1,170 research outputs found

    Pesquisa participativa para estratégias de manejo sustentável dos recursos forrageiros dos campos naturais: pressupostos e aspectos metodológicos

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    Os ecossistemas campestres; A diversidade vegetal; As estratégias de manejo; O papel dos manejadores; A destruição dos campos; A pecuária familiar e a conservação dos campos; Novos contextos; A crise ambiental como face da crise civilizatória; A conservação dos recursos naturais como oportunidade; O caso do campo nativo e a pecuária sustentável; O campo nativo como promotor do desenvolvimento; Proposta metodológica; Nova abordagem na produção do conhecimento; A participação como pressuposto; As unidades experimentais participativas; Passos metodológicos; A rede de pesquisa participativa; A rede de inovação; A rede de produção certificada.bitstream/item/55763/1/DT99.pd

    Electron Beam Adjustment in PLATO RTS 2 Including the Effect of Air Gaps

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    Background and Purpose: Beam characterization for electron dose calculations in PLATO RTS 2 treatment planning system requires the tuning of two adjustment parameters: sqx (the initial angular spread) and FMCS (a "fudge" multiple Coulomb scattering parameter). This work provides a set of suggestions to optimise electron dose calculations with PLATO, taking into account the effect of air gaps between the electron applicator and the patient skin. Material and Methods: Two adjustment criteria have been followed: one which uses just one input data set corresponding to the standard (null) air gap and another one that takes into account the whole range of clinically used distances between the electron applicator and the patient surface. The adjusted values of sqx were compared with experimental data and GEANT3 Monte Carlo code results. A systematic study has been carried out of the effect of both adjustment parameters on electron dose calculations in water. Comparisons of dose distributions and point dose values have been done between PLATO RTS2, GEANT3 Monte Carlo code and experimental data. Also the dependence on field size has been assessed. The values of sqx for the different electron energies obtained through the different approaches are discussed. Results and conclusions: The first adjustment criteria yield unrealistic dose distributions whenever the air gap is different from the standard one. A sqx balanced with a proper FMCS parameter leads to reasonably good dose distributions and point dose values that agree with experimental results within less than 1%

    Controle de doenças do maracujazeiro através do uso de produtos alternativos.

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    Publicado também em: Fitopatologia Brasileira, v. 30, p. S59, ago. 2005. Suplemento. Resumos do XXXVIII Congresso Brasileiro de Fitopatologia

    Couro de sapo em mandioca (Manihot esculenta Crantz) no Estado do Pará.

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