Federal University of São Carlos

About: Federal University of São Carlos is a education organization based out in São Carlos, Brazil. It is known for research contribution in the topics: Population & Microstructure. The organization has 16471 authors who have published 34057 publications receiving 456654 citations. The organization is also known as: UFSCar & Federal University of São Carlos.

Glass-forming ability versus stability of silicate glasses. I. Experimental test

Abstract: We recently proposed that the Hruby parameter of glass stability (KH) could be used to estimate the vitrification ability of glasses that nucleate internally. In that research, we used calculated critical cooling rates (qcr) for four glasses. In this article, we report on our measurements of the critical cooling rates of seven glasses: Li2O · 2SiO2, Na2O · 2CaO · 3SiO2, 2Na2O · CaO · 3SiO2, BaO · 2SiO2, Li2O · 2SiO2 · OH, 2BaO · TiO2 · 2SiO2 and 0.44Na2O · 0.56SiO2. We modified and used a method put forward by Colmenero and Barandiaran (CB) to estimate the qcr. The experiments were accomplished in two steps. In the first, monolithic pieces of each glass, obtained by splat cooling the melts, were heated in a Pt crucible, at the same heating rate, to estimate the glass transition, crystallization and melting temperatures. We then calculated the Hruby parameter, KH, based on these quantities. In the second step, the same samples were melted, then cooled at different rates and the crystallization temperatures observed were used to estimate qcr. In another set of tests, we used Al2O3 and graphite crucibles, repeating the same procedures for the LS2 glass. The effect of the crucible’s material (Pt, C and Al2O3) on the crystallization temperatures is discussed. A relationship between qcr and KH is experimentally demonstrated.

Brazilian bioethanol program

Abstract: Brazil is the largest producer of bioethanol, and sugarcane is the main raw material. Bioethanol is produced by both batch and continuous processes, and in some cases, flocculating yeast is used. This article analyzes the Brazilian Ethanol Program. For the 1996-1997 harvest, Brazil produced 14.16 billion L of ethanol and 13.8 million metric t of sugar, from 286 million metric t of sugarcane. These products were produced by 328 industries in activity, with 101 autonomous ethanol plants producing only ethanol, and 227 sugar mills producing sugar and ethanol. The sugar-ethanol market reaches about 7.5 billion US$/yr, accounting for direct and indirect revenues.