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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.
1

Forced convection solar maize drier with a directly coupled photovoltaic powered air mover for use in Malawian homesteads

Mumba, Joseph January 1993 (has links)
No description available.
2

Development of an impact assessment methodology and decision making tool to assist in the evaluation of site suitability for on-site sanitation systems / Johanna Christina Vivier

Viviers, Johanna Christina January 2006 (has links)
Thesis (Ph.D. (Geography and Environmental Studies))--North-West University, Potchefstroom Campus, 2007.
3

Sustainable water supply: rainwater harvesting for multistoried residential apartments in dhaka, bangladesh

Sultana, Farzana 15 May 2009 (has links)
Rainwater harvesting is a familiar term for Bangladesh. People in areas that lack drinking water, particularly the coastal areas and the rural areas in the country, practice rain water harvesting. The high annual rainfall in the country makes rainwater harvesting a logical solution for the arsenic contamination of ground water in Bangladesh (Rahman et al. 2003). Also, the increasing population in the urban as well as rural areas is putting increased load on underground aquifers which is evident in the fact that the piezometric level in Dhaka has decreased by more than 65 feet in the last decade. The annual rain fall that the city receives may be an effective answer to the recharge of aquifers. Rain water harvesting during the rainy season can reduce the increasing load on groundwater levels. This study aims to provide some guidelines for economic rainwater harvesting system, especially for urban areas for specific user groups. These guidelines were formulated through literature review, analysis of some case studies on rainwater harvesting, and, to a certain extent, practical experience of the researcher. Data from secondary sources have also been used for the purpose. The guidelines have been formulated using existing data on rainwater harvesting systems. Based on these guidelines, a mathematical model has been developed to figure out cistern sizes for collection of rainwater. The solution is applied to a typical plan of an apartment house in Dhaka (multistoried) using programming and visualization so as to demonstrate the scope and benefit of integration of rain water harvesting technique with the architectural design. The harvested rainwater definitely does not meet the basic domestic requirement, but supplements it during the rainy season which, most importantly, is usable for individual household use. Large-scale rainwater harvesting also, hopefully, results in a decrease of seasonal flooding in the urban areas. The products of this research are a) a computer program for sizing cisterns and b) an animation of the proposed rainwater harvesting system that may be used as a tool to demonstrate the benefits of the technique.
4

Development of an impact assessment methodology and decision making tool to assist in the evaluation of site suitability for on-site sanitation systems / Johanna Christina Vivier

Viviers, Johanna Christina January 2006 (has links)
Groundwater plays an important role in water supply to rural communities. This statement is supported by the survey conducted at clinics within the Limpopo Province where the majority of aquifers in the area can be classified as Sole Source aquifers, supplying 50 % or more of domestic water in the absence of any reasonable alternative. The water quality study also concluded that the impact from on site sanitation on the groundwater system is significant given that 44 % of water samples of clinics with their own water supply classified as either poor or dangerous quality according to DWAF criteria and poses a significant health risk to susceptible individuals. Groundwater quality should therefore be protected with an emphasis on prevention as in most cases groundwater pollution is difficult to reverse and remediation is often a lengthy and expensive exercise. Although South Africa has all the legal tools to promote sustainable development, financial considerations are usually the driving force behind technology selection and not social or environmental aspects. The aim of this research is to develop an environmental impact assessment methodology and decision support framework that will aid in the selection of the most appropriate on site sanitation technology for a given area integrating environmental, economical and social criteria. The decision support framework developed in this study had a strong stakeholder component, involving stakeholders in the decision making process from the conception of the project through to the resolution of actions. Providing objective information about the performance of options, coupled with an opportunity to participate in the decision-making process, increases the awareness and commitment of the community. Field testing of the decision support framework produced good results and sensible recommendations were made with regard to alternative selection. / Thesis (Ph.D. (Geography and Environmental Studies))--North-West University, Potchefstroom Campus, 2007.
5

Development of an impact assessment methodology and decision making tool to assist in the evaluation of site suitability for on-site sanitation systems / Johanna Christina Vivier

