Real Gas Effects of Supercritical CO₂ Flow through a Supersonic Nozzle Senthil kumar Raman and Heuy Dong Kim

Senthil kumar Raman,Heuy Dong Kim 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

The unique characteristics of supercritical carbon dioxide (SCO₂) are reason enough to find its use in various engineering applications. But still usability of SCO₂ is not completely explored due to lack of knowledge about its real gas effects. The present study mainly addresses the real gas effects on supercritical CO₂ flow through a supersonic convergent-divergent nozzle. With series of theoretical equations which are based on one-dimensional gas dynamics theory, computer program has been developed to predict the compressible flow characteristics of supercritical CO₂. With the data obtained from the computer program, properties of supercritical CO₂ near critical point is theoretically analyzed with different EOS. Computational analysis also has been carried out to reasonably predict the SCO₂ flows. The deviation in prediction of properties of SCO₂ by a EOS from other one is addressed. Several types of the equations of state were applied to the compressible Navier-Stokes equations. For effective use of available EOS, an attempt is made by coupling ideal gas EOS and real gas EOS to analyze the real gas effect of SCO₂. These results are compared with the computational results of SCO₂ flow through convergent divergent nozzle with a single real gas EOS. The obtained solutions were used to investigate the generic features of supercritical CO₂ flow, in terms of shock wave location, flow choking, total pressure loss, pressure recovery, etc.

A Simple Method for Solving Type-2 and Type-4 Fuzzy Transportation Problems

Senthil Kumar, P. Korean Institute of Intelligent Systems 2016 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.16 No.4

In conventional transportation problem (TP), all the parameters are always certain. But, many of the real life situations in industry or organization, the parameters (supply, demand and cost) of the TP are not precise which are imprecise in nature in different factors like the market condition, variations in rates of diesel, traffic jams, weather in hilly areas, capacity of men and machine, long power cut, labourer's over time work, unexpected failures in machine, seasonal changes and many more. To counter these problems, depending on the nature of the parameters, the TP is classified into two categories namely type-2 and type-4 fuzzy transportation problems (FTPs) under uncertain environment and formulates the problem and utilizes the trapezoidal fuzzy number (TrFN) to solve the TP. The existing ranking procedure of Liou and Wang (1992) is used to transform the type-2 and type-4 FTPs into a crisp one so that the conventional method may be applied to solve the TP. Moreover, the solution procedure differs from TP to type-2 and type-4 FTPs in allocation step only. Therefore a simple and efficient method denoted by PSK (P. Senthil Kumar) method is proposed to obtain an optimal solution in terms of TrFNs. From this fuzzy solution, the decision maker (DM) can decide the level of acceptance for the transportation cost or profit. Thus, the major applications of fuzzy set theory are widely used in areas such as inventory control, communication network, aggregate planning, employment scheduling, and personnel assignment and so on.

A Simple Method for Solving Type-2 and Type-4 Fuzzy Transportation Problems

P. Senthil Kumar 한국지능시스템학회 2016 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.16 No.4

In conventional transportation problem (TP), all the parameters are always certain. But, many of the real life situations in industry or organization, the parameters (supply, demand and cost) of the TP are not precise which are imprecise in nature in different factors like the market condition, variations in rates of diesel, traffic jams, weather in hilly areas, capacity of men and machine, long power cut, labourer’s over time work, unexpected failures in machine, seasonal changes and many more. To counter these problems, depending on the nature of the parameters, the TP is classified into two categories namely type-2 and type-4 fuzzy transportation problems (FTPs) under uncertain environment and formulates the problem and utilizes the trapezoidal fuzzy number (TrFN) to solve the TP. The existing ranking procedure of Liou and Wang (1992) is used to transform the type-2 and type-4 FTPs into a crisp one so that the conventional method may be applied to solve the TP. Moreover, the solution procedure differs from TP to type-2 and type-4 FTPs in allocation step only. Therefore a simple and efficient method denoted by PSK (P. Senthil Kumar) method is proposed to obtain an optimal solution in terms of TrFNs. From this fuzzy solution, the decision maker (DM) can decide the level of acceptance for the transportation cost or profit. Thus, the major applications of fuzzy set theory are widely used in areas such as inventory control, communication network, aggregate planning, employment scheduling, and personnel assignment and so on.

