825 resultados para Cálculo de resistências


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Esta investigação tem o objetivo de avaliar, quantitativamente, com que frequência os pesquisadores da ciência ortodôntica têm empregado o cálculo amostral e a análise do erro do método em pesquisas publicadas no Brasil e nos Estados Unidos.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Esta dissertação apresenta um método baseado em algoritmos genéticos para cálculo de equivalentes dinâmicos de sistemas de potência visando representar partes de um sistema para estudos de análise de estabilidade transitória. O modelo do equivalente dinâmico é obtido por meio da identificação de parâmetros de geradores síncronos, localizados nas barras de fronteira entre o sistema externo e o subsistema em estudo. Um indicie é usado para avaliar a proximidade entre as simulações realizadas usando o modelo completo e o modelo reduzido, após serem submetidos a grandes distúrbios no subsistema em estudo. Diferentes condições operacionais foram levadas em conta. As simulações foram realizadas usando os softwares GAOT “The Genetic Algorithm Optimization Toolbox”, ANAREDE e ANATEM. Esse método foi testado no sistema teste duas áreas do Kundur e no Sistema Interligado Nacional (SIN). Os resultados validaram a eficácia do método desenvolvido para o cálculo de equivalentes dinâmicos robustos.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Este artigo, inserido nos debates historiográficos sobre a ditadura civil-militar no Brasil (1964-1985), pretende contribuir para o conhecimento da história política do estado do Pará antes, durante e após o golpe de estado de 1964. Examinamos preferencialmente a participação dos militares e o apoio de setores da sociedade civil ao golpe militar, e a repressão que sofreram os estudantes e organizações de esquerda e políticos "populistas". Na perspectiva metodológica dos estudos de história local e regional, as principais fontes utilizadas foram os jornais de Belém, livros de memórias, trabalhos acadêmicos e fontes orais.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Civil - FEIS

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we present an alternative approach due to Bondi for the special theory of relativity. During the development, we analyse the Bondi diagrams, visual resources from which we can take some information about the analysed systems, and we discuss the K factor of Bondi's theory, which is in the core of this work. We then discuss some of the main results obtained from Einstein's special theory of relativity such as the time dilation, spatial contraction and simultaneity of spatially separated events, besides the Lorentz transformations. We also show other two important results in physics coming from K calculus: the relativistic linear momentum and the total relativistic energy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pós-graduação em Biometria - IBB

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The connections in the wood structures are the places with high concentrations of stresses and therefore are more fragile than the rest of the structure. The connections between pieces of wood can be made by metal pins (nails or screws). The compression and embedment strength has significant influence on the calculation of the connections. The main aim of this work was to evaluate the compression and embedment strength in the directions parallel, inclined at 45° and normal to the grain, using standard specimens according to ABNT NBR 7190/1997 standard. The compression and embedment strength were initially evaluated according to ABNT NBR 7190/1997, which admits the deformation of 2‰ as limit of embedment and the ratio between the ultimate strength and the area of application of load in the specimen for the compressive strength. Afterward, the embedment strength was evaluated by the EUROCEDE 5 /1995 European standard, which use the limit of 5 mm of the displacement for the embedment. Specimens of Pinus oocarpa, Cumaru and Pinus taeda were used in tests to calibration of equipment and specimens of Pinus taeda and Eucalipto citriodora were used to compare the results of strength. The results of strength were evaluated based on statistical analysis. The results of compressive strength for the Pinus taeda showed no significant differences in embedment strength in the directions parallel and normal to the grain. For the Eucalipto citriodora only in the direction parallel to grain the compression strength was not significant compared with the embedment strength. For both species, only the parallel compression strength and inclined at 45o to the grain, which were to the grain, which were admitted the strain of 2‰ were not significantly different compared with the compression strength determined according to ABNT NBR 7190/1997. The normal compression strength obtained according to ABNT NBR 7190/1997 and ultimate compression strength not ...

