Thermophysical Properties of Acetophenone with Ethylchloroacetate at Temperatures of 303.15, 313.15 and 323.15 K

Saravanakumar, K.,Baskaran, R.,Kubendran, T.R. Korean Chemical Society 2012 대한화학회지 Vol.56 No.4

Densities, viscosities, refractive indices and speed of sounds of the binary mixtures of Acetophenone with Ethylchloroacetate were measured over the entire mole fractions at (303.15, 313.15 and 323.15) K. From these experimental results, excess molar volume $V^E$, viscosity deviation ${\Delta}{\eta}$, refractive index deviation ${\Delta}n_D$, deviations in speed of sound ${\Delta}u$, deviations in isentropic compressibility ${\Delta}k_s$ and excess intermolecular free length ${\Delta}L_f$ were calculated. The viscosity data have been correlated with the equations of Grunberg and Nissan, Hind et al., Tamura and Kurata, Katti and Chaudri, Sedgwick, Krishnan-Laddha and McAllister. The thermo physical properties under study were fit to the Jouyban-Acree model. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. It was found that in all cases, the data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution.

3D Numerical investigation of a rounded corner square cylinder for supercritical flows

Nivedan Vishwanath,Aditya K. Saravanakumar,Kush Dwivedi,Kalluri R.C. Murthy,Pardha S. Gurugubelli,Sabareesh G. Rajasekharan 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.35 No.1

Tall buildings are often subjected to steady and unsteady forces due to external wind flows. Measurement and mitigation of these forces becomes critical to structural design in engineering applications. Over the last few decades, many approaches such as modification of the external geometry of structures have been investigated to mitigate wind-induced load. One such proven geometric modification involved the rounding of sharp corners. In this work, we systematically analyze the impact of rounded corner radii on the reducing the flow-induced loading on a square cylinder. We perform 3-Dimensional (3D) simulations for high Reynolds number flows (Re=1 × 105) which are more likely to be encountered in practical applications. An Improved Delayed Detached Eddy Simulation (IDDES) method capable of capturing flow accurately at large Reynolds numbers is employed in this study. The IDDES formulation uses a k-ω Shear Stress Transport (SST) model for near-wall modelling that prevents mesh-induced separation of the boundary layer. The effects of these corner modifications are analyzed in terms of the resulting variations in the mean and fluctuating components of the aerodynamic forces compared to a square cylinder with no geometric changes. Plots of the angular distribution of the mean and fluctuating coefficient of pressure along the square cylinder’s surface illustrate the effects of corner modifications on the different parts of the cylinder. The windward corner’s separation angle was observed to decrease with an increase in radius, resulting in a narrower and longer recirculation region. Furthermore, with an increase in radius, a reduction in the fluctuating lift, mean drag, and fluctuating drag coefficients has been observed.

THE INFLUENCE OF SUBSTRATE TEMPERATURE ON THE ELECTRICAL PROPERTIES OF ZnO FILMS PREPARED BY THE RF MAGNETRON SPUTTERING TECHNIQUE

K. SARAVANAKUMAR,V. SENTHILKUMAR,C. SANJEEVIRAJA,M. JAYACHANDRAN,V. GANESAN,RAUSHAN B. KOIZHAIGANOVA,T. VASUDEVAN,MU SANG LEE 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2008 NANO Vol.3 No.6

ZnO thin films were grown by the RF magnetron sputtering technique at different substrate temperatures, from RT to 300°C. The crystallite size was calculated from XRD and the grain size was measured from AFM for different substrate temperatures. The influence of the substrate temperature on the electrical properties of the films was investigated through the Hall effect, and conductivity studies were performed under UV light illumination. The conductivity and the carrier mobility of the films were found to increase with increasing substrate temperature, which can be due to the grain-boundary-dominated conduction mechanism. The thermal activation energy and photosensitivity of the films were calculated, and the results are presented in this paper.

Development and testing of nano particulate lubricant for worm gear application

N. Saravanakumar,M. L. Jothi Saravanan,K. E. Barathkumar,K. Gokula Kannan,R. Karthikeyan 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

Bio-degradable lubricants are an attractive alternative for the mineral based and synthetic based lubricants. Bio-degradable lubricants are environmental-friendly and non-toxic. The present study deals with the tribological investigation of bio-degradable nano lubricants for worm gear applications. Nano additives like CuO and TiO 2 were used. Bio-degradable oils like palm oil and sunflower oil were used as base oils. The nano lubricants were prepared by adding two nano additives and two bio-degradable oils each of 0.1 % and 0.2 % weight composition. Friction and wear characteristics were tested on pin-on-disc tribometer under varying load conditions. Extreme pressure tests for nano lubricants were carried out using four ball tester. The wear surface obtained was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy. From the tests conducted, it was found that the addition of nano additives in biodegradable oils reduced the friction co-efficient and wear rate to a considerable extent.

