991 resultados para Segunda circular


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Apresenta os dois enunciados mais importantes da segunda lei da termodinâmica. Apresenta as máquinas térmicas, dispositivos que produzem trabalho a partir de calor em processo cíclico, citando exemplo. Apresenta refrigeradores térmicos simples, que funcionam como aquecedores quando invertidos. Apresenta o ciclo de Carnot, definindo e equacionando as quatro etapas e ilustrando em um diagrama.

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Apresenta entropia por meio da desigualdade de Clausius, demonstrando essa desigualdade para máquinas térmicas e ciclos de refrigeração, concluindo que a igualdade se aplica a ciclos reversíveis e a desigualdade a ciclos irreversíveis. Define entropia como uma propriedade termodinâmica extensiva, e apresenta as equações para calcular a entropia. Apresenta o diagrama TS, faz a representação de um ciclo termodinâmico e do ciclo de Carnot nesse diagrama. Apresenta equações para cálculo de eficiência máquinas térmicas e rendimento de refrigeradores. Apresenta considerações de entropia para gases ideais.

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Apresenta algumas observações experimentais que fornecem embasamento para a segunda lei da termodinâmica, os enunciados de Clausius e Kelvin-Planck. Demonstra através de esquemas o princípio de funcionamento das máquinas térmicas e dos refrigeradores, das máquinas ideais (descrição do ciclo de Carnot) e a representação dos ciclos de potência e de refrigeração num diagrama p-v. Avalia o rendimento de máquinas térmicas ideais. Posteriormente, define o conceito de entropia e suas aplicações, como calcular variações desta propriedade termodinâmica em diferentes processos, em líquidos, sólidos e gases ideais.

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Orientadora: Teresa Ferreira Rodrigues

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Universidade da Madeira

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The Behavioral Finance develop as it is perceived anomalies in these markets efficient. This fields of study can be grouped into three major groups: heuristic bias, tying the shape and inefficient markets. The present study focuses on issues concerning the heuristics of representativeness and anchoring. This study aimed to identify the then under-reaction and over-reaction, as well as the existence of symmetry in the active first and second line of the Brazilian stock market. For this, it will be use the Fuzzy Logic and the indicators that classify groups studied from the Discriminant Analysis. The highest present, indicator in the period studied, was the Liabilities / Equity, demonstrating the importance of the moment to discriminate the assets to be considered "winners" and "losers." Note that in the MLCX biases over-reaction is concentrated in the period of financial crisis, and in the remaining periods of statistically significant biases, are obtained by sub-reactions. The latter would be in times of moderate levels of uncertainty. In the Small Caps the behavioral responses in 2005 and 2007 occur in reverse to those observed in the Mid-Large Cap. Now in times of crisis would have a marked conservatism while near the end of trading on the Bovespa speaker, accompanied by an increase of negotiations, there is an overreaction by investors. The other heuristics in SMLL occurred at the end of the period studied, this being a under-reaction and the other a over-reaction and the second occurring in a period of financial-economic more positive than the first. As regards the under / over-reactivity in both types, there is detected a predominance of either, which probably be different in the context in MLCX without crisis. For the period in which such phenomena occur in a statistically significant to note that, in most cases, such phenomena occur during the periods for MLCX while in SMLL not only biases are less present as there is no concentration of these at any time . Given the above, it is believed that while detecting the presence of bias behavior at certain times, these do not tend to appear to a specific type or heuristics and while there were some indications of a seasonal pattern in Mid- Large Caps, the same behavior does not seem to be repeated in Small Caps. The tests would then suggest that momentary failures in the Efficient Market Hypothesis when tested in semistrong form as stated by Behavioral Finance. This result confirms the theory by stating that not only rationality, but also human irrationality, is limited because it would act rationally in many circumstances

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This paper aims at studying how circular dance can afford to sight-disabled peoples movement and how they can learn to cope with the deep movement of relation, consciousness, appropriation and communion with the world. Inside circular dance, a cosmic metaphor, is inscribed the movement of the world, which tells and changes amorously the human history. In the works of Paulo Freire and Maurice Merleau-Ponty one can find the necessary support to discuss, as long as possible, movement and existence. Research-action is used as a methodological approach whose empirical center is placed on the Institute of Education and Rehabilitation of Blind, in Natal, which shelters eight sightdisabled adults. The research s data reveal that the practice of circular dance concurs to enlarge the movement of the research s subjects, to develop a more accurate perception of their selves and of their own capacities, as well as improve the relations Me/Others, Me/World, which require a context of differences. The study has revealed that the practice of dance develops a better perception of the limits and surpasses as a human condition and, in consequence, the discovery of one s own body and the other s body as a resource of lessons and representations of the self and of the world. It lets out the development of a new way of thinking and coping with discrimination surrounding the disabled persons. In movement, in circular dance, the barrier between sight disablement and vision loses force.

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Este trabalho teve como objetivo avaliar o efeito da levedura desidratada de álcool (Saccharomyces cerevisae) como substituto do suplemento vitamínico, em dietas de tilápia-do-nilo (Oreochromis niloticus). Trezentos alevinos machos, sexualmente revertidos, com peso médio de 1,5 g, foram distribuídos igualmente em 20 aquários de fibra de vidro, equipados com filtro biológico. Cinco dietas isoprotéicas com 32% de proteína bruta na primeira fase (40 dias) e com 28% de proteína bruta na segunda fase (74 dias) foram fornecidas ad libitum, duas vezes ao dia. A dieta-controle não conti-nha levedura, e as demais apresentavam 10% de levedura. O delineamento foi inteiramente casualizado, com cinco tratamentos e quatro repetições. Não houve influência significativa dos tratamentos sobre o ganho de peso e taxa de crescimento específico. Foi observada, nos peixes alimentados com dietas sem suplemento vitamínico, alta mortalidade. Os peixes que receberam levedura apresentaram menor conteúdo corporal de proteína, e maior, de lipídeos. A levedura desidratada de álcool pode ser usada como fonte de vitaminas hidrossolúveis em dietas para alevinos de tilápia-do-nilo.

