<p>Large environmental, health, social and economical problems are connected with the use of</p><p>fossil fuels and, in a dominating part of the world, also the use of firewood. The goal for this</p><p>project was to develop and design an optimal solar oven system intended for food cooking</p><p>and water pasteurisation. Further the advantages and disadvantages, compared with other</p><p>energy resources were evaluated. Tests were carried out in Sweden as well as in Sri Lanka.</p><p>An extensive range of prototypes were tested and sifted out to a small number of designs that</p><p>were tested in Sri Lanka. A large number of evaluations and tests were carried out on many</p><p>different materials, among others tests were conducted according to the international standard</p><p>“Testing and Reporting Solar Cooker Performance ASAE S580 JAN03”.</p><p>The report shows a number of benefits compared to previous reports on the subject, for</p><p>example the development of indoor tests, the extensiveness and objectiveness of the tests, and</p><p>the fact that the report combines extensive practical test results with solid theoretical</p><p>background information.</p><p>The test resulted in two solar ovens with the same parabolic design but made out of different</p><p>materials. One oven is cheaper, simpler to produce and is considered for the target group poor</p><p>people in developing countries. This is made out of a corrugated cardboard that is covered</p><p>with aluminium foil. The second oven is more expensive but also more durable and is</p><p>intended for more wealthy people in the west that wants a good alternative to regular ways of</p><p>cooking food. It is made out of aluminium plate and mirrors.</p>

Large environmental, health, social and economical problems are connected with the use of fossil fuels and, in a dominating part of the world, also the use of firewood. The goal for this project was to develop and design an optimal solar oven system intended for food cooking and water pasteurisation. Further the advantages and disadvantages, compared with other energy resources were evaluated. Tests were carried out in Sweden as well as in Sri Lanka. An extensive range of prototypes were tested and sifted out to a small number of designs that were tested in Sri Lanka. A large number of evaluations and tests were carried out on many different materials, among others tests were conducted according to the international standard “Testing and Reporting Solar Cooker Performance ASAE S580 JAN03”. The report shows a number of benefits compared to previous reports on the subject, for example the development of indoor tests, the extensiveness and objectiveness of the tests, and the fact that the report combines extensive practical test results with solid theoretical background information. The test resulted in two solar ovens with the same parabolic design but made out of different materials. One oven is cheaper, simpler to produce and is considered for the target group poor people in developing countries. This is made out of a corrugated cardboard that is covered with aluminium foil. The second oven is more expensive but also more durable and is intended for more wealthy people in the west that wants a good alternative to regular ways of cooking food. It is made out of aluminium plate and mirrors.

O objetivo deste trabalho foi abordar uma metodologia diferenciada para o ensino de FÃsica, a partir da construÃÃo e anÃlise de um forno solar como atividade prÃtica, sendo utilizado como uma ferramenta de ensino na aplicaÃÃo dos conceitos de TermodinÃmica, Energia Solar, Eletromagnetismo e RadiaÃÃo do Corpo Negro. AlÃm disso, questÃes como a sustentabilidade e ecologia tambÃm foram trabalhados, uma vez que a construÃÃo do forno solar priorizou o uso de materiais reciclÃveis, de baixo custo, usando a energia solar, uma fonte abundante, permanente e renovÃvel de energia, que nÃo polui ou prejudica o meio ambiente. O projeto envolveu 54 alunos de ensino mÃdio, de escolas das redes pÃblica e particular da cidade de Quixeramobim, no interior do CearÃ. Este trabalho procurou explorar FÃsica de uma maneira mais atraente, de modo a que os alunos se sentissem motivados a estudÃ-la, vendo a sua aplicabilidade na prÃtica, sem a necessidade de utilizaÃÃo de laboratÃrios jà que os laboratÃrios formais ainda nÃo fazem parte da realidade de algumas escolas da regiÃo. Verificada a viabilidade do forno no cozimento de alimentos, os alunos envolvidos no projeto o apresentaram a uma comunidade de trabalhadores rurais do municÃpio, incentivando-os a adotarem o forno solar como uma alternativa ao uso da lenha, ainda amplamente utilizada nessas comunidades. / The aim of this work was to describe a different methodology for teaching physics, from the construction and analysis of a solar oven as practical activity, being used as a teaching tool in the application of the concepts of Thermodynamics, Solar Energy, Electromagnetism and Blackbody Radiation. In addition, issues such as sustainability and ecology were also worked, since the construction of the solar oven prioritized the use of recyclable low cost materials, using solar energy, an abundant permanent and renewable energy supply, that does not pollute or harms the environment. The project involved 54 high school students from public and private schools of City Quixeramobim, in CearÃ. This study aimed to explore the Physics of a more attractive way, so that students feel motivated to study it, seeing its applicability in practice without the need for use of laboratories since the formal laboratories are not yet part of reality of many schools in the region. Verified the feasibility of the oven in cooking food, the students involved in the project introduced it to a community of rural workers in the city, encouraging them to adopt the solar oven as an alternative to the use of firewood, still widely used in these communities.

