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Donor stabilized germylenes and their transition metal complexes: structure, bonding, and thermochemistryMarc, Baumeister 09 January 2012 (has links)
This thesis investigates the stabilization of divalent germanium using substituted diethanol amine ligands. Germylenes of type RN(CH2CH2OH)2Ge were obtained from N-heterocyclic germylenes and N-alkyl diethanol amines in yields of up to 94%. Single crystal X-ray diffraction confims the presence of a transannular Ge-N dative bond in all cases. In addition, intermolecular dimers containing Ge2O2 rings are formed for R = Me and Et. Reaction of the four germylenes L with nickel carbonyl yielded the respective germylene complexes L2Ni(CO)2 and LNi(CO)3. The germylenes and their complexes were investigated with DFT methods. Only four methods, SVWN, BB1K, MPWB1K and M062x gave acceptable Ge-N distances. Dimerization energies of the germylenes were examined with the thermochemically accurate M062x method. At the M062x/Def2-TZVP level, the dimerization energies of the germylenes are very small (ΔG° ≈ 0 kcal/mol). The experimentally observed dimerization or lack thereof may accordingly be determined by packing effects in the solid state or solvation energies in solution.
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A study of powder making by the decomposition of nickel carbonyl in an aerosol tube reactorWasmund, Eric Bain. Coley, Ken. January 2005 (has links)
Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: Ken Coley. Includes bibliographical references (leaves 204-211).
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Multivariate Data Analysis for Process Evaluation, Prediction and Monitoring at INCO's Copper Cliff Smelting and Refining OperationsBradley, Jennifer 09 1900 (has links)
Industrial processes generate large quantities of process and product quality data. Most of this data is stored and is analyzed in a univariate fashion. However important information may be lost through the implementation of univariate analysis methods. This information is contained in the correlation structure amongst the process and product quality variables and between these two types of variables. Through multivariate analysis this information is retained. As a result process evaluation, prediction and monitoring are more effectively performed.
Multivariate data analysis techniques were therefore applied to data sets that summarized three of INCO's Copper Cliff smelting and refining processes. In the first instance the analysis of historical data pertaining to a batch leaching process was undertaken and the time required for leaching was predicted. In the second a multivariate soft sensor was developed in order to predict the concentration of nitric oxide contained in the feed gas to the smelter acid plant. The final project involved the analysis and monitoring of a continuous nickel carbonyl process.
The resulting models were evaluated and significant variables with respect to the variation in the process and product quality data and the correlation between them were identified. The product quality data was also well predicted using new process data only that was input to the models. Finally new data was input to the models and the process was monitored using a reduced number of latent variables. Contribution plots were used to identify the original variables that contributed most to the observations that exceeded the established control limits. / Thesis / Master of Science (MSc)
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High Rate, Large Area Laser-assisted Chemical Vapor Deposition of Nickel from Nickel CarbonylPaserin, Vladimir January 2009 (has links)
High-power diode lasers (HPDL) are being increasingly used in industrial applications. Deposition of nickel from nickel carbonyl (Ni(CO)4) precursor by laser-induced chemical vapor deposition (CVD) was studied with emphasis on achieving high deposition rates. An HPDL system was used to provide a novel energy source facilitating a simple and compact design of the energy delivery system. Nickel deposits on complex, 3-dimensional polyurethane foam substrates were prepared and characterized. The resulting “nickel foam” represents a novel material of high porosity (>95% by volume) finding uses, among others, in the production of rechargeable battery and fuel cell electrodes and as a specialty high-temperature filtration medium. Deposition rates up to ~19 µm/min were achieved by optimizing the gas precursor flow pattern and energy delivery to the substrate surface using a 480W diode laser. Factors affecting the transition from purely heterogeneous decomposition to a combined hetero- and homogeneous decomposition of nickel carbonyl were studied. High quality, uniform 3-D deposits produced at a rate more than ten times higher than in commercial processes were obtained by careful balance of mass transport (gas flow) and energy delivery (laser power). Cross-flow of the gases through the porous substrate was found to be essential in facilitating mass transport and for obtaining uniform deposits at high rates. When controlling the process in a transient regime (near the onset of homogenous decomposition), unique morphology features formed as part of the deposits, including textured surface with pyramid-shape crystallites, spherical and non-spherical particles and filaments.
Operating the laser in a pulsed mode produced smooth, nano-crystalline deposits with sub-100 nm grains. The effect of H2S, a commonly used additive in nickel carbonyl CVD, was studied using both polyurethane and nickel foam substrates. H2S was shown to improve the substrate coverage and deposit uniformity in tests with polyurethane substrate, however, it was found to have no effect in improving the overall deposition rate compared to H2S-free deposition process.
Deposition on other selected substrates, such as ultra-fine polymer foam, carbon nanofoam and multi-wall carbon nanotubes, was demonstrated.
The HPDL system shows good promise for large-scale industrial application as the cost of HPDL energy continues to decrease.
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High Rate, Large Area Laser-assisted Chemical Vapor Deposition of Nickel from Nickel CarbonylPaserin, Vladimir January 2009 (has links)
High-power diode lasers (HPDL) are being increasingly used in industrial applications. Deposition of nickel from nickel carbonyl (Ni(CO)4) precursor by laser-induced chemical vapor deposition (CVD) was studied with emphasis on achieving high deposition rates. An HPDL system was used to provide a novel energy source facilitating a simple and compact design of the energy delivery system. Nickel deposits on complex, 3-dimensional polyurethane foam substrates were prepared and characterized. The resulting “nickel foam” represents a novel material of high porosity (>95% by volume) finding uses, among others, in the production of rechargeable battery and fuel cell electrodes and as a specialty high-temperature filtration medium. Deposition rates up to ~19 µm/min were achieved by optimizing the gas precursor flow pattern and energy delivery to the substrate surface using a 480W diode laser. Factors affecting the transition from purely heterogeneous decomposition to a combined hetero- and homogeneous decomposition of nickel carbonyl were studied. High quality, uniform 3-D deposits produced at a rate more than ten times higher than in commercial processes were obtained by careful balance of mass transport (gas flow) and energy delivery (laser power). Cross-flow of the gases through the porous substrate was found to be essential in facilitating mass transport and for obtaining uniform deposits at high rates. When controlling the process in a transient regime (near the onset of homogenous decomposition), unique morphology features formed as part of the deposits, including textured surface with pyramid-shape crystallites, spherical and non-spherical particles and filaments.
Operating the laser in a pulsed mode produced smooth, nano-crystalline deposits with sub-100 nm grains. The effect of H2S, a commonly used additive in nickel carbonyl CVD, was studied using both polyurethane and nickel foam substrates. H2S was shown to improve the substrate coverage and deposit uniformity in tests with polyurethane substrate, however, it was found to have no effect in improving the overall deposition rate compared to H2S-free deposition process.
Deposition on other selected substrates, such as ultra-fine polymer foam, carbon nanofoam and multi-wall carbon nanotubes, was demonstrated.
The HPDL system shows good promise for large-scale industrial application as the cost of HPDL energy continues to decrease.
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