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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 %) … more
Date: March 1, 1997
Creator: Cooney, M. J.; Britt, P. F. & Buchanan, A. C., III
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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… more
Date: February 1, 1997
Creator: Braun, B.; Blanch, W. & Prausnitz, J.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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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… more
Date: October 4, 1999
Creator: KLOTZ,P.J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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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 concentr… more
Date: October 4, 1999
Creator: Klotz, P. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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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.… more
Date: January 1, 1982
Creator: Mason, C.F.V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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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 diffusi… more
Date: January 1, 1995
Creator: Levine, T. E.; Nastasi, M.; Alford, T. L.; Suchicital, C.; Russell, S.; Luptak, K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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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 solvent… more
Date: January 1, 1992
Creator: Augustine, Robert L. & Doyle, Lisa K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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(Production and environmental impacts of alternative motor fuels)

Description: The traveler participated in the 13th meeting of the Executive Committee on Alternative Motor Fuels (International Energy Agency). Participating countries in addition to the US are Canada, Italy, Finland, Japan, Sweden, and New Zealand (absent). The status of five existing annexes was reviewed and a pre-proposal for an additional annex to be a review of environmental impacts of fuels was presented by the traveler. This was well received by committee members, and a detailed proposal for such wor… more
Date: December 4, 1990
Creator: McGill, R.N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Direct Methane Conversion to Methanol

Description: Objective is to demonstrate the effectiveness of a catalytic membrane reactor (ceramic membrane combined with catalyst) to selectively produce methanol by partial oxidation of methane. None of the membranes tested in a high pressure system could selectively remove methanol, until a cooling tube was inserted inside the membrane reactor to quench the product stream; this effectively increased methanol selectivity 2[times] during methane oxidation. For both conditions, combined selectivity for met… more
Date: December 3, 1992
Creator: Falconer, J. L. & Noble, R. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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 wa… more
Date: November 1, 1996
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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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 hour… more
Date: January 1979
Creator: Anthony, Rayford G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Photoconductivity of activated carbon fibers

Description: The photoconductivity is measured on a high-surface-area disordered carbon material, namely activated carbon fibers, to investigate their electronic properties. Measurements of decay time, recombination kinetics and temperature dependence of the photoconductivity generally reflect the electronic properties of a material. The material studied in this paper is a highly disordered carbon derived from a phenolic precursor, having a huge specific surface area of 1000--2000m{sup 2}/g. Our preliminary… more
Date: August 1, 1990
Creator: Kuriyama, K. & Dresselhaus, M.S. (Massachusetts Inst. of Tech., Cambridge, MA (USA))
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Novel reactor configuration for synthesis gas conversion to alcohols

Description: Research continued on the conversion of synthesis gas to alcohols and reactor configuration. Our objective during this quarter was to complete Task IIIB, development of the algorithms for the dynamic response technique for parameter estimation; start Task IIIC, establishment of methodology for determination of the parameters of the trickle bed reactor in the microreactor assembly; and continue with Task IV, determination of the kinetics of the reaction in the slurry reactor. 3 figs.
Date: January 1, 1990
Creator: Akgerman, A. & Anthony, R. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Hydrodynamic instability induced liquid--solid contacts in film boiling. [Saturated ethanol and water]

Description: The film boiling liquid-solid contacts of saturated ethanol and water to horizontal flat gold plated copper are examined by using electric conductance probe. It is observed that the liquid-solid contacts occur over a wide temperature range, and generally, induced by hydrodynamic instabilities. The area of contact decreases exponentially with interface temperature and is liquid depth dependent. The averaged duration of contacts is strongly influenced by the dominant nucleation process, and thus,… more
Date: January 1, 1976
Creator: Yao, S. & Henry, R. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Casting warpage study

Description: Because of a need to reduce warpage in investment castings, and because of reported success in the use of aqueous polyalkylene glycol solutions for reducing warpage in heat-treated sheet-metal parts, particularly for aluminum alloys, an experiment was designed to include these solutions along with polyethylene glycol solutions in a study of quenching parameters. At the time of the study, the cost of polyethylene glycol was approximately one-third that of polyalkylene glycol. A total of 1032 cas… more
Date: August 1, 1976
Creator: Patterson, E. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Physical properties of gasoline/alcohol automotive fuels

Description: Non-petroleum derived alcohols are likely candidates for near-future use as alternative automotive fuels. Low molecular weight alcohols may be used alone or in combination with gasoline, but either usage presents its own unique set of advantages and disadvantages. This report addresses the physical property changes (both beneficial and detrimental) which occur when alcohols are added to gasoline as fuel extenders. The experimental data and discussion of results cover four physical property area… more
Date: January 1, 1979
Creator: Cox, F W
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ab initio calculations on hydrogen bonding in alcohols: dimers of CH/sub 3/OH, CH/sub 3/CH/sub 2/OH, and CF/sub 3/CH/sub 2/OH

Description: Ab initio calculations on a series of alcohol dimers including (CH/sub 3/OH)/sub 2/, (CH/sub 3/CH/sub 2/OH)/sub 2/, and (CF/sub 3/CH/sub 2/OH)/sub 2/ have been carried out to compare the effects of various substituents on the hydrogen bond energies and structures and to correlate the results with the wealth of new experimental data on them. Calculations were done with the minimal STO-3G basis set. The methanol and ethanol dimers both have nearly linear hydrogen bonds. The ethanol dimer is also … more
Date: January 1, 1977
Creator: Curtiss, L. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Comparative efficiency of acetone and methanol for purifying raw synthesized 2,2', 4,4', 6,6' hexanitrostilbene. Period covered: April--June 1976

Description: The purpose of this effort was to determine the washing efficiency of methanol as compared to acetone when used for purification of raw synthesized 2,2', 4,4', 6,6' hexanitrostilbene (HNS I). This study revealed that methanol is slightly inferior to acetone when used for this purpose.
Date: January 1, 1976
Creator: Stull, T. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Separation of glycols from dilute aqueous solutions via complexation with boronic acids

Description: This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylb… more
Date: July 1, 1991
Creator: Randel, L. A. & King, C. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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