1000 resultados para Campos eletricos - Teses


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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The main idea of this work is to understand and analyze the dynamical aspects of the motion of a particle moving in the annular billiard, which corresponds to two circles of radius R and r (r-elastic) cases. When we introduce magnetic and electric fields, the particle is submitted to the Lorentz force. It also can suffer successive collisions with the breathing circles, winning or losing energy. For the elastic time-dependent case, we have already observed that a particle can gain unlimited energy. The purpose of this work is to study the effects of both external fields in the mean energy of the system, for the time-dependent case with and without dissipation. Our initial results conduct us to believe that electrical field can contribute to the increasing of mean energy, and a magnetic field applied to the vertical axis of coordinate (what guarantees the particle do not travel away the billiard’s plane) uses to arrest the particle to the whispering gallery orbits and do not contribute to the Fermi acceleration indeed. However, in presence of the electric field, to same values, the magnetic one together can improve this referred process, obtaining greater energy values to the same number of iterations. These results are applied to the concentric case, that was reported did not haven any significant energy gain on the free particle motion

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This work offers an overview about didactic reflections in the introduction of the electrical field concept in Physics Teaching activities aimed to the High School by means of a teaching methodology based in a low cost experiment (FERREIRA E RAMOS, 2008). We analyzed the particular use of an experiment named electrostatic vector and its use in the teaching of the line force ideas, proposed by Faraday in 19th century. In the frame of this work we analyzed how this unconventional approach differs of the methodology generally presented in the didactic textbooks. We discussed that the use of low cost experiments, will not cause the student to learn, but the work of the teacher, offering an interaction between the student and the electrostatic vector, play an important role in the classroom

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A monitoring network of atmospheric electric field covering the Vale do Paraiba region was implemented. The sensors were located on different sites with different altitude and geographic topology. The present work reports the study carried on those sensors in order to verify the necessity of using some correction factor to the measured local electric field intensity due to effects of local environment. The measurements were done in continuous 24 hours per day with the data recorded on registers in each device accumulating information during a period of four months. The relation between the electric field values by each sensor was compared to the reference located on Sao Jose dos Campos city using the same period. In a graphical analysis using the local field intensity and the reference, the data were fitted to a straight line obtained by minimum square method. Variation up to 95% was observed between the field values in some sensors. Another method was proposed, comparing the mean values of the electric field in a function of time. The variation in some sensors reached up to 133%. We conclude that the variations are due to local atmospheric conditions and no correction factor is required on the electric field sensors

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Este estudo descreve a relação das teses de doutorado em enfermagem defendidas nos Programas de Pós-Graduação em Enfermagem, no Brasil, com as linhas de pesquisas definidas pela área da Enfermagem, em três campos: profissional, assistencial e organizacional. É uma pesquisa descritiva-exploratória, com base nos relatórios dos programas de Pós-Graduação, avaliados pela Capes e no Catálogo Informações sobre Pesquisas e Pesquisadores em Enfermagem CEPEn/ABEn, referentes ao período de 1983-2001, totalizando 448 resumos. O campo assistencial alberga o maior número de produção, seguido do organizacional e do profissional. As investigações evidenciam uma tendência para estudos de abordagem qualitativa, descortinando possibilidades de aprofundamento do conhecimento da realidade ou compreensão de fenômenos sociais que tangenciam a prática da enfermagem, porém, os estudos de intervenção na prática profissional e de desenvolvimento de tecnologia ainda estão em fase de construção.

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Realizou-se um estudo com objetivo de analisar a produção do saber da enfermagem em saúde coletiva, resultante da pós-graduação vinculada ao Departa-mento de Enfermagem em Saúde Coletiva da Escola de Enfermagem da Universidade de São Paulo, no período de 1992 a 2004. Foram produzidas 86 teses e dissertações sobre múltiplos objetos, principalmente sobre os perfis epidemiológicos e de reprodução social, articulados aos processos de saúde-doença dos grupos sociais. Houve predomínio de análises qualitativas e do referencial teórico-metodológico materialista-histórico e dialético. Grupos populacionais de determinados territórios constituíram a fonte empírica mais freqüente. Concluiu-se que a adoção de categorias analíticas relativas à produção e reprodução social, assim como gênero e geração, possibilitaram a aproximação real do objeto para interpretar e intervir, contribuindo para o avanço dos conheci-mentos em saúde coletiva.

