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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.
321

Vidros e vitroceramicos com alta concentracao de metais obtidos a partir de residuos industriais / Glass and glass-ceramics with high metal concentration of from industrial wastes

SILVA, ANTONIO C. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:55:33Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:06Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
322

Estudo da adição de lama de bauxita em polímero de poli(metacrilato de metila) por meio de polimerizaçao em massa e moldagem em casting / Study of red mud addition in the poli (methyl metacrylate) by mass polymerization and casting process molding

SOUZA, WANDER B. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:55:03Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:56Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
323

Nova alternativa para reaproveitamento do resíduo perigoso gerado na produção de alumínio primário (SPL): obtenção de vidros opacos e fritas / New alternative for reuse hazardous waste from the primary aluminum productio process (SPL): production of the opal glass and frits

PRADO, ULISSES S. do 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:36Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:58Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP
324

Procedimentos analíticos em determinações multi elementares de particulados do aerosol atmosférico para uso em modelo receptor

DANTAS, ELIZABETH S.K. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:08Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:21Z (GMT). No. of bitstreams: 1 12434.pdf: 5335647 bytes, checksum: a56abda29440b5de525348eee5d618da (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Quimica, Universidade de Sao Paulo - IQ/USP
325

Gestao de fontes radioativas seladas descartadas

VICENTE, ROBERTO 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:47:18Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:16Z (GMT). No. of bitstreams: 1 07974.pdf: 7652856 bytes, checksum: f4eff264fe7ae9ae4d05ffaefb1712a3 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
326

Nitrification and aerobic denitrification in cyanide-containing wastewater

Mpongwana, Ncumisa January 2016 (has links)
Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2016. / Anthropogenic activities that utilise cyanide in various chemical forms have resulted in the disposal of cyanide-contaminated effluents into drainage systems that ultimately reach wastewater treatment plants (WWTP), without prior treatment. Cyanides (CN) and soluble salts could potentially inhibit biological processes in WWTP, which are responsible for the removal of contaminants from incoming wastewaters. The removal of nitrogenous compounds from such waters in processes such as nitrification and denitrification is among the core biological processes used to treat wastewaters in WWTP. Electroplating and mining industries are among the perpetrators of cyanide contamination of WWTP. The presence of these hazardous contaminants results in the alteration of metabolic functions of the microbial populations that are utilised in WWTP, thus rendering the wastewater treatment process ineffective. In this study, bacterial isolates that were able to carry out nitrification and aerobic denitrification under high salinity cyanogenic conditions were isolated from poultry slaughterhouse effluent. These strains were referred to as I, H and G. The isolated bacterial species were found to be able to oxidise ammonium nitrogen (NH4-N) in the presence of free cyanide (CN-) under halophilic conditions. Isolates I, H and G were identified using the 16S rDNA gene and were identified to be Enterobacter sp., Yersinia sp. and Serratia sp., respectively. Furthermore, Response Surface Methodology was used to optimise the physicochemical conditions suitable for the proliferation of the isolates for free-cyanide degradation, nitrification and aerobic denitrification.
327

Techno-economic evaluation of using maize for bioethanol production compared to exporting it from South Africa

Ndokwana, Ayanda Lawrence January 2016 (has links)
Thesis ( MTech (Business Administration))--Cape Peninsula University of Technology, 2016. / Capital investment in bioethanol production requires sound economic feasibility studies. This study investigated the economic feasibility of using maize as a feedstock to produce bioethanol in South Africa. There is a huge opportunity to use dedicated underutilised arable land to grow maize which can be used for both consumption and bioethanol production. The study used 200 000 ton/year of maize that could have been exported to SADC countries to size a plant that produces 80 million litres per year of bioethanol. An advanced bioethanol processing technology that separates the fibre/bran which is burnt in a steam boiler to produce process steam was selected owing to advantages such as low energy consumption and capital expenditure on fermentation and distillation equipment. This study employed a combination of qualitative and quantitative methods to gather data. The findings from a qualitative instrument indicated that a majority of respondents were in favour of the decision of excluding maize made by the South African government. Putting security of food at risk and uncertainty in the profitability of a maize-fed bioethanol plant in the South African context, were two of the primary reasons the respondents opted for an explicit exclusion of maize as a feedstock. Findings from quantitative analysis revealed that the profitability of the bioethanol plant was largely influenced by the prices of feedstock and bioethanol. The 2016 fiscal year indicated the worst case scenario in terms of economic viability of the bioethanol. The astronomically high price of maize due to drought (R5000/ton) rendered the project unprofitable as all of the economic indicators were negative. In the same marketing year, however, the trade balance of maize was positive, indicating a surplus. The study recommended that all of the surplus maize should be exported because it is not economically viable to build a bioethanol plant. The 2011 fiscal year indicated the best case scenario in terms of the economics of the project. This was due to the decrease in price of maize (R1726/ton) and a slight increase in the price of bioethanol. All of the economic indicators were positive, suggesting the benefits of investing in bioethanol production. It was recommended that under normal conditions of maize production in South Africa, a bioethanol plant can be operated simultaneous to maize exportation to other countries without compromising food security, because a maize-fed bioethanol plant uses only a small proportion of maize (14.3%) from the total volume of maize that is exported. Furthermore, it generates more revenue (99.9%) compared to the maize export revenue. It was recommended that sensitivity analysis should be conducted in a holistic manner whereby all variables in the economic model must be adjusted to assess the impact of each on the overall project profitability.
328

