<p>The production of latex in a solvent-free process within a twin screw extruder is of great industrial interest given the associated reduction in environmental impact when compared to conventional solvent-based emulsification techniques. The ability to produce latex continuously is also advantageous, compared to batch-wise solvent-based processes.</p> <p>The process of solvent-free emulsification in a twin screw extruder is studied. An inline fiber optic spectroscopic system was installed in the extruder to study the residence time distribution profile of resin through the emulsification process. A design of experiment study was performed analyzing the response of latex particle size from screw speed and feed rate factors. Finally, scanning electron microscopy was used to determine the morphology of the poorly- emulsified and pre-emulsified resin.</p> <p>Experimental results demonstrate that the residence time distribution of the polymer within the extruder is largely invariant of screw speed; the system also demonstrated a very low degree of axial mixing – which was not expected but can be attributed to high degree-of-fill within the screw. The results of the design of experiments study show that the final latex particle size is more influenced by the feed rate of the polymer than the screw speed of the extruder. These results were found to be consistent with the literature based on both batch- phase inversion emulsification as well as continuous polymer blending of immiscible phases. Finally, results from a study on morphology provided evidence of water domains within the pre-inverted polymer domains, analogous to a ‘water-in-oil-in water’ dispersion. Evidence of a bicontinuous network of polymer and water was also found to exist. The summation of these experimental results leads to the hypothesis that the solvent-free emulsification process is a phase inversion-type emulsification mechanism as opposed to a direct emulsification mechanism.</p> / Master of Applied Science (MASc)

Antibiotic resistance is a worldwide threat to human health yet fewer new antibiotics are being approved. New antimicrobial drugs are urgently required. 3 Deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDO8PS) is a target for antimicrobial drug design. KDO8PS catalyzes the condensation of D-arabinose-5 phosphate (A5P) with phosphoenolpyruvate (PEP) to produce KDO8P. KDO8PS catalyzes the first committed step in the lipopolysaccharides (LPS) biosynthesis pathway in Gram-negative bacteria and is critical for bacterial pathogenicity/virulence. We have characterized KDO8PS from Campylobacter jejuni (cjKDO8PS), a new metal-dependent KDO8P synthase (KDO8PS). cjKDO8PS is a tetramer in solution and optimally active at pH 7.5 and 60 °C. We have kinetically established that cjKDO8PS follows a rapid equilibrium sequential ordered ter ter kinetic mechanism, where Mn2+ binds first, followed by PEP, then A5P. Pi dissociates first, before KDO8P, then Mn2+. cjKDO8PS was inhibited by KDO8P oxime, a novel slow tight-binding inhibitor. KDO8P oxime is a competitive inhibitor with respect to PEP and A5P, but uncompetitive with respect to Mn2+, with Ki = 10 ± 1 μM and an ultimate Ki* = 0.28 ± 0.10 μM. KDO8P oxime has a residence time (tR) of 5 days on the enzyme, a parameter that is highly correlated to in vivo efficacy. Crystallization conditions for the cjKDO8PS‧Mn2+‧KDO8P oxime complex have been found and can be optimized to obtain a crystal structure that shows how KDO8P oxime interacts with the active sites. / Thesis / Doctor of Science (PhD) / The relentless increase in global antibiotic resistance is, regrettably, not matched with an increase in new effective antibiotics. New antimicrobial drug discovery strategies are desperately needed. Enzymes are key targets for drug design because they catalyze the majority of biological processes. In this project we sought to study and inhibit the activity of KDO8P synthase (KDO8PS) from Campylobacter jejuni, a common cause of food poisoning. KDO8P synthase is a critical enzyme involved in the lipopolysaccharide (LPS) biosynthesis in Gram-negative bacteria. The LPS acts as a permeability barrier and is crucial for bacterial pathogenicity/virulence. We found that C. jejuni KDO8PS is potently inhibited by KDO8P oxime, a novel inhibitor of KDO8PS. This inhibitor presents a unique opportunity to study these enzymes and a platform from which antibiotics against Gram-negative bacteria can be developed.

