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Chinese Journal of Chemical Engineering 2021年第6期34卷 40-52页

作者： m.veera krishna Department of mathematics Rayalaseema UniversityKurnoolAndhra Pradesh 518007India

The investigation of radiation-absorption,chemical reaction,Hall and ion-slip impacts on unsteady mHD free convective laminar flow of an incompressible viscous,electrically conducting and heat generation/absorbing fluid enclosed with a semi-infinite porous plate within a rotating frame has been *** plate is assumed to be moving with a constant velocity in the direction of fluid movement.A uniform transverse magnetic field is applied at right angles to the porous surface,which is absorbing the fluid with a suction velocity changing with *** non-dimensional governing equations for present investigation are solved analytically making use of two term harmonic and non-harmonic *** graphical results of velocity,temperature and concentration distributions on the analytical solutions are displayed and discussed with reference to pertinent *** is found that the velocity profiles decreased with an increasing in Hartmann number,rotation parameter,the Schmidt number,heat source parameter,while it increased due to an increase in permeability parameter,radiation-absorption parameter,Hall and ion slip ***,the temperature profile is an increasing function of radiation-absorption parameter,whereas an increase in chemical reaction parameter,the Schmidt number Sc or frequency of oscillations decrease the temperature profile on ***,it is found that the concentration profile is decreased with an escalating in the Schmidt number or the chemical reaction parameter.

关键词： Chemical reaction Free convection Heat source Heat transfer mass diffusion Radiation absorption

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mathematical modelling on diffusion and control of COVIDe19

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Infectious Disease modelling 2020年第1期5卷 588-597页

作者： m.veera krishna Department of mathematics Rayalaseema UniversityKurnoolAndhra Pradesh518007India

In this paper,we develop a mathematical model for the spread and control of the coronavirus *** outbreak of COVID-19 has led to more than one million confirmed cases as of April 3rd,*** the early spread dynamics of the infection and evaluating the effectiveness of control measures is crucial for assessing the potential for sustained transmission to occur in new *** a mathematical model of severe COVID-19 spread with four datasets from within and outside of Wuhan,China;it is estimated how spread in Wuhan varied between January and February *** is used these estimates to assess the potential for sustained human-to-human spread to occur in locations outside Wuhan if disease holders were *** is combined SEIR framework model with data on cases of COVID-19 in China and International cases that originated in Wuhan to estimate how spread had varied over time during January and February *** on these estimates,it is calculated the probability that freshly introduced cases might produce outbreaks in other ***,it is calculated approximately the median day by day basic reproduction number in Wuhan,refused from 2$45(95%CI:1.16-4.87)one week before travel restrictions were introduced on Jan 23rd,2020,to 1.05(0.42-2.40)one week *** on our estimates of,presumptuous SARS approximating disparity,it is computed that in locations with a similar spread potential to Wuhan in near the beginning of January,some time ago there are at least four independently set up cases,there is a more than fifty percent chance the infection will found within those ***-19 spreading probably refused in Wuhan during delayed January 2020,corresponding with the prologue of voyage control *** more cases arrive in international locations with similar spread potential to Wuhan,before these organize measures,it is likely many chains of spread will fail to create initially but might lead to innovative outbreaks ultimately.

关键词： COVID-19 Coronavirus mathematical modelling Diffusion Reproduction number

mathematical modelling on phase based transmissibility of Coronavirus

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Infectious Disease modelling 2020年第1期5卷 375-385页

