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Venkatesh P.R.,Nehru Memorial College Autonomous | Venkatesan A.,Nehru Memorial College Autonomous | Lakshmanan M.,Bharathidasan University
Chaos | Year: 2017

We report the propagation of a square wave signal in a quasi-periodically driven Murali- Lakshmanan-Chua (QPDMLC) circuit system. It is observed that signal propagation is possible only above a certain threshold strength of the square wave or digital signal and all the values above the threshold amplitude are termed as "region of signal propagation." Then, we extend this region of signal propagation to perform various logical operations like AND/NAND/OR/NOR and hence it is also designated as the "region of logical operation." Based on this region, we propose implementing the dynamic logic gates, namely, AND/NAND/OR/NOR, which can be decided by the asymmetrical input square waves without altering the system parameters. Further, we show that a single QPDMLC system will produce simultaneously two outputs which are complementary to each other. As a result, a single QPDMLC system yields either AND as well as NAND or OR as well as NOR gates simultaneously. Then, we combine the corresponding two QPDMLC systems in a cross-coupled way and report that its dynamics mimics that of fundamental R-S flip-flop circuit. All these phenomena have been explained with analytical solutions of the circuit equations characterizing the system and finally, the results are compared with the corresponding numerical and experimental analysis.


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.


Gopal R.,Nehru Memorial College Autonomous | Gopal R.,Bharathidasan University | Venkatesan A.,Nehru Memorial College Autonomous | Lakshmanan M.,Bharathidasan University
Chaos | Year: 2013

We show that the recently introduced 0-1 test can successfully distinguish between strange nonchaotic attractors (SNAs) and periodic/quasiperiodic/chaotic attractors, by suitably choosing the arbitrary parameter associated with the translation variables in terms of the golden mean number which avoids resonance with the quasiperiodic force. We further characterize the transition from quasiperiodic to chaotic motion via SNAs in terms of the 0-1 test. We demonstrate that the test helps to detect different dynamical transitions to SNAs from quasiperiodic attractor or the transitions from SNAs to chaos. We illustrate the performance of the 0-1 test in detecting transitions to SNAs in quasiperiodically forced logistic map, cubic map, and Duffing oscillator. © 2013 AIP Publishing LLC.


Subash B.,Annamalai University | Krishnakumar B.,Annamalai University | Pandiyan V.,Nehru Memorial College Autonomous | Swaminathan M.,Annamalai University | Shanthi M.,Annamalai University
Materials Research Bulletin | Year: 2013

A novel WO3 loaded Ag-ZnO photocatalyst was successfully synthesized by a simple solvothermal method and characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) images, energy dispersive spectrum (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), cyclic voltammetry (CV) and Brunauer-Emmett- Teller (BET) surface area measurements. The photocatalytic activity of WO 3-Ag-ZnO was investigated for the degradation of RR 120 and RO 4 dyes in aqueous solution using UV-A light. WO3-Ag-ZnO is found to be more efficient than Ag-ZnO, WO3-ZnO, Ag-WO3, commercial ZnO, prepared ZnO, TiO2-P25 and TiO2 (Merck) at neutral pH for the mineralization of dyes. First time we have reported that novel WO 3 loaded Ag-ZnO has been found to be very efficient for two azo dyes removal when compared to commercially available catalyst (Degussa P25, ZnO (Merck) and TiO2 (Merck)). The mineralization of dyes has been confirmed by chemical oxygen demand (COD) measurements. A mechanism of degradation has been proposed for the higher efficiency of WO 3-Ag-ZnO. © 2012 Elsevier Ltd.


Venkatesh P.R.,Nehru Memorial College Autonomous | Venkatesan A.,Nehru Memorial College Autonomous | Lakshmanan M.,Bharathidasan University
Pramana - Journal of Physics | Year: 2016

The idea of synchronization can be explicitly demonstrated by both numerical and analytical means on a nonlinear electronic circuit. Also, we introduce a scheme to obtain various logic gate structures, using synchronization of chaotic systems. By a small change in the response parameter of unidirectionally coupled nonlinear systems, one is able to construct various logic behaviours by both numerical and analytical methods. © Indian Academy of Sciences.


