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In recent years, titanium oxide thin film has been studied extensively for using in optical devices and electronic devices such as waveguide and future ultra-large scale dynamic random access memory (DRAM). Titanium oxide film is very promising candidates for applications with exhibiting higher dielectric constant, high refractive index and high chemical stability. Liquid phase deposition is a novel method to grow oxide layer. It has the advantage of low-temperature deposition, good step coverage, and selective growth. We use this technology to deposition titanium oxide film instead of the conventional methods of growth titanium oxide film, such as sol-gel, sputtering, LPCVD, APCVD, and PECVD. But low deposition rate is one of the drawbacks drawbacks of LPD process. In previous study, deposition rate of titanium oxide films was very slow (6Å/min). The mixture of H2TiF6(aq) and H3BO3(aq) was used as the principal solution. In this study, we incorporated HNO3(aq) into the principal solution for enhance the deposition rate. In addition, we study the deposition rate and dielectric constant of titanium oxide films as functions of H2O addition, NH4OH(aq), and Ba(OH)2(aq) concentrations in our principal solution. We examine electrical characteristics and thickness of the titanium films by capacitance-voltage measurement and Spectroscopic Reflectance. The deposition rate of titanium oxide film increases from 6 Å/min to 475Å/min and the dielectric constant is about 36.1 with adding HNO3 and opportune NH4OH into the principal solution.

Master of Science / Food Science and Industry / Fadi M. Aramouni / Gluten-free products are becoming more prevalent in the market today, however there are a few types of products that have “hidden” gluten and people will not realize until after consumption. Products like soy sauce and beer are sources of gluten that people don’t know about. Soy sauce contains wheat as a main ingredient so replacing it with a gluten-free flour such as sorghum may produce a product similar to wheat-based soy sauce. Sorghum was used in this experiment since it is a grain grown in the mid-western region of the United States and a growing food ingredient in the global market. Sorghum can come in many different varieties and colors so we used different varieties in this study. Four treatments were done using three different sorghum flours (black, white, and waxy sorghum flour) and a wheat flour for a control. Cooked soybeans were mashed in a kitchenaid mixer and the treatment flour was added to make a dough. That dough was formed into a log and cut into slices. The slices were then staked with wet paper towels to mold. After 13 days of molding, the slices that were made were dried, placed in a salt solution, and fermented for 100 days. The solution was mixed with a spatula for 30 seconds to homogenize the mixture every 2-3 days and samples were taken every 10 days to test for pH, salinity, and color. Once the 100 days were complete and the pH of each treatment did not drop for consecutive testing periods, the liquid was removed from the solids and pasteurized. The pH curve did show that a fermentation process did occur, however there was no control over what microorganism could grow. Consumer testing was not performed since all test sauces were deemed unacceptable at the initial screening.

The preparation and characterisation of chelating sorbents suitable for the high efficiency separation of trace metals in complex samples, using a single column and isocratic elution, is described. Hydrophobic, neutral polystyrene divinylbenzene resins were either impregnated with chelating dyes or dynamically modified with heterocyclic organic acids, using physical adsorption and chemisorption processes respectively. A hydrophilic silica substrate was covalently bonded with a chelating aminomethylphosphonic acid group, to assess the chelating potential of this molecule. These substrates were characterised in terms of metal retention capability (selectivity coefficients and capacity factors), separation performance, column efficiency and suitability for analytical applications. Chelating molecules with different ligand groups were found to have unique selectivity patterns dependant upon the conditional stability constants of the chelate. Other factors, including mobile phase constituents - complexing agents, ionic strength and pH, column length and column capacity were additionally investigated to examine their effect upon the separation profiles achieved. The promising metal separation abilities illustrated by a number of these chelating columns were exploited for the determination of trace toxic metals in complex sample matrices using High Performance Chelation Ion Chromatography (HPCIC). This included the determination of beryllium in a certified stream sediment, uranium in seawater and a certified stream sediment, and cadmium, lead and copper in a certified rice flour. The results for each analysis fell within the certified limits, and reproducibility was good. The optimisation of post column detection systems using chromogenic ligands additionally gave good detection limits for the metals in each separation system.

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Homogeneous single C-S-H gels have been prepared for the investigation of alkali binding potential and crystallisation. A distribution coefficient, R_d, was introduced to express the partition of alkali between solid and aqueous phases at 25°C. R_d is independent of alkali hydroxide concentration and depends only on Ca:Si ratio over wide ranges of alkali concentration. The trend of numerical values of R_d indicates that alkali bonding into the solid improves as its Ca:Si ratio decreases. Reversibility is demonstrated, indicating a possibility of constant R_d value of the material. Al has been introduced to form C-A-S-H gels and their alkali sorption properties also determined. Al substituted into C-S-H markedly increases R_d, indicating enhancement of alkali binding. However, the dependence of R_d on alkali concentration is non-ideal with composition. A two-site model for bonding is presented. Crystallisation both under saturated steam and 1 bar vapour pressure has been investigated. It has been shown that heat treatment by saturated steam causes crystallisation of gels. The principal minerals obtained were (i) C-S-H gel and Ca(OH)₂ at ~55°C, (ii) 1.1 nm tobermorite, jennite and afwillite at 85-130°C, and (iii) xonotlite, foshagite and hillebrandite at 150-180°C. Properties of crystalline C-S-H were also reported for reversible phase transformation, pH conditioning ability, seeding effect and solubility. At 1 bar pressure, crystallisation is slower than in saturated steam due to lower water activity. Tobermorite-like nanodomains develop during reaction at low Ca/Si ratios. In some Ca-rich compositions, Ca(OH)₂ is exsolved and occurs as nano-sized crystallites.

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Made available in DSpace on 2014-10-09T12:35:53Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:31Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:43:48Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:09Z (GMT). No. of bitstreams: 1 06773.pdf: 7313261 bytes, checksum: afb0bc00fde188a0f75b9462245bb12d (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP