Abstract: A method of treating silicon carbide fibers comprises phosphating heat treatment in a reactive gas so as to form a coating around each fiber for protection against oxidation. The coating comprises a surface layer of silicon pyrophosphate crystals and at least one underlying bilayer system comprising a layer of a phosphosilicate glass and a layer of microporous carbon.

Abstract: A thermostructural composite material part including carbon or ceramic fiber reinforcement densified by a matrix having at least one thin portion in which: the thickness of the part is less than 2 mm, or indeed less than 1 mm; the fiber reinforcement is made as a single thickness of multilayer fabric made of spread yarns having a weight of not less than 200 tex; the fiber volume ratio lies in the range 25% to 45%; and the ratio between the number of layers of the multilayer fabric and the thickness in millimeters of the part is not less than four.

Abstract: A thermochromic ink composition includes, in a liquid medium, known as solvent, a dispersion of thermochromic microcapsules incorporating at least one leuco-dye and a thermoplastic binder selected from the group containing polyacrylic polyesters, polyurethanes and copolymers thereof. The composition is characterized in that the solvent is aprotic. A a method for producing a card and such a card incorporating at least one thermochromic pattern produced with a thermochromic ink composition are also described.

Abstract: The invention relates to a method for manufacturing a multi-layer data medium by hot rolling under pressure, able to be marked under the effect of laser radiation applied to at least one outer surface (11) of this medium, in which at least one marking (13) with optically variable effect is disposed with respect to a laser marking sub-layer so that said outer surface (11) has a portion with optically variable effect optically superimposed on at least one part of the laser marking sub-layer and a portion (16) without marking with optically variable effect optically superimposed on at least one part of the laser marking sub-layer. These portions are produced with contents of at least one marking agent which is sensitive to said laser radiation which are different.

Abstract: Disclosed is a method for the production of a multi-layer data medium by the hot rolling under pressure of a plurality of superimposed layers (12) having security inscriptions. Marking rolling is carried out on at least one layer to be marked (12a) covered with a marking film (20, 21) bearing inscriptions (22) in vitrophany applied in contact with the layer to be marked, then the marking film is separated from the layer to be marked, the latter having the security inscriptions.

Abstract: A part made of composite material includes fiber reinforcement densified by a ceramic matrix. The part presents an outside surface and is coated over at least a portion of its outside surface by a surface coating in solid form including an alloy of silicon and nickel presenting a content by weight of silicon lying in the range 29% to 45%, or an alloy of silicon and cobalt.

Abstract: Disclosed is a method for manufacturing a multilayer data medium having reflecting metallised inscriptions (23) visible from at least one outer surface (11). A basic pattern (24) is imprinted onto a transparent impression layer (21), the pattern being selected so as to be able to receive the inscriptions (23), to be transparent and to have a surface tension of more than 40 dynes/cm and a smooth surface condition with specular reflection of more than 50% measured according to the ISO 2813 standard at an angle of 60°, and no glass-transition temperature in the rolling temperature range; then the inscriptions (23) are imprinted in contact with the basic pattern (24), and then hot rolling under pressure of a stack including the impression layer (21) is carried out.

Abstract: A method of fabricating a sound attenuation panel of curved shape, the method including impregnating a fiber structure defining a cellular structure with a ceramic precursor resin; polymerizing the ceramic precursor resin while holding the fiber structure on tooling presenting a curved shape corresponding to the final shape of the cellular structure; docking the cellular structure with first and second skins, each formed by a fiber structure impregnated with a ceramic precursor resin, each skin being docked to the cellular structure before or after polymerizing the resin of the skins; pyrolyzing the assembly constituted by the cellular structure and the first and second skins; and densifying the assembly by chemical vapor infiltration.

Abstract: A document (15) includes at least: one first image (5) including at least one photoluminescent pigment which is invisible under illumination in visible light and is visible under illumination by at least one first source (20) of non-visible light emitting in the short ultraviolet domain, one second image including at least one photoluminescent pigment which is invisible under illumination in visible light and is visible under illumination by at least one second source of non-visible light emitting in the long ultraviolet domain, one layer, named a filtering layer, arranged facing the second image and including at least one material, named a filtering material, suitable for allowing the wavelengths emitted by the first source of non-visible light to be filtered without preventing the first image from being seen under illumination by the first light source.

Abstract: A method of assembling together by brazing two parts made of composite material, each part having an assembly face for brazing with the assembly face of the other part, the method including: making a plurality of cavities in the assembly face of at least one of the two composite material parts, at least some of the cavities opening out into one or more portions of the part that are situated outside the assembly face; interposing capillary elements between the assembly faces of the composite material parts; placing a brazing composition in contact with a portion of the capillary elements; and applying heat treatment to liquefy the brazing composition so as to cause the molten brazing composition to spread by capillarity between the assembly faces of the composite material parts.

Abstract: Fabricating a composite material part comprises the steps of making a consolidated fiber preform, the fibers of the preform being carbon or ceramic fibers that are coated in an interphase formed by at least one layer of pyrolytic carbon (PyC) or of boron-doped carbon (BC). Obtaining a partially densified consolidated fiber preform, where partial densification comprises forming a first matrix phase on the interphase, the first matrix phase comprising a plurality of layers of self-healing material alternating with one or more layers of PyC or of BC. Continuing densification by dispersing carbon and/or ceramic powder within the partially densified consolidated preform and by infiltrating molten silicon or a liquid composition formed for the most part of silicon.

