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ANTIPYRETIC POTENTIAL OF AQUEOUS LEAF EXTRACT OF ANNONA MURICATA.L AND SPERMACOCE ARTICULARIS. L.F.ON YEAST-INDUCED PYREXIA IN RATS
(Innovare Academic Sciences, 2018) Maruvoor Arasi, K; Krishnaveni, C
The objective of this study is to evaluate the potential of in vivo antipyretic activity of the aqueous leaf extracts of Annona muricata L. and Spermacoce articularis. L.f.
ASSESSMENT OF LOW CARBON STEEL CORROSION INHIBITION BY ECO-FRIENDLY GREEN CHAENOMELES SINENSIS EXTRACT IN ACID MEDIUM
(The Korean Electrochemical Society, 2018-07-16) Ill-Min, Chung; Venkatesan, Hemapriya; Kanchana, Ponnusamy; Natarajan, Arunadevi; Subramanian, Chitra; Chi-Hee, Youn; Seung-Hyun, Kim; Mayakrishnan, Prabakaran
The impact of methanol extract of Chaenomeles sinensis (C. sinensis) leaves on acid corrosion of low carbon steel was assessed by gravimetric and electrochemical methods. Phytochemical characterization by total phenolic content (TPC), and total flavonoids content (TFC) of the extract was performed. The TPC and TFC concentrations were identified as 193.50 and 40.55 mg/g. Efficiency increased remarkably in the presence of inhibitor and found as concentration dependent. A maximum inhibition efficiency of 93.19% was achieved using 2000 ppm of the C. sinensis inhibitor. Impedance and surface morphology analysis by SEM and AFM revealed that the anticorrosive activity results from the protective film of phytochemical components of C. sinensis extract adsorbed on the metal surface.
ASSESSMENT OF MACRONUTRIENTS (N, P AND K) OF MONOCULTURE, POLYCULTURE AND TERMITORIA SOILS IN POLLACHI, UDAMALPET TALUKS IN COIMBATORE AND TIRUPUR DISTRICTS, TAMIL NADU, INDIA
(Research Journal of Chemistry and Environment, 2018-04) Kalaichelvi, S; Ezhili, N
The objective of this research was to calculate the variation in pH and macro nutrients (N, P and K) of monoculture and polyculture soils compared with the termitoria soil from Pollachi and Udamalpet in Coimbatore and Tirupur Districts, Tamil Nadu, India during March 2013 to February 2014. The soil pH, N, P and K level are observed and compared in different soil samples. When compared to monoculture and polyculture soil, the termitoria soil pH, N, P and K favour agriculture and retain the plant nutrients. Through this study, we observed that termitoria soil pH and macronutrients are generally more than the monoculture and polyculture soils. Polyculture soil contains more nutrients when compared with monoculture soil. The study showed highly positive correlation between termitoria soil, monoculture and polyculture soils. The result highlights the value of termites and their beneficial role in soil and agriculture.
