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Estudo termohidraulico de um elemento combustivel tipo MTR visando a construcao de um dispositivo de radiacaoCORAGEM, HELIO B. de O. 09 October 2014 (has links)
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Desenvolvimento de um combustível de alta densidade à base da liga urânio-molibdênio com alta compatibilidade em altas temperaturas / Development of a high density fuel based on uranium-molybdenum alloys with high compatibility in high temperaturesOLIVEIRA, FABIO B.V. de 09 October 2014 (has links)
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Desenvolvimento de combustivel tipo placa, com nucleo constituido por dispersao U-Al, para reatores de materiaisBRESSIANI, JOSE C. 09 October 2014 (has links)
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Estudo termohidraulico de um elemento combustivel tipo MTR visando a construcao de um dispositivo de radiacaoCORAGEM, HELIO B. de O. 09 October 2014 (has links)
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Desenvolvimento de um combustível de alta densidade à base da liga urânio-molibdênio com alta compatibilidade em altas temperaturas / Development of a high density fuel based on uranium-molybdenum alloys with high compatibility in high temperaturesOLIVEIRA, FABIO B.V. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:53:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:28Z (GMT). No. of bitstreams: 0 / Este trabalho tem como objetivo o desenvolvimento de um combustível nuclear de alta densidade e baixo enriquecimento com base na liga ?-UMo, para aplicações nas quais seja necessário desempenho satisfatório a altas temperaturas, considerando-se a sua utilização na forma de dispersão. Para tanto, partiu-se da análise dos resultados dos testes RERTR (sigla em inglês para \"Reduced Enrichment of Research and Test Reactors\") e de alguns trabalhos teóricos envolvendo a elaboração de ligas metaestáveis de ?-urânio. Uma adição ternária é proposta, com base em propriedades de ligas binárias e ternárias de urânio-molibdênio estudadas, e que teve como objetivos um aumento na estabilidade da fase gama do urânio e a facilidade na obtenção dos pós. Assim, as ligas de urânio-molibdênio foram preparadas com adições de Mo de 5 a 10% em peso, e adição de 1 e 3% de elemento ternário (o silício), sobre uma liga base binária de U7Mo. Em todas as fases do processo de preparação, as ligas foram caracterizadas pelas técnicas tradicionais, para determinação de suas propriedades estruturais e mecânicas. Para a elaboração de um processo para a obtenção de pós destas ligas, o seu comportamento sob atmosfera de hidrogênio foi estudado em equipamento de análise térmica e gravimétrica diferencial. Temperaturas variaram da ambiente a 1000oC, por tempos de 15 minutos a 16 horas. A validação destes resultados foi feita em escala semi-piloto, na qual quantidades de 10 a 50g de pós de algumas das ligas foram preparados, sob atmosfera estática de hidrogênio. Os estudos de compatibilidade foram conduzidos expondo-se as ligas à atmosfera de oxigênio e ao contato com alumínio, para a verificação de possíveis reações por meio de análise térmica diferencial. As ligas foram submetidas a aquecimento constante até temperatura de 1000oC, e seu desempenho foi avaliado quanto a maior resistência à reação. 6 Com base nestes resultados, observou-se que as adições ternárias aumentam as temperaturas para a oxidação das ligas e reação com alumínio frente aos binários ?UMo. Um conjunto de condições para hidretação das ligas e fabricação dos pós foi estabelecido, tanto mais restritivos em termos de tempo, temperatura e necessidade de pré-tratamentos quanto mais estável a estrutura ?. Com a adição de ternário em pequeno excesso e formação de fase intergranular, mostrou-se que um aumento na estabilidade não prejudica a formação dos pós. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Marginal Tax Rates and Innovative Activity in the Biotech SectorDiaz, Pedro, Skrepnek, Grant January 2013 (has links)
Class of 2013 Abstract / Specific Aims: To assess the association between marginal tax rates (MTR) and innovative output of biotechnology firms. The MTR plays an important role in firms’ financing choices. Assessment of a firm’s tax status may reveal how firms decide on investment policies that affect R&D.
