Master of Science

The purpose of this project is to create a comprehensive sport marketing plan for the HBCU Basketball Tournament at Virginia State University. / Master of Science

No description available.

It is observed for the first time that telechelic ionomers based on sulfonated polyisobutylene exhibit primary and secondary SAXS peaks when the molecular weight distribution is narrow (Mw/Mn ca. 1.15). These SAXS peaks are interpreted as due to non-global lamellar or cylindrical ionic domain order. The non-global ordering strongly affects the tensile and dynamic mechanical properties of the ionomer. This effect is attributed to local ionic phase continuity and the concept of restriction of chain motion by the ionic domain. Triblock copolymer ionomers from t-butyl methacrylate (tBMA) end blocks and polybutadiene or tapered poly(styrenelbutadienel styrene) (tSBS) mid blocks exhibit complex SAXS patterns indicating dispersed spheroidal ionic end block domains in the matrix. TEM shows that ionization of the 9 mol % PtBMA-PBD triblock produces a morphological transformation from unoriented rodlike domains to ionic spheroids. / Ph. D.

Bisphenol A polycarbonate is an engineering thermosplastic which can be utilized for a variety of applications. Modifications to improve upon the properties of this useful material have been attempted since its invention. Three modifications of bisphenol A polycarbonate and its copolymers have been examined in this work. The hydrolytic stability of copolymers of polydimethylsiloxane and polycarbonate was improved by the synthesis of pre-formed phenol functional polydimethylsiloxane oligomers in which the Si is attached directly to the aromatic ring of the hydroxyaryl functional component. <i>In situ</i> random block copolymers of polydimethylsiloxane and polycarbonate were synthesized by interfacial polymerization techniques. The Si-aryl bonds of the novel polydimethylsiloxane oligomers were found to impart good thermal and hydrolytiC stability to the random block copolymers. Terminally reactive polycarbonate oligomers were also synthesized in order to form polycarbonate network materials. 4-Acetoxystyrene was utilized as a stable precursor to 4-vinylphenol which could then be used to quantitatvely control the molecular weight and functionality of the polycarbonate chains. The reactive oligomers were found to undergo a thermal cure above the respective glass transition temperatures to form insoluble networks. These network materials were found to have superior solvent resistance as compared to the linear material while retaining much of the useful mechanical properties (high fracture toughness, etc.) of bisphenol A polycarbonate. Furthermore, the glass transition temperatures of the networks were found to increase with a decrease in the molecular weight between crosslinks. The fire resistance properties of polycarbonate were modified by the copolymerization of bisphenol A with phenol derivatives of triphenylphosphine oxide. The effect of changes in the composition were determined by differential scanning calorimetry and thermogravimetric analysis. The glass transition temperature, as well as the residual char yield at elevated temperatures was found to increase with an increase in the phosphorus monomer content as measured by the two respective methods. Cone calorimetry was also performed on the samples to determine the heat release rate, which reflected an increase in the fire resistance properties with an increase in the phosphorus content. / Ph. D.

Wetland acreage in Southwest Virginia has increased because of formation of wetlands on relic surface mine benches. Prior to the Surface Mining Control and Reclamation Act of 1977 (PL 95-87) once mining operations were completed the sites were abandoned. These areas presented novel landscapes in the rugged Allegheny Plateau physiographic region. Specifically, flat, compacted areas were created. In microdepression of these sites wetlands have formed. This study investigates the macroinvertebrate community associated wetlands of relic surface mining operations. Surveys were conducted to identify what macroinvertebrates utilize these wetlands, to determine how this community was influenced by the physio-chemical characteristics of surface mine wetlands, and to develop design specifications for creating wetlands for current restoration efforts. Nine wetlands were sampled four times between July 1993 and May 1994. Seventy genera of macroinvertebrates were identified. The wetlands represented a range of physical and chemical parameters. The taxa richness appears to be related to these differences. Canonical Correspondence Analysis suggests that for the nine wetlands, the macro invertebrate taxa distribution is best explained by physical features of depth and duration of flooding, chemical parameters of iron, manganese, and sulfate concentration, and a biotic measure of plant litter biomass. The findings of this study can be applied to ecological restoration. Wetland creation can be incorporated into current surface mine reclamation projects. To maximize the macro invertebrate community of reclamation wetlands, sites must be positioned to avoid water quality problems, excavated to have a deeper portion which will remain inundated during all or most of the year, and have a gradually sloping substrate from the deepest area to the land surface. The final criteria being indirectly related to the macroinvertebrate community by influencing the macrophyte production, richness, and litter. / Master of Science

The addition of the lithium dienolate of ethyl crotonate to 2-cyclopentenone was studied to determine the stereochemical outcome of this Michael addition. Proof of the stereochemistry was provided via the unambiguous synthesis and comparison of ketone 73 from norcamphor 85. / Master of Science

