Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xiv, 131 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 91-94).

There is a need for low-cost switching and proportional electro-hydraulic valves with low contamination sensitivity and good reliability. In an attempt to meet this need, a novel electro-hydraulic floating double-disc valve has been developed to the stage where it can be used to control hydraulic cylinders or motors directly. As the valve is significantly underlapped, problems still remain in achieving adequate hydraulic stiffness in the proportional mode of operation. The valve operation, which relies on the complex interaction between fluid and electro-magnetic forces acting on the valve discs, is described and a theoretical model of the fluid and electro-magnetic characteristics of the valve is presented. The theory shows satisfactory agreement with experimental data. A pre-production version of the double-disc valve has been designed and manufactured and it incorporates ideas for manufacturing cost reduction while at the same time conforming to CETOP 3 international valve port standards. This valve has been successfully tested as a switching or proportional device when controlling two different cylinders. Proportional control of the valve is achieved using Pulse-Width-Modulation technique. British Technology Group and University of Surrey have applied for a patent on the valve. The patented floating-disc valve has the following features: (a) 3 way or 4 way 2-position or proportional action with minor changes to produce the two types of action, (b) cartridge construction with interchangeable components, (c) low contamination sensitivity, (d) few critical dimensions, (e) no sliding surfaces, (f) CETOP valve port configuration and (g) potentially capable of operating with corrosive or non-lubricating fluids.

Most musical instruments have undergone evolution over several hundred years. The pursuit of excellence in instrument building helps instruments in meticulously translating musicians's movement and gesture into sound. Musicians spend much of their time perfecting their movements and gestures to achieve the desired sound and expression. Digital technologies brought new perspective and possibilities to this performer-instrument relationship by detaching the tight relationship between gesture used and sound produced. This relationship can then be re-created with almost no restrictions, and composers have freedom to design their own controller or electronic instrument. The intention of this thesis is to further the development of gestural controller usage by understanding the evolution that has lead to the current trends in their use; how this evolution may inform newer development, and creating two new interactive systems for informed by the above. It also consists of a discussion of problems and challenges in interface building in terms of art and design. To demonstrate proficiency in traditional compositional genres, the first half of this dissertation consists of a composition portfolio. The second part of this dissertation is an investigation into the use of gestures and controllers in interactive electroacoustic music.

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A full electro-thermal simulation of a three-phase space-vector-modulated (SVM) inverter is performed and validated with measurements. Electrical parameters are extracted over temperature for the insulated gate bipolar transistor (IGBT) and diode electro-thermal models. A thermal network methodology that includes thermal coupling between devices is applied to a six-pack module package containing multiple IGBT and diode chips. The electro-thermal device models and six-pack module thermal model are used to simulate SVM inverter operation at several power levels. Good agreement between model and measurement is obtained for steady state operation of the three-phase inverter. In addition, transient heating of a single IGBT in the six-pack module is modeled and validated, yielding good agreement. / Master of Science

In this work, the opto-piezo actuation and piezoelectric actuation in gallium arsenide (GaAs) is experimentally and theoretically verified. Experimentally the response of the respective actuations are measured using the current generated from the inverse piezoelectric effect. The mechanical structure used to generate this current is a micron size torsional resonator fabricated from a GaAs photodiode heterostructure. The photodiode heterostructure is optically and electrically designed as a photovoltaic (PV) cell while mechanically the structure resembles a bimorph. The bimorph design is a result of the PV cell consisting of a pn junction and a heterojunction where the depletion regions have the additional property of being piezoelectric. The opto-piezo actuation results from using the photogenerated voltage to piezoelectrically drive a mechanical structure. Using light modulated at the resonance frequency of the torsional resonator the measured current is shown to linearly increase with intensity. For the electrical actuation case, the torsional resonator is driven using the non- linear response of the pn junction to an applied voltage. The non-linear response results in generation of voltage at the harmonic frequencies of the applied voltage. The voltage generated at twice the applied frequency is given the label 2f and is used to piezoelectrically drive the mechanical structure. The above results for the two methods of actuation are theoretically validated by deriving a model for the expected current. The model predicts the current as a function of the voltage. For the opto-piezo case this voltage is the photovoltage. The photovoltage is determined using the AC PV model. This model is derived using the DC PV model and predicts the AC operation of a photodiode in the 3rd and 4th quadrants to resistive and reactive loads. Using the opto-mechanical coupling coefficient the efficiency of the opto-piezo actuation is compared to opto-thermal actuation and radiation pressure actuation. It is shown that the opto-piezo effect, in general, is several orders of magnitude better than the other two in converting optical energy into mechanical energy. This is an important result because in situations where low optical powers are only available and power, in general, cannot be spared, for e.g. on a satellite, devices that make use of the opto-piezo effect could be used for either actuation or sensing. Generally however, using the opto-piezo effect can lead to either integration of existing photonic devices with mechanical resonators or new photonic devices all together. For e.g. using the opto-piezo effect an adaptable optical correlator can be made which could be used to make artificial intelligent machines. / Thesis / Doctor of Philosophy (PhD)

L'oxydation du phenol et des cresols en milieu aqueux par le procédé électro-Fenton en utilisant une cathode en feutre de carbone a été étudiée. 10?4 M de sulfate de fer (II) a été la concentration optimale de catalyseur, permettant d'éliminer 100% du carbone organique total (Cot) de solutions aqueuses de phenol. Les principaux intermédiaires formés (70%) au cours de la destruction du phenol ont été identifiés comme l'hydroquinone, p-benzoquinone et le catechol. Au cours de l'électrolyse de l'o-cresol, les intermédiaires identifiés (58%) ont été le 3-méthyl-catechol et le méthyl-hydroquinone. Pendant l'oxydation de phenols, les acides prédominants ont été identifiés. Ces expériences ont permis de proposer un mécanisme complet de minéralisation pour le phenol et l'o-cresol. Au cours du traitement des rejets de décapage d'avions, le remplacement des anodes de PT par diamant dope bore a augmenté l'efficacité, en supprimant environ 98% de TOC en 20 heures / The present work verified the efficiency of electro-Fenton to destroy phenolic compounds present in Stripping Aircraft Wastewater. This research aimed to elucidate the influence of the catalyst nature, its concentration and of electric current density in efficiency of electro-Fenton process using an indivisible cell with a carbon felt cathode and platinum or borod doped diamond anodes. The experiments compared the effect of these variables to destroy phenol, cresols and their intermediates. The compounds and many intermediates formed were identified in High Perfomance Liquid Chromatograph and allowed obtaining apparent and/or absolute constants and simplified degradation mechanisms. In optimum conditions, measures of Total Organic Carbon showed high mineralization rates. At the end, the application of electro-Fenton process to high organics loads of real Stripping Aircraft wastewater allowed obtaining almost complete mineralization replacing Pt anode by Boron Doped Diamond.

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