Methods: A retrospective database analysis was used. Subjects included were firms within the biotechnology sector with the Standard Industrial Classification code of 2836 from 1980 - 2011. MTR Data was obtained from the S&P Compustat database, and Patent data was obtained from the U.S. Patent and Trademark Office. Changes in MTR’s on outcomes of patents were analyzed by performing an inferential analysis. Generalized estimating equations (GEE) were used, specifically utilizing a GEE regression with a negative binomial distributional family with log link, independent correlation structure and robust standard error variance calculation. Patents were regressed by the lagged change in MTR, after interest deductions.
Main Results: The lag years 2 and 5 of the MTR change were statistically significant, (p = 0.031) and (p = 0.026) for each model respectively. Every one unit increase in the change of the MTRs was associated with large and significant drops in patents 78.8% (IRR = 0.212), 90.7% (IRR = 0.093), 92.7% (IRR = 0.073) at year 2 lag and 84.8% (IRR = 0.152), 92.6% (IRR = 0.074) at year 5 lag.
Conclusion: An increase in the change of the MTR results in significant drops in patenting activity.
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Associação entre deficiência de cobalamina e folato e presença dos polimorfismos MTR A2756C e MTRR A66G em gestantes e seus recém nascidos / Association between cobalamin and folate deficiency and the presence of the MTR A2756G and MTRR A66G polymorphisms in pregnant women and their newbornsFavaro, Patricia Barbosa 15 August 2005 (has links)
A metionina sintase redutase (MTRR) catalisa a redução da cobalamina (Cbl) oxidada a metilcobalamina. Em presença de folato, a metionina sintase (MTR) utiliza a metilcobalamina como cofator na metilação da homocisteína (tHcy) a metionina. O objetivo deste estudo foi avaliar os efeitos dos polimorfismos MTR A2756G e MTRR A66G nas concentrações dos metabólitos marcadores de deficiência de Cbl e folato em gestantes e neonatos. Os genótipos dos polimorfismos MTR A2756G e MTRR A66G foram obtidos por PCR-RFLP. O genótipo MTR 2756AA foi relacionado aos maiores valores de tHcy em gestantes e MMA em neonatos. Gestantes com genótipos MTRR 66AG e GG e com menores concentrações de Cbl apresentaram maior risco de apresentar concentrações elevadas de tHcy. Neonatos com genótipos com MTRR 66AG e GG apresentaram menores valores de SAM. Os polimorfismos MTR A2756G e MTRR A66G interferem nas reações dependentes de Cbl e folato em gestantes e neonatos. / Methionine synthase reductase (MTRR) catalyzes the reductive reaction of oxidized cobalamin to methylcobalamin. When folate is present, methionine synthase (MTR) uses methylcobalamin cofactor at homocysteine to methionine methylation process. The aim of this study was to evaluate the effects of MTR A2756G and MTRR A66G polymorphisms on total homocysteine (tHcy), methylmalonic acid (MMA), S-adenosylmethionine (SAM) concentrations and SAM/SAH ratio in Brazilian pregnant women and their newborns. Genotypes of two polymorphisms were determined by PCR-RFLP. MTR 2756AA genotype was associated with higher tHcy and MMA levels in mothers and babies, respectivelly. Lower cobalamin concentrations associated with MTRR 66AG and GG genotypes increased risk to elevated tHcy levels in pregnant women. The SAM levels were lower in neonates with MTRR 66AG e GG genotypes. The polymorphisms MTR A2756G and MTRR A66G could affect cobalamin and folate dependent reactions in pregnant women and newborns.
