Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A gas separation membrane module, comprising: a hollow fiber element having a hollow fiber bundle consisting of a number of hollow fiber membranes and a tube sheet provided at an end of the hollow fiber bundle for binding the hollow fiber membranes; a vessel having an opening through which the hollow fiber element is inserted or removed; a lid member having a gas outlet formed therein and attached to cover the opening of the vessel; and a perforated plate having a plurality of through holes for forming gas channels formed therein, the perforated plate being mounted between the tube sheet and the lid member, the gas separation membrane module performing gas separation by supplying mixed gas to the hollow fiber membranes.

Abstract: A process for producing nitrogen-rich air by feeding high temperature air at 150° C. or more to an air separation membrane module is described. After being placed at 175° C. for two hours, the air separation module exhibits a shape-retention ratio of 95% or more in one embodiment. The nitrogen-rich air can be fed to a fuel tank for an aircraft, for example.

Abstract: A gas separation membrane module, comprising: a hollow fiber element having a hollow fiber bundle consisting of a number of hollow fiber membranes and a tube sheet provided at an end of the hollow fiber bundle for binding the hollow fiber membranes; a vessel having an opening through which the hollow fiber element is inserted or removed; a lid member having a gas outlet formed therein and attached to cover the opening of the vessel; and a perforated plate having a plurality of through holes for forming gas channels formed therein, the perforated plate being mounted between the tube sheet and the lid member, the gas separation membrane module performing gas separation by supplying mixed gas to the hollow fiber membranes.

Abstract: There is provided a process for producing nitrogen-rich air by feeding a high temperature air at 150° C. or more to an air separation membrane module.

Abstract: An asymmetric hollow-fiber gas separation membrane is made of a soluble aromatic polyimide that is composed of a specific repeating unit. The tetracarboxylic acid component of the unit has a diphenylhexafluoropropane structure and a biphenyl structure. The diamine component of the unit essentially contains diaminobenzoic acids and any of diaminodibenzothiophenes, diaminodibenzothiophene=5,5-dioxides, diaminothioxanthene-10,10-diones, and diaminothioxanthene-9,10,10-triones.

Abstract: An asymmetric hollow-fiber gas separation membrane is made of a soluble aromatic polyimide that is composed of a specific repeating unit. The tetracarboxylic acid component of the unit has a diphenylhexafluoropropane structure and a biphenyl structure. The diamine component of the unit essentially contains diaminobenzoic acids and any of diaminodibenzothiophenes, diaminodibenzothiophene=5,5-dioxides, diaminothioxanthene-10,10-diones, and diaminothioxanthene-9,10,10-triones.

Abstract: A fishing line composed of a strand of a plurality of steel wires twisted together and coated with synthetic resin, wherein the steel wire is a low carbon duplex structure steel wire in the fibrous fine metallic structure having a tensile strength of 300 to 600 kgf/mm.sup.2 and coated by plating with anticorrosive metal on the outer surface, the twist pitch of the strand being 13 to 20 times the diameter thereof and the thickness of coating layer of synthetic resin being 4 .mu.m or more. This fishing line is high in tensile strength and knot strength, and is hardly kinked or curled when subjected to impact.

Abstract: An inspection probe which allows a plurality of such inspection probes to be arranged at a remarkably reduced pitch. The inspection probe comprises a very thin metal wire having a diameter of 120 .mu.m or less and so shaped as to have self resiliency, and a plated noble metal layer formed on a surface of the very thin wire. A probe pin head for the inspection of an electronic circuit board is constructed employing a plurality of such inspection probes. The inspection probes are secured to or embedded in a base made of a resin material. A process of producing the probe pin head is also disclosed.