Thesis (MAppSc in Physiotherapy)--University of South Australia, 1996

Thesis (PhDPhysiotherapy)--University of South Australia, 2001

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007. / Title from title screen (site viewed Apr. 29, 2008). PDF text: ix, 121 p. : ill. ; 1 Mb. UMI publication number: AAT 3278295. Includes bibliographical references. Also available in microfilm and microfiche formats.

Zugl.: Hannover, Univ., Diss, 2005

Thesis (Ph. D.)--University of Washington, 1994. / Vita. Includes bibliographical references (leaves 116-127).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 235-239).

A major addition to European research facilities is the Oxford University Engineering Laboratory (O.U.E.L.) blowdown tunnel which can provide full-scale Reynolds and Mach number simulations on large and small models of turbine stage components. The facility was designed to provide extended aerodynamic capabilities to complement the existing heat transfer research in the Isentropic Light Piston Tunnel (ILPT) at O.U.E.L. The blowdown tunnel will be used for fundamental investigations of the boundary layers and flow fields around turbine blades in a linear cascade. The study of these flow fields is necessary for the prediction of heat transfer rates and for the optimisation of materials and cooling schemes required to improve gas turbine efficiencies. As a commissioning exercise measurements were made on cascades of similar geometry to those which had been previously tested in the ILPT and in other European facilities in order to compare results and analyse differences which occur due to the influence of tunnel geometry. Measurements made on various rotor profiles identified regions on the suction surface where surface pressure data is sensitive to the various types of exit plenums and exit pressure gradients. A second phase of work included measurements and a theoretical study of the boundary layer on a large-chord turbine rotor profile. Measurements on the pressure surface of the blade suggested the presence of secondary longitudinal vortices which rapidly lose an identifiable structure towards the trailing edge. On the suction surface, boundary layer measurements were compared with theoretical models, and it was shown that current numerical models of compressible turbulent boundary layers approximately correspond with the data. An adjunct to the boundary layer work was research on the use of a hot-wire anemometer, intended for future boundary layer measurements, and for which calibration laws and temperature effects were studied.

The discovery of large, room temperature magnetoresistance (MR) in magnetic tunnel junctions in 1995 sparked great interest in these devices. Their potential applications include hard disk read head sensors and magnetic random access memory (MRAM). However, the fabrication of repeatable, high quality magnetic tunnel junctions is still problematic. This thesis investigates methods to improve and quantify the quality of tunnel junction fabrication. Superconductor-insulator-superconductor (SIS) and superconductor-insulator ferromagnet(SIF) tunnel junctions were used to develop the fabrication route, due to the ease of identifying their faults. The effect on SIF device quality of interchanging the top and bottom electrodes was monitored. The relationship between the superconducting and normal state characteristics of SIS junctions was investigated. Criteria were formulated to identify devices in which tunneling is not the principal conduction mechanism innormal metal-insulator-normal metal junctions. Magnetic tunnel junctions (MTJs) were produced on the basis of the fabrication route developed with SIS and SIF devices. MTJs in which tunneling is the principal conduction mechanism do not necessarily demonstrate high MR, due to effects such as magnetic coupling between the electrodes and spin scattering. Transmission electron microscope images were used to study magnetic tunnel junction structure, revealing an amorphous barrier and crystalline electrodes. The decoration of pinholes and weak-links by copper electrodeposition was investigated. A new technique is presented to identify the number of copper deposits present in a thin insulating film. The effect of roughness, aluminium thickness and voltage on the number of pinholes and weak-links per unit area was studied. High frequency testing of read heads at wafer level was performed with a network analyser. Design implications for read head geometry were investigated, independent of magnetic performance. This technique has great potential to aid the rapid development of read and write heads whilst improving understanding of the system.

As the surface areas of cities throughout the world become ever more congested/ and the quality of life deteriorates, those in authority are increasingly turning to the engineering use of created space underground. Transportation systems have been located at least partly underground for generations - particularly in London. Dozens of cities throughout the rest of the world are presently engaged in underground construction, not only for rail transportation schemes, but also for communications purposes, water supply, sewerage, roads, car parks, shopping centres, concert halls, museums and art galleries. Outside the cities underground construction continues to be used for hydro-electric purposes, gas storage, inter-city highways and rail systems, and for nuclear waste storage. This international engineering research study looks at the risks involved in underground construction, and in particular the nature of risks to people directly engaged on this work and to other persons who may be affected by the works and also looks at the nature of risks to the built and natural environment. The study brings together many details of past incidents and disasters that have occurred internationally, and from a broad analysis of the types and causes of failures of one type or another, looks to how such incidents may be prevented in the future. The identification and control of risk in underground engineering projects is seen as the duty and responsibility of all the main parties to the project - the client or promoter of the project, the engineering designers, and those chosen to undertake the construction work. Key components of a broad risk control strategy are described which are applicable regardless of the project's location or what the final purpose of the underground construction work might be. Within this study there are two international Case Studies to illustrate good and poor practice in the identification and control of risk in these types of projects.

This thesis describes a mathematical-graphical analysis and some analog computer simulation studies that were carried out to determine the feasibility of a proposed circuit to be used for analog-to-digital conversion. The circuit analysed and simulated contains a stack of tunnel diodes which are constructed from the same type of semiconductor material. The switching characteristics of this circuit are controlled primarily by the ratios and the values of the capacitances which shunt the individual tunnel diodes and to a lesser extent by the interdiode capacitances. This is revealed in a study of the effects of different circuit parameter variation A two tunnel diode stack circuit (two bits of information capacity) is analysed by studying the nature of the switching trajectories in the proximity of the singular points of the equations describing -the circuit operation. Three different modes of operation, each of which differs in the manner in which the 11 state is reached, are revealed for this circuit. The analysis indicates a feature of the circuit which can be used to determine the final state of the circuit before steady state conditions have been reached. An extension of the two tunnel diode stack circuit to one containing three tunnel diodes yielded eight stable and accessible states. This indicates that the circuit proposed will be able to realize 2[superscript n] states with n tunnel diodes. It is shown that different interdiode capacitance connections will facilitate the achievement of this result. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate