Implementação de um tuboexpansor na refinaria do Planalto Paulista – REPLAN com objetivo do aproveitamento da energia contida nos gases residuais do FCC – Fluid Catalytic Cracking na geração de energia elétrica

The steel type AISI 4130 (ultra-high strength steel) is an alloy of low carbon and its main alloying elements are chromium and molybdenum, which improves the toughness of the weld metal. It has numerous applications, especially where the need for high mechanical strength. It is widely used in equipment used by the aviation industry, such as cradle-tomotor, and this is the motivation for this study. Cots are of fundamental importance, because the engine supports and maintains balance in the fixed landing gear. This equipment is subjected to intense loading cycles, whose fractures caused by fatigue are constantly observed. Will be determined the effects caused by re-welding the structure of aeronautical equipment, and will also study the microstructure of the metal without welding. The studies will be done on materials used in aircraft, which was given to study. The results provide knowledge of microstructure to evaluate any type of fracture that maybe caused by fatigue. Fatigue is a major cause of aircraft accidents and incidents occurred, which makes the study of the microstructure of the metal, weld and re-solder the knowledge essential to the life of the material. The prevention and control of the process of fatigue in aircraft are critical, since the components are subjected to greater responsibility cyclic loading

Comportamento fractal de superfície da zona de estiramento em aço 300M temperado

Fracture surfaces are the fracture process marks, taht it is characterized by energy release guieded by failure mode. The fracture toughness express this energy em stress and strain terms in pre-cracked samples. The strectch zone is the characteristic region forms by the transition of fatigue fracture and final fracture and it width demonstrate the relation with failure energy release.The quantitative fractography is a broadly tool uses in failure surfaces characterization that it can point to a material’s aspect or a fracture process. The image processing works like an investigation tool, guinding a lot of studies in this area. In order to evaluate the characterization effectivity and it respectivity studies, it used 300M steel that it was thermal treated by an aeronautical process known and it characterized by tensile test and energy dispersive spectroscopy (EDS). The tensile test of this material, made by ASTM E8, allowed the head treatment effectivity confirmation, beyond of mechanics porperties determination. The EDS confirmed the material composition, beyond of base the discussion about fracture mechanism presence. The fracture toughness test has also made, that it works to obtain the fracture surfeaces studies below self-similarity and self-affinity approaches. In front of all the exposed it was possible to conclude that the fractal dimension works like a study parameter of fracture process, allowinf the relation of their values with changes in thickness, which interferes directly in material’s behaviour in fracture toughness approach

Comportamento fractal de superfícies de fadiga em ligas aeronaúticas

Fracture surfaces express sequences of events of energy release with crack propagation in metal alloys, the evolution of topographic features can indicate the lines of load action, failures during the use or processing. The quantitative fractography is an important tool in the study of fracture surfaces, because it allows their interpretation and characterization. In order to evaluate the effectiveness of the characterization of fracture surfaces grounded on concepts such as selfsimilarity and self-affinity, it used the 15-5PH steel that was characterized by metallographic and tensile tests. The metallography allows the microstructural characterization of this steel and proved the presence of the martensite phase in the slats form and a fine-grained, both in the radial and in the axial direction of the dowel. The tensile test (ASTM E8) of this material allowed the determination of the mechanical properties, so based on the obtained results it was possible to affirm that the 15-5PH steel has high mechanical properties and a good stretch. Besides, the specimens also underwent testing of crack propagation, standardized by ASTM E647-00, thus it was obtained the fracture surfaces for characterization under monofractal and multifractal approaches. In front of all the exposed it was possible to conclude that in all measurements the correlation between the crack tip position and the fractal dimension was established in accordance with changes in the thickness and in the fracture micromechanisms presents. Furthermore, the multifractal approach was more sensitive to these variations allowing a more detailed characterization of the morphology

Alterações microestruturais decorrentes dos sucessivos reparos de solda TIG aplicados ao longo da vida útil de uma estrutura aeronáutica crítica à segurança de vôo

