Investigation of some Natural Product Extracts as Corrosion Inhibitors for Mild Steel in Acid Medium

( A. Subramania ),( A. R. Sathiya Priya ),( S. Saravanan ),( A. J. Abdul Nasser ),( T. Vasudevan ) 한국부식방식학회(구 한국부식학회) 2005 Corrosion Science and Technology Vol.4 No.6

Combined effects of magnetic and electric fields on the interband optical transitions in InAs/InP quantum wire

Saravanan, S.,John Peter, A.,Lee, ChangWoo Elsevier 2015 Physica E, Low-dimensional systems & nanostructure Vol.67 No.-

<P><B>Abstract</B></P> <P>Combined effects of magnetic and electric fields on the confined exciton in an InAs<SUB>1−<I>x</I> </SUB>P<I> <SUB>x</SUB> </I>/InP (<I>x</I>=0.2) quantum well wire are investigated taking into account the geometrical confinement effect. Variational formulism, within the frame work of effective mass approximation, is applied to obtain the exciton binding energy. The second order harmonic generation and the optical gain are carried out using compact density method. The strain effects are included with the confinement potential in the Hamiltonian. The energy difference of the ground and the first excited state is found in the presence of magnetic and electric fields taking into the consideration of spatial confinement effect. The result shows that the optical properties are more influenced taking into account the effects of geometrical confinement, magnetic field and electric field. It is shown that the telecommunication wavelength can be achieved with the suitable doping barrier material with the wire material and the external perturbations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Combined effects of magnetic and electric fields on the confined exciton in an InAs<SUB>1−<I>x</I> </SUB>P<I> <SUB>x</SUB> </I>/InP wire are investigated. </LI> <LI> Variational formulism is applied to obtain the exciton binding energy. </LI> <LI> Second order harmonic generation and the optical gain are carried out using compact density method. </LI> <LI> The strain effects are included with the confinement potential in the Hamiltonian. </LI> <LI> Optical properties are more influenced with the effects of geometrical confinement and the external perturbations. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Variation of gain as a function of photon energy for various values of measure of magnetic field strength in a InAs<SUB>0.8</SUB>P<SUB>0.2</SUB>/InP quantum well wire is shown for <I>F</I>=0V/cm and <I>F</I>=100V/cm, with the constant electron density. The wire radius is taken as 50Å.</P> <P>[DISPLAY OMISSION]</P>

Prediction of stress intensity factor range for API 5L grade X65 steel by using GPR and MPMR

A. Ramachandra Murthy,S. Vishnuvardhan,M. Saravanan,P. Gandhi 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.81 No.5

The infrastructures such as offshore, bridges, power plant, oil and gas piping and aircraft operate in a harsh environment during their service life. Structural integrity of engineering components used in these industries is paramount for the reliability and economics of operation. Two regression models based on the concept of Gaussian process regression (GPR) and Minimax probability machine regression (MPMR) were developed to predict stress intensity factor range (K). Both GPR and MPMR are in the frame work of probability distribution. Models were developed by using the fatigue crack growth data in MATLAB by appropriately modifying the tools. Fatigue crack growth experiments were carried out on Eccentrically-loaded Single Edge notch Tension (ESE(T)) specimens made of API 5L X65 Grade steel in inert and corrosive environments (2.0% and 3.5% NaCl). The experiments were carried out under constant amplitude cyclic loading with a stress ratio of 0.1 and 5.0 Hz frequency (inert environment), 0.5 Hz frequency (corrosive environment). Crack growth rate (da/dN) and stress intensity factor range (K) values were evaluated at incremental values of loading cycle and crack length. About 70 to 75% of the data has been used for training and the remaining for validation of the models. It is observed that the predicted SIF range is in good agreement with the corresponding experimental observations. Further, the performance of the models was assessed with several statistical parameters, namely, Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Coefficient of Efficiency (E), Root Mean Square Error to Observation’s Standard Deviation Ratio (RSR), Normalized Mean Bias Error (NMBE), Performance Index (ρ) and Variance Account Factor (VAF).

