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Search Results: 1 - 10 of 22 matches for " Govindhan. Varadharajan "
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Analytical solution of the concentration and current in the electoenzymatic processes involved in a PPO-rotating-disk-bioelectrode  [PDF]
Govindhan. Varadharajan, Lakshmanan. Rajendran
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.31001
Abstract: A mathematical model for electroenzymatic process of a rotating-disk-bioelectrode in which polyphenol oxidase occurs for all values of concentration of catechol substrate is presented. The model is based on system of reaction-diffusion equations containing a non-linear term related to Michaelis-Menten kinetics of the enzymatic reaction. Approximate analytical method (He’s Homotopy perturbation method) is used to solve the non-linear differential equations that describe the diffusion coupled with a Michaelis-Menten kinetics law. Closed analytical expressions for substrate concentration, product concentration and corresponding current response have been derived for all values of parameter using perturbation method. These results are compared with simulation results and are found to be in good agreement. The obtained results are valid for the whole solution domain.
Analytical solution of coupled non-linear second order differential equations in enzyme kinetics  [PDF]
Govindhan Varadharajan, Lakshmanan Rajendran
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.36063
Abstract: The coupled system of non-linear second-order reaction differential equation in basic enzyme reaction is formulated and closed analytical ex-pressions for substrate and product concentra-tions are presented. Approximate analytical me-thod (He’s Homotopy perturbation method) is used to solve the coupled non-linear differential equations containing a non-linear term related to enzymatic reaction. Closed analytical expres-sions for substrate concentration, enzyme sub-strate concentration and product concentration have been derived in terms of dimensionless reaction diffusion parameters k, and us-ing perturbation method. These results are compared with simulation results and are found to be in good agreement. The obtained results are valid for the whole solution domain.
Analytical Solutions of System of Non-Linear Differential Equations in the Single-Enzyme, Single-Substrate Reaction with Non-Mechanism-Based Enzyme Inactivation  [PDF]
Govindhan Varadharajan, Lakshmanan Rajendran
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.29158
Abstract: A closed form of an analytical expression of concentration in the single-enzyme, single-substrate system for the full range of enzyme activities has been derived. The time dependent analytical solution for substrate, enzyme-substrate complex and product concentrations are presented by solving system of non-linear differential equation. We employ He’s Homotopy perturbation method to solve the coupled non-linear differential equations containing a non-linear term related to basic enzymatic reaction. The time dependent simple analytical expressions for substrate, enzyme-substrate and free enzyme concentrations have been derived in terms of dimensionless reaction diffusion parameters ε, λ1, λ2 and λ3 using perturbation method. The numerical solution of the problem is also reported using SCILAB software program. The analytical results are compared with our numerical results. An excellent agreement with simulation data is noted. The obtained results are valid for the whole solution domain.
Application of αδ-Closed Sets  [PDF]
Kokilavani Varadharajan, Basker Palaniswamy
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.41001
Abstract:

In this paper, we introduce the notion of αδ-US spaces. Also we study the concepts of αδ-convergence, sequentially αδ-compactness, sequentially αδ-continunity and sequentially αδ-sub-continuity and derive some of their properties.

FUZZY MULTINOMIAL CONTROL CHART WITH VARIABLE SAMPLE SIZE
A. PANDURANGAN,R. VARADHARAJAN
International Journal of Engineering Science and Technology , 2011,
Abstract: The control chart technique is being widely used in industries to monitor a process for quality improvement. One of the basic charts for attributes is the p-chart. For a p – chart each item is classified as either nonconforming or conforming to the specified quality characteristic. In Some cases, an item may be classified inmore than two categories such as “bad”, “medium”, “good”, and “excellent”. Based on this concept, Amirzadeh et al. [1] have developed Fuzzy Multinomial chart (FM-chart) with the fixed sample size (FSS). In this paper a Fuzzy Multinomial process with Variable Sample Size (VSS) is proposed and the control limits for the FM charthave been obtained using multinomial distribution. The proposed method is compared with the conventional p – chart. It is seen that FM chart with VSS performs better than the conventional chart.
Microbial Adhesion on Orthodontic Ligating Materials: An in Vitro Assessment  [PDF]
Pandurangan Harikrishnan, Thillai Saku Subha, Varadharajan Kavitha, Arumugam Gnanamani
Advances in Microbiology (AiM) , 2013, DOI: 10.4236/aim.2013.31017
Abstract:

Orthodontic fixed appliance therapy is the commonest mode of treatment for most types of malocclusions (teeth irregularities). However, these materials are liable for microbial adhesion, which predisposes the wearer to increased microbial burden. The present study aims to evaluate, microbial adhesion and growth on commonly used orthodontic ligating materials (Teflon coated wire, stainless steel wire, elastic rings) under in vitro condition. Furthermore, the role of saliva on adhesion and microbial colonization on said materials was also assessed. Experiments were conducted with three different orthodontic ligating materials each in 6 numbers. Growth OD, metabolic activity and cell viability were the experimental variables in addition to SEM (Scanning Electron Microscopy) analysis performed. Results revealed irespective of the nature of the ligating materials, microbial adhesion and growth were observed in all the materials and suggested that the chosen materials promotes microbial adhesion. Nevertheless, stainless steel ligatures were less prone to adhesion compared to Teflon coated and elastic ligatures. Presence of saliva accelerates adhesion and growth.

A New Historicist Approach to John Galsworty’s The Forsyte Saga
B. Krishnamurthy,T. S. Varadharajan
Journal of Literature, Culture and Media Studies , 2010,
Abstract:
用于电化学水氧化的铁、镍、钴金属及其二元金属纳米颗粒比较研究
Comparative Studies of Fe, Ni, Co and Their Bimetallic Nanoparticles for Electrochemical Water Oxidation

Maduraiveeran Govindhan, Brennan Mao, 陈爱成
Maduraiveeran Govindhan
, Brennan Mao, Aicheng Chen

