Instituto Tecnologico Of Cd Madero

Ciudad Madero, Mexico

Instituto Tecnologico Of Cd Madero

Ciudad Madero, Mexico
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Brachetti-Sibaja S.B.,Altamira | Brachetti-Sibaja S.B.,Instituto Tecnologico Of Cd Madero | Rodil S.E.,National Autonomous University of Mexico | Dominguez-Crespo M.A.,Altamira | And 3 more authors.
Thin Solid Films | Year: 2017

La2O3 thin films were successfully synthesized by r. f. magnetron sputtering technique. The effect of power, deposition time and substrate temperature on the formation and optical properties of the films was investigated. X-ray diffraction (XRD) studies revealed the formation of hexagonal phased La2O3 thin films. The influence of sputtering parameters on chemical composition and surface species was studied by X-ray photoelectron spectroscopy (XPS). The optical properties were investigated in the wavelength range of 200–1100 nm. The samples were modelled as a three-phase optical model. Optical constants were calculated at 2 eV from classical dispersion model based on the single Lorentz for dielectric materials. © 2017 Elsevier B.V.

Zamudio M.A.M.,Instituto Tecnologico Of Cd Madero | Perez A.,University of Huelva | Lopez F.,University of Huelva | Garcia J.C.,University of Huelva | And 2 more authors.
Journal of the Taiwan Institute of Chemical Engineers | Year: 2011

A central composite factorial design was used in conjunction with the software ANFIS Edit MATLAB 6.5 to develop fuzzy neural model that reproduced the experimental results of the dependent variables with errors less than 6%. The model is therefore effective with a view to simulating the autohydrolysis process. In this study it was evaluated the potential of a species trihybrid Paulownia fortunei, tormentosa and elongata as an industrial crop in terms of its contents in holocellulose, lignin, xylo-oligomers, monomers and other glucan and its use for making cellulose pulp. It was optimized biomass autohydrolysis processes to obtain valuable liquid and solid phases that can be used to produce liquid fuels and cellulosic pulp. The process was modelled in order to optimize the extraction of xylo-oligomers and xylose in the liquid phase while preserving the integrity of cellulose fibres. © 2010 Taiwan Institute of Chemical Engineers.

Saucedo-Rivalcoba V.,National Autonomous University of Mexico | Martinez-Hernandez A.L.,National Autonomous University of Mexico | Martinez-Barrera G.,National Autonomous University of Mexico | Velasco-Santos C.,Queretaro Institute of Technology | And 2 more authors.
Water, Air, and Soil Pollution | Year: 2011

The feasibility of employing a porous polyurethane-keratin hybrid membrane for the removal of hexavalent chromium was investigated. Keratin was extracted from chicken feathers and incorporated onto a synthetic polyurethane polymer to synthesize a hybrid membrane. Keratin supply active sites to bioadsorb Cr (VI) and polyurethane play an important role as the support to protein. Also, polyurethane-keratin biofiber membranes were synthesized. Biofibers obtained from chicken feathers were modified to activate their surface. The effective pore in membranes is less than 50 nm, which places these materials in the mesopore range. Scanning electron microscopy (SEM) was used to study the morphology of membranes, and mechanical dynamical analysis (DMA) was used to evaluate the viscoelastic properties. NH, C=O, S-S and C-S were determined via Fourier-transform infrared (FTIR) analysis as functional groups of keratin, which participate in the linking sorption of hexavalent chromium. Adsorption of Cr(VI) was carried out in a filtering system at low contact time in continuous flux; the maximum removal reached was 38% at neutral pH of chromium solution. Results indicate that the isoelectric point of keratin is relevant in the adsorption process. pH of keratin solution above the isoelectric point brings about higher adsorption of heavy metals, whereas lower pH causes minor adsorptions, due to the functional groups' ion charges. Based on the results, keratin extracted from feathers is a natural biosorbent that can be incorporated onto synthetic polymers to develop novel membranes and improve its applications in the heavy metal separation process. © Springer Science+Business Media B.V. 2010.

