A Four-Dimensional Viscoelastic Deformation Model For Long Valley...
Viscoelastic Deformation Model For Long Valley Caldera, California, Between 1995 And 2000 Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A...
A Multiscale Model for Coupled Heat Conduction and Deformations of Viscoelastic Composites
Khan, Kamran Ahmed
2012-07-16T23:59:59.000Z
This study introduces a multiscale model for analyzing nonlinear thermo-viscoelastic responses of particulate composites. A simplified micromechanical model consisting of four sub-cells, i.e., one particle and three matrix sub-cells is formulated...
Non-linear viscoelastic deformation of polymeric solutions
Sanchez Reyes, Javier
2000-01-01T23:59:59.000Z
December 2000 Major Subject: Chemical Engineering NON-LINEAR VISCOELASTIC DEFORMATION OF POLYMERIC SOLUTIONS A Thesis by JAVIER SANCHEZ REYES Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE Approved as to style and content by: Lynden A. Arc er Co-Chair of Committee) Michael P ishko (Co-Chair of Committee) John C. Slattery (Member) H' e (Member) yford G. Anthony ead of Department) December 2000 Major Subject: Chemical...
Viscoelastic models for explosive binder materials
Bardenhagen, S.G.; Harstad, E.N.; Maudlin, P.J.; Gray, G.T. [Los Alamos National Lab., NM (United States); Foster, J.C. Jr. [Wright Lab., Eglin AFB, FL (United States)
1997-07-01T23:59:59.000Z
An improved model of the mechanical properties of the explosive contained in conventional munitions is needed to accurately simulate performance and accident scenarios in weapons storage facilities. A specific class of explosives can he idealized as a mixture of two components: energetic crystals randomly suspended in a polymeric matrix (binder). Strength characteristics of each component material are important in the macroscopic behavior of the composite (explosive). Of interest here is the determination of an appropriate constitutive law for a polyurethane binder material. This paper is a continuation of previous work in modeling polyurethane at moderately high strain rates and for large deformations. Simulation of a large deformation (strains in excess of 100%) Taylor Anvil experiment revealed numerical difficulties which have been addressed. Additional experimental data have been obtained including improved resolution Taylor Anvil data, and stress relaxation data at various strain rates. A thorough evaluation of the candidate viscoelastic constitutive model is made and possible improvements discussed.
Kuravi, Ramachandra Srinivasa Chaitanya
2012-07-16T23:59:59.000Z
This thesis analyzes the implementation of surface bonded piezoelectric actuators to control or minimize the deformation in elastic or viscoelastic cantilever beams due to simultaneous heat and moisture diffusion. The problem is addressed...
Coupled heat conduction and deformation in a viscoelastic composite cylinder
Shah, Sneha
2010-01-16T23:59:59.000Z
This study analyzes the thermo-mechanical response of a composite cylinder made up of two layers of linear isotropic viscoelastic materials that belong to the class of non-Thermorheologically Simple Material. The effect of time-varying temperature...
Non-linear viscoelastic deformation of polymeric solutions
Sanchez Reyes, Javier
2000-01-01T23:59:59.000Z
The dynamics of entangled polymeric solutions were studied using drag of borosilicate discs and conventional shear rheometry devices in order to understand the effect of deformation on the relaxation process and the possible ...
Viscoelastic damage modeling of sinkhole formation Eyal Shalev*, Vladimir Lyakhovsky
Lyakhovsky, Vladimir
Viscoelastic damage modeling of sinkhole formation Eyal Shalev*, Vladimir Lyakhovsky Geological 2012 Keywords: Sinkholes Damage Viscoelasticity Modeling a b s t r a c t The sinkholes along the Dead Sea coast are observed in two main sedimentary environments: alluvial fan sinkholes, which usually
A micromechanical model for a viscoelastic cohesive zone
Searcy, Chad Randall, 1972-
1998-01-01T23:59:59.000Z
A micromechanical model for a viscoelastic cohesive aphics. zone is formulated herein. Care has been taken in the construction of a physically-based continuum mechanics model of the damaged region ahead of the crack tip. The homogenization...
Thermomechanical Constitutive Modeling of Viscoelastic Materials undergoing Degradation
Karra, Satish
2012-07-16T23:59:59.000Z
models. In the area of viscoelastic uids, the K-BKZ integral model [18], [19] has been extensively used. Recently, a thermodynamic framework has been developed by Rajagopal and co-workers [20], [21] that has been shown to model a variety of responses... production. ? te instantaneous elasticity t permanent set Fig. 2.: Illustration of a viscoelastic uid that shows instantaneous elasticity in creep. 5 aging, semiconductor, and automobile industries. In the aerospace industry, due to their extreme...
Viscoelastic Models of Tidally Heated Exomoons
Dobos, Vera
2015-01-01T23:59:59.000Z
Tidal heating of exomoons may play a key role in their habitability, since the elevated temperature can melt the ice on the body even without significant solar radiation. The possibility of life is intensely studied on Solar System moons such as Europa or Enceladus, where the surface ice layer covers tidally heated water ocean. Tidal forces may be even stronger in extrasolar systems, depending on the properties of the moon and its orbit. For studying the tidally heated surface temperature of exomoons, we used a viscoelastic model for the first time. This model is more realistic than the widely used, so-called fixed Q models, because it takes into account the temperature dependency of the tidal heat flux, and the melting of the inner material. With the use of this model we introduced the circumplanetary Tidal Temperate Zone (TTZ), that strongly depends on the orbital period of the moon, and less on its radius. We compared the results with the fixed Q model and investigated the statistical volume of the TTZ usi...
Modeling of the Aging Viscoelastic Properties of Cement Paste Using Computational Methods
Li, Xiaodan
2012-07-16T23:59:59.000Z
computational model using finite element method to predict the viscoelastic behavior of cement paste, and using this model, virtual tests can be carried out to improve understanding of the mechanisms of viscoelastic behavior. The primary finding from...
Kinetic viscoelasticity modeling applied to degradation during carbon–carbon composite processing
Drakonakis, Vasileios M.
Kinetic viscoelasticity modeling has been successfully utilized to describe phenomena during cure of thermoset based carbon fiber reinforced matrices. The basic difference from classic viscoelasticity is that the fundamental ...
Kuravi, Ramachandra Srinivasa Chaitanya
2012-07-16T23:59:59.000Z
variables in cases of actuated and unactuated beams. Four materials are chosen for this study; aluminium, epoxy, carbon fiber reinforced polymer with fiber volume fraction of 60 percent, and an epoxy-like viscoelastic material. The viscoelastic material...
Modeling magnetosensitive ion channels in viscoelastic environment of living cells
Igor Goychuk
2015-10-01T23:59:59.000Z
We propose and study a model of hypothetical magnetosensitive ionic channels which are long thought to be a possible candidate to explain the influence of weak magnetic fields on living organisms ranging from magnetotactic bacteria to fishes, birds, rats, bats and other mammals including humans. The core of the model is provided by a short chain of magnetosomes serving as a sensor which is coupled by elastic linkers to the gating elements of ion channels forming a small cluster in the cell membrane. The magnetic sensor is fixed by one end on cytoskeleton elements attached to the membrane and is exposed to viscoelastic cytosol. Its free end can reorient stochastically and subdiffusively in viscoelastic cytosol responding to external magnetic field changes and open the gates of coupled ion channels. The sensor dynamics is generally bistable due to bistability of the gates which can be in two states with probabilities which depend on the sensor orientation. For realistic parameters, it is shown that this model channel can operate in the magnetic field of Earth for a small number (5 to 7) of single-domain magnetosomes constituting the sensor rod each of which has a typical size found in magnetotactic bacteria and other organisms, or even just one sufficiently large nanoparticle of a characteristic size also found in nature. It is shown that due to viscoelasticity of medium the bistable gating dynamics generally exhibits power law and stretched exponential distributions of the residence times of the channels in their open and closed states. This provides a generic physical mechanism for explanation of the origin of such anomalous kinetics for other ionic channels whose sensors move in viscoelastic environment provided by either cytosol or biological membrane, in a quite general context, beyond the fascinating hypothesis of magnetosensitive ionic channels we explore.
Hanyk, Ladislav
The Aim effective evaluation of viscoelastic responses of arbitrarily stratified Earth models to surface loading Physical Model Maxwell viscoelastic prestressed selfgravitating sphere, compressible invoked [Press et al., 1996] #15; taking into account the block diagonal structure of P andQ desirable
On models for viscoelastic fluid-like materials that are mechanically incompressible and
Cerveny, Vlastislav
of state. Liquids.) Viscoelastic fluid like materials. (Internal energy has a non-thermal contributionOn models for viscoelastic fluid-like materials that are mechanically incompressible and thermallyBoussinesq approximation. Math. Models Methods Appl. Sci., 6(8):11571167, 1996 #12;OberbeckBoussinesq system
Cerveny, Vlastislav
The Aim effective evaluation of viscoelastic responses of arbitrarily stratified Earth models to surface loading Physical Model Maxwell viscoelastic pre-stressed self-gravitating sphere, compressible et al., 1996] ¯ taking into account the block diagonal structure of È and É desirable (see next panel
Protein viscoelastic dynamics: a model system
Craig Fogle; Joseph Rudnick; David Jasnow
2015-02-02T23:59:59.000Z
A model system inspired by recent experiments on the dynamics of a folded protein under the influence of a sinusoidal force is investigated and found to replicate many of the response characteristics of such a system. The essence of the model is a strongly over-damped oscillator described by a harmonic restoring force for small displacements that reversibly yields to stress under sufficiently large displacement. This simple dynamical system also reveals unexpectedly rich behavior, exhibiting a series of dynamical transitions and analogies with equilibrium thermodynamic phase transitions. The effects of noise and of inertia are briefly considered and described.
Darabi Konartakhteh, Masoud
2012-10-19T23:59:59.000Z
strongly depends on the temperature and loading conditions. This study proposes a new general thermodynamic-based framework to specifically derive thermo-viscoelastic, thermo-viscoplastic, thermo-viscodamage, and micro-damage healing constitutive models...
A Micromechanical Model for Viscoelastic-Viscoplastic Analysis of Particle Reinforced Composite
Kim, Jeong Sik
2011-02-22T23:59:59.000Z
This study introduces a time-dependent micromechanical model for a viscoelastic-viscoplastic analysis of particle-reinforced composite and hybrid composite. The studied particle-reinforced composite consists of solid spherical particle and polymer...
Finite Element Modeling of Drilling Using DEFORM
Gardner, Joel D.; Dornfeld, David
2006-01-01T23:59:59.000Z
Vijayaraghavan, A. (2005), “Drilling of Fiber- ReinforcedFINITE ELEMENT MODELING OF DRILLING USING DEFORM J. Gardner,of Comprehensive Drilling Simulation Tool” ABSTRACT DEFORM-
MECHANICAL MODELS FOR INTERSEISMIC DEFORMATION IN
Kanda, Ravi
MECHANICAL MODELS FOR INTERSEISMIC DEFORMATION IN SUBDUCTION ZONES Thesis by Ravi V. S. Kanda that mechanical coupling on such asperities alone is sufficient to explain currently available geodetic
On Deformable Models for Visual Pattern Recognition
Yeung, Dit-Yan
deformable models, but some existing 2 1 2 D and 3D deformable models are also briefly reviewed. Potential has been successfully applied to recognize rigid objects, such as machinery parts and printed def (w; H j ; Â¯ w), which represents the ``energy'' of the current model with respect to the reference
Freed, Alan D.; Einstein, Daniel R.; Carson, James P.; Jacob, Rick E.
2012-03-01T23:59:59.000Z
In the first year of this contractual effort a hypo-elastic constitutive model was developed and shown to have great potential in modeling the elastic response of parenchyma. This model resides at the macroscopic level of the continuum. In this, the second year of our support, an isotropic dodecahedron is employed as an alveolar model. This is a microscopic model for parenchyma. A hopeful outcome is that the linkage between these two scales of modeling will be a source of insight and inspiration that will aid us in the final year's activity: creating a viscoelastic model for parenchyma.
You, Taesun
2013-08-13T23:59:59.000Z
The main objective of this study is to develop and validate a framework for microstructural modeling of asphalt composite materials using a coupled thermo-viscoelastic, thermo-viscoplastic, and thermo-viscodamage constitutive model. In addition...
Viscoelasticity of stepped interfaces
Demkowicz, Michael J.
Using molecular dynamics modeling, we show that interfaces in sputter deposited Cu-Nb superlattices exhibit time-dependent elasticity, i.e., viscoelasticity, under shear loading. In the high temperature and small strain ...
Viscoelastic{Viscoplastic Damage Model for Asphalt Concrete
Graham, Michael A.
2010-10-12T23:59:59.000Z
in experiments, and their model was limited to uniaxial loading. Chehab et al. (2003) developed a continuum viscoelastoplastic model for undamaged asphalt concrete, but its scope was also limited to uniaxial characterization. Uzan (2005) developed a damaged...
Decoherence of spin-deformed bosonic model
Dehdashti, Sh., E-mail: shahram.dehdashti@gmail.com [Department of Physics, Faculty of Science, University of Isfahan, Hezar Jerib St., Isfahan 81746-73441 (Iran, Islamic Republic of); Mahdifar, A., E-mail: mahdifar_a@sci.sku.ac.ir [Science Department, Shahrekord University, Shahrekord (Iran, Islamic Republic of); Bagheri Harouni, M., E-mail: m-bagheri@phys.ui.ac.ir [Department of Physics, Faculty of Science, University of Isfahan, Hezar Jerib St., Isfahan 81746-73441 (Iran, Islamic Republic of); Quantum Optics Group, Department of Physics, Faculty of Science, University of Isfahan, HezarJerib St., Isfahan 81746-73441 (Iran, Islamic Republic of); Roknizadeh, R., E-mail: rokni@sci.ui.ac.ir [Department of Physics, Faculty of Science, University of Isfahan, Hezar Jerib St., Isfahan 81746-73441 (Iran, Islamic Republic of); Quantum Optics Group, Department of Physics, Faculty of Science, University of Isfahan, HezarJerib St., Isfahan 81746-73441 (Iran, Islamic Republic of)
2013-07-15T23:59:59.000Z
The decoherence rate and some parameters affecting it are investigated for the generalized spin-boson model. We consider the spin-bosonic model when the bosonic environment is modeled by the deformed harmonic oscillators. We show that the state of the environment approaches a non-linear coherent state. Then, we obtain the decoherence rate of a two-level system which is in contact with a deformed bosonic environment which is either in thermal equilibrium or in the ground state. By using some recent realization of f-deformed oscillators, we show that some physical parameters strongly affect the decoherence rate of a two-level system. -- Highlights: •Decoherence of the generalized spin-boson model is considered. •In this model the environment consists of f-oscillators. •Via the interaction, the state of the environment approaches non-linear coherent states. •Effective parameters on decoherence are considered.
Modeling of the Aging Viscoelastic Properties of Cement Paste Using Computational Methods
Li, Xiaodan
2012-07-16T23:59:59.000Z
1.2 Scope and Problem Statement ................................................ 3 1.3 Tasks ....................................................................................... 4... ............................................................................ 37 4.1.2 Viscoelastic ................................................................... 39 4.1.3 Dissolution...
Lindsay, Ron
of the Arctic geophysical environment. The deformation rate of pack ice, determined from the spatial gradientsRGPS/Model Ice Deformation July 3, 2003 1 Sea Ice Deformation Rates From Satellite Measurements The deformation of sea ice is an important element of the Arctic climate system because of its influence
Modeling the Non-linear Viscoelastic Response of High Temperature Polyimides
Karra, Satish
2010-01-01T23:59:59.000Z
A constitutive model is developed to predict the viscoelastic response of polyimide resins that are used in high temperature applications. This model is based on a thermodynamic framework that uses the notion that the `natural configuration' of a body evolves as the body undergoes a process and the evolution is determined by maximizing the rate of entropy production in general and the rate of dissipation within purely mechanical considerations. We constitutively prescribe forms for the specific Helmholtz potential and the rate of dissipation (which is the product of density, temperature and the rate of entropy production), and the model is derived by maximizing the rate of dissipation with the constraint of incompressibility, and the reduced energy dissipation equation is also regarded as a constraint in that it is required to be met in every process that the body undergoes. The efficacy of the model is ascertained by comparing the predictions of the model with the experimental data for PMR-15 and HFPE-II-52 ...
Modeling the Non-linear Viscoelastic Response of High Temperature Polyimides
Satish Karra; K. R. Rajagopal
2010-08-20T23:59:59.000Z
A constitutive model is developed to predict the viscoelastic response of polyimide resins that are used in high temperature applications. This model is based on a thermodynamic framework that uses the notion that the `natural configuration' of a body evolves as the body undergoes a process and the evolution is determined by maximizing the rate of entropy production in general and the rate of dissipation within purely mechanical considerations. We constitutively prescribe forms for the specific Helmholtz potential and the rate of dissipation (which is the product of density, temperature and the rate of entropy production), and the model is derived by maximizing the rate of dissipation with the constraint of incompressibility, and the reduced energy dissipation equation is also regarded as a constraint in that it is required to be met in every process that the body undergoes. The efficacy of the model is ascertained by comparing the predictions of the model with the experimental data for PMR-15 and HFPE-II-52 polyimide resins.
STATISTICAL MECHANICS MODELING OF MESOSCALE DEFORMATION IN METALS...
Office of Scientific and Technical Information (OSTI)
Technical Report: STATISTICAL MECHANICS MODELING OF MESOSCALE DEFORMATION IN METALS Citation Details In-Document Search Title: STATISTICAL MECHANICS MODELING OF MESOSCALE...
Stability analysis of a viscoelastic model for ion-irradiated silicon
Scott A. Norris
2012-01-12T23:59:59.000Z
To study the effect of stress within the thin amorphous film generated atop Si irradiated by Ar+, we model the film as a viscoelastic medium into which the ion beam continually injects biaxial compressive stress. We find that at normal incidence, the model predicts a steady compressive stress of a magnitude comparable to experiment. However, linear stability analysis at normal incidence reveals that this mechanism of stress generation is unconditionally stabilizing due to a purely kinematic material flow, depending on none of the material parameters. Thus, despite plausible conjectures in the literature as to its potential role in pattern formation, we conclude that beam stress at normal incidence is unlikely to be a source of instability at any energy, supporting recent theories attributing hexagonal ordered dots to the effects of composition. In addition, we find that the elastic moduli appear in neither the steady film stress nor the leading order smoothening, suggesting that the primary effects of stress can be captured even if elasticity is neglected. This should greatly simplify future analytical studies of highly nonplanar surface evolution, in which the beam-injected stress is considered to be an important effect.
Viscoelastic effects on frequency tuning of a dielectric elastomer membrane resonator
Zhou, Jianyou; Jiang, Liying, E-mail: lyjiang@eng.uwo.ca; Khayat, Roger E. [Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario N6A 5B9 (Canada)
2014-03-28T23:59:59.000Z
As a recent application of dielectric elastomers (DEs), DE resonators have become an alternative to conventional silicon-based resonators used in MEMS and have attracted much interest from the research community. However, most existing modeling works for the DE resonators ignore the intrinsic viscoelastic effect of the material that may strongly influence their dynamic performance. Based on the finite-deformation viscoelasticity theory for dielectrics, this paper theoretically examines the in-plane oscillation of a DE membrane resonator to demonstrate how the material viscoelasticity affects the actuation and frequency tuning processes of the resonator. From the simulation results, it is concluded that not only the applied voltage can change the natural frequency of the resonator, but also the inelastic deformation contributes to frequency tuning. Due to the viscoelasticity of the material, the electrical loading rate influences the actuation process of the DE resonator, while it has little effect on the final steady frequency tuned by the prescribed voltage within the safety range. With the consideration of the typical failure modes of the resonator and the evolution process of the material, the tunable frequency range and the safe range of the applied voltage of the DE membrane resonator with different dimension parameters are determined in this work, which are found to be dependent on the electrical loading rate. This work is expected to provide a better understanding on the frequency tuning of viscoelastic DE membrane resonators and a guideline for the design of DE devices.
Viscoelastic behavior of fiber-reinforced composite materials undergoing cure
Wang, Kai
1999-01-01T23:59:59.000Z
A viscoelastic material model has been proposed to characterize the curing and thermal effects on the viscoelastic material properties of both the matrix material and the composite lamina. Micromechanics simulations are used to generate...
M. V. Voinova; M. Rodahl; M. Jonson; B. Kasemo
1998-05-21T23:59:59.000Z
We have derived the general solution of a wave equation describing the dynamics of two-layere viscoelastic polymer materials of arbitrary thickness deposited on solid (quartz) surfaces in a fluid environment. Within the Voight model of viscoelastic element, we calculate the acoustic response of the system to an applied shear stress, i.e. we find the shift of the quartz generator resonance frequency and of the dissipation factor, and show that it strongly depends on the viscous loading of the adsorbed layers and on the shear storage and loss moduli of the overlayers. These results can readily be applied to quartz crystal acoustical measurements of the viscoelasticity of polymers, which conserve their shape under the shear deformations and do not flow, and layered structures such as protein films adsorbed from solution onto the surface of self-assembled monolayres.
A Four-Dimensional Viscoelastic Deformation Model For Long Valley Caldera,
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaP a g eWorksVillage of Brewster, OhioLonghui10 CFR Â§ 1021 Jump to:2-M Probe21st boroHawaii |California,
Nonlinear viscoelastic characterization of thin films using dynamic mechanical analysis
Payne, Debbie Flowers
1993-01-01T23:59:59.000Z
manner similar to the traditional time temperature superposition principle for linear viscoelastic materials where stress systematically compresses or expands the time scale. From dynamic mechanical testing and analysis, the experimental viscoelastic.... D. Nonlinear Characterization of Thin Film Materials. . . . Nonlinear Viscoelastic Models . Dynamic Mechanical Testing. Summary of Literature Reviewed. 5 5 7 8 III THEORETICAL ANALYSIS . A. B. C. D. Conversion of Experimental Values...
Coefficient of restitution for viscoelastic disks
Thomas Schwager
2007-01-08T23:59:59.000Z
The dissipative collision of two identical viscoelastic disks is studied. By using a known law for the elastic part of the interaction force and the viscoelastic damping model an analytical solution for the coefficient of restitution shall be given. The coefficient of restitution depends significantly on the impact velocity. It approaches one for small velocities and decreases for increasing velocities.
Integrable double deformation of the principal chiral model
Francois Delduc; Marc Magro; Benoit Vicedo
2014-10-29T23:59:59.000Z
We define a two-parameter family of integrable deformations of the principal chiral model on an arbitrary compact group. The Yang-Baxter sigma-model and the principal chiral model with a Wess-Zumino term both correspond to limits in which one of the two parameters vanishes.
Diffusion of a fluid through a viscoelastic solid
Satish Karra
2010-12-08T23:59:59.000Z
This paper is concerned with the diffusion of a fluid through a viscoelastic solid undergoing large deformations. Using ideas from the classical theory of mixtures and a thermodynamic framework based on the notion of maximization of the rate of entropy production, the constitutive relations for a mixture of a viscoelastic solid and a fluid (specifically Newtonian fluid) are derived. By prescribing forms for the specific Helmholtz potential and the rate of dissipation, we derive the relations for the partial stress in the solid, the partial stress in the fluid, the interaction force between the solid and the fluid, and the evolution equation of the natural configuration of the solid. We also use the assumption that the volume of the mixture is equal to the sum of the volumes of the two constituents in their natural state as a constraint. Results from the developed model are shown to be in good agreement with the experimental data for the diffusion of various solvents through high temperature polyimides that are used in the aircraft industry. The swelling of a viscoelastic solid under the application of an external force is also studied.
Relativistic viscoelastic fluid mechanics
Masafumi Fukuma; Yuho Sakatani
2011-09-01T23:59:59.000Z
A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski spacetime become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.
Fallon, Michael Brooks
2012-11-12T23:59:59.000Z
to assess the deformation demand on asymmetric offshore jacket platforms subject to wave and current loadings. The probabilistic model is constructed by adding correction terms and a model error to an existing deterministic deformation demand model...
Paris-Sud XI, Université de
Lungs PAUL CAZEAUX, Laboratoire J.L. Lions, UMR 7598, Université Pierre et Marie Curie-Paris 6, 4 Place of the deformation of the human lung tissue, called the lung parenchyma, during the respiration process bronchi and enters the lungs. It is then distributed by the bronchial tree to the acini or alveolar
Paulino, Glaucio H.
Asphalt Pavement Aging and Temperature Dependent Properties through a Functionally Graded simulation of functionally graded viscoelastic properties in asphalt concrete pavements. The techniques properties. A full-depth asphalt concrete pavement has been simulated to demonstrate the applicability
Neural network modelling of hot deformation of austenite
Cambridge, University of
Neural network modelling of hot deformation of austenite Mathew Peet Wolfson College University Neural Networks Neural networks to predict constitutive behaviour 6 6 7 17 20 Experimental Detail 21. Linear regression techniques are not capable of representing the data, however neural networks
Physical and Statistical Models in Deformation Geodesy
Lipovsky, Brad
2011-01-01T23:59:59.000Z
Pore pressure distributions at logarithmic time intervals (The model geometry of pore pressure di?usion through a faultin the text. . . . . . Pore pressure distributions at
Dynamics and Stability of Rolling Viscoelastic Tires
Potter, Trevor
2013-04-30T23:59:59.000Z
Current steady state rolling tire calculations often do not include treads because treads destroy the rotational symmetry of the tire. We describe two methodologies to compute time periodic solutions of a two-dimensional viscoelastic tire with treads: solving a minimization problem and solving a system of equations. We also expand on work by Oden and Lin on free spinning rolling elastic tires in which they disovered a hierachy of N-peak steady state standing wave solutions. In addition to discovering a two-dimensional hierarchy of standing wave solutions that includes their N-peak hiearchy, we consider the eects of viscoelasticity on the standing wave solutions. Finally, a commonplace model of viscoelasticity used in our numerical experiments led to non-physical elastic energy growth for large tire speeds. We show that a viscoelastic model of Govindjee and Reese remedies the problem.
CONSTITUTIVE MODELLING OF SHAPE MEMORY ALLOYS AND UPSCALING OF DEFORMABLE POROUS MEDIA
Popov, Peter
: Aerospace Engineering #12;CONSTITUTIVE MODELLING OF SHAPE MEMORY ALLOYS AND UPSCALING OF DEFORMABLE POROUSCONSTITUTIVE MODELLING OF SHAPE MEMORY ALLOYS AND UPSCALING OF DEFORMABLE POROUS MEDIA. Reed (Head of Department) May 2005 Major Subject: Aerospace Engineering #12;iii ABSTRACT Constitutive
INTERACTIVE MODELLING OF MPEG-4 DEFORMABLE HUMAN BODY MODELS
Cordier, Frederic
years, human characters have become more and more important in computer animation, virtual reality that are immediately usable for animation. In doing so, we aim to carry out realistic deformations on the human body that encompasses addition of props, face and body animation, coordination along with stages or virtual environments
Winding vacuum energies in a deformed O(4) sigma model
Vladimir V. Bazhanov; Gleb A. Kotousov; Sergei L. Lukyanov
2014-09-01T23:59:59.000Z
We consider the problem of calculating the Casimir energies in the winding sectors of Fateev's SS-model, which is an integrable two-parameter deformation of the O(4) non-linear sigma model in two dimensions. This problem lies beyond the scope of all traditional methods of integrable quantum field theory including the thermodynamic Bethe ansatz and non-linear integral equations. Here we propose a solution based on a remarkable correspondence between classical and quantum integrable systems and express the winding energies in terms of certain solutions of the classical sinh-Gordon equation.
Gavrilik, A M
2013-01-01T23:59:59.000Z
We consider the deformed Bose gas model with the deformation structure function that is the combination of a q-deformation and a quadratically polynomial deformation. Such a choice of the unifying deformation structure function enables us to describe the interacting gas of composite (two-fermionic or two-bosonic) bosons. Using the relevant generalization of the Jackson derivative, we derive a two-parametric expression for the total number of particles, from which the deformed virial expansion of the equation of state is obtained. The latter is interpreted as the virial expansion for the effective description of a gas of interacting composite bosons with some interaction potential.
Darabi Konartakhteh, Masoud
2012-10-19T23:59:59.000Z
for bituminous materials and asphalt mixes. The developed thermodynamic-based framework is general and can be applied for constitutive modeling of different materials such as bituminous materials, soft materials, polymers, and biomaterials. This framework...
Non-Linear Drying Diffusion and Viscoelastic Drying Shrinkage Modeling in Hardened Cement Pastes
Leung, Chin K.
2010-07-14T23:59:59.000Z
from creep tests of sealed specimens. 3 2. PREVIOUS WORK 2.1. Non-linear Drying Diffusion Drying mechanisms in porous materials, particularly gels, were extensively studied by Scherer [1]. After an initial period of constant rate of mass loss..., diffusion coefficients were then used as input parameters for the shrinkage model. To verify the poroviscoelastic shrinkage model, creep compliance coefficients of the materials also needed to be obtained from separate creep tests of sealed specimens...
Diffusion of a fluid through a viscoelastic solid
Karra, Satish
2010-01-01T23:59:59.000Z
This paper is concerned with the diffusion of a fluid through a viscoelastic solid undergoing large deformations. The constitutive relations for a mixture of a viscoelastic solid and a fluid (specifically Newtonian fluid) are derived using ideas from the classical theory of mixtures and a thermodynamic framework based on the notion of maximization of the rate of entropy production. We prescribe forms for the specific Helmholtz potential and the rate of dissipation and the relations for the partial stress in the solid, the partial stress in the fluid, and the interaction force between the solid and the fluid, and the evolution equation of the natural configuration of the solid are derived. We also use the assumption that the volume of the mixture is equal to the sum of the volumes of the two constituents in their natural state as a constraint. Results from the developed model are shown to be in good agreement with the experimental data for the diffusion of various solvents through high temperature polyimides t...
Non-Linear Drying Diffusion and Viscoelastic Drying Shrinkage Modeling in Hardened Cement Pastes
Leung, Chin K.
2010-07-14T23:59:59.000Z
The present research seeks to study the decrease in diffusivity rate as relative humidity (RH) decreases and modeling drying shrinkage of hardened cement paste as a poroviscoelastic respose. Thin cement paste strips of 0.4 and 0.5 w/c at age 3 and 7...
Efficient modelling of particle collisions using a non-linear viscoelastic contact force
Ray, Shouryya; Fröhlich, Jochen
2015-01-01T23:59:59.000Z
In this paper the normal collision of spherical particles is investigated. The particle interaction is modelled in a macroscopic way using the Hertzian contact force with additional linear damping. The goal of the work is to develop an efficient approximate solution of sufficient accuracy for this problem which can be used in soft-sphere collision models for Discrete Element Methods and for particle transport in viscous fluids. First, by the choice of appropriate units, the number of governing parameters of the collision process is reduced to one, thus providing a dimensionless parameter that characterizes all such collisions up to dynamic similitude. It is a simple combination of known material parameters as well as initial conditions. A rigorous calculation of the collision time and restitution coefficient from the governing equations, in the form of a series expansion in this parameter is provided. Such a first principles calculation is particularly interesting from a theoretical perspective. Since the gov...
Efficient modelling of particle collisions using a non-linear viscoelastic contact force
Shouryya Ray; Tobias Kempe; Jochen Fröhlich
2015-06-21T23:59:59.000Z
In this paper the normal collision of spherical particles is investigated. The particle interaction is modelled in a macroscopic way using the Hertzian contact force with additional linear damping. The goal of the work is to develop an efficient approximate solution of sufficient accuracy for this problem which can be used in soft-sphere collision models for Discrete Element Methods and for particle transport in viscous fluids. First, by the choice of appropriate units, the number of governing parameters of the collision process is reduced to one, which is a simple combination of known material parameters as well as initial conditions. It provides a dimensionless parameter that characterizes all such collisions up to dynamic similitude. Next, a rigorous calculation of the collision time and restitution coefficient from the governing equations, in the form of a series expansion in this parameter is provided. Such a calculation based on first principles is particularly interesting from a theoretical perspective. Since the governing equations present some technical difficulties, the methods employed are also of interest from the point of view of the analytical technique. Using further approximations, compact expressions for the restitution coefficient and the collision time are then provided. These are used to implement an approximate algebraic rule for computing the desired stiffness and damping in the framework of the adaptive collision model (Kempe & Fr\\"{o}hlich, J. Fluid Mech., 709: 445-489, 2012). Numerical tests with binary as well as multiple particle collisions are reported to illustrate the accuracy of the proposed method and its superiority in terms of numerical efficiency.
Anderson, C.A.
1981-01-01T23:59:59.000Z
Six years ago the Reactor Safety Research Division of the Nuclear Regulatory Commission (NRC) approached the Los Alamos National Laboratory to develop a comprehensive concrete structural analysis code to predict the static and dynamic behavior of Prestressed Concrete Reactor Vessels (PCRVs) that serve as the containment structure of a High-Temperature Gas-Cooled Reactor. The PCRV is a complex concrete structure that must be modeled in three dimensions and posseses other complicating features such as a steel liner for the reactor cavity and woven cables embedded vertically in the PCRV and wound circumferentially on the outside of the PCRV. The cables, or tendons, are used for prestressing the reactor vessel. In addition to developing the computational capability to predict inelastic three dimensional concrete structural behavior, the code response was verified against documented experiments on concrete structural behavior. This code development/verification effort is described.
Modeling Attractor Deformation in the Rodent Head-Direction JEREMY P. GOODRIDGE1
Touretzky, David S.
Modeling Attractor Deformation in the Rodent Head-Direction System JEREMY P. GOODRIDGE1 AND DAVID S attractor deformation in the rodent head-direction system. J Neurophysiol 83: 34023410, 2000. We present a model of the head-direction circuit in the rat that improves on earlier models in several respects
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
A Deformable Model for Bringing Particles in Anders Lindbjerg Dahl1
Dahl, Anders Lindbjerg
about particle distribution, size and shape, and these parameters are often essential for system designA Deformable Model for Bringing Particles in Focus Anders Lindbjerg Dahl1 , Thomas Martini Abstract. We provide a deformable model for particle analysis. We in- vestigate particle images from
Thermodynamics of viscoelastic fluids: the temperature equation.
Wapperom, Peter
Thermodynamics of viscoelastic fluids: the temperature equation. Peter Wapperom Martien A. Hulsen and Hydrodynamics Rotterdamseweg 145 2628 AL Delft (The Netherlands) Abstract From the thermodynamics with internal. The well- known stress differential models that fit into the thermodynamic theory will be treated
Roberts-Tompkins, Altramese L.
2010-07-14T23:59:59.000Z
of the Boltzmann superposition principle. Based on the strength of materials approach, the analytical solution for the deformation in a viscoelastic sandwich beam is determined based on the application of the Correspondence Principle and Laplace transform. Finite...
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Read, Randy J. [University of Cambridge, Cambridge CB2 0XY (United Kingdom); Adams, Paul D. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Brunger, Axel T. [Stanford University, 318 Campus Drive West, Stanford, CA 94305-5432 (United States); Afonine, Pavel V.; Grosse-Kunstleve, Ralf W. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720 (United States); Hung, Li-Wei [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2012-07-01T23:59:59.000Z
A density-based procedure is described for improving a homology model that is locally accurate but differs globally. The model is deformed to match the map and refined, yielding an improved starting point for density modification and further model-building. An approach is presented for addressing the challenge of model rebuilding after molecular replacement in cases where the placed template is very different from the structure to be determined. The approach takes advantage of the observation that a template and target structure may have local structures that can be superimposed much more closely than can their complete structures. A density-guided procedure for deformation of a properly placed template is introduced. A shift in the coordinates of each residue in the structure is calculated based on optimizing the match of model density within a 6 Å radius of the center of that residue with a prime-and-switch electron-density map. The shifts are smoothed and applied to the atoms in each residue, leading to local deformation of the template that improves the match of map and model. The model is then refined to improve the geometry and the fit of model to the structure-factor data. A new map is then calculated and the process is repeated until convergence. The procedure can extend the routine applicability of automated molecular replacement, model building and refinement to search models with over 2 Å r.m.s.d. representing 65–100% of the structure.
THERMOMECHANICS OF PV MODULES INCLUDING THE VISCOELASTICITY OF EVA Ulrich Eitner1,
by a comparison to displacement experiments where the thermomechanical deformation of solar cells in a PV laminate technology in order to measure the deformation of laminated solar cells contactless. We determinedTHERMOMECHANICS OF PV MODULES INCLUDING THE VISCOELASTICITY OF EVA Ulrich Eitner1, *, Matthias
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
Modeling Of Surface Deformation From Satellite Radar Interferometry...
the geothermal field, with maximum vertical and horizontal deformation rates of up to 30 mmyear, relative to a reference point on Obsidian Butte, less than 5 km away. Comparisons...
Kinematic models of interseismic deformation in Southern California
Meade, Brendan J. (Brendan Joseph), 1975-
2004-01-01T23:59:59.000Z
We develop a framework for interpreting geodetic measurements of interseismic deformation and geologic slip rate estimates in terms of block motions. This method accounts for the effects of block rotations and interseismic ...
Vigny, Christophe
Author's personal copy Interpretation of interseismic deformations and the seismic cycle associated online 11 January 2013 Keywords: Seismic cycle Finite element Subduction Earthquake Viscoelastic asthenosphere Low viscosity wedge The deformations of the overriding and subducting plates during the seismic
Long, Maureen Devaney
2006-01-01T23:59:59.000Z
In this thesis I report the results of several studies of elastic anisotropy and deformation in the Earth's mantle, using shear wave splitting measurements, numerical models of geodynamical processes, and laboratory ...
Graham, Caroline C.
2010-01-01T23:59:59.000Z
Acoustic emissions (AE) can provide information relating to the internal state of a deforming rock sample during laboratory testing and have been utilised to quantify damage progression for time-dependent failure modeling. ...
