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Computer science, Informatique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Capteurs (chimiques, optiques, électriques, de mouvement, de gaz, etc.); télédétection, Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing, Chimie, Chemistry, Chimie analytique, Analytical chemistry, Sciences appliquees, Applied sciences, Informatique; automatique theorique; systemes, Computer science; control theory; systems, Automatique théorique. Systèmes, Control theory. Systems, Robotique, Robotics, Pollution, Pollution atmosphérique, Atmospheric pollution, Méthodes d'analyse, Analysis methods, Capteur chimique, Chemical sensor, Captador químico, Cinétique, Kinetics, Cinética, Ecoulement gaz, Gas flow, Flujo gas, Ecoulement turbulent, Turbulent flow, Flujo turbulento, Etude expérimentale, Experimental study, Estudio experimental, Interface graphique, Graphical interface, Interfaz grafica, Localisation source, Source localization, Localización fuente, Modélisation, Modeling, Modelización, Panache, Plume, Penacho, Pollution air, Air pollution, Contaminación aire, Propriété dynamique, Dynamic properties, Propiedad dinámica, Robot, Robotique, Robotics, Robótica, Règle inférence, Inference rule, Regla inferencia, Règle production, Production rule, Regla producción, Réseau Pétri, Petri net, Red Petri, Système acquisition donnée, Data acquisition system, Sistema adquisición dato, Traçage, Tracing, Trazado, Chemical plume tracing, Diffusive and turbulent airflow, Knowledge, Petri nets, and Rule-based system

This paper presents a Petri net model for autonomous tracking of chemical plumes developed in both diffusive and turbulent airflow environments. It has been challenging to develop a generalized algorithm to effectively trace both types of chemical plumes due to the significant differences of their kinetic and dynamic properties. Our idea is to utilize a Petri net to model the change relationships of chemical concentrations acquired by two sensors mounted on the both sides of a DaNI robot during a tracing process. Because the relationships imply the effects of flow variation on chemical puffs, a flow sensor is eliminated. To express and maintain the knowledge of chemical concentration changes using the Petri net, we design a mapping algorithm for generating the Petri net from production rules. The Petri net model is implemented on the robot using LabVIEW. The chemical plume tracing experiments achieve 93.8% and 87.5% of source localization rates under both turbulent and diffusive airflow environments, respectively.

Cognition, Computer science, Informatique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Capteurs (chimiques, optiques, électriques, de mouvement, de gaz, etc.); télédétection, Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Transistors, Telecommunications et theorie de l'information, Telecommunications and information theory, Théorie de l'information, du signal et des communications, Information, signal and communications theory, Théorie du signal et des communications, Signal and communications theory, Signal, bruit, Signal, noise, Détection, estimation, filtrage, égalisation, prédiction, Detection, estimation, filtering, equalization, prediction, Analyse composante indépendante, Independent component analysis, Analisis componente independiente, Aveugle, Blind, Ciego, Calcul formel, Computer algebra, Cálculo formal, Effet non linéaire, Non linear effect, Efecto no lineal, Etalonnage, Calibration, Contraste, Etude expérimentale, Experimental study, Estudio experimental, Identification aveugle, Blind identification, Identificación ciega, Information mutuelle, Mutual information, Información mutual, Mesure, Measurement, Medida, Mélange signal, Signal mixing, Mezcla señal, Méthode séparation, Separation method, Método separación, Source linéaire, Linear source, Fuente lineal, Séparation aveugle, Blind separation, Separación ciega, Séparation source, Source separation, Separación señal, Transformation échelle, Scale transformation, Transformación escala, Transistor effet champ sensible ion, Ionosensible field effect transistor, Transistor efecto campo sensible ión, Transistor effet champ, Field effect transistor, Transistor efecto campo, Capteur intelligent, Intelligent sensors, Sensor inteligente, Ion-selective field-effect transistors, Nonlinear blind source separation, Post-nonlinear mixtures, and Smart sensors

The response of ion-sensitive field-effect transistors (ISFETs) can be seriously affected in mixed-ion solutions by different interfering ions. As has been demonstrated, this problem can be addressed using nonlinear semi-blind source separation (BSS) algorithms based on post-non-linear mixtures in which nonlinear transforms must be computed using supervised samples, i.e. calibration points for known concentrations of the main ion. In order to eliminate the cost of collecting such samples, this paper introduces a novel non-linear BSS algorithm that employs linearizing transforms computed only with unsupervised information. The scale indeterminacy of this transform is removed using a prior on the sources based on magnitude bounding and, besides, gaussianization is generalized by using a kernel estimator. Experiments with real ISFET measurements demonstrate that this BSS algorithm achieves a level of accuracy similar to that of the semi-blind counterpart based on independent component analysis and outperforms a post-nonlinear BSS algorithm which minimizes the mutual information.

