Made available in DSpace on 2014-06-11T19:25:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-06Bitstream added on 2014-06-13T19:53:01Z : No. of bitstreams: 1 marques_ml_me_ilha.pdf: 2611417 bytes, checksum: 92acf490f613feafc8592624dfbb25e9 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Diante dos vários casos registrados de anomalias surgidas em concretos de diferentes estruturas devidas às reações deletérias do tipo álcali-agregado (RAA), pesquisadores de todo o mundo têm buscado conhecer melhor o problema, entender seu mecanismo e caracterizar estruturas já afetadas. Realizou-se no presente trabalho um estudo de caso sobre a Tomada d’água (TA) da UHE Jaguari, visando estimar a expansibilidade do concreto dessa estrutura e a reatividade de agregados provenientes da região. Para isto, foram analisados testemunhos extraídos da TA por meio de ensaios de expansão, análises químicas e microestruturais, e um concreto com traço reconstituído em laboratório, reproduzindo o traço utilizado na construção da TA, avaliando a resistência mecânica, a propriedade elástica e a permeabilidade. Realizouse um estudo em separado dos agregados coletados da região (enrocamento da barragem, pedreira comercial e testemunho de sondagem da rocha de fundação da TA) por se tratar de materiais que provavelmente têm a mesma procedência que o empregado na barragem. Foram realizadas análises químicas, usando técnicas como difração de raios X e infravermelho, bem como análises do potencial expansivo, por meio de barras de argamassa e prismas de concreto, conforme as normas NBR 15577-4 e NBR 15577-6, respectivamente. Este conjunto de informações constitui uma contribuição para que venha a ser feita uma avaliação da real situação da estrutura no tocante à RAA, estabelecendo parâmetros iniciais para estimar em qual estágio de expansão a estrutura se encontra. / Ahead of some registered cases of anomalies appeared in concrete of different structures due to the deleterious reactions of the alkali-aggregate reaction (AAR) type, researchers of all over the world have studied this problem, to understand its mechanism and to characterize structures which were already affected. In the present work, a characterization of the concrete used in this dam and a study of residual expansion obtained from extracted cores was performed. The case study was the intake of Jaguari Hydra Power plant, because it presents cracks that are characteristic of alkali-aggregate reaction. Tests were made on the same core of Jaguari Hydra Power Plant and in concrete from laboratory, using a local aggregate in order to evaluate: the strength, the elastic property, the permeability and the expansibility; as well as, chemical and micro structural analysis. Another study was made with aggregate collected from the rockfill of the dam, because this aggregate probably has the same origin that the one which were used in the dam construction and collected from soundings of the foundation rock of intake structure of Jaguari Power plant. This study contemplated chemical analysis, using techniques such as X-ray diffraction and infra-red ray, as well as analysis of the expansive potential in mortar bars and concrete prisms, through method NBR 15577-4 e NBR 15577-6, respectively. All this information will be useful to establish initial parameters and estimate what is the stage of the structure expansion due to alkali-aggregate reaction.

Este trabalho trata de um estudo experimental da transferência de calor e de massa de um condensador evaporativo, bem como, da relação existente entre as grandezas envolvidas durante a sua operação. Para o desenvolvimento da pesquisa foi construído um condensador evaporativo de pequeno porte com dimensões proporcionais a condensadores comercialmente fabricados no Brasil para operar com R-22 como fluido refrigerante. Este condensador tem 35 colunas e 12 fileiras de tubos de cobre de 6,35 mm de externo e opera junto a uma instalação que proporciona o escoamento de R-22 por termossifao. O distribuidor de água também foi construído em cobre e o eliminador de gotas em alumínio, assim como a estrutura do condensador. As laterais e a bandeja de recolhimento de água foram construídas em vidro para permitir a visualização do escoamento da água que e aspergida sobre os tubos. A fim de variar as condições operacionais, este condensador foi acoplado a um ventilador centrifugo acionado por um conversor de freqüência e a um circuito que permitiu a variação da vazão de água aspergida sobre os tubos. Dos ensaios resultaram 79 amostras de medição, que serviram para verificar a relação existente entre grandezas, bem como avaliar os coeficientes de transferência de calor e massa. Foram determinados os coeficientes de transferência de calor médio e local para o R-22. Alem disso, foram verificadas as regiões onde ocorrem o dessuperaquecimento, a mudança de fase e o subresfriamento do fluido refrigerante, e foram confrontados os coeficientes globais de transferência de calor obtidos a partir dos dados experimentais com aqueles obtidos por correlações para as regiões de condensação e subresfriamento. Destas investigações, resultou uma correlação para o coeficiente global de transferência de calor que visa determinar esta grandeza através das condições operacionais e das características geométricas do condensador. O Maximo desvio encontrado entre os valores provenientes dos dados experimentais e aqueles calculados pela correlação foi inferior a 10%. / This work presents an experimental heat and mass transfer study of an evaporative condenser, as well as, the relationship between measured quantities obtained during its operation. A small scale evaporative condenser was built in agreement to the real size equipment geometric similarity. The small scale condenser has a bundle of 210 copper tubes, with the outer diameter equal to ¼ inch, which were arranged in 35 columns and 6 rows and operating connected to the thermosifon facility that promote R-22 flow. The spray water distributor is also built on copper and the drift eliminator on aluminum, as well as the evaporative condenser structure. This condenser bounds were constructed as a glass enclosure to allow for the spray water flow visualization. To evaluate the operational conditions, the equipment was attached to a centrifugal fan controlled by a frequency inverter and a spray water circuit which allows for water quantity changing. From the carried out tests, 79 measuring samples were obtained and used to verify the quantities relationship, as well as, to evaluate the heat and mass transfer coefficients For the R-22 were determined the local and average heat transfer coefficients. Furthermore, the dessuperheating, condensation and subcooling regions were verified and compared both, the experimental overall heat transfer coefficient and those calculated by correlations at condensation and subcooling zones. From these investigations a correlation for the overall heat transfer coefficient is proposed. Its application allows determining the coefficient using the operational conditions and the geometric condenser features. The higher deviation found between the experimental data and the presented correlation is lower to 10%.

Este trabalho trata de um estudo experimental da transferência de calor e de massa de um condensador evaporativo, bem como, da relação existente entre as grandezas envolvidas durante a sua operação. Para o desenvolvimento da pesquisa foi construído um condensador evaporativo de pequeno porte com dimensões proporcionais a condensadores comercialmente fabricados no Brasil para operar com R-22 como fluido refrigerante. Este condensador tem 35 colunas e 12 fileiras de tubos de cobre de 6,35 mm de externo e opera junto a uma instalação que proporciona o escoamento de R-22 por termossifao. O distribuidor de água também foi construído em cobre e o eliminador de gotas em alumínio, assim como a estrutura do condensador. As laterais e a bandeja de recolhimento de água foram construídas em vidro para permitir a visualização do escoamento da água que e aspergida sobre os tubos. A fim de variar as condições operacionais, este condensador foi acoplado a um ventilador centrifugo acionado por um conversor de freqüência e a um circuito que permitiu a variação da vazão de água aspergida sobre os tubos. Dos ensaios resultaram 79 amostras de medição, que serviram para verificar a relação existente entre grandezas, bem como avaliar os coeficientes de transferência de calor e massa. Foram determinados os coeficientes de transferência de calor médio e local para o R-22. Alem disso, foram verificadas as regiões onde ocorrem o dessuperaquecimento, a mudança de fase e o subresfriamento do fluido refrigerante, e foram confrontados os coeficientes globais de transferência de calor obtidos a partir dos dados experimentais com aqueles obtidos por correlações para as regiões de condensação e subresfriamento. Destas investigações, resultou uma correlação para o coeficiente global de transferência de calor que visa determinar esta grandeza através das condições