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Film Formation on Lithium in Propylene Carbonate Solutions Under Open Circuit Conditions

Description: The nature of protective surface layers formed on lithium in propylene carbonate solutions of LiClO{sub 4} and LiAsF{sub 6} at open circuit has been investigated by electrochemical pulse measurements. The results are consistent with the fastformation of a compact thin layer resulting from the reaction with residual water. This layer acts as a solid ionicconductor. Slow corrosion or decomposition processes produce a thicker porous overlayer.
Date: June 1, 1980
Creator: Geronov, Y.; Schwager, F. & Muller, R.H.
Partner: UNT Libraries Government Documents Department

Characterization and Process Development of Cyanate Ester Resin Composites

Description: Cyanate ester resins offer advantages as composite matrices because of their high thermal stability, low outgassing, low water absorption, and radiation resistance. This paper describes the results of a processing study to develop a high-strength hoop-wound composite by the wet-filament winding method using Toray TI 000G carbon fiber and YLA RS- 14A cyanate ester resin as the constituent materials. The study shows that the cyanate ester resin has a broad process envelope but that an inert-atmosphere cure is essential for obtaining optimum resin and composite properties. Minimizing moisture exposure prior to and during cure is also crucial as it affects the glass transition temperature of the resin and composite. Composite cylinders wound and cured with these methods yielded excellent ring tensile strengths both at room and elevated temperature. A summary of the measured mechanical and thermal property data for these composites is presented. Potential applications for these materials include flywheeI energy storage systems for space and satellite structures.
Date: May 23, 1999
Creator: Frame, B.J.
Partner: UNT Libraries Government Documents Department

Characterization and Process Development of Cyanate Ester Resin and Composite

Description: Cyanate ester (or polycyanate) resins offer advantages as composite matrices because of their high thermal stability, low outgassing, low water absorption and radiation resistance. This report describes the results of a processing study to develop high-strength hoop-wound composite by the wet-filament winding method using Toray T1000G carbon fiber and YLA RS-14A polycyanate resin as the constituent materials. Process trials, tests and analyses were conducted in order to gain insight into factors that can affect final properties of the cured cyanate ester resin and its composites. The study shows that the cyanate ester resin has a broad process envelope but that an inert-atmosphere cure is essential for obtaining optimum resin and composite properties. Minimizing moisture exposure prior to cure is also crucial as it affects the T{sub g} of the resin and composite. Recommendations for reducing moisture contact with the resin during wet-winding are presented. High fiber volume fraction ({approximately}80%) composites wound and cured with these methods yielded excellent hoop tensile strengths (660 to 670 ksi average with individual rings failing above 700 ksi), which are believed to be the highest recorded strengths for this class of materials. The measured transverse properties were also exceptional for these high fiber fraction composites. Based on the available data, this cyanate ester resin system and its composites are recommended for space and vacuum applications only. Further testing is required before these materials can be recommended for long term use at elevated temperatures in an ambient air environment. The results of all analyses and tests performed as part of this study are presented as well as baseline process for fabricating thick, stage-cured composites. The manufacture of a 1 in. thick composite cylinder made with this process is also described.
Date: March 1998
Creator: Frame, B. J.
Partner: UNT Libraries Government Documents Department

Vapor space characterization of waste Tank 241-C-107: Results from samples collected on 9/29/94

Description: This report describes inorganic and organic analyses results from samples obtained from the headspace of the Hanford waste storage Tank 241-C-107 (referred to as Tank C-107). The results described here were obtained to support safety and toxicological evaluations. A summary of the results for inorganic and organic analytes is listed in Table 1. Detailed descriptions of the results appear in the text. Quantitative results were obtained for the inorganic compounds ammonia (NH{sub 3}), nitrogen dioxide (NO{sub 2}), nitric oxide (NO), and water vapor (H{sub 2}O). Sampling for sulfur oxides (SO{sub x}) was not requested. Organic compounds were also quantitatively determined. Twenty organic tentatively identified compounds (TICs) were observed above the detection limit of (ca.) 10 ppbv, but standards for most of these were not available at the time of analysis, and the reported concentrations are semiquantitative estimates. In addition, the authors looked for the 55 TO-14 extended analytes. Of these, 3 were observed above the 5-ppbv detection limit. The 10 organic analytes with the highest estimated concentrations are listed in Summary Table 1 and account for approximately 96% of the total organic components in Tank C-107. Two permanent gases, carbon dioxide and nitrous oxide, were also detected.
Date: November 1, 1995
Creator: Pool, K.H.; Clauss, T.W. & Ligotke, M.W.
Partner: UNT Libraries Government Documents Department

CHARACTERIZATION OF THE PHOTOSYNTHETICALLY SYNTHESIZED 'gamma-KETOACID' PHOSPHATE AS A DIPHOSPHATE ESTER OF 2-KETO-L-GULONIC ACID

Description: The summary of this report is that a substance isolated from Chlorella Pyrenoidosa metabolizing {sup 14}CO{sub 2} in the light, previously believed to be a diphosphate ester of a 2-carboxy-4-pentulose, has now been shown to be a disphosphate of 2-keto-L-gulonic acid. The phosphate groups appear to be attached to two of the carbon atoms 3-6. Evidence is presented suggesting that this compound arises from glucose, or a glucose phosphate, which is not in rapid equilibrium with photosynthetically produced glucose derivatives.
Date: June 1, 1962
Creator: Moses, V.; Ferrier, R.J. & Calvin, M.
Partner: UNT Libraries Government Documents Department

THE STRUCTURE OF THE SO-CALLED ''ETHYLMETAPHOSPHATE'' (LANGHELDESTER)

Description: Phosphorus pentoxide reacts with ether to form bicyclo-tetraphosphate ester (II), cyclotetraphosphate ester (III), isocyclotetraphosphate ester (IV), and tetraphosphate ester (V). Phosphorus n.m.r. measurements show the content of the mixtures. The so-called 'ethyl metaphosphate' (Langheld ester) is a mixture of III (50% to 45%), IV (36% to 25%), and V (14% to 30%).
Date: June 1, 1964
Creator: Burkhardt, Gottfried; Klein, Melvin & Calvin, Melvin.
Partner: UNT Libraries Government Documents Department

Plasma membrane reorganization induced by tumor promoters in an epithelial cell line

Description: The effects of phorbol ester tumor promoters on the lateral diffusion in plasma membrane lipid environments were examined by the technique of fluorescence recovery after photobleaching. To this end, the probe collarein, a fluorescent lipid analog that has the property of exclusive localization in the plasma membrane, was synthesized. Measured decreases in three parameters [percentage of fluorescence bleached (30%), percentage of recovery (52%), and half-time for recovery (52%)] connoted the appearance of an immobile fraction upon exposure to tumor promoters. These data are consistent with lipid reorganization in response to a reorganization of the intra- and perimembranous macromolecular scaffolding upon the interaction of cells with tumor promoters. The idea of induced reorganization is supported by experiments in which cell shape change, brought about by either exposure to cytochalasin B or growth on matrices of collagen, fibronectin, or laminin, resulted in values in the fluorescence recovery after photobleaching technique similar to those with active phorbol esters.
Date: January 1, 1984
Creator: PACKARD, BEVERLY S.; SAXTON, MICHAEL J.; BISSELL, MINA J. & KLEIN, MELVIN P.
Partner: UNT Libraries Government Documents Department

Evaluation of bisphenol E cyanate ester for the resin-injection repair of advanced composites

Description: This thesis is a compilation of a general introduction and literature review that ties together the subsequent chapters which consist of two journal articles that have yet to be submitted for publication. The overall topic relates to the evaluation and application of a new class of cyanate ester resin with unique properties that lend it applicable to use as a resin for injection repair of high glass transition temperature polymer matrix composites. The first article (Chapter 2) details the evaluation and optimization of adhesive properties of this cyanate ester and alumina nanocomposites under different conditions. The second article (Chapter 3) describes the development and evaluation of an injection repair system for repairing delaminations in polymer matrix composites.
Date: December 19, 2009
Creator: Lio, Wilber Yaote
Partner: UNT Libraries Government Documents Department

