Physical Sciences and Mathematics Commons^™

The Analysis And Isolation Of Diarrhetic Shellfish Poisoning Toxins, Seán S. Kelly

Theses

This research was initiated to examine the Diarrhetic Shellfish Poisoning (DSP) toxin profiles in mussels (Mytilus edulis) in south-west Ireland. Extensive sampling and testing of shellfish was conducted during the toxic periods of 1991 to 1994. This was the most comprehensive study ever undertaken of toxin profiles in shellfish from a single cultivation area.

A new toxin named dinophysistoxin-2 (DTX-2), which is an isomer of okadaic acid (OA), was the major toxin during prolonged DSP episodes. This toxicity in shellfish occuired soon after high cell counts of Dinophysis acuta were observed. As well as seasonal variability in toxin levels, substantial …

Continuous Electron Stimulated Oxygen Atom Emission From Ag Permeation Membranes, Gilda Ann Newton Miner

Dissertations, Theses, and Masters Projects

No abstract provided.

Characterization Of Nylon-11 Degradation, Leslie Christian Mccullough

Dissertations, Theses, and Masters Projects

No abstract provided.

First Principles Linear Response Calculations Of Lattice Dynamics, Cheng-Zhang Wang

Dissertations, Theses, and Masters Projects

First principles calculations, using the density-functional theory and particularly the local density approximation (LDA), have achieved remarkable success in studying the properties of solid state systems. Although the basic results of these calculations are the electronic structures (eigenvalues, eigenfunctions, etc.) and the total energy of ground state, many other related physical properties can be deduced from them by investigating their response under external perturbations. Using the linear response method with linearized-augmented-plane-wave (LAPW) basis, we have calculated lattice dynamical properties of important semiconductors CuCl, SiC and ferroelectric KNbO{dollar}\sb3.{dollar} CuCl is known to exhibit large anharmonic effects and possibly a complicated multi-well …

The Synthesis, Characterization, And Application Of Ether-Containing Polymides, Catharine Croall Fay

Dissertations, Theses, and Masters Projects

Polyimides are a family of heterocyclic polymers that have received extensive evaluation as adhesives, fibers, films, moldings, composite matrices, insulators, coatings, membranes, and resists. their outstanding thermal stability, excellent mechanical and electrical properties, and chemical resistance make them attractive for many applications.;This research developed ether-containing polyimides for three applications: liquid crystalline polyimides as processing aids, polyimides for microelectronic applications, and polyimides for harsh environments. The approach consisted of three primary activities: (1) developed novel diether dianhydrides for polyimide fabrication, (2) designed, characterized, and evaluated polyimide architectures based on the material application requirements, and (3) provided extensive structure-property relationships utilizing a …

Mechanisms Of Poly(Vinyl Chloride) Pyrolysis In The Presence Of Transition Metals, William Stephen Bryant

Dissertations, Theses, and Masters Projects

No abstract provided.

Blends Of Reactive Diluents With Phenylethynyl-Terminated Arylene Ether Oligomers, Rachel Louise Knudsen

Dissertations, Theses, and Masters Projects

No abstract provided.

Metallization Of Polyimide Films To Enhance Dimensional Stability And To Achieve Reflective And Conductive Surfaces, David Scott Thompson

Dissertations, Theses, and Masters Projects

No abstract provided.

Calculations Of The Interactions Of Energetic Ions With Materials For Protection Of Computer Memory And Biological Systems, Myung-Hee Y. Kim

Dissertations, Theses, and Masters Projects

Theoretical calculations were performed for the propagation and interactions of particles having high atomic numbers and energy through diverse shield materials including polymeric materials and epoxy-bound lunar regolith by using transport codes for laboratory ion beams and the cosmic ray spectrum. Heavy ions fragment and lose energy upon interactions with shielding materials of specified elemental composition, density, and thickness. A fragmenting heavy iron ion produces hundreds of isotopes during nuclear reactions, which are treated in the solution of the transport problem used here. A reduced set of 80 isotopes is sufficient to represent the charge distribution, but a minimum of …

Determination Of Hydroxyl Radical Production Rates In Natural Waters Using The Fluorometric Reagent P-Hydroxyphenylacetic Acid, Jason D. Hosmer

