocharis; V. Andreev; V. E. Gusev; V. Tournat
2015-01-09
We theoretically study and experimentally report the propagation of nonlinear hysteretic torsional pulses in a vertical granular chain made of cm-scale, self-hanged magnetic beads. As predicted by contact mechanics, the torsional coupling between two beads is found nonlinear hysteretic. This results in a nonlinear pulse distortion essentially different from the distortion predicted by classical nonlinearities, and in a complex dynamic response depending on the history of the wave particle angular velocity. Both are consistent with the predictions of purely hysteretic nonlinear elasticity and the Preisach-Mayergoyz hysteresis model, providing the opportunity to study the phenomenon of nonlinear dynamic hysteresis in the absence of other type of material nonlinearities. The proposed configuration reveals a plethora of interesting phenomena including giant amplitude-dependent attenuation, short term memory as well as dispersive properties. Thus, it could find interesting applications in nonlinear wave control devices such as strong amplitude-dependent filters.
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...
M. Carcione, F. Cavallini, Simulation of waves in porn-viscoelastic rocks Saturated by immiscible ?uids. Numerical evidence ofa second slow wave,]. Comput.
Wave turbulence buildup in a vibrating plate
Auliel, Maria Ines; Mordant, Nicolas
2015-01-01
We report experimental and numerical results on the buildup of the energy spectrum in wave turbulence of a vibrating thin elastic plate. Three steps are observed: first a short linear stage, then the turbulent spectrum is constructed by the propagation of a front in wave number space and finally a long time saturation due to the action of dissipation. The propagation of a front at the second step is compatible with scaling predictions from the Weak Turbulence Theory.
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.
Wave propagation in anisotropic elastic materials and curvilinear...
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Wave propagation in anisotropic elastic materials and curvilinear
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaonfor DirectSciTech ConnectConnect Wavecoordinates using a
Experimental investigation of a horizontal flexible-membrane wave barrier
Choi, Hae-Jin
1997-01-01
A series of experiments is conducted in a two-dimensional glass-walled wave tank to confirm numerical solutions based on two-dimensional linear hydro-elastic theory for a horizontal flexible-membrane wave barrier. The model test is performed by a...
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.
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.
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.
Scaling Results for a Discontinuous Galerkin Finite-Element Wave Solver on Multi-GPU Systems
Schenk, Olaf
was adapted to work for the acoustic wave equation. MIDG provides both CPU and CUDA-based GPU solvers the acoustic wave #12;equation, which has fewer terms and provides a simpler scalabilty testbed. After this research are based on the elastic wave equation, but for simplicity in this paper we will explore
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
Andrey Beresnyak; Alex Lazarian
2008-05-06
We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave decay in three-dimensional MHD turbulence, and discuss the influence of turbulent damping on the development of linear instabilities in the interstellar medium and on other important astrophysical processes.
1.138J / 2.062J / 18.376J Wave Propagation, Fall 2004
Akylas, Triantaphyllos R.
This course discusses the Linearized theory of wave phenomena in applied mechanics. Examples are chosen from elasticity, acoustics, geophysics, hydrodynamics and other subjects. The topics include: basic concepts, one ...
Pratt, R. Gerhard
wave (V,s) velocity anomalies can be obtained by applying acoustic wave-equation imaging in two passes slightly better images of the V,] discontinuities than the acoustic wave-equation method. Errors in picking and algorithmic aspects of the method for acoustic and elastic wave equations and applied it to synthetic data
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.
Goldstein, Raymond E.
and Whirling: Viscous Dynamics of Rotating Elastic Filaments Charles W. Wolgemuth,1 Thomas R. Powers,3 for self-propulsion are investigated, and experimental tests proposed. PACS numbers: 87.16.2b, 05.45.2a, 46 in the inviscid limit (as in whirling shafts [15,16]), where twist waves propagate [15,17]. An elastic filament
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.
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.
Two-wave interaction in ideal magnetohydrodynamics
T. V. Zaqarashvili; B. Roberts
2006-02-24
The weakly nonlinear interaction of sound and linearly polarised Alfv{\\'e}n waves propagating in the same direction along an applied magnetic field is studied. It is found that a sound wave is coupled to the Alfv{\\'e}n wave with double period and wavelength when the sound and Alfv{\\'e}n speeds are equal. The Alfv{\\'e}n wave drives the sound wave through the ponderomotive force, while the sound wave returns energy back to the Alfv{\\'e}n wave through the parametric (swing) influence. As a result, the two waves alternately exchange their energy during propagation. The process of energy exchange is faster for waves with stronger amplitudes. The phenomenon can be of importance in astrophysical plasmas, including the solar atmosphere and solar wind.
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.
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.
Wave represents displacement Wave represents pressure Source -Sound Waves
Colorado at Boulder, University of
is wavelength Number of crests passing a point in 1 second is frequency Wave represents pressure Target - Radio. The Sound Waves simulation becomes the source of an analogical mapping to Radio Waves. Concepts Radio Waves 1 - Sound Waves references water waves 2 - Water is analogy for Sound Waves 3 - Radio
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
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
Using high-power lasers for detection of elastic photon-photon scattering
E. Lundstrom; G. Brodin; J. Lundin; M. Marklund; R. Bingham; J. Collier; J. T. Mendonca; P. Norreys
2006-02-01
The properties of four-wave interaction via the nonlinear quantum vacuum is investigated. The effect of the quantum vacuum is to generate photons with new frequencies and wave vectors, due to elastic photon-photon scattering. An expression for the number of generated photons is derived and using state-of-the-art laser data it is found that the number of photons can reach detectable levels. In particular, the prospect of using the high repetition Astra Gemini system at the Rutherford Appleton Laboratory is discussed. The problem of noise sources is reviewed, and it is found that the noise level can be reduced well below the signal level. Thus, detection of elastic photon-photon scattering may for the first time be achieved.
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...
Mechanical Surface Waves Accompany Action Potential Propagation
Ahmed El Hady; Benjamin B. Machta
2014-10-05
Many studies have shown that a mechanical displacement of the axonal membrane accompanies the electrical pulse defining the Action Potential (AP). Despite a large and diverse body of experimental evidence, there is no theoretical consensus either for the physical basis of this mechanical wave nor its interdependence with the electrical signal. In this manuscript we present a model for these mechanical displacements as arising from the driving of surface wave modes in which potential energy is stored in elastic properties of the neuronal membrane and cytoskeleton while kinetic energy is carried by the axoplasmic fluid. In our model these surface waves are driven by the traveling wave of electrical depolarization that characterizes the AP, altering the compressive electrostatic forces across the membrane as it passes. This driving leads to co-propagating mechanical displacements, which we term Action Waves (AWs). Our model for these AWs allows us to predict, in terms of elastic constants, axon radius and axoplasmic density and viscosity, the shape of the AW that should accompany any traveling wave of voltage, including the AP predicted by the Hodgkin and Huxley (HH) equations. We show that our model makes predictions that are in agreement with results in experimental systems including the garfish olfactory nerve and the squid giant axon. We expect our model to serve as a framework for understanding the physical origins and possible functional roles of these AWs in neurobiology.
Investigation of surface acoustic wave fields in silicon crystals by x-ray diffraction: A dynamical at different x-ray energies from a Si crystal subjected to a deformation produced by surface acoustic wave of the elastic model describing the acoustic wave fields inside the crystal. © 2005 American Institute of Physics
Generation of macroscopic pair-correlated atomic beams by four-wave mixing in Bose, and W. Ketterle, Generation of macroscopic pair-correlated atomic beams by four-wave mixing in Bose of the elastic scattering process. When a weak input beam (third wave) was applied as a seed, it was amplified
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.
DECAY OF SOLUTIONS TO A WATER WAVE MODEL WITH A ...
2009-07-15
Dutykh and F. Dias have introduced a system which models water waves in a fluid layer of finite depth under the influence of viscous effects. The model.
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.
Measurements of the Influence of Acceleration and Temperature of Bodies on their Weight
A. L. Dmitriev
2008-03-12
A brief review of experimental research of the influence of acceleration and temperatures of test mass upon gravitation force, executed between the 1990s and the beginning of 2000 is provided.Results of weighing a rotor of a mechanical gyroscope with a horizontal axis, an anisotropic crystal with the big difference of the speed of longitudinal acoustic waves, measurements of temperature dependence of weight of metal bars of non-magnetic materials, and also measurement of restitution coefficients at quasi-elastic impact of a steel ball about a massive plate are given. A negative temperature dependence of the weight of a brass core was measured. All observably experimental effects, have probably a general physical reason connected with the weight change dependent upon acceleration of a body or at thermal movement of its microparticles.
Paul S. Wesson
2012-12-11
As an example of the unification of gravitation and particle physics, an exact solution of the five-dimensional field equations is studied which describes waves in the classical Einstein vacuum. While the solution is essentially 5D in nature, the waves exist in ordinary 3D space, and may provide a way to test for an extra dimension.
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".
Korneev, Valeri A.
. In the prospecting seismology Krauklis wave might be an important component of the hydro- fracturing process, seismic Conference & Exhibition Geosciences: Making the most of the Earth's resources Saint Petersburg, Russia, 2 by an elastic halfspace. Nowadays, Love wave is a powerful instrument of subsurface studies in engineering
Quark Structure of the Nucleon and Angular Asymmetry of Proton-Neutron Hard Elastic Scattering
Carlos G. Granados; Misak M. Sargsian
2009-07-29
We investigate an asymmetry in the angular distribution of hard elastic proton-neutron scattering with respect to 90deg center of mass scattering angle. We demonstrate that the magnitude of the angular asymmetry is related to the helicity-isospin symmetry of the quark wave function of the nucleon. Our estimate of the asymmetry within the quark-interchange model of hard scattering demonstrates that the quark wave function of a nucleon based on the exact SU(6) symmetry predicts an angular asymmetry opposite to that of experimental observations. On the other hand the quark wave function based on the diquark picture of the nucleon produces an asymmetry consistent with the data. Comparison with the data allowed us to extract the relative sign and the magnitude of the vector and scalar diquark components of the quark wave function of the nucleon. These two quantities are essential in constraining QCD models of a nucleon. Overall, our conclusion is that the angular asymmetry of a hard elastic scattering of baryons provides a new venue in probing quark-gluon structure of baryons and should be considered as an important observable in constraining the theoretical models.
Radio Wave Propagation in Potato Fields John Thelen
Langendoen, Koen
Radio Wave Propagation in Potato Fields John Thelen Wageningen University Email: John has an important effect on the propagation of radio waves. The influence of the growth stage from 23 m to 10 m. Another important result is that radio waves propagate better in conditions
Wind spatial variability and topographic wave frequency Elad Shilo*1
Ashkenazy, Yossi "Yosef"
Wind spatial variability and topographic wave frequency Elad Shilo*1 , Yosef Ashkenazy2 , Alon of topographic waves with wind action has been documented in several natural lakes throughout the world. However, the influence of the wind's spatial variability (wind stress curl) on the frequency of topographic waves has
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.
Wave Propagation in Multiferroic Materials
Keller, Scott Macklin
2013-01-01
130 SAW Waves . . . . . . . . . . . . . .QuasiStatic MEE Waves . . . . . . . . . . . . . . . . . . .General MEE Wave Solution . . . . . . . . . . . .
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
Internal wave instability: Wave-wave versus wave-induced mean flow interactions
Sutherland, Bruce
Internal wave instability: Wave-wave versus wave-induced mean flow interactions B. R. Sutherland fluid, vertically propagating internal gravity waves of moderately large amplitude can become unstable, energy from primary waves is transferred, for example, to waves with half frequency. Self
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.
Energy dissipation in wave propagation in general relativistic plasma
Ajanta Das; S. Chatterjee
2009-11-03
Based on a recent communication by the present authors the question of energy dissipation in magneto hydrodynamical waves in an inflating background in general relativity is examined. It is found that the expanding background introduces a sort of dragging force on the propagating wave such that unlike the Newtonnian case energy gets dissipated as it progresses. This loss in energy having no special relativistic analogue is, however, not mechanical in nature as in elastic wave. It is also found that the energy loss is model dependent and also depends on the number of dimensions.
Shallow Water Waves and Solitary Waves
Hereman, Willy
2013-01-01
Encyclopedic article covering shallow water wave models used in oceanography and atmospheric science. Sections: Definition of the Subject; Introduction and Historical Perspective; Completely Integrable Shallow Water Wave Equations; Shallow Water Wave Equations of Geophysical Fluid Dynamics; Computation of Solitary Wave Solutions; Numerical Methods; Water Wave Experiments and Observations; Future Directions, and Bibliography.