A framework for comparing geomechanical models of InSAR-measured surface deformation
De Laplante, Neil Edward James
2011-01-01T23:59:59.000Z
High-quality Interferometric Synthetic Aperture Radar (InSAR) surface deformation data for field sites around the world has become widely available over the past decade. Geomechanical models based on InSAR data occur ...
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1
Minkoff, Susan E.
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1 reservoir properties. Pore pressures from flow are used as loads for the geomechanics code
Analysis of viscoelastic soft dielectric elastomer generators operating in an electrical circuit
Eliana Bortot; Ralf Denzer; Andreas Menzel; Massimiliano Gei
2014-11-13T23:59:59.000Z
A predicting model for soft Dielectric Elastomer Generators (DEGs) must consider a realistic model of the electromechanical behaviour of the elastomer filling, the variable capacitor and of the electrical circuit connecting all elements of the device. In this paper such an objective is achieved by proposing a complete framework for reliable simulations of soft energy harvesters. In particular, a simple electrical circuit is realised by connecting the capacitor, stretched periodically by a source of mechanical work, in parallel with a battery through a diode and with an electrical load consuming the energy produced. The electrical model comprises resistances simulating the effect of the electrodes and of the conductivity current invariably present through the dielectric film. As these devices undergo a high number of electro-mechanical loading cycles at large deformation, the time-dependent response of the material must be taken into account as it strongly affects the generator outcome. To this end, the viscoelastic behaviour of the polymer and the possible change of permittivity with strains are analysed carefully by means of a proposed coupled electro-viscoelastic constitutive model, calibrated on experimental data available in the literature for an incompressible polyacrilate elastomer (3M VHB4910). Numerical results showing the importance of time-dependent behaviour on the evaluation of performance of DEGs for different loading conditions, namely equi-biaxial and uniaxial, are reported in the final section.
Crystal Plasticity Modeling of Deformation and Creep in Polycrystalline Ti-6242
Ghosh, Somnath
Crystal Plasticity Modeling of Deformation and Creep in Polycrystalline Ti-6242 DHYANJYOTI DEKA computational model based on crystal plasticity for the analysis of two-phase a/b Ti-6242 polycrystalline alloys. A rate-dependent elastic-crystal plas- ticity model is incorporated in this model to accommodate
Deformation of the UI-14at%Nb shape memory alloy: experiments and modeling
Field, Robert D [Los Alamos National Laboratory; Tome, Carlos N [Los Alamos National Laboratory; Mc Cabe, Rodney J [Los Alamos National Laboratory; Clarke, Amy J [Los Alamos National Laboratory; Brown, Donald W [Los Alamos National Laboratory; Tupper, Catherine N [Los Alamos National Laboratory
2010-12-22T23:59:59.000Z
U-14at%Nb is a shape memory effect (SME) alloy that undergoes deformation by the motion of complex twins and twin related lath boundaries up to the limit of SME deformation ({approx}7%). All of the twins present in the as-transformed martensite and active during SME deformation are derived from those of the orthorhombic alpha-U phase, modified for the monoclinic distortion of the alpha martensite phase. In the SME regime a simple Bain strain model qualitatively predicts variant selection, texture development in polycrystalline samples, and stress-strain behavior as a function of parent phase orientation in single crystal micropillars. In the post-SME regime, unrecoverable deformation occurs by a combination of slip and twinning, with the first few percent of strain in tension apparently governed by a twin species specifically associated with the monoclinic distortion (i.e. not present in the orthorhombic alpha-U phase). The situation in compression is more complicated, with a combination of slip and twinning systems believed responsible for deformation. A review of the Bain strain model for SME deformation will be presented in conjunction with experimental data. In addition, results from modeling of post-SME behavior using the Visco-Plastic Self-Consistent (VPSC) model will be compared to experimental texture measurements.
Viscoelastic properties of seed cotton and their effect on module shape and density
Hardin, Robert Glen
2004-11-15T23:59:59.000Z
. ............................. 14 3 Peleg's viscoelastic model..............................................................................15 4 Viscoelastic model developed by Bilanski and Graham.................................. 18 5 Stress-strain curve of a work... of harvesting method-loading density tests..................................................... 34 4 Least-squares means for creep response of different loading densities............ 35 5 Least-squares means for creep response of different harvesting methods...
Pumping viscoelastic two-fluid media
Hirofumi Wada
2010-04-08T23:59:59.000Z
Using a two-fluid model for viscoelastic polymer solutions, we study analytically fluid transport driven by a transverse, small amplitude traveling wave propagation. The pumping flow far from the waving boundary is shown to be strongly wave number and viscosity dependent, in contrast to a viscous Newtonian fluid. We find the two qualitatively different regimes: In one regime relevant to small wave numbers, the fluidic transport is almost the same as the Newtonian case, and uniform viscoelastic constitutive equations provide a good approximation. In the other regime, the pumping is substantially decreased because of the gel-like character. The boundary separating these two regimes is clarified. Our results suggest possible needs of two-fluid descriptions for the transport and locomotion in biological fluids with cilia and flagella.
Viscoelastic contact mechanics between randomly rough surfaces
Michele Scaraggi; Bo N. J. Persson
2014-06-27T23:59:59.000Z
We present exact numerical results for the friction force and the contact area for a viscoelastic solid (rubber) in sliding contact with hard, randomly rough substrates. The rough surfaces are self-affine fractal with roughness over several decades in length scales. We calculate the contribution to the friction from the pulsating deformations induced by the substrate asperities. We also calculate how the area of real contact, $A(v,p) $, depends on the sliding speed $v$ and on the nominal contact pressure $p$, and we show how the contact area for any sliding speed can be obtained from a universal master curve $A(p)$. The numerical results are found to be in good agreement with the predictions of an analytical contact mechanics theory.
Thermo-mechanical modelling of Black Sea Basin (de)formation S. Cloetingh*, G. Spadini1
Beekman, Fred
Thermo-mechanical modelling of Black Sea Basin (de)formation S. Cloetingh*, G. Spadini1 , J.D. Van; received in revised form 7 January 2002; accepted 19 July 2002 Abstract We present the results of a thermo by rifting and subsequent sediment loading. Thermo-mechanical modelling of integrated lithospheric strength
Modeling the response of HCP polycrystals deforming by slip and twinning using a finite
Zabaras, Nicholas J.
developments in the field of crystal plasticity modeling and evolution of microstructure. For defor- mation that eliminates the need for increasing the number of discrete crystal orientations to account for new for modeling deformation processes. PACS: 61.72.Mm;61.72.-y;81.40.Ef Keywords: Polycrystal plasticity; Texture
Projected shell model study of neutron-rich deformed isotopes of Sr and Zr
Verma, Sonia; Dar, Parvaiz Ahmad; Devi, Rani [Department of Physics and Electronics, University of Jammu, Jammu-180006 (India)
2008-02-15T23:59:59.000Z
The projected shell model (PSM) study of {sup 98-102}Sr and {sup 100-104}Zr nuclei is carried out. The reliability of the ground-state wave function is checked by reproducing yrast spectra and electromagnetic properties. The mechanism for the onset of sudden and large deformation at N=60 is worked out. The present piece of research work has unified the two different, or conflicting, early explanations for the onset of deformation at N=60 by the spherical shell model and mean-field theory.
Using Nanotechnology in Viscoelastic Surfactant Stimulation Fluids
Gurluk, Merve Rabia 1986-
2012-11-12T23:59:59.000Z
Viscoelastic surfactant (VES) fluids are preferred for many applications in the oil industry. Their viscoelastic behavior is due to the overlap and entanglement of very long wormlike micelles. The growth of these wormlike micelles depends...
Hanyk, Ladislav
Viscoelastic Earth L. Hanyk1 , C. Matyska1 and D.A. Yuen2 1 Charles University in Prague, Czech Republic 2 principle in the Laplace-transformed domain to obtain the Earth's response to these processes. Our approach, based on direct integration of the Earth's deformation in time, has overcome difficult inversion
Jia, Yan-Bin
IEEE TRANSACTIONS ON ROBOTICS, VOL. 26, NO. 5, OCTOBER 2010 837 Modeling Deformations of General Parametric Shells Grasped by a Robot Hand Jiang Tian and Yan-Bin Jia, Member, IEEE Abstract--The robot hand and normal of the contact area. Design and analysis of a manipulation strategy thus depend on reliable
Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent numerical simulations of multiphase (liquid-gas), multicomponent (H2OÂCO2) hydrothermal fluid flow
Collision of viscoelastic bodies: Rigorous derivation of dissipative force
Denis S. Goldobin; Eugeniy A. Susloparov; Anastasiya V. Pimenova; Nikolai V. Brilliantov
2015-01-13T23:59:59.000Z
We report a new theory of dissipative forces acting between colliding viscoelastic bodies. The impact velocity is assumed not to be large, to avoid plastic deformations and fragmentation at the impact. The bodies may be of an arbitrary convex shape and of different materials. We develop a mathematically rigorous perturbation scheme to solve the continuum mechanics equation that deals with both displacement and displacement rate fields and accounts for the dissipation in the bulk of the material. The perturbative solution of this equation allows to go beyond the previously used quasi-static approximation and obtain the dissipative force. This force does not suffer from the physical inconsistencies of the latter approximation and depends on particle deformation and deformation rate.
Wave propagation in anisotropic viscoelasticity
Andrzej Hanyga
2015-04-30T23:59:59.000Z
We extend the theory of complete Bernstein functions to matrix-valued functions and apply it to analyze Green's function of an anisotropic multi-dimension\\-al linear viscoelastic problem. Green's function is given by the superposition of plane waves. Each plane wave is expressed in terms of matrix-valued attenuation and dispersion functions given in terms of a matrix-valued positive semi-definite Radon measure. More explicit formulae are obtained for 3D isotropic viscoelastic Green's functions. As an example of an anisotropic medium the transversely isotropic medium with a constant symmetry axis is considered.
Bonatsos, Dennis; Minkov, N; Karampagia, S; Petrellis, D
2015-01-01T23:59:59.000Z
The analytic quadrupole octupole axially symmetric model, which had successfully predicted 226Ra and 226Th as lying at the border between the regions of octupole deformation and octupole vibrations in the light actinides using an infinite well potential (AQOA-IW), is made applicable to a wider region of nuclei exhibiting octupole deformation, through the use of a Davidson potential (AQOA-D). Analytic expressions for energy spectra and B(E1), B(E2), B(E3) transition rates are derived. The spectra of 222-226Ra and 224,226Th are described in terms of the two parameters phi_0 (expressing the relative amount of octupole vs. quadrupole deformation) and beta_0 (the position of the minimum of the Davidson potential), while the recently determined B(EL) transition rates of 224Ra, presenting stable octupole deformation, are successfully reproduced. A procedure for gradually determining the parameters appearing in the B(EL) transitions from a minimum set of data, thus increasing the predictive power of the model, is out...
InitialValue and Modal Approaches for Transient Viscoelastic Responses
Hanyk, Ladislav
) and Peltier (1974) because of the availability of more precise uplift data with more extensive geographical principle and use of the viscoelastic normalmode approach (e.g., Peltier 1974; Yuen & Peltier 1982 in the presence of complicated stratified earth models (Han & Wahr 1995; Fang & Hager 1994, 1995; Peltier 1995
Initial-Value and Modal Approaches for Transient Viscoelastic Responses
Hanyk, Ladislav
) and Peltier (1974) because of the availability of more precise uplift data with more extensive geographical principle and use of the viscoelastic normal-mode approach (e.g., Peltier 1974; Yuen & Peltier 1982 in the presence of complicated stratified earth models (Han & Wahr 1995; Fang & Hager 1994, 1995; Peltier 1995
Initial-Value Approach for Viscoelastic Responses of the Earth's
Hanyk, Ladislav
. Viscoelastic models have been used to study the attenuation of the seismic normal modes (Peltier et al. 1981; Yuen & Peltier 1982), earth tides (Lambeck & Nakiboglu 1983; Sabadini et al. 1985), postseismic rebound. (Received July 6, 1997.) 85 #12;86 Chapter 7 Piersanti et al. 1995), postglacial rebound (e.g., Peltier 1974
InitialValue Approach for Viscoelastic Responses of the Earth's
Hanyk, Ladislav
. Viscoelastic models have been used to study the attenuation of the seismic normal modes (Peltier et al. 1981; Yuen & Peltier 1982), earth tides (Lambeck & Nakiboglu 1983; Sabadini et al. 1985), postseismic rebound. (Received July 6, 1997.) 85 #12; 86 Chapter 7 Piersanti et al. 1995), postglacial rebound (e.g., Peltier
The strain path dependence of plastic deformation response of AA5754: Experiment and modeling
Pham, Minh-Son [Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA and NIST Center for Automotive Lightweighting, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8553 (United States); Hu, Lin [Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA and Now at IBM (United States); Iadicola, Mark; Creuziger, Adam [NIST Center for Automotive Lightweighting, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8553 (United States); Rollett, Anthony D. [Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States)
2013-12-16T23:59:59.000Z
This work presents modeling of experiments on a balanced biaxial (BB) pre-strained AA5754 alloy, subsequently reloaded uniaxially along the rolling direction and transverse direction. The material exhibits a complex plastic deformation response during the change in strain path due to 1) crystallographic texture, 2) aging (interactions between dislocations and Mg atoms) and 3) recovery (annihilation and re-arrangement of dislocations). With a BB prestrain of about 5 %, the aging process is dominant, and the yield strength for uniaxially deformed samples is observed to be higher than the flow stress during BB straining. The strain hardening rate after changing path is, however, lower than that for pre-straining. Higher degrees of pre-straining make the dynamic recovery more active. The dynamic recovery at higher strain levels compensates for the aging effect, and results in: 1) a reduction of the yield strength, and 2) an increase in the hardening rate of re-strained specimens along other directions. The yield strength of deformed samples is further reduced if these samples are left at room temperature to let static recovery occur. The synergistic influences of texture condition, aging and recovery processes on the material response make the modeling of strain path dependence of mechanical behavior of AA5754 challenging. In this study, the influence of crystallographic texture is taken into account by incorporating the latent hardening into a visco-plastic self-consistent model. Different strengths of dislocation glide interaction models in 24 slip systems are used to represent the latent hardening. Moreover, the aging and recovery effects are also included into the latent hardening model by considering strong interactions between dislocations and dissolved atom Mg and the microstructural evolution. These microstructural considerations provide a powerful capability to successfully describe the strain path dependence of plastic deformation behavior of AA5754.
Deformation of layered rocks in the ramp regions of thrust faults: a study with rock models
Chester, Judith Savaso
1985-01-01T23:59:59.000Z
wall at an S/Lr of 0. 20. " . . . . . . " "" . . -" . 43 17 Diagram showing the thrust belt terminology used to refer to locations and structures in the models. . . . . . 47 18 Deformation maps of configuration A models layered with lead and a... of configuration A. 65 xi LIST OF FIGURES (continued) Figure Page 25 Plot of slip across the lowest lead or mica unit of the veneer at the apex of the anticline above the ramp (location c) versus S/Lr for models of configurations A and B. 67 26 27 Plot...
Song, Ahran
2012-10-19T23:59:59.000Z
of the kinematic and volumetric conditions of the specimen at different stages of deformation, combined with the readings of the global axial compression of the specimen. This allowed for the characterization of a Mohr-Coulomb plasticity model with hardening...
Deformed Matrix Models, Supersymmetric Lattice Twists and N=1/4 Supersymmetry
Unsal, Mithat
2008-09-24T23:59:59.000Z
A manifestly supersymmetric nonperturbative matrix regularization for a twisted version of N = (8, 8) theory on a curved background (a two-sphere) is constructed. Both continuum and the matrix regularization respect four exact scalar supersymmetries under a twisted version of the supersymmetry algebra. We then discuss a succinct Q = 1 deformed matrix model regularization of N = 4 SYM in d = 4, which is equivalent to a non-commutative A*{sub 4} orbifold lattice formulation. Motivated by recent progress in supersymmetric lattices, we also propose a N = 1/4 supersymmetry preserving deformation of N = 4 SYM theory on R{sup 4}. In this class of N = 1/4 theories, both the regularized and continuum theory respect the same set of (scalar) supersymmetry. By using the equivalence of the deformed matrix models with the lattice formulations, we give a very simple physical argument on why the exact lattice supersymmetry must be a subset of scalar subalgebra. This argument disagrees with the recent claims of the link approach, for which we give a new interpretation.
Lebensohn, Ricardo A [Los Alamos National Laboratory; Montagnat, Maurine [LGGE (FRANCE); Mansuy, Philippe [MICHELIN (FRANCE); Duval, Paul [LGGE (FRANCE); Philip, A [LGGE (FRANCE)
2008-01-01T23:59:59.000Z
A full-field formulation based on Fast Fourier Transforms (FFT) has been adapted and used to predict the micromechanical fields that develop in columnar Ih ice polycrystals deforming in compression by dislocation creep. The predicted intragranular mechanical fields are in qualitative good agreement with experimental observations, in particular those involving the formation of shear and kink bands. These localization bands are associated with the large internal stresses that develop during creep in such anisotropic material, and their location, intensity, morphology and extension are found to depend strongly on the crystallographic orientation of the grains and on their interaction with neighbor crystals. The predictions of the model are also discussed in relation with the deformation of columnar sea and lake ice, and with the mechanical behavior of granular ice of glaciers and polar ice sheets, as well.
Development of a Two-Phase Model for the Hot Deformation of Highly-Alloyed Aluminum
A. J. Beaudoin; J. A. Dantzig; I. M. Robertson; B. E. Gore; S. F. Harnish; H. A. Padilla
2005-10-31T23:59:59.000Z
Conventional processing methods for highly alloyed aluminum consist of ingot casting, followed by hot rolling and thermal treatments. Defects result in lost productivity and wasted energy through the need to remelt and reprocess the material. This research centers on developing a fundamental understanding for deformation of wrought 705X series alloys, a key alloy system used in structural airframe applications. The development of damage at grain boundaries is characterized through a novel test that provides initiation of failure while preserving a controlled deformation response. Data from these mechanical tests are linked to computer simulations of the hot rolling process through a critical measure of damage. Transmission electron microscopy provides fundamental insight into deformation at these high working temperatures, and--in a novel link between microscale and macroscale response--the evolution of microstructure (crystallographic orientation) provides feedback for tuning of friction in the hot rolling process. The key product of this research is a modeling framework for the analysis of industrial hot rolling.
A Simple Model for the Deformation-Induced Relaxation of Glassy Polymers
S. M. Fielding; R. G. Larson; M. E. Cates
2011-10-18T23:59:59.000Z
Glassy polymers show strain hardening: at constant extensional load, their flow first accelerates, then arrests. Recent experiments have found this to be accompanied by a striking and unexplained dip in the segmental relaxation time. Here we explain such behavior by combining a minimal model of flow-induced liquefaction of a glass, with a description of the stress carried by strained polymers, creating a non-factorable interplay between aging and strain-induced rejuvenation. Under constant load, liquefaction of segmental motion permits strong flow that creates polymer-borne stress. This slows the deformation enough for the segmental modes to re-vitrify, causing strain hardening.
Multi-scale Modeling Approach to Acoustic Emission during Plastic Deformation
Jagadish Kumar; G. Ananthakrishna
2011-02-20T23:59:59.000Z
We address the long standing problem of the origin of acoustic emission commonly observed during plastic deformation. We propose a frame-work to deal with the widely separated time scales of collective dislocation dynamics and elastic degrees of freedom to explain the nature of acoustic emission observed during the Portevin-Le Chatelier effect. The Ananthakrishna model is used as it explains most generic features of the phenomenon. Our results show that while acoustic emission bursts correlated with stress drops are well separated for the type C serrations, these bursts merge to form nearly continuous acoustic signals with overriding bursts for the propagating type A bands.
Dynamics of end to end loop formation for an isolated chain in viscoelastic fluid
Rajarshi Chakrabarti
2012-04-04T23:59:59.000Z
We theoretically investigate the looping dynamics of a linear polymer immersed in a viscoelastic fluid. The dynamics of the chain is governed by a Rouse model with a fractional memory kernel recently proposed by Weber et al. (S. C. Weber, J. A. Theriot, and A. J. Spakowitz, Phys. Rev. E 82, 011913 (2010)). Using the Wilemski-Fixman (G. Wilemski and M. Fixman, J. Chem. Phys. 60, 866 (1974)) formalism we calculate the looping time for a chain in a viscoelastic fluid where the mean square displacement of the center of mass of the chain scales as t^(1/2). We observe that the looping time is faster for the chain in viscoelastic fluid than for a Rouse chain in Newtonian fluid up to a chain length and above this chain length the trend is reversed. Also no scaling of the looping time with the length of the chain seems to exist for the chain in viscoelastic fluid.
Deformed Hamilton-Jacobi Method in Covariant Quantum Gravity Effective Models
Mu Benrong; Peng Wang; Haitang Yang
2014-08-21T23:59:59.000Z
We first briefly revisit the original Hamilton-Jacobi method and show that the Hamilton-Jacobi equation for the action $I$ of tunnelings of a fermionic particle from a charged black hole can be written in the same form as that of a scalar particle. For the low energy quantum gravity effective models which respect covariance of the curved spacetime, we derive the deformed model-independent KG/Dirac and Hamilton-Jacobi equations using the methods of effective field theory. We then find that, to all orders of the effective theories, the deformed Hamilton-Jacobi equations can be obtained from the original ones by simply replacing the mass of emitted particles $m$ with a parameter $m_{eff}$ that includes all the quantum gravity corrections. Therefore, in this scenario, there will be no corrections to the Hawking temperature of a black hole from the quantum gravity effects if its original Hawking temperature is independent of the mass of emitted particles. As a consequence, our results show that breaking covariance in quantum gravity effective models is a key for a black hole to have the remnant left in the evaporation.
A voxel-based finite element model for the prediction of bladder deformation
Chai Xiangfei; Herk, Marcel van; Hulshof, Maarten C. C. M.; Bel, Arjan [Radiation Oncology Department, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam (Netherlands); Radiation Oncology Department, Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands); Radiation Oncology Department, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam (Netherlands)
2012-01-15T23:59:59.000Z
Purpose: A finite element (FE) bladder model was previously developed to predict bladder deformation caused by bladder filling change. However, two factors prevent a wide application of FE models: (1) the labor required to construct a FE model with high quality mesh and (2) long computation time needed to construct the FE model and solve the FE equations. In this work, we address these issues by constructing a low-resolution voxel-based FE bladder model directly from the binary segmentation images and compare the accuracy and computational efficiency of the voxel-based model used to simulate bladder deformation with those of a classical FE model with a tetrahedral mesh. Methods: For ten healthy volunteers, a series of MRI scans of the pelvic region was recorded at regular intervals of 10 min over 1 h. For this series of scans, the bladder volume gradually increased while rectal volume remained constant. All pelvic structures were defined from a reference image for each volunteer, including bladder wall, small bowel, prostate (male), uterus (female), rectum, pelvic bone, spine, and the rest of the body. Four separate FE models were constructed from these structures: one with a tetrahedral mesh (used in previous study), one with a uniform hexahedral mesh, one with a nonuniform hexahedral mesh, and one with a low-resolution nonuniform hexahedral mesh. Appropriate material properties were assigned to all structures and uniform pressure was applied to the inner bladder wall to simulate bladder deformation from urine inflow. Performance of the hexahedral meshes was evaluated against the performance of the standard tetrahedral mesh by comparing the accuracy of bladder shape prediction and computational efficiency. Results: FE model with a hexahedral mesh can be quickly and automatically constructed. No substantial differences were observed between the simulation results of the tetrahedral mesh and hexahedral meshes (<1% difference in mean dice similarity coefficient to manual contours and <0.02 cm difference in mean standard deviation of residual errors). The average equation solving time (without manual intervention) for the first two types of hexahedral meshes increased to 2.3 h and 2.6 h compared to the 1.1 h needed for the tetrahedral mesh, however, the low-resolution nonuniform hexahedral mesh dramatically decreased the equation solving time to 3 min without reducing accuracy. Conclusions: Voxel-based mesh generation allows fast, automatic, and robust creation of finite element bladder models directly from binary segmentation images without user intervention. Even the low-resolution voxel-based hexahedral mesh yields comparable accuracy in bladder shape prediction and more than 20 times faster in computational speed compared to the tetrahedral mesh. This approach makes it more feasible and accessible to apply FE method to model bladder deformation in adaptive radiotherapy.
Paylor, E.D.; Lang, H.R.; Conel, J.E.; Adams, S.L. (California Institute of Technology, Pasadena (USA)); Muncy, H.L. (Tenneco Oil Exploration and Production, Englewood, CO (USA))
1989-01-01T23:59:59.000Z
The Thermopolis anticline is a typical structure in the Rocky Mountain foreland, southern Bighorn Basin, Wyoming. Photogeologic interpretation of Landsat Thematic Mapper data, in combination with the evaluation of topographic, bore hole, seismic reflection, and field data were used to analyze structure and constrain tectonic models. The anticline is near-concentric, asymmetric with a southwest sense of vergence, and plunges to the northwest. The steeply dipping to overturned southwest limb of the fold is cut at the surface by several thrust faults dipping northeast. Approximately 25% of the stratigraphic section on the southwest limb is missing due to faulting. Two east to northeast-striking, basement-controlled compartmental faults segment the anticline into three blocks that apparently deformed simultaneously but probably independently from one another. Slickensides indicate a dominant southwest tectonic transport direction. Additionally, subtle northeast-trending folds are superposed on the dominant northwest structural trend. Structural patterns at Thermopolis anticline can be explained using models that propose a single phase of northeast Laramide compression, combined with shear-zone deformation.
Deformed Hamilton-Jacobi Method in Covariant Quantum Gravity Effective Models
Benrong, Mu; Yang, Haitang
2014-01-01T23:59:59.000Z
We first briefly revisit the original Hamilton-Jacobi method and show that the Hamilton-Jacobi equation for the action $I$ of tunnelings of a fermionic particle from a charged black hole can be written in the same form as that of a scalar particle. For the low energy quantum gravity effective models which respect covariance of the curved spacetime, we derive the deformed model-independent KG/Dirac and Hamilton-Jacobi equations using the methods of effective field theory. We then find that, to all orders of the effective theories, the deformed Hamilton-Jacobi equations can be obtained from the original ones by simply replacing the mass of emitted particles $m$ with a parameter $m_{eff}$ that includes all the quantum gravity corrections. Therefore, in this scenario, there will be no corrections to the Hawking temperature of a black hole from the quantum gravity effects if its original Hawking temperature is independent of the mass of emitted particles. As a consequence, our results show that breaking covariance...
Barham, M; White, D; Steigmann, D; Rudd, R
2009-04-08T23:59:59.000Z
Recently a new class of biocompatible elastic polymers loaded with small ferrous particles (magnetoelastomer) was developed at Lawrence Livermore National Laboratory. This new material was formed as a thin film using spin casting. The deformation of this material using a magnetic field has many possible applications to microfluidics. Two methods will be used to calculate the deformation of a circular magneto-elastomeric film subjected to a magnetic field. The first method is an arbitrary Lagrangian-Eulerian (ALE) finite element method (FEM) and the second is based on nonlinear continuum electromagnetism and continuum elasticity in the membrane limit. The comparison of these two methods is used to test/validate the finite element method.
Modeling reactive transport in deformable porous media using the theory of interacting continua.
Turner, Daniel Zack
2012-01-01T23:59:59.000Z
This report gives an overview of the work done as part of an Early Career LDRD aimed at modeling flow induced damage of materials involving chemical reactions, deformation of the porous matrix, and complex flow phenomena. The numerical formulation is motivated by a mixture theory or theory of interacting continua type approach to coupling the behavior of the fluid and the porous matrix. Results for the proposed method are presented for several engineering problems of interest including carbon dioxide sequestration, hydraulic fracturing, and energetic materials applications. This work is intended to create a general framework for flow induced damage that can be further developed in each of the particular areas addressed below. The results show both convincing proof of the methodologies potential and the need for further validation of the models developed.
A phase-field model for systems with coupled large deformation and mass Wei Hong1,2
Hong, Wei
1 A phase-field model for systems with coupled large deformation and mass transport Wei Hong1 to introduce phase-field modeling to the field of soft materials, especially for studying polymeric gels-field methodology, and reveal some interesting phenomena due to the coupling. For example, the composition
Entanglement spectra of the q-deformed Affleck-Kennedy-Lieb-Tasaki model and matrix product states
Raul A. Santos; Francis N. C. Paraan; Vladimir E. Korepin; Andreas Klümper
2012-05-14T23:59:59.000Z
We exactly calculate the reduced density matrix of matrix product states (MPS). Our compact result enables one to perform analytic studies of entanglement in MPS. In particular, we consider the MPS ground states of two anisotropic spin chains. One is a q-deformed Affleck-Kennedy-Lieb-Tasaki (AKLT) model and the other is a general spin-1 quantum antiferromagnet with nearest-neighbor interactions. Our analysis shows how anisotropy affects entanglement on different continuous parameter manifolds. We also construct an effective boundary spin model that describes a block of spins in the ground state of the q-deformed AKLT Hamiltonian. The temperature of this effective model is given in terms of the deformation parameter q.
Ray, S Saha; Das, Shantanu
2015-01-01T23:59:59.000Z
The article presents the formulation and a new approach to find analytic solutions for fractional continuously variable order dynamic models viz. Fractional continuously variable order mass-spring damper systems. Here, we use the viscoelastic and viscous-viscoelastic dampers for describing the damping nature of the oscillating systems, where the order of fractional derivative varies continuously. Here, we handle the continuous changing nature of fractional order derivative for dynamic systems, which has not been studied yet. By successive iteration method, here we find the solution of fractional continuously variable order mass-spring damper systems, and then give a close form solution. We then present and discuss the solutions obtained in the cases with continuously variable order of damping for this oscillator with graphical plots.
Odegard, Gregory M.
2005-01-01T23:59:59.000Z
Properties of Polymeric Materials Through Nanoindentation G. M. Odegard Assistant Professor, Department testing was used to determine the dynamic viscoelastic properties of eight polymer materials, which, therefore, involves the development of accurate constitutive models, material property data
Shell model method for Gamow-Teller transitions in heavy, deformed nuclei
Gao Zaochun [Joint Institute for Nuclear Astrophysics and Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); Sun Yang [Joint Institute for Nuclear Astrophysics and Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Chen, Y.-S. [China Institute of Atomic Energy, P.O. Box 275(18), Beijing 102413 (China); Institute of Theoretical Physics, Academia Sinica, Beijing 100080 (China)
2006-11-15T23:59:59.000Z
A method for calculation of Gamow-Teller transition rates is developed by using the concept of the Projected Shell Model (PSM). The shell model basis is constructed by superimposing angular-momentum-projected multiquasiparticle configurations, and nuclear wave functions are obtained by diagonalizing the two-body interactions in these projected states. Calculation of transition matrix elements in the PSM framework is discussed in detail, and the effects caused by the Gamow-Teller residual forces and by configuration-mixing are studied. With this method, it may become possible to perform a state-by-state calculation for {beta}-decay and electron-capture rates in heavy, deformed nuclei at finite temperatures. Our first example indicates that, while experimentally known Gamow-Teller transition rates from the ground state of the parent nucleus are reproduced, stronger transitions from some low-lying excited states are predicted to occur, which may considerably enhance the total decay rates once these nuclei are exposed to hot stellar environments.
Squeeze flow of potato starch gel: effect of loading history on visco-elastic properties
Moutushi Dutta Choudhury; Shantanu Das; Sujata Tarafdar
2015-03-25T23:59:59.000Z
In this work gelatinized potato starch is shown to retain the memory of past loading history. It exhibits a visco-elastic response which does not depend solely on instantaneous conditions. A simple squeeze flow experiment is performed, where loading is done in two steps with a time lag $\\tau \\sim$ seconds between the steps. The effect on the strain, of varying $\\tau$ is reproduced by a three element visco-elastic solid model. Non-linearity is introduced through a generalized calculus approach by incorporating a non-integer order time derivative in the viscosity equation. A strain hardening proportional to the time lag between the two loading steps is also incorporated. This model reproduces the three salient features observed in the experiment, namely - the memory effect, slight initial oscillations in the strain as well as the long-time solid-like response. Dynamic visco-elasticity of the sample is also reported.
Nonlinear Viscoelastic Biomaterials: Meaningful Characterization and Engineering Inspiration
1/21 Nonlinear Viscoelastic Biomaterials: Meaningful Characterization and Engineering Inspiration Annual Meeting Symposium: Biomaterials: Properties, Variation and Evolution Keywords: biomechanics, mucus techniques for characterization, pedal mucus samples (and biomaterials in general) are viscoelastic
Fluid substitution in rocks saturated with viscoelastic fluids Dina Makarynska1
, Jyoti Behura3 , and Mike Batzle4 ABSTRACT Heavy oils have high densities and extremely high viscosities sands.We model the viscoelastic properties of a heavy- oil-saturated rock sample using CPA and a measured frequency- dependent complex shear modulus of the heavy oil. Comparison of modeled results
Surface Loading of a Multilayered Viscoelastic Pavement: Semianalytical Solution
Pan, Ernie
Surface Loading of a Multilayered Viscoelastic Pavement: Semianalytical Solution Ewan Y. G. Chen1 response of a linear viscoelastic pavement. The material parameters of the asphalt concrete analytically. Therefore, responses of the viscoelastic pavement are finally expressed analytically in the time
Avouac, Jean-Philippe
or to partial burying under younger sediments (Figure 1). In that case, the area conservation method for fault tip folds, where rocks are deformed in a broad zone above the termination (or ``tip'') of a thrust
Ghoniem, Nasr M.
, we plan to investigate the deformation characteris- tics of two classes of nano-structured materials. The proposed research will also impact graduate education world-wide by the developme
Solving the two-center nuclear shell-model problem with arbitrarily-orientated deformed potentials
Alexis Diaz-Torres
2008-10-02T23:59:59.000Z
A general new technique to solve the two-center problem with arbitrarily-orientated deformed realistic potentials is demonstrated, which is based on the powerful potential separable expansion method. As an example, molecular single-particle spectra for $^{12}$C + $^{12}$C $\\to$ $^{24}$Mg are calculated using deformed Woods-Saxon potentials. These clearly show that non-axial symmetric configurations play a crucial role in molecular resonances observed in reaction processes for this system at low energy.
Conformal higher-order viscoelastic fluid mechanics
Masafumi Fukuma; Yuho Sakatani
2012-05-28T23:59:59.000Z
We present a generally covariant formulation of conformal higher-order viscoelastic fluid mechanics with strain allowed to take arbitrarily large values. We give a general prescription to determine the dynamics of a relativistic viscoelastic fluid in a way consistent with the hypothesis of local thermodynamic equilibrium and the second law of thermodynamics. We then elaborately study the transient time scales at which the strain almost relaxes and becomes proportional to the gradients of velocity. We particularly show that a conformal second-order fluid with all possible parameters in the constitutive equations can be obtained without breaking the hypothesis of local thermodynamic equilibrium, if the conformal fluid is defined as the long time limit of a conformal second-order viscoelastic system. We also discuss how local thermodynamic equilibrium could be understood in the context of the fluid/gravity correspondence.
Implementation of the Log-Conformation Formulation for Two-Dimensional Viscoelastic Flow
Jensen, K E; Okkels, F
2015-01-01T23:59:59.000Z
We have implemented the log-conformation method for two-dimensional viscoelastic flow in COMSOL, a commercial high-level finite element package. The code is verified for an Oldroyd-B fluid flowing past a confined cylinder. We are also able to describe the well-known bistability of the viscoelastic flow in a cross-slot geometry for a FENE-CR fluid, and we describe the changes required for performing simulations with the Phan-Thien-Tanner (PTT), Giesekus and FENE-P models. Finally, we calculate the flow of a FENE-CR fluid in a geometry with three in- and outlets. The implementation is included in the supplementary material, and we hope that it can inspire new as well as experienced researchers in the field of differential constitutive equations for viscoelastic flow.
Nuclear-deformation energies according to a liquid-drop model with a sharp surface
Blocki, J.; Swiatecki, W.J.
1982-05-01T23:59:59.000Z
We present an atlas of 665 deformation-energy maps and 150 maps of other properties of interest, relevant for nuclear systems idealized as uniformly charged drops endowed with a surface tension. The nuclear shapes are parametrized in terms of two spheres modified by a smoothly fitted quadratic surface of revolution and are specified by three variables: asymmetry, sphere separation, and a neck variable (that goes over into a fragment-deformation variable after scission). The maps and related tables should be useful for the study of macroscopic aspects of nuclear fission and of collisions between any two nuclei in the periodic table.
Konstantinos Sfetsos; Daniel C. Thompson
2014-10-07T23:59:59.000Z
We examine a recently proposed class of integrable deformations to two-dimensional conformal field theories. These {\\lambda}-deformations interpolate between a WZW model and the non-Abelian T-dual of a Principal Chiral Model on a group G or, between a G/H gauged WZW model and the non-Abelian T-dual of the geometric coset G/H. {\\lambda}-deformations have been conjectured to represent quantum group q-deformations for the case where the deformation parameter is a root of unity. In this work we show how such deformations can be given an embedding as full string backgrounds whose target spaces satisfy the equations of type-II supergravity. One illustrative example is a deformation of the Sl(2,R)/U(1) black-hole CFT. A further example interpolates between the $\\frac{SU(2)\\times SU(2)}{SU(2)}\\times\\frac{SL(2,R)\\times SL(2,R)}{SL(2,R)} \\times U(1)^4$ gauged WZW model and the non-Abelian T-dual of $AdS_3\\times S^3\\times T^4$ supported with Ramond flux.
