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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.
201

A história da ciência nacional na formação e na prática de professores de física / History of Brazilian science in the education and practice of Physics teachers

Schmiedecke, Winston Gomes 08 June 2016 (has links)
As últimas duas décadas testemunharam a gradual difusão de iniciativas destinadas a tornar a História da Ciência uma aliada dos professores de ciências da escola básica interessados em discutir, em suas aulas, aspectos associados à estrutura e ao funcionamento da ciência, em sintonia com os ideais de uma educação crítica, ativa e transformadora. No caso particular da Física, diversos documentos oficiais reforçam essa necessidade, tornando a História da Ciência presente, por exemplo, nas disciplinas dos cursos de licenciatura, nos livros didáticos e em materiais destinados à divulgação científica. Todavia, a História da Ciência, por suas próprias características e particularidades como campo do conhecimento, é caracterizada por um nível de complexidade incompatível com sua apropriação direta e acrítica por parte de alunos e professores. A inobservância desse fato, inclusive no processo de formação dos docentes, é um dos motivos responsáveis pelo fracasso de parte das ações implementadas junto aos alunos do ensino médio. Esta investigação considera que o trabalho com episódios relacionados à história da ciência e da tecnologia nacionais poderia preencher parte das lacunas existentes no processo de formação dos futuros professores, favorecer a prática docente e despertar o interesse desses sujeitos acerca do estado da arte da ciência produzida e praticada no Brasil. Tomando a Moderna Historiografia da Ciência como referencial para dar sustentação às discussões a serem propostas em contextos didáticos, foram elaborados dois materiais: um episódio apresentando uma versão para o histórico da energia nuclear no Brasil; e um conjunto de dez atividades propostas para articular a História da Ciência com outros recursos de reconhecido valor didático. A elaboração desse material foi acompanhada pela aplicação de três questionários: dois respondidos por professores em formação, e outro por recém-formados, sendo que este último grupo avaliou os materiais elaborados. A análise das respostas reforçou o potencial da Moderna Historiografia da Ciência como referencial para a elaboração de materiais aproximando a História da Ciência do ensino de Física, tendo como elemento diferencial as temáticas relacionadas à ciência nacional. / The last two decades have witnessed the gradual diffusion of different initiatives to turn the History of Science into an ally for science teachers in elementary and secondary schools. History of Science may help those teachers who are interested in discussing features of science associated with the structure and functioning of science in tune with a critical, active and transformative approach to education in their classes. In the specific case of Physics, several official documents reinforce this need, making History of Science present, for example, in the initial training of teachers, textbooks and materials designed for scientific dissemination. However, due to its own peculiar features as a field of knowledge, History of Science is characterized by a level of complexity which is incompatible with its direct and acritical appropriation by students and teachers. Failure to observe this fact, also present in the process of teacher training, is one of the reasons responsible for the failure of many actions designed to introduce the History of Science in high school. This research is grounded on the premise that working with episodes related to the history of Brazilian science and technology could fill some of the existing gaps in the training of teachers, favor teaching practices, and arise the interest of teachers on the state of the art of science produced and practiced in Brazil. Holding the idea that Modern Historiography of Science is an appropriate strand to support the discussions to be proposed in educational contexts, two materials were elaborated: an episode describing a version for the history of nuclear energy in Brazil, and a set of ten suggested activities to articulate History of Science with other resources of recognized educational value. The elaboration of this material was accompanied by the application of three questionnaires: two of them were answered by pre-service teachers and the other by newly graduated teachers. This last group of participants evaluated the final materials. The analysis of the answers reinforced the potential of Modern Historiography of Science as a support for designing materials approaching History of Science to the teaching of physics, with issues related to national science as a distinctive element
202