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.
Michel Zamboni-Rached; Erasmo Recami; Hugo E. Harnandez-Figueroa
2002-10-02
By a generalized bidirectional decomposition method, we obtain many new Superluminal localized solutions to the wave equation (for the electromagnetic case, in particular) which are suitable for arbitrary frequency bands; various of them being endowed with finite total energy. We construct, among the others, an infinite family of generalizations of the so-called "X-shaped" waves. [PACS nos.: 03.50.De; 41.20;Jb; 83.50.Vr; 62.30.+d; 43.60.+d; 91.30.Fn; 04.30.Nk; 42.25.Bs; 46.40.Cd; 52.35.Lv. Keywords: Wave equations; Wave propagation; Localized beams; Superluminal waves; Bidirectional decomposition; Bessel beams; X-shaped waves; Microwaves; Optics; Special relativity; Acoustics; Seismology; Mechanical waves; Elastic waves; Gravitational waves; Elementary particle physics].
Microfabricated bulk wave acoustic bandgap device
Olsson, Roy H. (Albuquerque, NM); El-Kady, Ihab F. (Albuquerque, NM); McCormick, Frederick (Albuquerque, NM); Fleming, James G. (Albuquerque, NM); Fleming, legal representative, Carol (Albuquerque, NM)
2010-11-23
A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).
Microfabricated bulk wave acoustic bandgap device
Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming, Carol
2010-06-08
A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).
Wave turbulence served up on a plate
Pablo Cobelli; Philippe Petitjeans; Agnes Maurel; Vincent Pagneux; Nicolas Mordant
2009-10-28
Wave turbulence in a thin elastic plate is experimentally investigated. By using a Fourier transform profilometry technique, the deformation field of the plate surface is measured simultaneously in time and space. This enables us to compute the wavevector-frequency Fourier ($\\mathbf k, \\omega$) spectrum of the full space-time deformation velocity. In the 3D ($\\mathbf k, \\omega$) space, we show that the energy of the motion is concentrated on a 2D surface that represents a nonlinear dispersion relation. This nonlinear dispersion relation is close to the linear dispersion relation. This validates the usual wavenumber-frequency change of variables used in many experimental studies of wave turbulence. The deviation from the linear dispersion, which increases with the input power of the forcing, is attributed to weak non linear effects. Our technique opens the way for many new extensive quantitative comparisons between theory and experiments of wave turbulence.
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.
Wave variability and wave spectra for wind generated gravity waves
Bretschneider, Charles L.
1959-01-01
A series of experiments of forces on a fixed vertical truncated column due to Stokes 5th order like waves were done in a wave tank. An effort was made to generate the waves as close as possible to theoretical Stokes 5th order waves. A systematic...
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...
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.
Effects of pore fluids in the subsurface on ultrasonic wave propagation
Seifert, P.K.
1998-05-01
This thesis investigates ultrasonic wave propagation in unconsolidated sands in the presence of different pore fluids. Laboratory experiments have been conducted in the sub-MHz range using quartz sand fully saturated with one or two liquids. Elastic wave propagation in unconsolidated granular material is computed with different numerical models: in one-dimension a scattering model based on an analytical propagator solution, in two dimensions a numerical approach using the boundary integral equation method, in three dimensions the local flow model (LFM), the combined Biot and squirt flow theory (BISQ) and the dynamic composite elastic medium theory (DYCEM). The combination of theoretical and experimental analysis yields a better understanding of how wave propagation in unconsolidated sand is affected by (a) homogeneous phase distribution; (b) inhomogeneous phase distribution, (fingering, gas inclusions); (c) pore fluids of different viscosity; (d) wettabilities of a porous medium. The first study reveals that the main ultrasonic P-wave signatures, as a function of the fraction on nonaqueous-phase liquids in initially water-saturated sand samples, can be explained by a 1-D scattering model. The next study investigates effects of pore fluid viscosity on elastic wave propagation, in laboratory experiments conducted with sand samples saturated with fluids of different viscosities. The last study concentrates on the wettability of the grains and its effect on elastic wave propagation and electrical resistivity.
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...
Pole structure from energy-dependent and single-energy fits to $?N$ elastic scattering data
Alfred Švarc; Mirza Hadžimehmedovi?; Hedim Osmanovi?; Jugoslav Stahov; Ron L. Workman
2015-01-28
The pole structure of the current GW/SAID partial-wave analysis of elastic $\\pi N$ scattering and $\\eta N$ production data is studied. Pole positions and residues are extracted from both the energy-dependent and single-energy fits, using two different methods. For the energy-dependent fits, both contour integration and a Laurent+Pietarinen approach are used. In the case of single-energy fits, the Laurent+Pietarinen approach is used. Errors are estimated and the two sets of results are compared to other recent and older fits to data.
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...
Localization of Classical Waves I: Acoustic Waves.
Localization of Classical Waves I: Acoustic Waves. Alexander Figotin \\Lambda Department, 1997 Abstract We consider classical acoustic waves in a medium described by a position dependent mass the existence of localized waves, i.e., finite energy solutions of the acoustic equations with the property
Coda wave interferometry 1 Coda wave interferometry
Snieder, Roel
Coda wave interferometry 1 Coda wave interferometry An interferometer is an instrument that is sensitive to the interference of two or more waves (optical or acoustic). For example, an optical interferometer uses two interfering light beams to measure small length changes. Coda wave interferometry
Film Notes: Three Romanian Movies (On Belonging and Corporeality in the New Wave of Romanian Cinema)
Roman, Denise
2008-01-01
new wave of Romanian cinema also bear stylistic influences.in Romania after 1989 are cinema vérité, documentary, real-in the New Wave of Romanian Cinema) by Denise Roman the dim
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.
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.
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
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.
Broader source: Energy.gov [DOE]
Wave energy technologies extract energy directly from surface waves or from pressure fluctuations below the surface. Renewable energy analysts believe there is enough energy in ocean waves to provide up to 2 terawatts of electricity.
Wirosoetisno, Djoko
focussing: in crossing seas due to coastal or submarine convergences. Moreover, (rogue) wave energy devices maker to create the highest rogue wave? geometry and dynamo in a new rogue wave energy device? maximum
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.
Soliton Staircases and Standing Strain Waves in Confined Colloidal Crystals
Yu-Hang Chui; Surajit Sengupta; Kurt Binder
2009-12-07
We show by computer simulation of a two-dimensional crystal confined by corrugated walls that confinement can be used to impose a controllable mesoscopic superstructure of predominantly mechanical elastic character. Due to an interplay of the particle density of the system and the width D of the confining channel, "soliton staircases" can be created along both parallel confining boundaries, that give rise to standing strain waves in the entire crystal. The periodicity of these waves is of the same order as D. This mechanism should be useful for structure formation in the self-assembly of various nanoscopic materials.
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.
Plate damage identification using wave propagation and impedance methods.
Wait, J. R. (Jeannette R.); Park, G. H. (Gyu Hae); Sohn, H. (Hoon); Farrar, C. R. (Charles R.)
2004-01-01
This paper illustrates an integrated approach for identifying structural damage in an aluminum plate. Piezoelectric (PZT) materials are used to actuatehense the dynamic response of the structure. Two damage identification techniques are integrated in this study, including Lamb wave propagations and impedance methods. In Lamb wave propagations, one PZT launches an elastic wave through the structure, and responses are measured by an array of PZT sensors. The changes in both wave attenuation and reflection are used to detect and locate the damage. The impedance method monitors the variations in structural mechanical impedance, which is coupled with the electrical impedance of the PZT. Both methods operate in high frequency ranges at which there are measurable changes in structural responses even for incipient damage such as small cracks or loose connections. This paper summarizes two methods used for damage identification, experimental procedures, and additional issues that can be used as a guideline for future investigations.
Transport induced by Density Waves in a Andreev-Lifshitz Supersolid
Kwang-Hua W. Chu
2006-09-03
Macroscopic derivation of the entrainment in in a Andreev-Lifshitz Supersolid induced by a surface elastic wave propagating along the flexible interface is conducted by considering the nonlinear coupling between the interface and the rarefaction effect. We obtain the critical bounds for zero-volume-flow-rate states corresponding to specific rarefaction measure and wave number which is relevant to the rather small critical velocity of supersolid flows reported by Kim and Chan.
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...
Geometrical vs wave optics under gravitational waves
Raymond Angélil; Prasenjit Saha
2015-05-20
We present some new derivations of the effect of a plane gravitational wave on a light ray. A simple interpretation of the results is that a gravitational wave causes a phase modulation of electromagnetic waves. We arrive at this picture from two contrasting directions, namely null geodesics and Maxwell's equations, or, geometric and wave optics. Under geometric optics, we express the geodesic equations in Hamiltonian form and solve perturbatively for the effect of gravitational waves. We find that the well-known time-delay formula for light generalizes trivially to massive particles. We also recover, by way of a Hamilton-Jacobi equation, the phase modulation obtained under wave optics. Turning then to wave optics - rather than solving Maxwell's equations directly for the fields, as in most previous approaches - we derive a perturbed wave equation (perturbed by the gravitational wave) for the electromagnetic four-potential. From this wave equation it follows that the four-potential and the electric and magnetic fields all experience the same phase modulation. Applying such a phase modulation to a superposition of plane waves corresponding to a Gaussian wave packet leads to time delays.
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.
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.
Boal, David
PHYS 101 Lecture 22 - Standing and travelling waves 22 - 1 © 2001 by David Boal, Simon Fraser University. All rights reserved; further copying or resale is strictly prohibited. Lecture 22 - Standing Demonstrations: · retort stand, elastic band, 0.5 kg mass, monochord Standing and Travelling Waves If we pluck
Slow Waves in Fractures Filled with Viscous Fluid
Korneev, Valeri
2008-01-08
Stoneley guided waves in a fluid-filled fracture generally have larger amplitudes than other waves, and therefore, their properties need to be incorporated in more realistic models. In this study, a fracture is modeled as an infinite layer of viscous fluid bounded by two elastic half-spaces with identical parameters. For small fracture thickness, I obtain a simple dispersion equation for wave-propagation velocity. This velocity is much smaller than the velocity of a fluid wave in a Biot-type solution, in which fracture walls are assumed to be rigid. At seismic prospecting frequencies and realistic fracture thicknesses, the Stoneley guided wave has wavelengths on the order of several meters and an attenuation Q factor exceeding 10, which indicates the possibility of resonance excitation in fluid-bearing rocks. The velocity and attenuation of Stoneley guided waves are distinctly different at low frequencies for water and oil. The predominant role of fractures in fluid flow at field scales is supported by permeability data showing an increase of several orders of magnitude when compared to values obtained at laboratory scales. These data suggest that Stoneley guided waves should be taken into account in theories describing seismic wave propagation in fluid-saturated rocks.
DISSIPATIVE ENERGIZATION OF BAROCLINIC WAVES BY SURFACE EKMAN PUMPING
Lee, Sukyoung
DISSIPATIVE ENERGIZATION OF BAROCLINIC WAVES BY SURFACE EKMAN PUMPING Sukyoung Lee Department influences, the nonlinear behavior will be referred to as 1 #12;`dissipative energization' and the linear by which Ek- man pumping can energize baroclinic waves is not well understood. Dissipative energization
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.
Investigation of Nonequilibrium Internal Energy Excitation in Shock Waves by means of a Spectral energy) to a multi energy level gas. The numerical method is based on the weak form of the collision to account for both elastic and inelastic collisions, the latter being responsible for internal energy
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
California at Santa Barbara, University of
Verdes, Campus Point, Coal Oil Point (Sands) Waves propagate perpendicular to isobaths (lines of constant
Water Waves Roger Grimshaw May 7, 2003 Abstract A short review of the theory of weakly nonlinear water waves, prepared for the forthcoming Encyclopedia of Nonlinear Science 1 Introduction Water waves nonlinear waves. Throughout the theory is based on the traditional assumptions that water is inviscid
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
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.
