Fatores de decisão da adoção do gás natural na geração de energia elétrica em pequena escala em postos de combustíveis: um estudo de anális de decusão usando o processo de hierarquia analítica AHP

A modeling of criterias and alternatives is through and applied a questionnaire based on method AHP to proprietors of gas stations. The considered alternatives had been the maintenance of the current state with electric energy of the deliverer and the generation in small scale based on the natural gas. The used criteria had been Cost of the Investment, Final Cost of the Energy, Operational cost, Ambient Benefits, Risk and Variation of Costs. The study it was carried through in the city of Natal, RN in ranks that make use of the natural as for resale, where the generation alternative on the basis of the available gas is present. The main results evidence in a dimension the viability of use of method AHP with questionnaire by means of validation of the judgments with analysis of variance beyond proper the normal mechanisms of analysis of consistency to the method. The main results of the analysis help to show that in this in case that the profile of models of criteria and judgments of the actors is similar, with the final evidence of that it has a dominance of the maintenance of the energy of the deliverer. The main criterion to influence this decision was the risk

Fonte de energia alternativa: um estudo sobre a percepção ambiental, social e econômica do biodiesel com docentes do Centro de Tecnologia do gás da cidade de Natal RN

Meaning fuel and renewal energy source s derivative additives, the term biodiesel exists in Brazil since 1980, when it was signed its first patent by Expedito Parente. Since then, its importance has grown gradually due to the worsening of the ambient problems, since its use has became a highly promising alternative to the pollution decrease, as in the carbon dioxide issue as with the smoke and sulfur oxide. In Brazil, it was created the National Program of Production, whose objective is to insert the new product in the country s energy matrix, strengthening the economy and creating new employment opportunities, being an important product to the national energetic independence, since Brazil still imports diesel to its domestic consumption. This study aims to identify the ambient, social and economic perception of the teachers from the Technology Center of Natal city (CTGÁS-RN) to the biodiesel. For that, it was used a questionnaire closed questions, organized in the likart scale, directed to the tree spheres of the research analysis, the biodiesel and its social, ambient and economic nuances, totaling 31 questionnaires full answered. In its objectives, the research was descriptive and in its approach it was qualitative. To the data analysis it was used statistical tools (Statistic software, 6.1 version and Microsoft Excel 2003). The research revealed the predominance of the ambient aspect in the sight of the teachers, followed by the social ones. The economic factors represent a minor percentage in the analysis when compared to other

Modelos para estimar as exigências de energia metabolizável para poedeiras

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Coeficientes de digestibilidade aparente da proteína e energia de alguns ingredientes utilizados em dietas para o pintado (Pseudoplatystoma coruscans)

O presente trabalho foi desenvolvido com o objetivo de determinar os coeficientes de digestibilidade aparente da proteína e da energia dos principais alimentos utilizados na formulação de dietas para alevinos de pintado. Foram utilizados 600 alevinos com peso médio inicial de 9,80 ± 1,48 g e comprimento total médio de 13,00 ± 1,00 cm. Na coleta de fezes, foi utilizado o sistema de Guelph modificado. As 12 dietas-teste foram constituídas por 69,50% de uma dieta de referência, 0,50% de óxido de cromo (marcador inerte) e 30% do ingrediente estudado. Após receberem as dietas teste durante três dias, os peixes foram transferidos para os aquários de coleta (incubadoras de fibra de vidro de 80 litros de capacidade), onde as fezes foram coletadas em intervalos de meia hora. Com base nos coeficientes de digestibilidade da fração protéica, os alimentos que apresentaram maior aproveitamento para esse nutriente foram: farinha de peixe (84,14%), farelo de soja (67,10%), milho (64,18%) e farinha de vísceras de aves (61,25%). Foram observados valores razoáveis somente para a digestibilidade do conteúdo energético em metade dos ingredientes estudados; para as farinhas de peixe, milho, soja integral tostada e os farelos de soja, de trigo e de arroz, os coeficientes médios foram: 72,80; 57,39; 64,95; 61,66; 53,20 e 51,84%, respectivamente. A farinha de peixe foi o melhor ingrediente para o pintado (45,38% PD e 2790,42 kcal ED/kg), seguido do farelo de soja (30,86% PD e 2708,45 kcal ED/kg), da soja integral tostada (18,34% PD e 3121,06 kcal ED/kg), do milho (5,86% PD e 2691,53 kcal ED/kg) e do farelo de trigo (8,08% PD e 2265,13 kcal ED/kg).