Física nuclear no ensino médio com ênfase cts

Pires, Samuel Machado 27 September 2017 (has links)
Submitted by Larissa Vitoria Cardoso Cusielo (larissavitoria@id.uff.br) on 2017-09-05T20:08:16Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Samuel Machado Pires - Dissertacao Final.pdf: 1688848 bytes, checksum: 305a2b994baae30ceee3cedbb06fa9ba (MD5) / Approved for entry into archive by Biblioteca do Aterrado BAVR (bavr@ndc.uff.br) on 2017-09-27T19:33:51Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Samuel Machado Pires - Dissertacao Final.pdf: 1688848 bytes, checksum: 305a2b994baae30ceee3cedbb06fa9ba (MD5) / Made available in DSpace on 2017-09-27T19:33:51Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Samuel Machado Pires - Dissertacao Final.pdf: 1688848 bytes, checksum: 305a2b994baae30ceee3cedbb06fa9ba (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Ciências Exatas. Programa de Pós-Graduação em Ensino de Física. Volta Redonda, RJ. / Apresenta-se neste trabalho uma proposta educacional de abordagem do tema Energia Nuclear na disciplina de Física do Ensino Médio. O objetivo desta abordagem é oportunizar aos alunos uma formação que integre conceitos Físicos, pertinentes ao tema, com as implicações socioambientais, econômicas e políticas do uso deste tipo de energia. A proposta parte da polêmica em relação ao programa nuclear brasileiro e perpassa atividades de investigação em simulação computacional, discussões sobre vídeos, sistematização dos conceitos, debate e elaboração de texto dissertativoargumentativo. Fundamenta-se esta proposta no campo de estudos Ciência-Tecnologia-Sociedade (CTS), apresentando um estudo histórico deste movimento e seus contextos internacionais e brasileiro. No que tange ao contexto nacional, discute-se a legislação que regulamenta as práticas educacionais no país. O produto inclui material do aluno, material do professor e orientações ao professor. Valida-se a proposta por meio de sua aplicação, relatos da mesma e um instrumento avaliativo ao final. / In this work is being presented an educational proposal of approaching the Nuclear Energy theme in high school physics course. The purpose is to create opportunities for the students being able to integrate Physical concepts that may be relevant to the theme, with the social, environmental, economic and political implications of using this kind of energy. The proposal begins with the controversy in relation to the Brazilian nuclear program and permeates research activities in computer simulations, discussions about videos, systematization of concepts, argumentations and elaboration of an argumentative text. This study is based on the field of Science-Technology-Society (STS) knowledge’s, presenting a historical research about this movement and its international and Brazilian contexts. Regarding the national context, it discusses the legislation that regulates the educational practices in the country. The product includes student’s material, teacher’s material and guidelines to the teacher. The proposal was proved by means of its application, reports about it and an evaluative tool at the end.
203

Elaboração de indicadores de produção cientifica com base na análise cientométrica das dissertações e teses do IPEN / Construction of scientific production indicators based on scientometrics analysis of ipen dissertations and theses

Mery Piedad Zamudio Igami 10 May 2011 (has links)
A importância da elaboração de indicadores está amplamente difundida na sociedade atual. Observa-se seu uso rotineiro nos mais diversos segmentos da sociedade. Na área científica essa prática também já está consolidada, corrobora esta afirmação o número de trabalhos registrados nas principais bases de dados; prevalecem, no entanto, os estudos quantitativos, os quais fazem uso de dados obtidos a partir de bases de dados internacionais. Diante dessa constatação o objetivo deste trabalho foi obter indicadores científicos a partir da análise das dissertações e teses produzidas por um programa de pós-graduação no período de 1977 até 2009. Foram obtidos três tipos de indicadores bidimensionais, numéricos temáticos e de produtividade, para tanto foram utilizadas técnicas de bibliometria avançada. As dissertações e teses foram categorizadas tematicamente utilizando a Subject Categories and Scope Descriptions e o Tesauro do International Nuclear Information System (INIS). Por meio da técnica de análise de clusters e de trajetória, as dissertações e teses foram agrupadas em cinco grupos temáticos demonstrando o comportamento passado e a tendência de crescimento de cada grupo. Para a extração dos dados sobre a produtividade das teses, em nível de artigos, foi utilizado o Currículo Lattes e a base local do IPEN. Especificamente para se identificarem os níveis de correlação entre os artigos e as teses, foi utilizada a técnica de coocorrência de palavras (co-word analysis) e no caso foram utilizadas as palavras-chave de ambos os itens de literatura. Os autores das teses foram consultados, por meio de um questionário, para validação dos dados. Obtiveram-se indicativos de que 55,9% dos artigos produzidos em um período de cinco anos antes e cinco anos depois da defesa da tese têm forte correlação com esta. Foi observado também que os artigos correlacionados têm sido publicados, em média, 1,63 (ano) antes da apresentação da tese. Foi demonstrado, que as bases de dados, quando bem estruturadas, são instrumentos multifuncionais com grande potencial para o uso em estudos dessa natureza. Observou-se que a qualidade dos indicadores está fortemente associada à qualidade dos dados obtidos das bases de dados. / Construction of Indicators plays an important role in the contemporaneous society. It could be observed their ordinary use by all the activities segments. In scientific area it is not different; such practice has already been consolidated; this statement could be corroborated by the innumerous papers published about this matter in the main databases; however, there is a prevalence of quantitative studies, which obtain data from the international databases, analyzing journal articles. Concerning this finding, the main objective of this study was to elaborate scientific indicators from a local institutional data base, using as a corpus of the study the dissertations and theses, produced by a graduate program in the period of 1977 to 2009.Three types of two-dimensional indicators were obtained by using bibliometric techniques: numerical, thematic and productivity. For dissertations and theses thematic characterization it was used the Subject categories and scope descriptions and the International Nuclear Information System Thesaurus (INIS). Through the statistical technique of clustering analysis, it was possible to classify them in five main groups, showing former performance and growth future trends of each group; for data extraction about theses productivity, regarding articles published; the Curriculo Lattes, and the local institutional database were used. Co-word analysis technique was used to establish a more precise correlation, between articles and theses, and for this purpose it was used the keywords from a controlled vocabulary. In order to validate the results, it was performed a survey, with the theses authors. Results obtained indicated that 55.9% of the articles published, between 5 years, before and after the thesis presentation, are strongly correlated to it. It was also observed that, correlated articles have been published, in an average of, 1, 63 year before the thesis presentation. Concerning databases, it was shown that they are valuable tools and could be used with multifunctional purposes, with a great potential to be used in bibliometric studies. It was also observed that the indicators reliability is strongly associated to the quality of data obtained from the databases.
204

[en] BRAZILIAN NUCLEAR POLITICS IN THE CONTEXT OF CONTEMPORARY INTERNATIONAL RELATIONS: TECHNOLOGICAL DOMINANCE AS A STRATEGY OF INTERNATIONAL INSERTION / [pt] A POLÍTICA NUCLEAR BRASILEIRA NO CONTEXTO DAS RELAÇÕES INTERNACIONAIS CONTEMPORÂNEAS: DOMÍNIO TECNOLÓGICO COMO ESTRATÉGIA DE INSERÇÃO INTERNACIONAL