Spatial damping of propagating sausage waves in coronal cylinders
Guo, Ming-Zhe; Li, Bo; Xia, Li-Dong; Yu, Hui
2015-01-01
Sausage modes are important in coronal seismology. Spatially damped propagating sausage waves were recently observed in the solar atmosphere. We examine how wave leakage influences the spatial damping of sausage waves propagating along coronal structures modeled by a cylindrical density enhancement embedded in a uniform magnetic field. Working in the framework of cold magnetohydrodynamics, we solve the dispersion relation (DR) governing sausage waves for complex-valued longitudinal wavenumber $k$ at given real angular frequencies $\\omega$. For validation purposes, we also provide analytical approximations to the DR in the low-frequency limit and in the vicinity of $\\omega_{\\rm c}$, the critical angular frequency separating trapped from leaky waves. In contrast to the standing case, propagating sausage waves are allowed for $\\omega$ much lower than $\\omega_{\\rm c}$. However, while able to direct their energy upwards, these low-frequency waves are subject to substantial spatial attenuation. The spatial damping ...
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.
Pore-fluid effects on seismic waves in vertically fractured earth with orthotropic symmetry
Berryman, J.G.
2010-05-15
For elastically noninteracting vertical-fracture sets at arbitrary orientation angles to each other, a detailed model is presented in which the resulting anisotropic fractured medium generally has orthorhombic symmetry overall. Some of the analysis methods and ideas of Schoenberg are emphasized, together with their connections to other similarly motivated and conceptually related methods by Sayers and Kachanov, among others. Examples show how parallel vertical-fracture sets having HTI (horizontal transversely isotropic) symmetry transform into orthotropic fractured media if some subsets of the vertical fractures are misaligned with the others, and then the fractured system can have VTI (vertical transversely isotropic) symmetry if all of the fractures are aligned randomly or half parallel and half perpendicular to a given vertical plane. An orthotropic example having vertical fractures in an otherwise VTI earth system (studied previously by Schoenberg and Helbig) is compared with the other examples treated and it is finally shown how fluids in the fractures affect the orthotropic poroelastic system response to seismic waves. The key result is that fracture-influence parameters are multiplied by a factor of (1-B), where 0 {le} B < 1 is Skempton's second coefficient for poroelastic media. Skempton's B coefficient is itself a measurable characteristic of fluid-saturated porous rocks, depending on porosity, solid moduli, and the pore-fluid bulk modulus. For heterogeneous porous media, connections between the present work and earlier related results of Brown and Korringa are also established.
the wave model A traveling wave is an organized disturbance
Winokur, Michael
1 waves the wave model A traveling wave is an organized disturbance propagating at a well-defined wave speed v. · In transverse waves the particles of the medium move perpendicular to the direction of wave propagation. · In longitudinal waves the particles of the medium move parallel to the direction
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 -...
Long wave expansions for water waves over random topography
Anne de Bouard; Walter Craig; Oliver Díaz-Espinosa; Philippe Guyenne; Catherine Sulem
2007-10-01
In this paper, we study the motion of the free surface of a body of fluid over a variable bottom, in a long wave asymptotic regime. We assume that the bottom of the fluid region can be described by a stationary random process $\\beta(x, \\omega)$ whose variations take place on short length scales and which are decorrelated on the length scale of the long waves. This is a question of homogenization theory in the scaling regime for the Boussinesq and KdV equations. The analysis is performed from the point of view of perturbation theory for Hamiltonian PDEs with a small parameter, in the context of which we perform a careful analysis of the distributional convergence of stationary mixing random processes. We show in particular that the problem does not fully homogenize, and that the random effects are as important as dispersive and nonlinear phenomena in the scaling regime that is studied. Our principal result is the derivation of effective equations for surface water waves in the long wave small amplitude regime, and a consistency analysis of these equations, which are not necessarily Hamiltonian PDEs. In this analysis we compute the effects of random modulation of solutions, and give an explicit expression for the scattered component of the solution due to waves interacting with the random bottom. We show that the resulting influence of the random topography is expressed in terms of a canonical process, which is equivalent to a white noise through Donsker's invariance principle, with one free parameter being the variance of the random process $\\beta$. This work is a reappraisal of the paper by Rosales & Papanicolaou \\cite{RP83} and its extension to general stationary mixing processes.
GRAVITY WAVE DYNAMICS AND EFFECTS IN THE MIDDLE David C. Fritts and M. Joan Alexander
Alexander, M. Joan
GRAVITY WAVE DYNAMICS AND EFFECTS IN THE MIDDLE ATMOSPHERE David C. Fritts and M. Joan Alexander gravity waves have been a subject of intense research activity in recent years because of their myriad occasionally strong lower-atmospheric effects, the major wave influences occur in the middle atmosphere, be
FREAK WAVES AND CONCLUSIVE SIMULATION R. V. Shamin
Fominov, Yakov
, y, t) F2(x, y, t) Dissipation Calc error Errors of calculations Small external influences (wind error Errors of calculations Small external influences (wind)! Errors of calculations provide stability of our solutions. In particular, by us it is shown that freak waves can arise and at small external
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.
Imaging shock waves in diamond with both high temporal and spatial resolution at an XFEL
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Schropp, Andreas; Hoppe, Robert; Meier, Vivienne; Patommel, Jens; Seiboth, Frank; Ping, Yuan; Hicks, Damien G.; Beckwith, Martha A.; Collins, Gilbert W.; Higginbotham, Andrew; et al
2015-06-18
The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range, and protein crystallography. In this article, we access a new field of science by measuring quantitatively the local bulk properties and dynamics of matter under extreme conditions, in this case by using the short XFEL pulse to image an elastic compression wave in diamond. The elastic wave was initiated by an intense optical laser pulse and was imaged at different delay times after the optical pump pulse using magnifiedmore »x-ray phase-contrast imaging. The temporal evolution of the shock wave can be monitored, yielding detailed information on shock dynamics, such as the shock velocity, the shock front width, and the local compression of the material. The method provides a quantitative perspective on the state of matter in extreme conditions.« less
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.
Relativistic Quaternionic Wave Equation II
Schwartz, Charles
2007-01-01
Relativistic quaternionic wave equation. II J. Math. Phys.Relativistic quaternionic wave equation. II Charles Schwartzcomponent quaternionic wave equation recently introduced. A
Rogue Wave Modes for the Long Wave-Short Wave Resonance Kwok Wing CHOW*(1)
1 Rogue Wave Modes for the Long Wave-Short Wave Resonance Model Kwok Wing CHOW*(1) , Hiu Ning CHAN.45.Yv; 47.35.Fg ABSTRACT The long wave-short wave resonance model arises physically when the phase velocity of a long wave matches the group velocity of a short wave. It is a system of nonlinear evolution
Rogue Wave Modes for the Long WaveShort Wave Resonance Model Kwok Wing CHOW
Rogue Wave Modes for the Long WaveShort Wave Resonance Model Kwok Wing CHOW 1Ã , Hiu Ning CHAN 1 online June 11, 2013) The long waveshort wave resonance model arises physically when the phase velocity of a long wave matches the group velocity of a short wave. It is a system of nonlinear evolution equations
Rogue Wave Modes for the Long Wave-Short Wave Resonance Kwok Wing CHOW*(1)
of a long wave matches the group velocity of a short wave. Significant interactions and energy transfer can1 Rogue Wave Modes for the Long Wave-Short Wave Resonance Model Kwok Wing CHOW*(1) , Hiu Ning CHAN.45.Yv; 47.35.Fg ABSTRACT The long wave-short wave resonance model arises physically when the phase
Measurement of the analysing power in proton-proton elastic scattering at small angles
Z. Bagdasarian; D. Chiladze; S. Dymov; A. Kacharava; G. Macharashvili; S. Barsov; R. Gebel; B. Gou; M. Hartmann; I. Keshelashvili; A. Khoukaz; P. Kulessa; A. Kulikov; A. Lehrach; N. Lomidze; B. Lorentz; R. Maier; D. Mchedlishvili; S. Merzliakov; S. Mikirtychyants; M. Nioradze; H. Ohm; M. Papenbrock; D. Prasuhn; F. Rathmann; V. Serdyuk; V. Shmakova; R. Stassen; H. Stockhorst; I. I. Strakovsky; H. Ströher; M. Tabidze; A. Täschner; S. Trusov; D. Tsirkov; Yu. Uzikov; Yu. Valdau; C. Wilkin; R. L. Workman
2014-10-28
The proton analysing power in $\\vec{p}p$ elastic scattering has been measured at small angles at COSY-ANKE at 796 MeV and five other beam energies between 1.6 and 2.4 GeV using a polarised proton beam. The asymmetries obtained by detecting the fast proton in the ANKE forward detector or the slow recoil proton in a silicon tracking telescope are completely consistent. Although the analysing power results agree well with the many published data at 796 MeV, and also with the most recent partial wave solution at this energy, the ANKE data at the higher energies lie well above the predictions of this solution at small angles. An updated phase shift analysis that uses the ANKE results together with the World data leads to a much better description of these new measurements.
D. Mchedlishvili; D. Chiladze; S. Dymov; Z. Bagdasarian; S. Barsov; R. Gebel; B. Gou; M. Hartmann; A. Kacharava; I. Keshelashvili; A. Khoukaz; P. Kulessa; A. Kulikov; A. Lehrach; N. Lomidze; B. Lorentz; R. Maier; G. Macharashvili; S. Merzliakov; S. Mikirtychyants; M. Nioradze; H. Ohm; D. Prasuhn; F. Rathmann; V. Serdyuk; D. Schroer; V. Shmakova; R. Stassen; H. J. Stein; H. Stockhorst; I. I. Strakovsky; H. Ströher; M. Tabidze; A. Täschner; S. Trusov; D. Tsirkov; Yu. Uzikov; Yu. Valdau; C. Wilkin; R. L. Workman; P. Wüstner
2015-10-21
The differential cross section for proton-proton elastic scattering has been measured at a beam energy of 1.0 GeV and in 200 MeV steps from 1.6 to 2.8 GeV for centre-of-mass angles in the range from 12-16 degrees to 25-30 degrees, depending on the energy. Absolute normalisations of typically 3% were achieved by studying the energy losses of the circulating beam of the COSY storage ring as it passed repeatedly through the windowless hydrogen target of the ANKE magnetic spectrometer. It is shown that the data have a significant impact upon a partial wave analysis. After extrapolating the differential cross sections to the forward direction, the results are broadly compatible with the predictions of forward dispersion relations.
Mchedlishvili, D; Dymov, S; Bagdasarian, Z; Barsov, S; Gebel, R; Gou, B; Hartmann, M; Kacharava, A; Keshelashvili, I; Khoukaz, A; Kulessa, P; Kulikov, A; Lehrach, A; Lomidze, N; Lorentz, B; Maier, R; Macharashvili, G; Merzliakov, S; Mikirtychyants, S; Nioradze, M; Ohm, H; Prasuhn, D; Rathmann, F; Serdyuk, V; Schroer, D; Shmakova, V; Stassen, R; Stein, H J; Stockhorst, H; Strakovsky, I I; Ströher, H; Tabidze, M; Täschner, A; Trusov, S; Tsirkov, D; Uzikov, Yu; Valdau, Yu; Wilkin, C; Workman, R L; Wüstner, P
2015-01-01
The differential cross section for proton-proton elastic scattering has been measured at a beam energy of 1.0 GeV and in 200 MeV steps from 1.6 to 2.8 GeV for centre-of-mass angles in the range from 12-16 degrees to 25-30 degrees, depending on the energy. Absolute normalisations of typically 3% were achieved by studying the energy losses of the circulating beam of the COSY storage ring as it passed repeatedly through the windowless hydrogen target of the ANKE magnetic spectrometer. It is shown that the data have a significant impact upon a partial wave analysis. After extrapolating the differential cross sections to the forward direction, the results are broadly compatible with the predictions of forward dispersion relations.
Mathur, Manikandan S.
Internal waves are a ubiquitous and significant means of momentum and energy transport in the oceans, atmosphere, and astrophysical bodies. Here, we show that internal wave propagation in nonuniform density stratifications, ...
Mercier, Matthieu J.
We present the results of a combined experimental and numerical study of the generation of internal waves using the novel internal wave generator design of Gostiaux et al. (Exp. Fluids, vol. 42, 2007, pp. 123–130). This ...
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.
Gravitational Waves on Conductors
A. Lewis Licht
2004-03-12
We consider a gravitational wave of arbitrary frequency incident on a normal or a super-conductor. The gravitationally induced fields inside the conductor are derived. The outward propagating EM waves are calculated for a low frequency wave on a small sphere and for a high frequency wave incident on a large disk. We estimate for both targets the GW to EM conversion efficiencies and also the magnitude of the superconductor's phase perturbation.
