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


1

A Four-Dimensional Viscoelastic Deformation Model For Long Valley Caldera,  

Open Energy Info (EERE)

Four-Dimensional Viscoelastic Deformation Model For Long Valley Caldera, Four-Dimensional Viscoelastic Deformation Model For Long Valley Caldera, California, Between 1995 And 2000 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Four-Dimensional Viscoelastic Deformation Model For Long Valley Caldera, California, Between 1995 And 2000 Details Activities (3) Areas (1) Regions (0) Abstract: We investigate the effects of viscoelastic (VE) rheologies 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 magmatic inflation episode and slip across the South Moat fault (SMF) in late 1997. We extend the spherical VE shell model of Newman et al. (Newman, A.V., Dixon, T.H., Ofoegbu, G., Dixon, J.E.,

2

Deformation and break-up of viscoelastic droplets Using Lattice Boltzmann Models  

E-Print Network [OSTI]

We investigate the break-up of Newtonian/viscoelastic droplets in a viscoelastic/Newtonian matrix under the hydrodynamic conditions of a confined shear flow. Our numerical approach is based on a combination of Lattice-Boltzmann models (LBM) and Finite Difference (FD) schemes. LBM are used to model two immiscible fluids with variable viscosity ratio (i.e. the ratio of the droplet to matrix viscosity); FD schemes are used to model viscoelasticity, and the kinetics of the polymers is introduced using constitutive equations for viscoelastic fluids with finitely extensible non-linear elastic dumbbells with Peterlin's closure (FENE-P). We study both strongly and weakly confined cases to highlight the role of matrix and droplet viscoelasticity in changing the droplet dynamics after the startup of a shear flow. Simulations provide easy access to quantities such as droplet deformation and orientation and will be used to quantitatively predict the critical Capillary number at which the droplet breaks, the latter being ...

Gupta, Anupam

2014-01-01T23:59:59.000Z

3

A Four-Dimensional Viscoelastic Deformation Model For Long Valley...  

Open Energy Info (EERE)

and components of two continuous GPS time series. Additionally, the model explains the spatial extent of deformation observed by InSAR data covering the 1997-98 inflation...

4

Viscoelastic-cycle model of interseismic deformation in the northwestern United States  

Science Journals Connector (OSTI)

......Plateau and ESRP, eastern Snake River Plain. Modified...timescales led to the development of block models which...strength with increasing temperature. They also place block...motion of the eastern Snake River Plain: A campaign...California: stratigraphic development, Geol. soc. Am......

F. F. Pollitz; Patricia McCrory; Doug Wilson; Jerry Svarc; Christine Puskas; Robert B. Smith

2010-05-01T23:59:59.000Z

5

Kinetic viscoelasticity modeling applied to degradation during carbon–carbon composite processing  

E-Print Network [OSTI]

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 ...

Drakonakis, Vassilis M.

6

Controlling Deformation in Elastic and Viscoelastic Beams Due to Temperature and Moisture Changes Using Piezoelectric Actuator  

E-Print Network [OSTI]

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...

Kuravi, Ramachandra Srinivasa Chaitanya

2012-07-16T23:59:59.000Z

7

Thermomechanical Constitutive Modeling of Viscoelastic Materials undergoing Degradation  

E-Print Network [OSTI]

viscoelastic uid that shows instantaneous elas- ticity in creep. : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 3 Illustration of the various degradation mechanisms on a polyimide (that shows viscoelastic solid-like behavior...

Karra, Satish

2012-07-16T23:59:59.000Z

8

Micromechanical modeling of deployment and shape recovery of thin-walled viscoelastic composite space  

E-Print Network [OSTI]

Micromechanical modeling of deployment and shape recovery of thin-walled viscoelastic composite;Micromechanical Modeling of Deployment and Shape Recovery of Thin-walled Viscoelastic Composite Space Structures of the paper presents an experimental study of the deployment and shape recovery of composite tape

Pellegrino, Sergio

9

Modeling of the Aging Viscoelastic Properties of Cement Paste Using Computational Methods  

E-Print Network [OSTI]

Results from the Dissolution-Formation Viscoelastic Program, the NISTIR ELAS3D Program and the Abaqus Program ............................................................................................................ 38 Figure 14 Comparison... with an existent aging viscoelastic model which has some limitations in predicting the behavior of cement paste. Overview of the three dimensional linear elastic model ELAS3D is also included in this chapter. Chapter 3 develops the dissolution...

Li, Xiaodan

2012-07-16T23:59:59.000Z

10

Characterization of asphalt concrete using anisotropic damage viscoelastic-viscoplastic model  

E-Print Network [OSTI]

model developed at the Texas Transportation Institute (TTI) is improved and used to model the irrecoverable strain component. The influence of the anisotropic aggregate distribution is accounted for in both the viscoelastic and viscoplastic responses. A...

Abdel-Rahman Saadeh, Shadi

2007-04-25T23:59:59.000Z

11

A Micromechanical Model for Viscoelastic-Viscoplastic Analysis of Particle Reinforced Composite  

E-Print Network [OSTI]

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...

Kim, Jeong Sik

2011-02-22T23:59:59.000Z

12

Non-Linear Drying Diffusion and Viscoelastic Drying Shrinkage Modeling in Hardened Cement Pastes  

E-Print Network [OSTI]

modeling with an average diffusion coefficient and with determined viscoelastic parameters from creep tests agreed well compared to the shrinkage data from experiments, indicating that drying shrinkage of cement paste may be considered as a poroviscoelastic...

Leung, Chin K.

2010-07-14T23:59:59.000Z

13

Theory of the lattice Boltzmann method: Three-dimensional model for linear viscoelastic fluids Pierre Lallemand,1,  

E-Print Network [OSTI]

Theory of the lattice Boltzmann method: Three-dimensional model for linear viscoelastic fluids-dimensional lattice Boltzmann model with thirty two discrete velocity distribution functions for viscoelastic fluid is presented in this work. The model is based upon the generalized lattice Boltzmann equation constructed

Luo, Li-Shi

14

A novel model and sensitivity analysis for viscoelastic polymer flooding in offshore oilfield  

Science Journals Connector (OSTI)

Abstract Polymer flooding has been widely used in petroleum industry. With the development of theory and technology, some problems in the existing models of polymer flooding appear during simulation. Based on the characteristics of polymer and offshore oilfield such as viscoelasticity, degradation effect and strong salt-sensitive effect, a novel model of viscoelastic polymer flooding is built, and the validation is verified. After comparing the distributions of effective viscosity and residual oil of taking account of elasticity and taking no account of elasticity, it is used to investigate the effects of injection rate, polymer molecular weight, salinity, degradation rate and well space.

Jing Wang; Huiqing Liu

2014-01-01T23:59:59.000Z

15

Modeling of quasistatic and dynamic load responses of filled viscoelastic materials  

E-Print Network [OSTI]

are typically used for static finite element analysis (see [9]). The CRSC/Lord team worked, both theoreticallyModeling of quasi­static and dynamic load responses of filled viscoelastic materials H.T. Banks factors to the complications arising in the process of formulating models. Damping is highly complex

16

Force-free swimming of a model helical flagellum in viscoelastic fluids  

E-Print Network [OSTI]

Force-free swimming of a model helical flagellum in viscoelastic fluids Bin Liua,1 , Thomas R. Powersa,b , and Kenneth S. Breuera a School of Engineering, Box D, Brown University, Providence, RI 02912 fluids. The fluids are highly viscous to replicate the low Reynolds number environment of microorgan

Thomases, Becca

17

Defmod - Parallel multiphysics finite element code for modeling crustal deformation during the earthquake/rifting cycle  

E-Print Network [OSTI]

In this article, we present Defmod, a fully unstructured, two or three dimensional, parallel finite element code for modeling crustal deformation over time scales ranging from milliseconds to thousands of years. Defmod can simulate deformation due to all major processes that make up the earthquake/rifting cycle, in non-homogeneous media. Specifically, it can be used to model deformation due to dynamic and quasistatic processes such as co-seismic slip or dike intrusion(s), poroelastic rebound due to fluid flow and post-seismic or post-rifting viscoelastic relaxation. It can also be used to model deformation due to processes such as post-glacial rebound, hydrological (un)loading, injection and/or withdrawal of compressible or incompressible fluids from subsurface reservoirs etc. Defmod is written in Fortran 95 and uses PETSc's parallel sparse data structures and implicit solvers. Problems can be solved using (stabilized) linear triangular, quadrilateral, tetrahedral or hexahedral elements on shared or distribut...

Ali, S Tabrez

2014-01-01T23:59:59.000Z

18

Deformable human body model development  

SciTech Connect (OSTI)

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). A Deformable Human Body Model (DHBM) capable of simulating a wide variety of deformation interactions between man and his environment has been developed. The model was intended to have applications in automobile safety analysis, soldier survivability studies and assistive technology development for the disabled. To date, we have demonstrated the utility of the DHBM in automobile safety analysis and are currently engaged in discussions with the U.S. military involving two additional applications. More specifically, the DHBM has been incorporated into a Virtual Safety Lab (VSL) for automobile design under contract to General Motors Corporation. Furthermore, we have won $1.8M in funding from the U.S. Army Medical Research and Material Command for development of a noninvasive intracranial pressure measurement system. The proposed research makes use of the detailed head model that is a component of the DHBM; the project duration is three years. In addition, we have been contacted by the Air Force Armstrong Aerospace Medical Research Laboratory concerning possible use of the DHBM in analyzing the loads and injury potential to pilots upon ejection from military aircraft. Current discussions with Armstrong involve possible LANL participation in a comparison between DHBM and the Air Force Articulated Total Body (ATB) model that is the current military standard.

Wray, W.O.; Aida, T.

1998-11-01T23:59:59.000Z

19

Two- and Three-Dimensional Microstructural Modeling of Asphalt Particulate Composite Materials using a Unified Viscoelastic-Viscoplastic-Viscodamage Constitutive Model  

E-Print Network [OSTI]

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...

You, Taesun

2013-08-13T23:59:59.000Z

20

A micromechanical model for a viscoelastic cohesive zone  

E-Print Network [OSTI]

of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: David H. Allen (Chair of Committee) John D. Whitcomb (Member) ay R. Walton (Member) Kyle T. end (Head of Department) December 1998 Major Subject: Aerospace... proven successful in the analyses of several researchers, including Needleman (1987) and Tvergaard (1990). Certainly, the advent of cohesive zone modelling has marked a significant advancement in the ability to predict growing damage. Recent research...

Searcy, Chad Randall, 1972-

2012-06-07T23:59:59.000Z

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


21

Decoherence of spin-deformed bosonic model  

SciTech Connect (OSTI)

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.

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

22

Spatially resolved measurements of kinematics and flow-induced birefringence in worm-like micellar solutions undergoing high rate deformations  

E-Print Network [OSTI]

Worm-like micellar solutions are model non-Newtonian systems on account of their well understood linear viscoelastic behavior. Their high deformation rate, non-linear rheological response, however, remains inadequately ...

Ober, Thomas J. (Thomas Joseph)

2010-01-01T23:59:59.000Z

23

Thermo-Viscoelastic-Viscoplastic-Viscodamage-Healing Modeling of Bituminous Materials: Theory and Computation  

E-Print Network [OSTI]

Time- and rate-dependent materials such as polymers, bituminous materials, and soft materials clearly display all four fundamental responses (i.e. viscoelasticity, viscoplasticity, viscodamage, and healing) where contribution of each response...

Darabi Konartakhteh, Masoud

2012-10-19T23:59:59.000Z

24

Viscoelastic behavior of fiber-reinforced composite materials undergoing cure  

E-Print Network [OSTI]

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...

Wang, Kai

1999-01-01T23:59:59.000Z

25

Modeling Of Surface Deformation From Satellite Radar Interferometry In The  

Open Energy Info (EERE)

Modeling Of Surface Deformation From Satellite Radar Interferometry In The Modeling Of Surface Deformation From Satellite Radar Interferometry In The Salton Sea Geothermal Field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Modeling Of Surface Deformation From Satellite Radar Interferometry In The Salton Sea Geothermal Field, California Details Activities (1) Areas (1) Regions (0) Abstract: Surface deformation in the Salton Sea geothermal field is modeled using results from satellite radar interferometry, data from leveling surveys, and observations from the regional GPS network. The field is located in the Salton Trough, an active spreading center in southern California, which is traversed by the Brawley seismic zone. Deformation time series at thousands of points in the study area are obtained from a

26

A Multiscale Model for Coupled Heat Conduction and Deformations of Viscoelastic Composites  

E-Print Network [OSTI]

much appreciated. I am very thankful to all my friends who guided and supported me throughout my doctoral program. I am thankful to Pradeep, Kim, Abid, Ammar, Sohaib, Tariq, Ali, Salman and all others who supported and provided me constant...

Khan, Kamran Ahmed

2012-07-16T23:59:59.000Z

27

Marker-less Human Motion Estimation using Articulated Deformable Model  

E-Print Network [OSTI]

Marker-less Human Motion Estimation using Articulated Deformable Model Koichi Ogawara and Xiaolu Li and backtrack re-estimation algorithm enable accurate estimation. The power to track challenging whole body

Tokyo, University of

28

Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal fluid flow  

E-Print Network [OSTI]

and poroelastic deformation using a range of realistic physical parameters and processes. Hydrothermal fluidNumerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal. Although hydrothermal fluids have been discussed as a possible deformation agent, very few quantitative

29

Relativistic viscoelastic fluid mechanics  

SciTech Connect (OSTI)

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 space-time 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.

Fukuma, Masafumi; Sakatani, Yuho [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)

2011-08-15T23:59:59.000Z

30

Structured Deformations as Energy Minimizers in Models of Fracture and  

E-Print Network [OSTI]

Structured Deformations as Energy Minimizers in Models of Fracture and Hysteresis R. Choksi and for a bar experiencing both smooth exten- sion and macroscopic fractures then are determined, and applications to the shearing of single crystals and to the cohesive fracture of solids are discussed. Yield

31

Interactive Furniture Design: Using Deformable Models to Create Chairs  

E-Print Network [OSTI]

Brand, MIT Media Laboratory Abstract Deformable models that evolve under a set of mutual forces and structurally sound. We encode the input image and knowledge of furniture design into a set of force fields as input an image of the silhouette of a seated person, and then designs a chair that is comfortable

Agarwala, Aseem

32

Antilinear deformations of Coxeter groups, an application to Calogero models  

E-Print Network [OSTI]

We construct complex root spaces remaining invariant under antilinear involutions related to all Coxeter groups. We provide two alternative constructions: One is based on deformations of factors of the Coxeter element and the other based on the deformation of the longest element of the Coxeter group. Motivated by the fact that non-Hermitian Hamiltonians admitting an antilinear symmetry may be used to define consistent quantum mechanical systems with real discrete energy spectra, we subsequently employ our constructions to formulate deformations of Coxeter models remaining invariant under these extended Coxeter groups. We provide explicit and generic solutions for the Schroedinger equation of these models for the eigenenergies and corresponding wavefunctions. A new feature of these novel models is that when compared with the undeformed case their solutions are usually no longer singular for an exchange of an amount of particles less than the dimension of the representation space of the roots. The simultaneous scattering of all particles in the model leads to anyonic exchange factors for processes which have no analogue in the undeformed case.

Andreas Fring; Monique Smith

2010-04-06T23:59:59.000Z

33

Development and numerical implementation of nonlinear viscoelastic-viscoplastic model for asphalt materials  

E-Print Network [OSTI]

pavements is illustrated using finite element simulations. The constitutive model developed in this study can describe the behavior of asphalt materials (asphalt binder, asphalt mastic and mixtures) under various testing conditions. This study also achieved...

Huang, Chien-Wei

2009-05-15T23:59:59.000Z

34

Winding vacuum energies in a deformed O(4) sigma model  

E-Print Network [OSTI]

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.

Vladimir V. Bazhanov; Gleb A. Kotousov; Sergei L. Lukyanov

2014-09-01T23:59:59.000Z

35

Coupled flow and heat transfer in viscoelastic fluid with Cattaneo–Christov heat flux model  

Science Journals Connector (OSTI)

Abstract This letter presents a research for coupled flow and heat transfer of an upper-convected Maxwell fluid above a stretching plate with velocity slip boundary. Unlike most classical works, the new heat flux model, which is recently proposed by Christov, is employed. Analytical solutions are obtained by using the homotopy analysis method (HAM). The effects of elasticity number, slip coefficient, the relaxation time of the heat flux and the Prandtl number on velocity and temperature fields are analyzed. A comparison of Fourier’s Law and the Cattaneo–Christov heat flux model is also presented.

Shihao Han; Liancun Zheng; Chunrui Li; Xinxin Zhang

2014-01-01T23:59:59.000Z

36

Lattice Boltzmann method for viscoelastic fluids  

Science Journals Connector (OSTI)

A lattice Boltzmann model for viscoelastic flow simulation is proposed. Elastic effects are taken into account within the framework of a Maxwell model. To test the approach, we estimate the transverse velocity autocorrelation function for a freely evolving system, and find clear manifestations of shear at large frequencies. We then characterize boundary-driven shear waves, and the resonant enhancement of shear oscillations in a periodically driven fluid confined within a capillary. The measured shear-wave dispersion relation is compared to that obtained from the Navier-Stokes equation with a Maxwell viscoelastic term, and good agreement is obtained.

Iaroslav Ispolatov and Martin Grant

2002-05-03T23:59:59.000Z

37

Seismic viscoelastic attenuation Submitted to  

E-Print Network [OSTI]

Seismic viscoelastic attenuation Submitted to: Encyclopedia of Solid Earth Geophysics Harsh Gupta-3046 USA E-mail: vernon.cormier@uconn.edu Tel: 860-486-3547 Fax: 860-486-3346 #12;SEISMIC VISCOELASTIC ATTENUATION Synonyms Seismic intrinsic attenuation Definitions Linear viscoelastic attenuation. The loss

Cormier, Vernon F.

38

Finite element modeling of the temperature rise due to the propagation of ultrasonic waves in viscoelastic materials and experimental validation  

Science Journals Connector (OSTI)

The ultrasound stimulated thermography method is usually used to detect the temperature rise at a defect position. The temperature rise can be due to the friction between the edges of the defect and/or the plastic deformation around the defect. This paper presents another aspect of the method when the ultrasounds are propagating in a viscoelasticanisotropicmaterial such as polymers or fiber-reinforced polymers. The attenuation of the waves produces a distributed temperature field. Therefore even a defect that does not produce some heat can be detected the ultrasonic field is modified. A finite element model is used for computing the temperature field and for predicting the possibility for an infrared camera of detecting the temperature rise and its modification due to a defect. The model computes the stress and displacement fields associated with the propagation and the loss of energy. Then the heat equation is solved with this loss as a source of heating. An experiment is done with a sonotrode that excites a PVC plate. The ultrasonic displacement at the top of the plate is measured with a laser velocimeter and introduced in the model. Finally the model result is compared to the image produced by the camera.

B. Hosten; C. Bacon; C. Biateau

2008-01-01T23:59:59.000Z

39

Nano and viscoelastic Beck's column on elastic foundation  

E-Print Network [OSTI]

Beck's type column on Winkler type foundation is the subject of the present analysis. Instead of the Bernoulli-Euler model describing the rod, two generalized models will be adopted: Eringen non-local model corresponding to nano-rods and viscoelastic model of fractional Kelvin-Voigt type. The analysis shows that for nano-rod, the Herrmann-Smith paradox holds while for viscoelastic rod it does not.

Atanackovic, Teodor M; Zorica, Dusan

2014-01-01T23:59:59.000Z

40

On the Modeling of Plastic Deformation of Magnesium Alloys  

SciTech Connect (OSTI)

Magnesium alloys are promising materials due to their low density and therefore high specific strength. However, the industrial application is not well established so far, especially for wrought products such as sheets or profiles. Due to its hexagonal crystallographic structure, deformation mechanisms observed in magnesium alloys are rather different from those in face centered cubic metals such as aluminum alloys. This leads not only to a mechanical anisotropy, but also to a tension-compression asymmetry, i.e. unequal compressive and tensile yield strength. The resulting complexity in the yielding behavior of such materials cannot be captured by conventional models of J2 plasticity. Cazacu and Barlat, therefore, proposed a phenomenological yield potential which accounts for the respective phenomena by introducing the third invariant of the stress tensor. Simulations based on this model are performed with ABAQUS/Explicit and a user defined routine VUMAT for validating the respective implementation. The application aims at simulating the extrusion process of magnesium alloys.

Ertuerk, S.; Steglich, D.; Bohlen, J.; Letzig, D.; Brocks, W. [GKSS Research Center, Institute of Materials Research, Max-Plank-Str., D-21502 Geesthacht (Germany)

2007-05-17T23:59:59.000Z

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


41

Modeling Attractor Deformation in the Rodent Head-Direction JEREMY P. GOODRIDGE1  

E-Print Network [OSTI]

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

Touretzky, David S.

42

Post-Systolic Thickening in Ischaemic Myocardium: A Simple Mathematical Model for Simulating Regional Deformation  

Science Journals Connector (OSTI)

We present a one-dimensional mathematical model to explain changes in regional radial myocardial deformation during ischaemia. The model makes use of cellular contraction properties of normal and ischaemic myocytes extracted from an animal model of induced ...

Piet Claus; Bart Bijnens; Frank Weidemann; Christoph Dommke; Virginie Bito; Frank Heinzel; Karin Sipido; Ivan De Scheerder; Frank E. Rademakers; George R. Sutherland

2001-11-01T23:59:59.000Z

43

Scaling relations of earthquakes and aseismic deformation in a damage rheology model  

Science Journals Connector (OSTI)

......rheology model accounts for fundamental aspects of brittle rock...algorithm. Variable boundary forces applied to the model...seismology, in source Handbook of Earthquake and Engineering...deformation from point forces and force couples located in welded......

Vladimir Lyakhovsky; Yehuda Ben-Zion

2008-02-01T23:59:59.000Z

44

Analytical modeling of deformed plain woven thermoplastic composites  

Science Journals Connector (OSTI)

This research addressed the deformation predictability of post-manufactured, plain weave architecture composite panels. Often times during the production of deep drawn composite parts, a fabric preform experie...

John R. Smith; Uday K. Vaidya…

2014-12-01T23:59:59.000Z

45

Mathematical modeling of irreversible dynamic deformation, micro- and macrofracture of materials and structures  

National Nuclear Security Administration (NNSA)

7: Material Phase Transition, Modeling, and Others 7: Material Phase Transition, Modeling, and Others Mathematical Modeling of Irreversible Dynamic Deformation, Micro- and Macrofracture of Materials and Structures P. P. Zakharov and A. B. Kiselev All-Russia Research Institute of Automatics, Moscow 125412, Russia Thermomechanical processes, which proceed in deformable solids under intensive dynamic loading, consist of mechanical, thermal and structural ones, which correlate themselves. The structural processes involve the formation, motion and interaction of defects in metallic crystals, phase transitions, the breaking of bonds between molecules in polymers, the accumulation of microstructural damages (pores, cracks), etc. Irreversible deformations, zones of adiabatic shear and microfractures are caused by these

46

Analysis of viscoelastic soft dielectric elastomer generators operating in an electrical circuit  

E-Print Network [OSTI]

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.

Eliana Bortot; Ralf Denzer; Andreas Menzel; Massimiliano Gei

2014-11-13T23:59:59.000Z

47

Pumping viscoelastic two-fluid media  

E-Print Network [OSTI]

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.

Hirofumi Wada

2010-04-08T23:59:59.000Z

48

NUMERICAL MODELING OF DEFORMATION AND FRACTURE OF WOOD INCLUDING HETEROGENEITY AND ANISOTROPY  

E-Print Network [OSTI]

NUMERICAL MODELING OF DEFORMATION AND FRACTURE OF WOOD INCLUDING HETEROGENEITY AND ANISOTROPY John A. Nairn Wood Science & Engineering, Oregon State University, USA Abstract The challenge in numerical modeling of wood is to have the model closely match the structure of a real specimen. The model

Nairn, John A.

49

Discrete element modeling of rock deformation, fracture network development and permeability evolution under hydraulic stimulation  

SciTech Connect (OSTI)

Key challenges associated with the EGS reservoir development include the ability to reliably predict hydraulic fracturing and the deformation of natural fractures as well as estimating permeability evolution of the fracture network with time. We have developed a physics-based rock deformation and fracture propagation simulator by coupling a discrete element model (DEM) for fracturing with a network flow model. In DEM model, solid rock is represented by a network of discrete elements (often referred as particles) connected by various types of mechanical bonds such as springs, elastic beams or bonds that have more complex properties (such as stress-dependent elastic constants). Fracturing is represented explicitly as broken bonds (microcracks), which form and coalesce into macroscopic fractures when external and internal load is applied. The natural fractures are represented by a series of connected line segments. Mechanical bonds that intersect with such line segments are removed from the DEM model. A network flow model using conjugate lattice to the DEM network is developed and coupled with the DEM. The fluid pressure gradient exerts forces on individual elements of the DEM network, which therefore deforms the mechanical bonds and breaks them if the deformation reaches a prescribed threshold value. Such deformation/fracturing in turn changes the permeability of the flow network, which again changes the evolution of fluid pressure, intimately coupling the two processes. The intimate coupling between fracturing/deformation of fracture networks and fluid flow makes the meso-scale DEM- network flow simulations necessary in order to accurately evaluate the permeability evolution, as these methods have substantial advantages over conventional continuum mechanical models of elastic rock deformation. The challenges that must be overcome to simulate EGS reservoir stimulation, preliminary results, progress to date and near future research directions and opportunities will be discussed. Methodology for coupling the DEM model with continuum flow and heat transport models will also be discussed.

Shouchun Deng; Robert Podgorney; Hai Huang

2011-02-01T23:59:59.000Z

50

Semiclassical origin of anomalous shell effect for tetrahedral deformation in radial power-law potential model  

E-Print Network [OSTI]

Shell structures in single-particle energy spectra are investigated against regular tetrahedral type deformation using radial power-law potential model. Employing a natural way of shape parametrization which interpolates sphere and regular tetrahedron, we find prominent shell effects at rather large tetrahedral deformations, which bring about shell energies much larger than the cases of spherical and quadrupole type shapes. We discuss the semiclassical origin of these anomalous shell structures using periodic orbit theory.

Ken-ichiro Arita; Yasunori Mukumoto

2014-05-09T23:59:59.000Z

51

Lattice Boltzmann method for viscoelastic fluids Iaroslav Ispolatov1,2  

E-Print Network [OSTI]

Lattice Boltzmann method for viscoelastic fluids Iaroslav Ispolatov1,2 and Martin Grant1 1 Centre February 2002; published 3 May 2002 A lattice Boltzmann model for viscoelastic flow simulation is proposed sophisticated lattice Boltzmann schemes are straightforward. The evolution equations for an ith channel

Grant, Martin

52

Numerical Model for the Deformation of Nucleated Cells by Optical Stretchers  

E-Print Network [OSTI]

In this paper, we seek to model the deformation of nucleated cells by single diode-laser bar optical stretchers. We employ a recently developed computational model, the Dynamic Ray-Tracing method, to determine the stress distribution induced by the applied optical forces on a capsule encapsulating a nucleus of different optical properties. These forces are shape dependent and can deform real non-rigid objects; thus resulting in a dynamically changing optical stress distribution with cell and nucleus deformation. Chinese hamster ovary cell is a common biological cell that is of interest to the biomedical community because of their use in recombinant protein therapeutics and is an example of a nucleated cell. To this end, we model chinese hamster ovary cells as two three-dimensional elastic capsules of variable inner capsule size immersed in a fluid where the hydrodynamic forces are calculated using the Immersed Boundary Method. Our results show that the presence of a nucleus has a major effect on the force distribution on the cell surface and the net deformation. Scattering and gradient forces are reported for different nucleus sizes and the effect of nucleus size on the cell deformation is discussed.

Ihab Sraj; Joshua Francois; David W. M. Marr; Charles D. Eggleton

2015-01-15T23:59:59.000Z

53

A Lattice Boltzmann Fictitious Domain Method for Modeling Red Blood Cell Deformation and Multiple-Cell Hydrodynamic Interactions in Flow  

SciTech Connect (OSTI)

To model red blood cell (RBC) deformation in flow, the recently developed LBM-DLM/FD method ([Shi and Lim, 2007)29], derived from the lattice Boltzmann method and the distributed Lagrange multiplier/fictitious domain methodthe fictitious domain method, is extended to employ the mesoscopic network model for simulations of red blood cell deformation. The flow is simulated by the lattice Boltzmann method with an external force, while the network model is used for modeling red blood cell deformation and the fluid-RBC interaction is enforced by the Lagrange multiplier. To validate parameters of the RBC network model, sThe stretching numerical tests on both coarse and fine meshes are performed and compared with the corresponding experimental data to validate the parameters of the RBC network model. In addition, RBC deformation in pipe flow and in shear flow is simulated, revealing the capacity of the current method for modeling RBC deformation in various flows.

Shi, Xing; Lin, Guang; Zou, Jianfeng; Fedosov, Dmitry A.

2013-07-20T23:59:59.000Z

54

Analytical models of transient thermoelastic deformations of mirrors heated by high power cw laser beams  

E-Print Network [OSTI]

and are suspended in a vacuum vessel : the heat losses are only due to the thermal radiation. The resulting2243 Analytical models of transient thermoelastic deformations of mirrors heated by high power cw substrat. La distribution de température engendrée dans le substrat produit des déformations

Boyer, Edmond

55

Hybrid Lattice Boltzmann/Finite Difference simulations of viscoelastic multicomponent flows in confined geometries  

E-Print Network [OSTI]

We propose numerical simulations of viscoelastic fluids based on a hybrid algorithm combining Lattice-Boltzmann models (LBM) and Finite Differences (FD) schemes, the former used to model the macroscopic hydrodynamic equations, and the latter used to model the polymer dynamics. The kinetics of the polymers is introduced using constitutive equations for viscoelastic fluids with finitely extensible non-linear elastic dumbbells with Peterlin's closure (FENE-P). The numerical model is first benchmarked by characterizing the rheological behaviour of dilute homogeneous solutions in various configurations, including steady shear, elongational flows, transient shear and oscillatory flows. As an upgrade of complexity, we study the model in presence of non-ideal multicomponent interfaces, where immiscibility is introduced in the LBM description using the "Shan-Chen" model. The problem of a confined viscoelastic (Newtonian) droplet in a Newtonian (viscoelastic) matrix under simple shear is investigated and numerical resu...

Gupta, A; Scagliarini, A

2014-01-01T23:59:59.000Z

56

Training PDMs on models: The Case of Deformable Superellipses  

E-Print Network [OSTI]

- plicated mathematical shape model simpler while keeping a comparable level of representational power? The proposed solution is to use the original model itself { which represents a class of shapes { to train Introduction Superellipses and their 3-D extension superquadrics were introduced by the Danish designer Piet

Fisher, Bob

57

Cell resolved, multiparticle model of plastic tissue deformations and morphogenesis  

E-Print Network [OSTI]

We propose a three dimensional mechanical model of embryonic tissue dynamics. Mechanically coupled adherent cells are represented as particles interconnected with elastic beams which can exert non-central forces and torques. Tissue plasticity is modeled by a stochastic process consisting of a connectivity change (addition or removal of a single link) followed by a complete relaxation to mechanical equilibrium. In particular, we assume that (i) two non-connected, but adjacent particles can form a new link; and (ii) the lifetime of links is reduced by tensile forces. We demonstrate that the proposed model yields a realistic macroscopic elasto-plastic behavior and we establish how microscopic model parameters affect the material properties at the macroscopic scale. Based on these results, microscopic parameter values can be inferred from tissue thickness, macroscopic elastic modulus and the magnitude and dynamics of intercellular adhesion forces. In addition to their mechanical role, model particles can also act...

Czirok, Andras

2014-01-01T23:59:59.000Z

58

InitialValue and Modal Approaches for Transient Viscoelastic Responses  

E-Print Network [OSTI]

) 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

Hanyk, Ladislav

59

Initial-Value and Modal Approaches for Transient Viscoelastic Responses  

E-Print Network [OSTI]

) 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

Hanyk, Ladislav

60

The deformation models needed by the steel industry  

Science Journals Connector (OSTI)

...model for process control. pressing at an auto supply company. The design...transferred along the supply chain. In other words...used for process control, have to run in real...feedstock composition and temperature. Figure 12 illus...

1999-01-01T23:59:59.000Z

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


61

Investigation into the modeling of ground deformations induced by underground mining  

SciTech Connect (OSTI)

The mechanisms of strata deformation due to underground mining were analyzed in an effort to better understand immediate roof behavior and surface displacements. Strata deformation characteristics above longwall and room-and-pillar mines in the eastern US coal fields were evaluated and a numerical procedure was developed for calculating surface displacements. The model, based on the well-known finite element method, utilized empirical indices associated with subsidence engineering in order to incorporate the site-specific characteristics into the formulation. Different material behavior models and failure criteria were employed in an attempt to determine the areas highly deformed by underground excavation. Additionally, the method was sensitive to the ratios of the elastic moduli used to describe different rocks and/or rock conditions, and not to the magnitude of the elastic properties. Thus, the use of arbitrary reduction factors to convert laboratory to in situ property values was completely avoided and scaling of the calculated surface displacements was based on, the empirically predicted, regional or local parameters. The use of fixed displacement nodes around an opening to induce failure overcame the roof-floor overlap problem encountered in other formulations. The successful implementation of the proposed methodology for modeling surface deformations complements and enhances existing prediction techniques, which are primarily based on empirical approaches, by allowing parametric analysis for different excavation geometries, roof convergence curves and overburden properties.

Agioutantis, Z.G.

1987-01-01T23:59:59.000Z

62

Viscoelastic Model for Lung Parenchyma for Multi-Scale Modeling of Respiratory System Phase I: Hypo-Elastic Model for CFD Implementation  

SciTech Connect (OSTI)

An isotropic constitutive model for the parenchyma of lung has been derived from the theory of hypo-elasticity. The intent is to use it to represent the mechanical response of this soft tissue in sophisticated, computational, fluid-dynamic models of the lung. This demands that the continuum model be accurate, yet simple and effcient. An objective algorithm for its numeric integration is provided. The response of the model is determined for several boundary-value problems whose experiments are used for material characterization. The effective elastic, bulk, and shear moduli, and Poisson’s ratio, as tangent functions, are also derived. The model is characterized against published experimental data for lung. A bridge between this continuum model and a dodecahedral model of alveolar geometry is investigated, with preliminary findings being reported.

Freed, Alan D.; Einstein, Daniel R.

2011-04-14T23:59:59.000Z

63

Adsorption and viscoelastic properties of cationic xylan on cellulose film using QCM-D  

Science Journals Connector (OSTI)

The adsorption and viscoelastic properties of cationic xylan layers adsorbed from an aqueous electrolyte solution ... 10, 100 mM) on a cellulose model surface were studied using quartz crystal microbalance with ....

Sang Hoon Lee; Hak Lae Lee; Hye Jung Youn

2014-06-01T23:59:59.000Z

64

Enabling microscopic simulators to perform system-level analysis of viscoelastic flows  

E-Print Network [OSTI]

State-of-the-art methods for simulating viscoelastic flows couple the conservation equations for mass and momentum with a model from kinetic theory that describes the microstructural state of the polymer. Introduction of ...

Anwar, Zubair

2008-01-01T23:59:59.000Z

65

Anomalous Dimensions in Deformed WZW Models on Supergroups  

E-Print Network [OSTI]

We investigate a class of current-current, Gross-Neveu like, perturbations of WZW models in which the full left-right affine symmetry is broken to the diagonal global algebra only. Our analysis focuses on those supergroups for which such a perturbation preserves conformal invariance. A detailed calculation of the 2-point functions of affine primary operators to 3-loops is presented. Furthermore, we derive an exact formula for the anomalous dimensions of a large subset of fields to all orders in perturbation theory. Possible applications of our results, including the study of non-perturbative dualities, are outlined.

Candu, Constantin; Schomerus, Volker

2012-01-01T23:59:59.000Z

66

Mode-I fracture in a nonlinear lattice with viscoelastic forces Shay I. Heizler and David A. Kessler  

E-Print Network [OSTI]

Mode-I fracture in a nonlinear lattice with viscoelastic forces Shay I. Heizler and David A July 2002 We study mode-I fracture in a viscoelastic lattice model with a nonlinear force law force laws in mode-III fracture. At small driving, there is a strong dependency of the velocity curve

Levine, Herbert

67

Numerical Model for the Deformation of Nucleated Cells by Optical Stretchers  

E-Print Network [OSTI]

In this paper, we seek to model the deformation of nucleated cells by single diode-laser bar optical stretchers. We employ a recently developed computational model, the Dynamic Ray-Tracing method, to determine the stress distribution induced by the applied optical forces on a capsule encapsulating a nucleus of different optical properties. These forces are shape dependent and can deform real non-rigid objects; thus resulting in a dynamically changing optical stress distribution with cell and nucleus deformation. Chinese hamster ovary cell is a common biological cell that is of interest to the biomedical community because of their use in recombinant protein therapeutics and is an example of a nucleated cell. To this end, we model chinese hamster ovary cells as two three-dimensional elastic capsules of variable inner capsule size immersed in a fluid where the hydrodynamic forces are calculated using the Immersed Boundary Method. Our results show that the presence of a nucleus has a major effect on the force dis...

Sraj, Ihab; Marr, David W M; Eggleton, Charles D

2015-01-01T23:59:59.000Z

68

Deformed Matrix Models, Supersymmetric Lattice Twists and N=1/4 Supersymmetry  

SciTech Connect (OSTI)

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.

Unsal, Mithat

2008-09-24T23:59:59.000Z

69

Development of a Two-Phase Model for the Hot Deformation of Highly-Alloyed Aluminum  

SciTech Connect (OSTI)

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. J. Beaudoin; J. A. Dantzig; I. M. Robertson; B. E. Gore; S. F. Harnish; H. A. Padilla

2005-10-31T23:59:59.000Z

70

Multi-scale Modeling Approach to Acoustic Emission during Plastic Deformation  

E-Print Network [OSTI]

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.

Jagadish Kumar; G. Ananthakrishna

2011-02-20T23:59:59.000Z

71

Non-linear viscoelastic deformation of polymeric solutions  

E-Print Network [OSTI]

(ri) and BC I M (A) grafted slides along with the bare (o) and florinated glass (+) in PS20M6%. 45 Normalized drag dissipation vs. velocity for BC53K (x), BC192K (0), BCIM (5) and BC IP8M (a) grafted slides along with the bare (o) and florinated...

Sanchez Reyes, Javier

2000-01-01T23:59:59.000Z

72

Coupled heat conduction and deformation in a viscoelastic composite cylinder  

E-Print Network [OSTI]

conditions, Finite Element(FE) analysis of the composite cylinder is performed and the results of analytical and FE method are found to be in good agreement. Parametric studies are carried out to understand the effect of change in material parameters namely...

Shah, Sneha

2010-01-16T23:59:59.000Z

73

Metastable vacuum decay and $?$ dependence in gauge theory. Deformed QCD as a toy model  

E-Print Network [OSTI]

We study a number of different ingredients related to the $\\theta$ dependence, metastable excited vacuum states and other related subjects using a simplified version of QCD, the so-called "deformed QCD". This model is a weakly coupled gauge theory, which however preserves all the relevant essential elements allowing us to study hard and nontrivial features which are known to be present in real strongly coupled QCD. Our main focus in this work is to test the ideas related to the metastable vacuum states (which are known to be present in strongly coupled QCD in large $N$ limit) in a theoretically controllable manner using the "deformed QCD" as a toy model. We explicitly show how the metastable states emerge in the system, why their life time is large, and why these metastable states must be present in the system for the self-consistency of the entire picture of the QCD vacuum. We also speculate on possible relevance of the metastable vacuum states in explanation of the violation of local $\\cal{P}$ and $\\cal{CP}$ symmetries in heavy ion collisions.