Efeito da adição de feno de catingueira (Caesalpinea bracteosa) na ração sobre o balanço de energia e de nitrogênio em ovinos morada nova

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação de programa de ginástica laboral e desempenho funcional: um estudo em empresa distribuidora de energia elétrica

This thesis treats of a avaliation of a laboral gimnastics program of a electrical energy enterprise from Rio Grande do Norte. The leading aim of this work is to analyse the laboral gimnastics program with emphasis on functional performing and personal changes of staff of different categories. The work shows two divisions: at first, it was carried out the bibliographic study approaching the concepts and historic about the ergonomy and the main focus of study, the laboral gimnastics , performing factors and lifestyle.The second time , it was carried out the field study where was used a questionnaire to a 160 staff population which participate of laboral gymnastics program; then the data were analysed through three statistics analyses: multivaried__ clusters, qui-quadrado and multiple linear regression. The results aim to the confirmation that the laboral gymnastics program developed two years ago on enterprise proposes to the white-collar and operational workers an improving on their functional performing and also, to the changes in some aspects of lifestyle, like the food, leisure and stress level. In conclusion, it was checked that the investiment in life quality programs offer benefits both to the staff and the enterprise which will account with good services and satisfaction of customer. Therefore, it was concluded that the laboral gymnastics while a ergonomic tool and a physical activity, it is an investiment which needs more and more to be strengthened and inserted by many segments of society

Aspectos quantitativos de carcaças de bovinos de diferentes raças, alimentados com diferentes níveis de energia

Objetivou-se avaliar as características quantitativas da carcaça de bovinos machos não castrados, terminados em confinamento e abatidos aos 13-14 meses de idade. Foram utilizados 16 bezerros com nove meses de idade e peso médio inicial de 220 kg (oito Aberdeen Angus - AA e oito Hereford - HE), submetidos a dois níveis de energia (3,07 e 3,18 Mcal/kg de MS). O desenho experimental foi inteiramente casualizado, em arranjo fatorial 2 x 2 (duas raças e dois níveis de energia). O volumoso utilizado foi a silagem de milho, com 36% de grãos na matéria seca (MS). O concentrado nos tratamentos de menor nível de energia participou com 12% e naqueles de maior nível, com 32% da MS da dieta. Os animais foram abatidos quando, por estimativa, as carcaças apresentaram, na média, um mínimo de 190 kg. Os animais AA apresentaram maior rendimento de carcaça quente (54,95 contra 53,75%), maior comprimento de perna (64,12 contra 62,12 cm) e maior área do músculo Longissimus/100 kg de carcaça (29,31 contra 27,41 cm²). Os animais que receberam o maior nível de energia na dieta apresentaram maior comprimento de perna (71,75 contra 64,50 cm) e melhor conformação da carcaça (11,25 contra 10,12 pontos). Observou-se interação significativa entre raça e nível de energia para a espessura de gordura subcutânea, sendo a maior espessura verificada nas carcaças dos animais HE, que receberam o menor nível de energia.

Medição de desempenho na cadeia de suprimentos da energia eólica: proposta de um conjunto de indicadores de desempenho

Performance measurement in highly competitive markets is a necessary measure for those who aim the top positions. The business performance measurement approach have reached relevant results in the literature, however, a different approach has recently appeared that broadened the perception of competition, where companies do not seek the competition among companies only, but also among supply chains. Brazilian Wind energy supply chain is living a structuring and expanding moment, with the major global players in the industry making investments in the country. This research aims to answer which are the key performance indicators that must be considered by the Brazilian wind energy sector companies, which are part in a broad perspective of supply chain competition. The research was executed in two steps: exploratory (literature review and a field research in the companies) and later a survey was conducted with the Brazilian Wind energy companies workers with the purpose to validate the performance indicators found in the exploratory step. The survey evaluated 40 performance indicators distributed among five major activities: Project prospection, building/execution, operation and maintenance, logistics and transverse processes, which summarize the performance of the entire supply chain, pointing the sinergy and the competitive level of the supply chain. The selected performance indicators reflect the high relevance of the costs dimension in the Brazilian energy companies performance, acting as a key performance indicator, is also indicates the limited performance management integration throughout the Brazilian wind energy supply chain

Efeito do processamento da soja integral sobre a energia metabolizável e a digestibilidade dos aminoácidos para aves

