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Zr and Mo isotopes in single presolar graphite grains : a record of stellar nucleosynthesis.

Description: Thirty-two individual graphite grains from the Murchison meteorite were analyzed for their Mo and/or Zr isotopic compositions by laser ablation resonant ionization mass spectrometry. {sup 96}Zr/{sup 94}Zr ratios range from 0.074 times to 10 times the solar value. Five grains have depletions in {sup 96}Zr, suggestive of the s-process, and two grains have extraordinary enrichments in {sup 96}Zr, suggestive of the r-process. Most graphite grains have close-to-terrestrial Mo isotopic imposition, bu… more
Date: February 10, 1998
Creator: Nicolussi, G. K.
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Zr and Mo isotopic constraints on the origins of unusual types of presolar SiC grains.

Description: Although most presolar silicon carbide grains form in asymptotic giant branch red giant stars (the so-called mainstream grains) or supernovae (the X-grains), there are a number of other minor types of grains whose origin is less clear. The dominant mechanisms of heavy element nucleosynthesis, the s-process and r-process, are thought to occur mainly in AGB stars and supernovae, respectively [1], and the isotopic patterns in heavy elements in presolar grains can be used to constrain their origins… more
Date: March 1, 2000
Creator: Pellin, M. J.; Davis, A. M.; Calaway, W. F.; Lewis, R. S.; Clayton, R. N. & Amari, S.
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Zrclad Zirconium-Uranium Alloy Rod for Heat Thru-Put Test

Description: The purpose of this work was (1) to investigate the possibility of producing zirconium-clad zirconium-uranium alloy objects by casting the core alloy directly into zirconium and zirconium-3 w/o tin jackets, producing a diffusion bond at the jacket-core interfaces, and (2) to produce small scale heat thru-put test specimens by this method.
Date: April 17, 1952
Creator: Shuck, Arthur B., 1918-
Item Type: Refine your search to only Report
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ZrH-reactor-technology program. Progress report, April-June 1974

Description: The report on the 2 kW(e) reactor-organic Rankine system was drafted. This report details the design parameters of a minimum weight, 2 kW(e) reactor-organic Rankine system. The system is designed for 5 years unattended life in space. The reactor produces 16.2 kW of thermal power with a NaK outlet temperature of 800/sup 0/F and a 200/sup 0/F ..delta..T. The reactor contains 19 fuel elements, 1.25'' in diameter by 10'' long, hydrided to an N/sub H/ of 6.35. The terrestrial applications effort was… more
Date: July 12, 1974
Item Type: Refine your search to only Report
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ZrO sub 2 and ZrO sub 2 /SiC particle reinforced-MoSi sub 2 matrix composites

Description: ZrO{sub 2}-MoSi{sub 2} and ZrO{sub 2}/SiC-MoSi{sub 2} composites were fabricated by hot pressing and hot pressing/HIP at 1700{degrees}C. No reactions between ZrO{sub 2}, SiC, and MoSi{sub 2} were observed. An amorphous silica glassy phase was present in all composites. Composites with unstabilized ZrO{sub 2} particles exhibited the highest room temperature fracture toughness, reaching a level three times that of pure MoSi{sub 2}. Both the room temperature toughness and 1200{degrees}C strength o… more
Date: January 1, 1991
Creator: Petrovic, J. J.; Bhattacharya, A. K.; Honnell, R. E.; Mitchell, T. E. (Los Alamos National Lab., NM (United States)); Wade, R. K. (Arizona Materials Lab., Tucson, AZ (United States)) & McCellan, K. J. (Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering)
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THE ZrO$sub 2$-CaO-UO$sub 2$ CERAMIC FUEL FABRICATION FOR THE EBWR SPIKED CORE ELEMENTS. Final Report-Metallurgy Program 7.9.5

Description: A series of experiments was proposed in which the thermal output of the EBWR is increased to 100 Mw. The increase in thermal enengy will be accomplished by inserting 32 spike elements in the initial fuel core. The fuel selected for the spike elements was a cubic solid solution in the system ZrO/sub 2/- CaO- UO/ sub 2/. The ceramic fuel was fabricated in the form of pellets by compacting a mixture of U/sub 3/O/sub 8/, CaCO/sub 3/, and ZrO/sub 2/. The pressed pellets were sintered in air at 1675 … more
Date: May 1961
Creator: Lied, R. C.; Lynch, E. D. & Handwerk, J. H.
Item Type: Refine your search to only Report
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ZrO sub 2 reinforced-MoSi sub 2 matrix composites

