S.V.K. Varma

Epidemiological features of pneumonic plague outbreak in Himachal Pradesh, India

Four people admitted to a tertiary care hospital during February 2002 had similar respiratory symptoms; they belonged to one family residing in a village in Himachal Pradesh, India. The clustering of these cases in space and time led to the suspicion that it could be a pneumonic plague outbreak. A standard case definition, and treatment and prophylaxis guidelines were prepared. Active surveillance identified 30 cases. The incubation period ranged from 3 to 7 days. Among the affected people, 53.3% were males, and 90% were >15 years of age. Fever with cough was the most common presenting feature (43.3%). The diagnosis of pneumonic plague was confirmed from blood cultures using conventional biochemical tests, phage susceptibility of the identified organisms, and F1 antigen ELISA and PCR for the pla gene. Five patients died giving a case-fatality ratio of 16.6%. The other cases recovered following treatment. Early identification of cases and prompt institution of control measures, particularly among close family members, relatives and health care contacts is essential for containing outbreaks. To prevent future outbreaks, known endemic foci should be identified and essential information should be gathered on the epizoology of plague.

Chemical Reaction Effects on Nano Carreau Liquid Flow Past a Cone and a Wedge with Cattaneo-Christov Heat Flux Model

Abstract Chemical reaction aspect is utilized for heat mass transfer analysis of nano non-Newtonian liquid flow past a cone and a wedge. Flow is steady, laminar and two dimensional created due to a cone and a wedge. The Carreau liquid and Cattaneo-Christov heat flux models are utilized. The magneto-nano Carreau liquid material occupies the porous space. The relevant PDEs are rendered into coupled non-linear ODEs via appropriate transformations before treated them numerically through Runge-Kutta and Newton’s method. The computed results are plotted for employing the various values of physical constraints on the profiles of velocity, temperature and nanoparticle volume fraction. Moreover, vitiation of the friction factor, Nusselt number and Sherwood number against physical parameters are presented numerically. It is figured out that convective heating and Brownian motion effects are constructive for thermal boundary layer growth. Aspect of chemical reaction is significant to control the solute layer growth and mass transfer rate.

Entropy Generation Analysis in a Vertical Porous Channel with Navier Slip and Viscous Dissipation

The intension of this paper is to investigate the effects of Navier slip and buoyancy force on the entropy in a vertical generation porous channel with suction/injection. This problem is solved analytically by perturbation technique. Closed form solutions are obtained for the fluid velocity and the temperature. The leads of slip parameter, injection/suction Reynolds number, Peclet number and Brinkmann number on the fluid velocity, temperature profiles, Bejan number, and rate of entropy generation are showed graphically and quantitatively discussed.

MHD Boundary Layer Flow of Nanofluid Through a Porous Medium Over a Stretching Sheet with Variable Wall Thickness: Using Cattaneo–Christov Heat Flux Model

Abstract The hydromagnetic nanofluid flow over a stretching sheet in a porous medium with variable wall thickness in the presence of Brownian motion and thermophoresis is investigated. The heat transfer characteristics with variable conductivity are explored by using Cattaneo-Christov heat flux model. The governing non-linear ordinary differential equations are solved by using boundary value problem default solver in MATLAB bvp4c package. The impact of various important flow parameters on velocity, temperature and nanoparticle concentration as well as the friction factor coefficient and the rate of heat and mass transfer coefficients are presented and discussed through graphs and tables. It is found that the fluid velocity is accelerated with an increase in wall thickness parameter for n > 1, while the reverse trend is observed for n < 1.

Three- Dimensional Hydromagnetic Convective Flow of Chemically Reactive Williamson Fluid with Non-Uniform Heat Absorption and Generation

Abstract The electrically conducting three-dimensional Williamson fluid flow produced by the movement of sheet via porous medium under non-uniform heat sink and source, thermal radiation and convective boundary condition is examined. The system of nonlinear expressions is transformed into nonlinear ordinary differential system of equations. These governing expressions are evaluated numerically with the help of boundary value problem default solver in MATLAB bvp4c package. Pertinent results are demonstrated graphically to execute the effects of various governing parameters on dimensionless fields. The aspects of constraints on skin-friction, mass and heat transport rates are characterized via numerical benchmarks. It is noticed that the transverse and axial velocities are depreciated by respective Williamson fluid parameters, while the opposite trend is noticed on concentration and temperature fields.