The performance of membranes in various processes is largely dependent on their morphological properties. Thus, membrane structure has been continuously optimised for different applications. Anodic alumina membranes (AAMs) exhibit self-ordered pore structure and the pore size can be tuned in the sub-micrometre range. The aim of this PhD project is to propose and develop AAMs for the applications of membrane filtration and emulsification with potential for scale-up. In the project, the AAMs were initially fabricated in flat sheet form to optimise the process parameters to obtain membranes with a high quality of pore structure. The membrane pore diameter can be readily controlled by the anodization voltage. While AAMs are normally symmetric, by manipulating the anodization voltage, asymmetric AAMs consists of stem pores and active pores have been successfully made. After that, the flat AAMs with symmetric and homogeneous structure were used as a platform to study for surface modification and fluid transport in nano-channels. The surface chemistry and wettability of the membranes has been altered by grafting of silane molecules and carbon coating by chemical vapour deposition. Fluid flow measurement through pristine AAMs with pore diameter in the 20 nm to 100 nm range shows flow enhancement effect, experimentally for the first time, can occur in hydrophilic materials. Subsequently, tubular AAMs were fabricated using aluminium alloy tubes, to be assessed for ultrafiltration and membrane emulsification processes. The pore structure of the tubular AAMs was analogous to flat membranes. Despite the reduced pore circularity and hexagonal arrangement originated from the presence of impurities in the starting materials, the narrow pore size distribution was not compromised. In a selectivity-permeability analysis, the asymmetric tubular AAMs outperformed most of the commercial ceramic membranes but their flux was very low when compared to polymeric membranes. A bovine serum albumin filtration test showed that complete pore blocking-cake filtration model can be used to describe the fouling behaviour. Finally, symmetric tubular membranes were used to study dead-end and cross-flow emulsification processes. The resulting emulsions show low polydispersity. Using a membrane with 25 nm average pore diameter, the obtained average droplet size was as low as 120 nm during a cross-flow emulsification. This is by far the smallest achieved average droplet size by cross-flow membrane emulsification.

The effective separation of ammonia from the synthesis loop in ammonia synthesis plants is an important step in its manufacture. This work presents the use of nanocomposite MFI zeolite membranes prepared by a pore-plugging method for this separation process. Performance of a zeolite membrane is highly dependent on the operating conditions. Therefore, the influences of differential pressure, temperature, sweep gas flow, feed gas flow and gas composition are studied experimentally. Transport of NH3 in this membrane is by surface diffusion in the intracrystalline (zeolite) pores in parallel with capillary condensation in the intercrystalline (non-zeolite) pores. The separation of NH3 from a mixture with H2 and N2 is by preferential adsorption of NH3, which hinders the permeation of weakly adsorbed H2 and N2. Differential pressure has only relatively small effects in the pressure range 300kPa – 1550kPa. Increase in sweep flow rate has little effect on NH3 gas permeance, but H2 and N2 permeances increase thereby decreasing the selectivities. Increase in feed flowrate also has little effect on NH3 permeance. However, the N2 and H2 permeances increase and there is a subsequent decrease in selectivities. Membrane performance was found to be highly dependent on temperature. NH3 permeance in the mixture increases linearly with temperature. NH3 selectivity was found to increase with temperature up to 353K after which it starts to decrease due to N2 and H2 permeances increasing with temperatures beyond 353K (αNH3/N2 = 46 and αNH3/H2 = 15) and is therefore the optimum temperature for separation. A potential barrier model is developed to describe the hindering effect of NH3 on H2 and N2 permeance. The model fails to predict correctly H2 and N2 permeances in the ternary mixture using pure gas (H2 and N2) permeances. Binary mixture permeation H2/N2 studies showed that there are diffusion effects (single file diffusion) that have not been taken into account in the potential barrier model. When permeances of the individual components in the binary mixture are used in the model instead of the pure gas permeances, there is an improved agreement between experimental and predicted results.

