Thesis (M. Phil.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

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. Seu metabolismo ocorre no fígado pelo citocromo P450, resultando na produção de radicais livres e estimulação da lipoperoxidação, que induz um processo de necrose, inflamação e maior progressão da fibrose. Vários antioxidantes, entre eles os flavonoides, têm sido referidos como eficazes para diminuir a fibrose em modelos animais. Este estudo pretende avaliar a ação antioxidante da quercetina (Q) em um modelo experimental de cirrose induzida por CCl4 inalatório. Foram utilizados 25 ratos Wistar machos, com peso médio de 250g, divididos em 3 grupos: Controle (CO), CCl4 e CCl4+Q. Os ratos foram submetidos a inalações de CCl4 (2x/semana), durante 16 semanas, recebendo fenobarbital na água de beber na dose de 0,3g/dl, como indutor enzimático. A Q (50mg/Kg) via intraperitoneal foi iniciada na 10ª semana de inalação, perdurando até o final do experimento. A análise estatística foi ANOVA, seguida de Student Newmann Keuls (Média±SEM), considerando-se diferença estatisticamente significativa quando p<0,05. Após o tratamento com quercetina, observamos uma melhora na integridade hepática, diminuição da fibrose, do conteúdo de colágeno e re-estabelecimento nos níveis dos metabólitos do óxido nítrico, comparado ao grupo CCl4. Constatou-se também redução do dano oxidativo, verificada pela diminuição das substâncias que reagem ao ácido tiobarbitúrico (TBA-RS), assim como aumento na atividade das enzimas antioxidantes e da relação GSH/GSSG. A partir desses dados, sugerimos que o emprego da quercetina possa ser promissor como terapia antioxidante nas complicações hepáticas. / Carbon tetrachloride (CCl4) is a classic experimental model of oxidative damage to liver tissue, causing long-term fibrosis and cirrhosis. Metabolism in the liver via cytochrome P450 results in the stimulation of lipid peroxidation and production of free radicals, which induce a process of necrosis, inflammation and greater progression of fibrogenesis. Various antioxidants and flavonoids have been identified as effective in reducing fibrosis in animal models. This study aimed to assess the antioxidant activity of quercetin (Q) in an experimental model of cirrhosis induced by CCl4 inhalation. We used 25 male Wistar rats (250g) that were divided into 3 groups: control (CO), CCl4 and CCl4 + Q. The rats were subjected to CCl4 inhalation (2x/week) for 16 weeks, and they received phenobarbital in their drinking water at a dose of 0.3 g/dl as a P450 enzyme inducer. Q (50 mg/Kg) was initiated intraperitoneally at 10 weeks of inhalation and lasted until the end of the experiment. Statistical analysis was by ANOVA Student-Newman Keuls (mean ± SEM), and differences were considered statistically significant when p <0.05. After treatment with quercetin, we observed an improvement in liver integrity, decreased fibrosis, as analyzed by picrosirius for the quantification of collagen, and restored levels of nitric oxide metabolites compared with the CCl4 group. It also reduced oxidative stress, as confirmed by the decrease of substances reacting to thiobarbituric acid (TBARS), the increased activity of antioxidant enzymes and the reduced glutathione ratio and glutathione disulfide (GSH/GSSG). From these data, we suggest that the use of quercetin might be promising as an antioxidant therapy in liver complications.

