Abstract: A cap for an arc torch comprises a skirt (10) composed of plastics material having a generally annular shape and surrounding and spaced from the nose (2, 7) of the torch, and a tubular nose-piece (12) composed of refractory material fitted in the free end of the skirt. The arc torch can be applied to plasma-arc cutting torches.

Abstract: Arc torch for plasma arc cutting or welding comprising an interchangeable cartridge comprising an electrode and a nozzle, and connecting elements between the cartridge and the body of the arc torch to axially insert and remove the cartridge by a purely rectilinear movement. The arc torch can be used as part of a machine comprising a station for extracting used cartridges and a station for loading new cartridges into the arc torch.

Abstract: The invention relates to a laser cutting nozzle comprising at least two subsequent coaxial sections, the inside diameter of the first section decreasing from its inlet diameter to its outlet diameter and being devoid of a sharp corner, the inner envelope being tangent at its outlet to a cylinder having a diameter d, the second section being cylindrical and having a diameter D and a length l, the ratio D/d being between 1.1 and 1.3 and the ratio l/d being between 0.35 and 1. It relates to a laser cutting head comprising this nozzle and to a laser cutting method employing these elements.

Abstract: A method and apparatus for removing a waveguide from a mandrel. A helical waveguide is formed on a mandrel by electroplating. The mandrel has raised areas similar to a screw on which the waveguide is formed. A thin walled cylinder is slipped over the cylindrical mandrel and advanced axially as the mandrel rotates. A notch in the forward end of the cylinder acts to peel the waveguide from the mandrel. The cylinder then supports the waveguide in a helix as it continues to peel the remainder of the waveguide.

Abstract: The hood (1) comprises a fluidtight flexible cover (5) forming a cap and provided at its base with a closed C-shaped tube (2) constituting a reserve of oxygen under pressure. The ends of the C are interconnected by a normally convex spring strip (3) which is capable of being withdrawn within the confines of the C to permit the stowing away of a plurality of hoods in a box of small size. Application in the safety of aircraft passengers.

Abstract: The invention relates to a hood for protecting against smoke and hypoxia which is of use more particularly in the protection of flying personnel in aircraft. This hood comprises, at its base and within the fluidtight cover a closed tube (3) surrounding the neck of the wearer and containing a reserve supply of oxygen under pressure, and means (11-13) for automatically putting, when the hood is donned, the interior of this tube in communication with an automatic supply of oxygen to the wearer of the hood.

Abstract: To terminate welding, the mean energy of the arc is first reduced to obtain plugging of the hole, then this energy is briefly increased before again being decreased. Application to plasma arc welding of carbon steels.

Abstract: The closing device is constituted by a principal stopper (11) having a lateral notch (17) and an auxiliary stopper (12) having a general shape conjugate with that of this notch, the auxiliary stopper being provided with at least one bore (22) and means (19) for fixing on the edge of the opening of the container.

Abstract: As the apparatus consumes liquid nitrogen and discharges cold gaseous nitrogen under low pressure, an additional nitrogen stream is liquified under high pressure by heat exchange with the gaseous nitrogen discharged by the apparatus 1, the liquid thus obtained is expanded to the pressure of utilization and the expanded liquid is added to the principal supply of liquid nitrogen to the apparatus. Application in the supply of nitrogen to large cryogenic crushing apparatus.

Abstract: The present invention concerns a process for the control in real time of the etching in a process for manufacturing electronic components of the type obtained by reacting ionic etching of wafers of silicon utilizing a plasma produced between two electrodes, wherein the gaseous species of the plasma are analyzed during the etching, at least one of the wafers of silicon being removable in situ from the influence of the plasma.The invention also concerns a reactor therefore, comprising a housing under vacuum 31 including at least one support electrode 34 and one electrode 35 connected to ground between which a plasma is produced, means for producing a vacuum, means for loading and unloading wafers, means for introducing etching gas, wherein the reactor comprises at least two locations 40 for wafers 33, means for withdrawing at least one location from the influence of the plasma 37, said means and the locations being movable with respect to one another, and means for analyzing gaseous species of the plasma.

Abstract: Process for improving the quality of deinked papermaking pulps obtained by ecycling waste printed papers, in which:the papers are converted into a slush pulp (1),most of the ink (12) is removed (11) from this slush pulp, especially by selective primary flotation of the ink, andthe deinked pulp is washed (5) to remove the residual ink before being conveyed into the circuit (14) for utilization of the pulp,wherein the waters (24) from this washing (5) are first of all subjected to a selective secondary flotation (16) to remove (17) only the residual ink therefrom, the suspension of the remaining matter (fibers and fillers) (18-23) being subsequently mixed with the pulp (15) originating from the washing (5).The invention also relates to a plant for making use of this process.

