ObstractWhen using Fourier transform infrared spectroscopy (FT-IR) under the qualitative aspect for characterization of polymer blends, often a simple identification of each one of the existing polymers in the blend does not justify the material failure since different amounts of each component may result in different mechanical properties, which should be a possible cause for of material failure when applied to an automotive part. Thus, seeking for a better justification in the understanding of material failure analysis, a new quantitative FT-IR methodology was developed in the mid-infrared region (MIR), using the transmission techniques and universal attenuated reflectance for the determination of Acrylonitrile Butadiene Styrene (ABS) and polycarbonate (PC). Transmission mode was more suitable. The relative band (A 831 /A 2237 ) was chosen for the preparation of the calibration curve that showed a 0.99% error methodology, which is within the FT-IR spectrometer accuracy limit (≤ 2%); therefore, it is accurate for the analysis of the system.

ObstractRubber blends are important materials in automotive industry, as well as in other sectors. However, there are implications when suitable use of a polymer in an artifact is not made. In the automotive area, for example, the use of an elastomer without the fuel resistance requirement would result in component degradation, potential fuel leakage, and danger of fire. The use of polymer blends may be the solution to this problem. Fourier transform infrared spectroscopy (FT-IR) can be used for the knowledge of the polymer content of these blends. Then, FT-IR quantitative methodologies for determining acrylonitrile-butadiene copolymer (NBR) copolymer and butadiene-styrene copolymer (SBR) contents were developed by the transflectance accessory, NIRA, and the transmission mode, being the sample analyzed by transmission and universal attenuated total reflection (UATR) in the medium infrared (MIR). UATR and NIRA methodologies showed better accuracy. However, the MIR analysis showed a detection limit between 10-20% of NBR.

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Aves exercem grande participação no processo de dispersão, embora em algumas vezes o efeito possa ser negativo. O objetivo deste trabalho foi determinar quais espécies de aves no Brasil podem ser consideradas efetivas dispersoras. Para tanto, foi realizado um levantamento bibliográfico de estudos sobre frugivoria e elaborada uma matriz de dados relacionando espécies de aves e de plantas. Com o auxílio de uma análise discriminante multivariada baseada em 34 artigos entre os anos de 1990 e 2010, foi possível isolar 14 espécies com características extremamente favoráveis à dispersão, sendo consideradas dispersoras efetivas. Destas, destacam-se Turdus rufiventris, Turdus leucomelas, Turdus amaurochalinus e Tangara sayaca que, além de possuírem as principais características favoráveis à dispersão, apresentam uma alta frequência de ocorrência, contribuindo ainda mais para a qualidade da dispersão.

Due to the high value of the fruit, the European chestnut (Castanea sativa Mill.), usually grown in agroforestry systems, has been planted as a single species in orchards managed with increasingly intensive cropping practices, such as the regular use of fertilisers. This justifies research into establishing fertilisation programmes oriented towards ecological intensification. In this study, the results of fruit production, plant nutritional status and soil properties are reported from a field trial in which three NPK fertilisers (20:7:10, 13:11:21 and 7:14:14) and a control treatment were used. Chestnut yields did not vary significantly between treatments, although the mean values of the control showed a clear downward trend. N supplied by the fertilisers seems to have been the most important factor in the difference between the fertilised and control treatments, since leaf N concentrations were lower in the control and often below the lower limit of the sufficiency range. Soil inorganic N levels in the autumn, and tissue N concentrations of the herbaceous vegetation developing beneath the trees, indicated risks of N loss to the environment and highlighted the importance of this vegetation remaining during the winter. The chestnuts’ poor response to fertiliser applications was attributed to the buffering effect of the large perennial structure of the trees on the distribution of nutrients to the growing plant parts. In large trees, it seems appropriate to base the annual fertilisation plan on leaf nutrient concentration. Thus, farmers probably should avoid spending money on fertilizer applications as long as leaf nutrient concentrations do not approach the lower limits of sufficiency ranges.