Abstract: A method of assembling together by brazing first and second parts made of composite material, each of the first and second parts having an assembly face for brazing with the assembly face of the other part, the method including making at least one perforation in the assembly face of the first part; interposing capillary elements between the assembly faces of the first and second parts made of composite material; placing the first and second parts facing each other while inserting a peg in each perforation of the first part; placing a brazing composition in contact with a portion of the capillary elements; and applying heat treatment to liquefy the brazing composition so as to cause the molten brazing composition to spread by capillarity between the assembly faces of the composite material parts.

Abstract: A thermostructural composite material part including carbon or ceramic fiber reinforcement densified by a matrix having at least one thin portion in which: the thickness of the part is less than 2 mm, or indeed less than 1 mm; the fiber reinforcement is made as a single thickness of multilayer fabric made of spread yarns having a weight of not less than 200 tex; the fiber volume ratio lies in the range 25% to 45%; and the ratio between the number of layers of the multilayer fabric and the thickness in millimeters of the part is not less than four.

Abstract: Systems, devices, and methods that are effected in or by an electronic device in response to establishing and/or terminating a physical communications link are described. An electronic device may be entered into deep sleep and may include a power control circuit that activates the device out of deep sleep in response to establishing a physical communications link with a source of electric power, such as another electronic device. Either in combination with or separate from this, an electronic device may establish wireless communications with another electronic device in response to establishing and terminating a physical communications link with the other electronic device. The physical communications link may be used to transfer device identity data from one device to the other and thereby bypass the cumbersome “discovery” process common to conventional wireless communication techniques. Portable electronic devices and personal computing devices that are operative to perform the above are described.

Abstract: A thermostructural composite material part including carbon or ceramic fiber reinforcement densified by a matrix having at least one thin portion in which: the thickness of the part is less than 2 mm, or indeed less than 1 mm; the fiber reinforcement is made as a single thickness of multilayer fabric made of spread yarns having a weight of not less than 200 tex; the fiber volume ratio lies in the range 25% to 45%; and the ratio between the number of layers of the multilayer fabric and the thickness in millimeters of the part is not less than four.

Abstract: A method for the secure protection of a portion of the surface of an official document bearing markings, in which: a transparent security layer (17) is selected, the layer including at least one semi-transparent printed image including at least one transparent binder and at least one thermochromic pigment (14, 13, 12, 11); the semi-transparent printed image reveals at least one semi-transparent visible pattern in a first non-activated state at least a first temperature, such that the markings can be seen through the image, the pattern not being visible in a second activated state at least a second temperature different from the first temperature. A device for the secure protection of a portion of the surface of an official document and such an official document are also described.

Abstract: A thermochromic ink composition includes, in a liquid medium, known as solvent, a dispersion of thermochromic microcapsules incorporating at least one leuco-dye and a thermoplastic binder selected from the group containing polyacrylic polyesters, polyurethanes and copolymers thereof. The composition is characterised in that the solvent is aprotic. A a method for producing a card and such a card incorporating at least one thermochromic pattern produced with a thermochromic ink composition are also described.

Abstract: A method of fabricating a sound attenuation panel of curved shape, the method including impregnating a fiber structure defining a cellular structure with a ceramic precursor resin; polymerizing the ceramic precursor resin while holding the fiber structure on tooling presenting a curved shape corresponding to the final shape of the cellular structure; docking the cellular structure with first and second skins, each formed by a fiber structure impregnated with a ceramic precursor resin, each skin being docked to the cellular structure before or after polymerizing the resin of the skins; pyrolyzing the assembly constituted by the cellular structure and the first and second skins; and densifying the assembly by chemical vapor infiltration.

Abstract: A method of fabricating a curved cellular structure includes making an expandable fiber structure by multilayer weaving between layers of warp yarns and layers of weft yarns, the structure having zones of non-interlinking extending in the thickness of the structure, the non-interlinking zones spaced apart from one another by portions of interlinking between layers of weft yarns, the portions of interlinking offset by one or more weft yarns in a direction parallel to the direction of the layers of weft yarns between each series of these planes; impregnating the fiber structure with a resin; expanding the fiber structure on support tooling to form a cell in the fiber structure at each zone of non-interlinking, the tooling also presenting a curved shape corresponding to the shape of the cellular structure that is to be fabricated; and polymerizing the resin of the fiber structure to form a curved cellular structure.

Abstract: A method of locally treating a portion of a part made of composite material including fiber reinforcement densified by a matrix, the material presenting internal pores, the method including: determining a quantity of infiltration composition as a function of a volume of the portion of the part to be treated, the infiltration composition including at least silicon; placing the determined quantity of infiltration composition in contact with pores opening out in a surface of the portion of the part to be treated; and applying heat treatment at a temperature higher than or equal to a melting temperature of the infiltration composition so as to impregnate the portion with the treatment composition and fill in the pores present in the portion.