MARIANA MONTEZ CARPES 08 March 2007 (has links)
[pt] A presente dissertação analisa a retomada do debate sobre a recuperação do Programa Nuclear Brasileiro pelo governo Luis Inácio Lula da Silva, baseado na defesa pela utilização da já adquirida tecnologia própria para o enriquecimento de urânio. Tendo em vista que a utilização da tecnologia nuclear pelo Brasil visa fins pacíficos, apesar da dualidade intrínseca a essa matéria, a hipótese sustentada é de que a defesa do Programa é considerada uma estratégia de inserção internacional soberana com autonomia relativa e um instrumento de valorização nacional frente às demais potências. No intuito de verificar tal hipótese, analisaremos o atual governo em comparação a dois outros momentos da história nos quais a questão nuclear também adquiriu caráter estratégico, a saber, os governos Geisel e Sarney. O objetivo é identificar as similaridades entre esses três momentos que, apesar de serem divergentes quanto ao regime político interno, guardam continuidades no que se refere às estratégias de ação externa. / [en] The present dissertation analyses the retaking of the debate over Brazilian Nuclear Program´s recovery by Luis Inácio Lula da Silva government, based on the defense of the utilization of an already acquired technology of its own to enrich uranium. In spite of the intrinsic duality on this subject and having in mind the pacific ends concerning the utilization of such technology by Brazil, the hypotesis sustained in this work is that the Program´s defense is considered a strategy of sovereign international insertion with relative autonomy and an instrument of national valorization against other powers. In order to verify the hypotesis outlined above, we will analyse the actual government, comparing it to two other moments in Brazilian History in which the nuclear issue also acquired preponderance on the national agenda, namely, Geisel and Sarney governments. Although these three moments differ in relation to their internal political regime, our goal is to identify their similarities once they keep some continuities about their strategies of external action.
205

An autonomous long-term fast reactor system and the principal design limitations of the concept

Tsvetkova, Galina Valeryevna 30 September 2004 (has links)
The objectives of this dissertation were to find a principal domain of promising and technologically feasible reactor physics characteristics for a multi-purpose, modular-sized, lead-cooled, fast neutron spectrum reactor fueled with an advanced uranium-transuranic-nitride fuel and to determine the principal limitations for the design of an autonomous long-term multi-purpose fast reactor (ALM-FR) within the principal reactor physics characteristic domain. The objectives were accomplished by producing a conceptual design for an ALM-FR and by analysis of the potential ALM-FR performance characteristics. The ALM-FR design developed in this dissertation is based on the concept of a secure transportable autonomous reactor for hydrogen production (STAR-H2) and represents further refinement of the STAR-H2 concept towards an economical, proliferation-resistant, sustainable, multi-purpose nuclear energy system. The development of the ALM-FR design has been performed considering this reactor within the frame of the concept of a self-consistent nuclear energy system (SCNES) that satisfies virtually all of the requirements for future nuclear energy systems: efficient energy production, safety, self-feeding, non-proliferation, and radionuclide burning. The analysis takes into consideration a wide range of reactor design aspects including selection of technologically feasible fuels and structural materials, core configuration optimization, dynamics and safety of long-term operation on one fuel loading, and nuclear material non-proliferation. Plutonium and higher actinides are considered as essential components of an advanced fuel that maintains long-term operation. Flexibility of the ALM-FR with respect to fuel compositions is demonstrated acknowledging the principal limitations of the long-term burning of plutonium and higher actinides. To ensure consistency and accuracy, the modeling has been performed using state-of-the-art computer codes developed at Argonne National Laboratory. As a result of the computational analysis performed in this work, the ALM-FR design provides for the possibility of continuous operation during about 40 years on one fuel loading containing mixture of depleted uranium with plutonium and higher actinides. All reactor physics characteristics of the ALM-FR are kept within technological limits ensuring safety of ultra-long autonomous operation. The results obtained provide for identification of physical features of the ALM-FR that significantly influence flexibility of the design and its applications. The special emphasis is given to existing limitations on the utilization of higher actinides as a fuel component.
206

Teknik på bönders villkor : de tekniska och politiska aktörernas inflytande på den statsreglerade tekniska förändringen i Sverige 1806-1972