Viviers, Johanna Christina January 2006 (has links)
Groundwater plays an important role in water supply to rural communities. This statement is supported by the survey conducted at clinics within the Limpopo Province where the majority of aquifers in the area can be classified as Sole Source aquifers, supplying 50 % or more of domestic water in the absence of any reasonable alternative. The water quality study also concluded that the impact from on site sanitation on the groundwater system is significant given that 44 % of water samples of clinics with their own water supply classified as either poor or dangerous quality according to DWAF criteria and poses a significant health risk to susceptible individuals. Groundwater quality should therefore be protected with an emphasis on prevention as in most cases groundwater pollution is difficult to reverse and remediation is often a lengthy and expensive exercise. Although South Africa has all the legal tools to promote sustainable development, financial considerations are usually the driving force behind technology selection and not social or environmental aspects. The aim of this research is to develop an environmental impact assessment methodology and decision support framework that will aid in the selection of the most appropriate on site sanitation technology for a given area integrating environmental, economical and social criteria. The decision support framework developed in this study had a strong stakeholder component, involving stakeholders in the decision making process from the conception of the project through to the resolution of actions. Providing objective information about the performance of options, coupled with an opportunity to participate in the decision-making process, increases the awareness and commitment of the community. Field testing of the decision support framework produced good results and sensible recommendations were made with regard to alternative selection. / Thesis (Ph.D. (Geography and Environmental Studies))--North-West University, Potchefstroom Campus, 2007.
6

Produção familiar do camarão Litopenaeus vannamei (Boone, 1931): viabilidade e qualidade

Rolim, Nathiene Patrícia Ferreira de Amaral 31 March 2015 (has links)
Submitted by Maike Costa (maiksebas@gmail.com) on 2016-03-09T12:39:05Z No. of bitstreams: 1 arquivototal.pdf: 1651590 bytes, checksum: fcf66b8bdf6abf12b15b77c951cc2f8d (MD5) / Made available in DSpace on 2016-03-09T12:39:05Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1651590 bytes, checksum: fcf66b8bdf6abf12b15b77c951cc2f8d (MD5) Previous issue date: 2015-03-31 / The traditional shrimp farming has been associated with many negative environmental impacts on mangrove ecosystems, apicuns and areas of slopes, including the release of effluent, usually with high organic matter content, from the offered feed and droppings of shrimps. In this sense, it is essential that the food offered are appropriate with effective and environmentally sustainable costs, as the inappropriate use of feed can compromise both animal development and the environment. In order to meet the demand for seafood products, with quality and adequate nutritional value, employment of shrimp farming techniques in tanks associated with the production of organic food can be a viable alternative to obtain a product of good quality, environmentally responsible and with added commercial value. The purpose of this study was to evaluate the organic cultivation of shrimp Litopenaeus vannamei (Boone, 1931) along the lines of family production, fed organic feed, produced from food waste and industrial feed. In tanks with organic feed, animals still were attended to perifítons as additional power. In order to evaluate the two types of crops, were determined some physicochemical and microbiological parameters of the water and shrimps, the bromatologia the feed, the farmed shrimp, plus the biometrics of animals. The results were compared with each other and with existing environmental and health laws, to evaluate the proposed treatment and quality of farmed animals. The data indicated that there was no significant difference between the crops, as regards the nutritional and microbial composition of the animal, as well as the quality of the water tanks. Therefore, one can understand that organic food associated with regular supply of perifítons, is an acceptable alternative to replacement of industrial feed the family shrimp farming due to low cost of production, absence of additives and preservatives, waste recovery generated by community and the possibility of improving the quality of life of fishermen whose activity is increasingly threatened by commercial fishing development. / A carcinicultura tradicional tem sido associada a diversos impactos ambientais negativos em ecossistemas de mangues, apicuns e áreas de encostas, incluindo o lançamento de efluente, geralmente com alta carga de matéria orgânica, proveniente das rações ofertadas e dos excrementos dos camarões. Neste sentido, é imprescindível que os alimentos ofertados sejam apropriados com custos efetivos e ambientalmente sustentáveis, visto que o emprego inadequado das rações pode comprometer tanto o desenvolvimento animal como o meio ambiente. Com vistas a atender a demanda por alimentos de origem marinha, com qualidade e valor nutricional adequado, o emprego de técnicas de cultivo de camarões em tanques associadas à produção de ração orgânica pode ser uma alternativa viável para obtenção de um produto de boa qualidade, ambientalmente responsável e com valor comercial agregado. A proposta deste trabalho foi avaliar o cultivo orgânico de camarão Litopenaeus vannamei (Boone, 1931) nos moldes da produção familiar, alimentados com ração orgânica, produzida a partir de resíduos de alimentos e ração industrial. Nos tanques com ração orgânica, os animais contaram ainda com a presença de perifítons como alimentação adicional. Com o objetivo de avaliar os dois tipos de cultivos, foram determinados alguns parâmetros físico-químicos e microbiológicos da água e dos camarões, a bromatologia das rações, dos camarões cultivados, além da biometria dos animais. Os resultados foram confrontados entre si e com as legislações ambiental e sanitária vigentes, para avaliação do tratamento proposto e qualidade dos animais cultivados. Os dados indicaram que não houve diferença significativa entre os cultivos, no que se refere à composição nutricional e microbiológica dos animais, bem como da qualidade da água dos tanques. Portanto, pode-se entender que a ração orgânica associada à oferta regular de perifítons, é uma alternativa aceitável para substituição da ração industrial no cultivo familiar de camarões, devido ao baixo custo na produção, ausência de aditivos e conservantes, aproveitamento de resíduos gerados pela comunidade, além da possibilidade de melhoria da qualidade de vida dos pescadores, cuja atividade está cada vez mais ameaçada pelo desenvolvimento da pesca comercial.
7

