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The Development And Applications Of A Capacitively Coupled Microwave Induced Plasma Evolved Gas Analysis Instrument, Stephan Michael Koza

Doctoral Dissertations

The scope of this dissertation covers the development and subsequent utilization of an Evolved Gas Analysis (EGA) instrument using atomic emission from a microwave induced plasma source (MIP) as a detector. The majority of the effort during the course of the project was directed toward the design of a new plasma source that has a capacitively-coupled resonance cavity and a sheathed torch, and resolving a number of technical and scientific problems. This discourse also includes an account of the devices developed for use with the instrumentation.

Three applications are demonstrated. The detection, quantitation, and speciation of 10$\sp{-4}$ to 10$\sp{-6}$ gram …

Fundamental Studies Of Grafting Reactions In Free Radical Copolymerization, Nai-Jen Huang

Doctoral Dissertations

A new method of measuring the efficiencies of free radical grafting reactions is presented. This technique utilized the compositional analysis capability of dual detector (UV and RI) gel permeation chromatography in which the mixture of polymer resulting from the graft copolymerization reaction is also subjected to separation by molecular size. Samples of the reaction mass drawn from a reactor are diluted with GPC carrier solvent and injected directly into the chromatograph without any other preparative step. Grafting efficiency, graft ratio, molecular weight distributions, and the frequency of graft chains along the backbone polymer are simultaneously determined. This simple technique overcomes …

Characterization Of Radical Formation And Iron Oxidation/Hydrolysis During Iron Deposition In Ferritin, Yu Chen Barrett

Doctoral Dissertations

The functional roles of ferritin H and L subunits in ferrous iron oxidation and ferric iron hydrolytic polymerization were studied by combination of electrode oximetry and pH stat utilizing horse spleen and recombinant human H and L ferritins. Previous work has investigated ferrous ion oxidation kinetics, but no information on ferric core formation and its relationship to ferrous ion oxidation had been obtained. The kinetic pattern of iron oxidation/hydrolysis in H-chain homopolymer ferritin showed that the rate of iron hydrolysis is regulated by the rate of iron oxidation, and that both follow the iron ferroxidation pathway. In the early stage …

Studies On Heterocyclic Compounds: Synthesis And Reactivity Of 2,4-Disubstituted Bisthiazolones, Yuhui Lin

Doctoral Dissertations

A series of 4, 4$\sp\prime$-bisthiazolones have been synthesized. The study of the reactivities of these compounds was carried out in order to explore their use as possible precursors of dehydrodimeric amino acids, an almost unknown class of amino acids which might be the building blocks of cross-linked peptides. The synthesis of thiazolone monomers was achieved in several steps by using natural amino acids or their esters as starting materials. A new and efficient method has been developed to dehydrodimerize these monomers into bisthiazolones in high yield (more than 90% in many cases).

Theoretically, dimerization of thiazolones into the corresponding dimers …

Physical Studies Of Limulus Coagulogen, The Coagulin Gel And Coagulin Gel Formation, Thomas Paul Moody

Doctoral Dissertations

The blood of the horseshoe crab Limulus polyphemus gels upon contact with gram negative bacterial endotoxin. Such contact induces the discrete proteolytic cleavage of a single protein, coagulogen. The product, coagulin, then assembles into a highly turbid gel. An investigation of the gelation and the physical properties of coagulogen and coagulin is described here. Except where noted, polymerization was induced by limited trypsinolysis of coagulogen.

Analytical centrifugation demonstrates that coagulogen only weakly self-associates. Fluorescence quenching indicates that the single tryptophan of coagulogen lies near the surface of the protein. The effective charge of coagulogen at pH 8, measured by equilibrium …

Polymer Substrates For Use In Fiber Optic Sensors: Suspension Polymerization Of Kraton G1652 Modified Poly(Vinylbenzyl Chloride), Vicki Lynn Conway

Doctoral Dissertations

The polymerization of Kraton G1652 modified poly(vinylbenzyl chloride) in the presence of xylene and dodecane is complex. Scanning electron micrographs and porosimetry data suggest that as polymerization proceeds, the forming poly(vinylbenzyl chloride) and the porogenic solvent separate into distinct aromatic and aliphatic phases, respectively. The Kraton G1652 acts as a surfactant between the dodecane and the forming polymer swollen in monomer, and is directly involved in stabilizing the interface. Increasing the Kraton G1652 increases the surfactant content of the monomer mixture which decreases the surface tension between the forming polymer and the dodecane during polymerization, resulting in a morphology consisting …

Photoacoustic Spectroscopy And Heavy-Atom Overtone Transitions In The Near Infrared, Xiaoke Yang

Doctoral Dissertations

This thesis presents vibrational overtone studies on N$\sb2$O, $\rm\sp{12}CO\sb2,$ OCS, and $\rm\sp{13}CO\sb2$ in the energy range from 10000 cm$\sp{-1}$ to 14000 cm$\sp{-1}$ by means of photoacoustic spectroscopy. Many new overtone and combination transitions have been discovered and some of the band intensities have been measured for the carbon dioxide molecule. The observed values of the transition positions and relative intensities are in good agreement with the theoretical calculations that were also performed. In addition, improvements on the experimental apparatus have been made during the investigations on these heavy-atom systems.

The text of this thesis is composed of seven chapters. The …