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Model Of Chlorocarbon (Cfc-12) Chemisorption On Solid Rocket Motor Alumina Exhaust Particles, Gary E. Lund

Theses and Dissertations

Solid Rocket (SRMs) that power Titan IV rockets and Space Shuttles, exhaust large quantities of potentially ozone damaging pollutants directly into the stratosphere, while in powered flight. In the past, studies on potential stratospheric impact of the exhaust products from aluminum/ammonium perchlorate based SRMs have focused on the effect of gaseous HCl from SRMs on the stratosphere. Until recently, the impact of heterogeneous chemistry on stratospheric ozone was believed to be relatively insignificant. This research investigates the potential heterogeneous process of CFC-12 dissociative chemisorption on alumina surfaces and the release of reactive halogen species known to destroy ozone. Through a …

Effects Of Insulin And Insulin Mimetics On Antioxidant Enzyme Levels: In Vivo And In Vitro, Shikha Varma

Masters Theses

Tissue antioxidation status is considered to be an important factor for elucidating the etiology of diabetes and its physiological complications. This study was aimed to determine the in vivo antioxidant enzyme levels in the altered antioxidant status of diabetic rat liver with the treatment of two potent insulin mimetics, vanadium and selenate. The direct effects of vanadate, selenate, and zinc (another insulin mimetic) on the antioxidant enzyme levels in primary rat hepatocytes in culture was also determined. Levels of superoxide dismutase (SOD), catalase (CAT) and gluthahione peroxidase (GPX) were determined in both model systems.

In the vivo model, insulin treatment …

Regulation Of The Expression Of Lipogenic Enzymes By Insulin-Mimetics, Juiyu Wu

Masters Theses

Many researchers have shown that selenate (SeO₄^2-) and vanadate (VO₄^2-) have insulin-mimetic effects in certain biological processes. These mimetic effects include increasing glucose transport, regulating glycolytic enzymes, normalizing plasma glucose levels and activities of insulin regulated enzymes in diabetic rats. To clarify the functions and roles of these insulin-mimetics in different insulin-regulated metabolic pathways, the expression of the genes for glucose-6-phosphate dehydrogenase (G6PDH) and fatty acid synthase (FAS) were investigated. G6PDH is a key enzyme in the pentose phosphate pathway and is also involved in lipogenic metabolism by providing 55-70% of the NADPH utilization …

Study Of The Long-Term Desorption Of Trichloroethylene From Clay Soils Using Infrared Spectroscopy, Mary P. Stager

Theses and Dissertations

Slow desorption of contaminants from soil presents one of the greatest challenges to modeling contaminant fate and transport and implementing effective remediation technologies. The kinetics of long-term desorption of trichloroethylene (TCE) from powdered clay soils were studied to determine the desorption rates and mechanism. Infrared absorption spectroscopy was used to monitor the concentration of TCE desorbed from contaminated flint clay for 71 hours. Observed gas phase TCE concentrations as a function of time were compared to that predicted by a one-site Langmuir desorption mechanism. The Langmuir model, with a single type of bonding site, did not account for the release …

Atmospheric Transport And Diffusion Modeling Of Rocket Exhaust, Chad A. Burel

Theses and Dissertations

Space launches at Vandenberg Air Force Base (VAFB) and the Cape Canaveral Air Station (CCAS) produce exhaust from the solid rocket boosters and liquid hypergolic fuels containing several toxic substances including hydrogen chloride and hydrazine. In order to estimate the health risk that would be imposed upon the public by proposed launches, range safety officials rely on the Rocket Exhaust Effluent Diffusion Model to predict where the exhaust chemicals will go after the launch and how strong the concentrations will be. The original REEDM program averaged the meteorological parameters (wind speed, wind direction, shear, etc.) across the entire mixing level …

Effects Of Ammonium Perchlorate On The Thyroid Hormone Levels Of The Sprague-Dawley Rat, James H. King Jr.

