Abstract: Disclosed is a method for producing a chirped in-fiber Bragg grating, in which an interval between gratings varies continuously depending on a location of the gratings observed along an optical fiber, comprising a first step of winding the optical fiber in a spiral groove formed around a conical bobbin which is shaped in a frustum of a right circular cone having a predetermined vertex angle and a height between predetermined first and second diameters, and a second step of irradiating the optical fiber wound on the conical bobbin with ultraviolet rays at every crossing of the optical fiber with a predetermined number of uniformly distributed generating lines of the conical bobbin, each extending radially on the surface of the conical bobbin from an imaginary vertex thereof, for modifying the refractive index of a core of the optical fiber to form the grating at the every crossing.

Abstract: Method and apparatus for cleaning oxide scale from rolling mill rolls comprises a cleaning spray system including a fluid header juxtaposed to a mill work roll and an associated backup roll and a plurality of nozzles equidistantly spaced along the length of the header. High pressure cleaning water sprays, for which water is supplied by a descaling pump when not in use for descaling, are directed onto a work roll, and by rotation of the header, then directed onto the associated backup roll. The water sprays are directed against the rolls at an angle from 3.degree. to 10.degree. for optimum removal of oxide scale. For even restoration of the roll surface, the cleaning spray system periodically during the cleaning operation is shifted axially along the length of the rolls a distance about one-half the spacing between adjacent nozzles.