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Chihuahua, Mexico

Ramos-Escobedo G.T.,CIMAV | Pecina-Trevino E.T.,ESI UAdeC | Bueno Tokunaga A.,ESI UAdeC | Concha-Guerrero S.I.,CIMAV | And 3 more authors.
Fuel | Year: 2016

In this study a strain of Staphylococcus carnosus whose characteristics of hydrophobicity and ability to change the surface charge of some minerals such as coal, by excreting some exopolymers, has been used as bio-collector to evaluate the recovery of fine coal tailings mineral through micro-flotation, from the two sub-basins located in the Sabinas basin and identified as: Sabinas (CFP) and Rio Escondido (CFM), located in Coahuila, Mexico. Results show that in the absence of microorganism recovery is about 50% and that using S. carnosus recovery reaches values close to 90% in both samples of coal for a time of 12 h and a pH of 9. Mechanism has been investigated using techniques such as adhesion kinetics, adsorption isotherms, and infrared spectroscopy. It illustrates that biofilm consisted of excreted chemicals, such as fatty acids, improves the hydrophobicity of the coal surface. © 2016 Elsevier Ltd. All rights reserved. Source


Rivas-Arreola M.J.,Durango Institute of Technology | Rocha-Guzman N.E.,Durango Institute of Technology | Gallegos-Infante J.A.,Durango Institute of Technology | Gonzalez-Laredo R.F.,Durango Institute of Technology | And 4 more authors.
Pakistan Journal of Biological Sciences | Year: 2010

The aim of present study was to evaluate antioxidant capacity and cardioprotective potential of leaves infusions and partially purified fractions of Quercus sideroxyla and Q. eduardii (red oaks) and Q. resinosa (white oak). Consumption of polyphenol-rich beverages derived from plants, such as oak may represent a beneficial diet in terms of cardiovascular protection. Infusions from Oak leaves were obtained and probed for total phenolics by Folin-Ciocalteu, DPPH and hydroxyl radicals scavenging by DPPH test and Deoxy-D-ribose method, the antioxidant capacity was evaluated by FRAP and ORAC tests, inhibitions of Low Density Lipoproteins (LDL) oxidation and Angiotensin Converting Enzyme (ACE) activity were measured. A HPLC analysis was performed by HPLC-MS. Bioactive polyphenols such as gallic and ellagic acids, catechin, quercetin and derivatives: naringenin and naringin were detected in Quercus infusions. A distinctive HPLC profile was observed among the red and white oak samples. Q. resinosa infusions have exhibited the highest antioxidant activity in comparison with the other species, although in the inhibition of LDL oxidation no differences were observed. In the inhibition of the ACE, Q. resinosa was more effective (IC50, 18 ppm) than Q. sideroxyla, showing same effect as the control Captopril. From the results it is possible to postulate that not only chelating activity is important in these infusions, especially in Q. resinosa, © 2010 Asian Network for Scientific Information. Source


Ponce-Pena P.,Circuito Universitario | Lopez-Chipres E.,Circuito Universitario | Garcia-Sanchez E.,Autonomous University of Nuevo Leon | Escobedo-Bretado M.A.,Circuito Universitario | Gonzalez-Lozano M.A.,Circuito Universitario
Advances in Materials Science and Engineering | Year: 2015

An alloy type A16060 was exposed to severe plastic deformation to study its reaction using the finite element method (FEM). To perform this, six different configurations were used in the design of the die's channel for ECAP (equal channel angular pressing) to obtain nanostructure materials and to optimize the process. Thanks to simulation performed with FEM, it is possible to study the homogeneity in the deformation due to the variation of conditions affecting directly the material being processed using the ECAP technique, such as the friction coefficient, extrusion speed, and mainly the die's channel geometry being utilized in the ECAP process. Due to the tensile strain area being located mainly in the upper part of the deformed test cylinder (plastic deformation area) which increases the fracture and cracking tendency preventing the processing through ECAP the die being utilized was modified to eliminate the tensile strain area favoring the appearance of compressive stress which reduces the cracking tendency and the fracture of the sample being processed. The FEM analysis demonstrated that the strain state changed significantly from tension to compression when the modified die was used, facilitating the processing of the piece by ECAP. © 2015 Patricia Ponce-Peña et al. Source


Ramos-Sanchez V.H.,Circuito Universitario | Ramos-Sanchez V.H.,University of Sheffield | Jeans R.,University of Sheffield | Elder R.H.,University of Sheffield | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2015

The Sulfur Iodine cycle has great potential for large scale hydrogen production from water. The HIx processing stage (Section III) of the cycle exhibits the major challenges. Among them, experimental vapour liquid equilibrium data is scarce, mainly due to inherent hurdles to monitor the system under operating conditions of this section, i.e. temperature, acidity, and corrosion. Until now, UV-Visible and FTIR spectroscopies are the online monitoring techniques of choice, however due their selection rules, there is no experimental spectroscopic evidence of H2 during direct decomposition of HIx. Bearing this in mind, here we demonstrate the feasibility of exploiting two different Raman spectroscopic techniques as in situ monitoring tools, to gain substantial knowledge on the mechanisms of hydrogen production in Section III. Whereas resonance Raman spectra revealed the occurrence of HI·(H2O)3 in the vapour phase; coherent anti-Stokes Raman spectra of H2 allowed us to estimate kinetic data such as the activation energy for HI decomposition of a given hyper-azeotropic ternary mixture (i.e. xHI: 0.144; xI2:0.308; xH2O:0.548) is 149.15 kJ/mol. © 2014 Hydrogen Energy Publications, LLC. Source

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