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Investigation of metal hydrides using multiple wavelength neutron powder diffraction and the crystal structure determinations of the 2,4-dinitrophenylhydrazone derivative of 5-bromomethylidenecyclononanone and the 1-hydroxy-6-acetoxy-10. cap alpha. -bromo-bicyclo(4. 3. 1)deca-3-ene

Description: The problem of low neutron flux has been a major limitation in the study of both single crystals and powders by neutron diffraction. In general, for a conventional two-axis diffractometer the intensity of the neutron beam incident upon the sample is approximately three orders of magnitude less than the intensity of a typical x-ray beam used for diffraction studies. A method is described which, while not utilizing the entire neutron spectrum, can significantly increase the incident neutron flux … more
Date: June 1, 1977
Creator: DeHaven, P. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Defect characterization of electronic conducting pseudo-perovskite systems. Final report

Description: The goal of the program has been to study the interrelationships between electrical conductivity, oxidation-reduction kinetics, defect structure, and composition of n- and p-type binary and ternary transition metal oxides. The stimulus for making these studies was the observation that both conducting n and p type oxides displayed a dependence on oxygen activity that was not predicted by the defect chemistry of their majority defects. The project has focused primarily on the understanding of ele… more
Date: December 31, 1994
Creator: Anderson, H. U.; Nasrallah, M.; Sparlin, D. M. & Parris, P. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Characterization of lithium niobate electro-optic modulators at cryogenic temperatures

Description: This paper reports on the operation of lithium niobate electro-optic waveguide modulators at temperatures down to 15{degrees}K. Commercial and laboratory fiber pigtailed devices have successfully been cooled without any increases in insertion loss from temperature induced stresses in device packaging. Three x-cut devices exhibited a linear increase in V{pi} voltage of 8%{plus_minus}1% when cooled from room temperature to {approximately} 20{degree}K. The broadband frequency response improved at … more
Date: January 1, 1994
Creator: Morse, J.; McCammon, K.; McConaghy, C.; Masquelier, D.; Garrett, H. & Lowry, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Microstructural understanding and critical current optimization of advanced high field superconductors. Progress report, February 1, 1991--March 31, 1993

Description: It is of great importance to improve critical current density, J{sub c} in A15 superconductors for high field magnet applications. Most current work to improve J{sub c} in A15 wires concentrates on increasing the overall J{sub c} by increasing the fraction of superconducting phase in the wire, by improving the uniformity of the superconductor cross section along the length of the wire and by adjusting the strainstate of the A15 layer. The goal of the A15 work in this group was to investigate th… more
Date: April 1, 1993
Creator: Bonney, L. A.; Willis, T. C. & Larbalestier, D. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Critical Current Metrology for Nb3Sn Conductor Development: Final Technical Report

Description: NIST has played a key role in many of the one-on-one, domestic, and international interlaboratory comparisons of measurements on superconductors. The history of interlaboratory comparisons of measurements on superconductors tells us that careful measurement methods are needed to obtain consistent results. Inconsistent results can lead to many problems including: a mistrust of the results of others, unfair advantages in commerce, and erroneous feedback in the optimization of conductor performanc… more
Date: May 31, 2011
Creator: Goodrich, Loren F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Synthesis and properties of novel cluster phases. [LiMo sub 3 Se sub 3]

Description: Research on cluster compounds this period (past periods covered such compounds such as NbMTe{sub 2}, TaFe{sub 1.25}Te{sub 3}, Nb{sub 3}SiTe{sub 6}, etc.) was concentrated on LiMo{sub 3}Se{sub 3}. A LiMo{sub 3}Se{sub 3} bundle {approximately} 70 nm wide was grown on a holey carbon substrate; STEM was used to resolve individual 6 {angstrom} wires, and the Mo{sub 3}Se{sub 3} flat ''monomer'' units is resolved at 2.3 {angstrom} (Mo atoms wrapped in Se atoms). Inorganic-organic polymer composites ar… more
Date: May 15, 1992
Creator: DiSalvo, F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Carbide Coatings on Graphite

