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Wong, Fai George. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.iii / 摘要 --- p.v / Acknowledgment --- p.vii / Table of Contents --- p.ix / Abbreviations --- p.xiii / Selected List of Tables --- p.xv / List of Compounds --- p.xvi / Chapter Chapter 1 --- Introduction on Metal Amides / Chapter 1.1 --- General Background --- p.1 / Chapter 1.2 --- A General Classification of A/-anionic Ligands --- p.1 / Chapter 1.3 --- Development of Late Transition Metal Amides --- p.3 / Chapter 1.3.1 --- The First Reported Metal Amides from Each Major Block of the eriodic Table --- p.4 / Chapter 1.3.2 --- Metal Amides Supported by the Simple [N(SiMe3)2]- Ligand --- p.4 / Chapter 1.3.3 --- From Simple to Bulkier Silylamido Ligands --- p.6 / Chapter 1.3.4 --- Metal Complexes Supported by Borylamido Ligands --- p.7 / Chapter 1.3.5 --- Metal Complexes Supported by Arylamido Ligands --- p.9 / Chapter 1.3.6 --- Metal Complexes Supported by erfluorinated Arylamido Ligands --- p.10 / Chapter 1.4 --- Objectives of This Work --- p.11 / Chapter 1.5 --- References for Chapter 1 --- p.13 / Chapter Chapter 2 --- Ligand Substitution Reactions of Divalent Late Transition Metal Amides / Chapter 2.1 --- General Background --- p.17 / Chapter 2.2 --- Objectives of This Work --- p.19 / Chapter 2.3 --- Results and Discussion --- p.20 / Chapter 2.3.1 --- Previous Work in Our Group --- p.20 / Chapter 2.3.2 --- Synthesis of Metal Complexes --- p.20 / Chapter 2.3.3 --- Molecular Structure of the Fe(ll) Complex 11 --- p.22 / Chapter 2.3.4 --- Preparation of Mixed Amide-Alkyl Complexes --- p.24 / Chapter 2.3.5 --- Molecular Structures of the Methyl Complexes 12-15 --- p.29 / Chapter 2.3.6 --- Attempts to repare Mixed Amide-Alkoxide Complexes --- p.39 / Chapter 2.3.7 --- Reactivity of the [Co(L2)Me(tmeda)] Complex (17) --- p.39 / Chapter 2.3.8 --- Molecular Structure of the Co(ll) Iodide Complex 18 --- p.43 / Chapter 2.4 --- Summary --- p.45 / Chapter 2.5 --- Experimental Section for Chapter 2 --- p.48 / Chapter 2.6 --- References for Chapter 2 --- p.51 / Chapter Chapter 3 --- Reduction Chemistry of Divalent Late Transition Metal Amides / Chapter 3.1 --- General Background --- p.54 / Chapter 3.2 --- Objectives of This Work --- p.57 / Chapter 3.3 --- Results and Discussion --- p.57 / Chapter 3.3.1 --- Reduction of the Complexes Mn(ll) and Co(ll) Complexes 7 and 9 --- p.57 / Chapter 3.3.2 --- Attempted Synthesis of the Mononuclear Co(l) Complex --- p.59 / Chapter 3.3.3 --- Molecular Structures of the Complexes 19 and 20 --- p.61 / Chapter 3.3.4 --- Reactivity of the Univalent Co(l) Complex [Co(L2)]2 (20) --- p.65 / Chapter 3.4 --- Summary --- p.67 / Chapter 3.5 --- Experimental Section for Chapter 3 --- p.68 / Chapter 3.6 --- References for Chapter 3 --- p.69 / Chapter Chapter 4 --- A reliminary Study on the Coordination Chemistry of erfluorinated Late Transition Metal Amides / Chapter 4.1 --- General Background --- p.71 / Chapter 4.2 --- Objectives of This Work --- p.73 / Chapter 4.3 --- Results and Discussion --- p.73 / Chapter 4.3.1 --- Synthesis of the Ligand recursor[HN(SiMe3)(C6F5)] (21) --- p.73 / Chapter 4.3.2 --- Synthesis of the Lithium Reagent [Li(L3)tmeda]] (22) --- p.74 / Chapter 4.3.3 --- Synthesis of the Fe(ll) and Co(ll) Complexes of the L3 Ligand --- p.75 / Chapter 4.3.4 --- Molecular Structures of the Chloride Complexes 23 and 24 --- p.77 / Chapter 4.4 --- Summary --- p.82 / Chapter 4.5 --- Experimental Section for Chapter 4 --- p.83 / Chapter 4.6 --- References for Chapter 4 --- p.85 / "Appendix 1 General rocedures, hysical Measurements, and X-Ray Structure Analysis" --- p.87 / Appendix 2 Selected Crystallographic Data --- p.89 / Appendix 3 NMR Spectra of Compounds --- p.94

Magister Scientiae - MSc / Metal hydrides hydrogen storage materials have the ability to reversibly absorb and release large amounts of hydrogen at low temperature and pressure. In this study, metal hydride materials employed as negative electrodes in Ni-MH batteries are investigated. Attention is on AB5 alloys due to their intermediate thermodynamic properties. However, AB5 alloys a have tendency of forming oxide film on their surface which inhibits hydrogendissociation and penetration into interstitial sites leading to reduced capacity. To redeem this, the materials were micro-encapsulated by electroless deposition with immersion in Pd and Pt baths. PGMs were found to increase activation, electrochemical activity and H2 sorption kinetics of the MH alloys. Between the two catalysts the one which displayed better performance was chosen. The materials were characterized by X-ray difractommetry, and the alloys presented hexagonal CaCu 5–type structure of symmetry P6/mmm. No extra phases were found, all the modified electrodes displayed the same behavior as the parent material. No shift or change in peaks which corresponded to Pd or Pt were observed. Scanning Electron Microscopy showed surface morphology of the materials modified with Pd and Pt particles, the effect of using different reducing agents (i.e ., N2H4 and NaH2PO2), and alloys functionalized with γ-aminosopropyltrietheosilane solution prior to Pd deposition. From all the surface modified alloys, Pt and Pd particles were observed on the surface of the AB5 alloys. Surface modification without pre-functionalization had non-uniform coatings, but the pre- functionalized exhibited more uniform coatings. Energy dispersive X-ray Spectroscopy and Atomic Absorption Spectroscopy determined loading of the Pt and Pd on the surface of all the alloys, and the results were as follows: EDS ( Pt 13.41and Pd 31.08wt%), AAS (Pt 0.11 and Pd 0.78wt%). Checking effect of using different reducing agents N2H4 and NaH2PO2 for electroless Pd plating the results were as follows: EDS (AB5_N2H4_Pd- 7.57 and AB 5_NaH2PO2_Pd- 31.08wt%), AAS (AB5_N2H4_Pd- 11.27 and AB5_NaH2PO2_Pd- 0.78wt%). For the AB5 alloyspre-unctionalized with γ-APTES, the results were: EDS (10.24wt%) and AAS (0.34wt%). Electrochemical characterization was carried out by charge/discharge cycling controlled via potential to test the AB5 alloy. Overpotential for unmodified, Pt and Pd modified electrodes were-1.1V, -1.24V, and -1.60V, respectively. Both modified electrodes showed discharge overpotentials at lower values implying higher specific power for the battery in comparison with the unmodified electrodes. However, Pd electrode exhibited higher specific power than Pt. To check the effect of the reducing agent the results were as follows: AB5_ N2H4_Pd (0.4V) and AB5_NaH2PO2_Pd (-0.2V), sodium hypophosphite based alloy showing lower overpotential values, implying it had higher specific power than hydrazine based bath. Alloy pre-functionalized with γ-APTES, the overpotential was (0.28V), which was higher than -0.2V of the alloy without pre-functionalization, which means pre-functionalization with γ-APTES did not improve the performance of the alloy electrode. Polarization resistance of the electrodes was investigated with Electrochemical Impedance Spectroscopy. The unmodified alloy showed high resistance of 21.6884 while, both Pt and Pd modified electrodes exhibited decrease 14.7397 and 12.1061 respectively, showing increase in charge transfer for the modified electrodes. Investigating the effect of the reducing agent, the alloys exhibited the following results: (N2H497.8619 and NaH2PO212.1061 ) based bath. Alloy pre-functionalized with γ-APTES displayed the resistance of 9.3128. Cyclic Voltammetry was also used to study the electrochemical activity of the alloy electrodes. The voltammograms obtained displayed the anodic current peak at -0.64V to -0.65V for the Pt and Pd modified electrodes, respectively. Furthermore, the electrode which was not coated with Pt or Pd the current peak occurred at -0.59V. The Pd and Pt coated alloy electrodes represented lower discharge overpotentials, which are important to improve the battery performance. Similar results were also observed with alloy electrodes Pd modified using N2H4(-0.64V) and NaH2PO2(-0.65V). For the electrode modified with and without γ-APTES the over potentials were thesame (-0.65V). PGM deposition has shown to significantly improve activation and hydrogen sorption performance and increased the electro-catalytic activity of these alloy electrodes. Modified electrodes gave better performance than the unmodified electrodes. As a result, Pd was chosen as the better catalyst for the modification of AB5 alloy. Based on the results, it was concluded that Pd electroless plated using NaH2PO2 reducing agent had better performance than electroless plating using N2H4 as the reducing agent. Alloy electrode pre-functionalized with γ-APTES gave inconsistent results, and this phenomenon needs to be further investigated. In conclusion, the alloy modified with Pd employing NaH 2PO2 usased electroless plating bath exhibited consistent results, and was found to be suitable candidate for use in Ni-MH batteries / South Africa