COMPARATIVE STUDY OF ADSORPTION OF LINEAR ALIPHATIC/AROMATIC POLYESTERS AT METAL/0.5 M H2SO4 INTERFACE
(Elsevier, 2018-10) Nusrath Unnisa, C; Subramanian, Chitra
Two polyesters namely poly (glycerol adipate) (PGA) and 4-(1-(4-methoxyphenyl) cyclohexyl) phenyl 6-oxoheptanoate (MPOHP) were synthesised in a facile manner and characterised using Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic spectroscopy (NMR). The synthesised polyesters were subjected to evaluate the mild steel protecting ability at various concentrations of 10, 50, 100, 500, 1000 ppm in 0.5 M H2SO4 medium. A precise comparison of metal protecting ability rendered by both aliphatic and aromatic moiety was analysed. As an initiation, gravimetric measurements carried out at room temperature resulted with increased inhibition efficiency with increased concentration. Higher temperature studies suggested physisorption mechanism resulting with decreased inhibition efficiency. Experimental results were best fitted with Langmuir adsorption isotherm model. Electrochemical impedance measurements carried out for the selected concentrations of the inhibitors (10, 100, 1000 ppm) revealed increased charge transfer resistance (Rct) with a maximum inhibition efficiency of 54.07% (PGA) and 69.92% (MPOHP) at 1000 ppm indicating the formation of protective barrier. Potentiodynamic polarisation method suggested mixed type of inhibition of both PGA and MPOHP on the metal surface resulting in decreased metal dissolution that could be evidenced from lowered corrosion current density
CONFISCATION OF NITRATE ION FROM AQUEOUS MEDIUM USING A NOXIOUS AQUATIC WEED - A BOON FROM BANE
(Indian Journal of Environmental Protection, 2018-06) Shyamala Devi, N; Revathi, R
Water is an essential natural resource for sustaining life and environment. It is a nature's free gift, but clean and safe drinking water becomes scarce due to rapid industrialization and urbanization. The elevated levels of nitrate (N03∼) in drinking water leads to severe impacts on the environment. Water hyacinth (WH) an aquatic weed grow at a faster rate in polluted waters containing dissolved nitrogen and phosphorous. The present study focused on the removal of nitrate anions from aqueous solution through adsorption technique. The chosen biomaterial is chemically modified using phosphoric acid to enhance its sorption efficiency, thereafter referred as modified water hyacinth (MWH). To characterize the surface functional group and morphology of the adsorbent scanning electron microscopy and FT-IR analyses are recorded. The competence of the sorbent material is experimentally verified through various operating factors likely particle size, adsorbent dosage, agitation time, initial concentrations of nitrate ions, pH of the medium, an effect of co-ions and influence of temperatures on nitrate-modified water hyacinth system through batch mode. The residual concentrations of nitrate ions from aqueous solutions are analysed using the UV-visible spectrophotometer. Langmuir and Freundlich's models are applied to describe the adsorption capacity. Isotherm plots reveal the mono linearity of both the isotherms onto nitrate-modified water hyacinth system.
CORROSION RESISTANCE OF MILD STEEL IN SULPHURIC ACID SOLUTION BY COREOPSIS TINCTORIA EXTRACT: ELECTROCHEMICAL AND SURFACE STUDIES
(2018-07-24) Kathirvel, Kalaiselvi; Ill-Min, Chung; Seung-Hyun, Kim; Mayakrishnan, Prabakaran
The purpose of this paper is to investigate the inhibitive performance of Coreopsis tinctoria (C. tinctoria) plant extract for the corrosion of mild steel in 0.5 M H2SO4.
DEVELOPMENT OF POLY(GLYCEROL SUBERATE) POLYESTER (PGS)–PVA BLEND POLYMER ELECTROLYTES WITH NH4SCN AND ITS APPLICATION
(Springer Link, 2018-02-28) Nusrath Unnisa, C; Chitra, S; Selvasekarapandian, S; Monisha, S; Nirmala Devi, G; Moniha, V; Hema, M
Besides commercially available synthetic polymers, the present work has been undertaken to explore the significance of poly(glycerol suberate) (PGS) polyester synthesised under lab scale in energy storage device. In this regard, a blend polymer electrolyte comprising of polyvinyl alcohol (PVA), poly(glycerol suberate) (PGS) polyester along with the various proportions of ammonium thiocyanate (NH4SCN) was prepared adopting solution casting technique. The synthesised polyester PGS was characterised by Fourier transform infrared (FT-IR) spectroscopy, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The prepared electrolyte film was subjected to FT-IR analysis to study the complexation that has occurred within the blend. Its amorphous nature was revealed from X-ray diffraction (XRD) studies. Influence of NH4SCN on the glass transition temperature (Tg) was drawn from differential scanning calorimetry (DSC) technique. The dispersion of dopant within the polymer matrix was supported by scanning electron microscopy (SEM) followed by its elemental composition from energy dispersive spectroscopy (EDS). From the AC impedance technique, maximum conductivity of 3.01 × 10−4 S cm−1 was elicited for the optimised electrolyte (1 g PVA + 0.75 g PGS + 0.6 g NH4SCN). Frequency-dependent dielectric and modulus spectra were analysed to study the mechanism of transportation. Transport parameters evaluated by Wagner’s polarisation method proved that the conductivity was predominantly due to cations. Proton conducting battery was configured with the highest conducting electrolytic film and its cell parameters are presented.
