인도의 원자력 개발 현황과 전망

Chidambaram R. 한국원자력산업회의 1998 원자력산업 Vol.18 No.4

Theoretical and Computational Analysis of LNG Evaporator

Palani Kumar Chidambaram,Seok Woo Son,Heuy Dong Kim(김희동),Dong Wook Kim(김동욱),Yang Myung Jo(조양명) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

Theoretical and numerical predictions on fluid flow and heat transfer in a typical LNG evaporator is performed. Methane is used in lieu of LNG as it constitutes over 80% of LNG. The theoretical predictions are performed by simple energy balance between the steam and methane. This is augmented by the mass transfer between the liquid phase methane and gas phase methane. The theoretical predictions are made to calculate the pressure drop and temperature drop in the steam tubes. Numerical simulations are carried out by solving the governing equations of multiphase flow in a portion of the evaporator domain with a single layer of steam pipe. The basic flow equations of continuity, momentum and energy equations form the governing equations along with equations of species transport. Multiphase modelling is incorporated using VOF method. Liquid methane is taken as primary phase. It vaporizes into gaseous methane which is taken to be secondary phase. Steam is taken as another secondary phase which flows through the heating coils. Closure for turbulence is modelled by a two equation turbulence model. Both the analytical and numerical predictions match well with each other. Further parametric studies are planned based on the current research.

Impact of type 2 diabetes variants identified through genome-wide association studies in early-onset type 2 diabetes from South Indian population

Liju, Samuel,Chidambaram, Manickam,Mohan, Viswanathan,Radha, Venkatesan Korea Genome Organization 2020 Genomics & informatics Vol.18 No.3

The prevalence of early-onset type 2 diabetes (EOT2D) is increasing in Asian countries. Genome-wide association studies performed in European and various other populations have identified associations of numerous variants with type 2 diabetes in adults. However, the genetic component of EOT2D which is still unexplored could have similarities with late-onset type 2 diabetes. Here in the present study we aim to identify the association of variants with EOT2D in South Indian population. Twenty-five variants from 18 gene loci were genotyped in 1,188 EOT2D and 1,183 normal glucose tolerant subjects using the MassARRAY technology. We confirm the association of the HHEX variant rs1111875 with EOT2D in this South Indian population and also the association of CDKN2A/2B (rs7020996) and TCF7L2 (rs4506565) with EOT2D. Logistic regression analyses of the TCF7L2 variant rs4506565(A/T), showed that the heterozygous and homozygous carriers for allele 'T' have odds ratios of 1.47 (95% confidence interval [CI], 1.17 to 1.83; p = 0.001) and 1.65 (95% CI, 1.18 to 2.28; p = 0.006) respectively, relative to AA homozygote. For the HHEX variant rs1111875 (T/C), heterozygous and homozygous carriers for allele 'C' have odds ratios of 1.13 (95% CI, 0.91 to 1.42; p = 0.27) and 1.58 (95% CI, 1.17 to 2.12; p = 0.003) respectively, relative to the TT homozygote. For CDKN2A/2B variant rs7020996, the heterozygous and homozygous carriers of allele 'C' were protective with odds ratios of 0.65 (95% CI, 0.51 to 0.83; p = 0.0004) and 0.62 (95% CI, 0.27 to 1.39; p = 0.24) respectively, relative to TT homozygote. This is the first study to report on the association of HHEX variant rs1111875 with EOT2D in this population.

Antioxidant Activity of Talinum portulacifolium (Forssk) Leaf Extracts

Rao, Thalapaneni Nageswara,Kumarappan, Chidambaram,Lakshmi, Sabapathi Mohana,Mandal, Subhash C Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.4

The aim of the study is to investigate the antioxidant activity through, reducing power, 2, 2-diphenyl-1-picryl hydrazyl radical (DPPH), nitric oxide radical (NO), superoxide radical, hydrogen peroxide radical ($H_2O_2$) scavenging activity and the amount of total phenolic compounds of chloroform, ethyl acetate, methanol and aqueous extracts of the leaves of Talinum portulacifolium. Chloroform extract of leaves of T. portulacifolium showed highest antioxidant activity, with a direct relationship between activity and concentration of extracts ($15-240\;{\mu}g/mL$). Among all the extracts, the highest amount of the total polyphenolic compounds was found in the chloroform extract. Chloroform extract of T. portulacifolium showed an important free radical scavenging activity towards the DPPH, NO, Superoxide and $H_2O_2$ radicals, with $IC_{50}$ values of 133.26, 165.75, 156.34 and $135.29\;{\mu}g/mL$, respectively. In the lipid peroxidation assay, extracts of chloroform and ethyl acetate showed a remarkable inhibitory activity. The extracts showed significant activity in all the experiments but lower than the standard antioxidant, ascorbic acid.

