Nkr Government Arts College W

Namakkal Tamil, India

Nkr Government Arts College W

Namakkal Tamil, India
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Narayanasamy R.,National Institute of Technology Tiruchirappalli | Anuradha K.,Nkr Government Arts College W
Journal of Materials Engineering and Performance | Year: 2013

This study explores the effect of annealing temperature and chemical composition on crystallographic texture evolution of commercially pure aluminium alloy sheets using response surface methodology (RSM). The orientation of the crystal structure in Euler space using Bunge notation has been studied to know the behavior of the metal and estimate its volume fraction. The experimental procedure involves texture analysis with respect to annealing temperature and chemical composition in correlation with the results of formability and use of RSM. The effect of important input parameters, namely, annealing temperature and chemical composition (impurities) was used for predicting the numerical models using the volume fraction of texture output from the crystallographic study using Design Expert 8.0.7.1, trial software. Also this study explains the effect of individual chemical components, namely, iron, silicon, and copper in evolution of texture components. The volume fraction of Cube {1 0 0} 〈0 0 1âŒ, Bs {1 1 0} 〈1 1 2âŒ, and S {1 2 3} 〈6 3 4⌠components increase, whenever iron and copper content increase and silicon component decreases. © 2013 ASM International.


Krishnakumar V.,Periyar University | Barathi D.,Nkr Government Arts College W | Mathammal R.,Salem College | Balamani J.,Chikkanna Government Arts College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

Maltol (3-hydroxy-2-methyl-4pyrone) is widely known as metal ions chelator with many practical applications in catalysis, medicine and food chemistry. The FTIR and FT-Raman spectra of maltol have been recorded in the region 4000-400 and 4000-50 cm-1, respectively. The conformational analysis, optimized geometry, frequency and intensity of the vibrational bands of maltol were obtained by the density functional theory (DFT) with complete relaxation in the potential energy surface using 6-31G* basis set. The observed and the calculated frequencies are found to be in good agreement. The 1H and 13C NMR spectra have been recorded and 1H and 13C nuclear magnetic resonance chemical shifts of the molecule were also calculated using the gauge independent atomic orbital (GIAO) method and their respective linear correlations were obtained. The electronic properties HOMO and LUMO energies were measured. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound were calculated. The Mulliken charges, the values of electric dipole moment (μ) of the molecule were computed using DFT calculations. The first order hyperpolarizability (βo) and related properties (β, αo and Δα) of both are calculated using B3LYP/6-31G* method on the finite-field approach. The calculated first hyperpolarizability shows that the molecules are an attractive molecule for future applications in non-linear optics. The intramolecular contacts have been interpreted using Natural Bond Orbital (NBO). © 2013 Elsevier B.V. All rights reserved.


Krishna Kumar V.,Periyar University | Sangeetha R.,Nehru Memorial College Autonomous | Barathi D.,Nkr Government Arts College W | Mathammal R.,Salem College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

The vibrational spectra of 5-nitroindan (NI) was computed using B3LYP methodology with 6-31G* and 6-31G** basis sets. The FTIR and FT-Raman spectra were recorded in the region 4000-400 cm-1 and 4000-50 cm-1 respectively. A similarity was achieved between the observed and calculated frequencies by refinement of the scale factors. The 1H and 13C NMR chemical shifts results were also compared with the experimental values. The Mulliken charges, the values of electric dipole moment (μ) of the molecule were computed using DFT calculations. The first order hyperpolarizability (β0) and related properties (β, α0, and Δα) of both are calculated using B3LYP method on the finite-field approach. The electronic properties HOMO and LUMO energies are calculated. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound were calculated. © 2013 Elsevier B.V. All rights reserved.