operacionais e das características geométricas do condensador. O Maximo desvio encontrado entre os valores provenientes dos dados experimentais e aqueles calculados pela correlação foi inferior a 10%. / This work presents an experimental heat and mass transfer study of an evaporative condenser, as well as, the relationship between measured quantities obtained during its operation. A small scale evaporative condenser was built in agreement to the real size equipment geometric similarity. The small scale condenser has a bundle of 210 copper tubes, with the outer diameter equal to ¼ inch, which were arranged in 35 columns and 6 rows and operating connected to the thermosifon facility that promote R-22 flow. The spray water distributor is also built on copper and the drift eliminator on aluminum, as well as the evaporative condenser structure. This condenser bounds were constructed as a glass enclosure to allow for the spray water flow visualization. To evaluate the operational conditions, the equipment was attached to a centrifugal fan controlled by a frequency inverter and a spray water circuit which allows for water quantity changing. From the carried out tests, 79 measuring samples were obtained and used to verify the quantities relationship, as well as, to evaluate the heat and mass transfer coefficients For the R-22 were determined the local and average heat transfer coefficients. Furthermore, the dessuperheating, condensation and subcooling regions were verified and compared both, the experimental overall heat transfer coefficient and those calculated by correlations at condensation and subcooling zones. From these investigations a correlation for the overall heat transfer coefficient is proposed. Its application allows determining the coefficient using the operational conditions and the geometric condenser features. The higher deviation found between the experimental data and the presented correlation is lower to 10%.

L'écoulement d'un fluide au-dessus d'un lit granulaire peut provoquer son érosion lorsque la contrainte exercée dépasse une valeur seuil. La présence d'un obstacle immergé dans l'écoulement induit une perturbation, entraînant une survitesse locale du fluide et une plus grande contrainte. L'érosion est alors localement renforcée, phénomène également appelé affouillement. Dans ce travail, nous étudions expérimentalement cette situation d'érosion complexe à l'échelle du laboratoire. Nous nous intéressons en particulier à la question du seuil d'affouillement, c'est-à-dire la vitesse d'approche du fluide minimale nécessaire à l'apparition de l'érosion au voisinage de l'obstacle. Ce faisant, nous observons que deux motifs d'érosion différents peuvent se développer au voisinage d'un obstacle : si le classique affouillement en fer à cheval au pied de l’obstacle domine aux vitesses d'écoulement élevées, on observe pour des vitesses plus faibles un nouveau motif en aval, que nous appelons affouillement en oreilles de lapin. Les seuils d'apparition de ces deux motifs d'érosion sont mesurés visuellement pour différents grains et obstacles. En complément de ces observations, nous utilisons une technique de relevé topographique par profilométrie laser. Le suivi temporel de la topographie du lit au cours du processus d'affouillement nous permet de caractériser la morphologie des deux types de motifs, et de comprendre la compétition entre leurs dynamiques d'apparition par la mesure des temps caractéristiques de formation. L'affouillement en oreilles de lapin est dans la plupart des cas perturbé dans son développement par la formation plus rapide de l'affouillement en fer à cheval. L'étude de l'écoulement, s'appuyant notamment sur des mesures de vélocimétrie par image de particules (PIV), nous renseigne sur les contraintes exercées par le fluide sur les grains, avec ou sans obstacle. Nous pouvons ainsi expliquer les valeurs de seuil d'apparition mesurées pour les deux motifs d'affouillement, qui sont associés à différentes structures de l'écoulement. / Erosion occurs when a fluid flowing over a granular bed exerts a large enough shear stress. When the fluid encounters an obstacle, the modification of the flow leads to a local over speed, and thus on an increase of the shear stress in the vicinity of the obstacle. As a result, the erosion is locally enhanced and is called scouring. In this work, we investigate this complicated situation experimentally at the laboratory scale. In particular, we address the question of the scouring threshold, i.e., the minimum critical approach velocity of the fluid leading to erosion in the vicinity of the obstacle. We report the existence of two different scouring patterns: the traditional horseshoe scour at the base of the obstacle, which dominates at large flow velocities, and we also highlight another scouring pattern downstream, which is called rabbit ear scour, at moderate speeds. We determine the onset of both erosion patterns visually using different grains and obstacles. Besides, we measure the bed topography over time using a laser profilometer. By monitoring the bed topography during the scouring process, we characterize the morphology of both scouring patterns and rationalize their competitive dynamics by measuring their formation timescale. In most cases, the rabbit ear scour development is inhibited by the faster horseshoe scour growth. The characterization of the flow using Particles Image Velocimetry (PIV), provides information on the shear stress exerted by the fluid flow on the grains, with and without obstacle. We can thus rationalize the threshold values for both scouring patterns, associated with different flow structures.

