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École doctorale Génie électrique, électronique et télécommunications (Toulouse)

Overview
Works: 384 works in 613 publications in 2 languages and 614 library holdings
Roles: Other, Degree grantor, 996, Editor
Publication Timeline
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Most widely held works by électronique et télécommunications (Toulouse) École doctorale Génie électrique
Development of a lab-on-chip platform integrating electrochemical microsensors for the detection of water contaminants based on algal physiology monitoring by Aliki Theodora Tsopela( Book )

3 editions published in 2015 in English and held by 4 WorldCat member libraries worldwide

Le suivi de la qualité de l'eau a été d'une grande importance depuis ces dernières décennies afin de trouver des solutions de contrôler la contamination de l'eau, induite en grande partie par les activités agricoles et industrielles. Bien que les méthodes conventionnelles, comme la chromatographie, sont des outils très précis et sensibles, un intérêt grandissant a été placé sur des techniques prometteuses qui peuvent être utilisées sur site, sont bas coût, et offrent la possibilité d'effectuer des analyses rapides. Le travail présenté ici est dédié au développement de composant Laboratoire sur Puce pour l'analyse de la toxicité de l'eau. Il consiste en un système portable pour la détection sur site et offre la possibilité d'une double détection complémentaire : optique et électrochimique. Comme la partie dédiée au capteur électrochimique a préalablement été validée, cette étude est focalisée sur l'implémentation d'un biocapteur électrochimique basé sur l'utilisation d'une algue, pour la détection de polluants dans l'eau. Le principe basique de détection consiste au suivi de changements de l'activité métabolique d'algues induits par la présence d'herbicides. La réponse de l'algue est différente pour chaque concentration d'herbicide dans un échantillon examiné. Deux herbicides sélectionnés affectent l'activité photosynthétique de l'algue et par conséquent, induisent des modifications dans la quantité des espèces électroactives produites par l'algue : O2, H2O2 et H3O+/OH-. Avant le développement du composant final type Laboratoire sur Puce, les principes de détection aussi bien que les matériaux d'électrode qui vont être intégrés, ont été validés en utilisant un type de composant plus simple, qui a été réalisé grâce aux technologies de fabrication silicium et qui a été caractérisé par des procédures plus simples. Une puce sur silicium contenant un microsystème électrochimique intégrant trois électrodes a été mis en place. Une fois validés, les matériaux de détection et les configurations choisis précédemment ont été utilisés pour la fabrication des composants Laboratoire sur Puce. Les composants Laboratoire sur Puce ont été ensuite utilisés pour des tests biologiques afin de détecter les herbicides d'intérêt. Une attention spéciale a été placée sur le suivi de O2 comme indicateur de la présence d'herbicide, étant donné que cet élément est le plus représentatif de modifications de l'activité métabolique. Un effet d'inhibition sur la photosynthèse, dépendant de la concentration de l'herbicide a été démontré. La détection de l'herbicide a été réalisée avec une grande sensibilité et sur une gamme couvrant la limite de concentration maximale acceptable imposé par le gouvernement canadien
Mécanismes d'interaction entre les décharges à base d'azote et la matière vivante by Hayat Zerrouki( Book )

3 editions published in 2015 in French and held by 3 WorldCat member libraries worldwide

Electrical discharges (plasmas) are able to simultaneously produce large concentrations of charged species (electrons, ions), of neutral reactive species (atoms, metastable states) and of radiative states emitting radiation from infrared to ultraviolet. Some of them can operate at a temperature close to the room temperature, which confer them a strong interaction potential with the living matter. Most of the existing works in this field focus on the effects induced by the ROS (reactive oxygen species) but a study recently established that the nitrogen atoms produced in a pure nitrogen flowing late afterglow operating at reduced pressure (1-20 Torr, 1 Torr = 133.3 Pa) were probably the main agent of the interaction with the living. The goal of the present thesis is to pursue this initial work by seeking to confirm this hypothesis and by improving the general comprehension of the physical and bio-chemical processes involved in the interaction between nitrogen plasmas and living matter. To do such, two types of discharges were used : one is a flowing microwave afterglow operating at reduced pressure in pure nitrogen or in mixtures of argon and nitrogen, the other is a corona discharge jet working at atmospheric pressure in ambient air or in a controlled nitrogen atmosphere. The first part of the study is devoted to the physical characterization of both discharges by emission spectroscopy, temperature determination, and identification of the produced chemical species. For the nitrogen-based afterglows, it was possible to quantify the nitrogen atoms absolute concentration and to maximize their production through the operating parameters. In the second part of the study, the interaction between plasma species and living matter is quantified by the use of the logarithmic reduction of an initial Gram - bacteria population (Escherichia coli, E. coli) vs. the discharge exposure time. This reduction is correlated with morphologic changes observed by scanning electron microscopy (SEM) on treated bacteria and by an analysis of the cell viability obtained via MTT tests and DAPI. In parallel, the ability of the two discharges to remove or alter lipid A, a pyrogenic hydrophobic sub-component of an endotoxin (Lipopolysaccharide or LPS) present in the membrane of most of the Gram - bacteria is established. Considering these elements, a scenario of bacterial inactivation by the nitrogen atoms of the late nitrogen afterglow is proposed
Mesure et modélisation du comportement de matériaux diélectriques irradiés par faisceau d'électrons by Mallys Elliazar Banda Gnama Mbimbiangoye( Book )

