The removal of nitrate nitrogen from a munitions waste by means of bacterial reduction was investigated using packed anaerobic columns. The feasibility of using a munitions waste high in organic carbon (Water Dry Process Waste) as the organic carbon source was also investigated. Simultaneously the biological processing was accomplished in two manners, anaerobic packed columns and batch anaerobic vessels. It was found that anaerobic columns were effective in reducing 100 mg/l nitrate nitrogen by as much as 99.9% operating at an empty column detention time of 8.76 hours. No difference in denitrification capacity was found between columns packed with activated carbon or sand, but the activated carbon was found to be an undesirable media because of its low specific gravity which permitted it to float after gasification began, and because of foul-smelling odors associated with the activated carbon effluent. The Water Dry Process Waste was found to be a suitable organic carbon source for denitrification and it had a consumptive ratio of 1.47. Batch vessels were found to be ineffective in significantly reducing total nitrogen over a period of 46 days. Buildup of high concentrations of nitrite within the vessels suggested inhibition of the biomass to an extent that further denitrification would not occur. / Master of Science

M.S.

Solid-state reaction and sol-gel, processing techniques were used extensively to form chemically-modified mullite solid solutions in an effort to lower their thermal expansion coefficients. TiO₂, B₂O₃, CrPO₄, P2O₅, Ga₂O₃, Cr2O₃, and WO₃ and the half-breed SiO₂ compounds AlPas, BPO₄, GaPO₄, BAsO₄, AIAsO₄, GaAsO₄, and GeO₂ were chosen as the modifiers. The results indicate that, apart from TiO₂, none of the substitutions made in mullite significantly change the thermal expansion properties. The solubility of 3 wt% TiO₂ in mullite reduces the coefficient of thermal expansion by about 10%; That corresponds to a reduction in AAl₂O₃/SiO₂ molar ratio ( < 1.5) compared to stoichiometric mullite (3Al₂O₃·2SiO₂). The formation of TiO₂-modified mullite depends on processing condition and heat treatment. The possible mechanism of lowering the CTE of mullite by the addition of TiO₂ is discussed in terms of the bond strength. The axial expansion of a Ga2O₃-modified mullite was measured' up to 1200°C to show that the expansion is increased along the c-axis compared with that of the stoichiometric mullite. / Master of Science

A pesquisa por novos materiais e processos que possam garantir aeronaves mais leves e operacionalmente mais viáveis, tem-se dado praticamente em todos os componentes de uma aeronave, com consequência direta no menor consumo de combustível e benefícios para o fabricante, operadores e a população em geral com aplicação do conceito de \'aeronave verde\'. Nestes quesitos, materiais/processos, destacam-se as ligas de alumínio (2xxx e 7xxx) e a solda por fricção mistura (FSW- Friction Stir Welding) por sua relação custo/benefício. A soldagem por fricção de elementos estruturais aeronáuticos formados de materiais dissimilares que possuem propriedades mecânicas distintas é de grande interesse para a indústria aeronáutica, devido aos ganhos de peso e de custo de operação que esse tipo de junção pode gerar. Sendo assim foram avaliadas as principais propriedades mecânicas de interesse e correlacionar com a microestrutura de ligas dissimilares e similares soldadas pelo processo de FSW e a inteiração destas com os meios ambiente, criogênico e corrosivo aos quais, aeronaves podem ser sujeitas durante os voos. Para tal desenvolvimento a solda dissimilar foi realizada com as ligas de alumínio-lítio 2050-T84 e alumínio 7050-T7451, enquanto que a solda similar foi realizada com a liga de alumínio-lítio 2198-T851. Foram feitas análises de ciclo térmico durante a soldagem e ambas juntas foram classificadas como solda quente, que prevê intensa variação microestrutural e afetam as propriedades mecânicas de dureza, a tenacidade fadiga e corrosão fadiga. A caracterização microestrutural realizada pela técnica de EBSD evidenciou alta quantidade de CAA que resultou na redução da dureza e aumento da tenacidade à fratura na região de contato entre a peça de trabalho e o ombro da ferramenta. De contra partida, a taxa de propagação de trinca por fadiga aumentou ligeiramente no meio salino. / The research for new materials and processes that produce light materials and operationally viable, has occurred in almost all the components of an aircraft, with a direct consequence in the lower fuel consumption and benefits for the manufacturing, operators and the population in application of the concept of \'green aircraft\'. In these questions, materials/processes, the most important are aluminum alloys (2xxx and 7xxx) and friction stir welding for their cost/benefit ratio. Friction stir welding of aeronautical structural elements made of dissimilar materials with distinct mechanical properties is of great interest to the aeronautical industry due to the weight and operating costs that this type of joint can result. Thus, the main mechanical properties of interest and correlate with the microstructure of dissimilar and similar alloys welded by the FSW and their interaction with the ambient, cryogenic and corrosive environments to which aircraft may be subject during flight. To development, the dissimilar weld performed with the lithium-aluminum alloys 2050-T84 and aluminum 7050-T7451, while the similar solder performed with the lithium-aluminum alloy 2198-T851. Thermal cycle analyzes were done during welding and both joints were classified as hot welding, which provides intense microstructural variation and affect the mechanical properties of hardness, fatigue toughness and fatigue corrosion. The microstructural characterization performed by the EBSD technique evidenced a high amount of CAA that resulted in low hardness and high fracture toughness in the region of contact between the workpiece and the tool shoulder. On the other hand, the rate of crack propagation by fatigue increased slightly in the saline atmosphere.

