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Rapid quenching of molten lithium-aluminum jets in water under loss-of-control-rod-cooling conditions

Description: A series of fifteen tests were performed to investigate the thermal interactions between molten LiAl control rod material and water under conditions prototypic of the loss-of-control-rod-cooling (LCRC) accident scenario. The experimental parameters such as melt mass, stream diameter, melt temperature and flowrate, water depth and water temperature were controlled or varied to agree with analytically determined conditions, thus insuring prototypicality of the experiments and applicability of the… more
Date: January 1, 1992
Creator: Greene, G. A.; Finfrock, C. C.; Schwarz, C. E.; Allison, D. K. & Hyder, M. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Influence of compositional modifications on the corrosion of iron aluminides of molten nitrate salts

Description: The corrosion of iron-aluminum alloys by molten nitrate salt as a function of aluminum, chromium, and other minor elements has been studied as part of an alloy design effort aimed at the development of a strong, ductile, corrosion-resistant FeAl type of aluminide. Short- term weight change data were used to examine the compositional dependence of the corrosion processes that occurred upon exposure of iron aluminides to highly oxidizing nitrate salts of 650{degrees}C. Corrosion resistance was fo… more
Date: January 1, 1991
Creator: Tortorelli, P. F. & Bishop, P. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electron-beam fusion welding of beryllium

Description: Ingot-sheet beryllium (Be) having three different chemistries and three different thicknesses was fusion-welded by the electron-beam process. Several different preheats were used to obtain 100% penetration and crack-free welds. Cracking susceptability was found to be related to aluminum (Al) content; the higher Al-content material was most susceptable. However, adequate preheat allowed full penetration and crack-free welds to be made in all materials tested. The effect of a post-weld heat treat… more
Date: January 1, 1978
Creator: Campbell, R. P.; Dixon, R. D. & Liby, A. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Thermal strains in titanium aluminide and nickel aluminide composites

Description: Neutron diffraction was used to measure residual thermal strains developed during postfabrication cooling in titanium aluminide and nickel aluminide intermetallic matrix composites. Silicon carbide /Ti 14Al-21Nb, tungsten and sapphire/NiAl, and sapphire and SiC-coated sapphire/NiAl{sub 25}Fe{sub 10} composites were investigated. The thermal expansion coefficient of the matrix is usually greater than that of the fibers. As such, during cooldown, compressive residual strains are generated in the … more
Date: January 1, 1992
Creator: Saigal, A. (Tufts Univ., Medford, MA (United States). Dept. of Mechanical Engineering) & Kupperman, D.S. (Argonne National Lab., IL (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Flow instability in a vertical annulus under steady state and transient conditions

Description: Experimental data have been obtained for the occurrence of flow instability in a vertical annulus under steady state and transient down-flow conditions. The results show that the primary factor affecting the onset of flow instability is the Q{sub ratio} parameter (a measure of the void production in a channel). In addition, it is shown that for steady state conditions good agreement exists between the single annulus data and single tube data based upon the same L/D ratio. The results also indic… more
Date: January 1, 1992
Creator: Fighetti, C.; Kokolis, S.; Maciuca, C.; Reddy, D.G.; Yang, B.; Carrano, V. (Columbia Univ., New York, NY (United States)) et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High strain rate deformation in FCC metals and alloys

Description: The effect of strain rate, and particularly of high strain rates, on deformation mechanisms in materials is of fundamental interest to those who model and analyze dynamic loading. In many materials the strain rate sensitivity is known to increase dramatically when the strain rate is raised above approx.10/sup 3/ s/sup -1/. This increase has been interpreted previously as a transmission in deformation mechanism from thermal activation control at low strain rate to dislocation drag control at hig… more
Date: January 1, 1985
Creator: Follansbee, P.S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Hypervelocity launch capabilities to over 10 km/s

Description: Very high pressure and acceleration is necessary to launch flier plates to hypervelocities. In addition, the high pressure loading must be uniform, structured, and shockless, i.e., time-dependent to prevent the flier plate from either fracturing or melting. In this paper, a novel technique is described which allows the use of megabar level loading pressures, and 10{sup 9} g acceleration to launch intact flier plates to velocities of 12.2 km/s. 32 refs., 2 figs.
Date: January 1, 1991
Creator: Chhabildas, L.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Microstructure and tensile properties of heavily irradiated 5052-0 aluminum alloy

