Abstract: The present invention relates in particular to an autonomous container ship of the type having a hull, propulsion means, and loading and unloading means, characterized by having ballasting means and means (11, 12, 5) for varying the air draft without changing the draft.

Abstract: The present invention relates in particular to a method for generating a digital signature (c, d) of a message M as well as a method for authenticating such a signature having the steps of defining a modulo N and a base g, a public key Y, and a private key x, these parameters N, g, Y, and x being linked by the relationship Y=gx (mod N), defining a hash function H the size of whose result has S bits, choosing a number r of T bits with T>=2S, calculating u from the following relationship u=gr*Yz where Z=2s, hashing the concatenation of M and u, by function H, the number thus obtained being the value c of the signature, and calculating the value d of the signature by the relationship: d=r+c*x.

Abstract: The invention relates to a wall feedthrough, in particular for a metal wall and for a high-voltage coaxial cable, said feedthrough comprising an insulating socket which is affixed to the wall and which includes a central segment, an upstream end and a downstream end, said ends each projecting on its side from the wall.

Abstract: The present invention relates in particular to an autonomous container ship of the type having a hull, propulsion means, and loading and unloading means, characterized by having ballasting means and means (11, 12, 5) for varying the air draft without changing the draft.

Abstract: The invention concerns an autonomous container ship comprising a hull, a propulsion system, loading and unloading systems for loading and unloading containers, and a balancing system. The ship transports containers from larger ports equipped with facilities for loading and unloading containers to smaller ports which may not provide such equipment and may be less than 4 meters deep. The ship includes a propulsion system to propel the ship to cruising speed on the high seas and at lower speeds in estuaries and ports, loading and unloading systems adapted to ports not provided with appropriate equipment, and a balancing system for balancing the ship at sea by providing stability and trim during container handling operations.

Abstract: An electromagnetic device for producing cold neutral atoms having a ferromagnetic structure with four poles disposed in the same plane XOY excited by main coils (the quadrupole) supplying the main excitation, and two additional poles (the dipole) oriented along an axis Z and perpendicular to the plane of said four poles, the poles being magnetically coupled by one or more yokes.

Abstract: A heat target for producing, in particular, a thermal image composed of several bands and having at least one layer of electrically conducting material connected to two electrodes that are connected to means able to generate a potential difference between them, the target further comprising at least one module resting on a support and forming all or part of a band the at least one module having at least two longitudinal faces and a supporting structure on all or part of which rests a layer made of the electrically conducting material connected to two electrodes connected to means able to generate a potential difference between them.

Abstract: The invention relates to a water discharge device for a system for launching objects, including torpedoes, mines, or missiles, from at least one tube built into a fixed or movable submerged structure (e.g., a submarine). The tube is provided with at least one end door and one slide valve connecting it hydraulically to the water ram by a impulse tank filled with water. The impulse tank is built into the submarine hull, and comprises a closed, sealed space in which the water is driven to the tube, under the influence of a leading pneumatic ram acting on a following hydraulic ram controlled by the water contained in the chamber and previously drawn in from the marine environment by an intake line. The chamber is immovably located outside the hull.

Abstract: A boron and silicon oxynitride obtained by preparing a polyborosiloxane precursor, conducting nitriding pyrolysis of the precursor to obtain an amorphous boron and silicon oxynitride, and optionally conducting additional pyrolysis to obtain a crystallized boron and silicon oxynitride. The polyborosiloxane precursor is prepared by condensation, in the presence of a catalyst, of (2) a polychlorosilane represented by the formula R3R4SiCl2 in which the substituents R3 and R4 are identical or different and each represents a hydrogen atom, a chlorine atom, a linear or branched alkyl or alkenyl or alkynyl radical having 5 or less carbon atoms, or an aryl or aralkyl radical having 6 to 18 carbon atoms, with (2) an alkyl borate represented by the formula (R5O)3B in which R5 represents a linear or branched alkyl radical having 1 to 5 carbon atoms.

Abstract: A subsea thermoelectric generator has a plurality of flat thermoelectric modules attached concentrically to the outside wall of an undersea line in which petroleum products extracted from a subsea drilling well circulate. The thermoelectric modules are disposed in flat-bottomed pans machined into the outside wall of the line. The pans are sealed by lids made of heat-conducting material and in thermal contact with the thermoelectric modules. Each lid defines, with the walls of the corresponding pan, a peripheral sealed chamber. The various chambers in the pans communicate with each other through passages provided in partitions that separate the pans and are filled with a soft (compliant), preferably non-heat-conducting, resin. At least one of the pans is provided with an orifice closed by a sealed deformable element.

Abstract: The invention relates to the field of sonar antennas, in particular those intended to be installed on an underwater vehicle in order to constitute a mounted head of the vehicle. Specifically, the invention relates to a sonar antenna having at least two identical transducers that exhibit sensitivity peaks at at least two frequencies .nu., and .nu..sub.2, wherein the head mass dimension of the transducers is between 0.35 and 0.65 times the wavelength .lambda..sub.2 corresponding to the higher of the frequencies .nu..sub.1 and .nu..sub.2.