作者： m.veera krishna J.Prakash Department of mathematics Rayalaseema UniversityKurnoolAndhra Pradesh518007India Department of mechanical Engineering Science Faculty of Engineering and the Built EnvironmentUniversity of JohannesburgAuckland Park Kingsway CampusJohannesburgSouth Africa

mathematical and epidemiological simulation plays a pivotal role in predicting,anticipating,and controlling present and future *** better understand and model the dynamics of a specific infection,researchers need to consider the influence of many variables ranging from micro-hostepathogen interactions to host-to-host encounters,and the prevailing cultural,social,economic,and local customs *** reported by the WHO,a novel corona virus(COVID-19)is identified as the etiological virus through Wuhan pneumonia for unknown etiology with Chinese administration on Jan 7,*** virus is designated as an unsympathetic SARS-Cov-2 by International Commission for Taxonomy of Viruses on Feb 11,*** main aim is to enlarge a phase based mathematical modelling to specify the transferability of this *** is developed Reservoir-individuals spreading set of connections modelling for imitating the prospective broadcast as of the infectivity foundation in the direction of the person *** view of the fact that,the Reservoir has set of connections to rigid to see the sights obviously as well as communal anxieties are concentrating on top of the spreading starting reservoir to *** subsequent generation matrix methodology is endorsed towards compute the fundamental reproduction number(R0)through the RP modelling to measure the transferability by the *** values of R0 are estimated from reservoir to human being as well as starting individual to individual,that is to say,the accepted quantity of less important diseases this consequence from presenting a solitary contaminated personality addicted to differently susceptible *** present model demonstrated that the spreading of COVID-19 is superior to the middle-East pulmonary infirmity during the middle-East nationals,analogous to harsh sensitive pulmonary infirmity,but inferior than middle-East pulmonary infirmity within the Republic of *** can also extend this study to

关键词： COVID-19 Corona virus Phase based model Next generation matrix Reproduction number Virus spread

Investigations of Soret,Joule and Hall effects on mHD rotating mixed convective flow past an infinite vertical porous plate

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Journal of Ocean Engineering and Science 2019年第3期4卷 263-275页

作者： m.veera krishna B.V.Swarnalathamma Ali J.Chamkha Department of mathematics Rayalaseema UniversityKurnoolAndhra Pradesh 518007India Department of Science and Humanities Stanley College of Engineering&Technology for WomenAbidsHyderabadTelangana 500001India Department of mechanical Engineering Prince Sultan Endowment for Energy and EnvironmentPrince Mohammad Bin Fahd UniversityAl-Khobar 31952Saudi Arabia RAK Research and Innovation Center American University of Ras Al Khaimah10021United Arab Emirates

We made an elaborate scrutiny on the Soret and Joule effects of mHD mixed convective flow of an incompressible and electrically conducting viscous fluid past an infinite vertical porous plate taking Hall effects into *** technique is used to solve the non-dimensional *** effects of the various non-dimensional parameters on velocity,temperature and concentration within the boundary layer are *** that,computational deliberations or discussions are also undertaken on the effects of the pertinent or significant parameters on the skin-friction coefficient and rates of heat and mass transfer in terms of the Nusselt and Sherwood numbers *** concentration distribution increases with increase in Soret effect and decrease with increase in chemical reaction *** increase in Prandtl number results to decrease the temperature *** the primary and secondary velocity components and temperature increases with increasing heat source *** friction coefficient decreases with an increase in permeability parameter,whereas it shows reverse effect for thermal and mass Grashof *** number increases with an increase in Prandtl *** number reduces with increasing Soret number.

关键词： Hall effects Soret number Porous medium Joules dissipation Chemical reaction

Hall Current Effects on Unsteady mHD Flow in a Rotating Parallel Plate Channel Bound-ed by Porous Bed on the Lower Half—Darcy Lapwood model

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Open Journal of Fluid Dynamics 2015年第4期5卷 275-294页

作者： m. veera krishna Jagdish Prakash Department of mathematics Rayalaseema University Kurnool India Department of mathematics University of Botswana Gaborone Botswana

We discussed the unsteady flow of an incompressible viscous fluid in a rotating parallel plate channel bounded on one side by a porous bed under the influence of a uniform transverse magnetic field taking hall current into account. The perturbations are created by a constant pressure gradient along the plates in addition to the non-torsional oscillations of the upper plate. The flow in the clean fluid region is governed by Navier-Stoke’s equations while in the porous bed the equations are based on Darcy-Lapwood model. The exact solutions of velocity in the clean fluid and the porous medium consist of steady state and transient state. The time required for the transient state to decay is evaluated in detail and ultimate quasi-steady state solution has been derived analytically and also its behaviour is computationally discussed with reference to different flow parameters. The shear stresses on the boundaries and the mass flux are also obtained analytically and their behaviour is computationally discussed.

