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Nāgercoil, India

Mary Kensa V.,St Hindu College
Journal of Industrial Pollution Control | Year: 2011

Bioremediation is an ecologically sound and state of the art technique that employs natural biological processes to completely eliminate toxic contaminants. Any process that uses micro organisms, fungi, green plants or their enzymes to return the natural environment altered by contaminants to its original condition. Bioremediation technologies can be generally classified as in situ or ex situ. In situ bioremediation involves treating the contaminated material at the site while ex situ involves the removal of the contaminated material to be treated elsewhere. Some examples of bioremediation technologies are bioventing, landfarming, bioreactor, compositing, bioaugmentation, rhizofiltration, and bio-stimulaiton. Micro organism which perform the function of bioremediation is known as Bioremediators. (bioaugmentation). Not all contaminants, however, are easily treated by bioremediation using microorganisms. For example, heavy metals such as cadmium and lead are not readily absorbed or captured by organisms, the assimilation of metals such as mercury into the food chain may worsen matters. This paper gives an idea of what is bioremediation, principles of bioremediation, factors of bioremediation, strategies, types, genetic engineering approaches, monitoring bioremediation and advantages or disadvantages of bioremediation. © EM International. Source

Magdaline J.D.,Rani Anna Government College | Chithambarathanu T.,St Hindu College
Materials Today: Proceedings | Year: 2015

The molecular structure and vibrational spectra of 5-Nitro-2-furoic Acid (NFC) have been investigated by combined theoretical and experimental approaches. The FT-IR and FT-Raman spectra of NFC was recorded in the range 4000 - 400cm-1 and 3500 -50 cm-1. Density functional method B3LYP with 6-31G** basis set was applied to carry out the quantum mechanical calculations of the geometrical structure and vibrational analysis of NFC. The spectra were interpreted with the aid of normal coordinate analysis (NCA) based on scaled quantum mechanical force field (SQM). Stability of the molecule arising from the hyper conjugative interactions, charge delocalization have been analyzed using natural bond analysis(NBO). The influence of the substituents on the geometry of the furan ring and its normal modes of vibration have been discussed. © 2015 published by Elsevier Ltd. Source

Karthick T.,Vivekanandha College for Women | Balachandran V.,Aa Government Arts College | Perumal S.,St Hindu College | Nataraj A.,Th Roever College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

In this work, the vibrational characteristics of 2-chloro-5- (trifluoromethyl) aniline have been investigated and both the experimental and theoretical vibrational data indicate the presence of various functional groups within the title molecule. The influence of chlorine substituent on the vibrational wavenumbers of a molecule in comparison with aniline and trifluoromethyl aniline has been discussed in detail. The density functional theoretical (DFT) computations were performed at the B3LYP/6-31++G(3df,3pd)/6- 31G(3df,3pd) levels to derive the optimized geometry, vibrational wavenumbers with IR and Raman intensities. Furthermore, the molecular orbital calculations such as; natural bond orbitals (NBOs) and HOMO-LUMO energy gap and mapped molecular electrostatic potential (MEP) surfaces were also performed with the same level of DFT. The temperature dependence thermodynamic parameters of a molecule were illustrated on the basis of their correlation graphs. The detailed interpretation of the vibrational spectra has been carried out with the aid of potential energy distribution (PED) results obtained from MOLVIB program. The delocalization of electron density in various constituents of the molecule has been discussed with the aid of NBO and HOMO-LUMO energy gap analysis. © 2013 Elsevier B.V. All rights reserved. Source

Kalaivanan A.,Arignar Anna College | Perumal S.,St Hindu College | Neelakanda Pillai N.,Arignar Anna College | Murali K.R.,CSIR - Central Electrochemical Research Institute
Materials Science in Semiconductor Processing | Year: 2011

Zinc oxide (ZnO) films were deposited by solgel dip coating using the acrylamide route. The films were doped with different concentrations of gallium in the range 2501200 ppm. The films exhibited hexagonal structure. The grain size decreased from 100 to 10 nm as the dopant concentration increased. The resistivity of the doped samples decreased from 103 to 3×10-3 Ω cm. The band gap value shifted towards the short-wavelength region as the dopant concentration increased. XPS studies indicated doping of Ga in ZnO © 2011 Elsevier Ltd. All rights reserved. Source

Sankar U.,Sri Kgs Arts College | Chithambrathanu T.,St Hindu College
Optik | Year: 2014

Triglycine sulphate crystals admixtured with picric acid (TGSPi) were grown by slow evaporation method in 30 days. Solubility of the grown sample is found to be increasing with increase in temperature. The grown TGSPi crystals are observed to be crystallizing in monoclinic structure. The mechanical strength of the crystal was estimated by Vickers hardness test. FTIR studies were performed to identify the presence of various functional groups present in the grown crystals. UV-vis spectral studies explain the transmission ability of the grown crystals. EDAX analysis confirms the elemental confirmation in TGSPi crystal. Kurtz-Perry powder technique was used to check the nonlinear optical activity of the sample. The grown crystals were also subjected to thermal analysis and dielectric studies. The obtained results are presented and discussed. © 2013 Elsevier GmbH. Source

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