Abstract: The invention relates to a process fop trapping gaseous ruthenium on polyvinyl pyridine, more particularly usable for recovering radioactive ruthenium from irradiated nuclear fuels.This process consists of contacting a gas containing ruthenium in gaseous form with an adsorbent (11b) constituted by a vinyl pyridine polymer or copolymer for fixing the ruthenium to the latter. The gas can be constituted by yapours from a concentrate of fission products containing ruthenium, which has been heated (at 31) in the presence of an oxidizing agent for volatilizing the ruthenium.

Abstract: The invention relates to thiophenes substituted by an alkoxy group containing at least one fluorine atom.The invention also relates to the polymers derived from these substituted thiophenes and to the electrically conductive polymers containing these polymers.The invention also relates to processes for obtaining these thiophenes, these polymers and these electrically conductive polymers.The invention also relates to the uses of these thiophenes, of these polymers and of these electrically conductive polymers as well as to the devices containing the polymers and the electrically conductive polymers.

Abstract: The invention relates to a process for the separation of at least one element such as Nb, Sb, Ce+Pr, actinides and elements from groups VIIb and VIII of the Periodic Classification of Elements from aqueous solutions resulting from the reprocessing of spent nuclear fuels.This process consists of contacting said aqueous solution with a solid resin based on a vinyl pyridine polymer or copolymer and separating from said solution the resin used for fixing said element or elements.The resin is in particular a poly(vinyl-4-pyridine) powder in crosslinked from and the separated elements are e.g. ruthenium, rhodium, palladium, technetium, manganese, cobalt, iron, nickel, cerium and praseodymium.

Abstract: The invention concerns the recovery of Pu (IV) by using crown compounds.According to the invention, the aqueous solution containing the plutonium (IV) is placed in contact with at least one crown compound, for example DCH 18C6, dissolved in an organic diluting agent, such as benzonitrile. In the case where the solution only contains traces of Pu, it is possible to use a crown compound secured to a solid phase, such as silica.The aqueous solution is a concentrated solution of fission products, an effluent originating from an irradiated nuclear fuel reprocessing installation or a concentrated solution of plutonium with americium.

Abstract: Substituted thiophenes of general formula: ##STR1## in which: R represents hydrogen atom or an aliphatic group containing from 1 to 4 carbon atoms,X and Z may be identical or different and represent a hydrogen atom or a fluorine atom,Y represents an at least partially fluorinated aliphatic or aromatic group,m represents an integer equal to or greater than 1, andn represents an integer such that 0.ltoreq.n.ltoreq.12.The invention also relates to the electrically conducting polymers containing recurring units derived from monomers chosen from the substituted thiophenes.

Abstract: Electrically conductive polymers containing repeat units derived from five-membered aromatic heterocyclic monomers substituted, in the 3 position relative to the heteroatom, by an ether-type substituent linked to the heterocyclic ring by an alkylene radical containing at least two carbon atoms. The invention also relates to certain monomers enabling the above-mentioned conductive polymers to be obtained.

Abstract: The invention concerns the recovery of Pu (IV) by using crown compounds.According to the invention, the aqueous solution containing the plutonium (IV) is placed in contact with at least one crown compound, for example DCH 18C6, dissolved in an organic diluting agent, such as benzonitrile. In the case where the solution only contains traces of Pu, it is possible to use a crown compound secured to a solid phase, such as silica.The aqueous solution is a concentrated solution of fission products, an effluent originating from an irradiated nuclear fuel reprocessing installation or a concentrated solution of plutonium with americium.

Abstract: The invention relates to the use of thioether ligands in accordance with the formula: ##STR1## in which R.sup.1 and R.sup.2, which can be the same or different, represent alkyl radicals, R.sup.3 is an alkyl radical and A represents a divalent radical chosen from among the radicals of formula:--(CH.sub.2).sub.m ----(CH.sub.2).sub.n --X--(CH.sub.2).sub.p -- ##STR2## in which m is equal to 0 or is an integer from 1 to 6, n and p are integers between 1 and 6 and X represents O or S, for recovering the palladium present in a nitric aqueous solution (A.sub.0) for dissolving irradiated nuclear fuel elements.For example, it is possible to use the ligand of formula (I) with A representing CH.sub.2 --S--CH.sub.2 and R.sup.1 and R.sup.2 representing C.sub.10 H.sub.21.

Abstract: Substituted thiophenes of the general formula: ##STR1## in which: R represents a hydrogen atom, a halogen atom or an aliphatic group containing from 1 to 4 carbon atoms,X represents a hydrogen atom or a fluorine atom,Y represents an at least partially fluorinated aliphatic or aromatic group,m represents an integer equal to or greater than 2, andn represents an integer such that 0.ltoreq.n.ltoreq.7.The invention also relates to the electrically conducting polymers containing recurring units derived from monomers chosen from the substituted thiophenes.

