Estratégia de redução de consumo de energia em redes de sensores sem fio heterogêneas utilizando lógica fuzzy

O avanço nas áreas de comunicação sem fio e microeletrônica permite o desenvolvimento de equipamentos micro sensores com capacidade de monitorar grandes regiões. Formadas por milhares de nós sensores, trabalhando de forma colaborativa, as Redes de Sensores sem Fio apresentam severas restrições de energia, devido à capacidade limitada das baterias dos nós que compõem a rede. O consumo de energia pode ser minimizado, permitindo que apenas alguns nós especiais, chamados de Cluster Head, sejam responsáveis por receber os dados dos nós que formam seu cluster e propagar estes dados para um ponto de coleta denominado Estação Base. A escolha do Cluster Head ideal influencia no aumento do período de estabilidade da rede, maximizando seu tempo de vida útil. A proposta, apresentada nesta dissertação, utiliza Lógica Fuzzy e algoritmo k-means com base em informações centralizadas na Estação Base para eleição do Cluster Head ideal em Redes de Sensores sem Fio heterogêneas. Os critérios usados para seleção do Cluster Head são baseados na centralidade do nó, nível de energia e proximidade para a Estação Base. Esta dissertação apresenta as desvantagens de utilização de informações locais para eleição do líder do cluster e a importância do tratamento discriminatório sobre as discrepâncias energéticas dos nós que formam a rede. Esta proposta é comparada com os algoritmos Low Energy Adaptative Clustering Hierarchy (LEACH) e Distributed energy-efficient clustering algorithm for heterogeneous Wireless sensor networks (DEEC). Esta comparação é feita, utilizando o final do período de estabilidade, como também, o tempo de vida útil da rede.

Educação ambiental para gestão de bacias hidrográficas: a atuação da Itaipu binacional na bacia Paraná 3 - Estado do Paraná

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Simulação numérica da gaseificação de biomassa em leito fixo

O objetivo deste trabalho foi avaliar a potencialidade das sementes de açaí rejeitadas após beneficiamento em Belém – Pará, a fim de ser usada como fonte de biomassa para a produção de energia por gaseificação. Resultados da análise elementar obtidas no LABCAT – UNB em base seca foram obtidas com percentuais de Carbono, 46,06 %, Hidrogênio 6,01 % Oxigênio 43,37 %, Nitrogênio 4,33 % e Enxofre 0,08%. Tais valores entre outros parâmetros obtidos em estudo experimental realizados por Santos 2011 e Cruz, 2010, foram utilizados para realizar uma simulação numérica do processo de gaseificação por meio de um código FORTRAN zero dimensional desenvolvido especificamente para esta finalidade. Variações da influência da razão de equivalência e teor de umidade nas concentrações de CO, H2 e CH4 foram comparados a resultados experimentais. Um modelo transiente unidimensional também foi analisado. Utilizando a aplicação de um mecanismo de pirólise de dois passos onde o alcatrão primário (ou oxigenados) são inicialmente formados e então craqueados em alcatrão secundário (ou hidrocarbonetos) e outros gases combustíveis. Assim se revela a complexidade dos processos físicos e químicos que ocorrem no reator pelo uso do balanço de energia e massa e com informações das taxas de reação das reções químicas e os processos de transporte físicos. O modelo computacional é capaz de prever o perfil da composição de gases, temperatura, alcatrão primário e secundário ao longo do eixo longitudinal do gaseificador. Foram obtidos resultados para simulações realizadas nos dois modelos e posteriormente analisado tal comportamento em comparação ao resultado experimental obtidos por Santos (2011).

Da barranca do rio para a periferia dos centros urbanos: a trajetória do Movimento dos Atingidos por Barragens face às políticas do setor elétrico no Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Brasil e Alemanha: modelos comparativos para as energias renováveis

Pós-graduação em Engenharia Mecânica - FEG

Estudo teórico das reações de hidrogênio e do monóxido de carbono sobre fases intermetálicas

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

Estrutura eletrônica de derivados de C60 para aplicações em células solares orgânicas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Emprego de imageamento passivo na análise da variabilidade espacial da turbidez no espelho d'água do Lago Paranoá, Distrito Federal

The water has an important role in human society, especially in Brazil. Its uses are multiple, including supply, energy production, recreation and others. The National Policy for Water Resources (Law No 9.433/97) states in its articles the importance of water use in accordance to their multiple uses, prioritizing the supply for humans and animals. In this approach, it is important to consider the physical and chemical quality of water to meet these demands, scope of the legal framework applied to the Brazilian water bodies according to their main uses, in order to guarantee the water quality compatible with the most demanding uses and to reduce the costs of pollution control through ongoing preventive actions. Among the various parameters that seek to analyze the physical and chemical quality of water it is intended to understand the spatial distribution of turbidity in the lake's surface, since the variation of the components that alter this parameter can be detected by means of passive remote sensing. The application of the Linear spectral mixture model allowed, satisfactorily, the identification of turbidity spatial distribution patterns in the lake.