VISCOELASTIC PROPERTIES OF OBC AND PENTABLOCK
Petta, Jason
VISCOELASTIC PROPERTIES OF OBC AND PENTABLOCK POLYMERS Ramyata Upmaka CMU, Pittsburgh. REU 2010 #12;WHAT IS A POLYMER? "The simplest definition of a polymer is a useful chemical made of many repeating temperatures: Exhibits thermoplastic behavior i.e. soften when heated, harden when cooled. Recyclable
Devincre, Benoit
Orientation dependence of plastic deformation in nickel-based single crystal superalloys: Discrete of single-crystal nickel-based superalloys is simulated. At 1123 K, two uniaxial tensile loading cases though no cubic slip systems are activated. In the [001] case, the plastic flow is distributed more
Su, Ying-Yu
2012-02-14T23:59:59.000Z
Adhesively bonded joints have been investigated for several decades. In most analytical studies, the Bernoulli-Euler beam theory is employed to describe the behaviour of adherends. In the current work, three analytical models are developed...
W. X. Xue; J. M. Yao; K. Hagino; Z. P. Li; H. Mei; Y. Tanimura
2015-02-18T23:59:59.000Z
The impurity effect of hyperon on atomic nuclei has received a renewed interest in nuclear physics since the first experimental observation of appreciable reduction of $E2$ transition strength in low-lying states of hypernucleus $^{7}_\\Lambda$Li. Many more data on low-lying states of $\\Lambda$ hypernuclei will be measured soon for $sd$-shell nuclei, providing good opportunities to study the $\\Lambda$ impurity effect on nuclear low-energy excitations. We carry out a quantitative analysis of $\\Lambda$ hyperon impurity effect on the low-lying states of $sd$-shell nuclei at the beyond-mean-field level based on a relativistic point-coupling energy density functional (EDF), considering that the $\\Lambda$ hyperon is injected into the lowest positive-parity ($\\Lambda_s$) and negative-parity ($\\Lambda_p$) states. We adopt a triaxially deformed relativistic mean-field (RMF) approach for hypernuclei and calculate the $\\Lambda$ binding energies of hypernuclei as well as the potential energy surfaces (PESs) in $(\\beta, \\gamma)$ deformation plane. We also calculate the PESs for the $\\Lambda$ hypernuclei with good quantum numbers using a microscopic particle rotor model (PRM) with the same relativistic EDF. The triaxially deformed RMF approach is further applied in order to determine the parameters of a five-dimensional collective Hamiltonian (5DCH) for the collective excitations of triaxially deformed core nuclei. Taking $^{25,27}_{\\Lambda}$Mg and $^{31}_{\\Lambda}$Si as examples, we analyse the impurity effects of $\\Lambda_s$ and $\\Lambda_p$ on the low-lying states of the core nuclei...
Golden, Peter Joseph
1996-01-01T23:59:59.000Z
Traditional methods of viscoelastic material characterization lack the ability to rapidly characterize nonlinear viscoelastic materials. A method of rapidly identifying linear viscoelastic material properties is Dynamic Mechanical Analysis (DMA...
Constitutive modelling of shape memory alloys and upscaling of deformable porous media
Popov, Petar Angelov
2005-08-29T23:59:59.000Z
phases is also possible. The critical temperatures are denoted on the temperature axis. In addition, the critical uniaxial stresses for beginning sigmas and finish sigmaf of the detwinning deformation are shown on the stress axis. The shape memory effects.... For example, in copper-based alloys, twenty-four variants of martensite constitute six self-accommodated groups scattered around the angbracketleft011angbracketright poles of austenite with a typical diamond morphology. The growth of such groups 9 Fig. 2...
Deformation of layered rocks in the ramp regions of thrust faults: a study with rock models
Chester, Judith Savaso
1985-01-01T23:59:59.000Z
and thrust belts for example, thrust faults commonly occur along specific stratigraphic horizons, and folding and faulting within thrust sheets often involves slip along bedding planes (e. g. , Rich, 1934; Douglas, 1950; Dahl str om, 1970; Price, 1981...). With the regional framework of many fold and thrust belts well estab- lished, the current emphasis of many studies has turned to defining the geometries, kinematics, and deformation mechanisms of individual thrust belt structures, and the intrinsic and extrinsic...
Nonlinear viscoelastic materials : bioinspired applications and new characterization measures
Ewoldt, Randy H. (Randy Harold)
2009-01-01T23:59:59.000Z
Viscoelastic materials, such as biomaterials and non-Newtonian fluids, typically experience mechanical loading which evokes a nonlinear rheological response. Rheologically complex materials can provide novel functionality ...
VISCOELASTICITY OF POLYETHYLENES PRODUCED WITH SINGLE SITE METALLOCENE CATALYSIS
VISCOELASTICITY OF POLYETHYLENES PRODUCED WITH SINGLE SITE METALLOCENE CATALYSIS Esra Kucukpinar for non-homogeneous strain for the parallel plate geometry was applied [5]. Steady shear experiments were
Plane waves in anisotropic viscoelastic media
Andrzej Hanyga
2015-07-13T23:59:59.000Z
Two concepts of plane waves in anisotropic viscoelastic media are studied. One of these concepts allows for the use of methods based on the theory of complete Bernstein functions. This allows for a deeper study of frequency-domain asymptotics of the attenuation function and time-domain regularity at the wavefronts. A relation between the direction of the energy flux density and the attenuation vector is examined under much more general assumptions.
Huang, Jianbin
Thermo-responsive viscoelastic wormlike micelle to elastic hydrogel transition in dual report a thermo-responsive phase transition from a viscoelastic wormlike micelle solution to an elastic
Kramer, Sharlotte Lorraine Bolyard; Scherzinger, William M.
2014-09-01T23:59:59.000Z
The Virtual Fields Method (VFM) is an inverse method for constitutive model parameter identication that relies on full-eld experimental measurements of displacements. VFM is an alternative to standard approaches that require several experiments of simple geometries to calibrate a constitutive model. VFM is one of several techniques that use full-eld exper- imental data, including Finite Element Method Updating (FEMU) techniques, but VFM is computationally fast, not requiring iterative FEM analyses. This report describes the im- plementation and evaluation of VFM primarily for nite-deformation plasticity constitutive models. VFM was successfully implemented in MATLAB and evaluated using simulated FEM data that included representative experimental noise found in the Digital Image Cor- relation (DIC) optical technique that provides full-eld displacement measurements. VFM was able to identify constitutive model parameters for the BCJ plasticity model even in the presence of simulated DIC noise, demonstrating VFM as a viable alternative inverse method. Further research is required before VFM can be adopted as a standard method for constitu- tive model parameter identication, but this study is a foundation for ongoing research at Sandia for improving constitutive model calibration.
On the Rheology of Cold Drawing. 11. Viscoelastic Materials*
On the Rheology of Cold Drawing. 11. Viscoelastic Materials* BERNARD D. COLEMAN and DANIEL C. NEWMAN Department of Mechanics and Materials Science, Rutgers, The State University of New Jersey viscoelastic materials subject to inhomogeneous stretching. The formulae, which are valid to within an error
Viscoelastic response of Yukawa liquids and P. Hartmann1
Goree, John
interparticle potential. A change from viscous to elastic response is observed with increasing frequency elasticity involves energy storage. Most soft materials are viscoelastic since they exhibit both dissipativeViscoelastic response of Yukawa liquids Z. DonkÃ³,1 J. Goree,2 and P. Hartmann1 1 Research Institute
Anupam Gupta; Mauro Sbragaglia
2015-08-01T23:59:59.000Z
The effects of viscoelasticity on the dynamics and break-up of fluid threads in microfluidic T-junctions are investigated using numerical simulations of dilute polymer solutions at changing the Capillary number ($\\mbox {Ca}$), i.e. at changing the balance between the viscous forces and the surface tension at the interface, up to $\\mbox{Ca} \\approx 3 \\times 10^{-2}$. A Navier-Stokes (NS) description of the solvent based on the lattice Boltzmann models (LBM) is here coupled to constitutive equations for finite extensible non-linear elastic dumbbells with the closure proposed by Peterlin (FENE-P model). We present the results of three-dimensional simulations in a range of $\\mbox{Ca}$ which is broad enough to characterize all the three characteristic mechanisms of breakup in the confined T-junction, i.e. ${\\it squeezing}$, ${\\it dripping}$ and ${\\it jetting}$ regimes. The various model parameters of the FENE-P constitutive equations, including the polymer relaxation time $\\tau_P$ and the finite extensibility parameter $L^2$, are changed to provide quantitative details on how the dynamics and break-up properties are affected by viscoelasticity. We will analyze cases with ${\\it Droplet ~Viscoelasticity}$ (DV), where viscoelastic properties are confined in the dispersed (d) phase, as well as cases with ${\\it Matrix ~Viscoelasticity}$ (MV), where viscoelastic properties are confined in the continuous (c) phase. Moderate flow-rate ratios $Q \\approx {\\cal O}(1)$ of the two phases are considered in the present study. Overall, we find that the effects are more pronounced in the case with MV, as the flow driving the break-up process upstream of the emerging thread can be sensibly perturbed by the polymer stresses.
Rheology of human blood plasma: Viscoelastic versus Newtonian behavior
M. Brust; C. Schaefer; L. Pan; M. Garcia; P. E. Arratia; C Wagner
2013-02-17T23:59:59.000Z
We investigate the rheological characteristics of human blood plasma in shear and elongational flows. While we can confirm a Newtonian behavior in shear flow within experimental resolution, we find a viscoelastic behavior of blood plasma in the pure extensional flow of a capillary break-up rheometer. The influence of the viscoelasticity of blood plasma on capillary blood flow is tested in a microfluidic device with a contraction-expansion geometry. Differential pressure measurements revealed that the plasma has a pronounced flow resistance compared to that of pure water. Supplementary measurements indicate that the viscoelasticity of the plasma might even lead to viscoelastic instabilities under certain conditions. Our findings show that the viscoelastic properties of plasma should not be ignored in future studies on blood flow.
Luscher, Darby J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-05-08T23:59:59.000Z
We detail a modeling approach to simulate the anisotropic thermal expansion of polycrystalline (1,3,5-triamino-2,4,6-trinitrobenzene) TATB-based explosives that utilizes microstructural information including porosity, crystal aspect ratio, and processing-induced texture. This report, the first in a series, focuses on nonlinear thermal expansion of “neat-pressed” polycrystalline TATB specimens which do not contain any binder; additional complexities related to polymeric binder and irreversible ratcheting behavior are briefly discussed, however detailed investigation of these aspects are deferred to subsequent reports. In this work we have, for the first time, developed a mesoscale continuum model relating the thermal expansion of polycrystal TATB specimens to their microstructural characteristics. A self-consistent homogenization procedure is used to relate macroscopic thermoelastic response to the constitutive behavior of single-crystal TATB. The model includes a representation of grain aspect ratio, porosity, and crystallographic texture attributed to the consolidation process. A quantitative model is proposed to describe the evolution of preferred orientation of graphitic planes in TATB during consolidation and an algorithm constructed to develop a discrete representation of the associated orientation distribution function. Analytical and numerical solutions using this model are shown to produce textures consistent with previous measurements and characterization for isostatic and uniaxial “die-pressed” specimens. Predicted thermal strain versus temperature for textured specimens are shown to be in agreement with corresponding experimental measurements. Using the developed modeling approach, several simulations have been run to investigate the influence of microstructure on macroscopic thermal expansion behavior. Results from these simulations are used to identify qualitative trends. Implications of the identified trends are discussed in the context of thermal deformation of engineered components whose consolidation process is generally more complex than isostatic or die-pressed specimens. Finally, an envisioned application of the modeling approach to simulating thermal expansion of weapon systems and components is outlined along with necessary future work to introduce the effects of binder and ratcheting behavior. Key conclusions from this work include the following. Both porosity and grain aspect ratio have an influence on the thermal expansion of polycrystal TATB considering realistic material variability. Thepreferred orientation of the single crystal TATB [001] poles within a polycrystal gives rise to pronounced anisotropy of the macroscopic thermal expansion. The extent of this preferred orientation depends on the magnitude of deformation, and consequently, is expected to vary spatially throughout manufactured components much like porosity. The modeling approach presented here has utility toward bringing spatially variable microstructural features into macroscale system engineering modelsAbstract Not Provided
Deformation processing of HTS wire
Bingert, J. [Los Alamos National Lab., NM (United States)
1994-07-29T23:59:59.000Z
Methods to understand, control, and optimize deformation processing of HTS wire are outlined. Topics discussed include: technical progress, deformation processing effects on HTS - core uniformity in composite tapes, effects of rolling on tapes, deformation process modeling, channel die powder compaction stress-strain data, microhardness versus rolling reduction, minimum bifurcation strain versus material state, roll gap geometries for large versus small rolls, interactions, hydrostatic extrusion, and tensile properties.
Cappa, F.; Rutqvist, J.
2010-06-01T23:59:59.000Z
The interaction between mechanical deformation and fluid flow in fault zones gives rise to a host of coupled hydromechanical processes fundamental to fault instability, induced seismicity, and associated fluid migration. In this paper, we discuss these coupled processes in general and describe three modeling approaches that have been considered to analyze fluid flow and stress coupling in fault-instability processes. First, fault hydromechanical models were tested to investigate fault behavior using different mechanical modeling approaches, including slip interface and finite-thickness elements with isotropic or anisotropic elasto-plastic constitutive models. The results of this investigation showed that fault hydromechanical behavior can be appropriately represented with the least complex alternative, using a finite-thickness element and isotropic plasticity. We utilized this pragmatic approach coupled with a strain-permeability model to study hydromechanical effects on fault instability during deep underground injection of CO{sub 2}. We demonstrated how such a modeling approach can be applied to determine the likelihood of fault reactivation and to estimate the associated loss of CO{sub 2} from the injection zone. It is shown that shear-enhanced permeability initiated where the fault intersects the injection zone plays an important role in propagating fault instability and permeability enhancement through the overlying caprock.
Kinematic models of deformation in Southern California constrained by geologic and geodetic data
Eich, Lori A
2006-01-01T23:59:59.000Z
Using a standardized fault geometry based on the Community Block Model, we create two analytic block models of the southern California fault system. We constrain one model with only geodetic data. In the other, we assign ...
Mesoscopic theory of the viscoelasticity of polymers
S. M. Chitanvis
1999-01-26T23:59:59.000Z
We have advanced our previous static theory of polymer entanglement involving an extended Cahn-Hilliard functional, to include time-dependent dynamics. We go beyond the Gaussian approximation, to the one-loop level, to compute the frequency dependent storage and loss moduli of the system. The three parameters in our theory are obtained by fitting to available experimental data on polystyrene melts of various chain lengths. This provides a physical representation of the parameters in terms of the chain length of the system. We discuss the importance of the various terms in our energy functional with respect to their contribution to the viscoelastic response of the polymeric system.
Deformed shell model results for neutrinoless double beta decay of nuclei in A=60-90 region
R. Sahu; V. K. B. Kota
2015-03-20T23:59:59.000Z
Nuclear transition matrix elements (NTME) for the neutrinoless double beta decay of $^{70}$Zn, $^{80}$Se and $^{82}$Se nuclei are calculated within the framework of the deformed shell model based on Hartree-Fock states. For $^{70}$Zn, jj44b interaction in $^{2}p_{3/2}$, $^{1}f_{5/2}$, $^{2}p_{1/2}$ and $^{1}g_{9/2}$ space with $^{56}$Ni as the core is employed. However, for $^{80}$Se and $^{82}$Se nuclei, a modified Kuo interaction with the above core and model space are employed. Most of our calculations in this region were performed with this effective interaction. However, jj44b interaction has been found to be better for $^{70}$Zn. The above model space was used in many recent shell model and interacting boson model calculations for nuclei in this region. After ensuring that DSM gives good description of the spectroscopic properties of low-lying levels in these three nuclei considered, the NTME are calculated. The deduced half-lives with these NTME, assuming neutrino mass is 1 eV, are $1.1 \\times 10^{26}$ yr, $2.3 \\times 10^{27}$ yr and $2.2 \\times 10^{24}$ yr for $^{70}$Zn, $^{80}$Se and $^{82}$Se, respectively.
Mauroy, Benjamin; Pelca, Dominique; Fausser, Christian; Merckx, Jacques; Mitchell, Barrett R
2015-01-01T23:59:59.000Z
Chest physiotherapy is an empirical technique used to help secretions to get out of the lung whenever stagnation occurs. Although commonly used, little is known about the inner mechanisms of chest physiotherapy and controversies about its use are coming out regularly. Thus, a scientific validation of chest physiotherapy is needed to evaluate its effects on secretions. We setup a quasi-static numerical model of chest physiotherapy based on thorax and lung physiology and on their respective biophysics. We modeled the lung with an idealized deformable symmetric bifurcating tree. Bronchi and their inner fluids mechanics are assumed axisymmetric. Static data from the literature is used to build a model for the lung's mechanics. Secretions motion is the consequence of the shear constraints apply by the air flow. The input of the model is the pressure on the chest wall at each time, and the output is the bronchi geometry and air and secretions properties. In the limit of our model, we mimicked manual and mechanical ...
Joseph Ben Geloun; Jan Govaerts; M. Norbert Hounkonnou
2006-10-23T23:59:59.000Z
Classes of (p,q)-deformations of the Jaynes-Cummings model in the rotating wave approximation are considered. Diagonalization of the Hamiltonian is performed exactly, leading to useful spectral decompositions of a series of relevant operators. The latter include ladder operators acting between adjacent energy eigenstates within two separate infinite discrete towers, except for a singleton state. These ladder operators allow for the construction of (p,q)-deformed vector coherent states. Using (p,q)-arithmetics, explicit and exact solutions to the associated moment problem are displayed, providing new classes of coherent states for such models. Finally, in the limit of decoupled spin sectors, our analysis translates into (p,q)-deformations of the supersymmetric harmonic oscillator, such that the two supersymmetric sectors get intertwined through the action of the ladder operators as well as in the associated coherent states.
Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model
O'Neal, D.L.; Bassiouny, R.
2004-01-01T23:59:59.000Z
stream_source_info ESL-PA-04-03-01.pdf.txt stream_content_type text/plain stream_size 30589 Content-Encoding UTF-8 stream_name ESL-PA-04-03-01.pdf.txt Content-Type text/plain; charset=UTF-8 an short-tube using a finite... element model International Journal of Refrig Vol 27 No 2, pp. 176-183The short-tube is used by United States heat pump manufactures as an expansion device because of its lowAnalyse de l’e´coulement d’un frigorige`ne et de la de´formation d’un tube...
Constitutive modelling of shape memory alloys and upscaling of deformable porous media
Popov, Petar Angelov
2005-08-29T23:59:59.000Z
-D constitutive model for SMAs with special features, dictated by new experimental observations. The new rate independent model accounts in a unified manner for the stress/thermally induced austenite to oriented martensite phase transformation...
Ionic content dependence of viscoelasticity of lyotropic chromonic liquid crystal sunset yellow
Shuang Zhou; Adam J. Cervenka; Oleg D. Lavrentovich
2014-10-10T23:59:59.000Z
A lyotropic chromonic liquid crystal (LCLC) is an orientationally ordered system made by self-assembled aggregates of charged organic molecules in water, bound by weak non-covalent attractive forces and stabilized by electrostatic repulsions. We determine how the ionic content of the LCLC, namely the presence of mono- and divalent salts and pH enhancing agent, alter the viscoelastic properties of the LCLC. Aqueous solutions of the dye Sunset Yellow with a uniaxial nematic order are used as an example. By applying a magnetic field to impose orientational deformations, we measure the splay $K_1$, twist $K_2$ and bend $K_3$ elastic constants and rotation viscosity $\\gamma_1$ as a function of concentration of additives. The data indicate that the viscoelastic parameters are influenced by ionic content in dramatic and versatile ways. For example, the monovalent salt NaCl decreases $K_3$ and $K_2$ and increases $\\gamma_1$, while an elevated pH decreases all the parameters. We attribute these features to the ion-induced changes in length and flexibility of building units of LCLC, the chromonic aggregates, a property not found in conventional thermotropic and lyotropic liquid crystals formed by covalently bound units of fixed length.
/ free-slip / free-slip Numerical models of slab deformation in the upper mantle
Cerveny, Vlastislav
of the plate. Model: Model domain: Results: Effect of decoupling mechanism 410 km 660 km oceánska doska nadlozná doska Results: Effect of boundary condition Effect of yield stress Plate velocity Kinematic, crust.s 1020 Pa.s 1021 Pa.s Free-slip, crust = 1020 Pas, y = 108 Pa Kinematic, crust = 1020 Pas, y = 109 Pa
A Model for High-Strain-Rate Deformation of Uranium-Niobium Alloys
F.L.Addessio; Q.H.Zuo; T.A.Mason; L.C.Brinson
2003-05-01T23:59:59.000Z
A thermodynamic approach is used to develop a framework for modeling uranium-niobium alloys under the conditions of high strain rate. Using this framework, a three-dimensional phenomenological model, which includes nonlinear elasticity (equation of state), phase transformation, crystal reorientation, rate-dependent plasticity, and porosity growth is presented. An implicit numerical technique is used to solve the evolution equations for the material state. Comparisons are made between the model and data for low-strain-rate loading and unloading as well as for heating and cooling experiments. Comparisons of the model and data also are made for low- and high-strain-rate uniaxial stress and uniaxial strain experiments. A uranium-6 weight percent niobium alloy is used in the comparisons of model and experiment.
Visco-elastic fluid simulations of coherent structures in strongly coupled dusty plasma medium
Singh Dharodi, Vikram; Kumar Tiwari, Sanat; Das, Amita, E-mail: amita@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2014-07-15T23:59:59.000Z
A generalized hydrodynamic model depicting the behaviour of visco-elastic fluids has often been invoked to explore the behaviour of a strongly coupled dusty plasma medium below their crystallization limit. The model has been successful in describing the collective normal modes of the strongly coupled dusty plasma medium observed experimentally. The paper focuses on the study of nonlinear dynamical characteristic features of this model. Specifically, the evolution of coherent vorticity patches is being investigated here within the framework of this model. A comparison with Newtonian fluids and molecular dynamics simulations treating the dust species interacting through the Yukawa potential has also been presented.
3D Modeling of Coupled Rock Deformation and Thermo-Poro-Mechanical Processes in Fractures
Rawal, Chakra
2012-07-16T23:59:59.000Z
and failure of weak planes of the formation with creation of new fractures, which impacts reservoir response. Incorporation of geomechanical factor into engineering analyses using fully coupled geomechanics-reservoir flow modeling exhibits computational...
Deformed shell model results for neutrinoless double beta decay of nuclei in A=60-90 region
Sahu, R
2014-01-01T23:59:59.000Z
Nuclear transition matrix elements (NTME) for the neutrinoless double beta decay of $^{70}$Zn, $^{80}$Se and $^{82}$Se nuclei are calculated within the framework of the deformed shell model based on Hartree-Fock states. For $^{70}$Zn, jj44b interaction in $^{2}p_{3/2}$, $^{1}f_{5/2}$, $^{2}p_{1/2}$ and $^{1}g_{9/2}$ space with $^{56}$Ni as the core is employed. However, for $^{80}$Se and $^{82}$Se nuclei, a modified Kuo interaction with the above core and model space are employed. Most of our calculations in this region were performed with this effective interaction. However, jj44b interaction has been found to be better for $^{70}$Zn. After ensuring that DSM gives good description of the spectroscopic properties of low-lying levels in these three nuclei considered, the NTME are calculated. The deduced half-lives with these NTME, assuming neutrino mass is 1 eV, are $9.6 \\times 10^{25}$yr, $1.9 \\times 10^{27}$yr and $1.95 \\times 10^{24}$yr for $^{70}$Zn, $^{80}$Se and $^{82}$Se, respectively.
Propagation and Retention of Viscoelastic Surfactants in Carbonate Cores
Yu, Meng
2012-07-16T23:59:59.000Z
Viscoelastic surfactant have found numerous application in the oil fields as fracturing and matrix acidizing fluid additives in the recent years. They have the ability to form long worm-like micelles with the increase in ...
Nonlinear viscoelastic dynamics of nano-confined water
Tai-De Li; Elisa Riedo
2007-07-17T23:59:59.000Z
The viscoelastic dynamics of nano-confined water is studied by means of atomic force microscopy (AFM). We observe a nonlinear viscoelastic behavior remarkably similar to that widely observed in metastable complex fluids. We show that the origin of the measured nonlinear viscoelasticity in nano-confined water is a strain rate dependent relaxation time and slow dynamics. By measuring the viscoelastic modulus at different frequencies and strains, we find that the intrinsic relaxation time of nano-confined water is in the range 0.1-0.0001 s, orders of magnitude longer than that of bulk water, and comparable to the dielectric relaxation time measured in supercooled water at 170-210 K.
MODE II FRACTURE BEHAVIOR OF BONDED VISCOELASTIC THERMAL COMPRESSED WOOD
Nairn, John A.
MODE II FRACTURE BEHAVIOR OF BONDED VISCOELASTIC THERMAL COMPRESSED WOOD Andreja Kutnar* Graduate Student Department of Wood Science and Technology Biotechnical Faculty University of Ljubljana 1000 Ljubljana, Slovenia Frederick A. Kamke Professor John A. Nairn Professor Department of Wood Science
Viscoelastic transient of confined Red Blood Cells
Gaël Prado; Alexander Farutin; Chaouqi Misbah; Lionel Bureau
2014-09-17T23:59:59.000Z
The unique ability of a red blood cell to flow through extremely small microcapillaries depends on the viscoelastic properties of its membrane. Here, we study in vitro the response time upon flow startup exhibited by red blood cells confined into microchannels. We show that the characteristic transient time depends on the imposed flow strength, and that such a dependence gives access to both the effective viscosity and the elastic modulus controlling the temporal response of red cells. A simple theoretical analysis of our experimental data, validated by numerical simulations, further allows us to compute an estimate for the two-dimensional membrane viscosity of red blood cells, $\\eta_{mem}^{2D}\\sim 10^{-7}$ N$\\cdot$s$\\cdot$m$^{-1}$. By comparing our results with those from previous studies, we discuss and clarify the origin of the discrepancies found in the literature regarding the determination of $\\eta_{mem}^{2D}$, and reconcile seemingly conflicting conclusions from previous works.
Propagation and Retention of Viscoelastic Surfactants in Carbonate Cores
Yu, Meng
2012-07-16T23:59:59.000Z
Approved by: Chair of Committee, Hisham A. Nasr-El-Din Committee Members, Stephen A. Holditch A. Daniel Hill Mahmoud El-Halwagi Head of Department, Stephen A. Holditch May 2011 Major Subject: Petroleum Engineering iii ABSTRACT... Propagation and Retention of Viscoelastic Surfactants in Carbonate Cores. (May 2011) Meng Yu, B.S., Sichuan University; M.S., Texas A&M University Chair of Advisory Committee: Dr. Hisham A. Nasr-El-Din Viscoelastic surfactants have found numerous...
Nonlinear viscoelastic characterization of thin films using dynamic mechanical analysis
Payne, Debbie Flowers
1993-01-01T23:59:59.000Z
, experimental testing methods require extensive laboratory test time. The nonlinear results obtained from dynamic mechanical analysis require less laboratory time. This method assumes that the nonlinear stress dependent behavior may be characterized in a... manner similar to the traditional time temperature superposition principle for linear viscoelastic materials where stress systematically compresses or expands the time scale. From dynamic mechanical testing and analysis, the experimental viscoelastic...
Groleau, Julie; Marecaux, Christophe; Payrard, Natacha; Segaud, Brice; Rochette, Michel; Perrier, Pascal; Payan, Yohan
2008-01-01T23:59:59.000Z
A 3D biomechanical finite element model of the face is presented. Muscles are represented by piece-wise uniaxial tension cable elements linking the insertion points. Such insertion points are specific entities differing from nodes of the finite element mesh, which makes possible to change either the mesh or the muscle implementation totally independently of each other. Lip/teeth and upper lip/lower lip contacts are also modeled. Simulations of smiling and of an Orbicularis Oris activation are presented and interpreted. The importance of a proper account of contacts and of an accurate anatomical description is shown
The Asperity-deformation Model Improvements and Its Applications to Velocity Inversion
Bui, Hoa Q.
2010-01-16T23:59:59.000Z
-of-nails? (BNM) model. Existing analytic solutions include one that assumes the host rock is infinitely more rigid than the fractures, and one that takes the host-rock compliance into account. Inversion results indicate that although both solutions can fit...
Published in Medical Image Analysis, 1(2):91108, 1996. Deformable Models
Terzopoulos, Demetri
Tracking. 1 Introduction The rapid development and proliferation of medical imaging technologies, with the assistance of computers, clinically useful information about anatomic structures imaged through CT, MR, PET these elements into a coherent and consistent model of the structure. Traditional low-level image processing
MEMS Actuated Deformable Mirror
Papavasiliou, A; Olivier, S; Barbee, T; Walton, C; Cohn, M
2005-11-10T23:59:59.000Z
This ongoing work concerns the creation of a deformable mirror by the integration of MEMS actuators with Nanolaminate foils through metal compression boning. These mirrors will use the advantages of these disparate technologies to achieve dense actuation of a high-quality, continuous mirror surface. They will enable advanced adaptive optics systems in large terrestrial telescopes. While MEMS actuators provide very dense actuation with high precision they can not provide large forces typically necessary to deform conventional mirror surfaces. Nanolaminate foils can be fabricated with very high surface quality while their extraordinary mechanical properties enable very thin, flexible foils to survive the rigors of fabrication. Precise metal compression bonding allows the attachment of the fragile MEMS actuators to the thin nanolaminate foils without creating distortions at the bond sites. This paper will describe work in four major areas: (1) modeling and design, (2) bonding development, (3) nanolaminate foil development, (4) producing a prototype. A first-principles analytical model was created and used to determine the design parameters. A method of bonding was determined that is both strong, and minimizes the localized deformation or print through. Work has also been done to produce nanolaminate foils that are sufficiently thin, flexible and flat to be deformed by the MEMS actuators. Finally a prototype was produced by bonding thin, flexible nanolaminate foils to commercially available MEMS actuators.
Beese, Allison M
2011-01-01T23:59:59.000Z
The strain-induced phase transformation from austenite to martensite is responsible for the high strength and ductility of TRansformation-Induced Plasticity (TRIP)- assisted steels. The large deformation behavior of ...
Evolution of shock instability in granular gases with viscoelastic collisions
Nick Sirmas; Matei Radulescu
2014-09-04T23:59:59.000Z
Shocks in granular media have been shown to develop instabilities. We address the role that early stages of shock development have on this type of instability. We look at the evolution of shock waves driven by a piston in a dilute system of smooth inelastic disks, using both discrete-particle and continuum modelling. To mimic a realistic granular gas, viscoelastic collisions are approximated with an impact velocity threshold $u^*$ needed for inelastic collisions to occur. We show that behaviour of the shock evolution is dependent on the ratio of piston velocity to impact velocity threshold $u_p/u^*$, and the coefficient of restitution $\\varepsilon$. For $u_p/u^*=2.0$, we recover shock evolution behaving similar to that observed in purely inelastic media. This is characterized by a short period where the shock front pulls towards the piston before attaining a developed structure. No pullback is seen for $u_p/u^*=1.0$. Results show the onset of instability for these stronger shocks during this evolving stage. These results suggest that the early stages of shock evolution play an important role in the shock instability.
Dutcher, John
parameters were used to generate a full description of the dynamic viscoelastic behavior of the cells overDynamic viscoelastic behavior of individual Gram-negative bacterial cells Virginia Vadillo) to measure the viscoelastic properties of individual Escherichia coli K12 cells under fully hydrated
Cappa, F.; Rutqvist, J.; Yamamoto, K.
2009-05-15T23:59:59.000Z
In Matsushiro, central Japan, a series of more than 700,000 earthquakes occurred over a 2-year period (1965-1967) associated with a strike-slip faulting sequence. This swarm of earthquakes resulted in ground surface deformations, cracking of the topsoil, and enhanced spring-outflows with changes in chemical compositions as well as carbon dioxide (CO{sub 2}) degassing. Previous investigations of the Matsushiro earthquake swarm have suggested that migration of underground water and/or magma may have had a strong influence on the swarm activity. In this study, employing coupled multiphase flow and geomechanical modelling, we show that observed crustal deformations and seismicity can have been driven by upwelling of deep CO{sub 2}-rich fluids around the intersection of two fault zones - the regional East Nagano earthquake fault and the conjugate Matsushiro fault. We show that the observed spatial evolution of seismicity along the two faults and magnitudes surface uplift, are convincingly explained by a few MPa of pressurization from the upwelling fluid within the critically stressed crust - a crust under a strike-slip stress regime near the frictional strength limit. Our analysis indicates that the most important cause for triggering of seismicity during the Matsushiro swarm was the fluid pressurization with the associated reduction in effective stress and strength in fault segments that were initially near critically stressed for shear failure. Moreover, our analysis indicates that a two order of magnitude permeability enhancement in ruptured fault segments may be necessary to match the observed time evolution of surface uplift. We conclude that our hydromechanical modelling study of the Matsushiro earthquake swarm shows a clear connection between earthquake rupture, deformation, stress, and permeability changes, as well as large-scale fluid flow related to degassing of CO{sub 2} in the shallow seismogenic crust. Thus, our study provides further evidence of the important role of deep fluid sources in earthquake fault dynamics and surface deformations.
Rolling friction for hard cylinder and sphere on viscoelastic solid
B. N. J. Persson
2010-08-26T23:59:59.000Z
We calculate the friction force acting on a hard cylinder or spherical ball rolling on a flat surface of a viscoelastic solid. The rolling friction coefficient depends non-linearly on the normal load and the rolling velocity. For a cylinder rolling on a viscoelastic solid characterized by a single relaxation time Hunter has obtained an exact result for the rolling friction, and our result is in very good agreement with his result for this limiting case. The theoretical results are also in good agreement with experiments of Greenwood and Tabor. We suggest that measurements of rolling friction over a wide range of rolling velocities and temperatures may constitute an useful way to determine the viscoelastic modulus of rubber-like materials.
Nikoleris, Teo
1988-01-01T23:59:59.000Z
Fluid in a Rectangular Channel (December 1988) Teo Nikoleris, B. S. , Reed College Chairman of Advisory Committee: Dr. R. Darby An orthogonal collocation finite element program was used to numerically model the hydrodynamicslly and thermally... in negligible increase of Nw~ ~?. Also, the approach of Chang and Finlayson [6], [7] who applied orthogonal collocation finite elements in conjunction with bicubic Hermitian polynomials to approximate various viscoelastic flow problems, also met with little...
Tavgac, Tunc
1968-01-01T23:59:59.000Z
CHAPTER I INTRODUCTION Rheology can be described as the science of deformation and flow of matter. A body is said to be deformed when the application of a force system alters the shape or size of the body. It is said to flow if the deformation changes... rheological model. Therefore we can determine whether or not the assumed model really represents the behavior of the vrscoelastic I'luid. The rheological model (Voigt solid) used in this analysis represents a "solid" material which will not sustain...
Jeong-Yup Lee; Robert V. Moody
2009-10-23T23:59:59.000Z
A linear deformation of a Meyer set $M$ in $\\RR^d$ is the image of $M$ under a group homomorphism of the group $[M]$ generated by $M$ into $\\RR^d$. We provide a necessary and sufficient condition for such a deformation to be a Meyer set. In the case that the deformation is a Meyer set and the deformation is injective, the deformation is pure point diffractive if the orginal set $M$ is pure point diffractive.
Dynamics of multiple viscoelastic carbon nanotube based nanocomposites with axial magnetic field
Karli?i?, Danilo; Caji?, Milan [Mathematical Institute of the SASA, Kneza Mihaila 36, Belgrade 11001 (Serbia); Murmu, Tony [School of Engineering, University of the West of Scotland, Paisley PA12BE (United Kingdom); Kozi?, Predrag [Faculty of Mechanical Engineering, University of Niš, A. Medvedeva 14, 18000 Niš (Serbia); Adhikari, Sondipon [College of Engineering, Swansea University, Singleton Park, Swansea SA2 8PP (United Kingdom)
2014-06-21T23:59:59.000Z
Nanocomposites and magnetic field effects on nanostructures have received great attention in recent years. A large amount of research work was focused on developing the proper theoretical framework for describing many physical effects appearing in structures on nanoscale level. Great step in this direction was successful application of nonlocal continuum field theory of Eringen. In the present paper, the free transverse vibration analysis is carried out for the system composed of multiple single walled carbon nanotubes (MSWCNT) embedded in a polymer matrix and under the influence of an axial magnetic field. Equivalent nonlocal model of MSWCNT is adopted as viscoelastically coupled multi-nanobeam system (MNBS) under the influence of longitudinal magnetic field. Governing equations of motion are derived using the Newton second low and nonlocal Rayleigh beam theory, which take into account small-scale effects, the effect of nanobeam angular acceleration, internal damping and Maxwell relation. Explicit expressions for complex natural frequency are derived based on the method of separation of variables and trigonometric method for the “Clamped-Chain” system. In addition, an analytical method is proposed in order to obtain asymptotic damped natural frequency and the critical damping ratio, which are independent of boundary conditions and a number of nanobeams in MNBS. The validity of obtained results is confirmed by comparing the results obtained for complex frequencies via trigonometric method with the results obtained by using numerical methods. The influence of the longitudinal magnetic field on the free vibration response of viscoelastically coupled MNBS is discussed in detail. In addition, numerical results are presented to point out the effects of the nonlocal parameter, internal damping, and parameters of viscoelastic medium on complex natural frequencies of the system. The results demonstrate the efficiency of the suggested methodology to find the closed form solutions for the free vibration response of multiple nanostructure systems under the influence of magnetic field.
