921 resultados para reinforcement classes


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Como escreve Edgar Morin "..., a questão da origem do homem e da cultura não diz unicamente respeito a uma ignorância que é preciso reduzir, a uma curiosidade a satisfazer. É uma questão com um alcance teórico imenso, múltiplo e geral. E o nó górdio que sustem a soldadura epistemológica entre natureza/cultura, animal/homem. É o local exacto onde devemos procurar o fundamento da antropologia, i De que forma as tecnologias da comunicação vão influenciar as atitudes culturais e porquê a preocupação com as classes médias urbanas? Qual o motivo do seu isolamento como objecto e (ou) sujeito no domínio que estamos a tratar? Porque defendemos o ponto de vista de que se trata do grupo social (ou do conjunto de sub-grupos sociais) meno(s) enraizado(s) numa cultura própria e por esse motivo com maior exposição à manipulação televisiva, à influência dos jornais, à informação radiofônica e até às vagas da intemet. Neste contexto, os comportamentos das elites universitárias, das aristocracias operárias, dos rendeiros agrícolas e dos proletários rurais obedecem a padrões de comportamento diversos, mas em que o cosmopolitismo, a ancestralidade e o distanciamento face a valores socialmente dominantes dificultarão as condições de manipulação.

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Tese a apresentar para o cumprimento dos requisitos necessários à obtenção do grau de Doutor em Linguística – Especialidade de Lexicologia, Lexicografia e Terminologia

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A sorologia tem sido o método de escolha para o diagnóstico da toxoplasmose. Devido a isto, padronizamos um ensaio imunoenzimático (ELISA) e comparamos seus resultados com a técnica de imunofluorescência indireta (IFI). A técnica padronizada apresentou na pesquisa de IgG sensibilidade (S) de 96,7% e especificidade (E) de 75%, com valor de predição de positividade (VPP) de 83,3% e de negatividade (VPN) de 94,7%, com uma concordância ajustada (K) de 73,5%. A IFI apresentou S de 83,8%, E de 79,1% com VPP de 83,8 % e VPN de 79,1% com K de 63%. A concordância bruta entre os dois testes (ELISA/IFI) foi de 88,3% para pesquisa de IgG e de 81,5% para pesquisa de IgM, sendo o K de 70,8% para IgG e de 1,3% para IgM, sendo o índice de correlação (r) de 0,556 para IgG e de -0,023 para IgM. Podemos concluir que a ELISA-IgG padronizada é indicada nos processos de triagem sorológica, sendo a ELISA-IgM desaconselhada uma vez que apresentou baixos índices de concordância ajustada com a técnica de referência, sugerindo pouca confiabilidade dos resultados.

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Dissertation presented to obtain the Ph.D degree in Biology, Neuroscience

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Para estudar a freqüência da infecção pelo Toxocara canis em crianças de classes sociais diferentes de Brasília, Brasil, foram testados soros de 602 crianças de ambos os sexos, de 1 a 12 anos, distribuídas em dois grupos representativos de condições socioeconômicas distintas. As amostras do primeiro grupo foram obtidas em laboratório público que atende bairros pobres. As do segundo grupo foram colhidas em laboratório privado, que serve à classe média. Os anticorpos anti-Toxocara foram detectados pelo método ELISA, com antígenos de Toxocara canis, e absorção com antígenos do Ascaris suum. A prevalência de soropositividade foi de 21,8% (66/302) no primeiro grupo e de 3% (9/300) no segundo (p<0,0001). Não houve diferença quanto ao gênero ou idade das crianças. Os resultados sugerem significativa prevalência de toxocaríase na população infantil de Brasília, com predomínio nas classes sociais menos favorecidas economicamente.

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This paper studies the drivers of heuristic application in different decision types. The study compares differences in frequencies of heuristic classes' such as recognition, one-reason choice and trade-off applied in, respectively, memory-based and stimulus-based choices as well as in high and low involvement decisions. The study has been conducted online among 205 participants from 28 countries.

