Abstract: Composition which can be crosslinked under the effect of an ionizing radiation comprising a thermoplastic copolymer of vinylidene fluoride and of chlorotrifluoroethylene and an effective amount of a crosslinking promoter, such as a triallyl cyanurate or triallyl isocyanurate. Process for the crosslinking by irradiation of the crosslinkable composition under air by means of an ionizing radiation, such as &bgr;-radiation, at a dose of 10 to 100 kGray. Crosslinkable and crosslinked shaped articles, such as sheaths for electrical cables and pipes for oil products.

Abstract: A surface-emitting laser in which a first distributed Bragg reflector composed of an alternately stacked structure made of two kinds of thin film, an active layer and a second distributed Bragg reflector composed of an alternately stacked structure made of two kinds of thin film, are formed on a semiconductor substrate, successively, including a current stenosed layer having an oxidized area in a remote junction surface therein between at least one of the first and the second distributed Bragg reflectors and the active layer, and plural capacitance-reducing layers, each layer having a smaller oxidized area than the oxidized area in a remote junction surface constituting the current stenosed layer, at least one of the first and the second distributed Bragg reflectors, the plural capacitance-reducing layers, the current stenosed layer and the active layer being arranged successively, one of the first and the second distributed Bragg reflectors constituting a first conductive type Bragg reflector, the other co

Abstract: Novel silylene or ethylene bis(tetrahydrofluorenyl)metallocenes are synthesized and used as olefin polymerization catalysts.

Abstract: Methods for obtaining a protein by culture of hybridoma cells, wherein said protein is an immunoglobulin, are disclosed. The methods involve culturing animal hybridoma cells in continuous presence of an alkanoic acid or salt thereof, which enhances protein production, wherein said alkanoic acid or salt thereof is present at 2 concentration range of 0.1 mM to 200 mM.

Abstract: The olefin polymerization catalyst comprises a supported transition metal, magnesium and halogen; the support comprises aluminum phosphate and at least one oxide of silica or alumina. The catalyst is formed by impregnating the support with a liquid complex formed by reacting a magnesium compound and a transition metal compound, which can contain either oxygen or halogen, and then precipitating the complex on the support with an organoaluminum compound which may be halogenated. The catalyst is used with an organometallic cocatalyst.

Abstract: The present invention relates to photocatalyst-carrying structures which can be used particularly in an environment of high temperature and humidity or outdoor environment requiring alkali resistance and also to composites of photocatalyst coating materials to produce the said structures. The composites of photocatalyst coating materials are characterized in containing a photocatalyst and a zirconium compound and/or tin compound in order to endow alkali resistance. The photocatalyst-carrying structure has an adhesive layer between a photocatalyst layer and a carrier. The photocatalyst layer contains a photocatalyst, and a zirconium compound and/or tin compound to endow alkali resistance.

Abstract: Heterocyclic compounds of formula(I), wherein R1 represents a hydrogen atom or a —(CH2)m—Y group, wherein m is an integer from 0 to 4 and Y represents an alkyl, haloalkyl, alkoxy, alkoxycarbonyl, C3-C7 cycloalkyl, norbornyl or phenylalkenyl group, or an aromatic group which aromatic group {circumflex over ( )} may optionally be substituted by one or more halogen atoms; R2 represents an aromatic group which aromatic group may optionally be substituted by one or more halogen atoms or alkyl, alkoxy, C3-C6 cycloalkoxy, methylenedioxy, nitro, dialkylamino or trifluoromethyl groups, and R3 represents a hydrogen or halogen atom or an alkyl group, and pharmaceutically acceptable salts thereof, processes for preparing the same are disclosed herein. The compounds are phosphodiesterase 4 inhibitors.

Abstract: Process for the preparation of a composition containing ethylene polymers comprising a polymer of melt index MI2 of 5 to 1000 g/10 min and a polymer of melt index MI5 of 0.01 to 2 g/10 min, the ratio of these indices being from 500 to 50,000 and the weight ratio of the two polymers being equal to (30 to 70):(70 to 30), according to which part of the ethylene, a catalyst derived from a transition metal having an intrinsic molecular weight distribution defined by an intrinsic Mw/Mn ratio less than or equal to 10 and a deactivation constant less than or equal to 0.5 h−1, and a cocatalyst are introduced into a first reactor, polymerization of the ethylene is carried out therein, a mixture comprising one of the polymers, the catalyst and the cocatalyst is drawn off from this reactor and the mixture and another part of the ethylene are introduced into a second reactor, which ethylene is polymerized to form the other polymer.

Abstract: Process for the preparation of a catalyst for the polymerization of alpha-olefins involves contacting a porous polyolefin support with a solution containing an activator (ii) to form a suspension. The suspension is evaporated in a reactor fitted with a stirrer comprising a scraping element. The scraping element follows the walls of the reactor at a distance from 2 to 200 times the mean particle diameter of the support. The catalyst includes a compound of a transition metal (i) from Groups 4 to 6 of the Periodic Table and at least one optionally substituted cyclopentadiene ligand and an aluminoxane activator (ii). The aluminoxane activator (ii) and transition metal compound are supported on the porous polyethylene support (iii). The walls of the reactor show no traces of crusting.

Abstract: Process for producing sodium carbonate, according to which a sodium sesquicarbonate ore is successively calcined and dispersed in an aqueous solution substantially saturated with hydrated sodium carbonate and the resulting aqueous suspension is subjected to an aging, at the end of which an aqueous mixture of a powder comprising hydrated sodium carbonate crystals is collected. During the aging, a fine particle size fraction is extracted from the aqueous suspension and removed.

