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Flux pinning and flux flow studies in superconductors using flux flow noise techniques. Progress report, April 1, 1977--December 17, 1977

Description: A model has been developed for the flux flow state in type II superconductors in which flux motion is interrupted by local interactions between pinning centers and moving fluxoids. This model allows us to predict the functional forms for the flux flow noise power spectrum and for the dc voltage-current characteristics. Experimental results conform quite closely to the predictions of this model. Measurements of noise spectra, voltage-current characteristics, and volume pinning force curves have … more
Date: December 1, 1977
Creator: Joiner, W.C.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Influence of a simulated HTGR environment on the mechanical properties of a commercial Ni-Cr-Mo-Fe alloy (Hastelloy Alloy X)

Description: The influence of a simulated advanced-reactor helium environment, containing 500 ..mu..atm H/sub 2//50 ..mu..atm CH/sub 4//50 ..mu..atm CO/approx. 1 ..mu..atm H/sub 2/O, on the mechanical properties of two heats of Hastelloy Alloy X is discussed. Simultaneous exposures in air and controlled-impurity helium at temperatures in the range of 650/sup 0/ to 1000/sup 0/C for times of 3000 h or more were performed. A combination of tensile testing, Charpy V-notch impact toughness testing, and creep tes… more
Date: December 1, 1979
Creator: Li, C. C.; Johnson, W. R. & Thompson, L. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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TRANSMISSION ELECTRON MICROSCOPY STUDY OF HELIUM BEARING FUSION WELDS

Description: A transmission electron microscopy (TEM) study was conducted to characterize the helium bubble distributions in tritium-charged-and-aged 304L and 21Cr-6Ni-9Mn stainless steel fusion welds containing approximately 150 appm helium-3. TEM foils were prepared from C-shaped fracture toughness test specimens containing {delta} ferrite levels ranging from 4 to 33 volume percent. The weld microstructures in the low ferrite welds consisted mostly of austenite and discontinuous, skeletal {delta} ferrite.… more
Date: December 12, 2008
Creator: Tosten, M & Michael Morgan, M
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Evaluation of 2 1/4 Cr-1 Mo steel for liquid-lithium containment. III. Effect of velocity and lead content. Unabridged final report

Description: The intergranular penetration of specially heat treated 2-1/4 Cr-1 Mo steel by lead-lithium liquids containing 0, 17.6, and 53 w/o lead has been investigated at temperatures ranging from 300 to 600/sup 0/C and for times to 1000 hours. Limited tests using a 99.3 w/o lead-lithium liquid were also conducted.
Date: December 1981
Creator: Wilkinson, Bruce D. & Edwards, Glen R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Correlation of Acoustic Emission Generated During Uniform Biaxial Loading to Microstructural Sources in 7075-T651 Aluminum and 21Cr-6Ni-9Mn Stainless Steel. Final Report

Description: This paper reports on the effect on acoustic emission (AE) of uniform biaxial loading of a thin-walled tube designed by Hamstad, Patterson and Mukherjee. The AE generated during biaxial loading of 7075-T651 aluminum and 21Cr-6Ni-9Mn stainless steel had several anomalous features relative to tensile generated AE. The biaxial AE data was of a much higher level and peaked at a lower strain than the uniaxial AE response. A particle cracking model was proposed in which inclusions with the largest pr… more
Date: December 1, 1981
Creator: Leon, E. & Mukherjee, A. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Impurity effects on the creep of polycrystalline magnesium and aluminum oxides at elevated temperatures. Technical progress report, December 19, 1978-December 18, 1979

Description: Research is described on: the effect of mixed transition metal impurities (Fe-Ti, Mn-Ti, and Mg-Ti) on the steady state creep of polycrystalline aluminum oxide, stress relaxation deformation studies on polycrystalline MgO and Al/sub 2/O/sub 3/, pure and doped with iron, and the theoretical analysis of ambipolar diffusion taking into account interfacial defect creation and/or annihilation processes at grain boundaries, and impurity effects, particularly those with mixed dopants, on the diffusion… more
Date: December 1, 1979
Creator: Gordon, R. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Grain boundary diffusion in oriented Ni sub 3 Al bicrystals containing boron

Description: The present research program entitled Grain Boundary Diffusion in Oriented Ni{sub 3}Al Bicrystals Containing Boron'' was granted to Lehigh University for a period of three years (September 1, 1986 to August 31, 1989). The work on grain boundary diffusion in Ni{sub 3}Al was partially completed. On the other hand, a number of new properties have been explored. Some additional efforts have been made on diffusion in newly discovered oxide superconductors.
Date: December 20, 1990
Creator: Chou, Y.T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Growth kinetics of grain-boundary induced melting: A molecular-dynamics study

