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CONTAMINATION OF GROUNDWATER BY ORGANIC POLLUTANTS LEACHED FROM IN-SITU SPENT SHALE

Description: The potential for contamination of groundwater by organic pollutants leached from in-situ spent shale was studied in a series of laboratory leaching experiments. Both batch-mode and continuous-flow column experiments were conducted to study the leaching phenomenon. Experimental variables included retorting characteristics of spent shale, leaching time, initial quality of leach water, temperature of leach water, and particle size of spent shale. Several unique samples of spent shale were examined during the eaching experiments, including spent shale samples produced during combustion retorting, inert gas retorting, and combustion retorting employing recycle gas. The solid-phase organic carbon content of spent shale samples ranged from 0.2 to 3.9 percent by weight. Leachate derived from the batch-mode experiments was analyzed for organic carbon, organic nitrogen, phenols, and acid/base/netral fractions. The highest levels of organic carbon were detected in leachate derived from spent shale produced during either inert gas retorting or combstion retorting using recycle gas. The highest levels of phenols were observed in leachate obtained from spent shale produced during inert gas retorting; significant levels of organic nitrogen were also detected in various leachate samples. The most predominant organic fraction measured in leachate samples was the neutral fraction associated with spent shale produced during inert gas retorting. Batch-mode experimental results describing equilibrium conditions were analyzed according to the Freundlich and langmuir isotherm models. Those models were found to be appropriate for describing equilibrium relationships between leachate and spent shale produced during inert gas retorting. To a somewhat lesser extent, these same models were found to be appropriate for modeling equilibrium relationships involving combustion-retorted spent shale. A kinetic analysis of results derived from the continuous-flow column experiments was conducted in an attempt to identify a rate-controlling mass transfer mechanism. Internal diffusion appeared to be the most likely rate-limiting mechanism for leaching from combustion-retorted spent shale. In ...
Date: June 1, 1978
Creator: Amy, Gary L.
Partner: UNT Libraries Government Documents Department

Analysis and Development of FACE Automatic Apparatus for Rapid Identification of Transuranium Isotopes

Description: A description of and operating manual for the FACE Automatic Apparatus has been written along with a documentation of the FACE machine operating program, to provide a user manual for the FACE Automatic Apparatus. In addition, FACE machine performance was investigated to improve transuranium throughput. Analysis of the causes of transuranium isotope loss was undertaken both chemical and radioactive. To lower radioactive loss, the dynamics of the most time consuming step of the FACE machine, the chromatographic column output droplet drying and flaming, in preparation of sample for alpha spectroscopy and counting, was investigated. A series of droplets were dried in an experimental apparatus demonstrating that droplets could be dried significantly faster through more intensie heating, enabling the FACE machine cycle to be shortened by 30-60 seconds. Proposals incorporating these ideas were provided for FACE machine development. The 66% chemical loss of product was analyzed and changes were proposed to reduce the radioisotopes product loss. An analysis of the chromatographic column was also provided. All operating steps in the FACE machine are described and analyzed to provide a complete guide, along with the proposals for machine improvement.
Date: September 1, 1978
Creator: Sebesta, E.H.
Partner: UNT Libraries Government Documents Department

ELECTROCHEMICAL MACHINING OF CARBIDES AND BORIDES

Description: The use of high rate anodic dissolution (electrochemical machining) for shaping titanium carbide, zirconium carbide, titanium boride and zirconium boride has been investigated in 2N potassium nitrate and 3N sodium chloride under current densities ranging from 20 to 120 A/cm{sup 2} (corresponding to cutting rates of 0.3 to 1.8 mm/min). The dissolution stoichiometry for all these materials is independent of the current density in the range 20 to 120 A/cm{sup 2}. Both titanium and zirconium appear to dissolve in the +4 state, boron in the +3 state and the weight loss measurements indicate that carbon is oxidized to CO and CO{sub 2}. The current voltage curves permit to establish that, over the entire current density and flow range investigated, dissolution occurs in the transpassive state. The surface roughness obtained on TiC and ZrC is within 3-5 {micro}m and is independent of current density, applied voltage or flow rate.
Date: July 1, 1978
Creator: Dissaux, Bernard Antoine; Muller, Rolf H. & Tobias, Charles W.
Partner: UNT Libraries Government Documents Department

