Construção e avaliação térmica de um fogão solar tipo caixa

The present work presents a contribution in the study of modelings of transference of heat for foods submitted to the experimental tests in the considered solar oven, where the best modeling for the beefburger of chicken in study was evaluated, comparing the results, considering this food as a half-infinite(1er object considered model) and,after that, considered the chicken beefburger as a plain plate in transient regimen in two distinct conditions: not considering and another model considering the contribution of the generation term, through the Criterion of Pomerantsev. The Sun, beyond life source, is the origin of all the energy forms that the man comes using during its history and can be the reply for the question of the energy supplying in the future, a time that learns to use to advantage in rational way the light that this star constantly special tax on our planet. Shining more than the 5 billion years, it is calculated that the Sun still in them will privilege for others 6 billion years, or either, it is only in the half of its existence and will launch on the Earth, only in this year, 4000 times more energy that we will consume. Front to this reality, would be irrational not to search, by all means technical possible, to use to advantage this clean, ecological and gratuitous power plant. In this dissertation evaluate the performance of solar cooker of the type box. Laboratory of Solar Energy of the Federal University of the Great River of North - UFRN was constructed by the group (LES) a model of solar stove of the type box and was tested its viability technique, considering modeling foods submitted when baking in the solar oven, the cooker has main characteristic the easiness of manufacture and assembly, the low cost (was used material accessible composition to the low income communities) and simplicity in the mechanism of movement of the archetype for incidence of the direct solar light. They had been proposals modeling for calculations of food the minimum baking time, considering the following models of transference of heat in the transient state: object the halfinfinite, plain plate and the model of the sphere to study the necessary temperature for the it bakes of bread (considering spherical geometry). After evaluate the models of transmission of heat will be foods submitted you the processes of to it bakes of, the times gotten for the modeling with the experimental times of it bakes in the solar oven had been compared, demonstrating the modeling that more good that it portraies the accuracies of the results of the model

Desenvolvimento de uma unidade laboratorial para quantificação de BTX como poluentes atmosféricos, usando microextração em fase sólida

This dissertation aims the development of an experimental device to determine quantitatively the content of benzene, toluene and xylenes (BTX) in the atmosphere. BTX are extremely volatile solvents, and therefore play an important role in atmospheric chemistry, being precursors in the tropospheric ozone formation. In this work a BTX new standard gas was produced in nitrogen for stagnant systems. The aim of this dissertation is to develop a new method, simple and cheaper, to quantify and monitor BTX in air using solid phase microextraction/ gas chromatography/mass spectrometry (SPME/CG/MS). The features of the calibration method proposed are presented in this dissertation. SPME sampling was carried out under non-equilibrium conditions using a Carboxen/PDMS fiber exposed for 10 min standard gas mixtures. It is observed that the main parameters that affect the extraction process are sampling time and concentration. The results of the BTX multicomponent system studied have shown a linear and a nonlinear range. In the non-linear range, it is remarkable the effect of competition by selective adsorption with the following affinity order p-xylene > toluene > benzene. This behavior represents a limitation of the method, however being in accordance with the literature. Furthermore, this behavior does not prevent the application of the technique out of the non-linear region to quantify the BTX contents in the atmosphere.

Obtenção de Propriedades Físico-Químicas de Misturas de Hidrocarbonetos em Baixa e Alta Pressão Visando a Caracterização e a Modelagem

The composition of petroleum may change from well to well and its resulting characteristics influence significantly the refine products. Therefore, it is important to characterize the oil in order to know its properties and send it adequately for processing. Since petroleum is a multicomponent mixture, the use of synthetic mixtures that are representative of oil fractions provides a better understand of the real mixture behavior. One way for characterization is usually obtained through correlation of physico-chemical properties of easy measurement, such as density, specific gravity, viscosity, and refractive index. In this work new measurements were obtained for density, specific gravity, viscosity, and refractive index of the following binary mixtures: n-heptane + hexadecane, cyclohexane + hexadecane, and benzene + hexadecane. These measurements were accomplished at low pressure and temperatures in the range 288.15 K to 310.95 K. These data were applied in the development of a new method of oil characterization. Furthermore, a series of measurements of density at high pressure and temperature of the binary mixture cyclohexane + n-hexadecane were performed. The ranges of pressure and temperature were 6.895 to 62.053 MPa and 318.15 to 413.15 K, respectively. Based on these experimental data of compressed liquid mixtures, a thermodynamic modeling was proposed using the Peng-Robinson equation of state (EOS). The EOS was modified with scaling of volume and a relatively reduced number of parameters were employed. The results were satisfactory demonstrating accuracy not only for density data, but also for isobaric thermal expansion and isothermal compressibility coefficients. This thesis aims to contribute in a scientific manner to the technological problem of refining heavy fractions of oil. This problem was treated in two steps, i.e., characterization and search of the processes that can produce streams with economical interest, such as solvent extraction at high pressure and temperature. In order to determine phase equilibrium data in these conditions, conceptual projects of two new experimental apparatus were developed. These devices consist of cells of variable volume together with a analytical static device. Therefore, this thesis contributed with the subject of characterization of hydrocarbons mixtures and with development of equilibrium cells operating at high pressure and temperature. These contributions are focused on the technological problem of refining heavy oil fractions

