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Thiruvarur, India

Central University of Tamil Nadu was established by an Act of Parliament . The University was inaugurated on 30 September 2009 by Kapil Sibal who laid the foundation stone, in the presence of M Karunanidhi and M. K. Stalin. Presently CUTN is functioning in a temporary campus with an area of 55000 sq.ft. in the Thiruvarur District Collectorate. Wikipedia.

Nithyanandan K.,Pondicherry University | Raja R.V.J.,Central University of Tamil Nadu | Porsezian K.,Pondicherry University
Journal of the Optical Society of America B: Optical Physics | Year: 2013

A theoretical study of modulational instability (MI) in the semiconductor doped dispersion decreasing fiber (SD-DDF) is presented. We consider the combination of saturation of nonlinear response and the dispersion decreasing fiber (DDF). The exact dispersion relation is calculated by means of linear stability analysis. Different fiber systems are considered alongside the proposed SD-DDF for insight and to offer the cutting edge of the proposed model over the others. The two extreme physical effects considered lead to an exciting outcome, where decreasing dispersion leads to broadening the spectral width and saturation, on the other hand, suppresses the MI gain and the bandwidth. A bandwidth relation between different fiber systems is presented, and the idea can open the design of a fiber structure with desired dispersion profile by a suitable manipulation of these effects. We propose that instead of using DDF whose bandwidth is limited by the manufacturing constraints, the use of SDDDF offers better tailoring of the bandwidth profile by suitably altering the saturation parameter. Thus we emphasize that the proposed SD-DDF will be a feature prospect for wide range of applications, especially in the context of ultrashort pulse generation using MI. © 2012 Optical Society of America. Source

Purkayastha D.D.,Mizoram University | Madhurima V.,Mizoram University | Madhurima V.,Central University of Tamil Nadu
Journal of Molecular Liquids | Year: 2013

Contact angle, dielectric and IR studies of aqueous tetrahydrofuran (THF) are carried over the entire concentration range. IR studies indicate the formation of blue-shifted hydrogen bonds between water and THF molecules over the entire concentration region. On addition of small quantities of THF to water, THF molecules enter into the hydrogen bonded water network forming clathrate like complexes. Concentration dependent wetting of aqueous THF over various substrates is also reported. The effect of clathrate formation on the wetting properties of the substrate has also been explored. The clathrate structures formed are seen to influence the wetting properties on moderately hydrophobic substrates like Indium tin Oxide (ITO), Cubic Bismuth Zinc Niobate thin film on sapphire substrate (CBZN), Yttrium-stabilized zirconia (YSZ), Strontium Titanate (STO) and Si wafer. Contact angles decreases with an increase in THF concentration except in the region (0.03 ≤ XTHF ≤ 0.05 and 0.07 ≤ XTHF ≤ 0.09) where clathrate structure appears and hence no change of contact angle is seen. © 2013 Elsevier B.V. Source

Hemamalini A.,University of Madras | Mohan Das T.,University of Madras | Mohan Das T.,Central University of Tamil Nadu
New Journal of Chemistry | Year: 2013

A series of gel forming symmetrical bis-sugar-triazoles has been developed for the recognition of Hg2+ ions. Preferential interaction of Hg 2+ ions with organogelator based chemosensor 3f led to changes in the morphology as evidenced from FESEM and HRTEM analysis. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. Source

Gopi D.,Periyar University | Shinyjoy E.,Periyar University | Kavitha L.,Central University of Tamil Nadu
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

The present work is aimed at the synthesis of antibacterial and bioactive silver/magnesium co-substituted hydroxyapatite (Ag/Mg-HAP) powders. For this purpose, firstly, different concentrations (0.5, 1.5, 2.5 wt.%) of silver substituted HAP (Ag-HAP) powders were prepared by ultrasonic irradiation technique and were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Secondly, magnesium (Mg) is co-substituted as secondary material into Ag-HAP to offset the potential cytotoxicity of Ag, as higher concentration of Ag is toxic. The antibacterial activity of as-synthesized powders was evaluated by Escherichia coli (E. coli) and was found to be effectively high against bacterial colonization. Also, the in vitro cell-material interaction is evaluated with human osteosarcoma MG63 (HOS MG63) cells for cell proliferation. The results showed the evidence of cytotoxic effects of the higher concentration of Ag-HAP characterized by poor cellular viability whereas, Ag/Mg-HAP showed better cell viability indicating that co-substitution of Mg in Ag-HAP effectively offset the negative effects of Ag and improve performance compared with pure HAP. Thus, the as synthesized Ag/Mg-HAP will serve as a better candidate for biomedical applications with good antibacterial property and bone bonding ability. © 2014 Elsevier B.V. All rights reserved. Source

Nithyanandan K.,Pondicherry University | Raja R.V.J.,Central University of Tamil Nadu | Porsezian K.,Pondicherry University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

Modulational instability (MI) in a twin-core optical fiber with the combined effect of saturation of nonlinearity (SNL) and coupling coefficient dispersion (CCD) is presented. The CCD does not dramatically modify the spectrum of the symmetric or antisymmetric continuous wave (CW) case, but the SNL on the other hand behaves in a perceptible manner such that the gain and the unstable region inherently decrease. In the anomalous dispersion region, the gain of the instability spectrum increases (decreases) monotonously with power (coupling coefficient). The effective nonlinearity and the power threshold for the sustained CW solution becomes a function of power for the SNL case. The so-called nonlinear factor behaves in a unique way such that there exist two powers for the same value of nonlinear factor. The interplay between CCD and SNL is emphasized, where any nonzero value of CCD leads to new instability bands and the saturation on the other hand suppresses the gain of the instability band. We identified a pair of power corresponding to the constant value of the nonlinear factor, where the system becomes invariant, such that the number of instability bands, the gain, and the range of the unstable region are all preserved. In the case of the normal dispersion case, the MI is achieved purely by means of the coupling coefficient. In both cases, a critical CCD is predicted, where the system evolves dramatically in a different manner. © 2013 American Physical Society. Source

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