Chemistry, Chimie, Energy, Énergie, Chemical industry parachemical industry, Industrie chimique et parachimique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Physics, Physique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Capteurs (chimiques, optiques, électriques, de mouvement, de gaz, etc.); télédétection, Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Propriétés optiques, spectroscopie et autres interactions de la matière condensée avec les particules et le rayonnement, Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation, Photoluminescence, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Nanomatériaux et nanostructures : fabrication et caractèrisation, Nanoscale materials and structures: fabrication and characterization, Matériaux nanocristallins, Nanocrystalline materials, Points quantiques, Quantum dots, Absorption, Capteur, Sensors, Conversion fréquence, Frequency conversion, Conversión frecuencia, Ion métallique, Metal ion, Ión metálico, Nanomatériau, Nanostructured materials, Photoluminescence, Photon, Photons, Point quantique, Quantum dots, Processus 2 photons, Two-photon processes, 0707D, 8107B, 8107T, 8535B, Oxyde de graphène, and Graphene oxide

In-depth study on upconversion photoluminescence (UCPL) of graphene oxide quantum dots (GOQDs) was presented. Uniform GOQDs with a single-layer and a circular shape within 4 nm diameter were fabricated by acidic exfoliation from the graphite nanoparticles. The green UCPL of the GOQDs at ~563 nm was observed by a femto-second (fs) Ti:sapphire pulsed laser (λex: 800 nm), and the mechanism of the observed UCPL was systemically characterized. We further utilized the UCPL of GOQD as an optical biosensor for detecting aptamer-based metal ions with high sensitivity and selectivity, and verified that the fluorescence quenching of the UCPL GOQDs was mediated by the electron transfer between the GOQD and the captured metal ion rather than fluorescence energy transfer. The understanding of the UCPL of graphene quantum dots would enhance their applicability in the biosensing and bioimaging research fields.

Chemistry, Chimie, Energy, Énergie, Chemical industry parachemical industry, Industrie chimique et parachimique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Physics, Physique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Capteurs (chimiques, optiques, électriques, de mouvement, de gaz, etc.); télédétection, Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Matériaux particuliers, Specific materials, Fullerènes et matériaux apparentés; diamants, graphite, Fullerenes and related materials; diamonds, graphite, Nanomatériaux et nanostructures : fabrication et caractèrisation, Nanoscale materials and structures: fabrication and characterization, Matériaux nanocristallins, Nanocrystalline materials, Capteur de gaz, Gas sensors, Couche mince, Thin films, Film, Films, Graphène, Graphene, Hydrogène, Hydrogen, Modification chimique, Chemical modification, Modificación química, Nanocomposite, Nanocomposites, 0707D, 8105T, 8105U, and 8107B

In this study, we report the preparation of chemically modified graphene/(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) nanocomposites and their application in hydrogen (H2) gas sensing materials. The aqueous dispersions of graphene oxide (GO) and reduced graphene oxide (rGO) nanosheets were synthesized and further doped into the solution of PEDOT:PSS in dimethylsulfoxide (DMSO). Both the GO/PEDOT:PSS and rGO/PEDOT:PSS composite devices showed a decrease in the resistance upon hydrogen exposure at room temperature. The GO/PEDOT:PSS, a strong p-type material, formed by rectifying contact with tungsten was evaluated for the H2 gas sensing and identified as a contact-controlled type. The rGO/PEDOT:PSS, a weak n-type material, forming an ohmic contact with tungsten was investigated for its H2 gas sensing and identified as a body-controlled type.

Electronics, Electronique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Capteurs (chimiques, optiques, électriques, de mouvement, de gaz, etc.); télédétection, Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing, Sciences appliquees, Applied sciences, Electronique, Electronics, Appareillage électronique et fabrication. Composants passifs, circuits imprimés, connectique, Electronic equipment and fabrication. Passive components, printed wiring boards, connectics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Transistors, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electronique de puissance, alimentations électriques, Power electronics, power supplies, Algorithme, Algorithm, Algoritmo, Capteur mesure, Measurement sensor, Captador medida, Caractéristique électrique, Electrical characteristic, Característica eléctrica, Coefficient température, Temperature coefficient, Coeficiente temperatura, Contrainte mécanique, Mechanical stress, Tensión mecánica, Dispositif puissance, Power device, Dispositivo potencia, Double diffusion, Doble difusión, Défaillance, Failures, Fallo, Electronique puissance, Power electronics, Electrónica potencia, Fiabilité, Reliability, Fiabilidad, Implémentation, Implementation, Implementación, Mesure électrique, Electrical measurement, Medida eléctrica, Moniteur, Monitor, Point fonctionnement, Operating point, Punto funcionamiento, Semiconducteur, Semiconductor materials, Semiconductor(material), Système intelligent, Intelligent system, Sistema inteligente, Système électromécanique, Electromechanical system, Sistema electromecánico, Traitement signal, Signal processing, Procesamiento señal, Transistor MOS, MOS transistor, Transistor vertical, Vertical transistor, Vieillissement, Ageing, Envejecimiento, and 0707D