A pesquisa por novos materiais e processos que possam garantir aeronaves mais leves e operacionalmente mais viáveis, tem-se dado praticamente em todos os componentes de uma aeronave, com consequência direta no menor consumo de combustível e benefícios para o fabricante, operadores e a população em geral com aplicação do conceito de \'aeronave verde\'. Nestes quesitos, materiais/processos, destacam-se as ligas de alumínio (2xxx e 7xxx) e a solda por fricção mistura (FSW- Friction Stir Welding) por sua relação custo/benefício. A soldagem por fricção de elementos estruturais aeronáuticos formados de materiais dissimilares que possuem propriedades mecânicas distintas é de grande interesse para a indústria aeronáutica, devido aos ganhos de peso e de custo de operação que esse tipo de junção pode gerar. Sendo assim foram avaliadas as principais propriedades mecânicas de interesse e correlacionar com a microestrutura de ligas dissimilares e similares soldadas pelo processo de FSW e a inteiração destas com os meios ambiente, criogênico e corrosivo aos quais, aeronaves podem ser sujeitas durante os voos. Para tal desenvolvimento a solda dissimilar foi realizada com as ligas de alumínio-lítio 2050-T84 e alumínio 7050-T7451, enquanto que a solda similar foi realizada com a liga de alumínio-lítio 2198-T851. Foram feitas análises de ciclo térmico durante a soldagem e ambas juntas foram classificadas como solda quente, que prevê intensa variação microestrutural e afetam as propriedades mecânicas de dureza, a tenacidade fadiga e corrosão fadiga. A caracterização microestrutural realizada pela técnica de EBSD evidenciou alta quantidade de CAA que resultou na redução da dureza e aumento da tenacidade à fratura na região de contato entre a peça de trabalho e o ombro da ferramenta. De contra partida, a taxa de propagação de trinca por fadiga aumentou ligeiramente no meio salino. / The research for new materials and processes that produce light materials and operationally viable, has occurred in almost all the components of an aircraft, with a direct consequence in the lower fuel consumption and benefits for the manufacturing, operators and the population in application of the concept of \'green aircraft\'. In these questions, materials/processes, the most important are aluminum alloys (2xxx and 7xxx) and friction stir welding for their cost/benefit ratio. Friction stir welding of aeronautical structural elements made of dissimilar materials with distinct mechanical properties is of great interest to the aeronautical industry due to the weight and operating costs that this type of joint can result. Thus, the main mechanical properties of interest and correlate with the microstructure of dissimilar and similar alloys welded by the FSW and their interaction with the ambient, cryogenic and corrosive environments to which aircraft may be subject during flight. To development, the dissimilar weld performed with the lithium-aluminum alloys 2050-T84 and aluminum 7050-T7451, while the similar solder performed with the lithium-aluminum alloy 2198-T851. Thermal cycle analyzes were done during welding and both joints were classified as hot welding, which provides intense microstructural variation and affect the mechanical properties of hardness, fatigue toughness and fatigue corrosion. The microstructural characterization performed by the EBSD technique evidenced a high amount of CAA that resulted in low hardness and high fracture toughness in the region of contact between the workpiece and the tool shoulder. On the other hand, the rate of crack propagation by fatigue increased slightly in the saline atmosphere.

This research is a pioneering study focusing on the museum governance system. Governance in museums has been under-researched; however, recent disputes and development have drawn the public’s attention to this subject. Furthermore, there is still no proper theory or model to explain the decision- and policy- making process in museums. Regarding the scope of this thesis, a focus on national museums of the UK and Taiwan has been chosen because of their historical similarities. A literature review was conducted to aim at answering the question of ‘what is governance?’, including its definition and theories, not only in the private sector, but also in the public and non-profit sectors. Museum governance has been identified and compared with the application of marketing and management as well as museology. It was also significant to investigate the historical development of museum governance in the two selected countries. It has enabled the author to find out the most influential factors in the governance systems of museums and create a preliminary model. Six national museums were selected as cases and three trips of fieldwork were achieved in a period of more than a year. A background analysis of each case provided a fundamental understanding of their history, organisational structure and importance. Data collected was later analysed in detail and compared, to understand governance practices as well as to test the proposed model. This has proved that the Interactive Model of museum governance helps to explain the governance process in the museum; however, a minor change has also been made to refine this model. A further literature review was conducted to update the information and also to ensure the originality of this research. There are some suggestions for future research on this subject, and it is the hope of the author to have widened interest in museum governance both in academia and among museum professionals.