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. Seu metabolismo ocorre no fígado pelo citocromo P450, resultando na produção de radicais livres e estimulação da lipoperoxidação, que induz um processo de necrose, inflamação e maior progressão da fibrose. Vários antioxidantes, entre eles os flavonoides, têm sido referidos como eficazes para diminuir a fibrose em modelos animais. Este estudo pretende avaliar a ação antioxidante da quercetina (Q) em um modelo experimental de cirrose induzida por CCl4 inalatório. Foram utilizados 25 ratos Wistar machos, com peso médio de 250g, divididos em 3 grupos: Controle (CO), CCl4 e CCl4+Q. Os ratos foram submetidos a inalações de CCl4 (2x/semana), durante 16 semanas, recebendo fenobarbital na água de beber na dose de 0,3g/dl, como indutor enzimático. A Q (50mg/Kg) via intraperitoneal foi iniciada na 10ª semana de inalação, perdurando até o final do experimento. A análise estatística foi ANOVA, seguida de Student Newmann Keuls (Média±SEM), considerando-se diferença estatisticamente significativa quando p<0,05. Após o tratamento com quercetina, observamos uma melhora na integridade hepática, diminuição da fibrose, do conteúdo de colágeno e re-estabelecimento nos níveis dos metabólitos do óxido nítrico, comparado ao grupo CCl4. Constatou-se também redução do dano oxidativo, verificada pela diminuição das substâncias que reagem ao ácido tiobarbitúrico (TBA-RS), assim como aumento na atividade das enzimas antioxidantes e da relação GSH/GSSG. A partir desses dados, sugerimos que o emprego da quercetina possa ser promissor como terapia antioxidante nas complicações hepáticas. / Carbon tetrachloride (CCl4) is a classic experimental model of oxidative damage to liver tissue, causing long-term fibrosis and cirrhosis. Metabolism in the liver via cytochrome P450 results in the stimulation of lipid peroxidation and production of free radicals, which induce a process of necrosis, inflammation and greater progression of fibrogenesis. Various antioxidants and flavonoids have been identified as effective in reducing fibrosis in animal models. This study aimed to assess the antioxidant activity of quercetin (Q) in an experimental model of cirrhosis induced by CCl4 inhalation. We used 25 male Wistar rats (250g) that were divided into 3 groups: control (CO), CCl4 and CCl4 + Q. The rats were subjected to CCl4 inhalation (2x/week) for 16 weeks, and they received phenobarbital in their drinking water at a dose of 0.3 g/dl as a P450 enzyme inducer. Q (50 mg/Kg) was initiated intraperitoneally at 10 weeks of inhalation and lasted until the end of the experiment. Statistical analysis was by ANOVA Student-Newman Keuls (mean ± SEM), and differences were considered statistically significant when p <0.05. After treatment with quercetin, we observed an improvement in liver integrity, decreased fibrosis, as analyzed by picrosirius for the quantification of collagen, and restored levels of nitric oxide metabolites compared with the CCl4 group. It also reduced oxidative stress, as confirmed by the decrease of substances reacting to thiobarbituric acid (TBARS), the increased activity of antioxidant enzymes and the reduced glutathione ratio and glutathione disulfide (GSH/GSSG). From these data, we suggest that the use of quercetin might be promising as an antioxidant therapy in liver complications.

The Council for Scientific and Industrial Research (CSIR) in South Africa is developing a process to produce titanium tetrachloride from a low-grade material such as ilmenite. Titanium tetrachloride can then be used as feed material for titanium metal or pigment-grade titanium dioxide production. Titanium tetrachloride is commercially produced by chlorinating synthetic rutile (<92% TiO2) or titanium dioxide slag (<85% TiO2) at ~900 ˚C. A drawback of chlorination at this temperature is that any constituents other than TiO2 will end up as hazardous waste material. A characteristic step in the CSIR’s proposed process is to nitride titanium dioxide contained in the feed material before it is sent for chlorination. The chlorination of the resulting titanium nitride is achieved at a much lower temperature (~200 ˚C) than that of the existing titanium dioxide chlorination reaction. An added advantage of the low-temperature chlorination reaction is that chlorine is selective mostly towards titanium nitride and metallic iron, which means that any other constituents present are not likely to react with the chlorine. The result is reduced chlorine consumption and less hazardous waste produced. The nitrided ilmenite must, however, be upgraded by removing all iron before it can be sent for chlorination. Commercial ilmenite upgrading processes, called synthetic rutile production, also require the removal of iron and other transition metals before chlorination. A literature review of existing ilmenite upgrading processes revealed four possible process options that could remove iron from nitrided ilmenite. Two of these process options, the Becher and Austpac ERMS SR processes, are proven process routes. The other two are novel ideas – one to passivate iron contained in the nitrided ilmenite against chlorination and the other to use ammonium chloride (as used in the Becher process) as a stoichiometric reactant to produce a ferrous chloride solution. A preliminary experimental evaluation of these process options indicated that the Austpac ERMS SR process is the most viable option for removing iron from nitrided ilmenite. The Austpac ERMS SR process was therefore selected as a template for further process development. A detailed Austpac ERMS SR process review found that two process units in the Austpac ERMS SR process could be used in a process that separates iron from nitrided ilmenite. These are the Enhanced Acid Regeneration System and the Direct Reduced Iron process units. The review also concluded that another leach unit would have to be developed. It was therefore necessary to further investigate the dissolution of nitrided ilmenite in hydrochloric acid. A detailed experimental evaluation of nitrided ilmenite dissolution in hydrochloric acid found that hydrochloric acid could be used as the lixiviant to selectively remove iron from nitrided ilmenite. The dissolution of metallic iron in 90 ˚C hydrochloric acid reached levels of at least 96% after only 60 minutes. An average “combined resistance” rate law was found that could be used to describe this dissolution reaction. The observed activation energy and Arrhenius pre-exponential factor were found to be equal to 9.45 kJ.mol-1 and 30.8 s-1 respectively. The Austpac ERMS SR process review and experimental results described above were then combined and used to propose a process that could be employed to remove iron from nitrided ilmenite. The proposed process was modelled using the Flowsheet Simulation module in HSC Chemistry 7.0 / Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2010. / Chemical Engineering / MEng (Chemical Engineering) / unrestricted

No description available.

