Radial gas turbines engines have established prominence in the field of small turbomachinery because of their simplicity, relatively high performance and installation features. Thus they have been used in a variety of applications such as generator sets, small auxiliary power units (APu), air conditioning of aircraft cabins and hybrid electric vehicles turbines. The current research describes the design, manufacturing, construction and testing a radial type small gas turbine. The aim was to design and build the engine to drive directly a high-speed permanent magnet alternator running at 60000 rpmand developing a maximum of 60 W. This direct coupling arrangement produces a portable, light, compact, reliable and environment friendly power generator. These features make the generator set very attractive to use in many applications including emergency power generation for hospitals, in areas of natural disasters such as floods and earthquakes, in remote areas that cannot be served from the national grid, oil rigs, and in confined places of limited spaces. It is important to recognize that the design of the main components, that is, the inward flow radial UFR turbines, the centrifugal compressor and the combustion chamber involve consideration of aero-dynamics, thermodynamics, fluid mechanics, stress analysis, vibration analysis, selection of bearings, selection of suitable materials and the requirements for manufacturing. These considerations are all inter-linked and a procedure has been followed to reach an optimum design. This research was divided into three phases: phase I dealt with the complete design of the inward radial turbine, the centrifugal compressor, the power transmission shaft, the selection of combustion chamber and the bearing housing including the selection of bearings. Phase 2 dealt with mechanical consideration of the rotating components that is stress, thermal and vibration analyses of the turbine rotor, the impeller and the rotating shaft, respectively. Also it dealt with the selection of a suitable fuel and oil lubrication systems and a suitable starting system. Phase 3 dealt with the manufacturing of the gas turbine components, balancing the rotating components, assembling the engine and finally commissioning and then testing the engine. The current work in this thesis has put the light on a new design methodology on determining the optimum principal dimensions of the rotor and the impeller. This method, also, has defined the optimum number of blades and the axial length of the rotor and the impeller. Mathematical models linking the performance parameters and the design variables for the turbine and the compressor have been developed to assist in carrying out parametric studies to study the influence of the design parameters on the performance and on each other. Also, a new graphical matching procedure has been developed for the gas turbine components. This technique can serve as a valuable tool to determine the operating range and the engine running line. Furthermore, it would decide whether the gas turbine engine operates in a region of satisfactory compressor and turbine efficiencies.

This dissertation presents the development of electrically-powered, lamination-based microactuators for the realization of large arrays of high impulse and short duration micro-jets with potential applications in the field of micro-electro-mechanical systems (MEMS). Microactuators offer unique control opportunities by converting the input electrical or chemical energy stored in a propellant into useful mechanical energy. This small and precise control obtained can potentially be applied towards aerodynamic control and transdermal drug delivery applications. This thesis discusses the development of both chemical and physical microactuators and characterizes their performance with focus towards the feasibility of using them for a specific application. The development of electrically powered microactuators starts by fabricating an array of radially firing microactuators using lamination-based micro fabrication techniques that potentially enable batch fabrication at low cost. The microactuators developed in this thesis consist of three main parts: a micro chamber in which the propellant is stored; two electrode structures through which electrical energy is supplied to the propellant; and a micro nozzle through which the propellant or released gases from the propellant are expanded as a jet. The fabricated actuators are then integrated with MEMS-process-compatible propellants and optimized to produce rapid ignition of the propellant and generate a fluidic jet. This rapid ignition is achieved either by making the propellant itself conductive, thus, passing an electric current directly through the propellant; or by discharging an arc across the propellant by placing it between two closely spaced electrodes. The first concept is demonstrated with chemical microactuators for the application of projectile maneuvering and the second concept is demonstrated with physical microactuators for transdermal drug delivery application. For both the actuators, the propellant integrated microactuators are characterized for performance in terms of impulse delivered, thrust generated and duration of the jet. The experimentally achieved results are validated by comparing with results from theoretical modeling. Finally, the feasibility of using chemical microactuators for maneuvering the path of a 25 mm projectile spinning at 500 Hz is discussed and the feasibility of applying the physical microactuators for increasing skin's permeability to drug analog molecules is studied.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 108-114). Also available on the World Wide Web.

