Abstract: A crack-type fatigue detecting sensor comprises: a foil substrate having a first surface and a second surface fixed to a member to be tested; and a foil fracture piece having a slit formed in a central portion between opposite end portions in a longitudinal direction thereof such that the slit extends from one side portion toward the other side portion in a width direction thereof perpendicular to the longitudinal direction, wherein the opposite end portions of the fracture piece are respectively fixed to the first surface of the substrate and a portion including the central portion having the slit has a thickness smaller than a thickness of the opposite end portions over a whole width.

Abstract: A crack-type fatigue detecting sensor comprises: a foil substrate having a first surface and a second surface fixed to a member to be tested; and a foil fracture piece having a slit formed in a central portion between opposite end portions in a longitudinal direction thereof such that the slit extends from one side portion toward the other side portion in a width direction thereof perpendicular to the longitudinal direction, wherein the opposite end portions of the fracture piece are respectively fixed to the first surface of the substrate and a portion including the central portion having the slit has a thickness smaller than a thickness of the opposite end portions over a whole width.

Abstract: A finger skirt for an air-cushion vehicle wherein the bottom edge of each finger skirt, when it is in the state of inflation by the pressurized air for the levitation of the hull, is shaped so that it extends horizontally at the location where it comes in contact with the pressure-receiving surface, the bottom edge being formed so that its cross section is a circular arc.

Abstract: For cutting sheet metal or other work by means of a jet of water containing abrasive particles, an abrasive water jet nozzle assembly is provided to which there are separately supplied highly pressurized water and an abrasive suspension. The abrasive suspension is such that abrasive particles with an average size of up to 100 microns are held in suspension in water. The abrasive suspension is introduced into the ejected water by virtue of a partial vacuum created in the nozzle assembly by the pressurized water. The nozzle assembly directs the resulting mixture as an abrasive water jet against the work for cutting thereof. Preferably, the abrasive water jet is recovered for recirculation back to the nozzle assembly as an abrasive suspension of controlled abrasive concentration. Various constructions of the nozzle assembly and various recovery systems are also disclosed.