2 editions published in 2017 in French and held by 2 WorldCat member libraries worldwide

In their common uses as electrical insulators, organic solid materials are constitutive of electric power transmission cables, power control and conversion circuits as well as (micro) electronic components or embedded systems (thermal coating of satellites, batteries of accumulators, etc.). Under various constraints of use (electric field, radiation, temperature, humidity ...) they can accumulate charges in their bulk which could affect the reliability of the systems in which they are employed. One of the commonly used means to study the electrical behavior of these charges is to measure the spatiotemporal distribution of charges by subjecting the dielectrics to a continuous potential difference between two electrodes. However, this method does not always allow clearly distinguishing the contribution of charges due to generation on the one hand and the one due to transport phenomena on the other hand. This study proposes an alternative approach, consisting in generating charges (electrons) within the electrical insulation using an electron-beam under vacuum. The charges are hence deposited at a known position and in a controlled quantity. Other physical processes related to the implantation of electrons must then be taken into account in order to predict and model the behavior of these irradiated materials. Low-density polyethylene (LDPE) films, prepared by thermal molding, were irradiated by a 80 keV electron-beam with a current flux of 1 nA/cm2. Space charge measurements using the Pulsed Electro-Acoustic (PEA) method, performed first in-situ and then ex-situ under DC electrical polarization, confirm an effective localization of charges within the material. The results under electrical polarization after irradiation show an important amount of positive charges in the irradiated zone of the dielectric. The electrical characterizations of irradiated LDPE films show a completely different behavior compared to the same non-irradiated material, suggesting a modification of the chemical structure of the material. Physico-chemical measurements (infrared spectroscopy, Photoluminescence and Differential Scanning Calorimetry-DSC) on these irradiated PEbd films do not show a significant degradation of the chemical structure of the dielectric which would explain the observed electrical behavior under post-irradiation polarization. Additional measurements show the reversible behavior of the irradiated then polarized PEbd, which would be only related to the presence of the charges generated by the beam. The experimental data of this study have simultaneously fed a numerical model of charge transport, developed to take into account the irradiation constraints. This model allows reproducing the in-situ results of charge implantation by the electron beam as well as the majority of the electrical processes observed on irradiated and polarized LDPE. It confirms the impact of the electron-beam deposited charge on the behavior under polarization and allows concluding on the origin of the positive charges observed after irradiation, which would be due to injection at the electrodes as well as to the creation of electron-hole pairs by the electron-beam during irradiation
Etude expérimentale et numérique de la cinétique de plasmas d'air produits par rayonnement X impulsionnel by Mélissa Maulois( Book )

2 editions published in 2016 in French and held by 2 WorldCat member libraries worldwide

The irradiation of air by an X-ray, produces an air plasma which can affect the generation and the propagation of electromagnetic fields, disrupting the surrounding electronic systems. Quantifying these constraints requires beforehand a comprehensive study of the plasma generated by the energetic particles. A 0D chemical kinetics model was developed to characterize the time evolution of the air X-ray induced plasma for different air pressures. The model is defined by the coupling of the evolution equation of the densities of the main species plasma with the equation of conservation of the mean energy density of electrons. To develop and test the model, it was first applied to a theoretical case where the plasma is generated by an X-ray flash with a duration of 100 ns with a constant mean energy equal to 1 MeV. The irradiation of dry air by X-rays leads to the generation of two populations of electrons Compton "relativistic" and "non-relativistic". In fact, these Compton electrons initiate the electron avalanches leading to the formation of the studied plasma. The obtained results show that the plasma is primarily generated by ionization of the gas by the relativistic Compton electrons. Although initiated by hard X-rays, the plasma generated is weakly ionized with a maximum electron density of 1013 cm-3 at atmospheric pressure and a maximum electron mean energy of about 4 eV. The validation of the model is based on the electron density measurements. For various air pressures, the experiments performed consist of irradiating an air-filled waveguide, by an X-ray pulse during 90 ns. The aim of the experiment is to measure the absorption of an electromagnetic wave after its passage through the plasma contained in the guide. The absorption coefficient of the wave in the guide depends on the constant of propagation in free space, which is proportional to the plasma frequency and thus to the electron density. The experimental electron density is then determined using the formalism of absorption in a plasma filled waveguide. To compare the experimental and numerical results, the kinetic model was adapted to the experiments by considering more particularly the waveguide walls and the humidity of the air. In the case of air with 76% of relative humidity, between 30 mbar and atmospheric pressure, the relative gap between the measurements and the model for the maximum electron density is lower than 10% knowing that the maximum of the density varies from 3.5x1013 to 4x1011 cm-3. The deviation between the measured electron density and the simulated one, increases when the whole X-ray pulse duration is considered, with a mean relative deviation of about 30%. Knowing that the measurement of the electron density is determined with an uncertainty of ± 30%, the kinetic model results are satisfying and thus enable the model validation. The kinetic model has also allowed to determine the time evolution of the mean electron energy of the plasma
Modélisation des propriétés de transport des ions moléculaires de krypton et xénon pour l'optimisation des générateurs de plasma froids utilisant les gaz rares by Cyril Van de Steen( Book )