EFFECT OF CHELATING AGENT ON THE SOL-GEL THERMOLYSIS SYNTHESIS OF LINIPO4 AND ITS ELECTROCHEMICAL PROPERTIES FOR HYBRID CAPACITORS
(Elsevier, 2018-08) Priyadharsini, N; Rupa Kasturi, P; Shanmugavani, A; Surendran, S; Shanmugapriya, S; Kalai Selvan, R
The present work reports the preparation of olivine structured LiNiPO4 nanoparticles through sol-gel thermolysis method using three different chelating agents of citric acid (LiNi-C), l-ascorbic acid (LiNi-A) and D-sorbitol (LiNi-S). The flame temperature and enthalpy change of each reaction using the chelating agent is calculated. Further, the sharp X-ray diffraction peak reveals the phase pure and high crystalline nature of the prepared LiNiPO4 nanoparticles with the space group of Pnma (62) irrespective of the chelating agents. The four possible fundamental vibrations of phosphate anion PO43− are revealed through Fourier Transform Infrared Spectroscopy (FTIR) studies. The presence of elements such as Ni, P and O and its valence state is identified through X-Ray Photoelectron Spectroscopy analysis. The spherical shape particles with the uniform size distribution of LiNi –S is observed than the LiNi-C, LiNi-A particles through FESEM analysis. The redox peaks and plateau regions in the cyclic voltammetry (CV) and Galvanostatic charge-discharge (GCD) profiles infer the dominance of battery-type charge process rather than a capacitive mechanism. As a result, LiNiPO4 exhibits a maximum specific capacitance of 417 F g−1 at 2 mV s−1 and 357 F g−1 at 1 mA cm−2 in 1 M LiOH, which enables as a suitable cathode material for hybrid supercapacitor. Also, the assembled hybrid supercapacitor delivered a high energy density of 12.5 Wh kg−1 at 200 W kg−1 as well as a longer cycle life of 89% at a current density of 1 mA cm−2 over 2000 cycles is noticed. These results infer that LiNiPO4 could be used as a novel electrode material for hybrid supercapacitor application.
EFFECT OF ROTATION ON THERMAL STABILITY OF SUPERPOSED FLUID AND POROUS LAYER
(International Journal of Engineering Research and Technology, 2018) Aiswarya, S; Arunachalam, T; Sumathi, K
In this paper linear stability of a viscous incompressible fluid saturated porous medium under the influence of rotation is investigated. Closed form solutions of velocity, temperature and fluid vorticity in terms of wave number as perturbation parameter have been obtained. The influence of various non-dimensional parameters such as Taylor number, Grashof number, Prandtl number, Darcy number, porosity and wave number on stability characteristics of flow field are discussed numerically.
AN EFFICIENT CONVOLUTIONAL NEURAL NETWORK BASED CLASSIFIER TO PREDICT TAMIL WRITER
(Periodicals of Engineering and Natural Sciences, 2018-06) Thendral, Tharmalingam; Vijaya, Vijayakumar
Identification of Tamil handwritten calligraphies at different levels such as character, word and paragraph is complicated when compared to other western language scripts. None of the existing methods provides efficient Tamil handwriting writer identification (THWI). Also offline Tamil handwritten identification at different levels still offers many motivating challenges to researchers. This paper employs a deep learning algorithm for handwriting image classification. Deep learning has its own dimensions to generate new features from a limited set of training dataset. Convolutional Neural Networks (CNNs) is one of deep, feed-forward artificial neural network is applied to THWI. The dataset collection and classification phase of CNN enables data access and automatic feature generation. Since the number of parameters is significantly reduced, training time to THWI is proportionally reduced. Understandably, the CNNs produced much higher identification rate compared with traditional ANN at different levels of handwriting.
