Time filter

Source Type

Kottayam, India

Kalayathankal S.J.,Ke College | Suresh Singh G.,Kerala University
Mathematics and Computers in Simulation

A wide range of hydrological analyses for flood, water resources, water quality, ecological studies, etc., require reliable quantification of rainfall inputs. This work illustrates a fuzzy analysis that has the capability to simulate the unknown relations between a set of meteorological and hydrological parameters. A fuzzy approach to flood alarm prediction based on the fuzzy soft set theory is applied to five selected sites of Kerala, India to predict potential flood. © 2009 IMACS. Source

Panicker N.S.,Mahatma Gandhi University | Gopinathan T.G.,Ke College | Dhanya I.,Mahatma Gandhi University | Menon C.S.,Mahatma Gandhi University
Physica B: Condensed Matter

Vacuum deposited tin(II)2,3-naphthalocyanine (SnNc) crystalline thin films were produced. The structural properties of the thin films were characterized using Fourier transform infrared spectroscopy (FTIR), which reveals traces of organic compounds within the as-deposited films. Surface morphological studies by scanning electron microscopy (SEM) were done and the films were found to be grainy in nature, comprising of small agglomerated spherical particles. Heat treatment decreased the optical band gap of the films due to the dependence of dilatation of the lattice and/or electron-lattice interaction. The electrical conductivity of the films at various heat treated stages shows that SnNc has a better conductivity by 1050 times that of its earlier reported phthalocyanine counterpart and the activation energy was found to increase with annealing temperature. © 2010 Elsevier B.V. All rights reserved. Source

Sivakumar R.,Chungnam National University | Thomas J.,Chungnam National University | Thomas J.,Ke College | Yoon M.,Chungnam National University
Journal of Photochemistry and Photobiology C: Photochemistry Reviews

Polyoxometalates (POMs) have peculiar optoelectronic properties and high reduction potential, playing as excellent electron pools. Thus, during the recent decade, POMs have been increasingly recognized as important building blocks for highly efficient photocatalysts and photoelectrochemical devices by hybridizing with photofunctional semiconductor nanostructures and organic/inorganic molecules. In this review, development of various molecular and nano composites derived from POMs are discussed with regard to photocatalytic environmental remediation, hydrogen production, carbon dioxide reduction and photoelectrochemical solar cells. The mechanisms involved in photo-induced interfacial electron transfer processes and subsequent photochemical reactions are explored along with a brief description about their advances in emerging solar application areas. More fundamental information of the photocatalytic activities of the POM-based composites would be very useful in constructing next generation artificial photosynthetic systems with higher spectral response in visible region for efficient solar energy conversion into electricity and fuels. © 2012 Elsevier B.V. Source

Joseph P.V.,Ke College | Jacob C.,P.A. College
E-Journal of Chemistry

Some physicochemical characteristics of a fresh water wetland were investigated. The analysis was carried out for a period of two years. Physical parameters such as colour, odour, temperature, electrical conductivity (EC) total suspended solids (TSS) total dissolved substances (TDS), total solids (TS), turbidity and chemical parameters such as pH, alkalinity, hardness, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), chloride, salinity, flouride, phosphate & nitrate were examined. Results of the study indicated that water in Pennar river is highly contaminated and not safe for drinking. Uncontrolled use of chemical fertilizers and pesticides, unscrupulous dumping of domestic wastes are the major causes of deterioration of water. Poor quality of drinking water was recorded as the major risk factor for the large-scale water-borne diseases in the area. Source

Thomas J.,Chungnam National University | Thomas J.,Ke College | Yoon M.,Chungnam National University
Applied Catalysis B: Environmental

Pure and highly crystallized gold nanoparticles-doped-TiO 2(B) nanofibers (Au-T BNFs), with thickness of 50-200nm and length of several microns, were successfully synthesized by combination of low-temperature (150°C) hydrothermal reaction of titanium (IV) isopropoxide (Ti[OC 3H 7] 4) and sonication of the ensued precipitate with gold nanoparticles followed by post-heat treatment at 300°C. Formation of pure TiO 2(B) was confirmed by X-ray diffraction, high resolution transmission electron microscopy and Raman spectroscopy. The UV-vis diffuse reflectance spectra (DRS) of Au-TiO 2(B) nanofibers exhibited surface-state absorption beyond 400nm with band gap energy at 2.94eV and broad gold plasma resonance band around 550nm. The photoluminescence (PL) emission spectra of the Au-T BNFs exhibited structural emission band around 410nm with shoulders around 464nm and 540nm. Analysis of these optical properties revealed that the surface state absorption is attributed to the indirect transition. These results suggest that coupling of the surface charge carriers with the lattice phonon of Au-T BNFs is so strong that the charge recombination is mostly nonradiative as supported by the significantly quenched emission of Au-T BNFs as compared to that of free T BNFs. These optoelectronic properties were well correlated with highly efficient solar photocatalytic activities of Au-T BNFs for oxidation of methylene blue (MB). © 2011 Elsevier B.V. Source

Discover hidden collaborations