the new non-conventional cutting process by the use of thermal shock is a convenient procedure for cutting the brittle materials such as glasses and ceramics. this method is based on the application of localized thermal shock to brittle materials by the use of hot air jet, which induces thermal stresses at the tip of an existed pre-crack. due to the thermo-elastic behavior of materials, the pre...

Because of special structure, a dual reflector antenna has beam rotation capability in azimuth and elevation directions. In this structure, the antenna beam can be placed in any point in the space by mechanical movement of twist reflector which it is the most important ability of the antenna. Due to the antenna structure, if the polarization of incident wave is linear, it is expected that the p...

background: spermatogonial stem cells (sscs), a subset of undifferentiated type a spermatogonia, are the foundation of complex process of spermatogenesis and could be propagated in vitro culture conditions for long time for germ cell transplantation and fertility preservation. objective: the aim of this study was in vitro propagation of human spermatogonial stem cells (sscs) and improvement of ...