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Jaichandar S.,Sree Sastha Institute of Engineering and Technology | Annamalai K.,Indian Institute of Technology Madras
Fuel | Year: 2012

The present work investigates the effect of varying the combustion chamber geometry on the performance of a diesel engine using biodiesel in terms of brake specific fuel consumption, brake thermal efficiency as well as exhaust emissions and combustion characteristics. Engine tests have been carried out using a blend of 20% Pongamia Oil Methyl Ester (POME) with standard diesel as fuel and with three types of combustion chambers namely Hemispherical combustion chamber, Toroidal combustion chamber and Shallow depth combustion chamber without altering the compression ratio of the engine. The test results showed that brake thermal efficiency for toroidal combustion chamber is higher than for the other two types of combustion chambers. Significant improvement in reduction of particulates, carbon monoxide and unburnt hydrocarbons is observed for toroidal combustion chamber compared to the other two. However oxides of nitrogen were slightly higher for toroidal combustion chamber. The combustion analysis shows improved characteristics for toroidal combustion chamber compared to baseline engine at all loads of operation. © 2012 Elsevier Ltd. All rights reserved.

Sathiyapriya R.,Sree Sastha Institute of Engineering and Technology
Asian Journal of Chemistry | Year: 2011

An effective and environmental friendly method for the iodination of various moderately active methoxy arenes, phenols and anilines using hydrogen peroxide and acidified sodium periodate in aqueous ethanol medium is reported. The extent of iodination is easily controlled by stoichiometry and excellent yields of mono iodinated products are obtained.

Sagadevan S.,Sree Sastha Institute of Engineering and Technology
Optik | Year: 2015

Single crystals also play a vital role in the emerging technologies such as lasers, light emitting diodes, fibre optic communication components, solar cell, nonlinear optical devices, microelectronic components, transducers, memory elements and pyroelectric detectors. These are all the part of solid state devices that exist due to strong influence of single crystals as a result of recent development in technologies. Growth of large size single crystals of l-histidine hydrochloride monohydrate (LHHM) grown from aqueous solution by slow evaporation technique. Single crystal X-ray diffraction studies confirm that the grown crystal belongs to orthorhombic crystal system with space group P212121. The electrical properties such as plasma energy, Penn gap, Fermi energy and polarizability were calculated to analyze second harmonic generation (SHG). In addition, nonlinear optical properties were already performed to confirm the SHG efficiency of the grown crystal. Hence, LHHM is an excellent NLO material with enhanced SHG efficiency required for important applications in the field of optoelectronic and photonics. © 2014 Published by Elsevier GmbH.

Selvi M.,Saveetha Engineering College | Murugesan K.,Sree Sastha Institute of Engineering and Technology
Journal of Optics (United Kingdom) | Year: 2012

Radio on free space optics - RoFSO - has gained momentum in research because of its cost effectiveness and efficiency in transferring data at a high rate that is comparable to that for optical fiber media. While the transmission data rate is limited in fiber due to dispersion and nonlinearity, such effects do not prevail in FSO communication links. The data rate depends mainly on the switching speed of the optoelectronic devices. With the characteristics of free space being random in nature, the performance of RoFSO is primarily governed by atmospheric conditions. In this paper, we evaluate the performance of the orthogonal frequency division multiplexing (OFDM) signal in free space and compare against its counterpart radio frequency (RF) wireless communication systems. Simulations have been done on the atmospheric conditions by means of modeling the scintillation effect using log-normal distribution. The performance of the proposed system under two different base-band modulations, namely OFDM-PSK (phase shift keying) and QAM (quadrature amplitude modulation) in weak turbulence conditions is studied. It is found that PSK performs better than QAM. Also the M-ary performance analysis shows that 3-5 dB improvement in the signal to noise ratio is obtained for OFDM based FSO transmission compared to RF based wireless transmission. © 2012 IOP Publishing Ltd.

Sagadevan S.,Sree Sastha Institute of Engineering and Technology
International Journal of Nanoelectronics and Materials | Year: 2016

Silver oxide (Ag2O) nanoparticles were synthesized using a wet chemical technique. The synthesized nanoparticles were investigated by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV analysis and dielectric studies. The powder X-ray diffraction (XRD) shows that face- centered cube structure of silver oxide and the average crystallite sizes were calculated to be 18.6 nm. The particle size and morphology were studied using the scanning electron microscope (SEM) and transmission electron microscopy (TEM). The UV-Visible absorption spectrum analyzing showed the strong absorption peak and nearly transparent nature of the particle at visible region. The wide range of band gap energy value was found to be 4.70 eV. The dielectric properties of silver oxide nanoparticles were studied in the frequency range of 50 Hz-5 MHz at different temperatures. The frequency dependence of the dielectric constant and dielectric loss is found to decrease with an increase in the frequency at different temperatures. Further, electronic properties, such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability of the silver oxide nanoparticles were calculated. AC electrical conductivity measurement was studied. © 2015, Universiti Malaysia Perlis. All rights reserved.

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