The steel type AISI 4130 (ultra-high strength steel) is an alloy of low carbon and its main alloying elements are chromium and molybdenum, which improves the toughness of the weld metal. It has numerous applications, especially where the need for high mechanical strength. It is widely used in equipment used by the aviation industry, such as cradle-tomotor, and this is the motivation for this study. Cots are of fundamental importance, because the engine supports and maintains balance in the fixed landing gear. This equipment is subjected to intense loading cycles, whose fractures caused by fatigue are constantly observed. Will be determined the effects caused by re-welding the structure of aeronautical equipment, and will also study the microstructure of the metal without welding. The studies will be done on materials used in aircraft, which was given to study. The results provide knowledge of microstructure to evaluate any type of fracture that maybe caused by fatigue. Fatigue is a major cause of aircraft accidents and incidents occurred, which makes the study of the microstructure of the metal, weld and re-solder the knowledge essential to the life of the material. The prevention and control of the process of fatigue in aircraft are critical, since the components are subjected to greater responsibility cyclic loading

Análise do comportamento em fadiga de rodas ferroviárias fabricadas pelos processos de forjamento e fundição

Since the beginning of the railway industry until today, rail wheels are important components to the good working of a railway. For being a critical security item, design and maintenance are done with extremely care to avoid failures. Despite de fact of railway components be projected to support a big number of cyclic solicitation during its life, some accidents still occur. These accidents, despite the low frequency, always have great consequences, drawing in great financial, material, and people losses. Nowadays, railway component failure is relatively low, because it’s been projected to work below the materials Fatigue Resistance Limit, however, with the growing demand of faster trains and higher load for each axle, the occurrence probability is even bigger. This work includes a comparative study of two fabrication processes (casting and forging) applied in the production of rail wheels where it was measured the mechanical properties of traction and fatigue. The study also verified through microstructural analysis, hardness, traction and fatigue tests, statistical analysis of fatigue test results and fractographic analysis that forging process lead to better correlations between fatigue life and mechanical properties, providing more security in railroads, less wagon retention caused by corrective maintenance and smaller operational cost with its use

Efeito do tratamento da superfície dental com os lasers Nd:YAG e Er: Yag na adesão da resina composta à dentina recém clareada

To evaluate the effect of surface treatment with Er:YAG and Nd:YAG laser on resin composite bond strength to recently bleached dentin. Material and Methods: In this study 120 bovine incisors were used and distributed into two groups: Group C: without bleaching treatment; Group B: with bleaching treatment (35% hydrogen peroxide). Each group was divided into three subgroups: Subgroup N: without laser treatment; Subgroup Nd: irradiation with Nd:YAG laser; Subgroup Er: irradiation with Er:YAG laser. Next, the adhesive system (Adper Single Bond 2) was applied and composite buildups were constructed with Z350 composite. The teeth were sectioned to obtain dentin-resin sticks (1x1mm) and analyzed by microtensile bond testing. The data were statistically analyzed by the ANOVA and Tukey tests. Results: The results showed that the bond strength values in the bleached control group (16.17 MPa) presented no significant difference in comparison with the group bleached and irradiated with Er:YAG laser (14.69 MPa). The non bleached control group (26.79 MPa) presented significant difference in bond strength when compared with the non bleached group irradiated with Er:YAG laser (22.82 MPa) and with the group treated by bleaching and irradiation with Nd:YAG laser (28,792 MPa). The group without bleaching treatment and irradiated with Nd:YAG (36.1 MPa) presented a significant increase in bond strength in comparison with the other groups. Conclusion: The use of Nd:YAG laser on bleached specimens was able of completely reversing the immediate effects of bleaching, obtaining bond strength values similar to those of the control group

Significados da reforma agrária em bairros periféricos de Presidente Prudente (SP): uma tentativa de diálogo entre a luta pela Terra e a soberania alimentar