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Mapeamento das dissertações e teses referentes à subárea da comunicação popular, alternativa e comunitária (CPAC) desenvolvidas nos Programas de Pós-Graduação em Comunicação stricto sensu no Brasil, de 1972 a 2012. Dentre os objetivos estão localizar as pesquisas; os autores; sua distribuição no tempo e espaço; identificar as instituições e orientadores que impulsionam a subárea; definir as abordagens teórico-metodológicas; e apontar autores/conceitos referência. Por meio de pesquisa exploratória e aplicação de quatro filtros, chegou-se a uma amostra final de 102 pesquisas, 87 dissertações e 15 teses, submetidas à análise quantitativa, por meio de Análise de Conteúdo a partir de partes pré-definidas (Resumo, Palavras chave, Introdução, Sumário, Considerações Finais e capítulo metodológico, quando presente), e a uma análise qualitativa do conteúdo completo das 15 teses. O método que orienta esta pesquisa é o histórico dialético, na perspectiva da busca de uma análise de conjunto e atenta às contradições e mudanças que o objeto está implicado; e a pesquisa bibliográfica que a fundamenta se ancora em autores como Jorge González, Cicilia Peruzzo, Regina Festa, Pedro Gilberto Gomes, Gilberto Giménez e Augusto Triviños e foi realizada com o apoio do software NVivo. Resultados quantitativos indicam: a) predominância de pesquisas sobre comunicação comunitária (68%) b) predominância de estudos empíricos (79%); c) a variedade de denominações atribuídas às experiências pelos pesquisadores; d) a constante luta das classes populares por democratização da comunicação e por direitos sociais ao longo dos anos; e) a influência e importância dos intelectuais orgânicos nas experiências estudadas, f) problemas metodológicos; g) UMESP, USP e UFRJ como instituições protagonistas, e, h) Cicilia Peruzzo e Raquel Paiva como as que mais orientam teses e dissertações sobre a temática. Quanto à análise qualitativa verificaram-se alguns critérios que permeiam a CPAC: 1) a definição de classes subalternas; 2) a importância da participação ativa das comunidades nos processos de comunicação; e 3) formas, conteúdos e objetivos que se complementam e dão identidade às experiências

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In this work the archaea and eubacteria community of a hypersaline produced water from the Campos Basin that had been transported and discharged to an onshore storage facility was evaluated by 16S recombinant RNA (rRNA) gene sequence analysis. The produced water had a hypersaline salt content of 10 (w/v), had a carbon oxygen demand (COD) of 4,300 mg/l and contains phenol and other aromatic compounds. The high salt and COD content and the presence of toxic phenolic compounds present a problem for conventional discharge to open seawater. In previous studies, we demonstrated that the COD and phenolic content could be largely removed under aerobic conditions, without dilution, by either addition of phenol degrading Haloarchaea or the addition of nutrients alone. In this study our goal was to characterize the microbial community to gain further insight into the persistence of reservoir community members in the produced water and the potential for bioremediation of COD and toxic contaminants. Members of the archaea community were consistent with previously identified communities from mesothermic reservoirs. All identified archaea were located within the phylum Euryarchaeota, with 98 % being identified as methanogens while 2 % could not be affiliated with any known genus. Of the identified archaea, 37 % were identified as members of the strictly carbon-dioxide-reducing genus Methanoplanus and 59 % as members of the acetoclastic genus Methanosaeta. No Haloarchaea were detected, consistent with the need to add these organisms for COD and aromatic removal. Marinobacter and Halomonas dominated the eubacterial community. The presence of these genera is consistent with the ability to stimulate COD and aromatic removal with nutrient addition. In addition, anaerobic members of the phyla Thermotogae, Firmicutes, and unclassified eubacteria were identified and may represent reservoir organisms associated with the conversion hydrocarbons to methane.

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In Brazil, the campos rupestres occur over the Brazilian shield, and are characterized by acidic nutrient-impoverished soils, which are particularly low in phosphorus (P). Despite recognition of the campos rupestres as a global biodiversity hotspot, little is known about the diversity of P-acquisition strategies and other aspects of plant mineral nutrition in this region. To explore nutrient-acquisition strategies and assess aspects of plant P nutrition, we measured leaf P and nitrogen (N) concentrations, characterized root morphology and determined the percentage arbuscular mycorrhizal (AM) colonization of 50 dominant species in six communities, representing a gradient of soil P availability. Leaf manganese (Mn) concentration was measured as a proxy for carboxylate-releasing strategies. Communities on the most P-impoverished soils had the highest proportion of nonmycorrhizal (NM) species, the lowest percentage of mycorrhizal colonization, and the greatest diversity of root specializations. The large spectrum of leaf P concentration and variation in root morphologies show high functional diversity for nutritional strategies. Higher leaf Mn concentrations were observed in NM compared with AM species, indicating that carboxylate-releasing P-mobilizing strategies are likely to be present in NM species. The soils of the campos rupestres are similar to the most P-impoverished soils in the world. The prevalence of NM strategies indicates a strong global functional convergence in plant mineral nutrition strategies among severely P-impoverished ecosystems.

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No Tillage system is fully incorporated to farming in the region of Campos Gerais, state of Paraná. Accuracy and precision in the planting process are items of great importance for the success of this system. In order to evaluate the planting process, thirty eight farms were selected as sites for analysis of the placement depth of seeds. The research area was 4 or 5 planting rows, evaluating 10 plantlets per row. The average seed depth was around 46 mm, and significant differences between rows were observed in 21 areas. The average coefficient of variation was around 20%, the statistical limit between medium and high. Analyses of other parameters show that those coefficients may represent different errors in the process. The planting process in Campos Gerais can be considered efficient regarding to the average seed depth. However, the analysis of variability implies de need of actions concerning to anthropic and machinery factors.

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Universidade Estadual de Campinas . Faculdade de Educação Física