The thesis contains essential information on the methods and possibilities of using water power. The first part deals with the history of water works, and introduction to basic physics of energy conversion. Further research is made available sources of information on the history, technology, power generation and design of hydropower Lipno I and II, with mention of unrealized project pumping plant Lipno III. The conclusion evaluates the defined objectives and creates a short summary.

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Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2011. / Electrical energy is an important resource for human and economic development. On the demand side, electrical energy management is needed because of the tendency of manufacturing industries to consume large amount of energy and as a result lead them to spend more money in paying bills for the consumed electrical energy. In addition, the amount of electrical energy generated in Sub-Saharan Africa is incomparable with demand requirements. The predominant sources of electrical energy generation are fossil fuels and hydro. Generation of electricity by fossil fuel needs high capital investments and high running costs. Concurrently, the process of burning fossil fuels has an adverse effect on the environment. In order to minimize these effects, electrical energy management in manufacturing industries has to be instituted and implemented. In this research, a study has been undertaken to develop methods and strategies to be used as tools for electrical energy management in manufacturing industries and it is aimed at reducing electrical energy consumption. The research method adopted/used includes: survey of several cement industries in order to obtain current and historical electrical energy consumption, production data and to be acquainted with the methods used for energy management, measurement of electrical parameters, investigation of the use of electrical power in cement industries, analysis of power factor and power factor correction methods, analysis of energy efficiency potentials and technology used for energy saving. From the data gathered, the following were developed: strategies for the overall electrical energy management for cement plant, strategies for energy efficiency potential and technology used for energy saving, an algorithm for assessing the potential options of DSM, an algorithm for performing industrial load scheduling, an industrial energy consumption model using regression analysis technique and a Static Synchronous Compensator (STATCOM) for industrial power factor improvement. Also, a numerical analysis and computer simulation using MATLAB/Simulink were implemented. Moreover PSIM and Excel software were used in the developed energy consumption model and for the power factor improvement method. Numerical analysis and computer simulation showed that the developed STATCOM has the capability of improving and varying of power factor in accordance with the variation of plant loads, it improves power factor and reduces harmonics of the respective industries. Using the developed algorithm for assessing potentials of DSM options, it was found that, most of the energy management techniques used in manufacturing industries worldwide are not implemented in the visited industries. The developed methods and strategies can be used in improving power factor, prediction of electrical energy consumption and also for development of energy consumption benchmarking in cement industries. They can be also extended and used in mining and other manufacturing industries such as paper, textiles and this can create condition for sustainable energy management program in manufacturing industries.

Orientador: Marco-Aurelio De Paoli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-04T21:14:10Z (GMT). No. of bitstreams: 1 Nono_RogerioSilva_M.pdf: 4985675 bytes, checksum: c5784cee6e3e4bb52019ba970d1b2d00 (MD5) Previous issue date: 2005 / Resumo: A estrutura e a morfologia dos filmes de TiO2 exercem uma grande influência na eficiência de conversão de energia das células solares de TiO2/corante, principalmente quando estes dispositivos são preparados com eletrólitos poliméricos. O objetivo deste trabalho consistiu em otimizar os filmes de TiO2 visando obtê-los com uma morfologia porosa mais adequada à aplicação em células solares que utilizam eletrólito polimérico. Os filmes de TiO2 foram depositados em eletrodos transparentes de vidro-FTO ("Fluorine doped tin oxide") utilizando suspensões do óxido obtidas por diferentes técnicas. As suspensões aquosas do óxido foram obtidas por síntese sol-gel a partir da hidrólise e condensação de isopropóxido de titânio e estabilizadas com poli(etileno glicol). Os filmes também foram preparados pela técnica "template", utilizando membranas porosas de acetato de celulose como molde para que os poros da membrana fossem utilizados como padrão para o óxido. Após a deposição de filmes da suspensão de TiO2, esses foram submetidos a uma etapa de tratamento térmico a 450 °C para eliminação do material orgânico. Os óxidos foram caracterizados por microscopia eletrônica de varredura, difração de raios-X, termogravimetria, medidas de rugosidade, espessura, tamanho de partículas, análise elementar e espectroscopia de absorção na região UV-vis. Os filmes de TiO2 foram sensibilizados com um corante de rutênio (N3, Solaronix) e utilizados como fotoeletrodos na montagem de células solares com eletrólito polimérico (poli(óxido de etileno-co-epicloridrina)84:16, NaI e I2). As células foram investigadas por curvas de fotocorrente em função do potencial e por espectroscopia de impedância eletroquímica, para se avaliar a eficiência destes dispositivos na conversão de energia. Os melhores resultados foram obtidos utilizando fotoeletrodos com duas camadas de TiO2 depositados sobre vidro-FTO. Estas células apresentaram uma corrente de curto circuito Isc = 3,8 mA cm, um potencial de circuito aberto Voc = 0,75 V e uma eficiência na conversão de energia h = 1,3 % (h = 2,6 % sob 10 mW cm). A técnica de espectroscopia de impedância eletroquímica revelou que a resistência em série das células aumentou com os fotoeletrodos de dupla camada, mas esta metodologia melhorou a adesão dos filmes de TiO2 no substrato condutor, e aumentou a eficiência dos dispositivos. / Abstract: The structure and morfology of TiO2 films provide a great influence in the eficiency of light conversion to energy in the solar cells of TiO2/dye, mainly when these devices are prepared with polymer electrolyte. The goal of this work consisted in optimize the TiO2 films aiming to get films with porous structure and more suitable to apllied in solar cells with polymer electrolyte. The TiO2 films were deposited onto glass-FTO ("Fluorine doped tin oxide") utilizing TiO2 suspensions prepared by differents methodologies. Aqueous suspensions of oxide were obtained by sol-gel route from hydrolysis and condensation of titanium isopropoxide stabilized with poly(ethylene glycol). The films were prepared by template technique, utilizing porous celulose acetate membranes, the material produced has large porous structures inherited from the initial membrane form. After the deposition of films of TiO2 suspension, the photoelectrodes were submited to a thermal tratament the 450 °C to eliminate organic material. Oxides films were characterized by scanning electron microscopy, X-ray diffraction, thermogravimetry, rugosity and thickness measurements, particles size, elementar analysis and absorption spectroscopy. The TiO2 films were sensitized with a Ruthenium dye (N3, Solaronix) and used as photoelectrodes in the assemble of solar cells with polymer electrolyte (poly(ethylene oxide-co-epichlorohydrin)84:16, NaI e I2). The devices were investigated through photocurrent versus potential curves and electrochemistry impedance spectroscopy. Better results were obtained when we used photoelectrodes with double layer of TiO2 films deposited onto glass-FTO. This cells presented, short circuit current Isc = 3.8 mA cm, open circuit potential Voc = 0.75 V and efficiency h = 1.3 % (h = 2.6 % under 10 mW cm). Electrochemistry impedance spectroscopy revealed that the series resistance of cells increased with two films, but this methodology enhanced the adhesion of the TiO2 film onto glass-FTO, and improved the efficiency of the cells. / Mestrado / Quimica Inorganica / Mestre em Química

Orientadores : Luiz Fernando Milanez, Jose A. Velasquez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-06T09:13:18Z (GMT). No. of bitstreams: 1 Bueno_AndreValente_D.pdf: 1858642 bytes, checksum: 5d8ef42f35d6898a67cb77a3c73c0b7d (MD5) Previous issue date: 2006 / Resumo: As conseqüências da adição de biodiesel ao óleo diesel foram estudadas estabelecendo-se relações de causa e efeito entre o desempenho do motor e os processos de combustão e formação de mistura. Foram incluídos, nesta discussão, aspectos como emissões poluentes, formação de mistura, dinâmica do processo de combustão, eficiência de conversão do combustível,desempenho do motor em carga máxima e consumo específico.Utilizaram-se, sob tal propósito, técnicas tradicionalmente associadas à pesquisa e ao desenvolvimento dos motores de ciclo diesel, tais como a análise de liberação de energia, a análise exergética e ensaios dinamométricos. Devido às pequenas variações observadas nos parâmetros opcionais do motor com a introdução do biodiesel, algumas modificações nos métodos aplicados para a coleta de dados experimentais e nos modelos empregados em seu processamento se mostraram necessárias. Dentre tais ajustes, pode-se destacar a formulação de um novo modelo de análise exergética para os processos ocorrentes no cilindro e a utilização de um arranjo inédito de sistema indicador. Demonstrou-se que a adição de biodiesel em baixas concentrações favorece a conversão da exergia do combustível em trabalho no interior do cilindro, proporcionando uma elevação na eficiência de operação do motor. Para os combustíveis analisados, que compreendem a adição de até 20% de biodiesel em volume, a mistura contendo 10% desta substância ofereceu as melhores características quanto ao desempenho e ao consumo específico / Abstract: The consequences of the biodiesel blends with diesel fuel were analyzed establishing cause and effect relationships between the engine performance and the combustion and mixture preparation processes. In this investigation, aspects like pollutant emissions, mixture preparation,dynamic of the combustion process, fuel conversion efficiency, performance under full load and specific fuel consumption were included.Techniques traditionally associated with diesel engines research and development were utilized for this purpose, including heat release analysis, exergetic analysis and dynamometric bench tests. In order to account for the small effects of the biodiesel introduction on the engine operational parameters, some modifications of the methods and models applied to data acquisition and post-processment were necessary. These modifications include the formulation of a new model for the in cylinder exergetic analysis and a novel arrangement of indicator system. By using the exergetic analysis, it was demonstrated that the blending of biodiesel in low concentrations increases the conversion of fuel exergy into work within the cylinder, causing an elevation on the engine efficiency. For the analyzed fuels, which enclose up to 20% of biodiesel addition in volume, the 10% biodiesel blend has presented the best results of performance and specific fuel consumption / Doutorado / Termica e Fluidos / Doutor em Engenharia Mecânica

Made available in DSpace on 2014-10-09T12:28:17Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:04Z (GMT). No. of bitstreams: 0 / O objetivo deste trabalho foi investigar os ganhos ambientais e energéticos com o aproveitamento da biomassa residual de gado leiteiro no município de Lagoa da Prata-MG. Para este estudo realizaram-se trabalhos de campo, tanto para caracterizar a pecuária leiteira no município, como para conhecer os aspectos ambientais da localidade. Para se conseguirem dados de relevância energética e ambiental, visitaram-se nove fazendas da região onde os responsáveis responderam a um questionário. Recolheram-se amostras de resíduos do gado confinado em cada uma delas. Os resultados da pesquisa mostraram uma média de 3 toneladas de geração diária de biomassa residual por propriedade. Constatou-se um consumo médio de energia elétrica de 2.500 kW/h, pela utilização de uma série de equipamentos energointensivos. Encontrou-se um consumo médio de água de 27 m³/dia. Realizaram-se análises químicas por Espectrometria de Fluorescência com Raio X nas amostras de resíduos e observaram-se concentrações médias relativamente altas para os elementos P, Fe, S, Ti, Mn, Zn e Na, passíveis de comprometer o meio ambiente local e regional. Para diagnosticar os ganhos energéticos foi simulada a produção de biogás através de protótipos de biodigestores com as amostras de dejetos obtidas nas fazendas. Os resultados analíticos do biogás através de cromatografia gasosa demonstraram concentrações aproximadas de 70% de CH4 , logo concluiu-se que o biogás obtido possui alto valor energético. Portanto, a utilização dos dejetos do gado leiteiro na produção de biogás, além de resolver o problema dos resíduos, efluentes e diversas outras poluições ambientais, eventualmente geradas pela atividade na região, poderá trazer auto-suficiência energética às propriedades locais. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP