Power Tracking Control of Domestic Induction Heating System using Pulse Density Modulation Scheme with the Fuzzy Logic Controller

Nagarajan, Booma,Sathi, Rama Reddy,Vishnuram, Pradeep The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.6

Power requirement to the induction heating system varies during the heating process. A closed loop control is required to have a smooth control over the power. In this work, a constant frequency pulse density modulation based power tracking control scheme for domestic induction heating system is developed using the Fuzzy Logic Controller. In the conventional power modulation schemes, the switching losses increase with the change in the load. The proposed pulse density modulation scheme maintains minimum switching losses for the entire load range. This scheme is implemented for the class-D series resonant inverter system. Fuzzy logic controller based power tracking control scheme is developed for domestic induction heating power supply for various power settings. The open loop and closed loop simulation studies are done using the MATLAB/Simulink simulation tool. The control logic is implemented in hardware using the PIC16F877A microcontroller. Fuzzy controller tracks the set power by changing the pulse density of the gate pulses applied to the inverter. The results obtained are used to know the effectiveness of the fuzzy logic controller to achieve the set power.

NATURAL CONVECTION AROUND A HEAT CONDUCTING AND GENERATING SOLID BODY INSIDE A SQUARE ENCLOSURE WITH DIFFERENT THERMAL BOUNDARIES

NAGARAJAN NITHYADEVI,PERIYASAMY UMADEVI 한국산업응용수학회 2015 Journal of the Korean Society for Industrial and A Vol.19 No.4

Two-dimensional steady laminar natural convection around a heat conducting and generating solid body inside a square enclosure with different thermal boundaries is performed. The mathematical model is governed by the coupled equation of mass, momentum and energy. These equations are discretized by finite volume method with power-law scheme and solved numerically by SIMPLE algorithm with under-relaxation technique. Effect of Rayleigh number, temperature difference ratio of solid-fluid, aspect ratio of solid-enclosure and the thermal conductivity ratio of solid-fluid are investigated numerically for Pr = 0:7. The flow and heat transfer aspects are demonstrated in the form of streamlines and isotherms respectively.

Protein-Protein Interaction Analysis of Corticotropin - Releasing Hormone Receptor 1 with Corticotropin-Releasing Hormone and Sauvagine

Nagarajan, Santhosh Kumar The Basic Science Institute Chosun University 2018 조선자연과학논문집 Vol.11 No.2

Corticotropin - releasing hormone receptor 1 (CRHR1) forms an integral part of the pathophysiology of disorders like post-traumatic stress disorder, stress, anxiety, addiction, and depression. Hence it is essential to look for new, potent and structure-specific inhibitors of CRHR1. We have analysed the protein-protein interaction complexes of the CRHR1 receptor with its native ligand CRF and full agonist Sauvagine. The structure of Sauvagine was predicted using homology modelling. We have identified that the residues TYR253, ASP254, GLU256, GLY265, ARG1014 and LY1060 are important in the formation of protein-protein complex formation. Future studies on these residues could throw light on the crucial structural features required for the formation of CRHR1-inhibitor complex and in studies that try to solve the structural complexities of CRHR1.

Protein-Protein Interaction Analysis of KiSS1-Derived Peptide Receptor with Kisspeptin-10 and Kisspeptin-15

Nagarajan, Santhosh Kumar The Basic Science Institute Chosun University 2018 조선자연과학논문집 Vol.11 No.1

KiSS1-derived peptide receptor, a GPCR protein, binds with the hormone Kisspeptin plays a major role in the neuroendocrine regulation of reproduction. It is important in the onset of puberty and triggers the release of gonadotrophin-releasing hormone. It is a potential drug target for the disorders related to GnRH, hence, analysing the structural features of the receptor becomes important. The three dimensional of the receptor modelled in a previous study was utilised. In this study, we have analysed the protein - protein interaction of the receptor with Kisspeptin 10 and 15. The study revealed the important residues which are involved in the interaction. The result of this study could be helpful in understanding the mechanism of Kiss1 receptor activation and the pathophysiology of the disorders related to the receptor.

Mesoscopic numerical analysis of reinforced concrete beams using a modified micro truss model

Nagarajan, Praveen,Jayadeep, U.B.,Madhavan Pillai, T.M. Techno-Press 2010 Interaction and multiscale mechanics Vol.3 No.1

Concrete is a heterogeneous material consisting of coarse aggregate, mortar matrix and interfacial zones at the meso level. Though studies have been done to interpret the fracture process in concrete using meso level models, not much work has been done for simulating the macroscopic behaviour of reinforced concrete structures using the meso level models. This paper presents a procedure for the mesoscopic analysis of reinforced concrete beams using a modified micro truss model. The micro truss model is derived based on the framework method and uses the lattice meshes for representing the coarse aggregate (CA), mortar matrix, interfacial zones and reinforcement bars. A simple procedure for generating a random aggregate structure is developed using the constitutive model at meso level. The study reveals the potential of the mesoscopic numerical simulation using a modified micro truss model to predict the nonlinear response of reinforced concrete structures. The modified micro truss model correctly predicts the load-deflection behaviour, crack pattern and ultimate load of reinforced concrete beams failing under different failure modes.