História da ciência como estratégia didática no ensino médio: um breve olhar de conteúdos da óptica

From a critique of aspects of the current teaching of physics, we propose in this paper an investigation into the conceptions of Nature of Science (NOS) submitted by students from the high school level, as well as the inclusion of discussions about some elements of NOS, through the History and Philosophy of Science, understanding them as facilitating strategy for more effective learning of Physics and, more specifically, the contents of optics. Based on the historical period corresponding to Greek antiquity to the mid-nineteenth century, built and applied a teaching unit to a high school class at the Federal Institute of Education, Science and Technology of Rio Grande do Norte (IFRN) Ipanguaçu campus. Our teaching unit involved the reading and interpretation of texts with historical content, observation and assembling five experimental activities, among other activities. Data analysis occurred through questionnaires investigative applied before and after the completion of the teaching unit, as well as questionnaires for content present in the texts. Although not significant, the results indicated that the application of the teaching unit allowed the (re) construction of some conceptions about NOS targets students present in our work, and contribute to a better learning content and greater optical science approach and its nature

Política, canção e teatro: o conto Aqueles Dois de Caio Fernando Abreu reverberando no cotidiano brasileiro

Quand on se plonge sur l‟oeuvre de Caio Fernando Abreu, on est forcement mené à faire une profonde analyse social qui résulte dans une grande bataille entre l‟amour, la société et la politique. Cette Memoire de Master, Politique, chanson et théâtre : Le conte « Ces deux-là » de Caio Fernando Abreu répercute au quotidien brésilien, montre que la plongé faite ici cherche à analyser, à partir d‟une perspective comparative, les angles observés par l‟auteur dans son oeuvre écrite pendant les années de la Dictature Militaire brésilienne, l‟influence des Beatles et du musicien/poète Caetano Veloso avec le mouvement du Tropicalismo. Dans ce travail, on observe le rôle du narrateur au sein du développement du conte comme représentation de la société irrémédiable et comme cette narrative s‟ajuste en mode théâtral. La lecture de cette memoire est basée sur l‟analyse du conte « Ces deux-là », du livre Fraises Moisies, et l‟influence de la musique Strawberry Fields Forever, des Beatles chez l‟écriture de l‟auteur, ainsi que les discussions sur les images présentent dans la narrative comme la structure essentielle pour le processus du montage du spectacle homonyme par la Cia. Luna Lunera, Minas Gerais, à partir du mécanisme de la traduction, du littéraire au scénique, appuyée sur les idées de Patrice Pavis

Comparação da pressão plantar e dos sintomas osteomusculares por meio do uso de palmilhas customizadas e pré-fabricadas no ambiente de trabalho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

Identidade, espaço e tempo: negociações de sentido sobre a "gente de rua"

This research examines the street children s identity construction processes. Recently, the research about this population has focused on the socialization processes that organize their everyday, their situations of interaction, the meanings of their social practices, their street experience. The concept of identitary forms gives coherence to the set of these phenomena, articulating them theoretically, in order to describe their life conditions and details of their trajectories. This research utilized an ethnographic approach with a group of 11 street people, 9 of them boys and girls 16-18 years old, during 3 months. It included participant observation, informal and formal interviews, that resulted in young s narratives of lifestory. These narratives were interpreted according to the principles of positioning analysis and the Labovian Analysis model of oral narratives of personal experience. The observation of interaction among the studied group and other groups has showed that their social practices, supported on many particular bodily technologies, recreate space and time of these interactions semantically, as mediation of meaning negotiations among groups. Such meanings transform again the environment of these interactions, disclosing interpretative systems by means of which the groups apprehend this interaction in a particular way. These street children s bodily technologies imply identitary forms based on scarcity and abandonment, paradoxicalally related to their self-concept. The analysis of narratives revealed diversity and complexity in the meanings assembly for their street experience; it showed that the semantic arrangements reconstruct the temporal experience, creating a moral climate for each lifestory, and determining more or less aperture of identitary forms to change. The study concludes that space and time, builders of interaction regimes, produce identitary forms; that the narratives and the social practices of the studied group are sustained upon a master discourse that opposes the meanings of the home and the life in the streets

