Abstract: A pressure vessel liner includes a tubular trunk, and head plates for closing opposite end openings of the trunk. Provided inside the trunk is a reinforcing member integral with the trunk and extending longitudinally of the trunk for dividing the interior of the trunk into a plurality of spaces. The two head plates are joined respectively to opposite ends of the reinforcing member. The pressure vessel liner has an enhanced pressure resistant strength against longitudinal forces.

Abstract: This invention relates to a cerium-zirconium-base composite oxide, which is useful, e.g., for the purification of exhaust gas discharged from combustion engines such as internal combustion engines and boilers and can release a high level of oxygen in a low temperature region, a method for producing the same, an oxygen storage/release component using the same, an exhaust gas purification catalyst, and an exhaust gas purification method. The cerium-zirconium-base composite oxide satisfies requirements (1) that the oxygen release initiation temperature is 380° C. or below, (2) that the oxygen release amount is not less than 485 ?mol/g, and further (3) that the oxygen release amount at 400° C. is not less than 15 ?mol/g.

Abstract: A pressure vessel liner includes a tubular trunk and head plates for closing opposite end openings of the trunk. The pressure vessel liner includes a first liner component providing the trunk, and two second liner components joined respectively to opposite ends of the first liner component and providing the two head plates. The first and second liner components have reinforcing walls provided inside peripheral walls, respectively, and correspond to one another in the position of the reinforcing walls. Each adjacent pair of liner components have their reinforcing walls joined in corresponding relation. The liner has an increased pressure resistant strength against longitudinal forces.

Abstract: A NO.sub.x removal catalyst resistant to high temperatures, comprising an activated alumina wherein the specific surface area measured by the nitrogen adsorption method is 120 m.sup.2 /g or more, the bulk density measured by the mercury porosimetry is 0.60 g/cm.sup.3 or more, and the skeleton density measured by the mercury porosimetry is 1.80 g/cm.sup.3 or less and silver carried on said activated alumina. Then said catalyst or a structure having said catalyst coated on a substrate is brought in contact with exhaust gas from an internal combustion engine that is operated at a lean fuel/air ratio, such as a lean-burn engine, NO.sub.x can be removed efficiently within a quite short contact time.

Abstract: A NO.sub.x removal catalyst resistant to high temperatures, comprising an activated alumina wherein the specific surface area measured by the nitrogen adsorption method is 120 m.sup.2 /g or more, the bulk density measured by the mercury porosimetry is 0.60 g/cm.sup.3 or more, and the skeleton density measured by the mercury porosimetry is 1.80 g/cm.sup.3 or less and silver carried on said activated alumina. When said catalyst or a structure having said catalyst coated on a substrate is brought in contact with exhaust gas from an internal combustion engine that is operated at a lean fuel/air ratio, such as a lean-burn engine, NO.sub.x can be removed efficiently within a quite short contact time.