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Chapter One serves as an introduction to, and background information, on the thermal decomposition of metal oxalates and homonucleus carbonyl clusters. Emphasis is placed on the compounds under investigation, namely the oxalates of iron(II), cobalt(lI) and nickel(ll) oxalate dihydrate and their corresponding binary and ternary compounds, as well as triiron dodecacarbonyl and tetracobalt dodecacarbonyl. Topics specifically addressed are their structures as well as the thermodynamics of the dehydration and decomposition of compounds of this type. Given this background, the overall aims of the work are presented. These include finding the reaction conditions to form metal powders from metal oxalates, and a preliminary study of carbonyl clusters to see if they too may be used in the production of metal powders. Chapter Two gives the results of the dehydration and decomposition of the metal oxalates, characterised by way of infrared, scanning electron microscopy, X-ray diffraction and thermogravimetric analysis. The compounds under investigation are those of the single oxalates of iron, cobalt and nickel; the binary systems of Fe-Co, Fe-Ni and Co-Ni, in the molar ratios of 3:1, 1:1 and 1:3 for each system; and the ternary oxalate system in the molar ratios of Fe1 :Co1 :Ni1, Fe8:Co1 :Ni1, Fe1 :Co8:Ni1 and Fe1 :Co1 :Ni8. It was found that under certain reaction conditions all these compounds, excluding the ferrous oxalate dihydrate, decompose to the metal. It was found through experiments to modify the morphology of the crystals under investigation that the decomposition product is controlled by the crystal lattice system the starting material is synthesised in. When in the cobalt/nickel oxalate a-crystal system, decomposition is to the metal, or in the case of the binary and ternary systems, to the alloy. If the oxalate is synthesised in the crystal system of the iron oxalate, the resultant decomposition product is the respective oxide. Experiments were carried out on the iron/cobalt binary system to prove this hypothesis. Depending on the conditions of synthesis, the iron/cobalt binary system can form in either the crystal system analogous to iron (1), or analogous to cobalt (2). The products of pyrolysis for each case differs, with (1) decomposing to the oxide and (2) decomposing to the alloy. iii Chapter Three is a brief, preliminary study describing the thermal decomposition of triiron dodecacarbonyl and tetracobalt dodecacarbonyl. Characterisation of the pyrolysis products is given by infrared, scanning electron microscopy, X-ray diffraction and thermogravimetric analysis. A tentative theory for their decomposition route under an atmosphere of nitrogen is given. It was found that neither compound decomposed fully to the central metal, but that a mixture of oxide and metal were left. The conclusion reached from this study was that neither carbonyl under investigation was particularly successful. Although in both instances metal was produced, both contained large amounts of the respective oxide. This makes them unsuitable for an industrial application to form metal powders. Chapter Four describes in detail the all the experimental, materials, methods, techniques and equipment used in this study. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.