BioFacts: Fueling a stronger economy, Biodiesel. Revision 2

Description: Biodiesel is a substitute for or an additive to diesel fuel that is derived from the oils and fats of plants. It is an alternative fuel that can be used in diesel engines and provides power similar to conventional diesel fuel. It is a biodegradable transportation fuel that contributes little, if any, net carbon dioxide or sulfur to the atmosphere, and is low in particulate emission. It is a renewable, domestically produced liquid fuel that can help reduce US dependence on foreign oil imports. This overview presents the resource potential, history, processing techniques, US DOE programs cost and utilization potential of biodiesel fuels.
Date: January 1, 1995
Partner: UNT Libraries Government Documents Department

Synthesis of methyl methacrylate from coal-derived syngas: Quarterly report,, October 1-December 31, 1997

Description: Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of three steps of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Over the last quarter, Eastman developed two new processes which have resulted in two new invention reports. One process deals with carbonylation of benzyl ether which represents a model for coal liquefaction and the second focuses on the acceleration of carbonylation rates for propionic acid synthesis, via use of polar aprotic solvents. These two inventions are major improvements in the novel Mo-catalyzed homogeneous process for propionic acid synthesis technology, developed by Eastman. Over the last quarter, RTI completed three reaction cycles and two regeneration cycles as a part of long-term reaction regeneration cycle study on a 10% Nb{sub 2}O{sub 5}/Si0{sub 2} catalyst, for vapor phase condensation reaction of formaldehyde with propionic acid.
Date: September 1, 1998
Partner: UNT Libraries Government Documents Department

SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

Description: Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter(Oct.-Dec./98), we have investigated the condensation between methyl propionate and formaldehyde (MP/HCHO=4.5/1) at various reaction temperatures(280-360EC) over 5%, 10%, and 20% Nb O /SiO catalysts. The conversion of HCHO increases with reaction 2 5 2 temperature and niobium loading. MMA+MAA selectivity goes through a maximum with the temperature over both 10% and 20% Nb O /SiO . The selectivities to MMA+MAA are 67.2%, 2 5 2 72.3%and 58.1% at 320EC over 5%, 10%, 20% Nb O /SiO , respectively. However, the 2 5 2 conversion of formaldehyde decreases rapidly with time on stream. The results suggest that silica supported niobium catalysts are active and selective for condensation of MP with HCHO, but deactivation needs to be minimized for the consideration of commercial application. We have preliminarily investigated the partial oxidation of dimethyl ether(DME) over 5% Nb O /SiO catalyst. Reactant gas mixture of 0.1% DME, 0.1% O and balance nitrogen is 2 5 2 2 studied with temperature ranging from 200°C to 500°C. The conversion of DME first increases with temperature reaching an maximum at 400°C then decreases. The selectivity to HCHO also increases with reaction temperature first. But the selectivity to ...
Date: January 20, 1999
Creator: JANG, BEN W.-L.; CHOI, GERALD N.; SPIVEY, JAMES J.; ZOELLER, JOSPEH R. & COLBERG, RICHARD D.
Partner: UNT Libraries Government Documents Department

