Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 18, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Marjorie Skubic. Includes bibliographical references.

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Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [111]-119).

This thesis introduces a new type of walking machine that appears promising due to its relative simplicity and efficiency. After an introduction to a selection of previous walking machines, the new machine’s history, advantages, operation and a method for solving its kinematics are given. Early attempts to optimize the mechanism to a range of criteria are described and their shortfalls exposed. A second attempt to optimize the leg geometry by genetic algorithm is detailed and the results of this search discussed. A mechanics model of a hypothetical machine is developed from first principles and the implications of the analysis described. Stability limits and tractive abilities of the machine are explored. A method for determining the loads on the links that constitute the leg and the vehicle chassis is given. A series of prototypes has been constructed and discussions of these machines are given. The most recent prototype is used in a pair of experiments to validate the kinematic and kinetic models. The experimental method, a statistical analysis of results and a discussion are provided for each. The thesis concludes by considering what work remains to be done before a practical cargo carrying transport walking machine can be designed. / Prof. A.L. Nel

A gas-phase system to oxidize and remove the platinum and palladium from automotive catalytic converter units was studied. The effects of varying reaction temperature, time and reactant gas concentration upon yields were monitored using a colorimetric procedure based on the regent p-nitroso-N, N-dimethyl amiline. Chlorine plus carbon monoxide at 700°-900°C. displayed the most promise for commercial application.

A laser-based automated mechanical mobility measurement system has been developed that can obtain a very high spatial resolution of frequency response functions (FRFs) for experimental modal analysis where one-dimensional structural motion predominates. With this system FRFs are measured and recorded in a format that is readily imported into a popular modal analysis software. A scanning laser Doppler velocimeter is coupled to a multi-channel FFf analyzer system for efficient data collection and management of spatially distributed FRFs. The objectives in designing this measurement system is to take advantage of the laser's non-contacting nature, its high spatial resolution, and its fast point-to-point movement. By using the scanning capabilities of the laser, experimental mobility FRF data can be collected in those structures that have dominant response in one direction at up to 16,000,000 positions. Moreover, the laser does not mass load the structure thus making the structure time invariant unlike "roving" accelerometers. The design and implementation of this automated mechanical mobility measurement system is presented. Instrumentation interfacing and control issues as well as software development issues are addressed in this thesis. Procedures required to implement the laser-based measurement system are presented. The performance of the laser-based system is presented along with an illustrative example of its use on a free-free rectangular plate where the vibration response is primarily in one direction. / Master of Science

This thesis describes an investigation into the spatial species conversion profiles of a Cu-zeolite SCR under engine conditions at low exhaust gas temperatures; this was then compared with a CFD model that models the catalyst via a porous medium measuring 5 x 5 x 91 cells assuming a uniform cross-sectional flow distribution. Species conversion rates were sampled at fixed points in the axial direction. The analysis of the spatial conversion profiles is a more rigorous method in assessing the ability of a mathematical model to predict the experimental data. It can also assist in the optimisation of the catalyst size, minimising packaging requirements and manufacturing costs. The experiments were undertaken on a light-duty diesel engine at a speed of 1500rpm, and at a load of 6bar BMEP; this provided exhaust gas temeraqtures between 200 and 220°C. NO2:NOx ratios were controlled by changing the size and position of the diesel oxidation catalyst, the inlet NH3: NOx ratio was also also varied, ammonia gas was used instead of urea for the purposes of simlicity. The advantage of testing on an actual engine over lab-babed studies is that the conditions such as exhaust gas composition are more realistic. A 1D CFD model was constructed using the ‘porous medium approach’ with kinetics obtained from open literature. Results from the simulations were then compared with the experimental data for the same engine conditions. It was observed that the majority of the NOx conversion took place in the first half of the brick for all NH3: NOx ratios investigated, and that the formation of N2O via NO2 and ammonia had the same influence as the ‘fast’ SCR reaction just after the inlet, which the CFD model failed to predict for the base case analyses. The influence of the inlet ammonia on the model was also noticed to be greater than in the experiments. Simple transient analyses were also undertaken on the short SCR bricks for NO2: NOx ratios of 0.6 and 0.07, and it was observed that the response time to steady-state was noticeably higher in the experiments than in the model. Modifications made to the model, including decreasing the influence of the ‘fast’ SCR reaction, and the addition of an empirical term onto the ammonia adsorption provided a noticeably better agreement for different NH3: NOx injection ratios. The desorption kinetics in the model were also altered by increasing the strength of the bonding of the ammonia onto the adsorption sites. This improved the transient agreement between the model and the experiments, but reduced the steady-state concentrations at the exit of the brick for all NH3:NOx ratios investigated.

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