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Rh(I)-Catalyzed Arylation of Heterocycles via C-H Bond Activation: Expanded Scope Through Mechanistic Insight

Description: A practical, functional group tolerant method for the Rh-catalyzed direct arylation of a variety of pharmaceutically important azoles with aryl bromides is described. Many of the successful azole and aryl bromide coupling partners are not compatible with methods for the direct arylation of heterocycles using Pd(0) or Cu(I) catalysts. The readily prepared, low molecular weight ligand, Z-1-tert-butyl-2,3,6,7-tetrahydrophosphepine, which coordinates to Rh in a bidentate P-olefin fashion to provide… more
Date: July 18, 2007
Creator: Lewis, Jared; Berman, Ashley; Bergman, Robert & Ellman, Jonathan
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spectroscopic study of tetradecyltrimethylammonium bromide Pt-C14TAB nanoparticles: Structure and Stability

Description: The vibrational spectra of platinum nanoparticles (12 nm) capped with tetradecyltrimethylammonium bromide, C{sub 14}TAB, were investigated by Fourier transform infrared (FTIR) spectroscopy. We have shown that the thermal decay of Pt-C{sub 14}TAB nanoparticles in N{sub 2}, H{sub 2} and O{sub 2} atmospheres leads to the release of hydrocarbon chain of surfactant and the formation of strongly bonded layer of ammonium cations on the platinum surface. The platinum atoms accessible to CO chemisorptio… more
Date: January 9, 2009
Creator: Borodko, Y.; Jones, L.; Frei, H. & Somorjai, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Zinc Bromide Combustion: Implications for the Consolidated Incinerator Facility

Description: In the nuclear industry, zinc bromide (ZnBr2) is used for radiation shielding. At Savannah River Site (SRS) zinc bromide solution, in appropriate configurations and housings, was used mainly for shielding in viewing windows in nuclear reactor and separation areas. Waste stream feeds that will be incinerated at the CIF will occasionally include zinc bromide solution/gel matrices.The CIF air pollution systems control uses a water-quench and steam atomizer scrubber that collects salts, ash and tra… more
Date: December 16, 1998
Creator: Oji, L.N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurement of water diffusivity in aqueous lithium bromide solution

Description: The bulb apparatus developed was found to produce reliable data for measuring diffusivity for short duration. Diffusivity of water in aq. LiBr solution was found to increase from 13.2[times]10[sup [minus]10] to 16.7[times]10[sup [minus]10]m[sup 2]/s for concentration change from 0.5 to 4M and then decrease to a steady value of [approximately]6.5[times]10[sup [minus]10]m[sup 2]/s from 8 to 11 M.
Date: February 1993
Creator: Potnis, Shailesh V.; Lenz, Terry G. & Dunlop, Eric H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A shuttle mechanism for molten-electrolyte lithium batteries

Description: The lithium-transport rates arising from a lithium shuttle mechanism (LSM) were examined by potentiometric control of a lithium-alloy electrode in a temperature range of 400 to 515{degrees}C in three electrolytes: LiCl-KCl, LiCl-LiBr-KBr, and LiF-LiCl-LiBr. Lithium transport in Li/FeS{sub x} cells by LSM was found to occur by diffusion of reduced lithium species across the separator layer, which was controlled by the Li-activity of the Li-alloy electrode. Solubility of lithium was strongly affe… more
Date: November 1, 1993
Creator: Kaun, T. D. & Nelson, P. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Absorption spectrophotometric characterization of Sm(II), Sm(III), and Sm(II/III) bromides and Sm(III) oxybromide in the solid state

Description: Absorption spectra obtained from SmBr/sub 3/, SmBr/sub 2/, and Sm0Br were used in identifying the samarium species in several mixed-valence Sm(II/III) compounds produced by H/sub 2/ reduction of SmBr/sub 3/. The nature of the absorption of Sm0Br made it possible to detect even traces of Sm0Br in the Sm bromides.
Date: June 15, 1981
Creator: Wood, A. B.; Young, J. P.; Peterson, J. R. & Haschke, J. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Simulation and performance comparison of LiBr/H{sub 2}O triple-effect absorption cycles