Non-contact Method in Measuring the Viscoelastic
Petta, Jason
to be considered for effective usage in such applications Polymer solar cells Membranes 1Wikimedia Commons, Solar Cells 2Science Centric, Polymer Membranes 1 2 #12;Viscoelasticity · Has both viscous and elastic-off Experiment Modification of original blow-off setup: temperature control #12;Temperature Calibration · Upper
Biomaterials 26 (2005) 46954706 Viscoelastic and mechanical behavior of recombinant
Srinivasarao, Mohan
2005-01-01T23:59:59.000Z
Biomaterials 26 (2005) 46954706 Viscoelastic and mechanical behavior of recombinant protein of an Ala for the consensus Gly ARTICLE IN PRESS www.elsevier.com/locate/biomaterials 0142-9612/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.biomaterials.2004
RESEARCH ARTICLE Bubble growth in visco-elastic magma: implications
Lyakhovsky, Vladimir
RESEARCH ARTICLE Bubble growth in visco-elastic magma: implications to magma fragmentation modulus, bubble growth is slow and follows an exponential law in a viscous growth regime, while for low friction and the Mohr-Coulomb failure theory, and a strain related one based on fibre elongation
Thomas, Verghese
1994-01-01T23:59:59.000Z
, the structure must be inferred from the linear viscoelastic properties of the melt. To make this inference, the spectrum over a wide enough range of relaxation times to include the plateau modulus, GNI is required. For most polymers this is accomplished by time...
Deformable contours Slides from Prof. Kristen Grauman
Kosecka, Jana
;Deformable contours a.k.a. active contours, snakes Given: initial contour (model) near desired object [Snakes contours Given: initial contour (model) near desired object a.k.a. active contours, snakes Figure credit
Khan, Kamran-Ahmed
2009-05-15T23:59:59.000Z
solutions within a general displacement based FE structural analyses for small deformations and uncoupled thermo-mechanical problems. A previously developed recursive-iterative algorithm for a stress-dependent hereditary integral model which was developed...
ANALYSES OF DEFORMATION IN VISCOELASTIC SANDWICH COMPOSITES SUBJECT TO MOISTURE DIFFUSION
Joshi, Nikhil P.
2010-01-16T23:59:59.000Z
. During their service time, sandwich composites are exposed to various external mechanical and hygro-thermal stimuli. It is known that the constituent properties of the sandwich composites are greatly influenced by the temperature and moisture fields...
Quantifying non-axial deformations in rat myocardium
Aghassibake, Kristina Diane
2005-02-17T23:59:59.000Z
Nearly forty years after the introduction of the sliding filament theory, Zahalak expanded Huxley?s cross-bridge model from a uniaxial description of length changes in the fiber direction to a three-dimensional model that accounts for non-axial active..., and is therefore a viscoelastic material. However, in the case of cyclic loading, myocardium behaves elastically when the loading and unloading phases are considered independently; hence, 16 many investigators choose to treat myocardium as a pseudoelastic...
On study of nonlinear viscoelastic behavior of red blood cell membrane
Horacio Castellini; Bibiana Riquelme; Patricia Foresto
2007-03-15T23:59:59.000Z
The linear viscoelastic behavior of the red blood cell membrane of mammal and human was studied in previous works proposing different experimental methods to determine their viscoelastic parameters. In the present work the nonlinear component of dynamic viscosity of the red blood cell membrane by nonlinear time series analysis is used. For such aim, it obtained time series of test in vitro of samples of humans and rats red blood cells using the Erythrodeformeter in oscillating regime. The signal filtrate suppresses any linear behavior as well as represented by a system of linear ordinary differential equations. The test shown as much in humans as in rats resonance frequencies associated to an attractor of unknown nature independently of excitation in the physiological range. The preliminary studies shown that attractor could be correspond to a complex form bull. These results allow to extend the present knowledge on dynamic of the cellular membrane to similar stimulus which happens in the blood circulation and it will allows to make better models of the same one.
Integrable Deformations of Strings on Symmetric Spaces
Timothy J. Hollowood; J. Luis Miramontes; David M. Schmidtt
2014-07-16T23:59:59.000Z
A general class of deformations of integrable sigma-models with symmetric space F/G target-spaces are found. These deformations involve defining the non-abelian T dual of the sigma-model and then replacing the coupling of the Lagrange multiplier imposing flatness with a gauged F/F WZW model. The original sigma-model is obtained in the limit of large level. The resulting deformed theories are shown to preserve both integrability and the equations-of-motion, but involve a deformation of the symplectic structure. It is shown that this deformed symplectic structure involves a linear combination of the original Poisson bracket and a generalization of the Faddeev-Reshetikhin Poisson bracket which we show can be re-expressed as two decoupled F current algebras. It is then shown that the deformation can be incorporated into the classical model of strings on R x F/G via a generalization of the Pohlmeyer reduction. In this case, in the limit of large sigma-model coupling it is shown that the theory becomes the relativistic symmetric space sine-Gordon theory. These results point to the existence of a deformation of this kind for the full Green-Schwarz superstring on AdS5 x S5.
Ehgartner, Brian L.; Sobolik, Steven Ronald; Bean, James E.
2010-07-01T23:59:59.000Z
The U.S. Strategic Petroleum Reserve stores crude oil in 62 solution-mined caverns in salt domes located in Texas and Louisiana. Historically, three-dimensional geomechanical simulations of the behavior of the caverns have been performed using a power law creep model. Using this method, and calibrating the creep coefficient to field data such as cavern closure and surface subsidence, has produced varying degrees of agreement with observed phenomena. However, as new salt dome locations are considered for oil storage facilities, pre-construction geomechanical analyses are required that need site-specific parameters developed from laboratory data obtained from core samples. The multi-mechanism deformation (M-D) model is a rigorous mathematical description of both transient and steady-state creep phenomena. Recent enhancements to the numerical integration algorithm within the model have created a more numerically stable implementation of the M-D model. This report presents computational analyses to compare the results of predictions of the geomechanical behavior at the West Hackberry SPR site using both models. The recently-published results using the power law creep model produced excellent agreement with an extensive set of field data. The M-D model results show similar agreement using parameters developed directly from laboratory data. It is also used to predict the behavior for the construction and operation of oil storage caverns at a new site, to identify potential problems before a final cavern layout is designed.
Impact of Acid Additives on Elastic Modulus of Viscoelastic Surfactants
Khan, Waqar Ahmad
2012-02-14T23:59:59.000Z
Approved by: Chair of Committee, Hisham A. Nasr-El-Din Committee Members, Jerome J. Schubert Mahmoud El-Halwagi Head of Department, Stephen A. Holditch December 2011 Major Subject: Petroleum Engineering iii ABSTRACT Impact... of Acid Additives on Elastic Modulus of Viscoelastic Surfactants. (December 2011) Waqar Ahmad Khan, B.E., NED University of Engineering and Technology Chair of Advisory Committee: Dr. Hisham Nasr-El-Din In live acid solutions...
Poludnista Dorsa, Venus: History and context of a deformation belt
Hansen, Vicki
Poludnista Dorsa, Venus: History and context of a deformation belt D. A. Young and V. L. Hansen is combined with altimetry data test models of deformation belt evolution in Venus's lowlands. Poludnista Dorsa, a complex 2000-km-long deformation belt, is highly segmented and broadly time transgressive. Long
A thin film model for corotational Jeffreys fluids under strong slip
A. Münch; B. Wagner; M. Rauscher; R. Blossey
2006-05-14T23:59:59.000Z
We derive a thin film model for viscoelastic liquids under strong slip which obey the stress tensor dynamics of corotational Jeffreys fluids.
A fast multipole boundary element method for 2D viscoelastic problems X.Y. Zhu a,d
Liu, Yijun
A fast multipole boundary element method for 2D viscoelastic problems X.Y. Zhu a,d , W.Q. Chen b Available online 21 August 2010 Keywords: Boundary element method Fast multipole method Viscoelasticity Multi-inclusion composite a b s t r a c t A fast multipole formulation for 2D linear viscoelastic
Measurement of Local Viscoelasticity and Forces in Living Cells by Magnetic Tweezers
Bausch, Andreas
Measurement of Local Viscoelasticity and Forces in Living Cells by Magnetic Tweezers Andreas R measured the viscoelastic properties of the cytoplasm of J774 macrophages with a recently developed circuit, we measured the shear elastic modulus, the effective viscosities, and the strain relaxation time
The matching of 3D Rolie-Poly viscoelastic numerical simulations with experimental polymer melt flow
Jimack, Peter
Kingdom J. Embery and D. Auhl IRC in Polymer Science and Technology, Department of Physics and AstronomyThe matching of 3D Rolie-Poly viscoelastic numerical simulations with experimental polymer melt of commercial viscoelastic polymer melts. Numerical simulation techniques have steadily advanced over the last
Cappa, F.
2010-01-01T23:59:59.000Z
properties for an anisotropic (ubiquitous joint) elasto?plastic plastic constitutive mechanical model. Properties for an elasto?plastic behavior. The fluid?property module
Edinburgh, University of
'' or ``compiling down'' the results of previous searches to speed up running time. This paper is structured models are an attractive approach to recognizing objects which have considerable withinÂclass variability such as handwritten characters. However, there are severe search problems associated with fitting the models to data
A Brief Review of Elasticity and Viscoelasticity
with a brief introduction of some basic terminology and relationships in continuum mechanics, and a review example describing the motion of soil ex- periencing dynamic loading by incorporating a specific form. Key Words: Mathematical modeling, Eulerian and Lagrangian formulations in continuum mechanics
Evolution of deformations in medium-mass nuclei
H. Sagawa; X. R. Zhou; X. Z. Zhang
2005-10-28T23:59:59.000Z
Evolution of quadrupole deformations in $sd$ and $pf$ shell nuclei with mass A= 18$\\sim$56 is studied by using deformed Skyrme Hartree-Fock (HF) model with pairing correlations. We point out that the quadrupole deformations of the nuclei with the isospin T=0 and T=1 show strong mass number dependence as a clear manifestation of dynamical evolution of deformation in nuclear many-body systems. The competition between the deformation driving particle-vibration coupling and the closed shell structure is shown in a systematic study of the ratios between the proton and neutron deformations in nuclei with T=$|$T$_z|$=1. Calculated quadrupole and hexadecapole deformations are compared with shell model results and available experimental data. A relation between the skin thickness and the intrinsic Q$_2$ moments is also discussed.
G. S. CUNNINGHAM; A. LEHOVICH
2000-01-01T23:59:59.000Z
The Bayes Inference Engine (BIE) has been used to perform a 4D reconstruction of a first-pass radiotracer bolus distribution inside a CardioWest Total Artificial Heart, imaged with the University of Arizona's FastSPECT system. The BIE estimates parameter values that define the 3D model of the radiotracer distribution at each of 41 times spanning about two seconds. The 3D models have two components: a closed surface, composed of hi-quadratic Bezier triangular surface patches, that defines the interface between the part of the blood pool that contains radiotracer and the part that contains no radiotracer, and smooth voxel-to-voxel variations in intensity within the closed surface. Ideally, the surface estimates the ventricular wall location where the bolus is infused throughout the part of the blood pool contained by the right ventricle. The voxel-to-voxel variations are needed to model an inhomogeneously-mixed bolus. Maximum a posterior (MAP) estimates of the Bezier control points and voxel values are obtained for each time frame. We show new reconstructions using the Bezier surface models, and discuss estimates of ventricular volume as a function of time, ejection fraction, and wall motion. The computation time for our reconstruction process, which directly estimates complex 3D model parameters from the raw data, is performed in a time that is competitive with more traditional voxel-based methods (ML-EM, e.g.).
Probing deformed commutators with macroscopic harmonic oscillators
Mateusz Bawaj; Ciro Biancofiore; Michele Bonaldi; Federica Bonfigli; Antonio Borrielli; Giovanni Di Giuseppe; Lorenzo Marconi; Francesco Marino; Riccardo Natali; Antonio Pontin; Giovanni A. Prodi; Enrico Serra; David Vitali; Francesco Marin
2015-08-25T23:59:59.000Z
A minimal observable length is a common feature of theories that aim to merge quantum physics and gravity. Quantum mechanically, this concept is associated to a nonzero minimal uncertainty in position measurements, which is encoded in deformed commutation relations. In spite of increasing theoretical interest, the subject suffers from the complete lack of dedicated experiments and bounds to the deformation parameters are roughly extrapolated from indirect measurements. As recently proposed, low-energy mechanical oscillators could allow to reveal the effect of a modified commutator. Here we analyze the free evolution of high quality factor micro- and nano-oscillators, spanning a wide range of masses around the Planck mass $m_{\\mathrm{P}}$ (${\\approx 22\\,\\mu\\mathrm{g}}$), and compare it with a model of deformed dynamics. Previous limits to the parameters quantifying the commutator deformation are substantially lowered.
?-deformation and quantization
Junya Yagi
2014-08-30T23:59:59.000Z
We formulate a deformation of Rozansky-Witten theory analogous to the $\\Omega$-deformation. It is applicable when the target space $X$ is hyperk\\"ahler and the spacetime is of the form $\\mathbb{R} \\times \\Sigma$, with $\\Sigma$ being a Riemann surface. In the case that $\\Sigma$ is a disk, the $\\Omega$-deformed Rozansky-Witten theory quantizes a symplectic submanifold of $X$, thereby providing a new perspective on quantization. As applications, we elucidate two phenomena in four-dimensional gauge theory from this point of view. One is a correspondence between the $\\Omega$-deformation and quantization of integrable systems. The other concerns supersymmetric loop operators and quantization of the algebra of holomorphic functions on a hyperk\\"ahler manifold.
Galer, Meghan; Heiner, Jason
2014-01-01T23:59:59.000Z
Figure. Appearance of the patient’s affected right arm andnormal left arm. Volume XV, NO . 4 : July 2014 WesternI n E mergency M edicine Arm Weakness and Deformity Meghan
A Model of Viscoelastic Ice-Shelf Flexure
MacAyeal, Douglas R.; Sergienko, Olga V.; Banwell, Alison F.
2015-07-15T23:59:59.000Z
-shelf and ice-stream motion and stress fields. Examples of these phenomena27 include tide-driven grounding-line flexure and migration [e.g., Sayag and Worster, 2013, Tsai and28 Gudmundsson, 2015], tidally pulsed grounding line ice velocity variations [e... -shelf flexure that is applicable to circumstances where the114 ratio of vertical to horizontal length scales, H and L, respectively, is small (H/L ? 1), and where115 the vertical displacement (assumed constant through the depth of the ice shelf) due to flexure...
Thermomechanical Constitutive Modeling of Viscoelastic Materials undergoing Degradation
Karra, Satish
2012-07-16T23:59:59.000Z
.s, kD = 1:2 10 6 s 1 , = 10, = 0:3, = 0:5. : : : : : : : : : : : : : : : : : : : : : : : : 174 xviii FIGURE Page 36 Engineering spatial convergence of the solution for p at Z? = 0 and at t? = 0:5. The time-step was chosen to be t? = 0...
Guided Wave Propagation in Tubular Section with Multi-Layered Viscoelastic Coating
Kuo, Chi-Wei 1982-
2012-11-16T23:59:59.000Z
Three kinds of propagating waves physically admissible in a tubular section are derived to establish their dispersion characteristics in response to the presence of multi-layered viscoelastic coatings. One is the longitudinal wave that propagates...
Finite Element Analyses of a Cyclically Loaded Linear Viscoelastic Biodegradable Stent
Murphy, Jason Kyle
2014-12-03T23:59:59.000Z
degradation behaviors on the performance of cylindrical annuli that mimic stents under cyclic loadings is examined. Two polymers are considered: poly-L-lactic acid (PLLA) and polyoxymethylene (POM). A numerical algorithm for an isotropic, linear, viscoelastic...
Jeon, Jaehyeuk
2013-08-09T23:59:59.000Z
This study presents a combined viscoelastic (VE)-viscoplastic (VP) analysis for Fiber Reinforced Polymer (FRP) composites subject to simultaneous mechanical load and conduction of heat. The studied FRP composites consist of unidirectional fibers...
Biskup, Bruce Allen
1994-01-01T23:59:59.000Z
An investigation into the use of dynamic mechanical analysis to characterize the viscoelastic properties of thin film materials is presented. The methodology was investigated using polyethylene films used on high altitude research balloons. Time...
Correlation of mechanical viscoelastic properties to microstructure of equine cortical bone tissue
Ayers, Andrew Kerr
1995-01-01T23:59:59.000Z
Dynamic Mechanical Analysis (DMA) has long been used as a method of determining viscoelastic mechanical properties of polymeric materials. More recently, DMA has been used for characterizing the fiber/matrix interface in composite materials...
A Multi-scale Framework for Thermo-viscoelastic Analysis of Fiber Metal Laminates
Sawant, Sourabh P.
2010-01-14T23:59:59.000Z
Fiber Metal Laminates (FML) are hybrid composites with alternate layers of orthotropic fiber reinforced polymers (FRP) and isotropic metal alloys. FML can exhibit a nonlinear thermo-viscoelastic behavior under the influence of external mechanical...
Muddasani, Maithri
2009-05-15T23:59:59.000Z
This study presents experimental works and finite element (FE) analyses for understanding nonlinear thermo-viscoelastic behaviors of multilayered (pultruded) composites under tension. Uniaxial isothermal creep tests in tension are conducted...
Khan, Kamran-Ahmed
2009-05-15T23:59:59.000Z
A recursive-iterative algorithm is developed for predicting nonlinear viscoelastic behaviors of isotropic materials that belong to the thermorheologically complex material (TCM). The algorithm is derived based on implicit stress integration...
Guided Wave Propagation in Tubular Section with Multi-Layered Viscoelastic Coating
Kuo, Chi-Wei 1982-
2012-11-16T23:59:59.000Z
Three kinds of propagating waves physically admissible in a tubular section are derived to establish their dispersion characteristics in response to the presence of multi-layered viscoelastic coatings. One is the longitudinal wave that propagates...
2D Squeezing-flow of a Non-Newtonian Fluid Between Viscoelastic Walls: Numerical Simulations
Talbi, Zouhair
2013-08-31T23:59:59.000Z
of the vaginal tissue, vaginal geometry, effects of the neighbouring tissues, and dilution. This thesis presents an engineering approach to help understand the impact of the viscoelastic characteristics of the vaginal tissue on the spreading of different...
Nonlinear viscoelastic characterization of AS-3502 graphite/epoxy composite material
Kerstetter, Michael Scott
1980-01-01T23:59:59.000Z
NONLINEAR VISCOELASTIC CHARACTERIZATION OF AS-3502 GRAPHITE/EPOXY COMPOSITE MATERIAL A Thesis MICHAEL SCOTT KERSTETTER Submitted to the Graduate College of Texas A8M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1980 Major Subject: Aerospace Engineering NONLINEAR VISCOELASTIC CHARACTERIZATION OF AS-3502 GRAPHITE/EPOXY COMPOSITE MATERIAL A Thesis by MICHAEL SCOTT KERSTETTER Approved as to style and content by: Dr. Kenneth L...
Pre-Stressed Viscoelastic Composites: Effective Incremental Moduli and Band-Gap Tuning
Parnell, William J. [School of Mathematics, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom)
2010-09-30T23:59:59.000Z
We study viscoelastic wave propagation along pre-stressed nonlinear elastic composite bars. In the pre-stressed state we derive explicit forms for the effective incremental storage and loss moduli with dependence on the pre-stress. We also derive a dispersion relation for the effective wavenumber in the case of arbitrary frequency, hence permitting a study of viscoelastic band-gap tuning via pre-stress.
A. Besser; U. S. Schwarz
2007-10-24T23:59:59.000Z
Biochemistry and mechanics are closely coupled in cell adhesion. At sites of cell-matrix adhesion, mechanical force triggers signaling through the Rho-pathway, which leads to structural reinforcement and increased contractility in the actin cytoskeleton. The resulting force acts back to the sites of adhesion, resulting in a positive feedback loop for mature adhesion. Here we model this biochemical-mechanical feedback loop for the special case when the actin cytoskeleton is organized in stress fibers, which are contractile bundles of actin filaments. Activation of myosin II molecular motors through the Rho-pathway is described by a system of reaction-diffusion equations, which are coupled into a viscoelastic model for a contractile actin bundle. We find strong spatial gradients in the activation of contractility and in the corresponding deformation pattern of the stress fiber, in good agreement with experimental findings.
Electrically Deformable Liquid Marbles
Edward Bormashenko; Roman Pogreb; Tamir Stein; Gene Whyman; Marcelo Schiffer; Doron Aurbach
2011-02-17T23:59:59.000Z
Liquid marbles, which are droplets coated with a hydrophobic powder, were exposed to a uniform electric field. It was established that a threshold value of the electric field, 15 cgse, should be surmounted for deformation of liquid marbles. The shape of the marbles was described as a prolate spheroid. The semi-quantitative theory describing deformation of liquid marbles in a uniform electric field is presented. The scaling law relating the radius of the contact area of the marble to the applied electric field shows a satisfactory agreement with the experimental data.
Nanolaminate deformable mirrors
Papavasiliou, Alexandros P.; Olivier, Scot S.
2010-04-06T23:59:59.000Z
A deformable mirror formed out of two layers of a nanolaminate foil attached to a stiff substrate is introduced. Deformation is provided by an electrostatic force between two of the layers. The internal stiffness of the structure allows for high-spatial-frequency shapes. The nanolaminate foil of the present invention allows for a high-quality mirror surface. The device achieves high precision in the vertical direction by using foils with accurately controlled thicknesses, but does not require high precision in the lateral dimensions, allowing such mirrors to be fabricated using crude lithography techniques. Such techniques allow structures up to about the meter scale to be fabricated.
Nanolaminate deformable mirrors
Papavasiliou, Alexandros P. (Oakland, CA); Olivier, Scot S. (Santa Cruz, CA)
2009-04-14T23:59:59.000Z
A deformable mirror formed out of two layers of a nanolaminate foil attached to a stiff substrate is introduced. Deformation is provided by an electrostatic force between two of the layers. The internal stiffness of the structure allows for high-spatial-frequency shapes. The nanolaminate foil of the present invention allows for a high-quality mirror surface. The device achieves high precision in the vertical direction by using foils with accurately controlled thicknesses, but does not require high precision in the lateral dimensions, allowing such mirrors to be fabricated using crude lithography techniques. Such techniques allow structures up to about the meter scale to be fabricated.
M. Hassan Farshbaf-Shaker; Christian Heinemann
2015-02-10T23:59:59.000Z
In this work we investigate a phase field model for damage processes in two-dimensional viscoelastic media with nonhomogeneous Neumann data describing external boundary forces. In the first part we establish global-in-time existence, uniqueness, a priori estimates and continuous dependence of strong solutions on the data. The main difficulty is caused by the irreversibility as well as boundedness of the phase field variable which results in a doubly constrained PDE system. In the last part we consider an optimal control problem where a cost functional penalizes maximal deviations from prescribed damage profiles. The goal is to minimize the cost functional with respect to exterior forces acting on the boundary which play the role of the control variable in the considered model. To this end, we prove existence of minimizers and study a family of "local" approximations via adapted cost functionals.
M. Hassan Farshbaf-Shaker; Christian Heinemann
2015-07-08T23:59:59.000Z
In this work we investigate a phase field model for damage processes in two-dimensional viscoelastic media with nonhomogeneous Neumann data describing external boundary forces. In the first part we establish global-in-time existence, uniqueness, a priori estimates and continuous dependence of strong solutions on the data. The main difficulty is caused by the irreversibility of the phase field variable which results in a constrained PDE system. In the last part we consider an optimal control problem where a cost functional penalizes maximal deviations from prescribed damage profiles. The goal is to minimize the cost functional with respect to exterior forces acting on the boundary which play the role of the control variable in the considered model. To this end, we prove existence of minimizers and study a family of "local" approximations via adapted cost functionals.
Large Deformation Unbiased Diffeomorphic Nonlinear Image Registration: Theory and Implementation
Soatto, Stefano
Large Deformation Unbiased Diffeomorphic Nonlinear Image Registration: Theory and Implementation for con- structing large deformation log-unbiased image registra- tion models that generate theoretically the statistical distributions of Jacobian maps in the logarithmic space. To demonstrate the power of the proposed
Virtual Clay: Haptics-based Deformable Solids of Arbitrary Topology
McDonnell, Kevin
Virtual Clay: Haptics-based Deformable Solids of Arbitrary Topology Kevin T. McDonnell and Hong Qin|qin}@cs.sunysb.edu Abstract. This paper presents Virtual Clay as a novel, interactive, dy- namic, haptics-based deformable solid of arbitrary topology. Our Virtual Clay methodology is a unique, powerful visual modeling paradigm
DNA Deformation Energy as an Indirect Recognition Mechanism in
Lathrop, Richard H.
DNA Deformation Energy as an Indirect Recognition Mechanism in Protein-DNA Interactions Kimberly A. Senear Abstract--Proteins that bind to specific locations in genomic DNA control many basic cellular. Deformation energy, which models the energy required to bend DNA from its native shape to its shape when bound
Seismology of plastic deformation Jero^me Weiss *, Francois Louchet
Weiss, Jérôme
Seismology of plastic deformation Je´ro^me Weiss *, Franc¸ois Louchet Laboratoire de Glaciologie et-free critical picture of dislocational plasticity that challenges the classical continuum models of plasticity rights reserved. Keywords: Acoustic methods; Dislocation dynamics; Plastic deformation; Self
Banding in single crystals during plastic deformation
Mahesh, Sivasambu
Banding in single crystals during plastic deformation M. Arul Kumar a Sivasambu Mahesh a,b a. India. Abstract A rigid-plastic rate-independent crystal plasticity model capable of capturing band- ing such as dense dislocation walls. Key words: crystal plasticity, single crystal, macroscopic shear band, regular
HOMOGENIZATION OF A VISCOELASTIC MATRIX IN LINEAR FRICTIONAL CONTACT
Panchenko, Alexander
is assumed to be dry, and the friction law is given by a version of Coulomb's law 1991 Mathematics Subject, 18, 17, 11]. The authors of these articles study the deformation of a body coming into frictional as normal compliance. The contact conditions of Coulomb type are formulated as inequalities involving
Noncommutative Deformations of Wightman Quantum Field Theories
Harald Grosse; Gandalf Lechner
2008-08-26T23:59:59.000Z
Quantum field theories on noncommutative Minkowski space are studied in a model-independent setting by treating the noncommutativity as a deformation of quantum field theories on commutative space. Starting from an arbitrary Wightman theory, we consider special vacuum representations of its Weyl-Wigner deformed counterpart. In such representations, the effect of the noncommutativity on the basic structures of Wightman theory, in particular the covariance, locality and regularity properties of the fields, the structure of the Wightman functions, and the commutative limit, is analyzed. Despite the nonlocal structure introduced by the noncommutativity, the deformed quantum fields can still be localized in certain wedge-shaped regions, and may therefore be used to compute noncommutative corrections to two-particle S-matrix elements.
Loop-deformed Poincaré algebra
Jakub Mielczarek
2013-04-08T23:59:59.000Z
In this essay we present evidence suggesting that loop quantum gravity leads to deformation of the local Poincar\\'e algebra within the limit of high energies. This deformation is a consequence of quantum modification of effective off-shell hypersurface deformation algebra. Surprisingly, the form of deformation suggests that the signature of space-time changes from Lorentzian to Euclidean at large curvatures. We construct particular realization of the loop-deformed Poincar\\'e algebra and find that it can be related to curved momentum space, which indicates the relationship with recently introduced notion of relative locality. The presented findings open a new way of testing loop quantum gravity effects.
Forward Roll Coating Flows of Viscoelastic G. A. Zevallos1,2, M. S. Carvalho1, M. Pasquali2
Natelson, Douglas
Forward Roll Coating Flows of Viscoelastic Liquids G. A. Zevallos1,2, M. S. Carvalho1, M. Pasquali2, the film splitting flow that occurs in forward roll coating is three-dimensional and results in more is viscoelastic. #12;1 Introduction Roll coating is widely used to apply a thin liquid layer to a continuous
Experimental deformation of muscovite
Mares, Vanadis Marina
1992-01-01T23:59:59.000Z
deformed at 45' to (001) exhibit smooth undulatory extinction associated with dislocation glide, with few low-angle kink band boundaries. Basal shear strengths are insensitive to confining pressure between 100 and 400 MPa. Results for samples shortened... and an exponential constant a of 0. 5+0. 2 MPa-1. Samples loaded parallel to the basal plane shorten by the development of sharply defined kink bands. Strengths associated with kink band formation for samples loaded parallel to (001) are higher than those...
Gupta, Anupam
2015-01-01T23:59:59.000Z
Based on mesoscale lattice Boltzmann (LB) numerical simulations, we investigate the effects of viscoelasticity on the break-up of liquid threads in microfluidic cross-junctions, where droplets are formed by focusing a liquid thread of a dispersed (d) phase into another co-flowing continuous (c) immiscible phase. Working at small Capillary numbers, we investigate the effects of non-Newtonian phases in the transition from droplet formation at the cross-junction (DCJ) to droplet formation downstream of the cross-junction (DC) (Liu $\\&$ Zhang, ${\\it Phys. ~Fluids.}$ ${\\bf 23}$, 082101 (2011)). We will analyze cases with ${\\it Droplet ~Viscoelasticity}$ (DV), where viscoelastic properties are confined in the dispersed phase, as well as cases with ${\\it Matrix ~Viscoelasticity}$ (MV), where viscoelastic properties are confined in the continuous phase. Moderate flow-rate ratios $Q \\approx {\\cal O}(1)$ of the two phases are considered in the present study. Overall, we find that the effects are more pronounced in ...
Role of viscoelasticity and non-linear rheology in flows of complex fluids at high deformation rates
Ober, Thomas J. (Thomas Joseph)
2013-01-01T23:59:59.000Z
We combine pressure, velocimetry and birefringence measurements to study three phenomena for which the fluid rheology plays a dominant role: 1) shear banding in micellar fluids, 2) extension-dominated flows in microfluidic ...
Wide band Fresnel super-resolution applied to capillary break up of viscoelastic fluids
Fiscina, Jorge E; Sattler, Rainer; Wagner, Christian
2013-01-01T23:59:59.000Z
We report a technique based on Fresnel diffraction with white illumination that permits the resolution of capillary surface patterns of less than 100 nanometers. We investigate Rayleigh Plateaux like instability on a viscoelastic capillary bridge and show that we can overcome the resolution limit of optical microscopy. The viscoelastic filaments are approximately 20 microns thick at the end of the thinning process when the instability sets in. The wavy distortions grow exponentially in time and the pattern is resolved by an image treatment that is based on an approximation of the measured rising flank of the first Fresnel peak.
Wide band Fresnel super-resolution applied to capillary break up of viscoelastic fluids
Jorge E. Fiscina; Pierre Fromholz; Rainer Sattler; Christian Wagner
2013-10-05T23:59:59.000Z
We report a technique based on Fresnel diffraction with white illumination that permits the resolution of capillary surface patterns of less than 100 nanometers. We investigate Rayleigh Plateaux like instability on a viscoelastic capillary bridge and show that we can overcome the resolution limit of optical microscopy. The viscoelastic filaments are approximately 20 microns thick at the end of the thinning process when the instability sets in. The wavy distortions grow exponentially in time and the pattern is resolved by an image treatment that is based on an approximation of the measured rising flank of the first Fresnel peak.
Jordanian deformation of the open XXX-spin chain
P. P. Kulish; N. Manojlovic; Z. Nagy
2009-12-18T23:59:59.000Z
The general solution to the reflection equation associated with the jordanian deformation of the SL(2) invariant Yang R-matrix is found. The same K-matrix is obtained by the special scaling limit of the XXZ-model with general boundary conditions. The Hamiltonian with the boundary terms is explicitly derived according to the Sklyanin formalism. We discuss the structure of the spectrum of the deformed XXX-model and its dependence on the boundary conditions.
Ravindran, Parag
2009-06-02T23:59:59.000Z
. In proportion to the quantity of its usage and in acknowledgment of modeling complexity, the material has been interrogated by many researchers using a variety of mechanical tests, and a plethora of linear viscoelastic models have been developed. Most models...
Cyclic performance of viscoelastic dielectric elastomers with solid hydrogel Yuanyuan Bai,1
Suo, Zhigang
of manufacturing or fabrication by 3D printing, silent operation, and capability of large deformation.1
Wake measurements for flow around a sphere in a viscoelastic fluid Drazen Fabrisa)
Liepmann, Dorian
counterpart is made by a drag correction factor, K FD 6 0aUt , 3 where FD is the drag force on the sphere which balances the force due to gravity, ( s f)*( 4 3 ga3 ). The drag correc- tion factor is, in generalWake measurements for flow around a sphere in a viscoelastic fluid Drazen Fabrisa) Department
VISCOELASTIC BEHAVIOR OF POLYMER-THICKENED WATER-IN-OIL EMULSIONS
Natelson, Douglas
VISCOELASTIC BEHAVIOR OF POLYMER-THICKENED WATER-IN- OIL EMULSIONS MONTESI PEÑA HIRASAKI PASQUALI behavior of emulsions of water dispersed in a lubricant oil base and stabilized with a nonionic surfactant concentration, emulsions with and without polyisobutylene (PIB, MW = 2.1 ± 0.2 x 106 Da) added to the oil phase
Exceptional negative thermal expansion and viscoelastic properties of graphene oxide paper
Zhong, Zhaohui
and viscoelastic properties in graphene oxide paper. The paper was prepared from aqueous GO dispersions using]. Graphene oxide (GO), likely the most important graphene derivative, has also been prepared by oxidizing and temperature. 2. Experimental 2.1. Preparation of GO and GO paper Graphene oxide was synthesized by oxidation of
Formation of beads-on-a-string structures during breakup of viscoelastic filaments
of Technology, Cambridge, MA 02139, USA e-mail: obasaran@purdue.edu Breakup of viscoelastic filaments is pervasive in both nature and technology. If a filament is formed by placing a drop of saliva between a thumb the growth of the bead and delays pinch-off, which leads to a relatively long-lived beaded structure. We also
of an LCP. Liquid crystal polymers are useful because the photo- induced LC to isotropic phase transitionPolymer communication Rapid viscoelastic switching of an ambient temperature range photo, temperature sweeps measured G' and G" from 80°C to -5°C and identified glass transition temperatures (Tg) at 2
Overall response of viscoelastic composites and polycrystals: exact asymptotic relations and
Paris-Sud XI, Université de
to a creep test (see Subsection 2.2 and Figure 1). For simplicity the present study will be focused emphasis on their transient response. First, two new asymptotic relations for the overall creep function: linear viscoelasticity, homogenization, effective creep function, particulate composites, polycrystals
3.22 Mechanical Properties of Materials Test 2: Viscoelasticity and Plasticity
Goldwasser, Shafi
are allowed to bring one 8.5" x 11" sheet into the test. 1. The creep behaviour of polyethylene is given3.22 Mechanical Properties of Materials Test 2: Viscoelasticity and Plasticity April 25, 2002 You by the creep compliance data in the table below. Creep compliance of Polyethylene t (hours) J(t) (psi-1) 0 0
Elastic and Viscoelastic Properties of Non-bulk Polymer Interphases in Nanotube-reinforced Polymers
Fisher, Frank
Elastic and Viscoelastic Properties of Non-bulk Polymer Interphases in Nanotube-reinforced Polymers polymer composite materials with outstanding mechanical, electrical, and thermal properties. A hurdle to nanoscale interactions between the embedded NTs and adjacent polymer chains. This interphase region
J. Non-Newtonian Fluid Mech. 130 (2005) 96109 Forward roll coating flows of viscoelastic liquids
Natelson, Douglas
2005-01-01T23:59:59.000Z
J. Non-Newtonian Fluid Mech. 130 (2005) 96109 Forward roll coating flows of viscoelastic liquids G, USA Received 10 September 2004; received in revised form 23 July 2005 Abstract Roll coating to a substrate. Except at low speed, the two-dimensional film splitting flow that occurs in forward roll coating
Rothstein, Jonathan
the many existing web coating and printing techniques for large-scale fabrication such as slit, roll, dip]. The primary advantage of roll-to-roll processing that is large areas of coated/printed films can be processed March 2012 Keywords: Viscoelasticity Gravure printing Pickout process Extensional rheology Coating a b
Normal Stresses and Interface Displacement: Influence of Viscoelasticity on Enhanced Oil
Paris-Sud XI, Université de
Normal Stresses and Interface Displacement: Influence of Viscoelasticity on Enhanced Oil Recovery assistée -- Une des méthodes de récupération assistée du pétrole (EOR - Enhanced Oil Recovery) consiste à Recovery Efficiency -- One of chemical Enhanced Oil Recovery (EOR) methods consists in injecting aqueous
Forest, M. Gregory
viscoelastic layer to an oscillating boundary, greater than the gap-loading limit of typical shear rheometers oscillatory shear driving con- ditions on the mucus layer. Very little evidence is available on the details extend our previous studies [35] of viscoelas- tic layers under oscillatory driving conditions
A Viscoelastic Deadly Fluid in Carnivorous Pitcher Plants Laurence Gaume1
Paris-Sud XI, Université de
A Viscoelastic Deadly Fluid in Carnivorous Pitcher Plants Laurence Gaume1 *, Yoel Forterre2 * 1^teau-Gombert, Marseille, France Background. The carnivorous plants of the genus Nepenthes, widely distributed in the Asian of Nepenthes pitchers as simple passive traps and is of great adaptive significance for these tropical plants
Boubekeur, Tamy
for high resolution voxel grids. Our system exploits cages for high-level deformation control. We tackle embedding the voxel model. This cage acts as the unique deformation control interface and is cla the interactive session, resulting in a high resolution voxel grid containing the deformed model. We tested our
Deformation Expression for Elements of Algebra
H. Omori; Y. Maeda; N. Miyazaki; A. Yoshioka
2011-04-09T23:59:59.000Z
The purpose of this paper is to give a notion of deformation of expressions for elements of algebra. Deformation quantization (cf.[BF]) deforms the commutative world to a non-commutative world. However, this involves deformation of expression of elements of algebras even from a commutative world to another commutative world. This is indeed a deformation of expressions for elements of algebra.
