Thesis (PH. D.)--University of Minnesota, 1929. / Cover-title. Vita. The first article is from the Journal of physical chemistry, v. 33, no. 3, March 1929; the second is Preprint 59-5 of the Electrochemical society.

Thesis--Liège. / Summaries in Dutch, English, German, and Italian. Includes bibliographical references (p. [127]-130).

Thesis (Ph. D.)--University of Canterbury, 2006. / Typescript (photocopy). "January 2006." Includes bibliographical references (p. [173]-182). Also available via the World Wide Web.

D.Phil. / The work that is presented in this thesis describes the numerous detailed investigations that were conducted with a custom-made horizontally aligned, water-cooled, gas-filled DC arc-discharge reactor. A focus of the investigations was the establishment of the effects of high purity graphite electrodes in ultra-high purity (UHP) He, H2 or mixtures thereof, in the absence of a metal catalyst on the reaction. These studies showed that higher yields of MWCNTs were formed in reactions between graphite electrodes in H2 than in He. Additionally, a range of gaseous hydrocarbons were formed in H2 that were not formed in He. After the initial parameters were established, investigations examined the effects on the products that were formed by the addition of high purity Cu to graphite. The data from these studies revealed that H2 played a pivotal role in the reactions and that metallic copper nanoparticles were the active catalysts. In particular, they showed that when the Cu/C mole ratio and particle size ranges were fixed (i.e. 0.20 and < 150 μm respectively), then branched CNTs were exclusively found in a collar deposited around the cathode, with bamboo-shaped CNTs formed in the reaction chamber. Characterisation of these products revealed that the Cu nanoparticles were probably molten during the reactions and thus a growth model was proposed in which it was suggested that dehydrogenation reactions of gaseous hydrocarbon species on the surfaces of unsupported molten copper nanoparticles led to the formation of either bamboo-shaped or branched CNTs.

Electrical Discharge Machining (EDM) is a non-contact manufacturing process in which material is removed from a metal workpiece by high frequency electrical pulses produced between an electrode and the workpiece. EDM machines are usually stand-alone devices, and are quite expensive. The objective of this research was to integrate an EDM machine and an existing reconfigurable CNC machine tool, using a modular approach, to enable conventional milling and EDM to be conducted in a co-ordinated fashion on the same machine tool.

The perturbation in a glow discharge in hydrogen is studied theoretically and experimentally. In an ordinary glow discharge a perturbation has been produced by applying a small sinusoidal high frequency electric field. This modulates the electron energy and hence the number density of atoms in excited states; The relative phase and amplitude of light emitted in the first four lines of the Balmer series have been measured. A theory based on the work of Bates et al, is developed in this thesis and the results predicted give better agreement with the experimental values than do alternative theories which have been published recently. These if absorption of line radiation by the discharge is shown to have a critical effect on the behaviour of the plasma. The limitations and validity of assumptions are discussed and a modified experiment is suggested. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

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no abstract provided by author / Master of Science

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