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Search Results: 1 - 10 of 391192 matches for " Julio César Rolón-Aguilar "
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Developing Ontology Systems as a Base of an Environmental Quality Management Model in México  [PDF]
René Bernardo Elías Cabrera-Cruz, Erika Alarcón-Ruiz, Julio César Rolón-Aguilar, Salvador W. Nava-Díaz, Elena María Otazo-Sánchez, Ricardo Pérez Aviléz
Journal of Environmental Protection (JEP) , 2015, DOI: 10.4236/jep.2015.69095
Abstract: The process of identifying the attributes and relationships considered in an ontology is a complex task because there are many factors involved in the deterioration of environmental quality, the diversity of sources and data dispersion. This work presents an ontology that integrates the data required by an Environmental Quality Synoptic System (EQSS), which to date scatters in different Internet sites and concentrates by different agencies for example INEGI, CONABIO, SEMARNAT, CNA, among others. The methodology process consists of the collection of environmental information in Mexico through the application of computational techniques resulting ontology with environmental knowledge that will be processed by the system EQSS. Among the main advantages is than the selection and structure of information allow the automated generation of results in an environmental statement. The ontology proposal is based on knowledge of EQSS system that is based on the architecture of expert systems and through this important information for decision-making in regard to environmental quality and interaction with Geographic Information System (GIS) is obtained.
Perspectives of Waste Electrical and Electronic Equipment in Tampico, Mexico  [PDF]
René Bernardo Elías Cabrera-Cruz, María Esther Bautista-Vargas, Julio César Rolón-Aguilar, Ricardo Tobías-Jaramillo, Alberto José Gordillo-Martínez
Journal of Environmental Protection (JEP) , 2014, DOI: 10.4236/jep.2014.512120
Abstract: Waste electrical and electronic equipment (WEEE) has brought negative effects to the environment produced by the materials that compose them. The proper implementation of management plans of WEEE should integrate measures to prevent, mitigate and correct these affectations. As an initial step, it is necessary to make a diagnosis of the current situation of WEEE management which is the objective of this work. The studied zone was composed by the municipalities of Tampico, Ciudad Madero and Altamira located in southeast Tamaulipas, Mexico. The descriptive analysis of technical and regulatory aspects of the current management system in the study area was developed, including generation rates and analysis of waste streams. Among the main results, the generation of WEEE was estimated in 2040.38 tons/year for 2013, distributed in the municipalities of Tampico with 830.93 tons/year, Altamira with 650.18 tons/year, and Ciudad Madero with 559.27 tons/year. This calculation was estimated using Mexico’s WEEE generation indicators. The analysis of waste streams includes five categories of WEEE, Televisions with 61% of the total generation, followed by sound devices with 18%, personal computers with 17%; mobile phones with 2% as well as fixed phones with 1%. In the study area, reports of Tampico’s municipality indicated that 96 tons of WEEE was collected in the city of Tampico in 2013. In México, the national legislation considers WEEE in the category of waste requiring special handling (WRSH), however, it exists an inadequacy in the environmental laws about the specific classification of this kind of debris that makes their effective management more difficult. No companies who provide a management or treatment operations for WEEE are reported in Tampico, or in the near region. In addition, despite an initial interest for the municipality to attend the WEEE problematic, it exists a lack of sensibility of the population in the absence of environmental education programs.
Hypoglycemic Activity of Aqueous Extracts from Catharanthus roseus
Elisa Vega-ávila,José Luis Cano-Velasco,Francisco J. Alarcón-Aguilar,María del Carmen Fajardo Ortíz,Julio César Almanza-Pérez,Rubén Román-Ramos
Evidence-Based Complementary and Alternative Medicine , 2012, DOI: 10.1155/2012/934258
Abstract: Introduction. Catharanthus roseus (L.) is used in some countries to treat diabetes. The aim of this study was to evaluate the hypoglycemic activity of extracts from the flower, leaf, stem, and root in normal and alloxan-induced diabetic mice. Methods. Roots, leaves, flowers, and stems were separated to obtain organic and aqueous extracts. The blood glucose lowering activity of these extracts was determinate in healthy and alloxan-induced (75 mg/Kg) diabetic mice, after intraperitoneal administration (250 mg/Kg body weight). Blood samples were obtained and blood glucose levels were analyzed employing a glucometer. The data were statistically compared by ANOVA. The most active extract was fractioned. Phytochemical screen and chromatographic studies were also done. Results. The aqueous extracts from C. roseus reduced the blood glucose of both healthy and diabetic mice. The aqueous stem extract (250 mg/Kg) and its alkaloid-free fraction (300 mg/Kg) significantly () reduced blood glucose in diabetic mice by 52.90 and 51.21%. Their hypoglycemic activity was comparable to tolbutamide (58.1%, ). Conclusions. The best hypoglycemic activity was presented for the aqueous extracts and by alkaloid-free stem aqueous fraction. This fraction is formed by three polyphenols compounds.