Zirconium tetrachloride (ZrF4) is extensively used in the manufacturing of zirconium metal. The concept of producing zirconium tetrafluoride from dissociated zircon and ammonium bifluoride is well established at the South African Nuclear Energy Corporation (Necsa) State Owned Company (SOC) Limited. Zirconium and hafnium are always found in the same minerals. In nuclear application zirconium is used for structural construction and as a cladding material for fuel, because of the low thermal neutron absorption, while hafnium is used as control rod in nuclear reactor, because of the high thermal neutron absorption. The methods of separating hafnium from zirconium prefer the use of ZrCl4 than ZrF4. This is because of the high solubility in both aqueous solutions and organic solvents and low sublimation temperature of ZrCl4, while ZrF4 is almost insoluble in organic solvent and has a high sublimation temperature. Thermodynamic evaluations showed that chlorinating ZrF4 with either CaCl2, KCl, LiCl or NaCl respectively was not favourable, while chlorinating ZrF4 with either BeCl2 or MgCl2 was favourable. But due to cost consideration chlorinating ZrF4 with BeCl2 was not investigated. A thermogravimetric apparatus was used to investigate the isothermal and the non-isothermal kinetics of chlorinating analytical grade ZrF4 with MgCl2. The thermogravimetric apparatus revealed that chlorination of ZrF4 commence at temperature above 350°C. Isothermal kinetics of chlorinating analytical grade ZrF4 with MgCl2 was investigated at temperatures of 400, 450, 480, 500°C. The reaction progressed towards completion prematurely before the isothermal temperatures were reached, due to a low heating rate of 20 °C/minutes was used to heat up the reaction mixture to the desired isothermal temperatures. As a result, the isothermal kinetics could not be determined. Heating rates of 5, 10, 15 and 20 °C/minutes were used to investigate the non-isothermal kinetics. The apparent activation energy of chlorinating ZrF4 with MgCl2 varied significantly when the non-isothermal kinetics was investigated. The variation was due to changes in the reaction mechanism. As a result, rate law of chlorinating ZrF4 with MgCl2 could not be determined due to variation of the apparent activation energy. Crude ZrF4 prepared at Necsa SOC ltd. was chlorinated with MgCl2, a mixture of MgCl2 and KCl, a mixture of MgCl2 and LiCl, and a mixture of MgCl2 and NaCl respectively. Chlorination of the crude ZrF4 was conducted at temperatures of 400, 450 and 500°C respectively. The aim of chlorinating the crude ZrF4 was to investigating the effect of the chlorinating on the purity of the produced ZrCl4. A batch reactor was used in this study. The reactor was divided into two sections, namely the reaction zone and the condensation zone. The diameter of the condensation zone was larger than that of the reaction zone. Reactants were placed into the reaction zone and the products were collected at the reaction zone and the condensation zone. Samples were collected from these products and analysed using for X-Ray Diffraction analysis (XRD) and Inductive Coupled Plasma Optical Emissions Spectroscopy (ICP-OES). XRD was used to identify the compounds that were present in the products and ICP-OES was used to determine the concentration of the elements that were present in the products. The analysis of the results obtained showed that the highest recovery of zirconium in the products collected from the condensation zone, the sublimed products, was achieved by chlorinating ZrF4 with MgCl2 at 500°C. About 80% was recovered. About 96% of the concentration of the impurities in the sublimed products was reduced when ZrF4 was chlorinated with a mixture of MgCl2 and LiCl at 450°C. About 36% of hafnium in the sublimed products was reduced when ZrF4 was chlorinated with a mixture of MgCl2 and NaCl at 400°C. / Chemical Engineering / M.Tech. (Chemical Engineering)

