998 resultados para Gerador de indução duplamente excitado
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The use of inputs containing phosphites have been presenting results in many studies, taking on importance to the control of diseases in some cultures and demonstrating the resistance induction in seedlings, with ability to activate defense mechanisms, conferring protection to plants against microorganisms. The soybean crop is recognized for its importance in providing grains and derivatives for human consumption, animal, production of biofuels, pharmaceuticals, among others. Positive results obtained through studies based on resistance inducers in some cultures arouse the interest for further study. The objective of this study was to evaluate the effect of potassium phosphites on the resistance induction and treatment of soybean seeds. Therefore were conducted four laboratory studies at the Federal Technological University of Paraná, Campus of Dois Vizinhos. In the first study it was evaluated the quality attributes of the seeds and the resistance induction as seed treatment. Then it was verified that phosphites have action upon the seedlings metabolism in due to seed treatment, having the phosphite Reforce® contributed to seed quality attributes and phosphites FitofosK® and Fitofos K Plus® induced the resistance increasing the activity of β-1,3-glucanase. In the second study it was evaluated the the resistance induction in soybean cotyledons, in which the phosphites demonstrated induction potential of phytoalexin gliceolin. In the third study It was evaluated the soybean seed health treated with potassium phosphites.. it was observed that the phosphites reduced the incidence of many fungi on seeds, especially of storage fungi like Aspergillus sp. and Fusarium semitectum. In the fourth study it was evaluated the in vitro effect of potassium phosphites on pathogenic fungi of the culture. And it was found direct action of phosphites on the mycelial growth of Fusarium semitectum, Pythium sp. and Sclerotinia sclerotiorum. Based on these results, we concluded that potassium phosphites have potential in seeds treatment, as resistance inducer and on in vitro control of phytopathogens.
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Os avanços e a disseminação do uso das Tecnologias de Informação e Comunicação (TIC) descortinam novas perspetivas para a educação com suporte em ambientes digitais de aprendizagem usados via internet (Fiolhais & Trindade, 2003). A plataforma usada no Projeto Matemática Ensino (PmatE) da Universidade de Aveiro (UA) é uma das ferramentas informáticas que suporta esses ambientes através da avaliação baseada no Modelo Gerador de Questões (MGQ), possibilitando a obtenção da imagem do progresso feito pelos alunos (Vieira, Carvalho & Oliveira, 2004). Reconhecendo a importância didática desta ferramenta, já demonstrada noutras investigações (por exemplo, Carvalho, 2011; Pais de Aquino, 2013; Peixoto, 2009), o presente estudo tem como objetivo geral desenvolver material didático digital de Física, no contexto do programa moçambicano de Física da 12ª classe, para alunos e professores sobre radiações e conteúdos da Física Moderna. Pretendeu-se, ainda, propor estratégias de trabalho com recurso às TIC para a melhoria da qualidade das aprendizagens nesta disciplina. O estudo assentou nas três seguintes questões de investigação: (a) Como conceber instrumentos de avaliação das aprendizagens baseadas no modelo gerador de questões para o estudo das radiações e conteúdos da Física Moderna, no contexto do programa moçambicano de Física da 12ª classe? (b) Que potencialidades e constrangimentos apresentam esses instrumentos quando implementados com alunos e professores? (c) De que forma o conhecimento construído pode ser mobilizado para outros temas da Física e para o ensino das ciências em geral? O estudo seguiu uma metodologia de Estudos de Desenvolvimento, de natureza mista, que compreendeu as fases da Análise, Design, Desenvolvimento e Avaliação, seguindo como paradigma um estudo de cariz exploratório, com uma vertente de estudo de caso. Assim, na Análise, foi discutido o contexto da educação em Moçambique e a problemática da abordagem das radiações e conteúdos de Física Moderna no ensino secundário no quadro desafiante que se coloca atualmente à educação científica. No Design foram avaliadas as abordagens dasTIC no ensino e aprendizagem da Física e das ciências em geral e construída a árvore de objetivos nos conteúdos referidos na fase anterior. Na fase do Desenvolvimento foram construídos os instrumentos de recolha de dados, elaborados os protótipos de MGQ e sua posterior programação, validação e testagem em formato impresso no estudo exploratório. Na Avaliação, foi conduzido o estudo principal com a aplicação dos modelos no formato digital e feita sua avaliação, o que incluiu a administração de inquéritos por questionário a alunos e professores. Os resultados indicam que na conceção de MGQ, a definição dos objetivos de aprendizagem em termos comportamentais é fundamental na formulação de questões e na análise dos resultados da avaliação com o objetivo de reajustar as estratégias didáticas. Apontam também que a plataforma do PmatE que suporta os MGQ, embora possua constrangimentos devido a sua dependência da internet e limitações de ordem didática, contribui positivamente na aprendizagem e na identificação das dificuldades e principais erros dos alunos, por um lado. Por outro, estimula através da avaliação os processos de assimilação e acomodação do conhecimento. O estudo recomenda a necessidade de mudanças nas práticas de ensino e de aprendizagem para que seja possível a utilização de conteúdos digitais como complemento à abordagem didática de conteúdos.
