Copper deficiency causes significant annual losses in grain yield due to poor grain set. Cereals such as wheat and barley are particularly susceptible to low copper soils whereas,crops such as rye and triticale are better able to grow and yield under such conditions of nutrient stress. The ability of rye and triticale, which carries a complete set of rye chromosomes, to tolerate low copper conditions has been attributed to a gene on rye chromosome 5R. Wheat-rye translocation lines have previously been produced carrying segments of the long arm of chromosome 5 of rye (5RL). Although these lines have expressed copper efficiency in University of Adelaide trials, until now they have been considered agronomically inferior and so have not been used as commercial cultivars. The physical size of rye segment of the 4BS.4BL-5RL translocation in a Chinese Spring background derived from the Cornell Wheat Selection 82a1-2-4-7 was measured using GISH (genomic in situ hybridization) and found to be 16% of the long arm. The size of this translocation was similar to GISH measurements of another 4BS.4BL-5RL translocation in Viking wheat background, although both these lines arose spontaneously and at different times. Molecular maps of both 4BS.4BL-5RL translocations in the two different wheat backgrounds were developed and used to screen for rare recombinants between wheat and rye in a background homozygous for the Sears' ph1b mutant. The maps revealed the approximate genetic location of the translocation breakpoint involved in these two 4BS.4BL-5RL translocations to be similar even though they are known to have arisen at different times and in different experimental populations. The similarity of these translocations suggests a unique property of the region at or near the translocation breakpoint that could be responsible for their similarity and spontaneous formation. After screening 703 critical seedlings for evidence of recombination between the 5RL segment and wheat homoeologues, no confirmed recombinants were identified. Lines containing the 4BS.4BL-5RL translocation were shown to yield equally as well as their recurrent parent under normal field conditions. In addition the presence of the 4BS.4BL-5RL had no adverse effects on a range of grain quality characteristics measured in these lines. A pot trial using lines derived from a cross between the CSHN translocation and the wheat cultivar Warigal (five backcrosses) revealed that they provided copper-efficiency even under the severest of deficiency conditions. While the results of this pot trial did not show the outstanding copper efficiency previously observed in these lines, the translocation did consistently out yield the recurrent parent under severe copper deficiency conditions. Finally, a reliable PCR marker was developed for the rapid identification of lines containing the distal portion of the 5RL chromosome. / Thesis (Ph.D.)--School of Agriculture and Wine, 2004.

Thesis (Ph.D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 344-349).

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1912. / The entire thesis text is included in file. Typescript and handwritten. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed February 20, 2009)

Copper oxide supported on alumina (CuO/Al2O3), silica (CuO/SiO2) and chromia (CuO/Cr2O3) have been synthesized and characterized. These catalysts were characterized using XRD, SEM, TEM, ICP, BET surface area and pore volume, TPR, TPD, TGA-DSC and IR. The hydrogenation of octanal using these catalysts was investigated; however, the primary focus of the project was the influence of water on the reaction and the catalysts. The initial study using CuO/Al2O3 showed that the optimum operating conditions for subsequent catalytic testing was 160 °C and a hydrogen to aldehyde ratio of two. Under these conditions, a conversion of 99 % and selectivity to octanol of 97 % was achieved. Further catalytic testing, using CuO/Al2O3 and CuO/Cr2O3, was carried out by introducing water-spiked feed into the reaction system after steady state was reached using fresh feed. Based on literature, it was initially expected that the presence of water would cause catalyst poisoning and subsequently catalyst deactivation. However, contrary to the expectation, the presence of water did not influence the activity of these two catalysts. Furthermore, the selectivity to octanol increased to 98.5 % when CuO/Al2O3 was used for the reaction, whilst a minor change in the selectivity to octanol (0.5 %) was obtained when CuO/Cr2O3 was used. The interaction of the water with the surface hydroxyls on alumina is most likely the reason for the increase in the selectivity to octanol when using CuO/Al2O3. In contrast to the other two catalysts, the reaction over CuO/SiO2 showed a steady decrease in both the conversion of octanal and the selectivity to octanol with time-onstream when using fresh feed. After 55 hours on stream, the conversion reached 22 %, (from an initial 95 %) whilst the selectivity to octanol reached 89 % (from an initial 98 %). This decline in the conversion and selectivity to octanol was possibly due in part, to the low isoelectric point of silica, with mechanical failure being the major contributing factor to the catalyst’s deactivation. The decrease in the BET surface area and the presence of smaller particles in the SEM image, confirmed that mechanical failure occurred. Since steady state was not reached and deactivation occurred, the reaction over CuO/SiO2 was also carried out using water-spiked feed. The conversion of octanal was seen to gradually decrease to 73 % after 55 hours on stream, whilst the selectivity to octanol remained unchanged at 98 % for the duration of the reaction. This showed the beneficial effect of the presence of water by slowing down the decline in catalytic activity and maintaining the selectivity to octanol. The improved selectivity obtained in the presence of water was attributed to its interaction with the silica surface hydroxyls. Since octanal conversion continued to decrease, it indicated that mechanical failure was the primary cause in the loss of catalytic activity. The used catalysts were characterized using XRD, SEM, EDS composition scanning, TEM, BET surface area and pore volume, TGA-DSC and IR. The catalysts used for the reaction with the fresh feed and the water-spiked feed were characterized and compared. Except for the deactivation of CuO/SiO2, the characterization of these catalysts showed that the presence of water did not negatively impact the make-up of the catalyst. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2010.

