Abstract: An as-spun monofilament of thermotropic aromatic polyester(amide), which satisfies the following conditions: D≧40; Te>45; &Dgr;L≧0, D being its diameter (in &mgr;m), Te its tenacity (in cN/tex) and &Dgr;L its variation in length (in %) after 2 minutes at 235±5° C. at an initial tension of 0.2 cN/tex. A spinning process for obtaining such a monofilament, including, upon emergence from the spinneret, of structuring the flow of the polymer by stretching in a layer of gaseous fluid for a predetermined time which is a function of the diameter D, before thermally quenching the flow of polymer thus structured in a liquid, so as to solidify it.

Abstract: A cellulose formate fiber of liquid-crystal origin, having a high elongation at break and having the following characteristics: a) under an optical polarizing microscope, its filaments have a banded structure typical of its liquid-crystal origin; b) it satisfies the following relationships: DS≧2; Ar≧8; Te<45; Mi>500; Er>10, DS being the degree of substitution of the cellulose with formate groups in the fiber (in %), Ar the elongation at break (in %) of the fiber, Te its tenacity (in cN/tex), Mi its initial modulus (in cN/tex) and Er its energy at break (in J/g). Also, a process for obtaining this cellulose formate fiber by “dry-jet-wet-spinning” of a liquid-crystal solution of cellulose formate, in which water is used as coagulating agent. A fiber of cellulose regenerated from cellulose formate which itself has a high value of elongation at break, and a process for obtaining this fiber.

Abstract: Fiber made of cellulose formate and fiber made of cellulose regenerated from cellulose formate. These fibers exhibit high tenacity and modulus properties, combined with improved values of elongation at break and of energy at break. Their elongation at break, in particular, is greater than 6%. Methods for producing these fibers. The fiber made of cellulose formate is obtained by spinning a liquid crystal solution of cellulose formate according to the so-called dry-jet-wet spinning method, the coagulation stage and the neutral washing stage which follow both being carried out in acetone. The fiber made of cellulose formate in a highly concentrated aqueous sodium hydroxide solution. The spinning and regeneration methods can be employed in line and continuously. Reinforcing assemblies based on such fibers. Articles reinforced by such fibers or assemblies, these reinforced articles being in particular tires.

Abstract: In order to carry out the on-site determining of the error of orientational adjustment of an electronic scanning antenna, this error being due to defects of manufacture of the radiating face of this antenna, radioelectric measurements are used during the qualification of this antenna. These measurements are made for several directions of the antenna beam, and the most likely components of the aiming error are selected.

Abstract: A cellulose formate fiber of liquid-crystal origin, having a high elongation at break and having the following characteristics:a) under an optical polarizing microscope, its filaments have a banded structure typical of its liquid-crystal origin;b) it satisfies the following relationships:DS.gtoreq.2; Ar.gtoreq.8; Te<45; Mi>500; Er>10,DS being the degree of substitution of the cellulose with formate groups in the fiber (in %), Ar the elongation at break (in %) of the fiber, Te its tenacity (in cN/tex), Mi its initial modulus (in cN/tex) and Er its energy at break (in J/g).Also, a process for obtaining this cellulose formate fiber by "dry-jet-wet-spinning" of a liquid-crystal solution of cellulose formate, in which water is used as coagulating agent. A fiber of cellulose regenerated from cellulose formate which itself has a high value of elongation at break, and a process for obtaining this fiber.

Abstract: The present invention provides a fiber made of cellulose formate which exhibits high tenacity and modulus properties, combined with improved values of elongation at break and of energy at break. The elongation at break, in particular, is greater than 6%. The invention also provides a method of producing the fiber by spinning a liquid crystal solution of cellulose formate according to the so-called dry-jet-wet spinning method, the coagulation stage and the neutral washing stage which follow both being carried out in acetone.

Abstract: A method for positioning plural electromagnetic sensors in an array including the steps of: (1) designating one of the two sensors of the plural sensors that are a greatest distance apart as a point of origin of a reference system, (2) encoding in genotype form, the coordinates of the sensors relative to the reference system, and (3) applying a genetic algorithm to the encoded genotypes to obtain a given phenotype associated with a desired pattern. The method can be applied to the optimization of antenna arrays, especially planar or linear arrays.

Abstract: Process for preparing a solution of cellulose formate from cellulose plates, in particular high-density plates, without prior mechanical destruction of these plates. The plates are dissolved directly, by means of an impregnating step of the whole plates in a base liquid of formic acid, followed by an operation of kneading of the plates thus impregnated in contact with both formic acid and phosphoric acid. The process is preferably carried out in order to prepare ready-for-spinning solutions with, in particular, if necessary, an intermediate operation of adjustment of the final composition. Solutions prepared using such a process. Preparation of objects made of cellulose, starting with these solutions, in particular fibers or films. Assemblies of such fibers or films. Articles reinforced with such fibers or films or assemblies, these reinforced articles being especially tires.

Abstract: The disclosure relates to electronic scanning array antennas whose radiating elements are distributed within a volume instead of being distributed on a reflective surface that is plane or generated by revolution. It pertains to a method for broadening the beam of a volume antenna aimed in a direction without giving it asymmetrical deformation or substantially increasing the secondary lobes. This method consists of applying the following phase excitation law to the radiating elements of the volume antenna: ##EQU1## where .lambda. is the wavelength of the radiation transmitted or received and .rho..sub.n is the distance from the radiating element with an index n considered to a point I external to the volume antenna located on the axis of aiming direction on the side opposite the aiming direction.