This study focused on a single alternative school program with a strong outdoor component and featuring a theoretical and practical orientation very much concerned with personal relationships. Data were sought regarding this program with the intent of developing possible formats for alternative school programs. The case study approach was employed to gather and report data. It permitted the investigator to observe, interact, and record the multiple phenomena. The Theory of Personal Process was the framework utilized to observe the relationships between student and teacher. This theory was made up of five key words: (1) Contact, (2) Consult, (3) Find, (4) Share, and (5) Accompany. The study detailed the personal school relationships of the students and teacher. The investigator, as participant/observer, was the instructor of each of the five students. The investigator maintained records of interaction with the students. Furthermore, he had access to journals, term papers, and other written materials produced by the students. Each case study was presented as a specific phase of the alternative school. A specific student was described as he interacted with others in that phase of the program. The description of the student's relationship with the teacher was also correlated to the Theory of Personal Process. Optional formats for alternative school programs were developed from the case studies. The program featured the following phases: (1) Orientation, (2) Group, (3) Outdoor Experiences, (4) Classroom, (5) Creativity, and (6) Community. The key to the success of each phase was determined to be the relationship between the teacher and student. This relationship fostered a support basis for the student which, in turn, provided the necessary freedom to learn. The school was not so much an educational unit as it was a social unit, a "family."

Fairy tales are enchanting geographical stories, which affectively organize space-time in socially, politically, and ethically significant ways. Despite this, fairy tales have been neglected in the discipline of geography, and the inter-discipline of fairy tale studies has rarely interrogated the spatialities of tales, or of storytelling more widely. This thesis addresses this lacuna by theorizing the relationship between fairy tales, storytelling, and geography through the subversive folkloric figures of the trickster and crone. It posits, first, that we understand fairy tales as iterative stories that constitute mythic communities; and second, that trickster and crone figures are enchanting territorializing and deterritorializing refrains that subvert this mythic community. These two concerns are explored through Nolan’s (2008) Batman film The Dark Knight, and Maitland’s (2009) short story Moss Witch. An experimental research approach provides insight into these ‘worldly,’ enchanting, and symbolically rich stories, without sacrificing their liveliness or ‘systematizing’ them for ideological gain. The research begins with an interpretive textual analysis to address the symbolic traditions of the fairy tale refrains. Collage enables a ‘retelling’ of the stories as materially and visually expressive media. Genealogical analysis traces the material-discursive matterings of the geographical refrains within academic ‘storytelling.’ These combined approaches ‘story’ the trickster and crone as spatial patterns with affective force. Trickster refrains are animating forces of destruction and chaos. They shift between the centre and periphery of mythic community, violently overturn its seemingly ordered realities, and unfold insecure and profane in-between places, where (human) community can no longer be sustained. The crone refrain enacts a ‘wilding’ in fairy tales, entangling the civilized, storied human polis (or culture more generally) with the nonhuman ‘environment,’ and undermining both relational accounts of being and more romantic discourses of dwelling. Going forward, continued engagement with this nexus of geography, storytelling, and fairy tales promises to enrich our multidisciplinary endeavours, highlight our theoretical ‘matterings’ of fairy tales, and enable more responsible engagement with these endlessly enchanting stories.

