907 resultados para Solar energy in agriculture
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Pós-graduação em Engenharia Elétrica - FEB
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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An optimal control framework to support the management and control of resources in a wide range of problems arising in agriculture is discussed. Lessons extracted from past research on the weed control problem and a survey of a vast body of pertinent literature led to the specification of key requirements to be met by a suitable optimization framework. The proposed layered control structure—including planning, coordination, and execution layers—relies on a set of nested optimization processes of which an “infinite horizon” Model Predictive Control scheme plays a key role in planning and coordination. Some challenges and recent results on the Pontryagin Maximum Principle for infinite horizon optimal control are also discussed.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This work focuses basically on the design and analysis of simple and low cost hardware systems efficiency for temperature measurement in agricultural area. The main objective is to prove quantitatively, through statistical data analysis, to what extent a simple hardware designed with inexpensive components can be used safely in the indoor temperature measurement in farm buildings, such as greenhouses, warehouse or silos. To verify the of simple hardware efficiency, its data were compared with data from measurements with a high performance LabVIEW platform. This work proved that a simple hardware based on a microcontroller and the LM35 sensor can perform well. It presented a good accuracy but a relatively low precision that can be improved when performed some consecutive signal sampling and then used its average value. Although there are many papers that explain these components, this work has the distinction of presenting a data analysis in numerical form and using high performance systems to ensure critical data comparison.
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The University of Nebraska!Lincoln Department of Agricultural Economics hosted the 24th Women in Agriculture (WIA) Conference February 26-27, 2009. Over 350 women participated in the event. A majority came from across the great state of Nebraska, but there were a few individuals that made the trip from California, Colorado, North Carolina, Kansas, Iowa and South Dakota. For some women, this was their first time experiencing the conference and for others it was their 24th time. Average attendance among the women was approximately 6.5 times. The main goal of the conference was to heighten the womens’ skills and gain knowledge to take back to their agricultural operations.
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The badger (Taxidea taxus). because of its strong propensity for digging, is considered North America's fossorial carnivore, feeding mostly on ground squirrels, pocket gophers, and mice throughout much of the western and midwestern continent. Badger excavations, primarily in search of food, produce mounds and deep holes which can damage alfalfa and other crops and damage farm equipment and water systems. Depredations include poultry, waterfowl, and eggs. Overall, the badger is considered a relatively minor vertebrate pest. As a furbearer it is considered a renewable natural resource. Most local pest problems are currently reduced through leghold trapping and shooting. Habitat modification through continuous rodent control is effective and a long-lasting badger control method.
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Metadata is data that fully describes the data and the areas they represent, allowing the user to decide on their use as best as possible. Allow reporting on the existence of a set of data linked to specific needs. The use of metadata has the purpose of documenting and organizing a structured organizational data in order to minimize duplication of efforts to locate them and to facilitate maintenance. It also provides the administration of large amounts of data, discovery, retrieval and editing features. The global use of metadata is regulated by a technical group or task force composed of several segments such as industries, universities and research firms. Agriculture in particular is a good example for the development of typical applications using metadata is the integration of systems and equipment, allowing the implementation of techniques used in precision agriculture, the integration of different computer systems via webservices or other type of solution requires the integration of structured data. The purpose of this paper is to present an overview of the standards of metadata areas consolidated as agricultural.
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We study, in a d-dimensional space-time, the nonanalyticity of the thermal free energy in the scalar phi(4) theory as well as in QED. We find that the infrared divergent contributions induce, when d is even, a nonanalyticity in the coupling alpha of the form (alpha)((d-1)/2) whereas when d is odd the nonanalyticity is only logarithmic.
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We discuss two Lagrangian interacting dark energy models in the context of the holographic principle. The potentials of the interacting fields are constructed. The models are compared with CMB distance information, baryonic acoustic oscillations, lookback time and the Constitution supernovae sample. For both models, the results are consistent with a nonvanishing interaction in the dark sector of the Universe and the sign of coupling is consistent with dark energy decaying into dark matter, alleviating the coincidence problem-with more than 3 standard deviations of confidence for one of them. However, this is because the noninteracting holographic dark energy model is a bad fit to the combination of data sets used in this work as compared to the cosmological constant with cold dark matter model, so that one needs to introduce the interaction in order to improve this model.
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Sulfur (S) deficiency in soils is becoming increasingly common in many areas of the world as a result of agronomic practices, high biomass exportation and reduced S emissions to the atmosphere. In this review, the incidence and commercial exploitation of S pools in nature are discussed, as well as the importance of S for plants and the organic and inorganic S forms in soil and their transformations, especially the process of microbiological oxidation of elemental sulfur (S0) as an alternative to the replenishment of S levels in the soil. The diversity of S0-oxidizing microorganisms in soils, in particular the genus Thiobacillus, and the biochemical mechanisms of S0 oxidation in bacteria were also addressed. Finally, the main methods to measure the S0 oxidation rate in soils and the variables that influence this process were revised.