flow resistance(flow resistance quotient of the difference of air pressure between the two faces of a sheet of porous material by the volume velocity of airflow through the sheet Found on electropedia.orgAlexander Demidov)
backend(also thrust yoke – the part connecting the piston rods of the feed mechanism on a hydraulically driven diamond-drill swivel head to the thrust block, which forms the connecting link between the yoke and the drive rod, by means of which link the longitudinal movements of the feed mechanism are transmitted to the swivel-head drive rod. Also known as back end Taras)
