High-resolution spectropolarimetry sometimes suffers from a spectral modulation in polarization and position angle. It is shown that this artifact can be attributed to multiple reflections within the plates of the wave plate assembly and that the effect is inherent to the use of wave plates except at the design wavelength. The treatment given applies to strictly plane-parallel wave plate elemen...

The Casimir forces on two parallel plates in conformally flat de Sitter background due to conformally coupled massless scalar field satisfying mixed boundary conditions on the plates is investigated. In the general case of mixed boundary conditions formulae are derived for the vacuum expectation values of the energy-momentum tensor and vacuum forces acting on boundaries. Different cosmological ...

The purpose of the present paper is to study an unsteady laminar flow and heat transfer of an incompressible, conducting viscous dusty fluid between two infinitely non-conducting parallel plates. The flow is influenced by pulsatile pressure gradient, uniform magnetic field which is applied perpendicular to the plates and due to oscillations of the plates. The governing partial differential equa...

The unsteady Couette flow through a porous medium of a viscous, incompressible fluid bounded by two parallel porous plates is studied with heat transfer. A uniform suction and injection are applied perpendicular to the plates while the fluid motion is subjected to an exponential decaying pressure gradient. The two plates are kept at different but constant temperatures while the viscous dissipat...