Athenian cultural dominance continued throughout the Roman period, and the buildings added to the Agora reflect the educational role of the city, a role that ended only with the closing of the pagan philosophical schools by the Christian emperor Justinian in A.D. 529.
Bearing, in machine construction, a connector (usually a support) that permits the connected members to rotate or to move in a straight line relative to one another. Often one of the members is fixed, and the bearing acts as a support for the moving member. Most bearings support rotating shafts against either transverse (radial) or thrust (axial) loads.
Journal bearings are conformal contacts that experience much lower pressures than that experienced by gear teeth and REB's, which are non-conformal contacts Suppose an engineer needs to design a journal bearing to support a shaft of given diameter that is to be loaded with a prescribed load and rotated at a prescribed rate.