Description: A method has been developed for the uniform coating of graphite tubes with carbides of niobium, tantalum, and zirconinm by thermal decomposition of their respective halide vapors. Conditions of coating temperature and pressure are so chosen as to prevent the deposition of metal, but to permit the formation of the carbide as rapidly as carbon can diffuse to the surface. If the carbon diffusion can be made the rate-limiting step, the coating process becomes self- regulating and uniform thickness … more
Date: June 28, 1957
Creator: Blocher, J.M. Jr.; Ish, C.J.; Leiter, D.P.; Plock, L.F. & Campbell, I.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ARMY REACTORS PROGRAM ANNUAL PROGRESS REPORT FOR PERIOD ENDING OCTOBER 31, 1962

Description: ; 8 7 < 8 < : : : 6 9 9 = < 9 < : 5 < > ;" icipation in the program continued to include review, inspection, and support in various areas of reactor technology. An advanced fuel irradiation test program was established that is to be conducted in the pressurized-water loop in the Oak Ridge Research Reactor. Review of the design of the MH-1A reactor was initiated. This reactor, a pressurized-water system fueled with low- enrichment bulk UO/sub 2/ clad with stainless steel, is being designed as a … more
Date: April 10, 1963
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Structural studies of the metal-rich region in the ternary Ta-Nb-S system

Description: Six new solid solution type compounds have been prepared using high temperature techniques and characterized by means of single crystal x-ray techniques during a study of the metal-rich region of the ternary Ta-Nb-S system. The structures of Nb{sub x}Ta{sub 11-x}S{sub 4} are reminiscent of niobium-rich sulfides, rather than of tantalum-rich sulfides. The coordinations of sulfur are capped trigonal prismatic while the metal coordinations are capped distorted cubic prismatic for Nb{sub x}Ta{sub 1… more
Date: October 7, 1991
Creator: Yao, Xiaoqiang.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Development of a new family of cemented carbides for geothermal drilling. Final report

Description: The contractor fabricated samples of cemented carbides based on tantalum carbide and niobium carbide with cobalt and nickel binders. These materials were evaluated for use as rock-bit inserts in geothermal drilling. Carbon content in the niobium carbide (NbC/sub x/) and the tantalum carbide (TaC/sub x/) was varied (x is 0.83 to 1.0) and the effect of these changes on the carbides' mechanical properties was examined. Hardness, toughness, and abrasive wear resistance of the new materials were mea… more
Date: October 1, 1983
Creator: Rowcliffe, David J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Comparison of Nb/sub 3/Sn and NbTi superconductor magnet ITER (International Thermonuclear Experimental Reactor) devices

Description: The TETRA tokamak systems code is used to compare designs for the International Thermonuclear Experimental Reactor (ITER) that use Nb/sub 3/Sn and NbTi superconductor magnets. Similar minimum-cost devices are found with both types of conductors when superfluid helium (He-2) is used in conjunction with the NbTi. The cost of using NbTi with He-1 cooling is much higher than that of using Nb/sub 3/Sn or NbTi with He-2 cooling. Generally, the minimum-cost devices occur for peak fields at the toroida… more
Date: January 1, 1988
Creator: Galambos, J. D.; Peng, Y. K. M.; Reid, R. L.; Lubell, M. S.; Dresner, L. & Miller, J. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Test results of a prototype dielectric microcalorimeter

Description: The initial development work on a dielectric microcalorimeter is presented. It focuses on the dielectric properties of the ferroelectric material KTa{sub 1-x}Nb{sub x}O{sub 3} (KTN). Measurements of the temperature dependent dielectric constant are given together with the first alpha particle detection results from a prototype composite microcalorimeter operating at 1.3 K. a non-thermal mechanism for detecting 6 MeV alpha particles in a monolithic KTN sample is also reported. 7 refs, 16 figs., … more
Date: August 13, 1990
Creator: Pfafman, T. E.; Silver, E.; Labov, S.; Beeman, J.; Goulding, F.; Hansen, W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Progress in the optoelectronic analog signal transfer for high energy particle detectors

Description: We report the progress in the development of a radiation hard Optoelectronic analog system to transfer particle detector signals with high accuracy. We will present the motivation of this study, the operating principle of the optoelectronic system, the system noise study, the recent R D efforts on radiation effect, temperature stability, and the realization of an integrated l {times} l6 optical modulator. The issue of photon source for driving such a large-scale optoelectronic modulators is a m… more
Date: May 1, 1992
Creator: Tsang, T. & Radeka, V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Material science experience gained from the space nuclear rocket program: Insulators

