No description available.

Three--dimensional mapping has many applications including robot navigation, medical diagnosis and industrial inspection. However, many applications remain unfilled due to the large size and complex nature of typical 3--D mapping systems. The use of fiber optics allows the miniaturization and simplification of many optical systems. This research used a fiber optic coupler to project a fringe pattern onto an object to be profiled. The two outputs fibers of the coupler were brought close together to form the pinholes of a Young's Double Pinhole Interferometer. This provides the advantages of this simple interferometer without the disadvantage of power loss by the customary method of spatially filtering a collimated laser beam with a pair of pinholes. The shape of the object is determined by analyzing the fringe pattern. The system developed has a resolution of 0.1mm and a measurement error less than 1.5\% of the object's depth. The use of fiber optics provides many advantages including: remote location of the laser source (which also means remote location of heat sources, a critical requirement for many applications); easy accommodation of several laser sources, including gas lasers and high--power, low--cost fiber pigtailed laser diodes; and variation of source wavelength without disturbing the pinholes. The principal advantages of this mapping system over existing methods are its small size, minimum number of critically aligned components, and remote location of the laser sources. / Ph. D.

Laser surface modification involves rapid melting and solidification is an elegant technique used for locally tailoring the surface morphology of alumina in order to enhance its abrasive characteristics. COMSOL Multiphysics® based heat transfer modeling and experimental approaches were designed and used in this study for single and multiple laser tracks to achieve densely-packed multi-facet grains via temperature history, cooling rate, solidification, scanning electron micrographs, and wear rate. Multi-facet grains were produced at the center of laser track with primary dendrites extending toward the edge of single laser track. The multiple laser tracks study indicates the grain/dendrite size increases as the laser energy density increases resulting in multiplying the abrasive edges which in turn enhance the abrasive qualities.

No description available.

The hydrophobicity of a titania surface was increased by adsorption of octadecyltrihydrosilane (OTHS). The modified titania surface was characterised using a number of techniques: tapping mode AFM, streaming potential, X-Ray photoelectron spectroscopy and contact angle measurements. With a partial surface coverage of OTHS, a bell-shaped dependence of contact angle with respect to pH was observed, with the maximum advancing contact angle occurring at the point of zero charge of the titanium dioxide substrate. The contact angle change was also influenced by the surface coverage and salt concentration. At extreme pH values there was no further decrease in the contact angle, i.e. saturation occurred. A thermodynamic model was used to describe the influence of surface charge on the contact angle. The results were interpreted as a reduction in the solid-liquid interfacial free energy. The model described the results well until the point where saturation occurred.

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No description available.

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 67-71)

Thesis (Ph. D.)--Lehigh University, 1997. / Includes vita. Bibliography: leaves 122-127.

Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on July 14, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Department of Chemistry, University of Alberta. Includes bibliographical references.