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Orientational phase transitions in alloys. [CsPb; NaSn]

Description: Plastic crystal behavior is observed in semiconducting CsPb and NaSn at high temperature (600 and 500 C, respectively). This behavior is associated with M{sub 4}{sup 4{minus}} or A{sub 4}M{sub 4} structural units orientationally disordering about 50 C below the melting point where translational disorder sets in. This orientational disorder is different in the two phases, exhibiting jump reorientations in CsPb and a more isotropic behavior in NaSn. In other Zintl compounds such as KPb, there is … more
Date: September 22, 1992
Creator: Saboungi, M.L.; Johnson, G.K. & Price, D.L.
Partner: UNT Libraries Government Documents Department
open access

Measurement of local void fraction in a ribbed annulus

Description: The computer code FLOWTRAN-TF is used to analyze hypothetical hydraulic accidents for the nuclear reactor at the Savannah River Site. During a hypothetical Large Break Loss-of-Coolant Accident (LOCA), reactor assemblies would contain a two-phase mixture of air and water which flows downward. Reactor assemblies consist of nested, ribbed annuli. Longitudinal ribs divide each annulus into four subchannels. For accident conditions, air and water can flow past ribs from one subchannel to another. Fo… more
Date: December 22, 1992
Creator: Steimke, J. L.
Partner: UNT Libraries Government Documents Department
open access

Basic criticality relations for gas core design

Description: Minimum critical fissile concentrations are calculated for U-233, U-235, Pu-239, and Am-242m mixed homogeneously with hydrogen at temperatures to 15,000K. Minimum critical masses of the same mixtures in a 1000 liter sphere are also calculated. It is shown that propellent efficiencies of a gas core fizzler engine using Am-242m as fuel would exceed those in a solid core engine as small as 1000L operating at 100 atmospheres pressure. The same would be true for Pu-239 and possibly U-233 at pressure… more
Date: May 22, 1992
Creator: Tanner, J. E.
Partner: UNT Libraries Government Documents Department
open access

Choice and meaning in the quantum universe

Description: This report discusses whether the events that occur in the universe evolve deterministicly or randomly or both. (LSP).
Date: May 22, 1992
Creator: Stapp, Henry P.
Partner: UNT Libraries Government Documents Department
open access

Radionuclide inventories for short run-time space nuclear reactor systems

Description: Space Nuclear Reactor Systems, especially those used for propulsion, often have expected operation run times much shorter than those for land-based nuclear power plants. This produces substantially different radionuclide inventories to be considered in the safety analyses of space nuclear systems. This presentation describes an analysis utilizing ORIGEN2 and DKPOWER to provide comparisons among representative land-based and space systems. These comparisons enable early, conceptual consideration… more
Date: October 22, 1992
Creator: Coats, Richard L.
Partner: UNT Libraries Government Documents Department
open access

Measurement of local void fraction in a ribbed annulus

Description: The computer code FLOWTRAN-TF is used to analyze hypothetical hydraulic accidents for the nuclear reactor at the Savannah River Site. During a hypothetical Large Break Loss-of-Coolant Accident (LOCA), reactor assemblies would contain a two-phase mixture of air and water which flows downward. Reactor assemblies consist of nested, ribbed annuli. Longitudinal ribs divide each annulus into four subchannels. For accident conditions, air and water can flow past ribs from one subchannel to another. Fo… more
Date: December 22, 1992
Creator: Steimke, J. L.
Partner: UNT Libraries Government Documents Department
open access

Orientational phase transitions in alloys

Description: Plastic crystal behavior is observed in semiconducting CsPb and NaSn at high temperature (600 and 500 C, respectively). This behavior is associated with M{sub 4}{sup 4{minus}} or A{sub 4}M{sub 4} structural units orientationally disordering about 50 C below the melting point where translational disorder sets in. This orientational disorder is different in the two phases, exhibiting jump reorientations in CsPb and a more isotropic behavior in NaSn. In other Zintl compounds such as KPb, there is … more
Date: September 22, 1992
Creator: Saboungi, M. L.; Johnson, G. K. & Price, D. L.
Partner: UNT Libraries Government Documents Department
open access

Test facilities for evaluating nuclear thermal propulsion systems

Description: Interagency panels evaluating nuclear thermal propulsion (NTP) development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and baseline performance of some of the major subsystems designed to support a proposed ground test complex for evaluating nuclear thermal propulsion fuel elements and engines being developed for the Space Nuclear Thermal Propuls… more
Date: September 22, 1992
Creator: Beck, D. F.; Allen, G. C.; Shipers, L. R.; Dobranich, D.; Ottinger, C. A.; Harmon, C. D. et al.
Partner: UNT Libraries Government Documents Department
open access

Choice and meaning in the quantum universe

Description: This report discusses whether the events that occur in the universe evolve deterministicly or randomly or both. (LSP).
Date: May 22, 1992
Creator: Stapp, H. P.
Partner: UNT Libraries Government Documents Department
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