DR. BRIDGET R. SMITH-KONTER Department of Geological Sciences, University of Texas at El Paso
Smith-Konter, Bridget
Solar System Development of 3D visualization techniques for investigating crustal deformation Development and application of tidally-driven 3-D viscoelastic stress accumulation model for icy fractures evolution of the San Andreas fault Development of 3-D elastic and viscoelastic crustal deformation model
Habit tic deformity secondary to guitar playing
Wu, Jashin J
2009-01-01T23:59:59.000Z
KA. Treatment of habit- tic deformity with fluoxetine. ArchHabit tic deformity secondary to guitar playing Jashin J Wuchanges similar to the habit tic deformity may be produced
Morita Equivalence in Deformation Quantization Henrique Bursztyn
Bursztyn, Henrique
Morita Equivalence in Deformation Quantization by Henrique Bursztyn Engineer (Universidade Federal at Berkeley Spring 2001 #12;Morita Equivalence in Deformation Quantization Copyright 2001 by Henrique Bursztyn #12;1 Abstract Morita Equivalence in Deformation Quantization by Henrique Bursztyn Doctor
Khan, Saad A.
Viscoelastic Behavior of Cellulose Acetate in a Mixed Solvent System Collins Appaw, Richard D composition on the rheological and microstructural behavior of a ternary cellulose acetate (CA visualization of the gel microstructure through confocal microscopy. Introduction Cellulose and its derivatives
The effect of confinement on the deformation of microfluidic drops
Ulloa, Camilo; Cordero, María Luisa
2013-01-01T23:59:59.000Z
We study the deformation of drops squeezed between the floor and ceiling of a microchannel and subjected to a hyperbolic flow. We observe that the maximum deformation of drops depends on both the drop size and the rate of strain of the external flow and can be described with power laws with exponents 2.59 +/- 0.28 and 0.94 +/- 0.04 respectively. We develop a theoretical model to describe the deformation of squeezed drops based on the Darcy approximation for shallow geometries and the use of complex potentials. The model describes the steady-state deformation of the drops as a function of a non-dimensional parameter Ca d^2, where Ca is the capillary number (proportional to the strain rate and the drop size) and d is a confinement parameter equal to the drop size divided by the channel height. For small deformations, the theoretical model predicts a linear relationship between the deformation of drops and this parameter, in good agreement with the experimental observations.
Xue, W X; Hagino, K; Li, Z P; Mei, H; Tanimura, Y
2014-01-01T23:59:59.000Z
The impurity effect of hyperon on atomic nuclei has received a renewed interest in nuclear physics since the first experimental observation of appreciable reduction of $E2$ transition strength in low-lying states of hypernucleus $^{7}_\\Lambda$Li. Many more data on low-lying states of $\\Lambda$ hypernuclei will be measured soon for $sd$-shell nuclei, providing good opportunities to study the $\\Lambda$ impurity effect on nuclear low-energy excitations. We carry out a quantitative analysis of $\\Lambda$ hyperon impurity effect on the low-lying states of $sd$-shell nuclei at the beyond-mean-field level based on a relativistic point-coupling energy density functional (EDF), considering that the $\\Lambda$ hyperon is injected into the lowest positive-parity ($\\Lambda_s$) and negative-parity ($\\Lambda_p$) states. We adopt a triaxially deformed relativistic mean-field (RMF) approach for hypernuclei and calculate the $\\Lambda$ binding energies of hypernuclei as well as the potential energy surfaces (PESs) in $(\\beta, \\g...
Gupta, Anupam
2015-01-01T23:59:59.000Z
The effects of viscoelasticity on the dynamics and break-up of fluid threads in microfluidic T-junctions are investigated using numerical simulations of dilute polymer solutions at changing the Capillary number ($\\mbox {Ca}$), i.e. at changing the balance between the viscous forces and the surface tension at the interface, up to $\\mbox{Ca} \\approx 3 \\times 10^{-2}$. A Navier-Stokes (NS) description of the solvent based on the lattice Boltzmann models (LBM) is here coupled to constitutive equations for finite extensible non-linear elastic dumbbells with the closure proposed by Peterlin (FENE-P model). We present the results of three-dimensional simulations in a range of $\\mbox{Ca}$ which is broad enough to characterize all the three characteristic mechanisms of breakup in the confined T-junction, i.e. ${\\it squeezing}$, ${\\it dripping}$ and ${\\it jetting}$ regimes. The various model parameters of the FENE-P constitutive equations, including the polymer relaxation time $\\tau_P$ and the finite extensibility para...
Variable focal length deformable mirror
Headley, Daniel (Albuquerque, NM); Ramsey, Marc (Albuquerque, NM); Schwarz, Jens (Albuquerque, NM)
2007-06-12T23:59:59.000Z
A variable focal length deformable mirror has an inner ring and an outer ring that simply support and push axially on opposite sides of a mirror plate. The resulting variable clamping force deforms the mirror plate to provide a parabolic mirror shape. The rings are parallel planar sections of a single paraboloid and can provide an on-axis focus, if the rings are circular, or an off-axis focus, if the rings are elliptical. The focal length of the deformable mirror can be varied by changing the variable clamping force. The deformable mirror can generally be used in any application requiring the focusing or defocusing of light, including with both coherent and incoherent light sources.
Fabian Erdel; Michael Baum; Karsten Rippe
2014-09-23T23:59:59.000Z
The eukaryotic cell nucleus harbors the DNA genome that is organized in a dynamic chromatin network and embedded in a viscous crowded fluid. This environment directly affects enzymatic reactions and target search processes that access the DNA sequence information. However, its physical properties as a reaction medium are poorly understood. Here, we exploit mobility measurements of differently sized inert green fluorescent tracer proteins to characterize the viscoelastic properties of the nuclear interior of a living human cell. We find that it resembles a viscous fluid on small and large scales, but appears viscoelastic on intermediate scales that change with protein size. Our results are consistent with simulations of diffusion through polymers and suggest that chromatin forms a random obstacle network rather than a self-similar structure with fixed fractal dimension. By calculating how long molecules remember their previous position in dependence on their size, we evaluate how the nuclear environment affects search processes of chromatin targets.
Plasticity and deformation of crystals: Analogies to turbulence
Choi, Woosong; Papanikolaou, Stefanos; Sethna, James P
2011-01-01T23:59:59.000Z
We describe intriguing analogies between our model of material deformation (how crystals deform under load) and fluid turbulence (how liquids flow under shear). Our model present mathematical, physical, and computational challenges, but offer intriguing new predictions of fractal, scale-invariant structure formation for experiments. We show here that these challenges are shared with classic models of turbulence. In particular, we find precisely analogous physical and mathematical challenges associated with the formation of singularities in the evolving flows, and associated computational challenges with even defining a solution in the continuum limit where the grid size and the viscosities go to zero.
The Effect Of Viscoelastic Surfactants Used In Carbonate Matrix Acidizing On Wettability
Adejare, Oladapo
2012-07-16T23:59:59.000Z
fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee, Hisham A. Nasr-El-Din Committee Members, A. Daniel Hill Mahmoud El-Halwagi Head of Department, Stephen A... of Advisory Committee: Dr. Hisham Nasr-El-Din Carbonate reservoirs are heterogeneous; therefore, proper acid placement/diversion is required to make matrix acid treatments effective. Viscoelastic surfactants (VES) are used as diverting agents in carbonate...
S-matrix for strings on $\\eta$-deformed AdS5 x S5
Arutyunov, Gleb; Frolov, Sergey
2014-01-01T23:59:59.000Z
We determine the bosonic part of the superstring sigma model Lagrangian on $\\eta$-deformed AdS5 x S5, and use it to compute the perturbative world-sheet scattering matrix of bosonic particles of the model. We then compare it with the large string tension limit of the q-deformed S-matrix and find exact agreement.
S-matrix for strings on $?$-deformed AdS5 x S5
Gleb Arutyunov; Riccardo Borsato; Sergey Frolov
2014-04-07T23:59:59.000Z
We determine the bosonic part of the superstring sigma model Lagrangian on $\\eta$-deformed AdS5 x S5, and use it to compute the perturbative world-sheet scattering matrix of bosonic particles of the model. We then compare it with the large string tension limit of the q-deformed S-matrix and find exact agreement.
Numerical simulation of tsunami waves generated by deformable submarine landslides
Kirby, James T.
Numerical simulation of tsunami waves generated by deformable submarine landslides Gangfeng Ma a wave model Tsunami wave Numerical modeling a b s t r a c t This paper presents a new submarine of landslide motion and associated tsunami wave generation on parameters including sediment settling velocity
Viscoelastic-stiffness tensor of anisotropic media from oscillatory ...
Juan E. Santos
2010-12-27T23:59:59.000Z
Nov 19, 2010 ... Many geological systems can be modeled as effective trans- versely isotropic and ...... data for characterization purposes. References.
Soft-sediment and hard-rock deformation in the Chinle Formation, Northeastern Arizona
Scheevel, Jay Roger
1983-01-01T23:59:59.000Z
as to deformation-type are: (1) chevron-folds (1 to 300 m wavelengths), (2) decollement or truncated surfaces, (3) plunging folds, (4) slickensided shear- surfaces in claystones. Microscopic observation of the deformed sandstones reveals that the order.... Microscopic Study. Model Study. 1 1 2 3 10 10 11 11 13 13 14 16 17 17 17 18 FIELD OBSERVATIONS 19 Introduction Soft-sediment Deformation St. Johns, Arizona General description Folds and Decollement Soft-sediment Small-faults Subsidiary...
Srivastava, Vikas
2010-01-01T23:59:59.000Z
Amorphous polymers are important engineering materials; however, their nonlinear, strongly temperature- and rate-dependent elastic-viscoplastic behavior is still not very well understood, and is modeled by existing ...
Realistic Haptic Rendering of Interacting Deformable Objects in Virtual Environments
Duriez, Christian; Kheddar, Abderrahmane; Andriot, Claude
2008-01-01T23:59:59.000Z
A new computer haptics algorithm to be used in general interactive manipulations of deformable virtual objects is presented. In multimodal interactive simulations, haptic feedback computation often comes from contact forces. Subsequently, the fidelity of haptic rendering depends significantly on contact space modeling. Contact and friction laws between deformable models are often simplified in up to date methods. They do not allow a "realistic" rendering of the subtleties of contact space physical phenomena (such as slip and stick effects due to friction or mechanical coupling between contacts). In this paper, we use Signorini's contact law and Coulomb's friction law as a computer haptics basis. Real-time performance is made possible thanks to a linearization of the behavior in the contact space, formulated as the so-called Delassus operator, and iteratively solved by a Gauss-Seidel type algorithm. Dynamic deformation uses corotational global formulation to obtain the Delassus operator in which the mass and s...
Argatov, I; Mishuris, G; Ronken, S; Wirz, D
2012-01-01T23:59:59.000Z
In recent years, dynamic indentation tests have been shown to be useful both in identification of mechanical properties of biological tissues (such as articular cartilage) and assessing their viability. We consider frictionless flat-ended and spherical sinusoidally-driven indentation tests utilizing displacement-controlled loading protocol. Articular cartilage tissue is modeled as a viscoelastic material with a time-independent Poisson's ratio. We study the dynamic indentation stiffness with the aim of formulating criteria for evaluation the quality of articular cartilage in order to be able to discriminate its degenerative state. In particular, evaluating the dynamic indentation stiffness at the turning point of the flat-ended indentation test, we introduce the so-called incomplete storage modulus. Considering the time difference between the time moments when the dynamic stiffness vanishes (contact force reaches its maximum) and the dynamic stiffness becomes infinite (indenter displacement reaches its maximu...
Fluid-driven deformation of a soft granular material
Christopher W. MacMinn; Eric R. Dufresne; John S. Wettlaufer
2015-02-24T23:59:59.000Z
Compressing a porous, fluid-filled material will drive the interstitial fluid out of the pore space, as when squeezing water out of a kitchen sponge. Inversely, injecting fluid into a porous material can deform the solid structure, as when fracturing a shale for natural gas recovery. These poromechanical interactions play an important role in geological and biological systems across a wide range of scales, from the propagation of magma through the Earth's mantle to the transport of fluid through living cells and tissues. The theory of poroelasticity has been largely successful in modeling poromechanical behavior in relatively simple systems, but this continuum theory is fundamentally limited by our understanding of the pore-scale interactions between the fluid and the solid, and these problems are notoriously difficult to study in a laboratory setting. Here, we present a high-resolution measurement of injection-driven poromechanical deformation in a system with granular microsctructure: We inject fluid into a dense, confined monolayer of soft particles and use particle tracking to reveal the dynamics of the multi-scale deformation field. We find that a continuum model based on poroelasticity theory captures certain macroscopic features of the deformation, but the particle-scale deformation field exhibits dramatic departures from smooth, continuum behavior. We observe particle-scale rearrangement and hysteresis, as well as petal-like mesoscale structures that are connected to material failure through spiral shear banding.
Derivation of the action and symmetries of the q-deformed AdS_5 x S^5 superstring
Francois Delduc; Marc Magro; Benoit Vicedo
2014-09-01T23:59:59.000Z
We recently proposed an integrable q-deformation of the AdS_5 x S^5 superstring action. Here we give details on the hamiltonian origin and construction of this deformation. The procedure is a generalization of the one previously developed for deforming principal chiral and symmetric space sigma-models. We also show that the original psu(2,2|4) symmetry is replaced in the deformed theory by a classical analog of the quantum group U_q(psu(2,2|4)) with q real. The relation between q and the deformation parameter entering the action is given. The framework used to derive the deformation also enables to prove that at the hamiltonian level, the "maximal deformation" limit corresponds to an undeformed semi-symmetric space sigma-model with bosonic part dS_5 x H^5. Finally, we discuss the various freedoms in the construction.
Modeling and Algorithmic Approaches to Constitutively-Complex, Micro-structured Fluids
Forest, Mark Gregory [University of North Carolina at Chapel Hill] [University of North Carolina at Chapel Hill
2014-05-06T23:59:59.000Z
The team for this Project made significant progress on modeling and algorithmic approaches to hydrodynamics of fluids with complex microstructure. Our advances are broken down into modeling and algorithmic approaches. In experiments a driven magnetic bead in a complex fluid accelerates out of the Stokes regime and settles into another apparent linear response regime. The modeling explains the take-off as a deformation of entanglements, and the longtime behavior is a nonlinear, far-from-equilibrium property. Furthermore, the model has predictive value, as we can tune microstructural properties relative to the magnetic force applied to the bead to exhibit all possible behaviors. Wave-theoretic probes of complex fluids have been extended in two significant directions, to small volumes and the nonlinear regime. Heterogeneous stress and strain features that lie beyond experimental capability were studied. It was shown that nonlinear penetration of boundary stress in confined viscoelastic fluids is not monotone, indicating the possibility of interlacing layers of linear and nonlinear behavior, and thus layers of variable viscosity. Models, algorithms, and codes were developed and simulations performed leading to phase diagrams of nanorod dispersion hydrodynamics in parallel shear cells and confined cavities representative of film and membrane processing conditions. Hydrodynamic codes for polymeric fluids are extended to include coupling between microscopic and macroscopic models, and to the strongly nonlinear regime.
Low fault friction in Iran implies localized deformation for the ArabiaEurasia collision zone
Vernant, Philippe
Low fault friction in Iran implies localized deformation for the ArabiaEurasia collision zone P velocity field of the present-day deformation in Iran is modeled using a 3-dimensional (3D) finite element of the kinematics in Iran, but the complex velocity field of the surrounding South Caspian basin cannot be fitted
Mohammadyari, P [Nuclear Engineering Department, School of Mechanical Engineering, Shiraz Un, Ilam (Iran, Islamic Republic of); Faghihi, R [Nuclear Engineering Department, Shiraz University, Shiraz (Iran, Islamic Republic of); Shirazi, M Mosleh [Radiotherapy and Oncology Department, Namazi Hospital, Shiraz University of M, Shiraz (Iran, Islamic Republic of); Lotfi, M [Shiraz University of Medical Sciences, Medical Imaging Research Center, Shiraz (Iran, Islamic Republic of); Meigooni, A [Comprehensive cancer center of Nevada - University of Nevada Las Vegas UNL, Las Vegas, NV (United States)
2014-06-01T23:59:59.000Z
Purpose: the accuboost is the most modern method of breast brachytherapy that is a boost method in compressed tissue by a mammography unit. the dose distribution in uncompressed tissue, as compressed tissue is important that should be characterized. Methods: In this study, the mechanical behavior of breast in mammography loading, the displacement of breast tissue and the dose distribution in compressed and uncompressed tissue, are investigated. Dosimetry was performed by two dosimeter methods of Monte Carlo simulations using MCNP5 code and thermoluminescence dosimeters. For Monte Carlo simulations, the dose values in cubical lattice were calculated using tally F6. The displacement of the breast elements was simulated by Finite element model and calculated using ABAQUS software, from which the 3D dose distribution in uncompressed tissue was determined. The geometry of the model is constructed from MR images of 6 volunteers. Experimental dosimetery was performed by placing the thermoluminescence dosimeters into the polyvinyl alcohol breast equivalent phantom and on the proximal edge of compression plates to the chest. Results: The results indicate that using the cone applicators would deliver more than 95% of dose to the depth of 5 to 17mm, while round applicator will increase the skin dose. Nodal displacement, in presence of gravity and 60N forces, i.e. in mammography compression, was determined with 43% contraction in the loading direction and 37% expansion in orthogonal orientation. Finally, in comparison of the acquired from thermoluminescence dosimeters with MCNP5, they are consistent with each other in breast phantom and in chest's skin with average different percentage of 13.7±5.7 and 7.7±2.3, respectively. Conclusion: The major advantage of this kind of dosimetry is the ability of 3D dose calculation by FE Modeling. Finally, polyvinyl alcohol is a reliable material as a breast tissue equivalent dosimetric phantom that provides the ability of TLD dosimetry for validation.
The viscoelastic properties of linear-star blends
Lee, Jung Hun
2000-01-01T23:59:59.000Z
are more strongly affected by the constraint release, due to the different relaxation times of each chain, than by reptation or arm retraction. Material properties of this model linear-star blend deviate from the well-known scaling, []CR ~ M...
Effect of Hydrolysis on the Properties of a New Viscoelastic Surfactant-Based Acid
He, Zhenhua
2013-08-07T23:59:59.000Z
for the degree of MASTER OF SCIENCE Chair of Committee, Hisham A. Nasr-El-Din Committee Members, Jerome J. Schubert Mahmoud El-Halwagi Head of Department, A. Daniel Hill August 2013 Major Subject: Petroleum Engineering Copyright 2013... of this chapter are reprinted with permission from ?Hydrolysis Effect on the Properties of a New Class of Viscoelastic Surfactant-Based Acid and Damage Caused by the Hydrolysis Products? by Zhenhua He, Guanqun Wang, Hisham A. Nasr-El-Din, and Stuart Holt, 2013...
Vane shear determination of the visco-elastic shear modulus of submarine sediments
Stevenson, Herbert Scott
1973-01-01T23:59:59.000Z
viscoelastic theory and torque versus rotation data from vane shear tests. The modu- lus, G(t), is described by the power law: G(t) = G, t where t is time, and G, and n are constants. G, and n are deter- mined from vane tests on deep sediment core samples.... G, is rota- tion angle dependent. The validity of the procedure is supported by predict1ons of in situ vane test torque versus rotation curves wh1ch agree favorably with data obtained using an in s1tu vane device. G, correlates with maximum vane...
Accounting for inertia effects to access the high-frequency microrheology of viscoelastic fluids
P. Domínguez-García; Frédéric Cardinaux; Elena Bertseva; László Forró; Frank Scheffold; Sylvia Jeney
2014-12-03T23:59:59.000Z
We study the Brownian motion of microbeads immersed in water and in a viscoelastic wormlike micelles solution by optical trapping interferometry and diffusing wave spectroscopy. Through the mean-square displacement obtained from both techniques, we deduce the mechanical properties of the fluids at high frequencies by explicitly accounting for inertia effects of the particle and the surrounding fluid at short time scales. For wormlike micelle solutions, we recover the 3/4 scaling exponent for the loss modulus over two decades in frequency as predicted by the theory for semiflexible polymers.
Performance-Guided Character Bind Pose for Deformations
Pena, Benito
2011-08-08T23:59:59.000Z
Current production methods for creating a motion system for a deformable digital character model involve providing an underlying joint structure based o of a T-Pose, A-Pose or another arbitrary bind pose of the character. A bind pose is required...
DIFFUSION IN DEFORMING POROUS MEDIA R.E. SHOWALTER
of the deforming matrix and the pressure gradient of the diffusing pore fluid. In the classical consolidation process, a load is initially shared with the pore fluid, and with time the pore fluid pressure dissipates and application of mathematical models for the flow of fluids driven by the cou- pled pressure and stress
Degree-1 Earth deformation from very long baseline interferometry measurements
Faulds, James E.
of the center of mass of the Earth system through satellite orbit models and the former purely on observing earth and the center of mass of the entire Earth system (Earth, oceans and atmosphere). The load momentDegree-1 Earth deformation from very long baseline interferometry measurements D. Lavalle´e and G
Quantum mechanical effects from deformation theory
Much, A. [Max-Planck-Institute for Mathematics in the Sciences, 04103 Leipzig, Germany and Institute for Theoretical Physics, University of Leipzig, 04009 Leipzig (Germany)] [Max-Planck-Institute for Mathematics in the Sciences, 04103 Leipzig, Germany and Institute for Theoretical Physics, University of Leipzig, 04009 Leipzig (Germany)
2014-02-15T23:59:59.000Z
We consider deformations of quantum mechanical operators by using the novel construction tool of warped convolutions. The deformation enables us to obtain several quantum mechanical effects where electromagnetic and gravitomagnetic fields play a role. Furthermore, a quantum plane can be defined by using the deformation techniques. This in turn gives an experimentally verifiable effect.
Four-dimensional deformed special relativity from group field theories
Girelli, Florian [SISSA, Via Beirut 2-4, 34014 Trieste, Italy and INFN, Sezione di Trieste (Italy); School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia); Livine, Etera R. [Laboratoire de Physique, ENS Lyon, CNRS UMR 5672, 46 Allee d'Italie, 69007 Lyon (France); Oriti, Daniele [Perimeter Institute for Theoretical Physics, 31 Caroline St, Waterloo, Ontario N2L 2Y5 (Canada); Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, Utrecht 3584 TD (Netherlands); Albert Einstein Institute, Am Muehlenberg 4, Golm (Germany)
2010-01-15T23:59:59.000Z
We derive a scalar field theory of the deformed special relativity type, living on noncommutative {kappa}-Minkowski space-time and with a {kappa}-deformed Poincare symmetry, from the SO(4,1) group field theory defining the transition amplitudes for topological BF theory in 4 space-time dimensions. This is done at a nonperturbative level of the spin foam formalism working directly with the group field theory (GFT). We show that matter fields emerge from the fundamental model as perturbations around a specific phase of the GFT, corresponding to a solution of the fundamental equations of motion, and that the noncommutative field theory governs their effective dynamics.
A non-linear elastic constitutive framework for replicating plastic deformation in solids.
Roberts, Scott Alan; Schunk, Peter Randall
2014-02-01T23:59:59.000Z
Ductile metals and other materials typically deform plastically under large applied loads; a behavior most often modeled using plastic deformation constitutive models. However, it is possible to capture some of the key behaviors of plastic deformation using only the framework for nonlinear elastic mechanics. In this paper, we develop a phenomenological, hysteretic, nonlinear elastic constitutive model that captures many of the features expected of a plastic deformation model. This model is based on calculating a secant modulus directly from a material's stress-strain curve. Scalar stress and strain values are obtained in three dimensions by using the von Mises invariants. Hysteresis is incorporated by tracking an additional history variable and assuming an elastic unloading response. This model is demonstrated in both single- and multi-element simulations under varying strain conditions.
Viscoelastic modes in a strongly coupled cold magnetized dusty plasma
Banerjee, Debabrata; Chakrabarti, Nikhil
2013-01-01T23:59:59.000Z
A generalized hydrodynamical model has been used to study low frequency modes in a strongly coupled, cold, magnetized dusty plasma. Such plasmas exhibit elastic properties due to strong correlations among dust particles and the tensile stresses imparted by the magnetic field. It has been shown that longitudinal compressional Alfven modes and elasticity modified transverse shear mode exist in such a medium. The features of these collective modes are established and discussed.
Viscoelastic modes in a strongly coupled, cold, magnetized dusty plasma
Banerjee, Debabrata; Mylavarapu, Janaki Sita; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, I/AF Bidhannagar, Calcutta 700 064 (India)
2010-11-15T23:59:59.000Z
A generalized hydrodynamical model has been used to study the low frequency modes in a strongly coupled, cold, magnetized dusty plasma. Such plasmas exhibit elastic properties due to the strong correlations among dust particles and the tensile stresses imparted by the magnetic field. It has been shown that longitudinal compressional Alfven modes and elasticity modified transverse shear mode exist in such a medium. The features of these collective modes are established and discussed.
Deformation mechanisms of experimentally deformed Salina Basin bedded salt
Hansen, F.D.
1985-01-01T23:59:59.000Z
Petrofabrics of deformed salt from the Cleveland area within the Salina Basin are presented. Quasi-static compression at room temperature and 1 MPa confining pressure is dominated by fracture. Incipient failure is evidenced by wide zones of coalesced fractures at an axial strain of 5%. Strain hardening, evidenced by photoelastic effects, abounds under these conditions. At 5 MPa far fewer fractures are found at axial strains of 13%. Photoelastic effects are appreciably diminished at 5 MPa, which must mean more homogeneous ductile flow ensues, perhaps owing to activation of many dislocation mills. Clearly, the brittle-to-ductile transition requires additional petrographic work for documentation. Because the dominant mechanism is very pressure sensitive at relative low mean stresses, it appears necessary to include confining pressure in the deformation mechanism map. Creep at 15 MPa and temperatures >100/sup 0/C is dominated by thermally activated diffusion. Fracture and photoelastic effects are almost totally suppressed relative to quasi-static experiments at lower confining pressure and temperature. The mechanism of climb into stable polygons is fully documented by etch pit studies in samples that are deformed well into steady state. Creep properties of Cleveland and Avery Island salt are very similar under conditions of elevated temperature and intermediate stresses. As temperature is reduced the predicted flow stress of Cleveland becomes greater than that of Avery Island. However, extrapolation of either flow law to low temperature is not justified because the governing mechanisms change from climb to fracture and glide.
Noncommutative supergeometry, duality and deformations
Albert Schwarz
2002-10-28T23:59:59.000Z
We introduce a notion of $Q$-algebra that can be considered as a generalization of the notion of $Q$-manifold (a supermanifold equipped with an odd vector field obeying $\\{Q,Q\\} =0$). We develop the theory of connections on modules over $Q$-algebras and prove a general duality theorem for gauge theories on such modules. This theorem containing as a simplest case $SO(d,d,{\\bf Z})$-duality of gauge theories on noncommutative tori can be applied also in more complicated situations. We show that $Q$-algebras appear naturally in Fedosov construction of formal deformation of commutative algebras of functions and that similar $Q$-algebras can be constructed also in the case when the deformation parameter is not formal.
$?$-Deformed Statistics and Classical Fourmomentum Addition Law
M. Daszkiewicz; J. Lukierski; M. Woronowicz
2008-02-05T23:59:59.000Z
We consider $\\kappa$-deformed relativistic symmetries described algebraically by modified Majid-Ruegg bicrossproduct basis and investigate the quantization of field oscillators for the $\\kappa$-deformed free scalar fields on $\\kappa$-Minkowski space. By modification of standard multiplication rule, we postulate the $\\kappa$-deformed algebra of bosonic creation and annihilation operators. Our algebra permits to define the n-particle states with classical addition law for the fourmomenta in a way which is not in contradiction with the nonsymmetric quantum fourmomentum coproduct. We introduce $\\kappa$-deformed Fock space generated by our $\\kappa$-deformed oscillators which satisfy the standard algebraic relations with modified $\\kappa$-multiplication rule. We show that such a $\\kappa$-deformed bosonic Fock space is endowed with the conventional bosonic symmetry properties. Finally we discuss the role of $\\kappa$-deformed algebra of oscillators in field-theoretic noncommutative framework.
Peltier, W. Richard
of the Earth W. R. Peltier,1 I. Shennan,2 R. Drummond1 and B. Horton2 1 Department of Physics, University viscoelastic theory of the glacial isostatic adjustment (GIA) process, most recently reviewed in Peltier (1998a on the inverse problem for mantle viscosity (see the papers by Peltier 1998b and Wieczerkowski et al. 1999
Deymier, Pierre
Elastic and viscoelastic effects in rubber/air acoustic band gap structures: A theoretical rubber/air phononic crystal structures is investigated theoretically and experimentally. We introduce in a solid rubber matrix, as well as an array of rubber cylinders in an air matrix, are shown to behave
The effects of lithology and initial fault angle in physical models of fault-propagation folds
McLain, Christopher Thomas
2001-01-01T23:59:59.000Z
with a weak brittle layer that deforms by faulting and fracturing (dried pottery clay simulates an interbedded siliciclastic unit). The models were deformed in a triaxial deformation rig at confining pressure of 50 Mpa at room temperature. Each model...
An Integrable Deformation of the AdS5 x S5 Superstring
Timothy J. Hollowood; J. Luis Miramontes; David M. Schmidtt
2014-09-24T23:59:59.000Z
The S-matrix on the world-sheet theory of the string in AdS5 x S5 has previously been shown to admit a deformation where the symmetry algebra is replaced by the associated quantum group. The case where q is real has been identified as a particular deformation of the Green-Schwarz sigma model. An interpretation of the case with q a root of unity has, until now, been lacking. We show that the Green-Schwarz sigma model admits a discrete deformation which can be viewed as a rather simple deformation of the F/F_V gauged WZW model, where F=PSU(2,2|4). The deformation parameter q is then a k-th root of unity where k is the level. The deformed theory has the same equations-of-motion as the Green-Schwarz sigma model but has a different symplectic structure. We show that the resulting theory is integrable and has just the right amount of kappa-symmetries that appear as a remnant of the fermionic part of the original gauge symmetry. This points to the existence of a fully consistent deformed string background.
An Integrable Deformation of the AdS5 x S5 Superstring
Hollowood, Timothy J; Schmidtt, David
2014-01-01T23:59:59.000Z
The S-matrix on the world-sheet theory of the string in AdS5 x S5 has previously been shown to admit a deformation where the symmetry algebra is replaced by the associated quantum group. The case where q is real has been identified as a particular deformation of the Green-Schwarz sigma model. An interpretation of the case with q a root of unity has, until now, been lacking. We show that the Green-Schwarz sigma model admits a discrete deformation which can be viewed as a rather simple deformation of the F/F gauged WZW model, where F=PSU(2,2|4). The deformation parameter q is then a k-th root of unity where k is the level. The deformed theory has the same equations-of-motion as the Green-Schwarz sigma model but has a different symplectic structure. We show that the resulting theory is integrable and has just the right amount of kappa-symmetries that appear as a remnant of the fermionic part of the original gauge symmetry. This points to the existence of a fully consistent deformed string background.
Physical and Statistical Models in Deformation Geodesy
Lipovsky, Brad
2011-01-01T23:59:59.000Z
dvpb dvnw dvne dvlw dvls dvle dssc dsme dshs dhlg desc dam3dvpb dvnw dvne dvlw dvls dvle dssc dsme dshs dhlg desc dam3dvpb dvnw dvne dvlw dvls dvle dssc dsme dshs dhlg desc dam3
The Role of Climate in the Deformation of a Fold and Thrust Belt
Steen, Sean Kristian
2012-02-14T23:59:59.000Z
precipitation from a global climate model (GCM) as a proxy for rate of erosion. Deformation measurements were made on a portfolio of regional cross sections from Alabama to New England. During the Carboniferous Allegheny orogeny the Southern Appalachians moved...
Integrable $?$-deformations: Squashing Coset CFTs and $AdS_5\\times S^5$
Saskia Demulder; Konstantinos Sfetsos; Daniel C. Thompson
2015-04-10T23:59:59.000Z
We examine integrable $\\lambda$-deformations of $SO(n+1)/SO(n)$ coset CFTs and their analytic continuations. We provide an interpretation of the deformation as a squashing of the corresponding coset $\\sigma$-model's target space. We realise the $\\lambda$-deformation for $n=5$ case as a solution to supergravity supported by non-vanishing five-form and dilaton. This interpolates between the coset CFT $SO(4,2)/SO(4,1)\\times SO(6)/SO(5)$ constructed as a gauged WZW model and the non-Abelian T-dual of the $AdS_5\\times S^5$ spacetime.
Quantum limits to estimation of photon deformation
Giovanni De Cillis; Matteo G. A. Paris
2014-07-08T23:59:59.000Z
We address potential deviations of radiation field from the bosonic behaviour and employ local quantum estimation theory to evaluate the ultimate bounds to precision in the estimation of these deviations using quantum-limited measurements on optical signals. We consider different classes of boson deformation and found that intensity measurement on coherent or thermal states would be suitable for their detection making, at least in principle, tests of boson deformation feasible with current quantum optical technology. On the other hand, we found that the quantum signal-to-noise ratio (QSNR) is vanishing with the deformation itself for all the considered classes of deformations and probe signals, thus making any estimation procedure of photon deformation inherently inefficient. A partial way out is provided by the polynomial dependence of the QSNR on the average number of photon, which suggests that, in principle, it would be possible to detect deformation by intensity measurements on high-energy thermal states.
Jones, Ryan Edward, 1974-
2004-01-01T23:59:59.000Z
Understanding how fluids respond to various deformations is of great importance to a spectrum of disciplines ranging from bio-medical research on joint replacements to sealing technology in industrial machinery. Specifically, ...
Jeon, Jaehyeuk
2013-08-09T23:59:59.000Z
of thermal stresses, due to the mismatches in the coefficient of thermal expansions of the fibers and polymeric matrix, and stress concentrations/discontinuities near the fiber and matrix interfaces on the overall thermo-mechanical deformation of FRP...
Deformation-Twin-Induced Grain Boundary Failure
Yongfeng Zhang; Paul C. MIllett; Michael Tonks; Bulent Biner
2012-01-01T23:59:59.000Z
This work presents a mechanism of deformation-twin-induced grain boundary failure, and demonstrates the mechanism using molecular dynamics simulations. Deformation twinning is observed as the dominant mechanism during tensile deformation of columnar nanocrystalline body-centered cubic Mo. As a twin approaches a grain boundary, local stress concentration develops due to the incompatible plastic deformations in the two neighboring grains. The magnitude of the stress concentration increases as the twin widens, leading to grain boundary cracking by nucleation and coalescence of microcracks/voids.
Improving Preclinical Testing of Deformity Correction Surgery
Borkowski, Sean Leo
2015-01-01T23:59:59.000Z
permit subsequent testing. ” In other words, non-destructivenon-destructive and do not cause plastic deformation of the intervening tissues or spine structure, thus allowing repeated testing,
Deformed Geometric Algebra and Supersymmetric Quantum Mechanics
Peter Henselder
2006-09-09T23:59:59.000Z
Deforming the algebraic structure of geometric algebra on the phase space with a Moyal product leads naturally to supersymmetric quantum mechanics in the star product formalism.
Houston, Jack E.; Grest, Gary Stephen; Moore, Nathan W.; Feibelman, Peter J.
2010-09-01T23:59:59.000Z
This report summarizes the work completed under the Laboratory Directed Research and Development (LDRD) project 10-0973 of the same title. Understanding the molecular origin of the no-slip boundary condition remains vitally important for understanding molecular transport in biological, environmental and energy-related processes, with broad technological implications. Moreover, the viscoelastic properties of fluids in nanoconfinement or near surfaces are not well-understood. We have critically reviewed progress in this area, evaluated key experimental and theoretical methods, and made unique and important discoveries addressing these and related scientific questions. Thematically, the discoveries include insight into the orientation of water molecules on metal surfaces, the premelting of ice, the nucleation of water and alcohol vapors between surface asperities and the lubricity of these molecules when confined inside nanopores, the influence of water nucleation on adhesion to salts and silicates, and the growth and superplasticity of NaCl nanowires.
Jordan Hristov
2011-07-26T23:59:59.000Z
Integral balance solution employing entire domain approximation and the penetration dept concept to the Stokes' first problem of a viscoelastic generalized second grade fluid has been developed. The solution has been performed by a parabolic profile with an unspecified exponent allowing optimization through minimization of the norm over the domain of the penetration depth. The closed form solution explicitly defines two dimensionless similarity variables and, responsible for the viscous and the elastic responses of the fluid to the step jump at the boundary. The solution was developed with three forms of the governing equation through its two dimensional forms (the main solution and example 1) and the dimensionless version showing various sides of the flow field and how the dimensionless groups control it: mainly the effect of the Deborah number. Numerical simulations demonstrating the effect of the various operating parameter and fluid properties on the developed flow filed have been performed.
Kelemen, Peter
2012-08-24T23:59:59.000Z
Topics covered include: Failure At High Confining Pressure; Fluid-assisted Slip, Earthquakes & Fracture; Reaction-driven Cracking; Fluid Transport, Deformation And Reaction; Localized Fluid Transport And Deformation; Earthquake Mechanisms; Subduction Zone Dynamics And Crustal Growth.
