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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

The technologies and principles needed for the powering of remote nodes in an interoperability network

Beidalah, Chadrick J. Coudray, Aaron D. January 2009 (has links) (PDF)
Thesis (M.S. in Information Technology Management)--Naval Postgraduate School, March 2009. / Thesis Advisor(s): Buddenberg, Rex. "March 2009." Description based on title screen as viewed on April 24, 2009. Author(s) subject terms: Power Generation, Remote Network Node, Interoperability Network, Electric Generator, Wind Power, Solar Power, Photovoltaic, Thermoelectric, Energy Storage, Fuel Cell, Hybrid Power, Power Monitoring, Power Management. Includes bibliographical references (p. 117-120). Also available in print.
212

Fat and oil derivatives for use as phase change materials

Goff, Michael J., January 2004 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 181-189). Also available on the Internet.
213

Optimization in solar heating/photovoltaic systems

Vourazelis, Dimitrios G. January 1990 (has links) (PDF)
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 1990. / Thesis Advisor(s): Titus, Harold A. Second Reader: Michael, Sherif. "December 1990." Description based on title screen as viewed on March 30, 2010. DTIC Descriptor(s): Heat Transfer, Theory, Theses, Costs, Heating Elements, Fluid Dynamics, Photovoltaic Effect, Solar Heating, Swimming, Optimization, Installation. DTIC Identifier(s): Swimming Pools, Solar Heating, Photovoltaic Supplies, Filter Pumps, Theses. Author(s) subject terms: Optimization, Solar Heating, Photovoltaics. Includes bibliographical references (p. 57). Also available in print.
214

Fat and oil derivatives for use as phase change materials /

Goff, Michael J., January 2004 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 181-189). Also available on the Internet.
215

Solar power for deployment in populated areas a thesis /

Hicks, Nathan. Baltimore, Craig Victor. January 1900 (has links)
Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on September 23, 2009. Major professor: Craig Baltimore, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Architecture with a Specialization in Architectural Engineering." "June 2009." Includes bibliographical references (p. 65-67). Also available on microfiche.
216

Solar and wind energy development in Maine : 1973-1997 /

Rallis, Evan. January 2003 (has links) (PDF)
Thesis (M.A.) in History--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 69-71).
217

Análise do rendimento térmico do aquecedor solar parabólico cilíndrico /

Mattos, Sérgio Ricardo de. January 2011 (has links)
Orientador: Teófilo Miguel de Souza / Banca: Osiris Canciglieri Junior / Banca: Rubens Alves Dias / Resumo: Este aquecedor solar foi construído em uma estrutura metálica, que tem um revestimento de polietileno reflexivo parabólico cilíndrico, onde no foco da parábola passa uma serpentina com sete tubos em cobre de 9,5 mm e o projeto foi desenvolvido para obter temperaturas mais elevadas do que os aquecedores planos. O objetivo desta dissertação foi atingir temperaturas mais altas na fase líquida. As temperaturas alcançadas foram obtidas utilizando uma densidade de potência solar que variou entre (1.000±10) W/m2, nas vazões de: 66, 54, 42, 30, 27, 24, 21, 18, 15, 12 e 9 litros por hora. A máxima temperatura atingida utilizando-se a vazão de nove litros por hora foi de 71°C, permitindo uma diferença de temperatura, em relação a temperatura ambiente de 43°C. A máxima vazão utilizada no aquecedor solar parabólico cilíndrico foi de 66 litros por hora e obteve-se uma temperatura de 38°C, sendo a diferença em relação à temperatura ambiente de 6°C. Assim com o desenvolvimento do aquecedor solar parabólico cilíndrico obtiveram-se temperaturas maiores em uma área de captação menor, do que em aquecedor convencionais planos e com rendimentos superiores a 70% em sua maior faixa de operação / Abstract: This solar heater is constructed of a metallic structure, which has a polyethylene coating reflective parabolic cylindrical, where the focus of the parable is a serpentine seven copper pipes of 9.5 mm and the project was designed to obtain higher temperatures than the heaters plans and the objective of this thesis was to reach higher temperatures in the liquid phase. The temperatures reached were obtained using a solar power density ranged from (1000±10) W/m2, the flow rates: 66, 54, 42, 30, 27, 24, 21, 18, 15, 12 and 9 liters per hour. The maximum temperature reached by using the flow of nine liters per hour was 71°C, allowing a temperature difference in relation to ambient temperature of 43°C. The maximum flow rate used in the cylindrical parabolic solar heater was 66 liters per hour and obtained a temperature of 38°C, and the difference in the ambient temperature of 6°C. So with the development of a cylindrical parabolic solar heater temperatures were obtained in a larger area smaller than in conventional heating plans and with performance up to 70% on the higher range of operation / Mestre
218

Comparative analysis of characteristics of the various sugarcane bagasse types in terms of gasification

Kula, Mpumezo January 2016 (has links)
The insight that the fossil fuel reserves are limited, together with concerns over security of supply (i.e. the oil crises), initiated the first raise of interest in biomass and all other renewable energy forms. However, the concern grew that global warming and the resulting climate change were enhanced by carbon dioxide (CO2) emissions resulting from fossil fuel consumption. Meanwhile, biomass energy is thought to account for 14–15% of total world energy consumption. Hence, the exploitation and utilization of biomass energy are effective and necessary for relieving the pressures caused by environmental pollution and fossil fuel shortage (Lv et al., 2010). Recently, extensive research aimed at converting biomass to useful energy have been carried out, especially pyrolysis and gasification, which are particularly suitable for the effective and efficient utilization of biomass. Sugarcane bagasse is the main byproduct of sugarcane mill, ready available at the production site so that it may be a suitable raw material for the production of biofuels, chemicals, and electricity. Among the methods that have been previously studied, is this particular study we explore thermochemical process, gasification. The properties of sugarcane bagasse relevant to gasification are briefly reviewed. The compositions of the bagasse as a fuel are variable, especially with respect to inorganic constituents important to the critical problems of sintering, fouling and slagging. Alkali and alkaline earth metals, in combination with other fuel elements such as silica and sulfur, are responsible for many undesirable reactions in a gasifier system.
219

Conservação de energia: uma ferramenta para analisar o aproveitamento de energia solar em instalações residenciais /

Santos, Romi Stella dos. January 2008 (has links)
Orientador: Oscar Armando Maldonado Astorga / Banca: Durval Luiz Silva Ricciulli / Banca: George Alves Soares / Resumo: No Brasil, devido ao forte crescimento da demanda de energia elétrica nas últimas décadas e com a necessidade de atender a esta procura, torna-se indispensável a inclusão no sistema elétrico brasileiro de programas de eficiência energética e a utilização de fontes alternativas de energia, pois com a construção de novas hidrelétricas e termoelétricas para atender o consumidor, ocorre inundações de grandes áreas e diminuição da emissão de gases para a atmosfera, o que causa fortes impactos ambientais. O uso de fontes alternativas também diminui a dependência do Brasil de combustíveis fósseis, pois futuramente ocorrerá o esgotamento de reservas naturais no país, tendo a necessidade de importar energia, o que elevará os preços das tarifas de energia elétrica. Para que haja a conservação de energia proveniente de fontes tradicionais e incentivar a implantação de energia solar no sistema elétrico brasileiro, desenvolveu-se um programa que analisa a viabilidade técnico-econômica de inclusão do sistema fotovoltaico e fototérmico ao sistema tradicional de distribuição de energia nas diversas regiões do Brasil em residências, pois é o setor que possui um maior potencial de economia de energia. O programa é uma ferramenta de fácil manuseio, de acesso rápido que permitem tomadas de decisões rápidas e seguras quanto à implantação de energia solar por parte do consumidor, além de fornecer em qual região é mais viável essa implantação. / Abstract: In Brazil, due to a solid increasing in electrical energy demand at the last decades and due to the need to comply with this demand, became essential the inclusion of energetic efficiency programs and use of alternative energy resources in the Brazilian electrical supply system. However, the new hydro and thermo electrical power plants construction to attend the consumer cause strong environmental impacts, since they need big flooded lakes and eliminate theirs pollutants in the atmosphere, respectively. Moreover, the use of alternative energy resources decreases Brazil dependency of fossil fuels, besides it prevents the breakdown of the natural reserves and the need of energy importation, what would increase the charge for the electrical energy. To the energy conservation provided by traditional resources and to encourage the implementation of a solar energy based system in Brazil, it was developed a software that analyzes technical and economic feasibility of the photovoltaic and photothermical systems introduction in the traditional supply system on the several regions of Brazil to residential use, because this is a sector that has an elevated potential of energy saving. The software has a friendly interface, with quick access that allows the user to take quick and safe decisions, regarding to the solar energy implementation by consumers, and evaluate which area of the country is the most interesting to the implementation. / Mestre
220

Hybrid energy harvesting system for a condition monitoring mote

De Villiers, Daniel Johannes January 2009 (has links)
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009 / Traditional high voltage power transformers feature sensors measuring basic parameters from oil and gas and are limited to on-site monitoring. Unforeseen failures and breakdowns on these transformers have led to extensive financial losses even with planned maintenance schedules in place. A distinct need has arisen to actively monitor and identify causes of such failures. However, no or little infrastructure exists for effective remote condition monitoring. Wireless sensor networks can be introduced to actively monitor and identify causes of such failures. Sensor motes in the network are battery operated and therefore constrained by limited energy in these batteries. An alternative to battery-powered sensor motes is the conversion of available energy harvested from the surrounding environment into useable electrical energy powering the sensor motes. The primary objective of this research was to examine methods to harvest energy from both the environment and high voltage power transformer. A low cost and feasibly sized hybrid energy harvesting power management prototype was successfully developed that enabled sustained sensor mote operation for prolonged condition monitoring of high voltage transformers. The sensor mote utilised a piezoelectric cantilever to generate usable electrical energy from the transformer tank vibration. Together with solar energy harvesting, the system allowed for a battery-less self-sustained wireless sensor mote capable of autonomously monitoring its surroundings. The power management system's modular architecture provided for the inclusion of additional energy harvesting techniques. This allowed condition monitoring solutions not exclusively for power transformers but proposed an extensible condition monitoring solution for various applications.

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