Abstract: Transducers based on the variable reluctance concept, employing magnetiza, soft, plastic materials. These materials serve as the isolator between the conductors of a coaxial cable. Such materials exist in considerable variety. The magnetization is azimuthal, such as can be generated by electrical currents flowing through the coaxial cable. Any isolated section of the coaxial cable constitutes a transducer, the conductors at one end of which form the terminals, while those at the other end are connected together to provide a closed electrical circuit. Pressure changes, caused, for example, by acoustic signals, on the outer surface of this transducer produce changes in volume, which in turn induce electrical signals due to changes of the magnetic flux. The conductors of the cable transducer can be in the form of wire braids or metal films, neither of which will significantly change the elastic characteristics of the magnetizable plastic material.

Abstract: A device for modulating the intensity of light rays generated from a gas laser in which an input modulating signal is supplied to a switching element included in a modulating current supply source connected across a gas laser discharge tube to control the discharge current and hence modulate the laser light output. The gas laser discharge tube is eventually subjected to the influence of a magnetic field so as to stabilize the laser light output and modulating characteristic.

Abstract: The present invention relates to a miniaturized nuclear battery, consisting of several in series connected cells, wherein each cell contains a support which acts as positive pole and which supports on one side a .beta.-emitter, above said emitter is a radiation resisting insulation layer which is covered by an absorption layer, above which is a collector layer, and wherein the in series connected cells are disposed in an airtight case.

Abstract: A number of seismic detectors are located in a two-dimensional array on the surface of the earth, either on land or at sea. One or more seismic disturbances are produced in the vicinity of the seismic detectors at points located to produce sampling of various subsurface reflection points to form one or more two-dimensional areas of coverage. For each seismic disturbance, the subsurface reflections thereof received by the various seismic detectors are recorded. In some embodiments, the seismic disturbances are produced at points located to produce multi-directional or multi-azimuth sampling of each of various subsurface reflection points and recordings for different ones of the seismic disturbances are combined to produce stacked recordings wherein multi-directional reflections from common subsurface points are added.

Abstract: A system for systematical detecting a leak of fluid from a long pipe comprising a plurality of apparatuses like microphones set at relatively large intervals within a relatively long limited space, formed by utilizing the wall of the pipe like a space within the pipe and extending longitudinally of the pipe. The apparatuses intercept sonic waves caused by the leak of fluid from the pipe propagated in the limited space. The system further includes an apparatus for detecting that at least one first-mentioned apparatus has intercepted the sonic wave caused by the fluid leak.