Krishnakumar V.,Periyar University | Sangeetha R.,Nehru Memorial College | Mathammal R.,Salem College | Barathi D.,Nkr Government Arts College W
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

This work deals with the vibrational spectra of 2-fluoro 5-nitrotoluene and 2-bromo 5-nitrotoluene by quantum chemical calculations. The solid phase FTIR and FT-Raman spectra of the title compounds were recorded in the regions 4000-400 cm-1 and 4000-50 cm-1 respectively. The spectra were interpreted with the aid of normal co-ordinate analysis based on density functional theory (DFT) using standard B3LYP/6-31G* basis set for the most optimized geometry. The vibrational frequencies are calculated and scaled values are compared with experimental FTIR and FT-Raman spectra. The scaled theoretical wave numbers showed very good agreement with the experimental ones. The complete vibrational assignments are performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. 13C and 1H NMR chemical shifts results are compared with the experimental values. © 2012 Elsevier B.V. All rights reserved.


PubMed | Nkr Government Arts College W, King Saud University and Loyola College
Type: | Journal: Annals of clinical microbiology and antimicrobials | Year: 2015

Novel chemical molecules recovered from endangered medicinal plants have wide applications and have the potential to cure different diseases caused by microorganisms. The aim of this study was to investigate In vitro antimicrobial, -glucosidase inhibition and antioxidant activity of different solvent extracts of Epaltes divaricata L.Antimicrobial activity of hexane, ethyl acetate and methanol extract of Epaltes divaricata was determined against bacteria and fungi using disc diffusion and microdilution method respectively. -glucosidase inhibition, Total phenolic content (TPC), Reducing power activity, DPPH radical scavenging assay, hydroxyl radical scavenging activity, nitric oxide scavenging activity, superoxide scavenging activity and lipid peroxidation assay of plant extracts were performed according to standard protocol. Compound detection from the potential solvent extract was done through GC-MS analysis.Epaltes divaricata ethyl acetate extracts (EDEa) (1.25mg/disc) showed significant inhibition for E. lentum (23mm), E. aerogenes (18mm), P. fluorescence (15mm) and A. baumanii (15mm). Minimum inhibitory concentration (MIC) of EDEa was found to be 31.25g/ml, 62.5g/ml and 62.5g/ml against A. flavus, A. niger and T. rubrum respectively. EDEa showed more -glucosidase inhibition and antioxidant activity compared to hexane and methanol. EDEa showed 50% -glucosidase inhibition at the concentration of 525.202.37g/ml. The TPC of EDEa was 412.02.21mg of catechol equivalents/g extract. EDEa showed great scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC50 5602.02g/ml), hydroxyl (IC50 314.752.56g/ml), nitric oxide (IC50 648.202.09g/ml) and superoxide (IC50 361.141.45g/ml) radicals, as well as high reducing power. EDEa also showed a more suppressive effect on lipid peroxidation. Using Antioxidant -carotene linoleate method, the scavenging values of EDEa was significantly lower than BHT. GC-MS analysis of EDEa showed maximum amount of 2-butenamide, N-(4-fluorophenyl)-3-methyl trans-cinnamyl tiglate silane and trichlorocyclohexyl silane (36.86%).The results obtained in this study clearly indicate that EDEa can be used as a natural antimicrobial, -glucosidase inhibition and antioxidant agent.


Valarmathi M.,Nkr Government Arts College W | Gomathi A.,Sri Kgs Arts College | Manisankar P.,Alagappa University
Advanced Materials Research | Year: 2013

Two reactive azo dyes Reactive yellow 84 (RY84) and Reactive Red 120 (RR120) were investigated voltammetrically using plain glassy carbon electrode (GCE) and multiwalled carbon nanotube modified GCE (MWCNT/GCE). Influence of pH, scan rate and concentration on voltammograms were studied. The irreversible oxidation process observed for both dyes was adsorption controlled. The surface characterization of the modified electrode in the absence and presence of dyes was done using scanning electron microscopy (SEM). A systematic study of the experimental parameters that affects differential pulse stripping voltammetry (DPSV) was carried out and the optimized experimental conditions were arrived. Under optimized conditions, stripping voltammetry procedure was developed for the determination of reactive dyes. MWCNT/GCE seems to present better responses than plain GCE and the limit of detection (LOD) was 0.6 μg mL-1 for RY84 and 0.3μg mL-1 for RR120 on this modified system. Suitability of the differential pulse stripping voltammetric method using the developed Multiwalled carbon nanotube based sensor, for the trace determination of these textile dyes in real samples was also realized. © (2013) Trans Tech Publications, Switzerland.


