Abstract: The invention relates to a process and installation for treating heavy petroleum feedstocks for producing a gas oil fraction that has a sulfur content of less than 50 ppm and most often 10 ppm that includes the following stages: a) mild hydrocracking in a fixed catalyst bed, b) separation from hydrogen sulfide of a distillate fraction that includes a gas oil fraction and a heavier fraction than the gas oil, c) hydrotreatment (including desulfurization) of said distillate fraction, and d) separation of a gas oil fraction with less than 50 ppm of sulfur. Advantageously, the heavy fraction is sent into catalytic cracking. The process preferably operates with make-up hydrogen that is brought to stage c), and very advantageously all of the make-up hydrogen of the process in introduced in stage c).

Abstract: The invention relates to a process for treating heavy petroleum feedstocks for producing a gas oil fraction that has a sulfur content of less than 50 ppm and most often 10 ppm that includes the following stages: a) ebulliated-bed catalytic hydrocracking, b) separation from hydrogen sulfide of a distillate fraction that includes a gas oil fraction and a heavier fraction than the gas oil, c) hydrotreatment of said distillate fraction, and d) separation of a gas oil fraction with less than 50 ppm of sulfur. Make-up hydrogen, preferably all make-up hydrogen, is to stage c). Advantageously, the heavier fraction from step (b) is subjected to catalytic cracking. The invention also relates to an installation that can be used for implementing this process.

Abstract: An electrolytic cell is suitable for production of aluminium, and includes at least one collector bar made of first metal and at least one complementary bar made of a second metal having an electrical conductivity greater than the first metal and arranged adjacent to one of the side faces of the collector bar so that the external end of the complementary bar is at a specified distance from a specified end face of the block. The second end terminates so as to limit heat losses from said cell. The cell makes it possible to obtain significantly lower voltage drops while avoiding excessive heat losses through the collector bars.

Abstract: The invention relates to a process for treating heavy petroleum feedstocks for producing a gas oil fraction that has a sulfur content of less than 50 ppm and most often 10 ppm that includes the following stages: a) ebulliated-bed catalytic hydrocracking, b) separation from hydrogen sulfide of a distillate fraction that includes a gas oil fraction and a heavier fraction than the gas oil, c) hydrotreatment of said distillate fraction, and d) separation of a gas oil fraction with less than 50 ppm of sulfur. Make-up hydrogen, preferably all make-up hydrogen, is to stage c). Advantageously, the heavier fraction from step (b) is subjected to catalytic cracking. The invention also relates to an installation that can be used for implementing this process.

Abstract: A structure for producing a localized light source in a medium is provided. The structure includes a source generating incident light, a surface-plasmon-supporting layer, and means for transmitting and localizing plasmons between the surface-plasmon-supporting layer and the medium. The transmitter-localizer means includes between the surface-plasmon-supporting layer and the medium a discontinuity for providing a localized electromagnetic field deviation and a plasmon-transmitting interface with predetermined electromagnetic properties at the medium. The incident light excites a surface plasmon in the surface-plasmon-supporting layer, which plasmon in turn produces the localized light source at the plasmon-transmitting interface by localizing the energy of the surface plasmon.

Abstract: The invention relates to a process and installation for treating heavy petroleum feedstocks for producing a gas oil fraction that has a sulfur content of less than 50 ppm and most often 10 ppm that includes the following stages: a) mild hydrocracking in a fixed catalyst bed, b) separation from hydrogen sulfide of a distillate fraction that includes a gas oil fraction and a heavier fraction than the gas oil, c) hydrotreatment (including desulfurization) of said distillate fraction, and d) separation of a gas oil fraction with less than 50 ppm of sulfur. Advantageously, the heavy fraction is sent into catalytic cracking. The process preferably operates with make-up hydrogen that is brought to stage c), and very advantageously all of the make-up hydrogen of the process in introduced in stage c).

Abstract: The invention relates to a process for treating heavy petroleum feedstocks for producing a gas oil fraction that has a sulfur content of less than 50 ppm and most often 10 ppm that includes the following stages: a) ebulliated-bed catalytic hydrocracking, b) separation from hydrogen sulfide of a distillate fraction that includes a gas oil fraction and a heavier fraction than the gas oil, c) hydrotreatment of said distillate fraction, and d) separation of a gas oil fraction with less than 50 ppm of sulfur. Make-up hydrogen, preferably all make-up hydrogen, is to stage c). Advantageously, the heavier fraction from step (b) is subjected to catalytic cracking. The invention also relates to an installation that can be used for implementing this process.

Abstract: A method for balancing traffic among parallel links connecting two signalling points of a Common Channel Signalling System (SS7) when one or more of the links becomes unavailable. A change-over process causes SLS (Signalling Link Selection) field values originally associated with the unavailable link to be reassigned to remaining available links on a distributed basis. A change-back process, used where a previously unavailable link is restored to service, causes SLS field values to be reassigned from the other available links to the restored link.

Abstract: A long concrete unit, prestressed by tendons tensioned before concreting, at least one section of which, near the end of the said unit, is submitted to maximum loads, characterized by the fact that at least one improved-bond prestressing tendon is surrounded by spirals located on either side of the zone of maximum tensile stress.