Thesis (M.S. in chemical engineering)--Washington State University, August 2005. / Includes bibliographical references.

O uso de tetracloreto de carbono (CCl4) em ratos é um modelo experimental de dano ao tecido hepático, desencadeando fibrose e, a longo prazo, cirrose. A cirrose hepática é uma doença crônica progressiva que representa um estado de disfunção hepática irreversível ou lentamente reversível, caracterizado pela formação de nódulos fibróticos. Este estudo possui como objetivo avaliar as alterações hepáticas e pulmonares causadas pelo modelo de cirrose hepática através da utilização de CCl4 intraperitoneal. Foram utilizados 18 ratos Wistar machos divididos em 3 grupos: grupo controle (CO) e outros 2 grupos divididos pelo tempo de indução da cirrose por CCl4. G1 (11 semanas), G2 (16 semanas). Verificamos a elevação significativa no nível das transaminases hepáticas, na lipoperoxidação do tecido hepático e pulmonar (TBARS) e nas enzimas antioxidantes SOD e CAT, além de um aumento da expressão de TNF-M e IL-1N no pulmão dos animais cirróticos. Observamos alteração nas trocas gasosas de ambos os grupos cirróticos. Podemos concluir que nosso modelo reproduziu a cirrose hepática, além de causar alterações no sistema pulmonar, provocando alteração nas trocas gasosas e alterando o tamanho dos vasos pulmonares. / The use of carbon tetrachloride (CCl4) in rats is an experimental model of hepatic tissue damage, which leads to fibrosis, and at the long term, cirrhosis. Cirrhosis is a chronic progressive disease that represents a state of irreversible or slowly reversible hepatic disfunction, characterized by fibrotic nodules formation. The aim of this study is to evaluate the changes caused by cirrhosis in lung and liver, through the experimental model of intraperitoneal CCl4 administration. We used 18 male Wistar rats divided into three groups: control (CO) and two groups divided by the time of cirrhosis induction by CCl4. G1 (11semanas), G2 (16semanas). We found significant increase of transaminase levels and lipid peroxidation (TBARS) in liver and lung tissue. Also, increased antioxidant enzymes SOD and CAT, as well as the expression of TNF-M and IL-1N in the lung of cirrhotic animals. We observed changes in gas exchange in both cirrhotic groups. We can conclude that our model reproduces the liver cirrhosis, that causes alterations in the pulmonary system that leads to changes in gas exchange and size of pulmonary vessels.

O uso de tetracloreto de carbono (CCl4) em ratos é um modelo experimental de dano ao tecido hepático, desencadeando fibrose e, a longo prazo, cirrose. A cirrose hepática é uma doença crônica progressiva que representa um estado de disfunção hepática irreversível ou lentamente reversível, caracterizado pela formação de nódulos fibróticos. Este estudo possui como objetivo avaliar as alterações hepáticas e pulmonares causadas pelo modelo de cirrose hepática através da utilização de CCl4 intraperitoneal. Foram utilizados 18 ratos Wistar machos divididos em 3 grupos: grupo controle (CO) e outros 2 grupos divididos pelo tempo de indução da cirrose por CCl4. G1 (11 semanas), G2 (16 semanas). Verificamos a elevação significativa no nível das transaminases hepáticas, na lipoperoxidação do tecido hepático e pulmonar (TBARS) e nas enzimas antioxidantes SOD e CAT, além de um aumento da expressão de TNF-M e IL-1N no pulmão dos animais cirróticos. Observamos alteração nas trocas gasosas de ambos os grupos cirróticos. Podemos concluir que nosso modelo reproduziu a cirrose hepática, além de causar alterações no sistema pulmonar, provocando alteração nas trocas gasosas e alterando o tamanho dos vasos pulmonares. / The use of carbon tetrachloride (CCl4) in rats is an experimental model of hepatic tissue damage, which leads to fibrosis, and at the long term, cirrhosis. Cirrhosis is a chronic progressive disease that represents a state of irreversible or slowly reversible hepatic disfunction, characterized by fibrotic nodules formation. The aim of this study is to evaluate the changes caused by cirrhosis in lung and liver, through the experimental model of intraperitoneal CCl4 administration. We used 18 male Wistar rats divided into three groups: control (CO) and two groups divided by the time of cirrhosis induction by CCl4. G1 (11semanas), G2 (16semanas). We found significant increase of transaminase levels and lipid peroxidation (TBARS) in liver and lung tissue. Also, increased antioxidant enzymes SOD and CAT, as well as the expression of TNF-M and IL-1N in the lung of cirrhotic animals. We observed changes in gas exchange in both cirrhotic groups. We can conclude that our model reproduces the liver cirrhosis, that causes alterations in the pulmonary system that leads to changes in gas exchange and size of pulmonary vessels.

