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Mahalingam T.,Alagappa University | Dhanasekaran V.,Alagappa University | Rajendran S.,Alagappa University | Ravi G.,Alagappa University | And 2 more authors.
Journal of New Materials for Electrochemical Systems | Year: 2012

The effect of post heat treatment on structural, morphological and optical properties of electrodeposited CdSSe solid solution thin films were studied using X-ray diffractometer (XRD), scanning electron microscopy (SEM), and UV-Vis-NIR spectrophotometer, respectively. X-ray diffraction patterns revealed that polycrystalline nature with hexagonal structure of CdSSe thin films. Also the microstructural properties are calculated tends to increase and the face centred hexagonal orientation of CdSSe thin film is enhanced significantly by increasing the annealing temperature. Scanning electron microscopic images revealed that the hexagonal shaped grains are occupying the entire surface of the film. The optical transmittance and absorption spectra were recorded in the range 400 to1100 nm. The band gap of the CdSSe thin films was found to decrease from 2. 0 eV to 1. 8 eV due to annealing temperature. The real part of the complex refractive index (n) and the imaginary part extinction coefficient (k) were calculated before and after annealing. © J. New Mat. Electrochem. Systems. Source

Mahalingam T.,Alagappa University | Dhanasekaran V.,Alagappa University | Rajendran S.,Alagappa University | Chandramohan R.,Sree Sevugan Annamalai College | And 2 more authors.
Journal of New Materials for Electrochemical Systems | Year: 2012

Electrodeposited CdZnSe thin films have been prepared at various bath temperatures. The thickness of the films was estimated between 850 nm and 1500 nm by stylus method. The X-ray diffraction patterns revealed that the electrodeposited CdZnSe alloy thin films are polycrystalline in nature with cubic structure. Microstructural properties such as, crystallite size, dislocation density, microstrain and number of crystallites per unit area were calculated using predominant orientation of the films. SEM images revealed that the surface morphology could be tailored suitably by adjusting the pH value during deposition. The surface roughness of the film was estimated using topographical studies. Optical properties of the film were analyzed from absorption and transmittance studies. Optical band gap of the films increased from 1. 67 to 1. 72 eV with the increase of bath temperature from 30 to 90°C. The optical constants (refractive index (n) and extinction coefficient (k)) of CdZnSe thin films were evaluated using optical studies. © J. New Mat. Electrochem. Systems. Source

Hernandez Galvez G.,Centro del Cambio Global y la Sustentabilidad en el Sureste | Dorrego Portela J.R.,Istmo University of Mexico | Nunez Rodriguez A.,Istmo University of Mexico | Lastres Danguillecourt O.,Istmo University of Mexico | And 4 more authors.
International Journal of Energy Research | Year: 2014

This study presents a selection of optimal energy alternatives for electrical self-sufficiency in a rural university (Universidad del Istmo, UNISTMO), located in the state of Oaxaca, Mexico and for the electricity supply for a rural community (Gran Piedra) in Santiago, Cuba. The analysis follows a multicriteria approach. It uses a method called compromise programming and takes into account the technical, economical, environmental and social criteria. The hybrid optimization model for electric renewables (HOMER) software was used to generate alternative energy sets through enumerative search, with which decisional matrices were built for each case study. The influence of weighting for each criterion was assessed. In the case of self-sufficiency in UNISTMO, when the decision-making center has a preference for the minimization of equivalent emissions in the life cycle (ESLC), a wind system is suitable. On the other hand, when there is a preference for the minimization of levelized cost of energy, a photovoltaic (PV) system is suitable; both systems connected to the national electrical grid. Obviously, a preference for the minimization of capital cost led to keeping the power supply from the grid. In the case of Gran Piedra, a diesel generator-based system is suitable when the criterion 'capital cost' absorbs 70% or more of the preferences of the decision-making centers. When the preference is less than 70% regardless of the weighting given to other criteria, the best alternatives are those involving renewable technologies, reaching renewable fractions of 75% and 94% in two potential configurations of energetic systems. © 2013 John Wiley & Sons, Ltd. Source

Davila-Jimenez M.M.,Autonomous University of Puebla | Elizalde-Gonzalez M.P.,Autonomous University of Puebla | Garcia-Diaz E.,Autonomous University of Puebla | Gonzalez-Perea M.,Autonomous University of Puebla | And 2 more authors.
Adsorption Science and Technology | Year: 2014

In this study, we measured the adsorption of Basic Blue 41 (BB41) dye on a maize cob adsorbent and on two model adsorbents (cellulose triacetate and cellulose acetate propionate). The experimental adsorption data were evaluated with the isotherm equations of Langmuir, Freundlich, Langmuir-Freundlich and Dubinin-Radushkevich, and constants were obtained exclusively by non-linear regression. In order to select the optimal isotherm equation, Akaike information criterion was used. The celluloses obeyed the Langmuir isotherm in the temperature range tested, whereas the corncob followed the Freundlich equation. This comparative study shows that limited amounts of the cationic dye were adsorbed on the model celluloses than on the cob. BB41 was neither adsorbed horizontally nor vertically onto the cob, whereas it competed with water molecules and despite saturation, did not exhaustively occupy the surface of the celluloses. The Gibbs free energy of adsorption was evaluated using the equilibrium constants obtained by several procedures and the results were found to be inconsistent. Source

Rivera M.A.,Technical University Del Estado Of Guerrero | Gamboa S.A.,National Autonomous University of Mexico | Sebastian P.J.,National Autonomous University of Mexico
International Journal of Energy Research | Year: 2012

In this work are present the results obtained from the electrochemical characterization of a metal hydride type MmNi 5-XM X impregnated with palladium, palladium-nickel and nickel nanoparticles as catalytic precursors for hydrogen absorption. The hydrogen absorption was investigated in the charge/discharge mechanism of a metal hydride via electrochemical process. The complete study involved the analysis of linear and anodic polarization, charge/discharge cycles, the application of an electrochemical model and electrochemical impedance spectroscopy to investigate the amount of hydrogen absorbed as a function of the catalytic precursors. The use of Pd nanoparticles showed the best results as catalytic precursor to absorb more hydrogen than other precursor systems. © 2011 John Wiley & Sons, Ltd. Source

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