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Solid-State Heat-Capacity-Laser Review

Description: We describe our recent progress in the area of solid-state heat-capacity-lasers (SSHCL). In particular, we examine the physics of heat-capacity operation of a solid state laser and give the present technology status of our 10 kW flashlamp-pumped laser The current status of work leading to a diode-pumped Nd:GGG HCL is also described.
Date: May 7, 2002
Creator: Rotter, M D & Dane, C B
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Hybrid Heat Capacity - Moving Slab Laser Concept

Description: A hybrid configuration of a heat capacity laser (HCL) and a moving slab laser (MSL) has been studied. Multiple volumes of solid-state laser material are sequentially diode-pumped and their energy extracted. When a volume reaches a maximum temperature after a ''sub-magazine depth'', it is moved out of the pumping region into a cooling region, and a new volume is introduced. The total magazine depth equals the submagazine depth times the number of volumes. The design parameters are chosen to prov… more
Date: April 1, 2002
Creator: Stappaerts, E A
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Bulk superconductivity in PuCoGa[sub 5] at 18.5[sup +]

Description: Elemental plutonium is a fascinating metal yet poorly understood. A significant aspect of its complexity is the ambivalent nature of Pu's 5f electrons, which frequently appear to be neither completely localized nor hlly itinerant. This issue is emphasized in PuCoGas, the first Pu-based superconductor and with a T, exceeding 18 K. Though conventional phonon-mediated pairing may be responsible for its superconductivity, this view must be reconciled with three observations: (1) above T,, the stati… more
Date: January 1, 2002
Creator: Thompson, J. D. (Joe David)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Unanticipated results in the uranium niobium alloy system

Description: The uranium niobium binary alloy system exhibits a rich collection of phenomena for study. The composition range from 0 wt.% Nb to 10 wt.% Nb exhibits multiple crystallographic phases with interesting properties such as superconductivity, charge density waves and shape memory effects. We have measured the resistivity and heat capacity as a function of temperature from 2 to 325K in the above composition range in an effort to map out the phase boundaries of interest. Surprisingly the temperature … more
Date: January 1, 2002
Creator: Cooley, Jason C.; Hults, William L.; Dauelsberg, Lawrence B.; Thoma, Dan J.; Peterson, Eric J.; Teter, David F. et al.
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Partner: UNT Libraries Government Documents Department
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Fundamental thermodynamics of actinide-bearing mineral waste forms.

Description: This report summarizes work after completion of a three-year project and our current ongoing efforts. Research efforts at UC Davis have focused on establishing the thermodynamic properties of zirconolite and pyrochlore, and the synthesis of other minerals relevant to storage of nuclear material. Heat capacity, entropy, enthalpy of formation, and fkee energy of formation data were established for zirconolite, CaZrTi{sub 2}O{sub 7}, in the range from 0 to 1500 K. The heat capacity, entropy, entha… more
Date: January 1, 2002
Creator: Gallegos, Ubaldo F. & Putnam, Robert L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Sensitivity analysis of a nonlinear Newton-Krylov solver for heat transfer with phase change.

Description: Development of a complex metal-casting computer model requires information about how varying the problem parameters affects the results (metal flow and solidification). For example, we would like to know how the last point to solidify or the cooling rate at a given location changes when the physical properties of the metal, boundary conditions, or mold geometry are changed. As a preliminary step towards a complete sensitivity analysis of a three-dimensional casting simulation, we examine a one-… more
Date: January 1, 2002
Creator: Henninger, Rudolph J.; Knoll, D. A. (Dana A.); Kothe, D. B. (Douglas B.) & Lally, B. R. (Bryan R.)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Physical Properties of Intermetallic FE2VA1

Description: Fe{sub 2}VAl has recently been discovered to have a negative temperature coefficient of resistivity, moderately enhanced specific heat coefficient, and a large DOS at the Fermi level by photoemission. This triggered a round of heated research to understand the ground state of this material, both theoretically and experimentally. here they report a comprehensive characterization of Fe{sub 2}VAl. X-ray diffraction exhibited appreciable antisite disorder in all of our samples. FTIR spectroscopy me… more
Date: May 30, 2002
Creator: Feng, Ye
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Low Temperature Cryocooler Regenerator Materials

Description: There are four important factors which influence the magnitude of the magnetic heat capacity near the magnetic ordering transition temperature. These include the theoretical magnetic entropy, the deGennes factor, crystalline electric field, and the RKKY (Ruderman-Kittel-Kasuya-Yosida) interaction. The lattice contribution to the heat capacity also needs to be considered since it is the sum of the lattice and magnetic contributions which give rise to the heat capacity maxima. The lattice heat ca… more
Date: June 27, 2002
Creator: Gschneidner, K. A.; Pecharsky, A. O. & Pecharsky, V. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Phase diagram of single crystal MgB{sub 2}.

