Física do meio ambiente: desafios de uma disciplina focada na formação de habilidades gerais

A disciplina Física do Meio Ambiente (FMA) foi criada em 1976 no Departamento de Física Teórica e Experimental da UFRN e, atualmente, faz parte da estrutura curricular do curso de Licenciatura em Física da UFRN e é de caráter obrigatório. Tal caráter se justifica, dentre outros motivos, pelo fato de que esta disciplina representa uma boa oportunidade dos licenciandos estudarem de que forma a Física pode contribuir para a compreensão de fenômenos relativos ao nosso Meio Ambiente, sejam eles relacionados às atividades humanas ou aos fenômenos naturais propriamente ditos e que, de uma forma ou de outra, afeta a sociedade. O nosso trabalho de pesquisa teve como objetivo principal elaborar um novo programa de ensino para a disciplina de Física do Meio Ambiente adequado às necessidades da educação científica para o século XXI. A pesquisa foi conduzida inicialmente com um levantamento histórico da disciplina desde sua origem no Departamento de Física ate os dias atuais, analise dos Projetos Pedagógicos do curso de Licenciatura em Física da UFRN, revisão bibliográfica sobre as definições de competências e habilidades em um contexto de ensino e segundo o pensamento de vanguarda nesse campo de pesquisa, acompanhamento do curso durante um semestre através de aulas observacionais, aplicação de questionário para a coleta de dados e análise de alguns livros didáticos de Física do Ensino Médio. A partir do perfil ou modelo profissional para o licenciado em Física da UFRN definimos os objetivos gerais para a disciplina de FMA em termos de habilidades gerais relacionadas com as atividades que um futuro professor de Física irá desempenhar no seu dia a dia. O nosso programa de ensino foi pensado no sentido de introduzir conteúdos de didática específica ao longo da disciplina, isto é, familiarizar os professores em formação com investigação e inovação didáticas voltadas para o ensino de temas que envolvam a conexão entre Física e Meio Ambiente. Como resultado de nossa pesquisa foi proposto um novo Programa de Ensino para FMA que pode ser útil aos futuros professores desta disciplina e foi elaborado segundo uma metodologia de organização científica do processo ensino

Implementação da técnica de difração de elétrons de baixa energia

The purpose of this study is to describe the implementation of the Low Energy Electron Diffaction (LEED) technique in the Laboratory of Magnetic Nanostructures and Semiconductors of the Department of Theoretical and Experimental Physics of the Universidade Federal do Rio Grande do Norte (UFRN), Natal, Brazil. During this work experimental apparatus were implemented for a complete LEED set-up. A new vacuum system was also set up. This was composed of a mechanical pump, turbomolecular pump and ionic pump for ultra-high vacuum and their respective pressure measurement sensors (Pirani gauge for low vacuum measures and the wide range gauge -WRG); ion cannon maintenance, which is basically mini-sputtering, whose function is sample cleaning; and set-up, maintenance and handling of the quadrupole mass spectrometer, whose main purpose is to investigate gas contamination inside the ultra-high vacuum chamber. It should be pointed out that the main contribution of this Master's thesis was the set-up of the sample heating system; that is, a new sample holder. In addition to the function of sample holder and heater, it was necessary to implement the function of sustaining the ultra-high vacuum environment. This set of actions is essential for the complete functioning of the LEED technique

Estudos de sinterização da mistura de pós cerâmicos diatomita-titânia

This work is part of an effort of consolidation of a daily search for powder technology at the Department of Physics of the Universidade Federal do Rio Grande do Norte. This work objective the study and development of new ceramic materials from raw materials abundant at the region. For this, were studied ceramic mixtures of powders from diatomite-titania to aiming at a new ceramic material from powder technology. The experimental work involved a characterization of ceramic powders from a diatomite-titania mixture. The powders obtained were pressed and then parameters like variation of mass, linear shrinkage, activation energy and the mechanism of sintering are studied in function of the time and temperature of sintering, beyond microstructural analysis. The obtained results allow us estimate the optimizing of sintering conditions of this material

