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Determination of Basic Structure-Property Relations for Processing and Modeling in Advanced Nuclear Fuel: Microstructure Evolution and Mechanical Properties

Description: The project objective is to study structure-property relations in solid solutions of nitrides and oxides with surrogate elements to simulate the behavior of fuels of inert matrix fuels of interest to the Advanced Fuel Cycle Initiative (AFCI), with emphasis in zirconium-based materials. Work with actual fuels will be carried out in parallel in collaboration with Los Alamos National Laboratory (LANL). Three key aspects will be explored: microstructure characterization through measurement of globa… more
Date: March 1, 2009
Creator: Wheeler, Kirk; Parra, Manuel & Peralta, Pedro
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Statistical characterization of dislocation ensembles

Description: We outline a method to study the spatial and orientation statistics of dynamical dislocation systems by modeling the dislocations as a stochastic fiber process. Statistical measures have been introduced for the density, velocity, and flux of dislocations, and the connection between these measures and the dislocation state and plastic distortion rate in the crystal is explained. A dislocation dynamics simulation model has been used to extract numerical data to study the evolution of these statis… more
Date: May 17, 2006
Creator: El-Azab, A.; Deng, J. & Tang, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Plastic Straining of Iridium Alloy DOP-26 During Cup Sizing Operations

Description: DOP-26 iridium alloy cups are used for fuel cladding for radioisotope power systems. The cups are deep drawn and recrystallized prior to final fabrication operations. This study characterizes the plastic deformation of cups during a sizing operation following the recrystallization heat treatment. The purpose of the sizing operation is to achieve the specified roundness, diameter, and radius dimensions of the cup. The operation introduces various levels of plastic strain in the cup. Plastic stra… more
Date: September 1, 2007
Creator: Ohriner, Evan Keith; Ulrich, George B & Sabau, Adrian S
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Shape Determination for Deformed Electromagnetic Cavities

Description: The measured physical parameters of a superconducting cavity differ from those of the designed ideal cavity. This is due to shape deviations caused by both loose machine tolerances during fabrication and by the tuning process for the accelerating mode. We present a shape determination algorithm to solve for the unknown deviations from the ideal cavity using experimentally measured cavity data. The objective is to match the results of the deformed cavity model to experimental data through least-… more
Date: December 10, 2007
Creator: Akcelik, Volkan; Ko, Kwok; Lee, Lie-Quan; Li, Zhenghai; Ng, Cho-Kuen & Xiao, Liling
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Void Coalescence Processes Quantified Through Atomistic and Multiscale Simulation

Description: Simulation of ductile fracture at the atomic scale reveals many aspects of the fracture process including specific mechanisms associated with void nucleation and growth as a precursor to fracture and the plastic deformation of the material surrounding the voids and cracks. Recently we have studied void coalescence in ductile metals using large-scale atomistic and continuum simulations. Here we review that work and present some related investigations. The atomistic simulations involve three-dime… more
Date: January 12, 2007
Creator: Rudd, R E; Seppala, E T; Dupuy, L M & Belak, J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Metastable Supersymmetry Breaking and Multitrace Deformations of SQCD

Description: Metastable vacua in supersymmetric QCD in the presence of single and multitrace deformations of the superpotential are explored, with the aim of obtaining an acceptable phenomenology. The metastable vacua appear at one loop, have a broken R-symmetry, and a magnetic gauge group that is completely Higgsed. With only a single trace deformation, the adjoint fermions from the meson superfield are approximately massless at one loop, even though they are massive at tree level and R-symmetry is broken.… more
Date: February 23, 2009
Creator: Essig, Rouven; Fortin, Jean-Francois; Sinha, Kuver; Torroba, Gonzalo & Strassler, Matthew J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Center-stabilized Yang-Mills Theory:Confinement and Large N Volume Independence

Description: We examine a double trace deformation of SU(N) Yang-Mills theory which, for large N and large volume, is equivalent to unmodified Yang-Mills theory up to O(1/N{sup 2}) corrections. In contrast to the unmodified theory, large N volume independence is valid in the deformed theory down to arbitrarily small volumes. The double trace deformation prevents the spontaneous breaking of center symmetry which would otherwise disrupt large N volume independence in small volumes. For small values of N, if t… more
Date: March 21, 2008
Creator: Unsal, Mithat; /SLAC /Stanford U., Phys. Dept.; Yaffe, Laurence G. & /Washington U., Seattle
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Mechanical and Electrical Properties of CdTe Tetrapods Studied byAtomic Force Microscopy