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Given the increasing demand for fossil fuels to power the engines of the global economy, and also the slow process of synthesis of oil, it becomes necessary to develop new sources of renewable energy in addition to improve promising sources that already exist, turning them competitive. Based on this, biomass is shown very promising between the most popular energy sources due to its availability, applicability, and above all, the fact of not emitting green house gases when analyzing the whole carbon cycle. In this sense, this work presents, through an environmental, technical and economic analysis, the impact in an aluminum mill of replacing the use of electricity, in one process, by a boiler fueled with biomass from waste process of packaging the finished product with pallets. Thus, besides the reduction of CO2 emissions, financial gains are targeted, since the main goal of the corporations that require such power is to maximize its profits

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ultrasound is the term that describes the sound waves with higher frequencies than human hearing. Ultrasound used in medical diagnosis is a modality based on the use of sound energy and the acoustic properties of the various parts of the body to produce images of stationary and moving tissues. However, despite the ease of use and security that this modality offers for not using ionizing radiation, one should ensure the accuracy and optimum performance of the equipment, which results in precise diagnoses. To accomplish that, periodic quality control tests must be performed, which include: physical and mechanical inspection of the equipment, image uniformity, depth of penetration/visualization, accuracy of distances, axial and lateral resolution, dead zone and doppler sensitivity. This work intends to study a computerized method for calculating the depth of penetration of ultrasound, comparing it to the observerdependent method currently used. The images were collected during the quality control tests of ultrasound equipment. The results of the comparison between the visual and computerized methods were not conclusive for selecting the safest methodology for obtaining the depth of visualization

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The brachytherapy braquiterapia is an x-ray modality radiotherapy in which stamped or halfstamped radioactive sources in format of seeds are used, wires or to one short distance, in contact or implanted to the fabric to be treated. All the treatment modalities require a previous planning. The formalism recommended for calculation of dose was considered by the AAPM for the first TG-43 Report. In it distributions of dose of isolated seeds measured and calculated by Monte Carlo method in water instead of with models half-empiricists. In this work we in accordance with present some preliminary results of the calculation of functions of radial anisotropy and of dose in the distance for seed of 192Ir, wide used in brachytherapy treatments of high tax of dose (HDR), with the aid of the program based on the Monte Carlo method MCNPX v2.50 (Mount Carlo N ParticleeXtended). The materials chosen in the simulation beyond water, had been MS20 and estriado muscle

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study presents the results from a qualitative resource, based on research-action methodology, which examined the innovate teaching practices implementations in the Calculus I during 2011 year. The analysis of collected data from three used sources – an initial questionnaire, an exploratory-investigative classroom, and an interview with some students at the end of the second semester – reveals that the students had appropriated of the technological recourses, using it as a tool to look for the knowledge. The investigative activities with the use of information technologies made the use of multiple representations in solving mathematical tasks, making the transition of numerical, algebraic and geometrical results possible for the students when they have looking for validation of their hypotheses and conjectures during mathematical problems solving. This works helped in the insertion of new practices in the discipline, and their results validate the proposal presented by the teacher, which is the discipline of Calculus use, whose character is strongly linked to the training content of the student, as a discipline whose can contributed to the pedagogical formation of the graduation student, leading him to know the Mathematical Education possibilities, specially the Mathematical Investigation - Solving Problems, in the outlook of dialogued classes where the teacher assumes the facilitator role and where the students become actives in their pursuit of knowledge

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Not only the progress of the radiotherapy, but also the improve of the dose in the patient with adjusted radiotherapy plannings, calculation of shield, radiometric survey, among others, are responsibilities of the medical physic inside of a sector of radiotherapy. This monograph has as objective to above show some of these cited functions of the medical physicis, starting with a theoretical basement and at as a moment to present the calculations and the results found during a visit in the Institute of Radiotherapy of the Valley of the Paraíba, located in the city of São José dos Campos, and in the Regional Hospital of Taubaté in the period of 2006, 2007 and 2008

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O município de Rio Claro, localizado na região central do estado de São Paulo, durante o auge da era do café, da imigração tanto estrangeira como regional e da instalação de várias empresas, dentre elas a Companhia Paulista de Estradas de Ferro se urbanizou num acelerado ritmo, assim como tantas outras cidades do Brasil. Como resultado o aglomerado urbano cresceu, necessitando que seu perímetro expandisse para a zona rural, comprometendo tanto o seu patrimônio histórico quanto o cultural. Antigas propriedades datadas do final do século XIX que resistem à ação do tempo e mantém viva a riqueza e a cultura da época dão lugar à cidade. Esse processo é observado no bairro rural do Sobrado, localizado na região norte de Rio Claro, que vem sofrendo diretamente com a expansão urbana através da criação de novos loteamentos residenciais e comerciais. Portanto, o avanço da urbanização tem provocado à degradação e/ou desaparecimento dos fatos históricos e culturais ainda presentes nos bairros rurais do município