2 editions published in 2018 in English and held by 2 WorldCat member libraries worldwide

L'utilisation de plasmas froids à base de gaz rares (Rg) dans des applications biomédicales ainsi que dans la propulsion spatiale est en nette évolution. Pour optimiser ces réacteurs plasmas, une compréhension fine des processus ayant lieu dans ces réacteurs est nécessaire. Ce travail de thèse a pour objectif de fournir les données manquantes dans la littérature (coefficients de transport et réaction) en passant par des données mésoscopiques (sections efficaces) obtenues à partir de données microscopiques (potentiels d'interaction) pour le xénon et krypton dans leur gaz parent. Seul des plasmas froids composés d'un seul type d'atome sont considérés. Comme le krypton et le xénon sont des gaz rares, et ont donc, à l'état de neutralité peu/pas d'interaction entre eux. Par conséquent, seules les collisions ion - atome seront considérées. Du fait des faibles énergies des ions dans le plasma froid, seul les 6 premiers états excités du couple Rg2+ seront pris en compte. Ces 6 états seront classés en deux groupes, 2P1/2 et 2P3/2. Lors de ce travail, deux potentiels d'interaction différents disponibles dans la littérature sont utilisés et comparés pour les systèmes collisionnels Kr+/Kr et Xe+/Xe dans le calcul des sections efficaces. Pour les collisions impliquant des dimères ioniques (Kr2+/Kr et Xe2+/Xe), les potentiels d'interaction sont calculés à partir du modèle DIM (Diatomics In Molecules) qui est une combinaison des potentiels atomiques d'interaction neutre - neutre et ion - neutre. Les sections efficaces, requises pour obtenir les données mésoscopiques manquantes, sont calculées à partir de trois méthodes différentes. La première méthode est la méthode quantique qui permet, par une résolution de l'équation de Schrödinger, d'obtenir de manière exacte les sections efficaces à partir des potentiels d'interaction. Cette méthode exacte, étant grande consommatrice de temps de calcul, est utilisée en tant que référence pour valider les deux autres méthodes approchées. La seconde méthode, nommée semi-classique, est basée sur la même expression que la section efficace quantique mais utilise un déphasage approché (approximation JWKB), induit par le potentiel d'interaction, entre l'onde diffusée et l'onde incidente. [...]
Etudes expérimentales du concept de propulseur de Hall double étage by Loic Dubois( Book )

2 editions published in 2018 in French and held by 2 WorldCat member libraries worldwide

In Hall thrusters, the same physical phenomenon is used both to generate the plasma and to accelerate ions. Furthermore, only a single operating point is experimentally observed. The double stage Hall thruster (DSHT) design could allow a separate control of ionization (thrust) and ions acceleration (ISP) to make the system more versatile. The work carried out during this PhD aims to experimentally demonstrate the relevance and the feasibility of this concept. Firstly, a new design of DSHT, called ID-HALL, was proposed and a new prototype was built. It combines the concentric cylinder configuration of a single stage Hall thruster with a magnetized inductively coupled RF plasma source (ICP) whose coil is placed inside the inner cylinder. The ICP source was improved in terms of power coupling efficiency by adding ferrite parts and by decreasing the heating RF frequency. The ICP source used in the ID-HALL thruster was then characterized independently of the thruster using argon and xenon and varying pressure. The experimental setup has allowed to measure the spatial variations of the electron density and temperature. Finally, the thruster was mounted in its vacuum chamber and preliminary measures (voltage-current characteristics, RPA measurements) were led. At the same time, simulations using a two-dimensional hybrid model were performed in single and double stage. A versatile operation for voltages lower than 150 V was highlighted. An emphasis will be given to demonstrate that the current density (given by the ion flux probe) and the ions energy (given by the RPA) might be significantly decoupled
Study of photovoltaic system integration in microgrids through real-time modeling and emulation of its components using HILeS by Alonso Gutiérrez Galeano( Book )

2 editions published in 2017 in English and held by 2 WorldCat member libraries worldwide

