6,340 research outputs found

    Climatização de banana 'prata anã'.

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    Environmental assessment of humic acid coated magnetic materials used as catalyst in photo-fenton processes

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    Persistent organic pollutants have been increasingly detected in natural waters, and this represents a real challenge to the quality of this resource. To remove these species, advanced treatment technologies are required. Among these technologies, Fenton-like and photo-Fenton-like processes have been investigated for the removal of pollutants from water. Delicate aspects of photo-Fenton processes are that light-driven processes are energy intensive and require a fair amount of chemical inputs, which strongly affects their overall environmental burdens. At present, aside from determining the efficiency of the processes to remove pollutants of a particular technology, it becomes fundamental to assess also the environmental sustainability of the overall process. In this work, the methodology of the life cycle assessment (LCA) was applied to identify the hotspots of using magnetite particles covered with humic acid (Fe3O4/HA) as a heterogeneous photo-Fenton catalyst for water remediation. The sustainability of the overall process was considered, and a comparative LCA study was performed between H2O2 and persulfate activation at different pH. The addition of humic substances to the particles allows the effectiveness of the catalyst to improve without increasing the environmental impacts; these processes are strongly correlated with energy consumption and therefore with the efficiency of the process. For this reason, working at acidic pH allows us to contain the impacts

    Avaliação da qualidade e conservação pós-colheita de frutos de tomate orgânico produzidos com diferentes sistemas de irrigação.

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    Avaliou-se a influência de diferentes sistemas de irrigação na qualidade e conservação pós-colheita de frutos de tomate produzidos de forma orgânica. O estudo foi conduzido na Embrapa Hortaliças, Distrito Federal, durante período seco do ano (maio-outubro).Trabalho 10718. Trabalho apresentado no 7. Congresso Brasileiro de Agroecologia, Fortaleza, 2011

    Correlating Pedestrian Flows and Search Engine Queries

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    An important challenge for ubiquitous computing is the development of techniques that can characterize a location vis-a-vis the richness and diversity of urban settings. In this paper we report our work on correlating urban pedestrian flows with Google search queries. Using longitudinal data we show pedestrian flows at particular locations can be correlated with the frequency of Google search terms that are semantically relevant to those locations. Our approach can identify relevant content, media, and advertisements for particular locations.Comment: 4 pages, 1 figure, 1 tabl

    Folding model analysis of alpha radioactivity

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    Radioactive decay of nuclei via emission of α\alpha particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the α\alpha-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the α\alpha nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic α\alpha-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields microscopic calculations for the half lives of α\alpha decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations provide reasonable estimates for the lifetimes of α\alpha radioactivity of nuclei.Comment: 7 pages including 1 figur

    Consumo voluntário e digestibilidade aparente da matéria seca, matéria orgânica, energia e parede celular das silagens de quatro genótipos de girassol (Helianthus annus).

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    O valor nutricional de silagens de quatro genótipos de girassol (Rumbosol 91, M734, C11 e S430) foi avaliado a partir do consumo voluntário e da digestibilidade aparente da matéria seca, da matéria orgânica, da energia e dos componentes da parede celular. Vinte carneiros adultos foram alojados em gaiolas metabólicas, em delineamento inteiramente ao acaso, com quatro tratamentos e cinco repetições. Não foram observadas diferenças para consumo de matéria seca, matéria orgânica, energia digestível e metabolizável e dos componentes fibrosos entre os genótipos de girassol. A digestibilidade aparente da matéria orgânica foi superior para os genótipos R91, M734 e S430, no entanto não influenciou o consumo de matéria orgânica digestível. As silagens de girassol foram classificadas como alimento volumoso de boa qualidade, uma vez que o consumo de matéria seca foi acima dos requisitos recomendados para mantença animal, 63,6; 69,6; 50,2 e 74,5g MS/kg0,75/dia para R91, M734, C11 e S430, respectivamente. O baixo coeficiente de digestibilidade aparente médio da FDN (32,3%) e da FDA (28,7%) foi conseqüência da baixa qualidade dos constituintes da parede celular das silagens de girassol utilizadas
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