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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.


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.


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.


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 | Sundaram A.S.,Sree Sastha Institute of Engineering and Technology
Chalcogenide Letters | Year: 2014

Thin films of lead sulphide (PbS) were deposited on a glass substrate at room temperature using spin coating technique. X-ray diffraction (XRD) is used to establish the structure and crystallite size of these films and scanning electron microscopy is used to study the particle size and morphology. The dielectric properties of PbS thin films were studied in the different frequency range of 50Hz-5MHz at different temperatures. The frequency dependence of the dielectric constant and dielectric loss is found to decrease with increase in frequency at different temperatures. In addition, the electronic properties like valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability of the PbS thin films are also calculated.


Jaichandar S.,Sree Sastha Institute of Engineering and Technology | Annamalai K.,Anna University
Energy | Year: 2013

Improved thermal efficiency, reduction in fuel consumption and pollutant emissions from biodiesel fueled diesel engines are important issues in engine research. To achieve these, rapid and perfect air-fuel mixing are the most important requirements. The mixing quality of biodiesel spray with air can be improved by selecting the best injection parameters and better design of the combustion chamber. Experiments were performed using a DI (direct injection) diesel engine equipped with a conventional jerk type injection system and pistons having HCC (hemispherical combustion chamber) and TRCC (toroidal re-entrant combustion chamber) geometries. The combined effect of varying, injection pressure and combustion chamber geometries, on the combustion, performance and exhaust emissions, using a blend of 20% POME (pongamia oil methyl ester) by volume in diesel were evaluated. The test results showed that improvement in terms of brake thermal efficiency and specific fuel consumption for TRCC operated at higher injection pressure. Substantial improvements in reduction of emissions levels were also observed for TRCC operated at higher injection pressure. However improved combustion, due to better air motion inside the cylinder and high pressure injection, increased the oxides of nitrogen (NOx). Increasing injection pressure decreased ignition delay, and increased peak in-cylinder pressure and maximum heat release rate. © 2013 Elsevier 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.


Adalarasan R.,Saveetha Engineering College | Sundaram A.S.,Sree Sastha Institute of Engineering and Technology
Journal of Mechanical Science and Technology | Year: 2015

Continuous drive friction welding (FW) had found profound industrial applications as an economical solid state joining process. The welding parameters such as frictional pressure, upset pressure, burn off length and rotational speed were found to influence the quality of joints. In the present study, Al6061/SiCp rods were joined by friction welding. The welding trials were designed by using Taguchi’s L9 orthogonal array. Tensile strength and micro hardness of the joints were observed as the quality characteristics after each trial. The urge for parameter design had prompted the disclosure of a new integrated methodology based on technique for order of preference by similarity to ideal solution (TOPSIS) and grey relational analysis (GRA). The effectiveness of the proposed approach of T-GRA was validated by conducting a confirmation test and the field emission scanning electron microscope (FESEM) images of the fractured surface were also examined. © 2015, The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.


Sagadevan S.,Sree Sastha Institute of Engineering and Technology | Periasamy M.,Sree Sastha Institute of Engineering and Technology
Reviews on Advanced Materials Science | Year: 2014

Nanotechnology plays an important role in the development of biosensors. The sensitivity and performance of biosensors are improved by using nanomaterials through new signal transduction technologies. The development of tools and processes used to fabricate, measure and image nanoscale objects, has led to the development of sensors that interact with extremely small molecules that need to be analyzed. These advances are particularly exciting in the context of biosensing, where the demands are for low concentration detection and high specificity. The use of biomolecule-functionalized surfaces can drastically boost the specificity of the detection system, but may also pose reproducibility problems and increased complexity. Several nanobiosensor architecture-based mechanical devices, optical resonators, functionalized nanoparticles, nanowires, nanotubes, and nanofibers have been in use. As nanobiosensor technology becomes more refined and reliable, it will eventually make lab-on-a-chip devices for rapid screening of a wide variety of analyses at low cost. In particular, nanomaterials such as gold nanoparticles, carbon nanotubes, magnetic nanoparticles and quantum dots have been actively investigated for their applications in biosensors, which have become a new interdisciplinary frontier between biological detection and material science. This paper reviews the status of the various nanostructure-based biosensors and their applications. © 2014 Advanced Study Center Co. Ltd.


Sagadevan S.,Sree Sastha Institute of Engineering and Technology
Optik | Year: 2014

Bisthiourea nickel bromide (BTNB) single crystal has been grown by solution growth technique at room temperature. The crystal structure and lattice parameters were determined for the grown crystal by single crystal X-ray diffraction studies. Optical constants like band gap, refractive index, reflectance, extinction coefficient and electric susceptibility were determined from UV-vis-NIR spectrum. Nonlinear optical property was discussed to confirm the SHG efficiency of the grown crystal. The mechanical strength of the grown crystal was analyzed using Vickers microhardness tester. The dielectric constant and dielectric loss of bisthiourea nickel bromide are measured in the frequency range of 50 Hz to 5 MHz at different temperatures. The ac conductivity studies were carried out on bisthiourea nickel bromide crystals. In order to investigate the growth mechanism and surface features, etching studies are carried out for the crystal. Photoconductivity studies were carried out on bisthiourea nickel bromide crystals. © 2014, Elsevier GmbH. All rights reserved.

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