关键词： Darcy Lapwood model Hall Effects mHD Flows Porous Bed Unsteady Flows and Rotating Parallel Plate Channels

Run-Up Flow of a maxwell Fluid through a Parallel Plate Channel

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American Journal of Computational mathematics 2013年第4期3卷 297-303页

作者： Syed Yedulla Qadri m. veera krishna Department of mathematics Rayalaseema University Kurnool India Department of mathematics St. Josephs PG College Kurnool India

We consider the flow of an incompressible viscous maxwell fluid between two parallel plates, initially induced by a constant pressure gradient. The pressure gradient is withdrawn and the upper plate moves with a uniform velocity while the lower plate continues to be at rest. The arising flow is referred to as run-up flow. The unsteady governing equations are solved as initial value problem using Laplace transform technique. The expression for velocity, shear stresses on both plates and discharge are obtained. The behavior of the velocity, shear stresses and mass flux has been discussed in detail with respect to variations in different governing flow parameters and is presented through graphs.

关键词： Run-Up Flow maxwell’s Fluid Laplace Transforms Reynolds Number and Parallel Plate Channels

指示稳定性的反相超高效液相色谱评价原料药和制剂配方中奈必洛尔杂质的方法建立与验证(英文)

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色谱 2015年第10期33卷 1051-1058页

作者： veera Raghava Raju THUmmALA mohana krishna LANKA Analytical Research and Development Integrated Product DevelopmentDr.Reddy's Laboratories Ltd.Bachupally School of Chemistry Andhra University

A sensitive,stability-indicating gradient reverse phase ultra performance liquid chromatographic method has been developed for the quantitative estimation of nebivolol impurities in active pharmaceutical ingredient(API)and pharmaceutical *** chromatographic separation was achieved on an Acquity BEH C18 column(100 mm×2.1 mm,1.7μm)with mobile phase of a gradient *** flow rate of the mobile phase was 0.18 mL/min with column temperature of 30℃and detection wavelength of 281 *** relative response factor values of(R*)-2-(benzylamino)-1-((S*)-6-fluorochroman-2-yl)ethanol((R*S*)NBV-1),(R)-1-((R)-6-fluorochroman-2-yl)-2-((S)-2-((S)-6-fluoro-chroman-2-yl)-2-hydroxyethylamino)ethanol((RRSS)NBV-3),1-(chroman-2-yl)-2-(2-(6-fluorochroman-2-yl)-2-hydroxy ethyl amino)ethanol(monodesfluoro impurity),(S)-1-((R)-6-fluorochroman-2-yl)-2-((R)-2((S)-6-fluoro-chroman-2-yl)-2-hydroxyethylamino)ethanol hydrochloride((RSRS)NBV-3)and(R*)-1-((S*)-6-fluorochroman-2-yl)-2-((S*)-2-((S*)-6-fluoro-chroman-2-yl)-2-hydroxyethylamino)ethanol((R*S*S*S*)NBV-2)were 0.65,0.91,0.68,0.92 and 0.91 *** formulation sample was subjected to the stress conditions of acid,base,oxidative,hydrolytic,thermal,humidity and photolytic *** was found to degrade significantly under peroxide stress *** degradation products were well resolved from nebivolol and its *** peak purity test results confirmed that the nebivolol peak was homogenous and pure in all stress samples and the mass balance was found to be more than 98%,thus proving the stability-indicating power of the *** developed method was validated according to International Conference on Hormonization(ICH)guidelines with respect to specificity,linearity,limits of detection and quantification,accuracy,precision and robustness.