TAXONOMíA Y DISTRIBUCIóN DE LOS ANOFELINOS EN EL ESTADO DE VERACRUZ, MéXICO (DIPTERA: CULICIDAE, ANOPHELINAE)
Adriana Beltrán-Aguilar,Sergio Ibá?ez-Bernal,Fredy Mendoza-Palmero,César A. Sandoval-Ruiz
Acta zoológica mexicana , 2011,
Abstract: La malaria o paludismo es una enfermedad humana causada por protozoarios del género Plasmodium y es transmitida por hembras de mosquito de ciertas especies de Anopheles. Se estima que en México el 33.1% de la población vive en áreas donde puede ocurrir la transmisión de la malaria. Veracruz es un estado donde la enfermedad es endémica debido a diversos factores que lo hacen una zona de riesgo para la transmisión, entre ellos las condiciones climáticas y la migración humana. Por lo anterior, en este trabajo se presentan las bases para la reactivación de la vigilancia entomológica del paludismo en el estado de Veracruz, para lo cual se provee la diagnosis ilustrada de la larva, la pupa y los adultos de ambos sexos de las especies de anofelinos del estado, así como las claves taxonómicas que permiten su reconocimiento, con base en el examen de ejemplares recolectados o depositados en colecciones entomológicas de referencia. También se obtuvieron mapas de distribución conocida y potencial de las especies por medio de GARP. Se mencionan además algunos datos bionómicos y la importancia médica de cada especie. Se conocen en Veracruz 18 especies de anofelinos, agrupadas en dos géneros, Chagasia con una especie y Anopheles con 17 pertenecientes a los subgéneros An. (Anopheles), An. (Kerteszia) y An. (Nyssorhynchus). Se reconocen cuatro grupos de especies de acuerdo a su capacidad de transmisión de plasmodios y por su amplitud de distribución: el grupo de alto riesgo constituido por 2 especies; el grupo de riesgo moderado o regional, con 8 especies; el de escaso riesgo, con 3 especies y el de riesgo nulo con 5 especies. Prácticamente todo el estado posee vectores potenciales por lo que debe reestablecerse la vigilancia permanente de sus poblaciones. Este trabajo aporta elementos de juicio para que el estado pueda ser, en un futuro cercano, certificado como área libre de paludismo.
A hamiltonian control approach for the stabilization of the angular velocity of a rigid body system controlled by two torques
Aguilar-Ibá?ez, C.;Suárez-Casta?ón, M.S.;Guzmán-Aguilar, F.;
Revista mexicana de física , 2008,
Abstract: we present a hamiltonian control approach for the stabilization of a rigid body system that is controlled by two torques. the stabilization strategy consists in solving a feasible matching condition in order to derive a feedback controller which forces the closed-loop system to be globally asymptotically stable.
A hamiltonian control approach for the stabilization of the angular velocity of a rigid body system controlled by two torques
C. Aguilar-Ibá?ez,M.S. Suárez-Casta?ón,F. Guzmán-Aguilar
Revista mexicana de física , 2008,
Abstract: Presentamos un enfoque de control Hamiltoniano para la estabilización de un sistema de cuerpo rígido que es controlado por dos torques. La estrategia de control consiste en resolver una condición de acoplamiento conveniente con el fin de derivar un eontrolador de retroalimentaeión que haga al sistema en lazo cerrado global y asintóticamente estable.
A white dwarf cooling age of 8 Gyr for NGC 6791 from physical separation processes
Enrique García-Berro,Santiago Torres,Leandro G. Althaus,Isabel Renedo,Pablo Lorén-Aguilar,Alejandro H. Córsico,René D. Rohrmann,Maurizio Salaris,Jordi Isern
Physics , 2010, DOI: 10.1038/nature09045
Abstract: NGC 6791 is a well studied open cluster1 that it is so close to us that can be imaged down to very faint luminosities. The main sequence turn-off age (~8 Gyr) and the age derived from the termination of the white dwarf cooling sequence (~6 Gyr) are significantly different. One possible explanation is that as white dwarfs cool, one of the ashes of helium burning, 22Ne, sinks in the deep interior of these stars. At lower temperatures, white dwarfs are expected to crystallise and phase separation of the main constituents of the core of a typical white dwarf, 12C and 16O, is expected to occur. This sequence of events is expected to introduce significant delays in the cooling times, but has not hitherto been proven. Here we report that, as theoretically anticipated, physical separation processes occur in the cores of white dwarfs, solving the age discrepancy for NGC 6791.
