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Determination of the solubility of Np(IV), Pu(III) - (VI),Am(III) - (VI), and Te(IV), (V) hydroxo compounds in 0.5 - 14 M NaOH solutions

Description: The solubilities of Am(III), Np(IV), Pu(IV), Tc(IV), Np(V), Pu(V), Am(V), and Tc(V) hydroxo compounds were studied in 0.5 to 14 M NaOH solutions at 25{+-}2 {degrees}C. The effects of fluoride, phosphate, carbonate, oxalate, and some other organic complexing agents on the solubilities of Np(IV), Pu(IV), and TC(IV) hydroxides were investigated at 1.0 and 4.0 M NAOH. Some predictions were made on the dissolved (I.V) and (V) species present in alkali solutions.
Date: September 24, 1996
Creator: Delegard, C.H.
Partner: UNT Libraries Government Documents Department

Flash vacuum pyrolysis of lignin model compounds

Description: Despite the extensive research into the pyrolysis of lignin, the underlying chemical reactions that lead to product formation are poorly understood. Detailed mechanistic studies on the pyrolysis of biomass and lignin under conditions relevant to current process conditions could provide insight into utilizing this renewable resource for the production of chemicals and fuel. Currently, flash or fast pyrolysis is the most promising process to maximize the yields of liquid products (up to 80 wt %) from biomass by rapidly heating the substrate to moderate temperatures, typically 500{degrees}C, for short residence times, typically less than two seconds. To provide mechanistic insight into the primary reaction pathways under process relevant conditions, we are investigating the flash vacuum pyrolysis (FVP) of lignin model compounds that contain a {beta}-ether. linkage and {alpha}- or {gamma}-alcohol, which are key structural elements in lignin. The dominant products from the FVP of PhCH{sub 2}CH{sub 2}OPh (PPE), PhC(OH)HCH{sub 2}OPh, and PhCH{sub 2}CH(CH{sub 2}OH)OPh at 500{degrees}C can be attributed to homolysis of the weakest bond in the molecule (C-O bond) or 1,2-elimination. Surprisingly, the hydroxy-substituent dramatically increases the decomposition of PPE. It is proposed that internal hydrogen bonding is accelerating the reaction.
Date: March 1, 1997
Creator: Cooney, M.J.; Britt, P.F. & Buchanan, A.C. III
Partner: UNT Libraries Government Documents Department

Capillary electrophoretic separation of DNA restriction fragments using dilute polymer solutions

Description: Because the mechanism of DNA separation in capillary electrophoresis is not well understood, selection of polymers is a {open_quotes}trial-and-error{close_quotes} procedure. We investigated dilute-solution DNA separations by capillary electrophoresis using solutions of four polymers that differ in size, shape and stiffness. Hydroxyethylcellulose of high molecular weight provides excellent separation of large DNA fragments (2027 bp - 23130 bp). Polyvinylpyrrolidone separates DNA from 72 bp to 23 kbp and star-(polyethylene oxide), like linear poly (ethylene oxide), provides separation of fragments up to 1353 bp.
Date: February 1, 1997
Creator: Braun, B.; Blanch, W. & Prausnitz, J.M.
Partner: UNT Libraries Government Documents Department

Kinetics and mechanism of the oxidation of alkenes and silanes by hydrogen peroxide catalyzed by methylrhenium trioxide (MTO) and a novel application of electrospray mass spectrometry to study the hydrolysis of MTO

Description: Conjugated dienes were oxidized by hydrogen peroxide with methylrhenium trioxide (MTO) as catalyst. Methylrhenium bis-peroxide was the major reactive catalyst present. Hydroxyalkenes and trisubstituted silane were also tested. Mechanisms for each of these reactions are presented.
Date: November 8, 1999
Creator: Tan, Haisong
Partner: UNT Libraries Government Documents Department

