Quaid-i-Azam University

About: Quaid-i-Azam University is a education organization based out in Islamabad, Pakistan. It is known for research contribution in the topics: Heat transfer & Nanofluid. The organization has 6577 authors who have published 16865 publications receiving 381678 citations. The organization is also known as: Islamabad University.

Convective heat transfer in MHD slip flow over a stretching surface in the presence of carbon nanotubes

Abstract: In the present study, thermal conductivity and viscosity of both single-wall and multiple-wall Carbon Nanotubes (CNT) within the base fluids (water, engine oil and ethylene glycol) of similar volume have been investigated when the fluid is flowing over a stretching surface The magnetohydrodynamic (MHD) and viscous dissipation effects are also incorporated in the present phenomena Experimental data consists of thermo-physical properties of each base fluid and CNT have been considered The mathematical model has been constructed and by employing similarity transformation, system of partial differential equations is rehabilitated into the system of non-linear ordinary differential equations The results of local skin friction and local Nusselt number are plotted for each base fluid by considering both Single Wall Carbon Nanotube (SWCNT) and Multiple-Wall Carbon Nanotubes (MWCNT) The behavior of fluid flow for water based-SWCNT and MWCNT are analyzed through streamlines Concluding remarks have been developed on behalf of the whole analysis and it is found that engine oil-based CNT have higher skin friction and heat transfer rate as compared to water and ethylene glycol-based CNT

Evaluation of Pathogenic Potential of Avian Influenza Virus Serotype H9N2 in Chickens

Abstract: Recently seven isolates of avian influenza virus (AIV) serotype H9N2 recovered from an outbreak of AI were analyzed on the basis of their biological and molecular characteristics. All the isolates belonged to the low-pathogenicity group of AIV. To further evaluate their pathogenic potential in association with other organisms, an isolate was inoculated experimentally in chickens using different routes and subsequently challenged with infectious bronchitis virus, Ornithobacterium rhinotracheale or Escherichia coli. The virus isolation and seromonitoring data revealed a significant role of Escherichia coli in aggravating the clinical condition of the birds earlier infected with AIV (H9N2). The AIV-antigen was detected in lung, trachea, kidney, and cloacal bursa among the infected birds, using immunofluorescent antibody technique. In another experiment, chickens that were immunosuppressed chemically showed high mortality when challenged with AIV H9N2. The results indicated that this low pathogenicity AIV (H9N2) isolate could produce severe infection depending on the type of secondary opportunistic pathogens present under field conditions. This may explain the severity of infection with the present H9N2 outbreak in the field. A prolonged antibacterial therapy in flocks infected with AIV H9N2 and use of oil-based vaccine at an early age in new flocks has helped to control this infection and the disease.

Entropy generation minimization (EGM) of nanofluid flow by a thin moving needle with nonlinear thermal radiation

Abstract: Entropy generation minimization (EGM) and heat transport in nonlinear radiative flow of nanomaterials over a thin moving needle has been discussed. Nonlinear thermal radiation and viscous dissipation terms are merged in the energy expression. Water is treated as ordinary fluid while nanomaterials comprise titanium dioxide, copper and aluminum oxide. The nonlinear governing expressions of flow problems are transferred to ordinary ones and then tackled for numerical results by Built-in-shooting technique. In first section of this investigation, the entropy expression is derived as a function of temperature and velocity gradients. Geometrical and physical flow field variables are utilized to make it nondimensionalized. An entropy generation analysis is utilized through second law of thermodynamics. The results of temperature, velocity, concentration, surface drag force and heat transfer rate are explored. Our outcomes reveal that surface drag force and Nusselt number (heat transfer) enhanced linearly for higher nanoparticle volume fraction. Furthermore drag force decays for aluminum oxide and it enhances for copper nanoparticles. In addition, the lowest heat transfer rate is achieved for higher radiative parameter. Temperature field is enhanced with increase in temperature ratio parameter.