Abstract: One aspect of the present invention relates to a recovery method of 226Ra, and the recovery method of 226Ra includes a step (A1) of immersing a solid-state 226Ra containing substance and a carrier having a function of adsorbing 226Ra ions in a processing solution, and then irradiating the processing solution with ultrasonic waves.

Abstract: An improved tubular membrane filtration module including an outer cylinder and a plurality of water permeable non-woven fabric pipes formed on the inside thereof, the non-woven fabric pipes being inserted into the outer cylinder in a closely bundled state, the spaces between the fabric pipes and the outer cylinder at each end thereof being filled with hardened synthetic resin to fix and seal the assembly. The ends of the non-woven fabric pipes are coated with a resin such that the inside coating of resin at the end of the fabric pipes is less than that on the inside thereof.

Abstract: An improved tubular membrane filtration module comprising an outer cylinder and a plurality of water permeable non-woven fabric pipes formed on the inside thereof, said non-woven fabric pipes being inserted into the outer cylinder in a closely bundled state, the spaces between the fabric pipes and the outer cylinder at each end thereof being filled with hardened synthetic resin to fix and seal the assembly and wherein the ends of the non-woven fabric pipes are coated with a resin such that the inside coating of resin at the end of the fabric pipes is less than that on the inside thereof.

Abstract: An electroconductive organic polymer exhibiting outstanding electroconductivity is described, containing an electron acceptor as a dopant, and having electroconductivity of not less than 10.sup.-6 S/cm, substantially comprising a linear polymer having as a main repeating unit thereof a quinonediimine structure represented by formula (III) ##STR1## wherein R represents a hydrogen atom or an alkyl group. This polymer can be obtained by oxidative polymerization of an aniline compound or a water-soluble salt thereof with an oxidizing agent in a reaction medium containing a protonic acid.

Abstract: A drug administration material for continuously administering an active drug at a controlled rate through an integument or mucous membrane, which comprises a drug-retaining layer having provided on at least one side thereof a drug administration layer which continuously feeds an active drug to an integument or mucous membrane, said drug administration layer comprising a porous membrane containing in pores thereof a liquid having a limited solubility for the active drug.

Abstract: An electroconductive porous film is described comprising a porous film substrate having deposited thereon an electroconductive organic polymer containing an electron acceptor as a doptant, substantially comprising a linear polymer having as a main repeating unit thereof a quinonediimine structure represented by formula (III). ##STR1## wherein R.sub.1 and R.sub.2, which are the same or different, each represents a hydrogen atom or an alkyl group.

Abstract: A selective permeable membrane comprising a polyquinazolone-based polymer including a repeating unit represented by the formula ##STR1## wherein R.sup.1 is a tetravalent aromatic group, R.sup.2a and R.sup.2b are each independently, an alkyl group or aromatic group, and R.sup.3 is a divalent organic group.

Abstract: A process is described for preparing a selective permeable membrane comprising coating a solution consisting essentially of(i) a polyimide polymer consisting essentially of a repeating unit of the formula (I): ##STR1## wherein R.sup.1 is a divalent organic group, (ii) a swelling agent selected from the group of compounds represented by formula (II) and (III):R.sup.3 O----CH.sub.2 CHR.sup.2 O).sub.n R.sup.4 (II)R.sup.5 ----OH).sub.m (III)wherein R.sup.2, R.sup.3 and R.sup.4, which may be the same or different, can be hydrogen, a methyl group, or an ethyl group, and when R.sup.2 is hydrogen, n can be an integer of from 1 to 5, and when R.sup.2 is a methyl or ethyl group, n can be an integer of from 1 to 3, R.sup.

Abstract: A process for the production of polyquinazolone-based polymers by reacting bisquinazolone with a diamine or a diamine substituted with a carboxylic acid, sulfonic acid or metal salt thereof in the presence of a Lewis acid catalyst or a phosphorus-containing dehydrating agent, where the polymers are useful to produce permselective membranes.