Дисертації з теми "Capteur de gaz souterrain"
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Taher, Mohammad Iktiham Bin. "New HEMT Type Sensors for In-situ Bio‐Geochemical Analysis." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0229.
An innovative gas sensor generation based on AlGaN/GaN High Electron Mobility Transistor (HEMT) has been developed for complex geological environments. It is designed to study the mass transfer of gases (H2, CO2, CH4, O2, H2S, SO2, and He) from the underground to the Earth's atmosphere. It incorporates the key features for subsurface gas sensor development such as miniaturization, robustness, insensitivity to harsh environments, and low cost.Technological steps, design of the sensor layouts, micro-fabrication techniques, and optimization of the electrical performance of the HEMTs have been continuously investigated and improved. Current densities above 400 mA/mm and pinch-off current= (~1×10-5 A), and transconductance (gm)= ~0.03 S/mm have been achieved for certain bias conditions. At the same time, the processed AlGaN/GaN HEMT sensors with different functional layers (Pt, ITO, and IZO) are fabricated and characterized for different gases (H2, CO2, CH4, and He) in the laboratory, and real subsurface conditions (Borehole: 51 m) under different environmental conditions (temperature= 25 to 450°C, humidity= 0 to 100%). The measured adsorption enthalpies of hydrogen onto various sensing materials like Pt, ITO, and IZO are calculated -30.3 kJ mol^(-1), -32.5 kJ 〖mol〗^(-1), and -34 kJ 〖mol〗^(-1), respectively, indicating that ITO and IZO are complementary to Pt for the development of a hydrogen gas sensor.Pt/AlGaN/GaN-based HEMT devices have been studied to evaluate the performance of hydrogen sensors in pure atmospheric air and a fully N2-based atmosphere to simulate subsurface conditions where the O2 concentration changes over the depth of the soil. From the thermodynamic analysis, the affinity of hydrogen for Pt was found nearly 2000 times greater than the affinity of oxygen for platinum. This makes the sensor suitable for detecting hydrogen in the air or various mixtures of O2 and H2 at different underground depths imply.A dedicated gas sensor batch has been fabricated with passivated (i.e., non-active) sensor components as a reference for gas detection (active sensor). The active sensor Pt/AlGaN/GaN provided a change in current indicating a response to the hydrogen exposure, while the non-active (Passivated-Pt/AlGaN/GaN) provides no changes in current. But non-active sensor (reference) tracks and eliminates the changes caused by external environmental parameters.This thesis also presents new measurement techniques using pulse polarization for subsurface gas detection with a Pt-AlGaN/GaN HEMT sensor. Instead of imposing a continuous input bias (which always maintains the ON state) over a long period of the experiment, the sensor is activated several times with pulsed polarization for a short period of time (ON/OFF state). The sensors showed a sufficiently fast response to the target gas by changing the drain current in pulsed bias mode with a linear increase in output current even at very low concentrations such as 25 ppm. All the experiments conducted in the study demonstrated that the sensors could work in various measurement scenarios that may occur in the real situation of subsurface gas detection
Sáinz-García, Álvaro. "Dynamique de stockage souterrain de gaz : aperçu à partir de modèles numériques de dioxyde de carbone et d'hydrogène." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30187/document.
Climate change mitigation is one of the major challenges of our time. The anthropogenic greenhouse gases emissions have continuously increased since industrial revolution leading to global warming. A broad portfolio of mitigation technologies has to be implemented to fulfill international greenhouse gas emissions agreements. Some of them comprises the use of the underground as a storage of various substances. In particular, this thesis addresses the dynamics of carbon dioxide (CO2) and hydrogen (H2) underground storage. Numerical models are a very useful tool to estimate the processes taking place at the subsurface. During this thesis, a solute transport in porous media module and various multiphase flow formulations have been implemented in COMSOL Multiphysics (Comsol, 2016). These numerical tools help to progress in the understanding of the migration and interaction of fluids in porous underground storages. Three models that provide recommendations to improve the efficiency, monitoring and safety of the storages are presented in this manuscript: two in the context of carbon capture and storage (CCS) and one applied to underground hydrogen storage (UHS). Each model focus on a specific research question: Multiphase model on CCS. The efficiency and long-term safety of underground CO2 storage depend on the migration and trapping of the buoyant CO2 plume. The wide range of temporal and spatial scales involved poses challenges in the assessment of the trapping mechanisms and the interaction between them. In this chapter a two-phase dynamic numerical model able to capture the effects of capillarity, dissolution and convective mixing on the plume migration is applied to a syncline-anticline aquifer structure. In anticline aquifers, the slope of the aquifer and the distance of injection to anticline crest determine the gravity current migration and, thus, the trapping mechanisms affecting the CO2. The anticline structure halts the gravity current and promotes free-phase CO2 accumulation beneath the anticline crest, stimulating the onset of convection and, thus, accelerating CO2 dissolution. Variations on the gravity current velocity due to the anticline slope can lead to plume splitting and different free-phase plume depletion time is observed depending on the injection location. Injection at short distances from the anticline crest minimizes the plume extent but retards CO2 immobilization. On the contrary, injection at large distances from anticline crest leads to large plume footprints and the splitting of the free-phase plume. The larger extension yields higher leakage risk than injection close to aquifer tip; however, capillary trapping is greatly enhanced, leading to faster free-phase CO2 immobilization. Reactive transport model on convective mixing in CCS. Dissolution of carbon-dioxide into formation fluids during carbon capture and storage (CCS) can generate an instability with a denser CO2-rich fluid located above the less dense native aquifer fluid. This instability promotes convective mixing, enhancing CO2 dissolution and favouring the storage safety
Barochi, Guillaume. "Développement d'un capteur de gaz à transduction microonde." Phd thesis, Université de Bourgogne, 2013. http://tel.archives-ouvertes.fr/tel-00956823.
Erouel, Mohsen. "Etude sur les transistors organiques à vocation capteur de gaz : application à la détection de gaz nitrés." Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0040/these.pdf.
Organic field effect transistors (OFETs) are now widely recognized for their potential applications in all fields of so-called "plastic electronics". The high development of those transistors is related to the possibility to use its on nitrous gas sensor elaboration. The development of those systems needs the use of adapted technologies, a low elaboration cost, working at low temperature, to be easy to transport, selective and stable. In this field, the objective of our work consists on developing organic transistors for nitrous derivates detection usually used on classical explosive system. The sensor elaboration needed the good realisation of many tasks. The first one consists on the selection of the dielectric allowing us to have a stable transistor. For this, two insulator materials were used: inorganic oxides with high dielectric value (Ta2O5, HfO2, ZrO2, Al2O3/ZrO2) deposited with a low temperature process and an organic insulating material, the polymethylmethacrylate PMMA deposited by spin-coating. Pentacene transistors using different dielectrics were elaborated in order to compare their electric efficiencies. The results analysis (morphologic and electric) permitted to understand the comportment of those systems under their general aspect in addition to the comportment of the used dielectrics. The study of the stability of the oligothienylenevinylenes derivatives based transistors selected for the detection of dinitrotoluen (DNT) was conduced. The measure of components derivates was realized by studies based on the stress influence following, humidity and temperature. Sensors responses to DNT vapour were followed. Detection is related to donor-acceptor reaction
Erouel, Mohsen Sassi Zina Jaffrezic-Renault Nicole Maaref M'hamed Ali. "Etude sur les transistors organiques à vocation capteur de gaz application à la détection de gaz nitrés /." Villeurbanne : Doc'INSA, 2008. http://docinsa.insa-lyon.fr/these/pont.php?id=erouel.
Rosini, Sébastien. "Capteur potentiométrique tout solide pour le dosage de l'hydrogène dans l'air." Grenoble INPG, 2003. http://www.theses.fr/2003INPG0028.
Gravelle, Alexandre. "Optimisation de l'efficacité et de la durabilité des traitements de puits à base de polymères et de microgels dans un contexte de réduction des venues de sable." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL063N.