Lozano T.,Autonomous University of Tamaulipas | Laria J.,Autonomous University of Tamaulipas | Lafleur P.G.,Ecole Polytechnique de Montréal | Sanchez-Valdes S.,Research Center en Quimica Aplicada | And 2 more authors.
Polymer Engineering and Science | Year: 2012

The β-phase in polypropylene (PP) induced by shear rate in a single-screw extruder was studied. PP samples were extruded with and without a breaker plate at the exit of the extruder at five different screw rotational speeds: 20, 40, 60, 80, and 100 rpm. Differential scanning calorimeter was used to observe the melting behavior of the samples. The β-phase was quantified by wide angle X-ray diffraction. Extruded samples with a breaker plate showed higher values of β-phase of PP than those extruded without a breaker plate. With a breaker plate, the maximum percentage of β-phase was observed at 60 rpm (19.9%), whereas the maximum β-phase content without breaker plate was observed at 40 rpm (13.6%). The higher level of β-phase with the breaker plate was attributed to the shear rate induction and to the orientation by shear of the polymer chains through the orifices of the breaker plate. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers Copyright © 2012 Society of Plastics Engineers.

Lujan-Acosta R.,Research Center en Quimica Aplicada | Sanchez-Valdes S.,Research Center en Quimica Aplicada | Ramirez-Vargas E.,Research Center en Quimica Aplicada | Ramos-DeValle L.F.,Research Center en Quimica Aplicada | And 4 more authors.
Materials Chemistry and Physics | Year: 2014

The synergistic effect of organo-modified montmorillonite (Nanomer I28E and Cloisite 20A) and metal hydroxides (magnesium hydroxide MH and alumina trihydrate ATH) as flame retardants in LDPE/EVA nanocomposites compatibilized with amino alcohol grafted polyethylene (PEgDMAE) was studied. Morphological characterization of nanocomposites was carried out by means of X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM). Flame-retardant properties of nanocomposites were evaluated by the UL-94 horizontal burning and cone calorimeter tests and limiting oxygen index (LOI). Thermal degradation behavior was analyzed with a Fourier transform infrared coupled with the thermogravimetric analyzer (TG-FTIR). The XRD analysis showed a displacement of the d001 plane characteristic peak of clay to lower angles, which indicates an intercalated-exfoliated morphology. From STEM images it was observed a good dispersion of flame retardants (MH and ATH) throughout the polymer matrix which was reflected in flame-retardant properties. TG-FTIR showed a better thermal stability of nanocomposites and the gases evolved during combustion showed an important reduction. Based on thermal stability and thermal degradation results, the flame-retardant mechanism of LDPE/PEgDMAE/EVA/Clay/MH nanocomposites was proposed. © 2014 Elsevier B.V. All rights reserved.

Salas-Cabrera R.,Instituto Tecnologico Of Cd Madero | Hernandez-Colin A.,Instituto Tecnologico Of Cd Madero | Roman-Flores J.,Instituto Tecnologico Of Cd Madero | Salas-Cabrera N.,Instituto Tecnologico Of Cd Madero
International Journal of Bifurcation and Chaos | Year: 2015

This work deals with the bifurcation phenomena that occur during the open-loop operation of a single-fed three-phase wound rotor induction motor. This paper demonstrates the occurrence of saddle-node bifurcation, hysteresis, supercritical saddle-node bifurcation, cusp and Hopf bifurcation during the individual operation of this electromechanical system. Some experimental results associated with the bifurcation phenomena are presented. © 2015 World Scientific Publishing Company.

Paramo-Garcia U.,Metropolitan Autonomous University | Paramo-Garcia U.,Instituto Tecnologico Of Cd Madero | Ibanez J.G.,Ibero-American University of Mexico | Batina N.,Metropolitan Autonomous University
International Journal of Electrochemical Science | Year: 2011

The tailoring of key characteristics of conducting polymers (e.g., thickness, conductivity, degree of oxidation, color and morphology) is desirable for specific applications. We present results on the regulation of the thickness of polypyrrole films electrochemically grown on glassy carbon by potentiodynamic and potentiostatic techniques at circumneutral pH in the presence of selected aqueous dopant anions (i.e., I -, NO 3 -, Br -, Cl -, ClO 4 -, SO4 2 - and F -). In this manner, a supporting electrolyte containing KI yields relatively thick and highly conductive films whereas KF produces little conductive, very thin films. Other electrosynthesis parameters (i.e., applied potential range, number of cycles, time) also play a key role. For example, one can obtain insulating films by applying potentials in the region required for overoxidation of the film. © 2011 by ESG.