Montagem e construção de um magnetômetro a efeito Kerr magneto-óptico

n this master s dissertation a Kerr Magneto Optic s magnetometer effect was set up to do characterization of samples type films fine and ultra thin, these samples will be grown after the implementation of the sputtering technique at the magnetism laboratory of of this department. In this work a cooled electromagnet was also built the water and that it reaches close values to 10kOe with a gap of 22 mm including an area of uniform field of 25mm of diameter. The first chapter treats of the construction of this electromagnet from its dimensioning to the operation tests that involve measures of reached maximum field and temperature of the reels when operated during one hour. The second chapter is dedicated to the revision of the magnetism and the magnetization processes as well as it presents a theoretical base regarding the magnetic energies found in films and magnetic multilayer. In the sequence, the third chapter, is especially dedicated the description of the effects magneto opticians the effect kerr in the longitudinal, traverse and polar configurations, using for so much only the classic approach of the electromagnetism and the coefficients of Fresnel. Distinguished the two areas of observation of the effect regarding thickness of the film. The constructive aspects of the experimental apparatus as well as the details of its operation are explained at the room surrender, also presenting the preliminary results of the measures made in one serializes of permalloy films and concluding with the results of the characterization of the first films of iron and permalloy grown here at the theoretical and experimental physics department at UFRN

Imaginário radical e educação física: trajetória esportiva de corredores de longa distância

Cette étude propose une lecture du sport d endurance, prenant comme perspective théorique l imaginaire radical et considérant les dimensions socio-historiques e subjectives de la pratique de courses de longue distance. D abord, l échantillon la recherche a été composé de huit sujets-atlètes du groupe de courreurs de rue Sport Vida. Ainsi, em même temps que nous faisons une analyse socio-historique de cette pratique sportive, nous considérons l ensemble des aspects sócio-culturels et poursuivons la recherche avec comme objectif de comprendre les sens qui lui sont attribués par les sjuets-atlètes, au-delá de l aspect économique et de la consommation. Nous observons que, même si l altétismo qui est pratiqué a des aspects competitifs (economiques), les atlètes créent d autres sens pour continuer a pratiquer ce sport, comme les amitiés, être ensemble avec les amis. Ils rompent avec la logique déterministe du sport dépasser la limite du corps, vaincre à n importe quel prix, dépasser les collègues -, en cherchant des moments de solidarité, un sport sans violence et affectif. Nous percevons néanmoins des contradictions dans le discours de quelques atlètes quand confessent que le plus important est l amour du sport, les amitiés, mais réclament du manque de sponsorts et d appui pour pouvoir s entrainer tranquillement. Cette recherche a aussi montré que dans la pratique de ce sport, les atlètes construisent une obstination, sachant le sacrifice qu il impose au corps, mais cela se transforme en plaisir, excitation et recherche d émotions fortes. Valeurs éthiques sont aussi construites et valorisées dans l atlétisme, ce qui est observé lorsque que les sujets-atlètes critiquent avec véemence a propos de l usage de substances chimiques par les sportifs. En choisissant l imaginaire radical comme principale inspiration théorique pour cette recherche, il devient évident que le sport peut être ressignifié, à partir du moment que cet imaginaire est potencialisé dans l enseignement de l éducation physique, porvocant chez les élèves une réflexion critique sur la société et sur le sport, qui passe à être redimensionné vers la solidarité, avec démocratie et autonomie. Enfin, l étude a révélé que le sport d endurance est capable de créer des liens sociaux et structurer des relations à partir de cette pratique

Prototexto, narrativa poética da ciência: uma estratégia de construção do conhecimento e religação de saberes no ensino de física