Groups of students or employees working together to solve problems, gain conceptual understanding, or create new approaches are expected to yield results significantly better than when working individually. Classroom collaboration leads to increased learning and retention, improved interpersonal skills, and enhanced appreciation for and commitment to the educational process. With the increased discussion of its benefits, there is more emphasis on including collaboration in the classroom. The challenge for today's faculty and students is to learn what their roles and expectations are in the successful collaborative environment. The purpose of this study was to design a curriculum for instructors in techniques for creating collaborative environments. In addition to reviewing the current literature to learn about collaborative environments in the college classroom, instructors were interviewed to learn about their experiences and successes with collaborative learning. Information from the literature review and the faculty interviews were used to propose the curriculum. Principles of collaborative learning evident through the literature and the interviews are that it requires trust, development of relationships, conversation, incorporating differences, the teacher as learner, and students be responsible for their own learning. The instructor must be able to create that environment by teaching social and collaborative skills, being willing to self-disclose, assessing where students are and by taking care of technical tasks such as preplanning, assigning students to groups, designing collaborative activities and evaluating results of the collaborative process, the group's product and the individual's contribution. Caffarella's (1994) interactive model for program development provided the structure for the development of the curriculum. Through the application of the model, curriculum ideas were explored and narrowed into the development of the program objectives. Transfer of learning activities incorporated into the curriculum are reliant upon intense practice of collaborative skills throughout the course. The learning is experiential.

No description available.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os recentes desastres ocorridos no país, como o rompimento da adutora em Campo Grande e os desastres relacionados às enchentes urbanas, mostram a necessidade de desenvolvimento de pesquisas científicas que auxiliem na compreensão e no dimensionamento das estruturas projetadas para atender a demanda da população. Os métodos analíticos e experimentais mais utilizados possuem algumas limitações de ordem teórica ou prática. Por outro lado, os métodos numéricos, capazes de simular etapas construtivas e envolver materiais com diferentes modelos constitutivos numa mesma análise, buscam atender às necessidades práticas dos projetos de geotecnia e, ao mesmo tempo, complementam os modelos analíticos e experimentais. Nesse trabalho foram realizadas comparações entre resultados obtidos em ensaios experimentais e resultados extraídos do modelo computacional, buscando aumentar a compreensão sobre a interação solo-estrutura em relação à distribuição de tensões mobilizadas e aos deslocamentos e deformações provocados. A simulação numérica foi feita com a utilização do PLAXIS/3D, software de análise geotécnica baseado no método dos elementos finitos. Os ensaios foram confeccionados na Escola de Engenharia de São Carlos/USP por Costa (2005) e envolveram dutos enterrados submetidos à perda de apoio ou elevação localizada. O estudo experimental foi realizado através de modelos físicos compostos por um maciço de areia pura, contendo um tubo repousando sobre um alçapão no centro do vão. Os modelos físicos foram equipados com instrumental capaz de medir as deflexões e as deformações específicas ao longo do duto, além das tensões totais no maciço de solo circundante e na base do equipamento. / Recent disasters that occurred in this country, like the failure of a pipeline in Campo Grande and others disasters related to urban flooding, show us the need for developing scientific researches that help us to understand the behavior of these structures and to design them to serve the population. Analytical and experimental methods have some theoretical and practical limitations. On the other hand, numerical methods are capable to simulate staged constructions and to analyze together materials with different constitutive models, supplying practical necessities of geotechnical projects and complementing analytical and experimental models. In this dissertation comparisons between experimental results and numerical results have been made, trying to increase the comprehension about the interaction of soil and pipe with respect to mobilized stress distribution, displacements and strains. The numerical modeling was performed on PLAXIS 3D software, based on Finit Elements Method. The experimental test was made by Costa (2005) at São Carlos Engineering School/USP and involved buried pipes undergoing loss of support or elevation in a localized region along its length. Tests have been performed with physical models comprising dry and pure dry sand and a tube resting on a rigid trapdoor base located at the center of its length. The models were equipped with devices for measuring deflections and strains in the pipe, and total stresses in soil mass and in the lower boundary of the model.