by Fung-luen Kwong. / Thesis submitted in: August 1998. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 130-131). / Text in English; abstract also in Chinese. / by Fung-luen Kwong. / Acknowledgements --- p.i / Abstract --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Development of ceramic materials --- p.1 / Chapter 1.2 --- Alumina-Zirconia advanced ceramics --- p.2 / Chapter 1.3 --- About this thesis --- p.3 / Chapter 2 --- Related work and Motivation --- p.6 / Chapter 2.1 --- Introduction --- p.6 / Chapter 2.2 --- Powder synthesis --- p.7 / Chapter 2.2.1 --- Mechanical milling --- p.7 / Chapter 2.2.2 --- Sol-gel methods --- p.8 / Chapter 2.2.3 --- CVD methods --- p.12 / Chapter 2.2.4 --- Hydrothermal processing --- p.12 / Chapter 2.2.5 --- Wear of Zr02 milling media --- p.14 / Chapter 2.3 --- Powder fabrication --- p.14 / Chapter 2.3.1 --- Dry pressing --- p.14 / Chapter 2.3.2 --- Isostatic pressing --- p.19 / Chapter 2.3.3 --- Hot pressing --- p.23 / Chapter 2.4 --- Sintering mechanism --- p.26 / Chapter 2.4.1 --- Solid state sintering --- p.26 / Chapter 2.4.2 --- Liquid state sintering --- p.36 / Chapter 2.5 --- Toughening mechanism --- p.39 / Chapter 2.5.1 --- Stress-induced transformation toughening --- p.39 / Chapter 2.5.2 --- Microcrack toughening --- p.42 / Chapter 2.6 --- Motivation --- p.42 / Chapter 3 --- Experiments --- p.45 / Chapter 3.1 --- Methodology --- p.45 / Chapter 3.1.1 --- Procedures --- p.45 / Chapter 3.1.2 --- Verified parameters and potential difficulties --- p.53 / Chapter 3.2 --- Instrumentation --- p.56 / Chapter 3.2.1 --- Electronic balance --- p.56 / Chapter 3.2.2 --- Instron 4486 loading machine --- p.60 / Chapter 3.2.3 --- High temperature furnace --- p.63 / Chapter 3.2.4 --- Scanning electron microscope (SEM) --- p.65 / Chapter 3.2.5 --- Hardness tester --- p.67 / Chapter 3.2.6 --- X-ray powder diffraction --- p.69 / Chapter 4 --- Results ´ؤ The effects of conditions in fabrication --- p.71 / Chapter 4.1 --- Wet chemical reaction --- p.71 / Chapter 4.2 --- Pressure dependence analysis --- p.75 / Chapter 4.3 --- Sintering behavior --- p.80 / Chapter 4.3.1 --- Sintering temperature analysis --- p.80 / Chapter 4.3.2 --- Sintering duration analysis --- p.85 / Chapter 4.3.3 --- Program for counting pores --- p.94 / Chapter 5 --- Results ´ؤ The effects of Additives to Al203 - ZrO2 --- p.96 / Chapter 5.1 --- Introduction --- p.96 / Chapter 5.1.1 --- Effects of adding metal aluminum --- p.97 / Chapter 5.1.2 --- Effects of adding magnesium oxide --- p.103 / Chapter 6 --- Conclusions --- p.108 / Source code of the programs for counting pores --- p.111 / TIFF 6.0 --- p.124 / Bibliography --- p.131

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In order to examine the effects of industry processed pulse powder (navy bean, lentil and chickpea) on postprandial glycaemic response (BG) and subjective appetite (App) before and after a subsequent meal, three randomized, within-subject experiments on healthy young men were conducted. In experiment 1, all navy bean treatments reduced BG at 30 min and navy bean powder suppressed pre-meal App compared to whole wheat flour. In experiment 2, all lentil treatments reduced pre-meal BG compared to whole wheat flour. However, no App differences were observed. In experiment 3, all chickpea treatments reduced pre-meal BG compared to whole wheat flour. However, no App differences were observed. Therefore, navy bean powder, lentil powder and chickpea powder maintain their low GI and satiating effects, regardless of processing. Pulse powder can be used as a value-added food ingredient to moderate glycaemic response and increase satiety.

In order to examine the effects of industry processed pulse powder (navy bean, lentil and chickpea) on postprandial glycaemic response (BG) and subjective appetite (App) before and after a subsequent meal, three randomized, within-subject experiments on healthy young men were conducted. In experiment 1, all navy bean treatments reduced BG at 30 min and navy bean powder suppressed pre-meal App compared to whole wheat flour. In experiment 2, all lentil treatments reduced pre-meal BG compared to whole wheat flour. However, no App differences were observed. In experiment 3, all chickpea treatments reduced pre-meal BG compared to whole wheat flour. However, no App differences were observed. Therefore, navy bean powder, lentil powder and chickpea powder maintain their low GI and satiating effects, regardless of processing. Pulse powder can be used as a value-added food ingredient to moderate glycaemic response and increase satiety.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 232-244). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 220-229).

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