The focus of this work is to synthesize and immobilize novel rigid tetraphosphine linkers via the formation of phosphonium groups and by direct adsorption of tetraphosphine salts on oxide surfaces. These methods offer the possibility to study the mechanism of the phosphonium formation in more detail by utilizing solid-state NMR spectroscopy. It has also been a point of interest to study the linkers and catalysts under realistic conditions, in the presence of solvents. Therefore, HRMAS (high-resolution magic angle spinning) NMR spectra of several phosphonium salts, adsorbed on SiO2, have been studied. This technique allows one to probe the leaching and mobility of the linkers on the surface. The mobilities of the linkers and the catalysts are crucial factors for the performance and design of the immobilized catalysts. Finally, since the exact mode of binding to the surface is unknown and is being discussed in the literature, for example, as hydrogen bonding between the F atoms in BF4- and surface silanol protons, the influence of the counteranion on the binding of phosphonium salts on silica surfaces is of utmost interest. For surface mobility studies a monolayer of phosphonium salts on the silica surface, both without solvent and in the presence of solvent, has been studied via 31P and 2H CP/MAS and HRMAS. Our findings show that the integrity of the tetraphosphine scaffold linkers is based upon how it is immobilized. The best system is formed when the phosphine is immobilized on the SiO2 support by adding Cl(CH2)3Si(OEt)3 to the reaction mixture. In this way, phosphonium salts are obtained, which are bound to the surface irreversibly by electrostatic interactions, as proven by solid-state NMR. In addition, leaching and mobility studies prove that the solvents play a crucial role, and the more polar solvents, such as DMSO, lead to the most extensive leaching due to the solvents' strong adsorption on the SiO2 surface. Leaching studies also show that the counteranion has an influence on the binding of the phosphoniumn salts on the SiO2 surface. The leaching proceeds in the following manner: BF4- > I- > Br- > Cl-. This is an indication that there is an additional interaction between the anion and, most probably, the surface silanol protons.

The figure of the human body and notions of its sustenance, wellbeing and need for change are central, if often latent, within discussions of contemporary eco-social 'crises'. This dissertation considers cycling practices in Los Angeles as a 'case' to ask how conceptions of human bodies - the intertwined ideas and materials that constitute them - need reconsidering. Cycling, particularly when replacing car journeys, is increasingly promoted as a solution for some of these 'crises': Reducing greenhouse gas emissions, air pollution, traffic congestion and alleviating health concerns associated with sedentary lifestyles and mental health. Much cycling advocacy and research is focused on improving the cycling experience and enhancing rates of cycling in cities, yet rests on dominant ontological presumptions around human bodies, their categories of identity and their normativity - both what is considered 'normal' as well as aspirations of 'good' in terms of health and sustainability. In this dissertation, I work through a methodology of 'riding theory' by bringing together (material) feminist, queer and critical race theories with multi-sited ethnographic fieldwork on cycling practices, focusing mainly on Los Angeles, California. Rather than building on automatic assumptions of cycling as a 'solution', I ask in what ways cycling practices manifest through relations of power. This rests on an ontology of 'flesh' and 'enfleshment' - indebted to the work of corporeal and black feminist theorists - whereby cycling is understood not as modulated by relations of power, but becoming-as and through these relations in highly uneven ways. Through cycling in Los Angeles, intertwined techniques of power are discussed as: categorization (the naming and reproduction of identities and bodily difference); configuration of matter and meanings through spacetime (the configuration and affordances of cycling lungs, exposures, taking up spacetimes, speeds and locomotion) and valuation (the enrolment of cycling subjectivities and energies within the reproduction and circulation of value). As opposed to cycling futures reconfigured to fulfil alternative criteria of valuation, I consider what a cycling ethic of response-ability might do: An ethic that arises from the ontologies of enfleshment and that requires a working-with the affordances of cycling. Thinking through these ontologies and/as ethics, I argue, forces emergent reconsideration of how cycling subjectivities and responsibilities, justice, health and sustainability are understood.

<p> Residential stress is a key concept within residential mobility studies. Considerable research, in the past, has been devoted to the task of actually measuring, and quantifying residential stress. </p> <p> Many factors which affect residential stress have been outlined, however, the absolute effect of these factors, and their relative strengths are not known. Many suggest that this is mainly due to the fact that previous research designs have not provided adequate control over extraneous variance, there by preventing the isolation of the effects of individual factors. </p> <p> The body of literature in residential mobility studies exhibits this apparent lack of methodological rigidity through the occurrence of certain inconsistencies in the literature. An example of such an inconsistency deals with the relationship between length of residence and residential stress. studies have been done which actually support the "cumulative inertia hypothesis", that is stress decreases with increasing length of residence, while others have provided evidence for the "cumulative stress hypothesis", that is, stress increases with increasing length of residence. </p> <p> The present study is designed around the recognition of the need to develop and implement a methodology that would alleviate the seemingly contradictory findings presented in the mobility literature. The problem being addressed is to establish the separate and joint effects of life cycle stage and length of residence on residential stress, these being two factors identified in past studies as potentially important determinants of stress. The main findings of the study were that both life cycle stage, and length of residence have significant separate effects on residential stress. Also, when length of residence was introduced as a covariate with life cycle stage in an analysis of covariance, the variation in stress explained by life cycle stage decreased substantially, with length of residence having the greater predictive power. </p> / Thesis / Bachelor of Arts (BA)