Essa pesquisa foi desenvolvida para se avaliar o valor nutricional da soja integral submetida a diferentes processamentos. Quatro ensaios de metabolismo foram conduzidos para determinar os coeficientes de digestibilidade da matéria seca (CDMS), do extrato etéreo (CDEE) e dos aminoácidos e os valores de energia metabolizável aparente e verdadeira da soja integral desativada (SID) e extrusada (SIE) e das misturas de farelo de soja com óleo degomado de soja (FSO) ou com óleo ácido de soja (FSOA). Nos ensaios um e dois, utilizou-se a metodologia tradicional de coleta total de excretas com pintos e galos, respectivamente. A metodologia da alimentação forçada com galos adultos intactos foi utilizada no ensaio três, e com galos cecotomizados, no ensaio quatro. Os CDMS e CDEE e a energia metabolizável determinados com galos foram superiores aos determinados com pintos. Os maiores valores de CDMS, CDEE e de energia metabolizável foram obtidos para FSO, seguidos pelos da SIE e FSOA, e os menores, para a SID. O processo de extrusão proporcionou melhores resultados no aproveitamento da gordura do grão de soja e, conseqüentemente, da energia. Entretanto, a digestibilidade dos aminoácidos não foi influenciada pelos processamentos. Os diferentes processamentos conferiram à soja integral características nutricionais que se distinguiram, principalmente quanto ao valor de energia metabolizável, que também variou com a idade das aves.

Composição corporal e exigências nutricionais de proteína e energia para cordeiros Morada Nova

Este trabalho foi realizado objetivando-se determinar a composição corporal de proteína, gordura e energia e as exigências nutricionais de proteína e energia para mantença e ganho de peso de ovinos Morada Nova. Foram utilizados 30 cordeiros com peso vivo (PV) médio inicial de 15 kg. Para determinação da composição corporal, pela metodologia do abate comparativo, seis cordeiros (animais-referência) foram abatidos aos 15 kg, seis aos 20 kg (abate intermediário) e os demais foram distribuídos em seis grupos (um para cada dieta) de três animais, de acordo com a relação volumoso(V):concentrado(C): 40:60, 55:45 e 70:30. Os cordeiros em cada grupo foram abatidos quando o que recebia a dieta com maior teor de concentrado atingiu 25 kg de PV. A composição corporal variou de 181,53 a 178,74 g de proteína; 72,37 a 131,11 g de gordura e 1,81 a 2,34 Mcal de energia por kg de peso de corpo vazio (PCV). As exigências líquidas de ganho variaram de 222,30 a 218,6 g de proteína e de 3,30 a 4,28 Mcal de energia por kg de PV ganho. As perdas endógenas de nitrogênio foram de 0,332 g/kg0,75/dia. A exigência líquida de energia para mantença, estimada pela produção de calor em jejum, foi de 52,49 kcal/kg0,75 de PCV. As exigências de proteína e energia metabolizável para cordeiros dos 15 aos 25 kg de PV, com ganho de peso diário de 100 g, oscilaram de 53,46 a 60,19 g/dia e de 1,47 a 2,00 Mcal/dia, respectivamente.

Fator de decisão na adoção de um sistema de micro-cogeração de energia a gás natural :um estudo em Hotéis três estrelas

The natural gas perform a essential paper, not only in primary sectors of energy, but also in others sectors of economy. The use natural gas will have expansion in Brazil, motivated by governmental decision to increase the participation of this fuel in the Brazilian energy matrix from 4% to 12% up until 2010. in order to reach the objective related to increase the consumption of natural gas in the energy matrix and to propose solutions to attend the electric requirements of heart and refrigeration, using natural gas as primary power plant. This thesis has a main objective to analysis the perception of businessmen of hotel sector about the feasability of investment with micro-cogeneration system by natural gas in their hotel in turistic sector, in Natal/RN. It s show a case for the hotels selected analyzing the actual knowledge of businessmen about alternative of new technology in generation of owner energy. There was make a interview using a standard form researching information about this topic. In this interview has shown 4 (four) canaries for businessmen with different configurations of investment in micro-cogeneration. Two of this canaries uses the project finance like option to make fasible this projects. The resulteis showed who businessmen has insecurity to make decision to put in office alone, or with a local company, and perhaps with a national company to perform for a alternative energy system, justifying, the alone feasability and without information by local businessmen. Apart from that, they are receptive for a option to put in office in micro-cogeneration configured in the settings using project finance

Uso de técnicas de otimização baseadas em derivadas como suporte do planejamento operacional de redes de distribuição de energia elétrica

The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developing the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. It s important to point out that, in spite of the loads being normally connected to the transformer s secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

Níveis de energia metabolizável para machos de corte de crescimento lento criados em semiconfinamento

