904 resultados para Balanço energético (Agronomia)


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

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Obesity along with overweight, has been considered one of the most serious public health problems in the world, especially because they are the main risk factors for many chronic diseases, such as coronary heart disease, type II diabetes mellitus, hypertension and some types of tumors, which are associated with high mortality rates. The use of functional foods and appropriate diets to call health promotion has grown as a mechanism for prevention, control and treatment of chronic diseases such as obesity. Several ethnopharmacological studies indicate plant species for the treatment of disorders associated with obesity with a major attraction of this regimen is perceived as safer and more effective health than the traditional treatment with appetite suppressants. This work aims to develop and standardize models of biological assays in stress and obesity, also aims to evaluate the effect of oil green beans of Coffea arabica in the regulation of body weight and energy balance in mice. To this end, trials were made in vivo studies of this product and their effects on energy metabolism in non-obese mice with obesity induced by hypercaloric diet. After induction of obesity by 8 weeks, animals were treated for 21 days with the extracts orally. After 21 days the animals were killed to evaluate the effects of these products on daily feed intake and on body weight. The group treated with the oil of Coffea arabica L. showed significant weight loss and feed intake high. According to the results, we conclude that the standardized extract of Coffea arabica L. decreased body weight without restriction or decrease the amount of food ingested

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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

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This project aimed to analyze the feasibility of the methane yield associated to the anaerobic digestion of brewery residues, checking whether the energetic balance of the system is favorable. The methane yield efficiency was calculated for the parameters of two papers that treated solids with a particle-size <1mm. Theses solids are not degraded in conventional treatment systems. Calculations were based in the reactions of anaerobic degradation of the macromolecules that compose brewery residues, considering the theoretical production and the effective production of methane. The results were 50.44% and 52.86%. Regarding to the energy balance of the anaerobic treatment, we noted the high influence of the selection and operating regime of electrical equipment over the potential energy. The best situation, in which the energetic self-sufficiency was reached, was observed when using the mixer under an intermittent regime (1min/h), without employing the heating recirculator, for the maximum organic loading of 4.0 gVS/L.day (days 248-258). In this case, the system would generate an amount of energy equal to 0.0356 kWh/day, able to overcome the energy required by the equipment in about 6.5 times. Moreover, we also noted the interference of the application of different solid loadings in the reactors, once the application of the higher organic load generated 5 times more energy than the application of the smaller one

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Para avaliar e planejar dietas para indivíduos e grupos populacionais são necessárias estimativas muito acuradas das necessidades e do consumo de energia. O objetivo foi realizar uma revisão bibliográfica das metodologias de determinação das necessidades energéticas para adultos e dos métodos de avaliação do consumo. Em 1918, Harris e Benedict propuseram equações que estimam a necessidade energética basal a partir de calorimetria indireta para indivíduos, depois disso, foram propostas outras equações para o cálculo das necessidades de energia em repouso ou em atividade. Recentemente, a água duplamente marcada é empregada para propor equações mais apropriadas. Contudo, a acurácia destas equações pode ser questionada. Por outro lado, os métodos de avaliação do consumo energético apresentam limitações que demandam cuidado na escolha e aplicação, assim como na interpretação dos resultados. A escolha do método de avaliação depende e pode ser influenciada pela população avaliada, tipo e objetivo do estudo, tempo disponível e do treinamento dos avaliadores. Deste modo, a avaliação do balanço energético está condicionada, tanto às limitações da avaliação através de equações, quanto dos métodos existentes de avaliação do consumo alimentar.

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Obesity is fundamentally a problem of energy balance that develops when the energy intake is greater than the total energy expenditure (TEE). TEE is composed by the sum of resting energy expenditure (REE), thermal effect of foods and thermal effect of physical activity. Many factors can affect energy expenditure and energy homeostasis. Historically, the energy expenditure has been measured by indirect calorimetry. However, more recently, the use of doubly labeled water has allowed the assessment of energy expenditure in a 24 hour period, which expanded the knowledge on energy metabolism. Factors such as gender, age, thyroid disorders, physical activity and body composition affect REE as already established in the literature. However, there has been speculation whether other factors, such as adipocytokines and diet composition, which might be involved in the genesis of obesity by decreasing the REE. So, this paper aims to review the factors that can alter the energy metabolism.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The objective of this work was the analysis of the energetic ethanol production systems using as source of carbohydrates, manioc, sugar cane and maize crops. The searches were carried from the field in the Paranapanema River Valley, state of Sao Paulo in the operations of cultivation and industrial processing of raw materials for analysis. The expenditure of energy concerning the agricultural part was made by the energy consumption of stage production of one hectare of sugar cane, cassava and corn, tillage and planting procedure, inputs, driving the crop, harvest, transport industry and energy draining. The expenditure of energy referring to the part was made by the industry energy consumption of stage processing of one tonne of sugar cane, cassava and corn, in the operations of disintegration / milling, hydrolysis / treatment of the broth, fermentation, distillation and maintenance of equipment. Under the system of agronomic production of raw materials, manioc presented an energy expenditure below that of sugar cane and maize (9,528.33 MJ ha-1; 14,370.90 MJ ha-1 and 15,633.83 MJ ha-1, respectively). For the ethanol produced, the operations of cultivation has consumed 1.54 MJ l-1 with manioc; MJ 1.99 l-1 with sugar cane, and 7.9 MJ l-1 with the corn. In the industrial processing of a ton of raw material, sugar cane presented an energy cost less than the cassava and maize (1,641.56 MJ t-1; 2,208.28 MJ t-1 and MJ 3,882.39 t-1, Respectively), however, showed a higher cost than when they related to ethanol produced (19.38 MJ l-1; 11.76 MJ l-1 and 11.76 MJ l-1, respectively). In the final energy balance for each megajoules of energy invested in sugar cane were required 1.09 MJ (9%), for each megajoules of energy invested in manioc were required 1.76 MJ (76%) and for each megajoules energy invested in maize were required 1.19 MJ (19%). Overall, it appears that the manioc consumes less energy than sugar cane and corn crops in the process of agribusiness obtaining ethanol.

