Sifat Antirayap Ekstrak Kulit Biji Saga (Adenanthera Pavonina Linn) Antitermites Properties of Extract Shell Seed Saga (Adenanthera Pavonina Linn)

The aims of these research were to know the extract content of saga seed shell, to evaluated weight lost of cellulose paper, to evaluated mortality of termites and to evaluated termites consumption. Research was done by extracting sample with methanol then partitioning with n-hexane. Concentrated extractive of 2%, 4%, and 6% were used the toxic test of the termite Coptotermes curvignathus. The Result showed that extract content of saga seed shell was 15.82%. Mortality with concentration of 2%, 4% and 6% were not significantly so the concentration of 2% was effective, eficien and happened in 6th day. The tendency showed that increasing concentration of extract caused decreasing of weight lost of cellulose paper and consumption of termites. The percentage weight lost of cellulose paper was 3.88%–11.04% and consumption of termite was 0.26–0.73 mg. The extract with concentration of 2% was effective based of evaluated from mortality, weight lost of cellulose paper and rate consumption of termites

Effects of Dry and Wet Sieving of Soil on Identification and Interpretation of Microbial Community Composition

Soil aggregates are microhabitats for microorganisms, and directly influence microorganisms that live within and are influenced by microorganisms in return. Two methods are used to isolate soil aggregates by their size: dry sieving (sieving air-dried soil) and wet sieving (sieving soil in water). Wet-sieving methods are generally considered to represent separation of aggregate classes that are stable to physical disaggregation in water, a condition considered favorable for protecting soil structure over time. However, little is known about the effect of sieving methods on microbial abundance, diversity, and functions, hindering the understanding of the relationship between soil structure and soil aggregates as habitat and soil microorganisms. In this study, the effect of dry and wet sieving on bacterial diversity, and abundance of microorganisms involved in N fixation (nifH gene), nitrification (amoA bacteria and archaea), and denitrification (narG, nirS and nosZ genes), was determined for four sizes of soil aggregates from a cropland and grassland. Quantitative-PCR (Q-PCR) showed little differences in relative gene abundance between size fractions of soil aggregates, but wet-sieving method significantly increased gene abundance for amoA bacteria, nirS and nosZ genes. When the N functional genes were expressed as percentage of the bacterial 16S rRNA genes, the wet sieving resulted in significantly higher genes percentage for all the genes (except for narG gene), and significant differences between soil aggregate size fractions at the grassland site. The different sieving methods resulted in different bacterial community compositions, but only the wet-sieving method was able to reveal significant differences in bacterial community composition between soil fractions in grassland. The results demonstrate significantly different quantitative and qualitative interpretation of soil microbial community depending on whether aggregate samples were obtained from wet or dry sieving, highlighting the importance in the choice of the sieving method

Development and validation of a numerical model of a rotary steam engine for electric power micro generation using biomass

The use of fossil combustibles leads to the generation of large quantities of carbon dioxide. Though its effects on the environment are not fully explained, it is quite an highlighted fact that an alternative way to fossil fuels for heat and energy production has to be found. This paper presents a numerical model used for modeling a rotative steam engine to be employed to use the steam produced by a proper biomass boiler. This engine is based on the Wankel kinematic scheme and is developed using the one dimensional code AMESim. A proper numerical model was set up in order to take into account the volume and torque variation in function of the angular displacement of the rotor. A prototipe is also presented; this was built in the Energetica Department Laboratories modifying a commercial Wankel. This prototipe was tested at the engine test bench using compressed air at several inlet pressures and rotating speeds. The results of the experimental tests were then compared with the numerical ones in terms of delivered power, air consumption and ratio between inlet and outlet temperatures

Nitrification heterogeneity and impact on the vegetation cover in a wet tropical ecosystem (Lamto, Ivory Coast)

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