La lucha por la tierra en el Brasil se confunde con la própria historia del país, erigida sobre una cuestión agraria turbulenta en la cual ha predominado la hegemonía de los grandes proprietarios de tierra, tanto en la forma de latifundistas, cuanto, más recientemente, de los empresarios del agribusiness, caracterizando una versión más moderna de la dominación de la lógica del capital en detrimento de las demás formas de organización de la vida. A partir de la segunda mitad del siglo XX, ocurre un aguzamiento de los conflictos por la tierra con la emergencia de los principales movimientos sociales en Brasil, como el MST. Esos movimientos surgen en un contexto de transformación de la formación socioespacial brasileña, marcada por la creciente urbanización del país, lo que repercute em las sus formas de organización, pasando a comparecer una preocupación con la población urbana en las discusiones y acciones en pro de la Reforma Agraria. Yuxtaponiendo-se a eso proceso, también ha emergido fortemiente en las últimas décadas la problemática de la hambre en el mundo, tanto a través de los dados alarmantes de los organismos supranacionales (FAO), como del debate impulsado por los movimientos sociales acerca de la Soberanía Alimentaria (Via Campesina). Todos esos elementos merecen atención em esto trabajo, que busca aprehender cómo se efectiva la participación de barrios de la periferia pobre de la ciudad de Presidente Prudente/SP en el proceso de lucha por la tierra en el Pontal del Paranapanema, haciendo eso por lo medio de una lectura geográfica de esa realidad que prime por la superación analítica de la disociación entre ciudad y campo, como se fueran espacios inertes entre sí. Además, es nuestro objetivo destacar las motivaciones que llevan los sujetos protagonistas de eso proceso a dejaren la ciudad y adhieriren a la lucha por la tierra, permitiendo identificar elementos que extrapolan la esfera económico-material

Planejamento ambiental da bacia do Balneário da Amizade – São Paulo

Esta monografia esta relacionado à pesquisa de iniciação científica inserida no Grupo de Pesquisa em Gestão Ambiental e Dinâmica Socioespacial (GADIS), da Faculdade de Ciências e Tecnologia, UNESP, campus de Presidente Prudente, e vincula-se a projetos mais amplos desenvolvidos com apoio da FAPESP, do CNPq e FEHIDRO. De modo geral, este trabalho possui o objetivo de contribuir para o planejamento ambiental da bacia do Balneário da Amizade, como também para o gerenciamento de seus recursos hídricos, aprofundando conhecimentos teórico-metodológicos sobre o tema. Os procedimentos metodológicos seguem a proposta de Rodriguez (1994) adaptada por Leal (1995), na qual incluem etapas de elaboração do Inventário, Diagnóstico Ambiental, Prognóstico e Propostas, de modo a identificar as características de uso e ocupação da bacia do Balneário da Amizade, mapear seus principais problemas ambientais e elaborar propostas visando sua recuperação ambiental e a preservação de seus recursos hídricos, além de analisar políticas públicas direcionadas para a bacia. A importância desta pesquisa se inicia com a escolha da área de estudo, já que a mesma é uma importante bacia hidrográfica para os municípios de Presidente Prudente e Álvares Machado... (Resumo completo, clicar acesso eletrônico abaixo)

Os movimentos nas redes e em redes: das manifestações internacionais ao Movimento Prudente

Neste trabalho apresentamos uma leitura sobre o processo de articulação dos movimentos em redes e do uso das redes sociais pelos movimentos socioespaciais que mais se destacaram no mundo nos últimos cinco anos. Tendo suas bases nos marcos conceituais de movimentos socioespacial, movimentos socioterritorial, Rede e Redes Sociais, remontamos ao processo de formação da Via Campesina e das manifestações na Primavera Árabe, M12M, M15M, Occupy Wall Street, Movimento Passe Livre e o Movimento Prudente na escala local. Analisar e comparar estes movimentos e suas manifestações nos permitiu identificar a conexão entre a difusão de informações nas redes sociais e a materialização das manifestações no espaço público. Destaca-se que o uso destas tem acarretado em uma nova dinâmica não só na difusão de manifestação, mas também na realização de trabalho de base, caracterizando-se como um importante espaço de socialização política da atualidade

Desenvolvimento de aplicativo de análise técnica e econômica para adaptação de uma roda d’água acionada por cima para geração de energia elétrica no meio rural

