983 resultados para Engenharia física


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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O sistema WDM (Wavelength Division Multiplexing) é considerado como uma tecnologia madura para ser usada no backbone de redes ópticas. Entretanto, encontrar uma solução ótima para o algoritmo de atribuição de comprimento de onda no projeto e operação destas redes, ainda é uma questão em aberto. A pesquisa realizada nesta tese aborda os principais aspectos relacionados ao processo de atribuição de comprimento de onda em sistemas WDM, e como resultado foi proposta uma metodologia que minimiza a degradação do sinal óptico gerada pela modulação de fase cruzada (XPM – Cross-Phase Modulation). Esta proposta é composta por uma metodologia híbrida baseada em Coloração de Grafo e Algoritmo Genético (AG), sendo que o primeiro tem a função de reduzir o número de comprimentos de onda necessários para atender a matriz de tráfego (que é fornecida a priori) e o último tem a função de encontrar a ordem de ativação de canais na grade de comprimentos de onda, com o objetivo de reduzir o efeito XPM. A proposta foi comparada com o algoritmo First-Fit em diferentes cenários e topologias de redes, e demonstrou uma considerável redução na probabilidade de bloqueio.

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Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Engenharia Mecânica - FEG

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The adhesives used in the production of engineered boards have been object of study over the years in order to improve the properties of the boards with less energy consumption, lower production costs and reduced environmental impact. In addition to that, process variables may affect the properties of the board. The present study aimed to characterize sheets of plywood, manufactured with two types of adhesives, under two different pressing conditions. The adhesives used for the study were Phenol-formaldehyde and Polyurethane castor oil based. The pressure of pressing was varied in a range from 75 to 160 Bar, in order to verify how they influence the physical and mechanical properties of the board. The tests performed resulted in a conclusion that shows that the moister content of the veneers interferes on the physical and mechanical tests. In general, boards produced with polyurethane resin showed superior physical and mechanical results; although the ones produced with phenol formaldehyde at a pressure of 75 Bar had always equal or higher values, compared to what is found in literature

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This is a study on importance the discourse of the teacher associated with social interactions triggered in classroom from of an experimental activity. We will analyzed a trial class in which a physics teacher of a public school Guaratinguetá city interacted with their student, seeking to categorize certain movements of the teacher's speech and identify the moments when this could establish the definition of the situation, mediation semiotic and intersubjectivity

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This study presents the results of a study on the development of the concept of force and their possible applications in physics teaching. The historical study has focused on Aristotelian natural philosophy, medieval theories of strength in impressed and on classical Newtonian mechanics. The Newtonian concept of force was also an object lesson of physics analyzed in this study. In this lesson, conducted in a preuniversity course, spontaneous conceptions or alternative conceptions of students about the concept of force proved very entrenched, resulting in studies on the Model Change on Conceptual and epistemological obstacles in view Bachelardian. The theoretical frameworks adopted led us to trace parallels between spontaneous conceptions revealed by the students and some views about the concept of force found in the study of history. The results show that while some old conceptions have been replaced by scientifically Newtonian concept of force, they are still present in the students' ideas and resist to changes even after the study of Newton's laws. Like main result shows that the history of science can be a great ally for the deconstruction of alternative conceptions, particularly when these concepts were previously presented and overcome the course of history of the development of a concept

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This work was developed from a literature search in order to provide teachers of physics theoretical and methodological requirements for the use of experimentation in physics teaching, with the aim of contributing to the teaching practice of these teachers and, consequently, for improving teaching this discipline. Therefore, to deal in the course of this research, the goals and types of practical activities, new information and communication technologies that fit the experimental approaches and the role of the teacher in this context, specifying the variables that influence and relate with experimental activities. Studies are presented on the methodology and planning of experimental activities to draw attention to the teacher and the important issues relevant to the preparation of these activities as, for example, the proposed objectives and types of discourse and existing approaches for the conduct of practical activities. In this sense, the trend is highlighted for walks where the approach of practical activities, within the context of practices interactionist and are pointed out strengths and weaknesses of different types of activities presented. We also highlight aspects of the learning process associated with some theoretical reference that are on that subject, as Piaget, Vigotski and Ausubel, so that the teacher can apply the concepts in their theories worked in the practical lessons of physics

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The objective the work at hand has is to discuss the dropouts of students from the major Physics in the campus of Guaratinguetá – UNESP. A survey has been made about the number of graduated and evaded students of each class since 1989, year that this course was created, until the year 2011. For this purpose, lists were collected from the section of graduation of the university, in which you will find names, year of entry, way of entry and situation of each students already enrolled in the course. Data about the dropouts of other courses of Physics at UNESP were also collected, in order to compare with the results from the unity of Guaratinguetá. Besides that, the results from researches about the lack of physics professors in the country were also taken into consideration. Some of this research sought to identify the main reasons of dropouts from the students of Physics. The data collected indicates that the dropout of this course in the campus of Guaratinguetá is higher when compared to the dropouts of others in this institution. It’s also true that the dropout rates haven’t changed significantly over the years, the average being 66.2% in the period between 1989 and 2007. However, the reason for the dropouts has changed of the years, dropouts to change for other majors increased, especially after 2005, being responsible for almost half of the dropouts in the last three years. The survey with the enrolled students of 2012 showed that this is a group of young students that don’t work and many of them have enrolled with the intension to transfer to other courses. These data contradicts the results of some researches that point out difficulties for students to reconciling work with study as one of the main causes of the dropouts. This suggests the picture in this work about the dropouts... (Complete abstract click electronic access below)