FEM Analysis ofFEM Analysis of Deformation and Fracture ofDeformation and Fracture of
Grujicic, Mica
-Temperature Ductility ·Low Ambient-Temperature Fracture Toughness (KICFEM Analysis ofFEM Analysis of Deformation and Fracture ofDeformation and Fracture of Deformation and Fracture in Polycrystalline -TiAl + 2-Ti3Al Single Crystals #12;Use of -TiAl + 2-Ti3Al Alloys
Nuclear dynamical deformation induced hetero- and euchromatin positioning
Akinori Awazu
2015-06-12T23:59:59.000Z
The contributions of active deformation dynamics in cell nuclei to the intra-nuclear positioning of hetero- and euchromatin are investigated. We analyzed the behaviors of model chains containing two types of regions, one with high and the other with low mobility, confined in a pulsating container. Here, the regions with high and low mobility represent eu- and heterochromatic regions, respectively, and the pulsating container simulates a nucleus exhibiting dynamic deformations. The Brownian dynamics simulations of this model show that the positioning of low mobility regions transition from sites near the periphery to the central region of the container if the affinity between low mobility regions and the container periphery disappears. Here, the former and latter positioning are similar to the "conventional" and "inverted" chromatin positioning observed in nuclei of normal differentiated cells and cells lacking Lamin-related proteins like mouse rod photoreceptor cell.
Intrinsic excitations in deformed nuclei: characteristic predictions of the IBA
Casten, R.F.
1982-01-01T23:59:59.000Z
Deformed nuclei represent perhaps the largest and best studied class of nuclear level schemes. The Interacting Boson Approximation (IBA) model is devised so as to provide a general framework for the description of low lying collective states in nuclei spanning vibrational, rotational (i.e., deformed) and axially asymmetric types as well as the transitional species intermediate between these limiting cases. The juxtaposition of these two statements makes it all the more surprising that until recently there had been no thorough test of the model in such nuclei. Partly, the explanation for this lies in the type of data required for an adequate test. Since the IBA predicts a broad range of collective states it requires a correspondingly thorough empirical test. Moreover, in deformed nuclei, though the characteristic predictions that distinguish the IBA from the traditional, familiar collective model of harmonic ..beta.. and ..gamma.. vibrations are important, their clearest manifestation occurs in very weak, hard-to-detect low energy transitions between excited vibrational bands (in particular between ..beta.. and ..gamma.. bands), that had not heretofore been systematically observed. The present brief summary will begin with a review of the properties of the (n,..gamma..) reaction that render it a useful empirical tool for such studies, and follow this with a description of the results of the /sup 168/Er study and the application of the IBA model to the resultant level scheme. The discussion will then be generalized to other deformed nuclei and to the inherent systematic predictions that must characterize the IBA for such nuclei. Many of these ideas will be related to the role of finite boson number in the IBA.
Golden-Thompson's inequality for deformed exponentials
Frank Hansen
2014-10-21T23:59:59.000Z
Deformed logarithms and their inverse functions, the deformed exponentials, are important tools in the theory of non-additive entropies and non-extensive statistical mechanics. We formulate and prove counterparts of Golden-Thompson's trace inequality for q-exponentials with parameter q in the interval [1,3].
Damage and plastic deformation of reservoir rocks
Ze'ev, Reches
Damage and plastic deformation of reservoir rocks: Part 1. Damage fracturing Seth Busetti, Kyran mechanics, fluid flow in fractured reservoirs, and geomechanics in nonconventional reservoirs. Kyran Mish finite deformation of reservoir rocks. We present an at- tempt to eliminate the main limitations
Nikoleris, Teo
1988-01-01T23:59:59.000Z
NUMERICAL SIMULATION OF THE NON-ISOTHERMAL DEVELOPING FLOXV OF A NONLINEAR VISCOELASTIC FLUID IN A RECTANGULAR CHANNEL A Thesis by TEO NIKOLERIS Submitted to the Graduate College of Texas A&M University in partial fulfillment... developing flow of a nonlinear viscoelas- tic fluid. The temperature dependence of the rheological parameters was imposed using an Arrhenius-like exponential relationship. The flow was creeping, at the early stages of thermal development and wall cooling...
To mechanics of deformation, flow, and fracture
S. L. Arsenjev
2008-09-23T23:59:59.000Z
It is stated in the main in essence new approach to mechanics of the stressed state of the solid body from statistically isotropic material and the homogeneous liquid dynamics. The approach essence is in the detected property of the core-shell spontaneous structurization of internal energy of the solid and liquid bodies in its natural state and under action of external forces. The method elements of construction of physically adequate model of the stressed state of the solid and liquid bodies, reproduced exactly its behavior on the stages of elastic and plastic deformation, flow and fracture, are stated. It is adduced a number of the examples of the stressed state construction of the simple form bodies under action of its tension, compression, torsion and at its contact interaction. For the first time it is adduced structure of the principal - normal - stresses in cylindrical bar under action of the torsion moment. The detected property and the developed method is one of necessary bases for construction of physically adequate mathematical model of the stressed state of the body and fluid in contrast to traditional approach.
First Generation Advanced High-Strength Steels Deformation Fundamental...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Generation Advanced High-Strength Steels Deformation Fundamentals First Generation Advanced High-Strength Steels Deformation Fundamentals 2012 DOE Hydrogen and Fuel Cells Program...
A Discrete Complex Compliance Spectra Model of the Nonlinear Viscoelastic Creep and Recovery
Kumar, Vipin
, easily fit functions of stress. The new method is applied to a set of microcellular polycarbonate polycarbonate material system are very sensitive to relative density and therefore, this material system. Such foams have been created in polycarbonate using carbon dioxide as the gas for bubble nucleation.2
Karra, Satish
2009-05-15T23:59:59.000Z
of secondary electric field on electrospinning process and whipping instability. It is observed that the external secondary field unwinds the jet spirals, reduces the whipping instability and increases the tension in the fiber. Lattice Boltzmann method (LBM...
A non-local, ordinary-state-based viscoelasticity model for peridynamics.
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23TribalInformation Access toTen ProblemsU.S. DepartmentprotoclusterConnect A newA new(Technical
A non-local, ordinary-state-based viscoelasticity model for peridynamics.
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23TribalInformation Access toTen ProblemsU.S. DepartmentprotoclusterConnect A newA
Report on the IUTAM symposium on viscoelastic fluid mechanics: effects of molecular modeling
Shaqfeh, Eric
. These include a variety of optical polarimetry methods, scattering techniques (light and neutron primarily
Optical Deformations in Solar Glass Filters for High Precision Astrometry
Sigismondi, Costantino; Boscardin, Sérgio Calderari; Penna, Jucira Lousada; Reis-Neto, Eugênio
2015-01-01T23:59:59.000Z
Measuring the solar diameter at all position angles gives the complete figure of the Sun. Their asphericities have implications in classical physics and general relativity, and the behavior of the optical systems used in the direct measurements is to be known accurately. A solar filter is a plane-parallel glass with given absorption, and here we study the departures from the parallelism of the faces of a crystal slab 5 mm thick, because of static deformations. These deformations are rescaled to the filter's dimensions. Related to the Solar Disk Sextant experiment and to the Reflecting Heliometer of Rio de Janeiro a simplified model of the influences of the inclination between the external and the internal surfaces of a glass solar filter, is discussed.
Forced transport of deformable containers through narrow constrictions
Remy Kusters; Thijs van der Heijden; Badr Kaoui; Jens Harting; Cornelis Storm
2014-11-19T23:59:59.000Z
We study, numerically and analytically, the forced transport of deformable containers through a narrow constriction. Our central aim is to quantify the competition between the constriction geometry and the active forcing, regulating whether and at which speed a container may pass through the constriction and under what conditions it gets stuck. We focus, in particular, on the interrelation between the force that propels the container and the radius of the channel, as these are the external variables that may be directly controlled in both artificial and physiological settings. We present Lattice-Boltzmann simulations that elucidate in detail the various phases of translocation, and present simplified analytical models that treat two limiting types of these membrane containers: deformational energy dominated by the bending or stretching contribution. In either case we find excellent agreement with the full simulations, and our results reveal that not only the radius but also the length of the constriction determines whether or not the container will pass.
Deformable elastic network refinement for low-resolution macromolecular crystallography
Schröder, Gunnar F., E-mail: gu.schroeder@fz-juelich.de [Forschungszentrum Jülich, 52425 Jülich (Germany); Heinrich-Heine University Düsseldorf, 20225 Düsseldorf (Germany); Levitt, Michael [Stanford University School of Medicine, Stanford, CA 94305 (United States); Brunger, Axel T., E-mail: gu.schroeder@fz-juelich.de [Stanford University School of Medicine, J. H. Clark Center, 318 Campus Drive, Stanford, CA 94305 (United States); Forschungszentrum Jülich, 52425 Jülich (Germany)
2014-09-01T23:59:59.000Z
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.
Biaxial Deformations of Rubber: Entanglements or Elastic Fluctuations?
Xiangjun Xing
2010-11-01T23:59:59.000Z
The classical theory of rubber elasticity fails in the regime of large deformation. The un- derlying physical mechanism has been under debate for long time. In this work, we test the recently proposed mechanism of thermal elastic fluctuations by Xing, Goldbart and Radzi- hovsky1 against the biaxial stress-strain data of three distinct polymer networks with very different network structures, synthesized by Urayama2 and Kawabata3 respectively. We find that both the two parameters version and the one-parameter version of the XGR theory provide satisfactory description of the elasticity in whole deformation range. For comparison, we also fit the same sets of data using the slip-link model by Edwards and Vilgis with four parameters. The fitting qualities of two theories are found to be comparable.
Supersymmetric Deformations of Maximally Supersymmetric Gauge Theories
M. Movshev; A. Schwarz
2012-06-19T23:59:59.000Z
We study supersymmetric and super Poincar\\'e invariant deformations of ten-dimensional super Yang-Mills theory and of its dimensional reductions. We describe all infinitesimal super Poincar\\'e invariant deformations of equations of motion of ten-dimensional super Yang-Mills theory and its reduction to a point; we discuss the extension of them to formal deformations. Our methods are based on homological algebra, in particular, on the theory of L-infinity and A-infinity algebras. The exposition of this theory as well as of some basic facts about Lie algebra homology and Hochschild homology is given in appendices.
Deformation of Silica Aerogel During Fluid Adsorption
Tobias Herman; James Day; John Beamish
2005-06-30T23:59:59.000Z
Aerogels are very compliant materials - even small stresses can lead to large deformations. In this paper we present measurements of the linear deformation of high porosity aerogels during adsorption of low surface tension fluids, performed using a Linear Variable Differential Transformer (LVDT). We show that the degree of deformation of the aerogel during capillary condensation scales with the surface tension, and extract the bulk modulus of the gel from the data. Furthermore we suggest limits on safe temperatures for filling and emptying low density aerogels with helium.
Lee, M H [Ames Laboratory; Park, E S [Samsung Electronics Co., LTD; Ott, R T [Ames Laboratory; Kim, B S [Korea Institute of Industrial Technology; Eckert, J [Institute for Complex Materials
2014-08-11T23:59:59.000Z
We evaluated the role of effective strain on the plasticity of metallic glasses related to springback phenomena in both ductile Zr-based metallic glass and brittle Hf-based metallic glass. Experimental investigations of the deformation behavior and the intrinsic mechanical properties of metallic glass were performed by room temperature L-bending deformation. The modeling analysis clearly shows that an inhomogeneous effective strain for initiating shear band is generated during deformation, with the brittleness of a metallic glass being dependent on the effective strain reaching the critical fracture strain of the glass. The combined experimental and modeling results reveal broad and general criteria that should allow for deformability of a wide-variety of glass-forming alloys by adjusting the effective strain during deformation.
A Quantum Affine Algebra for the Deformed Hubbard Chain
Niklas Beisert; Wellington Galleas; Takuya Matsumoto
2012-08-12T23:59:59.000Z
The integrable structure of the one-dimensional Hubbard model is based on Shastry's R-matrix and the Yangian of a centrally extended sl(2|2) superalgebra. Alcaraz and Bariev have shown that the model admits an integrable deformation whose R-matrix has recently been found. This R-matrix is of trigonometric type and here we derive its underlying exceptional quantum affine algebra. We also show how the algebra reduces to the above mentioned Yangian and to the conventional quantum affine sl(2|2) algebra in two special limits.
A Quantum Affine Algebra for the Deformed Hubbard Chain
Beisert, Niklas; Matsumoto, Takuya
2011-01-01T23:59:59.000Z
The integrable structure of the one-dimensional Hubbard model is based on Shastry's R-matrix and the Yangian of a centrally extended sl(2|2) superalgebra. Alcaraz and Bariev have shown that the model admits an integrable deformation whose R-matrix has recently been found. This R-matrix is of trigonometric type and here we derive its underlying exceptional quantum affine algebra. We also show how the algebra reduces to the above mentioned Yangian and to the conventional quantum affine sl(2|2) algebra in two special limits.
Normal Ordering for Deformed Boson Operators and Operator-valued Deformed Stirling Numbers
Jacob Katriel; Maurice Kibler
2000-01-02T23:59:59.000Z
The normal ordering formulae for powers of the boson number operator $\\hat{n}$ are extended to deformed bosons. It is found that for the `M-type' deformed bosons, which satisfy $a a^{\\dagger} - q a^{\\dagger} a = 1$, the extension involves a set of deformed Stirling numbers which replace the Stirling numbers occurring in the conventional case. On the other hand, the deformed Stirling numbers which have to be introduced in the case of the `P-type' deformed bosons, which satisfy $a a^{\\dagger} - q a^{\\dagger} a = q^{-\\hat{n}}$, are found to depend on the operator $\\hat{n}$. This distinction between the two types of deformed bosons is in harmony with earlier observations made in the context of a study of the extended Campbell-Baker-Hausdorff formula.
Orienting Deformable Polygonal Parts without Sensors
Kristek, Shawn
2012-02-14T23:59:59.000Z
with low-precision robot manipulators and six parts made of four types of materials. The experimental trials resulted in 154 successes, which show the feasibility of deformable parts orienting. The analysis of the failures showed that for success...
MEMS deformable mirror CubeSat testbed
Marinan, Anne D.
To meet the high contrast requirement of 1 × 10[superscript ?10] to image an Earth-like planet around a Sun-like star, space telescopes equipped with coronagraphs require wavefront control systems. Deformable mirrors are ...
On q-deformed Stirling numbers
Yilmaz Simsek
2007-11-03T23:59:59.000Z
The purpose of this article is to introduce q-deformed Stirling numbers of the first and second kinds. Relations between these numbers, Riemann zeta function and q-Bernoulli numbers of higher order are given. Some relations related to the classical Stirling numbers and Bernoulli numbers of higher order are found. By using derivative operator to the generating function of the q-deformed Stirling numbers of the second kinds, a new function is defined which interpolates the q-deformed Stirling numbers of the second kinds at negative integers. The recurrence relations of the Stirling numbers of the first and second kind are given. In addition, relation between q-deformed Stirling numbers and q-Bell numbers is obtained.
Mechanics of deformation of carbon nanotubes
Garg, Mohit, S.M. Massachusetts Institute of Technology
2005-01-01T23:59:59.000Z
The deformation mechanics of multi-walled carbon nanotubes (MWCNT) and vertically aligned carbon nanotube (VACNT) arrays were studied using analytical and numerical methods. An equivalent orthotropic representation (EOR) ...
Experimental deformation of natural and synthetic dolomite
Davis, Nathan Ernest
2005-11-01T23:59:59.000Z
-grained dolomite deformed at low temperature (T ? 700??C for coarse-grained natural dolomite, T < 700??C for fine-grained natural and synthetic dolomite) exhibit mechanical behavior that is nearly plastic; differential stresses are insensitive to strain rate...
Simulation of Coating -Visco-Elastic liquid in the Mico-Nip of Metering Size Press
El-Sadi, Haifa
2008-01-01T23:59:59.000Z
For a set of operating conditions and coating color formulations, undesirable phenomena like color spitting and coating ribs may be triggered in the Micro-nip during the coating process. Therefore, our interest in this work focus on another parameter affect on the undesirable phenomena as the vortices in the Micro-nip. The problem deals with the flow through the Micro-nip of metering size press. The flow enters and exits at a tangential velocity of 20 m/s between two rollers with diameter 80 cm and 60 -m apart. In the upper and bottom part of the domain the angular velocity is 314 rad /s. It has one sub-domain. Previous studies focus on the Micro-nip without considering the inertia and the viscoelasticity of the material. Roll coating is a technique commonly used in the coating industry to meter a thin fluid film on a moving substrate. During the film formation, the fluid is subjected to very high shear and extensional rates over a very short period of time. The fluid domain changes as a function of the hydro...
Toshimasa Takanohashi; Takahiro Shishido; Ikuo Saito; Kensuke Masaki; Atsushi Dobashi; Kiyoshi Fukada [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan)
2006-12-15T23:59:59.000Z
To maximize the conversion of low-quality coal into good coke, we investigated the thermoplasticity of various binary blends of caking coals with slightly or noncaking coals using a dynamic viscoelastic technique with a temperature-variable rheometer. Coal blend samples were prepared by mixing two coals (1:1 by weight), which were heated from room temperature to 600 C at a rate of 3-80{sup o}C/min. At the slow rate of 3{sup o}C/min, the blends had a tan {delta} that was generally lower than the calculated value, showing that a negative interaction caused a loss of thermoplasticity. In contrast, at the rapid heating rate of 80{sup o}C/min, the tan {delta} of some blends was higher than the calculated value, indicating a positive interaction that enhanced the thermoplasticity. With rapid heating, the thermoplasticity of each coal itself increased, and their thermoplastic temperature ranges widened with rapid heating. Therefore, rapid heating was effective at converting these coal blends into good cokes. Moreover, even with slow heating, when a combination of coals (Gregory:Enshu, 1:1) showing some thermoplasticity in nearly the same temperature range was blended, a desirable synergistic effect of the blend was obtained. This suggests that blending coal with an overlapping thermoplastic temperature range is important for the synergistic effect, regardless of the heating rate. 15 refs., 9 figs., 2 tabs.
A fluid pressure and deformation analysis for geological sequestration of carbon dioxide
Xu, Zhijie; Fang, Yilin; Scheibe, Timothy D.; Bonneville, Alain
2012-06-07T23:59:59.000Z
We present a hydro-mechanical model and deformation analysis for geological sequestration of carbon dioxide. The model considers the poroelastic effects by taking into account the two-way coupling between the geomechanical response and the fluid flow process in greater detail. In order for analytical solutions, the simplified hydro-mechanical model includes the geomechanical part that relies on the theory of linear elasticity, while the fluid flow is based on the Darcy’s law. The model was derived through coupling the two parts using the standard linear poroelasticity theory. Analytical solutions for fluid pressure field were obtained for a typical geological sequestration scenario and the solutions for ground deformation were obtained using the method of Green’s function. Solutions predict the temporal and spatial variation of fluid pressure, the effect of permeability and elastic modulus on the fluid pressure, the ground surface uplift, and the radial deformation during the entire injection period.
Noncommutative scalar fields from symplectic deformation
Daoud, M. [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Hamama, A. [High Energy Laboratory, Faculty of Sciences, University Mohamed V, P.O. Box 1014, Rabat (Morocco)
2008-02-15T23:59:59.000Z
This paper is concerned with the quantum theory of noncommutative scalar fields in two dimensional space-time. It is shown that the noncommutativity originates from the the deformation of symplectic structures. The quantization is performed and the modes expansions of the fields, in the presence of an electromagnetic background, are derived. The Hamiltonian of the theory is given and the degeneracies lifting, induced by the deformation, is also discussed.
Large Deformation of Nitinol Under Shear Dominant Loading
Daly, Samantha
Large Deformation of Nitinol Under Shear Dominant Loading S. Daly & D. Rittel & K. Bhattacharya & G in Nitinol under large shear- dominated deformation are presented. To achieve a shear- dominated deformation transformation that is seen in uniaxial testing. The shear-dominant deformation of Nitinol in the plastic regime
Influence of plastic deformation on bimaterial fault rupture directivity
Dmowska, Renata
Influence of plastic deformation on bimaterial fault rupture directivity Nora DeDontney,1 Elizabeth of the role of the stress state on the distribution of plastic deformation and the direction of preferred in determining the location of plastic deformation. For different orientations, plastic deformation can
Nuclear ground-state masses and deformations: FRDM(2012)
Moller, P; Ichikawa, T; Sagawa, H
2015-01-01T23:59:59.000Z
We tabulate the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground-state microscopic corrections, and nuclear ground-state deformations of 9318 nuclei ranging from $^{16}$O to $A=339$. The calculations are based on the finite-range droplet macroscopic model and the folded-Yukawa single-particle microscopic model. Relative to our FRDM(1992) mass table in {\\sc Atomic Data and Nuclear Data Tables} [{\\bf 59} 185 (1995)], the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allows us to determine one additional macroscopic-model parameter, the density-symmetry coefficient $L$, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some high...
Dogan, Ebubekir
2014-12-12T23:59:59.000Z
deformation, for ultrahigh strength, ductility, and formability. Using a microstructure based visco-plastic self-consistent crystal plasticity model with detailed electron backscatter diffraction analyses and transmission electron microscopy, new equal...
Automated Brain Shift Correction Using A Pre-computed Deformation Atlas
Frey, Pascal
Automated Brain Shift Correction Using A Pre-computed Deformation Atlas Prashanth Dumpuria Dr. Reid, USA ABSTRACT Compensating for intraoperative brain shift using computational models has shown preoperatively and are combined with the help of a statistical model to predict the intraoperative brain shift
Lentz, Martin [Technische Universität Berlin, Institute of Material Science and Technologies - Metallic Materials; Clausen, Bjorn [Los Alamos National Laboratory; Reimers, Walter [Technische Universität Berlin, Institute of Material Science and Technologies - Metallic Materials
2012-08-06T23:59:59.000Z
EPSC-Model is able to predict the complex deformation behavior of Mg-RE and Mg-Li alloys within a wide range of strains. Modification of the texture by RE-elements and the addition of Li increases the activity of slip systems at low strains - Reorientation due to twinning is stretch over a larger range of plastic deformation. Deformation at high strains is realized mainly by the basal and the
Density fluctuations in $?$-deformed inflationary universe
Hyeong-Chan Kim; Jae Hyung Yee; Chaiho Rim
2005-10-27T23:59:59.000Z
We study the spectrum of metric fluctuation in $\\kappa$-deformed inflationary universe. We write the theory of scalar metric fluctuations in the $\\kappa-$deformed Robertson-Walker space, which is represented as a non-local theory in the conventional Robertson-Walker space. One important consequence of the deformation is that the mode generation time is naturally determined by the structure of the $\\kappa-$deformation. We expand the non-local action in $H^2/\\kappa^2$, with $H$ being the Hubble parameter and $\\kappa$ the deformation parameter, and then compute the power spectra of scalar metric fluctuations both for the cases of exponential and power law inflations up to the first order in $H^2/\\kappa^2$. We show that the power spectra of the metric fluctuation have non-trivial corrections on the time dependence and on the momentum dependence compared to the commutative space results. Especially for the power law inflation case, the power spectrum for UV modes is weakly blue shifted early in the inflation and its strength decreases in time. The power spectrum of far-IR modes has cutoff proportional to $k^3$ which may explain the low CMB quadrupole moment.
Limits of isotropic plastic deformation of Bangkok clay
P. Evesque
2005-07-08T23:59:59.000Z
A model assuming incremental plastic isotropic response has been recently proposed to model the deformation of isotropic packing of grains, in the small-strain range. It is used here on over-consolidated remould clay, to interpret the small-strain range behaviour obtained in [1,2] on Bangkok clay. The data published in [1,2] at constant volume are also used here to measure the size of the domain of validity in the (q/(M'p), p/po) plane, where po is the over-consolidation isotropic pressure, p is the mean stress and q the deviatoric stress, q . So, it is shown that the model works also for clay. This enlarges the application domain of model [3,4] to soft clay with OCR larger than 1.2 to 1.5. Pacs # : 45.70.-n ; 62.20.Fe ; 83.80.Fg, 83.80.Hj
Material models of dark energy
Jonathan A. Pearson
2014-09-16T23:59:59.000Z
We review and develop a new class of "dark energy" models, in which the relativistic theory of solids is used to construct material models of dark energy. These are models which include the effects of a continuous medium with well defined physical properties at the level of linearized perturbations. The formalism is constructed for a medium with arbitrary symmetry, and then specialised to isotropic media (which will be the case of interest for the majority of cosmological applications). We develop the theory of relativistic isotropic viscoelastic media whilst keeping in mind that we ultimately want to observationally constrain the allowed properties of the material model. We do this by obtaining the viscoelastic equations of state for perturbations (the entropy and anisotropic stress), as well as identifying the consistent corner of the theory which has constant equation of state parameter $\\dot{w}=0$. We also connect to the non-relativistic theory of solids, by identifying the two quadratic invariants that are needed to construct the energy-momentum tensor, namely the Rayleigh dissipation function and Lagrangian for perturbations. Finally, we develop the notion that the viscoelastic behavior of the medium can be thought of as a non-minimally coupled massive gravity theory. This also provides a tool-kit for constructing consistent generalizations of coupled dark energy theories.
Deformation quantization of the Pais-Uhlenbeck fourth order oscillator
Jasel Berra-Montiel; Alberto Molgado; Efraín Rojas
2015-05-12T23:59:59.000Z
We analyze the quantization of the Pais-Uhlenbeck fourth order oscillator within the framework of deformation quantization. Our approach exploit the Noether symmetries of the system by proposing integrals of motion as the variables to obtain a solution to the -genvalue equation, namely the Wigner function. We also obtain, by means of a quantum canonical transformation the wave function associated to the Schr\\"odinger equation of the system. We show that unitary evolution of the system is guaranteed by means of the quantum canonical transformation and via the properties of the constructed Wigner function, even in the so called equal frequency limit of the model, in agreement with recent results.
Dangerous Liouville Wave -- exactly marginal but non-conformal deformation
Chiu Man Ho; Yu Nakayama
2008-07-26T23:59:59.000Z
We give a non-trivially interacting field theory example of scale invariant but non-conformal field theory. The model is based on the exactly solvable Liouville field theory coupled with free scalars deformed by an exactly marginal operator. We show non-vanishing of the trace of the energy-momentum tensor by using the quantum Schwinger-Dyson equation for the Liouville field theory, which is a sophistication of the quantum higher equations of motion for the Liouville field theory introduced by Alyosha Zamolodchikov. Possibly dangerous implications for the super-critical string theory will be discussed.
Temperature and angular momentum dependence of the quadrupole deformation in sd-shell
P. A. Ganai; J. A. Sheikh; I. Maqbool; R. P. Singh
2009-06-16T23:59:59.000Z
Temperature and angular momentum dependence of the quadrupole deformation is studied in the middle of the sd-shell for 28Si and 27Si isotopes using the spherical shell model approach. The shell model calculations have been performed using the standard USD interaction and the canonical partition function constructed from the calculated eigen-solutions. It is shown that the extracted average quadrupole moments show a transitional behavior as a function of temperature and the inferred transitional temperature is shown to vary with angular-momentum. The quadrupole deformation of the individual eigen-states is also analyzed.
Semi-microscopic description of the double backbending in some deformed even-even rare earth nuclei
R. Budaca; A. A. Raduta
2013-01-25T23:59:59.000Z
A semi-microscopic model to study the neutron and proton induced backbending phenomena in some deformed even-even nuclei from the rare earth region, is proposed. The space of particle-core states is defined by the angular momentum projection of a quadrupole deformed product state. The backbending phenomena are described by mixing four rotational bands, defined by a set of angular momentum projected states, and a model Hamiltonian describing a set of paired particles moving in a deformed mean field and interacting with a phenomenological deformed core. The ground band corresponds to the configuration where all particles are paired while the other rotational bands are built on one neutron or/and one proton broken pair. Four rare earth even-even nuclei which present the second anomaly in the observed moments of inertia are successfully treated within the proposed model.
Tidal deformations of a spinning compact object
Pani, Paolo; Maselli, Andrea; Ferrari, Valeria
2015-01-01T23:59:59.000Z
The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole mom...
Structure of collective modes in transitional and deformed nuclei
M. A. Caprio
2005-03-21T23:59:59.000Z
The collective structure of atomic nuclei intermediate between spherical and quadrupole deformed structure presents challenges to theoretical understanding. However, models have recently been proposed in terms of potentials which are soft with respect to the quadrupole deformation variable beta. To test these models, information is needed on low-spin states of transitional nuclei. The present work involves measurement of electromagnetic decay properties of low-spin states for nuclei in the A=100 (gamma-soft) and N=90 (axially symmetric) transition regions. Population in beta-decay and thermal neutron capture are used, and measurements are carried out using gamma-ray coincidence spectroscopy, fast electronic scintillation timing, and gamma-ray induced Doppler broadening techniques, in experiments at Yale, TRIUMF ISAC, and the ILL. To facilitate interpretation of these nuclei, a new approach is developed that simplifies the application of the geometric collective model by use of scaling properties. Solutions are also obtained for the E(5) Hamiltonian for finite well depth.
CURRICULUM VITAE BRIDGET R. SMITH-KONTER
Smith-Konter, Bridget
tide gauge records · Refinement of 3D semi-analytic crustal deformation model of San Andreas Fault · Development, verification, & application of 3D elastic and viscoelastic body force model · Shuttle Radar tide gauge observations with 100-year vertical deformation models of California earthquake history; PI
Deformation of contour and Hawking temperature
Chikun Ding; Jiliang Jing
2010-01-19T23:59:59.000Z
It was found that, in an isotropic coordinate system, the tunneling approach brings a factor of 1/2 for the Hawking temperature of a Schwarzschild black hole. In this paper, we address this kind of problem by studying the relation between the Hawking temperature and the deformation of integral contour for the scalar and Dirac particles tunneling. We find that correct Hawking temperature can be obtained exactly as long as the integral contour deformed corresponding to the radial coordinate transform if the transformation is a non-regular or zero function at the event horizon.
A Noncommutative Deformation of Topological Field Theory
Hugo Garcia-Compean; Pablo Paniagua
2004-02-21T23:59:59.000Z
Cohomological Yang-Mills theory is formulated on a noncommutative differentiable four manifold through the $\\theta$-deformation of its corresponding BRST algebra. The resulting noncommutative field theory is a natural setting to define the $\\theta$-deformation of Donaldson invariants and they are interpreted as a mapping between the Chevalley-Eilenberg homology of noncommutative spacetime and the Chevalley-Eilenberg cohomology of noncommutative moduli of instantons. In the process we find that in the weak coupling limit the quantum theory is localized at the moduli space of noncommutative instantons.
Plastic Deformation of 2D Crumpled Wires
M A F Gomes; V P Brito; A S O Coelho; C C Donato
2008-11-17T23:59:59.000Z
When a single long piece of elastic wire is injected trough channels into a confining two-dimensional cavity, a complex structure of hierarchical loops is formed. In the limit of maximum packing density, these structures are described by several scaling laws. In this paper it is investigated this packing process but using plastic wires which give origin to completely irreversible structures of different morphology. In particular, it is studied experimentally the plastic deformation from circular to oblate configurations of crumpled wires, obtained by the application of an axial strain. Among other things, it is shown that in spite of plasticity, irreversibility, and very large deformations, scaling is still observed.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Nobre, G. P. A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palumbo, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Herman, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brown, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hoblit, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dietrich, F. S. [Walnut Creek, CA (United States)
2015-02-01T23:59:59.000Z
The coupled-channel theory is a natural way of treating nonelastic channels, in particular those arising from collective excitations characterized by nuclear deformations. A proper treatment of such excitations is often essential to the accurate description of experimental nuclear-reaction data and to the prediction of a wide variety of scattering observables. Stimulated by recent work substantiating the near validity of the adiabatic approximation in coupled-channel calculations for scattering on statically deformed nuclei, we explore the possibility of generalizing a global spherical optical model potential (OMP) to make it usable in coupled-channel calculations on this class of nuclei. To do this, we have deformed the Koning-Delaroche global spherical potential for neutrons, coupling a sufficient number of states of the ground state band to ensure convergence. We present an extensive study of the effects of collective couplings and nuclear deformations on integrated cross sections as well as on angular distributions for neutron-induced reactions on statically deformed nuclei in the rare-earth region. We choose isotopes of three rare-earth elements (Gd, Ho, W), which are known to be nearly perfect rotors, to exemplify the results of the proposed method. Predictions from our model for total, elastic and inelastic cross sections, as well as for elastic and inelastic angular distributions, are in reasonable agreement with measured experimental data. These results suggest that the deformed Koning-Delaroche potential provides a useful regional neutron optical potential for the statically deformed rare earth nuclei.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Nobre, G. P. A.; Palumbo, A.; Herman, M.; Brown, D.; Hoblit, S.; Dietrich, F. S.
2015-02-01T23:59:59.000Z
The coupled-channel theory is a natural way of treating nonelastic channels, in particular those arising from collective excitations characterized by nuclear deformations. A proper treatment of such excitations is often essential to the accurate description of experimental nuclear-reaction data and to the prediction of a wide variety of scattering observables. Stimulated by recent work substantiating the near validity of the adiabatic approximation in coupled-channel calculations for scattering on statically deformed nuclei, we explore the possibility of generalizing a global spherical optical model potential (OMP) to make it usable in coupled-channel calculations on this class of nuclei. To do this, wemore »have deformed the Koning-Delaroche global spherical potential for neutrons, coupling a sufficient number of states of the ground state band to ensure convergence. We present an extensive study of the effects of collective couplings and nuclear deformations on integrated cross sections as well as on angular distributions for neutron-induced reactions on statically deformed nuclei in the rare-earth region. We choose isotopes of three rare-earth elements (Gd, Ho, W), which are known to be nearly perfect rotors, to exemplify the results of the proposed method. Predictions from our model for total, elastic and inelastic cross sections, as well as for elastic and inelastic angular distributions, are in reasonable agreement with measured experimental data. These results suggest that the deformed Koning-Delaroche potential provides a useful regional neutron optical potential for the statically deformed rare earth nuclei.« less
G. P. A. Nobre; A. Palumbo; F. S. Dietrich; M. Herman; D. Brown; S. Hoblit
2014-12-22T23:59:59.000Z
The coupled-channel theory is a natural way of treating nonelastic channels, in particular those arising from collective excitations characterized by nuclear deformations. A proper treatment of such excitations is often essential to the accurate description of experimental nuclear-reaction data and to the prediction of a wide variety of scattering observables. Stimulated by recent work substantiating the near validity of the adiabatic approximation in coupled-channel calculations for scattering on statically deformed nuclei, we explore the possibility of generalizing a global spherical optical model potential (OMP) to make it usable in coupled-channel calculations on this class of nuclei. To do this, we have deformed the Koning-Delaroche global spherical potential for neutrons, coupling a sufficient number of states of the ground state band to ensure convergence. We present an extensive study of the effects of collective couplings and nuclear deformations on integrated cross sections as well as on angular distributions for neutron-induced reactions on statically deformed nuclei in the rare-earth region. We choose isotopes of three rare-earth elements (Gd, Ho, W), which are known to be nearly perfect rotors, to exemplify the results of the proposed method. Predictions from our model for total, elastic and inelastic cross sections, as well as for elastic and inelastic angular distributions, are in reasonable agreement with measured experimental data. These results suggest that the deformed Koning-Delaroche potential provides a useful regional neutron optical potential for the statically deformed rare earth nuclei.
Kinematic flow patterns in slow deformation of a dense granular material
Koushik Viswanathan; Anirban Mahato; Tejas G. Murthy; Tomasz Koziara; Srinivasan Chandrasekar
2015-07-19T23:59:59.000Z
The kinematic flow pattern in slow deformation of a model dense granular medium is studied at high resolution using \\emph{in situ} imaging, coupled with particle tracking. The deformation configuration is indentation by a flat punch under macroscopic plane-strain conditions. Using a general analysis method, velocity gradients and deformation fields are obtained from the disordered grain arrangement, enabling flow characteristics to be quantified. The key observations are the formation of a stagnation zone, as in dilute granular flow past obstacles; occurrence of vortices in the flow immediately underneath the punch; and formation of distinct shear bands adjoining the stagnation zone. The transient and steady state stagnation zone geometry, as well as the strength of the vortices and strain rates in the shear bands, are obtained from the experimental data. All of these results are well-reproduced in exact-scale Non-Smooth Contact Dynamics (NSCD) simulations. Full 3D numerical particle positions from the simulations allow extraction of flow features that are extremely difficult to obtain from experiments. Three examples of these, namely material free surface evolution, deformation of a grain column below the punch and resolution of velocities inside the primary shear band, are highlighted. The variety of flow features observed in this model problem also illustrates the difficulty involved in formulating a complete micromechanical analytical description of the deformation.
PLASTIC DEFORMATION OF CRYSTALS: ANALYTICAL AND COMPUTER SIMULATION STUDIES OF DISLOCATION GLIDE
Altintas, Sabri
2011-01-01T23:59:59.000Z
in Rate Processes in Plastic Deformation of Materials, J. C.PLASTIC DEFORMATION OF CRYSTALS: ANALYTICAL AND COMPUTERCAPTIONS FIGURES - iii - PLASTIC DEFORMATION OF CRYSTALS:
EFFECT OF GRAIN SIZE ON THE ACOUSTIC EMISSION GENERATED DURING PLASTIC DEFORMATION OF ALUMINUM
Baram, J.
2013-01-01T23:59:59.000Z
EMISSION GENERATED DURING PLASTIC DEFORMATION OF ALUMINUMEMISSION GENERATED DURING PLASTIC DEFORMATION OF ALUMINUM J.Al 1100 samples during plastic deformation were analyzed
Variation after full projection with triaxially deformed nuclear mean field
Gao, Zao-Chun; Chen, Y S
2015-01-01T23:59:59.000Z
We implemented a variation after projection (VAP) algorithm based on a triaxially deformed Hartree-Fock-Bogoliubov vacuum state. This is the first projected mean field study that includes all the quantum numbers (except parity), i.e., spin ($J$), isospin ($T$) and mass number ($A$). Systematic VAP calculations with $JTA$-projection have been performed for the even-even $sd$-shell nuclei with the USDB Hamiltonian. All the VAP ground state energies are within 500 keV above the exact shell model values. Our VAP calculations show that the spin projection has two important effects: (1) the spin projection is crucial in achieving good approximation of the full shell model calculation. (2) the intrinsic shapes of the VAP wavefunctions with spin projection are always triaxial, while the Hartree-Fock-Bogoliubov methods likely provide axial intrinsic shapes. Finally, our analysis suggests that one may not be possible to associate an intrinsic shape to an exact shell model wave function.