The steel type AISI 4130 (ultra-high strength steel) is an alloy of low carbon and its main alloying elements are chromium and molybdenum, which improves the toughness of the weld metal. It has numerous applications, especially where the need for high mechanical strength. It is widely used in equipment used by the aviation industry, such as cradle-tomotor, and this is the motivation for this study. Cots are of fundamental importance, because the engine supports and maintains balance in the fixed landing gear. This equipment is subjected to intense loading cycles, whose fractures caused by fatigue are constantly observed. Will be determined the effects caused by re-welding the structure of aeronautical equipment, and will also study the microstructure of the metal without welding. The studies will be done on materials used in aircraft, which was given to study. The results provide knowledge of microstructure to evaluate any type of fracture that maybe caused by fatigue. Fatigue is a major cause of aircraft accidents and incidents occurred, which makes the study of the microstructure of the metal, weld and re-solder the knowledge essential to the life of the material. The prevention and control of the process of fatigue in aircraft are critical, since the components are subjected to greater responsibility cyclic loading

A financeirização da moradia e o Programa Minha Casa Minha Vida

This paper has it is hypotesis on the government program “My Home, My Life” and the assumption that it is a public politic attached to the market logic of financialization of the housing. It is understood that this program encourage capital for the main constructors and incorporated of brazilian heritage elite. It also served as well to promote more rentability to international capital and intensified the sociospacial segregration process as real state speculation has been potencialized. This work aims to present and discuss the program contradictions that have been sustained on the speech of wide subsidy offer and habitance construcution for low income workers - month income until three minimum salaries. Documents have shown that in the first phase of the program, habitance construction for this sector of population corresponded only to 5,5% of total habitation deficit. Businessmen on residance civil construction and public politic representatives have confirmed that the program interests are linked to financial market logic.The real benefits are not for low income workers, but for real state agents through extraordinaty profits of land and the so called new medium workers class(worker class C).We will search for embasement on the country history through the different governments and housing policies, in value theory and the concept of land income to understand the financialization process of the housing. We will also analyse oficial documents and the agents speech involved in real state market to show program contradictions and whose the real benefts are for

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

Caracterização de cerâmicas a base de nitreto de silício para aplicações estruturais

The need for development of new materials is a natural process in the companies’ technological point of view, seeking improvements in materials and processes. Specifically, among the materials, ceramic exhibit valuable properties, especially the covalent ceramics which have excellent properties for applications which requires the abrasion resistance, hardness, high temperatures, resistence, etc. being a material that has applications in several areas. Most studies are related to improvement of properties, specially fracture toughness that allows the expansion of its application. Among the most promising ceramic materials are silicon nitride (Si3N4) which has excellent properties. The goal of this work was the development and caracterization of Si3N4-based ceramics, doped with yttrium oxide (Y2O3), rar earth concentrate (CTR2O3) and cerium oxide (CeO2) in the same proportion for the evaluation of properties. The powders' mixtures were homogenized, dried and compressed under pressure uniaxial and isostatic. Sintering was carried out in 1850 ⁰C under pressure of 0,1MPa N2 for 1 h with a heating rate of 25 ⁰C / min and cooling in the furnace inertia. The characterizations were performed using Archimedes principle to relative density, weight loss by measuring before and after sintering, phase analysis by X-ray diffraction, microstructure by scanning electron microscope (SEM), hardness and fracture toughness by the method Vickers indentation. The results obtained showed relative density of 97-98%, Vickers hardness 17 to 19 GPa, fracture toughness 5.6 to 6.8 MPa.m1/2, with phases varying from α-SiAlON and β-Si3N4 depending the types of additives used. The results are promising for tribological applications and can be defined according to the types of additives to be used

Estudo do efeito do processo de shot peening na taxa de propagação de trinca por fadiga na liga aeronáutica 2024 - T3

Pós-graduação em Engenharia Mecânica - FEG

Obtenção de rochas sintéticas a partir de resíduos de vidro comercial e pó de granito

Pós-graduação em Engenharia Mecânica - FEG