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.
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 ...
Degasperis, Antonio; Aceves, Alejandro B
2015-01-01
We derive the rogue wave solution of the classical massive Thirring model, that describes nonlinear optical pulse propagation in Bragg gratings. Combining electromagnetically induced transparency with Bragg scattering four-wave mixing, may lead to extreme waves at extremely low powers.
Keyser, John
Wave Particles Cem Yuksel Computer Science Texas A&M University Donald H. House Visualization captured from our real-time simulation system (approximately 100,000 wave particles) Abstract We present a new method for the real-time simulation of fluid sur- face waves and their interactions with floating
Internal wave instability: Wave-wave versus wave-induced mean flow interactions
Sutherland, Bruce
, known as parametric sub- harmonic instability, results generally when a disturbance of one frequency imparts energy to disturbances of half that frequency.13,14 Generally, a plane periodic internal wave, energy from primary waves is transferred, for example, to waves with half frequency. Self
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^{\
Performance Assessment of the Wave Dragon Wave Energy Converter
Hansen, René Rydhof
Performance Assessment of the Wave Dragon Wave Energy Converter Based on the EquiMar Methodology S of the wave energy sector, device developers are called to provide reliable estimates on power performanceMar, Nissum Bredning, Hanstholm, North Sea, Ekofisk, Wave-to-wire, Wave energy. I. INTRODUCTION The wave
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
Gravity, capillary and dilational wave mode resonance at a visco-elastic two-fluid interface
Brown, Susan Jayne, 1967-
2005-01-01
(cont.) space corresponding to experimental conditions to thereby interpret the experimental results. We tested this method on noisy simulated data sets and then applied it to published experimental data sets. We designed ...
Nonlinear Elastic Wave Experiments: Learning About the Behavior of Rocks and Geomaterials
(historically) the macroscopic experiments that led to our cur- rent understanding of the peculiar nonlinearity of rocks were studied and all were found to be highly nonlinear; notably, sedimentary rocks (which are oil
Application of the GBFP Method to Electron Partial-Wave Expansion Elastic
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnicalInformation4563AbuseConnectJournal Article:(Journalthe
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! ...
Coastal Wave Generation and Wave Breaking over Terrain: Two Problems in Mesoscale Wave Dynamics
Qian, Tingting
2010-07-14
Two problems in mesoscale wave dynamics are addressed: (i) wave-turbulence interaction in a breaking mountain wave and (ii) gravity wave generation associated with coastal heating gradients. The mean and turbulent structures in a breaking mountain...
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.
A synthetic example of anisotropic P-wave processing for a model from the Gulf of Mexico
Tsvankin, Ilya
A synthetic example of anisotropic P-wave processing for a model from the Gulf of Mexico Baoniu Han, typical for the Gulf of Mexico, has a moderate structural complexity and includes a salt body elastic properties of shale formations and thin-bed sedimentary sequences (Thomsen, 1986; Sayers, 1994
Daraio, Chiara
the stress wave propagation in curved chains of particles (granular crystals) confined by bent elastic guides Crystals Composed of Diatomic Particles Jinkyu Yang & Chiara Daraio Received: 19 January 2012 /Accepted: 25 the granular crystals with small-amplitude, broadband perturbations using a piezoelectric actuator to generate
J. M. Vogels; K. Xu; W. Ketterle
2002-03-13
By colliding two Bose-Einstein condensates we have observed strong bosonic stimulation of the elastic scattering process. When a weak input beam was applied as a seed, it was amplified by a factor of 20. This large gain atomic four-wave mixing resulted in the generation of two macroscopically occupied pair-correlated atomic beams.
On the difference between stiff and soft membranes: Capillary Waves
Sebastian Jaksch; Olaf Holderer; Michael Ohl; Henrich Frielinghaus
2015-08-14
One problem of non-crystalline condensed matter (soft matter) is creating the right equilibrium between elasticity and viscosity, referred to as viscoelasticity. Manifestations of that can be found in everyday live, where the viscoelasticity in a tire needs to be balanced so it is still flexible and can dissipate shock-energy, yet hard enough for energy-saving operation. Similarly, the cartilage in joints needs to absorb shocks while operating at low- level friction with high elasticity. Two such examples with a biological applicability are stiff membranes, which allow for the sliding of joints and therefore maintain their function over the lifetime of the corresponding individual (decades) and the softening of cell membranes, for example for antimicrobial effects by dissolution in the case of bacteria (seconds). While the first should allow for low- friction operation at high elasticity, in the second scenario energy dissipated into the membrane eventually leads to membrane destruction. Here we address the intrinsic difference between these two types of membranes, differing in stiffness and displaying different relaxation behavior on the nanosecond time scale. The harder membranes show additional elastic modes, capillary waves, that indicate the high degree of elasticity necessary for instance in cartilage or red blood cells. The energy of these modes is in the order of 1 micro-eV. As model systems we chose a hard phospholipidmembrane of SoyPC lipids and a D2O/C10E4/decane microemulsion system representing soft surfactant membranes. Our results help to explain properties observed for many membranes in nature, where hard membranes lubricate joints or stay intact as red blood particles in tiniest capillaries, both with extremely long lifetimes. Contrarily, softened membranes can be destroyed easily under little shear stress within seconds.
Cycloidal Wave Energy Converter
Stefan G. Siegel, Ph.D.
2012-11-30
This program allowed further advancing the development of a novel type of wave energy converter, a Cycloidal Wave Energy Converter or CycWEC. A CycWEC consists of one or more hydrofoils rotating around a central shaft, and operates fully submerged beneath the water surface. It operates under feedback control sensing the incoming waves, and converts wave power to shaft power directly without any intermediate power take off system. Previous research consisting of numerical simulations and two dimensional small 1:300 scale wave flume experiments had indicated wave cancellation efficiencies beyond 95%. The present work was centered on construction and testing of a 1:10 scale model and conducting two testing campaigns in a three dimensional wave basin. These experiments allowed for the first time for direct measurement of electrical power generated as well as the interaction of the CycWEC in a three dimensional environment. The Atargis team successfully conducted two testing campaigns at the Texas A&M Offshore Technology Research Center and was able to demonstrate electricity generation. In addition, three dimensional wave diffraction results show the ability to achieve wave focusing, thus increasing the amount of wave power that can be extracted beyond what was expected from earlier two dimensional investigations. Numerical results showed wave cancellation efficiencies for irregular waves to be on par with results for regular waves over a wide range of wave lengths. Using the results from previous simulations and experiments a full scale prototype was designed and its performance in a North Atlantic wave climate of average 30kW/m of wave crest was estimated. A full scale WEC with a blade span of 150m will deliver a design power of 5MW at an estimated levelized cost of energy (LCOE) in the range of 10-17 US cents per kWh. Based on the new results achieved in the 1:10 scale experiments these estimates appear conservative and the likely performance at full scale will exceed this initial performance estimates. In advancing the Technology Readiness Level (TRL) of this type of wave energy converter from 3 to 4, we find the CycWEC to exceed our initial estimates in terms of hydrodynamic performance. Once fully developed and optimized, it has the potential to not just outperform all other WEC technologies, but to also deliver power at a lower LCOE than competing conventional renewables like wind and solar. Given the large wave power resource both domestically and internationally, this technology has the potential to lead to a large improvement in our ability to produce clean electricity at affordable cost.
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.
Time Reversal in Solids (Linear and Nonlinear Elasticity): Multimedia Resources in Time Reversal
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Dynamic nonlinear elastic behavior, nonequilibrium dynamics, first observed as a curiosity in earth materials has now been observed in a great variety of solids. The primary manifestations of the behavior are characteristic wave distortion, and slow dynamics, a recovery process to equilibrium that takes place linearly with the logarithm of time, over hours to days after a wave disturbance. The link between the diverse materials that exhibit nonequilibrium dynamics appears to be the presence of soft regions, thought to be 'damage' at many scales, ranging from order 10-9 m to 10-1 m at least. The regions of soft matter may be distributed as in a rock sample, or isolated, as in a sample with a single crack [LANLhttp://www.lanl.gov/orgs/ees/ees11/geophysics/nonlinear/nonlinear.shtml]. The Geophysics Group (EES-11) at Los Alamos National Laboratory has posted two or more multimedia items under each of the titles below to demonstrate aspects of their work: 1) Source Reconstruction Using Time Reversal; 2) Robustness and Efficiency of Time Reversal Acoustics in Solid Media; 3) Audio Example of Time Reversal - Speech Privacy; 4) Crack Imagining with Time Reversal - Experimental Results; 5) Time Reversal of the 2004 (M9.0) Sumatra Earthquake.
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.
Sych, Robert
2015-01-01
The review addresses the spatial frequency morphology of sources of sunspot oscillations and waves, including their localization, size, oscillation periods, height localization with the mechanism of cut-off frequency that forms the observed emission variability. Dynamic of sunspot wave processes, provides the information about the structure of wave fronts and their time variations, investigates the oscillation frequency transformation depending on the wave energy is shown. The initializing solar flares caused by trigger agents like magnetoacoustic waves, accelerated particle beams, and shocks are discussed. Special attention is paid to the relation between the flare reconnection periodic initialization and the dynamics of sunspot slow magnetoacoustic waves. A short review of theoretical models of sunspot oscillations is provided.
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.
Ashkenazy, Yossi "Yosef"
Wind Spatial Variability and Topographic Wave Frequency ELAD SHILO Department of Soil and Water of topographic waves with wind action has been documented in several natural lakes throughout the world. However, the influence of the wind's spatial variability (wind stress curl) on the frequency of topographic waves has
Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino
Merlino, Robert L.
Dust-Acoustic Waves: Visible Sound Waves Robert L. Merlino Department of Physics and Astronomy and experimental work on dust acoustic waves is given. The basic physics of the dust acoustic wave and some findings and outstanding problems are also presented. Keywords: dusty plasmas, dust acoustic waves PACS: 52
Wave momentum flux parameter: a descriptor for nearshore waves
US Army Corps of Engineers
Wave momentum flux parameter: a descriptor for nearshore waves Steven A. Hughes* US Army Engineer Available online 7 October 2004 Abstract A new parameter representing the maximum depth-integrated wave momentum flux occurring over a wave length is proposed for characterizing the wave contribution
Structure-borne sound Flexural wave (bending wave)
Berlin,Technische Universität
1 Structure-borne sound · Flexural wave (bending wave) »One dimensional (beam) +(/x)dx +(/x)dx = (/x) (/x)dx=(2/x2)dx Mz +(Mz/x)dx Mz vy Fy Fy +(Fy/x)dx Structure-borne sound · Bending wave flexural wave #12;2 Structure-borne sound · Two obliquely propagating waves + - + + - + - Structure
REAL-TIME WATER WAVES WITH WAVE PARTICLES
Keyser, John
REAL-TIME WATER WAVES WITH WAVE PARTICLES A Dissertation by Cem Yuksel Submitted to the Office of DOCTOR OF PHILOSOPHY August 2010 Major Subject: Computer Science #12;REAL-TIME WATER WAVES WITH WAVE, Valerie E. Taylor August 2010 Major Subject: Computer Science #12;iii ABSTRACT Real-time Water Waves
GN Wave theory and TEBEM for Wave-Body Interaction
GN Wave theory and TEBEM for Wave-Body Interaction Dr. BinBin Zhao and Professor Wenyang Duan of simulating irregular nonlinear water wave interaction with arbitrary floating bodies, the Green-Naghdi wave corners. The results show that the high-level GN theory can predict wave transformation over uneven seabed
Mats Ehrnström; Erik Wahlén
2013-10-31
We construct three-dimensional families of small-amplitude gravity-driven rotational steady water waves on finite depth. The solutions contain counter-currents and multiple crests in each minimal period. Each such wave generically is a combination of three different Fourier modes, giving rise to a rich and complex variety of wave patterns. The bifurcation argument is based on a blow-up technique, taking advantage of three parameters associated with the vorticity distribution, the strength of the background stream, and the period of the wave.
Directed Relativistic Blast Wave
Andrei Gruzinov
2007-04-23
A spherically symmetrical ultra-relativistic blast wave is not an attractor of a generic asymmetric explosion. Spherical symmetry is reached only by the time the blast wave slows down to non-relativistic velocities, when the Sedov-Taylor-von Neumann attractor solution sets in. We show however, that a directed relativistic explosion, with the explosion momentum close to the explosion energy, produces a blast wave with a universal intermediate asymptotic -- a selfsimilar directed ultra-relativistic blast wave. This universality might be of interest for the astrophysics of gamma-ray burst afterglows.