REDUCTION OF NITRIC OXIDE BY CARBON MONOXIDE OVER A SILICA SUPPORTED PLATINUM CATALYST: INFRARED AND KINETIC STUDIES

Description: The reduction of nitric oxide by carbon monoxide over a 4.5 weight precent platinum catalyst supported on silica was studied at 300 C. Reaction rate data was obtained together with in situ infrared spectra of species on the catalyst surface. The kinetics of the system were found to exhibit two distinct trends, depending on the molar ratio of CO/NO in the reactor. For net reducing conditions (CO/NO> 1) the catalyst underwent a transient deactivation, the extent of which was dependent on the specific CO/NO ratio during reaction. Reactivation of the catalyst was obtained with both oxidizing and reducing pretreatments. For molar feed ratios of CO/NO less than one, carbon monoxide conversion was typically 95 to 100%, resulting in strongly oxidizing conditions over the catalyst. Under these conditions no deactivation was apparent. Infrared spectra recorded under reaction conditions revealed intense bands at 2075 and 2300 cm{sup -1} , which were identified as carbon monoxide adsorbed on Pt and Si-NCO, respectively. Isocyanate bands formed under reducing conditions were more intense and exhibited greater stability than those formed under oxidizing conditions. A reaction mechanism based on the dissociation of nitric oxide as the rate-limiting step was used to correlate nitric oxide reaction rates and nitrous oxide selectivities observed under reducing conditions. As part of this mechanism it is assumed that nitrous bxide is formed via a Langmuir-Hinshelwood process in which an adsorbed nitrogen atom reacts with an adsorbed nitric oxide molecule. The nitric oxide reaction rate was found to be first order in nitric oxide partial pressure, and inverse second order in carbon monoxide partial pressure. A mechanism is proposed to qualitatively explain the deactivation process observed under reducing conditions. The essential part of this mechanism is the formation of an isocyanate species on the Pt crystallites of the catalyst and the subsequent ...
Date: August 1, 1978
Creator: Lorimer, D.H.
Partner: UNT Libraries Government Documents Department

SUPERCONDUCTING TRANSITION EDGE BOLOMETER AND NOISE IN THIN FILMS

Description: We report the development of the composite superconducting transition edge bolometer. The temperature sensitive element is an aluminum strip evaporated onto the sapphire substrate. A bismuth film evaporated on the reverse side of the substrate is used to absorb the submillimeter radiation. The noise limitation of the bolometer is calculated. The fabrication and measured performance are described. The best electrical NEP (noise-equivalent-power) obtained is (1.7 {+-} 0.1) x 10{sup -15} WHz{sup -1/2} at 2 Hz at an operating temperature of 1.27 K. This NEP is within a factor of 2 of the thermal noise limit. The effective absorptivity of the bismuth film is measured to be 0.47 {+-} 0.05, and the corresponding detectivity D* is calculated to be (1.1 {+-} 0.1) x 10{sup 14} cm w{sup -1}Hz{sup 1/2}. Suggestions are made for further improvements in sensitivity. The current-dependent noise in thin metal films at the superconducting transition has been further investigated. The measured noise power spectrum of the tin film on sapphire substrate at the superconducting transition is compared with the cosine transforms of the decay curves obtained from step-function and {delta}-function thermal perturbations. The nature of the noise driving term is found to be a random current flowing inside the sample, in agreement with the uncorrelated thermal fluctuation model. This result is consistent with the case of a freely suspended tin fiber at the superconducting transition, but in contrast to the room temperature measurement where the cosine transform of the step-function response gives the noise power spectrum, in agreement with the correlated fluctuation model.
Date: June 1, 1978
Creator: Yeh, Nan-Hsiung
Partner: UNT Libraries Government Documents Department

