Prediction of Ionic Liquids Properties through Molecular Dynamics Simulations

Ionic liquids (ILs) are a new generation of molten salts possessing unique physical and chemical properties, which have gained attention from the academic and industries researchers. The design of new products and processes requires the knowledge of transport and thermophysical properties, yet, due to the large number of potential ILs, their characterization by experimental means alone is not feasible. Computer simulations are being used with success for the prediction of structures and properties of many different molecular systems. Among different computational approaches, molecular dynamics simulation (MD) has proved to be capable of providing a good understanding at the molecular level of how the structure and properties of ILs are related. - See more at: http://www.eurekaselect.com/118935/article#sthash.VDpluw1J.dpu

Phase diagrams of mixtures of ethyl palmitate with fatty acid ethyl esters

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The cloud point is an important property of biodiesel, controlling its low temperature behaviour, especially the fluidity of the fuel. Although biodiesel is an interesting renewable energy source, data for the melting/cloud point of biodiesel or simple binary or ternary mixtures of fatty acid ethyl esters (FAEE) are still scarce in the literature, particularly for those involving ethyl esters. The phase diagrams of six binary mixtures of ethyl palmitate with saturated and unsaturated fatty acid ethyl esters were determined by Differential Scanning Calorimetry (DSC). The determined systems were successfully described employing the UNIQUAC model. The experimental data indicates that the cloud point is controlled by the fatty acid ethyl ester in the mixture with higher melting temperature. (C) 2011 Elsevier Ltd. All rights reserved.911177181Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAEPEX/UNICAMPConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq [304495/2010-7, 480992/2009-6]FAPESP [08/09502-0, 08/56258-8

Crystallization Behavior of Mixtures of Fatty Acid Ethyl Esters with Ethyl Stearate

In spite of their interest to understand the low temperature behavior of biodiesel, data on the crystal lization behaviour of fatty acid esters mixtures are scarce. To overcome this limitation, the melting points of seven binary mixtures of saturated and unsaturated fatty acid ethyl esters with ethyl stearate were measured by differential scanning calorimetry (DSC) and are here reported. The Predictive UNIQUAC model, developed for the prediction of cloud points of diesels and previously applied to fatty acid methyl esters, is shown to produce in excellent prediction of the experiemental data measured in this work, It is shown that, alternatively, a simple ideal solution is able to describe the inciting points with identical accuracy to the Predictive UNIQUAC model and may prove to be able to describe cloud points of real biodiesel234625462

Effects of the Temperature and Maturation Stages on the Germination of Roystonea regia Seeds

Roystonea regia (Kunth) O.F. Cook is largely used as ornamental. The propagation is done almost exclusively by seeds; however, there is a great variation in the germination process influenced by many factors. The objective of this work was to study the effects of the temperature and maturation stages on the germination of R. regia seeds. The experimental design was entirely randomized in a factorial arrangement 6x3 (six temperatures: constant at 20, 25, 30 and 35 degrees C and alternated at 20-30 and 25-35 degrees C, with a photoperiod of 12 hours; and three fruit maturation stages: brown, yellow and black), with four replications of 25 disseminules (seed with stucked endocarp) each. The disseminules had their mesocarp and exocarp were removed and shade dried. Their moisture content was determined, and then they were placed in plastic boxes (gerbox type) containing vermiculite. The disseminules, with the germinative intumescence, were daily noted until germination was steady. The germination rate and the germination speed index were calculated, and the data were submitted to the variance analysis. The means were compared by the Tukey test. It was concluded that the highest germination rate (99.7%) and germination speed were obtained by seeds from mature (black) fruits at the temperature of 35 degrees C