Description: The mechanical and electrical properties of CdTe tetrapod-shaped nanocrystals have been studied with atomic force microscopy. Tapping mode images of tetrapods deposited on silicon wafers revealed that they contact the surface with the ends of three arms. The length of these arms was found to be 130 {+-} 10 nm. A large fraction of the tetrapods had a shortened vertical arm as a result of fracture during sample preparation. Fracture also occurs when the applied load is a few nanonewtons. Compress… more
Date: August 30, 2007
Creator: Fang, Liang; Park, Jeong Young; Cui, Yi; Alivisatos, Paul; Shcrier, Joshua; Lee, Byounghak et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Measuring Regional Changes in the Diastolic Deformation of the Left Ventricle of SHR Rats Using microPET Technology and Hyperelastic Warping

Description: The objective of this research was to assess applicability of a technique known as hyperelastic warping for the measurement of local strains in the left ventricle (LV) directly from microPET image data sets. The technique uses differences in image intensities between template (reference) and target (loaded) image data sets to generate a body force that deforms a finite element (FE) representation of the template so that it registers with the target images. For validation, the template image was… more
Date: April 4, 2008
Creator: Gullberg, Grant T; Veress , Alexander I.; Weiss, Jeffrey A.; Huesman, Ronald H.; Reutter, Bryan W.; Taylor , Scott E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Genus Oblivious Cross Parameterization: Robust Topological Management of Inter-surface Maps

Description: We consider the problem of generating a map between two triangulated meshes, M and M{prime}, with arbitrary and possibly differing genus. This problem has rarely been tackled in its generality. Early schemes considered only topological spheres. Recent algorithms allow inputs with an arbitrary number of tunnels but require M and M{prime} to have equal genus, mapping tunnel to tunnel. Other schemes which allow more general inputs are not guaranteed to work and the authors do not provide a charact… more
Date: October 23, 2007
Creator: Bennett, J C; Pascucci, V & Joy, K I
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Waste Isolation Pilot Plant Geotechnical Analysis Report for July 2004 - June 2005, Volume 1

Description: This Geotechnical Analysis Report (GAR) presents and interprets the geotechnical data from the underground excavations at the Waste Isolation Pilot Plant (WIPP). The data, which are obtained as part of a regular monitoring program, are used to characterize conditions, to compare actual performance to the design assumptions, and to evaluate and forecast the performance of the underground excavations. GARs have been available to the public since 1983. During the Site and Preliminary Design Valida… more
Date: April 3, 2006
Creator: Westinghouse TRU Solutions LLC
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electromigration-induced plasticity and texture in Cu interconnects

Description: Plastic deformation has been observed in damascene Cu interconnect test structures during an in-situ electromigration experiment and before the onset of visible microstructural damage (ie. voiding) using a synchrotron technique of white beam X-ray microdiffraction. We show here that the extent of this electromigration-induced plasticity is dependent on the texture of the Cu grains in the line. In lines with strong <111> textures, the extent of plastic deformation is found to be relatively… more
Date: October 31, 2007
Creator: Source, Advanced Light; Tamura, Nobumichi; Budiman, A. S.; Hau-Riege, C.S.; Besser, P. R.; Marathe, A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Deformation Behavior of Nanoporous Metals

Description: Nanoporous open-cell foams are a rapidly growing class of high-porosity materials (porosity {ge} 70%). The research in this field is driven by the desire to create functional materials with unique physical, chemical and mechanical properties where the material properties emerge from both morphology and the material itself. An example is the development of nanoporous metallic materials for photonic and plasmonic applications which has recently attracted much interest. The general strategy is to … more
Date: November 28, 2007
Creator: Biener, J.; Hodge, A. M. & Hamza, A. V.
Item Type: Refine your search to only Book
Partner: UNT Libraries Government Documents Department
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Waste Isolation Pilot Plant Geotechnical Analysis Report for July 2005 - June 2006, Volume 2, Supporting Data

Description: This report is a compilation of geotechnical data presented as plots for each active instrument installed in the underground at the Waste Isolation Pilot Plant (WIPP) through June 30, 2006. A summary of the geotechnical analyses that were performed using the enclosed data is provided in Volume 1 of the Geotechnical Analysis Report (GAR).
Date: March 25, 2007
Creator: Westinghouse TRU Solutions LLC
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Dynamic Imaging of Surface Motion with a Stereo Borescope

Description: A new stereo borescope has been investigated that would provide a time-resolved calibrated method of recording the motion and deformation of a three-dimensional (3-D) surface during explosively driven dynamic shock experiments at the Nevada Test Site. In these experiments, geometries would likely prove to be incompatible with conventional direct optical systems. Single line-of-sight borescopes lack adequate depth-of-field for quantitative imaging of the 3-D surface. To improve depth-of-field an… more
Date: December 11, 2008
Creator: Berninger, Michael & Baker, Stuart
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electro-Thermal-Mechanical Simulation Capability Final Report

