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...

Shahab national project has been implemented in Iran with the aim of identifying and guiding talented students with teacher-centeredness. Considering that the examination of the teachers' perception as the implementers of this plan plays an essential role in its successful implementation, in this research, the perception of the teachers of Birjand City about the Shahab plan has been investigate...

Introduction: The necessity of risk management in construction projects in order to reduce accidents, achievement of the project goals, guaranteeing the survival of the organization and satisfying customers is inevitable. Therefore, attention to the risk management issue as apart of the risk macro topic in PMBOK can also play a significant role in identifying, assessing and controlling the HSE ...

asymmetric membranes are widely used in many industrial membrane separation processes. the major advantage of membrane filtration over the conventional process is its ability to remove a wider spectrum of particles without using any chemicals. hollow fiber configuration offer many advantages over flat-sheet or tubular membranes. the spinning process of hollow fiber may look simple, yet it is te...

there are two major theories of measurement in psychometrics: classical test theory (ctt) and item-response theory (irt). despite its widespread and long use, ctt has a number of shortcomings, which make it problematic to be used for practical and theoretical purposes. irt tries to solve these shortcomings, and provide better and more dependable answers. one of the applications of irt is the as...