White dwarf constraints on a varying $G$
Enrique García-Berro,Santiago Torres,Leandro G. Althaus,Alejandro H. Córsico,Pablo Lorén-Aguilar,Alejandra D. Romero,Jordi Isern
Physics , 2013,
Abstract: A secular variation of $G$ modifies the structure and evolutionary time scales of white dwarfs. Using an state-of-the-art stellar evolutionary code, an up-to-date pulsational code, and a detailed population synthesis code we demonstrate that the effects of a running $G$ are obvious both in the properties of individual white dwarfs, and in those of the white dwarf populations in clusters. Specifically, we show that the white dwarf evolutionary sequences depend on both the value of $\dot G/G$, and on the value of $G$ when the white dwarf was born. We show as well that the pulsational properties of variable white dwarfs can be used to constrain $\dot G/G$. Finally, we also show that the ensemble properties of of white dwarfs in clusters can also be used to set upper bounds to $\dot G/G$. Precisely, the tightest bound --- $\dot G/G \sim -1.8 10^{-12}$ yr$^{-1}$ --- is obtained studying the population of the old, metal-rich, well populated, open cluster NGC 6791. Less stringent upper limits can be obtained comparing the theoretical results obtained taking into account the effects of a running $G$ with the measured rates of change of the periods of two well studied pulsating white dwarfs, G117--B15A and R548. Using these white dwarfs we obtain $\dot G/G\sim -1.8\times 10^{-10}$ yr$^{-1}$, and $\dot G/G\sim -1.3\times 10^{-10}$ yr$^{-1}$, respectively, which although less restrictive than the previous bound, can be improved measuring the rate of change of the period of massive white dwarfs.
Security Regulations in Mexican Renewable Energies: Case of Geothermal Projects  [PDF]
Alfonso Aragón-Aguilar, Georgina Izquierdo-Montalvo, Víctor Arellano-Gómez
Smart Grid and Renewable Energy (SGRE) , 2013, DOI: 10.4236/sgre.2013.46A003
Abstract:

A review of natural resources existing in México is done. The description of the renewable energies for electricity generation operating at date along the country, includes hydro, wind, solar, biomass and geothermal, among others. The installed capacity (to 2012) in México for electric generation from renewable energies is equivalent to 22% of total generation capacity. México has geothermal resources, which can be classified as high and low enthalpy, and of hot dry rock. To date, the exploitation has focused mainly on high enthalpy geothermal fields. Geothermal power plants do not burn fuel, preventing gas emissions helping to reduce global warming and greenhouse effect. Security risks in México geothermal fields, as a part of renewable energies linked to Smart Grids, are described emphasizing their geographical locations to facilitate the exposure to dangerous events. The results about research on Mexican Official Norms protecting environment related with geothermal operation projects are shown. The Mexican geothermal projects have developed under rules that provide security to workers and people, avoiding impacts on the environment. However, it was found that it necessarily emphasized previsions to damages and remedial actions for grids due to risks by natural contingencies (cyclones, winds, earthquakes) and by artificial causes such as vandalism (grids breaking, fire, explosions, etc.). Unfortunately, there are no preventive norms against natural risks. After all the analyses carried out, security must be considered by nature a dynamic and ever-changing process.

Double degenerate mergers as progenitors of high-field magnetic white dwarfs
E. García-Berro,P. Lorén-Aguilar,G. Aznar-Siguán,S. Torres,J. Camacho,L. G. Althaus,A. H. Córsco,B. Külebi,J. Isern
Physics , 2012, DOI: 10.1088/0004-637X/749/1/25
Abstract: High-field magnetic white dwarfs have been long suspected to be the result of stellar mergers. However, the nature of the coalescing stars and the precise mechanism that produces the magnetic field are still unknown. Here we show that the hot, convective, differentially rotating corona present in the outer layers of the remnant of the merger of two degenerate cores is able to produce magnetic fields of the required strength that do not decay for long timescales. We also show, using an state-of-the-art Monte Carlo simulator, that the expected number of high-field magnetic white dwarfs produced in this way is consistent with that found in the Solar neighborhood.
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