999 resultados para Inseticidas químicos


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Pressure drop and energy efficiency of compressors in chemical plants are the focus of this study. Its objective is an analysis of possible sources of energy loss through the study of pressure loss in pipes, calculation of thermodynamic efficiency of the compressors. Important issues are raised for this analysis such as the types of compressors, the operating range of each compressor, compression types, as well as a study of accessories such as filters and valves. After studying these issues was carried out calculations of pressure drop step-bystep and with a software WIPCD. Followed by the calculation of efficiency of compressors and monthly energy cost of each compressor in operation. Finally, the study shows some suggestions for immediate improvements, changes and suggestions for possible future purchases of compressors

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Compounds released into the environment can induce genetic alterations in living organisms. A group of chemicals that shows proven toxicity is the pesticides, and the insecticides are the most harmful. The insecticides of the family phenylpyrazole have wide application both in agriculture and in homes. Fipronil, an insecticide of this chemical group, is widely used in various cultures and in homes, mainly for fighting fleas and ticks on dogs and cats. The use of fipronil may represent a risk to man and the environmental health, since this pesticide can potentially induce cell death, regardless of cell type. Fipronil, when in contact with the environment, can undergo various degradation processes, including photodegradation. The toxic effect of one of its metabolites derived from photodegradation, sulfone-fipronil, is approximately 20 fold as great as fipronil itself. The A. cepa test system was used to evaluate cytotoxic, genotoxicity and mutagenic effects of fipronil before and after phptodegradation. Seeds of Allium cepa were subjected to solutions of fipronil, pre-exposed or not exposed to degradation by sunlight. The germination tests were conducted both under the effect of light and in the dark. We evaluated the cumulative potential of this insecticide using 48 and 72-hours recovery tests. The results showed that when fipronil was previously exposed to the sun, it presented a greater genotoxic and mutagenic potential, showing that the metabolites formed by photodegradation can show more harmfull effects

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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CHEMICAL CONSTITUENTS OF Hyptidendron canum (Pohl ex Benth.) R. Harley (LAMIACEAE). Chemical investigation of Hyptidendron canum stems resulted in the isolation of betulinic, ursolic and euscaphic acids. From the leaves were isolated 3β-O- β-galactopiranosilsitosterol, ursolic aldehyde, and mixtures of maslinic acid and 2α-hydroxyursolic acid, α and β-amyrin, uvaol and erythrodiol, sitosterol and stigmasterol, spathulenol and globulol. Hexane and chloroform leave fractions as well as ursolic and betulinic acids showed antifungal activities against the yeast form of Paracoccidioides brasiliensis.

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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