769 resultados para Diagramas de Voronoi esféricos


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This paper presents a study about the operation of the major system’s components of a linear particle acclerator (Linac). It addresses the components mainly responsible for the formation of the beam, through the inclusion of several block diagrams showing the details of the structure. Among the systems discussed may be mentioned the system modulator, automatic frequency control, dosimetry and auxiliary systems. The main objective is the dissemination of basic technology applied in linear accelerators and create literature about this subject in national language. Despite the high complexity and large number of devices that comprise a linear accelerator, it has been developed an easy to understand text that adresses the most relevant issues to the operation of the linear accelerator from the point of view of electrical engineering

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A destruição da camada de ozônio resulta em um preocupante aumento na incidência de radiação ultravioleta (UV) na superfície da Terra, radiação esta, responsável pela ocorrência de danos na pele e pelo aparecimento do câncer de pele, tipo mais comum de câncer. Assim, neste trabalho foram desenvolvidos sistemas líquido-cristalinos multifuncionais contendo nanopartículas de dióxido de titânio, cuja propriedade fotoprotetora é bem conhecida, e alfa-tocoferol, um composto com ação antioxidante. Com isso, pretendeu-se desenvolver uma formulação que atue como protetor solar inorgânico, bloqueando a radiação UV e impedindo sua penetração que pode causar sérios danos à pele, além de conter o alfa-tocoferol que interage com os radicais livres, diminuindo os danos causados por estes. Para tanto, inicialmente foram preparadas formulações baseadas em dois diagramas de fases, as amostras que apresentaram separação de fase foram excluídas do trabalho, e as outras foram submetidas à análise de microscopia de luz polarizadas. Através da microscopia de luz polarizada foi possível concluir que a estrutura líquido-cristalina é mantida com a incorporação dos ativos no sistema, o que posteriormente foi confirmado com a análise por SAXS. A análise do potencial zeta permitiu verificar que na faixa de pH entre 5 e 7, indicada para produtos de uso tópico, é possível evitar aglomeração das partículas, e com isso obter um visual transparente do produto. A avaliação do comportamento possibilitou concluir que todas as amostras apresentaram uma consistência ideal para aplicação do produto na pele

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Studies of mafic-ultramafic bodies have been carried out through the years due to their great use on the interpretation of geochemical and geotectonic processes that took place in Earth's history. Amongst them, chromitites are notably recognized for being excellent indicators of their parental magma chemistry and of different geotectonic environments, as well for frequently containing associated noble metals mineralization. Thus the investigation of one of this ultramafic bodies that occurs inside the Pilar de Goiás Greenstone Belt was proposed, resulting in a detailed map of the chromitites and country rocks, as well as innumerous new data on the chemistry of chromite and associated matrix and accessory minerals. These studies were based upon geological field observations, optic and Scanning Electron Microscope (SEM), besides electron microprobe and cathodoluminescence analysis performed at the “Eugen F. Stumpfl Laboratory” of the Montanuniversität Institute of Resource Mineralogy, University of Leoben - Leoben, Austria. The chromitites are composed of 40-70% in volume of chromite (~50% on average), 14-55% of talc (~30% on average), 3-60% of chromium rich chlorite (~20% on average), traces to 4% of iron hydroxides and traces to 3% of rutile (1,5% on average). The chromite occurs as large spherical aggregates or as fine grained subhedral crystals disseminated in the matrix. This aggregates have diameters of 0.3-1.5 cm (1 cm on average) and are extremely well rounded, massive to intensively fractured, and commonly deformed to ellipsoids. When observed under the microscope, these aggregates show well rounded to slightly irregular borders, but on their interiors, these structures are represented by fine to medium grained euhedral to subhedral chromite crystals that have sharp contacts between themselves. The rock's matrix is basically made of chlorite and talc that define a metamorphic foliation (Sn), being the talc an alteration product ...

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In this study we analyzed the influence of demographic parameters on the population dynamics of Tribolium castaneum, combining empiricism and population theory to analyze the different effects of environmental heterogeneity, by employing Ricker models, designed to study a two-patch system taking into account deterministic and stochastic analysis. Results were expressed by bifurcation diagrams and stochastic simulations. Dynamic equilibrium was widely investigated with results suggesting specific parametric spaces in response to environmental heterogeneity and migration. Population equilibrium patterns, synchrony and persistence in T. castaneum were discussed

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Structure is the resistant part of a construction that is able to support forces and transmit them to its supports or links. Knowing its importance, it is necessary to do a structural analysis. This study focuses on showing, in a different way, a method of understanding the bending moment and the shear beam diagrams. A real model was developed in laboratory to check what happens when certain loads are placed along. Throughout this study it was possible to verify that the practical application of the theory will provide the classroom a better understanding

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The Mesozoic acid volcanism of the Paraná-Etendeka Province can be considered as one of the biggest events of its kind in the Earth's surface, and its study have attracted special interest in characterizing the end of magmatism that preceded the rupture process and the formation of continental Africa and South America Although significant, the acid volcanism featuring Members Chapecó Palmas and Serra Geral Formation represents only 2.5% of the total generated by the magmatic rocks and perhaps therefore the existing literature on these rocks is well less significant than that on the basalts. However, there are still aspects still unclear about the origin and evolution of these rocks in relation to the associated basalts. Thus, two profiles were selected, called RA and TA, which be a systematic collection of samples from the base where the Botucatu Formation sandstones occur at the top, where they observe Palmas acid rock type. These samples should be analyzed for major, minor and trace elements and treated in specific diagrams to define the vertical variation lithochemistry and their possible relationships with the associated basalts

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The market has forced companies to maintain high levels of control over their processes , ensuring a product or service quality to its customers . This study comes in the issuance and registration carried out in a company of e-commerce , which is showing problems with the values of weights and dimensions used in the cases cited . The need to eliminate wasteful spending freight caused by shipment of products weighing more than the reality, and to increase the reliability of the information used in the management of processes led to the planning of this project . This work focuses on the development of a PDCA cycle to work in the identification and correction of the causes of the problem , in order to neutralize the current complications and ensure that the problem does not appear again. To aid the mapping of the processes involved , identifying the causes of the problem and implementation of the proposed improvements were used quality tools such as flowcharts , Ishikawa diagrams , Pareto diagrams , and applied statistics

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A survey we conducted, and bring expressed in this text is a preliminary study on the shape of asteroids and allowed us to understand a little more the dynamics around these bodies, in order that the images we have of asteroids are the most irregular possible. In this work, the asteroid is modeled by the method of the polyhedron, which provides a very good accuracy of the irregular shape of the body. Through study of models for non-spherical gravitational potential bodies, implementation of computational algorithms and numerical simulations a preliminary analysis was performed in relation to the shape of asteroids 4179 Toutatis, 6489 Golevka, 2063 Bacchus, 1620 Geographos and 1998 ML14, as well as regions of stability instability, we compute the coefficients of the gravitational potential. The work not only enables expansion for the case of asteroids, but also for other non-spherical bodies, contributing to the development of targeted studies the origin and evolution of the solar system, and perhaps the origin of the earth, and new technologies for modeling and mapping of non-spherical bodies. The main results were obtained by analyzing the graphics format and planning of asteroids, which confirmed how these bodies are irregular and show how distribution of non-homogeneous mass. Observe the behavior of the curves of zero velocity and equipotential curves as well as their respective surfaces. Also, compute some values of the gravitational potential and the spherical harmonic coefficients of each object. Furthermore, we find possible equilibrium points of asteroids except 4179 Toutatis, and analyze its stability

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Pós-graduação em Geografia - IGCE

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)