Description: Using magnetization, magneto-transport and single-crystal specific heat measurements the authors have determined the superconducting phase diagram of MgB{sub 2}. The superconducting anisotropy {gamma} changes monotonously from a value of around 2 near T{sub c} to above 4.5 at 22 K. For H{parallel}c a pronounced peak effect in the critical current occurs at the upper critical field. They present a strong evidence for a surface superconducting state for H{parallel}c which might account for the wi… more
Date: September 30, 2002
Creator: Karapetrov, G.; Welp, U.; Rydh, A.; Iavarone, M.; Kwok, W. K.; Crabtree, G. W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Properties and Cycle Performance of Refrigerant Blends Operating Near and Above the Refrigerant Critical Point, Task 1: Refrigerant Properties

Description: The main goal of this project was to investigate and compare the performance of an R410A air conditioner to that of an R22 air conditioner, with specific interest in performance at high ambient temperatures at which the condenser of the R410A system may be operating above the refrigerant's critical point. Part 1 of this project consisted of measuring thermodynamic properties R125, R410A and R507A, measuring viscosity and thermal conductivity of R410A and R507A and comparing data to mixture mode… more
Date: August 30, 2002
Creator: McLinden, Mark O.; Laesecke, Arno; Lemmon, Eric W.; Magee, Joseph W. & Perkins, Richard A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Numerical studies of gas production from several CH4-hydrate zones at the Mallik Site, Mackenzie Delta, Canada

Description: The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. A gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from several gas-hydrate-bearing zones at the Mallik site. The TOUGH2 general-purpose simulator with the EOSHYDR2 module were used for the analysis. EOSHYDR2 is designed to model the non-isothermal CH{sub 4} release, p… more
Date: May 8, 2002
Creator: Moridis, George J.; Collett, Timothy S.; Dallimore, Scott R.; Satoh, Tohru; Hancock, Steven & Weatherill, Brian
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A New Assessment of the LOFT-Wyle Blowdown Test WSB03R Using RELAP5-3D

Description: The RELAP-3D (version bt03) computer program was used to assess the LOFT-Wyle blowdown test (WSB03R). The primary goal of this new assessment is to represent faithfully the experimental facility and instrumentation using the latest three-dimensional fluid flow modeling capability available in RELAP5-3D. In addition, since RELAP5-3D represents a relatively new and significant upgrade to the capabilities of the RELAP5 series of computer programs, this study serves to add to its growing assessment… more
Date: April 16, 2002
Creator: Bandini, B. R.; Aumiller, D. L. & Tomlinson, E. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Superconducting Gamma/Neutron Spectrometer Task 1 Completion Report Evaluation of Candidate Neutron-Sensitive Materials

Description: A review of the scientific literature regarding boron- and lithium-containing compounds was completed. Information such as Debye temperature, heat capacity, superconductivity properties, physical and chemical characteristics, commercial availability, and recipes for synthesis was accumulated and evaluated to develop a list of neutron-sensitive materials likely to perform properly in the spectrometer. The best candidate borides appear to be MgB{sub 2} (a superconductor with T{sub c} = 39 K), B{s… more
Date: June 20, 2002
Creator: Bell, Z.W. & Lamberti, V.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Advanced High-Temperature Reactor for Production of Electricity and Hydrogen: Molten-Salt-Coolant, Graphite-Coated-Particle-Fuel

Description: The objective of the Advanced High-Temperature Reactor (AHTR) is to provide the very high temperatures necessary to enable low-cost (1) efficient thermochemical production of hydrogen and (2) efficient production of electricity. The proposed AHTR uses coated-particle graphite fuel similar to the fuel used in modular high-temperature gas-cooled reactors (MHTGRs), such as the General Atomics gas turbine-modular helium reactor (GT-MHR). However, unlike the MHTGRs, the AHTR uses a molten salt coola… more
Date: February 21, 2002
Creator: Forsberg, Charles W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Two energy scales and slow crossover in YbAl3

Description: We present results for YbAl{sub 3} which show that the susceptibility {chi}(T), 4f occupation number n{sub f}(T) and the entropy S(T) exhibit a slow crossover between the Fermi liquid and local moment regimes. In addition both {chi}(T) and the linear specific heat coefficient {gamma} = C/T exhibit low temperature peaks that imply that in addition to the Kondo scale (T{sub K} {approx} 500K) there is a second low temperature scale (T{sub coh} {approx} 50K) for the onset of coherence. We discuss t… more
Date: January 15, 2002
Creator: Lawrence, J. M.; Ebihara, T.; Riseborough, P. S.; Booth, C. H.; Pagliuso, P. G.; Sarrao, J. L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Magnetic, Caloric and Crystallographic Properties of Dy5(SixGe1-x)4 Alloys

Description: Polycrystals of the intermetallic compound of the Dy{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} system, where x = 0, 0.25, 0.5, 0.625, 0.675, 0.725, 0.75, 0.775, 0.825, 0.875, and 1, have been prepared by electric-arc-melting on water-cooled copper hearth in an argon atmosphere. A study of phase relationships and crystallography in the pseudobinary system Dy{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} using X-ray powder diffraction data and optical metallography was completed. It revealed that silicides in th… more
Date: July 19, 2002
Creator: Ivchenko, Vitaliy Vladislavovich
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Superconducting phase diagram of single crystal MgB{sub 2}.