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The microstrip antennas are largely used in wireless communication systems due to their low cost, weight, less complex construction and manufacturing, in addition to its versatility. UWB systems have emerged as an alternative to wireless communications over short distances because they offer of higher capacity and lower multipath distortion than other systems with the same purpose. Combining the advantages of microstrip antennas to the characteristics of UWB, it is possible to develop more and more smaller devices, with diverse geometries to operate satisfactorily in these systems. This paper aims to propose alternatives to microstrip antennas for UWB systems operate in the range between 3.1 and 10.6 GHz, with a patch on circular ring. Some techniques are analyzed and employed to increase the bandwidth of proposed antenna: the insertion of a parasitic elements and a rectangular slit in the displaced ground plane. For this, key issues are presented as the basic principles of UWB systems, the fundamental theory of antennas and microstrip antennas. The simulations and experimental characterization of constructed antennas are presented, as well as analysis of parameters such as bandwidth and radiation pattern

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O Sistema de Posicionamento Global (GPS) transmite seus sinais em duas freqüências, o que permite eliminar matematicamente os efeitos de primeira ordem da ionosfera através da combinação linear ionosphere free. Porém, restam os efeitos de segunda e terceira ordem, os quais podem provocar erros da ordem de centímetros nas medidas GPS. Esses efeitos, geralmente, são negligenciados no processamento dos dados GPS. Os efeitos ionosféricos de primeira, segunda e terceira ordem são diretamente proporcionais ao TEC presente na ionosfera, porém, no caso dos efeitos de segunda e terceira ordem, comparecem também o campo magnético da Terra e a máxima densidade de elétrons, respectivamente. Nesse artigo, os efeitos de segunda e terceira ordem da ionosfera são investigados, sendo que foram levados em consideração no processamento de dados GPS na região brasileira para fins de posicionamento. Serão apresentados os modelos matemáticos associados a esses efeitos, as transformações envolvendo o campo magnético da Terra e a utilização do TEC advindo dos Mapas Globais da Ionosfera ou calculados a partir das observações GPS de pseudodistância. O processamento dos dados GPS foi realizado considerando o método relativo estático e cinemático e o posicionamento por ponto preciso (PPP). Os efeitos de segunda e terceira ordem foram analisados considerando períodos de alta e baixa atividade ionosférica. Os resultados mostraram que a não consideração desses efeitos no posicionamento por ponto preciso e no posicionamento relativo para linhas de base longas pode introduzir variações da ordem de poucos milímetros nas coordenadas das estações, além de variações diurnas em altitude da ordem de centímetros.

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The human cyclin-dependent kinase 9 (CDK9) protein was expressed in E coli BL21 using the pET23a vector at 30 degrees C. Several milligrams of protein were purified from soluble fraction using ionic exchange and ATP-affinity chromatography. The structural quality of recombinant CDK9 and the estimation of its secondary structure were obtained by circular dichroism. Structural models of CDK9 presented 26% of helices in agreement with the spectra by circular dichroism analysis. This is the first report on human CDK9 expression in Escherichia coli and structure analysis and provides the first step for the development of CDK9 inhibitors. (c) 2006 Elsevier B.V. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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In the present paper we develop an algorithm to solve the time dependent Ginzburg-Landau equations, by using the link variables technique, for circular geometries. In addition, we evaluate the Helmholtz and Gibbs free energy, the magnetization, and the number of vortices. This algorithm is applied to a circular sector. We evaluate the superconduting-normal magnetic field transition, the magnetization, and the superconducting density. Our results point out that, as we reduce the superconducting area, the nucleation field increases. Nevertheless, as the angular width of the circular sector goes to small values the asymptotic behavior is independent of the sample area. We also show that the value of the first nucleation field is approximately the same independently of the form of the circular sector. Furthermore, we study the nucleation of giant and multivortex states for the different shapes of the present geometry.

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The present essay has how I aim to analyse the memories of the ex-combatants of Parelhas-RN, specially of the components of the Força de Vigilância e Segurança do Litoral - FVSL, protagonists of the Brazilian participation in the scenery of the Second World war. Along this we looked to understand in which surrounding geographicalpartner these men were living before the War and what were the consequences of a brusque change of space owing to the convocation for the Armed Brazilian Strength in that historical context. The defense of the Brazilian coast during the War was not a so simple task, I have in mind the precariedade logistics of the Armed Strength, the attacks of submarines of the Axle that killed hundreds of civilians and Brazilian soldiers and the net of espionage mounted by Germany in Brazil. Leaving from the notion of collective memory and estrangement in Maurice Halbwachs, we will use the oral history like principal methodology, with the end of rescue these underground memories what also will make possible us the vision realizes that the protagonists themselves have of the event, besides the use of documents, photos, maps and any sort of fountains that make possible us to rebuild the scenery of Parelhas in the beginning of the War and the trajectory of life of his veterans