Power device reliability is a multidisciplinary domain. It requires design and integration of sensors, implementation of signal processing algorithms that allow processing the different data provided by the different sensors in order to predict by statistical means the device failure occurrence and consequently anticipate the power device replacement. Currently, for device ageing studies in a laboratory, electrical measurements of device parameters are often used as an indicator of device ageing. Furthermore, smart metal-oxide semi-conductor technology integrates more and more sensors that permit to measure quantities such as on-state resistance or junction temperature of the device. In power vertical diffused metal oxide semiconductor (VDMOS) assemblies, it would be interesting to make use of the VDMOS electrical parameters deviations in order to monitor the ageing state of the power assembly. To that end, we carry-out in this paper a study mainly based upon electro-thermo-mechanical simulations in order to identify the power VDMOS electrical parameters that could be monitored in order to access to the mechanical state of the power assembly and therefore anticipate the assembly failure. The power VDMOS Ron as well as zero temperature coefficient (ZTC) point are of interest because they are sensitive to mechanical stress. Consequently, in this paper, a procedure to minimise temperature impact on the Ron of the VDMOS transistor such that one could use the Ron as mechanical state indicator is shown. Another solution that makes use of a specific operating point of VDMOS (ZTC) which is temperature independent is also studied by simulations and experiment.

Crystallography, Cristallographie cristallogenèse, Electronics, Electronique, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Actionneur, Actuators, Aimantation rémanente, Remanent magnetization, Imanación remanente, Aimantation, Magnetization, Commutation, Switching, Couche mince magnétique, Magnetic thin films, Déformation élastique, Elastic deformation, Effet magnétoélastique, Magnetoelastic effects, Magnétostriction, Magnetostriction, Matériau ferromagnétique, Ferromagnetic materials, Matériau multiferroïque, Ferroic material, Material ferroico, Monocristal, Monocrystals, Oxyde de fer, Iron oxide, Hierro óxido, Résonance ferromagnétique, Ferromagnetic resonance, A. Multiferroic hybrids, D. Magnetostriction, E. Ferromagnetic resonance, and E. SQUID magnetometry

We investigate different approaches towards a nonvolatile switching of the remanent magnetization in single-crystalline ferromagnets at room temperature via elastic strain using ferromagnetic thin film/piezoelectric actuator hybrids. The piezoelectric actuator induces a voltage-controllable strain along different crystalline directions of the ferromagnetic thin film, resulting in modifications of its magnetization by converse magnetoelastic effects. We quantify the magnetization changes in the hybrids via ferromagnetic resonance spectroscopy and superconducting quantum interference device magnetometry. These measurements demonstrate a significant strain-induced change of the magnetization, limited by an inefficient strain transfer and domain formation in the particular system studied. To overcome these obstacles, we address practicable engineering concepts and use a model to demonstrate that a strain-controlled, nonvolatile magnetization switching should be possible in appropriately engineered ferromagnetic/piezoelectric actuator hybrids.

Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Systèmes asservis et systèmes de commande; robots, Servo and control equipment; robots, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Mécanique des structures et des milieux continus, Structural and continuum mechanics, Mécanique de la rupture (fissure, fatigue, endommagement...), Fracture mechanics (crack, fatigue, damage...), Méthodes de mesure et d'essai, Measurement and testing methods, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Appareil circulatoire, Circulatory system, Aparato circulatorio, Basse vitesse, Low speed, Baja velocidad, Choc mécanique, Mechanical shock, Choque mecánico, Dualité, Duality, Dualidad, Délaminage, Delamination, Delaminación, Endommagement, Damaging, Deterioración, Epoxyde résine, Epoxy resin, Epóxido resina, Fiabilité, Reliability, Fiabilidad, Liquide, Liquid, Líquido, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Matériau stratifié, Stratified material, Material estratificado, Microfissuration, Microcracking, Microfisuración, Monitorage, Monitoring, Monitoreo, Restauration (propriété), Recovery (properties), Restauración (propiedad), Robustesse, Robustness, Robustez, Réparation, Repair, Reparación, Résistance choc, Impact strength, Resistencia choque, Résistance mécanique, Strength, Resistencia mecánica, Transducteur enfoui, Embedded transducer, Transductor embebido, Biomimétique, Biomimetics, Biomimética, Bio-inspired, compression after impact, polymer composites, self-healing, structural health monitoring, and vascular networks