For realistic predictions of vehicle performance in off-road conditions, it is critical to incorporate in the simulation accurate representations of the variability of the terrain profile. It is not practically feasible to measure the terrain at a sufficiently large number of points, or, if measured, to use such data directly in the simulation. Dedicated modeling techniques and computational methods that realistically and efficiently simulate off-road operating conditions are thus necessary. Many studies have been recently conducted to identify effective and appropriate ways to reduce experimental data in order to preserve only essential information needed to re-create the main terrain characteristics, for future use. This thesis focuses on modeling terrain profiles using the finite difference approach for solving linear second-order stochastic partial differential equations. We currently use this approach to model non-stationary terrain profiles in two dimensions (i.e., surface maps). Certain assumptions are made for the values of the model coefficients to obtain the terrain profile through the fast computational approach described, while preserving the stochastic properties of the original terrain topology. The technique developed is illustrated to recreate the stochastic properties of a sample of terrain profile measured experimentally. To further analyze off-road conditions, stochastic soil properties are incorporated into the terrain topology. Soil models can be developed empirically by measuring soil data at several points, or they can be created by using mathematical relations such as the Bekker's pressure-sinkage equation for homogeneous soils. In this thesis, based on a previously developed stochastic soil model, the polynomial chaos method is incorporated in the soil model. In a virtual proving ground, the wheel and soil interaction has to be simulated in order to analyze vehicle maneuverability over different soil types. Simulations have been created on a surface map for different case studies: stepping with a rigid plate, rigid wheel and flexible wheel, and rolling of a rigid wheel and flexible wheel. These case studies had various combinations of stochastic or deterministic terrain profile, stochastic or deterministic soil model, and an object to run across the surface (e.g., deterministic terrain profile, stochastic soil model, rolling rigid wheel). This thesis develops a comprehensive terrain and soil simulation environment for off-road mobility studies. Moreover, the technique developed to simulate stochastic terrain profile can be employed to simulate other stochastic systems modeled by PDEs. / Master of Science

This dissertation examines the constructed racial identities of African American settlers in colonial Liberia as they traversed the Atlantic between the United States and West Africa during the first half of the nineteenth century. In one of the great testaments that race is a social construction, the West African neighbors and inhabitants of Liberia, who conceived of themselves as “black,” recognized the significant cultural differences between themselves and these newly-arrived Americans and racially categorized the newcomers as “white.” This project examines the ramifications for these African American settlers of becoming simultaneously white and black through their Atlantic mobility. This is not to suggest that those African Americans who relocated to Liberia somehow desired to be white or hoped to “pass” as white after their arrival in Africa. Instead, the Americo-Liberians utilized their African whiteness to lay claim to an exotic, foreign identity that also escaped associations of primitivism. This project makes several significant contributions to scholarship on the colonization movement, whiteness, and Atlantic world. Importantly for scholarship on Liberia, it reestablishes the colony as but one evolving point within the Atlantic world instead of its usual interpretative place as the end of a transatlantic journey. Whether as disgruntled former settlers, or paid spokesmen for the American Colonization Society (ACS), or visitors returning to childhood abodes, or emancipators looking to free families from the chains of slavery, or students seeking medical degrees, Liberian settlers returned to the United States and they were remarkably uninterested in returning to their formerly downtrodden place in American society. This project examines the “tools” provided to Americo-Liberians by their African residence to negotiate a new relationship with the white inhabitants of the United States. These were not just metaphorical arguments shouted across the Atlantic Ocean and focusing on the experiences of Americo-Liberians in the United States highlights that these “negotiations” had practical applications for the lives of settlers in both the United States and Africa. The African whiteness of the settlers would function as a bargaining chip when they approached that rhetorical bargaining table.

La thèse interroge l'aménagement et l'expérience de quatre grands aéroports internationaux : Paris Roissy-Charles-De-Gaulle, Amsterdam Schiphol, Francfort-sur-le-Main et Dubai International. Elle fait l'hypothèse que ces quatre hubs ou plateformes de correspondance, loin de constituer des non-lieux, sont au contraire des lieux de pouvoir et des laboratoires privilégiés d'observation de nouveaux rapports au lieu et au territoire dans la mobilité. Pôles d'échange ou lieux-mouvements de grande complexité, ces commutateurs sont analysés au regard des mobilités qu'ils mettent en jeu dans l'entre-deux des territoires classiques. C'est la mise en pratique et en catégorie de ces mobilités qui est à l'épreuve dans ces espaces publics non idéalisés, et, par là même, le positionnement de leurs acteurs. L'investigation comparative multi-site des quatre terrains en réseau permet de montrer que ces espaces publics sont de puissants opérateurs d'intelligibilité, de classement et de performance d'un très large spectre de pratiques mobiles, habituellement abordées de manière séparée : notamment touristiques, migratoires ou de travail. La thèse questionne les catégorisations de la mobilité déployées par les acteurs institutionnels dans l'aménagement et le fonctionnement de ces vastes dispositifs spatiaux de savoir et de pouvoir. Elle les confronte aux pratiques et aux représentations des populations contrastées qui investissent ces microcosmes. Ce travail montre combien les expériences de ces lieux, mondiaux par excellence, prennent sens à bien plus large échelle que celle des espaces publics eux-mêmes et interrogent les propres catégories savantes de la mobilité. Soulignant l'efficacité symbolique et pratique de la diffusion de catégorisations normatives par ces lieux, elle en dégage aussi les limites. Elle analyse l'ampleur des formes d'appropriation à l'œuvre dans ces espaces comme des détournements et des contournements des dispositifs aéroportuaires. Elle souligne la contribution majeure des lieux de mobilité aux logiques de placement des individus et des collectifs, d'identification, de confrontation à l'altérité comme de ségrégation. Au cœur des mécanismes de mondialisation et de métropolisation, ce sont les territorialités en réseau, construites dans et par le déplacement, dont les aéroports sont les révélateurs.