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
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.
A robust absorbing layer method for anisotropic seismic wave modeling
Métivier, L.; Brossier, R.; Labbé, S.; Operto, S.; Virieux, J.
2014-12-15
When applied to wave propagation modeling in anisotropic media, Perfectly Matched Layers (PML) exhibit instabilities. Incoming waves are amplified instead of being absorbed. Overcoming this difficulty is crucial as in many seismic imaging applications, accounting accurately for the subsurface anisotropy is mandatory. In this study, we present the SMART layer method as an alternative to PML approach. This method is based on the decomposition of the wavefield into components propagating inward and outward the domain of interest. Only outgoing components are damped. We show that for elastic and acoustic wave propagation in Transverse Isotropic media, the SMART layer is unconditionally dissipative: no amplification of the wavefield is possible. The SMART layers are not perfectly matched, therefore less accurate than conventional PML. However, a reasonable increase of the layer size yields an accuracy similar to PML. Finally, we illustrate that the selective damping strategy on which is based the SMART method can prevent the generation of spurious S-waves by embedding the source in a small zone where only S-waves are damped.
Delia Ionescu-Kruse
2011-06-20
Two-dimensional periodic surface waves propagating under the combined influence of gravity and surface tension on water of finite depth are considered. Within the framework of small-amplitude waves, we find the exact solutions of the nonlinear differential equation system which describes the particle motion in the considered case, and we describe the possible particle trajectories. The required computations involve elliptic integrals of the first kind, the Legendre normal form and a solvable Abel differential equation of the second kind. Some graphs of the results are included.
Non-contacting transfer of elastic energy into explosive simulants for dynamic property estimation
Greeney, Nathan S.; Strovink, Kurt M.; Scales, John A. [Physics Department, Colorado School of Mines, Golden, Colorado 80401 (United States); Jessop, Andrew M.; Stuart Bolton, J. [Ray W. Herrick Laboratories, Purdue University, West Lafayette, Indiana 47907-2099 (United States); Watson, Christopher C.; Adams, Douglas E. [Purdue Center for Systems Integrity, Purdue University, Lafayette, Indiana 47905 (United States)
2014-05-21
Non-contacting acoustical methods can be used to extract various material properties of liquid or solid samples without disturbing the sample. These methods are useful even in the lab since they do not involve coupling anything to the sample, which might change its properties. A forteriori, when dealing with potentially dangerous materials, non-contacting methods may be the only safe solutions to mechanical characterization. Here, we show examples of using laser ultrasound to remotely insonify and monitor the elastic properties of several granular explosive simulants. The relatively short near-infrared laser pulse length (a few hundred nanoseconds) provides a broad-band thermoelastic source of ultrasound; we intentionally stay in the thermoelastic regime to avoid damaging the material. Then, we use a scanning laser Doppler vibrometer to measure the ultrasonic response of the sample. LDV technology is well established and very sensitive at ultrasonic frequencies; atomic level motions can be measured with modest averaging. The resulting impulse response of the explosive simulant can be analyzed to determine decay rates and wave speeds, with stiffer samples showing faster wave speeds and lower decay rates. On the other hand, at the low-frequency end of the acoustic spectrum, we use an electronically phased array to couple into a freely suspended sample's normal modes. This allows us to gently heat up the sample (3?°C in just under 5 min, as shown with a thermal IR camera). In addition to the practical interest in making the sample more chemically visible through heat, these two measurements (low-frequency resonant excitation vs high-frequency wave propagation) bracket the frequency range of acoustic non-destructive evaluation methods available.
Wave Energy challenges and possibilities
© Wave Energy challenges and possibilities By: Per Resen Steenstrup www.WaveStarEnergy.com Risø-R-1608(EN) 161 #12;© Wave energy is an old story.... The first wave energy patent is 200 years old. Over the last 100 years more than 200 new wave energy devices have been developped and more than 1.000 patents
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.
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.
Wave Energy Resource Analysis for Use in Wave Energy Conversion
Pastor, J.; Liu, Y.; Dou, Y.
2014-01-01
In order to predict the response of wave energy converters an accurate representation of the wave climate resource is crucial. This paper gives an overview of wave resource modeling techniques as well as detailing a methodology for estimating...
Wave-Corpuscle Mechanics for Electric Charges
Babin, Anatoli; Figotin, Alexander
2010-01-01
superposition in nonlinear wave dynamics. Rev. Math. Phys.6. Babin, A. , Figotin, A. : Wave-corpuscle mechanics forV. , Fortunato, D. : Solitary waves in the nonlinear wave
Microstructural Design for Stress Wave Energy Management /
Tehranian, Aref
2013-01-01
Nasser, S. , 2010. Stress-wave energy management throughNemat-Nasser, Stress-wave energy management through materialconstitute pressure wave energy and/or shear wave energy.
Harmonic generation of gravitational wave induced Alfven waves
Mats Forsberg; Gert Brodin
2007-11-26
Here we consider the nonlinear evolution of Alfven waves that have been excited by gravitational waves from merging binary pulsars. We derive a wave equation for strongly nonlinear and dispersive Alfven waves. Due to the weak dispersion of the Alfven waves, significant wave steepening can occur, which in turn implies strong harmonic generation. We find that the harmonic generation is saturated due to dispersive effects, and use this to estimate the resulting spectrum. Finally we discuss the possibility of observing the above process.
Crossing resonance of wave fields in a medium with an inhomogeneous coupling parameter
Ignatchenko, V. A., E-mail: vignatch@iph.krasn.ru; Polukhin, D. S., E-mail: polukhin@iph.krasn.ru [Russian Academy of Sciences, L. V. Kirensky Institute of Physics, Siberian Branch (Russian Federation)
2013-11-15
The dynamic susceptibilities (Green functions) of the system of two coupled wave fields of different physical natures in a medium with an arbitrary relation between the mean value ? and rms fluctuation ?? of the coupling parameter have been examined. The self-consistent approximation involving all diagrams with noncrossing correlation lines has been developed for the case where the initial Green’s function of the homogeneous medium describes the system of coupled wave fields. The analysis has been performed for spin and elastic waves. Expressions have been obtained for the diagonal elements G{sub mm} and G{sub uu} of the matrix Green’s function, which describe spin and elastic waves in the case of magnetic and elastic excitations, and for the off-diagonal elements G{sub mu} and G{sub um}, which describe these waves in the case of cross excitation. Change in the forms of these elements has been numerically studied for the case of one-dimensional inhomogeneities with an increase in ?? and with a decrease in ? under the condition that the sum of the squares of these quantities is conserved: two peaks in the frequency dependences of imaginary parts of G{sub mm} and G{sub uu} are broadened and then joined into one broad peak; a fine structure appears in the form of narrow resonance at the vertex of the Green’s function of one wave field and narrow antiresonance at the vertex of the Green function of the other field; peaks of the fine structure are broadened and then disappear with an increase in the correlation wavenumber of the inhomogeneities of the coupling parameter; and the amplitudes of the off-diagonal elements vanish in the limit ? ? 0.
Electromagnetic Wave Dynamics in
Kaiser, Robin
Mesoscopic Electromagnetic Wave Dynamics in Ultracold Atomic Gases Robin Kaiser and Mark D. Havey Mesoscopic Electromagnetic Wave Dynamics in Ultracold Atomic Gases #12;39 E xperimental developments permit in the transport proper- ties of electromagnetic radiation in strongly scattering random media. Even in weakly
Bieber, Michael
CATCHING THE FOURTH WAVE YOU MAY HAVE RIDDEN THEM YOURSELF -- the swells that develop farther out beyond Toffler, the fourth wave -- biologi- cal intelligence and medical technology -- is on the horizon second and fourth nationally in terms of cities that receive the most research funds from the National
J X Zheng-Johansson; P-I Johansson
2006-08-27
The electromagnetic component waves, comprising together with their generating oscillatory massless charge a material particle, will be Doppler shifted when the charge hence particle is in motion, with a velocity $v$, as a mere mechanical consequence of the source motion. We illustrate here that two such component waves generated in opposite directions and propagating at speed $c$ between walls in a one-dimensional box, superpose into a traveling beat wave of wavelength ${\\mit\\Lambda}_d$$=(\\frac{v}{c}){\\mit\\Lambda}$ and phase velocity $c^2/v+v$ which resembles directly L. de Broglie's hypothetic phase wave. This phase wave in terms of transporting the particle mass at the speed $v$ and angular frequency ${\\mit\\Omega}_d=2\\pi v /{\\mit\\Lambda}_d$, with ${\\mit\\Lambda}_d$ and ${\\mit\\Omega}_d$ obeying the de Broglie relations, represents a de Broglie wave. The standing-wave function of the de Broglie (phase) wave and its variables for particle dynamics in small geometries are equivalent to the eigen-state solutions to Schr\\"odinger equation of an identical system.
Rayleigh WaveInternal Wave Coupling and Internal Wave Generation Above a Model Jet Stream
Sutherland, Bruce
Rayleigh WaveInternal Wave Coupling and Internal Wave Generation Above a Model Jet Stream B. R to the study of unstable jet flows and applications of this work for internal wave generation by dynamic remains poorly understood. Most investigations of sheargeneration of inter nal waves in the atmosphere
Rayleigh Wave-Internal Wave Coupling and Internal Wave Generation Above a Model Jet Stream
Sutherland, Bruce
Rayleigh Wave-Internal Wave Coupling and Internal Wave Generation Above a Model Jet Stream B. R to the study of unstable jet flows and applications of this work for internal wave generation by dynamic remains poorly understood. Most investigations of shear-generation of inter- nal waves in the atmosphere
An unsteady wave driver for narrowbanded waves: modeling nearshore circulation driven by wave groups
Kirby, James T.
An unsteady wave driver for narrowbanded waves: modeling nearshore circulation driven by wave Abstract In this paper, we derive an unsteady refractiondiffraction model for narrowbanded water waves for use in computing coupled wavecurrent motion in the nearshore. The end result is a variable
Frequency-dependent attenuation and elasticity in unconsolidated earth materials: effect of damping
Yanqing Hu; Hernán A. Makse; John J. Valenza; David L. Johnson
2014-10-20
We use the Discrete Element Method (DEM) to understand the underlying attenuation mechanism in granular media, with special applicability to the measurements of the so-called effective mass developed earlier. We consider that the particles interact via Hertz-Mindlin elastic contact forces and that the damping is describable as a force proportional to the velocity difference of contacting grains. We determine the behavior of the complex-valued normal mode frequencies using 1) DEM, 2) direct diagonalization of the relevant matrix, and 3) a numerical search for the zeros of the relevant determinant. All three methods are in strong agreement with each other. The real and the imaginary parts of each normal mode frequency characterize the elastic and the dissipative properties, respectively, of the granular medium. We demonstrate that, as the interparticle damping, $\\xi$, increases, the normal modes exhibit nearly circular trajectories in the complex frequency plane and that for a given value of $\\xi$ they all lie on or near a circle of radius $R$ centered on the point $-iR$ in the complex plane, where $R\\propto 1/\\xi$. We show that each normal mode becomes critically damped at a value of the damping parameter $\\xi \\approx 1/\\omega_n^0$, where $\\omega_n^0$ is the (real-valued) frequency when there is no damping. The strong indication is that these conclusions carry over to the properties of real granular media whose dissipation is dominated by the relative motion of contacting grains. For example, compressional or shear waves in unconsolidated dry sediments can be expected to become overdamped beyond a critical frequency, depending upon the strength of the intergranular damping constant.
Piezooptic Coefficients and Acoustic Wave Velocities in Sn2P2S6 Crystals
O. Mys; I. Martynyuk-Lototska; A. Grabar; Yu. Vysochanskii; R. Vlokh
2007-06-28
Piezooptic coefficients of Sn2P2S6 crystals are experimentally determined for l=623.8 nm and T=293 K with the aid of interferometric technique. The components of the elastic stiffness tensor for these crystals are calculated on the basis of studies for the acoustic wave velocities. It is shown that acoustooptic figure of merit can achieve extremely high values for Sn2P2S6 crystals (M2 - 2x10-12s3/kg2).