Description: ZrO{sub 2} particle-MoSi{sub 2} matrix composites were fabricated by wet processing/hot pressing, using high quality unstabilized, partially stabilized, and fully stabilized ZrO{sub 2} powders. Composite room temperature indentation fracture toughness increased with increasing volume fraction of ZrO{sub 2} reinforcement. Unstabilized ZrO{sub 2} produced the highest composite fracture toughness, 7.8 MPa m{sup {1/2}} as compared to 2.6 MPa m{sup {1/2}} for pure MoSi{sub 2}. Unstabilized ZrO{sub 2… more
Date: January 1, 1991
Creator: Petrovic, J. J.; Honnell, R. E.; Mitchell, T. E. (Los Alamos National Lab., NM (USA)); Wade, R. K. (Arizona Materials Lab., Tucson, AZ (USA)) & McClellan, K. J. (Case Western Reserve Univ., Cleveland, OH (USA). Dept. of Materials Science and Engineering)
Item Type: Refine your search to only Article
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ZT-40 administrative plan

Description: An administrative plan for the ZT-40 project has been developed. It describes baselines and procedures that will be used for the remainder of the construction phase of the project.
Date: August 1, 1978
Creator: Thomas, K.S. (comp.)
Item Type: Refine your search to only Report
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ZT-40M system design, modification, and installation

Description: ZT-40 is a reversed field pinch experiment which had been operated as originally designed, with a ceramic discharge tube until November 1980. At that time, the experiment was shut down for major modifications. This paper will describe these modifications in general and discuss in detail the design of the energy system.
Date: January 1, 1981
Creator: Hammer, C. F.
Item Type: Refine your search to only Article
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ZT-P: an advanced air core reversed field pinch prototype

Description: The ZT-P experiment, with a major radius of 0.45 m and a minor radius of 0.07 m, was designed to prototype the next generation of reversed field pinch (RFP) machines at Los Alamos. ZT-P utilizes an air-core poloidal field system, with precisely wound and positioned rigid copper coils, to drive the plasma current and provide plasma equilibrium with intrinsically low magnetic field errors. ZT-P's compact configuration is adaptable to test various first wall and limiter designs at reactor-relevant… more
Date: January 1, 1986
Creator: Schoenberg, K. F.; Buchenauer, C. J.; Burkhardt, L. C.; Caudill, L. D.; Dike, R. S.; Dominguez, T. et al.
Item Type: Refine your search to only Report
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ZTI: An ignition class reversed-field pinch

Description: A cost-optimized conceptual design of an intermediate-step, ignition-class RFP device (ZTI)for the study of alpha-particle physics and burn control in a DT plasma is reported. With major and minor plasma radii R{sub T} = 2.4m and {tau}{sub p} = 0.4m, respectively, and for conservative extrapolations of experimental energy-confinement times, ion-density profiles, and impurity levels, the ZTI operating conditions during a 5-s period of constant fusion power are: toroidal plasma current I{sub {phi… more
Date: January 1, 1990
Creator: Bathke, C. G.; Krakowski, R. A.; Miller, R. L. & Werley, K. A.
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ZTI: Preliminary characterization of an ignition class reversed-field pinch

Description: A preliminary cost-optimized conceptual design of an intermediate-step, ignition-class RFP device (ZTI) for the study of alpha-particle physics in a DT plasma is reported. The ZTI design reflects potentially significant cost savings relative to similar ignition-class tokamaks for device parameters that reside on the path to a viable commercial RFP reactor. Reductions in both device costs and number of steps to commercialization portend a significantly reduced development cost for fusion. The me… more
Date: January 1, 1990
Creator: Bathke, C. G.; Krakowski, R. A.; Miller, R. L. & Werley, K. A.
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Zuni Mountains, New Mexico as a potential dry hot rock geothermal energy Site

Description: Many of the criteria for the successful exploitation of energy from dry hot rock are met in the Zuni Mountains, New Mexico. This area falls within a broad region of abnormally high heat flow on the Colorado Plateau. Within this region, a variety of evidence indicates that local ''hot spots'' may be present. These ''hot spots'' are prime targets for dry hot rock exploration. A site-evaluation program utilizing geological, geochemical-geochronological, and geophysical techniques is proposed to de… more
Date: December 1, 1975
Creator: Laughlin, A. W. & West, F. G.
Item Type: Refine your search to only Report
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ZX Pulsed-Power Design

Description: ZX is a new z-pinch accelerator planned as the next generation z-pinch driver at SNL, and as an intermediate step towards X-1. It is planned to drive either a single 50 MA z-pinch load, or two 25 to 30 MA z pinches. Three designs for the ZX accelerator are presented. All require 7 to 8 MV at the insulator stack to drive the z-pinch load to implosion in 100 to 120 ns. Two of the designs are based on the Z accelerator, and use water-line technology; a transit-time-isolated water adder, and a wate… more
Date: August 2, 1999
Creator: Corley, J. P.; Johnson, D. L.; McDaniel, D. H.; Spielman, R. B.; Struve, K. W. & Stygar, W. A.
Item Type: Refine your search to only Article
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