Made available in DSpace on 2014-12-17T14:57:48Z (GMT). No. of bitstreams: 1 AroldoVM.pdf: 1927767 bytes, checksum: 7bb8f196ea08d728e8c7ae690cff0a6b (MD5) Previous issue date: 2009-11-06 / An alternative box-type solar oven constructed from the scrap iron of a gas conventional cook is presented, which functions principles are the effect greenhouse and the concentration. The oven of the conventional cook is the baking enclosure where the absorber (pot) of the solar oven is located, being re-covered for a glass blade for the generation of the greenhouse effect isolated lateral and having deep its and for a composite the plaster base and EPS. Segments of plain mirrors had been placed in the laterals of the oven for the concentration of the radiation and a reflecting parabola was introduced in the baking enclosure for the exploitation of the incident reflected radiation in the interior of the oven. The oven is mobile to allow one better aiming of exactly in relation to the apparent movement of the sun. The thermal economic and of materials viabilities of the stove in study will be demonstrate The average internal temperature of the absorber was around 150?C and the internal temperature around 120?C. Will demonstrate that its low cost and good thermal performance represents basic characteristics for the viability of large use of such archetype, mainly for cooking the decreases and averages temperatures. One will reveal that the archetype in study is competitive with the box-type solar cooker conceived in the whole world / Apresenta-se um forno solar alternativo constru?do a partir da sucata de um fog?o convencional a g?s, que funciona segundo os princ?pios do efeito estufa e da concentra??o. O forno do fog?o convencional ? o recinto de cozimento onde o absorvedor (panela) do forno solar fica localizado, sendo recoberto por uma l?mina de vidro para a gera??o do efeito estufa e tendo seu fundo e laterais isolados por um comp?sito ? base de gesso e isopor. Segmentos de espelhos planos foram colocados nas laterais do forno para a concentra??o da radia??o e uma par?bola refletora foi introduzida no recinto de cozimento para o aproveitamento da radia??o refletida incidente no interior do forno. O forno ? m?vel para permitir um melhor direcionamento do mesmo em rela??o ao movimento aparente do Sol. Ser?o demonstradas as viabilidades t?rmicas, econ?mica e de materiais do fog?o em estudo. A temperatura interna m?dia do absorvedor ficou em torno de 150?C e a temperatura interna do forno em torno de 120?C. Demonstrar-se-? que seu baixo custo e bom desempenho t?rmico representam caracter?sticas fundamentais para a viabilidade de utiliza??o massiva de tal prot?tipo, principalmente para cozimento a baixas e m?dias temperaturas. Mostrar-se-? que o prot?tipo em estudo ? competitivo com os fog?es tipo caixa concebido em todo o mundo

A promising and novel solar concentrator design has been thoroughly investigated and optimised. A prototype concentrator based on this novel geometry was validated using ray tracing techniques. This ray tracing demonstrated the comparative performance of this novel concentrator in regards to equivalent parabolic dishes. The effect of mirror surface normal errors on performance was established using Monte-Carlo based ray tracing code, which agreed well with the optical performance of this prototype which was determined experimentally. A need for low-cost solar cookers to replace bio-mass worldwide was identified, and the concentrator design was then developed as a low-cost solar oven. Despite existing in some number, no current design is able to achieve high performance at low-cost. An industrial partner, Dytecna, was initially involved in the process of this development of the system as a solar cooker. In support of a field trial for the solar cooker developed with Dytecna, a detailed thermal model of the oven was developed. A low-cost lightmeter was constructed and calibrated in order to measure the direct normal irradiance during the field trial in Italy. Laboratory work provided baseline results for the heating of various thermal masses in the oven. The Italian field trials provided a wealth of feedback into the design of the system and many valuable results. The solar cooker was able to bring 0.75L of water to the boil in 33 minutes with an average heat throughput of 203W. Important benchmark results and practical experience of several competing receiver materials was obtained; further lab testing provided more accurate measurements of the receivers' performances. The experiences of the Italian field trial were fed back into the design of a subsequent prototype, intended for a much larger field trial in Tanzania. Improvements in the hotplate, receiver material, and the oven were all incorporated into the design. Additionally, the structure of the solar cooker was redesigned to incorporate a low-cost wooden construction. Supporting work was conducted for the month long trial in which 8 solar cookers would be distributed to families in Tanzania. The field trial in Tanzania provided a wealth of user feedback into the design. At the same time the new solar cooker exceeded previously established performances in Italy. The new design was able to provide an average of 246W of heat to 1kg of water, which was brought to boiling point in 25 minutes. This represents a heating efficiency of 66&percnt; compared to the incident solar flux on the hotplate. In response to findings during the Tanzanian trials, further laboratory work was conducted into establishing the reflectivities of low-cost candidate mirror materials. Throughout all phases of the project the design of the solar cooker was refined and improved with the goal of a solar cooker design that could reach price-point, performance, and usability standards which would ensure market success.

