Modelagem e simulação do mecanismo biela manivela e análise estrutural de biela automotiva

Nowadays, the automotive industry is working to optimize the design of engines, in order to reduce the fuel consumption with acceptable efficiency ratio. This undergraduate thesis is aimed at perform a kinematic/dynamic analysis of a slider-crank mechanism that is part of a four stroke internal combustion engine, the same engine that was used in the analysis described by Montazersadhd and Fatemi (2007). Two algorithms were developed based on Kane’s method to calculate velocities and accelerations of the mechanism bodies, and provide the acting forces at connecting rod joints. A SimMechanics model was developed to simulate the engine, and monitoring the same parameters that were calculated with the algorithms. The results obtained with both approaches were satisfactory and showed good agreement with the values provided by Montazersadhd and Fatemi (2007). The obtained results showed that the axial component of the rod joint efforts was caused by the pressure exerted on the piston head,whereas the radial component was related with the action of inertia loads. Besides, this thesis presents a connecting rod assembly mesh that is going to be used for static and fatigue finite element analysis in the future

Estudo da deformação heterogênea no ensaio do anel de atrito

The plastic deformation is widely used in the metallurgical market due to its positive factors such as low prices and high speed production. Forming process products are obtained in high quality, both surface quality and mechanical properties. Friction is an importante factor in metal forming. Friction study in metal forming can be accomplished indirectly, such as the ring test of friction. Two samples of different materials being mild steel and copper alloy were used. The results showed the influence of friction in the flow behavior of the deformation of the second phase, as evidenced by standard metallography. It is observed that in the outer regions of the ring, plastic deformation occured in the radial direction. In the central region of the disc deformation occured in the direction of compression and the inner region of the ring flux lines showed a significant deformation in the radial direction towards the center of the ring

Caracterização microestrutural de junta soldada com arco submerso e análise da propagação de trincas em um tubo de aço API X 70

In this work a study of an API 5L X70 steel, which is used in the manufacture of oil and gas pipelines, has been made. This class of steel show high strength and ductility values, and has been increasingly studied due the growing demand of oil and natural gas, which in consequence, increases the needing of new pipelines to transport them. The material studied has been directly taken from a tube provided by TenarisConfab, and a special attention has been given to the fatigue crack growth rate study, which proved that a crack will grow at different rates according to the tube position where it is growing

A magia em um texto técnico agronômico da antiguidade romana: o 'Opus agriculturae', de Paládio

This work analyses the chapter 35, book I, of the agricultural treatise Opus agriculturæ, written by Rutilius Taurus Aemilianus Palladius (V C.E.). In that chapter the author presents some recipes, called remedia, to protect the farm and the garden against weeds and weather phenomena, as blight and fogs. The magical practices are identified according to both the fundamental principles of magic (similarity, contiguity, contrariety), which rule magical thought, and some elements of magical symbology. As the author seems not to distinguish magic and science, for he brings together both kinds of recipes, the analysis of some remedia emphasizes a specific study on the materials and substances employed in those recipes and their value in Science today. This leads to the discussions of how magical thought works, what are the limits (if they actually exist) between Magic and Science and between Magic and Religion. This work covers the subjects above and it has the following pourposes: demonstrate the characteristics that authorize the remedia described by Palladius to be classified as folk magic; identify the relations between this kind of practice with more complex forms of magic, as with religion, with science; demonstrate the contribution of the folk magic in ancient Rome farming for the formulation of more apropriated criteria of evaluating magic in comparison to religious and scientific thought.

Estudo do aumento no diâmetro do corpo de um rebite a ser cravado em furos acima da tolerância de projeto

In this work are discussed the main types of rivets, their characteristics and applicability within the Aeronautical Industry branch. Here are highlighted the solid rivets, showing off its layout, forms and limits of installation, that are required by aviation regulators. The riveting is a popular and simple procedure of fixing and joining two or more parts, and like any other manufacturing process is subject to process deviations that in some situations are beyond the limits of tolerance. One of these deviations is when the hole diameter exceeds the one proposed in project and which is limited by the rule of edge distance. The overall objective here is to study a possible solution to this problem: the installation of a rivet that has his diameter previously increased by compression. Observe the hole filling after riveting, detect the presence of cracks, discover the yield curve of the fasteners and their the crushing limits for failure prediction are tools used to verify this proposal. They demonstrate, at the end of study, the inefficiency of this procedure, with results that go against the safe fixing of parts in a structure

Análise microestrutural de tubos API N80 soldados pelo processo HF/ERW para prospecção de petróleo e gás

On the grounds of the great advances achieved over recent years, the process HF/ERW (High-Frequency/Electric Resistance Welding)welded pipe have played an active role in the oil and gas industry for deep water applications, at high and extremely low temperatures, under high pressure and in highly corrosive environments, gradually replacing manufactured pipes by other processes. However, studies have shown that defects in the welded joints are a the leading causes of pipelines failures, which has required the determination of toughness values in this region, in compliance with the strict recommendations of the codes and standards with manufacturers and construction companies, on the oil and gas sector. As part of the validation process required toughness values, this research project focuses on a microstructural analysis in HF / ERW tubes microalloyed, steel grade API 5CT N80, designed to explore oil and gas in deep waters, the subject of strategic relevance to the country because of the recent discoveries in the Santos mega fields: Tupi and Libra (pre-salt). In this scientific work will be presented and discussed the results of mechanical tensile and Charpy, a few CTOD tests curves (showing the trend of toughness values to be obtained), and the microstructures of the base material obtained by optical microscopy, with special emphasis on the formation of non-metallic inclusions in the welded joint