Abstract: A high reflectivity, broad band mirror for a high flux laser and a process for producing such a mirror. The mirror includes a substrate on which is formed a metallic layer such as aluminum. A stack of layers are formed on the metallic layer. The stack includes alternating layers of two materials with the refractive index of one material being higher than that of the other. A surface layer of a third material is placed on the stack. The surface layer has a refractive index which varies in accordance with the continuous periodic profile. The mirror is formed by depositing the metallic layer on a substrate and forming the stack by an ion beam sputtering method.

Abstract: The invention relates to a microwave antenna having at least one tubular portion with a central axis, and magnets which are located within the tubular portion along the central axis. The magnets generate a magnetic field in the vicinity of the antenna, with each end of each magnet facing an end having the same polarity of an immediately adjacent magnet. This type of antenna is used in the manufacture of microtips on large surfaces.

Abstract: The invention relates to a device for controlling the kinematics of pivoting elements designed to open substantially simultaneously to allow a clear passage of a weapon in a weapon launch tube equipped with a weapon launch circuit via an air distributor on board a submarine. The invention includes on the axis of rotation of each pivoting element and on the axis of rotation of a rotary element connected to the air distributor, a mechanism for converting a rotation into a translation, a mechanism for converting a translation into a rotation, and an associated mechanism for quantifying these conversions. The mechanism for converting a translation into a rotation on the axis of rotation of the rotary element is activated by the mechanism for converting a rotation into a translation on the axis of rotation of each pivoting element in association with the quantification mechanisms.

Abstract: The present invention relates to a multilayer material useful as an anti-erosion and anti-abrasion coating, and to a process for producing the multilayer material at low temperatures. The multilayer material comprises a substrate covered with at least one metallic tungsten ductile layer and at least one hard layer of a solid solution of an additional element chosen from carbon or nitrogen or a mixture of carbon and nitrogen in tungsten or a tungsten alloy, the two types of layers ar alternating. The multilayer material is particularly useful as a coating for parts used in aeronautics.

Abstract: The invention is directed to the class of submersible electro-acoustic transducers such as double "Tonpilz" transducers, wherein it is desirable to reduce the resonant frequency of the transducers while maintaining a given output power emitted by the transducers. The transducer according to the invention includes at least one horn solid with the end of a motor pillar, a hollow rigid box surrounding the horn and delimiting with the horn a cavity. The cavity communicates via a port with an external fluid, and has determined dimensions and external volume. The transducer further includes a passive radiator made of a material denser than the external fluid. The radiator obturates the port and hangs at a periphery of the port by an elastic material.

Abstract: A Marx generator, includes a number of capacitors (E) connected in series via spark gaps (E), between two output terminals and a power supply circuit that charges the capacitors in parallel. The capacitors are connected in series by a flat line formed of two metal strips running parallel and facing one another. These strips are connected together electrically at one end of the line and respectively to the output terminals at the other end and consist of one continuous strip and a second strip subdivided by transverse slots into successive plane sections interconnected in series alternately by a capacitor and a surface spark gap. A structure of this kind reduces the inductance of the generator and hence improves the rise time of the output pulses.

Abstract: The present invention relates to a process and transducer for emitting wide and and low frequency acoustic waves in unlimited immersion depth.The invention is applied to tranducers comprising at least one electro-acoustic motor (1) causing any wall 3 of the said waves to vibrate, and a hollow shell 5 enclosing the said motor 1, and delimiting with the said vibrating wall 3 among others, a cavity 7, characterised in that:at least one opening 5, causing cavity 7 to communicate with ambient medium 4, is made in said shell 5;in at least part of the volume of the said cavity 7, at least one flexible bladder 7, is installed;this bladder 8 is filled with a fluid 9 more compressible than fluid 4.

Abstract: A process for detection of a new polymorphic locus in a DNA sequence is characterized by the following stages. Polynucleotides are prepared by forming an unspecified oligonucleotide including 5 to 10 bases which are repeated 5 to 100 times. A genomic bank is explored by hybridization under low stringency conditions using the prepared polynucleotides which are labelled. The clones that react with the polynucleotides are analyzed by the Southern method. The restriction fragments detected by the polynucleotides are purified and labelled. The genomic DNA of non-consanguineous individuals is analyzed by the Southern method under highly stringent hybridization conditions, with the obtained restriction fragments. The restriction fragments corresponding to new polymorphic loci are selected.

Abstract: A transducer includes at least one cylindrical driving assembly and at least one headmass coupled to an end of the cylindrical driving assembly. The headmass has an external ring that surrounds a core. The core is made from a core material that is less dense than the material from which the external ring is made. The headmass is dimensioned to occupy a predetermined volume so as to transmit waves within a predetermined frequency range. As a result, the transducer provides higher power waves, yet occupies the same volume as the transducers of the prior art.