Abstract: An optical device including an aerogel located in an encapsulating structure, an optically non isotropic material presenting a refractive index which can be changed upon submitting said material to an electrical field, preferentially a liquid crystal mixture, embedded in the aerogel, and first and second electrodes arranged to generate an electric field in the encapsulating structure.

Abstract: Process for the production of olefins and of middle distillates from a paraffinic feedstock, in which: a) a paraffinic feedstock resulting from a Fischer-Tropsch unit is recovered, the said feedstock containing a light fraction and a heavy fraction; b) the light fraction is sent to a catalytic cracking unit; c) the effluent resulting from the catalytic cracking unit is separated in a fractionation unit in order to obtain a fraction of light hydrocarbons, an olefinic fraction and a residual liquid fraction; d) the heavy fraction is sent to a hydrocracking/hydroisomerization unit; e) the effluent resulting from the hydrocracking/hydroisomerization unit is separated in a fractionation unit in order to obtain a middle distillates fraction, a naphtha cut having a maximum boiling point of less than 180° C. and an unconverted heavy fraction; f) a part of the naphtha cut resulting from the fractionation unit is sent to the catalytic cracking unit.

Abstract: The present invention relates to a process for fluid catalytic cracking of a feedstock comprising a light tight oil and at least one conventional feedstock in order to produce an effluent, in which the feedstock has a content of light tight oil so that the density of the feedstock is between 0.84 and 0.91.

Abstract: Process for the production of olefins and of middle distillates from a paraffinic feedstock, in which: a) a paraffinic feedstock resulting from a Fischer-Tropsch unit is recovered, the said feedstock containing a light fraction and a heavy fraction; b) the light fraction is sent to a catalytic cracking unit; c) the effluent resulting from the catalytic cracking unit is separated in a fractionation unit in order to obtain a fraction of light hydrocarbons, an olefinic fraction and a residual liquid fraction; d) the heavy fraction is sent to a hydrocracking/hydroisomerization unit; e) the effluent resulting from the hydrocracking/hydroisomerization unit is separated in a fractionation unit in order to obtain a middle distillates fraction, a naphtha cut having a maximum boiling point of less than 180° C. and an unconverted heavy fraction; f) a part of the naphtha cut resulting from the fractionation unit is sent to the catalytic cracking unit.

Abstract: The present invention describes a process for the simulated moving bed separation of xylenes which can be used for the treatment of paraxylene-rich feeds (more than 25% by weight of paraxylene), in which the operating conditions are optimized by means of a specific relationship between the cycle time and the desorbant flow rate.

Abstract: The present invention describes a process for the simulated moving bed separation of xylenes, in which the operating conditions are optimized by means of a specific relationship between the cycle time and the flow rate of the desorbant.

Abstract: The present invention describes a process for the simulated moving bed separation of xylenes which can be used for the treatment of paraxylene-rich feeds (more than 25% by weight of paraxylene), in which the operating conditions are optimized by means of a specific relationship between the cycle time and the desorbant flow rate.

Abstract: The present invention describes a process for the simulated moving bed separation of xylenes, in which the operating conditions are optimized by means of a specific relationship between the cycle time and the flow rate of the desorbant.

Abstract: The present invention describes a process for the separation of xylenes in simulated counter-current utilising at least one adsorber with a limited cumulated total height (Hcu) of adsorbent and a superficial velocity (Vsl) of less than 2 cm/s.

Abstract: This invention describes a process for separation of xylenes for the purpose of the production of high-purity metaxylene, a simulated countercurrent process using at least one adsorber with a limited cumulative total level (Hcu) of adsorbent at a surface velocity (Vsl) that is less than 2 cm/s.

Abstract: A method manufactures an optical element having a surface that includes cells filled with an aerogel that does not crack during its manufacture or during a subsequent step of impregnating the aerogel with a liquid. The disclosure also relates to the optical elements that can be obtained using the method.

Abstract: This invention describes a process for separation of xylenes for the purpose of the production of high-purity metaxylene, a simulated countercurrent process using at least one adsorber with a limited cumulative total level (Hcu) of adsorbent at a surface velocity (Vsl) that is less than 2 cm/s.

Abstract: The present invention describes a process for the separation of xylenes in simulated counter-current utilising at least one adsorber with a limited cumulated total height (Hcu) of adsorbent and a superficial velocity (Vsl) of less than 2 cm/s.

Abstract: A method manufactures an optical element having a surface that includes cells filled with an aerogel that does not crack during its manufacture or during a subsequent step of impregnating the aerogel with a liquid. The disclosure also relates to the optical elements that can be obtained using the method.

Abstract: The invention relates to a photo-crosslinkable composition obtainable by a method comprising: (a) the hydrolysis and condensation reaction of a [(epoxycycloalkyl)alkyl]trialkoxysilane in solution in an organo-aqueous medium as described in specification to obtain a solution of an organo-mineral hybrid prepolymer, in which the totality or quasi-totality of the alkoxysilane groups has been hydrolysed, and which comprises in average at least 4 (epoxycycloalkyl)alkyl groups; (b) cooling the obtained polyepoxide prepolymer composition as described in specification: (c) adding to said composition at least one cationic-polymerisation photo-photoinitiator and at least one specific photosensitiser as describes in specification and adding a surfactant; (d) agitating the obtained composition as described in specification thus obtained; (e) filtering the obtained composition as described in specification thus obtained; and (f) storing the obtained liquid filtrate as described in specification thus obtained.

Abstract: The invention relates to a photo-crosslinkable composition that can be obtained by a method including the following steps: (a) the hydrolysis and condensation reaction of a [(epoxycycloalkyl)alkyl]thalkoxysilane in solution in an organo-aqueous medium containing water in an initial water/monomer molar ratio of between 3 and 15, with at least one water-soluble solvent, at a pH of between 1.6 and 4.0, by heating the solution to a temperature of between 50 and 70° C. for a duration of between 180 and 350 minutes in order to obtain a solution of an organo-mineral hybrid prepolymer, in which the totality or quasi-totality of the alkoxysilane groups has been hydrolysed, and which comprises in average at least 4 (epoxycycloalkyl)alkyl groups; (b) cooling the polyepoxide prepolymer composition thus obtained down to a temperature of between 15 and 25° C.

Abstract: A method for manufacturing an optical waveguide component with several layers stacked on a silicon substrate. The layers include a buffer layer, a first substrate, a guiding layer on the buffer layer and including an optical waveguide, and an outer layer as protection against external stresses. The layers are made from an organic-inorganic hybrid using a sol-gel process. An additional layer is disposed on the guiding layer so that a symmetrical structure is produced that has the same refractive index around the waveguide in the guiding layer.

Abstract: A method for manufacturing an optical waveguide component with several layers stacked on a silicon substrate. The layers include a buffer layer, a first substrate, a guiding layer on the buffer layer and including an optical waveguide, and an outer layer as protection against external stresses. The layers are made from an organic-inorganic hybrid using a sol-gel process. An additional layer is disposed on the guiding layer so that a symmetrical structure is produced that has the same refractive index around the waveguide in the guiding layer.