A cable tray system including cable trays formed of a first side rail and a second side rail arranged substantially parallel to one another and transverse rungs extending between and connecting the first and second side rails. Thus, a waste of a communication channel can be prevented, and since a user can selectively receive contents or information according to hisher location, user’s satisfaction and convenience can be enhanced. The oxide layer can inhibit hydrogen formed by decomposition of water incorporated in the lubricants from intruding into the matrix of the bearing members, thereby preventing early peeling for the raceway surfaces of the bearing rings or the rolling contact surfaces of the rolling elements and, thus, greatly improving the rolling life. Some example systems may further comprise a second tile effective to receive the request, the second tile effective to determine a data tile including the data block, the second tile further effective to send the request to the data tile. NAND flash memory devices that include different pedestal heights and fabrication methods for integrated circuit memory devices are also disclosed. The remaining electrical energy produced by the converter is used external to the engine, such as to drive a load or for storage.