Abstract: An oxygen concentration apparatus (300) according to the present invention has: pressure swing adsorption type oxygen concentration means (310); and a control means (350) that controls switching means (316) that switches between intake of pressurized air into an adsorption column (312) and exhaust from the adsorption column. The switching means is controlled based on pressure in oxygen concentrated gas in the conduit measured by pressure measuring means to adjust a cycle of adsorption and regeneration processes of the oxygen concentration means so that pressure at the upstream of flow rate adjusting means (340) can be controlled and, as a result, the need for a mechanical pressure regulating valve, that has been needed conventionally, can be eliminated.

Abstract: An oxygen concentration apparatus (300) according to the present invention has: pressure swing adsorption type oxygen concentration means (310); and a control means (350) that controls switching means (316) that switches between intake of pressurized air into an adsorption column (312) and exhaust from the adsorption column. The switching means is controlled based on pressure in oxygen concentrated gas in the conduit measured by pressure measuring means to adjust a cycle of adsorption and regeneration processes of the oxygen concentration means so that pressure at the upstream of flow rate adjusting means (340) can be controlled and, as a result, the need for a mechanical pressure regulating valve, that has been needed conventionally, can be eliminated.

Abstract: An oxygen-concentrating equipment comprising an oxygen-concentrating means for separating oxygen from air and concentrating the oxygen, a humidifying means for humidifying the oxygen-concentrated air produced by said oxygen-concentrating means, and an oxygen-supplying means for supplying the humidified oxygen-concentrated air to a user, characterized in that said humidifying means has at least a cation-conducting solid electrolyte membrane equipped with electrodes on both the sides of the membrane and an electric source for applying an electric current to said electrodes.

Abstract: An oxygen-concentrating equipment comprising an oxygen-concentrating means for separating oxygen from air and concentrating the oxygen, a humidifying means for humidifying the oxygen-concentrated air produced by said oxygen-concentrating means, and an oxygen-supplying means for supplying the humidified oxygen-concentrated air to a user, characterized in that said humidifying means has at least a cation-conducting solid electrolyte membrane equipped with electrodes on both the sides of the membrane and an electric source for applying an electric current to said electrodes.

Abstract: Novel optically active compounds of 4-protected hydroxy-cyclopent-2-en-1-ones of the formula ##STR1## wherein R is a splittable protective group for an alcoholic hydroxyl group, and a process for preparing the 4-protected hydroxycyclopent-2-en-1-ones by oxidizing monohydroxy-protected derivatives of cyclopent-1-ene-3,5-diol expressed by the following formula ##STR2## wherein R is the same as defined above. Optically active 4-hydroxycyclopent-2-en-1-one which is an optically active isomer of the compound of formula (2); or optically active cyclopent-1-en-3,5-diol (R-isomer) and a novel diacyl derivative of the diol, a novel monoacylmonosilyl-derivative of the diol and a novel monoacylmonotetrahydropyranol-derivative of the diol, which are intermediates for the protective derivative of formula (1). Processes are also provided for preparing the protective derivatives of formula (1) by converting these intermediates by esterification, hydrolysis, enzymatic processes, etc.

Abstract: New optically active cyclopentene-diol and the mono- or diacyl esters thereof and a process for converting a diacyl ester of cyclopent-1-en-3,5-diol to its monoacyl ester and/or its diol which comprises subjecting a diacyl ester of cyclopent-1-en-3,5-diol containing at least one of the optically active or inactive diacyl ester of trans-cyclopent-1-en-3,5-diol (trans-isomer) and diacyl esters of cis-cyclopent-1-en-3,5-diol (cis-isomer), to the action of a microorganism or enzyme having at least a selectivity in its rates of hydrolyzing the acyloxy group (R) configuration and the acyloxy group (S) configuration of said diacyl ester. These new compounds are valuable as starting materials for the preparation of prostaglandin or its analogues.