The development and testing of an instrument to evaluate aesthetic judgments

Description: This study was concerned with the development and testing of an instrument to measure levels of aesthetic judgement making. The review of evaluation methods for aesthetic judgement resulted in a two-part instrument. Part one required the subject to select the better of two art works and to state the reasons for the choice. Part two, a self-scoring component, consisted of the Wilson categories presented as typical statements containing the primary criterion for the category. The subject was instructed to select the statements that were closest in meaning to his initial response.
Date: December 1978
Creator: Brumbach, Mary Alice
Partner: UNT Libraries

Clayton, Nancy Jean

Description: The purpose of this thesis was to make available for performance and study an edition of the twenty-two secular songs published in this collection by Johann Jacob Löwe and Julius Johann Weiland in 1657.
Date: May 1978
Creator: Löwe von Eisenach, Johann Jakob
Partner: UNT Libraries

The overtures of Samuel Wesley

Description: Born into one of the most distinguished families in eighteenth-century England, Samuel Wesley (176-1837) distinguished himself as a child prodigy, an ardent devotee of the music of J. S. Bach, and as a composer, performer and music lecturer. His four extant overtures, written from the year 1778 to 1824, offer an insight into his development as a composer. This edition, drawn from the Wesley manuscripts housed in the British Library, is preceded by a commentary dealing with Wesley's life, the history of the overture as an independent for, and with Wesley's place in the history of English instrumental music.
Date: May 1978
Creator: Walker, Jeremy
Partner: UNT Libraries

Cast-iron facades in Texas

Description: In this limited survey, nineteenth-century cast-iron facades in Texas were recorded and compared to iron-fronted buildings in New York City. It was found that generally, the still existing buildings in Texas cities and towns were similar to those in New York in style but differed to the extent to which the cast-iron elements were used. It appears that nineteenth-century builders in Texas knew of New York trends in cast-iron but had definite regional preferences.
Date: December 1978
Creator: Giritz, Cheryl A.
Partner: UNT Libraries

Seven string instrument treatises of Michel Corrette: translation with commentary

Description: This study is concerned with Michael Corrette (1709-1795) and his contribution to music pedagogy through seven of his extant string instrument treatises. Besides the translations from French into English, the dissertation includes an extensive commentary corroborating his information with ideas of other noteworthy, predominantly-French string writers of the period.
Date: August 1978
Creator: Farrar, Carol Reglin
Partner: UNT Libraries

A word processing curriculum model for post-secondary educational institutions

Description: The subject of this study is a curricular model in word processing for post-secondary programs of business education. The study had the following purposes: to survey the present emphasis upon word processing in programs of business education; to survey the current use of word processing in business; to identify the characteristic form of word processing systems; to survey the need for qualified personnel for employment in word processing; to evaluate current educational practices in educating individuals for positions in word processing; and to utilize findings from both business and education to construct a curricular model for post-secondary educational institutions.
Date: December 1978
Creator: Gillard, Sharlett Kay Wolfe
Partner: UNT Libraries

Gregory the Great: Exegesis and Audience

Description: The aim of this research was to trace the stages in Gregory's career, and the writings he produced during each of them, in order to examine his interest in biblical interpretation, and to link the form and content of his exegesis with the audiences which he was attempting to reach. Gregory's Old Testament homilies, the "Homilies on the Gospels," the "Pastoral Rule" and the "Dialogues" differ considerably one from another in literary form, in content, and in purpose. There were marked changes in Gregory's life from his first commitment to asceticism in the mid 570's, to his death as bishop of Rome in 604. Attention would be given concentrated on his explicitly exegetical writings: the Pastoral Rule and the Dialogues will be considered with the limited aim of assessing their relationship to his exegesis, in the Introduction, the main developments in Western biblical studies in the two centuries before Gregory will be sketched in broad outline, in order to establish a terminology for exegetical literary forms, and to draw attention to the forms which Gregory chose to adopt.
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Date: 1978
Creator: McClure, Judith
Partner: UNT Libraries