Abstract: A method is disclosed for determining, without carrying out a well-velocity survey or making an a priori assumption on the velocity of the first medium, the primary static corrections to be applied to sets of seismic traces after seismic prospecting operations in an underground zone. A velocity model allows calculation of the corrections is essentially obtained by performing, for each position of the common midpoint, a continuous and progressive inversion of the first arrival times (time-distance curves), from short offsets to longer offsets, so as to allow going from a sequence of pairs connecting the offsets to the arrival times picked to a sequence of vertical data connecting the depth to the velocity of propagation of the waves.

Abstract: A method and device for emitting radial seismic waves in a material medium by electromagnetic induction, used notably for generating seismic waves in cased or uncased wells or in a water mass is disclosed. Emission of radial waves is essentially obtained by radially expanding a metal tube (1) under the effect of a magnetic pressure generated by electromagnetic induction with elastic waves being created in the medium under the effect of this expansion. The magnetic pressure is obtained by connecting a coil (2) in line with the tube to a current generator (3). The winding pitch of coil (2) can be constant or variable. Tube (1) can for example be added into a well or hole or it can be a tube portion of a cased well.

Abstract: Vibrator comprising a single vibration generator coupled with the medium by a coupling element and means for controlling the generator, suited to apply thereto, on each emission, a single pilot signal obtained by combination of at least two signals of different frequencies (f1, f2), fixed or preferably variable within at least partly separate frequency bands, and non-linear elastic transmission means suited to generate in the medium vibrations at a frequency depending on the frequency difference of the two vibrational signals. The exploration method comprises using the vibrator in order to emit very low-frequency vibrations in the medium reception by pickups (R) of the waves reflected by the medium in response to the vibrations emitted and recording thereof, and selection by correlation of the vibrational signals with a synthetic signal whose frequency is connected with the frequency difference of the signals forming the pilot signal.

Abstract: A secure, optically readable data medium comprises a data-carrying zone readable by a read light beam, and at least a portion that is photosensitive, being provided with a photosensitive material and exposed to the read light beam. The photosensitive material contains an active compound taken from the family of diarylethenes.

Abstract: Method and device for emitting radial seismic waves in a material medium by electromagnetic induction, used notably for generating seismic waves in cased or uncased wells or in a water mass.

Abstract: Vibrator comprising a single vibration generator coupled with the medium by a coupling element and means for controlling the generator, suited to apply thereto, on each emission, a single pilot signal obtained by combination of at least two signals of different frequencies (f1, f2), fixed or preferably variable within at least partly separate frequency bands, and non-linear elastic transmission means suited to generate in the medium vibrations at a frequency depending on the frequency difference of the two vibrational signals.

Abstract: An electronic card having an electronic control circuit, an elector-optical element configured as a normal operation indicator, and a power supply source. Electrical tracks connect the electronic control circuit with the electro-optical element and the power supply source, and affixing elements attach the electronic card to a substantially planer surface. The electrical tracks having embrittlement grooves which destroy the connections made by the electrical tracks upon removal of the electronic card from the substantially planer surface to which the electronic card is attached. The electronic card is suited for applications in the identification and automatic detection of objects and in particular, stolen vehicles.

Abstract: A bank or identity type of magnetic card contains ferromagnetic elements that selectively absorb waves at microwave frequencies. The disclosure also relates to a reading device adapted to this card. The device has an active system and a resonant system capable of filtering the microwaves at the resonance frequencies of the ferromagnetic materials of the card to be read. The reading device, equipped with a system to measure the amplitude of the microwaves, can thus recognize the magnetic information elements on the card, through the disturbance or non-disturbance of the microwaves during the insertion of the card into the device. The value of the encoding of the card lies in fact that the information elements are hard to destroy.

Abstract: This invention concerns conductive materials based on an encapsulated conductive polymer. Encapsulation in a shell of polymer stabilizes the conductivity of these materials, which can be encapsulated in a shell of film-generating polymer, to give the material formed very good mechanical properties, unlike conductive polymers which existed in the prior art, which, if not encapsulated, form brittle materials that are less stable in time.

Abstract: A material based on a conductive polymer consisting of particles of conductive polymer (P.sub.0), each particle being wrapped in a shell of water-insoluble, cross-linked polymer (P.sub.1).