Cinema digital e um modelo de tecnologia alternativa de film transfer / Cinema digital e um modelo de tecnologia alternativa de film transfer

Guimarães, Paulo Ary Tender 30 May 2008 (has links)
O objetivo deste trabalho é a pesquisa dos processos para realização cinematográfica, em especial os que lançam mão de tecnologia digital, e a proposição de um modelo de tecnologia alternativa para a realização de film transfer. Tomando como objeto os principais processos para realização cinematográfica, discutimos seu fluxo de trabalho, equipamentos, vantagens, desvantagens e buscamos estabelecer paralelos com as tecnologias alternativas, de maneira a acumular conhecimento para a elaboração do modelo. O modelo de tecnologia alternativa para film transfer sugerido é o resultado da adaptação, numa premissa de baixo custo, de tecnologias de vanguarda evidenciadas nas reflexões sobre a realização. / This work objective is the research of the filmmaking process, particularly when utilizing digital technology, and the proposal of an alternative technology model to accomplish film transfer. Assessing the major filmmaking processes, we discuss their workflow, equipments, advantages, disadvantages and attempt to establish parallels with alternative technologies, in a way that knowledge is amassed towards the definition of said model. The proposed alternative technology model for film transfer results from the adaptation, restricted by a low cost premise, of high end technology ascertained during the reflections on the filmmaking process.
8

Cinema digital e um modelo de tecnologia alternativa de film transfer / Cinema digital e um modelo de tecnologia alternativa de film transfer

Paulo Ary Tender Guimarães 30 May 2008 (has links)
O objetivo deste trabalho é a pesquisa dos processos para realização cinematográfica, em especial os que lançam mão de tecnologia digital, e a proposição de um modelo de tecnologia alternativa para a realização de film transfer. Tomando como objeto os principais processos para realização cinematográfica, discutimos seu fluxo de trabalho, equipamentos, vantagens, desvantagens e buscamos estabelecer paralelos com as tecnologias alternativas, de maneira a acumular conhecimento para a elaboração do modelo. O modelo de tecnologia alternativa para film transfer sugerido é o resultado da adaptação, numa premissa de baixo custo, de tecnologias de vanguarda evidenciadas nas reflexões sobre a realização. / This work objective is the research of the filmmaking process, particularly when utilizing digital technology, and the proposal of an alternative technology model to accomplish film transfer. Assessing the major filmmaking processes, we discuss their workflow, equipments, advantages, disadvantages and attempt to establish parallels with alternative technologies, in a way that knowledge is amassed towards the definition of said model. The proposed alternative technology model for film transfer results from the adaptation, restricted by a low cost premise, of high end technology ascertained during the reflections on the filmmaking process.
9