Sridharan S.,SASTRA University | Gounder S.C.,Nehru Memorial College Autonomous
Asian Pacific Journal of Tropical Disease | Year: 2016

Objective: To investigate the pharmacognostic features and physiochemical properties of the leaves of Barleria montana Wight & Nees. Methods: The leaf samples were subjected to organoleptic, microscopic and macroscopic analysis. Physiochemical properties and fluorescence analysis of the sample under UV and daylight were studied as per World Health Organization norms. Results: Microscopic analysis showed that the plant possessed dorsiventral leaves, lamina, glandular trichomes, calcium carbonate cystoliths and adaxial epidermis. Physiochemical characters like ash and moisture content, extractive values, foreign matter and fluorescent characteristics of the leaf samples were determined and reported. Conclusions: Results obtained from these studies can be used as reliable markers in the identification and standardization of this plant as a herbal remedy. © 2016 Asian Pacific Tropical Medicine Press.


Venkatesh P.R.,Nehru Memorial College Autonomous | Venkatesan A.,Nehru Memorial College Autonomous
Pramana - Journal of Physics | Year: 2016

Additional sinusoidal and different non-sinusoidal periodic perturbations applied to the periodically forced nonlinear oscillators decide the maintainance or inhibitance of chaos. It is observed that the weak amplitude of the sinusoidal force without phase is sufficient to inhibit chaos rather than the other non-sinusoidal forces and sinusoidal force with phase. Apart from sinusoidal force without phase, i.e., from various non-sinusoidal forces and sinusoidal force with phase, square force seems to be an effective weak perturbation to suppress chaos. The effectiveness of weak perturbation for suppressing chaos is understood with the total power average of the external forces applied to the system. In any chaotic system, the total power average of the external forces is constant and is different for different nonlinear systems. This total power average decides the nature of the force to suppress chaos in the sense of weak perturbation. This has been a universal phenomenon for all the chaotic non-autonomous systems. The results are confirmed by Melnikov method and numerical analysis. With the help of the total power average technique, one can say whether the chaos in that nonlinear system is to be supppressed or not. © 2016 Indian Academy of Sciences.


Neelamegam P.,SASTRA University | Jamaludeen A.,St. Joseph's College | Rajendran A.,Nehru Memorial College Autonomous
Measurement: Journal of the International Measurement Confederation | Year: 2011

A predictive method, based on artificial neural network (ANN) has been developed to study absorbance and pH effects on the equilibrium of blood serum. This strategy has been used to analyze serum samples and to predict the calcium concentration in blood serum. A dedicated data acquisition system is designed and fabricated using a LPC2106 microcontroller with light emitting diode (LED) as source and photodiode as sensor to measure absorbance and to calculate the calcium concentration. A multilayer neural network with back propagation (BP) training algorithm is used to simulate different concentration of calcium (Ca2+) as a function of absorbance and pH, to correlate and predict calcium concentration. The computed calcium concentration by neural network is quite satisfactory with correlations R2 = 0.998 and 0.995, standard errors of 0.0127 and 0.0122 in validation and testing stages respectively. Statistical analysis are carried out to check the accuracy and precision of the proposed ANN model and validation of results produce a relative error of about 3%. These results suggest that ANN can be efficiently applied and is in good agreement with values obtained with the current clinical spectrophotometric methods. Hence, ANN can be used as a complementary tool for studying metal ion complexion, with special attention to the blood serum analysis. © 2010 Elsevier Ltd. All rights reserved.


Shalini R.,Nehru Memorial College Autonomous | Sasikumar C.,Nehru Memorial College Autonomous
International Journal of Pharma and Bio Sciences | Year: 2015

This article reveals the degradation of low density polyethylene by enriching the growth of microorganisms present in the garbage soil. Fresh LDP films were cut into 3×3mm size and inoculated into the enriched garbage soil and kept for six month incubation. During the incubation, the sample was mixed thoroughly thrice for effective microbial growth, after that the films were separated and washed with ethanol to remove the debris and dried it with the help of tissue paper. Significant changes in the LDP films were observed due to the formation of microbial colony and further they were analyzed by scanning electron microscope (SEM).


Shalini R.,Nehru Memorial College Autonomous | Sasikumar C.,Nehru Memorial College Autonomous
Research Journal of Pharmaceutical, Biological and Chemical Sciences | Year: 2016

Low density polyethylene wastes accumulating in the environment have posed an ever increasing ecological threat. In this investigation, the degradation of LDP were analyzed after 7 months of incubation period and the LDP samples were treated cattle dung and kitchen vegetable wastes and compared with control. The rate of degradation was studied through FTIR analysis. Further this study confirmed that the microorganisms present in the cow and sheep dung have more degrading ability of low density polyethylene material than the microbes in the kitchen vegetable wastes under controlled environmental condition.

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