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in subjects: "37 Inorganic, Organic, Physical And Analytical Chemistry"  
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High-Sensitivity Single-Molecule Fluorescence Detection in Theory and Practice

Description: The number of emitted photons that can be obtained from a fluorophore increases with the incident light intensity and the duration of illumination. However, saturation of the absorption transition and photodestruction place natural limits on the ultimate signal-to-noise ratio that can be obtained. Equations have been derived to describe the fluorescence-to-background-noise ratio in the presence of saturating light intensities and photodestruction. The fluorescence lifetime and the photodestruct… more
Date: 1989
Creator: Mathies, R. A.; Peck, K. & Stryer, L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Methane oxidation over dual redox catalysts

Description: Review and analysis of the literature data on electron transfer itself and electron transfer oxidation of alkyl radicals was done in order to understand the mechanism by which methyl radical can be oxidized to CH{sub 3}{sup +} and further substituted by OH{sup {minus}} to form methanol. This allowed to compare and classify the various possible reaction patterns, understand the mechanism and circumstances of operation of each of them and select those which can be involved in oxidation of methyl … more
Date: March 1, 1989
Creator: Klier, Kamil; Herman, Richard G. & Sojka, Zvigniew
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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Methane oxidation over dual redox catalysts

Description: The objective of this research is to develop approaches to direct catalytic oxidation of methane over oxides that are doubly doped with transition metal ions. The desired process aims at employing a double redox mechanism, where one redox couple is utilized for activation of oxygen and another for the trapping of CH{sub 3} radicals. The methyl radicals can either recombine, giving C{sub 2} hydrocarbons, or be converted, via electron transfer reaction, to carbocations. The latter species can rea… more
Date: September 1, 1989
Creator: Klier, Kamil; Herman, Richard G. & Sojka, Zbigniew
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Raman microprobe investigation of molecular structure and organization in the native state of woody tissue

Description: Although the primary emphasis of our program has remained with the application of Raman spectroscopy to the study of native tissue, the scope of the work has been expanded to include a number of complementary approaches. These have included Solid State 13C NMR, autoradiography of radiolabeled woody tissue sections, and the generation of biomimetic tertiary aggregates which simulate states of aggregation characteristic of cell walls. Our Raman spectroscopic studies have resulted in progress in t… more
Date: August 1, 1989
Creator: Atalla, R.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Arsenic Removal From Gaseous Streams

Description: Uranium feed materials, depending on the production process, have been found to contain arsenic (As) as a contaminant. Analyses show the As to be present as As pentafluoride (AsF{sub 5}) and/or hexafluoroarsenic acid (HAsF{sub 6}) and enter the enrichment cycle through contaminated hydrogen fluoride (HF). Problems related to corrosion of cylinder valves and plugging of feed lines and valves have been attributed to the As. Techniques to separate AsF{sub 5} from uranium hexafluoride (UF{sub 6}) u… more
Date: November 22, 1989
Creator: Russell, R. G. & Otey, M. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Aromatics oxidation and soot formation in flames

Description: Work during this contract period has been concerned with the mechanisms through which aromatics are formed and destroyed in flames, and the processes responsible for soot formation. Recent progress has been primarily in two areas: experiments and modeling of the soot nucleation process in low pressure benzene flames and preparation for experiments on the destruction mechanisms of benzene. In addition, we have incorporated weak collision'' formalisms into a fall-off computer code.
Date: January 1, 1989
Creator: Howard, J. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Surface electrochemical control for the fine coal and pyrite separation

Description: Ongoing work includes the characterization of coal pyrites, the floatability evaluation of typical US coal samples, the flotation behavior of coal pyrites, the electrochemical measurement of the surface properties of coal pyrites, and the characterization of species produced at pyrite surfaces.
Date: January 1, 1989
Creator: Chen, Wanxiong; Hu, Weibai; Wann, Jyi-Perng; Zhu, Ximeng & Wadsworth, M. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Methane oxidation over dual redox catalysts