EVALUATION OF IN VITRO ANTIOXIDANT ACTIVITY OF A MEDICINAL HERB, WEDELIA CHINENSIS (OSBECK) MERRILL.
(Innovare Academic Sciences Pvt Ltd, 2018-10-07) Rehana Banu, H; Nagarajan, N
The objective is to evaluate the antioxidant activity of the methanolic leaf extract of Wedelia chinensis.
EXPLORING THE STRUCTURE AND STABILITY OF Β-DIPEPTIDE – A QUANTUM CHEMICAL AND MOLECULAR DYNAMICS STUDY
(Indian Journal of Pure & Applied Physics, 2018-07) Abiram, A; Praveena, G
Density functional theory (DFT) calculations followed by molecular dynamics study has been performed to analyze the structure and stability of β-dipeptide structures in aqueous medium. From DFT study, three local minima with folded conformations and one local minimum with unfolded conformation have been identified. In gas phase, the most stable β-dipeptide has a folded conformation with a weak hydrogen bonding. The interaction of water molecules, approximated from the first solvation shell, also confirms the folded conformation to be the most stable structure. The DFT optimized β-dipeptide conformers have been simulated in explicit water to evaluate the tendency of folded and unfolded state formation. Simulations confirmed the transition of the structure from folded to unfolded and vice versa and further indicated the former to happen rapidly within a few pico second time scale.
EXPONENTIAL STABILITY BEHAVIOR OF NEUTRAL STOCHASTIC INTEGRODIFFERENTIAL EQUATIONS WITH FRACTIONAL BROWNIAN MOTION AND IMPULSIVE EFFECTS
(SpringerOpen, 2018-03-27) Yong-Ki, Ma; Arthi, G; Marshal Anthoni, S
In this paper, by employing the fractional power of operators, semigroup theory, and fixed point strategy we obtain some new criteria ensuring the existence and exponential stability of a class of impulsive neutral stochastic integrodifferential equations driven by a fractional Brownian motion. We establish some new sufficient conditions that ensure the exponential stability of mild solution in the mean square moment by utilizing an impulsive integral inequality. Also, we provide an example to show the efficiency of the obtained theoretical result.
FACILE SYNTHESIS, CHARACTERIZATION AND APPLICATION OF MAGNETIC NANO COMPOSITES IN SEQUESTRATION OF TEXTILE DYE
(Indian Journal of Environmental Protection, 2018-10) Thangamani, K S; Narasimman, Muthulakshmi Andal; Ranjith Kumar, E; Suba Arumugam, V
Prosopis juliflora bark activated carbon-cobalt ferrite magnetic composite (PJBAC-CFC) was syhthesised by the auto-combustion method and employed for the removal of direct brown 2 (DB2) from aqueous solutions. The prepared composite was characterized by powder XRD, SEM, EDAX, AFM, N2 adsorption-desorption isotherm and magnetisation measurement. Operating factors influencing the rate adsorption, namely initial dye concentrations, doses of sorbent materials, preset time intervals, variable pH and temperature environments are substantiated by batch equilibration method. Adsorption is observed to be more pronounced at pH 2. The magnetized composite material exhibited enhanced sorption characteristics. The isothermal adsorption data fit well with Freundlich isotherms. Kinetic studies favour the system to follow the second-order. The outcome of the present work indicates that Prosopis juliflora bark activated carbon - cobalt ferrite magnetic composite can be effectively used as a cost-effective potential adsorbent for trapping the dye molecules.