Nowadays, the integration of photovoltaic systems into electrical grids is encouraging the expansion of microgrids. However, this integration has also increased the power system complexity leading to new research challenges. Some of these research challenges require the development of innovative modeling approaches able to deal with this increasing complexity. Therefore, this thesis is intended to contribute with an innovative methodology component-based for modeling and emulating in real-time photovoltaic systems integrated to microgrids. The proposed modeling approach uses the Systems Modeling Language (SysML) to describe the structure and behavior of integrated photovoltaic systems. In addition, this study presents the High Level Specification of Embedded Systems (HiLeS) to transform automatically the developed SysML models in embedded code and Petri nets. These characteristics of automatic code generation and design based on Petri nets allow taking advantage of FPGAs for application of real-time emulation of photovoltaic systems. This dissertation is focused on partially shaded photovoltaic systems and flexible power electronics architectures because of their relevant influence on current microgrids. Furthermore, this research perspective is intended to evaluate control and supervision strategies in normal and fault conditions. This work represents the first step to develop an innovative real-time approach to model and emulate complex photovoltaic systems considering properties of modularity, high degree of scalability, and non-uniform working conditions. Finally, experimental and analytical results validate the proposed methodology
Etude de l'influence des plasmas dans les diodes à électrons pour la radiographie éclair by Jérémie-Marie Plewa( Book )

2 editions published in 2018 in French and held by 2 WorldCat member libraries worldwide

La radiographie éclair par faisceau X intense est spécifique en ce sens qu'elle doit permettre de photographier la matière soumise à des conditions extrêmes de densification, de température et de vitesse de déplacement. Le succès de ce type de radiographie repose sur la qualité de la source X qui doit nécessairement être pénétrante (quelques MeV), intense (plusieurs rads), brève (quelques dizaines de ns) et de petite dimension (quelques mm). L'impulsion X est ainsi générée à partir du rayonnement de freinage émis lors de l'interaction avec une cible en métal d'un faisceau focalisé d'électrons de haute énergie (MeV) et de haute intensité (kA). Ce procédé lie très fortement les propriétés du faisceau d'électrons à ceux du faisceau X et donc à la qualité de la radiographie. Dans ce contexte, la thèse porte sur la compréhension de la dynamique du faisceau dans la diode à l'électron (c'est-à-dire juste avant son entrée dans la ligne accélératrice) ainsi que sur la caractérisation du plasma de velours dont sont issus les électrons qui composent le faisceau. Dans un premier temps, la dynamique du faisceau intense d'électrons a été étudiée à l'aide du code LSP reposant sur la méthode " Particle-In-Cell ". Les simulations réalisées ont été comparées avec des mesures effectuées sur l'injecteur d'un accélérateur linéaire à induction, implanté au CEA Valduc sur l'installation Epure. Grâce au modèle de simulation développé, une nouvelle diode à électrons mono-impulsion a été conçue, dimensionnée et réalisée pendant ce travail de thèse afin d'augmenter l'intensité du faisceau d'électrons de 2,0 kA à 2,6 kA permettant ainsi d'améliorer les performances radiographiques de l'installation. Dans un second temps, un modèle permettant d'étudier les mécanismes mis en jeu dans la production du faisceau d'électrons au niveau de plasma de cathode a été développé. Ce dernier est un modèle collisionnel-radiatif (MCR) 0D qui permet de décrire l'évolution de la densité des espèces d'un plasma dont la composition est directement liée aux molécules et atomes désorbés par la cathode de velours. Trois différents mélanges ont été étudiés impliquant de l'hydrogène, de l'oxygène et du carbone dont les proportions ont été estimées par des mesures LIBS (spectroscopie de plasma induit par laser).[...]
Anisotropic composite elaboration and modeling : toward materials adapted to systems by Guillaume Belijar( Book )

2 editions published in 2016 in English and held by 2 WorldCat member libraries worldwide

This study was aimed to demonstrate the possibility, based on a predictive approach, to tailor the structure of a composite from isotropic to anisotropic when applying an electric field. This composites have great potential for future applications such as embed capacitors or thermally conductive composites. A theoretical approach of the forces and mechanisms acting in the elaboration of anisotropic composites by chaining allowed identifying the key parameters. Based on this approach a model of particle chaining under electric field was established to predict the structuration dynamics. This model (effective dipole moment) allowed simulating more than 4500 particles. The parameters previously identified were then measured, and for the particle permittivity, a dielectrophoretic measurement method was developed, which was a first for ceramic particles. The elaboration of anisotropic composites was coupled to a novel on-line monitoring of a chaining marker (permittivity), allowing to obtain the structuration dynamics. To validate the predictive aspect of the model, experimental and numerical dynamics were compared showing the robustness and accuracy of the model, even if improvement is still possible at low filler content. In the last part, a proof of concept was demonstrated of the elaboration of anisotropic composites with fillers oriented normally to the direction of the electric field
Etude et réalisation de jonctions tunnel à base d'hétérostructures à semi-conducteurs III-V pour les cellules solaires multi-jonction à très haut rendement by Kévin Louarn( Book )

2 editions published in 2018 in French and held by 2 WorldCat member libraries worldwide