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Power generation from alternative sources is at present the subject of numerous research and development in science and industry. Wind energy stands out in this scenario as one of the most prominent alternative in the generation of electricity, by its numerous advantages. In research works, computer reproduction and experimental behavior of a wind turbine are very suitable tools for the development and study of new technologies and the use of wind potential of a given region. These tools generally are desired to include simulation of mechanical and electrical parameters that directly affect the energy conversion. This work presents the energy conversion process in wind systems for power generation, in order to develop a tool for wind turbine emulation testing experimental, using LabVIEW® software. The purpose of this tool is to emulate the torque developed in an axis wind turbine. The physical setup consists of a three phase induction motor and a permanent magnet synchronous generator, which are evaluated under different wind speed conditions. This tool has the objective to be flexible to other laboratory arrangements, and can be used in other wind power generation structures in real time. A modeling of the wind power system is presented, from the turbine to the electrical generator. A simulation tool is developed using Matlab/Simulink® with the purpose to pre-validate the experiment setup. Finally, the design is implemented in a laboratory setup.
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This study presents a proposal of speed servomechanisms without the use of mechanical sensors (sensorless) using induction motors. A comparison is performed and propose techniques for pet rotor speed, analyzing performance in different conditions of speed and load. For the determination of control technique, initially, is performed an analysis of the technical literature of the main control and speed estimation used, with their characteristics and limitations. The proposed technique for servo sensorless speed induction motor uses indirect field-oriented control (IFOC), composed of four controllers of the proportional-integral type (PI): rotor flux controller, speed controller and current controllers in the direct and quadrature shaft. As the main focus of the work is in the speed control loop was implemented in Matlab the recursive least squares algorithm (RLS) for identification of mechanical parameters, such as moment of inertia and friction coefficient. Thus, the speed of outer loop controller gains can be self adjusted to compensate for any changes in the mechanical parameters. For speed estimation techniques are analyzed: MRAS by rotóricos fluxes MRAS by counter EMF, MRAS by instantaneous reactive power, slip, locked loop phase (PLL) and sliding mode. A proposition of estimation in sliding mode based on speed, which is performed a change in rotor flux observer structure is displayed. To evaluate the techniques are performed theoretical analyzes in Matlab simulation environment and experimental platform in electrical machinery drives. The DSP TMS320F28069 was used for experimental implementation of speed estimation techniques and check the performance of the same in a wide speed range, including load insertion. From this analysis is carried out to implement closed-loop control of sensorless speed IFOC structure. The results demonstrated the real possibility of replacing mechanical sensors for estimation techniques proposed and analyzed. Among these, the estimator based on PLL demonstrated the best performance in various conditions, while the technique based on sliding mode has good capacity estimation in steady state and robustness to parametric variations.
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Cancer is a term used to represent a set of more than 100 diseases, including malignant tumors from different locations. The malignancies are the second leading cause of death in the population, representing approximately 17% of deaths of known cause. Strategies that induce differentiation have had limited success in the treatment of established cancers. In this work, a lectin purified from the marine sponge Cinachyrella apion (CaL) was evaluated due to its hemolytic, cytotoxic and antiproliferative properties, besides the ability to induce cell death via apoptosis in tumor cells. The antiproliferative activity of CaL was tested against cell lines, with the highest inhibition of tumor growth for HeLa, reducing cell growth at a dose dependent manner, with a concentration of 10 μg/mL. The hemolytic activity and toxicity against peripheral blood cells were tested using the concentration of IC50 for both trials and twice the IC50 for analysis in flow cytometry, indicating that CaL is not toxic to these cells. To assess the mechanism of cell death caused by CaL in HeLa cells, we performed flow cytometry and western blotting. The results showed the lectin probably induces cell death by apoptosis activation by pro-apoptotic protein Bax, promoting mitochondrial membrane permeabilization, cell cycle arrest in S phase, with accumulation of cells of approximately 57% in this phase, and acting as both dependent and/or independent of caspases pathway. These results suggest that CaL has the potential to be used as drug treatment against cancer.
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Dissertação para obtenção do grau de Mestre em Arquitectura, apresentada na Universidade de Lisboa - Faculdade de Arquitectura.
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The main objective of this study is to apply recently developed methods of physical-statistic to time series analysis, particularly in electrical induction s profiles of oil wells data, to study the petrophysical similarity of those wells in a spatial distribution. For this, we used the DFA method in order to know if we can or not use this technique to characterize spatially the fields. After obtain the DFA values for all wells, we applied clustering analysis. To do these tests we used the non-hierarchical method called K-means. Usually based on the Euclidean distance, the K-means consists in dividing the elements of a data matrix N in k groups, so that the similarities among elements belonging to different groups are the smallest possible. In order to test if a dataset generated by the K-means method or randomly generated datasets form spatial patterns, we created the parameter Ω (index of neighborhood). High values of Ω reveals more aggregated data and low values of Ω show scattered data or data without spatial correlation. Thus we concluded that data from the DFA of 54 wells are grouped and can be used to characterize spatial fields. Applying contour level technique we confirm the results obtained by the K-means, confirming that DFA is effective to perform spatial analysis
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O presente estudo avaliou a atividade anestésica do óleo essencial de Lippia alba em tambaqui (Colossoma macropomum) e as respostas fisiológicas de estresse decorrentes da anestesia e do manuseio para biometria.
