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Propulsion and Power Research 2018年第4期7卷 329-341页

作者： k.ramesh Department of Mathematics Symbiosis Institute of TechnologySymbiosis International UniversityPune 412115India

In this article,we have presented the exact solutions of the Couette,Poiseuille and generalized Couette flows of an incompressible magnetohydrodynamic Jeffrey fluid between parallel plates through homogeneous porous medium.The effects of slip boundary conditions and heat transfer are considered.Viscous dissipation,radiation and Joule heating are also considered in the energy equation.The governing equations of the Jeffrey fluid flow are modeled in Cartesian coordinate system.Analytical solutions for the velocity and temperature the velocity and temperature profiles are studied and the results are presented through graphs.It Temperature behaves as a decreasing function due to the impact of Hartmann number,non-Newtonian parameter and slip parameter in all noted problems.

关键词： Jeffrey fluid Heat transfer Joule heating Radiation Viscous dissipation Slip boundary conditions

Entropy generation analysis of natural convective radiative second grade nanofluid flow between parallel plates in a porous medium

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Applied Mathematics and Mechanics(English Edition) 2019年第4期40卷 481-498页

作者： k.ramesh O.OJJELA Department of Applied Mathematics Defence Institute of Advanced Technology

The present article explores the entropy generation of radiating viscoelastic second grade nanofluid in a porous channel confined between two parallel plates. The boundaries of the plates are maintained at distinct temperatures and concentrations while the fluid is being sucked and injected periodically through upper and lower plates. The buoyancy forces, thermophoresis and Brownian motion are also considered due to the temperature and concentration differences across the channel. The system of governing partial differential equations has been transferred into a system of ordinary differential equations(ODEs) by appropriate similarity relations, and a shooting method with the fourth-order Runge-kutta scheme is used for the solutions. The results are analyzed in detail for dimensionless velocity components. The temperature, concentration distributions, the entropy generation number, and the Bejan number corresponding to various fluid and geometric parameters are shown graphically. The skin friction, heat and mass transfer rates are presented in the form of tables. It is noticed that the temperature profile of the fluid is enhanced with the Brownian motion, whereas the concentration profile of the fluid is decreased with the thermophoresis parameter, and the entropy and Bejan numbers exhibit the opposite trend for the suction and injection ratio.

关键词： nanofluid thermophoresis Brownian motion shooting method thermal radiation

Peristaltic transport of MHD Williamson fluid in an inclined asymmetric channel through porous medium with heat transfer

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Journal of Central South University 2015年第8期22卷 3189-3201页

作者： k.ramesh M.Devakar Department of Mathematics Visvesvaraya National Institute of Technology

The intention of this investigation is to study the effects of heat transfer and inclined magnetic field on the peristaltic flow of Williamson fluid in an asymmetric channel through porous medium. The governing two-dimensional equations are simplified under the assumption of long wavelength approximation. The simplified equations are solved for the stream function, temperature, and axial pressure gradient by using a regular perturbation method. The expression for pressure rise is computed numerically. The profiles of velocity, pressure gradient, temperature, heat transfer coefficient and stream function are sketched and interpreted for various embedded parameters and also the behavior of stream function for various wave forms is discussed through graphs. It is observed that the peristaltic velocity increases from porous medium to non-porous medium, the magnetic effects have increasing effect on the temperature, and the size of the trapped bolus decreases with the increasing of magnetic effects while the trend is reversed with the increasing of Darcy number. Moreover, limiting solutions of our problem are in close agreement with the corresponding results of the Newtonian fluid model.