Detailed Chemical Kinetic Mechanisms for Combustion of Oxygenated Fuels

Description: Thermodynamic properties and detailed chemical kinetic models have been developed for the combustion of two oxygenates: methyl butanoate, a model compound for biodiesel fuels, and methyl formate, a related simpler molecule. Bond additivity methods and rules for estimating kinetic parameters were adopted from hydrocarbon combustion and extended. The resulting mechanisms have been tested against the limited combustion data available in the literature, which was obtained at low temperature, subatmospheric conditions in closed vessels, using pressure measurements as the main diagnostic. Some qualitative agreement was obtained, but the experimental data consistently indicated lower overall reactivities than the model, differing by factors of 10 to 50. This discrepancy, which occurs for species with well-established kinetic mechanisms as well as for methyl esters, is tentatively ascribed to the presence of wall reactions in the experiments. The model predicts a region of weak or negative dependence of overall reaction rate on temperature for each methyl ester. Examination of the reaction fluxes provides an explanation of this behavior, involving a temperature-dependent competition between chain-propagating unimolecular decomposition processes and chain-branching processes, similar to that accepted for hydrocarbons. There is an urgent need to obtain more complete experimental data under well-characterized conditions for thorough testing of the model.
Date: January 11, 2000
Creator: Fisher, E.M.; Pitz, W.J.; Curran, H.J. & Westbrook, C.K.
Partner: UNT Libraries Government Documents Department

Utilization of CO{sub 2} in production of polycarbonate

Description: Our original thrust, that of developing a direct route to diphenyl carbonate (the monomer for bisphenol A polycarbonate) using carbon dioxide as a raw material, was unsuccessful. The appendix describes the experiments that were tried in this regard. The primary problem was that we were unable to replicate the literature results of Yamazaki, et al, despite using their conditions and reactants, which form the basis for the proposed work. Despite this setback, we have derived a new route to diphenyl carbonate, which we have described in a proposal to the NSF/EPA partnership for environmental research (the sustainable technology section) which was submitted in April 1995. This route would incorporate carbon dioxide into a dialkyl carbonate using a tin catalyst, followed by transesterification using an enzyme to diphenyl carbonate. Thus, this work may continue on the future. However, despite the setbacks in the original proposed work, we set up two new collaborations with both Miles (now Bayer) and Exxon which employ CO{sub 2} as both monomer and solvent in polymer processing.
Date: December 31, 1994
Creator: Beckman, E. J.
Partner: UNT Libraries Government Documents Department

Identification of subsurface microorganisms at Yucca Mountain. Quarterly report, July 1, 1995--September 30, 1995

Description: More than 1100 bacterial isolates were obtained over a two year period from 31 springs in a region along the southern boarder of California and Nevada. Water samples were collected from 17 springs in Ash Meadows National Wildlife Refuge and 14 springs in Death Valley National Park. Bacteria isolated from these samples were subjected to extraction and gas chromatography to determine the cellular fatty acid profile of each isolate. Fatty acid methyl esters (FAME) extracted from cell membranes were separated and classified using the Hewlett Packard by gas chromatography. The FAME profiles of each isolate were then subjected to cluster analysis by the unweighted pair-group method using arithmetic averages. During this quarter the relatedness of FAME patterns of bacterial isolates were examined at the genus level by counting the number of clusters produced in a MIDI dendrogram at a Euclidian distance of 25. This information was then used to determine microbiological relationships among springs.
Date: December 1, 1995
Creator: Stetzenbach, L.D.
Partner: UNT Libraries Government Documents Department

MALDI analysis of estane degradation

Description: SEUMALDI has been successfully used to accurately measure the MW of hydrolysis degradation products from Estane 5703. Reasonable structure assignments have been made to the degradation products and several observations reported. Most of the low MW degradation peaks have been identified as ester hydrolysis fragments. The data suggest that the polyester macrodiol may be shorter than the {approximately}2000 amu reported by the manufacturer. Experiments are ongoing to determine if hydrolysis occurs within the material's applied environment.
Date: March 26, 1999
Creator: Haining, J; Kober, E M; LeMay, J D; Mays, J; Nonidez, W; Overturf III, G E et al.
Partner: UNT Libraries Government Documents Department