Inspired by the sensory and autonomous healing processes of living organisms, whether from the Animalia or Plantae biological kingdoms, a microvascular network that undertakes a dual role of sensing structural damage before initiating a triggered healing response has been developed and embedded within an advanced fibre-reinforced composite [-45/90/ 45/0]2S laminate. In this study, a single vascule is used as a sensing pathway, which detects the introduction of ply delamination and matrix microcracking following a 10-J low-velocity impact event. Once damage connectivity between the sensing vascule and those open to the ambient environment is established, the delivery of a healing agent to the damage zone is triggered. An investigation into a commercially available epoxy healing agent (RT151) and an in-house healing resin formation (diglycidyl ether of bisphenol-A/diethylenetriamine) epoxy system has been evaluated. The pressure-assisted delivery of the liquid epoxy healing agent to the damage zone was observed to occur within 49 s across all specimens. The recovery of compression strength post impact was 91% and 94% for the RT151 and diglycidyl ether of bisphenol-A healing agents, respectively. This study provides further confirmation on how a bio-inspired vascular healing network could substantially enhance the reliability and robustness of advanced composite materials.

Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Systèmes asservis et systèmes de commande; robots, Servo and control equipment; robots, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Mécanique des structures et des milieux continus, Structural and continuum mechanics, Mécanique de la rupture (fissure, fatigue, endommagement...), Fracture mechanics (crack, fatigue, damage...), Méthodes de mesure et d'essai, Measurement and testing methods, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Infrastructure des transports, Transportation infrastructure, Construction routière. Chaussées. Entretien, Road construction. Pavements. Maintenance, Revêtements, Surfacing, Asphalte, Asphalt, Asfalto, Bitume, Bitumen, Chaussée, Pavement, Calzada, Durabilité, Durability, Durabilidad, Durée service, Service life, Duración servicio, Endommagement, Damaging, Deterioración, Eprouvette préfissurée, Precracked specimen, Probeta preagrietada, Essai charge, Loading test(mechanics), Ensayo carga, Essai fatigue, Fatigue test, Ensayo fatiga, Essai traction, Tension test, Ensayo tracción, Fissuration, Cracking, Agrietamiento, Fissure, Crack, Fisura, Longueur fissure, Crack length, Largo fisura, Polymère, Polymer, Polímero, Restauration (propriété), Recovery (properties), Restauración (propiedad), Revêtement routier, Carriageway surfacing, Revestimiento carretera, Réparation, Repair, Reparación, Résistance mécanique, Strength, Resistencia mecánica, Self-healing, bitumen, crack, envelope, and strength

Cracking is one of the main distresses responsible for the service life reduction of asphalt pavement. On the contrary, self-healing is a process that reverses to cracking and increases the service life. Understanding of the cracking and healing behavior of bituminous materials is very important for service life predictions. Instead of a complex and time-consuming fatigue test, a modified direct tension test with a loading-healing-reloading procedure was developed in this article to characterize the cracking and healing behavior of bituminous mastics. A displacement-controlled loading was applied to obtain damaged specimens with different crack sizes at various postpeak elongations. After unloading and healing, the reloading was applied to quantify the healing behavior under different conditions. The healing behavior is very dependent on rest periods, crack phases, and material types. A clear difference in self-healing property between a polymer-modified bituminous mastic and a conventional penetration grade bituminous mastic was observed for different phases of crack. As a result, the modified direct tension test is believed to be an effective tool for characterizing the self-healing capability of bituminous mastics.

Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Systèmes asservis et systèmes de commande; robots, Servo and control equipment; robots, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Mécanique des structures et des milieux continus, Structural and continuum mechanics, Mécanique de la rupture (fissure, fatigue, endommagement...), Fracture mechanics (crack, fatigue, damage...), Méthodes de mesure et d'essai, Measurement and testing methods, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Activation thermique, Thermal activation, Termoactivación, Adhérence, Adhesion, Adhésif, Adhesives, Assemblage collé, Adhesive joint, Ensambladura pegada, Cohésion, Cohesion, Cohesión, Conduction thermique, Thermal conduction, Conductivité thermique, Thermal conductivity, Force adhérence, Adhesive strength, Fuerza adherencia, Graphite, Matière charge, Fillers, Nitrure de bore, Boron nitride, Boro nitruro, Plastique thermodurcissable, Thermosetting plastics, Plástico termoendurecible, Propriété mécanique, Mechanical properties, Restauration (propriété), Recovery (properties), Restauración (propiedad), Réparation, Repair, Thermodurcissable, Thermosetting resin, Termoestable, Transfert chaleur, Heat transfer, Self-healing, adhesive, cohesion recovery, composites, and thermal conduction

Thermally conductive composites with a temperature-triggered self-healing response were produced by dispersing boron nitride or graphite particles into two types of polysulphide-based thermoset matrices. The composites produced exhibit recovery of both cohesion and adhesion properties upon thermally activated healing. Using a mild healing temperature (65°C), the materials show full recovery of their initial adhesive strength during multiple healing cycles. The composites behave differently regarding the cohesion recovery: 20%-100% recovery is achieved depending on the filler type, filler loading and the type of matrix. The thermal conductivity of the composites increases with the amount of filler. Values of I and 2 W/m K can be achieved for the boron nitride and graphite-based composite, respectively. The results presented in this work clearly show that multifunctional materials with different functionalities and mechanical self-healing responses can be designed using this strategy.

Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Systèmes asservis et systèmes de commande; robots, Servo and control equipment; robots, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Mécanique des structures et des milieux continus, Structural and continuum mechanics, Mécanique de la rupture (fissure, fatigue, endommagement...), Fracture mechanics (crack, fatigue, damage...), Méthodes de mesure et d'essai, Measurement and testing methods, Sciences appliquees, Applied sciences, Batiment. Travaux publics, Buildings. Public works, Construction (bâtiments et ouvrages), Construction (buildings and works), Structure construction, Building structure, Structure en béton, Concrete structure, Absorption eau, Water absorption, Absorción agua, Béton, Concrete, Hormigón, Carbonate de calcium, Calcium carbonate, Calcio carbonato, Ciment, Cement, Cemento, Construction béton, Concrete construction, Construcción de hormigon, Coût entretien, Maintenance cost, Costo manutención, Durabilité, Durability, Durabilidad, Essai flexion, Bending test, Ensayo flexion, Fissuration, Cracking, Agrietamiento, Fissure courte, Short crack, Fisura corta, Gonflement, Swelling, Inflamiento, Humidité relative, Relative humidity, Humedad relativa, Hydratation, Hydration, Hidratación, Joint étanchéité, Seal, Soldadura estanqueidad, Largeur fissure, Crack width, Ancho fisura, Mortier ciment, Cement mortar, Mortero cemento, Mélange, Mixture, Mezcla, Perméabilité, Permeability, Permeabilidad, Polymère, Polymer, Polímero, Propriété mécanique, Mechanical properties, Propiedad mecánica, Précipitation, Precipitation, Precipitación, Restauration (propriété), Recovery (properties), Restauración (propiedad), Rupture, Ruptura, Réparation, Repair, Reparación, Résistance traction, Tensile strength, Resistencia tracción, Thermogravimétrie, Thermogravimetry, Termogravimetría, Autogenous crack healing, calcium carbonate, four-point-bending, hydrogel, mortar, multiple cracking, thermogravimetric analysis, and water permeability

Concrete cracks due to its low tensile strength. The presence of cracks endangers the durability as they generate a pathway for harmful particles dissolved in fluids and gases. Without a proper treatment, maintenance costs will increase. Self-healing can prevail in small cracks due to precipitation of calcium carbonate and further hydration. Therefore, the use of microfibres is proposed to control the crack width and thus to promote the self-healing efficiency. In the current research, crack sealing is also enhanced by the application of superabsorbent polymers. When cracking occurs, superabsorbent polymers are exposed to the humid environment and swell. This swelling reaction seals the crack from intruding potentially harmful substances. Mortar mixtures with microfibres and with and without superabsorbent polymers were investigated on their crack sealing and healing efficiency. Regain in mechanical properties upon crack healing was investigated by the performance of four-point-bending tests, and the sealing capacity of the superabsorbent polymer particles was measured through a decrease in water permeability. In an environment with a relative humidity of more than 60%, only samples with superabsorbent polymers showed healing. Introducing I m% of superabsorbent polymer gives the best results, considering no reduction of the mechanical properties in comparison to the reference, and the superior self-sealing capacity.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Actionneur, Actuators, Alliage mémoire forme, Shape memory alloy, Aleación memoria forma, Application spatiale, Space application, Aplicación espacial, Commande réinitialisation, Reset control, Control reinicialización, Conception, Design, Effet mémoire forme, Shape memory effects, Méthode élément fini, Finite element method, aerospace, hold-down and release, resettable, shape memory alloy, and space actuators

A new HDRA based on SMA technology, called REACT, has been designed for development of loads and appendixes in space applications. This design involves a rod supported by spheres that block its axial movement during a preload application. The rod shape allows misalignment and blocks the rotation around axial axis for a proper installation of the device. Because of the high preload requirements for this type of actuators, finite element analysis (FEA) has been developed in order to check the structure resistance. The results of the FEA have constrained the REACT design, in terms of dimensions, materials, and shape of the mechanical parts. A complete test campaign for qualification of REACT is proposed. Several qualification models are intended to be built for testing in parallel. Therefore, it is a way to demonstrate margins which allows getting some statistics.