O uso de tetracloreto de carbono (CCl4) em ratos é um modelo experimental de dano ao tecido hepático, desencadeando fibrose e, a longo prazo, cirrose. A cirrose hepática é uma doença crônica progressiva que representa um estado de disfunção hepática irreversível ou lentamente reversível, caracterizado pela formação de nódulos fibróticos. Este estudo possui como objetivo avaliar as alterações hepáticas e pulmonares causadas pelo modelo de cirrose hepática através da utilização de CCl4 intraperitoneal. Foram utilizados 18 ratos Wistar machos divididos em 3 grupos: grupo controle (CO) e outros 2 grupos divididos pelo tempo de indução da cirrose por CCl4. G1 (11 semanas), G2 (16 semanas). Verificamos a elevação significativa no nível das transaminases hepáticas, na lipoperoxidação do tecido hepático e pulmonar (TBARS) e nas enzimas antioxidantes SOD e CAT, além de um aumento da expressão de TNF-M e IL-1N no pulmão dos animais cirróticos. Observamos alteração nas trocas gasosas de ambos os grupos cirróticos. Podemos concluir que nosso modelo reproduziu a cirrose hepática, além de causar alterações no sistema pulmonar, provocando alteração nas trocas gasosas e alterando o tamanho dos vasos pulmonares. / The use of carbon tetrachloride (CCl4) in rats is an experimental model of hepatic tissue damage, which leads to fibrosis, and at the long term, cirrhosis. Cirrhosis is a chronic progressive disease that represents a state of irreversible or slowly reversible hepatic disfunction, characterized by fibrotic nodules formation. The aim of this study is to evaluate the changes caused by cirrhosis in lung and liver, through the experimental model of intraperitoneal CCl4 administration. We used 18 male Wistar rats divided into three groups: control (CO) and two groups divided by the time of cirrhosis induction by CCl4. G1 (11semanas), G2 (16semanas). We found significant increase of transaminase levels and lipid peroxidation (TBARS) in liver and lung tissue. Also, increased antioxidant enzymes SOD and CAT, as well as the expression of TNF-M and IL-1N in the lung of cirrhotic animals. We observed changes in gas exchange in both cirrhotic groups. We can conclude that our model reproduces the liver cirrhosis, that causes alterations in the pulmonary system that leads to changes in gas exchange and size of pulmonary vessels.

no abstract provided by author / Master of Science

Throughout the United States, there are a large number of groundwater systems contaminated by chlorinated organic compounds. Of these compounds, carbon tetrachloride (CT) is one of the most frequently encountered due to its past, widespread industrial use. In anaerobic groundwater environments, CT has been shown to be susceptible to degradation by both biotic and abiotic processes. One abiotic process that has been researched extensively is the reduction of CT by iron metal and associated iron oxides and hydroxides. Magnetite, an iron oxide, is a ubiquitous component of many subsurface environments and has been investigated as a potential groundwater remediation technology. One beneficial characteristic of magnetite is the capability to be synthetically produced in various sizes and shapes - including particles within the nanoscale range. Nanoscale particles have been shown to be more reactive towards contaminants than larger sized particles due to their large surface areas and high surface reactivity. This project was designed to characterize the behavior of synthetic magnetite in the presence of carbon tetrachloride under anaerobic conditions. / Master of Science

Carbon tetrachloride (CCl₄ ) was closely evaluated as a carrier solvent in high-performance liquid chromatography (HPLC). The separation and retention trends of ninety-two selected compounds from eleven chemical classes (furans, thiophenes, aromatic hydrocarbons, ethers, esters, ketones, aldehydes, aromatic amines, azaarenes, alcohols and phenols) on three analytical silica-bonded phase (amino (NH₂), cyano (CN) and polar amino-cyano (PAC)) columns were investigated with CCl₄ and refractive index (RI) detection. The sample capacity and column efficiency of each of the NH₂ and PAC columns were measured and compared. Besides, a method of determining unmeasurable capacity factors (k' values) was found and illustrated. / M.S.

