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Vazquez-Cuchillo O.,Autonomous University of Nuevo León | Vazquez-Cuchillo O.,Polytechnic University of Puebla | Gomez R.,Metropolitan Autonomous University | Cruz-Lopez A.,Autonomous University of Nuevo León | And 4 more authors.
Journal of Photochemistry and Photobiology A: Chemistry | Year: 2013

Na2Ti6O13and Zr/Na2Ti 6O13prepared by the sol-gel method and impregnated with different amounts ofRuO2(0.1-10 wt%) were evaluated as photocatalysts for water splitting. The calcined materials at 800°Cwere characterized by X-ray diffraction (XRD) analysis, Raman spectroscopy, UV-vis spectroscopy withdiffuse reflectance spectroscopy (DRS), N2physisorption, scanning electron microscopy (SEM) and trans-mission electron microscopy (TEM). The physicochemical characterization confirmed that both materialshad the tunnel structure. However, the Zr/Na2Ti6O13sample revealed high Zr dispersion. The ideal amountof RuO2to load the samples with was shown to be 2.0 wt %, which produced hydrogen at a rate of265 μmol h-1. The apparent quantum yield efficiency was 21%. The improvement on the catalytic activ-ity of the impregnated materials suggested a synergistic effect between the Zr and RuO2, which actedlike an electron trap. © 2013 Elsevier B.V.

Sedeno-Monge V.,UPAEP University | Arcega-Revilla R.,Hospital Of Especialidades | Rojas-Morales E.,Polytechnic University of Puebla | Santos-Lopez G.,Instituto Mexicano del Seguro Social | And 6 more authors.
Journal of Neuroimmunology | Year: 2014

Multiple sclerosis (MS) is an autoimmune disease characterized by a triad of inflammation, demyelination and gliosis. Because the suppressors of cytokine signaling (Socs) regulate the immune response, we quantified SOCS1 and SOCS3 transcription in peripheral blood leukocytes of patients with MS. SOCS1 transcription decreased significantly in MS patients compared with neurologically healthy persons (0.08 ± 0.02 vs 1.02 ± 0.23; p= 0.0001); while SOCS3 transcription increased in MS patients compared with controls (2.76 ± 0.66 vs 1.03 ± 0.27; p= 0.0008). Our results showed an imbalance of SOCS1 and SOCS3 transcription in MS patients, and a moderated negative correlation between them (Spearman's r= - 0.57; p= 0.0003). © 2014 Elsevier B.V.

Barcenas E.,Polytechnic University of Puebla | Lavalle J.,Autonomous University of Puebla
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

The Semantic Web lays its foundations on the study of graph and tree logics. One of the most expressive graph logics is the fully enriched μ-calculus, which is a modal logic equipped with least and greatest fixed-points, nominals, inverse programs and graded modalities. Although it is well-known that the fully enriched μ-calculus is undecidable, it was recently shown that this logic is decidable when its models are finite trees. In the present work, we study the fully-enriched μ-calculus for trees extended with Presburger constraints. These constraints generalize graded modalities by restricting the number of children nodes with respect to Presburger arithmetic expressions. We show that the logic is decidable in EXPTIME. This is achieved by the introduction of a satisfiability algorithm based on a Fischer-Ladner model construction that is able to handle binary encodings of Presburger constraints. © Springer-Verlag 2013.

Sanchez-Lopez C.,Autonomous University of Tlaxcala | Mendoza-Lopez J.,Institute Microelectronica Of Seville Imsecnm | Carrasco-Aguilar M.A.,Autonomous University of Tlaxcala | Muniz-Montero C.,Polytechnic University of Puebla
IEEE Transactions on Circuits and Systems II: Express Briefs | Year: 2014

This brief introduces a new floating memristor emulator circuit based on second-generation current conveyors and passive elements. A mathematical model to characterize the memristor behavior was derived, showing a good accuracy among HSPICE simulations and experimental results. An analysis of the frequency behavior of the memristor is also described, showing that the frequency-dependent pinched hysteresis loop in the current-versus-voltage plane holds up to 20.2 kHz. Theoretical derivations and related results are experimentally validated through implementations from commercially available devices, and the proposed memristor emulator circuit can easily be reproducible at a low cost. Furthermore, the emulator circuit can be used as a teaching aid and for future applications with memristors, such as sensors, cellular neural networks, chaotic systems, programmable analog circuits, and nonvolatile memory devices. © 2004-2012 IEEE.

Hernandez J.A.,Autonomous University of the State of Morelos | Colorado D.,Autonomous University of the State of Morelos | Cortes-Aburto O.,Polytechnic University of Puebla | El Hamzaoui Y.,Autonomous University of the State of Morelos | And 2 more authors.
Applied Thermal Engineering | Year: 2013

In this paper, inverse neural network (ANNi) is applied to optimization of operating conditions or parameters in energy processes. The proposed method ANNi is a new tool which inverts the artificial neural network (ANN), and it uses a Nelder-Mead optimization method to find the optimum parameter value (or unknown parameter) for a given required condition in the process. In order to accomplish the target, first, it is necessary to build the artificial neural network (ANN) that simulates the output parameters for a polygeneration process. In general, this class of ANN model is constituted of a feedforward network with one hidden layer to simulate output layer, considering well-known input parameters of the process. Normally, a Levenberg-Marquardt learning algorithm, hyperbolic tangent sigmoid transfer-function, linear transfer-function and several neurons in the hidden layer (due to the complexity of the process) are considered in the constructed model. After that, ANN model is inverted. With a required output value and some input parameters it is possible to calculate the unknown input parameter using the Nelder-Mead algorithm. ANNi results on three different applications in energy processes showed that ANNi is in good agreement with target and calculated input data. Consequently, ANNi is applied to determine the optimal parameters, and it already has applications in different processes with a very short elapsed time (seconds). Therefore, this methodology can be useful for the controlling of engineering processes. © 2012 Published by Elsevier Ltd.