Made available in DSpace on 2014-12-17T14:57:38Z (GMT). No. of bitstreams: 1 CarlosAlbertoPQLF.pdf: 2273640 bytes, checksum: a4f60a823eb1d55227bb74c387319cef (MD5) Previous issue date: 2007-05-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / A model of a solar oven with a reflective surface composed of two mirror segments is presented, constituting a two semi-parabolic surfaces made of fiberglass, applied on a ceramic mold, intended to be used in residential and commercial cooking. The reflective surface of the semi-parable is obtained with the use of multiple plain segments of 2 mm wide mirrors. The semi-parabolic structure has visible movements that are comparable to that of the sun. The technical details of the manufacturing and assembling processes will be presented with an analysis of the viability of thermal, economic, and materials of such prototype. This prototype has important social implications and primordial aspects, which combats the ecological damages caused by the wide-scale use of firewood during cooking. It has been demonstrated that the solar oven has the capacity to cook simultaneous two meals distinct for a family of four / Apresenta-se um modelo de fog?o solar ? concentra??o composto por dois segmentos espelhados, constituindo duas semi-par?bolas, obtidas atrav?s da utiliza??o de fibra de vidro, aplicada sobre um molde cer?mico, destinado ao cozimento de alimentos para fins residenciais, urbanos e rurais. O espelhamento das semi-par?bolas foi obtido atrav?s da utiliza??o de m?ltiplos segmentos planos de espelho de 2 mm de espessura. A estrutura das semi-par?bolas tem mobilidade de movimentos para a corre??o do movimento aparente do sol. Ser?o apresentados detalhes t?cnicos dos processos de fabrica??o e montagem e uma an?lise das viabilidades, t?rmica, econ?mica e de materiais de tal prot?tipo, que tem uma conota??o social importante e um aspecto primordial, que ? o combate a danos ecol?gicos proporcionados pela utiliza??o, ainda em larga escala, da lenha para o cozimento dos alimentos. Comprovou-se que ? poss?vel o cozimento simult?neo de alimentos de duas refei??es distintas para uma fam?lia de quatro pessoas

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-25T12:31:53Z No. of bitstreams: 1 leonardotavaresdepaula.pdf: 1447065 bytes, checksum: 6a4ea2aff9798334815609d932200336 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-25T13:34:22Z (GMT) No. of bitstreams: 1 leonardotavaresdepaula.pdf: 1447065 bytes, checksum: 6a4ea2aff9798334815609d932200336 (MD5) / Made available in DSpace on 2017-05-25T13:34:23Z (GMT). No. of bitstreams: 1 leonardotavaresdepaula.pdf: 1447065 bytes, checksum: 6a4ea2aff9798334815609d932200336 (MD5) Previous issue date: 2017-02-21 / O presente trabalho trata do ensino de física por projetos, através da construção de um forno solar com as turmas do segundo ano do ensino médio de uma escola pública da rede estadual de Minas Gerais. No trabalho é estabelecida uma discussão sobre a aprendizagem significativa e a importância do professor em diversificar a prática pedagógica buscando uma maior interação dos alunos com o conhecimento. No processo metodológico foi criado um roteiro de trabalho, o qual foi aplicado para as turmas já mencionadas. Posteriormente foram efetuadas análises quanto a eficiência da prática pedagógica por projetos, por meio de um questionário aplicado aos alunos observando sua satisfação em participar da atividade e os conhecimentos adquiridos durante o trabalho. Pôde-se concluir a partir das análises que o uso de projetos como ferramenta pedagógica pode ajudar na relação do aluno com o conhecimento. Além disso essa prática mostrou-se eficiente para o fomento à aprendizagem significativa. / The present work deals with the teaching of physics by projects, through the construction of a solar oven with the classes of the second year of high school of a public school of the state network of Minas Gerais. In the work, a discussion about the significant learning and the importance of the teacher in diversifying the pedagogical practice is established, seeking a greater interaction of the students with the knowledge. In the methodological process a work script was created, which was applied to the classes already mentioned. Later, analyzes were performed on the efficiency of the pedagogical practice by projects, through a questionnaire applied to students observing their satisfaction in participating in the activity and the knowledge acquired during the work. It could be concluded from the analyzes that the use of projects as a pedagogical tool can help in the relation of the student with the knowledge. In addition, this practice proved to be efficient for the promotion of meaningful learning.