This dissertation focuses on the fundamental understanding of liquid dynamics confined in polymer membranes. Such knowledge guides the development of better polymer membranes for practical applications and contributes to the general understanding of confined liquid dynamics in various nanoporous materials. First, we investigate the membrane transport by experimental measurements on a PFSA membrane and computer modeling of the confined liquid molecules. We probe the nano-scale environment in the ionomer membrane by determining the activation energy of diffusion. We notice two structural features of the PFSA membrane that dominate membrane transport. At relatively high hydrations, the nano-scale phase-separation creates bulk-like water in the ionomer membrane and prompts fast transport of mobile species. At relatively low hydrations, the nanoconfinement of the polymer matrix leads to the ordering of confined water and prompts a high energy barrier for transport. We then delve deeper into the confinement effect by molecular modeling of various nanoconfining geometries, including carbon nanotubes, parallel graphene sheets, and parallel rigid rods. We notice retarded water dynamics under hydrophobic confinement regardless of the geometry. We further investigate the confined water by determining the residence time of water around water, which evaluates the timescale of associations between water molecules. We learn that a decreasing confinement size prompts longer associations among water molecules. Further, we propose that the prolonged associations are responsible for the retarded water dynamics under hydrophobic confinement. Next, we turn our attention to the effect of interactions between mobile species (mostly water molecules) and a confining surface. In ionomer membranes, interactions between mobile species and the ionic groups dominate the water-surface interactions. We start by looking at water-ion interactions in bulk solutions. Using solutions at varying concentrations, we notice a temperature-concentration superposition behavior from diffusion coefficients of water molecules and ions in the solutions in both experimental and computational results. Observation of this superposition behavior in bulk solutions is unprecedented. The temperature-concentration superposition parallels the well-known time-temperature superposition. We are able to extract the offset of reciprocal temperature, which fits well to a Williams-Landel-Ferry type equation. The temperature-concentration superposition points to the new perspective that the effect of ions on water dynamics can be similar to the effect of lowering temperature. We further investigate the effect of ions by modeling ions/charges onto confining geometries. Remarkably, we reveal that the presence of ions can break the ordered water structure induced by confinement. The hydrophobic confinement prompts the ordering of water molecules, which leads to slower diffusion and higher activation energy. The presence of ions/charges on the confining surface has multiple effects on the dynamics of confined water. First, the ions associate strongly with neighboring water molecules while breaking the hydrogen-bonding network between water molecules. Second, the disruption of the hydrogen-bonding network leads to decreased activation energy of diffusion and enhanced water mobility. At relatively high ion density, the water-ion interactions overcome the structure-breaking effect and lead to retarded water diffusion. Overall, the studies presented in this dissertation augment our understanding of water transport in nanostructures by revealing the rich behavior of liquid-water dynamics under both hydrophobic and ionic confinement. / Doctor of Philosophy / Polymer separations membranes contribute to important applications such as fuel cells and water desalination. Optimizing the separation ability of polymer membranes improves their practical performance. The transport property of a polymer membrane depends on its nanoscale and microscale structures. This dissertation focuses on the nanoscale structure-transport relations in ionic polymer membranes. We utilize nuclear magnetic resonance techniques and molecular dynamics simulations to probe the transport properties. We investigate the effects of membrane nanostructure and water-ion interactions on the dynamics of confined water. Such knowledge not only guides the development of high-performance membranes but also contributes to the fundamental understanding of liquid dynamics in nanoporous materials.

Though the phenomenon of young adults moving in with their parents is not a new one, it is one that has certainly become more common in recent decades. A new life stage of 'emerging adulthood' has become the norm, in which young adults delay marriage and career jobs in order to pursue other goals. This stage is, in part, marked by fluidity in residence. Yet even as a growing number of 'boomerang kids' move back in with their parents, there is a gap in the research regarding this phenomenon's effect on various parts of the family system. This study set out to address this gap by comparing separate interviews from young adult boomerangs and their parents. Findings suggest a disparity between parental and young adult opinions on a variety of topics, most notably: expected household responsibility, parent/child closeness, loss of autonomy, and appreciation. However, similarities emerged regarding the parental home as a safe haven, the arrangement as providing financial security, and the fact that all adult children reported being ready to move out. Ideally, the findings presented here will help illuminate both the similarities and disparities in the experiences of parents and their young adult children who return after launch, in order to increase empathy and promote a healthy family system. / Master of Science

The Vintnerâ s House is a Residence and Vineyard nestled between well-known wine regions on the central coast of California. It is a workerâ s house; for the cultivator, the grower, and the nurturer of the vines. The vineyard is set on terraces down a hill to give grapes the sunlight and drainage they desire. These south facing terraces allow the vines to receive full sunlight throughout the growing season. Drainage through the vineyard encourages the roots to grow deep into the soil, as a well-established root system will yield a better quality grape. As the terraces wrap around the site, they intersect and flow into the residence. The terraces help to organize and arrange the house as it steps up the hill alongside the vineyard. The house is small and simple, but appears much larger with the adjacent wine facilities. The main living space for the residence is on the lower level with the living room, kitchen, and dining areas all clustered together looking out towards the ocean. Upstairs is the bedroom, which overlooks the two-story living room much like the vineyard terraces overlook each other. The house accepts its role as the vineyardâ s accomplice. Without the vineyard, the Vintnerâ s House would not grow out of the hillside. / Master of Architecture

this thesis Presents an exploration of the residence hall as an institution through formal and conceptual play. / Master of Architecture

