This thesis is devoted to the study of a deformable material interface between two immiscible moving media, both of them being magnetizable. The first part concerns the establishment of a complete set of dynamical equations allowing a complete description of the non equilibrium phenomena including a coupling between the internal angular momentum and the electromagnetic field. The effects of the relaxation processes are also discussed. We show that the deformation of the interface introduces a nonlinear term, proportional to the mean curvature, in the surface dynamical equations of mass momentum and angular momentum. That term intervenes also in the singular magnetic and electric fields inside the interface which lead to the influence of currents and charge densities at the interface. In a second part, we give the expression for the entropy production inside the interface as well as in the bulk phase. Using the general principles of non equilibrium thermodynamics, we compute the different thermodynamical fluxes.

Porous antimony-doped tin oxide (ATO) cathodes formed by supercritical CO2 (SCCO2) treatment for silver electro-deposition devices were proposed. The porous ATO cathode with a thickness of 1.4£gm was formed by coating the nano-particle ATO solution on ITO glass. The porous structure of the cathodes was obtained by applying SCCO2 treatment at 60oC on the spin-coated ATO thin films. A layer of electrolyte(formed by AgI, NaI and DMSO)was enclosed by two electrodes to to form a so-called¡§sandwich¡¨ structure. After the fabrication process, white paint was spray on the back side of the glass substrate. Due to the thickness of the ATO cathode, the cathode is observed to be transparent during the oxidation process. The Black state of the device was observed during the reduction of silver molecules which were anchored onto the surface of the 1.4£gm thick ATO cathode. The average transmission contrast ratio of 4.4 was obtained in visible spectrum at a driving voltage of 1V and a saturation current density of 3.1 mA/cm2. In addition to that, 0.5 cm by 0.5 cm device with 65£gm cell gap and 0.08 M electrolyte concentration, an electrochromic switching time of 3.7 seconds was achieved .

Thesis (Ph. D.)--Drexel University, 2004. / Includes abstract and vita. Includes bibliographical references (leaves 198-202).

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2004. / Adviser: Ty A. Newell. Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Mechanical Engineering, 2007. / Includes bibliographical references (leaves 177-179).

Thesis (M.B.A.)--Boston University / From that eventful day in 1750 When electrical current was first discovered and through the succeeding years Where such famous inventions as the electric light, the telephone, and generation of alternating current, were brought into being, to this present age of electronic development, the electro~echanical aids available to industrial management have mounted in number. Many of the basic inventions of the Nineteenth Century, although they have been improved steadily, are accepted as commonplace. Take for instance, the telephone or the electric light, little thought is given to their importance in everyday life. It takes a sudden power failure to firmly indicate our dilemma. In the modern factory loss of power can result in stoppage of machinery, loss of time and costly damage. Many of the newer windowless plants depend on artificial light for their existence; thus, loss of light by power failure can cause accidents in addition to the foregoing results.

Recent developments of electro-hydraulic disc valves at Surrey University have shown that with a careful balance between the hydraulic and magnetic forces, this type of valve can be used as a digital or proportional device. As the valve is simpler in construction and involves very few critical dimension compared with a servo-valve, the sensitivity to contamination is considerably reduced. The dynamic response of the valve is fast due to utilising high electro-magnetic and fluid forces for actuation. The research described in this thesis is an extension of earlier work by Yuksel and Usman to improve electro-hydraulic disc valves by applying closed-loop position or pressure control to the disc. From an investigation of an unbalanced single disc valve, it was found that using position feedback can help to stabilise the disc under varying load conditions. A special differential capacitive transducer to measure the disc position was designed and constructed and was found to perform satisfactorily. As the pressure-flow characteristic of the valve can be varied by controlling the disc position, the function of the valve is similar to an electrically controlled variable orifice. Various modular configurations are proposed to perform more complicated control functions. In the final part of the research, a double disc valve is described for used in an application study to control the damping characteristic of a modified vehicle shock absorber. Initially, the valve was designed for closed-loop position control due to the non-linear hydraulic and magnetic forces. Results show that the valve can be controlled to generate the required range of damping force and has adequate dynamic performance with a response time in the range of 10 to 30 msec. However, tests using direct pressure control were also carried out. Preliminary results indicate that pressure feedback is preferable to position feedback and that by using lead compensation together with a proportional plus integral controller, stable operation is possible.