Crystallography, Cristallographie cristallogenèse, Electronics, Electronique, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Techniques, équipements et instruments mécaniques, Mechanical instruments, equipment and techniques, Systèmes et dispositifs micromécaniques, Micromechanical devices and systems, Condensation Bose Einstein, Bose-Einstein condensation, Couplage fort, Strong coupling, Acoplamiento fuerte, Dissipation, Hyperfréquence, Microwave radiation, Intrication quantique, Quantum entanglement, Nitrure de calcium, Calcium nitride, Calcio nitruro, Résonateur nanomécanique, Nanomechanical resonator, Resonador nanomecánico, Tellurure de gallium, Gallium tellurides, Théorie quantique, Quantum theory, Tomographie, Tomography, Transducteur, Transducers, C. Mechanical resonators, C. Microwave cavity, C. Spin, and D. Entanglement

Mechanical resonators are macroscopic quantum objects with great potential. They couple to many different quantum systems such as spins, optical photons, and Bose Einstein condensates. It is difficult to measure and manipulate a phonon state due to the tiny motion in the quantum regime. On the other hand, microwave resonators are powerful quantum devices since arbitrary photon states can be synthesized and measured with the quantum tomography. We show that linear coupling, strong and controlled with gate voltage, between mechanical and microwave resonators enables creation of quantum phonon states, manipulation of hybrid entanglement between phonons and photons, and generation of entanglement between two mechanical oscillators. In circuit quantum optomechanics, the mechanical resonator acts as a quantum transducer between an auxiliary quantum system and the microwave resonator, which is used as a quantum bus. As an example, we demonstrate how two mechanical resonators coupled to one microwave resonator and two spins can facilitate entanglement generation between the spins.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Capteurs (chimiques, optiques, électriques, de mouvement, de gaz, etc.); télédétection, Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Dispositifs optoélectroniques, Optoelectronic devices, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Domaines d'application, Application fields, Capteur mesure, Measurement sensor, Captador medida, Dispositif optoélectronique, Optoelectronic device, Dispositivo optoelectrónico, Electrostriction, Electroestricción, Etude expérimentale, Experimental study, Estudio experimental, Mesure champ électrique, Electric field measurement, Microparticule, Microparticle, Micropartícula, Particule composite, Composite particles, Particule sphérique, Spherical particle, Partícula esférica, Sensibilité, Sensitivity, Sensibilidad, Silice, Silica, Sílice, Siloxane élastomère, Silicone elastomer, Siloxano elastómero, Siloxane(diméthyl) polymère, Dimethylsiloxane polymer, Siloxano(dimetil) polímero, Laser diode, Résonance morphologiquement dépendante, composites, elastomers, electrostriction, fibers, microsphere, morphology dependent resonances (MDR), polydimethylsiloxane (PDMS), polymeric photonic sensor, refractive index, and whispering gallery optical modes (WGM)

The detection of electric field by monitoring the optical whispering gallery mode shifts of polymeric microspheres is demonstrated. Two types of spheres are considered; (i) a polydimethylsiloxane (PDMS) sphere with 60 parts base silicon elastomer-to-1 part polymer curing agent by volume and; (ii) a silica sphere coated with a PDMS (uncured) base. The optical mode shifts are caused by perturbations to the resonator morphology induced by electrostriction effect in the presence of an external electric field. Preliminary experiments show that the latter microsphere yields higher sensitivity (0.027 pm/V m-1) with a measurement precision of ∼1.8 V/m.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Actionneur, Actuators, Alliage mémoire forme, Shape memory alloy, Aleación memoria forma, Capteur intelligent, Intelligent sensors, Conception, Design, Effet mémoire forme, Shape memory effects, Fabrication, Fatigue, Nanomatériau, Nanostructured materials, Procédé dépôt, Deposition process, Procedimiento revestimiento, Propriété dynamique, Dynamic properties, Propiedad dinámica, Soupape, Valves, nanomaterials, service systems, shape memory alloys, and valves

Shape memory alloys (SMA) can be utilized as thermal and electrical-activated drives for valve applications. By using the high actuation forces and medium strokes in combination with SMA intrinsic sensor functions, smart and versatile valve elements for multi-purpose applications can be designed. The sensoric functions, based on the change of the electrical characteristics of the SMA drive, allow to detect the system's condition as well as the system's fatigue. The paper systematizes the usability of the intrinsic sensor function with particular emphasis on service potentials. A methodical overview over the design-options of different applications is presented in the first part of the publications. This is followed by a methodical analysis of the potentials of SMA in service applications. Since the product development process is not only a mechanical engineering matter, the production and the service options according to such valves have to be regarded. Besides this publication presents an innovative production process based on a fused deposition production process (FDPP) of valves which contains the installation of SMA actuators during production. The publications present several demonstrator systems which have been produced with FDPP and analyzed in applications.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Propriétés mécaniques et acoustiques de l'état condensé, Mechanical and acoustical properties of condensed matter, Propriétés mécaniques des solides, Mechanical properties of solids, Elasticité, constantes d'élasticité, Elasticity, elastic constants, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Diagrammes de phases et microstructures développées par solidification et par transformations de phases solide-solide, Phase diagrams and microstructures developed by solidification and solid-solid phase transformations, Transformations martensitiques, Martensitic transformations, Actionneur, Actuators, Alliage mémoire forme, Shape memory alloy, Aleación memoria forma, Calorimétrie différentielle balayage, Differential scanning calorimetry, Commande force, Force control, Courbure, Curvature, Effet mémoire forme, Shape memory effects, Elasticité, Elasticity, Modélisation, Modelling, Méthode analytique, Analytical method, Método analítico, Méthode élément fini, Finite element method, Nickel alliage, Nickel alloys, Ressort, Springs, Titane alliage, Titanium alloys, Transformation martensitique, Martensitic transformations, Ressort à enrouleur, actuator, experimental test, long-stroke, and simulation