Multi-Jonction Solar Cells (MJSCs) are leading the way of high efficiency photovoltaic devices, with conversion efficiency up to 46%. Their subcells are designed to absorb in a specific and complementary range of the solar spectrum, and are connected in series with tunnel junctions. The tandem architecture InGaP/GaAs - with bandgaps of 1.87 eV and 1.42 eV respectively - is mature and its efficiency could be enhanced by incorporating subcell(s) with bandgaps of 1 eV and/or 0.7 eV. The Molecular Beam Epitaxy (MBE) growth of such low bandgap materials has thus to be developed, as well as low-resistive tunnel junctions with good structural and optical properties. Based on the MBE growth and the simulation of GaAs tunnel junctions, we have identified interband tunneling as the predominant transport mechanism in such devices rather than trap-assisted-tunneling. The interband tunneling mechanism could be enhanced with the type II GaAsSb/InGaAs heterostructure. Using this material system, we have then demonstrated tunnel junctions with very low electrical resistivity with a limited degradation of the optical and structural properties inherently induced by the use of low band-gap and lattice-mismatched GaAsSb and InGaAs materials. Moreover, we fabricated an innovative AlInGaAs/AlGaAsSb tunnel junction as a graded buffer architecture that could be used for the incorporation of a 1 eV metamorphic subcell. We then developed and characterized InGaAsN(Bi) materials with band-gaps of ~1eV, taking advantage of in-situ wafer curvature measurements during the MBE growth to control the lattice-mismatch. Preliminary solar cells based on GaAs, 1 eV dilute nitride and metamorphic InGaAs have been fabricated and characterized validating the developed tunnel junction architectures. This work has enabled to demonstrate the potential of the type II GaAsSb/InGaAs heterostructure to meet the challenges posed by the conception and the fabrication of GaAs-based MJSCs, both for the tunnel junction and the 1 eV subcell
Etude des défauts induits par recuit laser excimère dans le silicium by Richard Monflier( Book )

2 editions published in 2019 in French and held by 2 WorldCat member libraries worldwide

The micro-electronic domain is constantly evolving in response to the continuous emerging of new application fields as well as new users' needs. The fabrication of heavily-doped regions for ultra-shallow junctions is a major issue to ensure its evolution. In this context, new doping techniques allowing to obtain ultra-shallow junctions have been developed. Nanosecond laser annealing in "melt mode" is one of these techniques. Indeed, it allows a very strong local activation (on surface and in depth) and a uniform distribution of doping. This process used in laboratory since the 1980s for the realization of solar cells offers also new technological possibilities such as the development of 3D architectures. However, degradation of several parameters sensitive to laser-induced defects were observed, such as carrier mobility and reverse current in MOS transistors or carrier lifetime in the case of photovoltaic cells. In this context, this thesis proposes a rigorous study of the defects generated by laser annealing in two parts. The first part analyses the impact of the laser annealing on the physical properties, thanks to infrared and photoluminescence spectroscopy characterizations of bare silicon samples submitted to different annealing conditions. The study highlights the formation of defects following the laser process. Their identification allowed to confirm the introduction of oxygen and carbon impurities during the annealing. From this identification, the impurities were followed in depth by secondary ion mass spectrometry allowing to reveal an increase of their concentration and diffusivity when increasing the laser energy density and/or the number of laser pulses. At high energy, the oxygen concentration profiles show the presence of an immobile peak (in agreement with the known solubility limit value in liquid silicon) which are related to silicon cavities observed by transmission electron microscopy. The origin of these impurities is also discussed and the characterization of dedicated test vehicles allowed to identify the native oxide as the source of the impurities. The objective of second part is to evaluate the impact of laser annealing on the electrical properties of silicon devices thanks to the characterization of PN and Schottky diodes. The obtained results provide an additional mean to localize the electrically active defects but also to identify them. The current-voltage characteristics of diodes systematically show an impact of the annealing on the leakage current, which is a strongly defect-sensitive parameter. More specifically, the leakage current deteriorates with increasing the laser energy. These measurements have allowed also to highlight the presence of defects at the liquid/solid interface, defects which also have a strong impact on diodes electric properties. The results are in agreement with the literature which suggests the presence of vacancies at the interface. To go further on this study, DLTS measurements have been carried out and reveal, depending on their localization (melt zone or liquid/solid interface), singular signatures suggesting several types of defects
Représentation de la lumière électrique dans les peintures de la fin du XIXe siècle à 1937 by Jean-Louis Izbicki( Book )

2 editions published in 2020 in French and held by 2 WorldCat member libraries worldwide

To justify his point of view in a scientific controversy, Volta made a device, later called "Volta pile" or "Volta battery", which was the first generator that made it possible to obtain a permanent current. After his travels in Europe to show his discovery, along with its publication in a scientific journal, the first applications followed immediately, thanks in particular to Davy. The "electric light" appeared and its development has continued ever since. The electric arc, the Jablochkoff candle, light bulbs, neon tubes. - these are the various technologies implemented in the 1840s - 1910. The most surprising, no doubt, is the fact that during all those years it was not possible to specify exactly what the notion of current covered. In what way can the knowledge of electricity, and therefore of electric light, be relevant and enriching for the eye, the pleasure, and the analysis of paintings related to the new artificial light that appeared at the very beginning of the 19th century? This work is based on the following assumption: a scientist's perspective can contribute to the understanding of a painting. The knowledge of the scientific facts, their observations or their conceptualizations, their hesitations, their inaccuracies accompanying the birth and the development of the electric light seem necessary to help establish a complete analysis of the works. In what places and at what times did this new light manifest itself? How was it received in the intellectual sphere or in the press? What evolutions did the electric light cause and how were they represented? From the mid- to late nineteenth century, what evolution in electric light technologies occurred? What, then, were the new subjects dealt with by painters? The analysis, under electric light, of one part of the history of art has revealed : frontal views of electric lights in paintings by Sonia Terk Delaunay, Goncharova and Balla; saturated illuminations in the works of Sluijters and Rockwell ; beams structuring the night space, from Nevinson to Vallotton; political action under Devambez's electric light in Deïneka and Steinlen's work; night landscapes of cities from Hassam to Ury; expressive approaches of the city from Kirchner to Masereel; interiors under electric lighting by Vuillard and Hopper. Even painters that we do not spontaneously associate with electricity and electric light such as Gérôme, Monet, Manet, and Picasso have also made a contribution to the artistic representations of electric light. This highly disparate collection of painters of all nationalities reflects the varied appropriations of the appearance, presence and development of electric light in society
Etude des transistors à effet de champ organiques : réalisation d'OFETs ambipolaires et étude des mécanismes d'injection dans les OFETs verticaux by Marjorie Morvan( Book )

2 editions published in 2020 in French and held by 2 WorldCat member libraries worldwide

L'utilisation de Transistors à Effet de Champ Organiques (OFETs) est de plus en plus attractive grâce à la possibilité de production de composants plus légers, fabriqués à un moindre coût et sur des substrats flexibles. Le fait de pouvoir coupler une fonction émission de lumière à une fonction transistor rend son utilisation d'autant plus intéressante. C'est le cas des applications d'affichage, où les pixels sont réalisés par une technologie de matrice active à diodes électroluminescentes organiques (AMOLED). Le fait d'avoir un OFET électroluminescent permet de combiner un OFET avec une diode électroluminescente organique (OLED) et donc de simplifier la conception, les étapes de fabrication ainsi que d'augmenter la durée de vie des pixels. Durant cette thèse, l'étude et la fabrication des OFETs émetteurs de lumière ont été menés selon deux approches. La première est basée sur l'étude d'OFETs ambipolaires à base de N,N'-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C13), un semi-conducteur de type-n, et de pentacène, un semi-conducteur de type-p, ce qui constitue une première étape à l'obtention d'OFET électroluminescent. La fabrication et la caractérisation de ces OFETs ambipolaires ont été réalisées pour la première fois dans l'équipe de recherche du laboratoire. Une étude de leur structure a été menée pour trouver les paramètres idéaux à l'obtention d'un transport de charges équilibré. La structure optimisée est une structure bicouche avec une épaisseur de pentacène de 8 nm et une épaisseur de PTCDI-C13 de 20 nm. L'ajout d'une couche émettrice entre les deux semi-conducteurs n'a pas permis d'obtenir une émission de lumière à cause du piégeage de charges trop important. Cependant, ce travail a ouvert de nouvelles perspectives pour les futurs travaux sur les OFETs ambipolaires. La deuxième approche pour étudier les OFETs émetteurs de lumière est plus innovante grâce au changement de la structure des transistors organiques classiques par une structure verticale. Cette structure présente l'avantage de pouvoir intégrer facilement une structure OLED et d'avoir une émission de lumière homogène sur une grande surface. Le principe de fonctionnement est totalement différent des OFETs classiques : ici, la modulation du courant ne se fait plus par un contrôle de la conductivité dans un canal semi-conducteur, mais par un contrôle de l'injection de charges au niveau de l'électrode source. L'étude de cette structure a permis d'obtenir des transistors organiques lumineux. Ensuite, l'étude des mécanismes d'injection de charges a permis de mieux comprendre le fonctionnement de ces transistors. Plusieurs matériaux ont été testés en tant qu'électrode source : l'or, l'argent, l'aluminium et l'ITO (Indium Tin Oxyde). Cela a permis de déterminer le mécanisme d'injection mis en jeu, soit l'injection de charges par la modulation de l'effet tunnel grâce à la courbure de bande induite par l'effet de grille dans la couche semi-conductrice proche de l'interface. Il a également été identifié que la qualité de l'interface électrode source/semi-conducteur joue un rôle majeur puisqu'une mauvaise qualité d'interface entraîne une diminution drastique des performances
Claquage microonde par retournement temporel by Valentin Mazières( Book )

2 editions published in 2020 in French and held by 2 WorldCat member libraries worldwide

