Disclosed herein is a composite hollow fiber polymer membrane including a porous core layer and a selective sheath layer. The porous core layer includes a polyamide-imide polymer, or a polyetherimide polymer, and the selective sheath layer includes a polyimide polymer, which is prepared from monomers A, B, and C. The monomer A is a dianhydride of the formula ##STR00001##
wherein X.sub.1 and X.sub.2 are independently halogenated alkyl group, phenyl or halogen and R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are independently H, alkyl, or halogen. The monomer B is a diamino cyclic compound without a carboxylic acid functionality and the monomer C is a diamino cyclic compound with a carboxylic acid functionality. The polyimide polymer further includes covalent ester crosslinks. Also disclosed herein is a method of making the composite polymer membrane and a process for purifying natural gas utilizing the composite polymer membrane.

Disclosed herein is a composite hollow fiber polymer membrane including a porous core layer and a selective sheath layer. The porous core layer includes a polyamide-imide polymer, or a polyetherimide polymer, and the selective sheath layer includes a polyimide polymer, which is prepared from monomers A, B, and C. The monomer A is a dianhydride of the formula ##STR00001##
wherein X.sub.1 and X.sub.2 are independently halogenated alkyl group, phenyl or halogen and R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are independently H, alkyl, or halogen. The monomer B is a diamino cyclic compound without a carboxylic acid functionality and the monomer C is a diamino cyclic compound with a carboxylic acid functionality. The polyimide polymer further includes covalent ester crosslinks. Also disclosed herein is a method of making the composite polymer membrane and a process for purifying natural gas utilizing the composite polymer membrane.

The invention describes a flexible tubular article for transport of volatile hydrocarbons comprising: (a) an inner layer of a polyvinylidene difluoride (PVDF) polymer or a polyvinylidene difluoride copolymer; (b) an intermediate thermoplastic polyurethane (TPU) layer extruded in tubular form over the inner PVDF layer, and (c) a polyvinyl chloride polymer extruded in tubular form over the outside surface of the intermediate layer and being coextensive therewith. The tubular articles of the invention have a maximum permeation rating of 15 g/m.sup.2/day under SAE J1737 test conditions.

The invention describes a flexible tubular article for transport of volatile hydrocarbons comprising: (a) an inner layer of a polyvinylidene difluoride (PVDF) polymer or a polyvinylidene difluoride copolymer; (b) an intermediate thermoplastic polyurethane (TPU) layer extruded in tubular form over the inner PVDF layer, and (c) a polyvinyl chloride polymer extruded in tubular form over the outside surface of the intermediate layer and being coextensive therewith. The tubular articles of the invention have a maximum permeation rating of 15 g/m.sup.2/day under SAE J1737 test conditions.

The teachings herein relate to devices for insertion into a cavity, opening or other passageway that requires the bending of the device to conform to a curved or even tortuous shape of the path. The devices include axial support components for translating forces for moving the device forward in the path. The axial support components preferably include adjacent components capable of rocking for tilting the device in one or more directions. The device preferably includes one or more lateral support components for limiting any lateral motion of an axial support component relative to an adjacent axial support component.

A boreable multiduct assembly packaged for sale includes a receiver, a continuous outer conduit having a central lumen and multiple innerducts held freely in that lumen.

A method and apparatus to facilitate learning while moving, efficient multitasking involving movement while the user processes or responds to different stimuli. The stimuli may include but are not limited to information related to education or entertainment or feedback concerning the user's movement. More specifically this movement may be related to coordination, exercise or physiotherapy. The methods and apparatuses of the disclosure involve the user conducting movement, while simultaneously processing information (via: learning; creating through typing, moving, or talking; or being entertained) and receiving feedback or assistance related to that movement, processing, or any combination thereof.

A method and apparatus to facilitate learning while moving, efficient multitasking involving movement while the user processes or responds to different stimuli. The stimuli may include but are not limited to information related to education or entertainment or feedback concerning the user's movement. More specifically this movement may be related to coordination, exercise or physiotherapy. The methods and apparatuses of the disclosure involve the user conducting movement, while simultaneously processing information (via: learning; creating through typing, moving, or talking; or being entertained) and receiving feedback or assistance related to that movement, processing, or any combination thereof.

A hose assembly includes an inner core tube, a connector including a stem portion inserted into a distal end of the inner core tube, an outer metal tube substantially coaxial with and surrounding the inner core tube, and a collar substantially coaxial with and surrounding the distal end of the inner core tube. The outer metal tube terminates at a distal end axially inward of the distal end of the inner core tube. The collar includes a flared first end welded to the distal end of the outer metal tube and a second end welded to the connector.

The invention features a packaging material including a film having a barrier layer formed from an admixture containing a base polymer and a surface-modifying macromolecule. The invention also features containers made from the packaging materials and methods of storing a good.