Abstract: The invention relates to a voice coil support (21) for a coil transducer motor structure (10) having a first surface (26) towards one end and a second surface (22) towards the other end along an axis of displacement Z, the voice coil support being adapted to receive at least one coil (22H, 22L) wound therearound an outer surface (27) arranged in use for displacing the voice coil support (21) along its axis of displacement Z, as a current is driven through the coils (22H, 22L) when the voice coil support (21) is placed in a magnetic field, characterized in that the voice coil support (21) comprises a material adapted to prevent airflow communication between at least the first surface (26) and the second surface (22).

Abstract: A method for manufacturing a composition including telechelic oligomers the ends of which carry reactive functions, the method including the contacting of at least one waste material containing rubber, preferable tire waste, with a chemical degradation agent selected from cleavage agents that are specific for double bonds; and a transfer agent in the presence of a catalysts; at a temperature from 15 to 400° C., preferably from 17 to 35° C.; at ambient pressure. The composition of oligomers that can be prepared by the method is also described.

Abstract: The disclosure relates to an electrodynamic-transducer magnetic motor device (10) having a moving coil comprising a magnetic circuit consisting of a tied angular magnet (11), characterized in that said tied annular magnet has a hollow annular structure, said hollow annular structure comprising an annular cavity (12) connected to an upper portion (13) of an external surface (14) of said hollow annular structure by a first annular channel (15) forming a first gap in which a first winding (17) of the moving coil can move.

Abstract: The present invention concerns an acoustic impedance sensor designed to measure the input acoustic impedance of a waveguide. This sensor is characterized in that the source is a piezoelectric pellet that makes it possible for the determination of the acoustic impedance of a passive acoustic element to remain coherent for low frequencies while preserving an inexpensive implementation of the sensor.

Abstract: The invention relates to a device for measuring a heat flux, comprising a thermopile formed of a plurality of thermojunctions of distributed type. The device is formed of a first and a second ceramic substrate (Ce1, Ce2), a first face of the first substrate (Ce1) is composed of cavities which are separated by ceramic spacers (Ca1, Ca2, Ca3, Ca4), the thermopile is placed on a second planar face of the first substrate which is located opposite the first face, the spacers of the first substrate are arranged beneath one thermojunction (Tj2, Tj4, Tj6, Tj8) in two of the thermopile, a face of the second substrate (Ce2) is composed of cavities which are separated by ceramic spacers (Ca5, Ca6, Ca7, Ca8, Ca9), the spacers of the second substrate rest on a thermojunction (Tj1, Tj3, Tj5, Tj7, Tj9) beneath which a spacer of the first substrate is not arranged.

Abstract: Said electrodynamic speaker structure having MEMS technology, comprising a stator-forming means (2), diaphragm-forming means (3), and resiliently shape-changing means (4) for connecting all of said means, is characterized in that the stator-forming means (2), diaphragm-forming means (3), and connecting means (4) are made of a single part by machining a silicon chip.

Abstract: Gossypol and apogossypol derivatives of general formula (1), preparation thereof and use thereof.

Abstract: The present disclosure relates to a coil transducer motor structure (20) including at least one coil (22), at least one magnetic element (23) arranged in use to provide a path for magnetic flux between the ends of said coil (22), wherein the magnetic element (23) has a structure providing a curvilinear path therethrough for said magnetic flux.

Abstract: The invention relates to processes for the modification of surfaces and on processes for the measurement of adhesion forces and of different forces of interaction (friction forces, adhesion forces) by scanning probe microscopy functioning in continuous <<curvilinear>> mode, as well as to a scanning probe microscope and a device permitting the implementation of said processes.

Abstract: A method for preparing aromatic carboxylic acid derivatives by nucleophilic aromatic substitution, involves reacting an aromatic carboxylic acid derivative supporting only one carboxyl function, or one of the salts thereof, the carboxylic acid derivative supporting, orthogonally to the carboxyl function, a leaving group which is a fluorine or chlorine atom or an alkoxy group, chiral or otherwise and, in the latter case, preferably a methoxy group; the carboxylic acid derivative being substituted by at least one electro-attractive group other than the leaving group, preferably by a fluorine atom, with a MNu reagent, wherein M is a metal and Nu an optionally chiral nucleophile, the nucleophilic aromatic substitution reaction being carried out without a catalyst and without a step of protecting/unprotecting the acid function of the initial compound, the method being selective in that the reaction leads to the formation of ketone derivatives in a very minority fashion during the reaction.

Abstract: A method for manufacturing a composition including telechelic oligomers the ends of which carry reactive functions, the method including the contacting of at least one waste material containing rubber, preferable tire waste, with a chemical degradation agent selected from cleavage agents that are specific for double bonds; and a transfer agent in the presence of a catalysts; at a temperature from 15 to 400° C., preferably from 17 to 35° C.; at ambient pressure. The composition of oligomers that can be prepared by the method is also described.