Diversidade e distribuição de siris (Decapoda: Brachyura: Portunidae) e dinâmica populacional de Callinectes ornatus no litoral norte de São Paulo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparação de junta soldada aço carbono/ aço inox utilizando como metal de adição aço carbono e aço inox

In contemporary industrial, welding processes are widely used, this is the most important process of joining metals used industrially. The welding can be used to build simple structures, like doors and gates for instance, in the same way can be used in situations of high responsibility, such as the nuclear industry and oil industry. Dissimilar welding is a case of welded joints, is characterized by the junction between different materials, for this case, stainless steel and carbon steel that are widely used in steam lines, power plants, nuclear reactors, petrochemical plants. Because their different mechanical and corrosive properties, the join, stainless steel with carbon steel, not only meets environmental requirements and also reduces cost. By using penetrating liquid tests, macrograph, hardness and tensile test was compared the possibility of replacing the current use of 309 rods as filler metal in dissimilar welding between carbon steel and stainless steel by add-on material carbon steel essentially, in this case E7018 coated electrode was used, but without the coating. After analysis of the results and for comparison, was proposed with some certainty that it is possible to replace the addition of materials, thus leading economy in this process widely used in the modern industry

Estudo do comportamento em fadiga de um tubo de aço microligado, grau API 5L X70

This work focuses on a study on the fatigue behavior of a microalloyed steel API 5L X70, used in pipes lines to transport oil and gas. These types of steels have excellent mechanical resistance values and ductility and therefore increased their study driven by increased demand for oil and especially natural gas, which consequently raises the need to build new pipelines to transport these products. The oil extraction units, composed of the risers (pipelines connecting the oil well to the ship), are dimensioned to remain installed for periods of 20 to 30 years in the marine environment, a hostile environment for high pressure, corrosion, low temperatures and the stresses caused by the movement of water and tides. For analysis, the S-N (stress versus number of cycles) curves were obtained from data collected from bodies-of-proof cylindrical longitudinal, transverse and that one removed from the weld area of the pipe, tested in accordance with ASTM E466. Tensile tests were performed for characterizing the mechanical properties of the samples and welded joints, concluded that the values meet the specifications of the standard API 5L. To characterize microstructural material, also metallographic analysis was made of regions of the base metal and the HAZ. The results of fatigue tests demonstrated a higher life for the specimens removed from the longitudinal direction the pipe, followed by those in the transverse direction and, finally, the welded joint. The origins of the fatigue cracks were determined by scanning electron microscopy (SEM)

Uso e conservação de plantas medicinais nativas por comunidades quilombolas no município de Alcântara, Maranhão

Pós-graduação em Agronomia (Horticultura) - FCA

Avaliação dos parâmetros tempo, corrente e pressão na soldagem por resistência elétrica de compósitos PEI/fibras contínuas: influência na resistência mecânica

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

Os efeitos psicológicos da atividade física nos cuidados de dependentes químicos

O profissional de educação física nos dias atuais deve ter amplo conhecimento sobre diversos assuntos relacionados à prevenção e manutenção da saúde de modo que este poderá atuar diretamente na melhora e reeducação da qualidade de vida de diferentes estados físicos e emocionais das pessoas em que irá trabalhar. O consumo abusivo de drogas ilícitas no século XXI, trás consequências emocionais e físicas, as dependências econômicas e de saúde geradas pelo seu consumo e propaga-se que, quando não tratadas adequadamente podem gerar um ciclo caótico de complicações, vindo a estabelecer problema real para a saúde pública mundial. O presente trabalho tem por objetivo enfatizar por meio da revisão de literatura os efeitos benéficos, tanto psicológicos como fisiológicos, que os programas de atividade física regular exerce no processo de cuidado e/ou zelo do dependente químico em meio ao tratamento. Constatou-se que a atividade física nos cuidados e/ou zelo do dependente proporciona inúmeros benefícios à saúde, além de contribuição fisiológica como desintoxicação, diminuição da frequência cardíaca de repouso e pressão arterial, melhorar a vascularização, diminuir a fadiga central, liberação do hormônio do prazer (endorfina) e as capacidades funcionais musculoesqueléticas. O exercício também é de fundamental importância para resgatar aspectos psicológicos como controle da ansiedade, depressão, alivio do estresse, melhora da autoimagem, autoestima, confiança e disciplina para seguir o tratamento e futuramente sua vida, e por fim possibilitou, ainda, entender as relações entre as funções fisiológicas e psicológicas do homem, de modo a deixar explícito que ambas caminham juntas e uma equipe multidisciplinar contando com psicólogos, nutricionista e profissionais de educação física se faz necessário, visto que eles trabalham em equipe levando em consideração as especificidades de cada...

Determinação simultânea de biomarcadores de função renal em urina utilizando dispositivo analítico microfluídico em papel

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização funcional e estrutural das proteínas RUV-1 e RUV-2 do fungo Neurospora crassa

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo e análise estatística no mercado de ações brasileiro

The objective of this paper is to verify and analyze the existence in Brazil of stylized facts observed in financial time series: volatility clustering, probability distributions with fat tails, the presence of long run memory in absolute return time series, absence of linear return autocorrelation, gain/loss asymmetry, aggregative gaussianity, slow absolute return autocorrelation decay, trading volume/volatility correlation and leverage effect. We analyzed intraday prices for 10 stocks traded at the BM&FBovespa, responsible for 52.1% of the Ibovespa portfolio on Sept. 01, 2009. The data analysis confirms the stylized facts, whose behavior is consistent with what is observed in international markets.