Essa dissertação tem o objetivo de analisar a complexidade do vínculo entre as indústrias eletrointensivas e o setor elétrico brasileiro, depois da década de 70, buscando responder à pergunta formulada no próprio título. 0 consumo de energia elétrica nas indústrias eletrointensivas teve um peso significativo na estrutura do consumo industrial, motivando análise por se tratar de um segmento industrial com demanda elevada de energia elétrica, exigindo consequentemente crescentes investimentos no setor de energia elétrica. Para efeito de análise, o trabalho está dividido em duas partes: a primeira aborda as questões relativas às indústrias eletrointensivas; a segunda analisa a indústria do alumínio primário brasileiro, simulando o cálculo do valor aproximado da \"perda potencial de receita\" do setor elétrico, ao fornecer energia elétrica com tarefas especiais para as duas empresas localizadas na região norte do país. Ao enfocar a implantação das duas indústrias de alumínio primário na região norte, o objetivo foi de mostrar um exemplo de decisão governamental que favoreceu investimentos pesados no Setor Elétrico, sem levar em conta o seu próprio planejamento. É bem verdade que a própria configuração do setor favoreceu esse tipo de decisão. A crise macroeconômica, que marcou a década de 80, provocou tanto a estagnação na produção e a retração do mercado interno, como o esgotamento na capacidade de financiamento do setor de energia elétrica. As indústrias de bens intermediários, como as eletrointensivas, conseguiram sobreviver graças ao mercado externo, ganhando competitividade mesmo com perda do dinamismo econômico. Num contexto de redefinição do papel do Estado, em que faltam recursos para o setor elétrico ampliar seus parque de origem hidráulica, é necessário analisar como se deu o vínculo entre o consumo de energia elétrica e as indústrias de bens intermediários, buscando respostas às necessidades do momento atual. / The aim of this study is to verify the amount of subsidie given by the electricity sector to Northern Region, as well as, the brazilian\'s option of the electricityintensive, mainly in the aluminium industry. In 1995, the Brazilian Primary Aluminium Industry consumed 18.189,5 GWh of electrical energy to produce 1188,2 thousands tons. Its growth occured after the establishment of the projects Albras and Alumar, in the Northern Region of Brazil. These two projects pay \"special tariffs\" for the electricity consumed which is generated by the Tucuruí Hydroelectric Power Plant in the State of Pará, for 20 years. When the Brazilien Government decided to build the Tucuruí Hydroelectric Power Plant, it did not take into account the criterion of lower cost projects. It has started giving incentives and allowing tariff discounts to new projects which aimed at exploring mineral reserves located in the Northern Region. The establishment of Primary Aluminium Industries in the Northern Region are typical examples of industrial policy decision, favouring heavy investments in the electricity sector without a coordinated process in its decision.

This work presents an exploration of autorotational behavior, observing naturally occurring structures to provide insight into the stability and design of autorotative mechanisms. A rotor is said to be in autorotation when, in the presence of airflow, a natural rotation generates lift to either suspend or slow the descent of a rotor. This phenomenon is observed in nature in the form of samaras, a seed pod morphology evolved in parallel by maple trees and many other organisms around the world. Simulation and experimental observation of samara vertical descent behavior provides insight into the stability of naturally evolved autorotative structures. A control-oriented model is presented to simulate the steady-state and dynamic behavior of single-winged samaras. The model is validated through experimentation and comparison to previous experimental data in the literature. This effort yields a compact model which allows for analytical exploration of design parameter bounds and stability. Autorotation provides a platform for development of unmanned aerial vehicles which can perform agile maneuvers and stable hovering in a power-efficient manner. The concept of tethered autogyros applies well to versatile surveillance platforms and high-altitude power generation; however, minimal prior literature exists on the tethered autogyro configuration. A generalized model is presented to explore the aerodynamic equilibrium space of autogyros in response to regenerative braking. Comparison with experimental data from the literature provides validation and visualizes the effects of varying inputs such as braking torque, wind speed, etc. This model is expanded to include the balancing forces of a catenary tether as well as the coupled aerodynamic and tether contributions within a wind field that varies with altitude in a physically accurate manner. Numerical methods are presented for solving aerodynamic equilibrium conditions and tether response coupling to explore the viability and practicality of high-altitude deployment for power generation as well as lower altitude extended and efficient flight of a smaller surveillance craft.

Most industrial manufacturing or processing plants use bolted connections between pipes that transfer media from one location to another. Gaskets are often used to seal these systems as they offer elevated levels of leak mitigation; however, despite their nearly universal usage, the current understanding of gasket mechanics at the meso-scale is still limited. Contemporary gaskets feature viscoelastic materials, fillers, textures, and are fabricated at various thicknesses. They are used in a wide range of thermal, mechanical, chemical, and temporal conditions. The current work characterizes polytetrafluoroethylene (PTFE) gaskets made with several different filler materials and having vastly different geometries. The chemically inert properties of this material and its relatively superior load retention properties make it appropriate for use in gaskets that are expected to retain load over hundreds of hours. As the degree to which certain factors influence gasket performance is still relatively unknown, several Analysis of Variance (ANOVA) studies are conducted to discover to what extent certain factors influence gasket load retention. Using a novel efficiency parameter (η) that compares experimental behavior to the behavior of an ideal gasket, these studies describe the impact of factors such as gasket texture, thickness, filler material, flange temperature, and the internal pressure of the flange. Additionally, component scale gasket behavior during service conditions is investigated via Finite Element Modeling. This model simulates the viscoelastic load retention behavior of these gaskets with a high degree of accuracy by using a Prony series approximation of Burger's model to characterize the viscoelastic properties of the material. A material database is used to verify and correct the model using experimental data. This collection contains data from gaskets of various textures, thicknesses and filler materials. Parameters for this model are obtained by using regression fits on a large number of data sets in the database and averaging the values of the parameters across the multiple tests. The collection of these research activities establishes a new framework that future engineers may use to characterize and even design new gaskets.