Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Jones, Christopher; Committee Member: Agrawal, Pradeep; Committee Member: Teja, Amyn; Committee Member: Weck, Marcus; Committee Member: Zhang, John.

Dissertation (Ph.D.)--Worcester Polytechnic Institute. / Keywords: supported catalyst; spin coating; atomic layer deposition; carbon nanotubes; model catalyst; ferrocene; thin film coating. Includes bibliographical references. (p.256-258)

The current upgrading catalysts are mainly based on the use of expensive noble metals, which are subject to deactivation due to sintering and coking. An alternative would be to introduce a non-noble metal-based catalyst. In this work, supported molybdenum carbide based systems have been assessed for this purpose. These catalysts were formed by impregnation of zirconia (and zirconium hydroxide) and sulfated zirconia (and zirconium hydroxide) with different loadings of MoO3, with an aim of finding a balance between acid sites and metal-like sites (a site capable of performing dehydrogenation and hydrogenation function without necessarily being a metal). The synthesised catalysts were carburised between 823 and 1123 K using a mixture of methane and hydrogen (4:1) in an attempt to obtain β-Mo2C/ZrO2 or β-Mo2C/S ZrO2. Carburisation at 923 K and above resulted in molybdenum carbide with minimal or no oxygen contents. The conversion and specific rate increased with temperature. Conversion was inversely proportional to space velocity. Analysis of the products distribution as a function of conversion implies that the reaction did not simply follow a consecutive reaction pathway, but that other parallel routes were involved. Conversion increased the research octane number (RON) to ca. 66 due to the increased fraction of pentane isomers. Catalyst carburised at 823 K was approximately four times more active compared to those carburised at 923 K and above, but were of similar activity with Pt/sulfated zirconia. The non-noble metal based catalysts were stable at the reaction temperature while the Pt/sulfated zirconia catalyst deactivates.

Employment supports have traditionally been available to help reduce barriers to employment, promote workforce participation, and empower individuals to achieve their career goals. However, there is very limited knowledge regarding the intersection of race and disability and how it can impact the delivery of employment supports for racialized disabled job seekers and workers. To address this gap, this thesis includes a scoping review and a qualitative study to understand the impact of race and disability in employment support systems. The scoping review consists of 73 studies and a grey literature search on vocational rehabilitation (VR). Data was extracted and thematically analyzed to synthesize the existing knowledge about VR services currently in place for racialized disabled job seekers and workers. The findings highlight the disparities in accessing VR and its delivery in the United States. The included studies reported lower acceptance rates to enter VR programs, and lower probabilities of a successful exit. These findings suggest the importance of service providers conducting comprehensive assessments to determine the unique requirements of each job seeker and worker to customize their supports accordingly. To capture the varied lived experiences and perspectives while navigating the Canadian employment support systems, a qualitative interpretive descriptive study was conducted. In-depth semi-structured interviews were performed with racialized disabled job seekers and workers, service providers, and employers. Interviews were thematically analyzed to identify common themes and patterns about the impact of race and disability in employment supports. The employment support process, as reported by the participants in this study, was identified to be inflexible and bounded by multifaceted structural, organizational, and attitudinal challenges that intersect across race, disability, and employment. Overall, an intersectional approach that is targeted, flexible and inclusive of changes and strategies is needed to create a more equitable employment landscape that better supports racialized disabled workers. / Thesis / Master of Science Rehabilitation Science (MSc) / This thesis examines the impact of race and disability in employment support systems. The first paper is a scoping review examining the existing literature to understand the process of accessing employment services for racialized disabled workers. The findings of the review highlighted that racialized disabled workers face disparities in accessing employment supports and require personalized supports that cater towards their intersecting identities. The second paper is a qualitative study drawing on interviews with racialized disabled workers, service providers, and employers to understand their experiences navigating the Canadian employment support systems. The findings show that several participants reflected on the lack of development regarding employer education, government policy and programs, service provider training and capacity to better serve disabled workers with multiple intersecting identities. This thesis expands our understanding of how social constructs such as race and disability can impact experiences of accessing employment supports and consequently affect employment outcomes.

No description available.

O trabalho proposto tem por objetivo a redução e uniformização de esforços em grelhas em função do posicionamento dos apoios, através de técnicas de otimização matemática. Busca-se, pela mudança nas posições inicialmente idealizadas para os apoios, a redistribuição dos esforços em edificações devido à alteração na rigidez relativa dos elementos, de modo a possibilitar maior economia no consumo dos materiais componentes. Objetiva-se ainda, com base na análise de estruturas correntes, verificar a eficiência do procedimento proposto, ainda que consideradas as limitações à livre mudança de posição dos apoios. Com as finalidades descritas, foi desenvolvido um programa de computador que pretende se constituir em uma ferramenta auxiliar ao projetista na fase de concepção da estrutura portante de edifícios. Apesar de direcionada a estruturas de concreto armado, a formulação proposta pode ser adotada para o emprego de outros materiais. / The aim of this work is to reduce and to balance the internal forces on grillages based on the support positions, by the application of optimization techniques. By changing the initial position of the supports, a better redistribution of internal forces on the building due to the changes on the relative rigidity of the elements is achieved, consequently reducing the material consumption. Also, the objective is to verify, by means of several examples, the usefulness of the proposed procedure, even considering the limitations to the free displacements of the supports in the plane of the structure. To achieve these objectives, a software was developed, which intends to constitute an auxiliar tool to designers during the process of idealization of the structure. Initially developed to be applied to reinforced concrete structures, the presented formulation can be adopted to the use of other structural materials.