Description: The objective of this research is to develop the scientific background for direct catalytic oxidation of methane over oxides that are doubly doped with transition metal ions. The desired process aims at employing of a double redox mechanism, where one redox couple is utilized for activation of oxygen and another for the conversion of CH{sub 3} radicals to carbocations via electron transfer reaction. The latter species can react with surface OH{sup {minus}} groups to form methanol or formaldehyd… more
Date: June 1, 1989
Creator: Klier, Kamil; Herman, Richard G. & Sojka, Zbigniew
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electroformation of uranium hemispherical shells

Description: This effort was directed at developing an electrochemical process for forming uniform and dendrite-free deposits of uranium from molten salts. This process is to be used for the electroformation of free-standing hemispherical shells of uranium for nuclear applications. Electrodeposition of uranium onto a substrate was accomplished with a fused chloride mixture containing 42 wt% UCl{sub 3} and a fused chloride-fluoride mixture containing 4 wt % UF{sub 4}. Under pulsed potential control at 504{de… more
Date: November 1, 1989
Creator: Marshall, S.L.; Redey, L.; Vandegrift, G.F. & Vissers, D.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Surface electrochemical control for the fine coal and pyrite separation

Description: Ongoing work includes the characterization of coal pyrites, the floatability evaluation of typical US coal samples, the flotation behavior of coal pyrites, the electrochemical measurement of the surface properties of coal pyrites, and the characterization of species produced at pyrite surfaces.
Date: January 1, 1989
Creator: Chen, Wanxiong; Hu, Weibai; Wann, Jyi-Perng; Zhu, Ximeng; Wadsworth, M. E. & Bodily, D. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analytical Chemistry Laboratory progress report for FY 1989

Description: The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1989 (October 1988 through September 1989). The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works… more
Date: December 1, 1989
Creator: Green, D. W.; Heinrich, R. R.; Graczyk, D. G.; Lindahl, P. C. & Erickson, M. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fundamental Studies of Retrograde Reactions in Direct Liquefaction

Description: Most of the proposed processing schemes for improving liquefaction yields involve favoring bond-breaking and radical stabilization reactions over the retrograde reactions. The retrograde reactions are often encountered before liquefaction temperatures are reached. The objective of this program is to elucidate and model the retrograde reaction chemistry in direct coal liquefaction through the application of experimental techniques and theoretical models which have been successfully employed at A… more
Date: January 1, 1989
Creator: Serio, M. A.; Solomon, P. R.; Bassilakis, R. & Kroo, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The effect of precipitation conditions and aging upon characteristics of particles precipitated from aqueous solutions

Description: Precipitation of a dissolved species from aqueous solutions is one of the techniques used to grow particles with certain size or composition characteristics. Various factors affecting the particle properties for sparingly soluble substances are briefly discussed here, including homogeneous versus heterogeneous nucleation, the effect of relative supersaturation on the number of nuclei and their relative size, particle growth by way of Ostwald Ripening, the Ostwald Step Rule and nucleation of met… more
Date: October 1, 1989
Creator: Rard, J.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Quantum mechanical reactive scattering theory for simple chemical reactions: Recent developments in methodology and applications

Description: It has recently been discovered that the S-matrix version of the Kohn variational principle is free of the Kohn anomalies'' that have plagued other versions and prevented its general use. This has made a major contribution to heavy particle reactive (and also to electron-atom/molecule) scattering which involve non-local (i.e., exchange) interactions that prevent solution of the coupled channel equations by propagation methods. This paper reviews the methodology briefly and presents a sample of … more
Date: August 1, 1989
Creator: Miller, William H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Atomic mass measurements with radioactive beams and/or targets: Where to start