Multi‑State Reconfgurable Antenna for Wireless Communications

A. Priya,S. Kaja Mohideen,Manavalan Saravanan 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

A compact frequency and polarization reconfgurable antenna is presented. The antenna comprises of a truncated corner square patch along with two strip lines running parallel to it. The entire model is fabricated on single layer roger RO 4350 substrate. Pin diodes are used for switching frequency and polarization states. Two ports are used for switching polarization states. The antenna can achieve two frequency bands and four polarization states. The antenna model is fabricated and the measured results are compared with simulated results. The antenna achieves −10 dB impedance bandwidth of 100 MHz for LP state and 50 MHz for CP state and also the antenna attains good cross-polarization isolation of>15 dB in all states. The antenna gives a maximum measured gain of 5.48 dBi for linear polarization (LP) state and 4.82 dBi for circular polarization (CP) state.

Design and Implementation of PIC/FLC plus SMC for Positive Output Elementary Super Lift Luo Converter working in Discontinuous Conduction Mode

S. Muthukaruppasamy,A. Abudhahir,A. Gnana Saravanan,J. Gnanavadivel,P. Duraipandy 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

This paper proposes a confronting feedback control structure and controllers for positive output elementary super lift Luo converters (POESLLCs) working in discontinuous conduction mode (DCM). The POESLLC offers the merits like high voltage transfer gain, good efficiency, and minimized coil current and capacitor voltage ripples. The POESLLC working in DCM holds the value of not having right half pole zero (RHPZ) in their control to output transfer function unlike continuous conduction mode (CCM). Also the DCM bestows superlative dynamic response, eliminates the reverse recovery troubles of diode and retains the stability. The proposed control structure involves two controllers respectively to control the voltage (outer) loop and the current (inner) loop to confront the time-varying ON/OFF characteristics of variable structured systems (VSSs) like POESLLC. This study involves two different combination of feedback controllers viz. the proportional integral controller (PIC) plus sliding mode controller (SMC) and the fuzzy logic controller (FLC) plus SMC. The state space averaging modeling of POESLLC in DCM is reviewed first, then design of PIC, FLC and SMC are detailed. The performance of developed controller combinations is studied at different working states of the POESLLC system by MATLAB-Simulink implementation. Further the experimental corroboration is done through implementation of the developed controllers in PIC 16F877A processor. The prototype uses IRF250 MOSFET, IR2110 driver and UF5408 diodes. The results reassured the proficiency of designed FLC plus SMC combination over its counterpart PIC plus SMC.

Relevance vector based approach for the prediction of stress intensity factor for the pipe with circumferential crack under cyclic loading

A. Ramachandra Murthy,S. Vishnuvardhan,M. Saravanan,P. Gandhi 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.1

Structural integrity assessment of piping components is of paramount important for remaining life prediction, residual strength evaluation and for in-service inspection planning. For accurate prediction of these, a reliable fracture parameter is essential. One of the fracture parameters is stress intensity factor (SIF), which is generally preferred for high strength materials, can be evaluated by using linear elastic fracture mechanics principles. To employ available analytical and numerical procedures for fracture analysis of piping components, it takes considerable amount of time and effort. In view of this, an alternative approach to analytical and finite element analysis, a model based on relevance vector machine (RVM) is developed to predict SIF of part through crack of a piping component under fatigue loading. RVM is based on probabilistic approach and regression and it is established based on Bayesian formulation of a linear model with an appropriate prior that results in a sparse representation. Model for SIF prediction is developed by using MATLAB software wherein 70% of the data has been used for the development of RVM model and rest of the data is used for validation. The predicted SIF is found to be in good agreement with the corresponding analytical solution, and can be used for damage tolerant analysis of structural components.

Design and Implementation of PIC/FLC plus SMC for Positive Output Elementary Super Lift Luo Converter working in Discontinuous Conduction Mode

Muthukaruppasamy, S.,Abudhahir, A.,Saravanan, A. Gnana,Gnanavadivel, J.,Duraipandy, P. The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

This paper proposes a confronting feedback control structure and controllers for positive output elementary super lift Luo converters (POESLLCs) working in discontinuous conduction mode (DCM). The POESLLC offers the merits like high voltage transfer gain, good efficiency, and minimized coil current and capacitor voltage ripples. The POESLLC working in DCM holds the value of not having right half pole zero (RHPZ) in their control to output transfer function unlike continuous conduction mode (CCM). Also the DCM bestows superlative dynamic response, eliminates the reverse recovery troubles of diode and retains the stability. The proposed control structure involves two controllers respectively to control the voltage (outer) loop and the current (inner) loop to confront the time-varying ON/OFF characteristics of variable structured systems (VSSs) like POESLLC. This study involves two different combination of feedback controllers viz. the proportional integral controller (PIC) plus sliding mode controller (SMC) and the fuzzy logic controller (FLC) plus SMC. The state space averaging modeling of POESLLC in DCM is reviewed first, then design of PIC, FLC and SMC are detailed. The performance of developed controller combinations is studied at different working states of the POESLLC system by MATLAB-Simulink implementation. Further the experimental corroboration is done through implementation of the developed controllers in PIC 16F877A processor. The prototype uses IRF250 MOSFET, IR2110 driver and UF5408 diodes. The results reassured the proficiency of designed FLC plus SMC combination over its counterpart PIC plus SMC.