Theoretical Structure Prediction of Bradykinin Receptor B2 Using Comparative Modeling

Nagarajan, Santhosh Kumar,Madhavan, Thirumurthy The Basic Science Institute Chosun University 2016 조선자연과학논문집 Vol.9 No.4

Bradykinin receptor B2, a GPCR protein, binds with the inflammatory mediator hormone bradkynin. It plays an important role in cross-talk between the renin-angiotensin system (RAS) and the kinin-kallikrein system (KKS). Also, it is involved in many processes including vasodilation, edema, smooth muscle spasm and pain fiber stimulation. Hence, studuying the structural features of the receptor becomes important. But the unavailability of the three dimensional structure of the protein makes the analysis difficult. Hence we have performed the homology modelling of Bradykinin receptor B2 with 5 different templates. 25 different homology models were constructed. Two best models were selected based on the model validation. The developed models could be helpful in analysing the structural features of Bradykinin receptor B2 and in pathophysiology of various disorders related to them.

3D QSAR Study of 2-Methoxyphenylpiperazinylakanamides as 5-Hydroxytryptamine (Serotonin) Receptor 7 Antagonists

Nagarajan, Santhosh Kumar,Madhavan, Thirumurthy The Basic Science Institute Chosun University 2016 조선자연과학논문집 Vol.9 No.2

5-hydroxytryptamine (serotonin) receptor ($5-HT_7R$) 7 is one of G-Protein coupled receptors, which is activated by the neurotransmitter Serotonin. After activation by serotonin, $5-HT_7$ activates the production of the intracellular signaling molecule cyclic AMP. $5-HT_7$ receptor has been found to be involved in the pathophysiology of various disorders. It is reported that $5-HT_7$ receptor antagonists can be used as antidepressant agents. In this study, we report the important structural and chemical parameters for 2-methoxyphenylpiperazinylakanamides as $5-HT_7R$ inhibitors. A 3D QSAR study based on comparative molecular field analysis (CoMFA) was performed. The best predictions were obtained for the best CoMFA model with $q^2$ of 0.594 with 6 components, $r^2$ of 0.986, Fisher value as 60.607, and an estimated standard error of 0.043. The predictive ability of the test set was 0.602. Results obtained the CoMFA models suggest that the data are well fitted and have high predictive ability. The contour maps are generated and studied. The contour analyses may serve as tool in the future for designing of novel and more potent $5-HT_7R$ derivatives.

Structure Prediction of KiSS1-derived Peptide Receptor Using Comparative Modelling

Nagarajan, Santhosh Kumar,Madhavan, Thirumurthy The Basic Science Institute Chosun University 2016 조선자연과학논문집 Vol.9 No.2

KiSS1-derived peptide receptor, a GPCR protein, binds with the hormone kiss peptin. They are important in the neuroendocrine regulation of reproduction and in the secretion of gonadotrophin-releasing hormone. Thus, analysing the structural features of the receptor becomes important. However, the three dimensional structure of the protein is unavailable. Hence in this study, we have performed the homology modelling of KiSS1-derived peptide receptor with 5 different templates. 30 models were constructed using two platforms - Easymodeller and ITasser. The optimal models were chosen based on the model validation. Two models were selected after validation. The developed models could provide useful for analysing the structural features of KiSS1-derived peptide receptor and their pathophysiological role in various disorders related to them.

Impact of Polyphenols from Banana Pseudostem on Sunflower Oil Stability

Nagarajan Anusuya,Rajkumar Gomathi,Jayaprakash Tharani,Ganapathipalayam Subbaiyan Murugesan 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.3

The present investigation is focused on the potential use of banana pseudostem, which otherwise is disposed off as a waste, as a source of polyphenols or antioxidants. The polyphenols extracted from the outer leaf sheaths of 3 Indian banana (Musa spp.) cultivars namely,‘Nendhran’, ‘Robusta’, and ‘Kathali’ were tested for antioxidant activities. The extracts showed effective DPPH,hydroxyl, and superoxide radical scavenging ability. Among the banana cultivars, ‘Nendhran’ followed by ‘Robusta’ contained the highest total phenolic (110.45 and 94.03 mg GAE/g extract, respectively) and total flavonoid (49.62 and 38.61 mg QE/g extract, respectively) contents and antiradical activity. Further, the study was aimed to evaluate the protective effects of the polyphenolic extracts in stabilizing sunflower oil, tested in terms of peroxide value, free fatty acid contents, and p-anisidine values in comparison with the synthetic antioxidants, butylated hydroxyanisole and butylated hydroxytoluene. In addition,the antioxidant activity and total phenolic contents of the extract-treated oil samples were also monitored to obtain a complete perspective of the influence exerted by the polyphenols in oil stability. The results demonstrated that polyphenols from pseudostem of banana cultivars are potent source of natural antioxidants and might serve as a substitute for synthetic antioxidants in oil industry.

Comparative Molecular Similarity Indices Analysis (CoMSIA) of 8-substituted-2-aryl-5-alkylaminoquinolines as Corticotropin-releasing factor-1 Receptor Antagonists

Nagarajan, Santhosh Kumar,Madhavan, Thirumurthy The Basic Science Institute Chosun University 2016 조선자연과학논문집 Vol.9 No.4

Corticotropin-releasing factor receptors (CRFRs) activate the hypothalamic-pituitary-adrenal axis, which is an integral part of the fight or flight response to stress. Increase in CRH level is observed in Alzheimer's disease and major depression and hypoglycemia. Here, we report on the relevant physicochemical parameters required for the CRFR inhibitors. Comparative molecular similarity indices analysis (CoMSIA) was performed with the derivatives of 8-substituted-2-aryl-5-alkylaminoquinolinesas CRFR inhibitors. The best predictions were obtained for the best CoMSIA model with a $q^2$ of 0.576 with 6 components and $r^2$ of 0.977. The statistical parameters from the generated CoMSIA models indicated that the data are well fitted and have high predictive ability. CoMSIA contour maps could be useful in the designing of more potent and novel CRFR derivatives.