Abstract: A power supply circuit includes PCU switches provided in respective positive wires of a first power source conduction path and a second power source conduction path which connect a first generator respectively to a first power transmission bus and a second power transmission bus, and further includes power transmission bus switches provided in respective negative wires of a first load conduction path and a second load conduction path which connect respectively the first power transmission bus and the second power transmission bus to a first load.

Abstract: A technology for widening the operating range of a high-pressure ratio centrifugal compressor including a vaned diffuser is provided. The solidity of each vane in the vaned diffuser is set to the optimum value at which the region, in which burbles do not occur when the air flows into the diffuser, is wider than the region, in which burbles may occur when the air flows into the diffuser. In addition, the solidity is set in such a manner that the straight line, which extends outward from the inner peripheral edge of the vane at a right angle with respect to the chord of the vane, does not cross the adjacent vane. In this way, formation of a throat between the vanes is suppressed.

Abstract: An ink jet recording head, which can effectively prevent any bubble and solid matter such as dust existing in supplied ink to reach the vicinity of a nozzle, includes a plurality of energy generating elements for generating energy for discharging the ink, a plurality of discharge ports provided at locations opposed to the respective energy generating elements to discharge the ink therethrough, a plurality of ink flow paths communicating with the respective discharge ports, and an ink supplying port for supplying the ink to the plurality of ink flow paths. Water repellent protruding portions having their surfaces formed of a material having surface energy smaller than the interfacial energy between them and the ink are provided upstream of the discharge ports with respect to an ink flow direction in which the ink flows from the ink supplying port into the ink flow paths and is discharged from the discharge ports.

Abstract: An ink jet recording head which makes it difficult for any bubble and solid matter such as dust existing in supplied ink to reach the vicinity of a nozzle includes a plurality of energy generating elements 2 for generating energy for discharging the ink, a plurality of discharge ports 1 provided at locations opposed to the respective energy generating elements to discharge the ink there through, a plurality of ink flow paths 4 communicating with the respective discharge ports 1, and an ink supplying port 7 for supplying the ink to the plurality of ink flow paths 4. Water repellent protruding portions 6 having their surfaces formed of a material having surface energy smaller than the interfacial energy between them and the ink are provided upstream of the discharge ports 1 with respect to an ink flow direction in which the ink flows from the ink supplying port 7 into the ink flow paths 4 and is discharged from the discharge ports 1.