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Mapping of upper electronic reaction surfaces by tuned laser photolysis and by absorption and emission spectroscopies

Description: Potential energy surfaces for photorotamerization of two intramolecularly hydrogen-bonded molecules, o-hydroxybenzaldehyde (OHBA) and methyl salicylate (MS), isolated in cryogenic matrices have been spectroscopically mapped. In addition, the external heavy atom effect of krypton and xenon matrices on the coupling between the S{sub 1} and T{sub 1} surfaces of 4-(dimethylamino)benzonitrile has been examined. Heavy atom matrices are known to increase rates of spin-forbidden processes. The phosphor… more
Date: July 1, 1989
Creator: Morgan, M.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A new simulation method for the efficient calculation of benchmarks for detonation products equations of state

Description: A new variation on the Monte Carlo method is presented here in the context of its potential impact on the development of detonation products equations of state (EOS). The configurational density of states and other quantities are determined for a nonstandard reference simulation. Then the EOS for a linear combinations of potentials is evaluated through a density of states transformation at arbitrary densities and temperatures in the fluid range. The computer time required for the EOS calculatio… more
Date: January 1, 1989
Creator: Shaw, M.S. (Los Alamos National Lab., NM (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Magnetic resonance studies of photosynthetic reaction centers and porphyrins

Description: During the period covered by this report research has been concerned with the study of photo-induced electron transfer reactions from porphyrins to acceptor molecules with time-resolved Electron Paramagnetic Resonance (EPR) methods. Excited-state electron transfer reactions are of importance from a fundamental point of view and in connection with applications in homogeneous and heterogeneous photosensitization, photopolymerization, and solar energy conversions. For this reason, the study of pho… more
Date: November 1, 1989
Creator: van Willigen, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigations of hydrogen/Li sub 2 O surface interactions via quantum chemical cluster methods

Description: Both in-reactor and laboratory experiments on ceramic breeder materials have indicated that substantial enhancement of tritium release rate results when small amounts of H{sub 2} ({approximately}0.1%) are added to the He purge gas stream. Although a comprehensive understanding of this empirical fact is still lacking, it is expected that surface processes would play a major role in the release process. Despite its significant improvement in tritium release in ceramic breeders, the interaction of… more
Date: January 1, 1989
Creator: Tam, S. W.; Wright, J.; Curtiss, L. A. & Johnson, C. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Distribution of metal and adsorbed guest species in zeolites

Description: Because of their high internal surface areas and molecular-size cavity dimensions, zeolites are used widely as catalysts, shape- selective supports, or adsorbents in a variety of important chemical processes. For metal-catalyzed reactions, active metal species must be dispersed to sites within the zeolite pores that are accessible to diffusing reactant molecules. The distribution of the metal, together with transport and adsorption of reactant molecules in zeolite powders, are crucial to ultima… more
Date: December 1, 1989
Creator: Chmelka, B.F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Discrete modeling of beds of propellant exposed to strong stimulus

Description: This paper is a description of experimental and theoretical modeling concepts that are being developed to describe the behavior of confined propellant beds made of discrete particles, when subjected to a strong stimulus such as the impact of a penetrating jet. A principal goal is to discover basic mechanisms within the bed that control a reactive wave that either fails and extinguishes, or propagates as a rapid burning or detonating wave. This paper is an extended version of a lecture given by … more
Date: January 1, 1989
Creator: Stewart, D.S. (Illinois Univ., Urbana, IL (USA). Dept. of Theoretical and Applied Mechanics) & Asay, B.W. (Los Alamos National Lab., NM (USA))
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Partner: UNT Libraries Government Documents Department
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Determination of Fe(II)Fe(II) ratio in glass

Description: The procedure was designed for the simple, rapid determination of the Fe(II)/Fe(III) ratio in glass samples. The procedure consists of the following steps: dissolution of the pulverized glass sample in a sulfuric-hydrofluoric acid mixture, containing ammonium vanadate, which preserves the Fe(II) content; addition of boric acid to destroy iron-fluoride complexes, making the iron available for color formation with Ferrozine; addition of pH 5 buffer and Ferrozine reagent to form the magenta-colore… more
Date: July 26, 1989
Creator: Baumann, E. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Topics in physico-chemical hydrodynamics

Description: This paper discusses the following topics: theory of turbulent flame speed; flame extinction by periodic flow-field; influence of swirl on the structure and extinction of premixed flames; propagation and extinction of nonsteady spherical flame fronts; geometrically invariant formulation of intrinsic dynamics of premixed flames; nonlinear dynamics of oscillatory regime of premixed combustion; and pattern formation in premixed flames. (LSP)
Date: January 1, 1989
Creator: Sivashinsky, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The determination of UO/sub 2/ and UF/sub 4/ in fused fluoride salts

