Current mathematical models, developed on straight asphalt binders, are inadequate to characterize the frequency dependence of response of polymer-modified asphalt binders. In an earlier study at Virginia Tech, mathematical models were developed to predict the storage and loss shear moduli of polymer-modified binders. However the model developed for the loss shear moduli is limited at high frequency (G" less than or equal to 10^7.5 Pa). This thesis presents a statistical modeling of loss shear modulus of polymer (random copolymers and thermoplastic block copolymers) modified binder. Data from dynamic mechanical analysis on modified binders, at temperatures between 5 and 75°C and frequencies ranging from 0.06 to 0188.5 rad/s, were reduced to dynamic master curves of moduli, and used to develop the model. Twenty-one polymer-binder blends prepared and tested earlier at Virginia Tech where included in the study. Realistic characterization of loss shear moduli values was obtained using the Gompertz statistical model. The model was validated by using mean square error of prediction (MSEP) in which a second set of frequency data was input in the model to obtain the moduli values, which were compared to the measured data of the second set. Although this model was successfully tested for shear loss modulus prediction of polymer-modified binders, caution should be exercised when it is applied, as such a model should be able to predict the storage modulus for a known phase angle. / Master of Science

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20177号 / 理博第4262号 / 新制||理||1613(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 佐々木 節, 教授 田中 貴浩, 教授 川合 光 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

The presence of wide spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC) in the environment has become a concern due to the adverse impact on the environment. Montmorillonite, a widely distributed clay mineral in the natural environment, has been used as an obstacle in landfills to avoid contamination of soil and water by contaminants in leachates due to its high surface area, cation exchange capacity, and abundance. The research reported here focuses on understanding the abiotic oxidative transformation of TCS and TCC by Fe(III)-modified montmorillonite. The overall objectives of this work were: 1) to investigate TCS and TCC oxidative transformation kinetics and transformation products in different environmental conditions, and 2) to elucidate their reaction pathways. TCS was reacted with Fe(III)-modified montmorillonite under the following experimental conditions: 1) at 40% relative humidity and room temperature for up to 100 d with and without UV light exposure; and 2) in aqueous environment with different initial TCS concentrations, light exposure, pH levels, and in the presence of natural organic matters. Reaction in the presence of Na- montmorillonite was conducted for comparison with results from TCS reaction in the presence of Fe(III)-modified montmorillonite. In addition, transformation of TCS in the presence of other types of minerals was also investigated. Transformation of TCC on Fe(III) and Na-montmorillonite in an aqueous environment with and without exposure to light was also studied at different initial TCC concentrations. TCS and TCC transformation products were a) characterized using LC/MS, GC/MS, and computational modeling, and b) quantified using HPLC/UV and GC/MS. The main TCS transformation products were 2,4-dichlorophenol, 2,4-dichlorophenol dimer, chlorophenoxy phenols and, TCS dimers and trimers. 2,8-dichlorodibenzo-p-dioxin was identified under UV light and the sun simulator experiments. Formation of 4-chloroaniline and 3,4-dichloroaniline were confirmed as transformation products of TCC. To the best of our knowledge, this is the first time that 4-chloroaniline and 3,4-dichloroaniline were confirmed as abiotic transformation of TCC. This research has generated a better understanding of the abiotic environmental fate of TCS and TCC and demonstrates the feasibility of utilizing Fe(III)-modified montmorillonite as remediation material for TCS, TCC and other related pharmaceutical and personal care products (PPCPs).

In recent years, the product placement industry has seen a significant boom. The growth of product placement continues as media seeks funding and branded products vie for increased audience attention. Because of the increased product placement, there are many studies that examine the attitudes towards product placement, the experiences and interpretations of brands post-product placement, the effects of product placement, and memory of product placement. However, while product placement is a popular trend, there are occasions when branded products are altered in movies and television (this thesis refers to the altered products as “brand-modified products”). Little, if any, research has been done on the effects, perceptions, or reactions toward brand-modified products. The brand modifications are made for various reasons, including branded product's lack of desired affiliation with the message of the media and/or casting a product in defamatory light. This study, through a test of unaided recall and aided recognition of four brand-modified products, demonstrates the immediate associations that were made between brand-modified products and authentic products when the four brand-modified products made appearances in various movie clips. The results of a survey of 211 undergraduate students' unaided recall and aided recognition of brand-modified products are reported in this study. It is demonstrated that the participants recalled and recognized authentic brands rather than the actual brand-modified products that appeared in the shown movie clips. Schema theory suggests that the brand-modified products were assimilated into preexisting knowledge structures, and that the recall and recognition of the products was due to prior exposure of the authentic brands. In terms of brand-modifications, this study demonstrates that associations are made to authentic products more often than to the brand-modified products that appeared in the movies.