α-Glucosidase and α-Amylase Inhibitory Activity of Senna surattensis

Ellappan Thilagam,Balasubramaian Parimaladevi,Chidambaram Kumarappan,Subhash Chandra Mandal 사단법인약침학회 2013 Journal of Acupuncture & Meridian Studies Vol.6 No.1

In this study, we investigated the inhibitory effects of ethanolic extract of the leaves of Senna surattensis (EESS) on α-glucosidase and α-amylase. We also studied the in vitro antidiabetic activity of S. surattensis using the glucose uptake by isolated rat hemidiaphragm model. In vitro studies using mammalian α-glucosidase extracted from the small intestine homogenate of mouse showed that the extract was found to be more effective in inhibiting the activities of maltase [half maximal inhibitory concentration (IC50): 209.15 μg/mL] and sucrase (IC50: 366.44 μg/mL) when compared with the control group (acarbose). The extract of S. surattensis were further quantified with respect to porcine pancreatic α-amylase inhibition using the chromogenic 3,5-dinitrosalicylic acid method. Interestingly, S. surattensis was also found to exhibit α-amylase (IC50: 123.95 μg/mL) inhibitory activity. The glucose uptake in the rat hemidiaphragm was significantly (p < 0.01) increased by EESS (220.95 ± 5.4 mg/g/30 minute) when compared with the control group. The total polyphenolic content of EESS was found to be 98 μg pyrocatechol/mg of the extract. These results suggest that EESS inhibited carbohydrate digestive enzymes and increased the peripheral uptake of glucose. This study endorses the use of this plant for further studies to determine their potential for managing type II diabetes.

Thermo-fluid dynamic analysis of wet compression process

Abhay Mohan,Palani Kumar Chidambaram,Abhilash Suryan,Heuy Dong Kim 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.12

Wet compression systems increase the useful power output of a gas turbine by reducing the compressor work through the reduction of air temperature inside the compressor. The actual wet compression process differs from the conventional single phase compression process due to the presence of latent heat component being absorbed by the evaporating water droplets. Thus the wet compression process cannot be assumed isentropic. In the current investigation, the gas-liquid two phase has been modeled as air containing dispersed water droplets inside a simple cylinder-piston system. The piston moves in the axial direction inside the cylinder to achieve wet compression. Effects on the thermodynamic properties such as temperature, pressure and relative humidity are investigated in detail for different parameters such as compression speeds and overspray. An analytical model is derived and the requisite thermodynamic curves are generated. The deviations of generated thermodynamic curves from the dry isentropic curves (PV γ = constant) are analyzed.

Antioxidant Activity of Talinum portulacifolium (Forssk) Leaf Extracts

Thalapaneni Nageswara Rao,Chidambaram Kumarappan,Sabapathi Mohana Lakshmi,Subhash C Mandal 경희대학교 융합한의과학연구소 2008 Oriental Pharmacy and Experimental Medicine Vol.8 No.4