Theses and Dissertations

The purpose of this research was to determine the threshold dose for ammonium perchlorate (AP) in the Sprague-Dawley rat. No dose response data exist for AP and the EPA has studied literature on the subject of perchlorates to determine a provisional reference dose. The Perchiorate Group, a consortium of DoD and industry representatives, believes this provisional reference dose is too conservative. This experiment was executed to provide dose response data on which to base a more accurate reference dose. The study consisted of eight groups of 12 Sprague-Dawley rats, six male and six female, which were exposed to incremental doses …

The Separation Of Aqueous Iron Species Found In Stepwise Complexation By Capillary Electrophoresis With Atomic Absorption Spectroscopy Detection, Robert E. Sutton

Dissertations

A capillary zone electrophoresis system was interfaced to an atomic absorption spectrom eter to permit the separation and detection o f various species of iron found in step wise complexation in aqueous solutions. The samples were introduced at the anodic end of the column employing the electroosmotic flow to drive all the species to the detector at the cathodic end. Aqueous solutions of iron(II) and iron (III) chloride salts were among the compounds studied. The buffer employed w as a 20 millimolar (2-[N-morpholino]ethanesulfonic acid adjusted to a pH of 6 with 6 .6 millimolar potassium hydroxide. The detection limit was …

Synthesis And Characterization Of Silicon Dioxide Thin Films By Plasma Enhances Chemical Vapor Deposition From Diethylsilane And Nitrous Oxide, Lan Chen

Theses

This study is focused on the synthesis and characterization of silicon dioxide thin films deposited on silicon wafers by plasma enhanced chemical vapor deposition(PECVD), using diethylsilane (DES) as a precursor and nitrous oxide (N₂O) as the oxidant. The process parameters, such as temperature, pressure and reactant gas composition have been systematically varied and their effects on the film growth rate and properties were investigated. The growth rate was found to be inversely proportional to the temperature in the examined range of 100-300°C. It increased with increasing N₂O/DES flow rate ratio as the total flow rate increased …

Factors Effecting Calcification Of Bioprosthetic Heart Valves, Sumei Yu

Theses

Calcification is the most frequent cause of clinical dysfunction of glutaraldehyde treated bioprosthetic heart valves. In this study, we compared calcification of bioprostheses of the No-ReactTM and the conventional glutaraldehyde treated pericardium by both in-vivo and in-vitro methods, and to further delineate the role of the host's inflammatory response in implant degeneration.

In the in-vitro study, the two types of pericardial samples were placed in individual polystyrene tubes containing physiological concentrations of calcium and phosphate and incubated for 21 days at 37°C. In the in-vivo study, the two types of pericardial samples were implanted subcutaneously in rats and subsequently retrieved …

Synthesis And Characterization Of Novel Fluorine Containing Alkylsulfonyls And Sulfonates : Fluorinated Sulfonyl Methanes And Derivatives, Nelson R. Holcomb

Dissertations and Theses

A series of salts of the strong fluorocarbon acid bis(trifluoromethylsulfonyl)methane were made: (CF3S02 ) 2CHK, (CF3S02 ) 2CHLi, [ (CF3S02 ) 2CH] 2Ca, [ (CF3S02 ) 2CH] 2Hg, (CF3S02 ) 2CHAg, [ (CF3S02 ) 2CH] 3La. Their reactivity and use as organic intermediates were investigated. The salts were made from their corresponding carbonates, oxides, or hydrides. The reaction times for the salts is generally short, however the purification process was laborious, involving recrystallization from organic solvents and drying under vacuum. The lithium salt is being evaluated as a solid state battery electrolyte. Derivatives of bis(trifluoromethylsulfonyl)methane were made by using the …

Synthesis And Characterization Of A Porphyrin Dyad, Dale A. Braden

Dissertations and Theses

The sun is a bountiful source of energy for our planet. .With the advent of photovoltaic cells, man has begun harnessing the sun's radiant energy, turning it into a form more directly useful: electricity. Commercially available solar cells currently operate at about 13% efficiency, sufficiently high to make them a viable source of electrical energy. It is of great interest, however, to improve their conversion efficiency, and to lower the cost of production so as to make them more economical, and thereby reduce our dependence upon traditional "dirty" sources of energy such as coal and oil. It has been found …

Applications Of A Diode-Laser-Based Detector To On-Line Determinations Involving Methylene Blue, Michelle Ann Spaziani

Honors Theses

The application of an inexpensive diode-laser-based detector for flow injection analysis (FIA), and the on-line determination of sulfide using the "Methylene Blue (MB) Method" is presented. The detector is designed for simultaneous measurements of transmittance and fluorescence. A 670-nm diode laser is the excitation source; photodiodes serve as detector elements. The flow cell is constructed of a piece of square-cross-section quartz capillary tubing. The MB Method employs N, N-dimethyl-p-phenylenediamine (DMPD), iron III, and sodium sulfide reacting to form MB; a triple-line flow-injection manifold is used. Performed previously using conventional UV-Vis instrumentation, optimized conditions included one reagent dissolved in 9 M …

