In the construction industry, non–destructive testing (NDT) methods are often used in field to inspect compressive strength of concrete. NDT do not cause damage existing structure and relatively economical. Two popular rebound hammer (RH) test ultrasonic pulse velocity (UPV) test. One major drawback RH UPV is that concrete estimations very accurate when comparing them results obtained from dest...

this paper tries to evaluate the nature of open market operation in the conventional banking system and to compare the usage of government securities and central bank securities for conducting this operation. in addition, the experience of the iranian central bank in using central bank musharakah certificates is reviewed. the main results of the paper, derived from an analytical- descriptive ap...

BACKGROUND Shift-work is suggested to affect fetal development negatively. In particular, maternal hormonal disturbance arising from sleep deprivation or circadian rhythm changes may disturb fetal growth or lead to complications during pregnancy. Exposure to constant light is an environmental stressor that can affect the circadian system and has been shown to induce neurochemical and behavioral...