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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Spectroscopic Studies of Copper-Thiomolybdate Interactions

Kuzma, Darina 06 August 2009
Cu is an important trace element in living systems, including animals. It is a part of many enzymes responsible for different processes occurring in the body. However, antagonists can severely decrease the amount of Cu available to the animal, which results in numerous health issues caused by Cu deficiency. The main antagonists of the Cu are thiomolybdates whose effect is especially harsh in ruminants due to their high potential to synthesize these compounds. Thiomolybdates (the ions MoOxS4-x2- ,where x = 0-3) are formed in the rumen from molybdate and sulfide (from degradation of sulfate), both of which come from the food and water ingested by the animal.<p> The first part of the project described in this thesis was to develop reproducible preparative methods of CuTM samples in solution and solids, under conditions as biologically relevant as possible. This crucial information is missing in the literature related to Cu deficiency. The second part studied the structure of the adduct formed between Cu and two of the thiomolybdates: tetrathiomolybdate, TM4 and trithiomolybdate, TM3, as these are the most important in Cu deficiency.<p> In solution, the appropriate solution medium and the concentration of reactants were chosen to study the stoichiometry of Cu:TM in solution before precipitation occurs.<p> Conditions for preparation of solid CuTM adducts were chosen to obtain the amount of solid necessary for further studies and to eliminate the formation of unwanted side-products. In the solid phase, the stoichiometry of Cu:TM was investigated by elemental analysis. EPR spectroscopy of solid CuTM samples revealed the presence of diamagnetic species which were partially identified.<p> EXAFS studies were performed on both the Mo and Cu K edges. Spectra defined the oxidation states of both main metal atoms, Cu and Mo. Fitting of the measured EXAFS spectra of solid CuTM samples prepared at three different Cu:TM ratios determined the interatomic distances involved in these compounds. This data was used to determine the structure of the CuTM units which polymerize to form the final product. IR spectroscopy was also used to confirm the presence of some of the groups in these adducts.<p> All the results from the various spectroscopic techniques were then combined to proposed a complete reaction scheme for the two-step formation of the CuTM4 and CuTM3 adduct species.
122

Spectroscopic Studies of Copper-Thiomolybdate Interactions

Kuzma, Darina 06 August 2009 (has links)
Cu is an important trace element in living systems, including animals. It is a part of many enzymes responsible for different processes occurring in the body. However, antagonists can severely decrease the amount of Cu available to the animal, which results in numerous health issues caused by Cu deficiency. The main antagonists of the Cu are thiomolybdates whose effect is especially harsh in ruminants due to their high potential to synthesize these compounds. Thiomolybdates (the ions MoOxS4-x2- ,where x = 0-3) are formed in the rumen from molybdate and sulfide (from degradation of sulfate), both of which come from the food and water ingested by the animal.<p> The first part of the project described in this thesis was to develop reproducible preparative methods of CuTM samples in solution and solids, under conditions as biologically relevant as possible. This crucial information is missing in the literature related to Cu deficiency. The second part studied the structure of the adduct formed between Cu and two of the thiomolybdates: tetrathiomolybdate, TM4 and trithiomolybdate, TM3, as these are the most important in Cu deficiency.<p> In solution, the appropriate solution medium and the concentration of reactants were chosen to study the stoichiometry of Cu:TM in solution before precipitation occurs.<p> Conditions for preparation of solid CuTM adducts were chosen to obtain the amount of solid necessary for further studies and to eliminate the formation of unwanted side-products. In the solid phase, the stoichiometry of Cu:TM was investigated by elemental analysis. EPR spectroscopy of solid CuTM samples revealed the presence of diamagnetic species which were partially identified.<p> EXAFS studies were performed on both the Mo and Cu K edges. Spectra defined the oxidation states of both main metal atoms, Cu and Mo. Fitting of the measured EXAFS spectra of solid CuTM samples prepared at three different Cu:TM ratios determined the interatomic distances involved in these compounds. This data was used to determine the structure of the CuTM units which polymerize to form the final product. IR spectroscopy was also used to confirm the presence of some of the groups in these adducts.<p> All the results from the various spectroscopic techniques were then combined to proposed a complete reaction scheme for the two-step formation of the CuTM4 and CuTM3 adduct species.
123

Recovery of carbonate copper ore by means of flotation at the Kennecott Copper Corporation plant, Kennecott, Alaska

Richert, George Leo. January 1926 (has links) (PDF)
Thesis (Professional Degree)--University of Missouri, School of Mines and Metallurgy, 1926. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed November 30, 2009) Includes index (p. 30-35).
124

The Ore Knob copper process

Lachmund, Oscar. January 1887 (has links) (PDF)
Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1887. / The entire thesis text is included in file. Holograph [Handwritten and illustrated in entirety by author]. Title from title screen of thesis/dissertation PDF file (viewed December 28, 2009)
125

THE KINETICS OF THE DISSOLUTION REACTIONS OF COPPER AND COPPER - IRON-SULFIDE MINERALS USING FERRIC-SULFATE SOLUTIONS

Lowe, Donald Frank, 1934- January 1970 (has links)
No description available.
126

Structure modifications produced in electrodeposited copper by an organic compound in the electrolyte

Hinton, Phillip Eugene, 1926- January 1968 (has links)
No description available.
127

A comparison of hydrometallurgical methods for treating a typical Arizona ore

Barney, Wayne K., 1929- January 1954 (has links)
No description available.
128

Experimental work involving the substitution of manganese for iron in copper mattes

Potter, George Michael, 1914- January 1936 (has links)
No description available.
129

Effect of stress relaxation on the kinetics of recovery and recrystallization in hot worked ETP copper

Vazquez Brisen̄o, Lucio. January 1980 (has links)
No description available.
130

Evaluation of modified montmorillonites in poultry diets

Butkeraitis, Paula, January 2007 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on January 30, 2007) Vita. Includes bibliographical references.

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