Abstract: A thermoelectric composition is provided that includes a nanocomposite comprising a copper selenide (Cu2Se) matrix having a plurality of nanoinclusions comprising copper metal selenide (CuMSe2) distributed therein. M may be selected from the group consisting of: indium (In), aluminum (Al), gallium (Ga), antimony (Sb), bismuth (Bi), and combinations thereof. The thermoelectric composition has an average figure of merit (ZT) of greater than or equal to about 1.5 at a temperature of less than or equal to about 850K (about 577° C.). Methods of making such a thermoelectric nanocomposite material by a sequential solid-state transformation of a CuSe2 precursor are also provided.

Abstract: A thermoelectric composition is provided that includes a nanocomposite comprising a copper selenide (Cu2Se) matrix having a plurality of nanoinclusions comprising copper metal selenide (CuMSe2) distributed therein. M may be selected from the group consisting of: indium (In), aluminum (Al), gallium (Ga), antimony (Sb), bismuth (Bi), and combinations thereof. The thermoelectric composition has an average figure of merit (ZT) of greater than or equal to about 1.5 at a temperature of less than or equal to about 850K (about 577° C.). Methods of making such a thermoelectric nanocomposite material by a sequential solid-state transformation of a CuSe2 precursor are also provided.

Abstract: A thermoelectric composition is provided that includes a nanocomposite comprising a copper selenide (Cu2Se) matrix having a plurality of nanoinclusions comprising copper metal selenide (CuMSe2) distributed therein. M may be selected from the group consisting of: indium (In), aluminum (Al), gallium (Ga), antimony (Sb), bismuth (Bi), and combinations thereof. The thermoelectric composition has an average figure of merit (ZT) of greater than or equal to about 1.5 at a temperature of less than or equal to about 850K (about 577° C.). Methods of making such a thermoelectric nanocomposite material by a sequential solid-state transformation of a CuSe2 precursor are also provided.

Abstract: A thermoelectric composition is provided that includes a nanocomposite comprising a copper selenide (Cu2Se) matrix having a plurality of nanoinclusions comprising copper metal selenide (CuMSe2) distributed therein. M may be selected from the group consisting of: indium (In), aluminum (Al), gallium (Ga), antimony (Sb), bismuth (Bi), and combinations thereof. The thermoelectric composition has an average figure of merit (ZT) of greater than or equal to about 1.5 at a temperature of less than or equal to about 850K (about 577° C.). Methods of making such a thermoelectric nanocomposite material by a sequential solid-state transformation of a CuSe2 precursor are also provided.

Abstract: A system for detecting deformation of a fan for an aeroengine, the fan including a rotor including plural blades made of composite material including woven fibers. At least one of the fibers in each of the blades is an optical fiber including at least one portion defining a Bragg grating. The system further includes a transceiver connected to the optical fiber and configured to send an optical signal into the optical fiber and to receive an optical signal in response from the optical fiber, and a detector module connected to the transceiver to detect deformation of the fan when the received optical signal presents correlation with a predetermined signature of a damped impact on a blade at a determined speed of rotation. This deformation may be the result of a foreign object impacting against a blade of the fan or may follow from variation in an internal defect.

Abstract: Device for measuring corrosion in a structure. It comprises: at least one assembly comprising a metallic part (2) intended to be fixed to the structure and able to deform under the effect of corrosion and/or a thermomechanical variation, and transduction means (4) comprising an optical fibre (3) fixed to the metallic part in a prestressed state, the transduction means being able to modify light propagating in the fibre under the effect of a stress applied to the fibre; means for measuring and processing the spectral responses supplied by the transduction means of said at least one assembly. The metallic part is segmented longitudinally in order to form an alternation of segments covered by a corrosion-protection material (8) and uncovered segments, in order to distinguish the thermomechanical influence of the structure from the mechanical effects caused by corrosion.