Variation after full projection with triaxially deformed nuclear mean field
Zao-Chun Gao; Mihai Horoi; Y. S. Chen
2015-09-10T23:59:59.000Z
We implemented a variation after projection (VAP) algorithm based on a triaxially deformed Hartree-Fock-Bogoliubov vacuum state. This is the first projected mean field study that includes all the quantum numbers (except parity), i.e., spin ($J$), isospin ($T$) and mass number ($A$). Systematic VAP calculations with $JTA$-projection have been performed for the even-even $sd$-shell nuclei with the USDB Hamiltonian. All the VAP ground state energies are within 500 keV above the exact shell model values. Our VAP calculations show that the spin projection has two important effects: (1) the spin projection is crucial in achieving good approximation of the full shell model calculation. (2) the intrinsic shapes of the VAP wavefunctions with spin projection are always triaxial, while the Hartree-Fock-Bogoliubov methods likely provide axial intrinsic shapes. Finally, our analysis suggests that one may not be possible to associate an intrinsic shape to an exact shell model wave function.
On a Model of Superconductivity and Biology
Monica De Angelis
2012-03-02T23:59:59.000Z
The paper deals with a semilinear integrodifferential equation that characterizes several dissipative models of Viscoelasticity, Biology and Superconductivity. The initial - boundary problem with Neumann conditions is analyzed. When the source term F is a linear function, then the explicit solution is obtained. When F is non linear, some results on existence, uniqueness and a priori estimates are deduced. As example of physical model the reaction - diffusion system of Fitzhugh Nagumo is considered.
Deformation and Forming of Joined Materials
Carsley, John; Hovanski, Yuri; Clarke, Kester D.; Krajewski, Paul E.
2014-09-23T23:59:59.000Z
Introductory article to a set of invited papers from the TMS committee on shaping and forming. This paper introduces a set of papers that were prepared to discussing the deformation and forming of joined materials, and to announce an upcoming symposium at the 2015 MS&T meeting in Columbus Ohio.
Tidal deformations of a spinning compact object
Paolo Pani; Leonardo Gualtieri; Andrea Maselli; Valeria Ferrari
2015-03-25T23:59:59.000Z
The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole moments of the central object, which are due to the difficulty in separating the tidal field from the linear response of the object in the solution. By extending the standard procedure to identify the linear response in the static case, we prove analytically that the Love numbers of a Kerr black hole remain zero to second order in the spin. As a by-product, we provide the explicit form for a slowly-rotating, tidally-deformed Kerr black hole to quadratic order in the spin, and discuss its geodesic and geometrical properties.
Joining of advanced materials by superplastic deformation
Goretta, Kenneth C. (Downers Grove, IL); Routbort, Jules L. (Hinsdale, IL); Gutierrez-Mora, Felipe (Woodridge, IL)
2008-08-19T23:59:59.000Z
A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.
Joining of advanced materials by superplastic deformation
Goretta, Kenneth C.; Routbort, Jules L.; Gutierrez-Mora, Felipe
2005-12-13T23:59:59.000Z
A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.
Deformable Transparent All-Carbon-Nanotube Transistors
Maruyama, Shigeo
and organic materials16,17 are candidates for next-generation flexible and transparent electronic devices-carbon-nanotube field-effect transistors (CNT- FETs), making use of the flexible yet robust nature of single than those used in other flexible CNT-FETs allowed our devices to be highly deformable without
On Lorentz Transformations in Symplectic Deformations
Cuesta, R.; Sabido, M. [Departamento de Fisica, DCI-Campus Leon, Universidad de Guanajuato, A.P. E-143, C.P. 37150, Guanajuato (Mexico); Guzman, W. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21945-970, Rio de Janeiro (Brazil)
2010-07-12T23:59:59.000Z
In this paper we study noncommutative Lorentz transformations using symplectic deformations. In this framework we define an infinitesimal line element that is invariant under this noncommutative Lorentz transformations. Using the symplectic geometry formalism, we find that noncommutative Lorentz transformations intertwine the canonical momentums with canonical position coordinates.
Tidal deformations of a spinning compact object
Paolo Pani; Leonardo Gualtieri; Andrea Maselli; Valeria Ferrari
2015-06-30T23:59:59.000Z
The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole moments of the central object, which are due to the difficulty in separating the tidal field from the linear response of the object in the solution. By extending the standard procedure to identify the linear response in the static case, we prove analytically that the Love numbers of a Kerr black hole remain zero to second order in the spin. As a by-product, we provide the explicit form for a slowly-rotating, tidally-deformed Kerr black hole to quadratic order in the spin, and discuss its geodesic and geometrical properties.
Steady state deformation of the Coso Range, east central California...
Coso Range using satellite radar interferometry show deformation rates of up to 35 mm yr -1 in an area approximately 10 km by 15 km. The deformation is most likely the result...
Effects of subsurface fracture interactions on surface deformation
Jerry, Ruel (Ruel Valentine)
2013-01-01T23:59:59.000Z
Although the surface deformation resulting from the opening of a single fracture in a layered elastic half-space resembles the observed deformation at the InSalah site, it seems unlikely that only a single fracture is ...
Effects of cryogenic equal channel angular deformation on copper 101
Horan, Christopher Sean
2001-01-01T23:59:59.000Z
101 was cold worked by being subjected to severe plastic deformation (SPD) at room temperature (23 °C) and at -196 °C under liquid nitrogen. Cold working was imparted by equal channel angular deformation (ECAD). Before extrusions were performed, a...
Severe plastic deformation of difficult-to-work alloys
Yapici, Guney Guven
2004-09-30T23:59:59.000Z
The present work aims to reveal the microstructural evolution and post-processing mechanical behavior of difficult-to-work alloys upon severe plastic deformation. Severe plastic deformation is applied using equal channel angular extrusion (ECAE...
Fortin, Jérôme
Acoustic Emissions Monitoring during Inelastic Deformation of Porous Sandstone: Comparison of Three, performed on Bleurswiller sandstone, which enable us to compare the acoustic emission signature during compaction bands formation and cataclastic compaction. Key words: Porous sandstone, acoustic
Atomic picture of elastic deformation in a metallic glass
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Wang, X. D.; Aryal, S.; Zhong, C.; Ching, W. Y.; Sheng, H. W.; Zhang, H.; Zhang, D. X.; Cao, Q. P.; Jiang, J. Z.
2015-03-17T23:59:59.000Z
The tensile behavior of a Ni??Nb?? metallic glass (MG) has been studied by using ab initio density functional theory (DFT) calculation with a large cell containing 1024 atoms (614 Ni and 410 Nb). We provide insight into how a super elastic limit can be achieved in a MG. Spatially inhomogeneous responses of single atoms and also major polyhedra are found to change greatly with increasing external stress when the strain is over 2%, causing the intrinsically viscoelastic behavior. We uncover the origin of the observed super elastic strain limit under tension (including linear and viscoelastic strains) in small-sized MG samples,more »mainly caused by inhomogeneous distribution of excess volumes in the form of newly formed subatomic cavities.« less
Global optimization-based deformable meshes for surface extraction from medical
Neumaier, Arnold
(GAGR). By global optimization of the energy of the de- formable models, we are capable of reducingGlobal optimization-based deformable meshes for surface extraction from medical images Jussi Tohka, Dual surface minimization (DSM) and a hybrid of real-coded genetic algorithms and a greedy algorithm
Feedback Control for Steering Needles Through 3D Deformable Tissue Using Helical Paths
O'Brien, James F.
Feedback Control for Steering Needles Through 3D Deformable Tissue Using Helical Paths Kris Hauser controller that steers a needle along 3D helical paths, and varies the helix radius to correct a model predictive control framework that chooses a needle twist rate such that the predicted helical
Reusable Skinning Templates Using Cage-based Deformations Qian-Yi Zhou2
Southern California, University of
Reusable Skinning Templates Using Cage-based Deformations Tao Ju1 Qian-Yi Zhou2 Michiel van de- lows skinning solutions to be shared and reused, and they allow a user to quickly explore many possible template. Skinning templates can be shared by users because they are not represented in a model
Permeability evolution during progressive development of deformation bands in porous sandstones
Permeability evolution during progressive development of deformation bands in porous sandstones B carried out on large (0.1 m) diameter cores of a porous sandstone in order to investigate the evolution from measured bulk parameters. In a test of the model for Clashach sandstone, the parameters vary
The Role of Climate in the Deformation of a Fold and Thrust Belt
Steen, Sean Kristian
2012-02-14T23:59:59.000Z
and uplifted in large folds. In order to test this and related ideas in a natural example, we have compared modeled rainfall to measured thrust sheet displacement, geometry, and internal deformation in the Appalachian fold and thrust belt. We use mean annual...
Analysis of the Energy Spectra of Ground States of Deformed Nuclei in rare-earth region
Abdurahim A. Okhunov; G. I. Turaeva; M. U. Khandaker; Noora B. Rosli
2014-05-28T23:59:59.000Z
The 62Sm, 64Gd, 64Dy, 70Y b, 72Hf and 74W nuclei are classified as deformed nuclei. Low-lying bands are one of the most fundamental excitation modes in the energy spectra of deformed nuclei. In this paper a theoretical analysis of the experimental data within the phenomenological model is presented. The energy spectra of ground states are calculated. It is found the low-lying spectra of ground band states are in good agreement with the experimental data.
Hiroyuki Yoshida; Shuhei Yabu; Hiroki Tone; Hirotsugu Kikuchi; Masanori Ozaki
2013-10-21T23:59:59.000Z
The electro-optic Kerr effect in cholesteric blue phase liquid crystals is known to occur on sub-millisecond time scales, which is much faster than director reorientation in nematic liquid crystals. Using two-beam interference microscopy, we report the presence of a very slow response in the Kerr effect, with a characteristic time of several seconds or more. Using a simplified model for the reorientation dynamics, we attribute the slow response to the coupling between the local director reorientation and field-induced deformation of the lattice. We provide evidence for our argument by showing that the slow response can be removed by inhibiting lattice deformation through polymer stabilization.
Koneru, Saradhi
2011-10-21T23:59:59.000Z
. . . . . . . . . . . . . . . . . . . . . . . . . . . 137 2. US 87 . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 3. US 259 . . . . . . . . . . . . . . . . . . . . . . . . . . 146 4. Observations from Field Compaction Simulations for US 87 and US 259 . . . . . . . . . . . . . . . . . . 149... : : : : : : : : : : : : : : : : : : : : : : : : 144 XIII Material properties used for the US 259 project : : : : : : : : : : : : 147 xi TABLE Page XIV Rolling pattern, % AV measured in the eld for US 259 project. Note: The total number of passes of the compaction process in- volving...
Non-Isothermal, Multi-phase, Multi-component Flows through Deformable Methane Hydrate Reservoirs
Gupta, Shubhangi; Wohlmuth, Barbara
2015-01-01T23:59:59.000Z
We present a hydro-geomechanical model for subsurface methane hydrate systems. Our model considers kinetic hydrate phase change and non-isothermal, multi-phase, multi-component flow in elastically deforming soils. The model accounts for the effects of hydrate phase change and pore pressure changes on the mechanical properties of the soil, and also for the effect of soil deformation on the fluid-solid interaction properties relevant to reaction and transport processes (e.g., permeability, capillary pressure, reaction surface area). We discuss a 'cause-effect' based decoupling strategy for the model and present our numerical discretization and solution scheme. We then identify the important model components and couplings which are most vital for a hydro-geomechanical hydrate simulator, namely, 1) dissociation kinetics, 2) hydrate phase change coupled with non-isothermal two phase two component flow, 3) two phase flow coupled with linear elasticity (poroelasticity coupling), and finally 4) hydrate phase change c...
Neutrinoless Double Beta Decay in Heavy Deformed Nuclei
Jorge G. Hirsch; O. Castaños; P. O. Hess
1994-07-12T23:59:59.000Z
The zero neutrino mode of the double beta decay in heavy deformed nuclei is investigated in the framework of the pseudo SU(3) model, which has provided an accurate description of collective nuclear structure and predicted half-lives for the two neutrino mode in good agreement with experiments. In the case of $^{238}U$ the calculated zero neutrino half-life is at least three orders of magnitude greater than the two neutrino one, giving strong support of the identification of the radiochemically determined half-life as being the two neutrino double beta decay. For $^{150}Nd$ the zero neutrino matrix elements are of the order of magnitude of, but lesser than, those evaluated using the QRPA. This result confirms that different nuclear models produce similar zero neutrino matrix elements, contrary to the two neutrino case. Using these pseudo SU(3) results and the upper limit for the neutrino mass we estimate the $\\beta\\beta_{0\
A new deformed Schioberg-type potential and ro-vibrational energies for some diatomic molecules
Omar Mustafa
2015-04-24T23:59:59.000Z
We suggest a new deformed Schioberg-type potential for diatomic molecules. We show that it is equivalent to Tietz-Hua oscillator potential. We discuss how to relate our deformed Schi\\"oberg potential to Morse, to Deng-Fan , to the improved Manning-Rosen, and to the deformed modified Rosen-Morse potential models. We transform our potential into a proper form and use the supersymmetric quantization to find a closed form analytical solution for the ro-vibrational energy levels that are highly accurate over a wide range of vibrational and rotational quantum numbers. We discuss our results using 4-diatomic molecules NO, O2, O2+, and N2. Our results turn out to compare excellently with those from a generalized pseudospectral numerical method.
Aharonov-Bohm interferences from local deformations in graphene
Fernando de Juan; Alberto Cortijo; María A. H. Vozmediano; Andrés Cano
2011-05-04T23:59:59.000Z
One of the most interesting aspects of graphene is the tied relation between structural and electronic properties. The observation of ripples in the graphene samples both free standing and on a substrate has given rise to a very active investigation around the membrane-like properties of graphene and the origin of the ripples remains as one of the most interesting open problems in the system. The interplay of structural and electronic properties is successfully described by the modelling of curvature and elastic deformations by fictitious gauge fields that have become an ex- perimental reality after the suggestion that Landau levels can form associated to strain in graphene and the subsequent experimental confirmation. Here we propose a device to detect microstresses in graphene based on a scanning-tunneling-microscopy setup able to measure Aharonov-Bohm inter- ferences at the nanometer scale. The interferences to be observed in the local density of states are created by the fictitious magnetic field associated to elastic deformations of the sample.
The Minimal Geometric Deformation Approach Extended
Casadio, Roberto; da Rocha, Roldao
2015-01-01T23:59:59.000Z
The minimal geometric deformation approach was introduced in order to study the exterior space-time around spherically symmetric self-gravitating systems, like stars or similar astrophysical objects as well, in the Randall-Sundrum brane-world framework. A consistent extension of this approach is developed here, which contains modifications of both the time component and the radial component of a spherically symmetric metric. A modified Schwarzschild geometry is obtained as an example of its simplest application.
Biaxially textured articles formed by plastic deformation
Goyal, Amit (Knoxville, TN)
2001-01-01T23:59:59.000Z
A method of preparing a biaxially textured article comprises the steps of providing a metal preform, coating or laminating the preform with a metal layer, deforming the layer to a sufficient degree, and rapidly recrystallizing the layer to produce a biaxial texture. A superconducting epitaxial layer may then be deposited on the biaxial texture. In some embodiments the article further comprises buffer layers, electromagnetic devices or electro-optical devices.
A shapeable material without plastic deformation
Naomi Oppenheimer; Thomas A. Witten
2015-05-06T23:59:59.000Z
Randomly crumpled sheets have shape memory. In order to understand the basis of this form of memory, we simulate triangular lattices of springs whose lengths are altered to create a topography with multiple potential energy minima. We then deform these lattices into different shapes and investigate their ability to retain the imposed shape when the energy is relaxed. The lattices are able to retain a range of curvatures. Under moderate forcing from a state of local equilibrium, the lattices deform by several percent but return to their retained shape when the forces are removed. By increasing the forcing until an irreversible motion occurs, we find that the transitions between remembered shapes show co-operativity among several springs. For fixed lattice structures, the shape memory tends to decrease as the lattice is enlarged; we propose ways to counter this decrease by modifying the lattice geometry. We survey the energy landscape by displacing individual nodes. An extensive fraction of these nodes proves to be bistable; they retain their displaced position when the energy is relaxed. Bending the lattice to a stable curved state alters the pattern of bistable nodes. We discuss this shapeability in the context of other forms of material memory and contrast it with the shapeability of plastic deformation. We outline the prospects for making real materials based on these principles.
Shock wave absorber having a deformable liner
Youngdahl, C.K.; Wiedermann, A.H.; Shin, Y.W.; Kot, C.A.; Ockert, C.E.
1983-08-26T23:59:59.000Z
This invention discloses a shock wave absorber for a piping system carrying liquid. The absorber has a plastically deformable liner defining the normal flow boundary for an axial segment of the piping system, and a nondeformable housing is spaced outwardly from the liner so as to define a gas-tight space therebetween. The flow capacity of the liner generally corresponds to the flow capacity of the piping system line, but the liner has a noncircular cross section and extends axially of the piping system line a distance between one and twenty times the diameter thereof. Gas pressurizes the gas-tight space equal to the normal liquid pressure in the piping system. The liner has sufficient structural capacity to withstand between one and one-half and two times this normal liquid pressures; but at greater pressures it begins to plastically deform initially with respect to shape to a more circular cross section, and then with respect to material extension by circumferentially stretching the wall of the liner. A high energy shock wave passing through the liner thus plastically deforms the liner radially into the gas space and progressively also as needed in the axial direction of the shock wave to minimize transmission of the shock wave beyond the absorber.
A shapeable material without plastic deformation
Naomi Oppenheimer; Thomas A. Witten
2015-06-01T23:59:59.000Z
Randomly crumpled sheets have shape memory. In order to understand the basis of this form of memory, we simulate triangular lattices of springs whose lengths are altered to create a topography with multiple potential energy minima. We then deform these lattices into different shapes and investigate their ability to retain the imposed shape when the energy is relaxed. The lattices are able to retain a range of curvatures. Under moderate forcing from a state of local equilibrium, the lattices deform by several percent but return to their retained shape when the forces are removed. By increasing the forcing until an irreversible motion occurs, we find that the transitions between remembered shapes show co-operativity among several springs. For fixed lattice structures, the shape memory tends to decrease as the lattice is enlarged; we propose ways to counter this decrease by modifying the lattice geometry. We survey the energy landscape by displacing individual nodes. An extensive fraction of these nodes proves to be bistable; they retain their displaced position when the energy is relaxed. Bending the lattice to a stable curved state alters the pattern of bistable nodes. We discuss this shapeability in the context of other forms of material memory and contrast it with the shapeability of plastic deformation. We outline the prospects for making real materials based on these principles.
Wall Adhesion and Constitutive Modelling of Strong Colloidal Gels
Daniel R. Lester; Richard Buscall; Anthony D. Stickland; Peter J. Scales
2014-06-24T23:59:59.000Z
Wall adhesion effects during batch sedimentation of strongly flocculated colloidal gels are commonly assumed to be negligible. In this study in-situ measurements of colloidal gel rheology and solids volume fraction distribution suggest the contrary, where significant wall adhesion effects are observed in a 110mm diameter settling column. We develop and validate a mathematical model for the equilibrium stress state in the presence of wall adhesion under both viscoplastic and viscoelastic constitutive models. These formulations highlight fundamental issues regarding the constitutive modeling of colloidal gels, specifically the relative utility and validity of viscoplastic and viscoelastic rheological models under arbitrary tensorial loadings. The developed model is validated against experimental data, which points toward a novel method to estimate the shear and compressive yield strength of strongly flocculated colloidal gels from a series of equilibrium solids volume fraction profiles over various column widths.
On constitutive modeling of soft tissue for the long-term prediction of cranio-maxillofacial
Frey, Pascal
-incompressible, nonlinear plasticviscoelastic material properties. Besides the properties well known from classic material in cranio-maxillofacial (CMF) surgery simulations. Since the biomechanical properties of living tissues and comprehensive data on material properties of a particular tissue are still very scarce. Thus, simplified models
Constitutive Behavior of a Twaron® Fabric/Natural Rubber Composite: Experiments and Modeling
Natarajan, Valliyappan D.
2011-02-22T23:59:59.000Z
-mechanisms and molecular features on the macroscopic responses of ballistic fabrics. In the present work, the constitutive behavior of Twaron CT709® fabric/natural rubber (Twaron®/NR) composite is studied using three viscoelasticity models (i.e., a four-parameter Burgers...
Deformation of a basement corner, Crazy Woman Canyon, northeastern Bighorn Mountains, Wyoming
Smith, Gretchen Louise
1989-01-01T23:59:59.000Z
24 Fracture data for the sedimentary rocks. 25 Photographs of small faults in the Tensleep Sandstone, . . . . . 26 Predefonned configuration of clay models. . 85 27 Photographs and interpreted line drawings of the deformed clay models.... . . . . . . . . 98 28 Simplified cross sections and interpretations of the Crazy Woman Canyon area, . . 110 29 Method of line length and area balancing to establish subsurface fault angle. . . . . 113 30 Block diagrams of basement geometry . 117 LIST OF PLATES...
Mechanical Deformation of a Lithium-Metal Anode Due to a Very Stiff Separator
Ferrese, A; Newman, J
2014-05-21T23:59:59.000Z
This work builds on the two-dimensional model presented by Ferrese et al. [J. Electrochem. Soc., 159, A1615 (2012)1, which captures the movement of lithium metal at the negative electrode during cycling in a Li-metal/LiCoO2 cell. In this paper, the separator is modeled as a dendrite-inhibiting polymer separator with an elastic modulus of 16 GPa. The separator resists the movement of lithium through the generation of stresses in the cell. These stresses affect the negative electrode through two mechanisms altering the thermodynamics of the negative electrode and deforming the negative electrode mechanically. From this analysis, we find that the dendrite-inhibiting separator causes plastic and elastic deformation of the lithium at the negative electrode which flattens the electrode considerably when compared to the liquid-electrolyte case. This flattening of the negative electrode causes only very slight differences in the local state of charge in the positive electrode. When comparing the magnitude of the effects flattening the negative electrode, we find that the plastic deformation plays a much larger role than either the pressure-modified reaction kinetics or elastic deformation. This is due to the low yield strength of the lithium metal, which limits the stresses such that they have only a small effect on the reaction kinetics. (C) 2014 The Electrochemical Society. All rights reserved.
Constitutive modeling of creep of single crystal superalloys
Prasad, Sharat Chand
2006-10-30T23:59:59.000Z
In this work, a constitutive theory is developed, within the context of continuum mechanics, to describe the creep deformation of single crystal superalloys. The con- stitutive model that is developed here is based on the fact that as bodies deform...
Towards quantum noncommutative {kappa}-deformed field theory
Daszkiewicz, Marcin; Lukierski, Jerzy; Woronowicz, Mariusz [Institute of Theoretical Physics, University of Wroclaw pl. Maxa Borna 9, 50-206 Wroclaw (Poland)
2008-05-15T23:59:59.000Z
We introduce a new {kappa}-star product describing the multiplication of quantized {kappa}-deformed free fields. The {kappa} deformation of local free quantum fields originates from two sources: noncommutativity of space-time and the {kappa} deformation of field oscillators algebra; we relate these two deformations. We demonstrate that for a suitable choice of {kappa}-deformed field oscillators algebra, the {kappa}-deformed version of the microcausality condition is satisfied, and it leads to the deformation of the Pauli-Jordan commutation function defined by the {kappa}-deformed mass shell. We show by constructing the {kappa}-deformed Fock space that the use of the {kappa}-deformed oscillator algebra permits one to preserve the bosonic statistics of n-particle states. The proposed star product is extended to the product of n fields, which for n=4 defines the interaction vertex in perturbative description of the noncommutative quantum {lambda}{phi}{sup 4} field theory. It appears that the classical four-momentum conservation law is satisfied at the interaction vertices.
DR. BRIDGET R. SMITH-KONTER Department of Geological Sciences, University of Texas at El Paso
Smith-Konter, Bridget
deformation mechanisms of fractures on satellites of the outer Solar System Development of 3D visualization Researcher, California Inst. of Technology, NASA JPL Development and application of tidally-driven 3-D-D elastic and viscoelastic crustal deformation model Shuttle Radar Topography Mission Data
Non-principal surface waves in deformed incompressible materials
Michel Destrade; Melanie Ottenio; Alexey V. Pichugin; Graham A. Rogerson
2013-04-23T23:59:59.000Z
The Stroh formalism is applied to the analysis of infinitesimal surface wave propagation in a statically, finitely and homogeneously deformed isotropic half-space. The free surface is assumed to coincide with one of the principal planes of the primary strain, but a propagating surface wave is not restricted to a principal direction. A variant of Taziev's technique [Sov. Phys. Acoust. 35 (1989) 535] is used to obtain an explicit expression of the secular equation for the surface wave speed, which possesses no restrictions on the form of the strain energy function. Albeit powerful, this method does not produce a unique solution and additional checks are necessary. However, a class of materials is presented for which an exact secular equation for the surface wave speed can be formulated. This class includes the well-known Mooney-Rivlin model. The main results are illustrated with several numerical examples.
by crystal plasticity FEM Z. Zhao a , S. Kuchnicki b , R. Radovitzky a,*, A. Cuitin~o b a Department Abstract The ability of three different crystal plasticity finite element models to predict deformation. Published by Elsevier Ltd. All rights reserved. Keywords: Texture; Crystal plasticity; Finite element models
Deformation of Equilibrium Shape of a Vesicle Induced by Injected Flexible Polymers
Yutaka Oya; Katsuhiko Sato; Toshihiro Kawakatsu
2010-11-17T23:59:59.000Z
Using field theoretic approach, we study equilibrium shape deformation of a vesicle induced by the presence of enclosed flexible polymers, which is a simple model of drug delivery system or endocytosis. To evaluate the total free energy of this system, it is necessary to calculate the bending elastic energy of the membrane, the conformation entropy of the polymers and their interactions. For this purpose, we combine phase field theory for the membrane and self-consistent field theory for the polymers. Simulations on this coupled model system for axiosymmetric shapes show a shape deformation of the vesicle induced by introducing polymers into it. We examined the dependence of the stability of the vesicle shape on the chain length of the polymers and the packing ratio of the vesicle. We present a simple model calculation that shows the relative stability of the prolate shape compared to the oblate shape.
Superplastic deformation in two microduplex stainless steels
Lesuer, D.R.; Nieh, T.G.; Syn, C.K. [Lawrence Livermore National Lab., CA (United States); Taleff, E.M. [Texas Univ., Austin, TX (United States)
1996-09-01T23:59:59.000Z
The deformation behavior and mechanisms of superplastic flow in two microduplex stainless steels (SuperDux64 and Nitronic 19D) were studied at {similar_to}0.7T{sub m}. The two steels differed in initial grain size by a factor of 3. Both steels exhibited solute-drag-controlled grain boundary sliding in a high temperature {gamma}+{delta} phase field. In a lower temperature {gamma}+{sigma} phase field, the fine-grained steel ({bar L}=5{mu}m) exhibited climb-controlled grain boundary sliding and the coarser- grained steel ({bar L}=15{mu}m) exhibited solute-drag-controlled slip creep.
Deformed relativistic and nonrelativistic symmetries on canonical noncommutative spaces
Banerjee, Rabin; Kumar, Kuldeep [S.N. Bose National Centre for Basic Sciences, JD Block, Sector 3, Salt Lake, Kolkata 700098 (India); Department of Physics, Panjab University, Chandigarh 160014 (India)
2007-02-15T23:59:59.000Z
We study the general deformed conformal-Poincare (Galilean) symmetries consistent with relativistic (nonrelativistic) canonical noncommutative spaces. In either case we obtain deformed generators, containing arbitrary free parameters, which close to yield new algebraic structures. We show that a particular choice of these parameters reproduces the undeformed algebra. The modified coproduct rules and the associated Hopf algebra are also obtained. Finally, we show that for the choice of parameters leading to the undeformed algebra, the deformations are represented by twist functions.
Structure and deformation mechanisms along the Tonale Line, n. Italy
Welker, Mary Clare
1985-01-01T23:59:59.000Z
of Advisory Committee: John M. Logan Field observations and sampling are combined with petrofabric and fracture analyses to characterize the structure and deformation mechanisms related to a segment of the Tonale Line fault zone in northern Italy. Mylonite... microstructures and fabrics are developed superimposed by cataclasites and fault gouge; the latter being character istic of deformation at shallow depths. The ductile deformation associated with faulting along the Tonale Line occurred under greenschist...
Deformation of the Long Valley Caldera, California: Inferences...
Caldera, California: Inferences from Measurements from 1988 to 2001 Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Deformation of the Long...
Relations Between Seismicity and Deformation During Unrest in...
1995 Through 1999 Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Relations Between Seismicity and Deformation During Unrest in Long Valley...
Cell Motility and Deformability in the Pathogenesis of Lung Cancer
Pagano, Paul Carmelo
2015-01-01T23:59:59.000Z
tumor-initiating cells (TICs), cells capable of repopulatingby deformability and analyzed for TIC properties, includingdeformability relates to the TIC phenotype and how they
Resonant states of deformed nuclei in complex scaling method
Quan Liu; Jian-You Guo; Zhong-Ming Niu; Shou-Wan Chen
2012-11-29T23:59:59.000Z
We develop a complex scaling method for describing the resonances of deformed nuclei and present a theoretical formalism for the bound and resonant states on the same footing. With $^{31}$Ne as an illustrated example, we have demonstrated the utility and applicability of the extended method and have calculated the energies and widths of low-lying neutron resonances in $^{31}$Ne. The bound and resonant levels in the deformed potential are in full agreement with those from the multichannel scattering approach. The width of the two lowest-lying resonant states shows a novel evolution with deformation and supports an explanation of the deformed halo for $^{31}$Ne.
A method to estimate the effect of deformable image registration uncertainties on daily dose mapping
Murphy, Martin J.; Salguero, Francisco J.; Siebers, Jeffrey V.; Staub, David; Vaman, Constantin [Department of Radiation Oncology, Virginia Commonwealth University, Richmond Virginia 23298 (United States)
2012-02-15T23:59:59.000Z
Purpose: To develop a statistical sampling procedure for spatially-correlated uncertainties in deformable image registration and then use it to demonstrate their effect on daily dose mapping. Methods: Sequential daily CT studies are acquired to map anatomical variations prior to fractionated external beam radiotherapy. The CTs are deformably registered to the planning CT to obtain displacement vector fields (DVFs). The DVFs are used to accumulate the dose delivered each day onto the planning CT. Each DVF has spatially-correlated uncertainties associated with it. Principal components analysis (PCA) is applied to measured DVF error maps to produce decorrelated principal component modes of the errors. The modes are sampled independently and reconstructed to produce synthetic registration error maps. The synthetic error maps are convolved with dose mapped via deformable registration to model the resulting uncertainty in the dose mapping. The results are compared to the dose mapping uncertainty that would result from uncorrelated DVF errors that vary randomly from voxel to voxel. Results: The error sampling method is shown to produce synthetic DVF error maps that are statistically indistinguishable from the observed error maps. Spatially-correlated DVF uncertainties modeled by our procedure produce patterns of dose mapping error that are different from that due to randomly distributed uncertainties. Conclusions: Deformable image registration uncertainties have complex spatial distributions. The authors have developed and tested a method to decorrelate the spatial uncertainties and make statistical samples of highly correlated error maps. The sample error maps can be used to investigate the effect of DVF uncertainties on daily dose mapping via deformable image registration. An initial demonstration of this methodology shows that dose mapping uncertainties can be sensitive to spatial patterns in the DVF uncertainties.
Deformed bubble growth and coalescence in polymer foam processing
Allaboun, Hussein Raji
1996-01-01T23:59:59.000Z
conditions (Table 34 0. 1 Viacoelaatic ? ? ? - - Newtoruan o. os V 2 10 4 10 6 10 8 10 1 10 1. 2 10 Time, 1* Figure 4. 1. The viscous limit of the viscoelastic melt. 35 0. 035 0. 03 0. 025 O. O2 0. 015 O. O1 - ti/90 =o. s ? ti/tl. =o. 75 q/q... q/q q/q, 0. 005 1O' 1O' 102 Time, 1* 10' 104 Figure 4. Effect of viscosity on bubble pressure. An increase in the viscosity resulted in a decrease of the rate of change of gaseous phase pressure ( See Figure 4. 2), and, consequently...
Inflation and deformation of conformal field theory
Garriga, Jaume; Urakawa, Yuko, E-mail: jaume.garriga@ub.edu, E-mail: yurakawa@ffn.ub.es [Departament de Física Fonamental i Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain)
2013-07-01T23:59:59.000Z
It has recently been suggested that a strongly coupled phase of inflation may be described holographically in terms of a weakly coupled quantum field theory (QFT). Here, we explore the possibility that the wave function of an inflationary universe may be given by the partition function of a boundary QFT. We consider the case when the field theory is a small deformation of a conformal field theory (CFT), by the addition of a relevant operator O, and calculate the primordial spectrum predicted in the corresponding holographic inflation scenario. Using the Ward-Takahashi identity associated with Weyl rescalings, we derive a simple relation between correlators of the curvature perturbation ? and correlators of the deformation operator O at the boundary. This is done without specifying the bulk theory of gravitation, so that the result would also apply to cases where the bulk dynamics is strongly coupled. We comment on the validity of the Suyama-Yamaguchi inequality, relating the bi-spectrum and tri-spectrum of the curvature perturbation.
Primordial fluctuations from deformed quantum algebras
Day, Andrew C. [Department of Applied Mathematics, University of Western Ontario London, ON, Canada N6A 5B7 (Canada); Brown, Iain A. [Institute of Theoretical Astrophysics, University of Oslo P.O. Box 1029 Blindern, N-0315 Oslo (Norway); Seahra, Sanjeev S., E-mail: aday46@uwo.ca, E-mail: ibrown@astro.uio.no, E-mail: sseahra@unb.ca [Department of Mathematics and Statistics, University of New Brunswick Fredericton, NB, Canada E3B 5A3 (Canada)
2014-03-01T23:59:59.000Z
We study the implications of deformed quantum algebras for the generation of primordial perturbations from slow-roll inflation. Specifically, we assume that the quantum commutator of the inflaton's amplitude and momentum in Fourier space gets modified at energies above some threshold M{sub *}. We show that when the commutator is modified to be a function of the momentum only, the problem of solving for the post-inflationary spectrum of fluctuations is formally equivalent to solving a one-dimensional Schr and quot;odinger equation with a time dependent potential. Depending on the class of modification, we find results either close to or significantly different from nearly scale invariant spectra. For the former case, the power spectrum is characterized by step-like behaviour at some pivot scale, where the magnitude of the jump is O(H{sup 2}/M{sub *}{sup 2}). (H is the inflationary Hubble parameter.) We use our calculated power spectra to generate predictions for the cosmic microwave background and baryon acoustic oscillations, hence demonstrating that certain types of deformations are incompatible with current observations.
Ruthenium Aluminides: Deformation Mechanisms and Substructure Development
Tresa M. Pollock
2005-05-11T23:59:59.000Z
Structural and functional materials that can operate in severe, high temperature environments are key to the operation of a wide range of energy generation systems. Because continued improvements in the energy efficiency of these systems is critical, the need for new materials with higher temperature capabilities is inevitable. Intermetallic compounds, with strong bonding and generally high melting points offer this possibility for a broad array of components such as coatings, electrode materials, actuators and/or structural elements. RuAl is a very unusual intermetallic compound among the large number of B2compounds that have been identified and investigated to date. This material has a very high melting temperature of 2050?C, low thermal expansion, high thermal conductivity and good corrosion resistance. Unlike most other high temperature B2 intermetallics, RuAl possesses good intrinsic deformability at low temperatures. In this program fundamental aspects of low and high temperature mechanical properties and deformation mechanisms in binary and higher order RuAl-based systems have been investigated. Alloying additions of interest included platinum, boron and niobium. Additionally, preliminary studies on high temperature oxidation behavior of these materials have been conducted.
In-situ Phase Transformation and Deformation of Iron at High Pressure andTemperature
Miyagi, Lowell; Kunz, Martin; Knight, Jason; Nasiatka, James; Voltolini, Marco; Wenk, Hans-Rudolf
2008-07-01T23:59:59.000Z
With a membrane based mechanism to allow for pressure change of a sample in aradial diffraction diamond anvil cell (rDAC) and simultaneous infra-red laser heating, itis now possible to investigate texture changes during deformation and phasetransformations over a wide range of temperature-pressure conditions. The device isused to study bcc (alpha), fcc (gamma) and hcp (epislon) iron. In bcc iron, room temperature compression generates a texture characterized by (100) and (111) poles parallel to the compression direction. During the deformation induced phase transformation to hcp iron, a subset of orientations are favored to transform to the hcp structure first and generate a texture of (01-10) at high angles to the compression direction. Upon further deformation, the remaining grains transform, resulting in a texture that obeys the Burgers relationship of (110)bcc // (0001)hcp. This is in contrast to high temperature results that indicate that texture is developed through dominant pyramidal {2-1-12}<2-1-13> and basal (0001)-{2-1-10} slip based on polycrystal plasticity modeling. We also observe that the high temperature fcc phase develops a 110 texture typical for fcc metals deformed in compression.