Resumo: O objetivo deste trabalho foi avaliar o efeito de diferentes tratamentos de superfície da cerâmica Y-TZP na resistência de união, durabilidade e discrepância marginal. Para os testes de resistência adesiva, foram obtidos 144 corpos de prova (cp) da cerâmica VITA In-Ceram YZ for InLab (5,25 x 3,75 x 4,5 mm), que foram divididos em 6 grupos (G) (n=24), conforme o tratamento de superfície: G1: sem tratamento (controle); G2: jateamento com partículas de alumínio revestidas por sílica (CoJet®-Sand, 3M ESPE AG) (silicatização); G3: vitrificação 1 (Glaze Spray VITA AKZENT), condicionamento com ácido fluorídrico (HF) (1 min); G4: vitrificação 1 (Glaze Spray VITA AKZENT), silicatização; G5: vitrificação 2 (Glaze VITA AKZENT), condicionamento com HF (1 min); G6: vitrificação 2 (Glaze VITA AKZENT), silicatização. Após todos os tratamentos, as superfícies foram silanizadas por 5 min (ESPE-SIL) e a cimentação com Panavia F (Kuraray) foi realizada. Metade dos espécimes de cada tratamento foi ensaiada 24h após cimentação (SECO), a outra metade foi submetida à armazenagem (150 dias) e termociclagem (12.000x) (TC), e então realizado o ensaio de cisalhamento (1 mm/min). G7: G1+TC; G8: G2+TC; G9: G3+TC; G10: G4+TC; G11: G5+TC; G12: G6+TC. Superfícies tratadas foram analisadas por perfilometria óptica 3D para obtenção dos dados de rugosidade (Ra) e microscopia eletrônica de varredura (MEV) (1000x). Análise por energia dispersiva de raio-X (EDS) foi realizada para determinar os elementos químicos presentes na superfície de cada grupo. Para a análise de adaptação marginal foram confeccionadas 60 infraestruturas (adaptadas em um troquel metálico) nas quais foram realizados os mesmos tratamentos de superfície / Abstract: The aim of this study was to evaluate the effect of different surface treatments of Y-TZP ceramic on bond durability and marginal fit. 144 specimens of VITA In-Ceram YZ for InLab ceramic (5.25 x 3.75 x 4.5 mm) were obtained and divided into 6 groups (n=24) according to the surface treatment: G1: no treatment (control); G2: chairside tribochemical silica coating system (CoJet®-Sand, 3M ESPE AG) (Cojet); G3: vitrification 1 (Glaze Spray VITA AKZENT), conditioning with hydrofluoric acid (HF) (1 minute); G4: vitrification 1 (Glaze Spray VITA AKZENT), Cojet; G5: vitrification 2 (Glaze VITA AKZENT), conditioning with HF (1 minute); G6: vitification 2 (Glaze VITA AKZENT), Cojet. Then, the ceramic surfaces were silanized and the cementPanavia F (Kuraray) was applied. Half of the specimens from each treatment was tested 24 hours after cementation (DRY), the remaining specimens were stored in distilled water for150 days,thermocycled(12,000x) (AGING) and then the shear test was performed (1mm/minute). Conditioned surfaces were evaluated by 3D optical profilometry in order to obtain roughness data (Ra) and analysed by scan electronic microscopy (SEM) (1000x). Analysis by energy x-ray dispersive (EDS) was performed to determine the chemical elements present in each surface group. For analysis of marginal adaptation 60 crowns were produced (adapted into a metal die) and the same surface treatments were carried out on the internal surface of the crowns. The data were analysed using. The results suggest the vitrification 1 and vitrification 2 groups showed the highest bond strength compared to the control group. The highest marginal discrepancies were observed in the vitrification groups (117.36±29.61 to 105.78±12.23) comparing with the other groups (55.29±8.71 and 55.04±8.55). / Orientador: Luiz Felipe Valandro / Coorientador: Fernando Eidi Takahashi / Banca: Marco Antonio Bottino / Banca: Renata Marques Melo / Banca: Paulo Francisco Cesar / Banca: Marcelo Giannini / Doutor

OBJECTIVES: To evaluate the marginal chipping of anterior veneers made with CAD/CAM by calculating the chipping factor, to evaluate the failure load of different veneering materials and thicknesses under static loading and cyclic loading. MATERIALS AND METHODS: An ivorine central incisor was prepared to receive a traditional veneer. Using epoxy resin, 120 replication dies were made of the prepared tooth. Four ceramic materials were used; IPS Empress CAD, IPS e.max CAD, VITA ENAMIC and Lava Ultimate. Veneers were milled using a Sirona InLab MCXL at three different thicknesses, 0.4mm, 0.7mm and 1.0mm, n=10 for each group. Veneers were inspected under the light microscope to calculate the chipping factor (CF). All veneers were cemented to their tooth replicas using Variolink Veneer resin cement. Five specimens/group were loaded under compression using an Instron universal testing machine at a rate of 0.5 mm/minute until fracture. Another five specimens were subjected to cyclic loading at 30% of the mean fracture load for 30,000 cycles at frequency rate of 1 Hz, and then were loaded under compression to fracture. Modes of failure were recorded after each test. RESULTS: IPS Empress CAD 0.4mm CF was higher than all other groups, and VITA ENAMIC and Lava Ultimate 1.0mm CF were the lowest. There was a significant difference in the failure load of the IPS Empress CAD and IPS e.max CAD groups under static loading but not in VITA EANMIC and Lava Ultimate groups. Cyclic fatigue had no significant effect on the failure load of different veneering materials and thicknesses. CONCLUSIONS: Chipping factor decreases as the material thickness increases and can be used as an indicator of material machinability. IPS e.max CAD at 1.0mm had the highest static failure load value when compared to other materials. Cyclic fatigue did not affect the failure load values within the groups tested. / 2019-09-26T00:00:00Z

I wish I could believe in something. Having grown up in a religious household, I have continually teetered between faith and doubt. Landscapes seen and unseen are my last source of awe; here my doubt is suspended – for a moment. Using unfired clay, I create alternate landscapes inspired by sublime philosophy. The sublime experience is born in a sense of amazement linked to fear of something beyond our understanding or control. The amazing intricacy of microbiology, a whole universe existing alongside and inside us, fascinates me. The abundance of unfamiliar life in my work triggers a cautious curiosity. My imagined worlds push beyond the boundaries provided for them invading our tense reality. These unfamiliar landscapes offer a window of escape, where viewers explore their relationship to an alternate world which bears similarities to our own.

generic of is a creative text paralleling the creation of my thesis exhibition. I use fragmented layers of narrative, description and prose in the same way each handbuilt ceramic is fired multiple times, allowing the glazes to build upon themselves. This is a close study of the still life, the intimacy of consuming, and how trauma is passed through the gut.