Description: The growth kinetics of melting nucleated at a high-angle twist boundary in silicon are investigated using molecular dynamics. Melting is found to be a two-stage process. In the first stage order is lost within a single plane at the interface and the density of the solid increases to that of the liquid. In the second stage the atomic coordination changes and an isotropic liquid is formed. 11 refs., 4 figs., 1 tab.
Date: December 1, 1988
Creator: Phillpot, S. R.; Lutsko, J. F.; Wolf, D. & Yip, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Evaluation of the current status of hydrogen embrittlement and stress-corrosion cracking in steels

Description: A review of recent studies on hydrogen embrittlement and stress-corrosion cracking in steels shows there are several critical areas where data is either ambiguous, contradictory, or non-existent. A relationship exists between impurity segregation and hydrogen embrittlement effects but it is not known if the impurities sensitize a preferred crack path for hydrogen-induced failure or if impurity and hydrogen effects are additive. Furthermore, grain boundary impurities may enhance susceptibility t… more
Date: December 1, 1981
Creator: Moody, N.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Plastic creep flow effects in the diffusive cavitation of grain boundaries

Description: The growth of cavities along grain interfaces was analyzed by the combined processes of grain boundary diffusion and plastic dislocation creep in the adjoining grains. It is shown that the coupling between the processes can be expressed in terms of a parameter L, which has the dimensions of length and which is a function of material properties, temperature and applied stress; L decreases with increasing temperature and stress and has values in the range of 0.25 to 25 ..mu..m for various pure me… more
Date: December 1, 1979
Creator: Needleman, A & Rice, J R
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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MIS Solar Cells on Thin Polycrystalline Silicon. Progress Report No. 3, September 1-November 30, 1980

Description: The first task of this project involves electron-beam deposition of thin silicon films on low cost substrates. The goal is to obtain 20 ..mu..m thick films having 20 ..mu..m diameter crystallites which may be recrystallized to > 40 ..mu..m. Material characterization and device studies are to be included in efforts to reach a 6% conversion efficiency. The second task deals with MIS solar cell fabrication on various types of silicon including poly-Si, ribbon-Si, silicon on ceramic, and thin film … more
Date: December 1, 1980
Creator: Anderson, W. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Thulium oxide fuel characterization study: Part 2, Environmental behavior and mechanical, thermal and chemical stability enhancement

Description: A study was performed of the correlation between fuel form stability and exposure environment of (temperature and atmosphere). 100% Tm/sub 2/O/sub 3/, 80% Tm/sub 2/O/sub 3//20% Yb/sub 2/O/sub 3/ and 100% Yb/sub 2/O/sub 3/ wafers were subjected to air, dynamic vacuum and static vacuum at temperatures to 2000/sup 0/C for times to 100 hours. Results showed the Tm/sub 2/O/sub 3//Yb/sub 2/O/sub 3/ cubic structure to be unaffected by elemental levels of iron, aluminum, magnesium and silicon and unaff… more
Date: December 1, 1970
Creator: Nelson, C.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Reactions and Spreading in the Cu--Ag System

Description: Sessile drop experiments were conducted using several liquid and solid compositions selected from the Cu--Ag phase diagram. Reactions between the solid and the liquid lead to spreading; a number of chemical nonequilibrium conditions were established using the various compositions. The Cu liquidus drop on the Cu solidus at 900/sup 0/C was in equilibrium assuming that the drop did not melt so as to form two phases. The eutectic liquid on the copper solidus at 780/sup 0/C was also in equilibrium. … more
Date: December 1, 1978
Creator: Sharps, P. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Microstructure and composition of electromagnetically-characterized YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} grain boundaries

Description: The electrical character (flux-pinning, Josephson junction, or resistive) of the grain boundaries in approximately twenty flux-grown YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} bicrystals was determined in previous studies. A selection of these same bicrystals now have been thinned for study by transmission and scanning transmission electron microscopy. High-spatial resolution imaging and analytical techniques reveal microstructural differences among these boundaries that are consistent with thei… more
Date: December 1, 1991
Creator: Babcock, S. E.; Zhang, Na; Cai, Xue Yu; Larbalestier, D. C.; Gao, Yufei; Merkle, K. L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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[Grain Boundary and Interface Kinetics During Ion Irradiation]

Description: Proposed here is renewed support of a research program focused on interface motion and phase transformation during ion irradiation, with emphasis on elemental semiconductors. Broadly speaking, the aims of this program are to explore defect kinetics in amorphous and crystalline semiconductors, and to relate defect dynamics to interface motion and phase transformations. Over the last three years, we initiated a program under DOE support to explore crystallization and amorphization of elemental se… more
Date: December 31, 1991
Creator: Atwater, H. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Preparation of high quality YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thick films on flexible Ni-based alloy substrates with textured buffer layers

Description: High current YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) thick films on flexible nickel substrates with textured buffer layers were deposited by using ion beam assisted deposition (IBAD). Pulsed laser deposited YBCO films were not only c-axis oriented with respect to the film surface but also strongly in-plane textured. The in-plane mosaic spread of YBCO films was {approximately} 10{degrees}. A critical current density of 8x10{sup 5} A/cm{sup 2} was obtained at 75 K and zero field for thin YBCO … more
Date: December 31, 1995
Creator: Wu, X. D.; Foltyn, S. R.; Arendt, P.; Townsend, J.; Campbell, I. H.; Tiwari, P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Synthesis and processing of nanostructured materials

