A partial decrease of the convective energy by the magnetic field of a sunspot causes the temperature of the magnetized plasma to decrease and this leads to a magneto-hydrostatic equilibrium. Thus, we expect a strong relation between magnetic field strength of a sunspot and its temperature/brightness. Here, we investigate this relation in the umbra of the large sunspot in NOAA10930 using spectr...

The microtubes are important structures in nano electromechanical system .in this study a nonlocal model is presented to investigate the static torsion behavior of microtubes made of bi-directional factionally graded material (BDFGM) subjected to a longitudinal magnetic field. Mechanical properties of BDFGM microtube varies in the radial and longitudinal direction according to an arbitrary func...

This paper presents the optical characteristics of a quantum well doped InP nanocavity.The resonance wavelength of the nanocavity and the optical field intensity is calculated before and after presence of the quantum wells. The resulting huge filed intensity of about 1.2×108 respect to the incident field is the effect of quantum wells placed in vicinity of center of nanocavity.