Analise da evolução de ações na difusão do aquecimento solar de agua para habitações populares : estudo de caso em Contagem - MG / Evolution actions difusion of solar water heating technology for low-cost house : study case Contagem - MG

Fantinelli, Jane Tassinari 22 February 2006 (has links)
Orientador: Jose Tomaz Vieira Pereira, Elizabeth Marques Duarte Pereira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-06T09:17:29Z (GMT). No. of bitstreams: 1 Fantinelli_JaneTassinari_D.pdf: 4761109 bytes, checksum: 24169f2686e7a2a24d1d355b5ef3e0d1 (MD5) Previous issue date: 2006 / Resumo: Os programas para a redução da pobreza e para o acesso das populações às condições básicas para uma boa qualidade de vida devem contemplar soluções que considerem os avanços tecnológicos e os benefícios da produtividade e da eficiência energética. O uso de sistemas termossolares (coletores solares) como forma de substituir a eletricidade para o aquecimento de água já foi uma solução adotada em diversos países do mundo, entre a Primeira e a Segunda guerras mundiais e no primeiro e segundo choques do petróleo. Hoje se insere como uma alternativa que causa menores danos ambientais e traz retorno financeiro para as populações de baixa renda, pela economia de energia elétrica. A eficiência energética alcançada com coletores solares dimensionados para pequenos volumes de água para o consumo no banho e a adaptação das famílias com a tecnologia foram constatados através de estudo de caso realizado no Bairro Sapucaias, em Contagem (MG). A economia com a redução da conta de energia se reflete na aquisição de eletrodomésticos e também nas aspirações e desejos que sinalizam novas perspectivas de futuro, como a posse de microcomputador. A investigação sobre as ações dos diversos agentes envolvidos na disseminação do uso de sistemas termossolares para os segmentos de interesse social no Brasil mostra que os sucessivos programas, planos e metas, estabelecidos para se incorporarem em políticas estratégicas de desenvolvimento do país, não foram implementados. A ausência de um planejamento energético específico para a parcela da população (49,7 milhões de pessoas - 27,6% da população) que ganha até 2 salários mínimos mostra que as políticas públicas deverão ser direcionadas para promover estratégias que considerem planos de longo prazo e de grande abrangência social. Para essa parcela, o gasto com energia elétrica para banho representa 14% a 23% de sua renda mensal. Ações que promovam o uso de tecnologias eficientes para o benefício de grandes parcelas da população devem estar inseridas no planejamento estratégico de desenvolvimento na nação, alinhadas com todas as demais estruturas: econômicas, energéticas, ambientais, educacionais / Abstract: The programs for reduction of poverty and for providing people with access to the basic conditions for a good life quality should include solutions that take into account technological advances and the benefits of productivity and energyc efficiency. The use of solar collectors to replace electricity in water heating has already been adopted in several countries of the world, between the First and Second World Wars and on the first and second oil crises. Today it appears as an alternative that causes less environmental harm and brings financial gains to low income populations through electric energy savings. The energyc efficiency attained with solar collectors designed for small water volumes for consumption in bathing and the families¿ adaptation to this technology have been verified by means of a case study conducted at the Sapucaias district, in Contagem, MG. The savings through the reduction of the energy bill are witnessed by the acquisition of electric and electronic goods and also by the aspirations and desires denoting new perspectives about the future, like possessing a personal computer. An inquiry on the actions of the several agents involved in the diffusion of the use of solar collectors among classes of lowcost houses in Brazil reveals that the successive programs, plans and goals proposed for incorporation in strategic development policies for the country have not been executed. The absence of an energy planning specific to the significant parcel of Brazilian population (49.7 million people, 27.6% of its population) earning up to 2 minimum wages shows that public policies should be directed to the promotion of strategies founded on long term planning of large social reach. For this, parcel the expenditure with electric energy for bathing represents approximately 14 to 23 percent of their monthly income. The actions promoting the use of efficient technologies for the benefit of great parcels of population should be inserted in the strategic planning for the nation¿s development, in line with all its other structures: economic, energetic, environmental, educational / Doutorado / Doutor em Planejamento de Sistemas Energéticos
10