Contractional deformation of porous sandstone: Insights from the Aztec Sandstone, SE Nevada, USA
Fossen, Haakon
Contractional deformation of porous sandstone: Insights from the Aztec Sandstone, SE Nevada, USA Available online 19 March 2015 Keywords: Sevier thrusting Porous sandstone deformation Deformation bands Contractional deformation a b s t r a c t Contractional deformation of highly porous sandstones is poorly
Type-IV Pilus Deformation Can Explain Retraction Behavior
Ranajay Ghosh; Aloke Kumar; Ashkan Vaziri
2014-09-18T23:59:59.000Z
Polymeric filament like type IV Pilus (TFP) can transfer forces in excess of 100pN during their retraction before stalling, powering surface translocation(twitching). Single TFP level experiments have shown remarkable nonlinearity in the retraction behavior influenced by the external load as well as levels of PilT molecular motor protein. This includes reversal of motion near stall forces when the concentration of the PilT protein is lowered significantly. In order to explain this behavior, we analyze the coupling of TFP elasticity and interfacial behavior with PilT kinetics. We model retraction as reaction controlled and elongation as transport controlled process. The reaction rates vary with TFP deformation which is modeled as a compound elastic body consisting of multiple helical strands under axial load. Elongation is controlled by monomer transport which suffer entrapment due to excess PilT in the cell periplasm. Our analysis shows excellent agreement with a host of experimental observations and we present a possible biophysical relevance of model parameters through a mechano-chemical stall force map
Theodore E. Liolios
2000-08-13T23:59:59.000Z
Thermonuclear fusion reaction rates in the solar plasma are enhanced by the presence of the electron cloud that screens fusing nuclei. The present work studies the influence of electron screening deformations on solar reaction rates in the framework of the Debye-Huckel model. These electron-ion cloud deformations, assumed here to be static and axially symmetric, are shown to be able to considerably influence the solar neutrino fluxes of the pp and the CNO chains, with reasonable changes in the macroscopic parameters of the standard solar model (SSM) . Various known deformation sources are discussed but none of them is found strong enough to have a significant impact on the SSM neutrino fluxes.
Platform Deformation Refined Pointing and Phase Correction for the AMiBA Hexapod Telescope
Koch, Patrick M; Chang, Yu-Yen; Huang, Yau-De; Raffin, Philippe; Chen, Ke-Yung; Chereau, Guillaume; Chen, Ming-Tang; Ho, Paul T P; Huang, Chih-Wie; Ibanez-Romano, Fabiola; Jiang, Homin; Liao, Yu-Wei; Lin, Kai-Yang; Liu, Guo-Chin; Molnar, Sandor M; Nishioka, Hiroaki; Umetsu, Keiichi; Wang, Fu-Cheng; Wu, Jiun-Huei Proty; Altamirano, Pablo; Chang, Chia-Hao; Chang, Shu-Hao; Chang, Su-Wei; Han, Chi-Chiang; Kubo, Derek; Li, Chao-Te; Martin-Cocher, Pierre; Oshiro, Peter
2009-01-01T23:59:59.000Z
The Array for Microwave Background Anisotropy (AMiBA) is a radio interferometer for research in cosmology, currently operating 7 0.6m diameter antennas co-mounted on a 6m diameter platform driven by a hexapod mount. AMiBA is currently the largest hexapod telescope. We briefly summarize the hexapod operation with the current pointing error model. We then focus on the upcoming 13-element expansion with its potential difficulties and solutions. Photogrammetry measurements of the platform reveal deformations at a level which can affect the optical pointing and the receiver radio phase. In order to prepare for the 13-element upgrade, two optical telescopes are installed on the platform to correlate optical pointing tests. Being mounted on different locations, the residuals of the two sets of pointing errors show a characteristic phase and amplitude difference as a function of the platform deformation pattern. These results depend on the telescope's azimuth, elevation and polarization position. An analytical model ...
Chen, Kai; Advanced Light Source; UCLA
2008-01-01T23:59:59.000Z
Plastic deformation in Al (Cu) interconnects stressed bygrain orientation [7], study plastic deformation [12-15] andThis aspect of EM-induced plastic deformation in grains
Medially Based Meshing with Finite Element Analysis of Prostate Deformation
Crouch, Jessica R.
Medially Based Meshing with Finite Element Analysis of Prostate Deformation Jessica R. Crouch1 have approached prostate imaging problems using meth- ods that incorporate finite element analysis. Assume the prostate is a linearly elastic body and compute its deformation using finite element analysis
Cortical Hemisphere Registration Via Large Deformation Diffeomorphic Metric Curve
Qiu, Anqi
on the relation between individual brains and the atlas. This is a powerful approach allowing us to study a largeCortical Hemisphere Registration Via Large Deformation Diffeomorphic Metric Curve Mapping Anqi Qiu1 Science, Johns Hopkins University Abstract. We present large deformation diffeomorphic metric curve
Large Deformation of Nitinol Under Shear Dominant Loading
Bhattacharya, Kaushik
Large Deformation of Nitinol Under Shear Dominant Loading S. Daly & D. Rittel & K. Bhattacharya & G Abstract Full-field quantitative strain maps of phase transformation and plasticity in Nitinol under large that is seen in uniaxial testing. The shear-dominant deformation of Nitinol in the plastic regime exhibits low
Micrographic detection of plastic deformation in nickel base alloys
Steeves, Arthur F. (Schenectady, NY); Bibb, Albert E. (Clifton Park, NY)
1984-01-01T23:59:59.000Z
A method for detecting low levels of plastic deformation in metal articles comprising electrolytically etching a flow free surface of the metal article with nital at a current density of less than about 0.1 amp/cm.sup.2 and microscopically examining the etched surface to determine the presence of alternating striations. The presence of striations indicates plastic deformation in the article.
Characterisation of severely deformed austenitic stainless steel wire
Cambridge, University of
Characterisation of severely deformed austenitic stainless steel wire H. S. Wang1 , J. R. Yang1 of 316L austenitic stainless steel has been examined using TEM and X-ray diffraction. The deformation: Martensite, Mechanical Stabilization, Interface structure, Stainless steel Introduction Textiles woven using
An experimental study on grain deformation and interactions in an
Tong, Wei
deformation; B. Crystal plasticity International Journal of Plasticity 20 (2004) 523542 www knowledge on the plasticity of single crystals, the plastic deformation behavior of a polycrystalline of crystal plasticity while the computational costs are increasingly affordable (Barbe et al., 2001; Goh et
On the thermomechanical deformation of silver shape memory nanowires
Lin, Xi
On the thermomechanical deformation of silver shape memory nanowires Harold S. Park *, Changjiang an analysis of the uniaxial thermomechanical deformation of single-crystal silver shape memory nanowires using atomistic simulations. We first demonstrate that silver nanowires can show both shape memory
Interactive modeler for cloth draping
Thumrugoti, Umakanth
1994-01-01T23:59:59.000Z
2. Bezier Curves . 3. Hyperpatches. . . B. Deformation 1. Free Form Deformation (FFD) 2. Extended Free Form Deformation (EFFD) . C. Overview of the Model 1. Lattice 2. Newton ? Raphson Method . 3. LU Decomposition . 4. Newell's Method... 14 14 15 20 25 25 29 30 30 33 35 37 38 39 39 40 41 46 46 51 54 Page REFERENCES . APPENDIX A A. Menubar B. Lattice Buttons VITA 59 59 59 vn LIST OF FIGURES FIGURE Page Parallelepipedical 3D lattice A Bezier curve...
Reversibility of Red blood Cell deformation
Maria Zeitz; Pierre Sens
2011-11-22T23:59:59.000Z
The ability of cells to undergo reversible shape changes is often crucial to their survival. For Red Blood Cells (RBCs), irreversible alteration of the cell shape and flexibility often causes anemia. Here we show theoretically that RBCs may react irreversibly to mechanical perturbations because of tensile stress in their cytoskeleton. The transient polymerization of protein fibers inside the cell seen in sickle cell anemia or a transient external force can trigger the formation of a cytoskeleton-free membrane protrusion of micrometer dimensions. The complex relaxation kinetics of the cell shape is shown to be responsible for selecting the final state once the perturbation is removed, thereby controlling the reversibility of the deformation. In some case, tubular protrusion are expected to relax via a peculiar "pearling instability".
High stroke pixel for a deformable mirror
Miles, Robin R.; Papavasiliou, Alexandros P.
2005-09-20T23:59:59.000Z
A mirror pixel that can be fabricated using standard MEMS methods for a deformable mirror. The pixel is electrostatically actuated and is capable of the high deflections needed for spaced-based mirror applications. In one embodiment, the mirror comprises three layers, a top or mirror layer, a middle layer which consists of flexures, and a comb drive layer, with the flexures of the middle layer attached to the mirror layer and to the comb drive layer. The comb drives are attached to a frame via spring flexures. A number of these mirror pixels can be used to construct a large mirror assembly. The actuator for the mirror pixel may be configured as a crenellated beam with one end fixedly secured, or configured as a scissor jack. The mirror pixels may be used in various applications requiring high stroke adaptive optics.
Fossen, Haakon
localization structures in porous sandstones, known as deformation bands, are reported to perturb functions to estimate the porosity and specific surface area in deformed sandstones from high anisotropy with regard to petrophysical properties in deformed sandstones, and demonstrated variations
EFFECT OF GRAIN SIZE ON THE ACOUSTIC EMISSION GENERATED DURING PLASTIC DEFORMATION OF COPPER
Baram, J.
2011-01-01T23:59:59.000Z
but only after some extent of plastic deformation, It can,The Inhomogeneity of Plastic Deformation, A.S.M. Seminar,EMISSION GENERATED DURING PLASTIC DEFORMATION OF COPPER J,
Interfacial deformation and jetting of a magnetic fluid
Afkhami, Shahriar; Griffiths, Ian M
2015-01-01T23:59:59.000Z
An attractive technique for forming and collecting aggregates of magnetic material at a liquid--air interface by an applied magnetic field gradient was recently addressed theoretically and experimentally [Soft Matter, (9) 2013, 8600-8608]: when the magnetic field is weak, the deflection of the liquid--air interface has a steady shape, while for sufficiently strong fields, the interface destabilizes and forms a jet that extracts magnetic material. Motivated by this work, we develop a numerical model for the closely related problem of solving two-phase Navier--Stokes equations coupled with the static Maxwell equations. We computationally model the forces generated by a magnetic field gradient produced by a permanent magnet and so determine the interfacial deflection of a magnetic fluid (a pure ferrofluid system) and the transition into a jet. We analyze the shape of the liquid--air interface during the deformation stage and the critical magnet distance for which the static interface transitions into a jet. We d...
Ling, Phyllis
2000-01-01T23:59:59.000Z
During embryonic development, the heart undergoes remarkable morphological changes due to genetic programming and epigenetic influences such as mechanical loads. L.A. Taber and colleagues at Washington University have proposed mathematical models...
Alexandru Oana; Mircea Neagu
2012-05-03T23:59:59.000Z
In this paper we expose on the dual 1-jet space J^{1*}(R,M^4) the distinguished (d-) Riemannian geometry (in the sense of d-connection, d-torsions, d-curvatures and some gravitational-like and electromagnetic-like geometrical models) for the (t,x)-conformal deformed Berwald-Moor Hamiltonian metric of order four.
Devincre, Benoit
Dislocation-dynamics based crystal plasticity law for the low- and high-temperature deformation; bcc; Crystal plasticity; Thermal activation 1. Introduction Crystal plasticity modeling at the level regimes of bcc crystal Ghiath Monnet a, , Ludovic Vincent b , Benoit Devincre c a EDF R&D, MMC, avenue
Paulino, Glaucio H.
Asphalt Pavement Aging and Temperature Dependent Properties through a Functionally Graded simulations, correspondence principle, finite-element method Abstract. Asphalt concrete pavements to climatic conditions are the major cause of such graded non-homogeneity. Current pavement analysis
EFFECT OF GRAIN SIZE ON THE ACOUSTIC EMISSION GENERATED DURING PLASTIC DEFORMATION OF ALUMINUM
Baram, J.
2013-01-01T23:59:59.000Z
PLASTIC DEFORMATION OF ALUMINUM LAWRENCE BERKELEY LABORATORYDURING PLASTIC DEFORMATION OF ALUMINUM J. Baram Materialsof polycrystalline aluminum, of different grain sizes and at
Perspectives on the viscoelasticity and flow behavior of entangled linear and branched polymers
Snijkers, F; Olmsted, P D; Vlassopoulos, D
2015-01-01T23:59:59.000Z
We briefly review the recent advances in the rheology of entangled polymers and identify emerging research trends and outstanding challenges, especially with respect to branched polymers. Emphasis is placed on the role of well-characterized model systems, as well as the synergy of synthesis-characterization, rheometry and modeling/simulations. The theoretical framework for understanding the observed linear and nonlinear rheological phenomena is the tube model which is critically assessed in view of its successes and shortcomings, whereas alternative approaches are briefly discussed. Finally, intriguing experimental findings and controversial issues that merit consistent explanation, such as shear banding instabilities, multiple stress overshoots in transient simple shear and enhanced steady-state elongational viscosity in polymer solutions, are discussed, whereas future directions such as branch point dynamics and anisotropic monomeric friction are outlined.
STATISTICAL MECHANICS MODELING OF MESOSCALE DEFORMATION IN METALS
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic CobySpeeding accessProject Final Report:Report) | Journals(Technical Report) |
Time-critical collision handling for deformable modeling
Teschner, Matthias
or surgical simula- tors, where a pre-defined response time should be guaranteed for each simulation step. We- quent simulation step. If an exact response can- not be computed in a given time frame, the algo- rithm forces. Detection, penetration depth estimation and response are di- vided into atomic tasks. In case
STATISTICAL MECHANICS MODELING OF MESOSCALE DEFORMATION IN METALS
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect JournalPentoxide.Conference: to be submitted to APPLIEDSciTech Connect SSGSS:
STATISTICAL MECHANICS MODELING OF MESOSCALE DEFORMATION IN METALS Anter
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalyticPreparationof LASL research, 1978Earth SciencesSMART BRIDGE: ASTATISTICAL
Computational Issues in Fitting Spatial Deformation Models for Heterogeneous
Washington at Seattle, University of
in the correlation structure however. For example, there may be pollutant sources that impact a small geo- graphic be irregularly located in space. Suppose that Z xi;t represent the data that result from standardization by the
Segmentation-aware Deformable Part Models Eduard Trulls1
Moreno-Noguer, Francesc
(a), and a set of SLIC superpixels at different scales (b)--we show two scales. We pick the superpix
Modeling fluid flow in deformation bands with stabilized localization mixed
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect Journal Article:UsingMeson to a J/PsiReaction (TechnicalOak(Journalfinite elements.
Modeling Of Surface Deformation From Satellite Radar Interferometry In The
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaPLawrence County,1980) | Open Energy InformationGeorgia: EnergySalton Sea Geothermal Field,
Coupling Deformable Models for Multi-Object Segmentation
Andrzejak, Artur
for regions on a femoral head and acetabulum and other adjacent structures, as well as prelimi- nary in these cases, knowledge about adjacent structures must be exploited. Op- timal graph searching based, in joint regions, thresholding is often not sufficient for separating adjacent individual bones from each
Continuum models of deformation mechanisms in nanocrystalline metals
Jérusalem, Antoine, 1979-
2007-01-01T23:59:59.000Z
Nanocrystalline metals are polycrystalline metals with grain sizes in the nanometer range. They have attracted significant interest in recent years due to their unique mechanical and electrical properties. The main objective ...
A new multilayered visco-elasto-plastic experimental model to study strike-slip
Cattin, Rodolphe
between kinematic and mechanical parameters, we have developed a new experimental approach allowing, results show that the model succeed in reproducing the deformation mechanisms and surface kinematics analysis of surface deformation associated with active fault seismic cycle. However, the study
Lauricella, Marco; Coluzza, Ivan; Pisignano, Dario; Succi, Sauro
2015-01-01T23:59:59.000Z
We investigate the effects of dissipative air drag on the dynamics of electrified jets in the early stage of the electrospinning process. The main idea is to use a Brownian noise to model air drag effects on the uniaxial elongation of the jets. The numerical model is used to probe the dynamics of electrified polymer jets at different conditions of air drag force. Numerical simulations show that the elongation of the charged jet filament is significantly affected by the presence of air drag force, providing prospective beneficial implications for the optimal design of future electrospinning experiments.
Marco Lauricella; Giuseppe Pontrelli; Ivan Coluzza; Dario Pisignano; Sauro Succi
2015-07-01T23:59:59.000Z
We investigate the effects of dissipative air drag on the dynamics of electrified jets in the initial stage of the electrospinning process. The main idea is to use a Brownian noise to model air drag effects on the uniaxial elongation of the jets. The developed numerical model is used to probe the dynamics of electrified polymer jets at different conditions of air drag force, showing that the dynamics of the charged jet is strongly biased by the presence of air drag forces. This study provides prospective beneficial implications for improving forthcoming electrospinning experiments.
Neutrinoless double beta decay of $^{150}$Nd with account for deformation
Dong-Liang Fang; Amand Faessler; Vadim Rodin; Fedor Simkovic
2010-11-02T23:59:59.000Z
A microscopic state-of-the-art calculation of the nuclear matrix element for neutrinoless double beta decay of $^{150}$Nd with an account for nuclear deformation is performed. The proton-neutron quasiparticle random phase approximation (QRPA) with a realistic residual interaction [the Brueckner $G$ matrix derived from the charge-depending Bonn (Bonn-CD) nucleon-nucleon potential] is used as the underlying nuclear structure model. The present calculated matrix element is suppressed by about 40% as compared with our previous QRPA result for $^{150}$Nd obtained with neglect of deformation. By making use of this newest nuclear matrix element, one may conclude that neutrinoless double beta decay of $^{150}$Nd, to be measured soon by the SNO+ collaboration, provides one of the best probes of the Majorana neutrino mass.
Neutrinoless double-{beta} decay of {sup 150}Nd accounting for deformation
Fang Dongliang; Faessler, Amand; Rodin, Vadim; Simkovic, Fedor [Institut fuer Theoretische Physik, Universitaet Tuebingen, D-72076 Tuebingen (Germany); BLTP, JINR, Dubna (Russian Federation) and Department of Nuclear Physics, Comenius University, SK-842 15 Bratislava (Slovakia)
2010-11-15T23:59:59.000Z
A microscopic state-of-the-art calculation of the nuclear matrix element for neutrinoless double-{beta} decay of {sup 150}Nd with an account for nuclear deformation is performed. The proton-neutron quasiparticle random phase approximation (QRPA) with a realistic residual interaction [the Brueckner G matrix derived from the charge-dependent Bonn (Bonn-CD) nucleon-nucleon potential] is used as the underlying nuclear structure model. The present calculated matrix element is suppressed by about 40% as compared with our previous QRPA result for {sup 150}Nd obtained with neglect of deformation. By making use of this newest nuclear matrix element, one may conclude that neutrinoless double-{beta} decay of {sup 150}Nd, to be measured soon by the SNO+ collaboration, provides one of the best probes of the Majorana neutrino mass.
Time-aging time-stress superposition in soft glass under tensile deformation field
Asima Shaukat; Ashutosh Sharma; Yogesh M. Joshi
2010-06-10T23:59:59.000Z
We have studied the tensile deformation behaviour of thin films of aging aqueous suspension of Laponite, a model soft glassy material, when subjected to a creep flow field generated by a constant engineering normal stress. Aqueous suspension of Laponite demonstrates aging behaviour wherein it undergoes time dependent enhancement of its elastic modulus as well as its characteristic relaxation time. However, under application of the normal stress, the rate of aging decreases and in the limit of high stress, the aging stops with the suspension now undergoing a plastic deformation. Overall, it is observed that the aging that occurs over short creep times at small normal stresses is same as the aging that occurs over long creep times at large normal stresses. This observation allows us to suggest an aging time - process time - normal stress superposition principle, which can predict rheological behaviour at longer times by carrying out short time tests.
Tsibidis, G. D. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology (FORTH), N. Plastira 100, Vassilika Vouton, 70013, Heraklion, Crete (Greece); Stratakis, E. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology (FORTH), N. Plastira 100, Vassilika Vouton, 70013, Heraklion, Crete (Greece); Department of Materials Science and Technology, University of Crete, 710 03 Heraklion, Crete (Greece); Aifantis, K. E. [Laboratory of Mechanics and Materials, Aristotle University of Thessaloniki, GR-54006 Thessaloniki (Greece)
2012-03-01T23:59:59.000Z
A hybrid theoretical model is presented to describe thermoplastic deformation effects on silicon surfaces induced by single and multiple ultrashort pulsed laser irradiation in submelting conditions. An approximation of the Boltzmann transport equation is adopted to describe the laser irradiation process. The evolution of the induced deformation field is described initially by adopting the differential equations of dynamic thermoelasticity while the onset of plastic yielding is described by the von Mises stress. Details of the resulting picometre sized crater, produced by irradiation with a single pulse, are discussed as a function of the imposed conditions and thresholds for the onset of plasticity are computed. Irradiation with multiple pulses leads to ripple formation of nanometre size that originates from the interference of the incident and a surface scattered wave. It is suggested that ultrafast laser induced surface modification in semiconductors is feasible in submelting conditions, and it may act as a precursor of the incubation effects observed at multiple pulse irradiation of materials surfaces.
q-Deformed Boson Oscillators and Zero Point Energy
P. Narayana Swamy
1999-09-22T23:59:59.000Z
Just as for the ordinary quantum harmonic oscillators, we expect the zero-point energy to play a crucial role in the correct high temperature behavior. We accordingly reformulate the theory of the statistical distribution function for the q-deformed boson oscillators and develop an approximate theory incorporating the zero-point energy. We are then able to demonstrate that for small deformations, the theory reproduces the correct limits both for very high temperatures and for very low temperatures. The deformed theory thus reduces to the undeformed theory in these extreme cases.
New version of $q$-deformed supersymmetric quantum mechanics
Gavrilik, A M; Lukash, A V
2013-01-01T23:59:59.000Z
A new version of the q-deformed supersymmetric quantum mechanics (q-SQM), which is inspired by the Tamm--Dankoff-type (TD-type) deformation of quantum harmonic oscillator, is constructed. The obtained algebra of q-SQM is similar to that in Spiridonov's approach. However, within our version of q-SQM, the ground state found explicitly in the special case of superpotential yiealding q-superoscillator turns out to be non-Gaussian and takes the form of special (TD-type) q-deformed Gaussian.
Emergent noncommutative gravity from a consistent deformation of gauge theory
Cortese, Ignacio; Garcia, J Antonio [Departamento de Fisica de Altas Energias, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico D. F. 04510 (Mexico)
2010-05-15T23:59:59.000Z
Starting from a standard noncommutative gauge theory and using the Seiberg-Witten map, we propose a new version of a noncommutative gravity. We use consistent deformation theory starting from a free gauge action and gauging a killing symmetry of the background metric to construct a deformation of the gauge theory that we can relate with gravity. The result of this consistent deformation of the gauge theory is nonpolynomial in A{sub {mu}.} From here we can construct a version of noncommutative gravity that is simpler than previous attempts. Our proposal is consistent and is not plagued with the problems of other approaches like twist symmetries or gauging other groups.
Non-linear viscoelastic response of magnetic fiber suspensions in oscillatory shear P. Kuzhira*
Paris-Sud XI, Université de
of 37 µm and diameter of 4.9 µm, dispersed in a silicon oil. Rheological measurements have been carried showed a high-frequency plateau, typical for Maxwell behavior. Our simple single relaxation time model. The magnetic fiber suspensions have shown better sedimentation stability [4
DYNAMIC, TRANSIENT, MODE I CRACK PROPAGATION WITH A NONLINEAR, VISCOELASTIC COHESIVE ZONE
Gorb, Yuliya
simplifying idealizations, presents many technical obstacles. In general, polymeric materials exhibit complex. The specific forms for the time dependent cohesive zone models studied below were derived through accelerating mode I cracks in elastic material but do not explicitly exhibit a full solution for general
A model for predicting the evolution of damage in the plastic bonded explosive LX17
Seidel, Gary Don
2002-01-01T23:59:59.000Z
in Viscoelastic Media. 2. 4 Application of Cohesive Zones in Modeling Fracture. . . 2. 5 Cohesive Zones and the Finite Element Method. . . . . . . . . . . . 2. 6 Modeling of Granular Composites. 5 . 6 . 6 . . . . . . 7 9 3 MATERIAL CHARACTER.... 3 Strain Rate to Strain Rate Comparisons 6. 4 Mesh Comparisons 6. 5 LX17 Animation . . . . . . 48 . 74 . 92 . 98 . 105 7 CONCLUSIONS. . 112 REFERENCES APPENDIX I: FEM Development and Validation Al. 1 FEM Development A1. 2 FEM Validation...
Seismic tomography and surface deformation in Krýsuvík, SW Iceland
Lu, Jing, S.M. Massachusetts Institute of Technology
2013-01-01T23:59:59.000Z
The Krýsuvík region of southwestern Iceland is a region of high potential for geothermal energy that is currently experiencing seismic swarm activity and active surface deformation. Understanding the subsurface structure ...
Origin and deformation of Holocene shoreline terraces, Yellowstone Lake, Wyoming
Meyer, G.A.; Locke, W.W.
1986-08-01T23:59:59.000Z
Geodetic surveys within the Yellowstone caldera have documented active uplift that is most likely caused by magmatic processes in the upper crust. Along the northeast shore of Yellowstone Lake, maximum relative uplift rates are 10 mm/yr for the period 1923-1975. However, information on deformation prior to historic instrumental records has been lacking. In this study, closely spaced data on elevations of postglacial shoreline terraces around the north end of Yellowstone Lake reveal complex tilting. Though most Holocene deformation is probably magma related, the pattern of shoreline tilting deviates significantly from the historic pattern of roughly symmetric inflation of the caldera. Along the northeast shore, where tilt directions of historic and shoreline deformation are similar, differential uplift of a > 2500-yr-old terrace is roughly 10 m; this gives a maximum uplift rate of 4 mm/yr. These unique Holocene terraces may exist due to episodic deformation because vertical movements affecting the lake outlet directly control lake level.
Wavefront control in space with MEMS deformable mirrors
Cahoy, Kerri
To meet the high contrast requirement of 1 × 10[superscript ?10] to image an Earth-like planet around a Sun-like star, space telescopes equipped with coronagraphs require wavefront control systems. Deformable mirrors (DMs) ...
Self-sorting of deformable particles in a microfluidic circuit
Raafat, Mohamed Salem
2010-01-01T23:59:59.000Z
In this thesis, a new microfluidic device is presented for sorting of deformable particles based on the hydrodynamic resistance induced in a microchannel. Hydrodynamic resistance can be related to physical properties, ...
3D deformation field throughout the interior of materials.
Jin, Huiqing; Lu, Wei-Yang
2013-09-01T23:59:59.000Z
This report contains the one-year feasibility study for our three-year LDRD proposal that is aimed to develop an experimental technique to measure the 3D deformation fields inside a material body. In this feasibility study, we first apply Digital Volume Correlation (DVC) algorithm to pre-existing in-situ Xray Computed Tomography (XCT) image sets with pure rigid body translation. The calculated displacement field has very large random errors and low precision that are unacceptable. Then we enhance these tomography images by setting threshold of the intensity of each slice. DVC algorithm is able to obtain accurate deformation fields from these enhanced image sets and the deformation fields are consistent with the global mechanical loading that is applied to the specimen. Through this study, we prove that the internal markers inside the pre-existing tomography images of aluminum alloy can be enhanced and are suitable for DVC to calculate the deformation field throughout the material body.
Overprinting Deformations in Mantle Rocks, Dun Mountain, New Zealand
Donnelly, Sara
2014-04-25T23:59:59.000Z
accommodated deformation (Goetze and Kohlstedt, 1973; Drury and Urai, 1990; Passchier and Trouw, 2005). Intermediate and fine grain size populations formed as a result of recrystallization-accommodated dislocation creep that overprinted, or partially...
Development of microelectromechanical deformable mirrors for phase modulation of light
Bifano, Thomas
Development of microelectromechanical deformable mirrors for phase modulation of light Raji, including adaptive optics and pattern recognition systems is described. The mirror will be supported systems; adaptive optics. Paper 38046 received April 29, 1996; revised manuscript received Sep. 18, 1996
Mineral Deformation at Earth's Core-Mantle Boundary
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Mineral Deformation at Earth's Core-Mantle Boundary Print Earth is a dynamic planet in which convection takes place on the scale of thousands of kilometers. Because Earth is mostly...
Experimental Study on Rock Deformation and Permeability Variation
Ding, Jihui
2013-08-01T23:59:59.000Z
The development of a petroleum reservoir would inevitably induce a rearrangement of the in-situ stress field. The rearrangement of the stress field would then bring about a deformation of the reservoir rock and a change of the permeability...
Minor Groove Deformability of DNA: A Molecular Dynamics Free...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
experimental DNA structures in complex with minor groove-binding proteins. The calculated free energy of minor groove deformation was 4–6 kcal mol-1 in the case of a central...
Activation of conductive pathways via deformation-induced instabilities
Ni, Xinchen
2014-01-01T23:59:59.000Z
Inspired by the pattern transformation of periodic elastomeric cellular structures, the purpose of this work is to exploit this unique ability to activate conductive via deformation-induced instabilities. Two microstructural ...
Experimental Study on Rock Deformation and Permeability Variation
Ding, Jihui
2013-08-01T23:59:59.000Z
The development of a petroleum reservoir would inevitably induce a rearrangement of the in-situ stress field. The rearrangement of the stress field would then bring about a deformation of the reservoir rock and a change of the permeability...
ORIGINAL ARTICLE LEGO-like assembly of peelable, deformable
Rogers, John A.
to the production of an integrated architecture without additional electrical connections. The free technologies that can release mechanical stress has enabled the production of various electronic circuits on non-conven- tional, deformable substrates including plastic, elastomeric rubber, fabric, paper
Effect of nuclear deformation on double beta decay
Rodin, Vadim [Institute fuer Theoretische Physik der Universitaet Tuebingen, D-72076 Tuebingen (Germany)
2009-11-09T23:59:59.000Z
The existing ways of accounting for deformation in recent calculations of neutrinoless double beta decay matrix elements are discussed. From an analysis of relevant experimental data it is argued that only {sup 150}Nd reveals convincing evidences of strong static deformation, which should eventually be taken into account in QRPA calculations. A proposal which allows in principle to measure the neutrino less double beta decay Fermi matrix element is briefly described.
Structure and deformation mechanisms along the Tonale Line, n. Italy
Welker, Mary Clare
1985-01-01T23:59:59.000Z
of brittle and ductile deformation and for evidence of pore fluids. Synthesis of the field relationships, compositional and petrofabric analyses were carried out to characterize the overall structure, deformation mechanisms and mechanical behavior... whole were leveled down to a chain of fairly low hill s (Tr'umpy, 1973). Currently, the Tonale Line shows no movement, and it is seismically inactive. Both vertical and horizontal displacements are recognized along the fault, most likely from...
Experimental deformation of multilithologic specimens simulating sedimentary facies changes
Dyke, Lawrence Dana
1976-01-01T23:59:59.000Z
EXPERIMENTAL DEFORMATION OF MULTILITHOLOGIC SPECIMENS SIMULATING SEDIMENTARY FACIES CHANGES A Thesis by LAWRENCE DANA DYKE Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1976 Major Subject: Geology EXPERIMENTAL DEFORMATION OF MULTILITHOLOGIC SPECIMENS SIMULATING SEDIMENTARY FACIES CHANGES A Thesis by LAWRENCE DANA DYKE Approved as to style and content by: (Chai n Committee) (Head...
Experimental deformation of multilithologic specimens simulating sedimentary facies changes
Dyke, Lawrence Dana
1976-01-01T23:59:59.000Z
EXPERIMENTAL DEFORMATION OF MULTILITHOLOGIC SPECIMENS SIMULATING SEDIMENTARY FACIES CHANGES A Thesis by LAWRENCE DANA DYKE Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE December 1976 Major Subject: Geology EXPERIMENTAL DEFORMATION OF MULTILITHOLOGIC SPECIMENS SIMULATING SEDIMENTARY FACIES CHANGES A Thesis by LAWRENCE DANA DYKE Approved as to style and content by: (Chai n Committee) (Head...
TDHF fusion calculations for spherical+deformed systems
A. S. Umar; V. E. Oberacker
2006-04-04T23:59:59.000Z
We outline a formalism to carry out TDHF calculations of fusion cross sections for spherical + deformed nuclei. The procedure incorporates the dynamic alignment of the deformed nucleus into the calculation of the fusion cross section. The alignment results from multiple E2/E4 Coulomb excitation of the ground state rotational band. Implications for TDHF fusion calculations are discussed. TDHF calculations are done in an unrestricted three-dimensional geometry using modern Skyrme force parametrizations.
Angularly Deformed Special Relativity and its Results for Quantum Mechanics
Lukasz Andrzej Glinka
2015-09-15T23:59:59.000Z
In this paper, the deformed Special Relativity, which leads to an essentially new theoretical context of quantum mechanics, is presented. The formulation of the theory arises from a straightforward analogy with the Special Relativity, but its foundations are laid through the hypothesis on breakdown of the velocity-momentum parallelism which affects onto the Einstein equivalence principle between mass and energy of a relativistic particle. Furthermore, the derivation is based on the technique of an eikonal equation whose well-confirmed physical role lays the foundations of both optics and quantum mechanics. As a result, we receive the angular deformation of Special Relativity which clearly depicts the new deformation-based theoretical foundations of physics, and, moreover, offers both constructive and consistent phenomenological discussion of the theoretical issues such like imaginary mass and formal superluminal motion predicted in Special Relativity for this case. In the context of the relativistic theory, presence of deformation does not break the Poincar\\'{e} invariance, in particular the Lorentz symmetry, and provides essential modifications of both bosons described through the Klein-Gordon equation and fermions satisfying the Dirac equation. On the other hand, on the level of discussion of quantum theory, there arises the concept of emergent deformed space-time, wherein the presence of angular deformation elucidates a certain new insight into the nature of spin, as well as both the Heisenberg uncertainty principle and the Schr\\"odinger wave equation.
DEFORMING MEYER SETS JEONG-YUP LEE AND ROBERT V. MOODY
Moody, Robert Vaughan
DEFORMING MEYER SETS JEONG-YUP LEE AND ROBERT V. MOODY For our friend Ludwig Danzer, on the occasion of his 80th birthday. Abstract. A linear deformation of a Meyer set M in Rd is the image of M and sufficient condition for such a deformation to be a Meyer set. In the case that the deformation is a Meyer
Van Vliet, Krystyn J.
Size effects on the onset of plastic deformation during nanoindentation of thin films and patterned; accepted 13 August 2003 Plastic deformation of materials exhibits a strong size dependence when, particularly the transition from elastic to plastic deformation and the early stages of plastic deformation. We
Napieralski, A
2005-01-01T23:59:59.000Z
Application Of Multilayer Piezoelectric Elements For Resonant Cavity Deformation In VUV-FEL DESY Accelerator
Surface Dynamic Deformation Estimates From Seismicity Near the Itoiz Reservoir, Northern Spain
Santoyo, Miguel A; García-Jerez, Antonio; Luzón, Francisco
2014-01-01T23:59:59.000Z
We analyzed the ground motion time histories due to the local seismicity near the Itoiz reservoir, in order to estimate the surface 3D displacement-gradients and dynamic deformations. The seismic data were obtained by a semi-permanent broadband and accelerometric network installed by the University of Almeria during 2008 and 2009. Seismic sensors were located on surface and at underground sites in the vicinity of the dam. The dynamic deformation field was calculated by two different methods. On one hand, by the Seismo-Geodetic method using the data from a three-station micro-array. On the other hand, by Single-Station estimates of displacement gradients, assuming the incidence of body wave fields propagating through the recording site. The dynamic deformations obtained from both methods were compared and analyzed in the context of the local effects near the dam. The shallow 1D velocity structure was estimated from seismic data by modeling the body-wave travel times. After the comparison of the dynamic displac...
Hansen, F.D.
1987-09-01T23:59:59.000Z
Effects of impurities and microprocesses on the creep of natural salt samples are presented. Salts are analyzed from four sites (Palo Duro Unit 4 and Palo Duro Unit 5, Texas; Avery Island, Louisiana; and Salina Basin, Michigan). The salts have been deformed at temperatures and pressures that simulate repository conditions. Bulk chemistry, optical petrology, and microprobe analyses are used to identify the species and to quantify the amount of each impurity. General effects of impurities on the rheology of natural salt are discussed. The physical processes that control creep deformation of salt are identified by etchpit techniques. The nature of desolation motion which controls the creep behavior of salt changes dramatically over the temperature range of 25 to 200/degree/C. Physical bases for constitutive modeling are established through observations documented in this report. Composition of the salts range from nearly pure, uniform halite to a heterogeneous composite of halite and anhydrite. Impurities evidently increase creep resistance at lower test temperatures. At higher test temperatures, creep deformation is much less sensitive to the presence of impurities. Anhydrite is the only mineral species that correlates strongly with creep response. Generally, greater amounts of anhydrite increase the creep resistance. 13 refs., 11 figs., 12 tabs.
Modeling-Computer Simulations At Long Valley Caldera Geothermal...
surrounding a vertically dipping prolate spheroid source during an active period of time-dependent deformation between 1995 and 2000 at Long Valley caldera. We model a rapid...
CO2 - brine behavior using a Black - oil model + geomechanics
Mathematical Model. The governing equations of coupled rock deformation and fluid flow are derived from mass conservation and momentum balance for both ...
Computational Modeling of Self-organization of Dislocations and...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Computational Modeling of Self-organization of Dislocations and Mesoscale Deformation of Metals Event Sponsor: Mathematics and Computing Science - LANS Seminar Start Date: Jun 19...
The constitutive modeling of nitrile elastomers
Helaire, Lumas Terence
1996-01-01T23:59:59.000Z
the development of constitutive modes, dynamic mechanical tests were also used to determine if the material exhibited nonlinear viscoelastic behavior....