Time filter

Source Type

Medinīpur, India

Ghosh S.K.,Narajole Raj College | Beg O.A.,Sheffield Hallam University | Zueco J.,Technical University of Cartagena | Prasad V.R.,Madanapalle Institute of Technology and Science
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2010

Closed-form solutions are presented for the transient hydromagnetic flow in a rotating channel with inclined applied magnetic field under the influence of a forced oscillation. Magnetic Reynolds number is large enough to permit the inclusion of magnetic induction effects. The Maxwell displacement current effect is also included and simulated via a dielectric strength parameter. The governing momentum and magnetic induction conservation equations are normalized with appropriate transformations and the resulting quartet of partial differential equations are solved exactly. A parametric study is performed of the influence of oscillation frequency parameter (ω), time (T), inverse Ekman number, i.e. rotation parameter (K2), square of the Hartmann magnetohydrodynamic (MHD) parameter (M2), and magnetic field inclination (θ) on the primary and secondary induced magnetic field components (bx, by) and velocity components (u, v) across the channel. Network solutions are also obtained to validate the exact solutions and shown to be in excellent agreement. Applications of the study arise in planetary plasma physics and rotating MHD induction power generators and also astronautical flows. © 2009 Birkhäuser Verlag Basel/Switzerland. Source

Bhunia A.K.,Vidyasagar University | Kamilya T.,Narajole Raj College | Saha S.,Vidyasagar University
Materials Today: Proceedings | Year: 2016

A simple wet chemical method has been successfully used to grow zinc oxide nanorods (ZnO NRs). The structural characteristics were investigated through XRD and TEM. The crystal unit cell of the NRs was found to be hexagonal and the size of the ZnO NR ≈27 nm. The interaction as well as the formation of bio-conjugate of Bovine Serum Albumin (BSA) and ZnO NRs is investigated using optical spectroscopy, zeta potential, TEM analysis. UV-VIS and fluorescence spectra show that a spontaneous binding process occurred between BSA and ZnO NRs. The binding constant and the number of binding sites were also calculated. © 2016 Elsevier Ltd. Source

Bhunia A.K.,Vidyasagar University | Samanta P.K.,Ghatal R.S. Mahavidyalaya | Saha S.,Vidyasagar University | Kamilya T.,Narajole Raj College
Applied Physics Letters | Year: 2013

The interaction as well as the formation of bioconjugate of Bovine Serum Albumin (BSA) and Zinc Oxide nanoparticles (ZnO NPs) is investigated. The surface binding along with reorganization of BSA on the surface of ZnO NPs forms stable hard corona. The time constants for surface binding and reorganization are found to be 1.10 min and 70.68 min, respectively. The close proximity binding of BSA with ZnO NPs via tryptophan is responsible for bioconjugate formation. Fibrillar aggregated structure of BSA is observed due to conformational change of BSA in interaction with ZnO NPs. © 2013 AIP Publishing LLC. Source

Patra R.R.,Vidyasagar University | Das S.,Vidyasagar University | Jana R.N.,Vidyasagar University | Ghosh S.K.,Narajole Raj College
Journal of Applied Fluid Mechanics | Year: 2012

The effect of radiation on natural convection incompressible viscous fluid near a vertical flat plate with ramped wall temperature has been studied. An analytical solution of the governing equation has been obtained by employing Laplace transform technique. It is examined that two different solutions for the fluid velocities, one valid for fluids of Prandtl number (Pr) different from 1 + Ra, Ra being the radiation parameter and the other for which the Prandtl number equal to 1 + Ra. The variations of velocities and fluid temperature are presented graphically. Furthermore, the radiative heat transfer on natural convection flow near a ramped plate temperature has been compared with the flow near a plate with the constant wall temperature. It is found that an increase in radiation parameter leads to rise the fluid velocity as well as temperature. Source

Kumar Bhunia A.,Vidyasagar University | Kanti Samanta P.,Ghatal R.S. Mahavidyalaya | Saha S.,Vidyasagar University | Kamilya T.,Narajole Raj College
Applied Physics Letters | Year: 2014

Semiconductor nanoparticles (NPs) with near-infrared (NIR) fluorescence has achieved great interest for early detection of colon tumors/cancer. We have synthesized lead sulphide (PbS) NPs (5-7 nm) having emission in NIR region and investigated its interaction with bovine serum albumin (BSA) to determine the bio-safety of PbS NPs. The interaction of PbS NPs with BSA occurs through formation of "hard" and "soft" protein NPs corona and follows exponential association. The hard corona represents that the core PbS NPs are fully covered by BSA with shell thickness of ∼8 nm, i.e., the dimension of BSA monomer. A large number of PbS NPs with hard corona of BSA forms "colony" with diameters in the range of 200-400 nm. The soft corona grows surrounding this colony. The quenching of fluorescence BSA in the presence of PbS NPs follows dynamic quenching process with tryptophan as major binding sites. Nearest to human body temperature, positive cooperative association between PbS NPs and BSA are found, and affinity of BSA to the PbS NPs gradually increases in superlinear fashion. The electrostatic interaction is the key force in binding of PbS NPs with BSA, and hydrophobic interaction between PbS NPs and BSA is responsible for conformational change of BSA. © 2014 AIP Publishing LLC. Source

Discover hidden collaborations