MyPersonal-EPG: um EPG personalizável e com suportes a recomendações para o SBTVD

In this work we present the architecture and implementation of MyPersonal-EPG, a personal EPG with support to recommendations, built on top of the Ginga middleware, that fulfill the following requirements: (i) to allow users to build their own personal programming grids, based on programming guides from several broadcasters; (ii) to offer a mechanism to tune the desired channels on the moment the selected programs are about to begin; (iii) to allow users to select the desired programs categories; (iv) to offer programs recommendations, in both synchronous and asynchronous way, based on the categories previously selected by users; (v) to allow users to modify the current configuration options; (vi) to allow the creation of several users accounts, so that each user can store its own information. The application‟s usability test is also presented and its results are discussed and analyzed

Avaliação histológica da regeneração óssea do rádio e ulna em cães submetidos ao alongamento com o fixador de Ilizarov

O objetivo do estudo foi analisar histologicamente a qualidade, tipo e orientação dos tecidos formados na área de regeneração óssea produzida durante alongamento simultâneo do rádio e da ulna, com fixador externo de Ilizarov, a partir de osteotomia subperiosteal diafisária distal, com dois incrementos diários de 0,5 mm. A montagem foi composta de dois anéis e quatro hastes telescópicas, sendo a distração óssea iniciada no sexto dia de pós-operatório. Utilizaram-se 15 cães, sem raça definida, adultos, com peso corpóreo entre 17 e 30 kg, divididos por sorteio em subgrupos (A, B, C, D e E) compostos por três animais, que foram submetidos a eutanásia após os seguintes procedimentos: A- oito dias de alongamento, B- 15 dias de alongamento, C- 22 dias de alongamento, D- 28 dias de alongamento e oito dias de fase neutra com o fixador, E- 28 dias de alongamento, 60 dias de fase neutra com fixador e 45 dias sem fixador. Os resultados obtidos mostram que o tipo e localização da osteotomia, bem como o ritmo de distração utilizado, não interferiram sobremaneira na regeneração óssea. A reparação óssea foi eficiente, notadamente intramembranosa, contudo nos subgrupos B e C foi observada a presença de cartilagem.

Estudo mecânico da estabilidade dorsal da osteossíntese intramedular associada à fixação externa (método de Ulson)

OBJETIVO: Avaliar o método de Ulson de fixação intramedular associado à fixação externa variando a altura do travamento externo dos fios de Kirschner e sem fixação externa. MÉTODO: Foram utilizadas 18 tíbias de porcos, sendo realizada osteotomia transversal na região da tuberosidade e introduzidos dois fios de Kirschner intramedulares em cada peça, em três diferentes padrões de montagem: grupo I - travamento com minifixador externo com 3,0cm de altura; grupo II - travamento com 4,5cm de altura; grupo III: sem travamento externo. Realizaram-se ensaios mecânicos de cisalhamento, obtendo-se: carga máxima, limite de proporcionalidade e coeficiente de rigidez. RESULTADOS: Não foram encontradas diferenças significativas de carga máxima e limite de proporcionalidade entre os grupos; o grupo II apresentou maior coeficiente de rigidez. CONCLUSÃO: A altura do travamento dos fios de Kirschner no método de Ulson, dentro dos limites avaliados, não prejudicou a estabilidade do sistema de fixação da fratura.

O papel da tecnologia cênica e seus desdobramentos para uma economia da produção cultural no nordeste

O papel da tecnologia na produção contemporânea em artes cênicas vem influenciando profundamente as formas de recepção e produção de Teatro, Dança, espetáculos de Circo, shows musicais, entre outras manifestações espetaculares organizadas. Sua aplicação se estende amplamente a outras áreas que necessitam enfatizar o caráter cênico de seus processos de fruição como é o caso dos museus, feiras de ciências, exibições e mostras em artes visuais e o aparato tecnológico de luz, som e configuração espacial usados para estes fins. Neste sentido, o desenvolvimento deste tipo de tecnologia vem gerando e alimentando cadeias produtivas que movimentam uma economia da produção cultural e criam uma rede de relações articuladas em diferentes níveis de atuação, envolvendo produtores de equipamento, fornecedores, lighting designers, cenógrafos, profissionais de sonorização, arquitetos, técnicos de montagem e operação, instituições ensino especializadas, associações de área, entre outros. O foco deste trabalho se concentra em demonstrar como a análise de demandas de tecnologia cênica articuladas pelos sistemas de produção cultural, em particular na região Nordeste do Brasil, possibilitam compreender modelos de organização em curso, contribuindo para o desenvolvimento de uma reflexão multidisciplinar acerca dos processos de produção artística de natureza cênica e como esta produção é afetada pelos limites e possibilidades dos aspectos que caracterizam uma economia destas produções