关键词：非对称信道流体模型传热介质蠕动 MHD 运输多孔介质倾斜磁场

Electro-magneto-hydrodynamic flow of couple stress nanofluids in micro-peristaltic channel with slip and convective conditions

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Applied Mathematics and Mechanics(English Edition) 2021年第4期42卷 593-606页

作者： k.ramesh M.G.REDDY B.SOUAYEH Department of Mathematics Symbiosis Institute of TechnologySymbiosis International(Deemed University)Pune 412115India Department of Mathematics Acharya Nagarjuna UniversityOngole CampusOngole 523001India Department of Physics College of ScienceKing Faisal UniversityAl-Ahsa 31982Saudi Arabia Laboratory of Fluid Mechanics Physics DepartmentFaculty of Sciences of TunisUniversity of Tunis El ManarTunis 2092Tunisia

This study explores the effects of electro-magneto-hydrodynamics,Hall currents,and convective and slip boundary conditions on the peristaltic propulsion of nanofluids(considered as couple stress nanofluids)through porous symmetric microchannels.The phenomena of energy and mass transfer are considered under thermal radiation and heat source/sink.The governing equations are modeled and non-dimensionalized under appropriate dimensionless quantities.The resulting system is solved numerically with MATHEMATICA(with an in-built function,namely the Runge-kutta scheme).Graphical results are presented for various fluid flow quantities,such as the velocity,the nanoparticle temperature,the nanoparticle concentration,the skin friction,the nanoparticle heat transfer coefficient,the nanoparticle concentration coefficient,and the trapping phenomena.The results indicate that the nanoparticle heat transfer coefficient is enhanced for the larger values of thermophoresis parameters.Furthermore,an intriguing phenomenon is observed in trapping:the trapped bolus is expanded with an increase in the Hartmann number.However,the bolus size decreases with the increasing values of both the Darcy number and the electroosmotic parameter.

关键词： peristalsis magnetohydrodynamics(MHD) nanofluid Hall current porous medium thermal radiation

Simultaneous effects of MHD and Joule heating on the fundamental flows of a Casson liquid with slip

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Propulsion and Power Research 2021年第2期10卷 118-129页

作者： k.ramesh Arshad Riaz Zahoor Ahmad Dar Department of Mathematics Symbiosis Institute of TechnologySymbiosis International(Deemed University)Pune412115India Department of Mathematics Division of Science and TechnologyUniversity of EducationLahore54770Pakistan Department of Mathematics Lovely Professional UniversityJalandhar144411India

Magnetic field plays a significant role in innumerable fields like mechanical,chemical,biological and medical research.Few examples include power generation systems,magnetohydrodynamic(MHD)accelerators,liquid metal fluids,cooling of nuclear reactors,hightemperature plasmas,chemical processing equipment and electronic components.In view of these facts,the current investigation discusses the fundamental flows of a Casson fluid in horizontal parallel plates(three fundamental situations considered such as the plate walls progresses in the conflicting directions,the progress of lower plate in the flow direction and other is in fixed position,and the progress of the plates in the flow direction respectively).Influences of radiation,velocity slip,porous medium and Joule heating are considered into account.The flow situation is assumed in Cartesian coordinate system.The momentum and energy equations are transformed into non-dimensional system utilizing appropriate nondimensional parameters.The exact solutions of the non-dimensional differential equations have been obtained.The pictorial representations are provided for the velocity as well as temperature characteristics in all the mentioned cases.It is concluded by graphical approach that velocity is enhanced in the case of increasing Darcy’s parameter and boundary slip while reduced for the large magnetic field.On the other hand,it is found that slip factor is reducing the heat transfer rate while magnetic field is giving rise to it.

关键词： Casson fluid Viscous dissipation Joule heating Porous medium Thermal radiation Magnetofluiddynamics

Cilia-assisted hydromagnetic pumping of biorheological couple stress fluids

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Propulsion and Power Research 2019年第3期8卷 221-233页

作者： k.ramesh D.Tripathi O.Anwar Bég Department of Mathematics Symbiosis Institute of TechnologySymbiosis International UniversityPune412115India Department of Mechanical Engineering Manipal University JaipurRajasthan303007India Fluid Mechanics/Propulsion Aeronautical/Mechanical Engineering DepartmentSalford UniversityManchesterUK

