Abstract: In a workpiece joining method using a joining jig, a distal end portion of a bolt shaft is inserted into each hole of at least one workpiece, and a sleeve is disposed onto a distal end portion of each bolt shaft. Then, an upper die of the joining jig is lowered toward the workpiece supported on a lower die so that while the workpiece is being pressed toward base end portions of the bolt shafts, a tightening portion of each nose provided on the upper die draws the outer wall of the corresponding sleeve, thus tightening the sleeves. As the tightening process progresses, the tightened portion of each sleeve progressively enters a relief portion formed immediately above the tightening portion. The thrust of the noses does not directly acts on the bolt shafts in the direction of their axes, so that the joining jig can apply a sufficient tightening force without being restricted by the strength of the bolt shafts.

Abstract: The present invention relates to a method for producing acrylonitrile comprising the steps of reacting propylene and/or propane, ammonia and molecular oxygen in the presence of a catalyst to form a reacted gas, contacting the reacted gas with a liquid containing water and an acid in a multi-stage quenching tower having three or more chambers and transferring the liquid contacted with the reacted gas in the second quenching chamber to the first quenching chamber. According to the present invention, high boiling point compounds are efficiently removed and clogging is prevented in an acrylonitrile recovery process so that the productivity of acrylonitrile is enhanced.

Abstract: A tester for measuring a durability of a knitted yarn portion in which at least two sets of yarns, including a set of first yarns and a set of second yarns, are intersected, the tester includes: a first holding unit holding ends of the two sets of yarns at first positions that are relative to the knitted yarn portion; a second holding unit holding opposite ends of the two sets of yarns at second positions that are relative to the knitted yarn portion; and a position adjusting unit, connected to the first holding unit and the second holding unit, allowing at least one of the first positions and the second positions, relative to the knitted yarn portion, to be moved to other positions, thus varying an intersecting angle of the yarns of the knitted yarn portion.

Abstract: The present invention relates to an improvement of an ionizing smoke sensor having one radiation source and a two chambered structure consisting of an internal ionization chamber housing an internal electrode having a radiation source and defined by an intermediate electrode, and an external chamber where smoke can flow in, defined by an external electrode and irradiated from the radiation source through an opening in the intermediate electrode. Hitherto, in an ionizing smoke sensor having one radiation source and a two chambered structure, there has been a problem in that the giving of misinformation and noinformation occur when a little amount of thread, moisture or dust invades or a current of air flows an internal ionization chamber through an opening and an external ionization chamber. In addition, the electric field in the internal ionization chamber loses its homogeneity because of the opening, hence V-I characteristics preferable for the internal ionization chamber can not be obtained.

Abstract: An ionization-type smoke sensor having a 2-chamber 1-radiation source structure including an inner electrode having a radiation source, an intermediate electrode having an opening through which radiation from the radiation source passes, an outer electrode through which smoke may flow inside from outside, and an insulator supporting and insulating the inner electrode, the intermediate electrode and the outer electrode. In the sensor, a fence portion made of an insulating material is formed on and projecting from a surface of the insulator which faces the outer electrode, the fence portion surrounding the periphery of the opening of the intermediate electrode. By virtue of this arrangement, even when the sensor is subjected to flow of air heading from outside toward the opening of the intermediate electrode, the fence serves to reduce the flow of air heading toward the opening, thereby enabling the characteristics of the sensor chambers to remain stable against flow of air.

Abstract: A fire detector and a fire alarm system wherein a plurality of fire detectors are connected across a pair of lines leading to a signal station and which is capable of detecting, at the signal station, removal of a detector head or heads from an associated socket or sockets of any one or more detectors and yet capable of keeping the succeeding fire detectors operative to send a possible fire alarm signal even after removal of the head or heads. Each of said fire detectors comprises a means for disconnecting the line connected therethrough to the succeeding detector, temporarily in the course of removal of the detector head or heads from the associated socket or sockets or periodically after the detector or detectors has or have been removed from the associated socket or sockets. The signal station comprises a means for detecting the temporary or periodical disconnection of the line.

Abstract: Disclosed is a two-wire system including a power source, a signal receiving section and a sensing device in series which supplies electric power to and receives sensing signals from signaling devices in the system. A capacitor is connected to each sensing device for preventing a voltage drop upon initiation of its sensing action. A buffer circuit is further coupled with the receiving section for protecting against false operation by an initial current which increases upon switching on the power source, thus ensuring the system becomes stable.

Abstract: In wet-oxidizing organic waste water containing cyanogen i.e. inorganic-CN, or a compound capable of forming cyanogen under oxidative conditions, if the wet oxidation is conducted in the presence of copper or a copper compound and a specific ammonium salt, COD and the cyanogen concentration can be reduced at highly improved removal ratios. Copper ions resulting from the copper component made present at the wet oxidation step can be effectively removed by precipitation or ion exchange. Accordingly, this treatment method does not cause secondary pollution at all. In case recovery of the copper ions is performed by ion exchange, good results are obtained when the oxidized liquid from the wet oxidation step is flashed at a temperature higher than 100.degree. C. and the pH of the oxidized liquid is adjusted to 4-7 after the cyanogen decomposition step but before the ion exchange treatment. A weakly acidic ion exchange resin is preferably employed.

Abstract: In a smoke sensor of the ionization type having as essential component parts an opposing pair of electrodes providing for high impedance effected by ionic current produced by a radioactive ray source, improvements are made to eliminate formation of dew at least on the surface of the radioactive ray source and also prevent the high impedance from being accidentally changed due to a cause other than smoke, for instance a comparatively intense air stream which may otherwise cause a casual change of the high impedance.