Description: The determination of uranium oxide solubilities in fused fluoride salts is important in the electrolytic preparation of uranium metal. This project was initiated to develop a method for the determination of UO/sub 2/ separately from UF/sub 4/ in UF/sub 4/-CaF/sub 2/-LiF fused salts. Previous methods used for the determination of UO/sub 2/ in fused fluoride salts involved inert gas fusions where oxygen was liberated as CO/sub 2/, and hydrofluorination where oxygen was released as H/sub 2/O; but … more
Date: 1989~
Creator: Batiste, D. J. & Lee, D. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Reconstitution of halorhodopsin

Description: Halobacterium halobium contains a family of retinal-bound proteins: bacteriorhodopsin (bR) which mediates phototrophic growth as a light-riven proton pump, halorhodopsin (hR) which is a light-driven chloride pump, and one or more sensory rhodopsins (sR) which mediate a phototactic response. Two-dimensional crystallization of halorhodopsin has been attempted though the reconstitution of purified halorhodopsin with purple membrane lipid for electron microscopy work. The first important step for c… more
Date: November 1, 1989
Creator: Kong, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Organolanthanide Reagents and the Mukaiyama Reaction

Description: The bis(pentamethylcyclopentadienyl) lutetium halide complex ((C/sub 5/Me/sub 5/)/sub 2/LuCl/center dot/THF) was synthesized and characterized. The crystal structure of this complex shows that the Lu is at the center of a distorted tetrahedron consisting of the centroids of two cyclopentadienyl rings, the oxygen atom of a tetrahydrofuran molecule and a chlorine atom. /sup 1/H NMR studies of toluene-d/sub 8/ solutions of (C/sub 5/Me/sub 5/LuCl(THF) + THF, (TMS/sub 2/CP)/sub 2/LuCl(THF) + THF, an… more
Date: January 1989
Creator: Gong, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Functional group analysis in coal and on coal surfaces by NMR spectroscopy

Description: The reaction of Cl{ovr POCH{sub 2}CH{sub 2}O} (2) with moisture in pyridine extracts of Argonne standard coal samples has been found to give results comparable with the ASTM D3302 moisture analyses of these samples. Differences in the two sets of results are discussed. Some exceptionally large solvent effects on {sup 31}P chemical shifts of model compounds derivatized with 2 and 8 have been discovered. Initial experiments aimed at labile hydrogen functional group analysis of solid coal samples … more
Date: October 1, 1989
Creator: Verkade, J.G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The behavior of matter under nonequilibrium conditions: Fundamental aspects and applications: Progress report, April 15, 1988--April 14, 1989

Description: This paper discusses two topics: microscopic simulators and stochastic aspects of hydrodynamics and chemical instabilities; and microscopic meaning of irreversibility. 15 refs., 3 figs. (LSP)
Date: January 1, 1989
Creator: Prigogine, I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The reactions of neutral iron clusters with D/sub 2/O: Deconvolution of equilibrium constants from multiphoton processes

Description: The chemical reactions of neutral iron clusters with D/sub 2/O are studied in a continuous flow tube reactor by molecular beam sampling and time-of-flight mass spectrometry with laser photoionization. Product distributions are invariant to a four-fold change in reaction time demonstrating that equilibrium is attained between free and adsorbed D/sub 2/O. The observed negative temperature dependence is consistent with an exothermic, molecular addition reaction at equilibrium. Under our experiment… more
Date: January 1, 1989
Creator: Weiller, B.H.; Bechthold, P.S.; Parks, E.K.; Pobo, L.G. & Riley, S.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Chemical Technology Division: Progress report, January 1, 1987--June 30, 1988

Description: This progress report summarizes the research and development efforts conducted in the Chemical Technology Division (Chem Tech) during the period January 1, 1987, to June 30, 1988. The following major areas are covered: waste management and environmental programs, radiochemical and reactor engineering programs, basic science and technology, Nuclear Regulatory Commission programs, and administrative resources and facilities. The Administrative Summary, an appendix, presents a comprehensive listin… more
Date: February 1, 1989
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Chemical pretreatment of coal in a stirred ball mill

Description: Present studies on the electrochemical aspects of pyrite flotation in the presence of reducing agents were conducted to explain the effects observed during flotation of the separated organic and mineral-rich fractions of coal independently when sodium dithionite was used as an additive during and after grinding. In addition, the electrochemical phenomena occurring on the surface of pyrites of different origin was studied to aid in explaining the differences observed in the flotation of various … more
Date: October 1, 1989
Creator: Birlingmair, D.; Chmielewski, T. & Pollard, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Reillex/trademark/ HPQ: A new, macroporous polyvinylpyridine resin for separating plutonium using nitrate anion exchange

