1000 resultados para Modelo da potência crítica


Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this work we report the development of a tube amplifier built to be used in magnetic probe diagnostic of plasma. The probe is used to measure the magnetic field in the theta-pinch system presently running in our university. We present the calculations and procedures to determine the configuration of circuits and specify the components of the power supply, the preamp stage and the power stage. The circuit configuration and the characteristics of the components was obtained. A representative model of the system behavior gave the transfer function of the amplifier. Theoretical predictions of frequency response and the feedback effects were compared to the experimental values and showed very good agreement. The amplifier works between a frequency bandwidth of 20 an 30 kHz and supply a maximum power of 12 W

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Tricyclic antidepressants, such as amitriptyline, are inhibitors of serotonin and norepinephrine neuronal reuptake and this action has been implied in changes in pain threshold supporting its use to alleviate neuropathic pain. Although is known that 1 adrenoceptors participate in the antinociceptive effect of amitriptyline it is unclear which receptor subtype is the target for the increased synaptic levels of norepinephrine resultant from the inhibition of neuronal uptake. Paradoxically, several tricyclic antidepressants including amitriptyline also behave as antagonists of 1 adrenoceptors with different affinities for its subtypes: these drugs have 10 to 100-fold higher affinities for 1A than for 1B and 1D adrenoceptors. This work investigated the involvement of 1 adrenoceptors subtypes in the antinociceptive effect of the amitriptyline in a constriction of the sciatic nerve in rats by determining the effects of subtype selective 1 adrenoceptors antagonists. Fifteen days later, mechanical hyperalgesia was analyzed in a Randall-Selitto test. The 1A-selective antagonist RS100329 was the most potent antagonist of the contractions of the rat prostate, whereas the 1D-selective antagonist BMY 7378 (up to 100g/Kg) was unable to affect these contractions. The antagonist prazosin, BMY 7378 and 5-methyl urapidil inhibited the antinociceptive effect of the amitriptyline. However, the highly selective 1A adrenoceptor antagonist RS100329 was unable to affect the antinociception induced by amitriptyline. These results point out that 1B and/or 1D adrenoceptors, but not 1A, are involved in the antinociceptive effects of amitriptyline

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The expansion of the electrical system is currently a subject of great importance to the development of Brazil. For its realization, large projects are needed, requiring large-scale investment and realization processes of great complexity. Thus, this type of project has a high strategic importance for the performance of companies that conduct. Seeking a way to determine a method to align traditional practices for measuring quality to the corporate strategic needs, this work is the study of the use of the balanced scorecard methodology, applying quality management and operational excellence, with a focus on projects in power systems. We analyzed some cases of successful application of the methodology in business segments in the next study, culminating in a proposed model of the method

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A extensa fragmentação das florestas tropicais e conseguinte perda da fauna de dispersores e predadores de sementes trazem importantes consequências às interações planta-animal. A predação de sementes, que representa uma etapa crítica no recrutamento de plantas tropicais, é um dos processos que sofrem com este impacto. A falta dos agentes dispersores e predadores de sementes pode alterar a dinâmica natural dessa interação trófica ao ponto de não corresponder mais ao modelo de Janzen-Connell, que prediz que quanto mais próximo da planta parental, maior a probabilidade de predação e, por conseqüência, menor será a dispersão. Esse estudo avaliou em três fragmentos com níveis diferenciado de defaunação (Mata São José, Reserva Municipal Santa Genebra e Estação Ecológica dos Caetetus) a predação (e/ou dispersão) de sementes de palmito juçara (Euterpe edulis Martius) abaixo e longe da planta-mãe, buscando testar o modelo Janzen-Connell. Em cada área cinco sementes foram dispostas em tratamento aberto e cinco em tratamento fechado, abaixo e distante 10 metros do parental em 15 palmeiras e avaliado o destino das sementes após 30 dias. Os resultados não oferecem suporte ao modelo, uma vez que apenas em um dos fragmentos pequenos e defaunados a predação abaixo do parental foi maior que distante, ou seja, nos demais fragmentos a distância da planta mãe não aumentou a sobrevivência das sementes. Nas áreas defaunadas a predação ocorreu principalmente por invertebrados e patógenos, enquanto que na área menos defaunada a predação foi feita principalmente por vertebrados. Diferenças significativas na predação de sementes entre os tratamentos só foram obtidas na área menos defaunada, o que mostra a importância dos predadores vertebrados de médio e grande porte na predação e/ou dispersão de sementes de E. edulis neste fragmento.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Elétrica - FEIS

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Elétrica - FEIS

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The British sports suffered an unprecedented crisis in the early 80s instabilities political, economic crisis and lack of planning put the English sport in a very critical situation. However, a number of sports public policies were proposed from the 80's, effectively, completely changed the situation of English sport, which has prompted the development of this research. Thus, the present study, qualitative, aims to analyze the organization and evolution of the sport in the UK, based on the British government projects of the last 30 years included in the Sport Development database. Therefore, the study was developed by the union of bibliographic research, exploratory and documentary. First, after literature, documents were selected, using the academic database Sport Development, in the library of policy documents, separate area of the database containing only the English sport policy documents. For delimitation of the study were analyzed documents from 1980 to 2013, of which eight were selected on which to base discussions in this study. The documents were analyzed using thematic content analysis technique, based on two thematic axes: Axis 1 - funding and Axis 2 - priority groups. The results indicate that the analyzed initiatives show a process of evolution and maturation of public policies of Sport England, both on the issue of financing, such as with regard to priority groups, which have changed and adjustments over the years. It was also noted that much can be learned from these initiatives, even in helping to solve problems of the Brazilian reality. Suggest new studies involving sports management from different countries, in order to leverage other perspectives to support the development of public policies for sport and recreation in the country, seeking successful examples

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This article discusses the policy implications of agricultural modernization implemented by the military - after 1964. This policy, which became known as the Green Revolution, on the one hand contributed to the development of big business, but another caused serious social and environmental impacts. Currently, not only in Brazil but all over the world, have been in a great debate about the need to find alternatives to contain the problems caused to the environment resulting from the use of high technology in the field. One alternative proposed by several researchers is to replace fossil fuels by biofuels. As we believe that the error is in the current model of agricultural production based on mass production, which serves the major markets, the attention in this article, the need to develop an agricultural model designed for small property, with the use of family work and agroecology.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The paper studies Otto Maria Carpeaux`s work in the context of Brazilian literary critic in the decades of 1940-1950. Starting from Pierre Bourdieu`s theoretical formulations about field concept, are set reflections concerning the place occupied by Carpeaux in the light of paradigm shifts occurred in the criticism field and new processes of legitimation resulting from this situation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The work and the trajectory of literary critic and journalist Austrian-Brazilian Otto Maria Carpeaux (1900-1978) are studied from the relationship between literary criticism and the diffusion field in Brazil. Between the decades of 1940-1970, Carpeaux has played a prominent role in the formation process of the reader and reading in Brazil, as evidenced by his intense activity as a critic and essayist. Will also be developed reflections on the place occupied by Carpeaux in the field of criticism in Brazil. Two hypotheses are developed: a) Carpeaux`s work was affected by a lack of legitimacy of his contemporaries in the decades of 1940-1950, as can be seen, for example, in peripheral treating conferred on him by the field of diffusion and consecration instances we can read, the editorial market. b) Carpeaux such as an Alvaro Lins`s heir in the Correio da Manha, also inherited a criticism model that lost prestige in the light of the New Criticism growing influence occurred in the country, which shifts the critical role from the newspaper to the university.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)