A measurement technique for hydroxyacetone

Description: Hydroxyacetone (HA) is mainly produced in the atmosphere from oxidation of hydrocarbons of the type, CH{sub 3}(R)C{double{underscore}bond}CH{sub 2}. Tuazon and Atkinson (1990) reported HA yield of 41% from the OH-initiated oxidation of methacrolein in the presence of NOx. Since methacrolein is a major product of isoprene oxidation (Carter and Atkinson, 1996), isoprene, a key biogenic hydrocarbon, is therefore expected to be an important source for HA. Consequently, knowledge of ambient concentration of HA would provide information needed to examine the applicability of isoprene reaction mechanisms developed in laboratory and to assess the contribution of isoprene to photooxidant production. The commonly used GC-FID technique involving cryo-focusing is unsuitable for HA owing to HA's thermal instability. When subjected to a temperature of 100 C for only a few seconds, HA was found to disappear completely. Since HA is highly soluble in water, the authors developed a wet chemical technique similar in principle to the one they reported earlier, namely, derivatization following liquid scrubbing. To increase the sensitivity, they adopted a fluorescence detection scheme based on o-phthaldialdehyde (OPA) chemistry. The technique was deployed in the field during two measurement periods at a NARSTO site located on Long Island, New York. The authors report the principle and the operation of this technique and the results obtained from these field studies.
Date: October 4, 1999
Creator: Klotz, P.J.
Partner: UNT Libraries Government Documents Department

A MEASUREMENT TECHNIQUE FOR HYDROXYACETONE.

Description: Hydroxyacetone (HA) is mainly produced in the atmosphere from oxidation of hydrocarbons of the type, CH{sub 3}(R)C=CH{sub 2}. Tuazon and Atkinson (1990) reported HA yield of 41% from the OH-initiated oxidation of methacrolein in the presence of NO{sub x}. Since methacrolein is a major product of isoprene oxidation (Carter and Atkinson, 1996), isoprene, a key biogenic hydrocarbon, is therefore expected to be an important source for HA. Consequently, knowledge of ambient concentration of HA would provide information needed to examine the applicability of isoprene reaction mechanisms developed in laboratory and to assess the contribution of isoprene to photooxidant production. The commonly used GC-FID technique involving cryo-focusing is unsuitable for HA owing to HA's thermal instability. When subjected to a temperature of 100 C for only a few seconds, HA was found to disappear completely. Since HA is highly soluble in water (it's Henry's law constant being {approx}2 x 10{sup 4} M atm{sup -1} at 20 C, Zhou and Lee, unpublished data), we developed a wet chemical technique similar in principle to the one we reported earlier (Lee and Zhou, 1993), namely, based on derivatization following liquid scrubbing. To increase the sensitivity, we adopted a fluorescence detection scheme based on o-phthaldialdehyde (OPA) chemistry. The technique was deployed in the field during two measurement periods at a NARSTO site located on Long Island (LI), New York. We report the principle and the operation of this technique and the results obtained from these field studies.
Date: October 4, 1999
Creator: KLOTZ,P.J.
Partner: UNT Libraries Government Documents Department

Catalytic oxidation of secondary alcohols

Description: The dioxygen oxidation of alcohols over platinum catalysts has been known for a long time. While of potential importance in synthetic procedures, this process has never found extensive use except in carbohydrate oxidations. Some reasons for this is the fact that this reaction only appears to work well in an aqueous medium in the presence of rather large amounts of a Pt black catalyst. Results obtained here show that supported Pt catalysts can be used to promote this oxidation in organic solvents provided a small amount of water is added to the reaction medium. It was also estabilished that the reaction takes place on the more coordinately unsaturated corner atoms on the Pt surface.
Date: January 1, 1992
Creator: Augustine, R.L. & Doyle, L.K.
Partner: UNT Libraries Government Documents Department

Possible thermochemical cycle based on methanol. [Tetramethylphosphine]

Description: The production of hydrogen from methanol is of particular interest since the two reactions: CH/sub 4/ + H/sub 2/O + CO + 3H/sub 2/ and CO + 2H/sub 2/ = CH/sub 3/OH are individually well known industrial processes. Thus, if a method can be found to obtain the overall reaction: CH/sub 3/OH = CH/sub 4/ + 1/2 O/sub 2/ then, in total, a cyclic water splitting process is complete for which much of the industrial development is already known. A possible method is through the use of trimethylphosphine. This reacts with methanol to form a salt, tetramethyl phosphonium hydroxide: CH/sub 3/OH + (CH/sub 3/)/sub 3/P = (CH/sub 3/)/sub 4/POH. Tetramethylphosphonium hydroxide gives methane and trimethylphosphine oxide very readily: (CH/sub 3/)/sub 4/POH = CH/sub 4/ + (CH/sub 3/)/sub 3/PO. When anhydrous takes place readily at room temperature, but in the presence of water, the rate is retarded. In summary, the overall reaction can be written as: CH/sub 3/OH + (CH/sub 3/)/sub 3/P = CH/sub 4/ + (CH/sub 3/)/sub 3/PO. Thus, provided a way of removing oxygen from trimethylphosphine oxide can be found, (CH/sub 3/)/sub 3/PO = (CH/sub 3/)/sub 3/P + 1/2 O/sub 2/ is a simple method of converting methanol to methane and oxygen.
Date: January 1, 1982
Creator: Mason, C.F.V.
Partner: UNT Libraries Government Documents Department

