Indian Institute of Technology Kharagpur

About: Indian Institute of Technology Kharagpur is a education organization based out in Kharagpur, India. It is known for research contribution in the topics: Natural rubber & Dielectric. The organization has 16887 authors who have published 38658 publications receiving 714526 citations.

Effect of viscous dissipation on the mixed convection heat transfer from an exponentially stretching surface

Abstract: The mixed convection flow and heat transfer from an exponentially stretching vertical surface in a quiescent fluid is analyzed using similarity solution technique. Wall temperature and stretching velocity are assumed to have specific exponential function forms. The influence of buoyancy along with viscous dissipation on the convective transport in the boundary layer region is analyzed in both aiding and opposing flow situations. The flow is governed by the mixed convection parameter Gr/Re2. The velocity and temperature inside the boundary layer are observed to be influenced by the parameters like Prandtl number Pr, Gebhart number Gb. Significant changes are observed in non-dimensional skin friction and heat transfer coefficients due to viscous dissipation in the medium. The flow and temperature distributions inside the boundary layer are analyzed and the results for non-dimensional skin friction and heat transfer coefficients are discussed through computer generated plots.

Effect of yttrium on improvement of dielectric properties and magnetic switching behavior in BiFeO3

Abstract: Yttrium (Y) modified nanocrystalline samples of BiFeO3 (BFO) were prepared by a metal ion ligand complex-based precursor-solution evaporation method. Partial substitution of Y (0–15%) at the Bi site results in structural change (rhombohedral to tetragonal) and single phase formation. With increasing Y concentration, enhancement in dielectric ordering, reduction in loss tangent and improvement in magnetic ordering in BFO were observed. Diffuse peaks in both permittivity and loss tangent were observed at 207 °C and 222 °C, respectively, for 15% substitution of Y. In all the Y substituted BFO samples, a switching behavior in low fields was observed in the field dependence of magnetization, even at room temperature, and this behavior was found to be improved with increasing Y concentration.