Abstract: An electromagnetic agitating method in a casting mold for the continuous casting of a slab in which electromagnetic agitating devices for generating a thrust force in the slab drawing direction are arranged at at least an inner wide surface of both inner and outer surfaces of the slab casting mold in a bending type continuous casting machine. The thrust force in the drawing direction applied to molten steel within the casting mold by the electromagnetic agitating devices is substantially applied from the narrow surface of the casting mold toward the center thereof in a range except a predetermined length in order to perform an electromagnetic agitation of molten steel.

Abstract: An optical pick-up device for use in an optical information recording/reproducing apparatus carries out a focusing and tracking control operation to keep the optical pick-up device located in a desired location relative to an associated optical disc. In accordance with the present invention, the focusing or tracking control operation is temporarily inhibited for a predetermined time period immediately after the initiation of recording of data to the optical disc and immediately after the termination of recording of data to the optical disc if a focusing or tracking error signal has been detected to exceed a predetermined range.

Abstract: A floppy disc device having a read/write head, a pair of erase heads and a delay mechanism for delaying the operation of the erase heads with respect to the operation of the read/write head is provided. The pair of erase heads is provided in the downstream direction of the read/write head with respect to the movement of a floppy disc recording medium, thereby avoiding cross coupling between the read/write and erase heads. In accordance with one aspect of the present invention, the delay mechanism delays energization and deenergization of the erase heads with respect to those of the read/write head. Another aspect of the present invention is that the delay mechanism delays energization of the erase heads with respect to energization of the read/write head for some of a plurality of concentic recording tracks. The present invention made it possible to carry out proper tunnel-erasing without under-erasing and/or over-erasing.

Abstract: A slag-forming agent comprising an aggregate of particulate material having a maximum diameter of 3.0 millimeters and containing at least 15 weight percent magnesium oxide, the aggregate being coated with from 5 to 20 weight percent cement, and a process for producing the agent in which the particulate material is wetted with water to form the aggregate, the wet aggregate is coated with cement and the wet coated aggregate is solidified as such or after being molded.

Abstract: An automatic sheet feeding system of a printing apparatus comprising a platen, a printing head, a sheet ejecting stacker and a sheet feeding stacker. The platen remains stationary when the leading edge of a sheet fed by the sheet feeding roller has abutted against the platen, whereby the tilting position of the sheet can be corrected. The system comprises further sheet leading edge detecting means disposed at the inlet of the sheet ejecting passage near the platen. When the detecting means detects the leading edge of a sheet, the platen can be rotated in the reverse direction through a predetermined angle for setting the printing initiating position on a sheet at a predetermined distance from the leading edge of the sheet.