Método para gestão de resíduos na cadeia cervejeira do Rio Grande do Sul

Bonato, Samuel Vinícius January 2016 (has links)
O presente trabalho tem como objetivo principal a proposta de um método para gestão de resíduos nas cervejarias do Estado do Rio Grande do Sul. Para isto, o trabalho se propõe a: (i) identificar as alternativas apontadas na literatura para reciclagem de resíduos em cervejarias; (ii) identificar, através de uma pesquisa exploratória, práticas já implementadas atualmente na indústria cervejeira do estado do Rio Grande do Sul e; (iii) priorizar as alternativas de reciclagem de resíduos identificadas. A metodologia de pesquisa utilizada é o Design Science Research sendo este a base para as etapas desenvolvidas no trabalho. O método de gestão de resíduos é apresentado e descrito para que as cervejarias executem a gestão de seus resíduos, incluindo-se proporções geradas, alternativas para a reciclagem e também uma possibilidade de retorno financeiro sobre a venda dos mesmos. Uma das principais contribuições desta tese foi criar um passo a passo para que novas cervejarias e também as já existentes no mercado do Rio Grande do Sul possam gerenciar seus resíduos de forma estruturada, buscando, ao invés do descarte inconsciente dos mesmos, a agregação de valor, o retorno financeiro e a preservação do meio ambiente. / This work has as main objective to purpose a waste management method at Rio Grande do Sul's breweries. As secundary objectives, it defines: (i) to identify the alternatives showed on the literature to breweries waste recycling; (ii) to identify, through an exploratory research, the practices that has already be implemented at the beer industry in Rio Grande do Sul and; (iii) to priorize the identified recycling alternatives. The research methotology applied is the Design Science Research, being it the basis to the steps developed in this work. The waste management method is presented and described aiming that the breweries start its waste management, including quantities, recycling alternatives and also a pay-back related to the wastes selling. One of this tesis mainly contributions was to create a step by step method to new and already running breweries in Rio Grande do Sul manage its wastes as an structured way, searching, instead of an anaware disposal, add value, obtain financial returns and to safeguard the environment.
329

Caracterização para o aproveitamento do resíduo de um triturador de sucata em uma usina siderúrgica