Amit Bhoonah; Evan Thomas; Ariel R. Zhitnitsky

2014-07-18T23:59:59.000Z

74

Nature of $?$-deformation in Ge and Se nuclei and the triaxial projected shell model description  

E-Print Network [OSTI]

Recent experimental data have demonstrated that $^{76}$Ge may be a rare example of a nucleus exhibiting rigid $\\gamma$-deformation in the low-spin regime. In the present work, the experimental analysis is supported by microscopic calculations using the multi-quasiparticle triaxial projected shell model (TPSM) approach. It is shown that to best describe the data of both yrast and $\\gamma$-vibrational bands in $^{76}$Ge, a rigid-triaxial deformation parameter $\\gamma\\approx 30^\\circ$ is required. TPSM calculations are discussed in conjunction with the experimental observations and also with the published results from the spherical shell model. The occurrence of a $\\gamma\\gamma$-band in $^{76}$Ge is predicted with the bandhead at an excitation energy of $ \\sim$ 2.5 MeV. We have also performed TPSM study for the neighboring Ge- and Se-isotopes and the distinct $\\gamma$-soft feature in these nuclei is shown to result from configuration mixing of the ground-state with multi-quasiparticle states.

G. H. Bhat; W. A. Dar; J. A. Sheikh; Y. Sun

2014-01-08T23:59:59.000Z

75

Modelling the large strain solid phase deformation behaviour of polymer nanoclay composites  

Science Journals Connector (OSTI)

This work concerns the solid phase deformation processing of polypropylene/nanoclay composites, for which the materials are stretched...

P. E. Spencer; R. Spares; J. Sweeney; P. D. Coates

2008-12-01T23:59:59.000Z

76

Thermo-mechanical-metallurgical modeling for hot-press forming in consideration of the prior austenite deformation effect  

Science Journals Connector (OSTI)

Abstract In this study, a prior austenite grain refinement model was incorporated into semi-empirical diffusive transformation kinetics for application to hot-press forming. In particular, the kinetics equations were modified to include the effects of boron addition and austenite deformation on transformation behaviors during forming. To simulate the hot-press forming process, a thermo-mechanical-metallurgical model was formulated implicitly and implemented into the finite element program ABAQUS using the user subroutines UMAT and UMATHT. This nonconventional finite element modeling is appropriate to consider thermal- and transformation-associated strains. The proposed model was validated through simple finite element simulation examples, i.e., dilatometry simulation with and without external loading, and hot torsion and quenching of a rod. Finally, the hot-press forming of a U-channel-type part was simulated to study the effect of austenite deformation on the phase kinetics, hardness and residual stress. The simulation results showed that the austenite deformation had considerable influence on the final strength and residual stress distribution in the hot-press formed sheet, which resulted from an increase in ferritic phases due to the modified kinetics. In particular, the austenite deformation effect was more noticeable in the side-wall region of the U-channel where plastic deformation was the most severe.

Hyun-Ho Bok; JongWon Choi; Frédéric Barlat; Dong Woo Suh; Myoung-Gyu Lee

2014-01-01T23:59:59.000Z

77

Intensity-Modulated Radiotherapy Optimization in a Quasi-Periodically Deforming Patient Model  

SciTech Connect (OSTI)

Purpose: To present the implementation of a probability-based, four-dimensional (4D) intensity-modulated radiotherapy (IMRT) planning approach that explicitly optimizes the accumulated dose to moving tissue, estimated using the patient's probability density function (pdf) of respiratory motion. This is termed 'optimization in tissue's-eye-view'. Methods and Materials: The method incorporates 4D Monte Carlo dose calculation in multiple geometries of a respiratory-correlated CT dataset. The instance doses are weighted according to the breathing pdf and accumulated in a common reference geometry, which involves dose warping based on deformable registration. The algorithm produces deliverable multileaf collimator segments and was tested on a sample lung cancer patient dataset with large target excursion. Accumulated doses of the moving target and organs at risk of this plan were compared with those of corresponding margin-based static IMRT plans for free-breathing and gated treatment, as well as target tracking. Results: Target tracking provided best target coverage. Both the presented 4D IMRT approach for free-breathing treatment and gated treatment gave similar results for target coverage and lung dose, with significantly better target coverage than the margin-based static IMRT plan for free-breathing treatment. Conclusions: The presented 4D planning concept offers an alternative to gating by providing the optimal dose for free-breathing IMRT treatment. Although the focus of this study was 4D lung planning, the approach can be generally applied for IMRT optimization in randomly deforming patient models.

Soehn, Matthias, E-mail: Matthias.Soehn@med.uni-tuebingen.d [Section for Biomedical Physics, University Hospital for Radiation Oncology, Tuebingen (Germany); Weinmann, Martin [Department of Radiotherapy, University Hospital for Radiation Oncology, Tuebingen (Germany); Alber, Markus [Section for Biomedical Physics, University Hospital for Radiation Oncology, Tuebingen (Germany)

2009-11-01T23:59:59.000Z

78

Asymptotic Green's function in homogeneous anisotropic viscoelastic media  

Science Journals Connector (OSTI)

...Green's function in realistic anisotropic viscoelastic materials...isotropic and some simple anisotropic media, the Green's function...function is calculated in two anisotropic viscoelastic materials: clay shale and carbon-epoxy composite...

2007-01-01T23:59:59.000Z

79

3D segmentation of mouse organs from MR images using deformable simplex mesh models G. Hamarneh1  

E-Print Network [OSTI]

3D segmentation of mouse organs from MR images using deformable simplex mesh models G. Hamarneh1 , H. Delingette2 , M. Henkelman1 1 Hospital for Sick Children, Toronto, ON, Canada, 2 INRIA brains and kidneys from MR images. Algorithmic details and 3D segmentation results are presented

Hamarneh, Ghassan

80

Phased?Array Focusing Potential in Pipe with Viscoelastic Coating  

Science Journals Connector (OSTI)

This work investigates the effectiveness of traditional guided?wave focusing techniques in piping with viscoelastic coating. Focusing results for an uncoated pipe are compared to that of pipe with a fusion?bonded epoxy coating a coal?tar mastic coating a coal?tar epoxy coating a coal?tar tape coating a wax coating and an enamel coating. Experimental results are compared to computationally derived models. Results show that for most coating types focusing can be achieved without special consideration of the coating. This is significant in that it demonstrates the immediate applicability of traditional focusing techniques to coated pipeline.

J. K. Van Velsor; L. Zhang; L. J. Breon; J. L. Rose

2007-01-01T23:59:59.000Z

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


81

Orientation dependent tensile deformation behavior of two-phase laminate composites: Model analysis and finite element results  

SciTech Connect (OSTI)

A model is presented which allows the distribution of stresses and strains within a two-phase laminate to be determined as a function of the angle between the normal vector to the laminate interfaces and the tensile axis during elastic and elastic-plastic deformation. The model is applied to {alpha}{sub 2}(Ti{sub 3}Al)/{gamma}(TiAl) and, for comparison, to Al/Al{sub 2}O{sub 3} laminates in order to study (a) the transfer of stresses between the two phases due to the mutual deformation constraint at the interphase boundaries and (b) the dependence of the yield stress on the orientation of the lamellae with respect to the tensile axis. The model predictions are in good agreement with the results of finite element computations within the composite except for certain boundary layers at the outer surfaces.

Mertins, H.; Lahann, H.J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung] [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

1996-03-01T23:59:59.000Z

82

Modeling the High-Frequency Component of Arctic Sea Ice Drift and Deformation  

Science Journals Connector (OSTI)

Buoy observations of sea ice drift show that sea ice motion and deformation contain substantial high-frequency variability at subdaily timescales. However, numerical simulations of the sea ice dynamics normally do not include processes on such ...

Petra Heil; William D. Hibler III

2002-11-01T23:59:59.000Z

83

Plastic deformation of a model glass induced by a local shear transformation  

E-Print Network [OSTI]

The effect of a local shear transformation on plastic deformation of a three-dimensional amorphous solid is studied using molecular dynamics simulations. We consider a spherical inclusion, which is gradually transformed into an ellipsoid of the same volume and then converted back into the sphere. It is shown that at sufficiently large strain amplitudes, the deformation of the material involves localized plastic events that were identified based on the relative displacement of atoms before and after the shear transformation. We found that the density profiles of cage jumps decay away from the inclusion, which correlates well with the radial dependence of the local deformation of the material. At the same strain amplitude, the plastic deformation becomes more pronounced in the cases of weakly damped dynamics or large time scales of the shear transformation.

Nikolai V. Priezjev

2014-08-28T23:59:59.000Z

84

Using Nanotechnology in Viscoelastic Surfactant Stimulation Fluids  

E-Print Network [OSTI]

USING NANOTECHNOLOGY IN VISCOELASTIC SURFACTANT STIMULATION FLUIDS A Thesis by MERVE RABIA GURLUK Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... .......................................... 9 1.7 Kinetics of Micellization ......................................................................... 10 1.8 Nanotechnology ....................................................................................... 16...

Gurluk, Merve Rabia 1986-

2012-11-12T23:59:59.000Z

85

The SL(2,R)WZWN string model as a deformed oscillator and its classical-quantum string regimes  

E-Print Network [OSTI]

We study the SL(2,R) WZWN string model describing bosonic string theory in AdS_3 space-time as a deformed oscillator together with its mass spectrum and the string modified SL(2,R) uncertainty relation. The SL(2,R) string oscillator is far more quantum (with higher quantum uncertainty) and more excited than the non deformed one. This is accompassed by the highly excited string mass spectrum which is drastically changed with respect to the low excited one. The highly excited quantum string regime and the low excited semiclassical regime of the SL(2,R) string model are described and shown to be the quantum-classical dual of each other in the precise sense of the usual classical-quantum duality. This classical-quantum realization is not assumed nor conjectured. The quantum regime (high curvature) displays a modified Heisenberg's uncertainty relation, while the classical (low curvature) regime has the usual quantum mechanics uncertainty principle.

M. Ramon Medrano; N. G. Sanchez

2006-06-12T23:59:59.000Z

86

Analytically driven experimental characterisation of damping in viscoelastic materials  

Science Journals Connector (OSTI)

Abstract The damping assessment of highly dissipative materials is a challenging task that has been addressed by several researchers; in particular Oberst defined a standard method to address the issue. Experimental tests are often hindered by the poor mechanical properties of most viscoelastic materials; these characteristics make experimental activities using pure viscoelastic specimens prone to nonlinear phenomena. In this paper, a mixed predictive/experimental methodology is developed to determine the frequency behaviour of the complex modulus of such materials. The loss factor of hybrid sandwich specimens, composed of two aluminium layers separated by the damping material, is determined by experimental modal identification. Finite element models and a reversed application of the modal strain energy technique are then used to recover the searched storage modulus and loss factor curves of rubber. In particular, the experimental setup was studied by comparing the solutions adopted with the guidelines given in ASTM-E756-05. An exhaustive validation of the values obtained is then reported.

Gian Luca Ghiringhelli; Mauro Terraneo

2014-01-01T23:59:59.000Z

87

Nonlinear viscoelastic materials : bioinspired applications and new characterization measures  

E-Print Network [OSTI]

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 ...

Ewoldt, Randy H. (Randy Harold)

2009-01-01T23:59:59.000Z

88

Boussinesq’s viscoelastic problem on normal concentrated force on a half-space surface  

Science Journals Connector (OSTI)

A problem on the action of a normal concentrated force on the surface of viscoelastic half-space (Boussinesq’s viscoelastic problem) is solved. The...

Latif K. Talybly

2010-08-01T23:59:59.000Z

89

Logarithmic correction in the deformed AdS5 model to produce the heavy quark potential and QCD beta function  

Science Journals Connector (OSTI)

We study the holographic QCD model, which contains a quadratic term -?z2 and a logarithmic term -c0log?[(zIR-z)/zIR] with an explicit infrared cutoff zIR in the deformed AdS5 warp factor. We investigate the heavy-quark potential for three cases, i.e., with only a quadratic correction, with both quadratic and logarithmic corrections, and with only a logarithmic correction. We solve the dilaton field and dilation potential from the Einstein equation and investigate the corresponding beta function in the Gürsoy-Kiritsis-Nitti framework. Our studies show that in the case with only a quadratic correction, a negative ? or the Andreev-Zakharov model is favored to fit the heavy-quark potential and to produce the QCD beta function at 2-loop level; however, the dilaton potential is unbounded in the infrared regime. One interesting observation for the case of positive ? is that the corresponding beta function exists in an infrared fixed point. In the case with only a logarithmic correction, the heavy-quark Cornell potential can be fitted very well, the corresponding beta function agrees with the QCD beta function at 2-loop level reasonably well, and the dilaton potential is bounded from below in the infrared. At the end, we propose a more compact model which has only a logarithmic correction in the deformed warp factor and has less free parameters.

Song He, Mei Huang, and Qi-Shu Yan

2011-02-25T23:59:59.000Z

90

Investigation of viscoelastic effect of moulding compound on the warpage and stresses of a power plastic package  

Science Journals Connector (OSTI)

In this paper, the creep deformation behaviour of a plastic power package under a thermal load condition was investigated by using a non-linear finite element technique coupled with a high-density laser moiré interferometry. The real-time moiré interferometry technique was used to monitor and measure the time-dependent deformation of the plastic power package during the test, while the finite element method was adapted to analyse the variation of stresses at the edges of all interfaces with time due to the viscoelastic properties of the molding compound. The results show that there does exist the obvious time-dependent deformation in the plastic power package under the thermal load due to the creep behaviour of the molding compound. The maximum steady state U-displacement is reduced by up to 21% compared with the maximum initial one. Likewise, the maximum steady state V-displacement is also reduced by up to 20% compared with the maximum initial state V-displacement. The creep deformation in the molding compound weakens the warpage situation of the plastic power package. In particular, such deformation greatly relieves part of the stresses at the edges of all interfaces and thereby effectively prevents interfaces from cracking. In addition, the predicted deformations of the plastic power package obtained from the finite element analysis were compared with the test data obtained from the laser moiré interferometry technique. It is shown that the deformations of the plastic power package predicted from the finite element analysis are in a fair agreement with those obtained from the test when the viscoelastic behaviour of the molding compound was considered.

Jianjun Wang; Daqing Zou; Sheng Liu

1999-01-01T23:59:59.000Z

91

Geophys.J. Int. (1996) 127,348-362 Initial-valueand modal approaches for transient viscoelastic  

E-Print Network [OSTI]

). Viscoelastic models were introduced by Cathles (1971) and Peltier (1974) because of the availability of more-mode approach (e.g. Peltier 1974;Yuen & Peltier 1982; Wu & Peltier 1982; Sabadini, Yuen & Boschi 1984a earth models (Han & Wahr 1995;Fang & Hager 1994, 1995; Peltier 1995; Hanyk et al. 1995). Han & Wahr

Hanyk, Ladislav

92

Stresses generated in cooling viscoelastic ice shells: Application to Europa  

E-Print Network [OSTI]

Stresses generated in cooling viscoelastic ice shells: Application to Europa F. Nimmo Department to cooling and the expansion of the shell due to the ice-water volume change. The former effect generates Citation: Nimmo, F. (2004), Stresses generated in cooling viscoelastic ice shells: Application to Europa, J

Nimmo, Francis

93

Viscoelastic response of Yukawa liquids and P. Hartmann1  

E-Print Network [OSTI]

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. Donkó,1 J. Goree,2 and P. Hartmann1 1 Research Institute

Goree, John

94

Fracture induced anisotropy in viscoelastic UNLP, 11 Octubre de 2012  

E-Print Network [OSTI]

Fracture induced anisotropy in viscoelastic media UNLP, 11 Octubre de 2012 . Fracture induced anisotropy in viscoelastic media ­ p. #12;Fractured media. I Fractures are common in the earth's crust due to different factors, for instance, tectonic stresses and natural or artificial hydraulic fracturing caused

Santos, Juan

95

Viscous and Viscoelastic Potential Flow 1 Viscous and Viscoelastic Potential Flow  

E-Print Network [OSTI]

and Terrence Y. Liao Department of Aerospace Engineering and Mechanics University of Minnesota, Minneapolis, MN of incompressible fluids admit a pressure (Bernoulli) equation when the divergence of the stress is a gradient as in inviscid fluids, viscous fluids, linear viscoelastic fluids and second-order fluids. We show

Joseph, Daniel D.

96

Analytical modeling of gravity changes and crustal deformation at volcanoes: The Long Valley caldera, California, case study  

Science Journals Connector (OSTI)

Joint measurements of ground deformation and micro-gravity changes are an indispensable component for any volcano monitoring strategy. A number of analytical mathematical models are available in the literature that can be used to fit geodetic data and infer source location, depth and density. Bootstrap statistical methods allow estimations of the range of the inferred parameters. Although analytical models often assume that the crust is elastic, homogenous and isotropic, they can take into account different source geometries, the influence of topography, and gravity background noise. The careful use of analytical models, together with high quality data sets, can produce valuable insights into the nature of the deformation/gravity source. Here we present a review of various modeling methods, and use the historical unrest at Long Valley caldera (California) from 1982 to 1999 to illustrate the practical application of analytical modeling and bootstrap to constrain the source of unrest. A key question is whether the unrest at Long Valley since the late 1970s can be explained without calling upon an intrusion of magma. The answer, apparently, is no. Our modeling indicates that the inflation source is a slightly tilted prolate ellipsoid (dip angle between 91° and 105°) at a depth of 6.5 to 7.9 km beneath the caldera resurgent dome with an aspect ratio between 0.44 and 0.60, a volume change from 0.161 to 0.173 km3 and a density of 1241 to 2093 kg/m3. The larger uncertainty of the density estimate reflects the higher noise of gravity measurements. These results are consistent with the intrusion of silicic magma with a significant amount of volatiles beneath the caldera resurgent dome.

M. Battaglia; D.P. Hill

2009-01-01T23:59:59.000Z

97

Mesoscopic theory of the viscoelasticity of polymers  

E-Print Network [OSTI]

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.

S. M. Chitanvis

1999-01-26T23:59:59.000Z

98

Implementation and Evaluation of the Virtual Fields Method: Determining Constitutive Model Parameters From Full-Field Deformation Data.  

SciTech Connect (OSTI)

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.

Kramer, Sharlotte Lorraine Bolyard; Scherzinger, William M.

2014-09-01T23:59:59.000Z

99

Modeling of coulpled deformation and permeability evolution during fault reactivation induced by deep underground injection of CO2  

SciTech Connect (OSTI)

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.

Cappa, F.; Rutqvist, J.

2010-06-01T23:59:59.000Z

100

A Gibbs-potential-based formulation for obtaining the response functions for a class of viscoelastic materials  

Science Journals Connector (OSTI)

...the response functions for a class of viscoelastic materials K...external stimuli under a certain class of process, such configurations...the concept to build a certain class of models. (a) The equation...potentials that have equal if not greater claim to primacy (the Gibbs...

2011-01-01T23:59:59.000Z

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


101

Nonlinear viscoelastic response of carbon black-filled butyl rubber and implications for o-ring aging  

SciTech Connect (OSTI)

Butyl rubber, unfortunately, has pronounced nonlinear viscoelastic behavior, which may be modelled by a separable KBKZ formalism. While these effects seem to have minimal impact on accelerated sealing force measurements, they do severely impact compression set tests. Therefore, a new test is suggested for evaluating field-return o-rings which is free from such confounding effects.

Adolf, D.

1997-11-01T23:59:59.000Z

102

Visco-elastic fluid simulations of coherent structures in strongly coupled dusty plasma medium  

SciTech Connect (OSTI)

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.

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

103

Visco-elastic fluid simulations of coherent structures in strongly coupled dusty plasma medium  

E-Print Network [OSTI]

A generalized hydrodynamic (GHD) 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 are being investigated here within the framework of this model. A comparison with Newtonian fluids and Molecular Dynamics (MD) simulations treating the dust species interacting through the Yukawa potential has also been presented.

Dharodi, Vikram Singh; Das, Amita

2014-01-01T23:59:59.000Z

104

Viscoelastic transient of confined Red Blood Cells  

E-Print Network [OSTI]

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.

Gaël Prado; Alexander Farutin; Chaouqi Misbah; Lionel Bureau

2014-09-17T23:59:59.000Z

105

VISCOELASTICITY OF BIOPOLYMER NETWORKS AND STATISTICAL MECHANICS OF  

E-Print Network [OSTI]

VISCOELASTICITY OF BIOPOLYMER NETWORKS AND STATISTICAL MECHANICS OF SEMIFLEXIBLE POLYMERS Erwin scattering . . . . . . . . . . . . . . . . . 11 II.C.2 Colloidal probes and micro-rheology . . . . . . . . . . . 14 IIIVISCOELASTICTY OF BIOPOLYMER NETWORKS 15 III.AExperimental techniques and results

Frey, Erwin

106

Measuring the viscoelastic properties of polytetrafluoroethylene copolymers at ultrasonic frequencies  

E-Print Network [OSTI]

properties must be measured directly. A new technique employing a piezoelectric ultrasonic composite oscillator has been developed to measure the viscoelastic properties, GI(w) and G"(w), of Tefzel 280 (a high molecular weight copolymer of ethylene...

Thomas, Verghese

1994-01-01T23:59:59.000Z

107

Analysis of complex viscoelastic flows using a finite element method  

E-Print Network [OSTI]

The field of computational fluid mechanics of viscoelastic flows has been well explored in the three decades since its inception. Still, even with the vast amount of work detailed in the literature, much remains to be done ...

Phillips, Scott David, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

108

MODE II FRACTURE BEHAVIOR OF BONDED VISCOELASTIC THERMAL COMPRESSED WOOD  

E-Print Network [OSTI]

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

Nairn, John A.

109

Properties of triaxial, strongly deformed bands in {sup 167}Ta and {sup 167}Lu and the top-on-top model  

SciTech Connect (OSTI)

Based on the particle-rotor model with one particle coupled to a triaxially deformed rotor, the experimental excitation energy relative to a reference E*-aI(I+1) and the ratio between interband and intraband electromagnetic transitions are well reproduced for {sup 167}Ta with {gamma}=19 deg. The same parameter set for the angular-momentum-dependent rigid-body moments of inertia attains good agreement with experimental data for the positive-parity triaxial, strongly deformed (TSD) band levels in {sup 167}Lu. An attempt is made to investigate the negative-parity TSD band in {sup 167}Lu.

Sugawara-Tanabe, Kazuko [Theoretical Nuclear Physics Laboratory, RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Otsuma Women's University, Tama, Tokyo 206-8540 (Japan); Tanabe, Kosai [Theoretical Nuclear Physics Laboratory, RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Department of Physics, Saitama University, Sakura-Ku, Saitama 338-8570 (Japan)

2010-11-15T23:59:59.000Z

110

PLASTIC DEFORMATIONPLASTIC DEFORMATION Modes of Deformation  

E-Print Network [OSTI]

PLASTIC DEFORMATIONPLASTIC DEFORMATION Modes of Deformation The Uniaxial Tension Test Mechanisms underlying Plastic Deformation Strengthening mechanisms Mechanical Metallurgy George E Dieter McClick here to know about all the mechanisms by which materials fail #12;Slip (Dislocation motion) Plastic

Subramaniam, Anandh

111

Constitutive modeling of the finite deformation behavior of membranes possessing a triangulated networked microstructure  

E-Print Network [OSTI]

Many biological, natural and synthetic materials possess a networked or micro-truss-like microstructure. In this thesis work, a general microstructurally-informed continuum level constitutive model of the large stretch ...

Arslan, Melis

2005-01-01T23:59:59.000Z

112

Deformed shell model results for neutrinoless double beta decay of nuclei in A=60-90 region  

E-Print Network [OSTI]

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.

Sahu, R

2014-01-01T23:59:59.000Z

113

Application of the Kerman-Klein Method to the Solution of a Spherical Shell Model for a Deformed Rare-Earth Nucleus  

Science Journals Connector (OSTI)

Put forward more than three decades ago as an alternative to conventional shell-model calculations, the Kerman-Klein method has proved feasible previously only when applied to unrealistically small configuration spaces or when phenomenological simplifications have been superposed. Starting from a spherical shell-model Hamiltonian, we describe a fully microscopic calculation, free of the above limitations, of the properties of the ground-state band of a typical deformed rare-earth nucleus, 158Gd.

Pavlos Protopapas and Abraham Klein

1997-06-09T23:59:59.000Z

114

Modelling Soft Tissue Deformations using Principal Component Analysis and Haptic Devices  

E-Print Network [OSTI]

. Gillies and Michail Bourmpos Department of Computing, Imperial College of Science, Technology and Medicine simulators designed to teach medical procedures. The technique is based on pre-computing a representative set training using computer graphics. However there is a computational problem in applying modern modelling

Gillies, Duncan

115

Time Scales and Mechanisms of Relaxation in the Energy Landscape of Polymer Glass under Deformation: Direct Atomistic Modeling  

Science Journals Connector (OSTI)

Molecular-dynamics simulation is used to explore the influence of thermal and mechanical history of typical glassy polymers on their deformation. Polymer stress-strain and energy-strain developments have been followed for different deformation velocities, also in closed extension-recompression loops. The latter simulate for the first time the experimentally observed mechanical rejuvenation and overaging of polymers, and energy partitioning reveals essential differences between mechanical and thermal rejuvenation. All results can be qualitatively interpreted by considering the ratios of the relevant time scales: for cooling down, for deformation, and for segmental relaxation.

Alexey V. Lyulin and M. A. J. Michels

2007-08-24T23:59:59.000Z

116

Effect of Hydrolysis on the Properties of a New Viscoelastic Surfactant-Based Acid  

E-Print Network [OSTI]

Viscoelastic surfactants (VES) have been widely used in acidizing and acid fracturing. They are used as diversion agents during matrix acid treatments and leakoff control agents during acid fracturing. At high temperatures, viscoelastic surfactants...

He, Zhenhua

2013-08-07T23:59:59.000Z

117

Form factors in sinh- and sine-Gordon models, deformed Virasoro algebra, Macdonald polynomials and resonance identities  

E-Print Network [OSTI]

We continue the study of form factors of descendant operators in the sinh- and sine-Gordon models in the framework of the algebraic construction proposed in [arXiv:0812.4776]. We find the algebraic construction to be related to a particular limit of the tensor product of the deformed Virasoro algebra and a suitably chosen Heisenberg algebra. To analyze the space of local operators in the framework of the form factor formalism we introduce screening operators and construct singular and cosingular vectors in the Fock spaces related to the free field realization of the obtained algebra. We show that the singular vectors are expressed in terms of the degenerate Macdonald polynomials with rectangular partitions. We study the matrix elements that contain a singular vector in one chirality and a cosingular vector in the other chirality and find them to lead to the resonance identities already known in the conformal perturbation theory. Besides, we give a new derivation of the equation of motion in the sinh-Gordon theory, and a new representation for conserved currents.

Michael Lashkevich; Yaroslav Pugai

2014-07-28T23:59:59.000Z

118

Form factors in sinh- and sine-Gordon models, deformed Virasoro algebra, Macdonald polynomials and resonance identities  

E-Print Network [OSTI]

We continue the study of form factors of descendant operators in the sinh- and sine-Gordon models in the framework of the algebraic construction proposed in [arXiv:0812.4776]. We find the algebraic construction to be related to a particular limit of the tensor product of the deformed Virasoro algebra and a suitably chosen Heisenberg algebra. To analyze the space of local operators in the framework of the form factor formalism we introduce screening operators and construct singular and cosingular vectors in the Fock spaces related to the free field realization of the obtained algebra. We show that the singular vectors are expressed in terms of the degenerate Macdonald polynomials with rectangular partitions. We study the matrix elements that contain a singular vector in one chirality and a cosingular vector in the other chirality and find them to lead to the resonance identities already known in the conformal perturbation theory. Besides, we give a new derivation of the equation of motion in the sinh-Gordon th...

Lashkevich, Michael

2013-01-01T23:59:59.000Z

119

Experimental investigation and constitutive modeling of the large deformation behavior of anisotropic steel sheets undergoing strain-induced phase transformation  

E-Print Network [OSTI]

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 ...

Beese, Allison M

2011-01-01T23:59:59.000Z

120

Mechanistic modeling of Zircaloy deformation and fracture in fuel element analysis  

SciTech Connect (OSTI)

A review is given of the comprehensive model developed in the 1960's at the Bettis Atomic Power Laboratory to explain the creep of Zircaloy during neutron irradiation and applied to fuel element analysis and design. The in-pile softening observed at low stresses was hypothesized to be due to a combination of the growth-directed Roberts-Cottrell yielding creep originally proposed for ..cap alpha..-uranium and the formation of point defect loops preferentially on certain planes in response to the applied stress, with the second process being of relatively greater importance. The in-pile hardening observed at high stresses (or strain-rates) was proposed to be due to the cutting by dislocations of radiation-produced obstacles. In this stress (strain-rate) region, in-pile behavior was proposed to be identical to post-irradiation behavior. At intermediate stresses (strain-rates) a mechanism of radiation-enhanced climb around obstacles was suggested as being rate controlling. As the stress is decreased, the climb process becomes easier and the rate was then predicted to be controlled by glide at a flow stress characteristic of unirradiated, annealed material, where radiation-enhanced diffusion enabled climbing around the normal strain-hardening obstacles. At still lower stresses, this glide process became negligibly slow compared with the growth-connected creep mechanism which was presumed to operate independently. The overall scheme was shown to be good agreement with all the in-pile data then available and implemented into the computer analysis of fuel element behavior. 48 refs., 1 fig.

Nichols, F.A.

1985-06-01T23:59:59.000Z

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


121

Rolling friction for hard cylinder and sphere on viscoelastic solid  

E-Print Network [OSTI]

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.

B. N. J. Persson

2010-08-26T23:59:59.000Z

122

Shape Recovery of Viscoelastic Deployable Structures and Sergio Pellegrino  

E-Print Network [OSTI]

and opposite sense folding. I. Introduction Deployable structures made of thin carbon fiber reinforced polymerShape Recovery of Viscoelastic Deployable Structures Kawai Kwok and Sergio Pellegrino California Institute of Technology, Pasadena, CA 91125 The paper investigates the shape recovery behavior of a simple

Pellegrino, Sergio

123

Propagation and Retention of Viscoelastic Surfactants in Carbonate Cores  

E-Print Network [OSTI]

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 pH and calcium concentration...

Yu, Meng

2012-07-16T23:59:59.000Z

124

ANALYSES OF DEFORMATION IN VISCOELASTIC SANDWICH COMPOSITES SUBJECT TO MOISTURE DIFFUSION  

E-Print Network [OSTI]

Sandwich composites with polymer foam core are currently used in load-bearing components in buildings and naval structures due to their high strength to weight and stiffness to weight ratios, excellent thermal insulation, and ease of manufacturing...

Joshi, Nikhil P.

2010-01-16T23:59:59.000Z

125

Fractional Order Transmission Line Modeling and Parameter Identification.  

E-Print Network [OSTI]

??Fractional order calculus (FOC) has wide applications in modeling natural behavior of systems related to different areas of engineering including bioengineering, viscoelasticity, electronics, robotics, control… (more)

Razib, Mohammad Yeasin

2010-01-01T23:59:59.000Z

126

An interactive deformation technique with triangles and distance functions  

E-Print Network [OSTI]

stiA' or rigid models can be made to look Fig. 15. Four triangle deformers used together in 3D. organic. Figure 16 is a fairly complicated 3D model of a castle. After deformation, the castle looks organic and elastic. Deformation can breathe life...

Palmer, James Dean

2012-06-07T23:59:59.000Z

127

Application of the multi-mechanism deformation model for three-dimensional simulations of salt : behavior for the strategic petroleum reserve.  

SciTech Connect (OSTI)

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.

Ehgartner, Brian L.; Sobolik, Steven Ronald; Bean, James E.

2010-07-01T23:59:59.000Z

128

Neutron scattering on deformed nuclei  

Science Journals Connector (OSTI)

Measurements of neutron elastic and inelastic differential cross sections around 14 MeV for 9Be C 181 Ta 232Th 238U and 239Pu have been analyzed using a coupled channel (CC) formalism for deformed nuclei and phenomenological global optical model potentials (OMP). For the actinide targets these results are compared with the predictions of a semi?microscopic calculation using Jeukenne Lejeune and Mahaux (JLM) microscopic OMP and a deformed ground state nuclear density. The overall agreement between calculations and the measurements is reasonably good even for the very light nuclei where the quality of the fits is better than those obtained with spherical OMP.

L. F. Hansen; R. C. Haight; B. A. Pohl; C. Wong; Ch. Lagrange

1985-01-01T23:59:59.000Z

129

A thermo-mechanical large deformation constitutive model for polymers based on material network description: Application to a semi-crystalline polyamide 66  

Science Journals Connector (OSTI)

Abstract A visco-hyperelastic constitutive model, based on an original approach initially developed by (Billon, 2012) and applied to amorphous rubbery polymers for a one-dimensional formalism, was extended in this study to three-dimensional constitutive equations based on a thermodynamic framework. The model was applied to a semi-crystalline polyamide polymer, PA66. The experiments included tension and shear testing coupled with synchronized digital image correlation and infrared measurements device for capturing the time, temperature, and stress state dependence, as well as the complex thermomechanical coupling exhibited by the material under large deformation. A notion of equivalent strain rate (based on the time–temperature principle superposition) was also introduced to show its capability to build master curves and therefore decrease the number of testing needed to build a material database. The model is based on the Edward Vilgis theory (1986) and accounts for chains network reorganization under external loading through the introduction of an evolution equation for the internal state variable, ? ¯ , representing the degree of mobility of entanglement points. The model accounting for the equivalent strain rate notion was calibrated using master curves. The thermomechanical model agreed well with the experimental mechanical and temperature measurements under tension and shear conditions. The approach developed in this study may open a different way to model the polymer behavior.

A. Maurel-Pantel; E. Baquet; J. Bikard; J.L. Bouvard; N. Billon

2015-01-01T23:59:59.000Z

130

Response of a bubble bearing viscoelastic fluid to rapid decompression: Implications for explosive volcanic eruptions  

E-Print Network [OSTI]

Response of a bubble bearing viscoelastic fluid to rapid decompression: Implications for explosive Abstract We conducted rapid decompression experiments using bubble-bearing viscoelastic fluid in a vertical of the bubbles, DP=Pg Ã?Po, to understand the behavior of bubbly-magmas under rapid decompression. We find

Manga, Michael

131

Tension Dynamics and Linear Viscoelastic Behavior of a Single Semiflexible Polymer Chain  

E-Print Network [OSTI]

We study the dynamical response of a single semiflexible polymer chain based on the theory developed by Hallatschek et al. for the wormlike-chain model. The linear viscoelastic response under oscillatory forces acting at the two chain ends is derived analytically as a function of the oscillation frequency . We shall show that the real part of the complex compliance in the low frequency limit is consistent with the static result of Marko and Siggia whereas the imaginary part exhibits the power-law dependence +1/2. On the other hand, these compliances decrease as the power law -7/8 for the high frequency limit. These are different from those of the Rouse dynamics. A scaling argument is developed to understand these novel results.

T. Hiraiwa; T. Ohta

2009-03-12T23:59:59.000Z

132

Viscoelastic effects in a spherical Gravitational Wave antenna  

E-Print Network [OSTI]

Internal friction effects are responsible for line widening of the resonance frequencies in spherical gravitational wave detectors, and result in exponentially damped oscillations of its eigenmodes with a decay time which is proportional to the quality factor of the mode and to its inverse frequency. We study the solutions to the equations of motion for a viscoelastic spherical GW detector based on various different assumptions about the material's constituent equations. Quality factor dependence on mode frequency is determined in each case, and a discussion of its applicability to actual detectors is made.

J. A. Lobo; J. A. Ortega

1998-02-09T23:59:59.000Z

133

Viscoelastic{Viscoplastic Damage Model for Asphalt Concrete  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.2.1 Yield surface . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2.2 Viscoplastic potential energy function . . . . . . . . . . . . . . 23 2.2.3 Hardening function . . . . . . . . . . . . . . . . . . . . . . . . 23 2.3 Numerical... viii LIST OF FIGURES FIGURE Page 1.1 Moisture-induced damage in pavements results in raveling and potholing 4 1.2 Adhesive and cohesive failure . . . . . . . . . . . . . . . . . . . . . . . 5 1.3 Damaged and e ective undamaged con gurations...

Graham, Michael A.

2010-10-12T23:59:59.000Z

134

Interaction with deformable displays  

Science Journals Connector (OSTI)

Technological developments in display technologies allow us to explore the design of mobile devices that extend beyond the rigid, flat screen surfaces with which we are familiar. The next generation mobile devices will instead include deformable displays ... Keywords: deformable displays, display surfaces, interaction, shape-changing displays

Jason Alexander; Johan Kildal; Kasper Hornbaek; Viljakaisa Aaltonen; Andrés Lucero; Sriram Subramanian

2012-09-01T23:59:59.000Z

135

Tumor Tracking Method Based on a Deformable 4D CT Breathing Motion Model Driven by an External Surface Surrogate  

SciTech Connect (OSTI)

Purpose: To develop a tumor tracking method based on a surrogate-driven motion model, which provides noninvasive dynamic localization of extracranial targets for the compensation of respiration-induced intrafraction motion in high-precision radiation therapy. Methods and Materials: The proposed approach is based on a patient-specific breathing motion model, derived a priori from 4-dimensional planning computed tomography (CT) images. Model parameters (respiratory baseline, amplitude, and phase) are retrieved and updated at each treatment fraction according to in-room radiography acquisition and optical surface imaging. The baseline parameter is adapted to the interfraction variations obtained from the daily cone beam (CB) CT scan. The respiratory amplitude and phase are extracted from an external breathing surrogate, estimated from the displacement of the patient thoracoabdominal surface, acquired with a noninvasive surface imaging device. The developed method was tested on a database of 7 lung cancer patients, including the synchronized information on internal and external respiratory motion during a CBCT scan. Results: About 30 seconds of simultaneous acquisition of CBCT and optical surface images were analyzed for each patient. The tumor trajectories identified in CBCT projections were used as reference and compared with the target trajectories estimated from surface displacement with the a priori motion model. The resulting absolute differences between the reference and estimated tumor motion along the 2 image dimensions ranged between 0.7 and 2.4 mm; the measured phase shifts did not exceed 7% of the breathing cycle length. Conclusions: We investigated a tumor tracking method that integrates breathing motion information provided by the 4-dimensional planning CT with surface imaging at the time of treatment, representing an alternative approach to point-based external–internal correlation models. Although an in-room radiograph-based assessment of the reliability of the motion model is envisaged, the developed technique does not involve the estimation and continuous update of correlation parameters, thus requiring a less intense use of invasive imaging.

Fassi, Aurora, E-mail: aurora.fassi@mail.polimi.it [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Schaerer, Joël; Fernandes, Mathieu [CREATIS, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Léon Bérard, Lyon (France); Riboldi, Marco [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy); Sarrut, David [CREATIS, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Léon Bérard, Lyon (France); Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy)

2014-01-01T23:59:59.000Z

136

Intrinsic Route to Melt Fracture in Polymer Extrusion: AWeakly Nonlinear Subcritical Instability of Viscoelastic Poiseuille Flow  

E-Print Network [OSTI]

Intrinsic Route to Melt Fracture in Polymer Extrusion: AWeakly Nonlinear Subcritical Instability generic route to melt fracture via a weakly nonlinear subcritical instability of viscoelastic Poiseuille ``subcritical'') instability due to normal stress effects; this instability appears to make melt fracture

van Saarloos, Wim

137

The Effect Of Viscoelastic Surfactants Used In Carbonate Matrix Acidizing On Wettability  

E-Print Network [OSTI]

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 matrix acidizing. However...

