Molecular contamination on optical surfaces is a serious issue for space payloads. For ultraviolet (UV) payloads, molecular contamination results in loss of throughput. Whereas, for visible (VIS) payloads loss of throughput ...

The effective potential appearing in the scattering of scalar, electromagnetic and gravitational waves by a Schwarzschild black hole is replaced with potentials for which the exact analytical solutions are known. It is ...

Detection of periodic structures, hidden in random surfaces has been addressed by us for some time and the `extended matched filter' method, developed by us, has been shown to be effective in detecting the ...

We address the problem of detecting periodic structures hidden behind roughness. We have shown that if r0 is the coherence length of the scattered radiation, due to the random part of the surface, and Lambda is the wavelength ...

The scattering of positronium (Ps) by lithium (Li) is investigated using the static-exchange approximation and a two-state close-coupling approximation (CCA) including exchange. The major effect of very high polarizability ...

The first part of this article sets up a nested three-stage model for the advent and growth of modern science in India. We have already discussed the first stage, the colonial-tool stage, where science was used by the ...