Un des défis auxquels sont confrontées les technologies plasmas est le développement de concepts de sources de plasma qui peuvent être transposés à des dimensions plus importantes, avec pour objectif par exemple le traitement de surface d'objets de grandes dimensions (panneaux solaires, écrans plats, grand wafer...). Cependant, plus la surface à traiter est grande, plus il devient difficile de la traiter. En fait, lorsqu'on augmente la surface, ces technologies se heurtent à des limites physiques et technologiques. Pour les sources plasmas microondes, l'incapacité à contrôler les plasmas vient du caractère multi-mode des grandes cavités, qui rend le contrôle de la distribution spatiale du champ électrique (et donc du plasma) en leur sein très difficile avec les technologies conventionnelles. L'objectif de la thèse est de développer une source plasma micro-onde répondant à ce besoin de contrôle des plasmas dans les grandes cavités (multimodes). Nous avons alors introduit un concept innovant de source de plasma micro-ondes : le "pinceau plasma ondulatoire". Le principe de cette source plasma consiste à contrôler dynamiquement la position du plasma dans une cavité en jouant sur la forme d'onde du signal transmis à la cavité. L'idée est alors d'utiliser le "Retournement Temporel", qui permet de focaliser spatio-temporellement l'énergie électromagnétique dans les cavités de grandes dimensions. Cette thèse propose les premières études théoriques et les premières démonstrations expérimentales du concept de "pinceau plasma ondulatoire"
On-line partial discharges detection in conversion systems used in aeronautics by Benjamin Cella( Book )

2 editions published in 2015 in English and held by 2 WorldCat member libraries worldwide

The more electrical airplane concept led industrial companies to focus a part of their efforts on risks linked to the use of high voltage in a severe environment (Low pressure, wide range of temperature and humidity ...). Associated risks are the existence and the growing of partial discharges ultimately leading to the breakdown of the system in which they occur. Considering this problematic, the Liebherr Elektronik GmbH group, in collaboration with the Laplace laboratory, launched the study of a method allowing partial discharges detection in converters intended to be used in aeronautical applications. The results of this work are the subject of this thesis. The first part brings the status of the current knowledge about partial discharges from their physical nature to the detection methods which are used. In the second part, three measurement phases assessing the efficiency of the studied method are introduced and their results discussed. Finally, in the third part, the conclusionsof our works and their perspectives are presented
Caractérisation du comportement du plasma dans un disjoncteur basse tension par le développement d'un outil numérique et d'expériences associées by Jingjing Lu( Book )

2 editions published in 2020 in French and held by 2 WorldCat member libraries worldwide

The arc splitting process and the quantification of additional voltage drops are the major phenomena to understand and to optimize the Low Voltage Circuit Breaker (LVCB). The aim of our work is to understand their behavior through experiments and then their representation by our model. Therefore, a three-dimensional (3D) magnetohydrodynamic modeling is carried out on a simplified LVCB geometry. The developments are based on the commercial code Ansys @Fluent with UDF (User Define Functions). The plasma is described by fluid equations and a finite volume method. To study and isolate the mechanisms, the experimental and numerical work were realized on a simplified geometry, composed by two parallel electrodes with or without splitter plates. Numerically, the additional voltage resulting from the sheaths at the plasma/material interfaces, is considered by an approximate method based on the theoretical characteristic of voltage variation, as the function of current density. This additional resistivity allows to present the current flow in the materials and create some delay at the switching during the splitting process. Further to the experiments, the arc behavior is characterized by electrical measurements (Voltage, current) and by high-speed camera. The arc ignition is realized by a copper fuse of 0.1 mm. The geometry can be more or less closed at its both extremities in order to highlight the effects of pressure force and/or Lorentz force. The description of arc behavior was found similar between the simulation and experiments results. However, the initial conditions of our model proved to be preponderate while at the same time, the conditions remained delicate to determine
Peignes de fréquences optiques par effet Kerr dans les micro et mini résonateurs optiques by Napoléon Gutierrez( Book )

2 editions published in 2019 in French and held by 2 WorldCat member libraries worldwide

Optical frequency combs find applications in optics, physics, precision spectroscopy and opto-electronics among others. The mode-locked laser is historically the system at the origin of these combs. More recently, in the quest for the miniaturization of optical frequency comb generators, micro-resonators and mini-resonators have emerged as attractive alternatives due to their compact nature as well as their mode selectivity and power enhancement properties. The work presented in this thesis is centered on the modeling of passive resonator based Kerr frequency combs. The first chapter of this thesis presents a state of the art of micro and mini Kerr frequency combs and puts forth the advantages of resonator-based platforms for the generation of optical frequency combs. The second chapter presents the model used to study passive optical resonators in the linear and non-linear regimes. The non-linear approach is based on an Ikeda map, allowing the study of Kerr comb formation in passive resonators. In the third chapter, Kerr frequency combs generated in an integrated resonator are presented. These results are compared to simulation results based on the model presented in the preceding chapter. The last chapter studies the impact of frequency-dependent access coupling parameters on the generation of Kerr frequency combs. Simulation results are presented, bringing to light the importance of the influence that these coupling parameters have on the combs generated in the resonator
Conception et optimisation en bruit de phase d'un oscillateur hyperfréquence à résonateur supraconducteur by David Chaudy( Book )

2 editions published in 2020 in French and held by 2 WorldCat member libraries worldwide