Hamilton, Ulf January 1997 (has links)
The dissertation deals with History of technology in Sweden before, during and after the industrialization. A theory that technical actors have a growing influence on state technology chiefly owing to the industrialization is presented. Five case-studies the Göta Canal 1806-1818, The railway-issue 1829-1848, The issue of motor traffic 1900- 1916, the issue of air transport 1912-1925 and the issue of nuclear power 1945-1972 are examined in order to test the theory. The principal results of the dissertation are as follows: The process of decision- making owing to state technology is dealt with not only by technical and political actors but also with technical/political actors. They are generally of two kinds; actors representing the technology in question and with an added political platform and politicians with an interest in technology and/or a profession with a relation to the technology in question. To this you can add a during time growing and more and more influential state bureaucracy. The possible decision on some state technical issue is framed by political actors. Inside this frame technical/political actors supported by the state bureaucracy are shaping the issues. Along with this it is apparent that technical actors with no or weak contact with political arenas take little part in the shaping- process. Owing to the study the process of industrialization and/or the professionalisation of technicians has no or a poor impact on the process of decision- making. Instead the agricultural political representation acts as a strong body with great influence on the state technical development up to the issue of nuclear power. The political representants of technology and/or industry on the other hand are not able to take advantage of the political structure in order to influence the technical issues. This depends to some extent on lack of political conformity. Another cause is however that technology when put into practice has a multiplex content which from time to time put technical actors in conflict with one another. This is apparent in the issue of air transport and nuclear power and to some extent in the choise between canal and railway. When technicians are not united the political actors, especially the ones representing agriculture, reinforce their influence on the studied state technical issues.
207

Measuring the Impacts of Nuclear Accidents on Energy Policy

Csereklyei, Zsuzsanna 03 1900 (has links) (PDF)
This paper examines the history of nuclear energy, safety developments of reactors and nuclear energy policy from the 1950s on. I investigate the effects of nuclear accidents on energy policy with the help of a panel dataset of 31 countries from 1965-2009, using annual data about the capacity of reactors under construction, primary energy consumption, as well as three nuclear accidents scaled INES five or higher by the International Atomic Energy Agency. After determining the extent of the accident impact in the different countries, I find that neither Three Mile Island nor Lucens had a worldwide negative effect on construction starts, while Chernobyl did. The effect of Chernobyl is however shown to wear-off in certain geographical clusters, after ten to thirty years. I find that nuclear capacity enlargement shows a significant persistence, but it was also driven by primary energy consumption in the past five decades. The effects of real interest rates, inflation, or gross domestic product on reactor construction were not found significant. Thus, an accident is likely to have a negative and long lasting impact in the country where it happened, and possibly in countries affected by the direct consequences, or where governments are subject to severe public pressure.It is difficult to estimate the consequences Fukushima is going to have on worldwide power plant constructions, but areas closer to the accident might be affected more negatively and for a longer time. Growing concerns of energy supply security and greenhouse gas emissions may counteract this impact at the legislative level. (author's abstract) / Series: Department of Economics Working Paper Series
208

Environmental Kuznets Curve for Carbon Intensity : a Global Survey

Figueres, Fernando, Popova, Elena January 2011 (has links)
The Environmental Kuznets Curve is an inverted U-shaped relationship which demonstrates how environmental degradation increases as countries begin to develop and lowers as they become wealthier. The classical EKC measures the effects of GDP per capita (a country’s wealth) on pollu-tion. This paper is a study of the connection of a number of factors- GDP per capita, fossil fuels, al-ternative and nuclear energy, rural population and life expectancy at birth to the Environmental Kuznets Curve. Two econometric approaches are applied in order to test whether the variables have a more pronounced linear or quadratic form. Four income groups of countries are investigated in order to check if the state of development plays a crucial role in environmental deterioration. The results of the study point out that EKC does not apply for the chosen variables. From the regression for GDP, however, it can be concluded that EKC forms in 1990s.
209

A real options analysis and comparative cost assessment of nuclear and natural gas applications in the Athabasca oil sands

