999 resultados para Transferência de elétrons


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Pós-graduação em Ciência e Tecnologia de Materiais - FC

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Radiotherapy is a field of medical physics, which has been going through a scientific and technological advancement, it is extreme important the professionals that work in this area continuous their study to improve the quality of service provided. For it, they should know the physical principles related as well their employment in radiotherapy. The electrons have been using in therapy of superficial tumors, because they show rapid decrease of dose in depth, they don’t expose the deeper tissues to radiation. The electron therapy has replaced the surface therapy with x-ray and mold brachytherapy, and nowadays, it represents 10 to 15% of radiotherapy treatments. This study brings the definition of physical parameters used in the dosimetry of electron beam, describes the tests for quality control of linear accelerator with a electrons beam, as well the activities realized in the Radiotherapy Division, of Hospital de Clinicas, in the Universidade Estadual of Campinas, in the Clinac 2100C machine

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The huge demand for procedures involving ionizing radiation promotes the need for safe methods of experimentation considering the danger of their biological e ects with consequent risk to humans. Brazilian's legislation prohibits experiments involving this type of radiation in humans through Decree 453 of Ministry of Health with determines that such procedures comply with the principles of justi cation, optimization and dose limitation. In this line, concurrently with the advancement of available computer processing power, computing simulations have become relevant in those situations where experimental procedures are too cost or impractical. The Monte Carlo method, created along the Manhattan Project duringWorldWar II, is a powerful strategy to simulations in computational physics. In medical physics, this technique has been extensively used with applications in diagnostics and cancer treatment. The objective of this work is to simulate the production and detection of X-rays for the energy range of diagnostic radiology, for molybdenum target, using the Geant4 toolkit. X-ray tubes with this kind of target material are used in diagnostic radiology, speci cally in mammography, one of the most used techniques for screening of breast cancer in women. During the simulations, we used di erent models for bremsstrahlung available in physical models for low energy, in situations already covered by the literature in earlier versions of Geant4. Our results show that although the physical situations seems qualitatively adequate, quantitative comparisons to available analytical data shows aws in the code of Geant4 Low Energy source

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This paper studies the frame deformations on a formula SAE vehicle in steady-state cornering and its influence on the lateral load transfers and, consequently, on the tires normal loads due to the applied lateral load. For a vehicle with a perfect rigid frame, the vehicle mass, the position of the center of gravity and the suspensions are the only factors responsible for the load distribution between the tires. When the frame deformations are no longer negligible, the frame deformations affect the loaddistribution between the tires. The frame flexibility turns it able to behave as an additional set of springs to the suspension system, thus changing the behavior of the set. This paper describes howit happens and suggests ways to minimize this phenomenon

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In radiation theraphy with electron beam, the electrons are produced in linear accelerators, and energy the most used have between 4MeV and 20MeV. Generally, the treatments are done for superficial injuries, because the low penetration of these particles. In this work a system for calculation of monitor units (U.M.) for cases of treatments with electron beam was developed. The Excel program of Microsoft was used and is easily found in the operational system of the personal microcomputers. In the Excel has been inserted the pertinent data of the linear accelerator of Varian, model 2100C, used in the Service of radiation theraphy of the Hospital of the Clinics of the College of Medicine of the UNESP of Botucatu. For some values of the physical parameters, such as: factors field and factors calibration, not supplied in the tests of acceptance of the machine, still proceeded calculations from interpolation and extrapolation. The mathematical formulas for automatic search of these and others factors used in the calculations of the determination of the U.M had been developed in agreement available routines in Excel. For this the functions had been used the function IF (that it imposes search condition) and the PROCH (that looks a value in a column from determined line), beyond the basic functions of addition, multiplication and division. It is intended to optimize the routine of the Services of radiation theraphy that perform through eletrontheraphy procedures, speeding the calculations and minimizing the occurrence of errors and uncertainties deriving of the maken a mistake manipulation of the parameters gotten in tables of data of electron beams

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Pós-graduação em Zootecnia - FCAV

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Based on the relationship between the concept of Historical Consciousness, as Jörn Rüsen and Reinhart Koselleck proposed, and the concept of Historical Explanation, proposed by Isabel Barca, the article presents an analytical course that allows you to check levels of explanation in historical narratives produced by students Brazilian and Portuguese from the interpretation of sources related to a historical fact: the transfer of the Portuguese royal family to Brazil (1808).

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Pós-graduação em Engenharia Elétrica - FEIS

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This study is to provide parameters from theoretical and exploratory research in the creation and institutionalization of information science to establish a link with Information Literacy. Approaches are presented in which contributions allow us to understand the relationships and kinds of science in general and their applicability to the population studied, since these theories have a big relationship with the deepening of the area and their social, cultural and economic relationships. We hope to contribute with selective reference to assist the understanding of the issues arising from information science and the knowledge generated by its researchers. This requires developing new skills of access and use of information, providing an interaction between information literacy and knowledge building in Information Science.

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In spite of education it was not main element of Freud's work, in elapsing of work he considered it in chapter denominated “Education Interest of the psychoanalysis” (1913). The objective is to intend to the teacher to consider the importance of psychoanalytic focus in pedagogic extent, demonstrating her contribution for understanding of the students' formative processes. Consequently, to contemplate, starting from the Freudian work, on transfer concept in that relationship introducing intervention forms in the teaching process and learning. We adopted the revision of literature related to the psychoanalytic aspect that it approaches the education, in interface with school physical education. In other words, we specifically looked for aspects on the theme of transfer in the interface of psychoanalysis with pedagogy. Also, part of the Freudian work was used regarding the theme approached in analytical indexes. Since then, we detected that the observed authors affirm that between teachers and students relationship transferencial exists. Therefore, the selection of contents sends the educators to organize and systematize as it will be worked in curriculum and transmitted to the students, since it should go to the encounter of students’ expectations, doing with that school physical education has sense and meaning. Therefore, it is important the physical education teacher, in school, to analyze that when working with the human being there are just no effects of work on content or about the use of correct teaching methodology, but, also the actions transferenciais that are present in learning process.

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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)