Foram conduzidos três ensaios para avaliar os níveis de energia metabolizável (EM) e a melhor relação energia:proteína (E:P) para aves de corte machos de crescimento lento criadas em semiconfinamento nas fases inicial (1 a 21), de crescimento (22 a 49) e de terminação (50 a 70 dias de idade). em cada ensaio, 400 machos da linhagem ISA Label na fase de criação foram alojados em instalação experimental constituída de 20 piquetes com área coberta de 3,13 m²para alimentação e recolhimento das aves e uma área de pastejo de 72,87 m². O delineamento experimental foi o inteiramente casualizado com cinco tratamentos e quatro repetições de 20 aves. Os níveis de energia metabolizável fornecidos na ração na fase inicial variaram de 2.600 a 3.200 kcal/kg; na fase de crescimento de 2.700 a 3.300 kcal/kg; e na fase final de 2.800 a 3.400 kcal/kg. A proteína bruta e os demais nutrientes foram mantidos constantes em todas as rações, de acordo com recomendações do NRC (1994) para cada fase. A relação energia:proteína e o nível de energia metabolizável que melhoraram o desempenho e as características da carcaça de frangos de corte ISA Label machos criados em sistema semiconfinado em cada fase estudada foram 128 e 2.750; 147 e 2.850 e 172 e 3.100 kcal de EM/kg nas fases inicial, de crescimento e de terminação, respectivamente.

Energia metabolizável de alimentos na formulação de ração para frangos de corte

O objetivo deste trabalho foi avaliar o efeito da formulação de rações para frangos de corte, com a utilização de valores de energia metabolizável (EM) dos alimentos determinados por diferentes métodos. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos, que consistiram na formulação de rações baseadas na: em aparente corrigida e em aparente, ambas determinadas pelo método da coleta total com pintos; em aparente corrigida, determinada pelo método da coleta total com galos; e em verdadeira corrigida, determinada pelo método da alimentação forçada com galos. Na fase inicial, foi obtido maior consumo de ração, ganho de peso e melhor conversão alimentar com a formulação baseada na em aparente corrigida (pintos). Durante a fase final, a formulação com em verdadeira corrigida (galos) promoveu maior ganho de peso e melhor conversão alimentar. No período de 1 a 49 dias, as aves alimentadas com as rações formuladas com em aparente corrigida (pintos) tiveram melhor desempenho. As características de carcaça não foram influenciadas pelos tratamentos. Até os 21 dias de idade, deve-se considerar os valores de em aparente corrigida (pintos), para a formulação das rações de frangos de corte; após essa idade, deve-se considerar os valores de em aparente corrigida (galos) ou em verdadeira corrigida (galos).

Um algoritmo para estimação de estado em alimentadores de distribuição de energia elétrica com base no método da soma de potências

Most algorithms for state estimation based on the classical model are just adequate for use in transmission networks. Few algorithms were developed specifically for distribution systems, probably because of the little amount of data available in real time. Most overhead feeders possess just current and voltage measurements at the middle voltage bus-bar at the substation. In this way, classical algorithms are of difficult implementation, even considering off-line acquired data as pseudo-measurements. However, the necessity of automating the operation of distribution networks, mainly in regard to the selectivity of protection systems, as well to implement possibilities of load transfer maneuvers, is changing the network planning policy. In this way, some equipments incorporating telemetry and command modules have been installed in order to improve operational features, and so increasing the amount of measurement data available in real-time in the System Operation Center (SOC). This encourages the development of a state estimator model, involving real-time information and pseudo-measurements of loads, that are built from typical power factors and utilization factors (demand factors) of distribution transformers. This work reports about the development of a new state estimation method, specific for radial distribution systems. The main algorithm of the method is based on the power summation load flow. The estimation is carried out piecewise, section by section of the feeder, going from the substation to the terminal nodes. For each section, a measurement model is built, resulting in a nonlinear overdetermined equations set, whose solution is achieved by the Gaussian normal equation. The estimated variables of a section are used as pseudo-measurements for the next section. In general, a measurement set for a generic section consists of pseudo-measurements of power flows and nodal voltages obtained from the previous section or measurements in real-time, if they exist -, besides pseudomeasurements of injected powers for the power summations, whose functions are the load flow equations, assuming that the network can be represented by its single-phase equivalent. The great advantage of the algorithm is its simplicity and low computational effort. Moreover, the algorithm is very efficient, in regard to the accuracy of the estimated values. Besides the power summation state estimator, this work shows how other algorithms could be adapted to provide state estimation of middle voltage substations and networks, namely Schweppes method and an algorithm based on current proportionality, that is usually adopted for network planning tasks. Both estimators were implemented not only as alternatives for the proposed method, but also looking for getting results that give support for its validation. Once in most cases no power measurement is performed at beginning of the feeder and this is required for implementing the power summation estimations method, a new algorithm for estimating the network variables at the middle voltage bus-bar was also developed