Studies Toward A Chiral, Charge Separated, Water Soluble Cyclophane, Danuta Trzebinska-Yager

Honors Theses

It has been suggested that the key issue in the structure-function correlation in enzyme catalysis is electrostatic stabilization of the ionic transition states. In order to mimic receptors in biological systems we designed a novel hydrophilic macrocycle, 10, with an electrostatic dipole across its hydrophobic cavity. The dipole moment would be established between a positively charged Fe(II)-terpyridyl complex on one end of the macrocycle and the two carboxylate substituents at the opposite end of the receptor. An experimental strategy based on a convergent synthesis is presented.

Fluorescence Studies Of Cyclodextrin Polymers: A Study Of The Binding Of Various Fluorescence Probes To Cyclodextrin Polymers, Karen Ann Colwell

Honors Theses

Cyclodextrins (CDs) are cyclical oligosaccarides which exist as 6, 7, or 8 glucopyranose units joined by α-1,4 linkages, referred to as α, β, and γ CDs, respectively. Their structure resembles that of a truncated cone in which the interior cavity is hydrophobic while the exterior remains hydrophilic. This allows CDs to form inclusion complexes with nonpolar molecules in an aqueous environment. Polymerization of CDs (CDPs) has been carried out using epichlorohydrin which connects the CD cavities by an average of 12-15 repeating glyceryl linker units. The binding of various fluorescence probes to CD monomers has been studied. In particular, pyrene …

Influence Of Salt Bridge Formation On Helix Stability, Angelo Carmine Nicoletta

Honors Theses

One of the most common structural elements in proteins is the a-helix. The main goal of this study was to see If the helical properties of short peptide chains could be increased by the formation of salt bridges between side chains. It has been shown that i,i+4 peptides posses helic; I characier. The research that has been done was to make a hybrid peptide chain, that had partial i,i+4 and partial i,i+3 salt bridge formation. The hybrid peptide was a i+4, i+3, i+4 peptide chain. The overall purpose of making this type of hybrid peptide was to make the approximate …

Transitions In Masculinity And Hemingway's Developed "Code", Daniel Polk

Honors Theses

The "Hemingway Code" is much more than two words that fit nicely together for a scholar's usage; the words signify a much deeper championing of masculinity, almost a haunting presence. For Ernest Hemingway living life every day, every moment with its fullest masculine fervor, became an obsession, a never-ending quest to be at one with the attitude of never complaining, never crying out, panicking, thinking too much, or regretting. To live a manly life in a series of tactical victories, performed with steadfast ritualistic mannerisms, is to embody masculinity, and therefore the "Hemingway Code."

Dna Interstrand Crosslinking Efficiencies, Sequence Preferences, And Organic Syntheses Of Diepoxide Metabolites In Fixation, Sara Charnecki

Honors Theses

Molecular Basis of Cancer: Cancer, a disease that has had a devastating and frightening impact on current society in the midst of a chemical revolution, represents a class of diseases comprising over 200 known types that affect various regions of the mammalian body (Farmer & Walker, 1985). This disease strikes randomly and is often diagnosed after the disease has progressed beyond present treatment capabilities. Cancer is the result of irregularities in growth, reproduction, and differentiation of cells due to pennanent flaws in genetic information. Mutations caused by environmental factors can be compounded over time to cause carcinomas of different tissues. …

Synthesis Of Nitrosyl Metallpoprphyrins, Thomas M. Braxton Jr.

McCabe Thesis Collection

Nitric oxide, NO, is a molecule with great versatility and importance. Made up of only a single atom of nitrogen and a single atom of oxygen, nitric oxide is perhaps one of the smallest paramagnetic molecules found in nature. The functions of NO in the body are not all known, but this molecule definitely plays a variety of roles. It is involved in the regulation of blood pressure, and it sometimes acts as a messenger for cells as well as a killer of them. It also is important in the defense of the body against foreign invaders. The significance of …

Iron-Dithiothreitol Dependent Production Of 8-Hydroxy-2'-Deoxyguanosine In Dna, David Allan Cook