<p dir="ltr">Borane-ammonia (BH₃-NH₃) has played an essential role in shaping and promoting the field of organic chemistry. However, we believe that the potential applications of BA in organic reductions have yet to be investigated. Our studies aimed to investigate BA as a reducing agent in organic reactions and to delve into the associated reduction mechanisms. In the second chapter of our research, we discovered that a combination of borane-ammonia and titanium tetrachloride (TiCl₄) has been explored as a versatile system for reducing various carbonyl compounds. By using BA with a small amount of TiCl₄ catalyst (10 mol%) in diethyl ether (Et₂O), we reduced different aryl and alkyl ketones into secondary alcohols at room temperature in just 30 minutes. This method is much faster than traditional uncatalyzed conditions, which usually take 24 hours or more to achieve the same reduction, and it does so without impacting other functional groups. Substituted cycloalkanones are selectively reduced to the thermodynamically favored product. Our deuterium labeling experiments found that the most probable pathway involves the hydroboration mechanism involving ketones and borane-ammonia in the presence of TiCl₄.</p><p><br></p><p dir="ltr">A slight variation in this chemical system can significantly impact the deoxyhalogenation process of aryl aldehydes, ketones, carboxylic acids, and esters. This process involves using a metal halide Lewis acid as a carbonyl activator, halogen carrier, and borane-ammonia. The selectivity of this process is determined by balancing the carbocation intermediate's stability with the Lewis acid's acidity. The choice of solvent and Lewis acid depends on the substituents present, and different substitution patterns have been explored. These principles have also been applied to selectively convert alcohols into alkyl halides. Furthermore, this system is used to selectively deoxygenate carbonyls of aldehydes and ketones into methyl and methylene hydrocarbons. The substituents on the benzene ring play a significant role in the deoxygenation process of carbonyl carbons in aldehydes and ketones.</p><p><br></p><p dir="ltr">In the third chapter of the study, various applications of the titanium system are examined. The TiCl₄/BH₃-NH₃ system was used to directly reduce a range of carboxylic acids to the corresponding alcohols at room temperature with good to excellent yields. This reduction method was achieved by adjusting the stoichiometry of borane-ammonia. This process is tolerant to various potentially reactive functional groups, such as N-protected amino acids, enabling the selective reduction of acids in the presence of amides and nitriles. Further, the titanium system was used to deoxygenation aromatic and aliphatic carboxylic esters into ethers. The ratio of borane-ammonia and catalyst controls the process. This method is the first practical borane-mediated process compatible with many sensitive functional groups and can convert challenging aromatic acid esters into ethers. Using BF₃–Et₂O as the catalyst changes the result products, reducing the esters to alcohols instead.</p><p><br></p><p dir="ltr">In the fourth chapter of our exploration, we looked at various applications of this system that involved reducing aliphatic and aromatic nitriles to primary amines. This was achieved by using 2.0 equivalents of <a href="" target="_blank">BH₃-NH₃ </a>and a molar equivalent of TiCl₄. We also found that the TiCl₄/BA system in dichloroethane (DCE) under reflux temperature efficiently reduces (deoxygenates) a range of aromatic and aliphatic primary, secondary, and tertiary carboxamides. We adjusted the catalyst and reductant stoichiometry accordingly, and the resulting amines were obtained in high yields using a simple acid-base workup.</p>

The purpose of this investigation was to redesign, construct, and operate a two-inch experimental pulse liquid-liquid extractor, and to determine the effects of the pulse amplitude, the number of plates, and the plate-free-area on the stage efficiency of the column. The optimum liquid flow rates were also determined. An examination of the literature was conducted for a review of the available information on pulse extractors. Although a great deal of literature was available on the topic of liquid-liquid extraction, detailed information on only two pulse extractors could be found. The results obtained during this investigation compare favorably with those reported in the literature. A two-inch experimental pulse-type extractor was constructed. The liquids were pulsed by means of a sylphon-type bellows operated by a push rod which was driven by an eccentric cam. For the satisfactory operation of the extractor various auxiliary apparatus was required; important among these were the supporting framework, the push-rod bearing, the reduction train for the can, the storage tanks, and the tubing and fittings. Twenty-seven individual experimental tests were conducted, extracting acetone from carbon tetrachloride with water, to determine the effects of the various operating parameters on the stage efficiency of the pulse column. During the experimental tests the following variables were studied: pulse amplitude at one, two, and three inches of vertical liquid displacement; number of plates with four, eight, and twelve plates; and plate-free-area with eight, sixteen, and thirty-two per cent free area. It was found that the pulse amplitude, the number of plates, and the plate-free-area each have an independent significant effect on the stage efficiency of the pulse column; the plate-free-area has the largest relative effect, while the pulse amplitude has the smallest relative effect. It was further proven by this investigation that the interactions between the pulse amplitude and number of plates, the pulse amplitude and plate-free-area, and the number of plates and plate-free-area have no significant effect on the stage efficiency of the pulse column. The flow rates for satisfactory column operation are 1807, 2211, 1478, and 2299 pounds per hour-square foot of column cross-section for the feed, solvent, raffinate, and extract, respectively. / Master of Science

Dissertation (Ph.D.)--University of South Florida, 2007. / Title from PDF of title page. Document formatted into pages; contains 141 pages. Includes vita. Includes bibliographical references.