Reckziegel, Viviana Nedel January 2012 (has links)
A indústria siderúrgica é grande consumidora de energia e de materiais e é responsável pela geração de significativo volume de resíduos sólidos bem como de efluentes líquidos e gasosos. As usinas semi-integradas de produção de aço têm como matéria-prima básica a sucata no processo de fusão. Os trituradores de sucata proporcionam a entrega de sucata ferrosa fragmentada com elevada limpeza. Entretanto, no processo de separação, são gerados resíduos não aproveitados pela indústria siderúrgica. Assim, o objetivo deste trabalho foi realizar a caracterização tecnológica do resíduo gerado em um triturador de sucata no Estado do Rio Grande do Sul e avaliar as possibilidades de aproveitamento do material. Através de peneiramento foi possível separar o material em uma fração fina (< 2 mm) e uma fração grossa (> 2 mm). A fração fina (< 2 mm) foi analisada em relação à granulometria, massa específica, composição elementar, composição mineralógica e periculosidade. Pode se concluir que a fração fina, rica em óxidos de ferro e sílica, possui potencial de aproveitamento em processos de redução de ferro na siderurgia e na indústria cimenteira. A fração com granulometria (> 2 mm), rico em materiais poliméricos, apresenta potencial para uso energético. Os resultados obtidos nas duas frações são discutidos em termos das implicações tecnológicas, ambientais e econômicas do processo. / The steel industry is a major consumer of energy and materials and it is responsible for generating a significant volume of atmospheric emissions, liquid effluents, and solid waste. The semi-integrated mills that produce steel have scrap as their basic raw material in the melting process. The scrap shredders provide the fragmented delivery of steel scrap with high cleanliness. However, the separation process generates wastes that are not used by the steel industry. The objective of this study was to characterize the waste generated in a scrap shredder in the State of Rio Grande do Sul and evaluate the potential use of the material. Through screening it was possible to separate the material into a fine fraction (< 2 mm) and a coarse fraction (> 2 mm). The fine fraction was characterized in terms of its particle size, specific weight, elemental composition, mineralogical composition, and environmental harm. It was possible to conclude that the fine fraction, rich in iron oxides and silica, can be potentially used as a raw material for iron reduction in steel plants or for cement production. The coarse fraction (> 2 mm), rich in polymeric material, presented potential in energy use. The results obtained in the two fractions are discussed in terms of technological, environmental and economic process.
330

Aplicação de ferramentas do pensamento enxuto na redução de perdas em operações de serviços. / Applying lean thinking tools for waste reduction in service operations.

Ruri Giannini 09 May 2007 (has links)
O setor industrial historicamente liderou o setor de serviços no desenvolvimento de soluções para melhoria de qualidade e produtividade e redução de perdas nos processos. Os conceitos do Pensamento Enxuto, originalmente aplicados em operações de manufatura na melhoria de processos, começaram a ser utilizados em operações de serviços a partir do ano de 2000, visando à redução de perdas tanto para a empresa como para os clientes. Este trabalho tem por objetivo investigar como as ferramentas que operacionalizam o Pensamento Enxuto podem ser adaptadas e aplicadas na redução de perdas em operações de serviços. Para resgatar fundamentos teóricos ao trabalho, a dissertação se inicia com uma revisão bibliográfica sobre conceitos-chave abordados na pesquisa: características de operações de manufatura e serviços, papel do cliente em serviços, definição de valor e qualidade e evolução dos conceitos e da aplicação do Pensamento Enxuto nas empresas. Traçou-se também um paralelo entre as sete grandes perdas em operações de manufatura (superprodução, transporte, movimento, processo, produtos defeituosos, tempo de espera e estoque) e perdas em serviços, que podem estar em atividades do front office ou do back office e podem afetar o cliente, a empresa ou ambos. A questão de pesquisa foi analisada através de três estudos de caso realizados em hotéis, com base em observação direta e entrevistas. Os hotéis estudados pertencem a categorias diferentes (econômica, super econômica e luxo), onde, portanto, identificaram-se diferentes ferramentas para redução de perdas. O presente trabalho apresenta e discute a aplicação de ferramentas do Pensamento Enxuto em serviços, tanto em atividades do back office quanto do front office, sempre orientadas para a redução de perdas de clientes ou da empresa. / The manufacturing sector has typically led the service sector in developing solutions for quality and productivity improvement and elimination of waste in the processes. The concepts of Lean Thinking, originally applied in manufacturing operations for processes improvement, was first used in services operations after 2000, aiming at the reduction of wastes as much for the organization as for the customers. The objective of this work is to investigate how Lean Thinking tools can be translated and applied in the reduction of wastes in services operations. In order to rescue theoretical support, the work initiates with a conceptual background about key concepts discussed in the research: characteristics of manufacturing operations and services operations, consumer role in services, definition of value and quality and evolution of Lean Thinking concepts and application in the organizations. A comparison among the seven wastes in manufacturing operations (overproduction, transportation, movement, processing, defects, waiting and inventories) and wastes in services was drawn, considering that wastes in services may occur in front office activities or in back office activities and can affect the consumer, the organization or both. The research question was analyzed through multiple case research in three hotels, based on direct observations and interviews. These hotels are classified in different categories (economic, super economic and luxury), where, therefore, different tools from Lean Thinking had been identified. This work presents and argues the application of Lean Thinking tools in services, as much in activities of back office as activities of front office, always guided for the reduction of wastes of consumers and of the organization.

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