关键词：高效液相色谱高分辨质谱稻曲病菌毒素水稻

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Steady rotation of a composite sphere in a concentric spherical cavity

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Acta mechanica Sinica 2012年第3期28卷 653-658页

作者： D.Srinivasacharya m.krishna Prasad Department of mathematics National Institute of Technology

The problem of steady rotation of a composite sphere located at the centre of a spherical container has been investigated. A composite particle referred to in this paper is a spherical solid core covered with a permeable spherical shell. The Brinkman＇s model for the flow inside the compos- ite sphere and the Stokes equation for the flow in the spheri- cal container were used to study the motion. The torque ex- perienced by the porous spherical particle in the presence of cavity is obtained. The wall correction factor is calculated. In the limiting cases, the analytical solution describing the torque for a porous sphere and for a solid sphere in an un- bounded medium are obtained from the present analysis.

关键词： Rotation Porous sphere Solid core Stokesflow Brinkman equation Stress jump coefficient. Torque Wall correction factor

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Experimental study on microstructural and corrosion behaviors of friction stir processed steel with CoCrFeCuTi HEA reinforcement and effect of annealing

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Science China Technological Sciences 2025年第1期 233-250页

作者： S.Aravind krishna N.RADHIKA Alokesh PRAmANIK N.JEYAPRAKASH Department of mechanical Engineering Amrita School of EngineeringAmrita Vishwa Vidyapeetham School of Civil and mechanical Engineering Curtin University School of mechanical and Electrical Engineering China University of Mining and Technology

The ability to perform against extreme corrosion environments in stainless steel depreciates under challenging conditions in industrial applications. This can be resolved by employing surface modification techniques to modify the surface with the required characteristics. The present study investigates the outcomes of friction stir processing of SS304 with CoCrFeCuTi high entropy alloy(HEA) as reinforcement and the property enhancements post-annealing. The synthesized CoCrFeCuTi HEA exhibited irregular fragments with 17 μm mean particle size and body centred cubic(BCC) phase. The microstructure of the processed surface revealed ultra-refined grains with a uniform distribution of HEA filler. The microstructures of the samples annealed at 400℃, 550℃, 700℃ and 850℃ for 2 h also showed significant grain growth and grain refinements. The processed sample with HEA reinforcement annealed at 700℃ exhibited enhanced microhardness and tensile strength by 63% and 0.88 times than that of the processed sample with HEA pre-annealing. The subsequent electrochemical corrosion test displayed better corrosion resistance for the HEA-processed and annealed sample. Hot corrosion tests at 900℃ showcased excellent resistance for the HEA processed and annealed samples by 14.92%, 12.75%, and 14.83% against the samples pre-annealed under three different salt mixtures, and the corroded surface was analyzed.

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Dielectric Function of Silicon Nanoclusters: Role of Hydrogen

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Chinese Physics Letters 2011年第9期28卷 241-244页

作者： SIB krishna Ghoshal m.R.Sahar m.S.Rohani Advanced Optical material Research Group Department of PhysicsFaculty of ScienceUniversiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia

Electronic and optical properties of small silicon quantum dots having 3 to 44 atoms per dot with and without surface passivation are investigated by computer simulation using the pseudo-potential *** empirical pseudo-potential Hamiltonian,a plane-wave basis expansion and a basic tetrahedral structure with undistorted local bonding configurations are *** structures of the quantum dots are relaxed and optimized before and after hydrogen *** is found that the gap increases more for a hydrogenated surface than the unpassivated ***,both quantum confinement and surface passivation determine the optical and electronic properties of Si quantum *** luminescence is probably due to the radiative recombination of electrons and holes in the quantum-confined *** effect of passivation of the surface dangling bonds by hydrogen atoms and the role of surface states on the gap energy is also *** results for the density of states,the dielectric function,the frequency dependent optical absorption cross section,the extinction coefficient and the static dielectric constants of the size are *** importance of the confinement and the role of surface passivation on the optical effects are discussed.

关键词： quantum dielectric extinction