Abstract: Method for preparing carboxylic acid derivatives by aromatic nucleophilic substitution, in which a carboxylic acid derivative having a single carboxyl functional group, or one of the salts thereof, the carboxylic acid derivative having, in the ortho position of the carboxyl functional group, a leaving group, which is preferably an atom of fluorine or of chlorine or an alkoxy group, chiral or not, preferably a methoxy group, the carboxylic acid derivative not being substituted by an electro attractive group other than the leaving group if any; is reacted with a reactant MNu, where M is a metal and Nu is a nucleophile, chiral or not, the aromatic nucleophilic substitution reaction being carried out without a catalyst and without a step of protecting/deprotecting the acid functional group of the starting compound.

Abstract: The invention relates to an electrodynamic transducer (1) with a dome type diaphragm (2), comprising an electrodynamic motor with a coil (6) borne by a mandrel (3) integral with the diaphragm suspended to a yoke (7), the coil being placed in an air gap of a vertical free space in which it can move and which is defined, toward the center, by an internal magnetic construction (4), and toward the periphery, by an external magnetic construction (5), wherein the suspension comprises neither peripheral suspension nor internal suspension, the transducer comprises at least two magnetic field confinement means (11) in the air gap in order to form by mean of a ferromagnetic liquid at least two ferrofluidic seals (12, 13, 14) stepped in the air gap, fulfilling at least the guidance of the coil and the pneumatic tightness between the front and rear faces of the diaphragm, at least one of the ferrofluidic seals being continuous. Application to loudspeakers.

Abstract: A method is provided for the non-destructive and contactless characterization of a multilayered structure having a substantially spherical shape and including at least two layers, separated by interfaces. The method includes using a laser for locally heating the structure in a thermoelastic state so that the structure is vibrated in a non-destructive manner, measuring the resonance frequencies of the vibration modes of the structure and deriving at least one characteristic concerning the integrity or the shape or the mechanical behavior of the structure from the resonance frequencies of the structure.

Abstract: An electrodynamic transducer includes a frame and contains at least one electric coil which is placed in a static magnetic field and which can move about a rest position in a vertical free space. The coil(s) is wound around and fixed to a mandrel and a return member is used to return the coil-bearing mandrel to the rest position in the absence of an external bias, the straight cylinder defining an inner volume and an outer volume. The magnetic field is produced by outer and inner magnetic structures which each comprise at least one fixed permanent magnet in the form of a ring. The motor does not contain any ferromagnetic or magnetic part between the outer volume and the inner volume. At least the part of the frame that is used to fix the magnets is made from a non-ferromagnetic and non-magnetic material.

Abstract: The invention relates to a moving part for an electro-dynamic transducer, including at least one mandrel supporting a winding of at least one coiled wire. The mandrel includes at least one first element rigidly connected inside at least one second element for guiding the moving part inside the transducer. The first element has a winding support for the coiled wire so that the coil is located inside the mandrel, as well as vibration transmitter, such as a diaphragm, the vibration being generated by the movement of the coil induced by the flow of current in the coil wire. The invention also relates to an electro-dynamic transducer including such a moving part.

Abstract: A magnetic structure generating a magnetic field for an ironless motor of an electrodynamic loudspeaker having a mobile coil, wherein the magnetic structure generates a magnetic field in a gap in which the coil is arranged. The magnetic structure includes of a stack of three magnets corresponding to one intermediate magnet and two top and bottom covering magnets, the magnets forming a straight gap border and being located side by side, the intermediate magnet having a radial magnetic polarization, the covering magnets having identical magnetic polarizations and remanent magnetizations. The covering magnets have a radial or axial magnetic polarization. When magnetic polarization of the covering magnets is radial, remanent magnetization of each covering magnet is higher than remanent magnetization of the intermediate magnet, and when magnetic polarization of the covering magnets is axial, remanent magnetization of each covering magnet is lower than remanent magnetization of the intermediate magnet.

Abstract: Photo-crosslinkable antifouling compositions, in particular antibacterial, antifungal and anti-algae ones, which include the combination of at least one telechelic oligoisoprene of a particular formula with an agent for crosslinking the oligoisoprene. The antifouling film is obtained by applying a thin layer of such a liquid composition on a substrate and is crosslinked at room temperature by exposure to visible and/or UV radiations. The film can be used for preventing the occurrence of a biofilm on any surface in a humid or aqueous environment, and can be used as an additive for preparing materials with a view to imparting bacteriostatic and/or bactericidal properties thereto.

Abstract: Gossypol and apogossypol derivatives of general formula (1), preparation thereof and use thereof.

Abstract: A magnetic structure generating a magnetic field for an ironless motor of an electrodynamic loudspeaker having a mobile coil, wherein the magnetic structure generates a magnetic field in a gap in which the coil is arranged. The magnetic structure includes of a stack of three magnets corresponding to one intermediate magnet and two top and bottom covering magnets, the magnets forming a straight gap border and being located side by side, the intermediate magnet having a radial magnetic polarization, the covering magnets having identical magnetic polarizations and remanent magnetizations. The covering magnets have a radial or axial magnetic polarization. When magnetic polarization of the covering magnets is radial, remanent magnetization of each covering magnet is higher than remanent magnetization of the intermediate magnet, and when magnetic polarization of the covering magnets is axial, remanent magnetization of each covering magnet is lower than remanent magnetization of the intermediate magnet.