The Impact of Property Management Services on Tenants’ Satisfaction with Industrial Buildings

Seetharaman,Arumugam,Saravanan,A,S,Patwa,Nitin,Bey,Jiann Ming 한국유통과학회 2019 KODISA ICBE (International Conference on Business Vol.2019 No.-

The aim of this research is to determine the impact of property management services on tenants’ satisfaction with the three identified variables. Structural equation modelling (SEM) is applied to build constructs and test the hypotheses with the collected survey samples. Of the three variables, facility management is the most influential factor that leads to tenant satisfaction with industrial buildings. Next, perceived quality is another important factor that contributes to tenants’ pleasure. Compared with these two, lease management fares worse, having the least extensive effect on tenant satisfaction, and could be disregarded. The ultimate impact of tenant satisfaction is about tenant retention and recommendation. The overall findings of this research will potentially help real estate developers to develop a better property management system, leasing program and tenant retention strategy.

The Impact of Property Management Services on Tenants’ Satisfaction with Industrial Buildings

Arumugam Seetharaman,A. S. Saravanan,Nitin Patwa,Jiann Ming Bey 한국유통과학회 2017 The Journal of Asian Finance, Economics and Busine Vol.4 No.3

In the current competitive marketplace of real estate business, tenant satisfaction measurement is one of the important indicators to monitor competitiveness in industrial property development. It has become an industry standard to measure tenant satisfaction, commonly called customer satisfaction. Customer satisfaction has become the widely used metric to manage customer loyalty (Keiningham, Gupta, Aksoy, & Buoye, 2014). The aim of this research is to determine the impact of property management services on tenants’ satisfaction with the three identified variables i.e. facility management, perceived quality and lease management. Structural equation modeling (SEM) is applied to build constructs and test the hypotheses with the collected survey samples. Of the three variables, facility management is the most influential factor that leads to tenant satisfaction with industrial buildings. Next, perceived quality is another important factor that contributes to tenants’ pleasure. Compared with these two, lease management fares worse, having the least extensive effect on tenant satisfaction, and could be disregarded. The ultimate impact of tenant satisfaction is about tenant retention and recommendation. The overall findings of this research will potentially help real estate developers to develop a better property management system, leasing program and tenant retention strategy.

In vitro antibacterial activity of nanoemulsion formulation on biofilm, AHL production, hydrolytic enzyme activity, and pathogenicity of Pectobacterium carotovorum sub sp. carotovorum

Joe, M.M.,Benson, A.,Saravanan, V.S.,Sa, T. Academic Press 2015 Physiological and molecular plant pathology Vol.91 No.-

In the present investigation the in vitro activity of nanoemulsion (AUSN1) was evaluated against the plant pathogen Pectobacterium carotovorum sub sp. carotovorum causing the soft rot disease in numerous horticultural crops. With AUSN1 nanoemulsion treatment, minimum inhibitory concentration (MIC) of 0.09 mg ml<SUP>-1</SUP>, minimum bacteriostatic concentration (MBC) of 1.30 mg ml<SUP>-1</SUP> and zone of inhibition of 2.90 cm was observed against P. carotovorum. This formulation was able to reduce the bacterial population by 32.2-51.6%, under biofilm formation condition and a complete elimination of population under normal cultivation conditions. When subjected AUSN1 treatment, reduction in biofilm formation, swarming and swimming motility was observed in P. carotovorum strain and also inhibited the N-acyl homoserine lactones (AHL) activity by 13.27-62.3% and AHL production by 32.4-76.13%. Reduction in exo polysaccharide (EPS) synthesis and hydrolytic enzymes production in P. carotovorum strain was observed due to AUSN1 treatment. Reduced hydrophobicity (36.9-56.4%) and adhesion to polystyrene (22.9-47.5%) and potato tuber surfaces (19.5-46.8%) was observed with AUSN1 treatment. All these collective evidences clearly show that, under laboratory conditions, AUSN1 treatment was able to inhibit the soft root incidence in potato tubers.