Abstract A continuous increase in levels of atmospheric pollution and emission restrictions has forced scientists and engineers to adopt new strategies to improve and develop internal combustion engines. One strategy is based on the development of new simulation methodologies using computational fluid dynamic (CFD) techniques, proposed in the present article. In this study,the dynamic loop methodology with ANSYS Fluent code is proposed to perform the numerical simulation ofa four-stroke spark ignition engine. The complexity of the real case was first simplified with three-dimensional CAD geometry, which was then discretized in ANSYS Meshing, whereby a hybrid mesh was created using prismatic and tetrahedral elements. Simulations for in-cylinder analyses were performed in cold flow and employing common flow parameters, such as swirl and tumble. The mesh quality results were classified as good or excellent, being higher than 0.79 for orthogonal quality criteria and lower than 0.36 for skewness criteria. Turbulent effects were introduced concerning the opening and closing of the valves. It was found that the turbulence increases during the intake stroke up to 90°, and during the power stroke, wherein the of the piston bowl, had a great contributionthat can be seen from the swirl and tumble profile for the engine cycle. In the case of the turbulence intensity, a sharp increase was registered during the admission step up to 90°, at which point the turbulence intensity was 4.0. It canbe concluded that this is an innovative approach, capable of simulating the engine motion profile in cold flow.

Abstract The objective of this research is to assess how much the improvement in the combustion reaction efficiency can reduce fuel consumption, maintaining the same thermal energy rate provided by the reaction in a pelletizing furnace. The furnace for pelletizing iron ore is a complex thermal machine, in terms of energy balance. It contains recirculation fan gases and constant variations in the process, and the variation of a single process variable can influence numerous changes in operating conditions. This study demonstrated how the main variables related to combustion in the burning zone influence fuel consumption (natural gas) from the furnace of the Usina de Pelotização de Fábrica (owned by VALE S/A), without changing process conditions that affect production quality. Variables were analyzed regarding the velocity and pressure of the fuel in the burners, the temperature of the combustion air and reactant gases, the conversion rate and the stoichiometric air/fuel ratio of the reaction. For the analysis, actual data of the furnace in operation was used, and for the simulation of chemical reactions, the software Gaseq® was used. The study showed that the adjustment of combustion reaction stoichiometry provides a reduction of 9.25% in fuel consumption, representing a savings of US$ 2.6 million per year for the company.

Abstract A novel lectin was isolated from the seeds of Chenopodium quinoa. To achieve this end, the crude extract from the quinoa was submitted to two purification steps, Sephadex G50 and Mono Q. The hemagglutinating activity showed that this lectin agglutinates human erythrocytes. Its activity is inhibited by glucose and mannose, and remained stable under a wide range of pH levels and temperatures. The quinoa lectin was found to be a heterodimeric lectin of approximately 60 kDa, consisting of two subunits of approximately 25 kDa and 35 kDa. This lectin had its antimicrobial activity tested against several bacteria strains and effectively inhibited three strains. These strains were all Gram-negative, making this lectin a promising antimicrobial tool.

O pequizeiro (Caryocar spp. - Caryocaraceae) é uma planta nativa do Cerrado e da Amazônia, cujo fruto é muito rico em óleo e proteína, e bastante apreciado pelos povos que vivem nestes ecossistemas. O objetivo desse trabalho foi avaliar o potencial de produção do "pequizeiro-anão", (Caryocar brasiliense subsp. intermedium), em seu habitat. Foram realizadas duas prospecções botânicas na região Sul do Estado de Minas Gerais, em 1997 e 1998, em áreas de vegetação de cerrado, nas proximidades do município de Ingaí-MG, onde se observou a ocorrência de pequizeiro de porte baixo. Foi observado que os frutos apresentam deiscência e grande heterogeneidade em relação ao número de frutos/planta. Nas plantas com tronco, encontraram-se até 86 frutos/planta e, nas sem tronco, até 16 frutos/planta. A época de maturação dos frutos concentra-se nos meses de fevereiro e março. O fruto de cor esverdeada e polpa amarelo-alaranjada possui em média duas sementes/endocarpo, com peso médio de 8g. Em plantios realizados no Distrito Federal, foi observado que as plantas de "pequizeiro-anão", oriundas de sementes, iniciaram a frutificação com altura de 60 cm, aos 18 a 24 meses após o plantio, evidenciando que são também precoces. O "pequizeiro-anão" apresenta potencial para sua exploração em cultivos comerciais e em programas de melhoramento genético.

The pequi tree (Caryocar spp. -- Caryocaraceae), a wild specie of Brazilian savannah and Amazon region, is an edible fruit for people living in these ecosystems. The "dwarf pequi tree" (Cariocar brasiliense subsp. intermedium), has a restricted occurrence in some parts of Brasilian savanna which is an incorporated process to arable farm, treating the survival of this specie. The objective of this work was to evaluate the production potencial of "dwarf pequi tree" in its natural habitat. The fruits can be harvested from February to March. In the plant with and without trunk there are up to 86 and 16 fruits per plant respectively. Each fruit has 2 dark yellow mesocarp and each mesocarp weighs 8 g. One year old seedlings of dwarf pequi plants raised from seeds started bearing fruits with 60 cm height 18 to 24 months after field planting in Federal District of Brazil, showing its early ripening character. The data obtained in these studies indicate that dwarf pequi has a great potential for commercial and genetic improvement program to reduce the common pequi tree height.