Honors Theses

A means of determining hydroxyl radical production rates in natural waters through the formation of a directly detectable fluorescent product has been developed. A method similar to the enzyme mediated oxidation of phydroxyphenylacetic acid by hydrogen peroxide is used (Miller and Kester, 1988). Due to the high reactivity of hydroxyl radicals, and subsequently low steady state concentrations, direct detection is very difficult. In the past detection was achieved through the introduction of a probe, usually a substituted aromatic or alcohol, that decays away at an observable rate upon reaction with hydroxyl radicals. Detection limits and accuracy of such difference based …

Syntheses Of Cross-Linking Agents, Molecular Modeling Of Oligonucleotides And Polypeptide-Ion Complexes, Michael J. Yunes

Honors Theses

Each section of this thesis will be subdivided into three parts encompassing all of the research in which I have been involved during the past three years. These will be referred to under the headings "Syntheses:' "Molecular Modeling," and "Cross-linking Efficiencies." Each of these subdivisions may have divisions within them when necessary in order to fully detail the research.

The Synthesis And Characterization Of Novel 5,6-Disubstituted 1,10-Phenanthrolines, Liansheng Zeng

Masters Theses

Two new ligands, 5-amino-6-nitro-1,10-phenanthroline (5-NH₂-6-NO₂-phen), produced by amination of 5-NO₂-1,10-phenanthroline, and 5,6-diamino-1,10-phenanthroline (5,6-(NH₂) ₂-phen) ,produced by reduction of 5-NH₂-6-NO₂-phen, have been synthesized and characterized. The ligand 5-NH₂-6-NO₂-phen has been coordinated to a Ru(II) metal center to produce the Ru(II)-polypyridine complex [ (bpy) ₂Ru (5-NH₂-6-NO₂-phen)] (PF₆ ) ₂ (bpy= 2, 2' -bipyridine) . This complex has been characterized by IR, UV-Vis, ¹H-NMR, and cyclic voltammetry (CV) .

The Synthesis And Characterization Of [Ruii (Bpy) 2 (Biphen) ] (Pf6)2 And [ (Bpy) 2ruii (Biphen) Ruii (Bpy) 2] (Pf6)4, Mei-Yueh Chang

Masters Theses

A new bidentate polypyridine bridging ligand (biphen), produced by the condensation of 1,10-phenanthroline-5,6-dione with 5,6-diamino-phenanthroline has been synthesized and characterized. In addition the monometallic complex [(bpy)₂Ru^II(biphen)](PF₆)₂ and the bimetallic complex [(bpy)₂Ru^II(biphen)Ru^II(bpy)₂](PF₆)₄ have been prepared. The complexes were characterized by elemental analysis, by ¹H-NMR spectroscopy and by cyclic voltsmmetry(CV).

The results of these analyses seem to indicate that biphen acts like two independent units when attached to a - Ru^II(bpy)₂ fragment. a bipyridine portion and a phenazine portion. Moreover, …

Novel Compounds (Including Transition-Metal Complexes) Based On 1,10-Phenanthroline-5,6-Dione, Hui Zhou

Masters Theses

This thesis describes the synthesis of the transition metal complex [(bpy) ₂Os^II (pptd)] (PF₆)₂^·2H₂O, an analog of [(bpy) ₂Ru^II (pptd)] (PF₆)₂^·2H₂O. Spectroscopic and electrochemical data on this complex are reported here. It was found that the electronic communication between the metal center and the pteridinedione portion of pptd did not appear to be enhanced in the Os(II) complex relative to its Ru(II) analog. The increased ability of Os(II) to undergo backbonding appeared to affect only the 1,10-phenanthroline portion of pptd.

A useful …

Equilibrium And Kinetic Studies Of Isomerization Of (Oc)5m[Η1-Pph2ch2ch(Pph2)2] And (Oc)5m[Η1-Pph2ch(Pph2)Ch2pph2] (M=Cr, Mo, W), Weiying Lin

Masters Theses

It has been found that (OC)₅M[η¹-PPh₂CH₂CH(PPh₂)₂] and (OC)₅M[η¹-PPh₂CH(PPh₂)CH₂PPh₂] (M=Cr, Mo, W) exist in equilibrium in solution. This linkage isomerization is the first experimental evidence for the exchange of terminal and coordinated phosphorus groups in pentacarbonyl complexes of group 6 metals.

(OC)₅M[η¹-PPh₂CH₂CH(PPh₂)₂] ⇌ (OC)₅M[η¹-PPh₂CH(PPh₂)CH₂PPh₂]

(M = Cr, Mo, W)

In this work, equilibrium …

Isomerization And Chelation Studies Of Dangling Phosphine Complexes Of Group 6, Zhongjiang Jia

Masters Theses

Vinyl addition reactions, catalyzed by 2,2'-azobis(isobutyronitrile) (AIBN), have been used to prepare six pentacarbonyl complexes of group 6, each of which contains a dangling Ph₂PCH₂CH₂P(p-tol)₂ ligand.