A theoretical study is conducted for magnetohydrodynamic pumping of electroconductive couple stress physiological liquids(e.***.blood)through a two-dimensional ciliated channel.A geometric model is employed for the cilia which are distributed at equal intervals and produce a whip-like motion under fluid interaction which obeys an elliptic trajectory.A metachronal wave is mobilized by the synchronous beating of cilia and the direction of wave propagation is parallel to the direction of fluid flow.A transverse static magnetic field is imposed transverse to the channel length.The Stokes’couple stress(polar)rheological model is utilized to characterize the liquid.The normalized two-dimensional conservation equations for mass,longitudinal and transverse momentum are reduced with lubrication approximations(long wavelength and low Reynolds number assumptions)and feature a fourth order linear derivative in axial velocity representing couple stress contribution.A coordinate transformation is employed to map the unsteady problem from the wave laboratory frame to a steady problem in the wave frame.No slip conditions are imposed at the channel walls.The emerging linearized boundary value problem is solved analytically and expressions presented for axial(longitudinal)velocity,volumetric flow rate,shear stress function and pressure rise.The flow is effectively controlled by three geometric parameters,viz cilia eccentricity parameter,wave number and cilia length and two physical parameters,namely magnetohydrodynamic(MHD)body force parameter and couple stress non-Newtonian parameter.Analytical solutions are numerically evaluated with MATLAB software.Axial velocity is observed to be enhanced in the core region with greater wave number whereas it is suppressed markedly with increasing cilia length,couple stress and magnetic parameters,with significant flattening of profiles with the latter two parameters.Axial pressure gradient is decreased with eccentricity parameter whereas it is elevated with cilia length,in the channel core regi

关键词： Magneto hydrodynamics Metachronal waves Cilia Synchronous beating Polar couple stress fluid Physiological transport Magnetic blood pumps

Sonochemical synthesis of nanostructured nickel hydroxide as an electrode material for improved electrochemical energy storage application

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Progress in Natural Science:Materials International 2017年第4期27卷 416-423页

作者： Arshid Numan Navaneethan Duraisamy Fatin Saiha Omar Dhanaraj Gopi k.ramesh S.ramesh Center for Ionics University of Malaya Department of Physics Faculty of Science University of Malaya Department of Chemistry Periyar University

A facile and fast approach for the synthesis of a nanostructured nickel hydroxide(Ni（OH）;) via sonochemical technique is reported in the present study. The X-ray diffraction results confirmed that the synthesized Ni（OH）;was oriented in β-phase of hexagonal brucite structure. The nanostructured Ni（OH）;electrode exhibited the maximum specific capacitance of 1256 F/g at a current density of 200 mA/g in 1 M kOH;. Ni（OH）;electrodes exhibited the pseudocapacitive behavior due to the presence of redox reaction. It also exhibited long-term cyclic stability of 85% after 2000 cycles, suggesting that the nanostructured Ni（OH）;electrode will play a promising role for high performance supercapacitor application.

关键词： Nickel hydroxide Sonochemical synthesis Surface morphology Electrode materials

Fuzzy Logic-Based Health Monitoring System for COVID’19 Patients

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Computers, Materials & Continua 2021年第5期67卷 2431-2447页

作者： M.Jayalakshmi Lalit Garg k.Maharajan k.Jayakumar kathiravan Srinivasan Ali kashif Bashir k.ramesh National Engineering College Kovilpatti628503India Faculty of Information and Communication Technology University of MaltaMsidaMSD2080Malta Vel Tech Rangarajan Dr.Sagunthala R&D Institute of Science and Technology Chennai600062India School of Computer Science and Engineering Vellore Institute of Technology(VIT)Vellore632014India School of Information Technology and Engineering Vellore Institute of Technology(VIT)Vellore632014India Department of Computing and Mathematics Manchester Metropolitan UniversityManchesterUK Department of Computer Science Karnataka State Akkamahadevi Women’s UniversityVijayapuraIndia