GAS CHROMATOGRAPHY AND MASS SPECTROMETRY OF THE ETHANOLIC EXTRACT OF NEST MATERIAL OF MUD DAUBER WASP, SCELIPHRON CAEMENTARIUM
(Innovare Academic Sciences, 2018-04-06) Susheela, P; Rosaline, Mary; Radha, R
The objective of the present study was to determine the chemical compounds present in the nests of the mud dauber wasp, Sceliphron caementarium
HEAT AND MASS TRANSFER OF UNSTEADY MHD FLOW OF KUVSHINSKI FLUID WITH HEAT SOURCE/SINK AND SORET EFFECTS
(IAEME Publication, 2018-09) Sakthikala, R; Prahala, S
The objective of the current paper is to study the effect of kuvshinski fluid on unsteady MHD flow through a porous medium past an infinite moving porous plate with consistent and variable temperatures. A uniform magnetic field is implemented perpendicular to the direction of the porous surface. The governing non – dimensional equations are solved analytically for velocity, temperature and concentration fields. Skin friction co-efficient, rate of heat and mass transfer co-efficient in terms of Nusselt number and Sherwood numbers are also derived. The effects of various parameters are presented graphically and tabulated forms
A HYBRID LINEAR KERNEL WITH PCA IN SVM PREDICTION MODEL OF TAMIL WRITING PATTERN
(International Journal of Simulation: Systems, Science and Technology, 2018) Thendral, Tharmalingam; Vijaya, Vijayakumar
Principal Component Regression (PCR) is a regression analysis technique based on Principal Component Analysis (PCA) which enables the identification of the principal components that can be used in a linear kernel and Support Vector Machine (SVM) as a classifier. In PCR, instead of regressing the dependent variable on the explanatory variables directly, the principal components of the explanatory variables are used as regresseors. Only a subset of all the principal components is made use of for regression, thus making PCR a kind of regularized procedure. The principal components with higher variances are selected as regressors and used in SVM linear kernel to estimate the coefficients of the kernel and the linear kernel is specified as Principal Component Kernel–Support Vector Machine (PCK-SVM). Writer Identification in Tamil handwriting is implemented by employing PCK-SVM and the results of the PCK-SVM are compared with our Weighted Least Square regression Kernel based Support Vector Machine (WLK-SVM) and Bayesian linear regression Kernel based Support Vector Machine (BLK-SVM)models. These methods are evaluated on several text images of handwriting at character, word and paragraph levels. The results show that modified linear kernel performs very well with minimum time taken to classify the writer. Performance comparison results of three kernels achieved highest performance of 94.9% accuracy in PCK-SVM than in WLK of 90.8% and BLK of 92.3% accuracy.
IMPROVED ELECTROCHEMICAL PERFORMANCES OF LIMNPO4 SYNTHESIZED BY A HYDROTHERMAL METHOD FOR LI-ION SUPERCAPATTERIES
(Springer Link, 2018-09-10) Natarjan, Priyadharsini; Amirthalingam, Shanmugavani; Subramani, Surendran; Baskar, Senthilkumar; Leonid, Vasylechko; Ramakrishnan, Kalai Selvan
Developing high-performance positrode materials are essential to attain high energy supercapatteries. In this regard, the electrochemical performances of the hydrothermally synthesized LiMnPO4 are studied. The crystal structures of the materials are elucidated using Full-profile XRD Rietveld refinement. The LiMnPO4 particles showed uniform elongated spherical shape with rice-like morphology. The rice-like LiMnPO4 showed a higher specific capacity of 492 C g−1 at 2 mV s−1 than highly agglomerated particles synthesized through sol–gel thermolysis method (191 C g−1) in 1 M LiOH aqueous electrolyte. The supercapattery is fabricated with rice-like LiMnPO4 and activated carbon (AC) as positrode and negatrode, respectively. The supercapattery (AC||LMP-H) delivered a higher capacitance around 99 F g−1 along with an improved energy density of 31 Wh kg−1. On the other hand, the LiMnPO4 prepared by sol–gel thermolysis method exhibited a very low capacitance of 35 F g−1 at 0.6 mA for the fabricated device (AC||LMP-S) with the lesser energy density about 11 Wh Kg−1 at a power density of 198 W kg−1. The reason behind the improved performance is explained based on the crystal structure as well as lower charge transfer resistance.