Catalytic conversion of oxygenated compounds to low molecular weight olefins. Annual report for January 1--December 31, 1978

Description: The conversion of methanol or synthesis gas is an attractive route for producing ethylene and propylene from coal. Utilizing a chabazite ion exchanged with ammonium and rare earth chlorides, methanol is converted to ethylene, propylene, and propane with carbon yields of 70 to 90% at reaction temperatures of 360 to 450/sup 0/C and pressures from 1 to 18 atmospheres. Carbon disulfide in the feed at concentrations less than 2000 ppm increases the operating time between regenerations from four hours to twenty hours. At carbon disulfide concentrations of 3000 ppm or greater, the catalyst goes through three stages. The first is that of a dehydrogenation catalyst that produces carbon monoxide and hydrogen. The second stage produces ethylene and propylene, and finally, the third stage is a dehydration catalyst that produces dimethyl ether. Water has no detrimental effect on the catalyst, and appears to enhance its activity. Increase in pressure increases the production of propylene and propane at the expense of ethylene. X-ray diffraction studies show the formation of an ultrastable zeolite. No permanent deactivation was observed even though the catalyst was overheated once, and had been deactivated and regenerated for as many as 21 times. Ethylene yields increase as the temperature increases from 360 to 450/sup 0/C. When synthesis gas is passed over the catalyst at pressures equal to or less than 500 psi, methane and carbon dioxide are produced.
Date: January 1, 1979
Creator: Anthony, R.G.
Partner: UNT Libraries Government Documents Department

Ion beam mixing of titanium overlayers with hydroxyapaptite substrates

Description: The mixing of titanium overlayers with hydroxyapatite (HA) substrates via ion irradiation has been demonstrated. Analysis via secondary ion mass spectroscopy (SIMS) indicates an interfacial broadening of titanium and calcium of the implanted sample compared to that of the unimplanted sample. Attendant to the observed ion beam mixing of titanium into the HA, the oxygen signal of the titanium overlayer increases as a result of ion irradiation. It is supposed that this change is evident of diffusion through the metal layer and possibly from titania formation at the free surface and perovskite formation at the film/substrate interface. This possibility is consistent with thermodynamic predictions. Additionally, the force required to separate the film from the substrate increased as a result of ion irradiation, validating the continued study of ion beam processing of Ti/HA systems towards the improvement of long term fixation of implant devices.
Date: January 1, 1995
Creator: Levine, T. E.; Nastasi, M.; Alford, T. L.; Suchicital, C.; Russell, S.; Luptak, K. et al.
Partner: UNT Libraries Government Documents Department

Oxidation of phenolics in supercritical water. Combined quarterly technical progress report, December 1, 1995--May 31, 1996

Description: Over the past two quarters, our work has focused on three main areas. The first area of interest involved a reexamination of the rate laws that were formed in past quarters. A possible error was discovered for the analytical methods used in the o-cresol oxidation study and the data were corrected, yielding a new rate equation. The data for hydroxybenzaldehydes were studied again, this time as a system of parallel oxidation and thermolysis reactions. The second area in which progress was made was the study of the thermolysis of nitrophenols and dihydroxybenzenes in supercritical water. These investigations were needed to determine the effect that pyrolysis or hydrolysis had on our previous supercritical water oxidation experiments. Thirdly, we have continued to investigate the use of molecular orbital theory in the determination reactivity indices. A reactivity index, such as the enthalpy of formation, may be used in a structure-reactivity relationship to summarize the kinetics for the oxidation of phenolics in supercritical water. Progress in each of these areas is summarized.
Date: November 1, 1996
Partner: UNT Libraries Government Documents Department

Production of high-energy chemicals using solar energy heat. Project 8999, final report for the period September 1, 1977--May 31, 1978

Description: The first phase of a study to identify candidate processes and products suitable for future exploitation using high-temperature solar energy is presented. This phase has been principally analytical, consisting of techno-economic studies, thermodynamic assessments of chemical reactions and processes, and the determination of market potentials for major chemical commodities that use significant amounts of fossil resources today. The objective was to identify energy-intensive processes that would be suitable for the production of chemicals and fuels using solar energy process heat. Of particular importance was the comparison of relative costs and energy requirements for the selected solar product versus costs for the product derived from conventional processing. The assessment methodology used a systems analytical approach to identify processes and products having the greatest potential for solar energy-thermal processing. This approach was used to establish the basis for work to be carried out in subsequent phases of development. It has been the intent of the program to divide the analysis and process identification into the following three distinct areas: (1) process selection, (2) process evaluation, and (3) ranking of processes. Four conventional processes were selected for assessment namely, methanol synthesis, styrene monomer production, vinyl chloride monomer production, and terephthalic acid production.
Date: December 1, 1978
Creator: Dafler, J.R.; Sinnott, J.; Novil, M.; Yudow, B.D. & Rackoff, M.G.
Partner: UNT Libraries Government Documents Department