Each of the six complexes undergoes slow isomerizationand chelation at 55 °C in perdeuterated toluene:

The reactions were monitored by ³¹P{¹H} NMR spectroscopy. The isomerization reactions are reversible in solution, while the chelated products form irreversibly with the loss of carbon monoxide. The rate constants, K₁ and K_-1, have been determined for the three pairs of linkage isomers. Equilibrium …

The Synthesis Of N-Chlorosulfonyl Β-Lactams And Their Rearrangements, Lihua Zhang

Masters Theses

The synthesis of several N-chlorosulfonyl-β-lactams and their rearrangements have been carried out via CSI (chlorosulfonylisocyanate) reaction. The mechanism of β-lactam synthesis as well as its rearrangements were also studied. The characterization of β-lactams was performed with IR, ¹H and ¹³C NMR, and HRMS. β-lactams 2-chlorosulfonyl-1-methyl-2-azabicyclo[4.2.0]octan-3-one (71), 1-chlorosulfonyl-4-methyl-4- (phenylmethyl)azetidin-2-one (74) and 1-chlorosulfonyl-4,4- (diphenylmethyl)azetidin-2-one (75) were synthesized for the first time. β-lactam 4-chlorosulfonyl-3, 9, 9-trimethyl-4-azatricyclo [6.1.0.0^3,6] nonan-5-one (73) was obtained as crystalline solid instead of liquid.

Different effects, such as temperature, solvents and catalysts, on the rearrangement of the …

The Synthesis Of Benzophenane 3,5-Dicarboxylic Acid For The Double Capping Of Beta-Cyclodextrin, Jaydee Dones Cabral

Dissertations, Theses, and Masters Projects

No abstract provided.

Characterization Of Pr500 For Use In Resin Transfer Molding, Rhonda Michelle Barksdale

Dissertations, Theses, and Masters Projects

No abstract provided.

Mechanisms Of Poly(Vinyl Chloride) Fire Retardance And Smoke Suppression Induced By Copper Additives, Jong Paul Jeng

Dissertations, Theses, and Masters Projects

The purpose of this study was to elucidate the mechanisms of PVC fire retardance and smoke suppression induced by copper additives.;The experimental approaches involved: (1) the use of activated copper (Cu{dollar}\sp0{dollar}) to study PVC model-compound reactions and the crosslinking of PVC and (2) the pyrolysis of PVC model compounds in the presence of several copper additives in order to examine all of the possible chemical reactions involved in the formation of heavy products.;The results obtained from experiments with activated copper and allylic chloride model compounds suggest that the reductive coupling mechanism is a viable process in PVC. The Cu{dollar}\sp0{dollar} that …

Acid Dissociation Of Chloroguaiacols And Ph Dependent Sorption To Estuarine Sediments, Jennifer Lisa Gundersen

Dissertations, Theses, and Masters Projects

Chloroguaiacols are common components of bleached kraft pulp mill effluent known to bioaccumulate in aquatic organisms, and sorb onto particulate material and sediments. Ionization properties of the chloroguaiacols must be known in order to explain their sorptive behavior in aquatic systems. to obtain this information, thermodynamic acid dissociation constants (p&K\sb{lcub}\rm a{rcub})& of guaiacol (o-methoxyphenol) and nine chloroguaiacols have been determined by spectrophotometric methods. These experimental p&K\sb{lcub}\rm a{rcub}& values have been compared with literature values, values predicted by the Hammett equation and predictions by quantum chemical calculations using MOPAC 6.0 with AM1 and MNDO Hamiltonian operators. Experimental and predicted acidities were …

Volatilization Of Contaminants From Wastewater, Shaoyan Wu

Theses

Emission of volatile organic compounds (VOCs) from many industrial wastewater treatment facilities are a major source of air pollution, and getting much attention from EPA. In order to determine "Best Available Control Technology" and "Lowest Achievable Emission Rate" for controlling emissions of VOCs from industrial wastewater, the accurate estimation of VOCs emission rate and realistic modeling of contaminant volatilization are required.

In this research, the volatilization of three compounds (Toluene, Xylene, and Aniline) were studied under varying aeration, stirring, and quiescent scenarios. The concentrations of contaminant were analyzed by HPLC. Experimental rate constants were obtained by using the first order …