A bi-objective genetic approach for the selection of sugarcane varieties to comply with environmental and economic requirements

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

Efeito da adição da L-carnitina e acetil-L-carnitina sobre a viabilidade espermática na refrigeração do sêmen equino

Pós-graduação em Biotecnologia Animal - FMVZ

Viabilidade de turbinas eólicas de pequeno porte no Brasil

Facing a global scenario where oil is scarce and the emission of CO2 in the atmosphere is a world concern, the search for new methods of energy production becomes the focus of all countries. Based on these assumptions, the wind power gains highlight and happen to be the most exploited around the world, since this does not produce toxic waste, since it uses the wind, no raw material shortage and its cost and efficiency are increasingly attractive. Taking advantage of the geographical features of Brazil, coastal and territorial extension, this study aims to analyze the feasibility of using wind turbines widely used in Germany, one of the countries with the highest production of energy through wind, in Brazil. In order to increase the energy production without causing more environmental impacts, geographical analyses will be made, and to determine the features and costs of production of this type of energy generation, and at the end of this dissertation, will finish for one of the turbines, Montana, is it feasible to install, however due to the Government's little incentive return is not very expressive. With respect to the turbine Passaat, this is infeasible to install under current conditions

Smart Grid e Carros Elétricos - Influência da Carga de Carros Elétricos Sobre o Sistema Elétrico

The technologies are advancing at a pace so expressive that allow the increase of the power quality from generation until the distribution to end customers. This improvement has been made possible through the automation of the energy that follows to a better quality of the energy provided, a lower energy supply disruptions and a very short recovery time. The trend of today and the near future is the distributed energy generation. To keep the automated control of the chain, the presence of Smart Grids is needed and that will be the most efficient and economical way to manage the entire system. Within this theme, is going to be necessary analyze the electric cars that promise to promote a more sustainable transport because it doesn’t uses fossil fuels, and more healthy because it does not emit pollutants into the atmosphere. The popularization of this type of vehicle is estimated to happen in a few decades and the case study analyzing its influence on the demand of the electrical system is something that will be very important in the near future. This paper presents a study of the influence of the inclusion of charges refering to electric cars

Aplicação de painéis fotovoltaicos em residências: estudos de caso em Guaratinguetá e Sevilha (Espanha)

In this paper we discussed the possibility of installing a photovoltaic panel in a house in order to reduce electrical consumption. Brazil is a country with a huge solar resource and photovoltaic technology allows transforming solar energy into electricity, helping to decentralize energy production. To enlarge the field of view, the study compares with the equivalent in a Spanish city, discussing how the law favors the initiative of using this type of energy. It will be seen that, with the encouragement of the government, the project can be done because the installation is amortized over a reasonable period of time, about eight years in Spain and three in Brazil

Avaliação da auto-suficiência energética de reatores anaeróbios no tratamento de esgoto sanitário e de água preta

The purpose of this project is to verify whether anaerobic reactors applied to sewage treatment are energetically self-sufficient. This evaluation can be made by balancing the methane produced through the anaerobic transformation stages (hydrolysis, acidogenesis, acetogenesis and methanogenesis) and the reactor energy consumption requirements. The original project included methanogenic activity tests, which could not be performed due to setbacks in the installation of an analytical instrument. Scientific articles about bench- and full-scale anaerobic reactors were investigated instead. An average substrate-to-methane conversion efficiency of 58,2±18,6% was found for the bench-scale reactors and higher efficiencies (89,2%) were found for the cases which had higher Organic Loading Rates (OLRs) values. The average energy output was 0,013 kWh/Lsewage, value unable to meet the energy needs for the reactor operation, considering equipments normally used such as temperature controller. This balance can become positive if few hypotheses are made, for example (i) to eliminate the use of temperature controller (ii) to alter the operation pattern from continuous to intermittent. Based on energy balance assessment of eight bench-scale reactors, it was observed that the implementation of a system for biogas utilization is not energetically feasible. However, interesting results were found for a full-scale sewage treatment plant, ETE Ouro Verde – Foz do Iguaçu, PR, Brazil. Even though its substrate-tomethane conversion efficiency was about 10% only, the energy balance was quite positive, with energy consumption of 68 kWh/month and energy production of 660 kWh/month. This analysis leads us to conclude that energy recovery from full-scale sewage treatment plants should be practiced by other plants

Análise da viabilidade econômica na implantação de inversores frequência em sistemas de bombeamento

The present work aims to conduct a study of the economic feasibility of the implementation of variable frequency inverters in pump systems with variable flow rates. The concern with the reduction of energy expenditure in industries raised in 2001 due to the energy crisis that hit Brazil at that time, forcing industries to reduce their electric costs under penalty of fines if this were not done (MOREIRA, 2008). Frequency inverter is an electronic device that allow greater control in the operation of pumping systems and also a reduction in electrical consumption, being a viable solution to achieve a reduction in energy consumption. For the development of this work, approaching important topics in pumping systems was necessary in order to make a correct choice of hydraulic pumping and also other components responsible for the operation of the system , such as electric motors and frequency inverters. In the case study, a theoretical analysis of the behavior of electrical consumption in systems with variable flow rates was performed, comparing when the system is operated via frequency inverters and when the system is operated without such a device. As expected, the result of the implantation of the device was quite satisfactory, and the primary goal of reducing energy expenditure was achieved. Also important to highlight the environmental issue of this work, as all forms of energy production affects nature in some way, achieving a reduction in consumption also contributes indirectly in environmental conservation