- , 2017, DOI: 10.13208/j.electrochem.161247
Abstract: 摘要 从环境兼容角度来设计应用于氧析出反应的电催化剂是否有效、耐用和廉价对能源转化过程至关重要. 本文报告了一种快速制备低成本、原料丰富的金属催化剂制备方法。通过一步电化学沉积法在钛金属基材上制备了铁、镍、钴金属及其钴镍、钴铁二元金属纳米颗粒. 采用场发射电子显微镜 (FE-SEM), 能量散射X-射线能谱 (EDX), X-射线衍射光谱 (XRD), X-射线光电子能谱 (XPS)和电化学技术对制备的不同纳米颗粒进行了表征. 电化学结果显示,在合成的五种钛基金属纳米催化剂中, 钛基上沉积钴金属纳米颗粒(Ti/Co)电极在0.l mol·L-1氢氧化钾溶液中氧析出反应的电催化活性最好,0.70 V(相对于银/氯化银电极)的电流密度为10.0 mA·cm-2. 经优化后Ti/Co电极的过电位(η)很小,当电流密度为10.0 mA·cm-2时η为0.43 V,质量活性高达105.7 A·g-1,逆转频率(TOF)值为1.63×10-3 s-1, 这些与当前最好的碳载铂(Pt/C)和氧化钌(RuO2)电催化剂的性能相当. 此外,通过计时电位技术对优化后Ti/Co电极的耐久性进行了测试, 发现该电极在碱性溶液中氧析出反应的稳定性良好. 本工作制备的钛金属基材上电化学沉积金属钴纳米颗粒具有高催化活性、高稳定性、原料来源丰富、廉价且易于大规模生产,在工业化水分解领域具有潜在的应用前景.
The design of efficient, durable, and earth-abundant electrocatalysts via environmentally compatible strategies for the oxygen evolution reaction (OER) is a vital for energy conversion processes. Herein we report a facile approach for the fabrication of low-cost and earth abundant metal catalysts, including iron (Fe), nickel (Ni), cobalt (Co), CoNi, and CoFe nanoparticles (NPs) on titanium (Ti) substrates through a one-step electrochemical deposition. Field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) spectrocopy, X-ray photoelectron spectroscopy (XPS), and electrochemical techniques were employed to characterize these nanoparticles. Our electrochemical results revealed that among the five synthesized nanomaterials, the Ti/Co electrode exhibited the highest electrocatalytic activity toward OER in 0.l mol·L-1 KOH with a current density of 10.0 mA·cm-2 at 0.70 V vs. Ag/AgCl. The optimized Ti/Co electrode exhibited a small overpotential (η) of 0.43 V at 10.0 mA·cm-2 and a high mass activity of 105.7 A·g-1 with a turnover frequency (TOF) value of 1.63×10-3 s-1, which are comparable to the values obtained with the state-of-the-art Pt/C and RuO2 electrocatalysts. In addition, the durability of the optimized Ti/Co electrode was tested using a chronopotentiometric technique, which revealed that the developed electrocatalyst possessed good stability for OER in an alkaline solution. The high catalytic activity, high stability, earth abundance, cost-effectiveness, and easy scale-up for mass production make the Co nanoparticles, which were electrochemically deposited on a Ti substrate, promising for industrial water splittin
PERFORMANCE EVALUATION OF VARIOUS STATISTICAL CLASSIFIERS IN DETECTING THE DISEASED CITRUS LEAVES
SUDHEER REDDY BANDI,VARADHARAJAN A,A CHINNASAMY
International Journal of Engineering Science and Technology , 2013,
Abstract: Citrus fruits are in lofty obligation because the humans consume them daily. This research aims to amend citrus production, which knows a low upshot bourgeois on the production and complex during measurements. Nowadays citrus plants grappling some traits/diseases. Harm of the insect is one of the major trait/disease. Insecticides are not ever evidenced effectual because insecticides may be toxic to some gracious of birds. Farmers get outstanding difficulties in detecting the diseases ended open eye and also it is quite expensive.Machine vision and Image processing techniques helps in sleuthing the disease mark in citrus leaves and sound job. In this search, Citrus leaves of four classes like Normal, Greasy spot, Melanose and Scab are collected and investigated using texture analysis based on the Color Co-occurrence Method (CCM) to take Hue, Saturation and Intensity (HSI) features. In the arrangement form, the features are categorised for all leafage conditions using k-Nearest Neighbor (kNN), Naive Bayes classifier (NBC), Linear Discriminate Analysis (LDA) classifier and Random Forest Tree Algorithm classifier (RFT). The experimental results inform that proposed attack significantly supports 98.75% quality in automated detection of regular and struck leaves using texture psychotherapy based CCM method using LDA formula. Eventually all the classifiers are compared using Earphone Operative Characteristic contour and analyzed the performance of all the classifiers.
Screening of methanol extract of roots and rhizomes of Smilax zeylanica L for hepatoprotective effect against carbontetrachloride induced hepatic damage
Anita Murali,Purnima Ashok,Varadharajan Madhavan
Journal of Experimental and Integrative Medicine , 2012, DOI: 10.5455/jeim.050512.or.028
Abstract: Objective: To evaluate the hepatoprotective potential of methanol extract of roots and rhizomes of Smilax zeylanica L on carbontetrachloride (CCl4) induced hepatotoxicity in Wistar albino rats. Methods: Hepatotoxicity was induced in Wistar albino rats of either sex by administration of CCl4 0.5 ml/kg p.o. once a day for 7 days. The methanol extract of roots and rhizomes of Smilax zeylanica L were administered p.o. at doses of 200, 400 and 600 mg/kg b.w for 7 days. On the 8th day, biochemical estimations were carried out to measure the serum levels of ALT, AST, ALP, albumin, total proteins and total bilirubin. Histopathological examination of liver sections was also performed to study the extent of damage to hepatic parenchyma. Preliminary phytochemical screening of the methanol extract was carried out to find out the presence of various phytoconstituents. HPTLC fingerprint profiles of the detected phytoconstituents were also obtained. Results: Administration of CCl4 produced profound hepatic damage as evidenced by the significant increase in serum levels of ALT, AST, ALP and total bilirubin and decrease in total proteins and albumin. The altered biochemical parameters were brought to near normal levels by the administration of methanol extract of roots and rhizomes of S.zeylanica. Conclusion: S.zeylanica roots and rhizomes possess significant hepatoprotective properties, which may due to the presence of potential hepatoprotective phytoconstituents present in them. [J Exp Integr Med 2012; 2(3.000): 237-244]
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