Valarmathi M.,Nkr Government Arts College W | Gomathi A.,Sri Kgs Arts College | Manisankar P.,Alagappa University
International Journal of Environmental Analytical Chemistry | Year: 2013

The voltammetric behaviour of two anthraquinone dyes such as Alizarin Red S (ARS) and Reactive blue 4 (RB4) was investigated at plain glassy carbon electrode (GCE), multiwalled carbon nano tube modified GCE (MWCNT/GCE) and zeolite modified GCE (ZE/GCE) using cyclic voltammetry. Effects of pH, scan rate and concentration were studied. The surface morphology of the modified electrode in the absence and presence of dye molecules was characterized by scanning electron microscopy (SEM). A systematic study on the variation of experimental parameters with differential pulse stripping voltammetry (DPSV) was carried out and the optimized experimental conditions were arrived. MWCNT/GCE performed well among the three electrode systems and the limit of detection (LOD) was 0.036 μg mL-1 for ARS and 0.05 μg mL-1 for RB4 on this modified system. Suitability of the differential pulse stripping voltammetric method for the trace determination of textile dyes in effluents was also realized. © 2013 Copyright Taylor and Francis Group, LLC.


Krishna Kumar V.,Periyar University | Suganya S.,Nkr Government Arts College W | Mathammal R.,Salem College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

This work deals with the vibrational spectra of 2,3,4,5,6-Penta Bromo Toluene (PBT) and Bromo Durene (BD) by quantum chemical calculations. The solid phase FTIR and FT-Raman spectra of the title compounds were recorded in the regions 4000-400 cm-1 and 4000-50 cm- 1, respectively. The spectra were interpreted with the aid of normal coordinate analysis based on density functional theory (DFT) using B3LYP/6-31Gâ̂ - level and basis set combinations and was scaled using various scale factors yielding a good agreement between observed and calculated frequencies. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of the simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes. The HOMO and LUMO energies were calculated within the molecule. 13C and 1H NMR chemical shifts results were also calculated and compared with the experimental values. Thermodynamical properties like entropy heat capacity, zero point energy have been calculated for the title molecules. © 2013 Elsevier B.V. All rights reserved.


Krishnakumar V.,Periyar University | Barathi D.,Nkr Government Arts College W | Mathammal R.,Salem College
Journal of Molecular Structure | Year: 2013

The present communication is aimed at comparing the molecular structural properties, vibrational and energetic data of 2,4-dimethoxy benzaldehyde and for 4-methoxy-3-methyl benzaldehyde, due to their commercial importance. The ground state properties of the title molecules have been calculated employing DFT/B3LYP level of theory using the 6-31G (d) basis set. In order to obtain a complete description of molecular dynamics, vibrational wavenumber calculation along with the normal mode analysis, have been carried out at the DFT level. The calculated spectra of both the molecules agree well with the experimental data. The 1H and 13C NMR spectra have been simulated using the gauge independent atomic orbital (GIAO) method. The electronic properties, such as HOMO, LUMO energies, absolute electronegativity X and absolute hardness η were performed by DFT approach. The first order hyperpolarizability (βo) of these novel molecular system and related properties (β, αo and Δα) of DMBA and MMBA are calculated using DFT/6-31G (d) method on the finite-field approach. © 2012 Elsevier B.V. All rights reserved.


Krishnakumar V.,Periyar University | Barathi D.,Nkr Government Arts College W | Mathammal R.,Salem College
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2012

The vibrational spectra of 1,2-dichloro-4-nitrobenzene (DCNB) and 2,3,5,6-tetrachloro-1-nitrobenzene (TCNB) were computed using B3LYP methodology with 6-31G* basis set. The solid phase FTIR and FT-Raman spectra were recorded in the region 4000-400 cm -1 and 4000-50 cm -1, respectively. A similarity was achieved between the observed and calculated frequencies by refinement of the scale factors. The HOMO and LUMO energies were calculated. 13C and 1H NMR chemical shifts results were also compared with the experimental values. © 2011 Elsevier B.V. All rights reserved.

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