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A responsabilidade social é considerada fundamental para a conquista de vantagens competitivas organizacionais. A integração dos seus princípios na estratégia da organização, apresenta-se como uma linha orientadora do foco na satisfação de necessidades das partes interessadas internas e externas. As actuais limitações orçamentais têm afectado significativamente as Instituições de Ensino Superior, nomeadamente as localizadas no interior de Portugal continental, o que dificulta ainda mais a crescente diminuição de estudantes sendo necessário a implementação de estratégias de captação de estudantes nos vários ciclos, fases de idade e locais de proveniência. O sistema de gestão da responsabilidade social, referenciado na NP 4469.1:2008, apresenta um grande desafio ao modelo de gestão das organizações que o implementam, já que este sistema de gestão tem o potencial de optimizar os interesses das diversas partes interessadas. O foco da instituição passa a ser os das suas partes interessadas, maximizando os seus impactes positivos e minimizando os seus impactes negativos em resultado das suas actividades e decisões. O aumento da eficácia organizacional e a equidade dos interesses das partes interessadas, podem clarificar as funções estratégicas das Instituições de Ensino Superior. Os programas e práticas de responsabilidade social implementados nas Instituições de Ensino Superior do interior de Portugal continental são assim estrategicamente vistos, como um factor de diferenciação positiva face às suas congéneres e em consequência, assumido como um factor para a sua sustentabilidade. A presente investigação procura identificar um modelo de governação socialmente responsável que se comprometa com a dinamização de uma estratégia que preveja práticas de responsabilidade social condutoras a aumentos na confiança e reputação organizacionais nos estudantes e colaboradores das Instituições de Ensino Superior. Tendo por base a abordagem de investigação qualitativa, realizaram-se estudos de caso em duas Instituições de Ensino Superior localizadas no Alentejo, recorrendo-se a várias fontes de informação: entrevistas a 45 entrevistados, entre elementos da governação, colaboradores e estudantes, análise documental e observação participante. Como técnica de tratamento dos dados utilizou-se a análise de conteúdo através do software Atlas Ti. Os resultados da investigação empírica permitem identificar que, as duas Instituições de Ensino Superior melhoraram em termos de visibilidade externa e interna, havendo entrevistados que referem uma melhoria na confiança e reputação em resultado da adesão a práticas de responsabilidade social. O líder de uma das Instituições de Ensino Superior é reconhecido pelos seus pares como de elevado compromisso para com os princípios da responsabilidade social enquanto que o outro líder não é reconhecido da mesma forma. Os estudantes entrevistados, não reconhecem vantagens em resultado das práticas de responsabilidade social tanto ao nível da confiança como reputação organizacional; ABSTRACT: Social responsibility is considered essential to the achievement of organizational competitive advantage. The integration of its principles in the organization's strategy, presents itself as a guiding line focus on meeting the needs of internal and external stakeholders. The current budgetary constraints have significantly affected the higher education institutions, further hindering the increasing decline of students being required to implement student recruitment strategies in the various cycles of age stages and places of origin. The management system of social responsibility, referenced in NP 4469.1:2008, presents a major challenge to the model of management of organizations implementing it, since this management system, has the potential to optimize the interests of the various stakeholders. The focus of the institution happens to be out of their stakeholders, maximizing its positive impacts and minimizing the negative impacts as a result of its activities and decisions. Increased organizational effectiveness and equity interests of stakeholders can clarify the strategic functions of the higher education institutions. Social responsibility programs and Social responsibility practices implemented in higher education institutions in the interior of mainland Portugal are so strategically seen as a positive differentiating factor compared to their counterparts and therefore assumed to be a factor in their sustainability. This research seeks to identify socially responsible governance model that is committed to the promotion of a strategy which envisages conducting social responsibility practices to increases in organizational trust and reputation among students and employees of higher education institutions. Based on the qualitative research approach, there were case studies in two higher education institutions located in the Alentejo, making use of several sources of information: interviews with 45 respondents, between elements of governance, employees and students, document analysis and participant observation. As data processing technique was used content analysis by instrumental Atlas Ti. The results of empirical research identifying that the two higher education institutions have improved in terms of internal and external visibility, with respondents who report an improvement in confidence and reputation as a result of adherence to Social responsibility practices. The leader of one of the higher education institutions are recognized by their peers as high commitment to the principles of social responsibility while the other leader is not recognized in the same way. Students do not recognize advantages as a result of social responsibility practices both in terms of trust and organizational reputation.
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2016
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2016
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2016
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2016
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2016