Abstract: To provide a differential refractive index detector free from fears for occurrence of personal errors in the judgement of stable condition and capable of performing highly efficient analysis operation, and a liquid chromatograph equipped with the detector.

Abstract: A method for hydroforming a metallic tube comprising primary hydroforming and secondary hydroforming, wherein in the primary hydroforming step, the metallic tube is formed such that a circumferential length of an expanded portion of the primary-hydroformed tube as measured at a wall center region of the expanded portion becomes substantially equal to or slightly shorter than a circumferential length of an expanded portion of a product as measured at a wall center region of the expanded portion, and in the secondary hydroforming step, movable forming plates incorporated in the dies press the expanded portion formed through primary hydroforming so as to finish the cross-sectional profile of the expanded portion into that of the expanded portion of the product, and said primary hydroforming and secondary hydroforming are continuously performed within the dies. Also disclosed is an apparatus for performing the hydroformation method.

Abstract: A method for hydroforming a metallic tube comprising primary hydroforming and secondary hydroforming, wherein in the primary hydroforming step, the metallic tube is formed such that a circumferential length of an expanded portion of the primary-hydroformed tube as measured at a wall center region of the expanded portion becomes substantially equal to or slightly shorter than a circumferential length of an expanded portion of a product as measured at a wall center region of the expanded portion, and in the secondary hydroforming step, movable pads incorporated in the dies press the expanded portion formed through primary hydroforming so as to finish the cross-sectional profile of the expanded portion into that of the expanded portion of the product, and said primary hydroforming and secondary hydroforming are continuously performed within the dies. Also disclosed is an apparatus for performing the hydroformation method.

Abstract: A method and apparatus for hydroforming a metallic tube including the steps of: preliminarily expanding the metallic tube over an axial section longer than the length of the expanded portion of a final product as measured in the axial direction of the metallic tube; and compressing the preliminarily expanded portion in the axial direction of the metallic tube so as to form the shape of the expanded portion of the final product. According to the method and apparatus of the invention, frictional resistance between the metallic tube and processing tools can be reduced, and moreover, the internal pressure within the metallic tube can be reduced during expansion processing.

Abstract: To provide inexpensively a connector constructed of a steel pipe and bearing a tie function of a ladder-type sleeper for railway tracks, in a connector constructed of a steel pipe 1 used in the ladder-type sleeper for railway tracks integrated with longitudinal beams made of concrete and the connectors constructed of steel pipes 1 by feeding concrete, both end portions of the connector constructed of the steel pipe 1 are flattened in the horizontal direction and a corrosion resistant coating 4 is coated at portions of the connector constructed of the steel pipe 1 exposed to the atmosphere.

Abstract: A remote subscriber control system for controlling communications between remote subscriber terminals and a switch includes a remote subscriber transmitter coupled to a subscriber line interface, a switch side transmitter coupled to the switch and a digital transmission path connecting the remote subscriber side transmitter to the switch side transmitter. The remote subscriber side transmitter includes a state change detector for detecting whether or not a state of a remote subscriber terminal has changed, and a state memory for storing state information of the remote subscriber terminal. A dialing number memory stores a dialing number specifying a called terminal. A transmitter/receiver transmits state information and a dialing number, as subscriber control information, to the switch side transmitter and receives control orders from the switch.

Abstract: A resin composition, which comprises (a) a copolymer containing isocyanate group prepared by subjecting a compound represented by the general formula ##STR1## wherein R.sub.1 stands for hydrogen or methyl group and an ethylenic unsaturated monomer to copolymerization, and (b) a copolymer containing amino group prepared by subjecting a compound represented by the general formula ##STR2## wherein R.sub.2 stands for hydrogen or methyl group and an ethylenic unsaturated monomer to copolymerization, has a pot life of such an extent as for permitting them to be used as spray-coating, and the resulting film is excellent in flexibility, chemical resistance, water resistance and corrosion resistance, and, besides, rapid in curability, thus being useful as cold-drying coatings on metals, plastics, woods, inorganic materials, etc. and also as adhesives, etc. The resin composition is very good in compatibility, thus being useful in such a field as required high gloss and beautiful finish.