Abstract: A method for separating plutonium from uranium and from fission products with the aid of crown ether compounds comprising contacting an aqueous solution A0 containing Pu, U and fission products with an organic solvent O0 containing at least one crown ether compound to obtain an organic solution O1 containing Pu and U; extracting U from the organic solution O1 with an aqueous solution A4 such as water or nitric acid to obtain an aqueous solution A5 containing U and an organic solution O3 containing mainly of Pu and recovering Pu from the organic solution using an aqueous solution A6 such as sulfuric acid.

Abstract: A method for separating the isomers of a crown ether compound and making it possible to recover in particular the pure cis-syn-cis isomer from DCH 18C6 includes:a) dissolving in an organic solvent a mixture of the isomers of said crown compound including the cis-anti-cis isomer and the cis-syn-cis isomer,b) adding uranyl nitrate to the solution obtained in stage a) in sufficient quantities so that virtually all of the isomers, except the cis-syn-cis isomer, are precipitated in the form of complexes with the uranyl nitrate,c) separating the formed precipitate,d) recovering the cis-syn-cis isomer from the solution, ande) recovering the cis-anti-cis isomer from the precipitate.

Abstract: There is provided a 3-substituted polypyrrole represented by the general formula (I) ##STR1## wherein R is an alkyl group having 1 to 5 carbon atoms, m is an integer of from 1 to 20, and n is an integer of 2 or more.

Abstract: Process for separating plutonium from uranium contained in a nitric acid aqueous solution from the reprocessing of irradiated fuels comprising plutonium, uranium and fission products by means of crown ethers. Nitric acid aqueous solution (5) containing plutonium, uranium and fission products is contacted at (2) with an organic liquid membrane (3) containing a crown ether. The uranium and plutonium are extracted in the liquid membrane (3) and then transferred by said membrane into a receiving solution (7), which becomes enriched with uranium, because the latter is transferred more rapidly than the plutonium. The crown ether can be DCH 18 C6 or DB 18 C6.

Abstract: The device permits a wide field of detection with high sensitivity and high locating precision. To this end, the device has a four-quadrant detector associated with a diaphragm formed by the central transparent zone of an opaque mask. The diaphragm preferably has a circular shape and no focusing lens. These elements are in parallel planes so that the line joining the centers of the diaphragm and the detector is perpendicular to these planes. The set is placed in a housing and is shielded by a transparent window. With a deviation measurement circuit that processes the detected signals, the assembly enables the computation of the angular offset of a pinpoint radiant source. With two elementary sensors of this type, it is possible to compute the spatial location of the source, for example a laser.

Abstract: The subject of the invention is mainly an electrically conductive polymer containing repeated units derived from 3-alkythiophenes in which the alkyl substituent contains from six to nine carbon atoms.The invention also relates to a process for manufacturing these polymers and to electroconductive devices containing them.

Abstract: A machine applies screwing and unscrewing torque between successive drill pipes with an essentially vertical axis extending through a tapered opening in a turntable for a well bore. The machine includes a mechanism for applying a high initial unthreading torque and a high final threading torque between successive drill pipes and a mechanism for rapid screwing and unscrewing of successive drill pipes. The machine also includes a clamping mechanism having a bolster and a plurality of shims. The shims have outer portions tapered to fit into the opening of the turntable and have inner portions with a shape corresponding to the shape of the drill pipes. Each shim is supported individually on the bolster by a device that moves the shim into engagement with a drill pipe to grip the same and with sufficient freedom to permit the shims to center the pipe between them automatically. The bolster is lowered to cause the shims to enter the opening in the turntable.

Abstract: Apparatus and method for the locking and releasing of a train of drilling shafts having an essentially vertical axis employ wedges adapted to penetrate an opening in a rotation table of a wellhole in order to lock upon a shaft projecting from the opening while another shaft is screwed to or unscrewed from the upper end of the first-mentioned shaft. The wedges have a tapered external shape complementary to the shape of the opening and an internal shape complementary to the external shape of the shafts. Each wedge is individually attached to an associated arm connected to a vertically movable plate by means of an articulation and a jack that applies the wedge to a shaft. The attachment of the wedges to the arms has sufficient freedom to permit the wedges to engage a shaft and center the shaft between the wedges automatically before the wedges are lowered into the opening of the rotation table to lock the engaged shaft therebetween.

Abstract: A machine to apply screwing and unscrewing torque to successive drilling shafts employs upper and lower claws, one of which is fixed and the other of which rotates through a limited angular range. Each claw comprises a pair of right-angle branches extending oppositely from a base and terminating in spaced relation to provide a permanent opening at one side of the claw opposite to the base. Each claw has a jaw comprising three gripping elements positioned essentially at the vertices of an equilateral triangle, one gripping element being fixed to the base and the other gripping elements being movably mounted on the branches at opposite sides of the opening. One claw comprises a pair of parts relatively movable vertically to form a viewing opening when the machine is not applying torque.

Abstract: The invention relates to a product for the treatment of cereal crops against the effect of Ophiobolus graminis which product comprises a culture of an abnormal homogeneous strain of Ophiobolus graminis carried on a divided support medium.