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Two bentonites from Paraíba (Northeastern Brazil) were impregnated with heteropoly phosphomolybdic H3PMo12O40 (HPMo). The materials produced were characterized by various techniques such as N2 adsorption-desorption (specific surface area, SSA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA/DTG), Scanning Electron Microscopy (SEM) equipped with Dispersive Energy X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-vis), acid-base titration analysis. The catalytic activity of these materials was tested in the esterification of a waste from palm oil deodorization and the main results obtained (about 93.3% of conversion) indicated that these materials have potential to act as heterogeneous solid acid catalysts. The prepared materials exhibited satisfactory catalytic performance even after a very simple recycling process in three reuse cycles, without significant loss of their activities.

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at high loads. The use of 7.5% EGR was found to be at an adequate rate to simultaneously reduce CO, THC and NO X emissions at low and moderate loads, without major penalties on CO 2 emissions and engine performance.

A new prepared catalyst, 12-molybdophosphoric acid (HPMo) anchored to the mesoporous aluminosilicate AlSiM, synthesized from Amazon kaolin, was characterized and used as a heterogeneous acid catalyst for the production of eugenyl acetate by acetylation of eugenol with acetic anhydride. The effect of various reaction parameters, such as catalyst concentration, eugenol/acetic anhydride molar ratio, temperature and reaction time, was studied to optimize the conditions of maximum conversion of eugenol. The kinetics studies showed that in eugenol acetylation, the substrate concentration follows a first order kinetics. The results of activation energy was 19.96 kJ mol−1 for HPMo anchored to AlSiM. The reuse of the catalyst was also studied and there was no loss of catalytic activity after four cycles of use (from 99.9% in the first cycle to 90% in the fifth cycle was confirmed), and an excellent stability of the material was observed. Based on catalytic and kinetic studies, HPMo anchored to AlSiM is considered an excellent catalyst.

Resumo -O objetivo deste trabalho foi identificar a estrutura de dependência espacial de atributos do solo e sua interferência na produção de biomassa epígea de pastagem de capim-marandu (Urochloa brizantha). Amostras de Latossolo Vermelho-Amarelo foram coletadas em rede de pontos georreferenciados, para a determinação de atributos físicos e químicos do solo e da produção de biomassa epígea da pastagem, no verão e outono de 2010/2011. Verificou-se dependência espacial das variáveis, por meio de análise geoestatística com construção e ajuste de semivariogramas, interpolação por krigagem ordinária e espacialização em mapas de isolinhas. A dependência espacial ocorreu para alguns atributos físicos e químicos do solo (areia, densidade, resistência à penetração, infiltração, pH, MO, P, K, Ca, Mg, H+Al, Al, CTC e V), e para a biomassa da pastagem medida nas estações verão e outono. A análise espacial de atributos físicos do solo permite identificar áreas degradadas da pastagem. A biomassa da pastagem é mais influenciada pelos atributos físicos do solo do que pelos químicos.Termos para indexação: Urochloa brizantha, atributos do solo, dependência espacial, espacialização. Variability of soil and pasture epigeal biomass identified by geostatisticsAbstract -The objective of this work was to identify the spatial structure dependence of soil attributes and its interference on the production of epigeal biomass of Urochloa brizantha. A Typic Hapludox was sampled at geocoded grid points in order to determine soil physical and chemical properties and the epigeal biomass production of pasture during the summer and fall seasons of 2010/2011. Spatial dependence of variables was verified by geostatistical analysis using construction and adjustment of semivariograms, ordinary kriging interpolation, and spatial maps. Spatial dependence occurred for some physical and chemical soil properties (sand, density, penetration resistance, infiltration, pH, MO, P, K, Ca, Mg, H+Al, Al, CEC, and base saturation), and for pasture biomass measured in the summer and fall seasons. Spatial analysis of soil physical attributes allows identifying areas with the highest pasture degradation. Biomass pasture is more influenced by the soil physical attributes than by the chemical ones.

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This work investigates a diesel engine operating with diesel oil containing 7% biodiesel (B7) and hydrous ethanol with concentrations varying from 5% to 30%. The experiments were conducted in a 49 kW diesel power generator, equipped with an electronic ethanol injection unit installed in the intake manifold and without any modifications in the diesel oil injection system. The results showed a decrease of in-cylinder pressure and net heat release rate with the use of ethanol at low loads and an increase at high loads, in comparison with B7. Increasing ethanol injection caused increased ignition delay and decreased combustion duration. Fuel conversion efficiency was raised up to 13% with the use of ethanol. The use of 30% ethanol in the fuel caused a reduction of carbon dioxide (CO2) emissions up to 12% and nitric oxide (NO) up to 53%. Carbon monoxide (CO), total hydrocarbons (THC) and oxides of nitrogen (NOX) emissions increased with ethanol addition. The replacement of 20% of diesel fuel by ethanol showed the lowest penalties on NOX emissions.