Gas production from underground geological reservoirs in aquifers is sometimes associated with the erosion of solid particles from the rock matrix. These solids venues generated by the gas flow can cause damages to the equipment on site leading the operator to limit or stop the production of wells. The injection of hydro-soluble polymers (linear polyacrylamide or microgels) is one of the promising techniques employed today to reduce and, in some cases, stop the production of solids as demonstrated by the results of tests conducted in France on reservoirs of Storengy - GDF Suez.An experimental study was conducted to better understand the mechanisms underlying the performance of polymer treatments and to increase their efficiency. Two main aspects have been experimentally evidenced: sand grains consolidation and polymer coating of the pore surface. Tests were carried out to accurately assess the impact of the adsorption of polymer on the mobilization of particles (called fines) and a comprehensive study was conducted showing the properties of treatments to (re)consolidate the rock matrix. In the first case, the polymer acts as a physicochemical barrier preventing the detachment of fines that can form the inter-granular cement and the effectiveness of treatments is based on the proportion of pores surface covered by the polymer. In the second case, the polymer takes the place of cleaved cement; the effectiveness and durability of treatments thus depend on mechanical properties of the inter-granular solids bounds formed after drying of capillary bridges
Buissart, Hubert. "Le Wealdien du Bassin de Paris : approches sédimentologique et paléogéographiqueApplications au stockage souterrain de gaz naturel." Lille 1, 1989. http://www.theses.fr/1989LIL10173.
Hallil, Hamida. "Conception et réalisation d'un nouveau capteur de gaz passif communicant à transduction RF." Toulouse 3, 2010. http://thesesups.ups-tlse.fr/1028/1/Hallil_Hamida.pdf.
In this work, feasibility of gas sensors based on Titanium Dioxide (TiO2) dielectric resonator, operating with whispering-gallery modes, is presented. The gas or humidity adsorption modifies the TiO2 dielectric permittivity and such modification induces variation in the resonant frequencies of high-Q whispering-gallery modes in the millimeter-wave frequency range. Full-wave electromagnetic simulation demonstrates that the measurement of this variation allows the derivation of few parts-per-million (ppm) fluctuations in gas or humidity concentration. For validation purposes very first prototypes of resonator operating with whispering-gallery modes in the millimeter-wave frequency range are micro-machined. The measured performances confirm that such high-Q resonant modes are very sensitive to small variations in dielectric resonator permittivity. Moreover we validate experimentally that these small variations can be remotely detected from the RADAR interrogation of an antenna loaded by the whispering-gallery modes resonator
Saikaly, Khalil. "Contrôle-commande préventif d'un moteur de cogénération alimenté en gaz naturel par intégration d'un capteur de qualité du gaz." Nantes, 2009. http://www.theses.fr/2009NANT2041.
The goal of this thesis is to conceive a preventive protection technique for the cogeneration engines under the knock problem. The work relies an on-line monitoring of the gas methane number. In a first stage, a combustion simulator is developed based on a two-zone thermodynamic model which allows the evaluation of a knock estimator. This estimator is based on the evaluation of the energy of the unburned gases. The main scientific contribution brought by this study can be resumed by the following postulate : if two gases have the same tendency to knock, i. E. The same methane number, then they have the same ignition delay and speed of flame under the same motor setting. In a second stage, a test bench which uses a single-cylinder Sl engine is set up for 3 purposes : (1)to automatically control the different engine settings (i. E. Spark advance, load, and air-fuel ratio) : to vary the composition of gas and throughout its methane number and (3) to detect the knock by evaluating the IMPO. Finally, experiences showed the effect ot the methane number and engine settings on knock tendency. Experimental results were also compared with the results of simulations, which were then used to calibrate the numerical model. Subsequent to numerical results, a control map that gives the optimal engine setting with respect to a given methane number was created. The map was then successfully applied to the single-cylinder SI
Bourhaleb, Houssine. "Etude et expérimentation d'une chaîne énergétique solaire avec capteur à air, stockage thermique souterrain et récupération par pompe à chaleur." Valenciennes, 1987. https://ged.uphf.fr/nuxeo/site/esupversions/69924e8c-5370-4c55-aef3-3e377d2fa6a1.
Bourhaleb, Houssine. "Etude et expérimentation d'une chaîne énergétique solaire avec capteur à air stockage thermique souterrain et récupération par pompe à chaleur /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37603347k.
Hallil, Hamida. "Conception et réalisation dun nouveau capteur de gaz passif communicant à transduction RF." Phd thesis, Université Paul Sabatier - Toulouse III, 2010. http://tel.archives-ouvertes.fr/tel-00546243.
Menini, Philippe. "Du capteur de gaz à oxydes métalliques vers les nez électroniques sans fil." Habilitation à diriger des recherches, Université Paul Sabatier - Toulouse III, 2011. http://tel.archives-ouvertes.fr/tel-00697471.