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Associação entre deficiência de cobalamina e folato e presença dos polimorfismos MTR A2756C e MTRR A66G em gestantes e seus recém nascidos / Association between cobalamin and folate deficiency and the presence of the MTR A2756G and MTRR A66G polymorphisms in pregnant women and their newbornsPatricia Barbosa Favaro 15 August 2005 (has links)
A metionina sintase redutase (MTRR) catalisa a redução da cobalamina (Cbl) oxidada a metilcobalamina. Em presença de folato, a metionina sintase (MTR) utiliza a metilcobalamina como cofator na metilação da homocisteína (tHcy) a metionina. O objetivo deste estudo foi avaliar os efeitos dos polimorfismos MTR A2756G e MTRR A66G nas concentrações dos metabólitos marcadores de deficiência de Cbl e folato em gestantes e neonatos. Os genótipos dos polimorfismos MTR A2756G e MTRR A66G foram obtidos por PCR-RFLP. O genótipo MTR 2756AA foi relacionado aos maiores valores de tHcy em gestantes e MMA em neonatos. Gestantes com genótipos MTRR 66AG e GG e com menores concentrações de Cbl apresentaram maior risco de apresentar concentrações elevadas de tHcy. Neonatos com genótipos com MTRR 66AG e GG apresentaram menores valores de SAM. Os polimorfismos MTR A2756G e MTRR A66G interferem nas reações dependentes de Cbl e folato em gestantes e neonatos. / Methionine synthase reductase (MTRR) catalyzes the reductive reaction of oxidized cobalamin to methylcobalamin. When folate is present, methionine synthase (MTR) uses methylcobalamin cofactor at homocysteine to methionine methylation process. The aim of this study was to evaluate the effects of MTR A2756G and MTRR A66G polymorphisms on total homocysteine (tHcy), methylmalonic acid (MMA), S-adenosylmethionine (SAM) concentrations and SAM/SAH ratio in Brazilian pregnant women and their newborns. Genotypes of two polymorphisms were determined by PCR-RFLP. MTR 2756AA genotype was associated with higher tHcy and MMA levels in mothers and babies, respectivelly. Lower cobalamin concentrations associated with MTRR 66AG and GG genotypes increased risk to elevated tHcy levels in pregnant women. The SAM levels were lower in neonates with MTRR 66AG e GG genotypes. The polymorphisms MTR A2756G and MTRR A66G could affect cobalamin and folate dependent reactions in pregnant women and newborns.
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Nuclear heating measurements in the Maria reactor and implementation of neutron and photon calculation scheme / Mesures de l'échauffement nucléaire dans le réacteur Maria et mise en oeuvre d'un schéma de calcul pour les neutrons et les photonsTarchalski, Mikolaj 14 December 2016 (has links)
Les travaux réalisés durant cette thèse rentrent dans cette problématique. Ils concernent d’une part le développement d’un schéma de calculs et d’évaluation des échauffements nucléaires générés dans le réacteur MARIA en utilisant les codes français de transport neutronique TRIPOLI-4 © et APOLLO-2. Les travaux dans ce volet ont concerné principalement les calculs des échauffements photoniques induits par les rayonnements gammas essentiellement. D’autre part des travaux expérimentaux ont été conduits durant cette thèse. Ils ont concerné la mesure des échauffements nucléaires dans des emplacements spécifiques du réacteur MARIA. Cela a permis une première validation des schémas de calcul adoptés. Des comparaisons C/E ont été effectuées. Elles sont présentées et discutées dans cette thèse. Cela a permis d’émettre des recommandations quant aux techniques de mesure des échauffements nucléaires dans le réacteur MARIA et les moyens de modélisation qui peuvent être associés. Les comparaisons calculs-expérience font l’objet du cinquième. Les écarts relevés entre les résultats des modélisations et les mesures des échauffements nucléaires pour différentes configurations de mesures (au moyen de GT et de calorimètre mono cellule KAROLINA) permettent de dégager grâce à ces premiers travaux de thèse des recommandations pertinentes pour les travaux futurs. / This thesis work presents a calculation scheme which enables evaluation of heat generation from nuclear reactions in the MARIA nuclear reactor by use French computational codes TRIPOLI-4 © (TRIPOLI-4 is a registered trademark of CEA) and Apollo-2. Particular attention was devoted to the heat induced by gamma radiation. The thesis also presents measurements of nuclear heating in selected locations inside MARIA MTR reactor. This allows reaching first steps of validation and qualification of computer calculations. Research and analysis presented in the thesis allow one to compare the results obtained by using proposed calculation scheme with the experimental measurement methods. Finally, further works and perspectives were proposed on the development of the calculations and experimental measurements of nuclear heating in nuclear reactors.Qualifying the calculations was possible by performing especially dedicated 7-day core measurement campaigns. Nuclear heating measurements were performed with gamma thermometers and specially designed KAROLINA calorimeter. All measurement devices used were mounted in a dedicated probe, designed and built for this purpose, which allowed for the adjustment of instruments position inside the MARIA core. The main scientific hypothesis of this work is that currently available Monte Carlo simulations of neutron and gamma transport can be used to correct and accurate calculations of prompt nuclear heating in nuclear reactor, whereas delayed component of nuclear heating can be determined experimentally. For this purpose new calculation scheme and improvements in nuclear heating measurements were implemented.