Geologia e geomorfologia dos recifes de Maracajaú-RN e plataforma rasa adjacente

This work focuses the geological and geomorphological characterization of the inner shelf in the West Coast of the Rio Grande do Norte state, particularly the reef coral barrier offshore of Maracajaú (Maxaranguape district). If developed without the necessary concerns, tourism and entertainment activities that have been widely increased during the last five years can lead to irreversible environmental damages to the biotic and abiotic ecosystems of the region. Regarding these aspects, it is crucial the realization of a detailed study to envisage the achievement of a self-sustainable development, especially with respect to the possibilities of a rational usage of the region. This is the aim of this manuscript, which consisted of an initial stage of digital modeling of the terrain with basis on digitalization and vectorization of the Nautical map number 803 (Naval Service of Brazil, 1971). Information obtained in this phase was improved with the digital processing of small format aerial photos acquired from six flights, which were integrated to form a photomosaic of the area. The refined maps produced with the data from Nautical and aerial photo-interpretations aided to locate 9 bathymetric profiles, which provided information about the sea floor relief of the whole area. This later aided in the choosing of areas to bottom sampling that, in its turn, helped to characterize sediments present in floor of the inner shelf. Sixty-four samples collected during this work were studied by granulometrical and chemical analysis; with the later one developed in order to measure carbonate and organic matter contents. Forty-two of these samples showed carbonate content higher than 80% and organic matter in the range of 0.58% to 24.06%. With respect to grain size, these samples are in the interval between fine- to mid-grained sands. Sands with grain sizes higher than this one are also composed by carbonate carapaces such as pale yellow to red rhodolites with ellipsoidal and spheroidal shapes. During determination of the submerse features, the small format aerial photos demonstrated to be a useful methodology to aid the delineation of the sea floor topography through shallow deep waters. The bathymetry, for its turn, revealed several features at the bottom of the platform, in which the most conspicuous are undulations and morphological details of the São Roque Channel. Examination of bottom, aside from sand, yielded the identification of bivalves, ostracods, fragments of bryozoans, spikes of sponges, spines of echinoderms, operculum of gastropods and foraminifers. From the above it is concluded that the multi-methodological approach developed in this study worked efficiently, permitting the geomorphological and environmental characterization of the inner shelf of the North Maracajaú

Fixador esquelético pino-resina acrílica e enxerto ósseo esponjoso no tratamento de complicações secundárias à imobilização inadequada de fratura do rádio e ulna em cães

O objetivo do estudo foi avaliar a eficácia do fixador esquelético pino-resina, configuração tipo II, coadjuvado pelo enxerto ósseo esponjoso autólogo, no tratamento das complicações secundárias à imobilização inadequada de fraturas do rádio e ulna em 10 cães, com peso entre 1,8 e 33,6 kg. Detectou-se não-união (n=4), osteomielite (n=1), má-união (n=1), falência ou quebra de implante (n=4), sendo 60% das lesões referente ao uso prévio de pino intramedular no rádio. A montagem do fixador foi realizada com transfixação de pinos lisos em sua maioria angulados, cujas extremidades excedentes foram dobradas e estabilizadas com resina acrílica. em todos os casos, utilizou-se enxerto esponjoso autólogo fresco, após debridamento do foco de fratura. O tempo de permanência do aparelho variou entre 45 dias e 5 meses e a maior complicação foi o afrouxamento dos pinos transfixantes. A consolidação das fraturas ocorreu por formação de calo periosteal de mínimo a moderado, indicando boa rigidez da montagem.

Efeitos de giberelina e ethephon na anatomia de plantas de cana-de-açúcar

O presente trabalho teve como finalidade analisar os efeitos da aplicação de giberelina (GA) e do ethephon (CEPA) na anatomia de plantas de cana-de-açúcar. Para o estudo da anatomia de caules e folhas foi realizada pulverização de plantas jovens a partir de sementes. Após 216 dias da semeadura, realizaram-se cortes das folhas +4, da região do nó +10 e dos entrenós +10 e montagem de lâminas permanentes. Observou-se que o tratamento com GA 50 mg L-1 manteve intensa atividade meristemática, havendo contínua formação de feixes vasculares com menor quantidade de fibras de esclerênquima. O GA 50 mg L-1 provocou diminuição em número e tamanho de células buliformes nas folhas +4. Verificou-se que CEPA 1.200 mg L-1, inibiu a atividade meristemática na região do nó +10, reduziu a quantidade de fibras de esclerênquima dos feixes vasculares e aumentou o número de células buliformes.