Abstract: The invention relates to a process for the production of a semipermeable membrane on a porous conductive support. The process involves the stages of finely dispersing in an aqueous or hydroorganic medium, insoluble solid mineral products in the presence of an electrodepositable coating resin, the preparation of an electrophoresis bath by adjusting the composition of the dispersion, deposition by electrophoresis of a layer of resin-coated, solid mineral products on a porous conductive support, possible deposition of several coatings and heat treatment of the porous conductive support and its layer of electrodeposited solid products. This gives filtering membranes suitable for microfiltration, ultrafiltration and reverse osmosis.

Abstract: The present invention relates to a method of manufacturing a medium for microfiltration, for ultrafiltration, or for reverse osmosis, wherein hydrolysis is performed on an alkoxide, an organo-metallic compound, or a metal salt of an organic or an inorganic acid, optionally dissolved in an anhydrous organic solvent, in order to obtain a sol of particles of the oxide or of the hydroxide of the corresponding chemical element, a thickening agent is added to the sol, and the resulting sol is slip cast onto a support layer having pores which are larger than pores desired for the filter medium, the thin layer deposited on the support medium is then dried, and then heat treated to eliminate the thickening agent and to sinter the particles of the deposited thin layer. The thickening agent is added to the sol in conjunction with a strong acid whose anion does not form a complex with ions of the oxide or hydroxide metal, and the slip casting is performed by mere putting into contact without filtering.

Abstract: Process for producing highly charged ions making it possible to ionize a gas of neutral atoms by electron impact, the gas being introduced into an ultra-high frequency cavity excited by at least one high frequency electromagnetic field which is associated with a magnetic field, whose amplitude is selected in such a way that the electronic cyclotron frequency associated with said magnetic field is equal to the frequency of the electromagnetic field also established in the cavity, the latter being provided with an opening for the extraction of ions by means of appropriate electrodes, wherein the said magnetic field is constituted by superimposing of a multipole radial magnetic field having a minimum amplitude in the central part of the cavity and a rotationally symmetrical axial magnetic field having a gradient along said axis, the resulting magnetic field being regulated in such a way that in the cavity there is at least one completely closed magnetic layer having no contact with the cavity walls, whereby on s

Abstract: A process for producing fritted alumina members having a high optical transparency and a high mechanical strength of the type involving the production of the members from a high purity alumina powder to which has been added an organic binder and a small percentage of oxide, particularly of magnesium and/or rare earth, followed by the shaping thereof and subjecting them to two successive heat treatments, namely a first treatment in an oxidizing atmosphere to remove the binder and consolidate the particles and a second treatment at a higher temperature and in a hydrogen-rich atmosphere for obtaining fritting, wherein the second heat treatment takes place by continuously passing the said members through a kiln kept at a temperature between 1820.degree. and 1970.degree. C.