The aim of the study is to investigate the antioxidant activity through, reducing power, 2, 2- diphenyl-1-picryl hydrazyl radical (DPPH), nitric oxide radical (NO), superoxide radical, hydrogen peroxide radical (H2O2) scavenging activity and the amount of total phenolic compounds of chloroform, ethyl acetate, methanol and aqueous extracts of the leaves of Talinum portulacifolium. Chloroform extract of leaves of T. portulacifolium showed highest antioxidant activity, with a direct relationship between activity and concentration of extracts (15 - 240 μg/mL). Among all the extracts, the highest amount of the total polyphenolic compounds was found in the chloroform extract. Chloroform extract of T. portulacifolium showed an important free radical scavenging activity towards the DPPH, NO, Superoxide and H2O2 radicals, with IC50 values of 133.26, 165.75, 156.34 and 135.29 μg/mL, respectively. In the lipid peroxidation assay, extracts of chloroform and ethyl acetate showed a remarkable inhibitory activity. The extracts showed significant activity in all the experiments but lower than the standard antioxidant, ascorbic acid. The aim of the study is to investigate the antioxidant activity through, reducing power, 2, 2- diphenyl-1-picryl hydrazyl radical (DPPH), nitric oxide radical (NO), superoxide radical, hydrogen peroxide radical (H2O2) scavenging activity and the amount of total phenolic compounds of chloroform, ethyl acetate, methanol and aqueous extracts of the leaves of Talinum portulacifolium. Chloroform extract of leaves of T. portulacifolium showed highest antioxidant activity, with a direct relationship between activity and concentration of extracts (15 - 240 μg/mL). Among all the extracts, the highest amount of the total polyphenolic compounds was found in the chloroform extract. Chloroform extract of T. portulacifolium showed an important free radical scavenging activity towards the DPPH, NO, Superoxide and H2O2 radicals, with IC50 values of 133.26, 165.75, 156.34 and 135.29 μg/mL, respectively. In the lipid peroxidation assay, extracts of chloroform and ethyl acetate showed a remarkable inhibitory activity. The extracts showed significant activity in all the experiments but lower than the standard antioxidant, ascorbic acid.

Behavior of FRP strengthened RC brick in-filled frames subjected to cyclic loading

Balvir Singh,R. Siva Chidambaram,Shruti Sharma,Naveen Kwatra 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.5

Fiber reinforced polymer (FRP) sheets are the most efficient structural materials in terms of strength to weight ratio and its application in strengthening and retrofitting of a structure or structural elements are inevitable. The performance enhancement of structural elements without increasing the cross sectional area and flexible nature are the major advantages of FRP in retrofitting/strengthening work. This research article presents a detailed study on the inelastic response of conventional and retrofitted Reinforced Concrete (RC) frames using Carbon Fibre Reinforced Polymers (CFRP) and Glass Fiber Reinforced Polymers (GFRP) subjected to quasi-static loading. The hysteretic behaviour, stiffness degradation, energy dissipation and damage index are the parameters employed to analyse the efficacy of FRP strengthening of brick in-filled RC frames. Repair and retrofitting of brick infilled RC frame shows an improved load carrying and damage tolerance capacity than control frame.

Ancillary Service Requirement Assessment Indices for the Load Frequency Control in a Restructured Power System with Redox Flow Batteries

Chandrasekar, K.,Paramasivam, B.,Chidambaram, I.A. The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

This paper proposes various design procedures for computing Power System Ancillary Service Requirement Assessment Indices (PSASRAI) for a Two-Area Thermal Reheat Interconnected Power System (TATRIPS) in a restructured environment. In an interconnected power system, a sudden load perturbation in any area causes the deviation of frequencies of all the areas and also in the tie-line powers. This has to be corrected to ensure the generation and distribution of electric power companies to ensure good quality. A simple Proportional and Integral (PI) controllers have wide usages in controlling the Load Frequency Control (LFC) problems. So the design of the PI controller gains for the restructured power system are obtained using Bacterial Foraging Optimization (BFO) algorithm. From the simulation results, the PSASRAI are calculated based on the settling time and peak over shoot concept of control input deviations of each area for different possible transactions. These Indices are useful for system operator to prepare the power system restoration plans. Moreover, the LFC loop coordinated with Redox Flow Batteries (RFB) has greatly improved the dynamic response and it reduces the control input requirements and to ensure improved PSASRAI, thereby improving the system reliability.

A Fundamental Study on Droplet Evaporation in Wet Compression Systems

Abhay Mohan,Palani Kumar Chidambaram,Abhilash Suryan,Heuy Dong Kim(김희동) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

For the current investigation, the gas liquid two-phase media are modeled as air involving fine droplet or droplets of water. A cylinder-piston system is modeled which contains air with single or multiple droplets of water. The compression process is achieved by the movement of the piston. During the compression process, thermodynamic properties such as temperature and pressure are investigated in detail. Analytical equations have been derived to obtain the transformation in fluid properties. The results thus obtained are discussed for different conditions of overspray and initial absolute humidity of the air inside the cylinder. The thermodynamic curves obtained are seen to deviate significantly from the dry isentropic curve ( PVγ=constant) with decreasing droplet diameters and increasing mass of droplets. This deviation can be associated with the latent heat absorbed by the evaporating droplets during the process of compression.