Desempenho de aerogeradores de pequeno porte: simulação do fornecimento de energia elétrica a cargas conectadas à rede pública ou isoladas

The successful in the implementation of wind turbines depends on several factors, including: the wind resource at the installation site, the equipment used, project acquisition and operational costs. In this paper, the production of electricity from two small wind turbines was compared through simulation using the computer software HOMER - a national model of 6kW and an imported one of 5kW. The wind resources in three different cities were considered: Campinas (SP/BR), Cubatão (São Paulo/BR) and Roscoe (Texas/ USA). A wind power system connected to the grid and a wind isolated system - batteries were evaluated. The results showed that the energy cost ($/kWh) is strongly dependent on the windmill characteristics and local wind resource. Regarding the isolated wind system batteries, the full supply guarantee to the simulated electrical load is only achieved with a battery bank with many units and high number of wind turbines, due to the intermittency of wind power.O sucesso na aplicação de aerogeradores depende de vários fatores, dentre os quais: o recurso eólico no local de instalação, os equipamentos utilizados, os custos de aquisição e operacionais do projeto. Neste trabalho, comparou-se a produção de energia elétrica de dois aerogeradores de pequeno porte, sendo um modelo nacional de 6kW e um importado de 5kW, por meio de simulação, utilizando o programa computacional HOMER. O recurso eólico de três cidades diferentes foi considerado: Campinas (SP/BR), Cubatão (SP/BR) e Roscoe (TX/EUA). Um sistema eólico conectado à rede elétrica e um sistema isolado eólico baterias foram avaliados. Os resultados mostraram que o custo da energia ($/kWh) é fortemente dependente das características do aerogerador e do recurso eólico local. Em relação ao sistema isolado eólico - baterias, a garantia de suprimento integral à carga elétrica simulada só é alcançada com um banco de baterias com muitas unidades e alto número de aerogeradores, devido à intermitência da fonte eólica.36228129

Elements of the immoral act in Augustin of Hipona

The question that will be posed as the objective of this research is part of a more general problem, i.e., trying to understand how Augustin of Hipona harmonizes in the interior of his thought the requirements of two imperatives imposed on man: the imperative of the return to interiority and the imperative of charity. We aim at elucidating the relationship between man and world, giving a special attention to the problem of social life. We are interested here especially in understanding the unfortunate man, seeking to comprehend the elements that compose an immoral act. The second book of the Confessions of the Bishop of Hipona guides our workA questão que será posta como objetivo desta pesquisa é parte de um problema mais geral, a saber, o de tentar compreender como Agostinho de Hipona harmoniza no interior de seu pensamento as exigências de dois imperativos impostos ao homem: o imperativo do retorno à interioridade e o imperativo da caridade. Trata-se de buscar elucidar o relacionamento do homem com o mundo, dando uma especial atenção ao problema da vida social. Contudo, na presente comunicação nos deteremos apenas com o homem mísero e soberbo, buscando compreender os elementos que participam de um ato imoral. Para tanto, um exercício de leitura do segundo livro das Confissões do Bispo de Hipona deve guiar o nosso trabalh

Comment on 'Relativistic shape invariant potentials'

In this comment we point out numerous errors in the paper of Alhaidari cited in the title.Comment: Latex,3pages,no figure

Combined effects of ultrasound and immobilization protocol on butyl acetate synthesis catalyzed by CALB

It is well established that the performance of lipase B from Candida antarctica (CALB) as catalyst for esterification reactions may be improved by the use of ultrasound technology or by its immobilization on styrene-divinylbenzene beads (MCI-CALB). The present research evaluated the synthesis of butyl acetate using MCI-CALB under ultrasonic energy, comparing the results against those obtained using the commercial preparation, Novozym 435. The optimal conditions were determined using response surface methodology (RSM) evaluating the following parameters: reaction temperature, substrate molar ratio, amount of biocatalyst, and added water. The optimal conditions for butyl acetate synthesis catalyzed by MCI-CALB were: Temperature, 48.8 °C; substrate molar ratio, 3.46:1 alcohol: Acid; amount of biocatalyst, 7.5%; and added water 0.28%, both as substrate mass. Under these conditions, 90% of conversion was reached in 1.5 h. In terms of operational stability, MCI-CALB was reused in seven cycles while keeping 70% of its initial activity under ultrasonic energy. The support pore size and resistance are key points for the enzyme activity and stability under mechanical stirring. The use of ultrasound improved both activity and stability because of better homogeneity and reduced mechanical stress to the immobilized system.This work was supported by grants from CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), and CTQ2013-41507-R from Spanish MINECO. We would like to thank Novozymes Spain for its comprehensive support of this research, in special Ramiro Martínez (Novozymes, Spain) for kindly supplying the enzymes used in the work. We also thank CNPq (Brazil) for a fellowship to A.M. Silva and FAPERGS (Brazil) for a fellowship to J.S. Alves. A Ph D. fellowship from Spanish Goberment to Miss Garcia-Galan is also acknowledged The help and suggestions from Ángel Berenguer-Murcia (Instituto de Materiales, Universidad de Alicante) are gratefully recognized. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe

Valorization of Oleuropein via Tunable Acid-Promoted Methanolysis

The acid-promoted methanolysis of oleuropein was studied using a variety of homogeneous and heterogeneous acid catalysts. Exclusive cleavage of the acetal bond between the glucoside and the monoterpene subunits or further hydrolysis of the hydroxytyrosol ester and subsequent intramolecular rearrangement were observed upon identification of the most efficient catalyst and experimental conditions. Furthermore, selected conditions were tested using oleuropein under continuous flow and using a crude mixture extracted from olive leaves under batch. Formation of (−)-methyl elenolate was also observed in this study, which is a reported precursor for the synthesis of the antihypertensive drug (−)-ajmalicine.Centro de Investigación y Desarrollo en Ciencias Aplicada