Description: This is the Final Report for LDRD 04-ERD-086, 'Electro-Thermal-Mechanical Simulation Capability'. The accomplishments are well documented in five peer-reviewed publications and six conference presentations and hence will not be detailed here. The purpose of this LDRD was to research and develop numerical algorithms for three-dimensional (3D) Electro-Thermal-Mechanical simulations. LLNL has long been a world leader in the area of computational mechanics, and recently several mechanics codes have… more
Date: February 6, 2008
Creator: White, D
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wind Tunnel Tests of Parabolic Trough Solar Collectors: March 2001--August 2003

Description: Conducted extensive wind-tunnel tests on parabolic trough solar collectors to determine practical wind loads applicable to structural design for stress and deformation, and local component design for concentrator reflectors.
Date: May 1, 2008
Creator: Hosoya, N.; Peterka, J. A.; Gee, R. C. & Kearney, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Deformed Matrix Models, Supersymmetric Lattice Twists and N=1/4 Supersymmetry

Description: 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 p… more
Date: September 24, 2008
Creator: Unsal, Mithat
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Shape optimization of a sheet swimming over a thin liquid layer

Description: Motivated by the propulsion mechanisms adopted by gastropods, annelids and other invertebrates, we consider shape optimization of a flexible sheet that moves by propagating deformation waves along its body. The self-propelled sheet is separated from a rigid substrate by a thin layer of viscous Newtonian fluid. We use a lubrication approximation to model the dynamics and derive the relevant Euler-Lagrange equations to simultaneously optimize swimming speed, efficiency and fluid loss. We find tha… more
Date: December 10, 2008
Creator: Wilkening, J. & Hosoi, A.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Plastic deformation in Al (Cu) interconnects stressed by electromigration and studied by synchrotron polychromatic X-ray microdiffraction

Description: We report here an in-depth synchrotron radiation based white beam X-ray microdiffraction study of plasticity in individual grains of an Al (Cu) interconnect during the early stage of electromigration. The study shows a rearrangement of the geometrically necessary dislocations (GND) in bamboo typed grains during that stage. We find that about 90percent of the GNDs are oriented so that their line direction is the closest to the current flow direction. In non-bamboo typed grains, the Laue peak pos… more
Date: May 14, 2008
Creator: Source, Advanced Light; UCLA; Chen, Kai; Chen, Kai; Tamura, Nobumichi; Valek, Bryan C. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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QCD-like Theories on R_3\times S_1: a Smooth Journey from Small to Large r(S_1)with Double-Trace Deformations

Description: We consider QCD-like theories with one massless fermion in various representations of the gauge group SU(N). The theories are formulated on R{sub 3} x S{sub 1}. In the decompactification limit of large r(S{sub 1}) all these theories are characterized by confinement, mass gap and spontaneous breaking of a (discrete) chiral symmetry ({chi}SB). At small r(S{sub 1}), in order to stabilize the vacua of these theories at a center-symmetric point, we suggest to perform a double trace deformation. With… more
Date: February 22, 2008
Creator: Shifman, Mikhail; U., /Minnesota; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Curved mesh generation and mesh refinement using Lagrangian solid mechanics

Description: We propose a method for generating well-shaped curved unstructured meshes using a nonlinear elasticity analogy. The geometry of the domain to be meshed is represented as an elastic solid. The undeformed geometry is the initial mesh of linear triangular or tetrahedral elements. The external loading results from prescribing a boundary displacement to be that of the curved geometry, and the final configuration is determined by solving for the equilibrium configuration. The deformations are represe… more
Date: December 31, 2008
Creator: Persson, P.-O. & Peraire, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Viability of Pushrod Dilatometry Techniques for High Temperature In-Pile Measurements

Description: To evaluate the performance of new fuel, cladding, and structural materials for use in advanced and existing nuclear reactors, robust instrumentation is needed. Changes in material deformation are typically evaluated out-of-pile, where properties of materials are measured after samples were irradiated for a specified length of time. To address this problem, a series of tests were performed to examine the viability of using pushrod dilatometer techniques for in-pile instrumentation to measure de… more
Date: March 1, 2008
Creator: Daw, J. E.; Rempe, J. L.; Knudson, D. L.; Condie, K. G. & Crepeau, J. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tantalum Shear Modulus from Homogenization of Single Crystal Data

Description: Elastic constants for tantalum single crystals have been calculated by Orlikowski, et al. [1] for a broad range of temperatures and pressures. These moduli can be utilized directly in continuum crystal simulations or dislocation dynamics calculations where the individual grains of the polycrystalline material are explicitly represented. For simulations on a larger size scale, the volume of material represented by the quadrature points of the simulation codes includes many grains, and average mo… more
Date: September 14, 2007
Creator: Becker, R
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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