Abstract: Device for measuring corrosion in a structure. It comprises: at least one assembly comprising a metallic part (2) intended to be fixed to the structure and able to deform under the effect of corrosion and/or a thermomechanical variation, and transduction means (4) comprising an optical fibre (3) fixed to the metallic part in a prestressed state, the transduction means being able to modify light propagating in the fibre under the effect of a stress applied to the fibre; means for measuring and processing the spectral responses supplied by the transduction means of said at least one assembly. The metallic part is segmented longitudinally in order to form an alternation of segments covered by a corrosion-protection material (8) and uncovered segments, in order to distinguish the thermomechanical influence of the structure from the mechanical effects caused by corrosion.

Abstract: A system for detecting deformation of a fan for an aeroengine, the fan including a rotor including plural blades made of composite material including woven fibers. At least one of the fibers in each of the blades is an optical fiber including at least one portion defining a Bragg grating. The system further includes a transceiver connected to the optical fiber and configured to send an optical signal into the optical fiber and to receive an optical signal in response from the optical fiber, and a detector module connected to the transceiver to detect deformation of the fan when the received optical signal presents correlation with a predetermined signature of a damped impact on a blade at a determined speed of rotation. This deformation may be the result of a foreign object impacting against a blade of the fan or may follow from variation in an internal defect.

Abstract: The invention involves a sensor (100) with a Bragg network fiber including a source (105) and detection system (101), operating at a wavelength of a given study, in addition to a Bragg (6) network fiber (1) linked to said source and said system, with said fiber being a microstructured optic fiber whose sheath (5) includes channels (3) adjacent to the heart (2) of the fiber (1), capable of receiving a product to be analyzed, characterized in that the number of channels (3) adjacent to the heart (2) is between 2 and 5, and that the size of the heart (2) of the fiber (1) is adapted so that an electromagnetic field of a wave guided by the fiber is not confined in the heart (2) of the fiber (1), and the electromagnetic field extends into the channels (3).

Abstract: The invention relates to an instrumented tubular device for transporting a pressurized fluid notably in the field of oil exploration and in that of the transport of gas or hydrocarbons. This device comprises a tube in which this fluid flows, with which are associated means for measuring the main deformations of this tube, and means for measuring the temperature of the fluid in the tube. This tube is equipped with measurement means integral with its surface and offset by at least one remote optical cable towards an electronic measurement system. These measurement means are means for assembling at least two non-parallel optical fibers which comprise at least three assemblies of at least two optical gages with Bragg gratings attached to at least three measurement locations and connected to the remote optical cable via optical fibers. At least one assembly further comprises a temperature gage.

Abstract: The invention relates to a system for distributed or dispersed measurement of axial and bending deformations of a structure including at least one threadlike device (10) equipped for the distributed or dispersed measurement of these axial and bending deformations, and means for processing measurement signals generated by said device, in which each device includes a cylindrical reinforcement (11) supporting, at its periphery, at least three optical fibres (12) locally parallel to the axis of the reinforcement, and in which the processing means implement means for spectral or time division multiplexing of signals coming from optical fibres.

Abstract: This refractometer includes at least one optical waveguide (2) comprising at least one slanted Bragg grating (4), formed in a part of the waveguide, which is placed in contact with the medium (7) of which the refraction index is to be determined, a light source (10) coupled to the waveguide in order to send this light there and have it interact with the grating, means (17) for measuring the optical power of the light diffracted to the radiation-mode continuum, when the light transmitted by the source interacts with the grating, and electronic processing means (22) for supplying the value of the refraction index of the medium based on this optical power.

Abstract: The invention relates to an instrumented tubular device for transporting a pressurized fluid notably in the field of oil exploration and in that of the transport of gas or hydrocarbons. This device comprises a tube (20) in which this fluid flows, with which are associated means for measuring the main deformations of this tube, and means for measuring the temperature of the fluid in the tube. This tube is equipped with measurement means integral with its surface and offset by at least one remote optical cable towards an electronic measurement system. These measurement means are means for assembling at least two non-parallel optical fibers which comprise at least three assemblies (B1, B2, B3) of at least two optical gages with Bragg gratings attached to at least three measurement locations (22) and connected to the remote optical cable (23) via optical fibers. At least one assembly further comprises a temperature gage.