Laser generation and detection of longitudinal and shear acoustic waves in a diamond anvil cell
Chigarev, Nikolay; Zinin, Pavel; Ming Lichung; Amulele, George; Bulou, Alain; Gusev, Vitalyi
2008-11-03
Laser ultrasonics in a point-source-point-receiver configuration is applied for the evaluation of elastic properties of nontransparent materials in a diamond anvil cell at high pressures. Measurement of both longitudinal and shear acoustic wave velocities in an iron foil at pressures up to 23 GPa does not require any information in addition to the one obtained by all-optical pump-probe technique.
Recirculation in multiple wave conversions
Brizard, A.J.
2008-01-01
model lies with the simple wave energy conservation law itthe recirculation of wave energy introduces interference e?particles, the tertiary-wave energy may be negative and thus
Center for Wave Phenomena Wave Phenomena
Snieder, Roel
research and education program in seismic exploration, monitoring and wave propagation. The main focus into a life of scientific discovery." Kurang Mehta, Ph.D. Class of 2007 Shell Exploration and Production Phil of CWP is on seismic modeling, imaging and inversion methods, as well as on improving the accuracy
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...
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
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.
B. V. Ivanov
1997-05-21
A coordinate transformation is found which diagonalizes the axisymmetric pp-waves. Its effect upon concrete solutions, including impulsive and shock waves, is discussed.
Effect of a nonlinear power take off on a wave energy converter
Bailey, Helen Louise
2011-11-22
This thesis is titled The influence of a nonlinear Power Take Off on a Wave Energy Converter. It looks at the effect that having a nonlinear Power Take Off (PTO) has on an inertial referenced, slack moored, point absorber, ...
Analysis of PS-converted wave seismic data in the presence of azimuthal anisotropy
Liu, Weining
2014-11-27
Shear-wave splitting and azimuthal variations of seismic attributes are two major anisotropic effects induced by vertically-aligned fractures. They both have influences on seismic data processing and interpretation, and ...
Wave-wave interactions in solar type III radio bursts
Thejappa, G.; MacDowall, R. J.
2014-02-11
The high time resolution observations from the STEREO/WAVES experiment show that in type III radio bursts, the Langmuir waves often occur as localized magnetic field aligned coherent wave packets with durations of a few ms and with peak intensities well exceeding the strong turbulence thresholds. Some of these wave packets show spectral signatures of beam-resonant Langmuir waves, down- and up-shifted sidebands, and ion sound waves, with frequencies, wave numbers, and tricoherences satisfying the resonance conditions of the oscillating two stream instability (four wave interaction). The spectra of a few of these wave packets also contain peaks at f{sub pe}, 2f{sub pe} and 3 f{sub pe} (f{sub pe} is the electron plasma frequency), with frequencies, wave numbers and bicoherences (computed using the wavelet based bispectral analysis techniques) satisfying the resonance conditions of three wave interactions: (1) excitation of second harmonic electromagnetic waves as a result of coalescence of two oppositely propagating Langmuir waves, and (2) excitation of third harmonic electromagnetic waves as a result of coalescence of Langmuir waves with second harmonic electromagnetic waves. The implication of these findings is that the strong turbulence processes play major roles in beam stabilization as well as conversion of Langmuir waves into escaping radiation in type III radio bursts.
Internal energy relaxation in shock wave structure
Josyula, Eswar, E-mail: Eswar.Josyula@us.af.mil; Suchyta, Casimir J. [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States)] [Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Boyd, Iain D. [University of Michigan, Ann Arbor, Michigan 48109 (United States)] [University of Michigan, Ann Arbor, Michigan 48109 (United States); Vedula, Prakash [University of Oklahoma, Norman, Oklahoma 73019 (United States)] [University of Oklahoma, Norman, Oklahoma 73019 (United States)
2013-12-15
The Wang Chang-Uhlenbeck (WCU) equation is numerically integrated to characterize the internal structure of Mach 3 and Mach 5 shock waves in a gas with excitation in the internal energy states for the treatment of inelastic collisions. Elastic collisions are modeled with the hard sphere collision model and the transition rates for the inelastic collisions modified appropriately using probabilities based on relative velocities of the colliding particles. The collision integral is evaluated by the conservative discrete ordinate method [F. Tcheremissine, “Solution of the Boltzmann kinetic equation for high-speed flows,” Comput. Math. Math. Phys. 46, 315–329 (2006); F. Cheremisin, “Solution of the Wang Chang-Uhlenbeck equation,” Dokl. Phys. 47, 487–490 (2002)] developed for the Boltzmann equation. For the treatment of the diatomic molecules, the internal energy modes in the Boltzmann equation are described quantum mechanically given by the WCU equation. As a first step in the treatment of the inelastic collisions by the WCU equation, a two- and three-quantum system is considered to study the effect of the varying of (1) the inelastic cross section and (2) the energy gap between the quantum energy states. An alternative method, the direct simulation Monte Carlo method, is used for the Mach 3 shock wave to ensure the consistency of implementation in the two methods and there is an excellent agreement between the two methods. The results from the WCU implementation showed consistent trends for the Mach 3 and Mach5 standing shock waves simulations. Inelastic contributions change the downstream equilibrium state and allow the flow to transition to the equilibrium state further upstream.
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
Byers, Loren W.; Ten Cate, James A.; Johnson, Paul A.
2012-06-28
Nonlinear resonance ultrasound spectroscopy experiments conducted on concrete cores, one chemically and mechanically damaged by alkali-silica reactivity, and one undamaged, show that this material displays highly nonlinear wave behavior, similar to many other damaged materials. They find that the damaged sample responds more nonlinearly, manifested by a larger resonant peak and modulus shift as a function of strain amplitude. The nonlinear response indicates that there is a hysteretic influence in the stress-strain equation of state. Further, as in some other materials, slow dynamics are present. The nonlinear response they observe in concrete is an extremely sensitive indicator of damage. Ultimately, nonlinear wave methods applied to concrete may be used to guide mixing, curing, or other production techniques, in order to develop materials with particular desired qualities such as enhanced strength or chemical resistance, and to be used for damage inspection.
The Influence of Basalt Layers on Seismic Wave Propagation
Hanssen, Peter
Large areas of the Earth are covered by intrusive and extrusive lavas, forming high velocity basalts, which are often opaque to cinventional seismicreflection surveys. On the North East Atlantic margin these basalts cover ...
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
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
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
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
A wave-mechanical model of incoherent neutron scattering II. Role of the momentum transfer
Frauenfelder, Hans; Fenimore, Paul W
2015-01-01
We recently introduced a wave-mechanical model for quasi-elastic neutron scattering (QENS) in proteins. We call the model ELM for "Energy Landscape Model". We postulate that the spectrum of the scattered neutrons consists of lines of natural width shifted from the center by fluctuations. ELM is based on two facts: Neutrons are wave packets; proteins have low-lying substates that form the free-energy landscape (FEL). Experiments suggest that the wave packets are a few hundred micrometers long. The interaction between the neutron and a proton in the protein takes place during the transit of the wave packet. The wave packet exerts the force $F(t) = dQ(t)/dt$ on the protein moiety, a part of the protein surrounding the struck proton. $Q(t)$ is the wave vector (momentum) transferred by the neutron wave packet to the proton during the transit. The ensuing energy is stored in the energy landscape and returned to the neutron as the wave packet exits. Kinetic energy thus is changed into potential energy and back. The ...
Shallow Water Waves and Solitary Waves Willy Hereman
Hereman, Willy A.M.
. Water Wave Experiments and Observations VII. Future Directions VIII. Bibliography Glossary Deep water A surface wave is said to be in deep water if its wavelength is much shorter than the local water depthShallow Water Waves and Solitary Waves Willy Hereman Department of Mathematical and Computer
On Generating Gravity Waves with Matter and Electromagnetic Waves
C. Barrabes; P. A. Hogan
2008-04-05
If a homogeneous plane light-like shell collides head-on with a homogeneous plane electromagnetic shock wave having a step-function profile then no backscattered gravitational waves are produced. We demonstrate, by explicit calculation, that if the matter is accompanied by a homogeneous plane electromagnetic shock wave with a step-function profile then backscattered gravitational waves appear after the collision.
Inverse elastic surface scattering with near-field data
Peijun Li
2015-02-06
Feb 11, 2015 ... potential functions and split the wave field into its compressional and shear ... by dropping higher order terms in the power series expansions;.
INVERSE ELASTIC SURFACE SCATTERING WITH NEAR-FIELD ...
2015-03-20
we use two scalar potential functions and split the wave field into its compressional ... by dropping higher order terms in the power series expansions and explicit ...
Lyakhovsky, Vladimir
1987-01-01
-elastic isotropic models (Zaichenko et al. 1984; Schukin 1984). Interpretation of seismic results based on the Hooke in seismic zones implies that the traditional interpretation of geophysical investigations basedGeophys. J. R. astr. SOC.(1987) 91,429437 On the relation between seismic wave velocity and stress
Evolution of Rogue Waves in Interacting Wave Systems
A. Grönlund; B. Eliasson; M. Marklund
2009-04-03
Large amplitude water waves on deep water has long been known in the sea faring community, and the cause of great concern for, e.g., oil platform constructions. The concept of such freak waves is nowadays, thanks to satellite and radar measurements, well established within the scientific community. There are a number of important models and approaches for the theoretical description of such waves. By analyzing the scaling behavior of freak wave formation in a model of two interacting waves, described by two coupled nonlinear Schroedinger equations, we show that there are two different dynamical scaling behaviors above and below a critical angle theta_c of the direction of the interacting waves below theta_c all wave systems evolve and display statistics similar to a wave system of non-interacting waves. The results equally apply to other systems described by the nonlinear Schroedinger equations, and should be of interest when designing optical wave guides.
Minnesota, University of
LABORATORY VII: WAVE OPTICS Lab VII - 1 In this lab, you will solve problems in ways that take-like behavior. These conditions may be less familiar to you than the conditions for which geometrical optics
Hietala, Vincent M. (Placitas, NM); Vawter, Gregory A. (Albuquerque, NM)
1993-01-01
The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size.
Halliday, David Fraser
2009-01-01
This thesis concerns the application of seismic interferometry to surface waves. Seismic interferometry is the process by which the wavefield between two recording locations is estimated, resulting in new recordings at ...
Relativistic quaternionic wave equation
Schwartz, C
2006-01-01
Schrodinger ?time dependent? equation, ? 1 and ? 2 , then?TCP?. The current conservation equation ?3.2? is still truefor this extended wave equation ?8.1?, however, Eq. ?6.7?
Hietala, V.M.; Vawter, G.A.
1993-12-14
The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size. 4 figures.
Decay of helical Kelvin waves on a quantum vortex filament
Van Gorder, Robert A.
2014-07-15
We study the dynamics of helical Kelvin waves moving along a quantum vortex filament driven by a normal fluid flow. We employ the vector form of the quantum local induction approximation (LIA) due to Schwarz. For an isolated filament, this is an adequate approximation to the full Hall-Vinen-Bekarevich-Khalatnikov dynamics. The motion of such Kelvin waves is both translational (along the quantum vortex filament) and rotational (in the plane orthogonal to the reference axis). We first present an exact closed form solution for the motion of these Kelvin waves in the case of a constant amplitude helix. Such solutions exist for a critical wave number and correspond exactly to the Donnelly-Glaberson instability, so perturbations of such solutions either decay to line filaments or blow-up. This leads us to consider helical Kelvin waves which decay to line filaments. Unlike in the case of constant amplitude helical solutions, the dynamics are much more complicated for the decaying helical waves, owing to the fact that the rate of decay of the helical perturbations along the vortex filament is not constant in time. We give an analytical and numerical description of the motion of decaying helical Kelvin waves, from which we are able to ascertain the influence of the physical parameters on the decay, translational motion along the filament, and rotational motion, of these waves (all of which depend nonlinearly on time). One interesting finding is that the helical Kelvin waves do not decay uniformly. Rather, such waves decay slowly for small time scales, and more rapidly for large time scales. The rotational and translational velocity of the Kelvin waves depend strongly on this rate of decay, and we find that the speed of propagation of a helical Kelvin wave along a quantum filament is large for small time while the wave asymptotically slows as it decays. The rotational velocity of such Kelvin waves along the filament will increase over time, asymptotically reaching a finite value. These decaying Kelvin waves correspond to wave number below the critical value for the Donnelly-Glaberson instability, and hence our results on the Schwarz quantum LIA correspond exactly to what one would expect from prior work on the Donnelly-Glaberson instability.
No solitary waves exist on 2D deep water
Hur, Vera Mikyoung
2015-01-01
The solitary wave problem at the free surface of a two-dimensional, infinitely-deep and irrotational flow of water, under the influence of gravity, is formulated as a nonlinear pseudodifferential equation. A Pohozaev identity is used to show that it admits no solutions which asymptotically vanish faster than linearly.
No solitary waves exist on 2D deep water
Vera Mikyoung Hur
2012-09-10
The solitary wave problem at the free surface of a two-dimensional, infinitely-deep and irrotational flow of water, under the influence of gravity, is formulated as a nonlinear pseudodifferential equation. A Pohozaev identity is used to show that it admits no solutions which asymptotically vanish faster than linearly.
Wave Propagation in Multiferroic Materials
Keller, Scott Macklin
2013-01-01
Waves in Magnetoelectric Materials . . . Need forApplication of Multiferroic Materials to Receive AntennaMaterials . . . . . . . . . . . . . . . . . . . . . . . . .
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.
Plane wave holonomies in loop quantum gravity II: sine wave solution
Donald E. Neville
2014-11-10
This paper constructs an approximate sinusoidal wave packet solution to the equations of loop quantum gravity (LQG). There is an SU(2) holonomy on each edge of the LQG simplex, and the goal is to study the behavior of these holonomies under the influence of a passing gravitational wave. The equations are solved in a small sine approximation: holonomies are expanded in powers of sines, and terms beyond $\\sin^2$ are dropped; also, fields vary slowly from vertex to vertex. The wave is unidirectional and linearly polarized. The Hilbert space is spanned by a set of coherent states tailored to the symmetry of the plane wave case. Fixing the spatial diffeomorphisms is equivalent to fixing the spatial interval between vertices of the loop quantum gravity lattice. This spacing can be chosen such that the eigenvalues of the triad operators are large, as required in the small sine limit, even though the holonomies are not large. Appendices compute the energy of the wave, estimate the lifetime of the coherent state packet, discuss coarse-graining, and determine the behavior of the spinors used in the U(N) SHO realization of LQG.
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.
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.
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
Propagation and dispersion of sausage wave trains in magnetic flux tubes
Oliver, R; Terradas, J
2015-01-01
A localized perturbation of a magnetic flux tube produces a pair of wave trains that propagate in opposite directions along the tube. These wave packets disperse as they propagate, where the extent of dispersion depends on the physical properties of the magnetic structure, on the length of the initial excitation, and on its nature (e.g., transverse or axisymmetric). In Oliver et al. (2014) we considered a transverse initial perturbation, whereas the temporal evolution of an axisymmetric one is examined here. In both papers we use a method based on Fourier integrals to solve the initial value problem. Previous studies on wave propagation in magnetic wave guides have emphasized that the wave train dispersion is influenced by the particular dependence of the group velocity on the longitudinal wavenumber. Here we also find that long initial perturbations result in low amplitude wave packets and that large values of the magnetic tube to environment density ratio yield longer wave trains. To test the detectability ...
Collision of arbitrary strong gravitational and electromagnetic waves in the expanding universe
Alekseev, G A
2015-01-01
A completely analytical model of the process of collision and nonlinear interaction of gravitational and electromagnetic soliton wave pulses and strong electromagnetic travelling waves of arbitrary profiles propagating in the expanding universe (symmetric Kasner space-time) is presented. In contrast to intuitive expectations that rather strong travelling waves can destroy the soliton, it occurs that the soliton survives during its interaction with electromagnetic wave of arbitrary amplitude and profile, but its parameters begin to evolve under the influence of this interaction. If a travelling electromagnetic wave possesses a finite duration, the soliton parameters after interaction take constant values again, but these values in general are different from those before the interaction. Based on exact solutions of Einstein - Maxwell equations, our model demonstrates a series of nonlinear phenomena, such as (a) creation of gravitational waves in the collision of two electromagnetic waves, (b) creation of electr...
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}\
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.
Gravitational-wave Detection With Matter-wave Interferometers Based On Standing Light Waves
Dongfeng Gao; Peng Ju; Baocheng Zhang; Mingsheng Zhan
2011-03-25
We study the possibility of detecting gravitational-waves with matter-wave interferometers, where atom beams are split, deflected and recombined totally by standing light waves. Our calculation shows that the phase shift is dominated by terms proportional to the time derivative of the gravitational wave amplitude. Taking into account future improvements on current technologies, it is promising to build a matter-wave interferometer detector with desired sensitivity.
Resonant Spheres: Multifrequency Detectors of Gravitational Waves
M. Angeles Serrano; J. Alberto Lobo
1999-11-15
We discuss the capabilities of spherical antenn\\ae as single multifrequency detectors of gravitational waves. A first order theory allows us to evaluate the coupled spectrum and the resonators readouts when the first and the second quadrupole bare sphere frequencies are simultaneously selected for layout tuning. We stress the existence of non-tuning influences in the second mode coupling causing draggs in the frequency splittings. These URF effects are relevant to a correct physical description of resonant spheres, still more if operating as multifrequency appliances like our PHCA proposal.
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.
Marsh, S.P.
1988-03-08
An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 4 figs.
Marsh, S.P.
1987-03-12
An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive. 3 figs., 3 tabs.
Yerganian, Simon Scott (Lee's Summit, MO)
2001-07-17
A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.
Lucas, Timothy S. (4614 River Mill Ct., Glen Allen, VA 23060)
1991-01-01
A compressor for compression-evaporation cooling systems, which requires no moving parts. A gaseous refrigerant inside a chamber is acoustically compressed and conveyed by means of a standing acoustic wave which is set up in the gaseous refrigerant. This standing acoustic wave can be driven either by a transducer, or by direct exposure of the gas to microwave and infrared sources, including solar energy. Input and output ports arranged along the chamber provide for the intake and discharge of the gaseous refrigerant. These ports can be provided with optional valve arrangements, so as to increase the compressor's pressure differential. The performance of the compressor in either of its transducer or electromagnetically driven configurations, can be optimized by a controlling circuit. This controlling circuit holds the wavelength of the standing acoustical wave constant, by changing the driving frequency in response to varying operating conditions.
Adaptive multiconfigurational wave functions
Evangelista, Francesco A.
2014-03-28
A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff ?. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than ?. The resulting ?-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (?+SD-CI), which is based on a small ?-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build ?-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The ?-CI and ?+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the ?-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the ?-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.
Thermoplastic waves in magnetars
Beloborodov, Andrei M
2014-01-01
Magnetar activity is generated by shear motions of the neutron star surface, which relieve internal magnetic stresses. An analogy with earthquakes and faults is problematic, as the crust is permeated by strong magnetic fields, which greatly constrain crustal displacements. We describe a new deformation mechanism that is specific to strongly magnetized neutron stars. The magnetically stressed crust begins to move because of a thermoplastic instability, which launches a wave that shears the crust and burns its magnetic energy. The propagating wave front resembles the deflagration front in combustion physics. We describe the conditions for the instability, the front structure and velocity, and discuss implications for observed magnetar activity.
Wave runup on cylinders subject to deep water random waves
Indrebo, Ann Kristin
2001-01-01
runup. Laboratory measurements of irregular waves interfering with vertical platform cylinders were used to obtain the Weibull coefficients necessary for the analytical model. Six data sets with different configurations where the wave elevation...
Real-time Water Waves with Wave Particles
Yuksel, Cem
2010-10-12
This dissertation describes the wave particles technique for simulating water surface waves and two way fluid-object interactions for real-time applications, such as video games. Water exists in various different forms in our environment...
Heat Waves, Global Warming, and Mitigation
Carlson, Ann E.
2008-01-01
Heat Waves, Global Warming, and Mitigation Ann E. Carlson*2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 175 stroke2001). 2008]HEAT WAVES, GLOBAL WARMING, AND MITIGATION 177
mm-Wave Phase Shifters and Switches
Adabi Firouzjaei, Ehsan
2010-01-01
combiners . . . . . . . . . . . 5.3 mm-Wave implementationfailed to predict current mm-wave design trend [1] . . . . .solutions . . . . . . . . mm-wave imaging for medical and
Cellular Mechanisms Underlying Retinal Wave Generation
Ford, Kevin
2011-01-01
Underlying Retinal Wave Generation By Kevin J Ford AUnderlying Retinal Wave Generation By Kevin J Ford Doctor ofwith age, so does the wave generation mechanism. The most
Guided wave monitoring of prestressing tendons
Nucera, Claudio
2010-01-01
and applications of ultrasonic waves. CRC series in pure andStrands by Guided Stress Waves, ASCE Journal of Materials inin Cable Stays via Guided Wave Magnetostrictive Ultrasonics,
mm-Wave Phase Shifters and Switches
Adabi Firouzjaei, Ehsan
2010-01-01
4.1.1 Slow wave transmissioncombiners . . . . . . . . . . . 5.3 mm-Wave implementationfailed to predict current mm-wave design trend [1] . . . . .
Super compact equation for water waves
Dyachenko, A I; Zakharov, V E
2015-01-01
We derive very simple compact equation for gravity water waves which includes nonlinear wave term (`a la NLSE) and advection term (may results in wave breaking).
California Small Hydropower and Ocean Wave Energy
California Small Hydropower and Ocean Wave Energy Resources IN SUPPORT OF THE 2005 INTEGRATED....................................................................................................................... 9 Ocean Wave Energy............................................................................................................. 20 Wave Energy Conversion Technology
Generating Electromagnetic Waves from Gravity Waves in Cosmology
P. A. Hogan; S. O'Farrell
2009-05-18
Examples of test electromagnetic waves on a Friedmann-Lemaitre-Robertson-Walker(FLRW) background are constructed from explicit perturbations of the FLRW space-times describing gravitational waves propagating in the isotropic universes. A possible physical mechanism for the production of the test electromagnetic waves is shown to be the coupling of the gravitational waves with a test magnetic field, confirming the observation of Marklund, Dunsby and Brodin [Phys.Rev. D62,101501(R) (2000)].
Wave refraction and wave energy on Cayo Arenas
Walsh, Donald Eugene
1962-01-01
WAVE REFRACTION AND WAVE ENERGY ON CAYO ARENAS A Thesis By Donald E. Welsh Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... January 1962 Major Subject: Physical Oceanography WAVE REFRACTION AND WAVE ENERGY ON CAYO ARENAS A Thesis Donald E. Walsh Approved as to style and content by: Chairman of the Committee ead of Department ' / January 1962 ACKNOWLEDGMENTS...
Finite-amplitude inhomogeneous plane waves in a deformed Mooney-Rivlin material
Michel Destrade
2013-06-02
The propagation of finite-amplitude linearly-polarized inhomogeneous transverse plane waves is considered for a Mooney-Rivlin material maintained in a state of finite static homogeneous deformation. It is shown that such waves are possible provided that the directions of the normal to the planes of constant phase and of the normal to the planes of constant amplitude are orthogonal and conjugate with respect to the B-ellipsoid, where B is the left Cauchy-Green strain tensor corresponding to the initial deformation. For these waves, it is found that even though the system is non-linear, results on energy flux are nevertheless identical with corresponding results in the classical linearized elasticity theory. Byproducts of the results are new exact static solutions for the Mooney-Rivlin material.
Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment
James, L. Allan
Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment L. Allan James* Geography Department, University South Carolina Abstract The concept of sediment waves is reviewed and clarifications are proposed for nomenclature con- cerning vertical channel responses to large fluvial sediment fluxes over a period of a decade
Wave Propagation Theory 2.1 The Wave Equation
2 Wave Propagation Theory 2.1 The Wave Equation The wave equation in an ideal fluid can be derived from hydrodynamics and the adia- batic relation between pressure and density. The equation for conservation of mass, Euler's equation (Newton's 2nd Law), and the adiabatic equation of state are respec
Rossen I. Ivanov
2007-07-12
The Euler's equations describe the motion of inviscid fluid. In the case of shallow water, when a perturbative asymtotic expansion of the Euler's equations is taken (to a certain order of smallness of the scale parameters), relations to certain integrable equations emerge. Some recent results concerning the use of integrable equation in modeling the motion of shallow water waves are reviewed in this contribution.
Menikoff, Ralph
2012-04-03
Shock initiation in a plastic-bonded explosives (PBX) is due to hot spots. Current reactive burn models are based, at least heuristically, on the ignition and growth concept. The ignition phase occurs when a small localized region of high temperature (or hot spot) burns on a fast time scale. This is followed by a growth phase in which a reactive front spreads out from the hot spot. Propagating reactive fronts are deflagration waves. A key question is the deflagration speed in a PBX compressed and heated by a shock wave that generated the hot spot. Here, the ODEs for a steady deflagration wave profile in a compressible fluid are derived, along with the needed thermodynamic quantities of realistic equations of state corresponding to the reactants and products of a PBX. The properties of the wave profile equations are analyzed and an algorithm is derived for computing the deflagration speed. As an illustrative example, the algorithm is applied to compute the deflagration speed in shock compressed PBX 9501 as a function of shock pressure. The calculated deflagration speed, even at the CJ pressure, is low compared to the detonation speed. The implication of this are briefly discussed.
Transformative Wave Technologies Kent, Washington
California at Davis, University of
Transformative Wave Technologies Kent, Washington www.transformativewave.com #12;#12;North America are shifted to off peak times #12;#12;Transformative Wave Technologies www.transformativewave.com #12
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).
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.
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.
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
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High elastic modulus polymer electrolytes (Patent) | SciTech Connect
Office of Scientific and Technical Information (OSTI)
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High elastic modulus polymer electrolytes suitable for preventing thermal
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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Elasticity of Pu -a window into fundamental understanding and aging
Office of Scientific and Technical Information (OSTI)
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Arnold Schwarzenegger CALIFORNIA OCEAN WAVE
Arnold Schwarzenegger Governor CALIFORNIA OCEAN WAVE ENERGY ASSESSMENT Prepared For: California, State and Federal Agencies and their expectations in respect to potential wave power deployments Jim a huge amount of wave measurement data from various data sources Asfaw Beyene of the Department
Water wave interactions Walter Craig
Thomann, Laurent
Water wave interactions Walter Craig Department of Mathematics & Statistics ´EquationsMaster University) Water wave interactions 25 janvier 2011 1 / 34 #12;Joint work with: Philippe Guyenne University, Killam Research Fellows Program, Fields Institute Walter Craig (McMaster University) Water wave
Extreme wave impinging and overtopping
Ryu, Yong Uk
2009-06-02
This investigates the velocity fields of a plunging breaking wave impinging on a structure through measurements in a two-dimensional wave tank. As the wave breaks and overtops the structure, so-called green water is generated. The flow becomes multi...
2, 70177025, 2014 Freaque wave
NHESSD 2, 70177025, 2014 Freaque wave occurrences in 2013 P. C. Liu Title Page Abstract to the corresponding final paper in NHESS if available. Brief Communication: Freaque wave occurrences in 2013 P. C. Liu7025, 2014 Freaque wave occurrences in 2013 P. C. Liu Title Page Abstract Introduction Conclusions References
Gustafsson, Torgny
2014 Tube - 1 STANDING WAVES IN AN AIR COLUMN The objective of the experiment is: · To study the harmonic structure of standing waves in an air column. APPARATUS: Computer, FFTScope software, PC speaker will produce nothing noteworthy. But, if the phase relationship is correct, standing waves can be formed
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
Rutledge, Steven
Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since radar involves the transmission, propagation and scattering of EM waves by various is the electrostatic force between two point charges. #12;Electromagnetic WavesElectromagnetic Waves Electric fields
Chiral Heat Wave and wave mixing in chiral media
Chernodub, M N
2015-01-01
We show that a hot rotating fluid of relativistic chiral fermions possesses a new gapless collective excitation associated with coherent propagation of energy density and chiral density waves along the axis of rotation. This excitation, which we call the Chiral Heat Wave, emerges due to a mixed gauge-gravitational anomaly. At finite density the Chiral Heat Wave couples to the Chiral Vortical Wave while in the presence of an external magnetic field it mixes with the Chiral Magnetic Wave. We find that the coupled waves - which are coherent fluctuations of the vector, axial and energy currents - have generally different velocities compared to the velocities of the individual waves. We also demonstrate that rotating chiral systems subjected to external magnetic field possess non-propagating metastable thermal excitations, the Dense Hot Spots.
Coupled ??, KK¯ scattering in P-wave and the ? resonance from lattice QCD
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Wilson, David J.; Briceño, Raúl A.; Dudek, Jozef J.; Edwards, Robert G.; Thomas, Christopher E.
2015-11-02
In this study, we determine elastic and coupled-channel amplitudes for isospin-1 meson-meson scattering in $P$-wave, by calculating correlation functions using lattice QCD with light quark masses such that $m_\\pi = 236$ MeV in a cubic volume of $\\sim (4 \\,\\mathrm{fm})^3$. Variational analyses of large matrices of correlation functions computed using operator constructions resembling $\\pi\\pi$, $K\\overline{K}$ and $q\\bar{q}$, in several moving frames and several lattice irreducible representations, leads to discrete energy spectra from which scattering amplitudes are extracted. In the elastic $\\pi\\pi$ scattering region we obtain a detailed energy-dependence for the phase-shift, corresponding to a $\\rho$ resonance, and we extend themore »analysis into the coupled-channel $K\\overline{K}$ region for the first time, finding a small coupling between the channels.« less
Viner, Kevin Carl
2011-02-22
IN COMPUTATIONAL WAVE DYNAMICS: KLEMP-WILHELMSON SPLITTING AT LARGE SCALES AND WAVE-WAVE INSTABILITIES IN ROTATING MOUNTAIN WAVES A Dissertation by KEVIN CARL VINER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2009 Major Subject: Atmospheric Sciences TWO PROBLEMS IN COMPUTATIONAL WAVE DYNAMICS: KLEMP-WILHELMSON SPLITTING AT LARGE SCALES AND WAVE-WAVE INSTABILITIES IN ROTATING MOUNTAIN WAVES A Dissertation...
Noise sustained waves in subexcitable media: From chemical waves to brain waves
Showalter, Kenneth
Noise sustained waves in subexcitable media: From chemical waves to brain waves P. Junga the threshold of pat- tern formation, noise can sustain locally coherent pat- terns. The patterns exhibit of nonequilibrium statistical phys- ics, noise has been recognized to play an important role in the formation
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.
Relevance of complex branch points for partial wave analysis
Ceci, S.; Svarc, A.; Doering, M.; Hanhart, C.; Krewald, S.; Meissner, U.-G.
2011-07-15
A central issue in hadron spectroscopy is to deduce--and interpret--resonance parameters, namely, pole positions and residues, from experimental data, for those are the quantities to be compared to lattice QCD or model calculations. However, not every structure in the observables derives from a resonance pole: the origin might as well be branch points, either located on the real axis (when a new channel composed of stable particles opens) or in the complex plane (when at least one of the intermediate particles is unstable). In this paper we demonstrate first the existence of such branch points in the complex plane and then show on the example of the {pi}N P{sub 11} partial wave that it is not possible to distinguish the structures induced by the latter from a true pole signal based on elastic data alone.
Fractional Electromagnetic Waves
J. F. Gómez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Guía
2011-08-31
In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.
Walker, D. Greg
-11 3.5e-11 4e-11 4.5e-11 5e-11 400 500 600 700 800 900 1000 location(nm) temperature(K) wave location 15 20 25 0 2 4 6 8 10 12 numberdensity(a.u.) frequency (THz) Summary Model Simulation Results Context. - Seitz and Koehler (1956) solve Boltzmann transport equations Monte Carlo approach is used to· 90 100 3e
L. Montagnier; J. Aissa; E. Del Giudice; C. Lavallee; A. Tedeschi; G. Vitiello
2010-12-23
Some bacterial and viral DNA sequences have been found to induce low frequency electromagnetic waves in high aqueous dilutions. This phenomenon appears to be triggered by the ambient electromagnetic background of very low frequency. We discuss this phenomenon in the framework of quantum field theory. A scheme able to account for the observations is proposed. The reported phenomenon could allow to develop highly sensitive detection systems for chronic bacterial and viral infections.
Chen, Changhua; Xiao, Renzhen; Sun, Jun; Song, Zhimin; Huo, Shaofei; Bai, Xianchen; Shi, Yanchao; Liu, Guozhi
2013-11-15
This paper provides a fresh insight into the effect of non-uniform slow wave structure (SWS) used in a relativistic backward wave oscillator (RBWO) with a resonant reflector. Compared with the uniform SWS, the reflection coefficient of the non-uniform SWS is higher, leading to a lower modulating electric field in the resonant reflector and a larger distance to maximize the modulation current. Moreover, for both types of RBWOs, stronger standing-wave field takes place at the rear part of the SWS. In addition, besides Cerenkov effects, the energy conversion process in the RBWO strongly depends on transit time effects. Thus, the matching condition between the distributions of harmonic current and standing wave field provides a profound influence on the beam-wave interaction. In the non-uniform RBWO, the region with a stronger standing wave field corresponds to a higher fundamental harmonic current distribution. Particle-in-cell simulations show that with a diode voltage of 1.02 MV and beam current of 13.2 kA, a microwave power of 4 GW has been obtained, compared to that of 3 GW in the uniform RBWO.
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.
Candan, Abdullah; U?ur, Gökay
2014-10-06
We have performed ab-initio calculations of the structural, electronic, elastic and dynamical properties for the spinel compounds CdX{sub 2}O{sub 4} (X=Al, Ga, In) using the plane wave pseudo-potential method within the generalized gradient approximation (GGA). The calculated lattice parameters, elastic constants for these compounds are in good agreement with the previous calculated values. The computed direct band gaps of CdAl{sub 2}O{sub 4}, CdGa{sub 2}O{sub 4} and CdIn{sub 2}O{sub 4} are 2.90 eV, 1.92 eV and 1.16 eV, respectively. The lattice vibrations were calculated by direct method. The calculated phonon dispersion curves show that all compounds are dynamically stable in the spinel structure.
Waves on the surface of the Orion molecular cloud
Olivier Berné; Núria Marcelino; José Cernicharo
2010-11-01
Massive stars influence their parental molecular cloud, and it has long been suspected that the development of hydrodynamical instabilities can compress or fragment the cloud. Identifying such instabilities has proved difficult. It has been suggested that elongated structures (such as the `pillars of creation') and other shapes arise because of instabilities, but alternative explanations are available. One key signature of an instability is a wave-like structure in the gas, which has hitherto not been seen. Here we report the presence of `waves' at the surface of the Orion molecular cloud near where massive stars are forming. The waves seem to be a Kelvin-Helmholtz instability that arises during the expansion of the nebula as gas heated and ionized by massive stars is blown over pre-existing molecular gas.
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
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
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
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
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.
SOLITARY-WAVE AND MULTI-PULSED TRAVELING-WAVE ...
1910-00-81
ential equations which model waves in a horizontal water channel traveling in ... undisturbed water depth and ? lies in [0,1]. ..... We content ourselves with.
Wave Energy Converter Effects on Nearshore Wave Propagation
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Energy Converter Effects on Nearshore Wave Propagation Jesse Roberts 1 , Grace Chang *2 , Craig Jones *3 Sandia National Laboratories 1515 Eubank SE, Albuquerque, NM 87123 USA 1...
Deep-water gravity waves: nonlinear theory of wave groups
Mindlin, I M
2014-01-01
Nonlinear initial-boundary value problem on deep-water gravity waves of finite amplitude is solved approximately (up to small terms of higher order) assuming that the waves are generated by an initial disturbance to the water and the horizontal dimensions of the initially disturbed body of the water are much larger than the magnitude of the free surface displacement. A numerable set of specific free surface waves is obtained in closed form and it is shown that free surface waves produced by an arbitrary initial disturbance to the water is a combination (not superposition: the waves are nonlinear) of the specific waves. A set of dispersive wave packets is found with one-to-one correspondence between the packets and positive integers, say, packet numbers, such that any initial free surface displacement gradually disintegrates into a number (limited or unlimited, depending on initial conditions) of the wave packets. The greater the packet number, the shorter the wavelength of the packet's carrier wave component,...
Catching a Wave: Innovative Wave Energy Device Surfs for Power...
Office of Environmental Management (EM)
and cost-effective electricity from clean energy resources, including water. Marine and hydrokinetic (MHK) technologies, which generate power from waves, tides, or...
Measurement of sound speed vs. depth in South Pole ice: pressure waves and shear waves
Klein, Spencer
2010-01-01
and ?tting a straight line. Radio waves are refracted signi?We note that while radio waves are refracted downward inwaves, similar to radio waves, propagate with small (