HIDRÓLISE ÁCIDA E ENZIMÁTICA DE CASCA DE ARROZ USANDO TECNOLOGIAS ALTERNATIVAS / ACID AND ENZYMATIC HYDROLYSIS OF RICE HULLS USING ALTERNATIVE TECHNOLOGIES

Moscon, Jéssica Machado 31 March 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Rice husk is a fairly abundant agro-industrial waste in the state of Rio Grande do Sul, hence the same has been suggested and studied to be used as in lignocellulosic hydrolysis to produce fermentable sugars material. However, processes of hydrolysis in most cases are more expensive and impractical. In this context, this work aimed to study which evaluated acid and enzymatic hydrolysis of rice hulls to obtain fermentable sugars using some alternative technologies such as ultrasound and supercritical CO2 to increase the yields of sugars. In the acid hydrolysis, the yields obtained at optimized conditions were 113.0 and 162.0 g.kg-1 for conventional and ultrasound-assisted hydrolysis, where the yield obtained by ultrasound-assisted hydrolysis was around 43% higher than for the conventional hydrolysis. In the enzymatic hydrolysis, it was evaluated the use of supercritical CO2 as co-solvent and ultrasound-assisted hydrolysis and the results were compared with conventional procedure. Maximum yield of fermentable sugar obtained was about 16 g.kg-1using conventional or ultrasound-assisted hydrolyses. The yield obtained in the hydrolysis using supercritical CO2 as co-solvent was around 4.2 g.kg-1. Enzymatic hydrolysis using conventional procedure showed to be the best alternative to obtain fermentable sugar from rice hulls since the innovative technologies employed did not lead to better results. For acid hydrolysis, it was possible to obtain high yield using less acid and low temperature, in a manner that ultrasound can be used as a device for process intensification. / A casca de arroz é um resíduo agroindustrial bastante abundante no estado do Rio Grande do Sul, deste modo à mesma vem sendo sugerida e estudada para ser usada como material lignocelulósico em hidrólises para a produção de açúcares fermentescíveis. Entretanto, processos de hidrólises na maioria das vezes não possuem um alto rendimento o que torna o processo ainda mais caro e inviável. Dentro desse contexto o presente trabalho teve o intuito de realizar um estudo onde avaliou hidrólise ácida e enzimática da casca de arroz para a obtenção de açúcares fermentescíveis utilizando algumas tecnologias alternativas, como o banho de ultrassom e CO2 supercrítico para aumentar os rendimentos de açúcares. Os ensaios foram realizados em diferentes condições de temperatura, concentrações de ácido e umidade, pressão e concentrações de enzima do meio. Na hidrólise acida convencional obteve-se um rendimento de 113,0 g.kg-1 e na hidrólise ácida assistida por ultrassom o rendimento foi de 162,0 g.kg-1, com base nesses resultados dos rendimentos de açúcares foi possível concluir que o uso do ultrassom intensificou o processo ocorrendo um aumento do rendimento em cerca de 43% quando comparado com o rendimento de açúcares fermentescíveis da hidrólise convencional. Já na hidrólise enzimática utilizando o CO2 Supercrítico o rendimento foi de 4.2 g.kg-1 enquanto que o rendimento da hidrólise enzimática convencional e assistida por ultrassom foi de 16 g.kg-1, neste caso o uso do CO2 supercrítico não foi uma alternativa promissora, uma vez que a mesma causou uma desnaturação das enzimas causando uma diminuição na eficiência do processo.

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