The nucleation and successful growth of copper (Cu) thin films on diffusion barrier/adhesion promoter substrates during metal-organic chemical vapor deposition (MOCVD) are strongly dependent on the initial Cu precursor-substrate chemistry and surface conditions such as organic contamination and oxidation. This research focuses on the interactions of bis(1,1,1,5,5,5-hexafluoroacetylacetonato)copper(II), [Cu(hfac)2], with polycrystalline tantalum (Ta) and polycrystalline as well as epitaxial titanium nitride (TiN) substrates during Cu MOCVD, under ultra-high vacuum (UHV) conditions and low substrate temperatures (T < 500 K). The results obtained from X-ray photoelectron spectroscopy (XPS), Auger Electron Spectroscopy (AES) and Temperature Programmed Desorption (TPD) measurements indicate substantial differences in the chemical reaction pathways of metallic Cu formation from Cu(hfac)2 on TiN versus Ta surfaces.

An iodine surface layer has been prepared on Ru(poly) and Ru(0001) electrodes by exposure to iodine vapor in UHV and polarizing in a 0.1 M HClO4/0.005 M KI solution, respectively. A saturation coverage of I on a Ru(poly) electrode passivates the Ru surface against significant hydroxide, chemisorbed oxygen or oxide formation during exposure to water vapor over an electrochemical cell in a UHV-electrochemistry transfer system. Immersion of I-Ru(poly) results in greater hydroxide and chemisorbed oxygen formation than water vapor exposure, but an inhibition of surface oxide formation relative that of the unmodified Ru(poly) surface is still observed. Studies with combined electrochemical and XPS techniques show that the iodine surface adlayer remained on top of the surface after cycles of overpotential electrodeposition/dissolution of copper on both Ru(poly) and Ru(0001) electrodes. These results indicate the potential bifunctionality of iodine layer to both passivate the Ru surface in the microelectronic processing and to act as a surfactant for copper electrodeposition. The electrodeposition of Cu on Ru(0001) or polycrystalline Ru was studied using XPS with combined ultrahigh vacuum/electrochemistry methodology (UHV-EC) in 0.1 M HClO4 with Cu(ClO4)2 concentrations ranging from 0.005 M to 0.0005 M, and on polycrystalline Ru in a 0.05M H2SO4/0.005 M CuSO4/0.001 M NaCl solution. The electrochemical data show well-defined cyclic voltammograms (CV) with a Cu underpotential deposition (UPD) peak and overpotential deposition (OPD) peak. XPS spectra of Ru electrodes emersed from perchloric acid solution at cathodic potentials indicate that ClO4- anions dissociate to yield specifically adsorbed Cl and ClOx species. Subsequent Cu deposition results in the formation of a thin, insoluble Cu(II) film with Cu(I) underneath. In contrast, similar deposition on polycrystalline Ru in the sulfuric acid/Cu sulfate solution with NaCl added yields only Cu(0), indicating that the formation of Cu(II) and Cu(I) involves both Cl and perchlorate interactions with the deposited Cu. A pre-adsorbed layer of iodine on the Ru(0001) surface inhibits perchlorate dissociation in iodide-free electrolyte and leads to the deposition of Cu(0) in the perchlorate bath. XPS depth profile analysis demonstrates that the iodine monolayer "floats" on top of the deposited film, in agreement with previous results, effectively protecting the Cu film from air oxidation.

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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.