any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

abstract: one of the most visited & important spaces in different countries by tourist are urban areas. the old tehran which major part is located in district 12 is historical showcase of the capital, but, its hiidden cultural attraction is not used as it should be. this thesis occasionally engage in studying the efficacy of correct installation of travel guide boards in welfare & easily acc...

This paper deals with a deterministic inventory model for deteriorating items under the condition of permissible delay in payments with constant demand rate is a function of time which differs from before and after deterioration for a single item. Shortages are allowed and completely backlogged which is a function of time. Under these assumptions, this paper develops a retailer's model for obta...