Velammal Engineering College
Chennai, India

Velammal Engineering College, is a private institution located in Chennai, India. Established in 1995. It was the first private engineering College to obtain an ISO 9001:2000 certificate from the National Board of Accreditation. Wikipedia.

Time filter
Source Type

Currently, atmospheric pollution and increased energy needs delineate the importance of alternate sources of fuels. In this current study, the performance and emission characteristics of papaya seed methyl ester (PSME) blended with diesel are studied at varying loads. PSME is blended at 5, 10 and 15% into the fuel and, in addition to that, a 10% concentration of n-butanol is also blended. The blends showed promising results where the CO, HC and smoke emissions were reduced significantly by addition of n-butanol despite the higher viscosity of papaya seed oil. Also, the effect of n-butanol addition was high in blends with lower concentration of biodiesels. Their effect was found to be predominant at medium operating loads rather than at lower and higher loads. In addition to that, PSME increased the brake thermal efficiency (BTE), exhaust gas temperature (EGT) and NOx emissions. © 2017 Informa UK Limited, trading as Taylor & Francis Group

Varatharajan K.,Velammal Engineering College | Pushparani D.S.,SRM University
Renewable and Sustainable Energy Reviews | Year: 2017

One of the major issues associated with the use of biodiesel is to maintain the fuel at specified standards for a longer period. Biodiesel is more prone to oxidization than a mineral diesel, and it starts turning rancid within a week or less, and complete degradation occurs after a period of 4 weeks. The final products of oxidation alter the physical and chemical properties of fuel which results in the formation of insoluble gums that can plug fuel filters. This instability of biodiesel is a long-standing issue, and it has not as yet been satisfactorily resolved. As the use of biodiesel has increased massively, this oxidation issue could become a significant barrier to market expansion. One very promising and cost-effective approach to improving the stability of biodiesel is that the addition of appropriate antioxidants to the biodiesel fuels. Antioxidants perform better or worse in different biodiesel fuels, and there is no unique inhibitor that suit for every kind of biodiesel fuels. To screen the antioxidants for a specific biodiesel, it is necessary to understand the chemistry of antioxidants and the key factors that influence their effectiveness against biodiesel oxidation. Most of the published studies had been carried out solely with some common antioxidants, and still, hundreds of antioxidants are out there for testing. This article provides an insight into the factors to be considered for the selection of antioxidants to improve the storage stability of biodiesel fuels. © 2017 Elsevier Ltd.

Varatharajan K.,Velammal Engineering College | Cheralathan M.,SRM University | Velraj R.,Anna University
Fuel | Year: 2011

Biodiesel offers cleaner combustion over conventional diesel fuel including reduced particulate matter, carbon monoxide and unburned hydrocarbon emissions. However, several studies point to slight increase in NOx emissions (about 10%) for biodiesel fuel compared with conventional diesel fuel. Use of antioxidant additives is one of the most cost-effective ways to mitigate the formation of prompt NOx. In this study, the effect of antioxidant additives on NOx emissions in a jatropha methyl ester fuelled direct injection diesel engine have been investigated experimentally and compared. A survey of literature regarding the causes of biodiesel NOx effect and control strategies is presented. The antioxidant additives L-ascorbic acid, α tocopherol acetate, butylated hydroxytoluene, p-phenylenediamine and ethylenediamine were tested on computerised Kirloskar-make 4 stroke water cooled single cylinder diesel engine of 4.4 kW rated power. Results showed that antioxidants considered in the present study are effective in controlling the NOx emissions of biodiesel fuelled diesel engines. A 0.025%-m concentration of p-phenylenediamine additive was optimal as NOx levels were substantially reduced in the whole load range in comparison with neat biodiesel. However, hydrocarbon and CO emissions were found to have increased by the addition of antioxidants. © 2011 Elsevier Ltd. All rights reserved.