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Physics governs all working patterns of the universe and could not be otherwise in a biological environment. Living things depend directly on laws and physical models to compose their body structure, allow its survival in certain environments, communication between individuals and groups and also to establish a complex sensorial system that allows interaction with the environment that surrounds them. With the advancement of science and technology, new ideas are required, and thus, many researchers began to turn their attention to those systems found in nature, as these systems often present practical solutions and with maximum efficiency. This imitation of biological systems, applied in creating innovative technological resources, is called Biomimetics. To study the biological systems based on physical concepts is essential the creation of models. These allow the distinction of the effects of the issue really essential and may be ignored side effects that do not have an effective participation in the phenomenon being analyzed. In this Work Completion of course will be studied the phenomenon of countercurrent heat exchangers, present in various situations of nature, focusing on their participation in the legs of birds, also the balance of certain birds that are supported on one leg and possible inspiration of these phenomena in the fields of engineering. Also included are videos that allow better understanding of the studied subjects

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This work consisted in analysing five materials which mean respect to subjects related to Particle Physics, aiming to explore their potentialities for the use in the High School levels, particularly by physics teachers. On this perspective, we sought to describe the contents of each material and point out their potentialities as material of didactic support. They are: 1. The purpose of Secretaria da Educação do Estado de São Paulo, presented in the Teacher's Guide of the Program São Paulo faz escola; 2. The Game Sprace Game, elaborated by the European Organization for Nuclear Research (CERN); 3. The book O discreto charme das partículas elementares, written by the professor Maria Cristina Abdalla; 4. The video O discreto charme das partículas elementares, based on the book of Professor Maria Cristina Abdalla which was produced by TV Cultura in association with the Ministério da Educação e Cultura” (MEC). The book Partículas elementares no ensino médio: uma abordagem a partir do LHC written by Wagner Franklin Balthazar and Alexandre Lopes de Oliveira, from the collection CBPF - Tópicos de Física. The work was constructed on a qualitative perspective, that is, it did not attempt to quantify the help that each material could offer to Physics teaching. One sought to describe and analyse, from different theoretical frames, their potentialities for the use in the High School level. The results indicate that all the materials analysed can contribute to the Physics teaching, and beyond, as they own format and approches distinct from the subject, they can be used as a whole or in parts, together or separately, depending on the objectives to be reached and on the profile of the target public

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This work presents the results of a study on the use of experimentation in physics teaching, presenting a survey on the use of this strategy in public high schools in the region of São José dos Campos. Data collection was carried out in schools by means of questionnaires prepared for physics teachers and students from three grades of high school. Data were obtained in eighteen schools distributed in the city of São José dos Campos (two in the central region, in the west, three on the east side, seven in the north and five in the south), a school in the district of Sao Francisco Xavier and a school in the town of Monteiro Lobato. Thus, data from 20 schools, 610 students and 20 teachers were analyzed. Among the main results, we highlight that over 80% of the students said that there is no physics lab at the school where they study, and less than 1% declares that uses laboratory weekly. We note that there is a laboratory in 25% of the schools in the northern region and 10% or less of the other schools. According to the students the proposition of the experimental activities by teachers is rare - only three schools in East Side the options sometimes and always exceeded the number of responses experimental activities are never proposed. We had 60% of the teachers who reported using the curriculum of the state of São Paulo to propose activities to students, and half of the teachers said they did not have classes experimental physics classes in initial training or had them in sufficient quantity to support the use of this feature in practice

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A remarkable characteristic of the physics subject is the abstraction ability needed during the learning process, which means a non-trivial comprehension and understanding. If the students could not link the themes learned in this subject with observable effects, physics would tend to be a group of mathematical formulas to be memorized. In general, it creates a distance between the student and the subject, and also a prejudice vision of the physics, sometimes for the whole life. Beyond this particular characteristics of physics, the education deals with a source of distraction reinforced by the popularization of mobile access such as cellphones and tablets. The traditional role played by the teacher becomes weak to attract student’s attention. It is necessary that the classes could be planned in such way to achieve three goals: attract student attention, link analytical concepts with real effects and, the most important, gives to the student the ability to use the learned concepts as the key to develop new knowledge. In this work, we present a research based in some experiments used in a CBEF (Brazilian magazine about physical education) and develop an activity consistent with the aims to be reached. To prepare of the experimental activity, we based on Piaget and Vygotsky theories. This work aimed to developed a theoretical research to obtain a didactical activity that deals with the current challenges of the society

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Pós-graduação em Física - FC