Description: Performance simulation has been carried out for several LiBr/H2O triple-effect cycles using the Absorption Simulation Model (ABSIM) . The systems investigated include the three-condenser-three-desorber (3C3D) cycle, forming an extension of the conventional double-effect cycle; and two cycles which additionally recover heat from the hot condensate leaving the highest temperature condenser by adding the heat to the lowest temperature desorber. These latter two cycles are called Double Condenser C… more
Date: January 1, 1994
Creator: DeVault, R. C.; Grossman, G. & Wilk, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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An Ultracentrifugal Method for the Determination of Serum Lipoproteins

Description: A convenient method was developed for the ultracentrifugal analysis of all classes of serum lipoproteins which requires a minimum of time, work and materials. The method utilizes the principle of flotation of lipoproteins in a medium of greater density than their own hydrated density. In this procedure the isolation and the analysis of lipoproteins are done in a NaBr mediumn of density 1.20 g/ml. The advantages of this procedure are compared with other available methods, and its application to … more
Date: September 29, 1958
Creator: Del Gatto, L.; Lindgren, F. T. & Nichols, A. V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Crevice Corrosion Susceptibility of Alloy 22 in Fluoride and Chloride Containing Solutions

Description: Alloy 22 (N06022) is highly resistant to crevice corrosion in pure chloride (Cl{sup -}) solutions. Little research has been conducted to explore the resistance of this alloy to other halides such as fluoride (F{sup -}) and bromide (Br{sup -}). Even less information is available exploring the behavior of localized corrosion for Alloy 22 in mixtures of the halide ions. Standard electrochemical tests such as polarization resistance and cyclic potentiodynamic polarization (CPP), were conducted to e… more
Date: November 22, 2004
Creator: Day, S D & Rebak, R B
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Variable temperature optoacoustic studies of 4f-states of neodymium in oxide phases

Description: An apparatus for recording high sensitivity photoacoustic spectra from strongly light scattering samples has been constructed and tested at temperatures from 4 to 295K. The apparatus is suitable for use with air- or moisture-sensitive samples or radioactive samples requiring containment. Unlike an earlier ambient temperature photoacoustic study on Nd{sub 2}O{sub 3}, the photoacoustic bands observed from high purity Nd{sub 2}O{sub 3} in the present work agree well with the Stark components of 4f… more
Date: September 1, 1993
Creator: Beitz, J. V.; Hinaus, B. M. & Huang, Jin
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Simulating infiltration tests in fractured basalt at the Box Canyon Site, Idaho

Description: The results of a series of ponded infiltration tests in variably saturated fractured basalt at Box Canyon, Idaho, were used to build confidence in conceptual and numerical modeling approaches used to simulate infiltration in fractured rock. Specifically, we constructed a dual-permeability model using TOUGH2 to represent both the matrix and fracture continua of the upper basalt flow at the Box Canyon site. A consistent set of hydrogeological parameters was obtained by calibrating the model to in… more
Date: April 1, 2003
Creator: Unger, Andre J. A.; Faybishenko, Boris; Bodvarsson, Gudmundur S. & Simmons, Ardyth M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effect of Mo on pitting corrosion of ferritic steels in bromide and chloride solutions

Description: A model for pitting corrosion of stainless steels, independent of changes of passive film properties, was tested using Fe-18%Cr-x%Mo alloys in bromide and chlorine solutions. In 1M LiCl the pitting potential improved from {minus}50 mV{sub sce} to about 1200 mV{sub sce} on increasing Mo from 2% to 10%. In 1M LiBr the pitting potential increased from 125 to only 560 mV{sub sce}. Active dissolution kinetics of these steels in saturated solutions in a simulated pit were measured. Tafel lines for di… more
Date: December 1, 1997
Creator: Kaneko, M. & Isaacs, H. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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In-situ observations of adsorption and film formation on metal electrodes by synchrotron far infrared reflectance spectroscopy.