Esta dissertação versa sobre a importância da roda, denominação atribuída a um grupo de pessoas que pauta suas ações individuais e coletivas em busca de mudanças comportamentais e sociais. Ganham espaço para reflexão, dois gêneros de rodas: o Fórum Social Mundial, ao se converter em espaço de debate das inquietações que afligem a humanidade, com a perspectiva de apontar os caminhos para o seu bem estar social e as Rodas Pedagógicas quando voltadas à promoção de uma aprendizagem significativa, oriunda da interatividade de seus pares, em especial na análise e produção textual. Estes dois gêneros de rodas são estudados a partir da possibilidade de fortalecer os valores humanos e auxiliar na construção de uma sociedade mais justa e cooperativa, menos individualista e competitiva. Nesta perspectiva, as rodas são encaradas como formas de contraposição ao individualismo, àquele que é sinônimo de egoísmo ou egocentrismo. Com relação ao Fórum Social Mundial são destacados os objetivos, bem como a sua importância no contexto global como a maior roda planetária que se estrutura sob o lema "um outro mundo é possível". Nas rodas dedicadas à aprendizagem, aqui denominadas pedagógicas, está descrito o método da roda, fruto de uma prática constante, direcionado à análise e produção textual compartilhada, e que revela a sua importância como forma de aprendizagem significativa. Também são apresentados os resultados obtidos a partir da aplicação do método em uma turma de alunos no ensino superior, partindo de critérios específicos. O método da roda foi submetido a uma avaliação pelos sujeitos que o experimentaram, através de questões que permitem constatar se a técnica aplicada auxilia no ensino e na aprendizagem e contribui para estreitar laços, bem como estruturar uma aprendizagem mais cooperativa e menos competitiva, capaz de provocar mudanças na sociedade em que vivemos. O Fórum Social Mundial e as rodas voltadas ao ensino e aprendizagem; tanto as pequenas quanto as grandes rodas aqui abordadas são consideradas pedagógicas porque ensinam e têm em comum, a cooperação e o desafio de vencer o individualismo que resulta de uma competitividade sem limites advinda da globalização neoliberal ou do triunfo do capitalismo. Quando assim estruturadas se constituem em núcleos fortalecedores das comunidades frente ao individualismo que se observa principalmente na sociedade ocidental, que nega qualquer forma de ética, pois esta pressupõe o outro. O que desponta neste início de século é uma vida comunitária fragilizada e enfraquecida, a qual dá margens à corrupção, à insegurança e ao descontrole social. As rodas aqui descritas se constituem em modelos para enfrentar a desestruturação social e fortalecer as comunidades e o seu conjunto, a sociedade. / This dissertation is about the importance of the circle, which is the name given to a group of persons that base their individual and collective actions in search of behavioral and social changes. Two kinds of circles will be discussed here: the World Social Forum as a discussion space of the concerns that afflict humanity, with the perspective of pointing ways for social well being of the people; and the Pedagogical Circles, when they are used to promote significant learning coming from interactivity among pairs, especially in text production and analysis. These two kinds of circles are studied from the possibility of strengthening human values and to help in the construction of a more just and cooperative society, less individualist and competitive. In this perspective the circles are seen as contraposition ways against individualism, in the sense of selfishness or egocentrism. About the World Social Forum, its objectives will be pointed out as well as its importance in the global context as the biggest world circle based on the slogan another world is possible. About the circles dedicated to learning, called here pedagogical, the circle method which results from constant practice directed to participative text analysis and production and that reveals its importance as a meaningful way of learning will be described. There are also presented the results obtained from using the method with a group of university students, based on specific criteria. The method of the circle was evaluated by the persons that have tried it, through questions that allow observing if the technique helps in teaching and learning and contributes to tighten relationships as well as structuring a more cooperative and less competitive learning able to instigate changes in the society in which we live. The World Social Forum and the circles dedicated to teaching and learning; the small circles as well as the big circles discussed here are considered pedagogical because they teach and they have in common the cooperation and the challenge to overcome individualism that results in a limitless competitiveness that comes from neoliberal globalization or the triumph of capitalism. When they are structured in this way they form strengthening nucleus of the communities in face of the individualism that is observed mainly in the western society, which denies any form of ethics because ethics presupposes the other. What arises in the beginning of this century is a fragile and weakened communitarian life that allows corruption, insecurity and social lack of control. The circles described here constitute models to confront the lack of social arrangement and to strengthen the communities and their whole, the society.