Adejare, Oladapo

2012-07-16T23:59:59.000Z

138

Heat transfer from a continuous surface in a parallel free stream of viscoelastic fluid  

Science Journals Connector (OSTI)

The effect of uniform suction or injection on flow and heat transfer from a continuous surface in a parallel free stream of viscoelastic second-order fluid is investigated. A perturbation method is used ... profi...

Dr. F. M. Hady; Dr. R. S. R. Gorla

1998-01-01T23:59:59.000Z

139

Heat transfer in the flow of a viscoelastic fluid over a stretching sheet  

Science Journals Connector (OSTI)

The problem of heat transfer in the viscoelastic fluid flow over a stretching sheet is examined. ... such as the skin-friction coefficient and the heat transfer coefficient, are determined. It is found that the heat

P. Sam Lawrence; Dr. B. Nageswara Rao

1992-01-01T23:59:59.000Z

140

A Viscoelastic-Viscoplastic Analysis of Fiber Reinforced Polymer Composites Undergoing Mechanical Loading and Temperature Changes  

E-Print Network [OSTI]

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...

Jeon, Jaehyeuk

2013-08-09T23:59:59.000Z

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


141

Run-up and spin-up in a viscoelastic fluid. I.  

Science Journals Connector (OSTI)

An incompressible viscoelastic fluid is contained between parallel rigid plates which at some instant of time are subjected to a translational velocity which is then held constant. The dependence on time of th...

Dr. J. Y. Kazakia; Prof. R. S. Rivlin

1997-01-01T23:59:59.000Z

142

Run-up and spin-up in a viscoelastic fluid. III  

Science Journals Connector (OSTI)

The problem is discussed of run-up in an incompressible viscoelastic fluid contained between infinite parallel rigid plates which are simultaneously given equal parallel velocities. The problem is analyzed in ...

Prof. R. S. Rivlin

1997-01-01T23:59:59.000Z

143

A Multi-scale Framework for Thermo-viscoelastic Analysis of Fiber Metal Laminates  

E-Print Network [OSTI]

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...

Sawant, Sourabh P.

2010-01-14T23:59:59.000Z

144

Nonlinear viscoelastic characterization of AS-3502 graphite/epoxy composite material  

E-Print Network [OSTI]

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...

Kerstetter, Michael Scott

2012-06-07T23:59:59.000Z

145

Probing shear-banding transitions of the VCM model for entangled wormlike micellar solutions using large amplitude oscillatory shear (LAOS) deformations  

E-Print Network [OSTI]

We explore the use of large amplitude oscillatory shear (LAOS) deformation to probe the dynamics of shear-banding in soft entangled materials, primarily wormlike micellar solutions which are prone to breakage and disentanglement ...

Zhou, Lin

146

A dynamic viscoelastic contact problem with normal compliance, finite penetration and nonmonotone slip rate dependent friction  

Science Journals Connector (OSTI)

Abstract We consider a mathematical model which describes the dynamic evolution of a viscoelastic body in frictional contact with an obstacle. The contact is modelled with normal compliance and unilateral constraint, associated to a rate slip-dependent version of Coulomb’s law of dry friction. In order to approximate the contact conditions, we consider a regularized problem wherein the contact is modelled by a standard normal compliance condition without finite penetrations. For each problem, we derive a variational formulation and an existence result of the weak solution of the regularized problem is obtained. Next, we prove the convergence of the weak solution of the regularized problem to the weak solution of the initial nonregularized problem. Then, we introduce a fully discrete approximation of the variational problem based on a finite element method and on a second order time integration scheme. The solution of the resulting nonsmooth and nonconvex frictional contact problems is presented, based on approximation by a sequence of nonsmooth convex programming problems. Finally, some numerical simulations are provided in order to illustrate both the behaviour of the solution related to the frictional contact conditions and the convergence result.

Mikäel Barboteu; Krzysztof Bartosz; Piotr Kalita

2015-01-01T23:59:59.000Z

147

Probing deformed commutators with macroscopic harmonic oscillators  

E-Print Network [OSTI]

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.

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

2014-11-24T23:59:59.000Z

148

Probing deformed commutators with macroscopic harmonic oscillators  

E-Print Network [OSTI]

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.

Bawaj, Mateusz; Bonaldi, Michele; Bonfigli, Federica; Borrielli, Antonio; Di Giuseppe, Giovanni; Marconi, Lorenzo; Marino, Francesco; Natali, Riccardo; Pontin, Antonio; Prodi, Giovanni A; Serra, Enrico; Vitali, David; Marin, Francesco

2014-01-01T23:59:59.000Z

149

Contractions, deformations and curvature  

E-Print Network [OSTI]

The role of curvature in relation with Lie algebra contractions of the pseudo-ortogonal algebras so(p,q) is fully described by considering some associated symmetrical homogeneous spaces of constant curvature within a Cayley-Klein framework. We show that a given Lie algebra contraction can be interpreted geometrically as the zero-curvature limit of some underlying homogeneous space with constant curvature. In particular, we study in detail the contraction process for the three classical Riemannian spaces (spherical, Euclidean, hyperbolic), three non-relativistic (Newtonian) spacetimes and three relativistic ((anti-)de Sitter and Minkowskian) spacetimes. Next, from a different perspective, we make use of quantum deformations of Lie algebras in order to construct a family of spaces of non-constant curvature that can be interpreted as deformations of the above nine spaces. In this framework, the quantum deformation parameter is identified as the parameter that controls the curvature of such "quantum" spaces.

Angel Ballesteros; Francisco J. Herranz; Orlando Ragnisco; Mariano Santander

2007-06-15T23:59:59.000Z

150

Nanolaminate deformable mirrors  

DOE Patents [OSTI]

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.

Papavasiliou, Alexandros P. (Oakland, CA); Olivier, Scot S. (Santa Cruz, CA)

2009-04-14T23:59:59.000Z

151

On deformation twinning in a 17.5%Mn-TWIP steel: A physically...  

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

On deformation twinning in a 17.5%Mn-TWIP steel: A physically-based phenomenological model. On deformation twinning in a 17.5%Mn-TWIP steel: A physically-based phenomenological...

152

Seismology of plastic deformation Jero^me Weiss *, Francois Louchet  

E-Print Network [OSTI]

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

Weiss, Jérôme

153

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

E-Print Network [OSTI]

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

Alexander N. Morozov; Wim van Saarloos

2004-11-10T23:59:59.000Z

154

Motion of a Viscoelastic Micellar Fluid Around a Cylinder: Flow and Fracture  

E-Print Network [OSTI]

We present an experimental study of the motion of a viscoelastic micellar material around a moving cylinder, which ranges in response from fluid-like flow to solid-like tearing and fracture, depending on the cylinder radius and velocity. The observation of viscoelastic crack propagation driven by the cylinder indicates an extremely low tear strength, approximately equal to the steady state surface tension of the fluid. At the highest speeds a driven crack is observed in front of the cylinder, propagating with a fluctuating speed equal on average to the cylinder speed, here as low as 5% of the elastic wave speed in the medium.

Joseph R. Gladden; Andrew Belmonte

2006-05-25T23:59:59.000Z

155

Role of viscoelasticity and non-linear rheology in flows of complex fluids at high deformation rates  

E-Print Network [OSTI]

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 ...

Ober, Thomas J. (Thomas Joseph)

2013-01-01T23:59:59.000Z

156

SUBCRITICAL INSTABILITIES IN PLANE COUETTE FLOW OF VISCO-ELASTIC FLUIDS  

E-Print Network [OSTI]

SUBCRITICAL INSTABILITIES IN PLANE COUETTE FLOW OF VISCO-ELASTIC FLUIDS Alexander N. Morozov of an eigenfunction of the linearized equations of motion becomes subcritically unstable, and the threshold value, subcritical instabilities, amplitude equation Introduction In the last decades, stability of flows of polymers

van Saarloos, Wim

157

3812 Macromolecules 1994,27, 3812-3820 Viscoelasticity of Adsorbed Polymer Layers  

E-Print Network [OSTI]

3812 Macromolecules 1994,27, 3812-3820 Viscoelasticity of Adsorbed Polymer Layers P. Sens,' C. M with the thickness of the adsorbed layers. At a high frequency,the complex modulus increases as G = u2/3and is independentof the thickness of the polymer layers. When the adsorbed polymer layers overlap

Sens, Pierre

158

Slow filament dynamics and viscoelasticity in entangled and active actin networks  

Science Journals Connector (OSTI)

...of biopolymers and molecular motors. ChemPhysChem 3, 270{275...networks through molecular motors. Nature 416, 413{416...vesicles, which will enable future studies of viscoelastic Phil...entangle- ment' refer to quantum coherence? Also, can you...

2003-01-01T23:59:59.000Z

159

Formation of beads-on-a-string structures during break-up of viscoelastic filaments  

E-Print Network [OSTI]

Break-up of viscoelastic filaments is pervasive in both nature and technology. If a filament is formed by placing a drop of saliva between a thumb and forefinger and is stretched, the filament’s morphology close to break-up ...

Bhat, Pardeep P.

160

The viscoelastic behaviour of raw and anaerobic digested sludge: strong similarities with soft-glassy materials  

E-Print Network [OSTI]

1 The viscoelastic behaviour of raw and anaerobic digested sludge: strong similarities with soft confronted with a dramatically increasing flow of sewage sludge. To improve treatment efficiency, process reliable flow properties to simulate the process, this work is an attempt to approach sludge rheological

Paris-Sud XI, Université de

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


161

Measurement of the viscoelastic properties of liquid crystals using the piezoelectric ultrasonic composite oscillator  

E-Print Network [OSTI]

and encouragements. It was a pleasure to meet Dr. Stuart I. Smedley who shared with me his personal experience and new ideas in the development and use of the PUCO for studying the viscoelastic properties of liquids. Dehors A. Fairbrother and Lloyd Steven Cook...

Seet, Tiong Boon

2012-06-07T23:59:59.000Z

162

Cyclic performance of viscoelastic dielectric elastomers with solid hydrogel Yuanyuan Bai,1  

E-Print Network [OSTI]

of manufacturing or fabrication by 3D printing, silent operation, and capability of large deformation.1

Suo, Zhigang

163

Quantifying non-axial deformations in rat myocardium  

E-Print Network [OSTI]

improve our experimental models. In order to do so, we must first understand the manner in which myocardial geometry changes in response to deformation, i.e., strain. The goal of this research project is to develop an experimental method to examine... muscle fiber deformations. However, Zahalak?s model maked assumptions about myocardial geometry that have yet to be validated, and he highlighted the need for more investigation in this area. GROWTH AND REMODELING During development and disease...

Aghassibake, Kristina Diane

2005-02-17T23:59:59.000Z

164

Investigation of Deformation Dynamics in a Wrought Magnesium Alloy  

SciTech Connect (OSTI)

In the present research, the deformation dynamics and the effect of the deformation history on plastic deformation in a wrought magnesium alloy have been studied using real-time in-situ neutron diffraction measurements under a continuous loading condition and elastic-viscoplastic self-consistent (EVPSC) polycrystal modeling. The experimental results reveal that the pre-deformation delayed the activation of the tensile twinning during subsequent compression, mainly resulting from the residual strain. No apparent detwinning occurred during unloading and even in the elastic region during reverse loading. It is believed that the grain rotation played an important role in the elastic region during reverse loading. The EVPSC model, which has been recently updated by implementing the twinning and detwinning model, was employed to characterize the deformation mechanism during the strain-path changes. The simulation result predicts well the experimental observation from the real-time in-situ neutron diffraction measurements. The present study provides a deep insight of the nature of deformation mechanisms in a hexagonal close-packed structured polycrystalline wrought magnesium alloy, which might lead to a new era of deformation-mechanism research.

Wu, Wei [ORNL; Qiao, Hua [McMaster University; An, Ke [ORNL; Wu, Peidong [McMaster University; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2014-01-01T23:59:59.000Z

165

Deformed "Commutative" Chern - Simons System  

E-Print Network [OSTI]

Noncommutative Chern - Simons' system is non-perturbatively investigated at a full deformed level. A deformed "commutative" phase space is found by a non-canonical change between two sets of deformed variables of noncommutative space. It is explored that in the "commutative" phase space all calculations are similar to the case in commutative space. Spectra of the energy and angular momentum of the Chern - Simons' system are obtained at the full deformed level. The noncommutative-commutative correspondence is clearly showed. Formalism for the general dynamical system is briefly presented. Some subtle points are clarified.

Jian-Zu Zhang

2009-07-30T23:59:59.000Z

166

Heat transfer in a visco-elastic fluid past a stretching sheet with viscous dissipation and internal heat generation  

Science Journals Connector (OSTI)

This paper deals with the study of heat transfer characteristics in the laminar boundary layer flow of a visco-elastic fluid over a linearly stretching continuous surface with ... . The study considers the effect...

P. H. Veena; Subhash Abel; K. Rajagopal…

2006-05-01T23:59:59.000Z

167

Flow and heat transfer from a continuous surface in a parallel free stream of viscoelastic second-order fluid  

Science Journals Connector (OSTI)

Boundary layer solutions are presented to investigate the steady flow and heat transfer characteristics from a continuous flat surface moving in a parallel free stream of viscoelastic fluid. Numerical results are...

I. A. Hassanien

1992-10-01T23:59:59.000Z

168

Experimental Studies on Visco-plastic Lubrication of Visco-elastic Fluid: Interfacial Instability and Geometry Effect  

E-Print Network [OSTI]

of application in industry, such as in co- extrusion processes and lubricated pipelining. In the case of a duct to establish the base multi-layer flows at all, using a visco-elastic fluid (Poly Ethylene Oxide solution

Ishii, Hitoshi

169

q-deformed dynamics and Josephson junction  

E-Print Network [OSTI]

We define a generalized rate equation for an observable in quantum mechanics, that involves a parameter q and whose limit $q\\to 1$ gives the standard Heisenberg equation. The generalized rate equation is used to study dynamics of current biased Josephson junction. It is observed that this toy model incorporates diffraction like effects in the critical current. Physical interpretation for q is provided which is also shown to be q-deformation parameter.

Ramandeep S. Johal

2000-10-04T23:59:59.000Z

170

Role of deformation in exotic decay studies  

SciTech Connect (OSTI)

We have recently constructed a model for exotic decay studies using a cubic potential for the overlapping region that is smoothly connected by a Yukawa-plus-exponential potential for the region after separation. In this model, the zero-point vibration energy is explicitly used without violating the energy conservation and the inertial mass coefficient is made dependent on the center of mass distance, but the deformation effect has not been included. In this work, it is taken into account in both the parent and the daughter nuclei, keeping the emitted nucleus always spherical. This model is applied to the cases of {sup 14}C and {sup 24}Ne emissions and also for the recently reported cases of {sup 26}Ne, {sup 28,30}Mg, and {sup 34}Si emissions. It is found that the effect of the fragment deformation (which is always very small in the above decays) on lifetime is negligible while the parent deformation plays an appreciable role in the lifetime calculations.

Shanmugam, G.; Kamalaharan, B. (Department of Physics, Presidency College, Madras 600 005, India (IN))

1990-03-01T23:59:59.000Z

171

A stable and convergent scheme for viscoelastic flow in contraction channels  

SciTech Connect (OSTI)

We present a new algorithm to simulate unsteady viscoelastic flows in abrupt contraction channels. In our approach we split the viscoelastic terms of the Oldroyd-B constitutive equation using Duhamel's formula and discretize the resulting PDEs using a semi-implicit finite difference method based on a Lax-Wendroff method for hyperbolic terms. In particular, we leave a small residual elastic term in the viscous limit by design to make the hyperbolic piece well-posed. A projection method is used to impose the incompressibility constraint. We are able to compute the full range of elastic flows in an abrupt contraction channel--from the viscous limit to the elastic limit--in a stable and convergent manner for elastic Mach numbers less than one. We demonstrate the method for unsteady Oldroyd-B and Maxwell fluids in planar contraction channels.

Trebotich, David; Colella, Phillip; Miller, Gregory

2004-02-15T23:59:59.000Z

172

Importance of Viscoelastic Property Measurement of a New Hydrogel for Health Care  

Science Journals Connector (OSTI)

A simple technology based new hydrogel “PVP?CMC?BA” has been prepared by the scientists of Tomas Bata University in Zlin Czech Republic. Its swelling property (in presence of water human blood and different pH) antimicrobial property (in presence of skin infection causing agents like: Staphylococcus aureus; bacteria and Candida albicans; fungi) and viscoelastic properties such as storage modulus (G’) loss modulus (G”) and complex viscosity (?*) were investigated at room temperature (25–28°?C) which demonstrate that PVP?CMC?BA hydrogel is maintaining requisite properties for health care application specially as a wound dressing material. The elasticity and antimicrobial property of PVP?CMC?BA is directly correlated with percentage of boric acid an antiseptic agent. The consequential values of viscoelastic properties of the hydrogel (before drying) enable us to understand its specific flexible condition to apply on the surface of human body.

Niladri Roy; Nabanita Saha; Takeshi Kitano; Petr Saha

2009-01-01T23:59:59.000Z

173

Habit tic deformity secondary to guitar playing  

E-Print Network [OSTI]

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

Wu, Jashin J

2009-01-01T23:59:59.000Z

174

On the asymptotic behavior of the quasi-static problem for a linear viscoelastic fluid  

E-Print Network [OSTI]

In this paper we study the quasi-static problem for a viscoelastic fluid by means of the concept of minimal state. This implies the use of a different free energy defined in a wider space of data. The existence and uniqueness is proved in this new space and the asymptotic decay for the problem with non vanishing supplies is obtained for a large class of memory kernels, including those presenting an exponential or polynomial decay.

Mauro Fabrizio; Barbara Lazzari; Roberta Nibbi

2011-04-14T23:59:59.000Z

175

Thermomechanical characterization of a membrane deformable mirror  

SciTech Connect (OSTI)

A membrane deformable mirror has been investigated for its potential use in high-energy laser systems. Experiments were performed in which the deformable mirror was heated with a 1 kW incandescent lamp and the thermal profile, the wavefront aberrations, and the mechanical displacement of the membrane were measured. A finite element model was also developed. The wavefront characterization experiments showed that the wavefront degraded with heating. Above a temperature of 35 deg. C, the wavefront characterization experiments indicated a dramatic increase in the high-order wavefront modes before the optical beam became immeasurable in the sensors. The mechanical displacement data of the membrane mirror showed that during heating, the membrane initially deflected towards the heat source and then deflected away from the heat source. Finite element analysis (FEA) predicted a similar displacement behavior as shown by the mechanical displacement data but over a shorter time scale and a larger magnitude. The mechanical displacement data also showed that the magnitude of membrane displacement increased with the experiments that involved higher temperatures. Above a temperature of 35 deg. C, the displacement data showed that random deflections as a function of time developed and that the magnitude of these deflections increased with increased temperature. We concluded that convection, not captured in the FEA, likely played a dominant role in mirror deformation at temperatures above 35 deg. C.

Morse, Kathleen A.; McHugh, Stuart L.; Fixler, Jeff

2008-10-10T23:59:59.000Z

176

The viscoelastic properties of linear-star blends  

E-Print Network [OSTI]

In order to understand the nature of polydispersity and characterize the effect of branching architecture, the model blend of linear and star polymer, which is the simplest branched polymer, is contrived. In this blend system, chain dynamics...

Lee, Jung Hun

2000-01-01T23:59:59.000Z

177

A large-deformation thermo-mechanically coupled elastic-viscoplastic theory for amorphous polymers : modeling of micro-scale forming and the shape memory phenomenon  

E-Print Network [OSTI]

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 ...

Srivastava, Vikas

2010-01-01T23:59:59.000Z

178

Microstructurally-based constitutive models of cytoskeletal networks for simulation of the biomechanical response of biological cells  

E-Print Network [OSTI]

The elastic and viscoelastic stress-strain behavior of cytoskeletal networks, important to many cellular functions, is modeled via a microstructurally-informed continuum mechanics approach. The force-extension behavior of ...

Palmer, Jeffrey Shane

2008-01-01T23:59:59.000Z

179

Deformed shell model calculations of half lives for {beta}{sup +}/EC decay and 2{nu} {beta}{sup +}{beta}{sup +}/{beta}{sup +}EC/ECEC decay in medium-heavy N{approx}Z nuclei  

SciTech Connect (OSTI)

The {beta}{sup +}/EC half-lives of medium heavy N{approx}Z nuclei with mass number A{approx}64-80 are calculated within the deformed shell model (DSM) based on Hartree-Fock states by employing a modified Kuo interaction in ({sup 2}p{sub 3/2},{sup 1}f{sub 5/2},{sup 2}p{sub 1/2},{sup 1}g{sub 9/2}) space. The DSM model has been quite successful in predicting many spectroscopic properties of N{approx}Z medium heavy nuclei with A{approx}64-80. The calculated {beta}{sup +}/EC half-lives, for prolate and oblate shapes, compare well with the predictions of the calculations with Skyrme force by Sarriguren et al. Going further, following recent searches, half-lives for 2{nu} {beta}{sup +}{beta}{sup +}/{beta}{sup +}EC/ECEC decay for the nucleus {sup 78}Kr are calculated using DSM and the results compare well with QRPA predictions.

Mishra, S.; Sahu, R. [Physics Department, Berhampur University, Berhampur 760 007, Orissa (India); Shukla, A. [Physical Research Laboratory, Ahmedabad 380 009 (India); Kota, V. K. B. [Physical Research Laboratory, Ahmedabad 380 009 (India); Department of Physics, Laurentian University, Sudbury, ON P3E 2C6 (Canada)

2008-08-15T23:59:59.000Z

180

Deformable Mirror Materials Issue Assessment  

SciTech Connect (OSTI)

It was a pleasure to speak with you and Dr. Olivier Guyon about your project to develop a coronagraph and in particular about materials science considerations in the development of the deformable mirror (DM) for the coronagraph. The coronagraph application will demand more of a DM than previous applications with regard to precision, and since the characterization and modeling tools are currently under development, you asked me to comment on materials issues that might impact the DM design and testing. I have not conducted research on this question, and my own research on modeling MEMS has not included DM systems. I am only in a position to discuss some general considerations that may help in developing a research plan for the DM system. As I understand it, the relevant points about the DM system are as follows. The DM surface needs to be positioned to less than 1 {angstrom} RMS of the desired shape, and be stable to 0.3 {angstrom} RMS for an hour. In the ultimate application in space the stability requirements may be greater. For example, the DM shape can be set using a bright star and then allow the coronagraph to be turned to a dim star to collect data for several hours, counting on the mirror shape to be stable. The DM is made of a polysilicon membrane coated with one or more metal layers for the reflective surface and actuated by 32x32 or 64x64 electrostatic actuators on the back side. The uncertainty in the position of any one actuator should be at the few-picometer level or less averaged over the 300-{micro}m region of the actuator. Currently, experiments are conducted that can characterize the surface shape to the 1 nm level, and it is anticipated that the experiments will be able to characterize the shape at the sub-Angstrom level but not in the immediate future. Regarding stability, under relatively large deformations (10's of nm), the DM mirror surface shows no hysteresis at the measurable nm level. Let me begin by saying that I am not aware of any article in the literature that directly assesses surface position stability at the sub-Angstrom level across 100's of microns of surface. Interferometry is typically used for precise metrology over areas this large, but not typically at the sub-Angstrom level. For the purpose of these comments, I assume that it will be possible to measure the precision of the mirror shape and stability at the requisite sub-Angstrom level at some point during the coronagraph development using interferometers or some other high-precision metrology technique. The hope is that the comments at this point may identify some potential issues that can be resolved early in the development to avoid costly surprises in the later stages.

Rudd, R E

2008-05-27T23:59:59.000Z

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


181

Reflection of Waterborne acoustic waves from a viscoelastic layer on a rigid hacking with perforations  

Science Journals Connector (OSTI)

The reflection coefficient is calculated for a plane acoustic wave normally incident on a viscoelasticrubber cover layer submerged in water. The rubber layer is mounted on a rigid backing with air?filled cylindrical perforations. Acoustical losses are attributed to motion of the layer over the perforations. This motion is calculated by treating the layer above each perforation as a vibrating circular viscoelastic plate. Different boundary conditions are assumed and in each case the soundreflection coefficient is calculated. The results are compared with the experimental data of R. Lane [Ultrason. 19 28–30 (1981)].

J. Jarzynski

1982-01-01T23:59:59.000Z

182

An analytical solution to steady-state temperature distribution of N-layer viscoelastic suspensions used in crawler vehicles  

Science Journals Connector (OSTI)

An analytical method is proposed for solving the steady-state temperature distribution of N-layer viscoelastic suspensions with non-uniform heat generation. To find the temperature distribution laws of the suspension, the heat flow and temperature distribution formulas are derived. Two numerical examples are performed to verify the correction of the derived formulas. The temperature results obtained by the derived formulas are compared with those obtained by Finite Element Method (FEM). The results show strong consistency with each other, which indicates that the proposed method is valid and feasible. The derived formulas can provide reference for the development of high performance N-layer viscoelastic suspensions.

Yong Song; Dagang Sun; Xin Zhang; Bijuan Yan

2012-01-01T23:59:59.000Z

183

Viscoelastic modes in a strongly coupled, cold, magnetized dusty plasma  

SciTech Connect (OSTI)

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.

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

184

Modeling and Algorithmic Approaches to Constitutively-Complex, Micro-structured Fluids  

SciTech Connect (OSTI)

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.

Forest, Mark Gregory [University of North Carolina at Chapel Hill] [University of North Carolina at Chapel Hill

2014-05-06T23:59:59.000Z

185

Deformation and failure of zircaloy fuel sheaths under LOCA conditions  

SciTech Connect (OSTI)

A unified, microstructural creep law which simulates the transient creep deformation of Zircaloy at temperatures above 750 K has been used to follow the interaction of diffusional and dislocation creep with changes in material microstructure (grain size, recrystallization, phase fraction and anisotropy) under loss-of-coolant accident (LOCA) conditions. Comparison of a membrane sheath model using this creep law with a large number of tube tests (>700) in an inert environment had demonstrated good predictive capability. This model has been extended to cover other aspects affecting deformation deformation and failure of CANDU fuel sheaths such as: nonuniform structure distribution resulting from temperature profiles along the sheath length, oxidation of the fuel sheaths, cracking of the oxidized layers and localized straining, large strain failure, and failure by beryllium-assisted cracking. 13 figures, 26 references.

Sagat, S.; Sills, H.E.; Walsworth, J.A.

1984-01-01T23:59:59.000Z

186

Fluid-driven deformation of a soft granular material  

E-Print Network [OSTI]

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. In growing, melting, granular, and fibrous materials, these interactions can be extremely complex. Here, we present a high-resolution measurement of poromechanical deformation driven by fluid injection. 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. While a continuum model based on a modification of conventional poroelastic theory captures certain macroscopic features of the deformation, the particle-scale deformation field exhibits dramatic departures from smooth, continuum behavior. We observe novel grain-scale plasticity and hysteresis, as well as petal-like mesoscale structures that are connected to material failure through spiral shear banding.

Christopher W. MacMinn; Eric R. Dufresne; John S. Wettlaufer

2014-05-28T23:59:59.000Z

187

Structural-borne sound mitigation in small wind turbines using constrained viscoelastic layer  

Science Journals Connector (OSTI)

As the growing acceptance of small wind turbines operating in suburban and rural communities coincides with increasingly stringent regulations on the sound emitted by these turbines the need for sound mitigation solutions becomes urgent. Small turbines need to be affordable for small business use and thus proposed solutions must be cost-effective and low maintenance. Easy retrofit to existing turbines is also desirable. Wind turbines generate sound via two main mechanisms: structural borne sound generated by the gearbox and generator and transmitted through the nacelle structure and aeroacoustic sound generated by the interaction of the airstream with the rotating blades and other turbine components. Current study focused on the mitigation of structural-borne sound in a 50 kW wind turbine using a constrained viscoelastic layer. The viscoelastic layer comprised of multiple tiles with normal force to the nacelle structure provided by ratcheting bands. Optimal value for the normal force was empirically determined and the resulting reductions in generated sound were documented both in the laboratory and on a working turbine under a number of operating conditions. The result is a cost-effective solution with zero cost of ownership and easy installation on a wide range of small to medium-size wind turbines.

Nic Strum; David Sampson; Ali Kheirabadi

2013-01-01T23:59:59.000Z

188

Deformation of subducted oceanic lithosphere  

Science Journals Connector (OSTI)

......versus strain-rate exponent of n...observed for large F. Penetration of the slab below...G.F. , 1995. Penetration of plates and plumes...Seismic strain rate and deep slab deformation...versus strain-rate exponent of n...observed for large F. Penetration of the slab below......

Gregory A. Houseman; David Gubbins

1997-12-01T23:59:59.000Z

189

A Framework for Coupled Deformation-Diffusion Analysis with Application to Degradation/Healing  

E-Print Network [OSTI]

deformation-dependent diffusivity tensor we did not use k3 just to be consistent with the theory of linearized elasticity. However, in the case of finite elas- ticity, one should also use the third invariant in modeling the deformation-dependent diffusivity...

Mudunuru, Maruti Kumar

2012-07-16T23:59:59.000Z

190

Low fault friction in Iran implies localized deformation for the ArabiaEurasia collision zone  

E-Print Network [OSTI]

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

Vernant, Philippe

191

Transient elastohydrodynamic drag on a particle moving near a deformable wall  

Science Journals Connector (OSTI)

......Sci. 43 (1988) 2673-2684. 9. M. S. Carvalho and L. E. Scriven, Effect of deformable roll cover on roll coating, TAPPI J. 77 (1993) 201-208. 10. M. J. Gostling, M. D. Savage, A. E. Young and P. H. Gaskell, A model for deformable......

S. J. Weekley; S. L. Waters; O. E. Jensen

2006-05-01T23:59:59.000Z

192

DEFORMATIONAL KINKS IN BRUCITE AND GYPSUM  

Science Journals Connector (OSTI)

DEFORMATIONAL KINKS IN BRUCITE AND GYPSUM Francis J. Turner Lionel...CALIFORNIA, BERKELEY DEFORMATIONAL KINKS IN BRUCITE AND GYPSUM. | DEPARTMENT OF GEOLOGY...cgi/georef/georef;1966012724 brucite Brucite and gypsum crystal structure...

Francis J. Turner; Lionel E. Weiss

1965-01-01T23:59:59.000Z

193

Twist deformation of rotationally invariant quantum mechanics  

SciTech Connect (OSTI)

Noncommutative quantum mechanics in 3D is investigated in the framework of an abelian Drinfeld twist which deforms a given Hopf algebra structure. Composite operators (of coordinates and momenta) entering the Hamiltonian have to be reinterpreted as primitive elements of a dynamical Lie algebra which could be either finite (for the harmonic oscillator) or infinite (in the general case). The deformed brackets of the deformed angular momenta close the so(3) algebra. On the other hand, undeformed rotationally invariant operators can become, under deformation, anomalous (the anomaly vanishes when the deformation parameter goes to zero). The deformed operators, Taylor-expanded in the deformation parameter, can be selected to minimize the anomaly. We present the deformations (and their anomalies) of undeformed rotationally invariant operators corresponding to the harmonic oscillator (quadratic potential), the anharmonic oscillator (quartic potential), and the Coulomb potential.

Chakraborty, B. [S.N. Bose National Center for Basic Sciences, JD Block, Sector III, Salt-Lake, Kolkata-700098 (India); Kuznetsova, Z. [UFABC, Rua Catequese 242, Bairro Jardim, cep 09090-400, Santo Andre (Brazil); Toppan, F. [CBPF, Rua Dr. Xavier Sigaud 150, cep 22290-180, Rio de Janeiro (Brazil)

2010-11-15T23:59:59.000Z

194

Subcritical Finite-Amplitude Solutions for Plane Couette Flow of Viscoelastic Fluids Alexander N. Morozov and Wim van Saarloos  

E-Print Network [OSTI]

Subcritical Finite-Amplitude Solutions for Plane Couette Flow of Viscoelastic Fluids Alexander N is shown to exhibit a purely elastic subcritical instability at a very small-Reynolds number in spite. In this Letter we show that visco- elastic plane Couette flow (PCF) exhibits a subcritical instability to finite

van Saarloos, Wim

195

On the postglacial isostatic adjustment of the British Isles and the shallow viscoelastic structure of the Earth  

E-Print Network [OSTI]

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

Peltier, W. Richard

196

Conformal Deformation from Normal to Hermitian Random Matrix Ensembles  

E-Print Network [OSTI]

We investigate the eigenvalues statistics of ensembles of normal random matrices when their order N tends to infinite. In the model the eigenvalues have uniform density within a region determined by a simple analytic polynomial curve. We study the conformal deformations of normal random ensembles to Hermitian random ensembles and give sufficient conditions for the latter to be a Wigner ensemble.

Alexei M. Veneziani; Tiago Pereira; Domingos H. U. Marchetti

2009-09-04T23:59:59.000Z

197

Virtual deformation of soft tissue using bulk variables  

Science Journals Connector (OSTI)

We present an alternative online simulation model for human tissue. Online simulation of human tissue deformation during surgical training or surgical assistance is becoming increasingly important within the medical community. Unfortunately, even classical ... Keywords: soft tissue simulation, surgical simulators, virtual reality

K. Sundaraj

2009-10-01T23:59:59.000Z

198

Cylindric Macdonald functions and a deformation of the Verlinde algebra  

E-Print Network [OSTI]

Cylindric Macdonald functions and a deformation of the Verlinde algebra Christian Korff (christian arxiv: 1110.6356 December 6, 2011 Christian Korff Cylindric Macdonald functions #12;Outline 1 q-Heisenberg algebra and exactly solvable lattice models 2 partition functions: cylindric Macdonald functions 3

Guo, Zaoyang

199

Measuring and segmentation in CT data using deformable Vclav Krajcek  

E-Print Network [OSTI]

tomography (CT). We take advantage of long-time research in the area of deformable models. We have developed Snakes, CT, Medical Segmentation, Volume Measurement. 1 INTRODUCTION Computed tomography is a common tool, that temperature of healthy body is about 36,5 C. Higher temperature means that body is fighting with an illness

Pelikan, Josef

200

MATLOC. Transient Non Lin Deformation in Fractured Rock  

SciTech Connect (OSTI)

MATLOC is a nonlinear, transient, two-dimensional (planer and axisymmetric), thermal stress, finite-element code designed to determine the deformation within a fractured rock mass. The mass is modeled as a nonlinear anistropic elastic material which can exhibit stress-dependent bi-linear locking behavior.

Boonlualohr, P.; Mustoe, G.; Williams, J.R.; Lester, B.H.; Huyakorn, P.S. [Geotrans Inc., (United States)

1983-04-01T23:59:59.000Z

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


201

Quantum mechanical effects from deformation theory  

SciTech Connect (OSTI)

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.

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

202

CubeSat deformable mirror demonstration  

E-Print Network [OSTI]

The goal of the CubeSat Deformable Mirror Demonstration (DeMi) is to characterize the performance of a small deformable mirror over a year in low-Earth orbit. Small form factor deformable mirrors are a key technology needed ...

Cahoy, Kerri

203

Instantaneous crankshaft torsional deformation during turbocharged diesel engine operation  

Science Journals Connector (OSTI)

An experimentally validated diesel engine code is used to study the crankshaft torsional deformations originating in the difference between instantaneous engine and load torques. The analysis aims in studying the phenomena under critical conditions, namely operation when one cylinder malfunctions ('open valves' or motoring situation) as well as during transient conditions. A detailed crankshaft torsional model is formulated; this takes into account cylinder gas, inertia, friction, load and stiffness and damping torques. Details are provided concerning the underlying mechanism of the crankshaft torsional deformations, which can assume significant values depending on the specific configuration, being important for safe engine operation.

E.G. Giakoumis; I.A. Dodoulas; C.D. Rakopoulos

2010-01-01T23:59:59.000Z

204

Nuclear reactions in hot stellar matter and nuclear surface deformations  

Science Journals Connector (OSTI)

Cross sections for capture reactions of charged particles in hot stellar matter turn out be increased by the quadrupole surface oscillations when the corresponding phonon energies are of the order of the star temperature. This increase is studied in a model that combines barrier distribution induced by surface oscillations and tunneling. The capture of charged particles by nuclei with well-deformed ground states is enhanced in stellar matter. It is found that the influence of quadrupole surface deformation on the nuclear reactions in stars grows when mass and proton numbers in colliding nuclei increase.

V. Yu. Denisov

2006-11-28T23:59:59.000Z

205

Plastic Deformations of Carbon Nanotubes  

Science Journals Connector (OSTI)

Although the elastic properties of a carbon nanotube are nearly independent of wrapping indices, we show that the onset of plastic deformation depends very strongly on the wrapping index. An (n,0) nanotube has an elastic limit nearly twice that of an (n,n) tube with the same radius. Such great variation has important consequences for structural applications of carbon nanotubes. In addition, the remnant bond rotations remaining after strain release strongly affect the electronic structure of the distorted nanotube.

Peihong Zhang; Paul E. Lammert; Vincent H. Crespi

1998-12-14T23:59:59.000Z

206

Model for late Neogene deformation in Panama  

SciTech Connect (OSTI)

Previous workers, mostly using earthquake data, have postulated both discrete faults and complex, diffuse zones for the Caribbean-Nazca plate boundary in Panama. We have better resolved the location and character of late Neogene plate-boundary structures by using satellite imagery and a compilation of existing geologic map data. On the basis of these results, we propose that Panama is moving northwestward away from a zone of active convergence along the continental margin of South America toward more easily subducted areas of the Colombian Basin. Movement is accommodated across a diffuse zone by a complex interaction of oroclinal bending, left-lateral strike-slip faulting, and subduction.

Mann, P.; Corrigan, J. (Univ. of Texas, Austin (USA))

1990-06-01T23:59:59.000Z

207

A Deformable Surface Model for Vascular Segmentation  

E-Print Network [OSTI]

­67, 2009. c Springer-Verlag Berlin Heidelberg 2009 #12;60 M.W.K. Law and A.C.S. Chung that is in contact intensity, the geometry of target structures and the contour smoothness to extract tubular structures. Klein

Chung, Albert C. S.

208

Heat and mass transfer in a visco–elastic fluid flow over an accelerating surface with heat source/sink and viscous dissipation  

Science Journals Connector (OSTI)

...?In this paper we present a mathematical analysis of heat and mass transfer phenomena in a visco–elastic fluid flow over an accelerating stretching sheet in the presence of heat source/sink, viscous dissipatio...

R. M. Sonth; S. K. Khan; M. S. Abel; K. V. Prasad

2002-02-01T23:59:59.000Z

209

Comment on Conjugate heat transfer of mixed convection for viscoelastic fluid past a stretching sheet, by Hsiao and Chen, Mathematical Problems in Engineering  

E-Print Network [OSTI]

Comment on Conjugate heat transfer of mixed convection for viscoelastic fluid past a stretching sheet, by Kai-Long Hsiao and Guan-Bang Chen, Mathematical Problems in Engineering, Volume 2007, article 17058, 21 pages

Pantokratoras, Asterios

2008-01-01T23:59:59.000Z

210

Heat and Mass Transfer in the MHD Flow of a Visco-elastic Fluid in a Rotating Porous Channel with Radiative Heat  

Science Journals Connector (OSTI)

This paper deals with heat and mass transfer in the magnetohydrodynamic flow of a visco-elastic fluid in a rotating porous channel with radiative heat. The flow phenomenon has been characterized by the fluid para...

M. Jena; M. Goswami; S. Biswal

2014-12-01T23:59:59.000Z

211

Thermally driven visco-elastic measurement technique via spectral variations in scanning probe microscopy cantilevers  

E-Print Network [OSTI]

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, ...

Jones, Ryan Edward, 1974-

2004-01-01T23:59:59.000Z

212

A two-dimensional deformable phantom for quantitatively verifying deformation algorithms  

SciTech Connect (OSTI)

Purpose: The incorporation of deformable image registration into the treatment planning process is rapidly advancing. For this reason, the methods used to verify the underlying deformation algorithms must evolve equally fast. This manuscript proposes a two-dimensional deformable phantom, which can objectively verify the accuracy of deformation algorithms, as the next step for improving these techniques. Methods: The phantom represents a single plane of the anatomy for a head and neck patient. Inflation of a balloon catheter inside the phantom simulates tumor growth. CT and camera images of the phantom are acquired before and after its deformation. Nonradiopaque markers reside on the surface of the deformable anatomy and are visible through an acrylic plate, which enables an optical camera to measure their positions; thus, establishing the ground-truth deformation. This measured deformation is directly compared to the predictions of deformation algorithms, using several similarity metrics. The ratio of the number of points with more than a 3 mm deformation error over the number that are deformed by more than 3 mm is used for an error metric to evaluate algorithm accuracy. Results: An optical method of characterizing deformation has been successfully demonstrated. For the tests of this method, the balloon catheter deforms 32 out of the 54 surface markers by more than 3 mm. Different deformation errors result from the different similarity metrics. The most accurate deformation predictions had an error of 75%. Conclusions: The results presented here demonstrate the utility of the phantom for objectively verifying deformation algorithms and determining which is the most accurate. They also indicate that the phantom would benefit from more electron density heterogeneity. The reduction of the deformable anatomy to a two-dimensional system allows for the use of nonradiopaque markers, which do not influence deformation algorithms. This is the fundamental advantage of this verification technique.

Kirby, Neil; Chuang, Cynthia; Pouliot, Jean [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708 (United States)

2011-08-15T23:59:59.000Z

213

Physical Simulation of an Embedded Surface Mesh Involving Deformation and Fracture  

E-Print Network [OSTI]

Simulating virtual objects which can deform or break apart within their environments is now common in state-of-the-art virtual simulations such as video games or surgery simulations. Real-time performance requires a physical model which provides...

Clack, Billy

2012-07-16T23:59:59.000Z

214

Formation Flying and Deformable Instruments  

SciTech Connect (OSTI)

Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

Rio, Yvon [CEA/IRFU/Sap, CEA Saclay, 91191 Gif sur Yvette (France)

2009-05-11T23:59:59.000Z

215

Quantum limits to estimation of photon deformation  

E-Print Network [OSTI]

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.

Giovanni De Cillis; Matteo G. A. Paris

2014-07-08T23:59:59.000Z

216

Cryogenic wavefront correction using membrane deformable mirrors  

Science Journals Connector (OSTI)

Micro-machined membrane deformable mirrors (MMDMs) are being evaluated for their suitability as wavefront correctors at cryogenic temperatures. Presented here are experimental...

Dyson, Harold; Sharples, Ray; Dipper, N; Vdovin, Gleb

2001-01-01T23:59:59.000Z

217

Earth tides, earthquake occurrence and earth deformation.  

E-Print Network [OSTI]

??An analysis of Earth deformation, earthquakes and tides has been undertaken using Earth tide and interferometric SAR data from ESA satellites. The ability of Earth… (more)

Kansowa, Tarek

2010-01-01T23:59:59.000Z

218

Origami-enabled deformable silicon solar cells  

SciTech Connect (OSTI)

Deformable electronics have found various applications and elastomeric materials have been widely used to reach flexibility and stretchability. In this Letter, we report an alternative approach to enable deformability through origami. In this approach, the deformability is achieved through folding and unfolding at the creases while the functional devices do not experience strain. We have demonstrated an example of origami-enabled silicon solar cells and showed that this solar cell can reach up to 644% areal compactness while maintaining reasonable good performance upon cyclic folding/unfolding. This approach opens an alternative direction of producing flexible, stretchable, and deformable electronics.

Tang, Rui; Huang, Hai; Liang, Hanshuang; Liang, Mengbing [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Tu, Hongen; Xu, Yong [Electrical and Computer Engineering, Wayne State University, 5050 Anthony Wayne Dr., Detroit, Michigan 48202 (United States); Song, Zeming; Jiang, Hanqing, E-mail: hanqing.jiang@asu.edu [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Yu, Hongyu, E-mail: hongyu.yu@asu.edu [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287 (United States)

2014-02-24T23:59:59.000Z

219

Influence of shockwave obliquity on deformation twin formation in Ta  

SciTech Connect (OSTI)

Energetic loading subjects a material to a 'Taylor wave' (triangular wave) loading profile that experiences an evolving balance of hydrostatic (spherical) and deviatoric stresses. While much has been learned over the past five decades concerning the propensity of deformation twinning in samples shockloaded using 'square-topped' profiles as a function of peak stress, achieved most commonly via flyer plate loading, less is known concerning twinning propensity during non-I-dimensional sweeping detonation wave loading. Systematic small-scale energetically-driven shock loading experiments were conducted on Ta samples shock loaded with PEFN that was edge detonated. Deformation twinning was quantified in post-mortem samples as a function of detonation geometry and radial position. In the edge detonated loading geometry examined in this paper, the average volume fraction of deformation twins was observed to drastically increase with increasing shock obliquity. The results of this study are discussed in light of the formation mechanisms of deformation twins, previous literature studies of twinning in shocked materials, and modeling of the effects of shock obliquity on the evolution of the stress tensor during shock loading.

Gray, George T., III [Los Alamos National Laboratory; Livescu, V [Los Alamos National Laboratory; Cerreta, E K [Los Alamos National Laboratory; Mason, T A [Los Alamos National Laboratory; Maudlin, P J [RETIRED; Bingert, J F [Los Alamos National Laboratory

2009-02-18T23:59:59.000Z

220

FEM Analysis ofFEM Analysis of Deformation and Fracture ofDeformation and Fracture of  

E-Print Network [OSTI]

FEM 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-Temperature Ductility ·Low Ambient-Temperature Fracture Toughness (KIC

Grujicic, Mica

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


221

Viscoelastic Properties, Ionic Conductivity, and Materials Design Considerations for Poly(styrene-b-ethylene oxide-b-styrene)-Based Ion Gel Electrolytes  

SciTech Connect (OSTI)

The viscoelastic properties and ionic conductivity of ion gels based on the self-assembly of a poly(styrene-b-ethylene oxide-b-styrene) (SOS) triblock copolymer (M{sub n,S} = 3 kDa, M{sub n,O} = 35 kDa) in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([EMI][TFSA]) were investigated over the composition range of 10-50 wt % SOS and the temperature range of 25-160 C. The poly(styrene) (PS) end-blocks associate into micelles, whereas the poly(ethylene oxide) (PEO) midblocks are well-solvated by this ionic liquid. The ion gel with 10 wt % SOS melts at 54 C, with the longest relaxation time exhibiting a similar temperature dependence to that of the viscosity of bulk PS. However, the actual values of the gel relaxation time are more than 4 orders of magnitude larger than the relaxation time of bulk PS. This is attributed to the thermodynamic penalty of pulling PS end-blocks through the PEO/[EMI][TFSA] matrix. Ion gels with 20-50 wt % SOS do not melt and show two plateaus in the storage modulus over the temperature and frequency ranges measured. The one at higher frequencies is that of an entangled network of PEO strands with PS cross-links; the modulus displays a quadratic dependence on polymer weight fraction and agrees with the prediction of linear viscoelastic theory assuming half of the PEO chains are elastically effective. The frequency that separates the two plateaus, {omega}{sub c}, reflects the time scale of PS end-block pull-out. The other plateau at lower frequencies is that of a congested micelle solution with PS cores and PEO coronas, which has a power law dependence on domain spacing similar to diblock melts. The ionic conductivity of the ion gels is compared to PEO homopolymer solutions at similar polymer concentrations; the conductivity is reduced by a factor of 2.1 or less, decreases with increasing PS volume fraction, and follows predictions based on a simple obstruction model. Our collective results allow the formulation of basic design considerations for optimizing the mechanical properties, thermal stability, and ionic conductivity of these gels.

Zhang, Sipei; Lee, Keun Hyung; Sun, Jingru; Frisbie, C. Daniel; Lodge, Timothy P. (UMM)

2013-03-07T23:59:59.000Z

222

Deformation and seismicity in the Coso geothermal area, Inyo County,  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Deformation and seismicity in the Coso geothermal area, Inyo County, California, observations and modeling using satellite radar interferometry Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Deformation and seismicity in the Coso geothermal area, Inyo County, California, observations and modeling using satellite radar interferometry Details Activities (2) Areas (1) Regions (0) Abstract: Interferometric synthetic aperture radar (InSAR) data collected in the Coso geothermal area, eastern California, during 1993-1999 indicate ground subsidence over a approximately 50 km 2 region that approximately

223

Computational Modeling of Brain Dynamics during Repetitive Head Motions  

E-Print Network [OSTI]

Computational Modeling of Brain Dynamics during Repetitive Head Motions Igor Szczyrba School motions in traumatic scenarios that are as- sociated with severe brain injuries. Our results are based on the linear Kelvin-Voigt brain injury model, which treats the brain matter as a viscoelastic solid, and on our

Burtscher, Martin

224

Experimental deformation of multilithologic specimens simulating sedimentary facies changes  

E-Print Network [OSTI]

in controlling the location of deformation. To investigate this problem, three-layered specimens of Coconino Sandstone (11 by 3 by 3 cm. , 1 cm. layer thickness), each containing a block inclusion of Indiana Limestone, polycrystalline halite, modeling clay... the stages 17 (1, 2, 3) of shortening referred to in the text. Curves are labeled according to confining pressure. Representative force-displacement curves for specimens. 18 a. Limestone inclusion, 1. 0 kb confining pressure; b. halite inclusion, 1. 0 kb...

Dyke, Lawrence Dana

2012-06-07T23:59:59.000Z

225

Numerical approach to the nuclear deformation energy  

E-Print Network [OSTI]

A numerical method close to the Strutinsky procedure (but better) is proposed to calculate the deformation energy of nuclei. Quadrupole (triaxial) deformations are considered. Theoretical as well as practical aspects of the method are reviewed in this paper. A complete fortran program illustrates the feasibility of the method.

B. Mohammed-Azizi

2010-02-20T23:59:59.000Z

226

Local Energy Gap in Deformed Carbon Nanotubes  

Science Journals Connector (OSTI)

......Local Energy Gap in Deformed Carbon Nanotubes Ken-ichi Sasaki 1 *) Yoshiyuki...gap along the axis of a deformed nanotube. We compare our energy gap results...experimental data on energy gaps in nanotubes and peapods. We also discuss the......

Ken-ichi Sasaki; Yoshiyuki Kawazoe; Riichiro Saito

2005-03-01T23:59:59.000Z

227

Finite-element analysis of the deformation of thin Mylar films due to measurement forces.  

SciTech Connect (OSTI)

Significant deformation of thin films occurs when measuring thickness by mechanical means. This source of measurement error can lead to underestimating film thickness if proper corrections are not made. Analytical solutions exist for Hertzian contact deformation, but these solutions assume relatively large geometries. If the film being measured is thin, the analytical Hertzian assumptions are not appropriate. ANSYS is used to model the contact deformation of a 48 gauge Mylar film under bearing load, supported by a stiffer material. Simulation results are presented and compared to other correction estimates. Ideal, semi-infinite, and constrained properties of the film and the measurement tools are considered.

Baker, Michael Sean; Robinson, Alex Lockwood; Tran, Hy D.

2012-01-01T23:59:59.000Z

228

Yang-Baxter deformations and rack cohomology  

E-Print Network [OSTI]

Every rack $Q$ provides a set-theoretic solution $c_Q$ of the Yang-Baxter equation. This article examines the deformation theory of $c_Q$ within the space of Yang-Baxter operators over a ring $\\A$, a problem initiated by Freyd and Yetter in 1989. As our main result we classify deformations in the modular case, which had previously been left in suspense, and establish that every deformation of $c_Q$ is gauge-equivalent to a quasi-diagonal one. Stated informally, in a quasi-diagonal deformation only behaviourally equivalent elements interact. In the extreme case, where all elements of $Q$ are behaviourally distinct, Yang-Baxter cohomology thus collapses to its diagonal part, which we identify with rack cohomology. The latter has been intensively studied in recent years and, in the modular case, is known to produce non-trivial and topologically interesting Yang-Baxter deformations.

Eisermann, Michael

2008-01-01T23:59:59.000Z

229

Clustering and Triaxial Deformations of $^{40}$Ca  

E-Print Network [OSTI]

We have studied the positive-parity states of $^{40}$Ca using antisymmetrized molecular dynamics (AMD) and the generator coordinate method (GCM). Imposing two different kinds of constraints on the variational calculation, we have found various kinds of $^{40}{\\rm Ca}$ structures such as a deformed-shell structure, as well as $\\alpha$-$^{36}$Ar and $^{12}$C-$^{28}$Si cluster structures. After the GCM calculation, we obtained a normal-deformed band and a superdeformed band together with their side bands associated with triaxial deformation. The calculated $B(E2)$ values agreed well with empirical data. It was also found that the normal-deformed and superdeformed bands have a non-negligible $\\alpha$-$^{36}$Ar cluster component and $^{12}$C-$^{28}$Si cluster component, respectively. This leads to the presence of an $\\alpha$-$^{36}$Ar higher-nodal band occurring above the normal-deformed band.

Yasutaka Taniguchi; Masaaki Kimura; Yoshiko Kanada-En'yo; Hisashi Horiuchi

2007-07-05T23:59:59.000Z

230

Synergistic Effect of coal blends on thermoplasticity evaluated using a temperature-variable dynamic viscoelastic measurement  

SciTech Connect (OSTI)

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.

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

231

To mechanics of deformation, flow, and fracture  

E-Print Network [OSTI]

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.

S. L. Arsenjev

2008-09-23T23:59:59.000Z

232

On the molecular orientation and viscoelastic behaviour of liquid crystalline polymers: the influence of macromolecular architecture  

Science Journals Connector (OSTI)

...strain deformation, is associated with the process of unravelling the molecular network under...a flow-induced molecular orientation process, whereas small-strain oscillatory measurements...shear flow. In Proc. 69th Soc. Rheology Mtg, Galveston, TX. Roviello, A. & Sirigu...

2001-01-01T23:59:59.000Z

233

Minor Groove Deformability of DNA: A Molecular Dynamics Free...  

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

Minor Groove Deformability of DNA: A Molecular Dynamics Free EnergySimulation Study. Minor Groove Deformability of DNA: A Molecular Dynamics Free EnergySimulation Study. Abstract:...

234

First Generation Advanced High-Strength Steels Deformation Fundamental...  

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

Deformation Fundamentals First Generation Advanced High-Strength Steels Deformation Fundamentals 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program...

235

Forced transport of deformable containers through narrow constrictions  

E-Print Network [OSTI]

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.

Remy Kusters; Thijs van der Heijden; Badr Kaoui; Jens Harting; Cornelis Storm

2014-05-06T23:59:59.000Z

236

A deformable elastic membrane embedded in a lattice Boltzmann fluid  

E-Print Network [OSTI]

A method is described for embedding a deformable, elastic, membrane within a lattice Boltzmann fluid. The membrane is represented by a set of massless points which advect with the fluid and which impose forces on the fluid which are derived from a free energy functional with a value which is dependent upon the geometric properties of the membrane. The method is validated in two dimensions with a free energy functional which imposes the constraint of constant membrane length, constant enclosed area, a bending rigidity and a preferred curvature. The method is shown to recover the expected equilibrium shape in the absence of flow and deformation in the presence of an applied shear flow. The method may have applications in a number of mesoscopic simulations, including discrete models of blood cells.

S V Lishchuk; C M Care

2006-07-14T23:59:59.000Z

237

Sound radiation due to rapid deformation of an impacted plate  

Science Journals Connector (OSTI)

Sound radiation due to forced deformation of an impacted plate was investigated. An initial sound pressure pulse due to rapid local deformation of a plate was generated before the radiation from natural modes of the plate occurred. On the axis of impact near the plate a distinct pressure pulse is observed to reproduce the velocity waveform of the plate at the opposite side of the impact point. Data from experiments involving impact of spheres on plates differing in size and material properties are presented to show the plate behavior and the radiated soundpressure. Theoretical results were obtained from an analytical model in which impulsive acceleration of a plate with Gaussian spatial distribution is convoluted with the acceleration?time history of the actual impact. Theoretical results for the on?axis pressure are compared with the experimental results.

Adnan Akay; Reginald O. Cook

1978-01-01T23:59:59.000Z

238

Surface Slope Metrology on Deformable Soft X-ray Mirrors  

SciTech Connect (OSTI)

We report on the current state of surface slope metrology on deformable mirrors for soft x-rays at the Advanced Light Source (ALS). While we are developing techniques for in situ at-wavelength tuning, we are refining methods of ex situ visible-light optical metrology to achieve sub-100-nrad accuracy. This paper reports on laboratory studies, measurements and tuning of a deformable test-KB mirror prior to its use. The test mirror was bent to a much different optical configuration than its original design, achieving a 0.38 micro-radian residual slope error. Modeling shows that in some cases, by including the image conjugate distance as an additional free parameter in the alignment, along with the two force couples, fourth-order tangential shape errors (the so-called bird shape) can be reduced or eliminated.

Yuan Sheng; Yashchuk, Valeriy V.; Celestre, Rich; Church, Matthew; McKinney, Wayne R.; Morrison, Greg; Warwick, Tony [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Goldberg, Kenneth A. [Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2010-06-23T23:59:59.000Z

239

Postearthquake deformation analysis of wildlife site  

SciTech Connect (OSTI)

Postearthquake deformations of the Wildlife site, Imperial Valley, Calif., following the 1987 Superstition Hills earthquake, have been interpreted by finite-element deformation analyses. The analyses consider the stress redistribution and reconsolidation caused by the development of liquefaction. The stress redistribution analysis was conducted under fully undrained condition to consider the effects of strain-softening behavior of liquefied materials. The reconsolidation analysis was conducted using Biot's theory to consider the effects of dissipation of excess pore-water pressures. The results reveal that the delayed pore-water pressure response and deformation may be due to the redistribution of stresses and pore-water pressures.

Gu, W.H. (EBA Engineering, Edmonton, Alberta (Canada)); Morgenstern, N.R.; Robertson, P.K. (Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Civil Engineering)

1994-02-01T23:59:59.000Z

240

Realistic modeling for facial animation  

Science Journals Connector (OSTI)

Keywords: RGB/Range scanners, discrete deformable models, facial animation, feature-based facial adaptation, physics-based facial modeling, texture mapping

Yuencheng Lee; Demetri Terzopoulos; Keith Waters

1995-09-01T23:59:59.000Z

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


241

Deformation development around mine roadways and simulation of roadway supports  

SciTech Connect (OSTI)

This paper describes the use of the sand and plaster physical modeling technique to investigate the deformation around mine roadways using a variety of support methods in a particular form of stress field. The characteristics and conditions of coal measures rock were considered prior to the preparation of the models and the insertion of support. The investigation has clearly shown how floor lift, roof failure and sidewall movements of mine roadways in laminated weak rock conditions gradually develops as a result of the increase in the stress and, also, how it is related to the level of support used.

Yasar, E.; Reddish, D.J. [Univ. of Nottingham (United Kingdom). Dept. of Mineral Resources Engineering; Daws, G. [Graham Daws Associates, Derbyshire (United Kingdom); Hayes, A.W. [H M Inspectorate of Mines, Merseyside (United Kingdom)

1995-11-01T23:59:59.000Z

242

Characterizations of severely deformed and annealed copper  

E-Print Network [OSTI]

microstructures for different processing routes. After recrystallization heat treatment, the nucleation of new grains from heavily deformed material was found to occur along sites with heavy distortions. Nucleation sites for recrystallized grains start in shear...

Haouaoui, Mohammed

2001-01-01T23:59:59.000Z

243

A COGNITIVE COMPENSATION MECHANSIM FOR DEFORMABLE ANTENNAS  

E-Print Network [OSTI]

This thesis presents the design, theory, and measurement of a linearly polarized microstrip patch antenna with a novel substrate-integrated mechanism that can compensate the detuning effects from a physical deformation. Specifically, this antenna...

Long, Stephen A.

2010-07-14T23:59:59.000Z

244

Arbitrary cutting of deformable tetrahedralized objects  

Science Journals Connector (OSTI)

We propose a flexible geometric algorithm for placing arbitrary cracks and incisions on tetrahedralized deformable objects. Although techniques based on remeshing can also accommodate arbitrary fracture patterns, this flexibility comes at the risk of ...

Eftychios Sifakis; Kevin G. Der; Ronald Fedkiw

2007-08-01T23:59:59.000Z

245

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

E-Print Network [OSTI]

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

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

2009-06-02T23:59:59.000Z

246

Maps between Deformed and Ordinary Gauge Fields  

E-Print Network [OSTI]

In this paper, we introduce a map between the q-deformed gauge fields defined on the GL$_{q}(N) $-covariant quantum hyperplane and the ordinary gauge fields. Perturbative analysis of the q-deformed QED at the classical level is presented and gauge fixing $\\grave{a} $ la BRST is discussed. An other star product defined on the hybrid $(q,h) $% -plane is explicitly constructed .

L. Mesref

2005-04-13T23:59:59.000Z

247

Deformable mirror for short wavelength applications  

DOE Patents [OSTI]

A deformable mirror compatible with short wavelength (extreme ultraviolet) radiation that can be precisely controlled to nanometer and subnanometer accuracy is described. Actuators are coupled between a reaction plate and a face plate which has a reflective coating. A control system adjusts the voltage supplied to the actuators; by coordinating the voltages supplied to the actuators, the reflective surface of the mirror can be deformed to correct for dimensional errors in the mirror or to produce a desired contour.

Chapman, Henry N. (2417 Kilkare Rd., Sunol, CA 94586); Sweeney, Donald W. (5020 Canyon Crest Dr., San Ramon, CA 94583)

1999-01-01T23:59:59.000Z

248

Deformation of C15 Laves phase alloys  

SciTech Connect (OSTI)

Details of the structure and previous work on the deformation of C Laves phases are reviewed. The phase diagram of the Hf-V-Nb system, some metallurgical and physical properties, mechanical behavior, and the deformation mechanisms of HfV{sub 2}+Nb (CI5 HfV{sub 2}+Nb and V-rich bcc solution) are presented based on our previous work. Theoretical approaches to understanding the results of these studies are discussed.

Chu, F.; Pope, D.P.

1995-12-31T23:59:59.000Z

249

Influence of plastic deformation on bimaterial fault rupture directivity  

E-Print Network [OSTI]

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

Dmowska, Renata

250

A multiscale overlapped coupling formulation for large-deformation strain localization  

Science Journals Connector (OSTI)

We generalize the multiscale overlapped domain framework to couple multiple rate-independent standard dissipative material models in the finite deformation regime across different length scales. We show that a fully coupled multiscale incremental boundary-value ... Keywords: Domain coupling, Energy based coupling method, Multiscale modeling, Variational principle

Waiching Sun, Alejandro Mota

2014-09-01T23:59:59.000Z

251

DNS on turbulent heat transfer of viscoelastic fluid flow in a plane channel with transverse rectangular orifices  

Science Journals Connector (OSTI)

Heat-transfer characteristics of a viscoelastic turbulence past rectangular orifices were investigated in the context of the reduction effects of fluid elasticity on drag and heat transfer. To simulate the fully-developed channel flow through transverse orifices located periodically at intervals of 6.4 times channel height, we imposed periodic conditions at the upstream and downstream boundaries. To discuss the dissimilarity between the velocity and thermal fields, the molecular Prandtl number was set to be 1.0 and any temperature dependence of the fluid and rheological properties was not considered. In the present condition, the ratio of the reduction rates in drag and heat transfer was found to be 2.8:1.0, revealing that the present flow configuration is better than a smooth channel for avoiding the heat-transfer reduction. This phenomenon was attributed to the sustainment of the quasi-streamwise vortex downstream of the reattachment point despite the absence of strong spanwise vortices emanating from the orifice edge in the viscoelastic fluid. The longitudinal vortices behind the reattachment point caused a high turbulent heat flux and increased the local Nusselt number.

Takahiro Tsukahara; Tomohiro Kawase; Yasuo Kawaguchi

2013-01-01T23:59:59.000Z

252

Limits of isotropic plastic deformation of Bangkok clay  

E-Print Network [OSTI]

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

P. Evesque

2005-07-08T23:59:59.000Z

253

Quantum reference frames and deformed symmetries  

SciTech Connect (OSTI)

In the context of constrained quantum mechanics, reference systems are used to construct relational observables that are invariant under the action of the symmetry group. Upon measurement of a relational observable, the reference system undergoes an unavoidable measurement 'back-action' that modifies its properties. In a quantum-gravitational setting, it has been argued that such a back-action may produce effects that are described at an effective level as a form of deformed (or doubly) special relativity. We examine this possibility using a simple constrained system that has been extensively studied in the context of quantum information. While our conclusions support the idea of a symmetry deformation, they also reveal a host of other effects that may be relevant to the context of quantum gravity, and could potentially conceal the symmetry deformation.

Girelli, Florian [SISSA, Via Beirut 2-4, 34014 Trieste (Italy) and INFN, Sezione di Trieste, Trieste (Italy); Poulin, David [Center for the Physics of Information, California Institute of Technology, Pasadena, CA 91125 (United States)

2008-05-15T23:59:59.000Z

254

Quantum reference frames and deformed symmetries  

Science Journals Connector (OSTI)

In the context of constrained quantum mechanics, reference systems are used to construct relational observables that are invariant under the action of the symmetry group. Upon measurement of a relational observable, the reference system undergoes an unavoidable measurement “back-action” that modifies its properties. In a quantum-gravitational setting, it has been argued that such a back-action may produce effects that are described at an effective level as a form of deformed (or doubly) special relativity. We examine this possibility using a simple constrained system that has been extensively studied in the context of quantum information. While our conclusions support the idea of a symmetry deformation, they also reveal a host of other effects that may be relevant to the context of quantum gravity, and could potentially conceal the symmetry deformation.

Florian Girelli and David Poulin

2008-05-12T23:59:59.000Z

255

Modeling Hot Mix Asphalt Compaction Using a Thermodynamics Based Compressible Viscoelastic Model within the Framework of Multiple Natural Configurations  

E-Print Network [OSTI]

asphalt (HMA) using the notion of multiple natural configurations. A thermodynamic framework is employed to study the non-linear dissipative response associated with HMA by specifying the forms for the stored energy and the rate of dissipation function...

Koneru, Saradhi

2011-10-21T23:59:59.000Z

256

Plastic Deformation of 2D Crumpled Wires  

E-Print Network [OSTI]

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.

M A F Gomes; V P Brito; A S O Coelho; C C Donato

2008-11-17T23:59:59.000Z

257

Tsunamigenic Sea-Floor Deformations  

Science Journals Connector (OSTI)

...geodetic data. The qualitative characteristics (that is, variation of...real-time estimation of source characteristics of the TREMORS model [HN12...of Mw , Okal compares the characteristics of the source at high and...the Internet and dedicated intranets. In 1986, NOAA's Pacific...

Costas Synolakis; Philip Liu; H. Abelson Philip; George Carrier; Harry Yeh

1997-10-24T23:59:59.000Z

258

Derivation of an optical potential for statically deformed rare-earth nuclei from a global spherical potential  

E-Print Network [OSTI]

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.

G. P. A. Nobre; A. Palumbo; F. S. Dietrich; M. Herman; D. Brown; S. Hoblit

2014-12-22T23:59:59.000Z

259

PLASTIC DEFORMATION OF CRYSTALS: ANALYTICAL AND COMPUTER SIMULATION STUDIES OF DISLOCATION GLIDE  

E-Print Network [OSTI]

in Rate Processes in Plastic Deformation of Materials, J. C.PLASTIC DEFORMATION OF CRYSTALS: ANALYTICAL AND COMPUTERCAPTIONS FIGURES - iii - PLASTIC DEFORMATION OF CRYSTALS:

Altintas, Sabri

2011-01-01T23:59:59.000Z

260

Deformable geometry design with controlled mechanical property based on 3D printing.  

E-Print Network [OSTI]

??Deformable products exist broadly in different industries. These deformable products undergo deformation to achieve specific mechanical properties. Custom made insoles are applied to redistribute plantar… (more)

Li, Yongqiang

2014-01-01T23:59:59.000Z

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


261

Flow and Heat Transfer of a MHD Viscoelastic Fluid in a Channel with Stretching Walls: Some Applications to Haemodynamics  

E-Print Network [OSTI]

Of concern in the paper is a study of steady incompressible viscoelastic and electrically conducting fluid flow and heat transfer in a parallel plate channel with stretching walls in the presence of a magnetic field applied externally. The flow is considered to be governed by Walter's liquid B fluid. The problem is solved by developing a suitable numerical method. The results are found to be in good agrement with those of earlier investigations reported in existing scientific literatures. The study reveals that a back flow occurs near the central line of the channel due to the stretching walls and further that this flow reversal can be stopped by applying a strong external magnetic field. The study also shows that with the increase in the strength of the magnetic field, the fluid velocity decreases but the temperature increases. Thus the study bears potential applications in the study of the haemodynamic flow of blood in the cardiovascular system when subjected to an external magnetic field.

Misra, J C; Rath, H J

2010-01-01T23:59:59.000Z

262

Gardner's deformations of the Boussinesq equations  

Science Journals Connector (OSTI)

Using the algebraic method of Gardner's deformations for completely integrable systems, we construct recurrence relations for densities of the Hamiltonians for the Boussinesq and the Kaup–Boussinesq equations. By extending the Magri schemes for these equations, we obtain new integrable systems adjoint with respect to the initial ones and describe their Hamiltonian structures and symmetry properties.

Atalay Karasu; Arthemy V Kiselev

2006-01-01T23:59:59.000Z

263

Ice deformation near SHEBA R. W. Lindsay  

E-Print Network [OSTI]

in the vicinity of the Surface Heat Budget of the Arctic Ocean (SHEBA) ice camp that is suitable for forcing factor for regional heat fluxes, ice growth and melt rates, and ice strength [Maykut, 1982Ice deformation near SHEBA R. W. Lindsay Polar Science Center, University of Washington, Seattle

Lindsay, Ron

264

Experimental deformation of natural and synthetic dolomite  

E-Print Network [OSTI]

Natural and hot isostatically pressed dolomite aggregates were experimentally deformed at effective pressures of Pe = 50 ?? 400 MPa, temperatures of 400 ?? 850??C, and strain rates of ?& = 1.2x10-4 s-1 to 1.2x10-7 s-1. Coarse- and fine...

Davis, Nathan Ernest

2005-11-01T23:59:59.000Z

265

Earth science: Radon and rock deformation  

Science Journals Connector (OSTI)

... crustal deformation. This ‘unproven’ category includes the well-documented precursory decrease and increase of radon concentration before the 1978 Izu-Oshima earthquake in Japan (Fig. 1), as well ... local electric field. Trique et al. now report that various phenomena — bursts of radon gas, changes of electric potential, and departures of ground tilt from that predicted on ...

Evelyn Roeloffs

1999-05-13T23:59:59.000Z

266

Learning Active Basis Model for Object Detection and Recognition  

Science Journals Connector (OSTI)

This article proposes an active basis model, a shared sketch algorithm, and a computational architecture of sum-max maps for representing, learning, and recognizing deformable templates. In our generative model, a deformable template is in the form of ... Keywords: Deformable template, Generative model, Shared sketch algorithm, Sum maps and max maps, Wavelet sparse coding

Ying Nian Wu; Zhangzhang Si; Haifeng Gong; Song-Chun Zhu

2010-11-01T23:59:59.000Z

267

Effects of subsurface fracture interactions on surface deformation  

E-Print Network [OSTI]

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 ...

Jerry, Ruel (Ruel Valentine)

2013-01-01T23:59:59.000Z

268

Hot deformation behavior of Hastelly C276 superalloy  

Science Journals Connector (OSTI)

Hot tensile behavior of C276 superalloy was studied in the deformation temperature range of 650–750 °C with the strain rate range of 0.35–35 mm/s. The results show that deformation temperature and strain rate both have significant influence on the flow stress. The flow stress decreases with the increase of deformation temperature, while increases with the increase of strain rate. The deformation of C276 superalloy exhibits dynamic recovery feature in the case of deformation temperature of 700 °C. However, when the deformation temperature increases to 750 °C, dynamic recrystallization behavior may occur. The flow stress of C276 alloy during hot deformation process can be characterized by Zener-Hollomon parameter including the Arrhenius term and the deformation activation energy is 327.66 kJ/mol. Therefore, a scientific basis is provided for the reasonable choice of processing parameters of C276 superalloy.

Yan-ling LU; Jin-xi LIU; Xiao-ke LI; Jian-ping LIANG; Zhi-jun LI; Guan-yuan WU; Xing-tai ZHOU

2012-01-01T23:59:59.000Z

269

Microstructure-strength relationships of heavily deformed magnesium-lithium composites containing steel fibers  

SciTech Connect (OSTI)

The successful development of deformation-processed metal-metal composites (DMMC) offers the potential for ductile, high-strength structural materials with high-temperature stability. An infiltration casting process was used to permeate steel wool preforms with molten magnesium-lithium (Mg-Li) alloys. The selected matrix alloys were hexagonal close packed (HCP) Mg-4wt%Li or body centered cubic (BCC) Mg-12wt%Li; the low carbon steel wool fibers were predominantly BCC ferrite. These cast HCP/BCC and BCC/BCC composites were deformed by rolling or by extrusion and swaging. Mechanical properties, microstructure, and texture development of the composites were characterized at various levels of deformation. The HCP/BCC composites had limited formability at temperatures up to 400 C while the BCC/BCC composites had excellent formability during sheet rolling at room temperature but limited formability during swaging at room temperature. The tensile strengths of these HCP/BCC and BCC/BCC composite materials increased moderately with deformation, though less than predicted from rule of mixtures (ROM) calculations. The microstructure was characterized to correlate the filament size to the deformation strain and mechanical properties of the composite material. Stereological measurements of the filament size were used to adjust ROM calculations to reflect the actual deformation strain in the fibers. However, the experimental strengths of these composite materials were still less than ROM predictions, possibly due to the presence of considerably large fibers. Of the many models used to describe the strengthening observed in DMMC materials, the Hall-Petch relationship adequately described the experimental data. Texture development was also characterized to explain the deformation characteristics of the composite materials. Chapters 2, 3 and 4 are not included here. They are being processed separately.

Jensen, J.

1997-10-08T23:59:59.000Z

270

Wall Adhesion and Constitutive Modelling of Strong Colloidal Gels  

E-Print Network [OSTI]

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.

Daniel R. Lester; Richard Buscall; Anthony D. Stickland; Peter J. Scales

2013-12-30T23:59:59.000Z

271

Constitutive relationships for elastic deformation of clay rock: Data Analysis  

SciTech Connect (OSTI)

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

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

2011-04-15T23:59:59.000Z

272

Organic experiences: (re)shaping interactions with deformable displays  

Science Journals Connector (OSTI)

Display technology developments mean the next generation of visual output devices will extend beyond the rigid, flat surfaces with which we are familiar to those that the user or the machine can deform. These will allow users to physically push, pull, ... Keywords: deformable displays, machine-initiated shape change, organic user experience, organic user interfaces, user-deformation

Jason Alexander; Ryan Brotman; David Holman; Audrey Younkin; Roel Vertegaal; Johan Kildal; Andrés A. Lucero; Anne Roudaut; Sriram Subramanian

2013-04-01T23:59:59.000Z

273

Neutrinoless Double Beta Decay in Heavy Deformed Nuclei  

E-Print Network [OSTI]

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\

Jorge G. Hirsch; O. Castaños; P. O. Hess

1994-07-12T23:59:59.000Z

274

Development of internal strains in textured Zircaloy-2 during uni-axial deformation  

Science Journals Connector (OSTI)

Internal strains can greatly affect the mechanical performance of Zircaloy-2 and the study of their development provides insight into the operating deformation mechanisms. In this study, neutron diffraction was used to track the development of internal strains in three dimensions in samples cut from a rolled Zircaloy-2 slab. The samples were subjected to room temperature compression or tension in situ in the neutron diffractometer with loading along each of the three principal directions of the slab. The recorded intensity changes for the different crystallographic planes also provided information on the grain reorientations during deformation. Strong evidence was found for tensile twinning in tensile tests in the plate normal direction and in compression tests in the transverse and rolling directions. This provides an extensive data set with which to develop and test models for plastic deformation and texture development in polycrystalline Zircaloy-2.

F. Xu; R.A. Holt; M.R. Daymond; R.B. Rogge; E.C. Oliver

2008-01-01T23:59:59.000Z

275

A method and software for segmentation of anatomic object ensembles by deformable m-reps  

SciTech Connect (OSTI)

Deformable shape models (DSMs) comprise a general approach that shows great promise for automatic image segmentation. Published studies by others and our own research results strongly suggest that segmentation of a normal or near-normal object from 3D medical images will be most successful when the DSM approach uses (1) knowledge of the geometry of not only the target anatomic object but also the ensemble of objects providing context for the target object and (2) knowledge of the image intensities to be expected relative to the geometry of the target and contextual objects. The segmentation will be most efficient when the deformation operates at multiple object-related scales and uses deformations that include not just local translations but the biologically important transformations of bending and twisting, i.e., local rotation, and local magnification. In computer vision an important class of DSM methods uses explicit geometric models in a Bayesian statistical framework to provide a priori information used in posterior optimization to match the DSM against a target image. In this approach a DSM of the object to be segmented is placed in the target image data and undergoes a series of rigid and nonrigid transformations that deform the model to closely match the target object. The deformation process is driven by optimizing an objective function that has terms for the geometric typicality and model-to-image match for each instance of the deformed model. The success of this approach depends strongly on the object representation, i.e., the structural details and parameter set for the DSM, which in turn determines the analytic form of the objective function. This paper describes a form of DSM called m-reps that has or allows these properties, and a method of segmentation consisting of large to small scale posterior optimization of m-reps. Segmentation by deformable m-reps, together with the appropriate data representations, visualizations, and user interface, has been implemented in software that accomplishes 3D segmentations in a few minutes. Software for building and training models has also been developed. The methods underlying this software and its abilities are the subject of this paper.

Pizer, Stephen M.; Fletcher, P. Thomas; Joshi, Sarang; Gash, A. Graham; Stough, Joshua; Thall, Andrew; Tracton, Gregg; Chaney, Edward L. [Medical Image Display and Analysis Group, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

2005-05-01T23:59:59.000Z

276

Uniformly accelerated detector in the $?$-deformed Dirac vacuum  

E-Print Network [OSTI]

In this paper, we investigate how a uniformly accelerated detector responds to vacuum state of a Dirac field in the $\\kappa$-Minkowski space-time. Starting from $\\kappa$-deformed Dirac theory, which is invariant under $\\kappa$-Poincare algebra, we derive $\\kappa$-deformed Wightmann function for Dirac field, which is valid up to first order in the deformation parameter $a$. Using this, we calculate the response function of the uniformly accelerated detector, which is coupled to massless Dirac field in $\\kappa$-spacetime. From this, we obtain the modification to Unruh effect for the $\\kappa$-deformed Dirac field, valid up to first order in the deformation parameter.

