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Leelavathy C.,Quaid e Millath Government College W | Antony S.A.,Presidency College at Chennai
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

(Chemical Equation Presented) Novel metal(II) complexes derived from furfurylidene-4-aminoantipyrine and 2-aminobenzothiazole were synthesized and characterized by spectroscopic (IR, 1H NMR, UV-Vis., ESR and DART-MS) and other analytical methods. IR spectral studies indicate the binding sites of the ligand with the metal ion. Molar conductance data and magnetic susceptibility measurements provide evidence for monomeric and neutral nature of the complexes. The X band ESR spectrum of the Cu(II) complex at 300 and 77 K was recorded. The electrochemical behaviour of the complexes in MeCN at 298 K was studied. Thermal studies of the ligand and its complexes show the presence of coordinated water in the complexes. The grain size of the complex was calculated by Scherrer formula using powder XRD. The surface morphology of the complexes was studied using SEM. The in vitro biological screening of the ligand and its complexes were tested against bacterial species S. aureus, E. coli, K. pneumoniae, P. vulgaris and P. aeruginosa and fungal species A. niger, R. stolonifer, A. flavus, R. bataicola and C. albicans. The DNA binding and cleavage activity of the ligand and its complexes were studied. Super oxide dismutase (SOD) activities of the ligand and its complexes have also been measured. © 2013 Elsevier B.V. All rights reserved.

Mani Rajan M.S.,Anna University | Mahalingam A.,Anna University | Uthayakumar A.,Presidency College at Chennai
Annals of Physics | Year: 2014

We investigated the soliton solution for N coupled nonlinear Schrödinger (CNLS) equations. These equations are coupled due to the cross-phase-modulation (CPM). Lax pair of this system is obtained via the Ablowitz-Kaup-Newell-Segur (AKNS) scheme and the corresponding Darboux transformation is constructed to derive the soliton solution. One and two soliton solutions are generated. Using two soliton solutions of 3 CNLS equation, nonlinear tunneling of soliton for both with and without exponential background has been discussed. Finally cascade compression of optical soliton through multi-nonlinear barrier has been discussed. The obtained results may have promising applications in all-optical devices based on optical solitons, study of soliton propagation in birefringence fiber systems and optical soliton with distributed dispersion and nonlinearity management. © 2014 Elsevier Inc.

Gnanam S.,Presidency College at Chennai | Rajendran V.,Presidency College at Chennai
Journal of Alloys and Compounds | Year: 2013

Nanometer scale cubic bixbyite α-Mn2O3 has been synthesized by a facile hydrothermal method, at a temperature of 450 °C in the presence of various surfactants. The X-ray diffraction (XRD) analysis shows that the average crystallite size of the sample is ∼35-42 nm. The shapes of the α-Mn2O3 nanoparticles include: Dumb-bell-like (anionic surfactant), Cauliflower-like (nonionic surfactant), spherical with rods (cationic surfactant) and spherical with wires (surface modifier). The shapes of α-Mn2O3 nanoparticles depend on the type of surfactant used in the synthesis. The magnetic property of the anionic surfactant assisted sample was primarily studied, using the vibrating sample magnetometer (VSM). The optical absorption spectra confirmed the effectiveness of the selected capping agents, as the anionic capped α-Mn 2O3 colloids absorbed at shorter wavelength than the other agents, indicating a much smaller crystallite size. The property of strong UV emissions may be attributed to the high purity and perfect crystallinity of the as-prepared α-Mn2O3. The surfactants-assisted catalyst was tested for its photocatalytic activity towards the photodegradation of the harmful organic dye Remazol Red B, using a multilamp photo reactor. Possible formation mechanisms have also been proposed for the as-synthesized anionic surfactant assisted samples. © 2012 Elsevier B.V. All rights reserved.

Elumalai S.,Presidency College at Chennai | Muthuraman G.,Presidency College at Chennai
Process Safety and Environmental Protection | Year: 2015

The recovery of anionic azo dyes namely Congo red (CR), methyl orange (MO) from acidic aqueous solutions using tri-octyl amine (TOA) as an extractant has been investigated. The percentage of extraction of MO and CR increases with an increasing TOA concentration. The anionic dyes were extracted from aqueous solution at pH 2.0 ± 0.1. The extracted dye has been back extracted into aqueous solutions using sodium hydroxide, sodium carbonate and sodium bicarbonate. The organic phase obtained after the stripping of dyes was washed with dilute sodium hydroxide solution to neutralize any sulphuric acid trapped or adhered to the solvent and then with distilled water. This solvent was reused in succeeding extraction of dyes. The influencing parameters were; the effect of diluents, effect of extractant concentration, effect of pH, effect of interference study, effect of equilibrium time, various stripping reagents and stripping phase ratio. The characterization studies such as UV and IR spectra of extracted and stripped MO and CR was also studied. © 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Muthuraman G.,Presidency College at Chennai | Sasikala S.,Presidency College at Chennai
Journal of Industrial and Engineering Chemistry | Year: 2014

The ability of three plant materials, seeds such as Moringa oleifera, Strychnos potatorum and Phaseolus vulgaris, to act as natural coagulants was tested using synthetic turbid water formulated to resemble the drinking water. An improved and alternative method for the extraction of the active coagulant agent M. oleifera, S. potatorum, P. vulgaris seeds was developed and compared with the conventional water extraction method. In the new method the seeds were extracted using different solvents of NaCl and NaOH to extract the active coagulant agent from natural coagulants. In addition, ultrasound was investigated as a potential method to assist the extraction process. Batch coagulation experiments were conducted to evaluate the performance of the extracted coagulant achieved through various schemes. The optimum turbidity removal at different values of initial synthetic wastewater turbidity from 100 to 500 NTU was investigated. Sodium chloride at 0.5. M was found to provide a high turbidity removal of >99% compared to NaOH and distilled water extract. Among these three coagulant M. oleifera seed extracts is the highest performance in turbidity removal. The optimum coagulant dosage showed the coagulation with blended coagulant M. oleifera, S. potatorum and P. vulgaris. The study was carried out for initial turbidity of the sample such as 100 NTU (low), 250 NTU (medium) and 500 NTU (high). For the natural coagulant dosage was found to be 250-1000. mg/L respectively. It was found that the percentage of removal is highest in M. oleifera. © 2013.