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 27, 2007) Vita. Includes bibliographical references.

Non-polar phase selective solubility of modified poly(4-n-alkylstyrene) supports can be measured using fluorescent dyes as catalyst surrogates with thermomorphic and latent biphasic systems. By modifying the solvent compositions in heptane/ethanol and heptane/N, N-dimethylacetamide, increased non-polar phase selective solubility of modified polystyrene supports can be attained. Likewise, by varying the structure and length of the pendant alkyl chain, an increase in non-polar phase selective solubility is measured. These heptane soluble polymer supports can be useful for applications involving heptane soluble polymer-bound reagents and catalysts. Various polar and non-polar polymer supports were synthesized with an attached solvatochromic catalyst surrogates to determine the solvent accessibility of the supported species in pure and mixed solvents. The results of these studies indicate that in pure solvents, the influence of both polar and non-polar polymer supports on the solvent microenvironment of these polymer-supported probes is minimal. In mixed solvent systems, a polymer-like solvent microenvironment is measured in solvent mixtures comprised of solvents the polymer has unfavorable interactions. Poly(4-n-alkylstyrene) and internally functionalized polyisobutylene supports are two such polymer supports that exhibit this behavior. For terminally functionalized polymers in mixed solvents, the solvatochromic behavior does not indicate a collapsed structure. In mixed solvents, there is minimal influence of the polymer support on the solvent microenvironment of these terminally functionalized polymers. The application of soluble polyisobutylene supported copper complexes in the ATRP polymerization of styrene was investigated. Using the difference in solubility of the product polystyrene and the polyisobutylene copper complex in heptane, a solid/liquid separation of the soluble copper complex from the solid product was achieved. The results of these polymerizations indicate that the polyisobutylene copper complex behaves exactly like a low molecular weight copper complex in terms of control over molecular weight and molecular weight distribution. After the polymerizations, the polyisobutylene complexes could be separated as a heptane solution and recycled in multiple polymerizations of styrene.

The technique of phase labeling has the ability to greatly enhance synthetic protocol by simplifying purification and increasing efficiency. Traditional insoluble supports offer efficient and simple recovery of the “phase tagged” material but suffer from problems inherent to their heterogeneous nature. A solution to these problems has been to utilize phase separable soluble polymers in the design of “smart” responsive systems that offer the option of homogenous reaction conditions with heterogeneous separation conditions. The subject of this dissertation focuses on the application of soluble polymeric phase tags in systems where the miscibility between solid-liquid and liquid-liquid systems is thermally induced. Low molecular weight poly(ethylene glycol) (PEG) oligomers were investigated as phase anchors for SCS palladacycle catalysts. The oligomeric PEG chains were sufficient to engender polar phase solubility in a heptane-DMA thermomorphic system. Microwave irradiation of these thermomorphic mixtures of palladium complexes and substrates was a viable scheme to recycle and significantly shorten reaction times for simple Heck reactions of aryl iodides. Soluble polymeric supports possessing a lower critical solution temperature (LCST) were utilized in the sequestration of the S-triazine herbicide, atrazine, from contaminated water samples. The ability of poly(N-isopropylacrylamide) to sequester hydrophobic guests like atrazine was examined. A functionalized PNIPAM derivative containing secondary cyclic amines exhibited superior sequestration ability that was credited to the covalent binding of the atrazine. In order to facilitate the design of tailored, thermally responsive, smart polymers, a high throughput temperature gradient microfluidic device was used to obtain LCST data in a fast, accurate manner. The specific ion effects of various alkali metal halide salts on the LCST of PNIPAM were investigated. The high precision in the measurements enabled more subtle effects such as changes in solvent isotope, polymer microstructure, molecular weight, and importance of end group effects on the LCST of poly(N-alkylacrylamide)s to be evaluated.

The present study focuses on families of children with disabilities living in low-income communities. Little research has been done previously on these families in poverty and the importance of social supports for children with disabilities. The sample consisted of 663 participants; there were 523 families of children without a disability and 140 families of children with a disability living in low-income communities. Poverty is associated with negative influences that may hinder a child’s development, moreso, the development of children with disabilities. Additionally, elevated levels of maternal depression, stress and diminished social support is related to poverty and/or at-risk situations. Importantly, social support may minimize the pressures faced by parents or children within the community. There were four parental variables used in this research along with the use of social supports (formal and informal), concerns about access to formal supports and perceived social support. Chi-squares, independent t-tests and correlation analyses were conducted to determine significant differences between both groups. The results indicated that both groups are quite similar; whereas families of children with a disability were statistically more likely to visit a health and social service professional.