Description: During neutron irradiation of an aluminum 2.2% magnesium solid solution alloy in the High Flux Isotope Reactor to fast and thermal fluences > 10/sup 27/ neutrons (n)m/sup 2/ at 328/sup 0/K (0.35 T/sub m/) about seven percent insoluble, transmutant silicon was produced. Some of this silicon reacted with the dissolved magnesium to form a fine precipitate of Mg/sub 2/Si. A tight dislocation structure was also created. The alloy showed good resistance to cavity formation. Tension tests at 323, 373,… more
Date: January 1, 1980
Creator: Farrell, K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Neutron scattering studies of heavy Fermions. [CeAl/sub 3/, UBe/sub 13/, CeCu/sub 2/Si/sub 2/, CeCu/sub 6/, ThBe/sub 13/, UPt/sub 3/, U/sub 2/Zn/sub 17/]

Description: Heavy Fermions are f electron materials characterized by a large linear term in the low temperature specific heat and a large magnetic susceptibility at low temperatures. This implies that there is a narrow peak in the f electron density of states at the Fermi energy. Typical examples are CeAl/sub 3/, UBe/sub 13/, CeCu/sub 2/Si/sub 2/, CeCu/sub 6/, U/sub 2/Zn/sub 17/ and UPt/sub 3/. Neutron scattering measurements can play an important role in understanding the magnetic interactions in these sy… more
Date: January 1, 1985
Creator: Shapiro, S.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Economic impact of corrosion and scaling problems in geothermal energy systems

Description: Corrosion and scaling problems have a significant impact on geothermal plant economics. A power plant must amortize the capital investment over a 20-year period and achieve satisfactory operating efficiency to achieve financial success. Corrosion and scale incrustations have been encountered in all geothermal plants, and to various degrees, adversely affected plant life times and power output. Using published data this report analyzes known geothermal corrosion and scaling phenomena for signifi… more
Date: January 1, 1975
Creator: Shannon, D. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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He self-pumping by tokamak pump limiter materials: Al, V, Ni, and Ni/Al alloys

Description: An ECR plasma and Colutron ion gun were used to study He self-pumping by several possible pump-limiter materials: Ni, V, Al, and Ni/Al multi-layers. Ni and V exhibited similar pumping capacities (6 {times} 10{sup 15} He/cm{sup 2}, 200 eV) whereas Al showed a reduced capacity (6 {times} 10{sup 14} He/cm{sup 2}, 200 eV) due to increased sputtering. A He retention model based upon ion implantation ranges and sputtering rates agreed with the experimental data. The pumping efficiency increased signi… more
Date: January 1, 1991
Creator: Outten, C. A.; Barbour, J. C.; Doyle, B. L. & Walsh, D. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Synthesis of Al/Al sub 3 Ti two-phase alloys by mechanical alloying

Description: We have mechanically alloyed mixtures of elemental powders to prepare fine-grain two-phase A1/A1{sub 3}Ti powders at the compositions A1-20at% Ti and Al-10at% Ti. Hexane was used to prevent agglomeration of the powder during MA. Carbon from the decomposition of the hexane was incorporated in the powder. It reacted with Ti to form a fine dispersion of carbides in the final hot-pressed compact. We consolidated the mechanically alloyed powders by hot-pressing. Yield strength and ductility were mea… more
Date: January 1, 1991
Creator: Srinivasan, S.; Chen, S.R. & Schwarz, R.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effect of casting temperature on the fatigue properties of cast nickel aluminide alloys

Description: The results of high cycle fatigue tests at 650{degree}C on several cast Ni{sub 3}Al alloys are reported and compared to cast IN-713C. These alloys include IC-221M and several variations to the IC-221M composition. The effect of casting temperature is investigated using castings poured at three different temperatures spanning a 56{degree}C range. The results show that IC-221M cast at the highest temperature has the best fatigue strength, exceeding that for IN-713C. In these alloys, crack initiat… more
Date: January 1, 1991
Creator: Gieseke, B. & Sikka, V.K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Oxide properties of a gamma titanium aluminide: A surface science study

Description: The surface properties of oxides grown on a gamma titanium aluminide (2 at. % Nb) have been examined using a x-ray photoelectron spectroscopy (XPS) and secondary-ion mass spectroscopy (SIMS). An oxide formed on the sample during air exposure at room temperature was thermally destabilized in ultra-high vacuum. The heating largely decomposed the advanced Ti oxidation states to give a predominate +2 valence configuration at 600{degrees}C, while the Al oxide was somewhat enhanced for the same treat… more
Date: January 1, 1991
Creator: Taylor, T. N. & Paffett, M. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Investigation of fracture toughness and fracture mechanisms using acoustic emission measurements

