964 research outputs found

    The isotopic composition (d15N, d13C) of agricultural wastes and derived composts.

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    The aim of this study was to measure variations in the isotopic composition (d13C and d15N) during the composting of different agricultural wastes using bench-scale bioreactors. Four different feedstocks of agricultural wastes (Horse bedding manure + legumes residues; Dairy manure + Jatropha mill cake; Dairy manure + sugarcane residues; Dairy manure) were used for aerobic-thermophilic composting. During composting no significant differences were found between the d13C values of the source material and the compost, except for Dairy manure + sugarcane residues. d15N values increased significantly in composts of Horse bedding manure + legumes residues and Dairy manure + Jatropha mill cake. d15N values of composts may be related to NH3 volatilization during the composting process. Isotopic signatures (d13C, d15N) can be used to differentiate composts from different feedstock sources and d15N values may be a quantitative indicator of NH3 volatilization during composting. Use of bench-scale bioreactors is a promising apparatus to study the dynamics of C and N and stable isotopes signatures during composting, but future adjustments regarding sampling methodology are necessary

    Saturnus: Um Simulador Discreto Baseado em Eventos para Sistemas de Arquivos Paralelos

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    The focus of this work is to study parallel file systems, their elements and present Saturnus, a simulator under development for systems like these. The proposal is to use it to extract data and generate information, focusing on load balancing through the studied environment, showing experiments and possible uses for the tool. (O foco desse trabalho e ́ estudar sistemas de arquivos paralelos, seus elementos e apresentar o Saturnus, um simulador em desenvolvimento para sistemas como esses. A proposta consiste em utilizar o mesmo para extrair dados e gerar informacoes, com foco no balanceamento de carga atrave ́s do ambiente estudado, mostrando experimentos e poss ́ıveis usos para a ferramenta.

    Tatu-Bolinha (artrópodo, gênero Armadillium) como ferramenta de ecoalfabetização.

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    A cultura ocidental promove o distanciamento dos fundamentos ecológicos, o que gera desequilíbrios como os decorrentes da substituição das funções ecológicas da biodiversidade pelos agrotóxicos. Os relatos apresentados proveem de atividades de Educação Ambiental com ênfase na ecoalfabetização, desenvolvidas à partir de 2005, em Sete Lagoas, MG. O Projeto de Ecoalfabetização Tatu Bolinha foi idealizado para ampliar a discussão relativa à biodiversidade em curso de formação de professores de Geografia nas Faculdades UNIFEMM. Foram desenvolvidos trabalhos relativos à absorção de água pelas fezes do tatu-bolinha, resgate de convivência com a biodiversidade, contação de história, história em quadrinho, matéria ilustrada no "Jornal do Manuelzão", projeto pedagógico com terráreo, ferramenta no Programa Embrapa & Escola e teatro de bonecos. A fundamentação ecológica é ferramenta para contribuir com a transição da cultura antropocêntrica por uma cultura que incorpore as leis naturais e valorize a diversidade

    Herbage Characteristics as Affected by the Canopies of Dominant Trees in a Savanna of Southern Mozambique

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    This study surveyed the species composition, forage yield and forage nitrogen concentration of the herbaceous layer 50, 100 and 200% of the canopy radius from the trunks of many-stemmed false thorn, knob thorn, scented thorn and marula trees in a southern Mozambican savanna. Tree species did not affect herbaceous DM yield or species diversity. Neither direction nor distance from the tree trunk affected DM or specific diversity. Crude protein percentages were 15% higher for legumes and 9% higher for grasses at 50% canopy than at 200% canopy. Grasses under the marulas, the only non-legume tree in the study, had 18% lower CP than the average for the other three tree species. Green panic was the predominant grass species under the canopies while no single grass species predominated outside the canopy where common urochloa, Themeda triandra and Aristida spp. were the most common grasses. Vigna spp. and Stylosanthes fruticosa were evenly distributed whereas Tephrosia spp. was found predominantly outside the canopy
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