Abstract: A process for processing a thermoplastic, which includes, in succession, the following steps: (1) a molten semicrystalline thermoplastic extrudate is cooled to a temperature T1 which is greater than the crystallization temperature (Tc) of the thermoplastic and is less than Tf+5° C., Tf denoting the melting point of the thermoplastic; (2) next, the extrudate is drawn in the molten state; (3) next, the extrudate is relaxed, at a temperature T3 which is between Tc and Tf, for a duration at least equal to the average relaxation time (&tgr;3) of the thermoplastic at the relaxation temperature, and after the drawing; (4) next, the extrudate is quenched to a temperature T4 which is less than Tc.

Abstract: Disclosed is for the preparation of a catalytic composition for the polymerization of alpha-olefins. The catalyst comprises a compound of a transition metal (i) of Groups 4 to 6 of the Periodic Table, containing at least one possibly substituted cyclopentadiene ligand, and an activator (ii) chosen from aluminoxanes and ionizing agents supported on a support (iii) consisting of porous particles of polyolefin(s). Preparation includes a preliminary polymerization which includes contact with an alpha-olefin, under polymerizing conditions, in a diluent whose kinematic viscosity, measured at 20° C., is from 3 to 3000 cSt (centistokes) from 3 to 3000 mm2/s, such as mineral oil which may be derived from coal tars and petroleum fractions, to form from 0.01 to 50 g of polyolefin per g of catalyst containing compounds (i), (ii) and (iii).

Abstract: A polyester containing aromatic moieties is contacted with microorganisms having the activity of decomposing the polyester to decompose or reduce it. Preferably, either or both of Trichosporon FERM BP-6445 or Arthrobacter FERM BP-6444 was contacted with the polyester to decompose or reduce it. A fiber made of the polyester or a cloth made of such fiber may be reduced by contacting it with the microorganisms having the activity of decomposing the polyester.

Abstract: Machine for welding hollow articles and process for welding these articles, for example half-shells of a plastic fuel tank, using the technique of hot-plate welding, in which the mirror is in the form of separate elements which can be moved independently. Particular processes in which the articles to be welded together are preshaped by pressing against cold-plate elements, which might not be plane, by stretching or compressing the side walls of the articles or by pressing against the walls of a mould. Process applied to the manufacturer of injection-moulded/welded fuel tanks. Use of the machine for manufacturing such tanks.

Abstract: Polyamide-based compositions whose processability is improved by the addition of a processing agent chosen from fluoropolymers. These compositions are useful for molding shaped articles by extrusion, extrusion blowing, extrusion thermoforming or injection molding.

Abstract: The invention relates to a process for the production of ethylene polymers by the polymerization of ethylene or the copolymerization of ethylene with one or more C3 to C8 olefins in contact with a chromium-based catalyst deposited on a support essentially consisting of silica. According to the invention, the chromium catalyst is subjected in succession to a heat treatment in nitrogen and then to a heat treatment in air under defined temperature conditions before bringing it into contact with ethylene and, optionally, one or more olefins under polymerizing conditions. The process of the invention makes it possible to manufacture ethylene polymers having an improved compromise between processability, stiffness and resistance to slow crack growth.

Abstract: Asymmetric silicon-bridged metallocenes represented by the general formula: wherein M represents a transition metal selected from Ti, Zr and Hf. X and X′ represent a halogen atom, R1, R2, R3 represent alkyl groups containing 1 or 2 carbon atoms or hydrogen atoms, providing that at least two of R1, R2, R3 are alkyl groups, and R4 and R5 represent alkyl or aryl group containing from 1 to 10 carbon atoms. A process for their preparation and polymerization of olefins in the presence of the asymmetric silicon-bridged metallocenes are disclosed.

Abstract: A method for producing a porous diamond according to the present invention comprises steps of forming an anodized alumina layer, which functions as a mask, on a diamond substrate; and performing a plasma etching treatment to form pores on the diamond substrate, which pores have the same arrangement as those of the anodized alumina mask.

Abstract: Process for the preparation of a composition containing ethylene polymers comprising a polymer of melt index MI2 of 5 to 1000 g/10 min and a polymer of melt index MI5 of 0.01 to 2 g/10 min, the ratio of these indices being from 500 to 50,000 and the weight ratio of the two polymers being equal to (30 to 70):(70 to 30), according to which part of the ethylene, a catalyst derived from a transition metal having an intrinsic molecular weight distribution defined by an intrinsic Mw/Mn ratio less than or equal to 10 and a deactivation constant less than or equal to 0.5 h−1, and a cocatalyst are introduced into a first reactor, polymerization of the ethylene is carried out therein, a mixture comprising one of the polymers, the catalyst and the cocatalyst is drawn off from this reactor and the mixture and another part of the ethylene are introduced into a second reactor, which ethylene is polymerized to form the other polymer.

Abstract: Process for the emergency stopping of a polymerization reaction in the gas phase, comprising the injection of a poison of the reaction into a polymerization reactor and the evacuation of the gaseous content of the polymerization reactor via delaying means to a burner at the maximum limited feed rate, characterized in that the delaying means simultaneously serve to obtain a homogeneous distribution of the poison of the reaction inside the polymerization reactor so as to interrupt the polymerization reaction, and to regulate the flow of gasses evacuated to the burner so as not to exceed the maximum feed rate of the burner.