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Com o presente trabalho estudamos a Primeira República do pós-guerra (1919-1926), procurando compreender o sentido histórico desses anos atribulados, caracterizados por uma permanente instabilidade governativa e pelo desassossego dos agentes sociais. Defendemos existir uma explicação que torna os últimos anos do regime republicano, aparentemente caóticos, compreensíveis: à semelhança de outros países europeus, a especificidade dos anos 20 portugueses reside num fenómeno de polarização política da sociedade, na mobilização e organização de forças mediante os quadrantes da esquerda e da direita modernas. Concretamente, o nosso objecto de estudo consiste na esquerda republicana, um campo que se autonomizou dentro do republicanismo durante o pós-guerra, e no bloco radical, conceito analítico sob o qual englobamos manifestações heteróclitas (partidárias, armadas, intelectuais, unitárias) do fenómeno de polarização política à esquerda.

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This working paper explores the use of interactive learning tools, such as business simulations, to facilitate the active learning process in accounting classes. Although business simulations were firstly introduced in the United States in the 1950s, the vast majority of accounting professors still use traditional teaching methods, based in end-of-chapter exercises and written cases. Moreover, the current students’ generation brings new challenges to the classroom related with their video, game, internet and mobile culture. Thus, a survey and an experimentation were conducted to understand, on one hand, if accounting professors are willing to adjust their teaching methods with the adoption of interactive learning tools and, on the other hand, if the adoption of interactive learning tools in accounting classes yield better academic results and levels of satisfaction among students. Students using more interactive learning approaches scored significantly higher means than others that did not. Accounting professors are clearly willing to try, at least once, the use of an accounting simulator in classes.

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Applying a certain prestress level to the carbon fiber reinforced polymer (CFRP) reinforcement according to either externally bonded reinforcing (EBR) or near surface mounted (NSM) techniques can mobilize the strengthening potentialities of this high tensile strength composite material. For the prediction of the flexural behavior of reinforced concrete (RC) structures strengthened with prestressed EBR or NSM CFRPs, however, simplified analytical and design formulations still need to be developed as a guidance for engineers to design this type of strengthened structures by hand calculation without any programming help. Hence, the current work aims to briefly explain a developed simplified analytical approach, with a design framework, to predict the flexural behavior of RC beams flexurally strengthened with either prestressed EBR or NSM CFRP reinforcements. Moreover, an upper limit for the prestress level is proposed in order to optimize the ductility performance of the NSM prestressing technique. The good predictive performance of the analytical approaches was appraised by simulating the results of experimental programs composed of RC beams strengthened with prestressed NSM CFRP reinforcements.

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High performance fiber reinforced concrete (HPFRC) is developing rapidly to a modern structural material with unique rheological and mechanical characteristics. Despite applying several methodologies to achieve self15 compacting requirements, some doubts still remain regarding the most convenient strategy for developing a HPFRC. In the present study, an innovative mix design method is proposed for the development of high17 performance concrete reinforced with a relatively high dosage of steel fibers. The material properties of the developed concrete are assessed, and the concrete structural behavior is characterized under compressive, flexural and shear loading. This study better clarifies the significant contribution of fibers for shear resistance of concrete elements. This paper further discusses a FEM-based simulation, aiming to address the possibility of calibrating the constitutive model parameters related to fracture modes I and II.

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The present paper deals with the experimental assessment of the effectiveness of steel fibre reinforcement in terms of punching resistance of centrically loaded flat slabs, and to the development of an analytical model capable of predicting the punching behaviour of this type of structures. For this purpose, eight slabs of 2550 x 2550 x 150 mm3 dimensions were tested up to failure, by investigating the influence of the content of steel fibres (0, 60, 75 and 90 kg/m3) and concrete strength class (50 and 70 MPa). Two reference slabs without fibre reinforcement, one for each concrete strength class, and one slab for each fibre content and each strength class compose the experimental program. All slabs were flexurally reinforced with a grid of ribbed steel bars in a percentage to assure punching failure mode for the reference slabs. Hooked ends steel fibres provided the unique shear reinforcement. The results have revealed that steel fibres are very effective in converting brittle punching failure into ductile flexural failure, by increasing both the ultimate load and deflection, as long as adequate fibre reinforcement is assured. An analytical model was developed based on the most recent concepts proposed by the fib Mode Code 2010 for predicting the punching resistance of flat slabs and for the characterization of the behaviour of fibre reinforced concrete. The most refined version of this model was capable of predicting the punching resistance of the tested slabs with excellent accuracy and coefficient of variation of about 5%.