E. Harikumar; Ravikant Verma

2012-11-19T23:59:59.000Z

277

Biaxially textured articles formed by plastic deformation  

DOE Patents [OSTI]

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.

Goyal, Amit (Knoxville, TN)

2001-01-01T23:59:59.000Z

278

Steady state deformation of the Coso Range, east central California,  

Open Energy Info (EERE)

Steady state deformation of the Coso Range, east central California, Steady state deformation of the Coso Range, east central California, inferred from satellite radar interferometry Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Steady state deformation of the Coso Range, east central California, inferred from satellite radar interferometry Details Activities (2) Areas (1) Regions (0) Abstract: Observations of deformation from 1992 to 1997 in the southern 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 of subsidence in an area around the Coso geothermal field. The deformation signal has a short-wavelength component, related to production in the field, and a long-wavelength component,

279

Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations  

E-Print Network [OSTI]

multiphase fluid flow, heat transfer, and deformation infor multiphase fluid flow, heat transfer and deformation in

Rutqvist, J.

2011-01-01T23:59:59.000Z

280

Deformation of Diopside Single Crystal at Mantle Pressure 2 TEM Characterization of Deformation Microstructures  

SciTech Connect (OSTI)

The dislocation microstructures of diopside single crystals deformed at high-pressure (4 {<=} P {<=} 9 GPa), high-temperature (1100{sup o} {<=} T {<=} 1400 {sup o}C) using a Deformation-DIA high-pressure apparatus (D-DIA) have been characterized by transmission electron microscopy using weak-beam dark-field (WBDF), precession electron diffraction (PED), large-angle convergent-beam electron diffraction (LACBED) and the thickness-fringe method. Dislocation glide is the dominant deformation mechanism under these conditions. The 1/2<110>{l_brace}110{r_brace} glide is controlled by lattice friction on the edge segments and shows extensive cross-slip. The [001] glide occurs mostly on {l_brace}110{r_brace}; no evidence for [001](010) glide has been found. The [100] dislocations bear a strong lattice friction probably due to complex (out of glide) core structures.

E Amiguet; P Cordier; P Raterron

2011-12-31T23:59:59.000Z

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


281

Constitutive modeling of creep of single crystal superalloys  

E-Print Network [OSTI]

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...

Prasad, Sharat Chand

2006-10-30T23:59:59.000Z

282

Deformation of the Gorda Block of the Juan de Fuca Plate  

E-Print Network [OSTI]

of the deformation mechanism within the block have been proposed, These are the rigid central block rotation model, the left-lateral slip model, the right-lateral shear model, and the flex- ural slip model. In the rigid central block model, the central portion... fracture zones. SAF San Andreas, ' SGF San Gabriel, CF = Calaveras, HF = Hayward, LMF Lake Mountain, PRF = Pistol River, POF Port Orford (from Dott, 1979) 14 Figure 8: Focal mechanism solutions within the Garde Block (after Bolt et al. , 1967) 16...

Stoddard, Paul Richard

2012-06-07T23:59:59.000Z

283

Analysis of cladding deformation over plenum axial gaps in Zircaloy-clad fuel rods. LWBR Development Program  

SciTech Connect (OSTI)

An analytical model has been developed to predict deformation of unirradiated Zircaloy cladding over axial gaps in plenum regions of fuel rods. This model uses the ACCEPT finite element computer program to calculate the elastic-plastic deformation of cladding due to net external pressure. Progressive increase in gap length (from elongation of cladding below the gap due to Zircaloy growth and pellet-cladding interaction induced creep and from fuel stack shrinkage due to densification of fuel pellets) and deformations of fuel pellets and support sleeve which bound the axial gap in LWBR type blanket fuel rods are included in the model. The thermal creep representation used is based on data from uniaxial creep testing of fuel rod tubing.

Gorscak, D.A.; Pfennigwerth, P.L.

1982-12-01T23:59:59.000Z

284

Ruthenium Aluminides: Deformation Mechanisms and Substructure Development  

SciTech Connect (OSTI)

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.

Tresa M. Pollock

2005-05-11T23:59:59.000Z

285

Deformation correction in ultrasound imaging in an elastography framework  

E-Print Network [OSTI]

Tissue deformation in ultrasound imaging is an inevitable phenomenon and poses challenges to the development of many techniques related to ultrasound image registration, including multimodal image fusion, freehand ...

Sun, Shih-Yu

2010-01-01T23:59:59.000Z

286

Geothermal: Sponsored by OSTI -- Monitoring deformation at the...  

Office of Scientific and Technical Information (OSTI)

Monitoring deformation at the Geysers Geothermal Field, California, using C-band and X-band interferometric synthetic aperture radar Geothermal Technologies Legacy Collection Help...

287

Contemporary Tectonic Deformation of the Basin and Range Province...  

Open Energy Info (EERE)

Journal Article: Contemporary Tectonic Deformation of the Basin and Range Province, Western United States: 10 Years of Observation with the Global Positioning System Abstract...

288

Consistent Deformed Bosonic Algebra in Noncommutative Quantum Mechanics  

E-Print Network [OSTI]

In two-dimensional noncommutive space for the case of both position - position and momentum - momentum noncommuting, the consistent deformed bosonic algebra at the non-perturbation level described by the deformed annihilation and creation operators is investigated. A general relation between noncommutative parameters is fixed from the consistency of the deformed Heisenberg - Weyl algebra with the deformed bosonic algebra. A Fock space is found, in which all calculations can be similarly developed as if in commutative space and all effects of spatial noncommutativity are simply represented by parameters.

Jian-Zu Zhang

2009-07-09T23:59:59.000Z

289

Free motion in deformed (quantum) four-dimensional space  

E-Print Network [OSTI]

It is shown that trajectories of free motion of the particles in deformed ("quantum") four dimensional space-time are quadratic curves.

A. N. Leznov

2007-07-23T23:59:59.000Z

290

A method to estimate the effect of deformable image registration uncertainties on daily dose mapping  

SciTech Connect (OSTI)

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.

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

291

Guided Wave Propagation in Tubular Section with Multi-Layered Viscoelastic Coating  

E-Print Network [OSTI]

. The dispersion of phase velocity and wave attenuation for coated pipes are evaluated against a baseline model which is the bare, uncoated tubing to establish the propagation characteristics of the guided shear and longitudinal waves in the presence of multiple...

Kuo, Chi-Wei 1982-

2012-11-16T23:59:59.000Z

292

A study of the effect of adding viscoelastic dampers between adjacent buildings to reduce pounding  

E-Print Network [OSTI]

code developed at the Lawrence Livermore National Laboratory and used extensively for the solution of impact and blast problems. This programs' past success at accurately modeling the behavior of impact problems made it a natural choice for use... code developed at the Lawrence Livermore National Laboratory and used extensively for the solution of impact and blast problems. This programs' past success at accurately modeling the behavior of impact problems made it a natural choice for use...

Antwiler, Douglas Dean

2012-06-07T23:59:59.000Z

293

Improved measurement of brain deformation during mild head acceleration using a novel tagged MRI sequence  

Science Journals Connector (OSTI)

Abstract In vivo measurements of human brain deformation during mild acceleration are needed to help validate computational models of traumatic brain injury and to understand the factors that govern the mechanical response of the brain. Tagged magnetic resonance imaging is a powerful, noninvasive technique to track tissue motion in vivo which has been used to quantify brain deformation in live human subjects. However, these prior studies required from 72 to 144 head rotations to generate deformation data for a single image slice, precluding its use to investigate the entire brain in a single subject. Here, a novel method is introduced that significantly reduces temporal variability in the acquisition and improves the accuracy of displacement estimates. Optimization of the acquisition parameters in a gelatin phantom and three human subjects leads to a reduction in the number of rotations from 72 to 144 to as few as 8 for a single image slice. The ability to estimate accurate, well-resolved, fields of displacement and strain in far fewer repetitions will enable comprehensive studies of acceleration-induced deformation throughout the human brain in vivo.

Andrew K. Knutsen; Elizabeth Magrath; Julie E. McEntee; Fangxu Xing; Jerry L. Prince; Philip V. Bayly; John A. Butman; Dzung L. Pham

2014-01-01T23:59:59.000Z

294

Simulation of Piezoelectric Flying Height Control Slider Using Shear-Mode Deformation  

Science Journals Connector (OSTI)

The piezoelectric flying height control slider has recently been implemented in magnetic recording disk drives to reduce the flying height. This paper has examined the piezoelectric flying height control slider using shear-model deformation of piezoelectric transducer (PZT). A finite element model of the PZT slider using shear-model deformation has been built, and the electromechanical simulation and air-bearing simulation have been performed to investigate the effects of the shear-model deformation on the static flying attitude of the PZT slider. The results show that the flying height and pitch angle of the PZT slider can be significantly reduced with an increase in the drive voltage on the PZT sheet. However, beyond the drive voltage of 80 V for the proposed PZT slider, the reduction in the flying height of PZT slider is limited owing to the high air bearing stiffness at low flying height region. Furthermore, the PZT slider can be rotated and balanced at a negative pitch angle.

Hui Li; Shengnan Shen; Kensuke Amemiya; Bo Liu; Hejun Du

2011-01-01T23:59:59.000Z

295

Progress in Biophysics and Molecular Biology, 69(2-3):333351, 1998. 1 Physical and Geometrical Modeling for  

E-Print Network [OSTI]

Modeling for Image-Based Recovery of Left Ventricular Deformation James Duncan, Ph.D., , Pengcheng Shi, Ph

Duncan, James S.

296

Micrographic detection of plastic deformation in nickel base alloys  

DOE Patents [OSTI]

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.

Steeves, Arthur F. (Schenectady, NY); Bibb, Albert E. (Clifton Park, NY)

1984-01-01T23:59:59.000Z

297

Image Deformation Using Moving Least Squares Scott Schaefer  

E-Print Network [OSTI]

: · Interpolation: The handles p should map directly to q under deformation. (i.e; f (pi) = qi). · Smoothness: f should be the identity function. (i.e; qi = pi f (v) = v). These properties are very similar to thoseImage Deformation Using Moving Least Squares Scott Schaefer Texas A&M University Travis Mc

Schaefer, Scott

298

Image Deformation Using Moving Least Squares Scott Schaefer  

E-Print Network [OSTI]

: The handles p should map directly to q under deformation. (i.e; f(pi) = qi). · Smoothness: f should produce be the identity function. (i.e; qi = pi f(v) = v). These properties are very similar to those used in scatteredImage Deformation Using Moving Least Squares Scott Schaefer Texas A&M University Travis Mc

Warren, Joe

299

DEFORMED MACDONALD-RUIJSENAARS OPERATORS AND SUPER MACDONALD POLYNOMIALS  

E-Print Network [OSTI]

DEFORMED MACDONALD-RUIJSENAARS OPERATORS AND SUPER MACDONALD POLYNOMIALS A.N. SERGEEV AND A.P. VESELOV Abstract. It is shown that the deformed Macdonald-Ruijsenaars op- erators can be described as the restrictions on certain affine subvarieties of the usual Macdonald-Ruijsenaars operator in infinite number

300

Coordinate realizations of deformed Lie algebras with three generators  

Science Journals Connector (OSTI)

Differential realizations in coordinate space for deformed Lie algebras with three generators are obtained using bosonic creation and annihilation operators satisfying Heisenberg commutation relations. The unified treatment presented here contains as special cases all previously given coordinate realizations of so(2,1), so(3), and their deformations. Applications to physical problems involving eigenvalue determination in nonrelativistic quantum mechanics are discussed.

R. Dutt; A. Gangopadhyaya; C. Rasinariu; U. Sukhatme

1999-11-01T23:59:59.000Z

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


301

DESCRIBING THE PLASTIC DEFORMATION OF ALUMINUM SOFTBALL BATS  

E-Print Network [OSTI]

DESCRIBING THE PLASTIC DEFORMATION OF ALUMINUM SOFTBALL BATS E. BIESEN1 AND L. V. SMITH2 Washington-mail: lvsmith@wsu.edu Hollow aluminum bats were introduced over 30 years ago to provide improved durability over durability. Accordingly, the plastic deformation from a ball impact of a single-wall aluminum bat

Smith, Lloyd V.

302

Use of high-temperature, high-torque rheometry to study the viscoelastic properties of coal during carbonization  

SciTech Connect (OSTI)

When coal is heated in the absence of oxygen it softens at approximately 400 degrees C, becomes viscoelastic, and volatiles are driven off. With further heating, the viscous mass reaches a minimum viscosity in the range of 10{sup 3}-10{sup 5} Pa s and then begins to resolidify. A high-torque, high-temperature, controlled-strain rheometer with parallel plates has been used to study the theology during this process. Under shear, the viscosity of the softening mass decreases with increasing shear rate. During resolidification, the viscosity increases as C-C bond formation and physical interactions gives rise to an aromatic network, but, under shear, the network breaks apart and flows. This is viewed as a yielding of the structure. The higher the shear rate, the earlier the yielding occurs, such that if the shear rate is low enough, the structure is able to build. Also, further into resolidification lower shear rates are able to break the structure. It is proposed that resolidification occurs through the formation of aromatic clusters that grow and become crosslinked by non-covalent interactions. As the clusters grow, the amount of liquid surrounding them decreases and it is thought that the non-covalent interactions between clusters and liquid could decrease and the ability of growing clusters to move past each other increases, which would explain the weakening of the structure under shear. This work is part of a program of work aimed at attaining a greater understanding of microstructural changes taking place during carbonization for different coals, in order to understand the mechanisms that give rise to good quality cokes and coke oven problems such as excessive wall pressure.

Diaz, M.C.; Duffy, J.J.; Snape, C.E.; Steel, K.M. [University of Nottingham, Nottingham (United Kingdom)

2007-09-15T23:59:59.000Z

303

Plastic deformation in Al (Cu) interconnects stressed by electromigration and studied by synchrotron polychromatic X-ray microdiffraction  

E-Print Network [OSTI]

Plastic deformation in Al (Cu) interconnects stressed bygrain orientation [7], study plastic deformation [12-15] andThis aspect of EM-induced plastic deformation in grains

Chen, Kai; Advanced Light Source; UCLA

2008-01-01T23:59:59.000Z

304

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 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 solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of the constituent minerals. To understand the deformation mechanisms of mineral phases at this depth, researchers from Yale and UC Berkeley re-created the ultrahigh pressures of the deep Earth at ALS Beamline 12.2.2 while conducting in situ x-ray diffraction experiments to probe changes in crystal orientations.

305

Surface Deformation from Satellite Data and Geothermal Assessment,  

Open Energy Info (EERE)

Surface Deformation from Satellite Data and Geothermal Assessment, Surface Deformation from Satellite Data and Geothermal Assessment, Exploration and Mitigation in Imperial Valley Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Surface Deformation from Satellite Data and Geothermal Assessment, Exploration and Mitigation in Imperial Valley Author Mariana Eneva Published N/A, 2012 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Surface Deformation from Satellite Data and Geothermal Assessment, Exploration and Mitigation in Imperial Valley Citation Mariana Eneva. Surface Deformation from Satellite Data and Geothermal Assessment, Exploration and Mitigation in Imperial Valley [Internet]. 2012. N/A. N/A. [cited 2013/09/17]. Available from: http://www.energy.ca.gov/research/notices/2012-02-29_workshop/presentations/Geothermal/Eneva-Imageair_Inc_Presentation.pdf

306

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 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 solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of the constituent minerals. To understand the deformation mechanisms of mineral phases at this depth, researchers from Yale and UC Berkeley re-created the ultrahigh pressures of the deep Earth at ALS Beamline 12.2.2 while conducting in situ x-ray diffraction experiments to probe changes in crystal orientations.

307

Deformation-induced accelerated dynamics in polymer glasses  

E-Print Network [OSTI]

Molecular dynamics simulations are used to investigate the effects of deformation on the segmental dynamics in an aging polymer glass. Individual particle trajectories are decomposed into a series of discontinuous hops, from which we obtain the full distribution of relaxation times and displacements under three deformation protocols: step stress (creep), step strain, and constant strain rate deformation. As in experiments, the dynamics can be accelerated by several orders of magnitude during deformation, and the history dependence is entirely erased during yield (mechanical rejuvenation). Aging can be explained as a result of the long tails in the relaxation time distribution of the glass, and similarly, mechanical rejuvenation is understood through the observed narrowing of this distribution during yield. Although the relaxation time distributions under deformation are highly protocol specific, in each case they may be described by a universal acceleration factor that depends only on the strain.

Mya Warren; Joerg Rottler

2010-08-16T23:59:59.000Z

308

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 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 solid (except for its liquid-iron outer core), this convection causes deformation of solid rocks by plastic flow. At the core-mantle boundary (CMB), 2900 km deep, seismologists have discovered that seismic waves travel faster in certain directions. This seismic anisotropy appears to be related to the deformation of the constituent minerals. To understand the deformation mechanisms of mineral phases at this depth, researchers from Yale and UC Berkeley re-created the ultrahigh pressures of the deep Earth at ALS Beamline 12.2.2 while conducting in situ x-ray diffraction experiments to probe changes in crystal orientations.

309

Neutron shell structure and deformation in neutron-drip-line nuclei  

E-Print Network [OSTI]

Neutron shell-structure and the resulting possible deformation in the neighborhood of neutron-drip-line nuclei are systematically discussed, based on both bound and resonant neutron one-particle energies obtained from spherical and deformed Woods-Saxon potentials. Due to the unique behavior of weakly-bound and resonant neutron one-particle levels with smaller orbital angular-momenta $\\ell$, a systematic change of the shell structure and thereby the change of neutron magic-numbers are pointed out, compared with those of stable nuclei expected from the conventional j-j shell-model. For spherical shape with the operator of the spin-orbit potential conventionally used, the $\\ell_{j}$ levels belonging to a given oscillator major shell with parallel spin- and orbital-angular-momenta tend to gather together in the energetically lower half of the major shell, while those levels with anti-parallel spin- and orbital-angular-momenta gather in the upper half. The tendency leads to a unique shell structure and possible deformation when neutrons start to occupy the orbits in the lower half of the major shell. Among others, the neutron magic-number N=28 disappears and N=50 may disappear, while the magic number N=82 may presumably survive due to the large $\\ell =5$ spin-orbit splitting for the $1h_{11/2}$ orbit. On the other hand, an appreciable amount of energy gap may appear at N=16 and 40 for spherical shape, while neutron-drip-line nuclei in the region of neutron number above N=20, 40 and 82, namely N $\\approx$ 21-28, N $\\approx$ 41-54, and N $\\approx$ 83-90, may be quadrupole-deformed though the possible deformation depends also on the proton number of respective nuclei.

Ikuko Hamamoto

2012-05-29T23:59:59.000Z

310

Interfacial deformation and jetting of a magnetic fluid  

E-Print Network [OSTI]

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...

Afkhami, Shahriar; Griffiths, Ian M

2015-01-01T23:59:59.000Z

311

Characterization of laterally deformable elastomer membranes for microfluidics  

Science Journals Connector (OSTI)

This work presents experimental characterization and numerical modeling of laterally deflecting polydimethylsiloxane (PDMS) membranes under pneumatic actuation. The device for this study is a membrane valve seat that partially closes a perpendicular fluid microchannel, fabricated using single-layer soft lithography. Membranes with thickness between 8 and 14 µm have been experimentally tested up to 207 kPa, and maximum lateral displacement beyond 20 µm has been demonstrated. Investigation of geometric parameters by factorial design shows that the height of the membrane is more dominant than the width and thickness, and this is attributed to the zero-displacement boundary condition at the foot of the membrane where it is bonded to a flat substrate. A numerical model that incorporates hyperelastic material testing data shows close agreement with the deflection behavior of experimental samples, accurately predicting that a membrane of 10 µm thick, 100 µm wide and 45 µm tall deflects approximately 13 µm at 207 kPa. Simulation further shows that sidewall effects from bulk compression of the elastomer material in the actuation cavity have a significant effect, reducing maximum displacement by as much as 15% over predictions based on deformation that is limited strictly to the membrane only. Experimental yield, SEM imaging and stress simulations emphasize that the membrane foot region requires the greatest attention in terms of process development.

S J Lee; J C-Y Chan; K J Maung; E Rezler; N Sundararajan

2007-01-01T23:59:59.000Z

312

Modeling Of Surface Deformation From Satellite Radar Interferometry...  

Open Energy Info (EERE)

interferometric synthetic aperture radar) analysis of two-year Radarsat satellite data covering the period May 2006 - March 2008. SAR scenes from two orbit geometries are...

313

Neural network modelling of hot deformation of austenite  

E-Print Network [OSTI]

Professor A. H. Windle for the provision of laboratory facilities in the department of Materials Science. Phil. course, either in organising the course in this first year or by lecturing. 6 #12;Abstract logarithms exp10 base 10 exponential function Q activation energy G Free energy F Helmholtz energy F force

Cambridge, University of

314

Modifications in the AA5083 Johnson-Cook Material Model for Use in Friction Stir Welding  

E-Print Network [OSTI]

Modifications in the AA5083 Johnson-Cook Material Model for Use in Friction Stir Welding- turing processes involving plastic deformation of metallic materials. The main attraction to this model (e.g., those associated with the influence of plastic deformation, rate of deformation

Grujicic, Mica

315

Deformation and Vibration Measurement and Data Evaluation on Large Structures Employing Optical Measurement Techniques  

Science Journals Connector (OSTI)

Deformation and vibration measurements and frequency analysis are part of complex ... development and testing time optimization for deformation and vibration measurement procedures. This paper focuses on one rece...

Hagen Berger; Markus Klein; Theodor Möller

2011-01-01T23:59:59.000Z

316

EFFECT OF GRAIN SIZE ON THE ACOUSTIC EMISSION GENERATED DURING PLASTIC DEFORMATION OF ALUMINUM  

E-Print Network [OSTI]

PLASTIC DEFORMATION OF ALUMINUM LAWRENCE BERKELEY LABORATORYDURING PLASTIC DEFORMATION OF ALUMINUM J. Baram Materialsof polycrystalline aluminum, of different grain sizes and at

Baram, J.

2013-01-01T23:59:59.000Z

317

EFFECT OF GRAIN SIZE ON THE ACOUSTIC EMISSION GENERATED DURING PLASTIC DEFORMATION OF COPPER  

E-Print Network [OSTI]

PLASTIC DEFORMATION OF COPPER J, Baram Materials Engineeringfrom plastically deformed copper specimens were analyzedrelated to the behavior of copper while undergoing plastic

Baram, J.

2011-01-01T23:59:59.000Z

318

E-Print Network 3.0 - aligned breakup deformation Sample Search...  

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

drop deformation and breakup within time... .g., oil-in-water, polymer blends, biological fluids by causing deformation ... Source: Cristini, Vittorio - Departments of Biomedical...

319

Viscoelastic and thermal properties of full and partially cured DGEBA epoxy resin composites modified with montmorillonite nanoclay exposed to UV radiation  

Science Journals Connector (OSTI)

Abstract Effects of UV radiation and associated elevated temperature on properties of polymeric composites have been well documented, limiting the scope of their usage in outdoor applications. In order to improve on this limitation, current study focused on incorporating nanoparticles into epoxy polymer composites and delay onset of deleterious effects of UV radiation by partially curing these samples. Samples were fabricated and cured to 80% conversion (partially cured) based on isothermal cure kinetic studies. Influence of 1, 2 and 3 wt. % loading of montmorillonite nanoclay on the cure behavior and development of physical properties of these composites were evaluated. Results of the study revealed that for optimization of modified epoxy composite properties a different curing cycle was necessary due to interaction of different amounts of nanoclay and epoxy molecules. Fabricated samples infused with 1, 2 and 3 wt. % montmorillonite nanoclay were exposed to 2500 h of continuous UV radiation, where effects of UV radiation on viscoelastic and thermal properties were evaluated and compared with identical set of fabricated samples using manufacturers' recommended cycle (fully cured). Addition of nanoclay increased the viscoelastic properties, and at the end of the study, storage modulus and activation energy of decomposition of partially cured samples evolved over exposure time, while fully cured samples degraded over the same period. Samples cured to 80% showed delayed UV radiation degradation effects.

Alfred Tcherbi-Narteh; Mahesh Hosur; Eldon Triggs; Peter Owuor; Shaik Jelaani

2014-01-01T23:59:59.000Z

320

The 3-Dimensional q-Deformed Harmonic Oscillator and Magic Numbers of Alkali Metal Clusters  

E-Print Network [OSTI]

Magic numbers predicted by a 3-dimensional q-deformed harmonic oscillator with Uq(3) > SOq(3) symmetry are compared to experimental data for alkali metal clusters, as well as to theoretical predictions of jellium models, Woods--Saxon and wine bottle potentials, and to the classification scheme using the 3n+l pseudo quantum number. The 3-dimensional q-deformed harmonic oscillator correctly predicts all experimentally observed magic numbers up to 1500 (which is the expected limit of validity for theories based on the filling of electronic shells), thus indicating that Uq(3), which is a nonlinear extension of the U(3) symmetry of the spherical (3-dimensional isotropic) harmonic oscillator, is a good candidate for being the symmetry of systems of alkali metal clusters.

Bonatsos, Dennis; Raychev, P P; Roussev, R P; Terziev, P A; Bonatsos, Dennis

1999-01-01T23:59:59.000Z

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


321

Evidence for Deformed Ground States in Light Kr Isotopes  

Science Journals Connector (OSTI)

The levels in Kr74,76 were studied with in-beam ?-spectroscopy techniques and the ?+ decay of Rb76. The energies of the 21+ states in Kr74,76 deviate from smooth behavior compared with the higher spin levels. The yrast cascade B(E2)'s are highly collective. The Kr74,76 ground states have unusually large deformation. The origin of this deformation and of shape coexistence in this region is described in terms of the protons driving the deformation.

R. B. Piercey; J. H. Hamilton; R. Soundranayagam; A. V. Ramayya; C. F. Maguire; X. -J. Sun; Z. Z. Zhao; R. L. Robinson; H. J. Kim; S. Frauendorf; J. Döring; L. Funke; G. Winter; J. Roth; L. Cleemann; J. Eberth; W. Neumann; J. C. Wells; J. Lin; A. C. Rester; H. K. Carter

1981-11-23T23:59:59.000Z

322

Deformation twinning mechanisms in FCC and HCP metals  

SciTech Connect (OSTI)

We report the recent work on twinning and detwinning in fcc and hcp metals based on the in situ and ex situ TEM observations and molecular dynamics simulations. Three aspects are discussed in this paper. (1) Detwinning in single-phase Cu with respect to growth twins, (2) deformation twinning in Ag-Cu composites, and (3) deformation twinning mechanisms in hcp metals. The main conclusion is that atomic structures of interfaces (twin boundaries, two-phases interface, and grain boundaries) play a crucial role in nucleating and propagating of deformation twins.

Wang, Jian [Los Alamos National Laboratory; Tome, Carlos N [Los Alamos National Laboratory; Beyerlein, Irene J [Los Alamos National Laboratory; Misra, Amit [Los Alamos National Laboratory; Mara, N [Los Alamos National Laboratory

2011-01-31T23:59:59.000Z

323

Oxidation induced localized creep deformation in Zircaloy-2  

Science Journals Connector (OSTI)

Abstract Extensive plastic deformation in the metal underneath the oxide scale in autoclave tested Zircaloy-2 was studied using transmission electron microscopy (TEM). It was concluded that the plastic deformation is created by creep during oxidation, and is not caused by surface treatment, sample preparation or cooling from autoclave temperatures. Evidence of large strains was found in the form of dislocation tangles, dislocation patches and sub-grain formation, and also indications of twinning were found. The heavily deformed layer is around a few ?m thick and no obvious difference could be seen between alloys with different strength or different oxide thickness.

Pia Tejland; Hans-Olof Andrén

2014-01-01T23:59:59.000Z

324

Symmetry energy of deformed neutron-rich nuclei  

E-Print Network [OSTI]

The symmetry energy, the neutron pressure and the asymmetric compressibility of deformed neutron-rich even-even nuclei are calculated on the examples of Kr and Sm isotopes within the coherent density fluctuation model using the symmetry energy as a function of density within the Brueckner energy-density functional. The correlation between the thickness of the neutron skin and the characteristics related with the density dependence of the nuclear symmetry energy is investigated for isotopic chains of these nuclei in the framework of the self-consistent Skyrme-Hartree-Fock plus BCS method. Results for an extended chain of Pb isotopes are also presented. A remarkable difference is found in the trend followed by the different isotopic chains: the studied correlations reveal a smoother behavior in the Pb case than in the other cases. We also notice that the neutron skin thickness obtained for $^{208}$Pb with SLy4 force is found to be in a good agreement with recent data.

Gaidarov, M K; Sarriguren, P; de Guerra, E Moya

2012-01-01T23:59:59.000Z

325

Milestone L3:MPO.GTRF.P8.01 Microscale Model for Simulating  

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

the model include the ability to generate new wear debris particles through brittle fracture of elastically-deforming asperities and modeling contact with friction and adhesion...

326

Geodetic Constraints on Contemporary Deformation in the Northern Walker  

Open Energy Info (EERE)

Geodetic Constraints on Contemporary Deformation in the Northern Walker Geodetic Constraints on Contemporary Deformation in the Northern Walker Lane: 2. Velocity and Strain Rate Tensor Analysis- In: Late Cenozoic Structure and Evolution of the Great Basin-Sierra Nevada Transition Jump to: navigation, search OpenEI Reference LibraryAdd to library Book Section: Geodetic Constraints on Contemporary Deformation in the Northern Walker Lane: 2. Velocity and Strain Rate Tensor Analysis- In: Late Cenozoic Structure and Evolution of the Great Basin-Sierra Nevada Transition Abstract Abstract unavailable Authors C. Kreemer, Geoffrey Blewitt and William C. Hammond Editors John S. Oldow and Patricia H. Cashman Published Geological Society of America, 2009 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Geodetic Constraints on Contemporary Deformation

327

Applications of Radar Interferometry to Detect Surface Deformation in  

Open Energy Info (EERE)

Applications of Radar Interferometry to Detect Surface Deformation in Applications of Radar Interferometry to Detect Surface Deformation in Geothermal Areas of Imperial Valley in Southern California Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Applications of Radar Interferometry to Detect Surface Deformation in Geothermal Areas of Imperial Valley in Southern California Abstract InSAR (interferometric synthetic aperture radar) is applied in Imperial Valley of southern California to detect and characterize surface deformation in existing geothermal fields, possible future geothermal developments, and around faults. The data used are from the Envisat satellite, collected over the period 2003-2010. The specific InSAR technique applied, SqueeSARTM, identifies permanent and distributed scatterers (PS and DS), which play the role of numerous benchmarks

328

Kinematics of compressional and extensional ductile shearing deformation in  

Open Energy Info (EERE)

Kinematics of compressional and extensional ductile shearing deformation in Kinematics of compressional and extensional ductile shearing deformation in a metamorphic core complex of the northeastern basin and range Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Kinematics of compressional and extensional ductile shearing deformation in a metamorphic core complex of the northeastern basin and range Details Activities (1) Areas (1) Regions (0) Abstract: Analysis of shear criteria enables the kinematics of two main ductile-shearing events (D1 and D2) to be established in the Raft River, Grouse Creek and Albion 'metamorphic core complex'. The first event (D1) is a NNE-thrusting and corresponds to Mesozoic shortening. A well developed non-coaxial ductile deformation (D2), of Cenozoic age, is marked by the occurrence of opposing eastward (in Raft River) and westward shear

329

Activation of conductive pathways via deformation-induced instabilities  

E-Print Network [OSTI]

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 ...

Ni, Xinchen

2014-01-01T23:59:59.000Z

330

Experimental Study on Rock Deformation and Permeability Variation  

E-Print Network [OSTI]

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...

Ding, Jihui

2013-08-01T23:59:59.000Z

331

EXISTENCE OF SOLUTIONS TO A NONLINEAR PROBLEM INVOLVING ISOTROPIC DEFORMATIONS  

E-Print Network [OSTI]

EXISTENCE OF SOLUTIONS TO A NONLINEAR PROBLEM INVOLVING ISOTROPIC DEFORMATIONS ANA CRISTINA BARROSO manuscript, published in "Journal of Nonlinear Systems and Applications (2010) ?" #12;2 ANA CRISTINA BARROSO

Paris-Sud XI, Université de

332

Hardening of a bismuth crystal due to electroplastic deformation  

Science Journals Connector (OSTI)

The surface texture of a bismuth crystal after deformation of the surface by a diamond pyramid and simultaneous passage of a pulse of high-density electric current is studied. The fact of hardening is establis...

1 V. S. Savenko

2007-03-01T23:59:59.000Z

333

3D deformation field throughout the interior of materials.  

SciTech Connect (OSTI)

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.

Jin, Huiqing; Lu, Wei-Yang

2013-09-01T23:59:59.000Z

334

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...

335

Mineral Deformation at Earth's Core-Mantle Boundary  

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

Deformation at Earth's Core-Mantle Boundary Print Wednesday, 31 August 2011 00:00 Earth is a dynamic planet in which convection takes place on the scale of thousands of...

336

ORIGINAL ARTICLE LEGO-like assembly of peelable, deformable  

E-Print Network [OSTI]

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

Rogers, John A.

337

Wavefront control in space with MEMS deformable mirrors  

E-Print Network [OSTI]

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) ...

Cahoy, Kerri L.

338

Localized Deformation and Fracture in Neutron Irradiated Zircaloy-2  

Science Journals Connector (OSTI)

A detailed examination of the deformation bands and the fracture surface morphologies was made with neutron irradiated Zircaloy-2 sheet that had been prepared with similar compositions and microstructures, but...

H. S. Rosenbaum; G. F. Rieger; D. Lee

1974-08-01T23:59:59.000Z

339

Mechanics of inelastic deformation and delamination in paperboard  

E-Print Network [OSTI]

Paperboard is one of the most widely used materials. The inelastic deformation of paperboard plays a crucial role during many manufacturing processes (e.g., the converting process whereby paperboard is converted into a ...

Xia, Qingxi, 1973-

2002-01-01T23:59:59.000Z

340

Lifetime measurements of Triaxial Strongly Deformed bands in $^{163}$Tm  

E-Print Network [OSTI]

With the Doppler Shift Attenuation Method, quadrupole transition moments, $Q_t$, were determined for the two recently proposed Triaxial Strongly Deformed (TSD) bands in $^{163}$Tm. The measured $Q_t$ moments indicate that the deformation of these bands is larger than that of the yrast, signature partners. However, the measured values are smaller than those predicted by theory. This observation appears to be valid for TSD bands in several nuclei of the region

X. wang; R. V. F. Janssens; E. F. Moore; U. Garg; Y. Gu; S. Frauendorf; M. P. Carpenter; S. S. Ghugre; N. J. Hammond; T. Lauritsen; T. Li; G. Mukherjee; N. S. Pattabiraman; D. Seweryniak; S. Zhu

2007-05-14T23:59:59.000Z

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


341

TDHF fusion calculations for spherical+deformed systems  

E-Print Network [OSTI]

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.

A. S. Umar; V. E. Oberacker

2006-04-04T23:59:59.000Z

342

Deformed Kazhdan-Lusztig elements and Macdonald polynomials  

E-Print Network [OSTI]

We introduce deformations of Kazhdan-Lusztig elements and specialised nonsymmetric Macdonald polynomials, both of which form a distinguished basis of the polynomial representation of a maximal parabolic subalgebra of the Hecke algebra. We give explicit integral formula for these polynomials, and explicitly describe the transition matrices between classes of polynomials. We further develop a combinatorial interpretation of homogeneous evaluations using an expansion in terms of Schubert polynomials in the deformation parameters.

Jan de Gier; Alain Lascoux; Mark Sorrell

2011-06-06T23:59:59.000Z

343

Size effects on the onset of plastic deformation during nanoindentation of thin films and patterned lines  

E-Print Network [OSTI]

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

Van Vliet, Krystyn J.

344

Rate-dependent deformation behavior of Zr-based metallic-glass coatings examined by nanoindentation.  

SciTech Connect (OSTI)

Zr-based metallic-glass coatings with micrometer-scale thickness are prepared by the radio-frequency magnetron-sputtering technique on silicon substrates. Using the load- and displacement-sensing nanoindentation technique, we have examined the dependence of their deformation behavior, especially the indentation hardness, on the strain rate and maximum indentation depth. For shallow indentation in which the substrate effect can be neglected, the increase of the penetration rate leads to the decrease of the hardness. This seemingly "negative" strain-rate-sensitivity is actually a result of the dependence of the degree of elastic deformation on the effective strain rate. The coating interface will block the shear-band propagation and promote the shear-band multiplication, so that the plastic flow is much easier to occur as the increase of the maximum penetration depth from a few percent of, to that comparable to, the coating thickness. We use a power-law viscoplastic constitutive relationship to illustrate key issues related to the indentation response of rate-dependent materials, while a phenomenological viscoplastic model with strain softening behavior is used to understand the unique features of the inhomogeneous deformation in metallic glasses. The scanning electron microscopy and atomic force microscopy are used to examine the shear bands and pileup around the indents.

Liu, F. X. [University of Tennessee, Knoxville (UTK); Gao, Yanfei [ORNL; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2008-01-01T23:59:59.000Z

345

The influence of bi-metal interfaces on deformation mechanisms in bulk nanolaminar composites  

SciTech Connect (OSTI)

In this presentation, we report on the plastic deformation mechanisms in Ag-Cu and Cu-Nb nanocomposites rolled to large reductions. Starting with an Ag-Cu alloy with eutectic lamellar bilayer thickness of 200 nm, we roll the as-cast rods from 9.5 mm diameter to sheets of final thickness varying from 2.4 mm to 500 {micro}m, corresponding to 75% to 95% nominal reduction in thickness. Cu(111) X-ray pole figures of the rolled nanocomposites indicate a measured texture similar to that of Ag but different from that expected during rolling of pure bulk Cu involving dislocation slip alone. Visco-Plastic Self Consistent (VPSC) polycrystal modeling indicate that both silver and copper deformed by slip and twinning and the twin fraction reached over 30%, depending on rolling reduction. Because pure Cu is not expected to twin under these processing conditions, we hypothesize that twinning in Cu is induced by twinning in Ag, aided by the presence of high Ag-Cu interfacial content. Molecular Dynamics (MD) simulations are then carried out on perfect and defective Ag-Cu interfaces and the results support this hypothesis. In the Cu-Nb system, it has been found that at individual layer thicknesses of 40 nm and above, physical vapor deposited foils can be rolled to large strains. However, when the layer thickness decreases to {approx}5nm, shear instability during rolling limits ductility. In this work, we show the effects of cladding 5nm CuINb multilayers with 40 nm CuINb multilayers to limit the onset of geometric instability, thereby facilitating the deformation of 5nm Cu/Nb multi layers to large rolling strains. Results will be discussed in terms of the effects of the interface on deformation processes at diminishing length scales.

