Saranya S.,Bharathiar University |
Selvan R.K.,Bharathiar University |
Priyadharsini N.,Bharathiar University |
Priyadharsini N.,PSGR Krishnammal College For Women
Applied Surface Science | Year: 2012
Polyaniline (PAni)/MnWO 4 nanocomposite was successfully synthesized by in situ polymerization method under ultrasonication and the MnWO 4 was prepared by surfactant assisted ultrasonication method. The thermal stability of PAni was determined by TG/DTA (Thermo Gravimetric/ Differential thermal analysis). The structural and morphological features of PAni, MnWO 4 and PAni/MnWO 4 composite was analyzed using Fourier transform infrared spectrometry, X-ray diffraction (XRD), scanning electron microscope (SEM) and Transmission electron microscope (TEM) images. The electro-chemical properties of PAni, MnWO 4 and its composites with different weight percentage of MnWO 4 loading were studied through cyclic voltammetry (CV) for the application of supercapacitors as active electrode materials. From the cyclic voltammogram, 50% of MnWO 4 impregnated PAni showed a high specific capacitance (SC) of 481 F/g than their individual counterparts of PAni (396 F/g) and MnWO 4 (18 F/g). The galvanostatic charge-discharge studies indicate the in situ polymerized composite shows greater specific capacitance (475 F/g) than the physical mixture (346 F/g) at a constant discharge current of 1 mA/cm 2 with reasonable cycling stability. The charge transfer resistance (R ct) of PAni/MnWO 4 composite (22 ohm) was calculated using electrochemical impedance spectroscopy (EIS) and compared with its physical mixture (58 ohm). © 2012 Elsevier B.V. All rights reserved.
Muthulakshmi Andal N.,PSGR Krishnammal College For Women |
E-Journal of Chemistry | Year: 2010
Biosorption equilibrium and kinetics of Pb(II) and Hg(II) on coconut shell carbon (CSC) were investigated by batch equilibration method. The effects of pH, adsorbent dosage, contact time, temperature and initial concentration of Pb(II) and Hg(II) on the activated carbon of coconut shell wastes were studied. Maximum adsorption of Pb(II) occurred at pH 4.5 and Hg(II) at pH 6. The sorptive mechanism followed the pseudo second order kinetics. The equilibrium data were analysed by Langmuir, Freundlich and Dubinin- Radushkevich isotherm models. The equilibration data fitted well with both Langmuir and Freundlich isotherm model. The Langmuir adsorption capacity for Pb(II) was greater than Hg(II). The mean free energy of adsorption calculated from Dubinin- Radushkevich (D-R) isotherm model indicated that the adsorption of metal ions was found to be by chemical ion exchange. Thermodynamic parameter showed that the sorption process of Pb(II) onto SDC was feasible, spontaneous and endothermic under studied conditions. A comparison was evaluated for the two metals.
Kavitha T.,PSGR Krishnammal College For Women |
Kavitha T.,Kyungpook National University |
Yuvaraj H.,Yeungnam University
Journal of Materials Chemistry | Year: 2011
This report describes a new approach to successfully synthesize high-quality nickel oxide (NiO) nanorods with an average diameter of about 60 nm and a length of less than one micrometre via thermal decomposition of a precursor complex nickel benzoate dihydrazinate at 100 °C. The structural features, crystallinity, purity and morphology of the as-synthesized NiO nanorods were investigated by Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), selected area electron diffraction (SAED) and transmission electron microscopy (TEM). The electrochemical property of the as-synthesized NiO nanorods was investigated to determine their suitability as anode materials for lithium-ion batteries. The nanorod electrode exhibited better reversibility and high capacity. In addition, the nanorods showed good antibacterial properties. The magnetic measurement demonstrated that the NiO nanorods are ferromagnetic and may be used in the fields of MR imaging and magnetic drug delivery. © 2011 The Royal Society of Chemistry.
Ruban P.,Alagappa University |
Gajalakshmi K.,PSGR Krishnammal College For Women
Asian Pacific Journal of Tropical Biomedicine | Year: 2012
Objective: To access the in vitro antibacterial activity of Hibiscus rosa-sinensis (H. rosa- sinensis)flower extract against human pathogens. Methods: Antibacterial activity was evaluated by using disc and agar diffusion methods. The protein was run through poly acrylmide gel electrophoresis to view their protein profile. Results: The results showed that the cold extraction illustrates a maximum zone of inhibition against Bacillus subtillis (B. subtillis), Escherichia coli (E. coli) viz., (17.00 ± 2.91), (14.50 ± 1.71) mm, followed by hot extraction against, E. coli, Salmonella sp. as (11.66 ± 3.14), (10.60 ± 3.09) mm. In methanol extraction showed a highest zone of inhibition recorded against B. subtillis, E. coli as (18.86 ± 0.18), (18.00 ± 1.63) mm pursued by ethanol extraction showed utmost zone of inhibition recorded against Salmonella sp. at (20.40 ± 1.54) mm. The crude protein from flower showed a maximum inhibitory zone observed against Salmonella sp., E. coli viz., (16.55 ± 1.16), (14.30 ± 2.86) mm. The flower material can be taken as an alternative source of antibacterial agent against the human pathogens. Conclusions: The extracts of the H. rosasinensis are proved to have potential antibacterial activity, further studies are highly need for thedrug development.
Lakshmi V.S.,PSGR Krishnammal College For Women
Procedia Engineering | Year: 2012
Phishing is one of the luring techniques used by phishing artist in the intention of exploiting the personal details of unsuspected users. Phishing website is a mock website that looks similar in appearance but different in destination. The unsuspected users post their data thinking that these websites come from trusted financial institutions. Several antiphishing techniques emerge continuously but phishers come with new technique by breaking all the antiphishing mechanisms. Hence there is a need for efficient mechanism for the prediction of phishing website. This paper employs Machine-learning technique for modelling the prediction task and supervised learning algorithms namely Multi layer perceptron, Decision tree induction and Naïve bayes classification are used for exploring the results. It has been observed that the decision tree classifier predicts the phishing website more accurately when comparing to other learning algorithms.