El Hamzaoui Y.,Mexico State University | Ali B.,National Autonomous University of Mexico | Alfredo Hernandez J.,Mexico State University | Aburto O.C.,Polytechnic University of Puebla | Oubram O.,National Autonomous University of Mexico
Chemical Product and Process Modeling | Year: 2012

The coefficient of performance (COP) for a water purification process integrated to an absorption heat transformer with energy recycling was optimized using the artificial intelligence. The objective of this paper is to develop an integrated approach using artificial neural network inverse (ANNi) coupling with optimization methods: genetic algorithms (GAs) and particle swarm algorithm (PSA). Therefore, ANNi was solved by these optimization methods to estimate the optimal input variables when a COP is required. The paper adopts two cases studies to accomplish the comparative study. The results illustrate that the GAs outperforms the PSA. Finally, the study shows that the GAs based on ANNi is a better optimization method for control on-line the performance of the system, and constitutes a very promising framework for finding a set of "good solutions". © 2012 De Gruyter. All rights reserved.

Chigo Anota E.,Autonomous University of Puebla | Escobedo-Morales A.,Autonomous University of Puebla | Salazar Villanueva M.,Autonomous University of Puebla | Vazquez-Cuchillo O.,Polytechnic University of Puebla | Rubio Rosas E.,Autonomous University of Puebla
Journal of Molecular Modeling | Year: 2013

The influence of vacancies and substitutional defects on the structural and electronic properties of graphene, graphene oxide, hexagonal boron nitride, and boron nitride oxide two-dimensional molecular models was studied using density functional theory (DFT) at the level of local density approximation (LDA). Bond length, dipole moment, HOMO-LUMO energy gap, and binding energy were calculated for each system with and without point defects. The results obtained indicate that the formation of a point defect does not necessary lead to structural instability; nevertheless, surface distortions and reconstruction processes were observed, mainly when a vacancy-type defect is generated. For graphene, it was found that incorporation of a point defect results in a semiconductor-semimetal transition and also increases notably its polar character. As with graphene, the formation of a point defect in a hexagonal boron nitride sheet reduces its energy gap, although its influence on the resulting dipole moment is not as dramatic as in graphene. The influence of point defects on the structural and electronic properties of graphene oxide and boron nitride oxide sheets were found to be mediated by the chemisorbed species. © 2012 Springer-Verlag Berlin Heidelberg.

Martinez-Miron E.-A.,Polytechnic University of Puebla | Rebolledo-Mendez G.,University of Veracruz
CEUR Workshop Proceedings | Year: 2015

The development of motivationally intelligent tutoring systems has been based on a variety of motivational models from the psychology field. These models mainly consider characteristics from de areas of values, expectancies and feelings [1]. However, this paper proposes to take into account some cultural aspects when operationalizing such models. The basis of this proposal is presented from the perspective of some cultural aspects that effect career choice in particular for a Mexican context.

de la Calleja E.M.,Federal University of Rio Grande do Sul | de la Calleja E.M.,Brazilian National Council for Scientific and Technological Development | Cervantes F.,CINVESTAV | de la Calleja J.,Polytechnic University of Puebla
Annals of Physics | Year: 2016

In this study, we determined the degree of order for 22 Jackson Pollock paintings using the Hausdorff-Besicovitch fractal dimension. Based on the maximum value of each multi-fractal spectrum, the artworks were classified according to the year in which they were painted. It has been reported that Pollock's paintings are fractal and that this feature was more evident in his later works. However, our results show that the fractal dimension of these paintings ranges among values close to two. We characterize this behavior as a fractal-order transition. Based on the study of disorder-order transition in physical systems, we interpreted the fractal-order transition via the dark paint strokes in Pollock's paintings as structured lines that follow a power law measured by the fractal dimension. We determined self-similarity in specific paintings, thereby demonstrating an important dependence on the scale of observations. We also characterized the fractal spectrum for the painting entitled Teri's Find. We obtained similar spectra for Teri's Find and Number 5, thereby suggesting that the fractal dimension cannot be rejected completely as a quantitative parameter for authenticating these artworks. © 2016 Elsevier Inc.

Barcenas E.,Polytechnic University of Puebla | Lavalle J.,Autonomous University of Puebla
Logical Methods in Computer Science | Year: 2014

We introduce a logical foundation to reason on tree structures with constraints on the number of node occurrences. Related formalisms are limited to express occurrence constraints on particular tree regions, as for instance the children of a given node. By contrast, the logic introduced in the present work can concisely express numerical bounds on any region, descendants or ancestors for instance. We prove that the logic is decidable in single exponential time even if the numerical constraints are in binary form. We also illustrate the usage of the logic in the description of numerical constraints on multi-directional path queries on XML documents. Furthermore, numerical restrictions on regular languages (XML schemas) can also be concisely described by the logic. This implies a characterization of decidable counting extensions of XPath queries and XML schemas. Moreover, as the logic is closed under negation, it can thus be used as an optimal reasoning framework for testing emptiness, containment and equivalence. © E. Bárcenas and J. Lavalle.

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