Ethanol production by vapor compression distillation

Description: The goal of this project is to develop and demonstrate a one gallon per hour vapor compression distillation unit for fuel ethanol production that can be profitably manufactured and economically operated by individual family units. Vapor compression distillation is already an industrially accepted process and this project's goal is to demonstrate that it can be done economically on a small scale. Theoretically, the process is independent of absolute pressure. It is only necessary that the condenser be at higher pressure than the evaporator. By reducing the entire process to a pressure of approximately 0.1 atmosphere, the evaporation and condensation can occur at near ambient temperature. Even though this approach requires a vacuum pump, and thus will not represent the final cost effective design, it does not require preheaters, high temperature materials, or as much insulation as if it were to operate a near ambient pressure. Therefore, the operation of the ambient temperature unit constitutes the first phase of this project. Presently, the ambient temperature unit is fully assembled and has begun testing. So far it has successfully separated ethanol from a nine to one diluted input solution. However the production rate has been very low.
Date: January 1, 1981
Creator: Ellis, G.S.
Partner: UNT Libraries Government Documents Department

Operational safety report for the cleaning of non-radioactive, sodium-wetted reactor components with ethyl alcohol

Description: The safety aspects of the removal of sodium from nonradioactive reactor components by the alcohol process are described in detail. Pertinent properties of alcohol and hydrogen are presented. Relevant excerpts from the Occupational Safety and Health Act safety codes are presented, and a conceptual system is shown illustrating the application of these safety measures.
Date: January 1, 1974
Creator: Humphrey, L.; Felton, L.; Goodman, L.; Pilicy, G. & Welch, F.
Partner: UNT Libraries Government Documents Department

Design of a high activity and selectivity alcohol catalyst

Description: In order to explore the secondary dehydration of methanol over [gamma]-Al[sub 2]O[sub 3] support and over bimetallic Rh-Mo/[gamma]- Al[sub 2]O[sub 3], a new series of K-doped Rh-Mo/[gamma]-Al[sub 2]O[sub 3] catalysts was synthesized. Work on synthesis of bimetallic Rh-Mo clusters is reported.
Date: June 4, 1992
Creator: Foley, H.C. & Mills, G.A.
Partner: UNT Libraries Government Documents Department

A novel process for methanol synthesis

Description: A bench-scale reactor is being used to study the conversion of synthesis gas to methanol (MEOH) in the liquid phase by a novel method. In previous reports, we provided evidence for a two step reaction consisting of a carbonylation reaction taking place mainly in the film'' close to a copper chromite surface followed by a hydrogenolysis reaction taking place on the surface of the copper chromite. The interaction between the two catalysts enhances the rate of methanol formation. In this quarter, we reexamined the equilibrium concentration for methyl formate and obtained data at higher loadings of copper chromite.
Date: January 1, 1992
Creator: Tierney, J.W. & Wender, I.
Partner: UNT Libraries Government Documents Department

Materials compatibility and lubricants research on CFC-refrigerant substitute: Miscibility of lubricants with refrigerants

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. (Iowa State Univ. of Science and Technology, Ames, IA (United States). Dept. of Mechanical Engineering)
Partner: UNT Libraries Government Documents Department

Distribution of naphthalene between commercial resins and water--methanol solutions

Description: Several XAD resins, two of their chemically modified derivatives, and two carbon absorbents were evaluated by measurement of distribution coefficients using the batch method. Numerical comparison of distribution data and graphical interpretation of these resins were also presented. The distribution differences were explained in terms of resin structure and solvent compositions. Naphthalene was the solute for the study, and methanol the solvent. It was found that Spherocarb, a newly developed carbon adsorbent, had very large distribution coefficient. However, in the application for separation, desorption can conceivably be a problem. Distribution data collected can be a valuable aid in the choice of adsorbent, solvent composition and other operating conditions in separation work.
Date: December 1, 1977
Creator: Chu, F.K.C.
Partner: UNT Libraries Government Documents Department