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Railway development and colonial governance in Hong Kong since the 1960s. / 一九六零年代起香港的鐡路發展與殖民管治 / Yi jiu liu ling nian dai qi Xianggang de tie lu fa zhan yu zhi min guan zhiJanuary 2009 (has links)
Leung, Yan Cheong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 150-159). / Abstract also in Chinese. / Chapter Chapter 1: --- Introduction --- p.1 / Chapter ■ --- Research Objectives --- p.3 / Chapter ■ --- Literature Review --- p.5 / Chapter ■ --- Use of Primary Sources --- p.9 / Chapter ■ --- Structure --- p.11 / Chapter Chapter 2: --- Governing Objectives behind the Railway Developments --- p.13 / Chapter ■ --- Initial Motives --- p.13 / Chapter ■ --- Political Objectives and Financial Concerns as the Determinative Factors --- p.22 / Chapter ■ --- Railway Developments since the 1970s --- p.33 / Chapter ■ --- Changing Meanings of Success in Railway Development --- p.35 / Chapter ■ --- Summary of Chapter 2 --- p.35 / Chapter Chapter 3: --- Hong Kong-London Relations and the MTR Development (I): Bilateral Negotiation and the Decisions on the MTR --- p.37 / Chapter ■ --- Nature of London-Hong Kong Relations after the WWII --- p.37 / Chapter ■ --- The Contract Approaches --- p.40 / Chapter ■ --- The Process of Bilateral Negotiation --- p.42 / Chapter ■ --- Hong Kong Government´ةs Strategy --- p.43 / Chapter ■ --- London´ةs Strategy --- p.46 / Chapter ■ --- Summary of Chapter 3 --- p.53 / Chapter Chapter 4: --- Hong Kong-London Relations and the MTR Development (II): Negotiation Breakdown and Its Impacts --- p.55 / Chapter ■ --- The Negotiation Breakdown --- p.55 / Chapter ■ --- The Adoption of Multi-contract Approach: a Contingency Plan --- p.59 / Chapter ■ --- Collaborate with London --- p.64 / Chapter ■ --- Summary of Chapter 4 --- p.68 / Chapter Chapter 5: --- Colonial Governance and Major Decisions on the MTR in the 1970s --- p.70 / Chapter ■ --- The Establishment of MTRC --- p.70 / Chapter ■ --- Optimizing the Project --- p.75 / Chapter ■ --- Civil Protests and Crises Management --- p.83 / Chapter ■ --- Summary of Chapter 5 --- p.91 / Chapter Chapter 6: --- A Review on the Modernization of Kowloon-Canton Railway --- p.93 / Chapter ■ --- KCR´ةs Operational Problems before the Modernization --- p.93 / Chapter ■ --- Evolution of KCR Modernization Programme --- p.100 / Chapter ■ --- Bureaucratic and Administrative Concerns behind the Establishment of KCRC --- p.108 / Chapter ■ --- KCRC´ةs Service Provision and Corporate Strategy --- p.111 / Chapter ■ --- Summary of Chapter 6 --- p.115 / Chapter Chapter 7: --- "Railway Development, Transport Policy and the Competitions among Public transport Operators" --- p.118 / Chapter ■ --- Transformation of the Transport Industry in the 1970s --- p.118 / Chapter ■ --- The Changing Role of Railways in the Transport System --- p.121 / Chapter ■ --- Rivalries between the Railways and Other Transport Operators --- p.129 / Chapter ■ --- Summary of Chapter 7 --- p.138 / Chapter Chapter 8: --- Conclusion --- p.140 / Chapter ■ --- Hong Kong-London Relations and Decisions on Railway Developments --- p.141 / Chapter ■ --- Governing Concerns and the Railway Development --- p.144 / Chapter ■ --- Further Studies --- p.148 / Bibliography --- p.150
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