Yang Lei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 141-148). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Abstract (Chinese Version) --- p.iv / Table of Contents --- p.vi / List of Abbreviations --- p.xii / List of Figures --- p.xiii / List of Tables --- p.xviii / Chapter Chapter 1 --- Literature review --- p.1 / Chapter 1.1 --- Carbon tetrachloride (CC14) --- p.1 / Chapter 1.2 --- Major uses of CC14 --- p.1 / Chapter 1.3 --- Potential human exposure pathways to CC14 --- p.2 / Chapter 1.4 --- Toxicity of CC14 --- p.3 / Chapter 1.5 --- Mechanism of CCl4-induced hepatotoxicity --- p.5 / Chapter 1.6 --- Role of CYP2E1 involved in CCl4-induced hepatotoxicity --- p.7 / Chapter 1.7 --- Definite proof of the involvement of CYP2E1 in CCl4-induced hepatotoxicity by CYP2El-null mouse in vivo model --- p.10 / Chapter 1.8 --- Identification of CYP2E1 -dependent genes involved in CCl4-induced hepatotoxicity by fluorescent differential display (FDD) --- p.11 / Chapter 1.9 --- Objectives of the study --- p.14 / Chapter Chapter 2 --- Materials and methods --- p.16 / Chapter 2.1 --- Animals and treatments --- p.16 / Chapter 2.1.1 --- Materials --- p.16 / Chapter 2.1.2 --- Methods --- p.16 / Chapter 2.2 --- Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) analyses --- p.17 / Chapter 2.2.1 --- Materials --- p.17 / Chapter 2.2.2 --- Methods --- p.17 / Chapter 2.2.2.1 --- Serum preparation --- p.17 / Chapter 2.2.2.2 --- Activity determination --- p.18 / Chapter 2.3 --- Tail-genotyping by PCR --- p.18 / Chapter 2.3.1 --- Materials --- p.18 / Chapter 2.3.2 --- Methods --- p.20 / Chapter 2.3.2.1 --- Preparation of genomic DNA from mouse tail --- p.20 / Chapter 2.3.2.2 --- PCR reaction --- p.20 / Chapter 2.4 --- Total RNA isolation --- p.21 / Chapter 2.4.1 --- Materials --- p.21 / Chapter 2.4.2 --- Methods --- p.21 / Chapter 2.5 --- DNase I treatment --- p.23 / Chapter 2.5.1 --- Materials --- p.23 / Chapter 2.5.2 --- Methods --- p.23 / Chapter 2.6 --- Reverse transcnption of mRNA and amplification by fluorescent PCR amplification --- p.26 / Chapter 2.6.1 --- Materials --- p.27 / Chapter 2.6.2 --- Methods --- p.27 / Chapter 2.7 --- Fluorescent differential display (FDD) --- p.28 / Chapter 2.7.1 --- Materials --- p.28 / Chapter 2.7.2 --- Methods --- p.28 / Chapter 2.8 --- Excision of differentially expressed cDNA fragments --- p.29 / Chapter 2.8.1 --- Materials --- p.29 / Chapter 2.8.2 --- Methods --- p.29 / Chapter 2.9 --- Reamplification of differentially expressed cDNA fragments --- p.34 / Chapter 2.9.1 --- Materials --- p.34 / Chapter 2.9.2 --- Methods --- p.34 / Chapter 2.10 --- Subcloning of reamplified cDNA fragments --- p.36 / Chapter 2.10.1 --- Materials --- p.36 / Chapter 2.10.2 --- Methods --- p.37 / Chapter 2.11 --- Purification of plasmid DNA from recombinant clones --- p.39 / Chapter 2.11.1 --- Materials --- p.39 / Chapter 2.11.2 --- Methods --- p.39 / Chapter 2.12 --- DNA sequencing of differentially expressed cDNA fragments --- p.40 / Chapter 2.12.1 --- Materials --- p.40 / Chapter 2.12.2 --- Methods --- p.40 / Chapter 2.12.3 --- BLAST search against the GenBank DNA databases --- p.41 / Chapter 2.13 --- Northern blot analysis of differentially expressed cDNA fragments --- p.41 / Chapter 2.13.1 --- Formaldehyde