Description: Significant and growing interest is being exhibited in the novel and enhanced properties of nanostructured materials. These materials, with their constituent phase or grain structures modulated on a length scale less than 100 nm, are artificially synthesized by a wide variety of physical, chemical, and mechanical methods. In this NATO Advanced Study Institute, where mechanical behavior is emphasized, nanostructured materials with modulation dimensionalities from one (multilayers) to three (nano… more
Date: December 1, 1992
Creator: Siegel, R. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Weld repair of helium degraded reactor vessel material

Description: Welding methods for modification or repair of irradiated nuclear reactor vessels are being evaluated at the Savannah River Site. A low-penetration weld overlay technique has been developed to minimize the adverse effects of irradiation induced helium on the weldability of metals and alloys. This technique was successfully applied to Type 304 stainless steel test plates that contained 3 to 220 appm helium from tritium decay. Conventional welding practices caused significant cracking and degradat… more
Date: December 31, 1990
Creator: Kanne, W. R., Jr.; Lohmeier, D. A.; Louthan, M. R., Jr.; Rankin, D. T.; Franco-Ferreira, E. A.; Bruck, G. J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Fundamental alloy design of oxide ceramics and their composites. [Annual] report, May 1, 1990--August 31, 1992

Description: The main research was on microstructural development of oxide ceramics. Projects were completed and the publications given. Abstracts are given on: Reactive CeO{sub 2}powders by homogeneous precipitation, SiC whisker-reinforced lithium aluminosilicate composite, solute drag on grain boundary in ionic solids (space charge effect), in-situ alumina/aluminate platelet composites, exaggerated texture and grain growth of superplastic silicon nitride (SiAlON), hot extrusion of ceramics, control of gra… more
Date: December 31, 1992
Creator: Chen, I. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Hall-Petch relationship and mechanisms of fracture in B2 compounds. Third year progress report

Description: A study was initiated in 1987 to examine structure and properties of grain boundaries in the B2 ordered alloys FeAl and NiAl. This project continued from 1990, with initial emphasis on CoAl, FeCo, and CuZn, but with continued work on FeAl and NiAl. Effect of alloy composition on structure/chemistry and properties of grain boundaries were examined by measuring yield strength vs grain size, measuring grain boundary composition using a scanning Auger electron microprobe, examining dislocation/grai… more
Date: December 30, 1992
Creator: Baker, I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Storage of LWR (light-water-reactor) spent fuel in air

Description: An experimental program is being conducted at Pacific Northwest Laboratory (PNL) to determine the oxidation response of light-water-reactor (LWR) spent fuels under conditions appropriate to fuel storage in air. The program is designed to investigate several independent variables that might affect the oxidation behavior of spent fuel. Included are temperature (135 to 230{degree}C), fuel burnup (to about 34 MWd/kgM), reactor type (pressurized and boiling water reactors), moisture level in the air… more
Date: December 1, 1989
Creator: Thomas, L. E.; Charlot, L. A.; Coleman, J. E. (Pacific Northwest Lab., Richland, WA (USA)) & Knoll, R. W. (Johnson Controls, Inc., Madison, WI (USA))
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analyses of grain boundary reactions in aluminum--zinc alloys utilizing lattice imaging electron microscopy

Description: Lattice imaging and conventional transmission electron microscopy have been applied in an investigation of the relationship between grain boundary structure and boundary-nucleated phase transformations. The study encompassed three reactions associated with grain boundaries in the Al-Zn system: heterogeneous nucleation at grain boundaries, discontinuous precipitation involving the R-phase and the low temperature discontinuous reaction. In conjunction with image computations, lattice images were … more
Date: December 1, 1976
Creator: Gronsky, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of heat treatments on the mechanical properties of CuNiFe spinodal alloys

Description: Non-conventional heat treatments were designed to produce spinodal microstructures in two CuNiFe alloys for the improvement of mechanical properties with a reduction in total aging time. The microstructures were characterized by measuring the Curie temperature to determine the composition of the NiFe rich phase and by TEM to measure the spinodal wavelength. In most cases the material failed intergranularly. However, it was only after the longer aging times that any discontinuous grain boundary … more
Date: December 1, 1976
Creator: Kubarych, K. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Attempts to model the generation of new grain boundaries during the deformation of polycrystals

Description: We explore ways by which new orientations (``nuclei``) can arise during essentially homogeneous deformation in polycrystals. All of these can be categorized as generating new large-angle boundaries: one is due to excessive storage of dislocations of one sign parallel to existing grain boundaries; another is due to reactions of cell walls with grain edges; and in the last, new boundaries are created surrounding a domain of different slip system distribution.
Date: December 31, 1993
Creator: Kocks, U. F.; Cotton, J. D.; Chen, S. R.; Wright, S. I.; Rollett, A. D.; Embury, J. D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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