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This study presents an experimental program to assess the tensile strain distribution along prestressed carbon fiber reinforced polymer (CFRP) reinforcement flexurally applied on the tensile surface of RC beams according to near surface mounted (NSM) technique. Moreover, the current study aims to propose an analytical formulation, with a design framework, for the prediction of distribution of CFRP tensile strain and bond shear stress and, additionally, the prestress transfer length. After demonstration the good predictive performance of the proposed analytical approach, parametric studies were carried out to analytically evaluate the influence of the main material properties, and CFRP and groove cross section on the distribution of the CFRP tensile strain and bond shear stress, and on the prestress transfer length. The proposed analytical approach can also predict the evolution of the prestress transfer length during the curing time of the adhesive by considering the variation of its elasticity modulus during this period.

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The reinforcement of soil is defined as an effective and reliable technique to improve strength and stability. For this propose, the use of natural fibers has been commonly. Over the past years, a series of studies have been performed in order to investigate the influence of randomly oriented fibers, especially for compressible clayey soils. However, less attention has been given to the reinforcing of sandy materials, as well as the use of oriented fibers meshes in order to improve mechanical behaviour. The main aim of this study is to identify the influence that different percentages of fibers, as well as the use of meshes of oriented fibers, has on soil mechanical behaviour. For this purpose, unconfined compression tests with local strain measurements were performed on a silty sand reinforced with Sisal fibers and a comparative study between randomly oriented and 0° and 90° fibers is presented.

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[Excerto] Antes de mais, impõe-se este esclarecimento: estamos na presença da 1.ª reimpressão da 3.ª edição (a 1.ª é de 2004) do livro em epígrafe, e a razão de só agora o estar a recensear (sabia contudo da sua existência há já alguns anos) tem simplesmente a ver com o facto de não há muito me ter chegado às mãos e, sobretudo, de só muito recentemente ter tido a oportunidade de o ler como deve ser, isto é, reflexivamente. Trata-se de um pequeno grande texto de uma especialista na matéria (Margarida Basílio, professora titular da Pontifícia Universidade Católica do Rio de Janeiro), que conheço há longos anos de outros, de que destacaria Teoria lexical (São Paulo: Ática, 1987) e Estruturas lexicais do português: uma abordagem gerativa (Petrópolis: Vozes, 1980). Pequeno, é claro, só no número de páginas: nem sequer chega às cem (noventa e cinco, contabilizadas já as duas com as referências bibliográficas). Grande, deveras, no que diz respeito à temática e de modo particular ao seu tratamento: uma descrição de pendor didático dos padrões gerais e dos principais processos de formação de palavras na variedade brasileira do português. (...)

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OBJECTIVE: To describe a surgical procedure utilizing a malleable bovine pericardium ring in mitral valve repair and clinical and echodopplercadiographic results. METHODS: Thirty-two (25 female and 7 male) patients, aged between 9 and 66 (M=36.4±17.2) years, were studied over a 16-month period, with 100% follow-up. In 23 (72%) of the patients, the mitral approach was the only one applied; 9 patients underwent associated operations. The technique applied consisted of measuring the perimeter of the anterior leaflet and implanting, according to this measurement, a flexible bovine pericardium prosthesis for reinforcement and conformation of the posterior mitral annulus, reducing it to the perimeter of the anterior leaflet with adjustment of the valve apparatus. RESULTS: The patient survival ratio was 93.8%, with 2 (6.2%) fatal outcomes, one from unknown causes, the other due to left ventricular failure. Only one reoperation was performed. On echodopplercardiography, 88% of the patients had functional recovery of the mitral valve (50% without and 38% with mild insufficiency and no hemodynamic repercussions). Of four (12%) of the remaining patients, 6% had moderate and 6% had seigre insufficiency. Twenty-eight percent of class II patients and 72% of class III patients passed into classes I (65%), II (32%), and III (3%), according to NYHA classification criteria. CONCLUSION: Being flexible, the bovine pericardium ring fit perfectly into the valve annulus, taking into account its geometry and contractility. Valve repair was shown to be reproducible, demonstrating significant advantages during patient evolution, which did not require anticoagulation measures.