This work aims at the experimental characterization and modeling validation of shape memory alloy (SMA) Negator springs. According to the classic engineering books on springs, a Negator spring is a spiral spring made of strip of metal wound on the flat with an inherent curvature such that, in repose, each coil wraps tightly on its inner neighbor. The main feature of a Negator springs is the nearly constant force displacement behavior in the unwinding of the strip. Moreover the stroke is very long, theoretically infinite, as it depends only on the length of the initial strip. A Negator spring made in SMA is built and experimentally tested to demonstrate the feasibility of this actuator. The shape memory Negator spring behavior can be modeled with an analytical procedure, which is in good agreement with the experimental test and can be used for design purposes. In both cases, the material is modeled as elastic in austenitic range, while an exponential continuum law is used to describe the martensitic behavior. The experimental results confirms the applicability of this kind of geometry to the shape memory alloy actuators, and the analytical model is confirmed to be a powerful design tool to dimension and predict the spring behavior both in martensitic and austenitic range.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Traitement des matériaux et son effet sur la microstructure et les propriétés, Treatment of materials and its effects on microstructure and properties, Autres traitements thermiques et thermomécaniques, Other heat and thermomechanical treatments, Actionneur, Actuators, Alliage mémoire forme, Shape memory alloy, Aleación memoria forma, Alliage ternaire, Ternary alloys, Conductivité électrique, Electrical conductivity, Cuivre alliage, Copper alloys, Dureté, Hardness, Effet mémoire forme, Shape memory effects, Essai traction, Tensile tests, Microdureté, Microhardness, Microscopie électronique balayage, Scanning electron microscopy, Microstructure, Métal transition alliage, Transition element alloys, Nickel alliage, Nickel alloys, Renforcement mécanique, Strengthening, Refuerzo mecánico, Superalliage, Superalloys, Titane alliage, Titanium alloys, Traitement thermique, Heat treatments, Traitement thermomécanique, Thermomechanical treatments, Transformation martensitique, Martensitic transformations, NiTiCu, SMA, creep and stress rupture, hardness, mechanical, nondestructive testing, shape memory alloys, and superalloys

NiTiCu alloys are one of the most investigated shape memory alloys (SMAs) because of their better performance as SMA actuators in a variety of industrial and engineering applications. However, NiTiCu alloys are strongly influenced by thermomechanical cycling (TMC), which causes degradation depending on the stress and strain level applied. Since heat treatment (HT) and TMC are essential for NiTiCu alloys, understanding how hardness evolves at different levels of TMC and different HT temperatures is a useful tool for characterizing the material. The aim of this paper is to investigate the relationship between hardness and different HT temperatures and different TMCs. All the microhardness tests were done below martensite finish temperature (Mf) because the apparent material hardness measured below Mf fairly reflects the relative strengthening of SMAs without involving martensitic transformation artifacts. Resistivity and break tensile tests were carried out as a first step in order to understand the effect of different HT temperatures. Microstructure was also examined to provide a basis for a mechanistic understanding of the effect of different HT temperatures. Next, the degradation of mechanical properties (functional fatigue) at different levels of TMC was evaluated to assess their relationship to the evolution of hardness. Finally, an attempt was made to establish a link between the increase in hardness and different HT temperatures with different levels of TMC.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Actionneur, Actuators, Alliage mémoire forme, Shape memory alloy, Aleación memoria forma, Analyse structurale, Structural analysis, Análisis estructural, Conception, Design, Cycle thermique, Thermal cycle, Ciclo térmico, Effet mémoire forme, Shape memory effects, Effet pression, Pressure effects, Haute température, High temperature, Alta temperatura, Rigidité, Stiffness, Rigidez, Transducteur thermique, Thermal transducer, Transductor térmico, Vibration, Vibrations, Pin Puller, aerospace, qualification campaign, shape memory alloy, and space actuators