gel electrophoresis of total RNA --- p.41 / Chapter 2.13.1.1 --- Materials --- p.42 / Chapter 2.13.1.2 --- Methods --- p.42 / Chapter 2.13.2 --- Preparation of cDNA probes for hybridization --- p.42 / Chapter 2.13.2.1 --- EcoRI digestion of cDNA inserts from plasmid DNA --- p.42 / Chapter 2.13.2.1.1 --- Materials --- p.42 / Chapter 2.13.2.1.2 --- Methods --- p.43 / Chapter 2.13.2.2 --- Purification of DNA from agarose gel --- p.43 / Chapter 2.13.2.2.1 --- Materials --- p.43 / Chapter 2.13.2.2.2 --- Methods --- p.43 / Chapter 2.13.2.3 --- DIG labeling of cDNA --- p.44 / Chapter 2.13.2.3.1 --- Materials --- p.44 / Chapter 2.13.2.3.2 --- Methods --- p.44 / Chapter 2.13.3 --- Hybridization --- p.45 / Chapter 2.13.3.1 --- Materials --- p.45 / Chapter 2.13.3.2 --- Methods --- p.45 / Chapter Chapter 3 --- Results --- p.47 / Chapter 3.1 --- Liver morphology --- p.47 / Chapter 3.2 --- Serum ALT and AST activities --- p.47 / Chapter 3.3 --- Tail-genotyping by PCR --- p.51 / Chapter 3.4 --- DNase I treatment --- p.51 / Chapter 3.5 --- FDD RT-PCR and excision of differentially expressed cDNA fragments --- p.51 / Chapter 3.6 --- Reamplification of excised cDNA fragments --- p.61 / Chapter 3.7 --- Subcloning of reamplified cDNA fragments --- p.61 / Chapter 3.8 --- DNA sequencing of subcloned cDNA fragments --- p.69 / Chapter 3.9 --- Confirmation of differentially expressed patterns by Northern blot analysis --- p.106 / Chapter 3.10 --- Temporal expression of differentially expressed genes --- p.113 / Chapter 3.11 --- Tissue distribution of differentially expressed genes --- p.117 / Chapter Chapter 4 --- Discussion --- p.125 / Chapter 4.1 --- Liver morphology and serum ALT and AST activities --- p.126 / Chapter 4.2 --- Identification of CYP2E1 -dependent genes involved in CCl4-induced hepatotoxicity --- p.127 / Chapter 4.3 --- Functional roles of the identified differentially expressed genes --- p.129 / Chapter 4.3.1 --- Fragment B4 --- p.129 / Chapter 4.3.2 --- Fragment C12 --- p.130 / Chapter 4.3.3 --- Fragment B13 --- p.131 / Chapter 4.3.4 --- Fragment A5 --- p.132 / Chapter 4.4 --- Temporal expression of differentially expressed genes --- p.133 / Chapter 4.4.1 --- Fragment B4 --- p.133 / Chapter 4.4.2 --- Fragment C12 --- p.134 / Chapter 4.4.3 --- Fragment B13 --- p.134 / Chapter 4.4.4 --- Fragment A5 --- p.135 / Chapter 4.5 --- Tissue distribution of differentially expressed genes --- p.136 / Chapter 4.5.1 --- Fragment B4 --- p.136 / Chapter 4.5.2 --- Fragment C12 --- p.136 / Chapter 4.5.3 --- Fragment B13 --- p.137 / Chapter 4.5.4 --- Fragment A5 --- p.137 / Chapter 4.5.5 --- Roles of the identified genes involved in CCl4-induced hepatotoxicity --- p.138 / Chapter 4.6 --- Normalization of Northern blot analysis --- p.13 8 / Chapter 4.7 --- Limitations of FDD technique to identify differentially expressed genes --- p.138 / Chapter 4.8 --- Future studies --- p.139 / Chapter 4.8.1 --- Investigation of the differential expression patterns of the identified genes in acetaminophen-induced liver injury --- p.139 / Chapter 4.8.2 --- Dot blot analysis --- p.140 / Chapter 4.8.3 --- DNA microarray --- p.140 / References --- p.141