Description: Radioactive beams or radioactive targets (or both) can significantly increase the yields of exotic isotopes, allowing studies to be performed in regions which are currently inaccessible. An important goal to pursue with these exotic species is a broad program of nuclidic mass measurements. This is motivated by the observation that mass model predictions generally diverge from one another in regions far from beta-decay stability where well measured masses are sparse or nonexistent. Stringent tes… more
Date: January 1, 1989
Creator: Haustein, P.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Computerized procedure for preparation of secondary standards

Description: Laboratory quality control programs depend on the analysis of known standards to judge the accuracy and reliability of the results they generate. The standards used for routine checks are generally made by diluting and mixing well characterized and traceable primary standards because the primary standards are too expensive and difficult to certify to use in large quantities. We have developed a computer program to help automate the production of secondary standards and to help assure their accu… more
Date: January 1, 1989
Creator: O'Rourke, P. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Advanced Hydride Laboratory

Description: Metal hydrides have been used at the Savannah River Tritium Facilities since 1984. However, the most extensive application of metal hydride technology at the Savannah River Site is being planned for the Replacement Tritium Facility, a $140 million facility schedules for completion in 1990 and startup in 1991. In the new facility, metal hydride technology will be used to store, separate, isotopically purify, pump, and compress hydrogen isotopes. In support of the Replacement Tritium Facility, a … more
Date: January 1, 1989
Creator: Motyka, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Fluorescence dynamics and cross relaxation of 4+ curium in cerium tetrafluoride

Description: Fluorescence from Cm{sup 4+} has been observed for the first time. The dynamics of its emitting 5f state have been probed using time- and frequency-resolved laser-induced fluorescence. Nonexponential fluorescence decays were found from Cm{sub 0.001}Ce{sub 0.999}F{sub 4} and Cm{sub 0.05}Ce{sub 0.95}F{sub 4} at temperatures from 4.2 K to 300 K. A simple cross-relaxation model was found to fit the excited f-state dynamics of the Cm{sub 0.001}Ce{sub 0.999}F{sub 4} sample at low excitation intensity… more
Date: January 1, 1989
Creator: Liu, G.K. & Beitz, J.V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Publications of Los Alamos research 1988

Description: This bibliography lists unclassified publications of work done at the Los Alamos National Laboratory for 1988. The entries, which are subdivided by broad subject categories, are cross-referenced with an author index and a numeric index.
Date: December 1, 1989
Creator: Varjabedian, K.; Dussart, S. A.; McClary, W. J. & Rich, J. A. (comps.)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Perturbations in high-velocity gas flow

Description: High velocity explosive products or other low-density gases are often used to accelerate metal plates to high velocities. Perturbations in otherwise uniform flow configurations are sometimes sufficient to cause interactions that can rapidly destroy the integrity of the plates. In this study perturbations were introduced in uniform gas flows of detonated HE products and strongly shocked polyethylene, CH{sub 2}. The primary diagnostics were smear-camera records obtained when these gases impinged … more
Date: January 1, 1989
Creator: Harvey, W.B. & McQueen, R.G. (Los Alamos National Lab., NM (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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(Mechanistic examination of organometallic electron transfer reactions: Annual report, 1989)

Description: Our mechanistic examination of electron transfer reactions between organometallic complexes has required data from our stopped-flow infrared spectrophotometer that was constructed in the first year. Our research on organometallic electron transfer reaction mechanisms was recognized by an invitation to the Symposium on Organometallic Reaction Mechanisms at the National ACS meeting in Miami. We have obtained a reasonable understanding of the electron transfer reactions between metal cations and a… more
Date: January 1, 1989
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Photoinitiated electron transfer in multichromophoric species: Synthetic tetrads and pentads

Description: This research project involves the design, synthesis and study of molecules which mimic many of the important aspects of photosynthetic electron and energy transfer. Specifically, the molecules are designed to mimic the following aspects of natural photosynthetic multistep electron transfer: electron donation from a tetrapyrrole excited singlet state, electron transfer between tetrapyrroles, electron transfer from tetrapyrroles to quinones, and electron transfer between quinones with different … more
Date: April 12, 1989
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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