Two different versions of the Pin Puller were designed during this activity, such as one with 100 N and other with 500 N of pull force. The design of both versions is based on spheres which support the pin at the initial position and a compression spring driving once the release takes place by means of the SMA. The mechanical design of the Pin Pullers has been conceived in order to optimize the device's weight, reduce the parts complexity, and achieve a suitable stiffness. A qualification test campaign for the Pin Puller with 500 N of pull force has been developed in order to check the success of the proposed mechanism for space applications. The main performed tests have been thermal-vacuum actuation, thermal-vacuum cycling, sine vibration, and random vibration. The Pin Puller has presented successful results of actuation during the test campaign.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Radiotherapie. Traitement instrumental. Physiotherapie. Reeducation. Readaptation, orthophonie, crenotherapie. Traitement dietetique et traitements divers (generalites), Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects), Technologie. Biomatériaux. Equipements. Matériel. Appareillage, Technology. Biomaterials. Equipments. Material. Instrumentation, Actionneur, Actuators, Antagonisme, Antagonism, Antagonismo, Biomatériau, Biomedical materials, Charge composée, Combined load, Carga compuesta, Effet mémoire forme, Shape memory effects, Equation constitutive, Constitutive equation, Ecuación constitutiva, Modèle 3 dimensions, Three dimensional model, Modelo 3 dimensiones, Modélisation, Modelling, Méthode numérique, Numerical method, Método numérico, Orthèse, Orthotics, Propriété dynamique, Dynamic properties, Propiedad dinámica, Propriété thermomécanique, Thermomechanical properties, Propriedad termomecánica, Système intelligent, Intelligent system, Sistema inteligente, Torsion, biomaterials, non-ferrous metals, and titanium

There are SMA medical applications which undergo complex thermo-mechanical loading paths to meet specific and accurate requirements. In this work, a 3D model and its implementation techniques are presented. This model is currently deployed to design and model SMA medical devices subjected to multiaxial loading in both isothermal and dynamic regimes. Some of these devices are introduced and studied as examples to show the efficiency of the proposed platform.

Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Systèmes asservis et systèmes de commande; robots, Servo and control equipment; robots, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Mécanique des structures et des milieux continus, Structural and continuum mechanics, Méthodes de mesure et d'essai, Measurement and testing methods, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Propriétés et essais, Properties and testing, Essais et contrôles, Testing and control, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Agent surface anionique, Anionic surfactant, Agente superficie aniónico, Agent surface cationique, Cationic surfactant, Agente superficie catiónico, Autoassemblage, Self assembly, Autoensamble, Calorimétrie différentielle balayage, Differential scanning calorimetry, Análisis calorimétrico barrido exploración, Charge dynamique, Dynamic load, Carga dinámica, Charge thermique, Thermal load, Carga térmica, Durcissement (matière plastique), Curing (plastics), Endurecimiento (material plástico), Entaille, Notch, Entalla, Epoxyde résine, Epoxy resin, Epóxido resina, Etat solide, Solid state, Estado sólido, In situ, Masse moléculaire, Molecular mass, Masa molecular, Mesure, Measurement, Medida, Polymère réticulé, Crosslinked polymer, Polímero reticulado, Propriété dynamomécanique, Dynamic mechanical properties, Propiedad dinamomecánica, Propriété thermomécanique, Thermomechanical properties, Propriedad termomecánica, Rayonnement IR proche, Near infrared radiation, Radiación infrarroja cercana, Restauration (propriété), Recovery (properties), Restauración (propiedad), Réparation, Repair, Reparación, Spectrométrie IR, Infrared spectrometry, Espectrometría IR, Thermoplasticité, Thermoplasticity, Termoplasticidad, Thermoplastique, Thermoplastics, Termoplástica, Viscoélasticité, Viscoelasticity, Viscoelasticidad, Polymer networks, self-healing, and thermoplastic healing

Solid-state healing of epoxy networks is shown to be an effective and robust mechanism for highly cross-linked epoxy networks. Using diglycidyl ether of bisphenol A epoxy resin and diethyltoluenediamine, the cured epoxy network is transformed into a mendable system using phenoxy resin and low-molecular-weight polybisphenol A-co-epichlorohydrin) thermoplastic modifiers. Using functionally terminated low-molecular-weight poly(bisphenol A-co-epichlorohydrina) thermoplastic modifiers as healing agents reveals that salicylic acid or neutralized sodium salicylate groups produce healing similar to high-molecular-weight non-functional phenoxy resin as measured using single-end notched beam testing. The miscibility of both thermoplastics in the diglycidyl ether of bisphenol A/diethyltoluenediamine system was evaluated using differential scanning calorimetry and dynamic mechanical thermal analysis and identified as being important to promoting healing. Near-infrared spectroscopy showed that the network structure was unaffected by the thermoplastic modification, suggesting that healing occurred primarily through physical or non-covalent mechanisms rather than covalent bonding. The potential for self-assembly of the salicylic acid and neutralized sodium salicylate groups to form a high-molecular-weight thermoplastic in situ was also discussed as being a possible reason for the improved level of healing with the low-molecular-weight thermoplastic.