Salmonella enterica serovar Typhi, a major public health concern in developing countries, continues to be a priority for the World Health Organization. S. Typhi possesses a viaB locus responsible for the biosynthesis of the Vi-capsular antigen, a significant virulence factor at the focus of developing improved prophylaxis for typhoid fever. Tissue culture experiments have demonstrated that S. Typhi wild-type capsule-expressing strain elicits less chemokine secretion than a viaB mutant. Calf experiments using the viaB mutant resulted in an increase inflammatory response. Osmolarity is one of the control signals that affect the biosynthesis of the Vi antigen. Under high osmolarity growth conditions of 300 mM and greater, Vi production is suppressed and S. Typhi is highly invasive. Studies reveal that the viaB mutant displays increased invasion towards intestinal epithelial cells. Our first objective was to implement direct and indirect methods to localize and detect Vi expression within intestinal epithelial cells and bovine Peyer's patch. The second objective was to compare the invasiveness between a viaB mutant, an ompR mutant, and S. Typhi grown under hyperosmolarity. We also measured the effects of these strains in eliciting inflammation in the calf model. We report that tviB was significantly up regulated intracellularly within T84 polarized cells. In the calf experiments, tviB was expressed at levels significantly higher in calf tissue following invasion compared to inoculum grown under Vi-suppressing conditions. Together, these results support the idea that the Vi capsular antigen is expressed after invasion of intestinal epithelial cells in vivo. We found that S. Typhi grown under high osmolarity, the viaB mutant, and the ompR mutant had increased invasion in polarized T84 cells and bovine ileal tissue. Fluid accumulation among Vi-deficient and Vi-suppressed strains was similar. The histopathology of the inflammatory lesions of the small intestine produced by the Vi-deficient and suppressed strains was quite comparable. Our data supports the notion that Vi-suppressed and Vi mutants of S. Typhi exhibit similar levels of increased invasion and inflammation, perhaps mechanistically through the inactivation of the Vi antigen.

The time- and dose-dependent effects of wortmannin on transepithelial electrical resistance (R(te)) and forskolin-stimulated chloride secretion in T84 monolayer cultures were studied. In both instances, maximal effects developed over 2 h and were stable thereafter. Inhibition of forskolin-stimulated chloride secretion, as measured by the short-circuit current (I(SC)) technique, had an IC50 of 200-500 nM, which is 100-fold higher than for inhibition of phosphatidylinositol 3-kinase (PI3K), but similar to the IC50 for inhibition of myosin light chain kinase (MLCK) and mitogen-activated protein kinases (MAPK). Previous work demonstrated that 500 nM wortmannin did not inhibit the cAMP activation of apical membrane chloride channels. We show here that 500 nM wortmannin has no affect on basolateral Na/K/2Cl-cotransporter activity, but inhibits basolateral membrane Na/K-ATPase activity significantly. The MLCK inhibitors ML-7 and KT5926 were without affect on forskolin-stimulated I(SC). Similarly, the p38- and MEK-specific MAPK inhibitors SB203580 and PD98059 did not reduce forskolin-stimulated I(SC). In contrast, the non-specific MAPK inhibitor apigenin reduced forskolin-stimulated I(SC) and basolateral membrane Na/K-ATPase activity similar to wortmannin. In isolated membranes from T84 cells, wortmannin did not inhibit Na/K-ATPase enzymatic activity directly. We conclude that one or more MAPK may regulate the functional expression of basolateral membrane Na/K-ATPase by controlling the abundance of enzyme molecules in the plasma membrane.

Indiana University-Purdue University Indianapolis (IUPUI) / Carbon nanotubes (CNTs) are one of the most common nanoparticles (NP) found in workplace air. Therefore, there is a strong chance that these NP will enter the human body. They have similar physical properties to asbestos, a known toxic material, yet there is limited evidence showing that CNTs may be hazardous to human barrier epithelia. In previous studies done in our laboratory, the effects of CNTs on the barrier function in the human airway epithelial cell line (Calu-3) were measured. Measurements were done using electrophysiology, a technique which measures both transepithelial electrical resistance (TEER), a measure of monolayer integrity, and short circuit current (SCC) which is a measure of vectorial ion transport across the cell monolayer. The research findings showed that select physiologically relevant concentrations of long single-wall (SW) and multi-wall (MW) CNTs significantly decreased the stimulated SCC of the Calu-3 cells compared to untreated cultures. Calu-3 cells showed decreases in TEER when incubated for 48 hours (h) with concentrations of MWCNT ranging from 4µg/cm2 to 0.4ng/cm2 and SWCNT ranging from 4µg/cm2 to 0.04ng/cm2. The impaired cellular function, despite sustained cell viability, led us to investigate the mechanism by which the CNTs were affecting the cell membrane. We investigated the interaction of short MWCNTs with model lipid membranes using an ion channel amplifier, Planar Bilayer Workstation. Membranes were synthesized using neutral diphytanoylphosphatidylcholine (DPhPC) and negatively charged diphytanoylphosphatidylserine (DPhPS) lipids. Gramicidin A (GA), an ion channel reporter protein, was used to measure changes in ion channel conductance due to CNT exposures. Synthetic membranes exposed to CNTs allowed bursts of currents to cross the membrane when they were added to the membrane buffer system. When added to the membrane in the presence of GA, they distorted channel formation and reduced membrane stability.