Microgeneration of Wind Energy for Micro and Small Businesses: Application of ANN in Sensitivity Analysis for Stochastic Economic Feasibility

To reduce the risks of a new energy crisis and increase energy availability, the use of renewable energy sources (RES) is important and recommended. In Brazil, micro and small companies contribute about 25% of gross domestic product (GDP), and electric energy is employed intensively, so the importance of microgeneration is observable. This research aims to analyze the economic viability of the micro-generation wind energy project for micro and small businesses. Thus, three Brazilian states, Rio Grande do Norte, Rio Grande do Sul and Minas Gerais were considered, and different scenarios were proposed. A feasibility analysis is then performed, followed by a stochastic analysis using Monte Carlo simulation (MCS). Finally, models of artificial neural networks (ANN) are used to evaluate the relative importance (RI) of the variables. The results show that none of the states appears economically feasible under the conditions presented. In the stochastic analysis, the probability of viability is between 17% and 24% in all states, which shows the low probability of viability for microgeneration. Through ANN training, it was possible to calculate the RI, in which it is possible to identify the variables that have most impact on the net present value (NPV) in all states; it is considered the most important variable in the project's viability. In addition, the discussion explores the importance of public incentives for promoting investment in renewable energy, which can reduce investment costs and make it attractive to small and medium-sized businesses

Comparing Soil Compaction under Different Grazing Systems with a Virgin Forest Soil to Determine Optimal Stocking Rates

The understanding of how soil physical properties respond to differing grazing practices may help explain the main causes of pasture degradation. Soil compaction has been shown to be a main degradation form of soil and the knowledge of techniques to quantify and rectify this are necessary to maintain optimal yields. This research aims to measure the rupture lines of red yellow latossol under differing pasture grazing practices compared to cropping and a natural forest. With this information it is aimed to calculate the correction factor for stocking rates and traffic of tillage tools. The differing soil management practices examined was, pasture grazed by sheep, and dairy cattle, a maize crop in no tillage cover-crop system and a natural forest. To quantify the soil physical changes, the direct shear test was used, which calculated the resultant force of a load. The resultant forces of the natural forest were compared against pasture systems and crop system, and a correction factor for stocking rates was calculated. The samples of Red yellow Latossol were equilibrated in the matrix potential (ψ): -6 kPa. In the shear test, the normal stress used was the 450kPa. The correction factor (CF) indicates whether the soil has structural degradation compared to natural forest. Values less than 1 indicated soil degradation. The pastures grazed by sheep and dairy cattle had values observed to be less than 1, excessive loads at high soil moisture may be attributed to this soil structural deformation. For these systems, grazing management and stocking rates should be corrected. The correction factor gives an indication of the magnitude of management change that is required (i.e. the stocking rate decreased). The crop area was found to have no soil strength issues, using the stress test

Estimativa da Eto pelo modelo Penman-Monteith FAO com dados mínimos integrada a um Sistema de Informação Geográfica.

O objetivo do presente trabalho foi avaliar a metodologia de estimativa da EtoPM utilizando dados mínimos integrados a um Sistema de Informação Geográfica, na bacia do Jaguaribe, Ceará. Foi utilizado o sistema integrado de modelagem regional PRECIS (Providing Regional Climates for Impacts Studies), versão 1.2, utilizando as condições de contorno do Modelo Climático Global, HadAM3P, acoplado ao Modelo Climático Regional (HadRM3P), através da técnica dinâmica de redução de escala (downscaling). Dados mensais de temperaturas máxima e mínima e precipitação foram gerados para o período de 1961-1990, os quais foram analisados quanto a sua variabilidade espacial (latitude/longitude), utilizando-se geoestatística (krigagem). Para validação, foi aplicada regressão linear entre EtoPM estimada com dados mínimos e estimada com dados medidos através de uma estação meteorológica de referência. A média da EtoPM anual estimada com dados mínimos situou-se em 1.719 mm. A metodologia funcionou satisfatoriamente na região estudada, considerando-se os resultados da regressão (coeficiente angular de 0,95, coeficiente de determinação de 0,902, resíduos menores que 0,45 mm dia-1 e Raiz do Quadrado Médio do Erro (RQME) igual a 0,067 mm dia-1)

Avaliação de clones de mandioca de mesa sob irrigação e em condições de sequeiro.

A mandioca (Manihot esculenta Crantz) é uma planta originária das Américas, provavelmente do Brasil, e cultivada em todo o território brasileiro, com suas raízes e folhas largamente utilizadas na nossa culinária. Embora tolerante ao déficit hídrico, seu crescimento e rendimento são reduzidos por prolongados períodos de seca

Linhagens eretas de feijão-caupi avaliadas no Amapá: safra 2010/2011.

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