Description: Adsorption and film formation are key processes associated with the passivation and inhibition of metallic corrosion. New experimental approaches are needed to advance our knowledge in these areas. We have developed the technique of Synchrotron Far Infrared Reflectance Spectroscopy (SFIRS) for in situ investigations of the structure and composition of surface films and adsorbed layers on metals. We demonstrate its application to the determination of the nature of surface films on copper in aque… more
Date: May 17, 1999
Creator: Bowmaker, G. A.; Hahn, F.; Leger, J. M. & Melendres, C. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electromodulation spectroscopy of sc and fcc phase TlCl and TlBr

Description: Electromodulation measurements were made on these compounds and the spectra were reduced to the electric field induced changes in the dielectric function. The results indicate the importance of photocarrier effects in both theory and experiment in the electromodulation of exciton states. In the future, calculations should include the effect of photocarriers on the field seen by the exciton and experimentally samples should be developed with known and reproducible photocarrier properties with te… more
Date: June 1, 1976
Creator: McClelland, J. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Sum frequency generation and catalytic reaction studies of the removal of the organic capping agents from Pt nanoparticles by UV-ozone treatment

Description: We report the structure of the organic capping layers of platinum colloid nanoparticles and their removal by UV-ozone exposure. Sum frequency generation vibrational spectroscopy (SFGVS) studies identify the carbon-hydrogen stretching modes on poly(vinylpyrrolidone) (PVP) and tetradecyl tributylammonium bromide (TTAB)-capped platinum nanoparticles. We found that the UV-ozone treatment technique effectively removes the capping layer on the basis of several analytical measurements including SFGVS,… more
Date: December 10, 2009
Creator: Aliaga, Cesar; Park, Jeong Y.; Yamada, Yusuke; Lee, Hyun Sook; Tsung, Chia-Kuang; Yang, Peidong et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The Correlation of Coupled Heat and Mass Transfer Experimental Data for Vertical Falling Film Absorption

Description: Absorption chillers are gaining global acceptance as quality comfort cooling systems. These machines are the central chilling plants and the supply for cotnfort cooling for many large commercial buildings. Virtually all absorption chillers use lithium bromide (LiBr) and water as the absorption fluids. Water is the refrigerant. Research has shown LiBr to he one of the best absorption working fluids because it has a high affinity for water, releases water vapor at relatively low temperatures, and… more
Date: November 14, 1999
Creator: Keyhani, M. & Miller, W. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Stability of eutectic interface during directional solidification

Description: Directional solidification of eutectic alloys shows different types of eutectic morphologies. These include lamellar, rod, oscillating and tilting modes. The growth of these morphologies occurs with a macroscopically planar interface. However, under certain conditions, the planar eutectic front becomes unstable and gives rise to a cellular or a dendritic structure. This instability leads to the cellular/dendritic structure of either a primary phase or a two-phase structure. The objective of thi… more
Date: April 23, 1996
Creator: Han, S.H.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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AQUEOUS BIPHASE EXTRACTION FOR PROCESSING OF FINE COAL

Description: Ever-stringent environmental constraints dictate that future coal cleaning technologies be compatible with micron-size particles. This research program seeks to develop an advanced coal cleaning technology uniquely suited to micron-size particles, i.e., aqueous biphase extraction. The partitioning behaviors of silica in the polyethylene glycol (PEG)/dextran (Dex) and dextran/Triton X-100 (TX100) systems have been investigated, and the effects of sodium dodecylsulfate (SDS) and dodecyltrimethyla… more
Date: June 30, 2001
Creator: Osseo-Asare, K. & Zeng, X.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation of some lanthanide boron, carbon, nitrogen, chalcogen and halogen systems at elevated temperatures. Progress report, February 1, 1959--March 31, 1976. [Gd(III)Cl-I-phases; Yb-Br/sub 2/]

Description: Research is summarized on thermodynamic properties of borides, ThC/sub 2/, EuC/sub 2/, oxide-carbide phases, YbOC, Eu bromides, vaporization, fluorides, Y chlorides, etc. Preliminary results are given for the preparation of Gd(III) Cl-I phases and the vaporization of YbBr/sub 2/.
Date: January 1, 1976
Creator: Eick, H. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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THE REACTION OF ALUMINUM HYDRIDE WITH 3d TRANSITION METAL HALIDES. Progress Report for March 17, 1955 to November 1, 1955

Description: The reactions of AlH/sub 3/ in ether and in tetrahydrofuran solution with anhydrous halides of Fe, Co, and Ni are described. Reactions were carried out anaerobically at room temperature and below. In all instances, finely divided black products were obtained, some of which may contain metal to hydrogen bonds. Analytical results are presented for more than forty reactions, and possible mechanisms are discussed in a preliminary way. Observations are reported on the magnetic behavior of the produc… more
Date: November 1, 1955
Creator: Rice, M.J. Jr.; Gibb, T.R.P. Jr. & Meloni, E.G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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