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Arul Jeevan T.S.,TJS Engineering College | Nagaraja K.S.,Loyola Institute of Frontier Energy LIFE
Journal of Chemistry

The thermal behaviour of tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionato) zirconium(IV), [Zr(tmhd)4] was investigated by nonisothermal and isothermal thermogravimetric methods in a high pure nitrogen atmosphere. The influence of the heating rate in dynamic measurements (6, 8, 10, and 12°C/min) on activation energy was also studied. The nonisothermal sublimation activation energy values determined following the procedures of Arrhenius, Coats and Redfern, Kissinger, and Flynn-Wall yielded 76 ± 5, 92 ± 2, 81 ± 8, and 72 ± 7 kJ/mol, respectively, and the isothermal sublimation activation energy was found to be 87 ± 4 kJ/mol over the temperature range of 411-462 K. Different reaction mechanisms were used to compare with this value. Analysis of the experimental results suggested that the actual reaction mechanism was an R n deceleration type. © 2013 T. S. Arul Jeevan and K. S. Nagaraja. Source

Ramesh T.,Loyola Institute of Frontier Energy LIFE | Jahir Hussain K.,Indira Gandhi Center for Atomic Research | Satpathy K.K.,Indira Gandhi Center for Atomic Research | Selvanayagam M.,Loyola Institute of Frontier Energy LIFE
Herpetology Notes

Baseline data on the species composition and distribution of herpetofauna at different habitats of Kalpakkam nuclear campus is provided to facilitate environmental impact assessment studies. We documented forty four species belonging to 32 genera and 16 families, including some South Asian endemic amphibian species such as Kaloula taprobanica, Hoplobatrachus tigerinus, Hoplobatrachus crassus, Fejervarya rufescens, Sphaerotheca rolandae and Duttaphrynus scaber. The Dicroglossidae and Colubridae were the dominant families in terms of richness, and species such as Euphlyctis hexadactylus, Ptyas mucosus were common and Microhyla ornata, Chamaeleo zeylanicus, Eryx johnii and Dryocalamus nympha were rare and patchy in their distribution, not only inhabiting undisturbed scrub, but also the human conquered building area. Structural complexity, area availability of habitats and seasonal rainfall are chief factors influencing the herpetofaunal assemblages at Kalpakkam nuclear campus. Source

Rotte N.K.,University of Hyderabad | Yerramala S.,Loyola Institute of Frontier Energy LIFE | Boniface J.,Loyola Institute of Frontier Energy LIFE | Srikanth V.V.S.S.,University of Hyderabad
Chemical Engineering Journal

MgO decked multi-layered graphene (MDMLG) is synthesized using a rudimentary combustion process involving ignition of Mg in the presence of dry ice. MDMLG is used as an adsorbent to remove Safranin O (SO) dye from water. Adsorption related experimental data is best fitted to Langmuir adsorption isotherm indicating that adsorption of SO dye onto MDMLG is uniform. Mono layer adsorption capacity of MDMLG is ~3.92×10-4mol/g. Mean adsorption energy is ~36.23kJ/mol indicating that chemisorption is the major mode of adsorption. Pseudo 2nd order rate equation best describes the adsorption kinetics of SO dye onto MDMLG. Regeneration of SO dye in ethanol is ~73.5%, which also indicates chemisorption type adsorption. MDMLG is also found to remove a mixture of dyes from a real textile effluent. © 2014 Elsevier B.V. Source

Valliammai S.,Loyola Institute of Frontier Energy LIFE | Nagaraja K.S.,Loyola Institute of Frontier Energy LIFE | Jeyaraj B.,Loyola Institute of Frontier Energy LIFE
International Journal of ChemTech Research

Activated carbon was prepared from Varagu millet husk (ACVMH). The Characterizations of prepared activated carbon (ACVMH) was determined using SEM, XRD, BET and FTIR analysis. The surface area was found to be 397.33m2/g. Experiments were carried out to evaluate the batch adsorption isotherms and kinetics of Acid blue (AB113) on ACVMH at different temperatures. Experimental equilibrium data were analyzed by the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The results show that the best fit was achieved with the Langmuir isotherm equation with a maximum adsorption capacity of 231.92mg/g. Pseudo-first order and pseudo-second order models were used to analyze the kinetic data. The adsorption kinetic data were well described by the pseudo-second order model. The calculated thermodynamic parameters, namely ∆G0, ∆H0, and ∆S0 showed that adsorption of AB113 onto activated carbon of Black gram husk was spontaneous and endothermic under examined conditions. © 2015, Sphinx Knowledge House. All rights reserved. Source

Ganesh T.,Loyola Institute of Frontier Energy LIFE | Ganesh T.,Presidency College at Chennai | Rajesh S.,Loyola Institute of Frontier Energy LIFE | Rajesh S.,Am Jain College | And 2 more authors.
Materials Science in Semiconductor Processing

Thin films of undoped and doped ZnO, with different Al concentrations (1-5 wt%) were deposited onto glass substrates, by the sol-gel spin coating method. Grazing incidence X-ray diffraction (GIXRD) studies confirmed the nature of films as poly-crystalline, with typical hexagonal wurtzite structure. The films showed variation in crystallite size and change in relative intensities, upon different Al doping concentrations. The surface morphology of the films examined using FE-SEM, showed the grain size becoming smaller upon Al doping. The influence of Al with different concentrations, onto ZnO on the optical absorption and transmittance was studied using UV-Vis-NIR spectrophotometer in the wavelength range 300-2500 nm. The UV absorption shifted towards shorter wavelength upon Al doping. The average transmittance in the visible region increased for Al doped films up to 1-2 wt% and decreased for other concentration. The dark and photo conductivity measurements of the films indicated increase in the current values upon doping up to 1-2 wt% of Al and decreased for further concentrations. The rise and decay time measured from the photoresponse study, indicate larger values of rise time for the doped films compared to undoped ZnO. However, the film with 1-2 wt% doping of Al showed better response within the doping concentration. The thermal activation energy obtained from temperature-dependant conductivity showed decrease in the value upon Al doping up to 2 wt% and increased beyond this concentration in the temperature range 300-400 K. © 2012 Elsevier Ltd. Source

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