Mara, Nathan Allan [Los Alamos National Laboratory; Ledonne, Jon [Los Alamos National Laboratory; Wynn, Thomas A [Los Alamos National Laboratory; Rollett, Anthony D [Los Alamos National Laboratory; Beyerlein, I. J. [Los Alamos National Laboratory; Misra, Amit [Los Alamos National Laboratory

2011-01-04T23:59:59.000Z

346

Hydrothermal Systems Rock Deformation and Geodynamics  

E-Print Network [OSTI]

Update Seminar Process Modelling of Hydrothermal Systems using SHEMAT / Processing SHEMAT 20 - 22 August to develop a process understanding of reactive transport in hydrothermal systems and to make responsible.rwth-academy.com/geophysics.html With contributions from #12;Process Modelling of Hydrothermal Systems using SHEMAT / Processing SHEMAT Hydrothermal

347

Permeation of low-Z atoms through carbon sheets: Density functional theory study on energy barriers and deformation effects  

SciTech Connect (OSTI)

Energetic and geometric aspects of the permeation of the atoms hydrogen to neon neutral atoms through graphene sheets are investigated by investigating the associated energy barriers and sheet deformations. Density functional theory calculations on cluster models, where graphene is modeled by planar polycyclic aromatic hydrocarbons (PAHs), provide the energies and geometries. Particularities of our systems, such as convergence of both energy barriers and deformation curves with increasing size of the PAHs, are discussed. Three different interaction regimes, adiabatic, planar and vertical, are investigated by enforcing different geometrical constraints. The adiabatic energy barriers range from 5 eV for hydrogen to 20 eV for neon. We find that the permeation of oxygen and carbon into graphene is facilitated by temporary chemical bonding while for other, in principle reactive atoms, it is not. We discuss implications of our results for modeling chemical sputtering of graphite.

Huber, Stefan E., E-mail: s.huber@uibk.ac.at, E-mail: Michael.probst@uibk.ac.at; Mauracher, Andreas; Probst, Michael, E-mail: s.huber@uibk.ac.at, E-mail: Michael.probst@uibk.ac.at [Institute of Ion Physics and Applied Physics, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck (Austria)] [Institute of Ion Physics and Applied Physics, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck (Austria)

2013-12-15T23:59:59.000Z

348

Modeling and Algorithmic Approaches to Constitutively-Complex, Microstructured Fluids  

SciTech Connect (OSTI)

We present a new multiscale model for complex uids based on three scales: microscopic, kinetic, and continuum. We choose the microscopic level as Kramers' bead-rod model for polymers, which we describe as a system of stochastic di#11;erential equations with an implicit constraint formulation. The associated Fokker-Planck equation is then derived, and adiabatic elimination removes the fast momentum coordinates. Approached in this way, the kinetic level reduces to a dispersive drift equation. The continuum level is modeled with a #12;nite volume Godunov-projection algorithm. We demonstrate computation of viscoelastic stress divergence using this multiscale approach.

Miller, Gregory H.; Forest, Gregory

2011-12-22T23:59:59.000Z

349

Ocean contribution to co-seismic crustal deformation and geoid anomalies: Application to the 2004 December 26 Sumatra–Andaman earthquake  

Science Journals Connector (OSTI)

Large earthquakes do not only heavily deform the crust in the vicinity of the fault, they also change the gravity field of the area affected by the earthquake due to mass redistribution in the upper layers of the Earth. Besides that, for sub-oceanic earthquakes deformation of the ocean floor causes relative sea level changes and mass redistribution of water that have again a significant effect on the gravity field. To model these deformations, sea level changes and gravity field perturbations self-consistently we use an adapted version of the sea level equation (SLE) that has been used for glacial isostatic adjustment studies. The sea level equation, next to our normal mode model for seismic solid earth modeling, allows us to compute a gravitationally self-consistent solution for the co-seismic relative sea level, surface deformation and geoid height changes. We apply our geographically detailed models to the case of the 2004 December 26 Sumatra–Andaman earthquake. Recent studies that have modeled the ocean mass effect on co-seismic gravity change for this specific earthquake show model results that indicate a broad negative change in geoid height around the fault due to ocean water redistribution (de Linage et al., 2009; Melini et al., 2010). Our model results for the ocean contribution to geoid height differ from these studies in the sense that we find a pattern similar to the elongated dipole pattern of the solid earth model outputs for gravity and vertical deformation, together with a relatively small broad negative geoid height change. We explain the relation between outcomes for geoid height, relative sea level and vertical deformation of the ocean floor and we confront our model results with a least squares estimation of the co-seismic discontinuity in GRACE-derived gravity field time series. We show that taking into account the contribution of ocean water redistribution to the co-seismic geoid height change next to a compressible solid earth model is essential to explain the predominant negative co-seismic geoid anomalies from the GRACE gravity field solutions. Besides, we introduce a detailed approach to modeling an earthquake in a normal mode model that better approximates realistic continuous slip on the fault plane than models that do not distribute slip with depth. To demonstrate the importance of the slip distribution we show the differences in outcomes for modeled geoid height and vertical deformation.

D.B.T. Broerse; L.L.A. Vermeersen; R.E.M. Riva; W. van der Wal

2011-01-01T23:59:59.000Z

350

Continuum-kinetic-microscopic model of lung clearance due to core-annular fluid entrainment  

SciTech Connect (OSTI)

The human lung is protected against aspirated infectious and toxic agents by a thin liquid layer lining the interior of the airways. This airway surface liquid is a bilayer composed of a viscoelastic mucus layer supported by a fluid film known as the periciliary liquid. The viscoelastic behavior of the mucus layer is principally due to long-chain polymers known as mucins. The airway surface liquid is cleared from the lung by ciliary transport, surface tension gradients, and airflow shear forces. This work presents a multiscale model of the effect of airflow shear forces, as exerted by tidal breathing and cough, upon clearance. The composition of the mucus layer is complex and variable in time. To avoid the restrictions imposed by adopting a viscoelastic flow model of limited validity, a multiscale computational model is introduced in which the continuum-level properties of the airway surface liquid are determined by microscopic simulation of long-chain polymers. A bridge between microscopic and continuum levels is constructed through a kinetic-level probability density function describing polymer chain configurations. The overall multiscale framework is especially suited to biological problems due to the flexibility afforded in specifying microscopic constituents, and examining the effects of various constituents upon overall mucus transport at the continuum scale.

Mitran, Sorin, E-mail: mitran@unc.edu

2013-07-01T23:59:59.000Z

351

Evidence for a Smooth Onset of Deformation in the Neutron-Rich Kr Isotopes  

Science Journals Connector (OSTI)

The neutron-rich nuclei Kr94,96 were studied via projectile Coulomb excitation at the REX-ISOLDE facility at CERN. Level energies of the first excited 2+ states and their absolute E2 transition strengths to the ground state are determined and discussed in the context of the E(21+) and B(E2;21+?01+) systematics of the krypton chain. Contrary to previously published results no sudden onset of deformation is observed. This experimental result is supported by a new proton-neutron interacting boson model calculation based on the constrained Hartree-Fock-Bogoliubov approach using the microscopic Gogny-D1M energy density functional.

M. Albers et al.

2012-02-10T23:59:59.000Z

352

Determination of the effective stress law for permeability and deformation in low-permeability rocks  

SciTech Connect (OSTI)

This paper reports that laboratory experiments were performed to determine the effective stress law of tight sandstones and chalk for permeability and deformation. Permeability and volumetric strain data were taken at various stresses and pore pressures and were analyzed with a statistical model-building approach. Results show that the effective stress laws for both processes are variable with stress and pressure, depend on the material, and do not agree well with present theories. This may be applied for a greater understanding of oil reservoir formations.

Warpinski, N.R.; Teufel, L.W. (Sandia National Lab. (US))

1992-06-01T23:59:59.000Z

353

Deformation of a basement corner, Crazy Woman Canyon, northeastern Bighorn Mountains, Wyoming  

E-Print Network [OSTI]

to differential uplift and rotation of basement blocks. The objectives of the pmject are as follows: 1. To study how the crystalline basement deforms and how it interacts with the sedimentary cover rocks, 2. To produce a detailed geologic map of the area... mapping at a scale of 1:12, 000, clay models, and geologic cross sections suggest two possible interpretations of how the uplifted and rotated basement blocks in the Crazy Woman Canyon area are related to the regional geometry of the eastern Bighorn...

Smith, Gretchen Louise

2012-06-07T23:59:59.000Z

354

Contemporary Tectonic Deformation of the Basin and Range Province, Western  

Open Energy Info (EERE)

Contemporary Tectonic Deformation of the Basin and Range Province, Western Contemporary Tectonic Deformation of the Basin and Range Province, Western United States: 10 Years of Observation with the Global Positioning System Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Contemporary Tectonic Deformation of the Basin and Range Province, Western United States: 10 Years of Observation with the Global Positioning System Abstract [1] We have estimated patterns and rates of crustal movement across 800 km of the Basin and Range at ∼39° north latitude with Global Positioning System surveys in 1992, 1996, 1998, and 2002. The total rate of motion tangent to the small circle around the Pacific-North America pole of rotation is 10.4 ± 1.0 mm/yr, and motion normal to this small circle is 3.9 ± 0.9 mm/yr compared to the east end of our network. On the Colorado

355

Nuclear skin emergence in Skyrme deformed Hartree-Fock calculations  

E-Print Network [OSTI]

A study of the charge and matter densities and the corresponding rms radii for even-even isotopes of Ni, Kr, and Sn has been performed in the framework of deformed self-consistent mean field Skyrme HF+BCS method. The resulting charge radii and neutron skin thicknesses of these nuclei are compared with available experimental data, as well as with other theoretical predictions. The formation of a neutron skin, which manifests itself in an excess of neutrons at distances greater than the radius of the proton distribution, is analyzed in terms of various definitions. Formation of a proton skin is shown to be unlikely. The effects of deformation on the neutron skins in even-even deformed nuclei far from the stability line are discussed.

Sarriguren, P; de Guerra, E Moya; Antonov, A N

2007-01-01T23:59:59.000Z

356

Kinematic quantities of finite elastic and plastic deformation  

E-Print Network [OSTI]

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

T. Fülöp; P. Ván

2012-03-05T23:59:59.000Z

357

Influence of ensemble boundary conditions (thermostat and barostat) on the deformation of amorphous polyethylene by molecular dynamics  

E-Print Network [OSTI]

Molecular dynamics simulations are increasingly being used to investigate the structural evolution of polymers during mechanical deformation, but relatively few studies focus on the influence of boundary conditions on this evolution, in particular the dissipation of both heat and pressure through the periodic boundaries during deformation. The research herein explores how the tensile deformation of amorphous polyethylene, modelled with a united atom method potential, is influenced by heat and pressure dissipation. The stress-strain curves for the pressure dissipation cases (uniaxial tension) are in qualitative agreement with experiments and show that heat dissipation has a large effect on the strain hardening modulus calculated by molecular dynamics simulations. The evolution of the energy associated with bonded and non-bonded terms was quantified as a function of strain as well as the evolution of stress in both the loading and non-loading directions to give insight into how the stress state is altered within the elastic, yield, strain softening, and strain hardening regions. The stress partitioning shows a competition between `tensile' Van der Waal's interactions and `compressive' bond stretching forces, with the characteristic yield stress peak clearly associated with the non-bonded stress. The lack of heat dissipation had the largest effect on the strain hardening regime, where an increase in the calculated temperature correlated with faster chain alignment in the loading direction and more rapid conformation changes. In part, these observations demonstrate the role that heat and pressure dissipation play on deformation characteristics of amorphous polymers, particularly for the strain hardening regime.

M. A. Tschopp; J. L. Bouvard; D. K. Ward; D. J. Bammann; M. F. Horstemeyer

2013-10-02T23:59:59.000Z

358

Motion-Induced Radiation from a Dynamically Deforming Mirror  

E-Print Network [OSTI]

A path integral formulation is developed to study the spectrum of radiation from a perfectly reflecting (conducting) surface. It allows us to study arbitrary deformations in space and time. The spectrum is calculated to second order in the height function. For a harmonic traveling wave on the surface, we find many different regimes in which the radiation is restricted to certain directions. It is shown that high frequency photons are emitted in a beam with relatively low angular dispersion whose direction can be controlled by the mechanical deformations of the plate.

Faez Miri; Ramin Golestanian

1998-03-25T23:59:59.000Z

359

A microscopic view of accelerated dynamics in deformed polymer glasses  

E-Print Network [OSTI]

A molecular level analysis of segmental trajectories obtained from molecular dynamics simulations is used to obtain the full relaxation time spectrum in aging polymer glasses subject to three different deformation protocols. As in experiments, dynamics can be accelerated by several orders of magnitude, and a narrowing of the distribution of relaxation times during creep is directly observed. Additionally, the acceleration factor describing the transformation of the relaxation time distributions is computed and found to obey a universal dependence on the global strain, independent of age and deformation protocol.

Mya Warren; Joerg Rottler

2010-02-09T23:59:59.000Z

360

Deformation effects on the coexistence between neutron-proton and particle like pairing in N=Z medium mass nuclei  

E-Print Network [OSTI]

A model combining self-consistent mean-field and shell-model techniques is used to study the competition between particle like and proton-neutron pairing correlations in fp-shell even-even self-conjugate nuclei. Results obtained using constant two-body pairing interactions as well as more sophisticated interactions are presented and discussed. The standard BCS calculations are systematically compared with more refined approaches including correlation effects beyond the independent quasi-particle approach. The competition between proton-neutron correlations in the isoscalar and isovector channels is also analyzed, as well as their dependence on the deformation properties. Besides the expected role of the spin-orbit interaction and particle number conservation, it is shown that deformation leads to a reduction of the pairing correlations. This reduction originates from the change of the single-particle spectrum and from a quenching of the residual pairing matrix elements. The competition between isoscalar and i...

Gambacurta, D

2014-01-01T23:59:59.000Z

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


361

Microscopic and self-consistent description for neutron halo in deformed nuclei  

SciTech Connect (OSTI)

A deformed relativistic Hartree-Bogoliubov theory in continuum has been developed for the study of neutron halos in deformed nuclei and the halo phenomenon in deformed weakly bound nuclei is investigated. Magnesium and neon isotopes are studied and some results are presented for the deformed neutron-rich and weakly bound nuclei {sup 44}Mg and {sup 36}Ne. The core of the former nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurrence of this decoupling effect are discussed.

Li Lulu [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Meng Jie [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China) and Department of Physics, University of Stellenbosch, Stellenbosch (South Africa); Zhao Enguang; Zhou Shangui [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China) and Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China)

2013-05-06T23:59:59.000Z

362

Modeling Micro-Damage Healing Mechanism at Micro-Scale  

E-Print Network [OSTI]

), the corresponding results of stress and displacement fields in elastic media are converted into viscoelastic media. Since asphalt has time-dependent material properties, the viscoelastic result is more accurate than the elastic. It is shown that an increase...

Arastoo, Mahsa

2013-08-06T23:59:59.000Z

363

Master Thesis: Simulation of plastic deformation in cemented carbide inserts  

E-Print Network [OSTI]

Master Thesis: Simulation of plastic deformation in cemented carbide inserts Background Sandvik in cemented carbide, high-speed steel and other hard materials such as diamond, cubic boron nitride in cemented carbide inserts will be performed using the FEM software Ansys and AdvantEdge. The work

Haviland, David

364

Anisotropic phonon-dislocation scattering in deformed LiF  

Science Journals Connector (OSTI)

By direct imaging of ballistic phonons having equivalent temperatures near 4 K in LiF, we have found that a subset of fast-transverse phonons can propagate without scattering even in heavily deformed samples. The highly anisotropic phonon-scattering cross section is consistent with the concept of fluttering dislocations. The magnitude of the scattering cross section has been obtained for the first time. For small plastic deformation the measured cross section agrees with that calculated theoretically using a measured dislocation density. However, at large deformation the calculated cross section is too small, supporting the speculation that a larger density of dislocation dipoles may provide the dominant scattering. Also consistent with the concept of fluttering dislocations, ? irradiation reduces the phonon scattering created by deformation, presumably by pinning of the dislocations. It is demonstrated that the method of phonon imaging used here provides details of phonon scattering processes which are not available from conventional thermal-transport measurements, especially when the scattering is anisotropic.

G. A. Northrop; E. J. Cotts; A. C. Anderson; J. P. Wolfe

1983-05-15T23:59:59.000Z

365

CONTAINED PLASTIC DEFORMATION NEAR CRACKS AND NOTCHES UNDER LONGITUDINAL SHEAR  

E-Print Network [OSTI]

CONTAINED PLASTIC DEFORMATION NEAR CRACKS AND NOTCHES UNDER LONGITUDINAL SHEAR James R. Rice* ABSTRACT An exact linear elastic-perfectly plastic solution is presented for the problem of a sharp notch coordinates corresponding to given stresses, position of the elastic-plastic boundary, and accompanying

366

Graded Materials for Resistance to Contact Deformation and Damage  

E-Print Network [OSTI]

Graded Materials for Resistance to Contact Deformation and Damage S. Suresh The mechanical response, materials sci- entists increasingly aim to engineer graded materials that are more damage-resistant than of materials with spatial gradients in composition and structure is of considerable interest in disciplines

Suresh, Subra

367

Labeling the Brain Surface Using a Deformable Multiresolution Mesh  

E-Print Network [OSTI]

Labeling the Brain Surface Using a Deformable Multiresolution Mesh Sylvain Jaume1 , Beno^it Macq2 Abstract. We propose to match a labeled mesh onto the patient brain surface in a multiresolution way for labeling the patient brain. Labeling the patient brain surface provides a map of the brain folds where

Desbrun, Mathieu

368

Deformable Organisms and Error Learning for Brain Segmentation  

E-Print Network [OSTI]

Deformable Organisms and Error Learning for Brain Segmentation Gautam Prasad1,2 , Anand A. Joshi3 be easily incorporated into the plan. We validate this framework by creating a plan to locate the brain in 3D magnetic resonance images of the head (skull-stripping). This is important for surgical planning

Boyer, Edmond

369

TRANSMISSION ELECTRON MICROSCOPY OF WEAKLY DEFORMED ALKALI HALIDE CRYSTALS  

E-Print Network [OSTI]

377 TRANSMISSION ELECTRON MICROSCOPY OF WEAKLY DEFORMED ALKALI HALIDE CRYSTALS H. STRUNK Max'importance croissante du durcissement de la solution solide. Abstract. 2014 Transmission electron microscopy (TEM Abstracts 7j66 - 7 I' 1. Introduction. - It is only some years ago that transmission electron microscopy

Boyer, Edmond

370

Deformed dispersion relations and the degree of coherence function  

E-Print Network [OSTI]

The analysis of the modifications that the presence of a deformed dispersion relation entails in the roots of the so--called degree of coherence function, for a beam embodying two different frequencies and moving in a Michelson interferometer, is carried out. The conditions to be satisfied, in order to detect this kind of quantum gravity effect, are also obtained.

A. Camacho; A. Macias

2006-08-16T23:59:59.000Z

371

Large Deformation Constitutive Laws for Isotropic Thermoelastic Materials  

SciTech Connect (OSTI)

We examine the approximations made in using Hooke's law as a constitutive relation for an isotropic thermoelastic material subjected to large deformation by calculating the stress evolution equation from the free energy. For a general thermoelastic material, we employ the volume-preserving part of the deformation gradient to facilitate volumetric/shear strain decompositions of the free energy, its first derivatives (the Cauchy stress and entropy), and its second derivatives (the specific heat, Grueneisen tensor, and elasticity tensor). Specializing to isotropic materials, we calculate these constitutive quantities more explicitly. For deformations with limited shear strain, but possibly large changes in volume, we show that the differential equations for the stress components involve new terms in addition to the traditional Hooke's law terms. These new terms are of the same order in the shear strain as the objective derivative terms needed for frame indifference; unless the latter terms are negligible, the former cannot be neglected. We also demonstrate that accounting for the new terms requires that the deformation gradient be included as a field variable

Plohr, Bradley J. [Los Alamos National Laboratory; Plohr, Jeeyeon N. [Los Alamos National Laboratory

2012-07-25T23:59:59.000Z

372

Possible Ground-State Octupole Deformation in Pa229  

Science Journals Connector (OSTI)

Evidence is presented for the occurrence of a 52± parity doublet as the ground state of Pa229, in agreement with a previous theoretical prediction. The doublet splitting energy is measured to be 0.22±0.05 keV. The relation of this doublet to ground-state octupole deformation is discussed.

I. Ahmad; J. E. Gindler; R. R. Betts; R. R. Chasman; A. M. Friedman

1982-12-13T23:59:59.000Z

373

Adiabatic plastic deformation: the case of cutting process  

Science Journals Connector (OSTI)

Numerical and experimental research program was developed taking into account the high speed machining particularities. The results was analyzed by approaching the cutting process as adiabatic plastic deformation process. Firstly, the process of material ... Keywords: adiabatic cutting process, cutting thermodynamic system, high speed machining, surface layer

C. Maier; V. Vacarus; M. Banu; A. Epureanu

2009-10-01T23:59:59.000Z

374

Structural control of elastic moduli in ferrogels and the importance of non-affine deformations  

E-Print Network [OSTI]

One of the central appealing properties of magnetic gels and elastomers is that their elastic moduli can reversibly be adjusted from outside by applying magnetic fields. The impact of the internal magnetic particle distribution on this effect has been outlined and analyzed theoretically. In most cases, however, affine sample deformations are studied and often regular particle arrangements are considered. Here we challenge these two major simplifications by a systematic approach using a minimal dipole-spring model. Starting from different regular lattices, we take into account increasingly randomized structures, until we finally investigate an irregular texture taken from a real experimental sample. On the one hand, we find that the elastic tunability qualitatively depends on the structural properties, here in two spatial dimensions. On the other hand, we demonstrate that the assumption of affine deformations leads to increasingly erroneous results the more realistic the particle distribution becomes. Understanding the consequences of the assumptions made in the modeling process is important on our way to support an improved design of these fascinating materials.

Giorgio Pessot; Peet Cremer; Dmitry Y. Borin; Stefan Odenbach; Hartmut Löwen; Andreas M. Menzel

2014-10-21T23:59:59.000Z

375

Mode I fracture of a biopolymer gel: rate-dependent dissipation and large deformations disentangled  

E-Print Network [OSTI]

We have designed a new experimental setup able to investigate fracture of soft materials at small scales. At high crack velocity, where energy is mostly dissipated through viscoelastic processes, we observe an increasingly large high strain domain in the crack tip vicinity. Taking advantage of our ability to determine where linear elasticity breaks down, we derive a simple prediction for the evolution of the energy release rate with the crack velocity.

Maxime Lefranc; Elisabeth Bouchaud

2015-01-06T23:59:59.000Z

376

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

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

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Wednesday, 25 November 2009 00:00 Magnetic...

377

Deformable Image Registration of Liver With Consideration of Lung Sliding Motion  

SciTech Connect (OSTI)

Purpose: A feature based deformable registration model with sliding transformation was developed in the upper abdominal region for liver cancer. Methods: A two-step thin-plate spline (bi-TPS) algorithm was implemented to deformably register the liver organ. The first TPS registration was performed to exclusively quantify the sliding displacement component. A manual segmentation of the thoracic and abdominal cavity was performed as a priori knowledge. Tissue feature points were automatically identified inside the segmented contour on the images. The scale invariant feature transform method was utilized to match feature points that served as landmarks for the subsequent TPS registration to derive the sliding displacement vector field. To a good approximation, only motion along superior/inferior (SI) direction of voxels on each slice was averaged to obtain the sliding displacement for each slice. A second TPS transformation, as the last step, was carried out to obtain the local deformation field. Manual identification of bifurcation on liver, together with the manual segmentation of liver organ, was employed as a ''ground truth'' for assessing the algorithm's performance. Results: The proposed two-step TPS was assessed with six liver patients. The average error of liver bifurcation between manual identification and calculation for these patients was less than 1.8 mm. The residual errors between manual contour and propagated contour of liver organ using the algorithm fell in the range between 2.1 and 2.8 mm. An index of Dice similarity coefficient (DSC) between manual contour and calculated contour for liver tumor was 93.6% compared with 71.2% from the conventional TPS calculation. Conclusions: A high accuracy ({approx}2 mm) of the two-step feature based TPS registration algorithm was achievable for registering the liver organ. The discontinuous motion in the upper abdominal region was properly taken into consideration. Clinical implementation of the algorithm will find broad application in radiation therapy of liver cancer.

Xie, Yaoqin; Chao, Ming; Xiong, Guanglei [Key Laboratory for Health Informatics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China and Department of Radiation Oncology, Stanford University School of Medicine, 875 Blake Wilbur Drive, Stanford, California 94305-5847 (United States); Department of Radiation Oncology, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, Arkansas 72205-7199 (United States); Department of Biomedical Informatics, Stanford University School of Medicine, 251 Campus Drive, Stanford, California 94305-5479 (United States)

2011-10-15T23:59:59.000Z

378

EXPERIMENTAL & NUMERICAL STUDY OF CERAMIC BREEDER PEBBLE BED THERMAL DEFORMATION BEHAVIOR  

E-Print Network [OSTI]

EXPERIMENTAL & NUMERICAL STUDY OF CERAMIC BREEDER PEBBLE BED THERMAL DEFORMATION BEHAVIOR Zhiyong involved in ceramic breeder pebble bed thermal deformation are complex. First, unlike solid material.25 and 0.63 mm) at temperatures of 700-800ºC. The experimental results show that the thermal deformation

Abdou, Mohamed

379

PLASTIC VERSUS ELASTIC DEFORMATION EFFECTS ON MAGNETIC BARKHAUSEN NOISE IN STEEL  

E-Print Network [OSTI]

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

Clapham, Lynann

380

Stroke amplifier for deformable mirrors Robert H. Webb, Marc J. Albanese, Yaopeng Zhou, Thomas Bifano, and  

E-Print Network [OSTI]

Stroke amplifier for deformable mirrors Robert H. Webb, Marc J. Albanese, Yaopeng Zhou, Thomas stroke of a deformable mirror. By arranging for the wavefront to traverse the deformable mirror more than to produce lower- cost mirrors. Unfortunately, most commercial MEMS mirrors have only a limited stroke

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


381

Scale Dependence and Localization of the Deformation of Arctic Sea Ice David Marsan  

E-Print Network [OSTI]

, and internal stress gradients, producing spatial gradients in the ice velocity that we refer to as deformationScale Dependence and Localization of the Deformation of Arctic Sea Ice David Marsan Laboratoire de of Arctic sea ice over a 3-day time period is performed for scales of 10 to 1000 km. The deformation field

382

Modeling the mechanical response of PBX 9501  

SciTech Connect (OSTI)

An engineering overview of the mechanical response of Plastic-Bonded eXplosives (PBXs), specifically PBX 9501, will be provided with emphasis on observed mechanisms associated with different types of mechanical testing. Mechanical tests in the form of uniaxial tension, compression, cyclic loading, creep (compression and tension), and Hopkinson bar show strain rate and temperature dependence. A range of mechanical behavior is observed which includes small strain recoverable response in the form of viscoelasticity; change in stiffness and softening beyond peak strength due to damage in the form microcracks, debonding, void formation and the growth of existing voids; inelastic response in the form of irrecoverable strain as shown in cyclic tests, and viscoelastic creep combined with plastic response as demonstrated in creep and recovery tests. The main focus of this paper is to elucidate the challenges and issues involved in modeling the mechanical behavior of PBXs for simulating thermo-mechanical responses in engineering components. Examples of validation of a constitutive material model based on a few of the observed mechanisms will be demonstrated against three point bending, split Hopkinson pressure bar and Brazilian disk geometry.

Ragaswamy, Partha [Los Alamos National Laboratory; Lewis, Matthew W [Los Alamos National Laboratory; Liu, Cheng [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

383

Influence of deep-seated gravitational slope deformations on landslide distributions: A statistical approach  

Science Journals Connector (OSTI)

Abstract The influence of deep-seated gravitational slope deformations (DSGSDs) on the distribution of translational landslides was analyzed in the Milia basin, Tuscany, Italy. Detailed geomorphological mapping, combined with the analysis of aerial photography, enabled us to build two landslide inventories. One inventory including landslides before 1975 was used to create statistical models, whereas the other inventory including landslides after 1975 was used to validate the models. Geology, slope angle, slope aspect, distance to hydrographic elements, and distance to tectonic lineaments were considered as landslide-predisposing factors. To quantify the importance of \\{DSGSDs\\} as another landslide-predisposing factor, the DSGSD presence/absence map was introduced in the stepwise statistical analysis. The landslide inventory maps and factor maps were processed using a conditional analysis on all possible factor combinations to produce landslide susceptibility maps with five susceptibility classes. The results indicate that the \\{DSGSDs\\} significantly affect landslide distribution.

M. Capitani; A. Ribolini; P.R. Federici

2013-01-01T23:59:59.000Z

384

Modeling of thermally driven hydrological processes in partially saturated fractured rock  

E-Print Network [OSTI]

multiphase fluid flow, heat transfer, and deformation insimulations of fluid flow, heat transfer, and phaseeither included no fluid flow and modeled heat transfer by

Tsang, Yvonne

2010-01-01T23:59:59.000Z

385

A Lattice Boltzmann model for polymeric liquids  

Science Journals Connector (OSTI)

A Lattice Boltzmann model for polymeric liquids is developed. In the proposed model, polymers are modelled as dumbbells suspended in a solvent. A distribution function is introduced to describe the configuration of the dumbbells, and is used to evaluate the viscoelastic stresses in flow fields. A discrete kinetic equation for the configurational distribution is derived, and is shown to recover the Oldroyd-B constitutive equation at the continuous level, when coupled with the standard Lattice Boltzmann equation for the flow of the solvent. Numerical simulations of both steady and unsteady flows are performed in order to investigate the validity of the current model. In the simulation of small-amplitude oscillatory shear flows, numerical results are quantitatively compared with the analytical solutions obtained with the Oldroyd-B equation, and good agreements are observed.

Junya Onishi; Yu Chen; Hirotada Ohashi

2005-01-01T23:59:59.000Z

386

Single-particle resonances in a deformed Dirac equation  

SciTech Connect (OSTI)

Single-particle bound and resonant states are obtained by solving the Dirac equation with quadrupole-deformed Woods-Saxon potential in coordinate space with the coupled-channel approach. Taking the m{sup {pi}}=1/2{sup +} resonant states at deformation {beta}=0.1 as examples, the roles of their spherical components have been investigated based on the behaviors of the eigenphases and the corresponding probabilities weighted by the scalar spherical potential. It is shown that the realization of the m{sup {pi}}=1/2{sup +} resonances is supported mainly by the lnot =0 components, and the mixture of the s{sub 1/2} component can lead to the disappearance of some resonances at finite energy. The dominance of the lnot =0 component (d{sub 3/2}) in the small-energy region guarantees the continuation of a certain resonance to the corresponding bound state.

Li, Z. P.; Zhang, Y. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Meng, J. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100190 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); Zhou, S. G. [Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100190 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); Savushkin, L. N. [Department of Physics, St. Petersburg University for Telecommunications, RU-191065 St. Petersburg (Russian Federation)

2010-03-15T23:59:59.000Z

387

Deformation of shale: mechanical properties and indicators of mechanisms  

E-Print Network [OSTI]

Basins, shales of Devonian age are commonly considered reservoir rocks I' or natural gas [Woodward, 1958; Lockett, 1968; Long, 1979; Gonzales and Johnson, 1985], Economic gas production from the Devonian shales of these basins is associated..., 1967; Chang et al. , 1979; Smith and Cheatham, 1980; Jordan and Nuesch, 1989; Nuesch, 1991]. Shales deform by fracture and friction-controlled slip at low mean stresses (& 200 MPa), while semi-brittle cataclasis and kinking are observed at high...

Ibanez, William Dayan

2012-06-07T23:59:59.000Z

388

Method for making biaxially textured articles by plastic deformation  

DOE Patents [OSTI]

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.

Goyal, Amit (Knoxville, TN)

2002-01-01T23:59:59.000Z

389

Mecanica del Solido Deformable Presentacion de la asignatura  

E-Print Network [OSTI]

· Despacho: En la c´atedra de Resistencia de Materiales, junto a la F2 I2 . · Horario tutor´ias: Jueves 9 resistencia de materiales, del c´alculo de estructuras, de la mec´anica de suelos, dise~no de elementos de m´olidos deformables y de la formulaci´on de modelos fenomenol´ogicos de sus materiales. · La primera parte es com

Romero, Ignacio

390

Whittaker vector of deformed Virasoro algebra and Macdonald symmetric functions  

E-Print Network [OSTI]

We give a proof of Awata and Yamada's conjecture for the explicit formula of Whittaker vector of the deformed Virasoro algebra realized in the Fock space. The formula is expressed as a summation over Macdonald symmetric functions with factored coefficients. In the proof we fully use currents appearing in the Fock representation of Ding-Iohara-Miki quantum algebra. We also mention an interpretation of Whittaker vector in terms of the geometry of the Hilbert schemes of points on the affine plane.

Shintarou Yanagida

2014-02-12T23:59:59.000Z

391

Deformation analysis of local ply curvature in laminated composites  

E-Print Network [OSTI]

composite laminates with local ply curvatures in the main load- carrying layers, Strains in corrugated layers, In-Phase layers, and Out-of-Phase layers are predicted for various geometries and material configurations by assuming matrix layers as elastic.... 2 Copper Matrix Metal Composite Fig. 3 Wavy Layers 12 Fig. 4 Moment Equilibrium in a Corrugated Beam without Matrix Material 18 Fig. 5 Deformation of the Matrix Naterial Due to Stretching of the Initial Curvature of the Main Load...

Lee, Jong-Won

1987-01-01T23:59:59.000Z

392

Transient deformation properties of Zircaloy for LOCA simulation. Final report  

SciTech Connect (OSTI)

This experimental data report is Volume 4 of a series of 5 volumes describing the oxidation and deformation rate behavior of Zircaloy cladding under simulated LOCA conditions. It contains listings of strain versus stress, time, and temperature evaluated from the numerical constitutive relationships and the original data used to develop them. This volume also contains listings of the ramp load, pressure, and temperature test data from both current and previous phases of the series, as well as material describing applications of the data.

Hann, C. R.; Mohr, C. L.; Busness, K. M.; Olson, N. J.; Reich, F. R.; Stewart, K. B.

1980-05-01T23:59:59.000Z

393

Deformation behavior of duplex zircaloy-4-oxygen alloys  

SciTech Connect (OSTI)

Mechanical properties at thermal equilibrium have been determined. The strengthening behavior for alloys having isolated /alpha/ grains in the softer /beta/ matrix is similar to dispersed particle strengthening. Yield strength obeys the Petch relationship. The strength obeys a modified rule of mixtures. Deformation behavior is interpreted in terms of dislocation slip in the /beta/ matrix and diffusion assisted climb near the interphase boundary. 9 refs.

Tseng, D.; Tangri, K.

1982-06-01T23:59:59.000Z

394

Superfluid and Metamagnetic Phase Transitions in $?$-deformed Gauged Supergravity  

E-Print Network [OSTI]

We study non-supersymmetric truncations of $\\omega$-deformed ${\\cal N}=8$ gauged supergravity that retain a $U(1)$ gauge field and three scalars, of which two are neutral and one charged. We construct dyonic domain-wall and black hole solutions with AdS$_4$ boundary conditions when only one (neutral) scalar is non-vanishing, and examine their behavior as the magnetic field and temperature of the system are varied. In the infrared the domain-wall solutions approach either dyonic AdS$_2 \\times \\mathbb{R}^2$ or else Lifshitz-like, hyperscaling violating geometries. The scaling exponents of the latter are $z=3/2$ and $\\theta = -2$, and are independent of the $\\omega$-deformation. New $\\omega$-dependent AdS$_4$ vacua are also identified. We find a rich structure for the magnetization of the system, including a line of metamagnetic first-order phase transitions when the magnetic field lies in a particular range. Such transitions arise generically in the $\\omega$-deformed theories. Finally, we study the onset of a superfluid phase by allowing a fluctuation of the charged scalar field to condense, spontaneously breaking the abelian gauge symmetry. The mechanism by which the superconducting instability ceases to exist for strong magnetic fields is different depending on whether the field is positive or negative. Finally, such instabilities are expected to compete with spatially modulated phases.

Sera Cremonini; Yi Pang; C. N. Pope; Junchen Rong

2014-10-31T23:59:59.000Z

395

Surface deformation of Long Valley caldera and Mono Basin, California, investigated with the SBAS-InSAR approach  

Science Journals Connector (OSTI)

We investigate the surface deformation of the eastern California area that includes Long Valley caldera and Mono Basin. We apply the SAR Interferometry (InSAR) algorithm referred to as Small \\{BAseline\\} Subset (SBAS) approach that allows us to generate mean deformation velocity maps and displacement time series for the investigated area. The results presented in this work represent an advancement of previous InSAR studies of the area that are mostly focused on the deformation affecting the caldera. In particular, the proposed analysis is based on 21 SAR data acquired by the ERS-1/2 sensors during the 1992–2000 time interval, and demonstrates the capability of the SBAS procedure to identify and analyze displacement patterns at different spatial scales for the overall area spanning approximately 5000 km2. Two previously unreported localized deformation effects have been detected at Paoha Island, located within the Mono Lake, and in the McGee Creek area within the Sierra Nevada mountains, a zone to the south of the Long Valley caldera. In addition a spatially extended uplift effect, which strongly affects the caldera, has been identified and analyzed in detail. The InSAR results clearly show that the displacement phenomena affecting the Long Valley caldera have a maximum in correspondence of the resurgent dome and are characterized by the sequence of three different effects: a 1992–1997 uplift background, a 1997–1998 unrest phenomenon and a 1998–2000 subsidence phase. Moreover, the analysis of the retrieved displacement time series allows us to map the extent of the zone with a temporal deformation behavior highly correlated with the detected three-phases deformation pattern: background uplift-unrest-subsidence. We show that the mapped area clearly extends outside the northern part of the caldera slopes; accordingly, we suggest that future inversion models take this new evidence into account. The final discussion is dedicated to a comparison between the retrieved InSAR measurements and a set of GPS and leveling data, confirming the validity of the results achieved through the SBAS-InSAR analysis.

P. Tizzani; P. Berardino; F. Casu; P. Euillades; M. Manzo; G.P. Ricciardi; G. Zeni; R. Lanari

2007-01-01T23:59:59.000Z

396

Monitoring deformation at the Geysers Geothermal Field, California, using C-band and X-band interferometric synthetic aperture radar  

E-Print Network [OSTI]

multiphase fluid flow, heat transfer, and deformation inthe coupled multiphase fluid flow, heat transfer, and defor-

Vasco, D.W.

2014-01-01T23:59:59.000Z

397

Project #04: Andrs J. Garca and Hongwei Ma: Study of Cell Adhesion Strength Responses to Substrate Deformation  

E-Print Network [OSTI]

to substrate deformation. Photolithography techniques widely used in microfluidic systems will be applied here

Weber, Rodney

398

Beta relaxation in the shear mechanics of equilibrium viscous liquids: Phenomenology and network modeling of the alpha-beta merging region  

E-Print Network [OSTI]

The phenomenology of the beta relaxation process in the shear-mechanical response of glass-forming liquids is summarized and compared to that of the dielectric beta process. Furthermore, we discuss how to model the observations by means of standard viscoelastic modeling elements. Necessary physical requirements to such a model are outlined, and it is argued that physically relevant models must be additive in the shear compliance of the alpha and beta parts. A model based on these considerations is proposed and fitted to data for Polyisobutylene 680.

Bo Jakobsen; Kristine Niss; Claudio Maggi; Niels Boye Olsen; Tage Christensen; Jeppe C. Dyre

2010-05-26T23:59:59.000Z

399

Rheological Model for Wood  

E-Print Network [OSTI]

Wood as the most important natural and renewable building material plays an important role in the construction sector. Nevertheless, its hygroscopic character basically affects all related mechanical properties leading to degradation of material stiffness and strength over the service life. Accordingly, to attain reliable design of the timber structures, the influence of moisture evolution and the role of time- and moisture-dependent behaviors have to be taken into account. For this purpose, in the current study a 3D orthotropic elasto-plastic, visco-elastic, mechano-sorptive constitutive model for wood, with all material constants being defined as a function of moisture content, is presented. The corresponding numerical integration approach, with additive decomposition of the total strain is developed and implemented within the framework of the finite element method (FEM). Moreover to preserve a quadratic rate of asymptotic convergence the consistent tangent operator for the whole model is derived. Functionality and capability of the presented material model are evaluated by performing several numerical verification simulations of wood components under different combinations of mechanical loading and moisture variation. Additionally, the flexibility and universality of the introduced model to predict the mechanical behavior of different species are demonstrated by the analysis of a hybrid wood element. Furthermore, the proposed numerical approach is validated by comparisons of computational evaluations with experimental results.