LINEAR POLYESTERS AS EFFECTIVE CORROSION INHIBITORS FOR STEEL REBARS IN CHLORIDE INDUCED ALKALINE MEDIUM – AN ELECTROCHEMICAL APPROACH
(Elsevier, 2018-03-20) Chan Basha, Nusrath Unnisa; Gowraraju, Nirmala Devi; Venkatesan, Hemapriya; Subramanian, Chitra; Ill-Min, Chung; Seung-Hyun, Kim; Mayakrishnan, Prabakaran
As a motto of framing the strategies to minimise the deterioration in steel reinforced concrete structures as well as the fact that the work carried out with polymers are rare and scanty, polyesters namely Poly (Glycerol azealate) (PGAZ) and 4-(1-(4-methoxy phenyl) cyclo hexyl)phenyl 9-oxodecanoate (MPOD) were synthesised and evaluated for rebar corrosion in simulated concrete pore solution (SCP) for the first time at selected concentrations of 10, 100, 1000 ppm levels with an aid of electrochemical impedance and potentiodynamic polarisation techniques. Nyquist plots favoured increased Rct values suggesting the formation of barrier. Tafel plots represented cathodic inhibition. The experimental datas were best fitted with Langmuir adsorption isotherm facilitating monolayer adsorption. Both the methods employed were in good agreement with each other favouring maximum inhibition efficiency of 71.81% for MPOD and minimum of 57.64% for PGAZ primarily due the difference in aromatic sites as revealed in mechanism.
MACROCYCLIC COMPOUNDS AS GREEN CORROSION INHIBITORS FOR ALUMINIUM: ELECTROCHEMICAL, SURFACE AND QUANTUM CHEMICAL STUDIES
(International Journal of Corrosion and Scale Inhibition, 2018-09-28) Ansari, K R; Ramkumar, S; Chauhan, D S; Salman, Md; Nalini, D; Srivastava, V; Quraishi, M A
In the present work, two macrocyclic compounds namely 5,6,11,12-tetramethyl1,2,4,7,8,10 hexaazacyclododeca-4,6,10,12-tetraene-3,9-dithione (TMCD) and 5,6,11,12- tetraphenyl-1,2,4,7,8,10-hexaazacyclododeca-4,6,10,12-tetraene-3,9-dithione (TMPD) have been synthesized and for the first time reported as inhibitors against the corrosion of aluminium in 1 M hydrochloric acid. The synthesized compounds were characterized using 1H NMR and 13C NMR. The corrosion inhibition behaviour of TMCD and TMPD was studied using gravimetric measurements, electrochemical impedance spectroscopy and potentiodynamic polarization studies. The surface analysis was carried out using AFM and SEM. Theoretical studies on the adsorption behaviour of inhibitor were carried out using the Density Functional Theory method. A detailed study of the effect of temperature and the influence of immersion time is presented using weight loss technique. Potentiodynamic polarization study proves that the corrosion inhibition efficiencies of TMCD and TMPD at 400 mg L –1 concentration are 97.30% and 89.71% respectively. Both the inhibitors behaved as mixed type but exhibit cathodic predominance. The results of EIS-Nyquist plots show inductive behavior at low frequency characteristic of the electrochemical behaviour of aluminium. The increase in polarization resistance with concentration suggests the adsorption and corrosion inhibition behaviour for both TMCD and TMPD. The AFM studies reveal a considerable decrease in surface roughness in the presence of inhibitors compared to blank sample and the SEM images show a highly smooth surface of the metal sample in the presence of inhibitors. The Fukui functions, global softness and Mulliken charges reveal that the sites for electrophilic attack are the hetero atoms. The frontier molecular orbital energies, the molecular orbital energy gap and the other quantum chemical parameters corroborated the experimental observations and suggested a better performance of TMCD compared to TMPD molecule.