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The Effect of Ozonation in Reducing Trihalomethane Formation Potential

Description: Trihalomethanes such as chloroform, dichlorobromomethane, dibromochloromethane, and bromoform are formed when natural water is chlorinated in water treatment. This investigation explores the use of ozone to remove organic precursors from natural water, thus decreasing trihalomethane formation potential. The data suggest a mechanism involving formation of secondary precursors after prolonged contact with ozone, suggesting that trihalomethane precursors may be minimized by using low doses of ozone and short contact time.
Date: May 1981
Creator: Lin, Simon H.
Partner: UNT Libraries

Experimental and Theoretical Study of Electronic Transitions in Phosphorus, Phosphoryl, and Thiophosphoryl Trichlorofluorides

Description: This thesis is an investigation of the vacuum uv spectra of the phosphorus, phosphoryl, and thiophosphoryl trichlorofluorides in the region 1250 to 3000A. Assignments for absorption bands are made utilizing results from photoelectron spectra and ab initio calculations, oscillator strengths for absorption bands, and CNDO/2 molecular orbital calculations. Results from CNDO/2 calculations are compared with theoretical calculations, and experimental data are discussed with regard to the bonding in the compounds.
Date: May 1973
Creator: McAdams, Mary Jane
Partner: UNT Libraries

Synthesis of Ether-free Organomagnesium Compounds

Description: At the time this work was begun, there was some confusion about the technique necessary for the successful synthesis of organomagnesium compounds in hydrocarbon solvents and without solvents. It was decided to repeat the work of Bryce-Smith and Zakharkin. Thus began the study of the synthesis of organomagnesium compounds without solvents; the study of the reaction products of these organomagnesium compounds in hydrocarbons plus 2-butanone compared to the reaction products of the corresponding etheral Grignard reagent plus 2-butanone; and a preliminary study of the nature of these organomagnesium compounds in hydrocarbon solvents.
Date: August 1967
Creator: Hanicak, John E.
Partner: UNT Libraries

Base Effects on the Thermal Decomposition of Sec-butyllithium Solutions

Description: The pyrolysis of sec-butyllithium in solution was studied in an attempt to understand the loss of stereo-specificity and the atypical kinetics that have been reported. Additionally, the effect of added lithium alkoxides was studied to determine their effects on the highly reactive sec-butyllithium substrate.
Date: June 1966
Creator: Adams, George Michael
Partner: UNT Libraries

Organomagnesium Compounds in Benzene Solvent and Their Application in Synthesis of Organoberyllium Compounds

Description: The work reported by D. Bryce-Smith and G. F. Cox, along with several recent publications describing experimental results designed to elucidate the long disputed question of the structure of the Grignard reagent in ether stimulated the work reported here, in an effort to obtain additional evidence of the structure of the organomagnesium complex in benzene solvent. Since the primary objective of this work was to prepare organoberyllium compounds using the organomagnesium complexes in hydrocarbon solvents, it seemed an insight into the structure of these complexes would be beneficial in this work. The techniques used and experimental evidence obtained from the structure elucidation of the ethereal Grignard reagent have been most helpful in organization of the methods used to study the structure of organomagnesium halide complexes in benzene solvent. It seemed that an insight into the structure of these organomagnesium halide complexes in hydrocarbon solvents would be beneficial in accomplishing the second objective of this work. This objective was to prepare organoberyllium compounds using the organomagnesium halide complexes prepared in hydrocarbon solvents.
Date: January 1966
Creator: Selman, Charles M.
Partner: UNT Libraries

The Photolytic Ozonation of Organics in Aqueous Solutions

Description: The aim of the investigation described in this work is to gain a better understanding of the processes involved in the oxidation of organic compounds by photolytic ozonation in a laboratory scale reactor. The results and discussions are presented in Chapter III. This chapter contains four parts. In the first part, mass transfer efficiency and the calculation of the mass transfer coefficient, KLa, as well as the ozone decomposition rate constant, KD, are presented and compared with those obtained by other investigators. The second part deals with the kinetics of the photolysis of 2,2',4,4',6,6'-hexachlorobiphenyl both in purified and natural lake water. Mathematical expressions and a discussion of the possible reaction processes involved are given. Kinetic models of ozonation and photolytic ozonation in purified and natural lake water are developed and discussed in part three. Rate constants are calculated from experimental data and used to predict values of substrate destruction with a mathematical model. The fourth part of this chapter deals with the identification of products from the photolysis, ozonation and photolytic ozonation of 2,2'4,4',6,6'-hexachlorobiphenyl. The products are isolated and identified using combined gas chromatography and mass spectroscopy, and reaction mechanisms are suggested.
Date: May 1980
Creator: Huang, Francis Y.
Partner: UNT Libraries

Kinetics and Mechanism Study of Diphenylketene Cycloadditions

Description: From a review of the published work in the field of cycloadditions, it is evident that further research is needed to establish the mechanism of ketene cycloadditions. This work was initiated with the intent of obtaining kinetic data which will contribute to the elucidation of the mechanism of ketene cycloadditions.
Date: August 1967
Creator: O'Neal, Hubert Ronald
Partner: UNT Libraries

Nuclear Magnetic Resonance Spectra of Some 1,2,4-triazoles

Description: In the work undertaken here, NMR has been used to ascertain the structure of some 1,2,4-triazoles. The investigation provides information concerning the structure of potentially tautomeric triazoles such as hydroxy- and aminotriazole. Connected with this aspect of triazole chemistry is the larger problem of mesohydric tautomerism. The present study also yields information for a comparison of substituent effects in triazoles, N-heteroaromatic substances and benzene.
Date: January 1967
Creator: Creagh, Linda Truitt
Partner: UNT Libraries

Isolation and Identification of an Odor Compound Produced by a Selected Aquatic Actinomycete

Description: The purpose of this study was to develop an efficient method for the concentration of specific volatile taste and odor compounds produced by a selected aquatic actinomycete. A second purpose was to isolate and identify the specific taste and odor compound present in the highest concentration.
Date: August 1968
Creator: Henley, Don E.
Partner: UNT Libraries

An Investigation of Gas Chromatographic Separation of Tastes and Odors Produced by Actinomycetes

Description: It is the purpose of this thesis to evaluate a few selected gas chromatographic materials for the separation of odorants produced by an actinomycete culture under laboratory conditions. Also to compare the results obtained with concentrated solutions of a surface water containing similar odors under natural conditions.
Date: January 1965
Creator: Matlock, James K.
Partner: UNT Libraries

Ketene Reactions: I. The Addition of Acid Chlorides to Dimethylketene ; II. The Cycloaddition of Ketenes to Carbonyl Compounds

Description: Part I describes the addition of several acid chlorides to dimethylketene. The resulting 3-ketoacid chlorides were isolated and characterized. Part II describes the cycloaddition of several aldoketenes to chloral. The ketenes were generated in situ by dehydrohalogenation and dehalogenation of appropriately substituted acyl halides.
Date: December 1970
Creator: Smith, Larry
Partner: UNT Libraries

The Recombination Rate Coefficient of Molecular Helium Ions in a Pulsed Afterglow at 1.86 Torr

Description: The recombination rate coefficient for molecular helium ions has been measured in a pulsed afterglow at 1.86 Torr as a function of electron temperature and electron density without making a priori assumptions about the functional dependence. The concentrations of the molecular ions and electrons were measured and the source terms for the molecular ions were included in the rate equation.
Date: August 1972
Creator: Hicks, Helen Segrave
Partner: UNT Libraries