Gnanam S.,Presidency College at Chennai | Rajendran V.,Presidency College at Chennai
Journal of Sol-Gel Science and Technology | Year: 2011

Nanocrystalline cubic fluorite/bixbyite CeO2 or α-Mn 2O3 has been successfully synthesized by using methanol as a solvent via sol-gel method calcined at 400°C. The obtained products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-vis absorption and Photoluminescence (PL) spectroscopy. TEM reveals that the as-synthesized ultra-fine samples consist of elliptical/spherical and sheet-like morphology of crystalline particles of 8/30 nm, which are weakly aggregated. Optical absorbance spectra reveal that the absorption of ceria in the UV region originates from the charge- transfer transition between the O2- (2p) and Ce4+ (4f) orbit in CeO2. However, α-Mn2O3 nanostructures with nearly pure band gap emission should be of importance for their applications as UV emitters. © 2010 Springer Science+Business Media, LLC.

Anandan K.,Presidency College at Chennai | Rajendran V.,Presidency College at Chennai
Materials Science in Semiconductor Processing | Year: 2011

Different morphologies of NiO nanoparticles have been achieved controllably by the solvents-assisted facile solvothermal method. The size of the NiO nanoparticles was estimated by X-ray powder diffraction (XRD) pattern, which was in good agreement with the particle size calculated by transmission electron microscopy (TEM) analysis. The chemical structure information of the products was studied by Fourier transform infrared (FT-IR) spectroscopy. Spherical, elliptical, sheet- or snowflake-like, rod-like and rod morphologies were obtained by scanning electron microscopy (SEM) analysis. The band gap value of the NiO nanoparticles is about 3.743.99 eV calculated by ultravioletvis (UVvis) spectroscopy. The very prominent strong UV emission peak was observed at 346 nm (3.58 eV) in the luminescence spectra, which was studied by photoluminescence (PL) spectroscopy. The magnetic property was studied using the vibrating sample magnetometer (VSM). The possible formation mechanisms also have been phenomenologically proposed for the as-synthesized NiO nanoparticles with different morphologies. © 2010 Elsevier Ltd. All rights reserved.

Gajendiran J.,Presidency College at Chennai | Rajendran V.,Presidency College at Chennai
Materials Letters | Year: 2014

Aggregated tin oxide (SnO2/SnO) nanostructures were produced in the presence of double tin salts (SnCl4·5H2O, SnCl2·2H2O), metal hydroxyl precursors (caustic soda and ammonia), poly(oxy)ethylene glycol-400 and water as a solvent, by a hydrothermal method. The crystal structure, functional groups, morphology, and photoluminescence properties of the SnO2/SnO nanostructures are characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and Photoluminescence (PL) analysis. The XRD and SEM studies indicated the formation of a mixed phase of SnO2/SnO with a nanocrystalline nature. The FTIR and EDX analyses also confirmed the formation of the Sn-O bond. The PL emission spectrum of the SnO2/SnO nanostructures was observed in the visible region (blue, green, yellow and red emission peaks), due to the oxygen vacancies or other defects, and it could be used for luminescent device applications. © 2014 Elsevier Ltd. All rights reserved.

Gnanam S.,Presidency College at Chennai | Rajendran V.,Presidency College at Chennai
Journal of Sol-Gel Science and Technology | Year: 2010

Tin oxide (SnO2) nanoparticles were synthesized by the reaction of SnCl4•5H2O in methanol, ethanol and water via sol-gel method. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared, Scanning electron microscopy and Transmission electron microscopy. The optical properties of the as-prepared samples were investigated. The XRD analysis showed well crystallized tetragonal SnO 2 can be obtained and the crystal sizes were 3.9, 4.5 and 5 nm for the sample calcined at 400 °C for 2 h. It was found that solvents played important roles in the particle size effect of nanocrystalline SnO2. © 2009 Springer Science+Business Media, LLC.

Gajendiran J.,Presidency College at Chennai | Rajendran V.,Presidency College at Chennai
Materials Letters | Year: 2014

ZnO/CuO nanocomposites were synthesized, using a co-precipitation method with different kinds of solvents such as water, water/monohydric alcohol (ethanol), and water/dihydric alcohol (ethane-1,2-diol).The structural and optical properties of the ZnO/CuO nanocomposite were studied by X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), Transmission electron microscope (TEM) and Photoluminescence spectroscopy (PL). The XRD and FTIR results show the formation of the ZnO/CuO nanocomposite (hexagonal wurtzite/monoclinic phase). The TEM images showed that the ZnO/CuO nanocomposite consists of spherical particles in the size range of 10-50 nm. The PL emission spectra of the water/ethane-1,2-diol assisted ZnO/CuO nanocomposite show enhanced higher visible emission peaks than the other solvents, such as water and water/ethanol. The magnetic studies of the water/ethane-1,2-diol assisted ZnO/CuO nanocomposite were carried out by the vibrating sample magnetometer (VSM) analysis, which showed that the hysteresis loop exhibited ferromagnetic behavior. © 2013 Elsevier B.V.

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