Abstract: Disclosed is a device to compensate for the aiming errors caused by malfunctions in phase-shifters of electronic scanning antennas. With the electronic scanning antenna being plane and having a power distribution that is symmetrical in amplitude and in phase, the device has means positioning a malfunctioning phase-shifter and its symmetrical phase-shifter in supplementary phase states. Application notably to landing systems requiring high precision for the aiming of the beam in free space.

Abstract: A position-adjusting device for a safety belt guide loop includes a rail provided with retaining slots, a carriage which is slidably mounted on the rail and on which are mounted the guide loop and two locking bolts urged by respective springs to a position of engagement in the rail slots in order to lock the carriage in a corresponding position along the rail. The length of the rail slots in the direction of sliding motion of the carriage is greater than the corresponding dimension of the locking bolts. The bolts are so arranged in relation to each other that, in any position of the carriage along the rail, at least one locking bolt is located opposite to one rail slot and capable of engaging therein. The slots form a single row and are each capable of receiving both locking bolts, depending on the position of the carriage along the rail.

Abstract: In a reflective angle of a radar, auxiliary elementary sources are positioned beneath the main source. By the division of the measurement signals of the measurement channel of the main source and of the auxiliary measurement channel, a monotonous characteristic is obtained, enabling the elevation angle to be measured with high precision. FIG. 1.

Abstract: An antenna of the random spare volume array type comprising a plurality of elementary antennas with almost omnidirectional individual radiation distributed according to a statistically isotropic random relationship of distribution within an enveloping volume having a shape generated by revolution, the mean spacing between elementary antennas being notably greater than a half wavelength of the minimum frequency to be received or transmitted, each elementary antenna being connected to an active module comprising individually controllable phase-shifters themselves connected to a common distributor. According to the disclosure, the elementary antennas are formed by dipoles oriented vertically and supplied by a supply line comprising a first section, extending horizontally between the respective dipole and a common vertical tower coaxial with the enveloping volume having a shape generated by revolution, and a second section extending to the interior of this tower and ending in the distributor.

Abstract: A microwave reflector having metallic surfaces and nonmetallic surfaces is perfectly reflecting for the waves of a first polarization and partly transparent for the waves of a second polarization orthogonal to the first. The reflector is primarily applicable to radar systems.

Abstract: An antenna with pseudo-toric cover for transmitting and/or receiving a microwave, comprising principally an array transmitting a microwave towards a first reflector in the form of an elliptic or parabolic skull cap, whose concave side is turned towards the array and which reflects the energy towards a second reflector in the form of a concave ring, whose center is occupied by the array and whose concavity is turned towards said first reflector. The reflector is preferably supported by a radome.

Abstract: Secondary lobe cancellation (SLC) is used to reduce the power of jamming signals received by the sidelobes of a main radar antenna. The signal from the radiation pattern of the main antenna is summed with signals from auxiliary radiation patterns. Each auxiliary pattern is chosen to be directional, to have a null or at least a gain minimum in the direction of maximum radiation in the main antenna pattern, to have its phase center close to that of the main antenna pattern, and to have gain minimums in those directions for which the sidelobes of the main antenna pattern are low enough to be insensitive to jamming signals. The various patterns may all be derived from an array antenna, e.g. a multibeam antenna, an aplanatic lens antenna, or a chandelier fed antenna.

Abstract: An antenna having two crossed cylindro-parabolic reflectors in which the generatrices of said reflectors are orthogonal. The source is placed close to the center of the main reflector, which is further provided with polarization rotation means. The auxiliary reflector is placed facing the main reflector and it is such that it is transparent to a wave polarized linearly in one direction and reflecting to the waves polarized in an orthogonal direction.

Abstract: A frame for holding a glass sheet in a substantially vertical position. The frame has two uprights joined by upper and lower crosspieces. A lower support means adapted to engage a bottom edge of a glass sheet is carried by the lower crosspiece. Upper support means freely movable in a vertical direction are adopted to engage the upper edge of the glass sheet and form part of the frame.

Abstract: The invention relates to a method of differentiated rate of hardening of a glass sheet by blowing a cooling gas in the direction of this sheet having two zones from nozzles. According to the invention, a simultaneous solidification of the glass sheet is produced at both zones of the sheet in spite of the differentiated treatments applied to establish a difference of hardening between the different zones of the sheet. Application is to the production of flat glass sheets.

Abstract: A dual-band antenna for the transmission and reception of radiant energy has a Cassegrain-type reflector assembly, rotatable about an azimuth axis and pivotable about an elevational axis, to which two outgoing beams are directed in a transmitting mode by a periscopic supply system including a set of four mirrors, two of them flat and two of them concave. The lower-band beam originates at a first feed comprising a horizontally radiating horn and two confronting concave mirrors, one of these mirrors training the beam onto a slanting dichroic mirror reflecting same upward into the periscopic supply system. The higher-band beam originates at a second feed also comprising a horizontal horn which radiates onto a concave mirror reflecting the beam upward through the dichroic mirror into the periscopic supply system along a path coinciding with that of the other beam.