Abstract: A hollow fiber oxygenator including a hollow fiber bundle having first and second ends located within an oxygenator chamber. The oxygenator chamber includes a hollow core around which the hollow fibers are spirally wound and includes an outer casing adjacent the fibers. A gas entry port is coupled to the interior of the fibers adjacent the first end of the bundle and a gas outlet is coupled to the interior of the fibers at the second end of the bundle. A blood inlet to the oxygenator chamber, exterior of the fibers, is provided adjacent the second end of the bundle, and a blood outlet from the oxygenator chamber is provided adjacent the first end of the bundle. The resulting structure provides an axial flow oxygenator, in which the direction of blood flow through the oxygenator chamber is opposite the direction of gas flow through the fibers.

Abstract: A method of selectively sensing the quantity of methane gas in an oxygen containing gas stream, which method, as taught in one of its preferred embodiment, includes the step of providing a platinum catalyst (12) and a palladium catalyst (14). The platinum and the palladium catalysts are electrically interconnected (16--16) so as to obtain an electrical output reading (24) therefrom. The electrically interconnected catalysts are heated to a temperature in a range of 350.degree.-450.degree. C. whereby a reference electrical output reading is obtained therefrom. A gas stream containing suspected methane is passed over the electrically interconnected catalysts. Methane gas contained in the gas stream is oxidized only by the palladium catalyst while all other oxidizable components of the gas stream are oxidized by both catalysts.

Abstract: A locking microcentrifuge tube (10) is provided which is capable of being sealed in either of two manners, one being a friction-fit seal which is easily opened and the other being a "locked" seal for higher stress applications. The tube body (12) is adapted to mate with the cap (14) at an aperture (24) such that the plug portion (36) of the cap (14) and the aperture (24) form the friction-fit seal at the early stages of insertion. A collar (26) is provided about the aperture (24) on the tube body (12). The collar (26) is formed to include one or more circumferential projections (28, 30). The cap (14) is formed to include depressions (32, 34) adapted to mate with the projections (28, 30) upon full insertion of the plug portion (36) to create the "locked" seal. The cap (14) is secured to the tube body (12) by a hinge (38) and a tab (40). The primary usage of the locking microcentrifuge tube (10) is in biomedical laboratory analysis.