Description: Using magnetization, transport and single-crystal specific heat measurements we have determined the superconducting phase diagram of MgB{sub 2}. A zero-temperature in-pane coherence length of 9.4 nm is found. The superconducting anisotropy changes monotonously from a value around 2 near T{sub c} to above 4.5 near 22 K. We present strong evidence for a surface superconducting state for H{parallel}c which might account for the wide spread in reported values of the superconducting anisotropy.
Date: September 17, 2002
Creator: Welp, U.; Rydh, A.; Karapetrov, G.; Kwok, W. K.; Crabtree, G. W.; Marcenat, C. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Lithium: Measurement of Young's Modulus and Yield Strength

Description: The Lithium Collection Lens is used for anti-proton collection. In analyzing the structural behavior during operation, various material properties of lithium are often needed. properties such as density, coefficient of thermal expansion, thermal conductivity, specific heat, compressability, etc.; are well known. However, to the authors knowledge there is only one published source for Young's Modulus. This paper reviews the results from the testing of Young's Modulus and the yield strength of li… more
Date: November 7, 2002
Creator: Schultz, Ryan P
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Generalizing the Thermodynamics State Relationships in KIVA-3V

Description: The Peng-Robinson equation of state has been implemented into the KIVA-3V code to better handle high-pressure conditions typical of Diesel engine environments. The implementations modify pressure-volume-temperature relationships, specific heats, and departures in internal energy, among other thermodynamic partial derivatives. Computations show that significant deviations do occur for progressively heavier hydrocarbons. However, when these hydrocarbons exist in a mixture with a non-negligible po… more
Date: October 1, 2002
Creator: Trujillo, M.F.; O'Rourke, P. & Torres, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Thermodynamical Properties of 56Fe

Description: Average nuclear level densities close to the nuclear binding energy in {sup 56}Fe and {sup 57}Fe are extracted from primary {gamma}-ray spectra. Thermal properties of {sup 56}Fe are studied within the statistical canonical ensemble. The experimental heat capacity is compared with the theoretical heat capacity calculated within the shell model Monte Carlo approach.
Date: August 30, 2002
Creator: Tavukcu, E.; Becker, J. A.; Bernstein, L. A.; Garrett, P. E.; Guttormsen, M.; Mitchell, G. E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ALE3D Model Predictions and Materials Characterization for the Cookoff Response of PBXN-109

Description: ALE3D simulations are presented for the thermal explosion of PBXN-109 (RDX, AI, HTPB, DOA) in support of an effort by the U. S. Navy and Department of Energy (DOE) to validate computational models. The U.S. Navy is performing benchmark tests for the slow cookoff of PBXN-109 in a sealed tube. Candidate models are being tested using the ALE3D code, which can simulate the coupled thermal, mechanical, and chemical behavior during heating, ignition, and explosion. The strength behavior of the solid … more
Date: March 19, 2002
Creator: McClelland, M. A.; Maienschein, J. L.; Nichols, A. L.; Wardell, J. F.; Atwood, A. I. & Curran, P. O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A Composite Target Concept for Multi-Pulse Radiography

Description: Multi-pulse radiographic accelerators, such as the DARHT-II facility under construction at Los Alamos National Laboratory, generate X-rays by striking a solid, high-Z ''bremsstrahlung converter target'' with a tightly focused, high-current, relativistic electron beam. In the process, the converter target is heated to a plasma state and significant thermal expansion can occur during the interval between pulses, depleting the beam focus region of target material and reducing the X-ray output. Bea… more
Date: June 4, 2002
Creator: McCarrick, J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Superconducting High Energy Resolution Gamma-ray Spectrometers

Description: We have demonstrated that a bulk absorber coupled to a TES can serve as a good gamma-ray spectrometer. Our measured energy resolution of 70 eV at 60 keV is among the best measurements in this field. We have also shown excellent agreement between the noise predictions and measured noise. Despite this good result, we noted that our detector design has shortcomings with a low count rate and vulnerabilities with the linearity of energy response. We addressed these issues by implementation of an act… more
Date: February 22, 2002
Creator: Chow, Daniel Tun Lai
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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