Description: Although Rover reactors are viewed as the ultimate in high-temperature operating systems, many of the materials used in these reactors (for example, support rods, control drums, and the reflector) have to be held at relatively low temperatures while the reactor operates, in order to maintain their structural integrity. Thus the insulators needed to separate these temperature domains are crucial to the reactor's ultimate operating times and temperatures. All of the reactors that were tested used… more
Date: July 1, 1992
Creator: Wagner, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Applications of nuclear analytical methods to materials analysis

Description: Nuclear analytical methods have now become important in the characterization of many types of materials and have been shown to be an extremely important extension of many more common methods. To illustrate the breadth of their use, some recent Brookhaven experiments are described that deal with the depth distribution of hydrogen in Nb-H alloys, the diffusion of Mo in graphite at high temperatures, and the measurement of Al and Si concentrations in zeolite catalysts. It is hoped that the present… more
Date: January 1, 1982
Creator: Jones, K. W.; Hanson, A. L. & Kraner, H. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A model for the prediction of Nb sub 3 Sn critical current as a function of field, temperature, strain, and radiation damage

Description: Conductors designed for fusion machines must operate at high fields, under large mechanical loads, and in a high neutron flux. Present designs favor the use of Nb{sub 3}Sn with force-cooling by supercritical helium to extract large nuclear and ac loss heat loads. Consequently, the magnet designer must have a good knowledge of the critical current of the superconductor as a function of field, strain, temperature, and radiation damage. Expanding on work by Hampshire, et al. and Ekin, combined wit… more
Date: September 21, 1990
Creator: Summers, L. T.; Guinan, M. W.; Miller, J. R. & Hahn, P. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Particle-like absorption spectra in small transition metal clusters

Description: Research at Argonne has found that small clusters of certain transition metal atoms display optical absorption spectra that are fundamentally different from those typically observed for other small molecules. A new laser technique known as photodissociation spectroscopy was used to record the absorption spectra of nickel clusters containing three to seven atoms and of niobium clusters containing between seven and twenty atoms. Instead of displaying spectra with distinct and separate absorption … more
Date: February 1, 1995
Creator: Knickelbein, M. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Studies of high temperature ternary phases in mixed-metal-rich early transition metal sulfide and phosphide systems

Description: Investigations of ternary mixed early transition metal-rich sulfide and phosphide systems resulted in the discovery of new structures and new phases. A new series of Zr and Hf - group V transition metal - sulfur K-phases was synthesized and crystallographically characterized. When the group V transition metal was Nb or Ta, the unit cell volume was larger than any previously reported K-phase. The presence of adventitious oxygen was determined in two K-phases through a combination of neutron scat… more
Date: January 4, 1994
Creator: Marking, G. A.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Electron-activated carbon diffusion in niobium compounds for RF superconductivity

Description: The higher energies planned for the next generation of particle accelerators and storage rings makes the use of superconducting hi-Q RF cavities highly desirable. Past efforts to produce reliable cavities for such projects have met with limited success. Among the barriers to achieving the maximum electric field gradient are oxide layer charging, single surface multipactoring and field emission. These are suface effects. At SLAC, a multi-technique surface analysis system has been constructed to … more
Date: March 1, 1981
Creator: Garwin, E. L.; Kirby, R. E.; Hoyt, E. W. & Momose, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Conversion of ethane and of propane to higher olefin hydrocarbons

Description: Binary catalysts for oxydehydrogenation of ethane were prepared and tested: Mo[sub 19]NbO[sub x], Mo[sub 4]VO[sub x], V[sub 5]NbO[sub x]. The combination of Mo and V is more active, selective than V-Nb or Mo and Nb. Nb in catalysts, particularly ternary, inhibits CO[sub 2] formation. Propane oxydehydrogenation occurs at lower temperature than ethane conversion over both binary and ternary catalysts; however selectivity to propylene is lower than for ethylene from ethane. Propylene is completely… more
Date: June 1, 1992
Creator: Heinemann, H. & Somorjai, G.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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