Varatharajan K.,Velammal Engineering College | Cheralathan M.,SRM University
Renewable and Sustainable Energy Reviews | Year: 2012

Biodiesel has proved to be an environment friendly alternative fuel for diesel engine because it can alleviate regulated and unregulated exhaust emissions. However, most researchers have observed a significant increase in NO x emissions with biodiesel when compared to petrodiesel. The exact cause of this increase is still unclear; however, researchers believe that the fuel properties have been shown to effect the emissions of NO x. The present work reviews the effect of fuel properties and composition on NO x emissions from biodiesel fuelled engines. The paper is organised in three sections. The first section deals with the NO x formation mechanisms. In the following section, the reasons for increased NO x emissions of biodiesel fuel are discussed. After this, the influence of composition and fuel properties on NO x emissions from biodiesel fuelled engines has been reviewed. Finally, some general conclusions concerning this problem are summarised and further researches are pointed out. © 2012 Elsevier Ltd. All right reserved.

Varatharajan K.,Velammal Engineering College | Cheralathan M.,SRM University
Fuel Processing Technology | Year: 2013

It is an overwhelming argument that the use of biodiesel instead of petrodiesel causes a reduction in harmful exhaust emissions from engines. A number of studies, however, indicate substantial increases in engine out NO x emissions with biodiesel fuel. Some studies have pointed out that the increased formation of prompt NOx is responsible for biodiesel NOx effect. Treatment of biodiesel with antioxidants is a promising approach because it reduces the formation of hydrocarbon free radicals, which are responsible for prompt NOx production in combustion process. Aromatic amine antioxidants are known as to be efficient inhibitors of free radicals. This study examines the use of p-phenylenediamine derived aromatic amine antioxidants for NOx reduction in a soybean biodiesel fuelled DI diesel engine. The antioxidant additives, N,N′-diphenyl-1,4- phenylenediamine (DPPD) and N-phenyl-1,4-phenylenediamine (NPPD) were tested on a computerised Kirloskar-make 4 stroke water cooled single cylinder diesel engine of 4.4 kW rated power. Results show that significant reduction of NO x could be achieved by the addition of antioxidants but smoke, CO and HC emissions were found to have increased. © 2012 Elsevier B.V.

Selvaraj M.D.,Velammal Engineering College | Mallik R.K.,Indian Institute of Technology Delhi
IEEE Transactions on Vehicular Technology | Year: 2010

Consider a cooperative diversity network that consists of a source, N cooperating relays, and a destination. The relays cooperate with the source through the decode and forward protocol to transmit a data symbol from the source to the destination. In a conventional signal-to-noise ratio based selection combining scheme at the destination, the effect of the source-to-relay links is not accounted for when choosing one link from the set consisting of the source-to-destination and N relay-to-destination links. To overcome this drawback, we modify the conventional scheme by including, in the selection process, a deterministic scale factor that incorporates the effect of the source-to-relay links. For statistically independent links that undergo flat Rayleigh fading, we derive, in closed form, the exact end-to-end symbol error probability (SEP) of this modified scheme, which we call a scaled selection combining scheme for M-ary phase-shift keying constellation. We also give a method of obtaining the optimum scale factor that minimizes the end-to-end SEP. A system designer should select the optimum scale factor to achieve the best performance of the scheme. © 2006 IEEE.

Malathi G.,Velammal Engineering College | Shanthi V.,St. Joseph's College
Journal of Information Hiding and Multimedia Signal Processing | Year: 2011

Medical diagnosis is the major challenge faced by the medical experts. Highly specialized tools are necessary to assist the experts in diagnosing the diseases. Gestational Diabetes Mellitus is a condition in pregnant women which increases the blood sugar levels. It complicates the pregnancy by affecting the placental growth. The ultrasound screening of placenta in the initial stages of gestation helps to identify the complication induced by GDM on the placental development which accounts for the fetal growth. This work focus on the classification of ultrasound placenta images into normal and abnormal images based on statistical measurements. The ultrasound images are usually low in resolution which may lead to loss of characteristic features of the ultrasound images. The placenta images obtained in an ultrasound examination is stereo mapped to reconstruct the pla- centa structure from the ultrasound images. The dimensionality reduction is done on stereo mapped placenta images using wavelet decomposition. The ultrasound placenta image is segmented using watershed approach to obtain the statistical measurements of the stereo mapped placenta images. Using the statistical measurements, the ultrasound placenta images are then classified as normal and abnormal using Back Propagation neu- ral networks. © 2011 ISSN 2073-4212.

