X-ray observations have shown that the chemical abundance in the starburst galaxy M82 is quite rich in Si and S compared with oxygen. Such an abundance pattern cannot be explained with any combination of conventional Type I and II supernova yields. Also the energy to heavy element mass ratio of the observed hot plasma is much higher than the value resulted from normal supernovae. We calculate e...

Conventional material removal of BK7 optical glass will normally result in brittle fracture at the surface, generating severe subsurface damage and poor surface finish. Subsurface damages induced by grinding strongly influence the mechanical strength and optical quality of optical glasses. However, through ductile mode grinding it is possible to reduce the surface and subsurface cracks. It is m...

severe accidents of process industries in iran have increased significantly in recent decade. this study quantitatively analyzes the hazards of severe accidents imposed on people, equipment and building by a hydrogen production facility. a hazard identification method was applied. then a consequence simulation was carried out using phast 6.54 software package and at the end, consequence evaluat...

Abstract Many explosive astrophysical events, like magnetars’ bursts and flares, are magnetically driven. We consider dynamics of such magnetic explosions—relativistic expansion highly magnetized overpressurized clouds. The corresponding qualitatively different from fluid explosions due to the topological constraint conservation flux. Using analytical, relativistic MHD as well force-free calcul...