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The pregnancy toxaemia affects pregnant females in the final third of pregnancy and, in most cases, with multiple fetuses characterizing its relationship with pathology of multiple pregnancy, because, in this situation, the energy demand of the female is very large. The pregnancy toxaemia develops from a negative energy balance and the consequent mobilization of lipids. Fatty acids produced are directed to the liver to be oxidized via acid cycle to produce energy and causing the ketosis. This paper describes the case of a sheep treated at the Veterinary Hospital of Paranaense University - UNIPAR, Campus II - Umuarama/PR with multiple pregnancy of four lambs and consequent pregnancy toxaemia.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This paper, having as a hypothesis that greater energetic inputs don't keep ratio with economical outputs, has tried to study the economical and energetic flows in the maize cultivation to several production systems used in Ipanema Settling Area I, having as analysis instrument the indexes of Cultural, Energetic, Economical efficiency, which were added to the methodological proposal of Cultural Economical and Energetic Economical Efficiency indexes, built for probability settings. Four different systems have been identified: "A", "B", "C" and "D". The energetic expenditure were, respectively, 4,836.19 MJ x ha-1, 4,4647.17 MJ x ha-1, 4,639.49 MJ x ha-1 and 4,450.47 MJ x ha-1. In "A", where the use of machines is more intensive, the participation of biological source energy was 23.26%, whereas the ones of fossil origin are 76.74%. The "D" system has the greatest Cultural Efficiency, with average index of 16.26, whereas "A" showed the lowest Cultural Efficiency indexes, with average values of 14.83. For the analysis of the Energetic Efficiency, that indicates the dependence of energy from non renewable sources, the highest index was the "D" system with an average index of 53.84. The Economical Efficiency Indexes, which ranged from 1.84 to 1.96, show that all systems are efficient. The "D" system, with index equal to 8.84, showed the highest index of Economical Cultural efficiency. The Economical Energetic analysis for "A", "B", "C" and "D" systems, has resulted, respectively, in the following indexes: 21.14 ; 23.86 ; 22.87 and 29.26. Through the outcome analysis, it was concluded that the more intensive use of energy from nonrenewable sources ("A" system) didn't necessarily mean a higher efficiency when compared to "D" (labor intensive), what comes to prove the paper's initial hypothesis.

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The objective of this work was to evaluate the energy and economic efficiency indexes per unit of cotton agro-ecosystem area in family production systems of Paraguay and Brazil; and, to establish a relationship between the energy and economic. Typologies presented by the Program to Support Small Cotton Holdings (Paraguay), and by the National Program for Strengthening Family Agriculture (Brazil). Family systems of the two countries were identified; these are located from Paraguay (San Juan–CA) and from Brazil (Leme–SP). To construct the energy expenditure structure of the cotton agro-ecosystem, as well as to assess the economic efficiency, the mean values obtained were considered, when they presented similarities in production systems and they were within the typology proposed in this study. From the technical itinerary observed the Paraguayan agro-ecosystem depended (fossil fuel 56.76%) and industrial source (35.99%). Thus, the energy balance of the agricultural stage was established, which attained a value of 17,740.69 MJ ha-1; an energy efficiency of 5.28, and a cultural efficiency of 3.04. The Brazilian agro-ecosystem depended on energy from industrial source (insecticides 39.82%) and from fossil fuel (33.59%); it reached an energy balance of 19,547.88 MJ ha-1; an energy efficiency of 2.12, and a cultural efficiency index of 0.71. In the economic and energy indicator ratio, with regard to the months referring to the harvest time, that is to say, March, April, and May, the maximum economic efficiency indicator of paraguay was attained in the month of May (1,00), and from Brazil in the month of May (1,71). Both production systems analyzed were presented efficient, however, dependent of external circumstances and non-renewable energy sources.

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The objective of this work was to evaluate the energy and economic efficiency indexes per unit of cotton agro-ecosystem area in family production systems of Paraguay and Brazil; and, to establish a relationship between the energy and economic. Typologies presented by the Program to Support Small Cotton Holdings (Paraguay), and by the National Program for Strengthening Family Agriculture (Brazil). Family systems of the two countries were identified; these are located from Paraguay (San Juan–CA) and from Brazil (Leme–SP). To construct the energy expenditure structure of the cotton agro-ecosystem, as well as to assess the economic efficiency, the mean values obtained were considered, when they presented similarities in production systems and they were within the typology proposed in this study. From the technical itinerary observed the Paraguayan agro-ecosystem depended (fossil fuel 56.76%) and industrial source (35.99%). Thus, the energy balance of the agricultural stage was established, which attained a value of 17,740.69 MJ ha-1; an energy efficiency of 5.28, and a cultural efficiency of 3.04. The Brazilian agro-ecosystem depended on energy from industrial source (insecticides 39.82%) and from fossil fuel (33.59%); it reached an energy balance of 19,547.88 MJ ha-1; an energy efficiency of 2.12, and a cultural efficiency index of 0.71. In the economic and energy indicator ratio, with regard to the months referring to the harvest time, that is to say, March, April, and May, the maximum economic efficiency indicator of paraguay was attained in the month of May (1,00), and from Brazil in the month of May (1,71). Both production systems analyzed were presented efficient, however, dependent of external circumstances and non-renewable energy sources.