Deepa N.,Velammal Engineering College | Balaji Ganesh A.,Velammal Engineering College
Measurement: Journal of the International Measurement Confederation | Year: 2015

The paper presents a hand-held optical sensor for simultaneous and minimal invasive measurement of pH and dissolved oxygen using sol-gel based sensing membranes which are attached internally in any see-through container. The sensing system shows the stable results over the period of time and possess the characteristics such as, minimum response time and repeatability. The disposable membranes are prepared using simple procedures and are very thin in size that can be attached the inner surfaces of transparent columns such as, measuring jar, conical flask, cuvettes and bio reactors. The pH sensor can be applied to the range between 3 pH and 9 pH, however, it shows good sensitivity between 4 pH and 9 pH with the response time of less than 10 s. The dissolved oxygen is measured in the range from 2 mg/L to 9 mg/L. It is found that, the opto electronic system posses the features, such as in-situ, simple, cost efficient, handheld and field deployable. © 2014 Elsevier Ltd. All rights reserved.

Velayudham A.,Cape Institute of Technology | Kanthavel R.,Velammal Engineering College
International Review on Computers and Software | Year: 2013

Computed tomography (CT) images are generally corrupted by several noises from the measurement process complicating the automatic feature extraction and analysis of clinical data. To achieve the best possible diagnosis it is important that medical images be sharp, clear, and free of noise and artifacts. While the technologies for acquiring digital medical images continue to improve, resulting in images of higher and higher resolution and quality, noise remains an issue for many medical images. Removing noise in these digital images remains one of the major challenges in the study of medical imaging. A variety of literatures have been developed to solve the problem of medical images denoising which is a significant stage in an automatic diagnosis system. In this paper, we propose a new image denoising technique using EMD and Dual Tree Complex Wavelet Packets. Here, histon process is used in order to overcome the smoothing filter type and it will not affect the lower dimensions. We have used two noises, like as Gaussian and salt & pepper for the proposed technique. The performance of the proposed image denoising technique is evaluated on the five CT images using the PSNR and SDME. For comparison analysis, our proposed denoising technique is compared with the existing work in various noise levels. From the results, we can conclude that the proposed denoising technique has shown the SDME of 48.33 but the existing technique show the PSNR of 39.84 for salt & pepper noise. © 2013 Praise Worthy Prize S.r.l. - All rights reserved.

Sivakumar V.,Rmk Engineering College | Ganapathy Sundaram E.,Velammal Engineering College
Renewable and Sustainable Energy Reviews | Year: 2013

A technique used to convert brackish or saline water into potable water is called as solar desalination. The demand of consumable water keeps on increasing due to high population density and automation. Solar energy is used for the conversion phenomenon and the device used for desalination is known as a solar still. Active and passive solar stills are the major types of solar stills. Without the utilization of high grade energy (electrical energy), freshwater is derived from the passive solar still. The yield from the solar still (active or passive solar still) depends upon meteorological, and design and operational parameters. By the mercy of nature, meteorological parameters cannot be controlled by human beings. Many researchers framed mathematical expressions, conducted experiments and validated the outcome from the various types of solar stills by varying the design and operating parameters. The methodologies used in the past years to improve the performance of the active and passive solar stills were reviewed in this paper. © 2013 Elsevier Ltd.

Loading Velammal Engineering College collaborators
Loading Velammal Engineering College collaborators