Nāgercoil, India
Nāgercoil, India

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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.

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.

Muthucumaraswamy R.,Sri Venkateswara College of Engineering | Prasad G.E.,St Hindu College
Journal of Applied Fluid Mechanics | Year: 2013

An exact analysis of rotation effects on unsteady flow of an incompressible and electrically conducting fluid past a uniformly accelerated infinite isothermal vertical plate with variable mass diffusion, under the action of transversely applied magnetic field has been presented. The plate temperature is raised to Tw and the concentration level near the plate is raised linearly with time. The dimensionless governing equations are solved using Laplace-transform technique. The velocity profiles, temperature and concentration are studied for different physical parameters like magnetic field parameter, chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number and time. It is observed that the velocity increases with increasing values of thermal Grashof number or mass Grashof number. It is also observed that the velocity increases with decreasing magnetic field parameter or rotation parameter Ω.

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.

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.

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.

Mary Kensa V.,St Hindu College
Ecology, Environment and Conservation | Year: 2011

Emergence of resistance among mosquitoes is a recent problem. Safe and ecofriendly agents from biological origin is need of the hour. An attempt is made in the present study to analyse the larvicidal effects of the plant leaves extract against anopheles mosquito. Among these selected plants, Catharanthus roseus, Phyllanthus amarus, Acalypha indica, zingiber officinale, cynodon dactylon and Aerva lanata showed the highest level of activity against mosquito larvae. In conclusion, the results obtained that the leaves extract used had some bioactive constituents which resulted in the larvicidal effects. Such findings are useful in promoting research aimed at the development of new agents for mosquitoe control, based on bioactive natural chemical components from indigenous plant sources. The use of indigenous plant based products by individual and community can provide a prophylactic measure for protecting against various mosquito borne diseases. Copyright© EM International.

Balachandran V.,Aa Government Arts College | Karthick T.,Vivekanandha College for Women | Perumal S.,St Hindu College | Nataraj A.,Thanthai Hans Roever College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

The potential energy surface scan for the selected dihedral angle of 6-nitro-m-toluic acid (NTA) has been performed to identify stable conformer. The optimized structure parameters and vibrational wavenumbers of stable conformer have been predicted by density functional B3LYP method with 6-311++G(d,p) basis set. The formation of dimer species through carboxylic acid group of the title molecule has also been discussed. The theoretical dimer geometries have been compared with that of monomer and the variations of bond lengths and bond angles upon dimerization were also discussed. Natural bond orbital (NBO) analysis has been performed on both monomer and dimer geometries. The significant changes in occupancies and the energies of bonding and anti-bonding orbitals upon dimerization have been explained in detail. The predicted frontier molecular orbital energies at B3LYP/6-311++G(d,p) method set show that charge transfer occurs within the molecule. The nucleophilic and electrophilic sites obtained from the molecular electrostatic potential (MEP) surface were compared with their derived fitting point charges. The vibrational wavenumbers of NTA affected profusely by the nitro group substitution in comparison to the toluic acid have been interpreted in this work. Copyright © 2012 Published by Elsevier B.V. All rights reserved.

Murali K.R.,CSIR - Central Electrochemical Research Institute | Kalaivanan A.,Arignar Anna College | Perumal S.,St Hindu College | Pillai N.N.,St Hindu College
Journal of Alloys and Compounds | Year: 2010

Cadmium oxide (CdO) films were deposited by the sol-gel dip coating using acrylamide route. The films were doped with different concentrations of gallium in the range of 500-3500 ppm. X-ray diffraction studies indicated the films to possess cubic structure. The grain size, strain, lattice parameter, dislocation density, texture coefficient were estimated from the XRD pattern. The texture coefficient varies in the range of 0.16-0.61 for the different peaks. Optical transmission measurements indicated direct and indirect band gap values of 2.59 and 2.06 eV. Electrical conductivity of the undoped film was 0.5 x 103 mho cm-1, after doping with aluminium, the conductivity increased to 1.5 x 103 mho cm-1. Mobility decreased from 250 to 35 cm2 V-1 s-1 with an increase of Al concentration. Solar cell studies made on the Si/CdO cells under an illumination of 90 mWcm-2 yielded an Voc of 0.62 V, Jsc of 16 mAcm-2, ff=0.76 and ν = 9.55%. © 2009 Elsevier B.V. All rights reserved.

Sujatha S.,St Hindu College | Sathik M.,Sadakathullah Appa College
International Arab Journal of Information Technology | Year: 2013

The central idea of this paper is to propose an innovative watermarking scheme which embeds watermark signal into the host image in order to authenticate it. In this novel technique, some pixels are randomly selected from original image, o that all of them have a valid 3x3 neighborhoods. A binary sequence is constructed from those pixels by comparing them against average values of neighborhoods. The binary sequence is then converted into a watermark pattern in the form of a Toeplitz matrix to improve security of watermarking process and is then embedded within the host image. The operation of embedding and extraction of watermark is done in high frequency domain of Discrete Wavelet Transform since small modifications in this domain are not perceived by human eyes. This watermarking scheme deals with the extraction of the watermark information in the absence of original image, hence the blind scheme is obtained. The proposed algorithm is more secure and robust against most of the common image processing attacks. Finally computer simulations demonstrate that the proposed method is better than the recent algorithm proposed in [5] by Lin Q. et al. in terms of Peak Signal to Noise Ratio.

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