Abstract The objective of this study is to compare the performance over copper oxide catalyst under nonselective catalytic reduction of nitric oxide with methane and selective catalytic reduction of nitric oxide with propane. The copper catalysts was prepared by impregnating the support Al2O3 with copper nitrate. In order to find the favorable kind and concentration of acid solution¡Awe conducted the modification of three acid solutions on the support Al2O3 in the same normal concentration in the first¡Aand followed by the test of various concentration of the most-favoured acid. The experiment operated condition was as follow¡G reaction temperature 623K-1023K¡AF/W¡×108000ml/hr.g¡Aoxygen concentration 2¢M¡ANOx inlet concentration 1000ppm. In view of the result of NSCR reactions with methane over Cu/£^-Al2O3 catalyst¡Athe conversion of De-NOx increased with the increasing loading of copper on Cu/£^-Al2O3¡Aand achieved a max. value when copper loading was 8¢Mwt.. The performance of De-NOx over the modified copper catalysts three different acid with the same normal concentraion¡Ashowed that the best reduction efficiency was with nitric acid modified¡Athen with¡Aand followed with acetic acid¡Aphosphoric acids. Through compared the conversion of De-NOx between non-modified Cu/£^-Al2O3 with modified Cu/£^-Al2O3¡Athere had the best efficiency in treating for NO conversion. It showed that the best efficiency in raising the conversion of NO over copper catalyst is modified with nitric acid¡Athere is not helpful on reduction efficiency of NO by modification with acetic and phosphatic acids. Nevertheless¡Athe higher concentration¡]N¡^ of nitric acid is¡Athe higher efficiency of De-NO is¡F For the SCR reactions with propane, when the inlet concentraion NO/C3H8 was 1¡Athere has better reductive activity. The trends for the NO conversion versus reaction temperature were similar for the same catalysts used. In general, the NO conversion was an increasing function of copper loading for these copper catalysts. The 8¢Mwt. Cu/£^-Al2O3 was found to enhance the NO conversion. The activity of acid-treated catalysts in nitric acid with 2¢MO2 present had the best NO conversion, while the same order was in NSCR reaction. Treating the supports with a higher concentration of acid would result in a higher activity for the copper catalyst, implying that acid treatment not only duces surface area to decrease on catalyst and enhance the reactivity, but also the presence of Cu+ and Cu2+ might be responsible for the reaction efficiency. no matter what the reactant is propane or methan , propane is better reactant to catalyst NO to N2.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 149-161). Available also in a digital version from Dissertation Abstracts.

Not available / text

published_or_final_version / abstract / toc / Clinical Psychology / Master / Master of Social Sciences

published_or_final_version / Botany / Master / Master of Philosophy

The current investigation examined the effects of a differential attentional training task on subsequent emotional reactivity in response to a task that was aimed to either induce positive or negative affectivity. Specifically, the study employed a dot-probe attentional training paradigm to train attention toward positive images (Attend-Positive condition), toward neutral images (Attend-Neutral condition), or to not train attention at all (Control condition). The hypothesis was that individuals whose attention was trained toward positive images would exhibit faster response times toward positive images (compared to the Attend-Neutral and Control conditions) at post assessment, individuals whose attention was trained toward neutral images would exhibit faster response times toward neutral images (compared to the Attend-Positive and Control conditions) at post assessment, and individuals in the Control condition would maintain similar response times from baseline to post assessment, aside from general practice effects. It was also hypothesized that those in the Attend-Positive condition would better regulate emotion, as measured by less negative affect in response to a stress task and more positive affect in response to a positive mood induction task, compared to individuals who have engaged in a control task involving no attentional bias training (Control condition). It was also hypothesized that those in the Attend-Neutral condition would better regulate emotion, as measured by less negative affect in response to a stress task and more positive affect in response to a positive mood induction task, compared to individuals who have engaged in a control task involving no attentional bias training (Control condition). Last, it was hypothesized that individuals in the Attend-Positive condition would report differentially less negative affect in response to the stress task (failure anagrams) than those in the Attend-Neutral condition, and that individuals in the Attend-Positive condition would report differentially more positive affect in response to the positive mood induction task (success anagrams) than those in the Attend-Neutral condition. In all conditions, the dot-probe attentional training did not effectively modify biases in the hypothesized directions. While there was differential affectivity change for individuals who underwent a Failure Anagram task versus a Success Anagram task, there is no way to definitively interpret the meaning of these changes given the failure of the attentional manipulation. The findings from the current investigation provide no evidence for single-session dot-probe attentional bias modification procedures to manipulate attentional bias toward positive stimuli or toward neutral stimuli. Possible explanations for these results, including lack of reliability of the dot-probe task, are discussed.

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