The work I create attempts to explore the vast precipice between adolescence and adulthood. Our whole lives we are essentially labeled one or the other yet we are often striving to be the one we are not. Childhood is fleeting, gone the moment we realize how truly special it is. Adulthood is elusive, ever looming yet continually out of reach. I choose to work with materials and imagery that is commonly known to us as children and attempt to make it a more "grown-up" version of itself. This allows for several layers of meaning. It can be a simple reminder of days past and an encouragement to not take ourselves too seriously. It is also an attempt to find the fine line between children acting like adults and adults being children. Often we dress ourselves up and pretend to be something we're not. Maybe we're fooling everyone. Maybe we're only fooling ourselves.

Surface engineering provides solutions to wear and corrosion degradation of engineering components. Laser cladding is a surfacing process used to produce wear and corrosion resistant surfaces by covering a particular part of the substrate with another material that has superior properties, producing a fusion bond between the two materials with minimal dilution of the clad layer by the substrate. The advantages of laser cladding compared to conventional techniques include low and controllable heat input into the workpiece, a high cooling rate, great processing flexibility, low distortion due to the low heat input to the workpiece and minimal post-treatment. The main processing parameters of laser cladding include laser power, laser spot size, processing speed, and powder feed rate. Within an optimized operational window, all these variables have some effect on the temperature of the clad interaction zone. The laser cladding technique is very complicated because it involves metallurgical and physical phenomena, such as laser beam-materials interaction, heat transfer between the clad and the substrate, and the interdiffusion of the clad and the substrate materials. Laser cladding is currently an open-loop process, relying on the skills of the operator and requiring dedication to specialty to make it successful. Unless the required expertise is provided, attempts to make the process successful will be futile. The objective in conducting the project was to investigate and develop prototype sensors to monitor and control Nd:YAG laser cladding process. Through a LabVIEW software based monitoring program, real-time process monitoring of optical emissions in the form of light and heat radiation was carried out, and correlated with the properties of the produced clad layers. During various experiments, single- and multiple-track laser cladding trials were performed. The responses of such sensors to the selected conditions were examined and an in depth analysis of detected heat and optical radiation signals was carried out. The results of these experiments showed the ability of such sensors to recognize changes in process parameters, and detected defects on layer surfaces along with the presence of oxides. A multi-function closed-loop laser power and CNC motion table feed rate control interface based on a LabVIEW platform has been designed and built, which is capable of accepting and interpreting sensors� data and adjusting accordingly the laser power and CNC motion table feed rate to produce sound clad layers. The developed dual control strategy utilized in this study forms a relatively inexpensive and less-complicated system that allows end-users to achieve lower failure rates during laser cladding (within its own limitations) and, therefore, through successful concurrent control of melt pool temperature and motion table feed rate provide better productivity and quality in the experimentally produced clad layers.

[Typescript] / Includes bibliographical references. / 1 v. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1966

Thesis (Ph. D.)--State University of New York at Binghamton, Chemistry Dept., 2006. / Includes bibliographical references.

Bibliography: leaves 143-153. Studies the complexation of metal ions with the macrocyclic ligand, 1, 4, 8, 11-tetrakis (2-hydroxyethyl)-1, 4, 8, 11-tetraazacyclotetradecane (THEC)

Metallic foams have become widely available and have unique properties that make them attractive for use in a variety of engineering applications. Due to their complex structure, the behavior of foams under complex loading conditions is a subject of continued research. Digital volume correlation is a technique wherein full-field strains in three dimensions can be measured from high resolution x-ray CT image data. This technique was employed to measured strains in two commercially available aluminum foams, one each of open and closed-cell morphology, under two complex loading scenarios: rigid spherical indention, and uniaxial compression of a sample with a central hole. In addition to comparing the behavior of the two foams, results are also compared to strain fields analytically predicted by a third-party constitutive model implemented in finite element analysis. Under indention loading, the two examined foams showed a distinct difference in deformation and strain field, however the foams behaved similarly under uniaxial compression of rectangular samples with central holes. The constitutive model was found to be unsuitable for modeling the experimentally measured foams. / Graduation date: 2004