Abstract: The invention is a new process to produce polyparaphenylene vinylene or polyparathienylene vinylene polymers using a sulfonium-based polyelectric precursor. This precursor is treated directly with acid to obtain the polymers required. These polymers have high molecular weights and are particularly advantageous in the plastics transformation field.

Abstract: The invention is a series of amorphous copolymers which, used in association with a small molecule, provide photorefractive materials that can be used in optical signal processing. These copolymers contain an active non-linear optical group and a group which contributes to their photoconductivity. ##STR1## where: X is H, CH.sub.3, Cl or FY is H, CH.sub.3, Cl or F2.ltoreq.n.ltoreq.42.ltoreq.m.ltoreq.4The electron-donor group D being: --O--, --S--, ##STR2## or --COO-- The electron-accepter group A.sub.e being: --CN, --NO.sub.

Abstract: An identification system is disclosed which includes marks on an object for locating a region of the object which contains an identification in the form of either an etching or a responsive electronic circuit and a detection device for detecting the proximity of the first mark in order to localize the position of the etching or responsive electronic circuit so that the etching or responsive electronic circuit may be read.

Abstract: This invention concerns new molecules with active, non-linear optical properties and which can be thermally reticulated (more precisely, these molecules include terminal functions which can be reticulated, attached to either side of the groups active in non-linear optics, which can be oriented under an electrical field). When reticulated and oriented under an electrical field, these materials are particularly stable and can be employed for industrial applications, using non-linear optics (electrooptical modulators, frequency doublers, etc.).

Abstract: The invention relates to the obtaining of a structure generating non-linear electrooptical effects, the effects being due to molecules or inter-molecular groupings possessing a non-linear susceptibility and the orientation of the molecules or groupings being induced by an applied electric field. According to the invention, the orientation of the molecules or inter-molecular groupings (5) is obtained by of a dielectric having a permanent polarisation such as an electret (6).

Abstract: Disclosed is a process for the synthesizing of polysilsesquioxane, including a first step for the hydrolysis, in the presence of ether, of trichlorosilane with the general formula RSiCl.sub.3 where R represents an organic radical, notably an alkyl, an aryl, a vinyl or an allyl, said process further including the following steps;2nd step: the dissolving of the solid product obtained at the end of the first step in an anhydrous ketonic solvent and the addition of a base, the reaction taking place under heat, a solid product being obtained after evaporation and drying;3rd step: the dissolving of the solid product obtained at the end of the second step in an anyhydrous ketone, the addition of a chain-terminating agent, the reaction taking place under heat and the solution obtained being filtered, evaporated and dried to give the desired polysilsesquioxane,wherein the second step is repeated several times.

Abstract: The invention is a series of amorphous copolymers which, used in association with a small molecule, provide photorefractive materials that can be used in optical signal processing. These copolymers contain an active non-linear optical group and a group which contributes to their photoconductivity. ##STR1## where: X is H, CH.sub.3, Cl or FY is H, CH.sub.3, Cl or F2.ltoreq.n.ltoreq.42.ltoreq.m.ltoreq.4The electron-donor group D being:--O--, --S--, ##STR2## or --COO-- The electron-acceptor group A.sub.e being: --CN, --NO.sub.

Abstract: The invention is a process to manufacture a controlled-porosity ceramic material by synthesizing an aerogel produced by hypercritical drying of a high-porosity gel.Applications in the submarine acoustic field (active and passive sonars).

Abstract: A guiding system for driving a non rigid exploration device in wells where progression by gravity is difficult includes a tubular column for guiding the displacement of the device which includes a plurality or set of sondes joined together by non-rigid connecting means into a deflected well zone. A first sonde of the set is at least fitted with anchoring arms and its cross-section and possibly that of all the remaining sondes of the set can be larger than the cross-section of the tubular column. In this case, a more or less long protective housing is provided at the end of the column. A delayed electric connection device for the set of sondes linked to a surface laboratory is utilized. The first sonde is pushed out of the column by a fluid pressure and anchoring arms of the first sonde are opened. The tubular column is pulled backward and upward in order to make the plurality of sondes to come out of the column and to be positioned in the well and, thereafter, measuring cycles are carried out.

Abstract: Disclosed is an electrically conductive composite polymer film formed from an organic matrix and conductive charges. The matrix is a polymer obtained from a filmogenic macromolecular latex and the conductive charges consist of a conductive polymer diffused in the matrix. The invention can be applied to microwave absorbent layers.