Application of QUASAR Modelling in the Uppanar River of Cuddalore District of Tamil Nadu, India

P. Mullai,M. K. Yogeswari,Bibin Oommen,K. Saravanakumar,K. Kathiresan 대한환경공학회 2012 Environmental Engineering Research Vol.17 No.-

Quality simulation along river system (QUASAR) is a water quality and flow model for river networks. This paper presents the study on the determination of the physicochemical parameters of the water sample in the Uppanar River, Cuddalore district of Tamil Nadu, India at 3 different points from November 2009 to July 2010 and application of QUASAR software modeling. From the analysis of various physicochemical parameters that exceeded the permissible limits of the Indian Council for Medical and Research, the river was said to be moderately polluted. In this paper, the measured data of dissolved oxygen (DO), biological oxygen demand (BOD) and pH along the three sampling stations was used for QUASAR modelling. The average percentage error values obtained for station I, II, and III regarding DO were 3.49%, 2.38%, and 2.26%, for BOD 1.2%, 5.9%, and 1.98%, and for pH 2.57%, 2.41%, and 1.51%, respectively. It was observed that there is a one to one correlation among the simulated and observed values for DO, BOD, and pH values. From these results, it is concluded that the QUASAR model can reliably be used as a simulation model for analyzing the water quality parameters in the river.

A polymeric conjugate foreignizing tumor cells for targeted immunotherapy in vivo

Lee, Y.H.,Yoon, H.Y.,Shin, J.M.,Saravanakumar, G.,Noh, K.H.,Song, K.H.,Jeon, J.H.,Kim, D.W.,Lee, K.M.,Kim, K.,Kwon, I.C.,Park, J.H.,Kim, T.W. Elsevier Science Publishers 2015 Journal of controlled release Vol.199 No.-

Antigen-specific CD8<SUP>+</SUP> cytotoxic T lymphocytes (CTLs) are key elements of immunological rejection in transplantation as well as cancer immunotherapy. Most tumors, however, are not immunologically rejected because they have self antigens, which are not recognized as the foreigner by CTLs. In this study, we hypothesized that ''foreignizing'' tumor cells by delivering non-self foreign antigens into the tumors would result in rejection by foreign antigen-reactive CTLs. As the model system to foreignize the tumors, we prepared a polymeric conjugate consisting of hyaluronic acid as the CD44<SUP>+</SUP> tumor-targeting ligand and ovalbumin (OVA) as a foreign antigen. When the conjugate was treated with CD44<SUP>high</SUP> TC-1 tumor cells, it was effectively taken up and allowed for displaying of antigenic OVA<SUB>257-264</SUB> peptide at MHC class I on the surface of the cells. In addition, the conjugate was effectively accumulated into tumor tissue after its systemic administration to mice which are immunized with a vaccine for a vaccinia virus expressing OVA to generate OVA<SUB>257-264</SUB> specific CTLs, resulting in substantial inhibition of tumor growth. Overall, these results suggest that the polymeric conjugates bearing foreign antigens may be innovative and promising cancer immunotherapeutic agents by foreignizing tumor cells, leading to immunological rejection.

Identification of Diapause and Non-diapause Associated Proteins in the Eggs of Multivoltine Silkworm Bombyx mori by MALDI MS Analysis

Saravanakumar, Ragunathan,Ponnuvel, Kangayam M.,Velu, Dhanikachalam,Koundinya, Panguluri R.,Sinha, Randir K.,Qadri, Syed M. Hussaini Korean Society of Sericultural Science 2008 International Journal of Industrial Entomology Vol.16 No.2

The diapause and non diapause associated proteins of multivoltine silkworm eggs were analysed by two dimensional (2D) gel electrophoresis. The study was made at 0 hr, 24 hrs and 48 hrs after oviposition. A total of four protein spots in diapause eggs at 24 hrs of oviposition and two protein spots in non diapause eggs at 0 hrs of oviposition were observed. All the six protein spots were considered to have association with diapause and non diapause characters. The molecular weight (MW) and isoelectric point (PI) of these 6 protein spots were calculated. The protein spots 1 and 2 observed in 0 hr of non diapause eggs were found to have the MW of 67 and 75 KDa and PI of 8.6 and 8.4 respectively. Similarly the four protein spots observed in diapause egg at 24 hrs of oviposition exhibited MW viz., 15, 17,20 and 25 KDa and PI of 5.3, 5.8, 6.5 and 6.0 respectively. All these 6 identified protein spots were subjected to in-gel digestion and resulted tryptic peptides were analyzed by Matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI TOF-MS). Databases searched based on experimentally determined molecular weights of peptides for the determination of the identities of proteins. The identified proteins indicated homology of 34% to 95%. The results indicate that the proteins may playa role in development of diapause and non diapause eggs.

Research Articles : Identification of Diapause and Non-diapause Associated Proteins in the Eggs of Multivoltine Silkworm Bombyx mori by MALDI MS Analysis

( Ragunathan Saravanakumar ),( Kangayam M. Ponnuvel ),( Dhanikachalam Velu ),( Panguluri R. Koundinya ),( Randir K. Sinha ),( Syed M. Hussaini Qadri ) 한국잠사학회 2008 International Journal of Industrial Entomology Vol.16 No.2

The diapause and non diapause associated proteins of multivoltine silkworm eggs were analysed by two dimensional (2D) gel electrophoresis. The study was made at 0 hr, 24 hrs and 48 hrs after oviposition. A total of four protein spots in diapause eggs at 24 hrs of oviposition and two protein spots in non diapause eggs at 0 hrs of oviposition were observed. All the six protein spots were considered to have association with diapause and non diapause characters. The molecular weight (MW) and isoelectric point (PI) of these 6 protein spots were calculated. The protein spots 1 and 2 observed in 0 hr of non diapause eggs were found to have the MW of 67 and 75 KDa and PI of 8.6 and 8.4 respectively. Similarly the four protein spots observed in diapause egg at 24 hrs of oviposition exhibited MW viz., 15, 17, 20 and 25 KDa and PI of 5.3, 5.8, 6.5 and 6.0 respectively. All these 6 identified protein spots were subjected to in-gel digestion and resulted tryptic peptides were analyzed by Matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI TOF-MS). Databases searched based on experimentally determined molecular weights of peptides for the determination of the identities of proteins. The identified proteins indicated homology of 34% to 95%. The results indicate that the proteins may play a role in development of diapause and non diapause eggs.

Plasma-induced photoresponse in few-layer graphene

Thiyagarajan, K.,Ananth, A.,Saravanakumar, B.,Mok, Y.S.,Kim, S.J. Pergamon Press ; Elsevier Science Ltd 2014 Carbon Vol.73 No.-

A device consisting of a few layers of graphene (FLG) sheets was exposed to atmospheric plasma, resulting in the generation of significant number of defects, oxygen absorption, and doping. The plasma-induced electrical transformation and photoconducting properties of pristine FLG and plasma-irradiated FLG (p-FLG) were compared under visible and ultraviolet (UV) light illumination. The visible light photoresponsivity of p-FLG was 0.47AW<SUP>-1</SUP> at 535nm, comparatively higher than that observed for pristine FLG (10mAW<SUP>-1</SUP>); this result was attributed to the formation of defect midgap states band by plasma irradiation. Photoinduced molecular desorption causes the responsivity of the higher energy (UV) photons. Our results suggest that plasma irradiation is a simple, novel way to tailor the optoelectronic properties of graphene layers.

Finite-time resilient reliable sampled-data control for fuzzy systems with randomly occurring uncertainties

Sakthivel, R.,Saravanakumar, T.,Ma, Y.K.,Marshal Anthoni, S. North-Holland 2017 Fuzzy sets and systems Vol.329 No.-

<P>This paper deals with the problem of finite-time passivity-based H-infinity resilient reliable state feedback sampled-data control for Takagi-Sugeno fuzzy systems with randomly occurring uncertainties and gain variations, where the randomly occurring characteristics are designed by stochastic variables satisfying the Bernoulli distribution. The main objective of this paper is to design a resilient reliable sampled-data controller such that the resulting closed-loop system is finite-time bounded and satisfies finite-time mixed H-infinity and passive performance index gamma. Based on the constructed Lyapunov-Krasovskii functional and Wirtinger integral inequality, some delay-dependent sufficient conditions are derived for achieving the required result of the considered systems. Moreover the derived finite-time stability conditions are established in the form of linear matrix inequalities (LMIs) which can be solved by Matlab LMI toolbox. Finally two numerical examples are presented to demonstrate the applicability of the proposed control design technique. (C) 2017 Elsevier B.V. All rights reserved.</P>