De novo assembly and transcriptome analysis of bulb onion (Allium cepa) during cold acclimation using contrasting genotypes

Senthil Kumar Thamilarasan,Jeong Suk Hyeon Han,Jong-In Park,Ill-sup Nou 한국육종학회 2015 한국육종학회 심포지엄 Vol.2015 No.07

Bulb onion (Allium cepa) is one of the second most widely cultivated and consumed vegetable crops in the world. During winter where the temperature can be as low, plant could get cold injury and limit the production of bulb onion. However, the genomic resources available for bulb onion are still very limited. To date, no studies about heritably durable cold and freezing tolerance were carried out in bulb onion genotypes using high-throughput sequencing technology was applied. We sequenced cold (2°C) freezing (-5 and -15°C) treated and control (25°C) samples of contrasting genotypes of A. cepa lines and obtained 4,52,194,370 total high quality reads. After de novo assembly reads were assembled into 54,047 genes finally generated with an average length of 1,331 bp. Based on the similarity search aligning all genes with known public non-redundant (NR) database, including Swiss-prot, KEGG and COG. Differentially expressed genes (DEGs) were investigated using FPKM method. Overall, 92,862 genes were differentially regulated in all libraries were identified. Additionally, increase our understanding of the DEGs, we performed GO and KEGG pathway enrichment analyses. Based on FDR<=0.01 value in cold freezing tolerant line candidate genes were selected and discussed. Finally 25 candidate genes were examined using qRT-PCR were differentially regulated and known to be associated with cold and freezing stresses. Moreover, in silico prediction of putative molecular marker 4,437 SSRs and 6,076 SNPs. Our study is the first to provide the transcriptome sequence resource of Allium spp., for cold and freezing stress. We identified large set of genes to determine its DEGs profile under cold and freezing condition using two different genotypes. These data provides a valuable resource of genetic and genomic studies of Allium spp.

Influence of ultrasonication on preparation of novel material for heavy metal removal from wastewater

Senthil Kumar Ponnusamy,Saravanan Anbalagan,Sundar Rajan Panneer Selvam,Abishek Sankaranarayan,Abhishek Dutta 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.9

The present research introduces a new concept on rapid removal of Pb(II) ions from wastewater using novel agro-based material. The two types of materials such as sulfuric acid modified Caryota urens seeds (SMCUS) and ultrasonic assisted Caryota urens seeds (UACUS) were prepared and performance was compared for Pb(II) ions removal. The functional groups available on the C. urens were discussed by using FT-IR report. Adsorption influencing parameters such as initial metal ion concentration, pH, contact time, adsorbent dosage and temperature were studied to predict the optimum conditions. Several isotherm and kinetic models were applied to examine the experimental data. The present adsorption-adsorbate system best obeys the Freundlich and pseudo-first-order models. Langmuir monolayer capacity of the SMCUS and UACUS for Pb(II) ions was found to be 93.7 and 175.9mg/g, respectively. Thermodynamic parameters explain that the adsorption of Pb(II) ions was spontaneous and exothermic.

Genome-wide identification of AP2/ERF transcription factors and profiling of CBFs genes in abiotic stresses in Brassica oleracea

Senthil Kumar Thamilarasan,Jong-In Park,Hee-Jeong Jung,Ill-Sup Nou 한국육종학회 2014 한국육종학회 심포지엄 Vol.2014 No.07