Abstract: The present invention relates to a temperature-compensated optical fiber pressure detector for detecting pressure variations in at least one medium in relation to a reference medium such as the atmosphere or a medium where a back pressure prevails. The detector essentially comprises a deformable element (2) such as a bellows (5) exposed on one side to the reference medium and on the opposite side to the pressure to be measured, an optical fiber portion (F1) including at least one optical grating such as a Bragg grating (B1), which is connected on one side to deformable element (2) and on the opposite side to a fixed point. The optical fiber portion is subjected to a prestress by a device (6, 15, 20, 21) and its elongation varies with the displacements of the deformable element. The device applies the prestress to optical fiber portion (F1) between deformable element (2) and another fixed element (15) isolated from the medium by a rigid housing (1).

Abstract: A refractometer with blazed Bragg gratings. In order to measure the refractive index of a medium, for example a liquid or a gas, the refractometer includes a waveguide having a blazed Bragg grating, the spectral response of which depends on the refractive index of the medium and a light source in order to make this light interact with the grating. Further, spectral analysis of the light which has interacted with the grating is performed, the spectrum provided by the spectral analysis is recovered, and, from the recovered spectrum, the spectral response of the grating is correlated with one value of the refractive index of the medium.

Abstract: Extensometer with flexible test specimen and Bragg gratings applied in particular to the monitoring of concrete structures, is configured to measure deformations of a host material and comprises at least one test specimen which undergoes linear bending stresses, and at least one Bragg grating formed in an optic fibre and fixed to the test specimen. The extensometer configured such that any deformation of the host material is transmitted to the grating via the test specimen. The extensometer also comprises mechanical means which transform deformation of the material into bending of the test specimen, which deforms the grating.

Abstract: The present invention relates to a temperature-compensated optical fiber pressure detector for detecting pressure variations in at least one medium in relation to a reference medium such as the atmosphere or a medium where a back pressure prevails. The detector essentially comprises a deformable element (2) such as a bellows (5) exposed on one side to the reference medium and on the opposite side to the pressure to be measured, an optical fiber portion (F1) including at least one optical grating such as a Bragg grating (B1), which is connected on one side to deformable element (2) and on the opposite side to a fixed point. The optical fiber portion is subjected to a prestress by a device (6, 15, 20, 21) and its elongation varies with the displacements of the deformable element. The device applies the prestress to optical fiber portion (F1) between deformable element (2) and another fixed element (15) isolated from the medium by a rigid housing (1).

Abstract: This extensometer, applied in particular to the monitoring of concrete structures, is intended to measure deformations of a host material and comprises at least one test specimen (18) which undergoes linear bending stresses, and at least one Bragg grating (14) formed in an optic fibre (16) and fixed to the test specimen. Any deformation of the host material is transmitted to the grating via the test specimen. The extensometer also comprises mechanical means (20, 22) which transform deformation of the material into bending of the test specimen, which deforms the grating.

Abstract: An extensometer including a base, a tensioned optical fiber, and a Bragg grating. The extensometer relates particularly to monitoring of structures. Part of the optical fiber containing the Bragg grating is arranged in a tube. This part is tensioned between the two ends of the tube. The ends of this part are fixed to the ends of the tube, and the tube is rigidly fixed to a host material.

Abstract: A differential measurement system using pairs of Bragg gratings including at least one optical sensor having two Bragg gratings in two optical waveguides and having sensitivities adjusted so that respective spectra of the two gratings have a relative spectral shift dependent on a parameter or parameters to be measured. The system also includes an optical source to supply light to the two optical waveguides to interrogate them, a mechanism enabling light to pass successively through the two Bragg gratings of the same sensor, photodetectors to measure the power level of light having passed only through one of the two optical waveguides and the power level of light having passed successively through the two optical waveguides, and a processor to process the power levels and supply values of the parameter or parameters measured. The system is applicable in particular to measurements of temperatures, stresses, and pressures.