Soil, water and nutrient losses by interrill erosion from green cane cultivation

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

Protocolo de Quioto e as possibilidades de inserção do Brasil no Mecanismo de Desenvolvimento Limpo por meio de projetos em energia limpa

Este artigo pretende estudar a inserção do Brasil no Mecanismo de Desenvolvimento Limpo (MDL) do Protocolo de Quioto, por meio de projetos em energia limpa, enfatizando a cooperação entre países desenvolvidos e em desenvolvimento e visando as ações práticas que esse mecanismo permite desenvolver para se alcançar o desenvolvimento sustentável e para conter o aquecimento global. Para isto, realizou-se extensa revisão bibliográfica dos acordos internacionais referentes às mudanças climáticas e de livros e artigos sobre a inserção brasileira no Protocolo de Quioto e no Mecanismo de Desenvolvimento Limpo. O Protocolo de Quioto é um acordo internacional que prevê a redução das emissões de gases de efeito estufa por intermédio de mecanismos flexibilizadores. O Mecanismo de Desenvolvimento Limpo é o único que permite a participação de países em desenvolvimento, para que eles reduzam emissões por meio de projetos que busquem o desenvolvimento sustentável. Neste contexto, o Brasil surge como um país atrativo para o recebimento destes projetos, por sua vocação para desenvolver fontes alternativas de energia e pela sua liderança no processo negociador do Protocolo. O MDL configura-se, portanto, em uma grande oportunidade para o Brasil, visto que esses projetos representam uma fonte de recursos financeiros para que o país busque o desenvolvimento sustentável, além de incentivarem um maior conhecimento científico e a adoção de novas tecnologias.

Power electronics courses for the new paradigms of the electrical system

This paper presents a historical perspective of the Power Electronics education that has lead to the present situation in which such technology is indispensable for the exploitation of almost all type of clean energy primary sources. Some academic initiatives in Brazil are here discussed focusing the institutions grouped in a CAPES-Pró-Engenharia program. The curricula aspects and innovations are presented, emphasizing the multidisciplinary character of this field of Power Electronics application. © 2011 IEEE.

Avaliação da eficiência térmica de um coletor solar tipo tubo evacuado modificado

Pós-graduação em Engenharia Mecânica - FEB

Uso da técnica de análise de óleo lubrificante em motores diesel estacionários, utilizando-se misturas de biodiesel e diferentes níveis de contaminação do lubrificante

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da viabilidade energética de amortecedores regenerativos por indução com ênfase nos carros elétricos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eficiência econômica da produção de cana-de-açúcar de produtores independentes do Estado do Paraná

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Hydropower recovery in water supply systems: Models and case study

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos técnico, econômicos e ecológicos de processos de produção de hidrogênio

Pós-graduação em Engenharia Mecânica - FEG

Análise da eficiência do cobre, alumínio e PVC como condutores hidráulicos em aquecedores solares

One of society concerns are preserving the environment and the growing energy demand. These two issues are in conflict since most of the energy used today in some way harms the environment. Then is essential to develop and implement ways to clean and renewable energy. In this way, solar energy stands out as a source of clean energy, renewable, abundant and acessible. Solar energy can be harnessed by photovoltaic cells or by solar collectors. The aim of this article is analysethe yield of the solar heather assembled with hydraulic conductive and plastic bottles using three different materials for hydraulic conductors, in order to compare these efficiences and analyze material which has the best cost-benefit in this type of application. The materials analyzed in this study were copper, aluminum and PVC. For this analysis were assembled three alike solar heaters using each one of these materials, and were done several series of measurements of the temperature water output to each heat with flow between 10 and 30 liters per hour. With these data we can analyze the yield and the performance of copper, aluminum and PVC in this application. So we can conclude that aluminum has a higher efficiency, followed by PVC, and the copper had the lowest efficiency. This behavior kept for all values of flow rates examined

Produção de hidrogênio por reforma a vapor de biogás

A new approach to generating clean energy has been studied by several researchers, among which one can highlight the steam reforming of biogas. The Biogas is result of decomposition of organic matter and it hasn’t been availed in the global level, instead, the biogas has been burned in flare or discarded into the atmosphere providing damage to the environment. The generation of vector biogas energy can be realized through its steam reforming and this work examines briefly the types of digesters used for biogas generation, studying the process of steam reforming to generate hydrogen as energy vector, analyzing each step in detail, seeking to adapt its main features an ethanol reformer for a biogas reformer. Besides this it is estimated the yield of the reform process and the boiler efficiency for efficiency of the process

Bioconversion of Cellulose to Hydrogen by dark fermentation

Hydrogen is known as a clean energy resource. The biological production of hydrogen has been attracting attention as an environmentally friendly processs that does not consume fossil fuels. Cellulosic plant and waste materials are potential resources for fermentative hydrogen production. Cellulose is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Enzymatic hydrolysis of cellulose requires the presence of cellulase. The present study aimed to investigate the efficiency of acid pretreatment on ruminal fluid in order to enrich H2 producing bacteria consortia to enhance biohydrogen rate and substrate removal efficiency. In this study, fermentative hydrogen producers were enriched on cellulose (2g/L) in a modificated Del Nery medium (DNM) at 37ºC and initial pH 7.0 using rumen fluid (10% v/v) as inoculum. To increase the hydrogen production it was added cellulose (10mL) to the medium. The gas products (mainly H2 and CO2) was analyzed by gas chromatography (Shimadzu GC 2010) using a thermal conductivity detector. The volatile fatty acids and ethanol were also detected by GC using a flame ionization detector. Cellulose degradation was quantified by using the phenolsulfuric acid method. Analysis showed that the biogas produced from the anaerobic fermentation contained only hydrogen and carbon dioxide, without detectable methane after acid pretreatment test. On DNM the hydrogen production started with 4 h (5,3 x 105 mmol H2/L) of incubation, and the maximum H2 concentration was observed with 34 h (7,1 x 106 mmol H2/L) of incubation. During the process, it was observed a predominance of acetic acid and butyric acid as well as a low production of acetone, ethanol and nbutanol in all experimental phases. Butyrate accounted for more than 77% of total. As a result of the accumulation of volatile fatty acids (VFAs), the pH value in anaerobic digestion system was reduced to 4,0. On microscopy analyses there were observed rods with endospores. The batch anaerobic fermentation assays performed on anaerobic mixed inoculum from rumen fluid demonstrated the feasibility of H2 generation utilizing cellulose as substrate. Based on the results, it can be concluded that the acid treatment was efficient to inhibit the methanogenic archaea cells present in rumen fluid. The rumen fluid cells present a potential route in converting renewable biomass such as cellulose into hydrogen energy.

Geração de energia por microturbina alimentada à biogás em uma propriedade rural: estudo de caso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Construção e avaliação térmica de um sistema concentrador parabólico com seguidor solar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Analisys of thermal efficiency of a modified solar collector type evacuated tube

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)