Zirconium tetrachloride (ZrF4) is extensively used in the manufacturing of zirconium metal. The concept of producing zirconium tetrafluoride from dissociated zircon and ammonium bifluoride is well established at the South African Nuclear Energy Corporation (Necsa) State Owned Company (SOC) Limited. Zirconium and hafnium are always found in the same minerals. In nuclear application zirconium is used for structural construction and as a cladding material for fuel, because of the low thermal neutron absorption, while hafnium is used as control rod in nuclear reactor, because of the high thermal neutron absorption. The methods of separating hafnium from zirconium prefer the use of ZrCl4 than ZrF4. This is because of the high solubility in both aqueous solutions and organic solvents and low sublimation temperature of ZrCl4, while ZrF4 is almost insoluble in organic solvent and has a high sublimation temperature. Thermodynamic evaluations showed that chlorinating ZrF4 with either CaCl2, KCl, LiCl or NaCl respectively was not favourable, while chlorinating ZrF4 with either BeCl2 or MgCl2 was favourable. But due to cost consideration chlorinating ZrF4 with BeCl2 was not investigated. A thermogravimetric apparatus was used to investigate the isothermal and the non-isothermal kinetics of chlorinating analytical grade ZrF4 with MgCl2. The thermogravimetric apparatus revealed that chlorination of ZrF4 commence at temperature above 350°C. Isothermal kinetics of chlorinating analytical grade ZrF4 with MgCl2 was investigated at temperatures of 400, 450, 480, 500°C. The reaction progressed towards completion prematurely before the isothermal temperatures were reached, due to a low heating rate of 20 °C/minutes was used to heat up the reaction mixture to the desired isothermal temperatures. As a result, the isothermal kinetics could not be determined. Heating rates of 5, 10, 15 and 20 °C/minutes were used to investigate the non-isothermal kinetics. The apparent activation energy of chlorinating ZrF4 with MgCl2 varied significantly when the non-isothermal kinetics was investigated. The variation was due to changes in the reaction mechanism. As a result, rate law of chlorinating ZrF4 with MgCl2 could not be determined due to variation of the apparent activation energy. Crude ZrF4 prepared at Necsa SOC ltd. was chlorinated with MgCl2, a mixture of MgCl2 and KCl, a mixture of MgCl2 and LiCl, and a mixture of MgCl2 and NaCl respectively. Chlorination of the crude ZrF4 was conducted at temperatures of 400, 450 and 500°C respectively. The aim of chlorinating the crude ZrF4 was to investigating the effect of the chlorinating on the purity of the produced ZrCl4. A batch reactor was used in this study. The reactor was divided into two sections, namely the reaction zone and the condensation zone. The diameter of the condensation zone was larger than that of the reaction zone. Reactants were placed into the reaction zone and the products were collected at the reaction zone and the condensation zone. Samples were collected from these products and analysed using for X-Ray Diffraction analysis (XRD) and Inductive Coupled Plasma Optical Emissions Spectroscopy (ICP-OES). XRD was used to identify the compounds that were present in the products and ICP-OES was used to determine the concentration of the elements that were present in the products. The analysis of the results obtained showed that the highest recovery of zirconium in the products collected from the condensation zone, the sublimed products, was achieved by chlorinating ZrF4 with MgCl2 at 500°C. About 80% was recovered. About 96% of the concentration of the impurities in the sublimed products was reduced when ZrF4 was chlorinated with a mixture of MgCl2 and LiCl at 450°C. About 36% of hafnium in the sublimed products was reduced when ZrF4 was chlorinated with a mixture of MgCl2 and NaCl at 400°C. / Chemical Engineering / M.Tech. (Chemical Engineering)

published_or_final_version / abstract / Chinese Medicine / Master / Master of Philosophy

No description available.