Abstract: A urea synthesis process with improved heat economy, wherein a urea synthesis solution obtained by removing most of the unreacted ammonium carbamate by stripping with carbon dioxide at a pressure approximately equal to a urea synthesis pressure is subjected to a high and low pressure decomposition. The gas mixture obtained from the high-pressure decomposition is condensed in at least two steps.

Abstract: To provide economical high-speed optical communications through an optical module a silicon substrate with a ball lens and semiconductor luminescence element mounted thereon, and a laser driver IC are provided. A silicon subassembly includes a silicon substrate with a pyramidal cavity etched into the substrate near its edge. A ball lens is precision-mounted in the pyramidal cavity by bonding it at multiple points. This provides a high-strength connection and a small, inexpensive silicon substrate. Also provided on the silicon substrate is a semiconductor luminescence element and a slit on the opposite side of the ball lens. The slit enables collimated light emitted from the ball lens to be optically coupled without being blocked or reflected by the substrate. The semiconductor luminescence element and its laser driver IC are placed in close proximity to each other, and ribbon wires are kept short (approximately 300 &mgr;m) to reduce signal line impedance mismatch for high-speed transmission.

Abstract: Urea is prepared by reacting ammonia and carbon dioxide in an apparatus comprising a vertical condensation and synthesis column and a stripper, to provide a urea synthesis solution comprising urea, unreacted ammonia, unreacted carbon dioxide and water. The urea synthesis solution is transferred from the top of the vertical condensation and synthesis column to the top of a stripper. Carbon dioxide is introduced into the bottom of the stripper and contacted with the urea synthesis solution, thereby separating the unreacted ammonia and the unreacted carbon dioxide from the urea, and providing a mixed gas comprising ammonia, carbon dioxide and water. The mixed gas is transferred into the bottom of the vertical condensation and synthesis column, where it is reacted with liquid ammonia injected into the bottom and a middle of the vertical condensation and synthesis column. The mixed gas and liquid ammonia are condensed and react to form urea.

Abstract: A printing machine comprises a printing drum rotationally driven around a central axis of itself. The drum has a cylindrical circumferential wall with an ink-permeable image area and an ink supplying device disposed to an inside of the circumferential wall for supplying ink to an inner surface of the circumferential wall. The machine also comprises a rotatable press roller vertically movably disposed below the drum and for sandwiching a printing body between the drum and the press roller. The machine also comprises a first supporting roller and a second supporting roller. The first supporting roller is disposed before the press roller in a printing body conveyance direction. The second supporting roller is disposed after the press roller in the printing body conveyance direction. Both the first and the second rollers are vertically movable in synchronization with a vertical movement of the press roller and supporting the printing body to be movable in the printing body conveyance direction.

Abstract: A line protection switch equipment (LPSW) in a communication system, having a plurality of two-input and two-output switches connected between lines including a protection line and working lines, the switches being connected in series by a loop line which forms a loop, whereby by switching the switches connected to a faulty working line and to a protection line, the faulty working line is switched to become a protection line, and the former protection line becomes a working line.