Description: This report is the FINAL PROGRESS REPORT'' for the research program Investigation of Fracture Toughness and Fracture Mechanisms using Acoustic Emission Measurements.'' The time period covered by this report is from 1 March 1988 through August 1991. The research program consisted of three separate but closely related investigations: (1) An Investigation of the Acoustic Emission Generated during the Deformation and Fracture of Premium Grade 4340 Steel as a function of Mechanical Properties. (2) A… more
Date: January 1, 1991
Creator: Carpenter, S.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Pulsed reactivity measurements of large /sup 235/U--Al castings in H/sub 2/O

Description: The safe storage and handling of large /sup 235/U-Al castings at the Savannah River Plant are assured by limiting the number of fuel pieces and their spacing such that the k/sub eff/ calculated by KENO-IV with Hansen-Roach cross sections does not exceed some conservative limit with complete, accidental water immersion. For economic reasons, the conservative limit on the calculated k/sub eff/ is generally chosen as high as possible consistent with an accurate knowledge of the margin of error in … more
Date: January 1, 1977
Creator: Pellarin, D.J. & Jarriel, J.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Nuclear chemistry progress report. [Physics Department, Princeton University]

Description: Research in the physics department at Princeton University is reviewed briefly. Results on the Coulomb capture of negative muons by the binary alloy systems Cu/Al and Ag/Zn show that (within experimental error) there is no change in the per atom ..mu../sup -/ capture probability when the atomic ratio in these alloys varies over a range of approximately 40. The K muonic x-ray intensity pattern observed from ..mu.. capture in atmospheric N/sub 2/ was strikingly different from that observed when .… more
Date: January 1, 1977
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Structural examination of iridium-based single-crystal preparations. [AlIr; IrSi]

Description: A high-temperature crystal growth experiment produced discrete single-crystal products of AlIr and IrSi. The preparation and examination of these phases is described within. This project is part of a materials compatibility study relating to radioisotopic heat sources. These heat sources are comprised of a PuO/sub 2/ fuel pellet encapsulated in an Ir alloy containment shell. Th is introduced as an additive within the Ir to maintain ductility. Si and P are picked up inadvertently in the fuel pro… more
Date: January 1, 1985
Creator: Axler, K.M. & Roof, R.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The Effect of Elastic Stress on Ostwald Ripening Phenomena

Description: The purpose of our research program is to understand the influence of elastic misfit strain and applied stress on the development of microstructure in two-phase coherent alloys. The long-term goal of our research is to identify those material parameters that promote microstructural stability in multiphase systems at elevated temperatures. Our efforts since the last progress report in February 1991 have been twofold. First, we have continued performing coarsening simulations of elastically and d… more
Date: January 1, 1992
Creator: Johnson, W. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Transient effects of ionizing radiation in Si, InGaAsP, GaAlSb, and Ge photodiodes

Description: Certain military applications require the continuous operation of optoelectronic information transfer systems during exposure to ionizing radiation. In such an environment the optical detector can be the system element which limits data transmission. We report here the measured electrical and optical characteristics of an irradiation tolerant photodiode fabricated from a double heterojunction structure in the gallium aluminum antimonide (GaAlSb) ternary semiconductor system. A series of tests a… more
Date: January 1, 1980
Creator: Wiczer, J. J.; Barnes, C. E. & Dawson, L. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Photon stimulated desorption of neutral species from aluminum

Description: Photon Simulated Desorption of neutral species (PSD) is the major dynamic gas load in electron synchrotron light source. In the National Synchrotron Light Source, PSD presented initial machine commissioning difficulty. Sensitivity to surface contamination on PSD had been experienced during an incident of Fomblin Oil contamination. U10B-Photon Stimulated Desorption Experimental Station is constructed to investigate: (1) the degree of the contribution to the photon stimulated desorption (PSD) fro… more
Date: January 1, 1991
Creator: Chou, T.S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Lifetime improvement of sheathed thermocouples for use in high-temperature and thermal transient operations

Description: Premature failure of small-diameter, magnesium-oxide-insulated sheathed thermocouples occurred when they were placed within nuclear fuel rod simulators (FRSs) to measure high temperatures and to follow severe thermal transients encountered during simulation of nuclear reactor accidents in Oak Ridge National Laboratory (ORNL) thermal-hydraulic test facilities. Investigation of thermally cycled thermocouples yielded three criteria for improvement of thermocouple lifetime: (1) reduction of oxygen … more
Date: January 1, 1982
Creator: McCulloch, R.W. & Clift, J.H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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