Mohammad Masoud Hassani; Falk K. Wittel; Stefan Hering; Hans J. Herrmann

2014-10-15T23:59:59.000Z

400

High Shear Deformation to Produce High Strength and Energy Absorption in Mg Alloys  

SciTech Connect (OSTI)

Magnesium alloys have the potential to reduce the mass of transportation systems however to fully realize the benefits it must be usable in more applications including those that require higher strength and ductility. It has been known that fine grain size in Mg alloys leads to high strength and ductility. However, the challenge is how to achieve this optimal microstructure in a cost effective way. This work has shown that by using optimized high shear deformation and second phase particles of Mg2Si and MgxZnZry the energy absorption of the extrusions can exceed that of AA6061. The extrusion process under development described in this presentation appears to be scalable and cost effective. In addition to process development a novel modeling approach to understand the roles of strain and state-of-strain on particle fracture and grain size control has been developed

Joshi, Vineet V.; Jana, Saumyadeep; Li, Dongsheng; Garmestani, Hamid; Nyberg, Eric A.; Lavender, Curt A.

2014-02-01T23:59:59.000Z

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


401

Coupled reservoir-geomechanical analysis of CO2 injection and ground deformations at In Salah, Algeria  

SciTech Connect (OSTI)

In Salah Gas Project in Algeria has been injecting 0.5-1 million tonnes CO{sub 2} per year over the past five years into a water-filled strata at a depth of about 1,800 to 1,900 m. Unlike most CO{sub 2} storage sites, the permeability of the storage formation is relatively low and comparatively thin with a thickness of about 20 m. To ensure adequate CO{sub 2} flow-rates across the low-permeability sand-face, the In Salah Gas Project decided to use long-reach (about 1 to 1.5 km) horizontal injection wells. In an ongoing research project we use field data and coupled reservoir-geomechanical numerical modeling to assess the effectiveness of this approach and to investigate monitoring techniques to evaluate the performance of a CO{sub 2}-injection operation in relatively low permeability formations. Among the field data used are ground surface deformations evaluated from recently acquired satellite-based inferrometry (InSAR). The InSAR data shows a surface uplift on the order of 5 mm per year above active CO{sub 2} injection wells and the uplift pattern extends several km from the injection wells. In this paper we use the observed surface uplift to constrain our coupled reservoir-geomechanical model and conduct sensitivity studies to investigate potential causes and mechanisms of the observed uplift. The results of our analysis indicates that most of the observed uplift magnitude can be explained by pressure-induced, poro-elastic expansion of the 20 m thick injection zone, but there could also be a significant contribution from pressure-induced deformations within a 100 m thick zone of shaly sands immediately above the injection zone.

Rutqvist, J.; Vasco, D.W.; Myer, L.

2009-11-01T23:59:59.000Z

402

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

E-Print Network [OSTI]

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

Philippe Marmottant; François Graner

2007-07-06T23:59:59.000Z

403

Deformation and fracture characteristics of spent Zircaloy fuel cladding  

SciTech Connect (OSTI)

For a better understanding of Zircaloy fuel-rod failure by the pellet-cladding interaction (PCI) phenomenon, a mechanistic study of deformation and fracture behavior of spent power reactor fuel cladding under simulated PCI conditions was conducted. Zircaloy-2 cladding specimens, obtained from fuel assemblies of operating power reactors, were deformed to fracture at 325/sup 0/C by internal gas pressurization in the absence of fission product simulants. Fracture characteristics and microstructures were examined via SEM, TEM, and HVEM. Numerous dislocation tangles and cell structures, observed in TEM specimens of cladding tubes that failed in a ductile manner, were consistent with SEM observations of a limited number of dimples characteristic of microvoid coalescence. A number of brittle-type failures were produced without the influence of fission product simulants. The brittle cracks occurred near the areas compressed by the Swagelok fittings of the internally pressurized tube and propagated from the outer to the inner surface. Since the outer surface was isolated and maintained under a flowing stream of pure helium, it is unlikely that the brittle-type failure was influenced by any fission product traces. SEM fractography of the brittle-type failure revealed a large area of transgranular pseudocleavage with limited areas of ductile fluting, which were similar in appearance to the surfaces produced by in-reactor PCI-type failures. A TEM evaluation of the cladding in the vicinity of the through-wall crack revealed numerous locations that contained an extensive amount of second-phase precipitate (Zr/sub 3/O). We believe that the brittle-type failures of the irradiated spent fuel cladding in the stress rupture experiments are associated with segregation of oxygen, which leads to the formation of the order structure, an immobilization of dislocations, and minimal plastic deformation in the material.

Chung, H.M.; Yaggee, F.L.

1982-09-01T23:59:59.000Z

404

Deformed one-quasiparticle states in covariant density functional theory  

E-Print Network [OSTI]

Systematic investigation of the accuracy of the description of the energies of deformed one-quasiparticle states has been performed in covariant density functional theory in actinide and rare-earth mass regions. The sources of the discrepancies between theory and experiment are analyzed. Although some improvements in the description of ground state configurations and one-quasiparticle spectra can be achieved by better parametrization of the relativistic mean field Lagrangian, the analysis suggests that spectroscopic quality of their description can be achieved only in theoretical framework which takes into account particle-vibration coupling.

A. V. Afanasjev; S. Shawaqfeh

2012-05-10T23:59:59.000Z

405

Evidence for residual elastic strain in deformed natural quartz  

SciTech Connect (OSTI)

Residual elastic strain in naturally deformed, quartz-containing rocks can be measured quantitatively in a petrographic thin section with high spatial resolution using Laue microdiffraction with white synchrotron x-rays. The measurements with a resolution of one micrometer allow the quantitative determination of the deviatoric strain tensor as a function of position within the crystal investigated. The observed equivalent strain values of 800-1200 microstrains represent a lower bound of the actual preserved residual strain in the rock, since the stress component perpendicular to the cut sample surface plane is released. The measured equivalent strain translates into an equivalent stress in the order of {approx} 50 MPa.

Kunz, Martin; Chen, Kai; Tamura,Nobumichi; Wenk, Hans-Rudolf

2009-01-30T23:59:59.000Z

406

Giant Monopole Resonance in Transitional and Deformed-Nuclei  

E-Print Network [OSTI]

=129 MeV on ' ' Sm and ' ' ' Nd to investigate the giant monopole resonance in transitional and deformed nuclei. The experimental data reveal a mixing of I.=0 and I.=2 modes in '" Sm resulting in almost identi- cal angular distributions for the two... components of the giant resonance peaks in the angular range 2'?6. A "splitting" of the giant monopole resonance is observed in ' Nd; the extent of this split- ting is sma11er than that reported for ' "Sm. Comparison is made with the predictions of various...

Garg, U.; Bogucki, P.; Bronson, J. D.; Lui, YW; Youngblood, David H.

1984-01-01T23:59:59.000Z

407

Spontaneous-fission half-lives of deformed superheavy nuclei  

Science Journals Connector (OSTI)

Spontaneous-fission half-lives of the heaviest nuclei are analyzed in a multidimensional deformation space. They are calculated in a dynamical approach, without any adjustable parameters. The potential energy is obtained by the macroscopic-microscopic method and the inertia tensor by the cranking method. The action integral is minimized by a variational procedure. Even-even nuclei with proton number Z=104–114 and neutron number N=142–176 are considered. The results reproduce existing experimental data rather well. Relatively long half-lives are predicted for many unknown nuclei, sufficient to detect them if synthesized in a laboratory.

R. Smola?czuk; J. Skalski; A. Sobiczewski

1995-10-01T23:59:59.000Z

408

THEORETICAL INVESTIGATION OF MICROSTRUCTURE EVOLUTION AND DEFORMATION OF ZIRCONIUM UNDER CASCADE DAMAGE CONDITIONS  

SciTech Connect (OSTI)

This work is based on our reaction-diffusion model of radiation growth of Zr-based materials proposed recently in [1]. In [1], the equations for the strain rates in unloaded pure crystal under cascade damage conditions of, e.g., neutron or heavy-ion irradiation were derived as functions of dislocation densities, which include contributions from dislocation loops, and spatial distribution of their Burgers vectors. The model takes into account the intra-cascade clustering of self-interstitial atoms and their one-dimensional diffusion; explains the growth stages, including the break-away growth of pre-annealed samples; and accounts for some striking observations, such as of negative strain in prismatic direction, and co-existence of vacancy- and interstitial-type prismatic loops. In this report, the change of dislocation densities due to accumulation of sessile dislocation loops is taken into account explicitly to investigate the dose dependence of radiation growth. The dose dependence of climb rates of dislocations is calculated, which is important for the climb-induced glide model of radiation creep. The results of fitting the model to available experimental data and some numerical calculations of the strain behavior of Zr for different initial dislocation structures are presented and discussed. The computer code RIMD-ZR.V1 (Radiation Induced Microstructure and Deformation of Zr) developed is described and attached to this report.

Barashev, Alexander V [ORNL; Golubov, Stanislav I [ORNL; Stoller, Roger E [ORNL

2012-06-01T23:59:59.000Z

409

Un-equivalency Theorem between Deformed and undeformed Heisenberg-Weyl's Algebras  

E-Print Network [OSTI]

Two fundamental issues about the relation between the deformed Heisenberg-Weyl algebra in noncommutative space and the undeformed one in commutative space are elucidated. First the un-equivalency theorem between two algebras is proved: the deformed algebra related to the undeformed one by a non-orthogonal similarity transformation is explored; furthermore, non-existence of a unitary similarity transformation which transforms the deformed algebra to the undeformed one is demonstrated. Secondly the uniqueness of realizing the deformed phase space variables via the undeformed ones is elucidated: both the deformed Heisenberg-Weyl algebra and the deformed bosonic algebra should be maintained under a linear transformation between two sets of phase space variables which fixes that such a linear transformation is unique. Elucidation of this un-equivalency theorem has basic meaning both in theory and experiment.

Jian-Zu Zhang

2006-12-23T23:59:59.000Z

410

The $?$-deformed Segal-Bargmann transform is a Hall type transform  

E-Print Network [OSTI]

We present an explanation of how the $\\mu$-deformed Segal-Bargmann spaces, that are studied in various articles of the author in collaboration with Angulo, Echevarria and Pita, can be viewed as deserving their name, that is, how they should be considered as a part of Segal-Bargmann analysis. This explanation relates the $\\mu$-deformed Segal-Bargmann transforms to the generalized Segal-Bargmann transforms introduced by B. Hall using heat kernel analysis. All the versions of the $\\mu$-deformed Segal-Bargmann transform can be understood as Hall type transforms. In particular, we define a $\\mu$-deformation of Hall's "Version C" generalized Segal-Bargmann transform which is then shown to be a $\\mu$-deformed convolution with a $\\mu$-deformed heat kernel followed by analytic continuation. Our results are generalizations and analogues of the results of Hall.

Stephen Bruce Sontz

2009-07-13T23:59:59.000Z

411

Modeling  

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

a single-fluid diffuse interface model in the ALE-AMR hydrodynamics code to simulate surface tension effects. We show simula- tions and compare them to other surface tension...

412

Modeling  

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

sion effects. We show the result of a test case, and compare it to the result without surface tension. The model describes droplet formation nicely. Application The ARRA-funded...

413

Deformation mechanisms in TiAl/Ti{sub 3}Al structures  

SciTech Connect (OSTI)

The deformation behavior of two-phase titanium aluminide alloys with different microstructures has been investigated in a wide temperature range using deformation tests and electron microscope observations. The structure of lamellar interfaces was characterized with respect to their role as dislocation sources. Thermally activated processes governing the dislocation mobility were characterized in terms of activation volumes and activation energies. The analysis is aimed at the identification of the dislocation processes operating under deformation conditions which are relevant for practical applications.

Appel, F.; Wagner, R. [GKSS Research Center, Geesthacht (Germany). Inst. for Materials Research

1995-12-31T23:59:59.000Z

414

PHYSICAL NATURE OF SHEAR BANDS FORMATION AND CONSTITUTIVE MODELLING FOR PLASTIC INSTABILITY  

E-Print Network [OSTI]

697 PHYSICAL NATURE OF SHEAR BANDS FORMATION AND CONSTITUTIVE MODELLING FOR PLASTIC INSTABILITYtokrzyska 21,00-049 Warsaw,Poland Revue Phys. Appl. 23 (1988) 697 AVRIL 1988, Studies of plastic deformation dependent hardening property can be pivotal in the modelling for plastic deform- ation instability

Paris-Sud XI, Université de

415

Sediment chemistries and chironomid deformities in the Buffalo River (NY)  

SciTech Connect (OSTI)

The authors examined the surficial sediment chemistry (heavy metals) and the frequency of chironomid (Diptera) larvae mouthpart deformities from multiple PONAR grabs samples at each of 20 sites along the Buffalo River (NY) area of concern (AOC). Because of the potential for patchy invertebrate distribution and high variance in sediment chemistry, repeated spatial and temporal sampling is important to obtain a better integrated picture of contamination in rivers. The findings suggest that the Buffalo River has one of the highest percentages of deformed chironomids in AOC`s of the Great Lakes basin. One river site that was traditionally thought to be a chemical hot spot was less contaminated than another downstream section. At another site, sediment concentrations for V., Mn and AS appeared to be strongly associated with the proximity of combined sewer overflows from a region which is primarily residential. Interestingly, a demonstration project of the US Army Corps of Engineers, during which three types of dredges were used to carefully remove upper sediments from two different short reaches along the river, seemed to have no significant impact on proximate sediment chemistries or biota.

Stewart, K.M.; Diggins, T.P. [State Univ. of New York, Buffalo, NY (United States). Dept. of Biological Science

1994-12-31T23:59:59.000Z

416

Method to adjust multilayer film stress induced deformation of optics  

DOE Patents [OSTI]

A buffer-layer located between a substrate and a multilayer for counteracting stress in the multilayer. Depositing a buffer-layer having a stress of sufficient magnitude and opposite in sign reduces or cancels out deformation in the substrate due to the stress in the multilayer. By providing a buffer-layer between the substrate and the multilayer, a tunable, near-zero net stress results, and hence results in little or no deformation of the substrate, such as an optic for an extreme ultraviolet (EUV) lithography tool. Buffer-layers have been deposited, for example, between Mo/Si and Mo/Be multilayer films and their associated substrate reducing significantly the stress, wherein the magnitude of the stress is less than 100 MPa and respectively near-normal incidence (5.degree.) reflectance of over 60% is obtained at 13.4 nm and 11.4 nm. The present invention is applicable to crystalline and non-crystalline materials, and can be used at ambient temperatures.

Mirkarimi, Paul B. (Sunol, CA); Montcalm, Claude (Livermore, CA)

2000-01-01T23:59:59.000Z

417

Effect of Thermoplastic Binder on Flow Deformation Behavior of Wood  

Science Journals Connector (OSTI)

Abstract A processing technique was recently developed to realize plastic deformation in wood impregnated with a thermoset binder. This paper proposes a new flow forming technique where a thermoplastic binder is used instead of a thermoset binder with the expectation that the formability and recyclability of the products will be improved. To clarify the effect of the thermoplastic binder on the flow deformation behavior of wood, capillary fluidity tests were performed using impregnated wood with various contents of thermoplastic binder (polymer). The extrusion load of the impregnated wood through the capillary decreased with an increase of the polymer content in the wood. Results of the second fluidity test using the first extruded material reveals that the recycled impregnated wood can flow again. The extrusion load of the second extrusion was equal to or lower than the first. These results indicate that the recyclability of the wood impregnated with a thermoplastic binder is highly promising. The internal configuration of the impregnated wood during extrusion was also dependent on the polymer content.

Masako Seki; Tsunehisa Miki; Soichi Tanaka; Ichinori Shigematsu; Kozo Kanayama

2014-01-01T23:59:59.000Z

418

Cyclic deformation behaviour of austenitic steels at ambient and elevated temperatures  

Science Journals Connector (OSTI)

The aim of the present investigation is to characterise cyclic deformation behaviour and plasticity-induced martensite formation of metastable austenitic stainless steels at ambient and elevated temperatures, ...

Th. Nebel; D. Eifler

419

Morphology, deformation, and defect structures of TiCr{sub 2} in Ti-Cr alloys  

SciTech Connect (OSTI)

The morphologies and defect structures of TiCr{sub 2} in several Ti-Cr alloys have been examined by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM), in order to explore the room-temperature deformability of the Laves phase TiCr{sub 2}. The morphology of the Laves phase was found to be dependent upon alloy composition and annealing temperature. Samples deformed by compression have also been studied using TEM. Comparisons of microstructures before and after deformation suggest an increase in twin, stacking fault, and dislocation density within the Laves phase, indicating some but not extensive room-temperature deformability.

Chen, K.C.; Allen, S.M.; Livingston, J.D.

1992-12-31T23:59:59.000Z

420

Un-equivalency Theorem of Deformed Heisenberg-Weyl's Algebra in Noncommutative Space  

E-Print Network [OSTI]

An extensively tacit understandings of equivalency between the deformed Heisenberg-Weyl algebra in noncommutative space and the undeformed Heisenberg-Weyl algebra in commutative space is elucidated. Equivalency conditions between two algebras are clarified. It is explored that the deformed algebra related to the undeformed one by a non-orthogonal similarity transformation. Furthermore, non-existence of a unitary similarity transformation which transforms the deformed algebra to the undeformed one is demonstrated. The un-equivalency theorem between the deformed and the undeformed algebras is fully proved. Elucidation of this un-equivalency theorem has basic meaning both in theory and practice.

Jian-Zu Zhang

2006-02-22T23:59:59.000Z

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


421

E-Print Network 3.0 - akinesia-hypokinesia deformation sequence...  

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

Collection: Computer Technologies and Information Sciences 8 Efficient Path Planning for Mobile Robots in Environments with Deformable Objects Summary: Efficient Path Planning for...

422

E-Print Network 3.0 - andstrongly deformed structure Sample Search...  

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

UCLA, Ion Microprobe Facility Collection: Geosciences 25 Efficient Path Planning for Mobile Robots in Environments with Deformable Objects Summary: hierarchies 8 are less...

423

Atomic trigger shatters mystery of how glass deforms | ornl.gov  

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

Atomic trigger shatters mystery of how glass deforms Bond switching underpins warping of strong metallic glasses Joint Institute for Neutron Sciences Director Takeshi Egami, left,...

424

A unified continuum representation of post-seismic relaxation mechanisms: semi-analytic models of afterslip, poroelastic rebound and viscoelastic flow  

Science Journals Connector (OSTI)

......conjunction with our body-force method. The Green's function...Abramowitz M. , Stegun I., 1972. Handbook of Mathematical Functions with...Cheng A.H.-D., 1993. Fundamentals of poroelasticity, inComprehensive...Fluid mass sources and point forces in linear elastic diffusive......

Sylvain Barbot; Yuri Fialko

2010-09-01T23:59:59.000Z

425

Modeling  

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

ALE-AMR ALE-AMR code Wangyi Liu, John Bernard, Alex Friedman, Nathan Masters, Aaron Fisher, Velemir Mlaker, Alice Koniges, David Eder June 4, 2011 Abstract In this paper we describe an implementation of a single-fluid inter- face model in the ALE-AMR code to simulate surface tension effects. The model does not require explicit information on the physical state of the two phases. The only change to the existing fluid equations is an additional term in the stress tensor. We show results of applying the model to an expanding Al droplet surrounded by an Al vapor, where additional droplets are created. 1 Introduction The Neutralized Drift Compression Experiment II (NDCX II) is an induction accelerator planned for initial commissioning in 2012. The final design calls for a 3 MeV, Li+ ion beam, delivered in a bunch with characteristic pulse duration of 1 ns, and transverse dimension of order 1 mm. The

426

Hydraulic-fracture growth in dipping anisotropic strata as viewed through the surface deformation field  

SciTech Connect (OSTI)

In 1983 and 1984 Oak Rdige National Laboratory conducted a series of precision ground deformation measurements before, during, and after the generation of several large hydraulic fractures in a dipping member of the Cambrian Conasauga Shale. Each fracture was produced by the injection of approximately 500,000 L of slurry on a single day. Injection depth was 300 m. Leveling surveys were run several days before and several days after the injections. An array of eight high-precision borehole tiltmeters monitored ground deformations continuously for a period of several weeks. Analysis of the leveling and the tilt measurements revealed surface uplifts as great as 25 mm and tilts of tens of microradians during each injection. Furthermore, partial recovery (subsidence) of the ground took place during the days following an injection, accompanied by shifts in the position of maximum resultant uplift. Interpretation of the tilt measurements is consistent with stable widening and extension of hydraulic fractures with subhorizontal orientations. Comparison of the measured tilt patterns with fracture orientations established from logging of observation wells suggests that shearing parallel to the fracture planes accompanied fracture dilation. This interpretation is supported by measured tilts and ground uplifts that were as much as 100 percent greater than those expected from fracture dilation alone. Models of elastically anisotropic overburden rock do not explain the measured tilt patterns in the absence of shear stresses in the fracture planes. This work represents the first large-scale hydraulic-fracturing experiment in which the possible effects of material anisotropy and fracture-parallel shears have been measured and interpreted.

Holzhausen, G.R.; Haase, C.S.; Stow, S.H.; Gazonas, G.

1985-01-01T23:59:59.000Z

427

DEFORMATION SUBSTRUCTURES AND THEIR TRANSITIONS IN LASER SHOCK-COMPRESSED COPPER-ALUMINUM ALLOYS  

SciTech Connect (OSTI)

It is shown that the short pulse durations (0.1-10 ns) in laser shock compression ensure a rapid decay of the pulse and quenching of the shocked sample in times that are orders of magnitude lower than in conventional explosively driven plate impact experiments. Thus, laser compression, by virtue of a much more rapid cooling, enables the retention of a deformation structure closer to the one existing during shock. The smaller pulse length also decreases the propensity for localization. Copper and copper aluminum (2 and 6 wt% Al) with orientations [001] and [{bar 1}34] were subjected to high intensity laser pulses with energy levels of 70 to 300 J delivered in an initial pulse duration of approximately 3 ns. The [001] and [{bar 1}34] orientations were chosen since they respectively maximize and minimize the number of slip systems with highest resolved shear stresses. Systematic differences of the defect substructure were observed as a function of pressure, stacking-fault energy and crystalline orientation. The changes in the mechanical properties for each condition were compared using micro- and nano-hardness measurements and correlated well with observations of the defect substructure. Three regimes of plastic deformation were identified and their transitions modeled: dislocation cells, stacking-faults, and twins. An existing constitutive description of the slip to twinning transition, based on the critical shear stress, was expanded to incorporate the effect of stacking-fault energy. A new physically-based criterion accounting for stacking-fault energy was developed that describes the transition from perfect loop to partial loop homogeneous nucleation, and consequently from cells to stacking-faults. These calculations predict transitions that are in qualitative agreement with the effect of SFE.

Meyers, M A; Schneider, M S; Jarmakani, H; Kad, B; Remington, B A; Kalantar, D H; McNaney, J; Cao, B; Wark, J

2007-10-17T23:59:59.000Z

428

Evaluation of fracture properties of cold deformed 450 YS TMCP steel  

SciTech Connect (OSTI)

In the present study, 450 YS TMCP steel of 20 mm thickness was used to characterize the cold deformation capacity and respective mechanical and fracture toughness properties. The present work is part of a joint research project by the Dillinger Huette and GKSS Research Center on the cold deformation, weldability and various fracture aspects of the 450 YS TMCP steel. The paper, however, only refers to the investigation on cold deformation and respective fracture characteristics of the 450 YS TMCP steel. In particular, it is aimed at understanding the effect of cold deformation and anisotropy on the fracture behavior through tensile, Charpy-V notch impact, CTOD and wide-plate testing as well as via microstructural examination. As part of the program, tests were performed at RT, {minus}40 C and {minus}80 C on specimens machined from plates in six conditions, namely: (1) as-rolled (0% CD), (2) 5% cold deformed (pre-strained in tension) (5% CD), (3) 10% cold deformed (pre-strained in tension) (10% CD), (4) as-rolled + SR (580 C for 1 hour) (0% CD + SR), (5) 5% cold deformed + SR (5% CD + SR) and (6) 10% cold deformed + SR (10% CD + SR). An increasing degree of cold deformation increased both YS and TS combined with a reduction in ductility and toughness. The shift of the CVN transition curve was of the same order as experienced for normalized and Q+T steels. Thanks to the excellent as-rolled properties, even after 10% cold deformation, impact requirements were satisfied at least down to {minus}50 C. The YS to TS ratio was increased and was highest with the specimen axis parallel to the rolling and straining direction. The SR helped to regain a ratio of 0.90 even for 10% cold deformation.

Dobi, D.; Kocak, M.; Petrovski, B.I. [GKSS Research Center, Geesthacht (Germany). Inst. of Materials Research; Hanus, F. [Dillinger Huette AG, Saar (Germany). Welding Lab.

1994-12-31T23:59:59.000Z

429

Deformed Statistics Formulation of the Information Bottleneck Method  

E-Print Network [OSTI]

A candidate variational principle for the information bottleneck (IB) method is formulated within the ambit of the generalized nonadditive statistics of Tsallis. Given a nonadditivity parameter $ q $, the role of the \\textit{additive duality} of nonadditive statistics ($ q^*=2-q $) in relating Tsallis entropies for ranges of the nonadditivity parameter $ q 1 $ is described. Defining $ X $, $ \\tilde X $, and $ Y $ to be the source alphabet, the compressed reproduction alphabet, and, the \\textit{relevance variable} respectively, it is demonstrated that minimization of a generalized IB Lagrangian defined in terms of the nonadditivity parameter $ q^* $ self-consistently yields the \\textit{nonadditive effective distortion measure} to be the \\textit{$ q $-deformed} generalized Kullback-Leibler divergence: $ D_{K-L}^{q}[p(Y|X)||p(Y|\\tilde X)] $. This result is achieved without enforcing any \\textit{a-priori} assumptions. Finally, it is proven that the nonadditive free energy of the system in $ q^* $ space is non-ne...

Venkatesan, R C

2008-01-01T23:59:59.000Z

430

Deformations of Quantum Symmetric Algebras Extended by Groups  

E-Print Network [OSTI]

algebra S(V ). Let G be a group acting linearly on V . If the action of G on V extends to all of Sq(V ), then the smash product algebra Sq(V )#G is obtained by using Sq(V ) kG as a vector space but with a new multiplication given by (a#g)(b#h) = a g...(b) # gh for all a; b 2 Sq(V ); g; h 2 G: For further details, see De nition II.29 and Example II.31. Graded Hecke algebras, also known as Drinfeld Hecke algebras [9], can be viewed as deformations of S(V )#G of type (T (V )#G) = (wiwj wjwi X g2G...

Shakalli Tang, Jeanette

2012-07-16T23:59:59.000Z

431

Ricci flow deformation of cosmological initial data sets  

E-Print Network [OSTI]

Ricci flow deformation of cosmological initial data sets in general relativity is a technique for generating families of initial data sets which potentially would allow to interpolate between distinct spacetimes. This idea has been around since the appearance of the Ricci flow on the scene, but it has been difficult to turn it into a sound mathematical procedure. In this expository talk we illustrate, how Perelman's recent results in Ricci flow theory can considerably improve on such a situation. From a physical point of view this analysis can be related to the issue of finding a constant-curvature template spacetime for the inhomogeneous Universe, relevant to the interpretation of observational data and, hence, bears relevance to the dark energy and dark matter debates. These techniques provide control on curvature fluctuations (intrinsic backreaction terms) in their relation to the averaged matter distribution.

Mauro Carfora; Thomas Buchert

2008-01-03T23:59:59.000Z

432

Pseudoplastic deformation pits on polished ceramics due to cavitation erosion  

Science Journals Connector (OSTI)

In a previous study, pseudoplastic deformation pits created by cavitation exposure were reported in silicon nitride and zirconia. In this research, further comparison of the size and number of pits between several silicon nitride and zirconia materials is carried out. The pits are larger and much more numerous in silicon nitride than in zirconia although silicon nitride is harder than zirconia. An explanation of this phenomenon is given. Also, in the previous study it was reported that apparently a partially stabilized zirconia with yttria oxide developed a delay in the phase transformation from tetragonal to monoclinic after being exposed to cavitation. In this research, further experiments related with this phase transformation delay are carried out. Also, the phase transformation is verified with X-ray diffraction analysis. It is concluded that the “activation” of the partial stabilized zirconia happens regardless of the oxide used to stabilize it.

G. García-Atance Fatjó; M. Hadfield; K. Tabeshfar

2011-01-01T23:59:59.000Z

433

Noise-assisted Thouless pump in elastically deformable molecular junctions  

E-Print Network [OSTI]

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

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

2014-04-16T23:59:59.000Z

434

Correlation of microseismic and chemical properties of brittle deformation in Locharbriggs sandstone  

E-Print Network [OSTI]

: stress corrosion, acoustic emission, silica dissolution, subcritical crack growth, deformation rate), 2268, doi:10.1029/2002JB002277, 2003. 1. Introduction [2] Water is ubiquitous in the Earth's crust of water influences the brittle deformation properties of rocks in two ways. The poroe- lastic effect

435

Viscosity of magmas containing highly deformable bubbles M. Mangaa,*, M. Loewenbergb  

E-Print Network [OSTI]

Viscosity of magmas containing highly deformable bubbles M. Mangaa,*, M. Loewenbergb a Department The shear viscosity of a suspension of deformable bubbles dispersed within a Newtonian ¯uid is calculated. For small Ca, bubbles remain nearly spherical, and for suf®ciently large strains the viscosity of suspension

Manga, Michael

436

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

E-Print Network [OSTI]

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

437

Interfaces and Plastic Deformation in Materials: From Theory to Engineering (3 Credits)  

E-Print Network [OSTI]

Interfaces and Plastic Deformation in Materials: From Theory to Engineering (3 Credits) Instructor in their plastic deformation. The interface structures and defects will be described at different scales. Interfaces and high temperature plasticity 11. Triple junctions: from free to constrained interfaces 12

Chen, Zheng

438

Structural Signature of Plastic Deformation in Metallic Glasses H. L. Peng,1,2  

E-Print Network [OSTI]

Structural Signature of Plastic Deformation in Metallic Glasses H. L. Peng,1,2 M. Z. Li,2,* and W the degree of local fivefold symmetry (LFFS) as the structural indicator to predict plastic deformation of local structures and find that the plastic events prefer to be initiated in regions with a lower degree

Wang, Wei Hua

439

Parametric dislocation dynamics: A thermodynamics-based approach to investigations of mesoscopic plastic deformation  

E-Print Network [OSTI]

plastic deformation N. M. Ghoniem, S.-H. Tong, and L. Z. Sun Mechanical and Aerospace Engineering 3D interacting dislocation loops. The approach is appropriate for investigations of plastic defor formation of dislocation junctions. I. INTRODUCTION A fundamental description of plastic deformation is now

Ghoniem, Nasr M.

440

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

E-Print Network [OSTI]

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

Sivaloganathan, J.

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


441

Deformation-induced inverted metamorphic eld gradients: an example from the southeastern Canadian Cordillera  

E-Print Network [OSTI]

Deformation-induced inverted metamorphic ®eld gradients: an example from the southeastern Canadian allochthon and Monashee complex, exhibits an inverted metamorphic ®eld gradient. New data presented preserving evidence of strongly diachronous deformation and an apparent inverted metamorphism. # 1999

Gibson, Dan

442

Dielectric elastomer membranes undergoing inhomogeneous deformation Tianhu He,1,2  

E-Print Network [OSTI]

online 29 October 2009 Dielectric elastomers are capable of large deformation subject to an electric voltage and are promising for use as actuators, sensors, and generators. Because of large deformation inhomogeneous, and that the membrane is susceptible to several modes of failure, including electrical breakdown

Suo, Zhigang

443

Friction, Adhesion, and Deformation: Dynamic Measurements with the Atomic Force Phil Attard  

E-Print Network [OSTI]

Friction, Adhesion, and Deformation: Dynamic Measurements with the Atomic Force Microscope Phil. Adhesion Sci. Technol. 16, 753­791 (2002).) Running title: Friction, Adhesion, and Deformation Abstract for the friction force microscope, quantitative measurements of friction and the ef- fect of adhesion, measurement

Attard, Phil

444

SoundFLEX: Designing Audio to Guide Interactions with Shape-Retaining Deformable Interfaces  

Science Journals Connector (OSTI)

Shape-retaining freely-deformable interfaces can take innumerable distinct shapes, and creating specific target configurations can be a challenge. In this paper, we investigate how audio can guide a user in this process, through the use of either musical ... Keywords: audio feedback, deformable interfaces, multimodal interaction, shape-retaining interfaces, sonic interaction, sound design

Koray Tahiro?lu, Thomas Svedström, Valtteri Wikström, Simon Overstall, Johan Kildal, Teemu Ahmaniemi

2014-11-01T23:59:59.000Z

445

Three-dimensional deformation caused by the Bam, Iran, earthquake and the  

E-Print Network [OSTI]

Three-dimensional deformation caused by the Bam, Iran, earthquake and the origin of shallow slip on seismogenic faults. We derive the full vector displacement field due to the Bam, Iran, earthquake of moment on deformation associated with the Mw ¼ 6.5 Bam earthquake in Iran determined using the SAR data from the ERS

446

Multiphase Fluid Flow in Deformable Variable-Aperture Fractures - Final Report  

SciTech Connect (OSTI)

Fractures provide flow paths that can potentially lead to fast migration of fluids or contaminants. A number of energy-­?related applications involve fluid injections that significantly perturb both the pressures and chemical composition of subsurface fluids. These perturbations can cause both mechanical deformation and chemical alteration of host rocks with potential for significant changes in permeability. In fractured rock subjected to coupled chemical and mechanical stresses, it can be difficult to predict the sign of permeability changes, let alone the magnitude. This project integrated experimental and computational studies to improve mechanistic understanding of these coupled processes and develop and test predictive models and monitoring techniques. The project involved three major components: (1) study of two-­?phase flow processes involving mass transfer between phases and dissolution of minerals along fracture surfaces (Detwiler et al., 2009; Detwiler, 2010); (2) study of fracture dissolution in fractures subjected to normal stresses using experimental techniques (Ameli, et al., 2013; Elkhoury et al., 2013; Elkhoury et al., 2014) and newly developed computational models (Ameli, et al., 2014); (3) evaluation of electrical resistivity tomography (ERT) as a method to detect and quantify gas leakage through a fractured caprock (Breen et al., 2012; Lochbuhler et al., 2014). The project provided support for one PhD student (Dr. Pasha Ameli; 2009-­?2013) and partially supported a post-­?doctoral scholar (Dr. Jean Elkhoury; 2010-­?2013). In addition, the project provided supplemental funding to support collaboration with Dr. Charles Carrigan at Lawrence Livermore National Laboratory in connection with (3) and supported one MS student (Stephen Breen; 2011-­?2013). Major results from each component of the project include the following: (1) Mineral dissolution in fractures occupied by two fluid phases (e.g., oil-­?water or water-­?CO{sub 2}) causes changes in local capillary forces and redistribution of fluids. These coupled processes enhance channel formation and the potential for development of fast flow paths through fractures. (2) Dissolution in fractures subjected to normal stress can result in behaviors ranging from development of dissolution channels and rapid permeability increases to fracture healing and significant permeability decreases. The timescales associated with advective transport of dissolved ions in the fracture, mineral dissolution rates, and diffusion within the adjacent porous matrix dictate the sign and magnitude of the resulting permeability changes. Furthermore, a high-­? resolution mechanistic model that couples elastic deformation of contacts and aperture-­?dependent dissolution rates predicts the range of observed behaviors reasonably well. (3) ERT has potential as a tool for monitoring gas leakage in deep formations. Using probabilistic inversion methods further enhances the results by providing uncertainty estimates of inverted parameters.

Detwiler, Russell

2014-04-30T23:59:59.000Z

447

Deformability-based red blood cell separation in deterministic lateral displacement devices - a simulation study  

E-Print Network [OSTI]

We show, via three-dimensional immersed-boundary-finite-element-lattice-Boltzmann simulations, that deformability-based red blood cell (RBC) separation in deterministic lateral displacement (DLD) devices is possible. This is due to the deformability-dependent lateral extension of RBCs and enables us to predict a priori which RBCs will be displaced in a given DLD geometry. Several diseases affect the deformability of human cells. Malaria-infected RBCs or sickle cells, for example, tend to become stiffer than their healthy counterparts. It is therefore desirable to design microfluidic devices which can detect those diseases based on the cells' deformability fingerprint, rather than preparing samples using expensive and time-consuming biochemical preparation steps. Our findings should be helpful in the development of new methods for sorting cells and particles by deformability.

Timm Krueger; David Holmes; Peter V. Coveney

2014-06-07T23:59:59.000Z

448

Can mouth part deformities of Chironomus riparius serve as indicators for water and sediment pollution? A laboratory approach  

Science Journals Connector (OSTI)

For nickel, the absence of deformities was unexpected due to the fact that this is a widely distributed heavy metal. Heavy metals have been investigated in connection with deformity induction, both in the labo...

Miriam Langer-Jaesrich; Heinz-R. Köhler; Almut Gerhardt

2010-04-01T23:59:59.000Z

449

Investigating the role of calcium in the biomechanical response of neutrophils to mechanical deformation experienced in the pulmonary capillaries  

E-Print Network [OSTI]

Neutrophils in the pulmonary microcirculation are subjected to mechanical deformation while traveling through capillaries of sizes much smaller than the mean neutrophil diameter. This deformation has been shown to result ...

Hsu, Jeffrey J

2006-01-01T23:59:59.000Z

450

deForm: An interactive malleable surface for capturing 2.5D arbitrary objects, tools and touch  

E-Print Network [OSTI]

We introduce a novel input device, deForm, that supports 2.5D touch gestures, tangible tools, and arbitrary objects through real-time structured light scanning of a malleable surface of interaction. DeForm captures ...

Ishii, Hiroshi

451

Modeling Elasto-Plastic Behavior of Polycrystalline Grain Structure of Steels at Mesoscopic Level  

E-Print Network [OSTI]

Modeling Elasto-Plastic Behavior of Polycrystalline Grain Structure of Steels at Mesoscopic Level. The constitutive model of crystal grains utilizes anisotropic elasticity and crystal plasticity. Commercially be considered macroscopically homogeneous. Elastic and rate independent plastic deformation modes are considered

Cizelj, Leon

452

A continuum constitutive model for amorphous metallic materials  

E-Print Network [OSTI]

A finite-deformation, Coulomb-Mohr type constitutive theory for the elastic-viscoplastic response of pressure-sensitive and plastically-dilatant isotropic materials has been developed. The constitutive model has been ...

Su, Cheng, Ph. D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

453

Modeling-Computer Simulations At Long Valley Caldera Geothermal...  

Open Energy Info (EERE)

and components of two continuous GPS time series. Additionally, the model explains the spatial extent of deformation observed by InSAR data covering the 1997-98 inflation...