Paramo-Garcia U.,Metropolitan Autonomous University | Paramo-Garcia U.,Instituto Tecnologico Of Cd Madero | Ibanez J.G.,Ibero-American University of Mexico | Batina N.,Metropolitan Autonomous University
International Journal of Electrochemical Science | Year: 2013

This paper analyzes surface changes of polypyrrole films deposited on vitreous carbon substrates by electrochemical methods in the presence of different doping anions: I-, Br-, Cl-, F-, NO3 -, ClO4- and SO4 2-. Surface characterization of each electrode modified by electrodeposition at constant potential is performed by atomic force microscopy, AFM. The thickness of PPy films is observed to increase with anion size in halide electrolytes. AFM analysis confirms that the dopant involved in the electrosynthesis of PPy determines the topographic characteristics of the film deposited on a vitreous carbon electrode. The quantitative analysis of the surface roughness of different PPy films, [RMS]Rq establishes definite differences among the various synthesis conditions. Larger anions result in more uniform structures, as the associated nodular sizes are found to be more homogenous. Thick films and large nodule areas result in high film roughness. © 2013 by ESG.

Rodolfo A.P.R.,Instituto Tecnologico Of Cd Madero | Alan G.A.L.,Instituto Tecnologico Of Cd Madero | Marco A.A.L.,Instituto Tecnologico Of Cd Madero | Jose A.M.F.,Instituto Tecnologico Of Cd Madero
Lecture Notes in Artificial Intelligence (Subseries of Lecture Notes in Computer Science) | Year: 2015

In most business activities, decision-making has a very important role, since it may benefit or harm the business. Nowadays decision-making is based on information obtained from databases, which are only accessible directly by computer experts; however, the end-user that requires information from a database is not always a computer expert, so the need arises to allow inexperienced users to obtain information directly from a database. To this end, several tools are commercially available such as visual query building and natural language interfaces to databases (NLIDBs). However, the first kind of tools requires at least a basic level of knowledge of some formal query language, while NLIDBs, despite the fact that users do not require training for using the interface, have not obtained the desired performance due to problems inherent to natural language processing. In this paper an intuitive interface is presented, which allows inexperienced users to easily compose queries in SQL, without the need of training on its operation nor having knowledge of SQL. © Springer International Publishing Switzerland 2015.

Pecero J.E.,University of Luxembourg | Bouvry P.,University of Luxembourg | Huacuja H.J.F.,Instituto Tecnologico Of Cd Madero | Khan S.U.,North Dakota State University
Proceedings - IEEE 9th International Conference on Dependable, Autonomic and Secure Computing, DASC 2011 | Year: 2011

We address the problem of scheduling precedence-constrained scientific applications on a heterogeneous distributed processor system with the twin objectives of minimizing simultaneously energy consumption and schedule length. Previous research efforts on scheduling have focused on the minimization of a quality of service metric based on the completion time of applications (e.g., the schedule length). Recently, many researchers are working on the design of new scheduling algorithms that consider the minimization of energy consumption. We report a new scheduling algorithm accounting for both objectives. The new scheduling algorithm is based on a multi-start randomized adaptive search technique (GRASP framework) that adopts Dynamic Voltage Scaling technique to minimize energy consumption. This technique enables processors to operate in different voltage supply levels at the cost of sacrificing clock frequencies. This multiple voltage implies a trade-off between the quality of the schedules and energy consumption. Therefore, the new proposed approach is designed as a multi-objective algorithm that simultaneously optimize both objectives. Simulation results on a set of real-world applications emphasize the robust performance of the proposed approach. © 2011 IEEE.

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