The western yew, Taxus brevifolia, was for many years the source of the important anticancer drug taxol, but it also contains many other natural taxoids. These compounds are of interest both from a structural viewpoint and also as a starting point for the synthesis of paclitaxel analogs. As a complement to our ongoing studies on the chemistry of paclitaxel and on its structure-reactivity relationships, we have investigated T. brevifolia extracts and have isolated two new taxoids. These are the A-nortaxol analog 7,13-deacetyl-9,10-debenzoyltaxchinin C 2.1 and 9-deacetyl-9-benzoyl-10-debenzoylbrevifoliol 2.4. The structures were elucidated by spectral methods, including extensive 2D nmr techniques. An approach to the synthesis of a novel A-nortaxol analog from one of the new compounds has been developed. / Master of Science

The release rates of two Pacific Biocontrol codling moth, one AgriSense grape berry moth and two Pacific Biocontrol grape berry moth dispensers were studied using gravimetric measurements. It was found that the addition of titanium dioxide to the polyethylene mixture significantly reduced the release rate of the dispenser when compared with a transparent design. The AgriSense dispenser's release rate could not be determined gravimetrically, possibly due to water absorption. The Pacific Biocontrollong life grape berry moth dispenser was more effective than the normal type. The effect of other species' sex pheromone blends and generic blends upon the mating behavior of Platynota flavedana Clemens, Platynota idaeusalis (Walker), Argyrotaenia velutinana (Walker) and Choristoneura rosaceana (Harris) was studied using small plots. It was determined that the sex pheromone blend for P. flavedanamay control populations of P. idaeusalis and that the two generic blends developed may control P. flavedana, P. idaeusalis and A. velutinana. The impact of a low spray mating disruption program upon the ground dwelling arthropods was investigated. It was determined that a low spray mating disruption program may be more compatible with populations of natural enemies. More taxa, species and individuals were present because of the absence of damaging prays. Orchard management of ground cover also seemed to play an important role in determining taxa and species present in orchards. / Master of Science

The surface presentations of CD18 and β-integrin-like neutrophil antigens were evaluated in six clinically normal horses twice at seven to 30 day intervals. The monoclonal antibodies (MAb) 60.3 and #38 recognize portions of CD18, the β₂-subunit of heterodimeric integrins LFA-1 (i.e. CD11a/CD18), Mac-1 (i.e. CD11b/CD18) and p150,95 (i.e. CD11c/CD18). Monoclonal antibody #25 putatively recognizes a β-integrin-like surface antigen. Neutrophils were isolated from whole blood and incubated with either Hanks’ balanced salt solution or lipopolysaccharide (LPS, No. L7261 from Salmonella typhimurium) and then with one of three primary MAbs (60.3, #38 or #25). Cells were then incubated with the secondary MAb [fluorescein isothiocyanate (FITC)-conjugated affinipure F(ab')₂ fragment-goat antimouse (GAM) IgG], which acted as a label for fluorescence activated cell sorting. Cell viability measurements were performed pre- and post-incubation; and cell type was confirmed. Results indicate that unstimulated equine neutrophils expressed CD18 cell surface adhesion molecules almost constitutively (p < 0.05) using MAbs 60.3 and #38. Unstimulated cells incubated with MAb #25 had a labeling percentage of 87.67%, indicating that most equine neutrophils express a β-integrin-like antigen on their surface. The labeling percentages, and mean and peak channel numbers (i.e. indicators of fluorescence intensity) were significantly greater (p < 0.05) in neutrophils incubated with MAbs 60.3, #38, and #25 in comparison to control cells (i.e. not incubated with primary MAb). Some autofluorescence was evident in control neutrophils; however, non-selective fluorescence was minimized by use of a secondary MAb composed of F(ab')₂. Monoclonal antibody 60.3 labeled significantly more (p < 0.05) neutrophils than MAb #38 and had greater fluorescence intensity. Conversely, LPS-stimulated cells incubated with MAbs 60.3 and #38 showed significant decreases (p < 0.05) in the percentage of CD18 moieties labeled compared to unstimulated cells. However, there was no significant alteration in percentage labeling with MAb # 25. Mean and peak channel numbers tended to increase after LPS-stimulation in cells incubated with MAbs 60.3 and # 38; however, no significant differences could be ascribed. This data showed that whilst fewer neutrophils were labeled for CD18 after LPS-stimulation, the neutrophils had a higher density of labeling indicative of quantitative up-regulation. Qualitative up-regulation may also have occurred as the number of cells labeled decreased. Viability pre- and post- incubation ranged from 94 to 100% and was not different, indicating that MAb incubation did not adversely effect equine neutrophils. It was -concluded that unstimulated neutrophils from horses almost constitutively express important integrin cell surface antigens, which are crucial to adhesion, interactive communication, and the immune response. Lipopolysaccharide stimulation of neutrophils causes quantitative up-regulation, and may facilitate qualitative alterations in CD18 moieties. Also MAb 60.3 appears superior to MAb #38 in its ability to label CD18 subunit of equine neutrophils. These MAb modalities could be used to manipulate certain diseases, exacerbated by excessive neutrophil numbers and degranulation (eg. ischemia/reperfusion and respiratory distress syndromes). / Master of Science