Thesis (Ph. D.)--University of Chicago, 1918. / "Private Edition, Distributed by the University of Chicago Libraries, Chicago, Illinois, 1921." "Reprinted from the Journal of the American Chemical Society, Vol. XXXVIII, February, 1916; Vol. XXXIX, March, 1917; Vol. XLI, April, 1919." Includes bibliographical references. Also available on the Internet.

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Th. univ.--Rennes 1, 1999. / Textes en français ou en anglais. Bibliogr. p. 161-170. Notes bibliogr. Résumés en français et en anglais.

Th.--Sci. phys.--Grenoble 1, 1978. N°: 53.

Thesis (PhD) - Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology, 2009. / Submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy, Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology, 2009. Typescript. Bibliography: p. 223-240.

Thesis (Ph. D.)--School of Chemistry, Faculty of Science, University of Sydney, 2006. / Title from title screen (viewed 13 January 2009). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Chemistry, Faculty of Science. Includes bibliographical references. Also available in print form.

Industrial recognition of the importance of optimising engineering component performance has recently led to a significant increase in the use of surface coating technologies. An important process for the production of such coatings is Physical Vapour Deposition (PVD) which has proved to be a consistent, reliable and improving technique for industry. In the area of advanced wear resistant coatings however, fundamental research to improve deposition efficiency and enhance coating performance has been required. This thesis describes research investigating the following three areas: A series of experiments was carried out to study the design, metallurgy and performance of TiZr, ZrMo and TiMo segmented targets for use in steered cathodic arc evaporation and unbalanced magnetron sputter PVD techniques. A hot isostatic pressing technique was used to manufacture a range of prototype targets by diffusion bonding of appropriate metallic segments to controllable depths. In steered arc evaporation trials, a deleterious evaporation phenomenon occurred at segment interfaces when the cathode spot traversed from high vapour pressure to low vapour pressure materials. Analysis of the spot motion has led to the proposal of a simple model. Reactive unbalanced magnetron sputtering trials successfully produced a range of TiZrN, TiMoN and ZrMoN coatings of compositions in good agreement with Monte-Carlo simulation predictions. However, preferential poisoning of the high reactivity metal segments on TiMo and ZrMo targets was found to occur during high N[2] partial pressure processes. A comparative study of unbalanced magnetron sputtering, steered arc evaporation and the hybrid arc-bond sputter technique has been made during deposition trials on the ternary TiZrN hard coating system. Examination of the influence of two process parameters, substrate bias voltage and nitrogen partial pressure, on the mechanical and physical properties of TiZrN coatings is also reported. Stoichiometric TiZrN films were generally found to exhibit a single phase, face centred cubic structure with lattice parameters which followed Vegard's law. Alteration of the elemental composition of the alloy could be achieved by altering the power to individual magnetron cathodes or varying the current of the arc discharge during co-deposition. Solid solution strengthening mechanisms produced high hardness values (2500-3600H[k]) which maximised as the alloy composition approached Ti[0.6]Zr[0.4]. Further studies have been undertaken where Al was partially substituted for Zr within the lattice to enhance oxidation resistance properties and a range of fully adherent TiAlZrN quaternary films on high speed steel substrates were produced. The development of an original technique for industrial scale fabrication of a range of hard, low period (< 150A) multi-layer PVD thin films is outlined and the effects of substrate rotation velocity, type of rotation (1-fold or 3-fold) and deposition rate have been investigated. The high level of lattice mis-match and substantial differences in dislocation line energy and shear modulus has given rise to TiAlN-ZrN films exhibiting Knoop micro-hardness in excess of 4000H[k]. Bulk and micro-analysis techniques have indicated a reproducible lamella coating structure can be formed, with accurate control of the layer period. Excellent levels of coating adhesion were implemented by a metal ion etch substrate pre-treatment and the deposition of a sputtered base layer and films exhibited relatively low surface roughness and high density. A coating strategy, based upon the reactivity of the individual target materials and the characteristics of arc evaporated and magnetron sputtered vapour fluxes, has been determined which provides high flexibility in the coating elemental composition. The investigations clearly indicate that the multi-layer coating methods utilised allow the deposition of 3rd generation films without a productivity loss in comparison to 1st generation and 2nd generation hard coatings.

Les modèles de champ archéomagnétique et les simulations numériques de dynamos fournissent des informations importantes sur la géodynamique. J'ai étudié l’existence et la mobilité des patches de flux inverse (PFI) dans les modèles de champ archéomagnétique. J'ai comparé le suivi des PFIs avec les anomalies sismologiques à la base du manteau pour explorer si les PFIs ont des emplacements privilégiés prescrits par l'hétérogénéité latérale à la base du manteau. Les PFI sont ainsi interprétés en termes de dynamique de noyau et d'interactions thermiques noyau-manteau. La corrélation en co-latitude et le décalage en longitude permettent d'inférer l'orientation azimutale du champ toroidal et la présence d'un large upwelling au sommet du noyau. L'Anomalie de l'Atlantique Sud (AAS) est une région de faible intensité géomagnétique à la surface de la Terre, qui est communément attribuée aux PFIs sur la frontière noyau manteau (FNM). Alors que l’AAS est clairement affecté par la région de flux inverse sous l'Atlantique Sud, je montre que la relation entre l’AAS et les PFIs n'est pas simple. L'anomalie est déterminée par l'interaction de plusieurs patches de flux (normal et inverse) à la FNM. Des scenarios simples de variation séculaire (VS) suggèrent que si le déplacement de l’AAS peut être expliqué par l'advection, sa chute d'intensité nécessite la diffusion magnétique. J'ai déterminé si l'hétérogénéité thermique du manteau inférieur pouvait expliquer l'emplacement de l’AAS avec des dynamos numériques dont le flux de chaleur à la FMN est hétérogène. Les histogrammes des coordonnées des minima d'intensité de surface montrent deux pics de position longitudinale préférée dont un est proche de la longitude actuelle de l’AAS. Les ingrédients pour reproduire les coordonnées de l'AAS sont liés à l'asymétrie nord-sud du flux normal et inverse. / Archeomagnetic field models and numerical dynamo simulations provide important insights to the geodynamo. I investigated the existence and mobility of reversed flux patches (RFPs) in archeomagnetic field models. I compared the tracking of RFPs with seismic anomalies of the lowermost mantle to explore if RFPs have preferred locations prescribed by lower mantle lateral heterogeneity and interpreted in terms of core dynamics and core-mantle thermal interactions. Correlation in co-latitude and a shift in longitude allowed inferring azimuthal orientation of toroidal field below the core-mantle boundary (CMB) and the presence of large fluid upwelling structures at the top of the core. The South Atlantic Anomaly (SAA) is a region of weak geomagnetic field intensity at the Earth's surface, which is commonly attributed to RFPs on the CMB. While the SAA is clearly affected by the reversed flux region below the South Atlantic, I showed that the relation between the SAA and RFPs is not straightforward. The SAA minimum is determined by the interplay among several robust flux patches at the CMB. Simple secular variation (SV) scenarios suggest that while the SAA path can be explained by advection, its intensity decrease requires magnetic diffusion. Investigating whether lower mantle thermal heterogeneity may explain the location of the SAA was tested with run numerical dynamos with heterogeneous CMB heat flux. Histograms of the coordinates of surface intensity minima show two peaks of preferred longitudinal position of weakest surface field intensity, one close to the present SAA minimum longitude. The ingredients to reproduce the SAA coordinates are related to north-south asymmetry of normal and reversed flux.