In several countries,the ageing population contour focuses on high healthcare costs and overloaded health care environments.Pervasive health care monitoring system can be a potential alternative,especially in the COVID-19 pandemic situation to help mitigate such problems by encouraging healthcare to transition from hospital-centred services to self-care,mobile care and home care.In this aspect,we propose a pervasive system to monitor the COVID’19 patient’s conditions within the hospital and outside by monitoring their medical and psychological situation.It facilitates better healthcare assistance,especially for COVID’19 patients and quarantined people.It identies the patient’s medical and psychological condition based on the current context and activities using a fuzzy context-aware reasoning engine based model.Fuzzy reasoning engine makes decisions using linguistic rules based on inference mechanisms that support the patient condition identication.Linguistics rules are framed based on the fuzzy set attributes belong to different context types.The fuzzy semantic rules are used to identify the relationship among the attributes,and the reasoning engine is used to ensure precise real-time context interpretation and current evaluation of the situation.Outcomes are measured using a fuzzy logic-based context reasoning system under simulation.The results indicate the usefulness of monitoring the COVID’19 patients based on the current context.

关键词： Pervasive healthcare COVID’19 context-aware fuzzy reasoning engine fuzzy logic role-based expert system

An Efficient Sound and Data Steganography Based Secure Authentication System

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Computers, Materials & Continua 2021年第4期67卷 723-751页

作者： Debajit Datta Lalit Garg kathiravan Srinivasan Atsushi Inoue G.Thippa Reddy M.Praveen kumar Reddy k.ramesh Nidal Nasser School of Computer Science and Engineering Vellore Institute of Technology(VIT)Vellore632014India Faculty of Information and Communication Technology University of MaltaMsidaMSD2080Malta School of Information Technology and Engineering Vellore Institute of Technology(VIT)Vellore632014India Department of Information Systems&Business Analytics Eastern Washington UniversitySpokaneWA99202USA Department of Computer Science Karnataka State Akkamahadevi Women’s UniversityVijayapuraIndia College of Engineering Alfaisal UniversityRiyadh1153Saudi Arabia

The prodigious advancements in contemporary technologies have also brought in the situation of unprecedented cyber-attacks.Further,the pin-based security system is an inadequate mechanism for handling such a scenario.The reason is that hackers use multiple strategies for evading security systems and thereby gaining access to private data.This research proposes to deploy diverse approaches for authenticating and securing a connection amongst two devices/gadgets via sound,thereby disregarding the pins’manual verification.Further,the results demonstrate that the proposed approaches outperform conventional pin-based authentication or QR authentication approaches.Firstly,a random signal is encrypted,and then it is transformed into a wave file,after which it gets transmitted in a short burst via the device’s speakers.Subsequently,the other device/gadget captures these audio bursts through its microphone and decrypts the audio signal for getting the essential data for pairing.Besides,this model requires two devices/gadgets with speakers and a microphone,and no extra hardware such as a camera,for reading the QR code is required.The first module is tested with realtime data and generates high scores for the widely accepted accuracy metrics,including precision,Recall,F1 score,entropy,and mutual information(MI).Additionally,this work also proposes a module helps in a secured transmission of sensitive data by encrypting it over images and other files.This steganographic module includes two-stage encryption with two different encryption algorithms to transmit data by embedding inside a file.Several encryption algorithms and their combinations are taken for this system to compare the resultant file size.Both these systems engender high accuracies and provide secure connectivity,leading to a sustainable communication ecosystem.

关键词： Cyber-attacks signals privacy security organization encryption decryption authentication effective communication steganography

Novel and efficient supramolecular synthesis of pyrroles in the presence of β-cyclodextrin in water

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Chinese Chemical Letters 2012年第12期23卷 1331-1334页

作者： k.ramesh k.karnakar G.Satish Y.V.D.Nageswar CSIR-Natural Product Chemistry Indian Institute of Chemical Technology

高度代替的吡咯的简单、有效的合成在经由多部件策略中等的水里被完成，用 CD 催化的胺， DMAD/DEAD 以及 phenacyl 溴化物。利用这个协议各种各样的吡咯衍生物被综合在对优秀收益好。

关键词：分子合成取代吡咯水介质有效率环糊精吡咯衍生物多组分苯甲酰