Universidad Autónoma del Estado de México

About: Universidad Autónoma del Estado de México is a education organization based out in Toluca, Mexico. It is known for research contribution in the topics: Population & Adsorption. The organization has 7086 authors who have published 8748 publications receiving 72501 citations.

Preparation and Characterization of CaO Nanoparticles/NaX Zeolite Catalysts for the Transesterification of Sunflower Oil

Abstract: Biodiesel is produced by the transesterification of oil triglycerides with methanol or ethanol, in the presence of a homogeneous or heterogeneous catalyst. This study aims to report the results of the transesterification of sunflower oil with methanol to produce biodiesel using CaO nanoparticles supported on NaX zeolite as catalyst. The effect of the CaO nanoparticles concentration on the NaX zeolite surface was studied in the range of 5−25 wt %. The transesterification reaction was carried out at reflux temperature of methanol, atmospheric pressure, a reaction time of 6 h, and with a 6:1 molar ratio of methanol to sunflower oil. Catalyst characterization was carried out by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. It was concluded that methyl esters content is highly influenced by basicity and that the best catalyst was the one holding 16 wt % CaO nanoparticles. The produced biodiesel was 93.5% methyl esters and was found to fulfill the specifications of Europ...

Government 2.0: Making connections between citizens, data and government

Abstract: The revolution in information and communication technologies (ICT) has been changing not only the daily lives of people but also the interactions between governments and citizens. The digital government or electronic government (e-government) has started as a new form of public organization that supports and redefines the existing and new information, communication and transaction-related interactions with stakeholders (e.g., citizens and businesses) through ICT, especially through the Internet and Web technologies, with the purpose of improving government performance and processes [1].

Light transmission in quasiperiodic multilayers of porous silicon

Abstract: Porous silicon is an efficient photo- and electro-luminescent material and represents a promising candidate for opto-electronic applications On the other hand, quasiperiodic structures have been shown to be effective media for light localization and third harmonic generation In this work, we present a photonic model for quasiperiodic multilayer structures, which are built experimentally by alternating porous silicon layers with high and low refractive indices The analysis of the light propagation through these structures is based on the transfer matrix theory The theoretical reflectance spectrum is compared with experimental data, observing a good agreement

Insights on the evolution of trehalose biosynthesis

Abstract: The compatible solute trehalose is a non-reducing disaccharide, which accumulates upon heat, cold or osmotic stress. It was commonly accepted that trehalose is only present in extremophiles or cryptobiotic organisms. However, in recent years it has been shown that although higher plants do not accumulate trehalose at significant levels they have actively transcribed genes encoding the corresponding biosynthetic enzymes. In this study we show that trehalose biosynthesis ability is present in eubacteria, archaea, plants, fungi and animals. In bacteria there are five different biosynthetic routes, whereas in fungi, plants and animals there is only one. We present phylogenetic analyses of the trehalose-6-phosphate synthase (TPS) and trehalose-phosphatase (TPP) domains and show that there is a close evolutionary relationship between these domains in proteins from diverse organisms. In bacteria TPS and TPP genes are clustered, whereas in eukaryotes these domains are fused in a single protein. We have demonstrated that trehalose biosynthesis pathways are widely distributed in nature. Interestingly, several eubacterial species have multiple pathways, while eukaryotes have only the TPS/TPP pathway. Vertebrates lack trehalose biosynthetic capacity but can catabolise it. TPS and TPP domains have evolved mainly in parallel and it is likely that they have experienced several instances of gene duplication and lateral gene transfer.