An efficient, stereoselective method for the synthesis of α-phosphonoenamines based on a modified Peterson olefination was developed. The carbanion derived from Diethyl 1-dimethylamino-1-trimethylsilylmethanophosphonate reacted with aromatic or aliphatic aldehydes selectively eliminating in Peterson fashion to deliver functionally rich α-phosphonoenamines. A highly efficient method was developed for the one-carbon homologation of aldehydes to carboxylic acid derivatives employing the reaction of a 1, 1-bis-dimethylphosphonate derivative with the aldehyde and controlled acid hydrolysis of the derived α-phosphonoenamine intermediate. The reaction of bis(trimethylsilyl)chloromethane with s-BuLi was found to proceed via transmetallation rather than deprotonation yielding the nucleophilic bistrimethylsilylmethyl anion quantitatively which reacted readily with aldehydes providing a general entry to vinylsilanes. The reaction of α-silylated ylides with non-enolizable aldehydes proceeded via selective Peterson-type elimination, in contrast to prior literature reports, providing a direct route to synthetically useful vinylphosphonium salts. The chemoselective formation of trialkylbenzyl phosphoranes in water and their Wittig reaction with aromatic and aliphatic aldehydes provided a practical, stereoselective and environmentally benign route to valuable trans-stilbenes and alkenes. The synthesis of the phytoalexin resveratrol was described. In addition, the method allowed for a gramscale synthesis of the anticancer agent DMU-212 utilizing no organic solvent at any stage. A direct synthesis of 1,3-dienes and 1,3,5-trienes from the reaction of semi-stabilized ylides and a range of saturated and unsaturated aldehydes was reported in water as solvent, employing sodium hydroxide as base. The water-soluble phosphine oxide side product was removed simply by aqueous partitioning of the organic products. / Thesis / Doctor of Philosophy (PhD)

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Improved corneal epithelial cell growth over artificial cornea materials is required to improve device retention within the eye. In this work, varying concentrations of epidermal growth factor (EGF), a potent mitogen for epithelial cells, were immobilized to polydimethylsiloxane (PDMS) substrates, and the cellular response was analyzed. Three methods were developed to bind EGF to PDMS via polyethylene glycol (PEG) tethers. 1) Plasma Modification: EGF was first reacted with homobifunctional NHS2PEG and then bound to allylamine plasma-modified PDMS. 2) Hydrosilylation: PDMS was modified with heterobifunctional allyl-PEG-NBS and then EGF was attached to the surface-bound PEG. 3) Thiol Modification: EGF was first reacted with heterobifunctional NHS-PEG-maleimide and then bound to thiol-modified PDMS. Using Method 1 (Plasma Modification), 40 to 90 ng/cm2 of EGF was bound, however 70% of this was adsorbed even under optimized EGF-PEG reaction conditions. Cells rapidly grew to confluence on these surfaces, and cell counts increased significantly compared to control surfaces. Extracellular matrix protein production was also increased on the EGF-modified surfaces, corresponding to significantly higher levels of cell adhesion observed under a detachment force. Modification by Method 2 (Hydrosilylation) resulted in 10 to 300 ng/cm2 of bound EGF, of which 20% was adsorbed. However, despite increased EGF binding homogeneity, the cell growth was slower on these surfaces than on those prepared by Method 1, and coverage was non-uniform at all EGF concentrations. This is likely due to a higher underlying PEG density, and binding of the PEG and EGF in clusters on the surface. Simultaneous tethering of the cell adhesion peptide YIGSR had no further effect on cell coverage. Using Method 3 (Thiol Modification), 24 to 65 ng/cm2 of EGF was bound, of which 22% was adsorbed. This method enables more homogeneous EGF surface binding than Method 1, with a lower PEG density than Method 2. However, free thiol groups were inhibitory to corneal epithelial cell growth, even in the presence of bound EGF. Defunctionalization of free thiols by reaction with 3-maleimidopropionic acid restored cell growth and morphology on the PDMS, and may hence allow for retention of the proliferative effect of the EGF. These results indicate that while tethering of EGF to PDMS can improve the coverage by corneal epithelial cells, and presents a promising strategy for modification of polymeric artificial cornea materials, the effects are highly dependent on the underlying surface chemistry. / Thesis / Doctor of Philosophy (PhD)

Fish products under vacuum (VAC) and/or modified atmosphere packaging (MAP) conditions can have a significantly extended shelf life. Prevention of toxin production by Clostridium botulinum is essential for processors of VAC and MAP refrigerated fishery products. The objective of this study was to determine if C. botulinum toxin development precedes microbiological spoilage and sensory rejection in fully cooked breaded and battered Alaskan Pollock or raw aquacultured flounder fillets. Aquacultured summer flounder (Paralichthys dentatus) fillets and fully cooked breaded and battered Alaskan pollock (Theragra chalcogramma) were either aerobically packed (Oxygen Transmission Rate (OTR) of 3,000 cc/m2/24h@70°F for flounder and 6,000 cc/m2/24h@70°F for Pollock), vacuum packed or MAP packaged in a 100% CO₂ atmosphere (OTR of 7.3 cc/m2/24h@70°F). Flounder fillets were stored at either 4 or 10°C while pollock portions were stored at 8 and 12°C. Based on the time to spoilage (counts >107 CFU/g), additional samples were inoculated with five strains of nonproteolytic C. botulinum and analyzed qualitatively for botulinum toxin using a mouse bioassay. For flounder at 4°C, toxin formation did not occur after 35 days in aerobically packed fillets. Vacuum packed and 100% CO2 fillets produced toxin before spoilage at days 20 and 25, respectively. In the aerobic packages at 10°C, toxin production occurred after spoilage at day 8, but before spoilage in the vacuum and 100% CO₂ packages at day 9. Sensory evaluation of toxic vacuum and 100% CO₂ packages at 4°C revealed toxin production proceeded spoilage and absolute sensory rejection. However, at 10°C toxin production was evident only after absolute sensory rejection and microbiological spoilage for aerobically packed fillets. Vacuum packages and 100% CO₂ packages were toxic during spoilage but before absolute sensory rejection. Toxin was not present in the aerobically and 100% CO₂ packed pollock samples at 8°C and the 100% CO2 packed samples at 12°C after 35 days. Aerobically packed portions stored at 12°C first produced toxin at day 25; toxicity occurred after absolute sensory rejection and before spoilage. The vacuum packed portions first formed toxin at day 25 for 8 and 12°C storage before spoilage and absolute sensory rejection. / Ph. D.