1. Mohorovicic discontinuity-the boundary between the Earth's crust and the underlying mantle; the Mohorovicic discontinuity averages 5 miles down under oceans and 20 miles down under continents.
PAR â Project Authorization Request An approved PAR is needed before official work is begun on a standard project. It serves as the work authorization by the IEEE-SA Standards Board. NesCom examines PARs and makes recommendations to the IEEE-SA Standards Board regarding their approval. An approved PAR is valid for 4 years. The PAR is referred to when the standard is submitted to RevCom for approval.
A parabolic aluminized reflector lamp (also PARCAN light, PARcan, or simply PAR) is a type of electric lamp that is widely used in commercial, residential, and transportation illumination.he glass envelope or bulb of all incandescent lamps is measured in eighths of an inch. Thus a PAR 64 is, nominally, 64 eighths of an inch in diameter. The approximate nominal lamp bell diameter in inches can be found by dividing the PAR size by 8. For example, a PAR30 lamp is approximately 3.75 inches in diameter.