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In vitro Antioxidant Activity of Ethanolic Extract of Chlorophytum borivilianum
R. Govindarajan1,,N. Sreevidya1,,M. Vijayakumar1,,M. Thakur2,,V.K. Dixit2,,S. Mehrotra*1,,P. Pushpangadan1 한국생약학회 2005 Natural Product Sciences Vol.11 No.3
Chlorophytum borivilianum Baker (Antharicaceae) comonly referred as ‘Safed Musli’ has beenwidely used in the Indian traditional systems of medicine to treat various diseases like rheumatism apart fromaphordisiac properties. C. borivilianum was screened for the first time to determine its antioxidant activity,isolation of the sapogenins and standardization of the isolated sapogenin fraction using HPTLC. Potent antioxidantactivity of ethanolic extract was found by their ability to scavenge DPPH (84.51%), hydroxyl radical (48.95 %),feryl bi-pyridyl complex (84.53%) along with the inhibition of lipid peroxidation (67.17%) at 100g/mlconcentration. The ethanolic extract also exhibited significant inhibition of superoxide anion radical generated byplant in the traditional system especially its use as a Rasayana drug.
CFD estimation of HDCs for varying bodies of revolution of underwater gliders
R.V. Shashank Shankar,R. Vijayakumar Techno-Press 2023 Ocean systems engineering Vol.13 No.3
Autonomous Underwater Gliders (AUGs) are a type of Underwater Vehicles that move without the help of a standard propeller. Gliders use buoyancy engines to vary their weight or buoyancy and traverse with the help of the Lift and Drag forces developed from the fuselage and the wings. The Lift and Drag Coefficients, also called Hydrodynamic coefficients (HDCs) play a major role in glider dynamics. This paper examines the effect of the different types of glider fuselages based on the bodies of revolution (BOR) of NACA sections. The HDCs of the glider fuselages are numerically estimated at a low-speed regime (10<sup>5</sup> Reynolds Number) using Computational Fluid Dynamics (CFD). The methodology is validated using published literature, and the results of CFD are discussed for possible application in the estimation of glider turning motion.
R. Palanisamy,K. Vijayakumar 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1
This paper elucidates a hysteresis current controller for enhancing the performance of static synchronous compensator (STATCOM) using cascaded H-bridge multilevel inverter. Due to the rising power demand and growing conventional generation costs a new alternative in renewable energy source is gaining popularity and recognition. A five level single phase cascaded multilevel inverter with two separated dc sources, which is energized by photovoltaic - wind hybrid energy source. The voltages across the each dc source is balanced and standardized by the proposed hysteresis current controller. The performance of STATCOM is analyzed by connecting with grid connected system, under the steady state & dynamic state. To reduce the Total Harmonic Distortion (THD) and to improve the output voltage, closed loop hysteresis current control is achieved using PLL and PI controller. The performance of the proposed system is scrutinized through various simulation results using matlab/simulink and hardware results are also verified with simulation results.
( Vijayakumar M. Malathi ),( Ravi P. More ),( Rangasamy Anandham ),( Gandhi R. Gracy ),( Muthugounder Mohan ),( Thiruvengadam Venkatesan ),( Sandipan Samaddar ),( Sushil K. Jalali ),( Tongmin Sa ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.6
Knowledge about the gut bacterial communities associated with insects is essential to understand their roles in the physiology of the host. In the present study, the gut bacterial communities of a laboratory-reared insecticide-susceptible (IS), and a field-collected insecticide-resistant (IR) population of a major rice pest, the brown planthopper Nilaparvata lugens, were evaluated. The deep-sequencing analysis of the V3 hypervariable region of the 16S rRNA gene was performed using Illumina and the sequence data were processed using QIIME. The toxicological bioassays showed that compared with the IS population, IR population exhibited 7.9-, 6.7-, 14.8-, and 18.7-fold resistance to acephate, imidacloprid, thiamethoxam, and buprofezin, respectively. The analysis of the alpha diversity indicated a higher bacterial diversity and richness associated with the IR population. The dominant phylum in the IS population was Proteobacteria (99.86%), whereas the IR population consisted of Firmicutes (46.06%), followed by Bacteroidetes (30.8%) and Proteobacteria (15.49%). Morganella, Weissella, and Enterococcus were among the genera shared between the two populations and might form the core bacteria associated with N. lugens. The taxonomic-tophenotypic mapping revealed the presence of ammonia oxidizers, nitrogen fixers, sulfur oxidizers and reducers, xylan degraders, and aromatic hydrocarbon degraders in the metagenome of N. lugens. Interestingly, the IR population was found to be enriched with bacteria involved in detoxification functions. The results obtained in this study provide a basis for future studies elucidating the roles of the gut bacteria in the insecticide resistance-associated symbiotic relationship and on the design of novel strategies for the management of N. lugens.
R. Palanisamy,V. Shanmugasundaram,S. Vidyasagar,V. Kalyanasundaram,K. Vijayakumar 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.6
A Space Vector Pulse Width Modulation (SVPWM) control strategy is implemented for capacitor voltage balancing of Flying Capacitor (FC) based 4-level Neutral Point Clamped (NPC) inverter. This fl ying capacitor based 4-level NPC inverter is developed for medium voltage and high power applications. This system includes 6 power switching devices, 2 clamping diodes and 2 fl ying capacitors per leg. The fl ying capacitors ensure to operate inverter normally and all the switching devices share the voltage stresses in identical manner. Also it controls the voltage across each capacitor and maintained at V dc /3 times of applied dc voltage. The proposed SVPWM method takes advantage of utilizing redundancy switching states to control and balance the voltage across the capacitor using nearest switching state vector selection method. Moreover, this system provides reduced total harmonic distortion (THD), and minimized voltage stress. The control technique is implemented without using any look-up tables or eff ective logic tables or trigonometric functions. The simulation and experimental results of this proposed verifi ed are verifi ed using Matlab-simulink and FPGA controller respectively.
GLOBAL EXISTENCE FOR VOLTERRA-FREDHOLM TYPE FUNCTIONAL IMPULSIVE INTEGRODIFFERENTIAL EQUATIONS
V. VIJAYAKUMAR,K. ALAGIRI PRAKASH,R. MURUGESU 한국산업응용수학회 2013 Journal of the Korean Society for Industrial and A Vol.17 No.1
In this paper, we study the global existence of solutions for the initial value problems for Volterra-Fredholm type functional impulsive integrodifferential equations. Using the Leray-Schauder Alternative, we derive conditions under which a solution exists globally.
Palanisamy R.,Karthikeyan D.,Vidyasagar S.,Kalyanasundaram V.,Selvakumar K.,Vijayakumar K.,Selvabharathi D. 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4
In this paper, three phase four wire fi ve level Neutral Point Clamped Inverter (NPCI) based Static synchronous Compensator (STATCOM) is implemented for reactive power control and neutral current elimination. Three dimensional Space Vector Pulse Width Modulation (3D-SVPWM) control strategy is developed to control this 5-level NPC inverter. The behaviour of static synchronous compensator is analyzed and reactive power control is done using constant DC voltage. The objective of this compensating method is to provide balanced and sinusoidal source currents under unbalanced and nonlinear load conditions and reactive power control. The 3D-SVPWM technique provides reduced harmonic content in output voltage and current, controlled source current, minimized common mode voltage and improved output voltage. In 3D-SVPWM, switching pulses are generated with non-redundant switching states, which lead to reduce the complexity in switching time calculation and computational time is less. The highlights of the paper includes the neutral current is reduced to 0.25A, source current harmonics is minimized and it provides balanced and sinusoidal source currents with help of STATCOM compensation. The simulation and experimental results demonstrates the sinusoidal and harmonics free source current and minimized neutral current for four wire fi ve level NPCI based STATCOM.
Palanisamy, R.,Vijayakumar, K. The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.1
This paper elucidates a hysteresis current controller for enhancing the performance of static synchronous compensator (STATCOM) using cascaded H-bridge multilevel inverter. Due to the rising power demand and growing conventional generation costs a new alternative in renewable energy source is gaining popularity and recognition. A five level single phase cascaded multilevel inverter with two separated dc sources, which is energized by photovoltaic - wind hybrid energy source. The voltages across the each dc source is balanced and standardized by the proposed hysteresis current controller. The performance of STATCOM is analyzed by connecting with grid connected system, under the steady state & dynamic state. To reduce the Total Harmonic Distortion (THD) and to improve the output voltage, closed loop hysteresis current control is achieved using PLL and PI controller. The performance of the proposed system is scrutinized through various simulation results using matlab/simulink and hardware results are also verified with simulation results.
Diagnosis of Non-invasive Glucose Monitoring by Integrating IoT and Machine Learning
V. K. R. Rajeswari Satuluri,Vijayakumar Ponnusamy 대한전자공학회 2022 IEIE Transactions on Smart Processing & Computing Vol.11 No.6
Diabetes Mellitus (DM) is a term collectively used for all types of diabetes. DM increases the risk factor for health complications if not treated early. The Internet of Things (IoT) and artificial intelligence (AI) in healthcare have become a huge benefit for managing DM. The selfsupervision of healthcare has become convenient because of IoT-enabled devices. This paper reviews the management of diabetes, such as invasive, non-invasive, and minimally invasive methods. Justification for the need for non-invasive monitoring of glucose is discussed. Different AI and IoT-enabled management for non-invasive diabetes are also briefed. This review aims at the type of machine learning algorithms applied to non-invasive glucose monitoring. The following are to be considered to achieve an effective non-invasive method of monitoring glucose: Near Infrared spectroscopy (NIR) and Machine learning algorithms(ML). IoT in glucose monitoring has empowered doctors and caretakers to deliver outstanding care. Self-care by every person has become essential, which can be achieved by handheld or wearable IoT devices. Using current technologies, the possibility of making a wearable to monitor the glucose level is becoming closer to reality and has enormous potential.
S. Sahana,G. R. Vijayakumar,R. Sivakumar,D. Sriram,D. V. Saiprasad 대한화학회 2022 대한화학회지 Vol.66 No.3
A simple, efficient, and cost-effective method has been employed for the synthesis of 2,4,5-trisubstituted imidazole derivatives (3a-j) containing quinoline substituent at 2nd position. Title compounds were obtained by multicomponent reaction (MCR), involving aryl substituted 1,2-diketone, quinoline carbaldehyde and ammonium acetate in the presence of acetic acid solvent under mild reaction conditions. The newly synthesized quinoline containing imidazole derivatives were confirmed through FT-IR, 1H-NMR, 13C-NMR and mass spectral analysis. In-vitro microplate alamar blue assay (MABA) to determine the MIC (minimum inhibitory concentration) values against Mycobacterium tuberculosis H37Rv was performed for the synthesized compounds. The synthesized compounds exhibited activity against Mycobacterium tuberculosis and among which compounds, 3d, 3f and 3i showed good activity. The highest activity was showed with compound 3i. The anti-mycobacterial activity results are well correlated with the computational molecular docking analysis, which was performed for the synthesized compounds prior to the evaluation of the activity.