Abstract: A novel gas laser apparatus is disclosed, which comprises a hermetic container with a gas laser medium sealed therein, a plurality of main discharge electrodes arranged in the hermetic container for causing the main discharge in the gas laser medium thereby to generate a laser beam, and a device for subjecting the discharge space between the main discharge electrodes to preionization over a wide range thereof before the main discharge by use of a reflected laser beam or an ultraviolet ray lamp.

Abstract: Disclosed is a picture display apparatus connected to a low resolution ultrasonic inspector so as to display a picture with high resolution. In the apparatus, an approximate spectrum of a theoretical spectrum representing an object having a known shape as a reference and a spectrum obtained through measurement of the known-shaped object are subject to Fourier transformation so that a transfer function of a measurement device is calculated from the ratio between the respective values obtained through the two operations of Fourier transformation, whereby an unknown shape of an object is displayed on the basis of the transfer function and Fourier transformation values of a measured spectrum of the object having the unknown shape.

Abstract: A two-stage air compressor unit having an intercooler and aftercooler placed in side by side relationship to form an integral unit which is cooled by forced air blown by a motor driven fan and which has the inlet and outlet parts located in such a manner that little, if any, heat transfer occurs between the intercooler and the aftercooler so that greater cooling efficiency is realized.

Abstract: An ultrasonic inspection apparatus and method in which a linear array of acoustic transmitters and receivers are disposed adjacent to a workpiece, and alternating potential source is connected to some of the acoustic transmitters to project a side lobe of an acoustic wave toward a specific zone of the workpiece. Thereafter, the connections between some of the acoustic transmitters and the potential source are automatically changed, to move the specific zone as many times as may be necessary to provided scanning of the workpiece.

Abstract: A compact, balanced and lightweight air compressor unit for a railroad vehicle which includes a motor-driven compressor, a suction strainer and suction silencer. The compressor and motor are interconnected by an intermediate hollow flanged mounting member which has a cross-sectional dimension that is smaller than the cross-sectional dimension of the motor and compressor. The suction strainer is located in a space between the motor and compressor and is attached to one side of the intermediate hollow mounting member while the suction silencer is located in a space between the motor and compressor and is attached to the other side of the intermediate hollow mounting member to form a substantially balanced structure which is suspended to the underside of the floor of the railroad vehicle by a plurality of resilient bumper connectors.

Abstract: A two-probe ultrasonic flaw detection apparatus, in which an ultrasonic wave is transmitted from a transmission probe into an object being inspected and ultrasonic waves reflected from a reflection surface in the object are received by a reception probe, operates to determine the position at which the combined intensity of ultrasonic waves reflected from each part of the reflection surface form a maximum. The reception probe is then moved to the position of maximum reception intensity. The position of maximum reception intensity is determined using as input parameters the ultrasonic characteristics of the object being inspected and of the transmission and reception probes, and the position of the transmission probe and the angle of incidence of the ultrasonic wave into the object.

Abstract: An ultrasonic flaw detecting technique in which reflection echoes of ultrasonic waves transmitted from a plurality of vibrator elements are received, and a composite signal obtained by composing the reception signals is supplied to a composite signal reception processing circuit. A method and an apparatus in which the existence of the composite signal is detected at a first time point at which the composite signal based on the reflection echoes from an inspection target in a main lobe can be detected and at a second and a third time point which are in advance of and later than the first time point respectively and at which the composite signal based on the reflection echoes from an inspection target in the main lobe can not be detected, so that when the existence of the composite signal is detected only at the first time point, it is determined that the composite signal is that based on the reflection echoes from the inspection target.