Energies of organic compounds. Technical progress report

Description: A procedure was developed for carbonyl group reduction using triethylborohydride. Esters and lactones are readily reduced and are suitable as substrates. Some enthalpies of hydrolysis of lactones and esters were measured. Heats of trifluoroacetolysis of alkenes leading to tertiary alcohols were measured; some cyclic systems were also investigated. In order to study the effect of {alpha}-alkyl substituents on ketones, rotational barriers adjacent to carbonyl groups were studied.
Date: August 12, 1987
Creator: Wiberg, K.B.
Partner: UNT Libraries Government Documents Department

POTENTIAL IMPACT OF TANK F FLUSH SOLUTION ON H-CANYON EVAPORATOR OPERATION

Description: Previous chemical analysis of a sample from the liquid heel found in Tank F of the High Activity Drain (HAD) system in F/H laboratory revealed the presence of n-paraffin, tributyl phosphate (TBP), Modifier from the Modular Caustic-Side Solvent Extraction Unit (MCU) process and a vinyl ester resin that is very similar to the protective lining on Tank F. Subsequent analyses detected the presence of a small amount of diisopropylnaphthalene (DIN) (major component of Ultima Gold{trademark} AB liquid scintillation cocktail). Indications are that both vinyl ester resin and DIN are present in small amounts in the flush solution. The flush solution currently in the LR-56S trailer likely has an emulsion which is believed to contain a mixture of the reported organic species dominated by TBP. An acid treatment similar to that proposed to clear the HAD tank heel in F/H laboratory was found to allow separation of an organic phase from the cloudy sample tested by SRNL. Mixing of that clear sample did re-introduce some cloudiness that did not immediately clear but that cloudiness is attributed to the DIN in the matrix. An organic phase does quickly separate from the cloudy matrix allowing separation by a box decanter in H-Canyon prior to transfer to the evaporator feed tank. This separation should proceed normally as long as the emulsion is broken-up by acidification.
Date: September 13, 2010
Creator: Kyser, E.; Fondeur, F. & Fink, S.
Partner: UNT Libraries Government Documents Department

Materials compatibility and lubricants research on CFC-refrigerant substitute: Miscibility of lubricants with refrigerants. Quarterly report, 6 February 1992--31 March 1992

Description: During this reporting period, modifications were made to the experimental apparatus in preparation for performing the experiments required in this project. In addition, new procedures for charging the lubricant and refrigerant into the cells for high temperature tests have been adopted. All of the refrigerants (10 different types) and lubricants (seven different types) have been ordered from the manufacturers. To date, the data obtained includes that for R-134a and four lubricants, namely, two esters and two polypropylene glycols (PAGs). Methods for quantifying immiscibility based on observation by different lab workers have been developed.
Date: April 1, 1992
Creator: Pate, M. B.; Zoz, S. & Berkenbosch, L.
Partner: UNT Libraries Government Documents Department

Thermal properties. Period covered: October--December 1975

Description: The thermal decomposition investigation of PETN using an LX-13 type PETN was begun this quarter. Samples are being conditioned at 373, 353 and 333/sup 0/K and others will be conditioned at 393 and 383/sup 0/K. Data from five samples are reported. A series of chemical reactivity tests was made using PETN to determine if decomposition rates could be calculated from the results. The data fit a semilogarithmic plot of the gas evolved as a function of time reasonably well. The last of a series of HNAB and PETN samples was evaluated to determine if the two are compatible. These samples were conditioned at 80/sup 0/C for 26 and 25 months and showed no indication of reactivity. The investigation into methods of improving the chemical reactivity test data has continued and a source of a small variation in the instrument sensitivity was determined.
Date: January 1, 1975
Creator: Myers, L.C.
Partner: UNT Libraries Government Documents Department

Shock initiation sensitivity of PETN: A steric hindrance model

Description: In this report, shock initiation sensitivity of PETN crystals is discussed. A new molecular model for shock sensitivity in crystalline solids is proposed in terms of steric hindrance to edge dislocation motion. This model is successful in predicting the relative shock sensitivities of the four PETN orientations studied, especially at low stresses. (JL)
Date: January 1, 1991
Creator: Dick, J.J.
Partner: UNT Libraries Government Documents Department