Harvey, Julia Blum, 1982- 04 January 2011 (has links)
This report offers a comparative valuation of two bitumen production technologies, using real options analysis (ROA) techniques to incorporate strategic flexibility into the investment scenario. By integrating a probabilistic cost model into a real options framework, the value of an oil recovery facility is modeled to reflect the realistic alternatives available to decision-makers, where the course of the investment can be altered as new information becomes available. This approach represents a distinct advantage to traditional discounted cash flow (DCF) estimation, which is unable to capture operational adaptability, including the ability to expand, delay, or abandon a project. The analysis focuses on the energy inputs required for the recovery of heavy oil bitumen from Alberta, Canada, and examines both natural gas and nuclear steam plants as heat sources. The ACR-1000 reactor is highlighted as a substitute for conventional natural gas-fueled means of production, in light of the recent volatility of natural gas prices and the potential for emissions compliance charges. The methodology includes a levelized cost assessment per barrel of bitumen and estimation of cost ranges for each component. A mean-reversion stochastic price model was also derived for the both natural gas and oil price. By incorporating cost ranges into a ROA framework, the benefit of retaining project flexibility is included in its valuation. Formulated as a decision tree, built-in options include the initial selection to pursue nuclear or natural gas, site selection and licensing, the ability to switch heat source in the planning stage, and the final commitment to construct. Each decision is influenced by uncertainties, including the course of bitumen and natural gas price, as well as emissions policy. By structuring the investment scenario to include these options, the overall value of the project increases by over $150 million. The ability to switch technology type allows for an assessment of the viability of nuclear steam, which becomes economically favorable given high natural gas prices or high emissions taxes. Given an initial selection of natural gas SAGD, there is a 25% probability that a switch to nuclear steam will occur, as evolving financial conditions make nuclear the optimal technology. / text
210

An autonomous long-term fast reactor system and the principal design limitations of the concept

Tsvetkova, Galina Valeryevna 30 September 2004 (has links)
The objectives of this dissertation were to find a principal domain of promising and technologically feasible reactor physics characteristics for a multi-purpose, modular-sized, lead-cooled, fast neutron spectrum reactor fueled with an advanced uranium-transuranic-nitride fuel and to determine the principal limitations for the design of an autonomous long-term multi-purpose fast reactor (ALM-FR) within the principal reactor physics characteristic domain. The objectives were accomplished by producing a conceptual design for an ALM-FR and by analysis of the potential ALM-FR performance characteristics. The ALM-FR design developed in this dissertation is based on the concept of a secure transportable autonomous reactor for hydrogen production (STAR-H2) and represents further refinement of the STAR-H2 concept towards an economical, proliferation-resistant, sustainable, multi-purpose nuclear energy system. The development of the ALM-FR design has been performed considering this reactor within the frame of the concept of a self-consistent nuclear energy system (SCNES) that satisfies virtually all of the requirements for future nuclear energy systems: efficient energy production, safety, self-feeding, non-proliferation, and radionuclide burning. The analysis takes into consideration a wide range of reactor design aspects including selection of technologically feasible fuels and structural materials, core configuration optimization, dynamics and safety of long-term operation on one fuel loading, and nuclear material non-proliferation. Plutonium and higher actinides are considered as essential components of an advanced fuel that maintains long-term operation. Flexibility of the ALM-FR with respect to fuel compositions is demonstrated acknowledging the principal limitations of the long-term burning of plutonium and higher actinides. To ensure consistency and accuracy, the modeling has been performed using state-of-the-art computer codes developed at Argonne National Laboratory. As a result of the computational analysis performed in this work, the ALM-FR design provides for the possibility of continuous operation during about 40 years on one fuel loading containing mixture of depleted uranium with plutonium and higher actinides. All reactor physics characteristics of the ALM-FR are kept within technological limits ensuring safety of ultra-long autonomous operation. The results obtained provide for identification of physical features of the ALM-FR that significantly influence flexibility of the design and its applications. The special emphasis is given to existing limitations on the utilization of higher actinides as a fuel component.

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