Estudo de flutuações de potenciais em poços quânticos de InGaAsN

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A atuação internacional do Brasil para as mudanças climáticas: as COP de 2009 a 2015

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Utilização de trocadores de calor de placas em espiral em processos da indústria siderúrgica

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

Gás natural no panorama brasileiro e um estudo de caso no setor automotivo

The intended purpose of this paper is to present the main aspects of natural gas applied to the public transportation as well as the environmental, economical and technical impacts in this sector. Also it is given specific information to be considered when comparing natural gas to other fuels, specially the diesel. At this point is presented the types of internal combustion engines (Otto and Diesel cycle) and which type is used in each vehicle. Moreover, it is presented the main standards pollutant emission (Euro, US and Proconve) with a brief explanation of the tests made in order to approve the engines. This paper is focused on heavy duty vehicles. Also in this paper is exposed the economic impact due to the natural gas use in the public transportation fleet. In addition is presented a real case (of Berlin) and an estimative to a Brazilian city, presenting the potential of natural gas as vehicular fuel in Brazil, as well as financial and environmental aspects of the substitution

Importância da resposta auditiva de estado estável no diagnóstico da surdez em lactentes com risco para a deficiência auditiva: correlações com os achados do potencial evocado auditivo de tronco encefálico

Pós-graduação em Bases Gerais da Cirurgia - FMB