Abstract: An optical communications system includes a plurality of optical fiber spans. An optical loss of one of the plurality of optical fiber spans is different from an optical loss of another one of the plurality of optical fiber spans. At least one of the plurality of optical fiber spans includes an optical loss that is greater than or equal to 35 dB and at least one of the plurality of optical fiber spans includes an optical loss that is less than 30 dB. An optical amplification system includes at least one discrete optical amplifier, at least one distributed optical amplifier, and an optical loss element. The optical amplification system has spectral gain that compensates for substantially all losses experienced by the optical signals propagating in the plurality of optical fiber spans.

Abstract: A method and apparatus for accelerating solid particles entrained in a carrier gas so as to maximize the velocity of the particles at the output end of a duct is presented. This maximized or optimal acceleration is achieved by varying the cross section of the duct over at least the last 5 meters upstream from the opening thereof. Preferrably, the cross section of the duct should continuously increase i.e. diverge, towards the opening. This diverging cross section is preferrably in accordance with a nonlinear function of the length.

Abstract: A rotatable drum, which bears beater bars and is intended for use in pulverizing metallurgical slag, is defined by abutting conduits which are welded to one another and to a tubular support. The arrays of conduits, through which a coolant is circulated, is interrupted at a number of locations spaced radially about the support where radially outwardly extending beater bars are welded to the same support. The beater bars are also provided with internal passages through which the coolant is circulated.

Abstract: Entrained particulate matter is separated from the pressurized gas released from an intermediate charge material storage hopper of a blast furnace charging installation, the hopper alternately being pressurized to the furnace pressure for release of charge materials into the furnace and the pressure being relieved to atmospheric to permit reloading, at a point upstream of the filters and/or silencers through which the pressurized gas is released to the ambient atmosphere. The separator comprises a series of perforated discs, which may be heated, associated with a collection chamber into which separated material will fall under the influence of gravity.