Bibliography: leaves 210-223.

The design of a fabric composite heat pipe has been completed. It is composed of two end caps, between which a fluid containment liner composed of metal foil and an outer structural layer composed of a ceramic fabric is stretched. The interior of the heat pipe is layered with a ceramic fabric wick. This heat pipe is being constructed currently at Oregon State University. The heat pipe test facility has been designed and built. Final assembly of the various components is now under way. This test facility consists of a vacuum chamber with a coolant jacket on the outside. Inside this chamber a test stand is placed which is composed of radiation shields and a supporting stand for the heat pipe and the heaters. Experimental work has been performed to ensure material compatibility of the metal foils used as a fluid containment liner. Specific materials tested include copper, aluminum, titanium, FEP teflon and three ceramic fabrics. These materials have been exposed to a variety of working fluids for up to 5000 hours at various sub-boiling temperatures. The best combinations of materials include aluminum or copper and acetone, or titanium and water. The least compatible combinations included aluminum or copper and water. An experimental apparatus to measure the wettability of candidate ceramic fabric wicks was designed and built. This apparatus included a pressure chamber to allow measurements to be taken at elevated pressures and temperatures. The liquid front velocity in one meter lengths of unwetted samples of ceramic fabrics was measured. A computer was used to determine liquid front position at 30 finite points along the fabric sample. Analysis of the data allowed calculation of a constant composed of two wicking parameters to be measured. Analysis of various analytical methods for predicting these parameters was performed. / Graduation date: 1993

Ph.D. / Materials Science and Engineering / Polytitanates in the BaO- TiO2 system with Ba:Ti ratios ranging from 1:2 to 1:5 were prepared using a low temperature technique developed by Pechini. The samples were heated at 600 to 1300°C in oxygen. Room temperature Raman spectroscopy was used to investigate the phase relations in this system. Results of this study indicate the following: except for BaTi4O9, the powders of these compounds were amorphous when heated at 600°C for 4hrs; the compound BaTi2O5 is a low temperature stable phase; Ba6Ti17O40 forms only at temperatures above 1100°C; Ba4Ti13O30 does not form below 1000°C; the single phase BaTi4O9 structure was observed at 1200°C'; the Ba2Ti9O20 phase is obtained only after long heat treatment at 1200°; BaTi5O11 was stable up to 1200°C, at which it decomposes into Ba2Ti4O20 and TiO2. After determination of stability relationships in this system, the electrical conductivities of these compounds were examined as a function of temperature and oxygen partial pressure. For all the temperatures (850-1150°C) studied, the conductivities of these compounds increased with decreasing oxygen partial pressure resulting in n-type properties throughout the whole P[subscript O2] range (10[superscript -19 - 1atm). The P[subscript O2] dependencies of the electrical conductivity were found to be linear for an extensive range of oxygen partial pressures. On the basis of structural considerations the conductivity data was described by a majority defect model consisting of both singly and doubly ionized oxygen vacancies. For lower oxygen partial pressure values a drastic change in the electrical conductivity was observed. This is believed to result from increasing defect interaction for larger departures from stoichiometry. A defect model based on this interaction is proposed to account for the observed sharp change in the electrical conductivity values.

Abstract When Taiwanese ceramic tile industry invested in the Mainland China, they are facing the differences between cross-strait strategies. Shall the Taiwanese businessmen change their business management strategy? This is the subject of present study. The objectives of present study include the following: (1) to find out the knowledge of Taiwanese ceramic tile industry regarding the cross-strait strategies and to see if there¡¦s any differences among them, (2) to find out the effects of differences in cross-strait management strategy, This study includes only Taiwanese ceramic tile industry of KwangTong and Shanghai Districts and this is the main source of our sampling and information gathering. The scope of present study is limited to the differences between cross-strait strategies, emphasizing on the social and political aspects. The principal manageable variables are: 1. differences in cross-strait strategies, 2. business strategies of Taiwanese companies, 3. management strategies. Using the Taiwanese ceramic tile industry companies or factories who had investment in Mainland China, we study the effect of above independent variables and the interaction between them. methods used include: case study analysis, confidential analysis, main factor analysis. 1. There¡¦s significant effect for Taiwanese business on management strategies. 2. There¡¦s no significant effect for differences of cross-strait cultures on management strategies. Also the present study had presented four new kinds of business strategies, namely: 1. Hierarchy strategies: based on the hierarchy and rules. 2. Control strategies: based oneself-discipline and managerial intervention. 3. Freedom strategies: there¡¦s free style for management. The competitiveness is from productivity and innovation not low wages, or a valued currency. Key words : Business strategies, Taiwan company,managment