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Comportamento mecânico em fadiga da liga de titânio beta metaestável Ti-5553
(Universidade Federal de São Carlos, 2016-10-14) Campanelli, Leonardo Contri; Silva, Paulo Sérgio Carvalho Pereira da; https://lattes.cnpq.br/4783514460488161; Bolfarini, Claudemiro; https://lattes.cnpq.br/9231627080617037; https://lattes.cnpq.br/8983259236829248
The microstructure of metastable beta Ti alloys is a decisive factor that governs their properties and, therefore, the assessment of the relation between the microstructure and the fatigue response means an advance in the still incipient knowledge on these alloys. The purpose of this work was to study the fatigue behavior of Ti-5Al-5Mo-5V-3Cr (Ti-5553) alloy recently developed for landing gear applications, which was kindly supplied by Boeing for this work. The material was subjected to different heat treatments (BASCA and double aging) aiming at to comprehend the influence of the alpha phase precipitation over the beta matrix, as well as to understand the effect of hydrogen even in commercially acceptable contents. BASCA microstructure comprised large laths and fine needles of primary and secondary alpha phase respectively, with a film of approximately 2 μm of thickness at grain boundaries. A refined and aligned structure of alpha phase resulted from the double aging treatment, reducing to 0.2 μm the thickness of the grain boundary alpha film. The fatigue limit at 5x106 cycles raised by the standardized staircase method initially showed an improved result for the harder microstructure, which resulted from the double aging, for 100 ppm of hydrogen. The fatigue crack nucleation, whether at the surface or subsurface, was attributed to the thickness of the grain boundary alpha film. In spite of this film brittleness, crack propagation predominantly occurred through the grains and exhibited quasi-cleavage facets and dimples. For the structure arising from the BASCA treatment, the decrease of the hydrogen content for 25 ppm led to a significant increase of the fatigue resistance as a consequence of the absence of hydrides and the higher toughness, overcoming the effect of the coarse alpha phase particles in the beta phase matrix.
O efeito do tamanho do lote de transferência no lead time em um ambiente flow shop: uma análise quantitativa
(Universidade Federal de São Carlos, 2016-10-14) Barco, Clarissa Fullin; Godinho Filho, Moacir; https://lattes.cnpq.br/6136685270563354; https://lattes.cnpq.br/1250853082206361
This thesis proposes to evaluate the effect of transfer batch size on lead time reduction in flow shop environments (balanced and unbalanced, with a bottleneck). In order to achieve this objective, Design Science was used as a research method, in which a static simulation model is proposed and several scenarios are analyzed and evaluated in relation to important Production Management theories. The model proposed to represent a flow shop uses the Factory Physics equations (HOPP; SPEARMAN, 2008) e considers the following shop-floor variables: i) the average setup time; ii) average defect rate; iii) mean time between failures; iv) mean time to repair the machine; v) variability in processing time; vi) variability of the time between arrivals of orders and vii) transfer batch size. The results demonstrate that for both balanced and unbalanced environment, transfer batch size has little effect on lead time, when operating with a process batch size away from optimal batch size (minimum point of the lead time - lot size curve proposed by Karmarkar et al. (1985)). To get a good lead time performance, it is first necessary to reduce process batch size before making efforts to reduce transfer batch. For an unbalanced environment, reducing process batch size only at the bottleneck, coupled to transfer batch size reduction across the flow shop, provided a lead time reduction on the order of 30%, while the remainder flow shop operated with large process batches. In such configuration, the contribution from setup time reduction at the bottleneck machine has generated a small effect on the lead time performance considering the parameters used in this work.
Efeito do treinamento resistido e reposição de hormônio sobre o transportador de glicose hepático (GLUT2) de ratas ovariectomizadas
(Universidade Federal de São Carlos, 2016-10-14) Tomaz, Luciane Magri; Lavoie, Jean Marc; Perez, Sergio Eduardo de Andrade; https://lattes.cnpq.br/9408953831211309; https://lattes.cnpq.br/8430651176725216
Oestrogens withdrawal in rats, through ovariectomy (Ovx), has been repeatedly associated with disturbances in lipid metabolism. Among them, liver fat accumulation is well substantiated. On the other hand, there is few information on how liver fat in Ovx rats may affect glucose metabolism in liver. The purpose of the study was to investigate the effects of Ovx and 12 weeks resistance training (RT) program on gene expression of GLUT2 the main glucose transporter in liver and on PPARy a transcription factor known to target GLUT2 gene expression. RT in rat is an exercise training model that has received little attention but that has been shown to result in metabolic adaptations in Ovx rats as well as in post-menopausal women. Holstman rats were divided into 5 groups: Sham-sedentary (Sed), Sham-resistance trained (RT), Ovx-Sed, Ovx-RT, and Ovx-Sed with hormone replacement (E2). The RT protocol consisted of resistance training sessions held every 72 h for 12 weeks, during which session the animals performed 4 to 9 vertical climbs (1.1 m) with progressive weights (up to 30 g) tied to the tail at 2 min intervals. In addition to liver fat, GLUT2 protein levels and PPARy transcripts were all increased (P < 0.05) in Ovx compared to Sham-Sed animals, suggesting an increase hepatic glucose uptake under oestrogens withdrawal. Resistance training as well as oestrogens replacement in Ovx rats decreased liver fat accumulation as well as GLUT2 and PPARy gene expression to the level of Sham-Sed group. The present results suggest that liver fat accumulation in Ovx rats is accompanied by an increased glucose uptake thus providing substrate for an increased de novo lipogenesis. RT appears to be an appropriate exercise model to circumvent these effects.
Urbanização, planejamento e mudanças climáticas : desafios da capital paulista e da Região Metropolitana de São Paulo
(Universidade Federal de São Carlos, 2016-10-14) Back, Adalberto Gregório; Vargas, Marcelo Coutinho; https://lattes.cnpq.br/8869018482093008; https://lattes.cnpq.br/7945490786499120
The aim of this thesis is to investigate how the recent urban development agenda of São Paulo contributes to overcoming the challenges related to addressing climate change at the local and regional/metropolitan area. Methodology. First we identify the main challenges related to addressing climate change within the MRSP, taking into account the historical development of both the city of São Paulo and the municipalities of Greater São Paulo. We focus our attention on the challenges of urban mobility, taking into account this is the main source of GHG emissions; Housing, given that the main risk areas in the city and region were generated by a lack of adequate housing policies along the urban development of São Paulo; and Environmental Protection because it is related to containment of urban sprawl. Given this identification, we analyze the policy responses to these questions given by the Climate Change Policy and the instruments of the Master Plan of the São Paulo’s city. The results They reveal that the strategies referring to the climate change policy in the city of São Paulo do not address the main determinants involved in generating GHG emissions and vulnerabilities to climate change, nor do they apply to regional / metropolitan challenges. On the other hand, the urban planning instruments act in the municipality promoting the construction and population densification in areas of consolidated urban infrastructure and with mixed use of the soils, promote mechanisms for a social housing construction prioritizing a low income population, incentive to Generation of Jobs in a decentralized way in the city in order to reduce the commuting displacements of great distances and to create mechanisms to contain the irregular and excluding urban sprawl over a rural area of the municipality. In this sense, the regulatory instruments foreseen in the municipality's master plan act on the main causes that generated social and environmental risks and GHG emission levels in the city of São Paulo, and are reflected in the metropolitan context.