Undergraduate Honors Capstone Projects

Oxidative damage to DNA in a metal-thiol system was studied. Calf thymus DNA was incubated in an iron(IIl)-dithiothreitol system prepared in various buffers. Damage was measured by monitoring the production of 8-hydroxy-2'-deoxyguanosine. DNA oxidation was proportional to the concentration of dithiothreitol (DTT) in HEPES and tris(hydroxymethyl)aminomethane (Tris) buffers while it was only roughly related to DTT concentration in sodium chloride. Incubation in potassium phosphate buffer produced no damage. The results indicate that hydroxyl radicals may be generated by the iron-OTT system in HEPES, Tris, and sodium chloride, while in the phosphate buffer an iron phosphate complex may be formed which …

Structural Effects On Micellar Catalyzed Hydrolysis Of Hydroxamic Acids With Perfluorooctanoic Acid As Surfactant, Xing Zhang

Masters Theses

This thesis demonstrated the structural effects on micellar catalyzed hydrolysis of hydroxamic acids with prefluorooctanoic acid as the reactive counterion surfactant in aqueous acetonitrile solution.

For different hydroxamic acids, the observed pseudo-first order rate constant-surfactant concentration profiles were obtained and were used in the determination of critical micellar concentrations (cmc).

The micellar catalytic effect was satisfactorily explained by the pseudo-phase ion exchange (PPIE) model. The PPIE model was successfully applied in the determination of the reaction rate constants both in the water phase and in micellar pseudo-phase.

Further investigation into more appropriate hydroxamic acids is suggested in order to obtain …

Structural Characterization Of A Novel Inhibitor Of Hiv Reverse Transcriptase (Hiv Rt), Greggory Jon Woitte

Chemistry & Biochemistry Theses & Dissertations

Human immunodeficiency virus (HIV) infections have become a leading cause of death among young people in the United States today. As the number of HIV infections increases, so too does the cost of treatment. Together, these numbers have prompted an increase in the development of pharmaceutical interventions. HIV reverse transcriptase (HIV RT) has become a suitable target for drug therapy because it is the sole enzyme responsible for HIV replication.

Fucoidan, a sulfated polysaccharide isolated from the brown algae Fucus vesiculosus, has been shown to block a variety of cell adhesion related events including metastasis. In addition, fucoidan has also …

Removal Of Chlorinated Hydrocarbons From Water By Air Stripping And Solvent Sublation, Alpana Gami

Theses

Removal of trichloroethylene, monochlorobenzene and 1,3 dichlorobenzene from water by air stripping and solvent sublation into an organic phase was investigated. The sublation solvents used were paraffin oil and decyl alcohol. The rate of removal from water by solvent sublation and air stripping was highest for trichloroethylene, followed by chlorobenzene and finally 1,3 dichlorobenzene. For the three compounds, solvent sublation had the greatest advantage over air stripping in the reduction of emission of the compounds to the atmosphere. For the three compounds, the removal was enhanced at higher flowrate in both air stripping and solvent sublation. For the removal of …

Electrochemical, Chromatographic, And Spectrometric Studies Of An Osmium Containing Polymer, Lawrence John Rhodes

Master's Theses

No abstract provided.

Studies On The Cyclization Of Cis-1,4-Dichloro-2-Butene With Sodium Dialkylmalonates, Hovis M. E. Imade

Master's Theses

No abstract provided.

Electrochemical Studies Of Hemoglobin And Cross-Linked Hemoglobin, Ayoola O. Alabi

Master's Theses

No abstract provided.

Synthesis Of Model Tripeptides And Approaches To The Preparation Of A Transition State Analogue Of Phosphoramidon, Nadina Monberg

Master's Theses

No abstract provided.

Effect Of Electrolyte Concentration, Temperature And Clay Type On The Diffusional Properties Of Anions In Clay-Modified Electrodes, Jennifer A. Stein

Dissertations

No abstract provided.

X-Ray Crystallographic Studies On Cross-Linked Hemoglobins, Elias J. Fernandez

Dissertations

No abstract provided.

Phosphorus Bearing Substrates In Ring Expansion Reactions, Bradley K. Norwood

Theses and Dissertations

A variety of substituted phosphonium salts, phosphorus ylides and phosphonates were studied to assess their utility in ring expansion reactions. The strategy involved formation of fused ring systems whose ring strain could be exploited to accomplish ring expansion to medium sized rings. β-Alkoxy vinylphosphonium salts were found to be unreactive with species such as the dimethylsulfoxonium methylide anion, Simmons-Smith type reagents. and carbenes in attempts to produce cyclopropyl phosphonium salts.

C-Alkylation of β-keto phosphorus ylides using haloalkanes bearing terminal groups that could be converted and reacted with the B-carbonyl, was also examined as a method for accessing strained rings bearing …

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 …