5 resultados para Estrelas. Gigantes vermelhas. Lítio. Convecção

em Repositório Institucional da Universidade Estadual de São Paulo - UNESP


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After realizing two interviews, with distinct managers/businessmen working in the cotton industry, the objective is to put in evidence the political, economical and social factors that contributed to the formation and configuration of the Mato Grosso state, after the trade liberalization that occurred in the early 90's, it's effects and consequences in the eyes of the interviewed. The study of public policies is primordial to the discovery of the configuration of determined place, evaluating advances and possible errors in the social, economical and environmental areas. Through the analysis of the interviews it has been found that the urban centers have been developing with a direct link to the industrial activities related to agriculture and that the labor work force have also been attracted because of these changes, and as a consequence this labor force is now becoming more specialized to be able to accompany the jobs requirements in the industry. Analyzing the interviews, it is possible to highlight some information about the development of Mato Grosso, among those the following factors and public policies. The creation and expansion of the cities in the state are possible through public and private investment in infrastructure the socioeconomic development of the state is linked with the advances made in the private sector that grows because of advances made in crops technology in contrast to the occupation of the cerrado, in relation to the cotton crops. The problems that Mato Grosso is facing are mainly linked to the region infrastructure, that can count on investment plans to transportation and production flow that dates before the globalization era. The pattern that is seen today with top of the line agricultural production, big monoculture with high productivity and the arrival of multinational giants, was implanted because of two important events: the trade liberalization in the 1990's and the cambial depreciation in the 1999's...

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Stricter environmental policies are shown necessary to ensure an effective pollutant emission control. It is expected for the present year of 2015, that Brazil will assume, at the 21th United Nation's Climate Change Conference (COP21), implementation of commitment to a low carbon economy. This positioning affects the industrial environment, so that is deemed necessary to search for new technologies, less aggressive to the environment, so the adequacies to the new emission policies do not cause a negative effect on production. Almost all of the processes performed in the steel industry demand burning fuel and, therefore, flue gases are sent to the atmosphere. In this present work is discussed the utilization of heat exchangers so, by recovering part of the available heat from the flue gases of certain industrial process, the combustion air is preheated. The combustion air preheat results in less energy requirement, i.e., less need of fuel consumption and, in addition, minor amount of pollutants to be emitted. Due to better fitting to the process, it is studied the utilization of spiral plate heat exchangers. The heat exchanger dimensioning is made by an iterative method implemented in the software Microsoft Excel. Subsequently are analyzed the gains in terms of process's thermal efficiency improvement and the percentage of fuel saving. The latter implies in reduction of the same percentage of greenhouse gases emission

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Currently there are two car models that use electricity in their propulsion systems, the electric vehicle and the hybrid electric vehicle. The electric vehicles are classified as vehicles that use electric motors in their propulsion system and batteries as a power source, on the other hand, the hybrid vehicles are classified as vehicles that use both electric motors and internal combustion engines in their propulsion system, using both batteries and líquid fuels as a power source. The main goal of this work is to analyze the characteristics of electric and hybrid electric vehicles and demonstrate the unfeasibility of the electric vehicle in the current economic, political, energetic and environmental brazilian scenario, for this purpose it was realized a study about the current brazilian situation regarding to electricity generation, current conservation status of road network, lack of electrical infrastructure for charging batteries, national lithium reserves, environmental characteristics, tax incentives, economic scenario, oil market and political positioning related to the implantation of electric or hybrid electric fleets in nacional territory. The operational characteristics analysis of electric and hybrid electric vehicles in this current scenario leads to the conclusion that currently a growth of electric vehicles fleets on a national scale is totally impractical in the Brazil, Thus, the introduction of green vehicles probably will occur primarily with hybrid electric models, motivated mainly due the bigger autonomy of this models compared to electric models, lower cost of hybrid electric models compared to electric models, factors related to the lack of recharging infrastructure and also factors related to political positioning

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)