Recent research on high-temperature superconductors (HTS) has led to the development of planar resonators with a very high quality factor in the low microwave range (some GHz). Such resonators, associated with an amplification circuit, make it possible to produce microwave sources of high spectral purity (or low phase noise). Indeed, quality factors of 300 000 could be demonstrated on these resonators around 1 GHz. However, prior to this thesis work, no oscillator with HTS resonator had been able to include an amplification system that had also been cooled. We began our work by a fine characterization at low temperature of the components constituting the oscillation loop: the resonator, the transistor (amplifier) ??and the varactor (phase control). Accurate characterization of different superconducting resonators has been performed over a wide temperature range and at different RF power levels. This work allowed us to extract a non-linear model of the resonator that can be used in a 1 GHz circuit design. As regards the amplifier, different transistors have been tested with respect to their phase noise and gain performance at 1 GHz and 80 K (and then 60 K thereafter). Following these measurements, a component was selected and modeled. The transistor model, extracted from the I(V) and low temperature S parameters, includes noise sources to simulate the residual phase noise of the transistor (1/f component and noise floor). Using this model, a low noise phase cryogenic amplifier could be designed and noise optimized on the Keysight ADS software. Similar work has been done on varactor diodes to include a frequency tuning circuit for the oscillator to allow frequency lock on an external reference. Finally, using these models, an all cryogenic oscillator could be simulated and realized in hybrid technology on alumina. To our knowledge, this is the first entirely cryogenic oscillator with HTS resonator. This circuit was measured by advanced metrology techniques and the results are presented in the thesis
Approche mathématique pour la modulation de largeur d'impulsion pour la conversion statique de l'énergie électrique : application aux onduleurs multiniveaux by Karima Berkoune( Book )

2 editions published in 2016 in French and held by 2 WorldCat member libraries worldwide

Les convertisseurs d'électronique de puissance sont de plus en plus exploités notamment dans les applications nécessitant la variation de vitesse de machines. L'utilisation de composants plus performants et plus puissants couplés à de nouvelles structures multiniveaux autorise l'accès à de nouveaux champs applicatifs, ou des fonctionnements à plus haut rendement. Ces convertisseurs statiques sont capables de gérer, par un pilotage adapté, les transferts d'énergie entre différentes sources et différents récepteurs selon la famille de convertisseur utilisée. Au sein de l'interface de pilotage, un schéma particulier permet de générer des signaux de commande pour les interrupteurs, il s'agit de la modulation et peut être vue par deux approches différentes : L'approche intersective issue d'une comparaison modulante-horteuse (appelée en anglais carrier based PWM) et l'approche vectorielle où les signaux de pilotage des trois bras de ponts sont considérés comme un vecteur global unique (appelée Modulation Vectorielle SVM). Le but de la MLI est de générer une valeur moyenne de la tension la plus proche possible du signal modulé. La commande usuelle par comparaison modulante-porteuse dans le cas des architectures multiniveaux nécessite autant de porteuses triangulaires qu'il y a de cellules à commander au sein d'un bras. Plus généralement, la stratégie de modulation de chacune des topologies multiniveaux est choisie en se basant sur des critères à optimiser liés à la qualité les formes d'ondes produites ou obtenues, suite à la conversion. Le choix de la variable de commande à implémenter dans le schéma MLI fait appel à l'expertise de l'expérimentateur et se réfère peu au modèle mathématique initial qui peut-être établit pour caractériser le fonctionnement de l'architecture d'électronique de puissance. En ce qui concerne les stratégies vectorielles SVM, une absence de modèle compatible avec les modèles, basés sur une comparaison modulante porteuse, d'onduleurs est constatée. Les types d'onduleurs triphasés à deux ou à N niveaux de tension admettent un modèle sous forme d'équations d'un système linéaire compatible qui s'écrit sous la forme V = f(a) dans le cas d'une MLI sinusoïdale et V = f(1) dans le cas d'une SVM, avec V les tensions de phase, a les rapports cycliques et f les instants de commutation. Dans cette configuration basique il est constaté que la matrice liant ces tensions aux rapports cycliques (ou aux instants de commutation) n'admet pas d'inverse, ce qui revient à dire qu'il n'est pas possible, avec les théories usuelles des fonctions linéaires, de résoudre ce système afin d'exprimer les rapports cycliques (ou les instants de commutation) en fonction des tensions de références. C'est ce qui explique qu'aujourd'hui un bon nombre d'implémentations pratiques de modulation se fait, suite à une analyse expérimentale des conséquences d'un choix de stratégie sur les variables d'intérêt
 
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Alternative Names
Ecole doctorale d'électronique (Toulouse)

Ecole Doctorale GEET (Toulouse)

École Doctorale Génie Électrique, Électronique et Télécommunications : du microsystème au système (Toulouse)

École Doctorale Génie Électrique, Électronique et Télécommunications : du système au nanosystème (Toulouse)

Ecole Doctorale Génie Électrique, Électronique et Télécommunications (Toulouse)

Ecole Doctorale Génie Electrique, Electronique, Télécommunications

GEET

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French (29)

English (13)