454

Analytical modeling of composite steel-concrete frame systems  

E-Print Network [OSTI]

of reinforced concrete or composite steel shapes encased in reinforced concrete (SRC), structural steel beams, and composite beam-column joints. To facilitate the modeling of inelastic deformations in joint regions, a panel element capable of representing joint...

Atahan, Ali Osman

1996-01-01T23:59:59.000Z

455

Automatic Preparation, Calibration, and Simulation of Deformable Objects  

E-Print Network [OSTI]

simulation method in the interest of focusing on automation of model preparation (rather than simulation), prohibiting manual intervention in the model preparation process. This paper provides a pipeline for rapid (preparing solid meshes from surface models), automated calibration of models to finite element reference

Stanford University

456

Neotectonics of the Panama region. II. Deformation of the southern Colobian Basin  

SciTech Connect (OSTI)

The southern Colombian Basin is currently undergoing deformation as a result of convergence between Panama and the Caribbean plate. The structural expression of this convergence north of Panama is the Panama Deformed Belt (PDB), a marginal wedge of highly deformed sediments. The authors interpretation of UTIG multichannel data suggest that deformation of the PDB initiated during the Miocene and that the deformation front is migrating northward with respect to the Caribbean plate. Earthquake activity along the PDB is concentrated toward the east where the Mono Rise is underthrusting the PDB. The hypo-central distribution of these events indicate the presence of a seismic zone which has shallow dip to the southwest. Multichannel data also indicate that the style of deformation within the PDB changes from east to west. The authors propose that the observed variations in seismicity and deformation of the PDB are dependent on two factors: 1. The difference in Panama-Caribbean plate convergence along the PDB and 2. The fluctuation in oceanic crustal thickness of the Colombian Basin.

Adamek, S.H.

1985-01-01T23:59:59.000Z

457

Erythrocyte deformation in high-throughput optical stretchers  

Science Journals Connector (OSTI)

Optical stretchers can be used to quantify elastic and homeostatic properties of cells. Because they can apply forces to cells without requiring direct contact, they may noninvasively measure mechanical properties related to cell and membrane health. Present-day optical stretchers are, however, limited to measurements on individual stationary cells, limiting throughput. To overcome this limitation and allow study of variations in cell populations, we recently developed and tested a microfluidic chamber that measures optical stretching parameters for erythrocytes under dynamic flowing conditions. The method uses a single linear diode laser bar and permitted measurements at low flow rates and higher throughput. Here, we numerically investigate the feasibility of further increasing the measurement rates of the optical stretcher in parameter domains where hydrodynamic and optical forces are of comparable magnitude. To do this we couple a recently implemented dynamic optical ray-tracing technique with a fluid-structure interaction solver to simulate the deformation of osmotically swollen erythrocytes in fluid flow of variable rate. Our results demonstrate that a detectable steady-state stretch is induced at nominal optical powers and flow rates. In addition, we find that flow rates can be increased significantly with no major effect on net cell stretch showing the feasibility of application of this technique at greatly increased throughputs.

Ihab Sraj; Alex C. Szatmary; Sanjay A. Desai; David W. M. Marr; Charles D. Eggleton

2012-04-30T23:59:59.000Z

458

Role of material properties and mesostructure on dynamic deformation and shear instability in Al-W granular composites  

E-Print Network [OSTI]

Dynamic experiments with Al-W granular/porous composites revealed qualitatively different behavior with respect to shear localization depending on bonding between Al particles. Two-dimensional numerical modeling was used to explore the mesomechanics of the large strain dynamic deformation in Al-W granular/porous composites and explain the experimentally observed differences in shear localization between composites with various mesostructures. Specifically, the bonding between the Al particles, the porosity, the roles of the relative particle sizes of Al and W, the arrangements of the W particles, and the material properties of Al were investigated using numerical calculations. It was demonstrated in simulations that the bonding between the "soft" Al particles facilitated shear localization as seen in the experiments. Numerical calculations and experiments revealed that the mechanism of the shear localization in granular composites is mainly due to the local high strain flow of "soft" Al around the "rigid" W particles causing localized damage accumulation and subsequent growth of the meso/macro shear bands/cracks. The "rigid" W particles were the major geometrical factor determining the initiation and propagation of "kinked" shear bands in the matrix of "soft" Al particles, leaving some areas free of extensive plastic deformation as observed in experiments and numerical calculations.

K. L. Olney; P. H. Chiu; C. W. Lee; V. F. Nesterenko; D. J. Benson

2011-05-24T23:59:59.000Z

459

Unified description of magic numbers of metal clusters in terms of the 3-dimensional q-deformed harmonic oscillator  

E-Print Network [OSTI]

Magic numbers predicted by a 3-dimensional q-deformed harmonic oscillator with Uq(3)>SOq(3) symmetry are compared to experimental data for atomic clusters of alkali metals (Li, Na, K, Rb, Cs), noble metals (Cu, Ag, Au), divalent metals (Zn, Cd), and trivalent metals (Al, In), as well as to theoretical predictions of jellium models, Woods-Saxon and wine bottle potentials, and to the classification scheme using the 3n+l pseudo quantum number. In alkali metal clusters and noble metal clusters the 3-dimensional q-deformed harmonic oscillator correctly predicts all experimentally observed magic numbers up to 1500 (which is the expected limit of validity for theories based on the filling of electronic shells), while in addition it gives satisfactory results for the magic numbers of clusters of divalent metals and trivalent metals, thus indicating that Uq(3), which is a nonlinear extension of the U(3) symmetry of the spherical (3-dimensional isotropic) harmonic oscillator, is a good candidate for being the symmetry ...

Bonatsos, Dennis; Lenis, D; Raychev, P P; Roussev, R P; Terziev, P A

2000-01-01T23:59:59.000Z

460

Thermodynamics of electromechanically coupled mixed ionic-electronic conductors: Deformation potential, Vegard strains, and flexoelectric effect  

Science Journals Connector (OSTI)

Strong coupling among external voltage, electrochemical potentials, concentrations of electronic and ionic species, and strains is a ubiquitous feature of solid state mixed ionic-electronic conductors (MIECs), the materials of choice in devices ranging from electroresistive and memristive elements to ion batteries and fuel cells. Here, we analyze in detail the electromechanical coupling mechanisms and derive generalized bias-concentration-strain equations for MIECs including contributions of concentration-driven chemical expansion, deformation potential, and flexoelectric effect. This analysis is extended toward the bias-induced strains in the uniform and scanning-probe-microscopy-like geometries. Notably, the contribution of the electron-phonon and flexoelectric coupling to the local surface displacement of the mixed ionic-electronic conductor caused by the electric field scanning probe microscope tip has not been considered previously. The developed thermodynamic approach allows evolving the theoretical description of mechanical phenomena induced by the electric fields (electromechanical response) in solid state ionics toward analytical theory and phase-field modeling of the MIECs in different geometries and under varying electrical, chemical, and mechanical boundary conditions.

A. N. Morozovska; E. A. Eliseev; A. K. Tagantsev; S. L. Bravina; Long-Qing Chen; S. V. Kalinin

2011-05-11T23:59:59.000Z

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


461

Experimental study of hot deformation behavior in API X65 steel  

Science Journals Connector (OSTI)

The hot deformation behavior of API X65 steel was investigated by hot compression tests. A temperature range between 950 and 1150 °C was used for experiments with different strain rates of 0.01, 0.1 and 1 s?1. The obtained flow curves were used together with work hardening rate analyses to study the dynamic recrystallization (DRX) behavior of the tested steel. The retardation of DRX in higher Zener–Hollomon parameter (Z) values was observed. In lower Z values however, transition from single peak DRX to multiple peaks DRX occurred. Different constitutive equations, including the power law, the exponential law and the hyperbolic sine law were used to express the Z parameter as a function of the peak stress. A new procedure was proposed to determine the optimum value of stress multiplier (?) in the hyperbolic sine law equation. This equation with the proposed procedure had the best performance for modeling the DRX behavior of API X65 steel. Furthermore, the relationship between the Z parameter and the peak stress was investigated using the power law relation. This gave the Z exponent of 0.173 for peak stress and 0.153 for peak strain. The normalized critical stress and strain for initiation of DRX were found to be 0.89 and 0.6, respectively. The obtained results are in general consistent with the experimental results from similar works.

M. Rakhshkhorshid; S.H. Hashemi

2013-01-01T23:59:59.000Z

462

Progress in sub-grid scale modeling of shock-turbulence interaction  

SciTech Connect (OSTI)

The authors report on progress in the development of sub grid scale (SGS) closure relationships for the unresolved motion scales in compressible large eddy simulations (LES). At present they are refining the SGS model and overall LES procedure to include: a linearized viscoelastic model for finite thickness shock distortions and shocked turbulence field response; multiple scale asymptotic considerations to improve predictions of average near-wall surface behavior; and a spectral statistical model simulating the effects of high wave number stochastic feed-back from the unresolved SGS nonlinear motion influences on the explicitly resolved grid scale motions. Predicted amplification levels, modal energy partition, shock translational to turbulence kinetic energy transfer, and viscoelastic spatio-temporal response of turbulence to shock interaction are examined in comparison with available experimental evidence. Supplemental hypersonic compressible turbulence experimental information is developed from sub nanosecond interval pulsed shadowgraph evidence of laser impulse generated hypervelocity shocks interacting with intense, previously developed and carefully characterized initial turbulence. Accurate description of the influence of shock-turbulence interactions is vital for predicting their influence on: Supersonic/hypersonic flow field analysis, aerodynamic design, and aerostructural materials selection. Practical applications also include interior supersonic combustion analysis and combustion chamber design. It is also the essential foundation for accurately predicting the development and evolution of flow-field generated thermal and electromagnetic radiation important to hypersonic flight vehicle survivability, detection and communication.

Buckingham, A.C. [Lawrence Livermore National Lab., CA (United States). Center for Advanced Fluid Dynamics Applications; Grun, J. [Naval Research Lab., Washington, DC (United States). Plasma Physics Div.

1994-12-01T23:59:59.000Z

463

Formation of bands and ridges on Europa by cyclic deformation: Insights from analogue wax experiments  

E-Print Network [OSTI]

, California, USA Antoine Sinton Departement des Sciences de la Matiere, Ecole Normale Superieure, Lyon, France); KEYWORDS: Europa, ridges, tidal deformation Citation: Manga, M., and A. Sinton (2004), Formation of bands

Manga, Michael

464

Biomass Production, Structural Deformation, Self-Thinning and Thinning Mechanisms in Monocultures  

Science Journals Connector (OSTI)

29 July 1991 research-article Biomass Production, Structural Deformation...Consideration is given to the production of biomass in three of the possible growth phases...with uniformly augmented and diminished biomass, and the boundaries separating and distinguishing...

1991-01-01T23:59:59.000Z

465

INTEGRATED INSAR AND GPS STUDIES OF CRUSTAL DEFORMATION IN THE WESTERN GREAT BASIN, WESTERN UNITED STATES  

E-Print Network [OSTI]

UK - Zhenhong.Li@ges.gla.ac.uk KEY WORDS: InSAR, GPS, crustal deformation, Yucca Mountain, vertical GPS networks which are limited by their station spacing. We select the Yucca Mountain, Nevada region

Tingley, Joseph V.

466

Power law scaling of lateral deformations with universal Poissons index for randomly folded thin sheets  

E-Print Network [OSTI]

We study the lateral deformations of randomly folded elastoplastic and predominantly plastic thin sheets under the uniaxial and radial compressions. We found that the lateral deformations of cylinders folded from elastoplastic sheets of paper obey a power law behavior with the universal Poissons index nu = 0.17 pm 0.01, which does not depend neither the paper kind and sheet sizes, nor the folding confinement ratio. In contrast to this, the lateral deformations of randomly folded predominantly plastic aluminum foils display the linear dependence on the axial compression with the universal Poissons ratio nu_e = 0.33 pm 0.01. This difference is consistent with the difference in fractal topology of randomly folded elastoplastic and predominantly plastic sheets, which is found to belong to different universality classes. The general form of constitutive stress-deformation relations for randomly folded elastoplastic sheets is suggested.

Alexander S. Balankin; Didier Samayoa Ochoa; Ernesto Pineda Leon; Rolando Cortes Montes de Oca; Antonio Horta Rangel; Miguel Angel Martinez Cruz

2008-08-24T23:59:59.000Z

467

D\\'{e}formations isospectrales non compactes et th\\'{e}orie quantique des champs  

E-Print Network [OSTI]

The aim of this thesis is to study the isopectral deformations from the point of view of Alain Connes' noncommutative geometry. This class of quantum spaces constituts a curved space generalisation of Moyal planes and noncommutative tori. First of all, we look at the construction of non-unital spectral triples, for which we propose modified axioms. We then check that Moyal planes fit into this axiomatic framework, and give the keypoints for the construction of non-unital spectral triples from generic non-compact isospectral deformations. To this end, numerous analytical tools on non-compact Riemannian manifolds are developped. Thanks to Dixmier traces computations, we show that their spectral and classical dimensions coincide. In a second time, we study certain features of quantum fields theory on curved isospectral deformations, with a particular view on the ultraviolet infrared mixing phenomenon. We show its intrinsic nature for all such quantum spaces (compacts or not, periodic or not deformations), and we...

Gayral, V

2005-01-01T23:59:59.000Z

468

Fermi-Energy-Dependent Structural Deformation of Chiral Single-Wall Carbon Nanotubes  

E-Print Network [OSTI]

In this work, we use an extended tight-binding approach for calculating the Fermi-energy dependence of the structural deformation of chiral single-wall carbon nanotubes (SWNTs). We show that, in general, nanotube strains ...

Vieira, Bruno G.?M.

469

E-Print Network 3.0 - ankle deformity secondary Sample Search...  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: ankle deformity secondary Page: << < 1 2 3 4 5 > >> 1 Abstract--The aim of this study was to...

470

On Coating Durability of Polymer Coated Sheet Metal under Plastic Deformation  

E-Print Network [OSTI]

process. Thus, the effect of plastic deformation on coating adhesion is of primary interest to many engineers and researchers. This research aims at developing a methodology to predict the adhesion of coating after metal forming processes. A pull...

Huang, Yu-Hsuan

2011-08-08T23:59:59.000Z

471

Evaluation of the filler effects on fatique cracking and permanent deformation of asphalt concrete mixtures  

E-Print Network [OSTI]

The addition of hydrated lime to asphalt has shown to be beneficial with an improvement in the Theological properties of the binder, as well as resistance to permanent deformation (rutting) and fatigue cracking of asphalt concrete mixtures...

Izzo, Richard P

1997-01-01T23:59:59.000Z

472

Study of permanent deformation mechanism in asphalt mixes in relation to microcrack growth  

E-Print Network [OSTI]

Recent developments by Lytton et al. (1998) indicate phics. that the growth of micrographs in asphalt layers under repeated loading is also a cause for the accumulation of permanent deformation or rutting in pavements besides the plastic strain...

Bhairampally, Rajesh Kumar

1998-01-01T23:59:59.000Z

473

An investigation of bulk nanocrystalline copper fabricated via severe plastic deformation and nanoparticle consolidation  

E-Print Network [OSTI]

obtained respectively by a top down approach of severe plastic deformation of wrought copper and a bottom up approach of consolidation of copper nanoparticles using equal channel angular extrusion (ECAE). A critical assessment and correlation...

Haouaoui, Mohammed

2007-04-25T23:59:59.000Z

474

Nuclear fusion as a probe for octupole deformation in $^{224}$Ra  

E-Print Network [OSTI]

$\\textit{Background}$: Nuclear fusion has been shown to be a perfect probe to study the different nuclear shapes. However, the possibility of testing octupole deformation of a nucleus with this tool has not been fully explored yet. The presence of a stactic octupole deformation in nuclei will enhanced a possible permanent electric dipole moment, leading to a possible demonstration of parity violation. $\\textit{Purpose}$: To check whether static octupole deformation or octupole vibration in fusion give qualitatively different results so that both situations can be experimentally disentangled. $\\textit{Method}$: Fusion cross sections are computed in the Coupled-Channels formalism making use of the Ingoing-Wave Boundary Conditions (IWBC) for the systems $^{16}$O+$^{144}$Ba and $^{16}$O+$^{224}$Ra. $\\textit{Results}$: Barrier distributions of the two considered schemes show different patterns. For the $^{224}$Ra case, the octupole deformation parameter is large enough to create a sizeable difference. $\\textit{Con...

Kumar, Raj; Vitturi, A

2015-01-01T23:59:59.000Z

475

The effects of deformation parameter on thermal witdth of moving quarqonia in plasma  

E-Print Network [OSTI]

In general we can say that the thermal width of quarqonia corresponds to imaginary part of potential. The gravity dual of theories give explicit form of potential as $V_{Q\\bar{Q}}$. The Variable gravity dual's backgrounds of moving pair in plasma have different results for potential. Our paper shows that the first order deformation parameter $c$ in warp factor lead us to take new results. We compare our results to case of no deformation parameter is in metric background. We will find out altough in a deformed AdS meson is not visible in some regions of bulk, but thermal width is similar to the case that dipole is in $AdS_{5}$. Also, we note here in a deformed AdS, meson feels moving plasma in all values of velocity.

J. Sadeghi; S. Tahery

2014-12-29T23:59:59.000Z

476

The morphology and deformation behavior of poly(butylene terephthalate)/BPA polycarbonate blends  

Science Journals Connector (OSTI)

In this communication the results of a series of recent studies of the morphology and deformation behavior of toughened poly(butylene terephthalate) (PBT)/BPA polycarbonate (PC) blends are briefly summarized....

S. Y. Hobbs; M. E. J. Dekkers; V. H. Watkins

1987-04-01T23:59:59.000Z

477

Chronostratigraphy and tectonic deformation of the North EcuadorianSouth Colombian offshore Manglares forearc basin  

E-Print Network [OSTI]

Chronostratigraphy and tectonic deformation of the North Ecuadorian­South Colombian offshore.5°, where it is fronted by the Colombian accretionary wedge (Mountney and Westbrook, 1997). This study

Vallée, Martin

478

Coseismic sediment deformation during the 1989 Loma Prieta Ronaldo I. Borja1  

E-Print Network [OSTI]

Coseismic sediment deformation during the 1989 Loma Prieta earthquake Ronaldo I. Borja1 and WaiChing Sun1 Received 31 July 2007; revised 6 February 2008; accepted 14 April 2008; published 19 August 2008

Borja, Ronaldo I.

479

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

E-Print Network [OSTI]

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

Di Leo, Claudio V

2012-01-01T23:59:59.000Z

480

The evolution of lithospheric deformation and crustal structure from continental margins to oceanic spreading centers  

E-Print Network [OSTI]

This thesis investigates the evolution of lithospheric deformation and crustal structure from continental margins to mid-ocean ridges. The first part (Ch. 2) examines the style of segmentation along the U.S. East Coast ...

Behn, Mark Dietrich, 1974-

2002-01-01T23:59:59.000Z

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


481

Deformation behavior in bulk nanocrystalline-ultrafine aluminum :in situ evidence of plastic strain recovery.  

SciTech Connect (OSTI)

The plastic deformation behavior of bulk nanocrystalline-ultrafine Al was investigated under in situ compressive loading using high-energy synchrotron X-ray diffraction. After one loading-unloading cycle, to 2% strain, we find reversible peak broadening within the nanocrystalline grain volume and tensile residual stress (80 MPa) within the ultrafine grain volume. Upon unloading, we detect recovery of 12% of the plastic strain, and this recovery increases up to 28% at even higher applied deformations to 4%.

Lonardelli, I.; Almer, J.; Ischia, G; Menapace, C.; Molinari, A.; Univ. of Trento

2009-04-01T23:59:59.000Z

482

Nuclear Deformation and the Moment of Inertia of Nuclear Rotational States  

Science Journals Connector (OSTI)

Evidence concerning nuclear deformation from isotope shifts and from rotational states in even-even nuclei is compared for nuclei near neutron number 82. It is concluded that the moment of inertia of the rotational states is 4±1 times greater than the theory predicts, if the nuclear radius is 1.20×10-13A13 cm, and if the interpretation of isotope shifts in terms of nuclear deformation is correct.

Kenneth W. Ford

1954-09-01T23:59:59.000Z

483

A shear deformable, doubly curved finite element for the analysis of laminated composite structures  

E-Print Network [OSTI]

A SHL'AR DEFORMABLE, DOUBLY CURVED FINITE ELEMENT FOR THE ANALYSIS OF LAMINATED COMPOSITE STRUCTURES A Thesis by JOSEPH PATRICK FUEHNE Submitted to the Graduate College of Texas AE-M University in partial fulfiHment of the requirement... for the degree of MASTER OF SCIENCE May 1988 Major Subject: Mechanical Engineering A SHEAR DEFORMABLE, DOUBLY CURVED FINITE ELEMENT FOR THE ANALYSIS OF LAMINATED COMPOSITE STRUCTURES A Thesis by JOSEPH PATRICK FUEHNE Approved as to style and content by...

Fuehne, Joseph Patrick

2012-06-07T23:59:59.000Z

484

Laramide deformation of the Rocky Mountain Foreland, southeastern corner of the Bighorn Basin, Wyoming  

E-Print Network [OSTI]

nearly the enure length of South America. Jordan et al. (1983) describe two regions where the character of deformation changes significantly along strike of the Andean chain. The northern area is between 2'S to 15'S, the other, more southern region... is the simplest method, and assumes 1. ) strata are parallel to a planar, but not necessarily horizontal, upper basement surface and 2. ) strata do not change line length throughout deformation history. Sections should also be balanced by cross sectional area...

Derr, Douglas Neanion

2012-06-07T23:59:59.000Z

485

Topics in Noncommutative Gauge Theories and Deformed Relativistic Theories  

E-Print Network [OSTI]

This is my PhD thesis. In this thesis we study the gauge theories on noncommutative Moyal space. We find new static solitons and instantons in terms of the so called generalized Bose operators. Generalized Bose operators are constructed to describe reducible representation of the oscillator algebra. They create/annihilate $k$-quanta, $k$ being a positive integer. We start with giving an alternative description to the already found static magnetic flux tube solutions of the noncommutative gauge theories in terms of generalized Bose operators. The Nielsen-Olesen vortex solutions found in terms of these operators reduce to the already found ones. On the contrary we find a class of new instaton solutions which are unitarily inequivalant to the the ones found from ADHM construction on noncommutative space. The charge of the instaton has a description in terms of the index representing the reducibility of the Fock space, i.e., $k$. After studying the static solitonic solutions in noncommutative Minkowski space and the instaton solutions in noncommutative Euclidean space we go on to study the implications of the time-space noncommutativity in Minkowski space. To understand it properly we study the time-dependent transitions of a forced harmonic oscillator in noncommutative 1+1 dimensional spacetime. We also try to understand the implications of the found results in the context of quantum optics. We then shift to the so called DSR theories which are related to a different kind of noncommutative ($\\kappa$-Minkowski) space. DSR (Doubly/Deformed Special Relativity) aims to search for an alternate relativistic theory which keeps a length/energy scale (the Planck scale) and a velocity scale (the speed of light scale) invariant. We study thermodynamics of an ideal gas in such a scenario.

Nitin Chandra

2013-01-17T23:59:59.000Z

486

Mentum deformities in Chironomidae communities as indicators of anthropogenic impacts in Swartkops River  

Science Journals Connector (OSTI)

Swartkops River is located in Eastern Cape of South Africa and drains a heavily industrialised catchment and has suffered deterioration in water quality due to pollution. Water quality impairment in the Swartkops River has impacted on its biota. Deformities in the mouth parts of larval Chironomidae, particularly of the mentum, represent sub-lethal effects of exposure to pollutants, and were therefore employed as indictors of pollution in the Swartkops River. Chironomid larvae were collected using the South African Scoring System version 5 (SASS5) protocol. A total of 4838 larvae, representing 26 taxa from four sampling sites during four seasons were screened for mentum deformities. The community incidences of mentum deformity were consistently higher than 8% at Sites 2–4, indicating pollution stress in the river. Analysis of variance (ANOVA) conducted on arcsine transformed data revealed that the mean community incidence of mentum deformity was significantly higher (p  0.05) between seasons across sites. Severe deformities were consistently higher at Site 3. Strong correlations were found between deformity indices and the concentrations of dissolved oxygen (DO), total inorganic nitrogen (TIN), orthophosphate–phosphorus (PO4–P), electrical conductivity (EC) and turbidity.

O.N. Odume; W.J. Muller; C.G. Palmer; F.O. Arimoro

2012-01-01T23:59:59.000Z

487

Localized Amorphism after High-Strain-Rate Deformation in TWIP Steel  

SciTech Connect (OSTI)

The microstructural features of shear localization, generated by a high strain rate (~105 s-1) deformation, of a twinning-induced plasticity (TWIP) steel containing about 17.5 wt. % Mn were well characterized by means of transmission electron microscopy and electron back scatter diffraction. The high deformation rate was obtained by a ballistic impact penetration test on a TWIP steel sheet. In addition to the deformation twins observed as the domain microstructural characterization of high-strain-rate deformation outside shear bands, some shear bands consisting of complex microstructures were also evidenced in the highly-deformed area. Inside the shear band, there exist a large region of amorphous phase and a smooth transition zone containing nano-crystalline (NC) phase. The grain size decreased gradually in the transition zone, changing from coarse-scale (> 100 nm) next to the fully amorphous zone to fine-scale (<10nm) adjacent to the amorphous region. The coexistence of amorphous state and fine-grained nano-crystalline phase obviously suggests that melting occurred inside the shear bands, which is corroborated by calculations showing a very high temperature rise due to the localized plastic deformation and the extremely rapid cooling rate through heat dissipation to the rest of the specimen.

Li, Nan; Wang, Y. D.; Peng, R. Lin; Sun, Xin; Liaw, Peter K.; Wu, G. L.; Wang, L.; Cai, H. N.

2011-09-01T23:59:59.000Z

488

Deformation-Driven Diffusion and Plastic Flow in Two-Dimensional Amorphous Granular Pillars  

E-Print Network [OSTI]

We report a combined experimental and simulation study of deformation-induced diffusion in compacted two-dimensional amorphous granular pillars, in which thermal fluctuations play negligible role. The pillars, consisting of bidisperse cylindrical acetal plastic particles standing upright on a substrate, are deformed uniaxially and quasistatically by a rigid bar moving at a constant speed. The plastic flow and particle rearrangements in the pillars are characterized by computing the best-fit affine transformation strain and non-affine displacement associated with each particle between two stages of deformation. The non-affine displacement exhibits exponential crossover from ballistic to diffusive behavior with respect to the cumulative deviatoric strain, indicating that in athermal granular packings, the cumulative deviatoric strain plays the role of time in thermal systems and drives effective particle diffusion. We further study the size-dependent deformation of the granular pillars by simulation, and find that different-sized pillars follow self-similar shape evolution during deformation. In addition, the yield stress of the pillars increases linearly with pillar size. Formation of transient shear lines in the pillars during deformation becomes more evident as pillar size increases. The width of these elementary shear bands is about twice the diameter of a particle, and does not vary with pillar size.

Wenbin Li; Jennifer M. Rieser; Andrea J. Liu; Douglas J. Durian; Ju Li

2015-02-04T23:59:59.000Z

489

Supersymmetric deformations of F1-NS5-branes and their exact CFT description  

E-Print Network [OSTI]

We consider certain classes of operators in the exact conformal field theory SL(2,R) x SU(2) x U(1)^4 describing strings in an AdS(3) x S(3) x T4 geometry supported by Neveu--Schwarz 3-form fluxes. This background arises in the near-horizon limit of a system of NS5-branes wrapped on a 4-torus and F1-branes smeared on the 4-torus when both types of branes are located at the same point in their common transverse space. We find a class of operators that lead to spacetime supersymmetric deformations. It is remarkable that most of these operators are not chiral primary with respect to the N=2 superconformal algebra on the wordsheet. A subset of these worldsheet conformal field theory deformations admits an interpretation either as a geometric deformation of the brane system or as a deformation of the distribution of the F1-branes, viewed as smooth instantons, inside the wrapped NS5-brane worldvolume. The 2-dimensional conformal field theory, however, seems to lack operators corresponding to arbitrary NS5-brane deformations, in contrast to pure NS5-brane systems where all geometric deformations can be accounted for by chiral primary operators.

P. Marios Petropoulos; Nikolaos Prezas; Konstadinos Sfetsos

2009-05-11T23:59:59.000Z

490

The Aerodynamics of Deforming Wings at Low Reynolds Number  

E-Print Network [OSTI]

and Karl G. Gotz. Unsteady aerodynamic performance of model26] G. Du and M. Sun. Aerodynamic effects of corrugation andof flexibility on the aerodynamic performance of a hovering

Medina, Albert

2013-01-01T23:59:59.000Z

491

Equilibria and Instabilities of a Slinky: Discrete Model  

E-Print Network [OSTI]

The Slinky is a well-known example of a highly flexible helical spring, exhibiting large, geometrically nonlinear deformations from minimal applied forces. By considering it as a system of coils that act to resist axial, shearing, and rotational deformations, we develop a discretized model to predict the equilibrium configurations of a Slinky via the minimization of its potential energy. Careful consideration of the contact between coils enables this procedure to accurately describe the shape and stability of the Slinky under different modes of deformation. In addition, we provide simple geometric and material relations that describe a scaling of the general behavior of flexible, helical springs.

Douglas P. Holmes; Andy D. Borum; Billy F. Moore III; Raymond H. Plaut; David A. Dillard

2014-03-26T23:59:59.000Z

492

Is it sensible to 'deform' dose? 3D experimental validation of dose-warping  

SciTech Connect (OSTI)

Purpose: Strategies for dose accumulation in deforming anatomy are of interest in radiotherapy. Algorithms exist for the deformation of dose based on patient image sets, though these are sometimes contentious because not all such image calculations are constrained by physical laws. While tumor and organ motion has been a key area of study for a considerable amount of time, deformation is of increasing interest. In this work, we demonstrate a full 3D experimental validation of results from a range of dose deformation algorithms available in the public domain. Methods: We recently developed the first tissue-equivalent, full 3D deformable dosimetric phantom-'DEFGEL.' To assess the accuracy of dose-warping based on deformable image registration (DIR), we have measured doses in undeformed and deformed states of the DEFGEL dosimeter and compared these to planned doses and warped doses. In this way we have directly evaluated the accuracy of dose-warping calculations for 11 different algorithms. We have done this for a range of stereotactic irradiation schemes and types and magnitudes of deformation. Results: The original Horn and Schunck algorithm is shown to be the best performing of the 11 algorithms trialled. Comparing measured and dose-warped calculations for this method, it is found that for a 10 Multiplication-Sign 10 mm{sup 2} square field, {gamma}{sub 3%/3mm}= 99.9%; for a 20 Multiplication-Sign 20 mm{sup 2} cross-shaped field, {gamma}{sub 3%/3mm}= 99.1%; and for a multiple dynamic arc (0.413 cm{sup 3} PTV) treatment adapted from a patient treatment plan, {gamma}{sub 3%/3mm}= 95%. In each case, the agreement is comparable to-but consistently {approx}1% less than-comparison between measured and calculated (planned) dose distributions in the absence of deformation. The magnitude of the deformation, as measured by the largest displacement experienced by any voxel in the volume, has the greatest influence on the accuracy of the warped dose distribution. Considering the square field case, the smallest deformation ({approx}9 mm) yields agreement of {gamma}{sub 3%/3mm}= 99.9%, while the most significant deformation ({approx}20 mm) yields agreement of {gamma}{sub 3%/3mm}= 96.7%. Conclusions: We have confirmed that, for a range of mass and density conserving deformations representative of those observable in anatomical targets, DIR-based dose-warping can yield accurate predictions of the dose distribution. Substantial differences can be seen between the results of different algorithms indicating that DIR performance should be scrutinized before application todose-warping. We have demonstrated that the DEFGEL deformable dosimeter can be used to evaluate DIR performance and the accuracy of dose-warping results by direct measurement.

Yeo, U. J.; Taylor, M. L.; Supple, J. R.; Smith, R. L.; Dunn, L.; Kron, T.; Franich, R. D. [School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002 (Australia) and Medical Physics, William Buckland Radiotherapy Centre, Alfred Hospital, Melbourne, Victoria 3181 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia) and Medical Physics, William Buckland Radiotherapy Centre, Alfred Hospital, Melbourne, Victoria 3181 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia) and Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia)

2012-08-15T23:59:59.000Z

493

Use of chironomid deformities in field and laboratory assessments of contaminated sediments  

SciTech Connect (OSTI)

Benthic invertebrate samples were collected from 23 pools in the Upper Mississippi River (UMR), the Saint Croix River (SCR), Wisconsin, the Clark Fork River (CFR)/Milltown Reservoir (MR) Superfund Site, Montana, and three Great Lakes rivers classified as Areas of Concern (AOC). Contamination consisted of organic and inorganic contaminants at the UMR and AOC sites, and primarily heavy metals in the CFR/MR sites. Samples were collected with a ponar grab sampler from stations in Indiana Harbor, IN (n = 7), Buffalo River, NY (n = 10), Saginaw River, MI (1989 n = 7; 1990, n = 7), Upper Mississippi River (n = 24), Clark Fork River (n = 6), and Milltown Reservoir (n = 7). Compared to literature values for incidence of deformities in uncontaminated sediments, frequency of chironomid mouthpart deformities was significantly greater at most stations sampled from the AOC sites, with only a few stations sampled from the CFR/MR and UMR sites having significantly greater incidence of mouthpart deformities. Occurrence of mouthpart deformities ranged from 0 to 100% at stations from the AOC`S, 0 to 18% at CFR/MR stations, and 0 to 13% at UMR stations. Sediment contamination was generally lowest in UMR samples and highest in AOC samples. These data show organic contaminants may have a greater potential for causing teratogenic effects in chironomid mouthparts. Frequency of mouthpart deformities in Chironomus riparius laboratory exposures to contaminated sediments from all AOC and CFR sites were evaluated and analysis shows that frequency of mouthpart deformities from laboratory-exposed chironomids are generally lower than those found in field-collected samples. Additional analysis of chironomid laboratory cultures background deformity levels which must be addressed before laboratory evaluations can be used with reliability.

Canfield, T.J.; Kemble, N.E.; Ingersoll, C.G. [National Biological Service, Columbia, MO (United States)

1995-12-31T23:59:59.000Z

494

Compressive deformation and yielding mechanisms in cellular Al alloys determined using X-ray tomography and surface strain mapping  

SciTech Connect (OSTI)

The mechanisms of compressive deformation that occur in closed cell Al alloys have been established. This has been achieved by using x-ray computed tomography (CT) and surface strain mapping to determine the deformation modes and the cell morphologies that control the onset of yielding. The deformation is found to localize in narrow bands having width of order of a cell diameter. Outside the bands, the material remains elastic. The cells within the bands that experience large permanent strains are primarily elliptical. A group of cells work collectively to allow large localized deformation. Size does not appear to be the initiator of the deformation bands. Equiaxed cells remain elastic. The implications for manufacturing materials with superior mechanical properties are discussed. Visualization of internal deformation of a closed cell Al alloy core, as part of a sandwich panel construction, is also possible using x-ray tomography. Preliminary results for a punch indentation test are presented.

Bart-Smith, H.; Bastawros, A.F.; Mumm, D.R.; Evans, A.G. [Harvard Univ., Cambridge, MA (United States). Div. of Engineering and Applied Sciences; Sypeck, D.J.; Wadley, H.N.G. [Univ. of Virginia, Charlottesville, VA (United States). School of Engineering and Applied Science

1998-12-31T23:59:59.000Z

495

Kinematics and kinetics of single-limb heel rise in diabetes related medial column foot deformity  

Science Journals Connector (OSTI)

AbstractBackground Diabetes-related medial column foot deformities contribute to high plantar pressure, joint instability, ulceration and amputation. Impaired foot function may be an early indicator of foot structural incompetence and contribute to deformity progression. This study examines the ability of single-limb heel rise multi-segmental kinematics and kinetics to identify midfoot and hindfoot dysfunction in those with diabetes-related medial column foot deformity. Methods Single-limb heel rise foot kinematics and kinetics were examined in adults with diabetes mellitus and peripheral neuropathy with and without medial column foot deformity and age-, weight-matched controls. Findings Hindfoot relative to shank plantarflexion, peak and excursion, were reduced in both diabetes groups compared to controls (P power was reduced in the diabetes deformity group compared to controls (P < 0.017). Interpretation The single-limb heel rise task identified movement dysfunction in those with diabetes mellitus and peripheral neuropathy. Failure to plantarflex the forefoot relative to hindfoot may compromise midfoot joint stability and increase the risk of injury and arch collapse.

Mary K. Hastings; James Woodburn; Michael J. Mueller; Michael J Strube; Jeffrey E. Johnson; David R. Sinacore

2014-01-01T23:59:59.000Z

496

Late Paleozoic foreland deformation in northern Mexico: paleogeographic and tectonic implications  

SciTech Connect (OSTI)

Deformation in north-central Mexico reflects the existence of an actively evolving foreland basin during the late Paleozoic. The Pedregosa and Orogrande basins formed the northern extensions of this north-northwest-trending foreland basin, which was flanked on the north and west by several large block uplifts. Deformation along the southeastern margin of the basin, in Coahuila, is postulated to represent part of a foreland fold-thrust belt, while structures in Chihuahua and adjacent parts of New Mexico and Texas are related to basement-involved block uplifts. The unconformities, sedimentation patterns and deformation styles of several localities in Chihuahua, southern New Mexico, and west Texas indicate similar, but not necessarily time-equivalent, deformational histories. Uplift began in Late Mississippian and culminated between latest Pennsylvanian (in the north) and Late Permian (in the south). The geographic distribution and sequential timing of deformation are consistent with our knowledge of the Ouachita system in the US. The distributions of the fold-thrust belt and basement-involved uplifts of the Ouachita foreland in northern Mexico is not only similar to other parts of the Ouachita system but also to portions of the Laramide in the northern Rocky Mountains. These similarities and distribution of late Paleozoic calcalkaline igneous rocks in the region suggest that a subduction zone and associated magmatic arc were present in eastern Mexico during the late Paleozoic.

Handschy, J.W.

1985-02-01T23:59:59.000Z

497

Mountain building in the Nepal Himalaya: Thermal and kinematic model  

E-Print Network [OSTI]

Mountain building in the Nepal Himalaya: Thermal and kinematic model L. Bollinger a,, P. Henry b. Courtillot Abstract We model crustal deformation and the resulting thermal structure across the Nepal: thermal model; temperature-time paths; inverted metamorphism; underplating; Himalayan orogen; Nepal

Avouac, Jean-Philippe

498

Learning Non-linear Models Shape and Motion  

E-Print Network [OSTI]

Models or Eigen Models have been introduced. These statistical models of deformation overcome some, from a training set of examples. This semi-automated learning procedure provides a more generic. A special word of thanks for Dr Dave Cohen for the many valued discussions related to this work. Id like

Bowden, Richard

499

Mechanical deformation of neutrophil into pulmonary capillaries induces cytoskeletal remodeling, pseudopod projection and changes in biomechanical properties  

E-Print Network [OSTI]

Neutrophils traversing the pulmonary microcirculation are subjected to mechanical stimulation during their deformation into narrow capillaries. To better understand the time- dependant changes caused by this mechanical ...

Yap, Belinda

2005-01-01T23:59:59.000Z

500

Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1  

E-Print Network [OSTI]

in the coupled code despite dynamically changing reservoir parameters via a modification to the Newton system plastic constitutive relationships available in the coupled code. The results mimic behavior which and Engineering 38 (2003) 37­56 #12;observed in a real field but difficult to capture with a fully coupled

Minkoff, Susan E.