Description: Anion exchange in nitric acid is the major aqueous process used to recover and purify plutonium from impure scrap materials. Most strong-base anion exchange resins incorporate a styrene-divinylbenzene copolymer. A newly available, macroporous anion exchange resin based on a copolymer of 1-methyl-4-vinylpyridine and divinylbenzene has been evaluated. Comparative data for Pu(IV) sorption kinetics and capacity are presented for this new resin and two other commonly used anion exchange resins. The … more
Date: January 1, 1989
Creator: Marsh, S.F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spectroscopy and reaction kinetics of HCO

Description: The high-resolution infrared spectrum of the C-H stretching fundamental of HCO has been studied by means of infrared flash kinetic spectroscopy. HCO was generated by flash photolysis of acetaldehyde or formaldehyde using a 308 nm (XeCl) excimer laser. The transient absorption was probed with an infrared difference frequency laser system. The high resolution spectra obtained were assigned and fitted with rotational, spin-rotational, and centrifugal distortion constants. The ..nu../sub 1/ band or… more
Date: January 1, 1989
Creator: Guo, Yili
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Free Energy of Formation of CaCsCl/Sub 3/

Description: The free energy of formation of the compound CaCsCl/sub 3/ from CaCl/sub 2/ and CsCl has been determined by measuring the sublimation pressure of CsCl(g) over CaCsCl/sub 3/(s) and over CsCl(s) using Knudsen effusion mass spectrometry. The free energy change for the reaction CaCl/sub 2/(s) + CsCl(s) = CaCsCl/sub 3/(s) at 298 K is /minus/40.7 +/- 6.4 kJ mol/sup /minus/1/. The enthalpy change is /minus/33.5 +//minus/ 5.2 kJ mol /sup /minus/1/ and the entropy change is 23.4 +//minus/ 3.7 J K/sup /m… more
Date: January 1, 1989
Creator: Kleinschmidt, P. D. & Axler, K. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Isotopic anomalies in high Z elements: Uranium

Description: Uranium in terrestrial volcanic ejecta from mantle-related sources has been analyzed mass spectrometrically. The objective was to seek supporting evidence for or refutation isotopic variations reported by Fried et al. (1985) for some such samples. The possibility that terrestrial U is not of constant isotopic composition is extraordinary. If true, mechanisms for creating the variation must be sought and the lack of homogenization within the earth addressed. Samples of 100 grams or more were pro… more
Date: March 1, 1989
Creator: Jovanovic, S.; Reed, Jr., G. W.; Essling, A. M.; Rauh, E. G. & Graczyk, D. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Studies of the Ag/Cu(110) bimetallic interface using optical second-harmonic generation

Description: Optical second harmonic generation (SHG) has recently been shown to be a sensitive, real-time, in situ probe for studying interfaces under many different environments. With regard to atomically clean well-characterized surfaces, SHG has been shown to be sensitive to submonolayer coverages of adsorbates, the structural symmetry or molecular arrangement on the surface, and the surface reordering observed during laser induced melting and recrystallization. Previous SHG studies of bimetallic system… more
Date: January 1, 1989
Creator: Muenchausen, R. E.; Hoffbauer, M. A. & Taylor, T. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of an altered simple silicate glass using different mineral and glass standards

Description: Quantitative analyses of alteration products formed during the aqueous corrosion of glass were performed using four different sets of standards: relevant mineral standards, an NBS glass standard, and the unreacted center of the reacted glass. A simple silicate glass (containing Na, Mg, Al, Si, and Ca) was reacted in water vapor at 200/degree/C for 14 days. Up to eight alteration phases, including a Mg-rich smectite clay and a zeolite intermediate in composition between Ca-harmotome and phillips… more
Date: March 1, 1989
Creator: Mazer, J.J. & Bates, J.K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A program to study CH reactions relevant to combustion/gasification processes. Final report, July 1983--July 1988

Description: The goal of the proposed work has been to study a small, but important family of CH reactions of interest in combustion-related systems; namely CH + N{sub 2}, H{sub 2}, O{sub 2}, NO, and N{sub 2}O. Until now, these reactions have been studied almost exclusively by IR or UV flash photolysis at moderate temperatures, and little quantitative information about product species has been obtained. The explicit objectives of the present effort were: (1) to develop and characterize a new CW source of CH… more
Date: January 1, 1989
Creator: Anderson, S. M.; Freedman, A. & Kolb, C. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Simulation of ethylbenzene dehydrogenation in microporous catalytic membrane reactors

Description: Current state-of-the-art inorganic oxide membranes offer the potential of being modified to yield catalytic properties. The resulting modules may be configured to simultaneously induce catalytic reactions with product concentration and separation in a single processing step. Processes utilizing such catalytically active membrane reactors have the potential for dramatically increasing yield of reactions which are currently limited by either thermodynamic equilibria, product inhibition, or kineti… more
Date: April 1, 1989
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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