Abstract: Each ozonization loop (1) which includes a compressor (2), an ozonizer (3), and a heat exchanger (8) for cooling the oxygen-ozone mixture, is associated with three cylinders (4,5,6) filled with silica gel. Each cylinder operates in succession in a cocurrent adsorption, in countercurrent desorption by a substitution gas, and in scavenging by taking off a part of the flow circulating in the loop. The scavenging flow is recovered and combined with the substitution gas. The substitution gas may be in particular impure nitrogen supplied by an air distillation apparatus producing the necessary oxygen.

Abstract: This process comprises eliminating the ammonia from a gaseous effluent of the treatment of scrubbing with a liquid essentially comprising water, regenerating the scrubbing liquid by stripping countercurrent with respect to the gas to be treated, then recycling at least most of the regenerated scrubbing liquid by putting it into thermal exchange relation with the scrubbing liquid to be regenerated.Application in the production of CO.sub.2 by the treatment of smoke with ammonia.

Abstract: The adsorption cycle comprises the following stages:(a) an isobaric adsorption stage at a high pressure of the cycle in which the mixture to be treated is admitted into the adsorber through a first end, termed inlet end, of the adsorber, circulates through the adsorber and is withdrawn therefrom by its other end, termed outlet end, the direction of circulation of the mixture being termed cocurrent;(b) a first stage for the cocurrent decompression of the adsorber to a medium pressure of the cycle;(c) a second stage for the countercurrent decompression of the adsorber to a low pressure of the cycle, the gas withdrawn in the course of this stage being the production gas, and(d) a stage for raising the pressure of the adsorber to the high pressure of the cycle.Application in the recovery of carbon dioxide from sources which contain only 10 to 30% thereof.

Abstract: A process for reducing aliphatic nitro compounds to the corresponding nitroalcohols. Chemical electroreduction is performed on a bimetallic cathode consisting of a copper support metal and a zinc or cadmium active element.

Abstract: A gaseous mixture comprising oxygen, nitrous oxide, and an optional inert gas, is useful for radiosensitizing tissues in radiotherapy, particularly for treatment of cancer.

Abstract: Liquid oxygen and gaseous nitrogen are remixed in a roughly reversible manner in an auxiliary column (3); rich liquid without argon, withdrawn at an intermediate place of the auxiliary column is remixed in another auxiliary column section (4) with impure nitrogen of the top of a low pressure column (6), and the gas of the top of this auxiliary section constitutes a residual gas (R1) of the plant. Application in the production of argon.

Abstract: The process for preparing concentrated amounts of lyophilized micro-organisms employs an ultrafiltration with a supply of nutritive substrates and the supply of a neutralizing agent in the fermenter, and further comprises the following steps:(a) ceasing to supply substrates while cooling;(b) continuing the ultrafiltration until the obtainment of a primary concentrate (40-80 kg dry weight of bacteria/cu. m) and cooling to 15.degree.-20.degree. C.;(c) washing the primary concentrate with mineral salts and amino acids, oligo-elements and vitamins;(d) concentrating by ultrafiltration to 90-220 kg dry weight of bacteria/cu. m;(e) cooling to 5.degree. C. and adding a protector;(f) deep freezing and lyophilizing.The process particularly applies to the preparation of lactic bacteria.

Abstract: Device for detecting insipient cracks or tears on the edges (4) of a moving heet (5), of the type comprising:a light source (6),and a receiving cell for picking up the light transmitted by the source (6) through the sheet (5) moving between the source (6) and the cell,characterized in that:on the one hand, the light source (6) is a laser source;and on the other hand, the receiving cell (17) is an optoelectronic cell placed in such a way that the solid angle under which the serviceable surface of said cell (17) or of its image by an optical system, can be seen from the sheet, is less than 0.01 steradian.

Abstract: Liquid oxygen of a low pressure column forms a bath 5 at the top of a heat exchanger 2 of the type having plates defining vertical passages 17, 18. This liquid is predistributed along every other passage 17 by a series of apertures 27 formed for example in the plates, and then is uniformly distributed in a fine manner in the same passages by a packing 24 so as to form a continuous running liquid film. The gaseous nitrogen of a medium pressure column is introduced into the remaining passages 18 and condensed by heat exchange with the oxygen which is vaporized.