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Santiago de Querétaro, Mexico

Mantilla A.,CICATA | Mantilla A.,Metropolitan Autonomous University | Jacome-Acatitla G.,Metropolitan Autonomous University | Morales-Mendoza G.,Metropolitan Autonomous University | And 2 more authors.
Industrial and Engineering Chemistry Research

MgAl hydrotalcites, or layered double hydroxides (LDHs), with different Mg/Al molar ratios were synthesized by the coprecipitation method. The structure of the solids was collapsed by thermal treatment at 723 K obtaining MgAl mixed oxides with high specific surface areas (264-318 m2/g). When these oxides were put in contact with aqueous solutions containing 4-chlorophenol and para-cresol (80 ppm:0.62 and 0.73 mmol, respectively) the layered structure was recovered by rehydration of the material showing the named "memory effect" of LDH materials. Mg/Al LDHs were active for chlorophenol and p-cresol degradation under UV irradiation, being more active and selective to the mineralization of the pollutants than TiO2 P-25 photocatalysts. Since Mg/Al hydrotalcites are not semiconductors their high photoassisted activity was surprising; this activity was explained by a photo excitation which produces mobility of charges in the lamellar structure, inducing the formation of photoactive defects. © 2010 American Chemical Society. Source

Banana and lentil flour blends were processed in a single screw extruder modifying the flour properties of the blend (20.5-79.5%), at selected range of die temperature (145-175 oC) and the feeding moisture content (20-24%).Functional characteristics evaluated in the extrudates were water absorption index (WAI), water solubility index (WSI), bulk density (BD), paste viscosity properties, microstructure and resistant starch content. The concentration of lentil/banana blends and temperature were the most important variables affecting dependent variables WAI, WSI, BD and viscosity properties. The results of this study indicated that extrusion cooking induced desirable functional characteristics to lentil/banana blends by increasing their resistant starch content. Source

Castillo E.,CICATA
International Journal of Advanced Robotic Systems

In this paper the workspace and payload capacity of a new design of reconfigurable Delta-type parallel robot is analysed. The reconfiguration is achieved by adjusting the length of the kinematic chains of a given robot link simultaneously and symmetrically during the operation of the robot. This would produce a dynamic workspace in shape and volume. A numerical analysis of the variation of shape and volume of the workspace and payload capacity of the robot is presented. Based both on the results of this analysis and on practical requirements, a proposal for the design of a reconfiguring mechanism is presented. © 2013 Maya et al. Source

De Moure-Flores F.,CINVESTAV | Nieto-Zepeda K.E.,CINVESTAV | Guillen-Cervantes A.,CINVESTAV | Gallardo S.,CINVESTAV | And 6 more authors.
Journal of Physics and Chemistry of Solids

Fluorine-doped CdS films were deposited on glass substrates at 70 °C by chemical bath deposition using HF as fluorine source. The as-grown films were immersed in a 0.25 M CdCl2 solution and annealed at 400 °C in a nitrogen atmosphere. Effects of doping and post-deposition treatment on structural, topography, optical and electrical properties were investigated. The post-deposition treatment causes an increase in the grain size, a decrease in the rms roughness and a reduction in the resistivity of the CdS:F films. After treatment a CdS:F film with a roughness of 2.39 nm and a resistivity of 2.96 cm was obtained. © 2012 Elsevier Ltd. All rights reserved. Source

Romero J.A.,Autonomous University of Queretaro | Lozano-Guzman A.A.,CICATA | Betanzo-Quezada E.,Autonomous University of Queretaro | Lopez-Cajun C.S.,Autonomous University of Queretaro
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

In this paper a critical review of road infrastructure and vehicle robotic technologies is presented. It is found that many infrastructure-related robotic technologies have not reached the implementation stage, which is attributed to reliability concerns as such technologies involve high risk operations such as crack sealing. However, that the greatest effort to robotize operations in road transportation has been aimed at getting driver assisted and autonomous vehicles. The use of a crash avoidance system to prevent the impact of a double tractor-semitrailer truck onto a scholar bus is further analyzed, finding that a longitudinal crash-avoidance robotic system might have saved as many as seven lives. It is found that the main limitation of autonomous vehicles has to do with their ability to recognize atypical road irregularities that might endanger driving. © Springer International Publishing Switzerland 2014. Source

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