This design project is a house located in Locust Grove, Virginia. The materials and spatial characteristics, such as stone and wood, are inspired by the indigenous barns of the area. Architecture can be a means of communication, it can speak to us. I chose to design a residence that speaks of the past yet is one that lives in the present. / Master of Architecture

College administrators have been in the business of employing students as RAs or an equivalent position for many years. Over those many years, the students and the type of students hired for this position changed. Once again, it is time for a generational change. Gen Y students are currently entering at least their second year of college and are now eligible to apply for RA positions. The present study operated on the assumption that student motivations to seek the RA position may have changed over time as new generations of students have entered higher education. The perceived benefits of student employments in positions such as the RA position may shift with the change in the characteristics, needs, motivations, and desires of the students to seek employment. Researching employment motivations periodically to gauge shifts in reasons for seeking employment in the RA position may be helpful. The present study has significance for both future practice and future research in student affairs. In terms of future practice, three constituencies might be interested in the results of the study: Residence Life practitioners (RLPs), RAs, and student affairs practitioners. In the current study, there were several significant findings. First, Gen Y students sought the RA position for the following reasons (by order of importance), Helping Behaviors, Career Development, Financial Obligations, RA Cohesiveness, Personal Growth, and Desire for Power. Second, Gen Y females reported Helping Behaviors as an important reason for seeking the RA position significantly more often than did their male counterparts. Third, the research found no statistically significant differences in the reasons majority and minority Gen Y students sought the RA position. Finally, statistically significant differences were found when the reasons Gen X and Gen Y students sought the RA position were examined. Although the study examined only a limited number of Gen Y students, the results indicate that Residence Life professionals and RA staff selections teams may want to reconsider the way in which RA applicants are recruited. / Master of Arts

The purpose of this study was to determine the practicality of quick-frozen, fresh and canned vegetables in quantity feeding operations of a college residence hall cafeteria.

This Master´s thesis examines structural links on the number of foreigner nationals legally staying in the territory of South Bohemia between 2000 and 2016. The following objectives have been defined: Objective 1: To acquire a comprehensive overview of the number of foreigners with long-term or permanent residence living in the territory of South Bohemia between 2000 and 2016 and to demonstrate the current trends Objective 2: To demonstrate the link between the annual approved long-term or permanent residence in the territory of South Bohemia between 2000 and 2016 Objective 3: To perform a comparison of the results achieved with the European trends Due to the results achieved by the applied quantitative research, the objectives of the thesis are considered to have been met. The theoretical part of the thesis covered the strategy of the migration policy of the Czech Republic. This part defines a concept of migration, in conjunction with the legislative aspect of the given case, the concept of a foreign national and categories of residential permits, as long-term and permanent residence, depending on their duration, including an analysis of different types of long-term and permanent residence. Initially, the purpose of the practical part consisted in the collection of statistical data necessary for the examination of a dependence in the form of the most important statistical indicators for the specified years, i.e. between 2000 and 2016. The tables and charts necessary for the regression analysis of long-term and permanent residence, and for the correlative research of a dependence between long-term and permanent residence needed to evaluate the objectives of this research, were created based on acquired data files. The aim of this Master´s thesis was to evaluate, confirm or refute the following hypotheses: H1 Hypothesis: The annual numbers of foreigner nationals with permanent residence can be expressed by a linear regression model, which shows an increasing trend. H2 Hypothesis: The annual numbers of foreigner nationals with long-term residence can be expressed by a linear regression model, which shows an increasing trend. H3 Hypothesis: The annual numbers of foreigner nationals with permanent and long-term residence positively correlate. The H1 hypothesis was verified by a linear regression model for approved permanent residence. The H2 hypothesis was verified for the first interval (the first 7 years with a rising linear regression) and partly for the second interval (the remaining years until 2016 with a decreasing linear regression). In general, the adoption of the H2 hypothesis should be assumed distantly (the economic crisis intervention, the role of the 5-year period). The H3 hypothesis is on the verge of rejection - the consequences of the economic crisis and the 5-year period reveal either a very weak positive correlation between permanent and long-term residence or an uncorrelated form. The findings provided in the Master´s thesis generate a number of other topics for follow-up research (a link to economic cycles, connection to the parameters of asylum procedures).