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Chennai, India

Dhanasekaran C.,Vels University
International Journal of Hydrogen Energy | Year: 2016

During the past two decades considerable effort has been taken to develop and introduce alternate source of energy for the conventional gasoline and diesel. Environmental pollution and uncertainty in cost of petroleum products are the principal driving forces for this movement. The major pollutants from a diesel engine system are NOx, Smoke, particulate matter and Soot. Several alternative fuels were tried but all of them are carbon based fuels, therefore net carbon based pollutants cannot be reduced. One alternative to carbon based fuels is hydrogen, a non-carbon fuel, can only meet zero emission vehicles standards in future. Hydrogen can be commercially used as a fuel even though it has a number of technical and economical barriers. In the present investigation hydrogen is used in a diesel engine in the dual fuel mode and in neat form using DEE. In neat form DEE is injected into the intake manifold. In order to have a precise control of hydrogen flow and to avoid the backfire and pre-ignition problems, hydrogen is injected into the intake port and DEE injection follows hydrogen injection. DEE mixes with air and flows into the combustion chamber and DEE auto ignites first followed by hydrogen combustion. A single cylinder-four stroke water-cooled naturally aspirated constant speed D.I. diesel engine with a rated output of 3.7 kW at 1500 rpm is used for the experimental work. Measurements are taken with respect to the performance, combustion and emission studies. Experiments are conducted to determine the optimized injection timing, injection duration and injection quantity of the fuel in port injected operated engine using diesel as an ignition source for hydrogen. Experiments are conducted using hydrogen-DEE and with DEE injection quantity is optimized. © 2015 Hydrogen Energy Publications, LLC.

Sangeetha R.,Vels University | Arulpandi I.,Asan Memorial College | Geetha A.,Bharathi Womens College
Research Journal of Microbiology | Year: 2011

Lipases are hydrolytic enzymes which hydrolyse triglycerides to free fatty acids and glycerol. These enzymes also catalyse transesterification, aminolysis and acidolysis reactions. Their potential to function in non-aqueous and micro-aqueous environments makes them a versatile biotechnological tool. Lipases are ubiquitous in nature and those from microbes have occupied a prominent position as industrial biocatalysts. Both fungal and bacterial lipases have been exploited by various industries. The chemo, regio and enantio-selectivity of lipases are properties which widen their range of industrial applications. This review was aimed at providing a collective knowledge about bacterial lipases and this article discusses the fundamental details about the sources and cellular location of lipase and the production and purification of the enzyme. Immobilisation and bioimprinting techniques which improve the catalytic efficacy of lipase have also been discussed. This overview also enumerates and describes briefly the extensive applications of bacterial lipases. © 2011 Academic Journals Inc.

Vijaya Ramnath B.,Sri Sairam Engineering College | Manickavasagam V.M.,Vels University | Elanchezhian C.,Sri Sairam Engineering College | Vinodh Krishna C.,Sri Sairam Engineering College | And 2 more authors.
Materials and Design | Year: 2014

Composites made with natural fibers are finding applications in a wide variety of engineering fields due to their low cost and eco-friendly nature. This paper deals with the fabrication and evaluation of hybrid natural fiber composite using jute and abaca fibers along with glass fibers. Each composite is made up of five layers with three layers of jute and abaca enclosed by two layers of glass fibers. The composites are manufactured with three different fiber orientations and the compositions are varied in three different proportions. The fabricated composite samples are tested to investigate their various mechanical properties. From the test results, it is observed that fiber orientation plays a vital role in determining the mechanical properties of the composite. Morphological analysis is done using Scanning Electron Microscope (SEM). © 2014 Elsevier Ltd.

Binuramesh C.,Center for Fish Immunology | Michael R.D.,Vels University
Fish and Shellfish Immunology | Year: 2011

Almost all metabolic processes in an organism alternate through high and low activity phases with a regular periodicity of nearly 24. h. These daily/diel variations are governed by factors such as light, weather conditions, availability of food or predator activity. The immune system in fish is expected to follow the same routine based on external cues from the environment which it lives. The present study was carried out to investigate such daily/diel variations in selected immune parameters such as serum lysozyme and peroxidases activity, total serum globulin level and peripheral blood leukocyte count in Oreochromis mossambicus. The fish were maintained in semi natural condition (i.e.12L:12D). The results showed significant rise in serum peroxidases and lysozyme between 0200. h and 0600. h of the day and serum cortisol exhibited elevated level between 2200. h and 0600. h. Total serum globulin exhibited peak concentration from 1400. h to 1800. h. Thus suggesting the possibility of rhythmic functioning of immune system in O. mossambicus. © 2011 Elsevier Ltd.

Megala J.,Vels University | Geetha A.,Bharathi Womens College Autonomous
Food Chemistry | Year: 2010

The free radical-scavenging property and the inhibitory action on H+, K+-ATPase activity of aqueous (AEPD) and hydroalcoholic (HAEPD) fruit extracts of Pithecellobium dulce (PD) were screened in various in vitro models. HAEPD showed the greatest free radical-scavenging activity in all the experimental models. Further, HAEPD has shown a potent H+, K+-ATPase inhibitory activity and comparable to that of Omeprazole, the antiulcer drug. HPLC chromatogram of HAEPD was found to contain rich quantity of phenolic compounds and revealed the presence of flavonoids - quercitrin, rutin, kaempferol, naringin, daidzein. Thus HAEPD was found to possess a good antioxidant capacity when compared to AEPD. The study indicates that PD can be screened for antiulcer activity, since overexpression of H+, K+-ATPase results in gastric ulceration. So the free radical-scavenging and antiacid secretory activities of PD may be claimed for its traditional consumption for gastric complications. © 2010 Elsevier Ltd. All rights reserved.

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