In this thesis I present the prototexto notion and to I base as a complex system while strategy of knowledge construction and reconexion of you know in physics teaching. Prototexto is a poetic narrative of the science, proposal and used initially as "instrument of creative" learning for students apprentice of science of the medium and technical teaching of the Vitória da Conquista's CEFET-BA, in the period of 1997-2004. Later become pregnant as a strategy of knowledge construction, in the Universidade Estadual da Bahia - UESB, the prototexto notion configures a complement to the mathematical formulation. The proposal of a poetic narrative of the science is that the apprentice of science starts to organize in an aesthetic-literary way your knowledge, dispersed in disciplines, starting from a theme of the physics. The prototexto emerges of my reflections concerning the classic science, identified for Edgar Morin as tends a thought excessively numeric, and that it has been reproduced in physics teaching, in most of the schools, limiting him/it to an order pattern with the mistake absence. They are operations of the prototexto: the poetic language, the pedagogic stamp, the unfinished of the argument, the system character and the apprentice's of science inclusion as subject implicated in the construction of the knowledge. the theoretical foundations are based Morin's proposition of the method as strategy, the beginning of the complementarity of Niels Bohr in conceiving excluding categories as face of a same phenomenon and the conception of creative time of Ilya Prigogine that enunciates the alliance among the nature and the man that it describes her

Consciência corporal e educação física escolar: possibilidades de intervenção

The investigation about the body consciousness in school Physical Education had as main objective reporting a possibility of intervention, linking it directly to the contents of Physical Education and considering it as a crosscutting theme in this research. In this scope, we worked specifically with two contents of Physical Education - knowledge about the body and fights. During the study, we are going to discuss about teaching strategies for the themes of body awareness. To develop this work, we used the following study questions: how is treated the body consciousness in Physical Education and how it has been addressed in educational interventions? What are the difficulties found to the themes of body awareness on different issues of school Physical Education? How body awareness thematized in contents in Physical Education is received by the students and what are the attitudes demonstrated by them during the development of these lessons? Based from questions of study, we used the following methodological tools: participant observation, interviews, photographic records, debates, films, dramatizations and dynamics, which they were performed to stimulate students' critical thinking about their body and the other children s one. The research with ethnographic characteristics was conducted in two schools: one elementary school I, in Natal and one elementary school II, held in the municipality of the João Câmara, in the state of Rio Grande do Norte. We developed a structure in order that the three dimensions of contents conceptual, procedural and attitudinal were experienced by students. The work is structured in five chapters. At first, we made an introduction to justify the motivations that led us to write about body awareness at school. In the second chapter, we discussed reflection about the body and its possibilities of understanding, reflecting on the body and how this awareness was being treated in physical education classes at school. In the third chapter, dealing with the body awareness and dialogue with the Physical Education, we had made a theoretical approach, from authors such as CLARO (1988), NÓBREGA (2000), ARAGÃO (2004), MELO (2006), LORENZETTO and MATTHIESEN (2008) in order to situate the body consciousness and its relationship with physical education. In the fourth chapter, we talked about body awareness thematized in physical education contents: knowledge about the body and fights. We introduced the teaching experience developed in the school and we discussed with authors such as OLIVIER (2000), DARIDO AND RANGEL (2008), among others, about how was the reflection about the body leaving of these experiences. The fifth chapter was intended to closing remarks, in which we concluded that the body awareness, treated in physical education in school by sociocultural and historical aspects, it will contribute in building a man, a body and a society. Although the body consciousness is crafted in a few moments of Physical Education, based on the practices of body awareness or alternatives; in our proposal, we pointed out another perspective to work with body awareness, bringing its elements to permeate and pass through the contents of Physical Education. At work we can see a suggestion for that these experiences are carried out by other Physical Education professionals, obviously adapting the activities according to age and educational level of students

Uma análise teórica da evolução da rotação estelar

In the past 50 years, large efforts have been made toward the understanding of the stellar evolution. In the observational context, large sets of precise measurements of projected rotational velocity were produced, in particular by the Natal and Geneva groups. From these data, it is now possible to establish the behavior of stellar rotation from the turnoff to the red giant branch. In addition, these data have shown the role of tidal effects on stellar rotation in close binary systems. Nevertheless, relatively little attention has been paid to theoretical studies on the evolution of rotation along the HR Diagram, a topic itself directly associated to the evolution of the stars. Basically, there are two reasons for such a fact, (i) spherical symmetry is not assumed, what leads to a substantial increase in the numerical complexity of equations and (ii) non rotating models have been very successful in explaining relevant observational data, including the mass-luminosity relation and chemical abundances. In spite of these facts, it is clear that considerable work remains to be done on the role of rotation in the later stages of the evolution, where clear disagreements arise from confrontations between theoretical predictions and observations. In the present work we study the evolutionary behavior of stellar rotation along the HR Diagram, taking into account constraint conditions issued from recent observational survey of rotational velocity carried out with high precision procedures and new evolutionary codes

Lítio e rotação nas estrelas análogas solares: análise teórica das observações

The projected rotational velocity together with lithium abundance and the onset of the dilution by the deepening in mass of the convective envelope provide a key tool to investigate the so far poorly understood processes at work in stellar interiors of solar-analog stars. To investigate the link between abundances, convection and rotational velocities in solar-analog G dwarf stars, we study a bona fide sample of 118 selected solar-analog G dwarf stars presenting measured lithium abundances, rotational velocities, and fundamental parameters together with computed evolutionary tracks (Toulouse-Geneva code) for a range of stellar masses around 1 M and metallicity consistent with the solar-analog range. The aim of this work is to build up an evolution of lithium and rotation as a function of stellar age, mass, effective temperature, and convection. We analyze the evolutionary status of the sample of 118 solar-analog G dwarf in the HR diagram based on Hipparcos data and using a grid of stellar models in the effective temperature and mass range of the solar-analog stars. We discuss the deepening (in mass) of the convective envelope and the influence on the Li abundances and projected rotational velocities. We determined the stellar mass and the mass of the convective envelope for a bona fide sample of 118 selected solar-analog G dwarf and checked the evolutionary link between the rotational velocity, lithium abundance, and the deepening of the convective envelope. Fast rotators (vsini 6 km s��1) are also stars with high Li content. Slow rotators present a wide range of values of log n(Li). Our results shed new light on the lithium and rotational behavior in G dwarf stars. We confirmed the presence of a large Li abundance spread among the solar-analog stars and concluded that the solar twins probably share a similar mixing history with the Sun

Corpos Queer e a experiência da sexualidade: notas para o conhecimento da educação física

This study had the goal of make a dialogue between queer theory and the thoughts of the French philosopher Maurice Merleau-Ponty in the categories of body and sexuality. From this dialogue, other goals were designed, namely: identify possible recurrences of the experience of bodies and queer sexualities, designed under Merleau-Ponty’s perspective, to the knowledge of Physical Education and reflect on this domain of knowledge using the notions of queer epistemology and esthesia. The study had as methodology the phenomenological attitude proposed by Merleau-Ponty and use the reduction as technic of research. Trying linking these thoughts we used the cinema of the Spanish director Pedro Almodóvar as perceptive strategy, an exercise of look as possibility of reading the world and new ways of perceiving the human being. We appreciate three films, namely: All About My Mother (1999), The Skin I Live In (2011) and Bad Education (2004), which put us in touch with bodies and queer sexualities, with the body of esthesia, of the ecstasy, sensations and lived experiences, un type of art whose contours are not fixed or determinable, postulate by Merleau-Ponty. The philosopher, provide a rich conceptual view of the body and their sexual experience, extends and opens horizons of thought and reflection about queer experience, one experience indeterminate and contingent as a singular way of inhabiting the world. Those horizons opened by the philosopher and added to the queer perspective contribute to put in question the modes of knowledge production and the knowledge about body and sexuality in Physical Education. Finally, we point that this theoretical conversation give us clues to reflect about the reverberations of a queer epistemology for Physical Education usiging one type of knowledge guided by esthesia and sensitivity as marks of another scientific rationality.