sequence and more than fifty thousand proteins have been obtained to date. Transcription factors (TFs) are important regulators involved in plant development and physiological processes and the AP2/ERF protein family contains TFs that also plays a crucial role as well and response to biotic and abiotic stress conditions in plants. However, no detailed expression profile of AP2/ERF-like genes is available for B. oleracea. In the present study, 226 AP2/ERF TFs were identified from B. oleracea based on the available genome sequence. Based on sequence similarity, the AP2/ERF superfamily was classified into five groups (DREB, ERF, AP2, RAV and Soloist) and 15 subgroups. The identification, classification, phylogenetic construction, conserved motifs, chromosome distribution, functional annotation, expression patterns and interaction network were then predicted and analyzed. AP2/ERF TFs expression levels exhibited differences in response to varying abiotic stresses based on expressed sequence tags (ESTs). BoCBF1a, 1b, 2, 3 and 4, which were highly conserved in Arabidopsis and B. rapa CBF/DREB genes families were well characterized. Expression analysis enabled elucidation of the molecular and genetic level expression patterns of cold tolerance (CT) and susceptible lines (CS) of cabbage and indicated that all BoCBF genes responded to abiotic stresses. Comprehensive analysis of the physiological functions and biological roles of AP2/ERF superfamily genes and BoCBF family genes in B. oleracea is required to elucidate AP2/ERF, which will provide rich resources and opportunities to understand abiotic stress tolerance in crops.

Experimental and Computational Studies on the Reentry Capsule Aerodynamics with a Flap

Senthil Kumar,J K Prasad,Kim H D 한국추진공학회 2016 한국추진공학회 학술대회논문집 Vol.2016 No.5

Flow field around a typical reentry capsule has been investigated adopting experiments and computations. The reentry capsule has the flap which could be useful to obtain control force. All the studies have been made at a free stream Mach number of 2 and Reynolds number of 30 X 106. Experiments consisted of schlieren flow visualization and measurement of axial force only. Three dimensional computation has been made using FLUENT and adopting k-ω turbulence model. Effect of angle of attack and flap angle has been obtained. Based on present study, it is observed the flap increases the axial force.

Characterization and Expression Profiling of the CBF/DREB Genes Family in Brassica oleracea

Senthil Kumar Thamil Arasan,Jong-In Park,Nasar Uddin Ahmed,Hee-Jeong Jung,Ill-Sup Nou 한국원예학회 2013 한국원예학회 학술발표요지 Vol.2013 No.5

Experimental investigation of palm kernel fibre reinforced epoxy based composite

Senthil Kumar KM,Thirumalai Ramanathan,Seenivasan Murugesan,Venugopal Thangamuthu 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.6

The composite specimen consisting of eight layers of palm kernel and coir fibers with different weight proportions wereprepared through hand lay-up technique. The experimental investigation of delamination factor, surface roughness, machiningforce and tool life are carried out in this work. The hand layup technique was used for the processing of the compositematerial, which constitutes the epoxy resin as the matrix material and fibre as the reinforcing material. Also silicon carbidewas added to the composite material in several percentages to increase the strength of the composite material. The specimenwas tested according to the testing standards and the values of surface roughness, delamination factor, machining force andtool life were recorded. ANOVA and Taguchi analysis for all responses were carried out and discussed here.

Computation of stress-deformation of deep beam with openings using finite element method

Senthil, K.,Gupta, A.,Singh, S.P. Techno-Press 2018 Advances in concrete construction Vol.6 No.3

The numerical investigations have been carried out on deep beam with opening subjected to static monotonic loading to demonstrate the accuracy and effectiveness of the finite element based numerical models. The simulations were carried out through finite element program ABAQUS/CAE and the results thus obtained were validated with the experiments available in literature. Six simply supported beams were modelled with two square openings of 200 and 250 mm sides considered as opening at centre, top and bottom of the beam. In order to define the material behaviour of concrete and reinforcing steel bar the Concrete Damaged Plasticity model and Johnson-Cook material parameters available in literature were employed. The numerical results were compared with the experiments in terms of ultimate failure load, displacement and von-Mises stresses. In addition to that, seventeen beams were simulated under static loading for studying the effect of opening location, size and shape of the opening and depth, span and shear span to depth ratio of the deep beam. In general, the numerical results accurately predicted the pattern of deformation and displacement and found in good agreement with the experiments. It was concluded that the structural response of deep beam was primarily dependent on the degree of interruption of the natural load path. An increase in opening size from 200 to 250 mm size resulted in an average shear strength reduction of 35%. The deep beams having circular openings undergo lesser deflection and thus they are preferable than square openings. An increase in depth from 500 mm to 550 mm resulted in 78% reduced deflection.