Viguier, Françoise. "Ecoulements diphasiques lors de la vidange d'un réservoir de gaz liquéfiés sous pression. Comparaison Eau - CFC11-CFC113." Paris, ENMP, 1992. http://tel.archives-ouvertes.fr/tel-00844457.
Lauque, Pascal. "De la couche sensible au système :dépôt par plasma froid et capteurs de gaz." Habilitation à diriger des recherches, Université Paul Cézanne - Aix-Marseille III, 2009. http://tel.archives-ouvertes.fr/tel-00428567.
Roumanie, Marilyne. "Microréacteur pour la catalyse hétérogèneApplications : Stockage d'hydrogène dans les hydrocarbures Filtre pour capteur gaz." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2005. http://tel.archives-ouvertes.fr/tel-00012119.
Pelé, Anne-Laure. "Conversion d'énergie dans des matériaux dopés terre-rares pour capteur tout optique de gaz." Caen, 2015. http://www.theses.fr/2015CAEN2033.
This work is devoted to the study of rare earth ions doped low phonon energy chalcogenide glasses for the all optical gas sensor development using an IR signal conversion to a near IR or visible signal. The principle of the sensor is as follow: a diode pumped Dy3+ doped chalcogenide fiber first produces the infrared signal, which is then sent to the gas cell to probe the gas absorption at 4. 4µm. The probe IR signal is then converted to 810 nm by excited state absorption within a diode-pumped Er3+ doped chalcogenide fiber making possible to transport the probe signal through a silica optical fiber over large distances considerably increasing the scope of possible applications. The spectroscopic study of Dy3+ doped GeGaSbS fibers has brought to light the 6H11/26H13/2 transition potential as IR source at 4. 4µm. The corresponding IR source at the absorption wavelength of the CO2 at 4. 4µm is based on the Dy3+ doped GeGaSbS fibers and has been developed in the laboratory of Caen in collaboration with the “Verre et Céramiques” team of the ISCR of Rennes. In order to optimize the luminescent fiber in the IR, a simulation of the generated power has been realized and the impact of various parameters involved in the Dy3+ emission has been studied in detail. Model results have been validated successfully by comparison with experimental measurements. The energy conversion mechanism from 4. 4µm to 810 nm has been successfully implemented in Er3+ doped GeGaSbS chalcogenide fibers because of their simultaneous excitation at 980 nm and 4. 4µm. A fluorescence intensity of the 810 nm signal simulation in function of the experimental set-up parameters and the fiber characteristics has also been developed. This simulation permits to determine the optimal parameters for a fluorescence as effective as possible but also to describe in detail the physical phenomena taking place during the conversion. In fact, in addition to the essential excited state absorption process, energy transfers occur, involving a parasitic upconversion signal at 810 nm in competition with the conversion. The conversion of a signal at 3. 4µm to a signal at 665 nm have also been demonstrated into Er3+ doped sulfide glasses as well as the conversion of a 4. 4µm signal to a 810 nm signal into an Er3+ doped KPb2Cl5 crystal. Finally, the conversion of a distant-range IR signal at 10µm has been explored in a Sm3+ doped KPb2Cl5 crystal
Kante, Ibrahima. "Elaboration et caractérisation de nanoagrégats d'étain : application à la réalisation d'un capteur de gaz." Orléans, 2004. http://www.theses.fr/2004ORLE2023.
Harakeh, Aref. "Optimisation de la conception d'un nouveau capteur multi-gaz pour les concentrations d'émissions gazeuses." Electronic Thesis or Diss., Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0610.
A gas sensor is a device whose role is to obtain either information on the exact concentration of certain gases in a selected atmosphere, or information on the presence or absence of certain gases. In this dissertation, we discussed the optimization of the design of a new optical multi-gas sensor, digital image processing and new genetic algorithms for the calculation of gaseous concentrations in mixtures containing up to five gases. In addition, a new method for measuring the gas concentration in ppm, a theoretical validation and an optimization of the parameters of the gas discharge tube (the essential part of our sensor), as well as a new approach for identifying gases using neural networks were also discussed. The research results have been validated experimentally by performing numerous tests in the laboratory on the experimental test bench designed and built for this purpose. In addition, theoretical validation was also carried out using finite element simulation software. Our technology validated during this research work is promising and, in the future, our miniature multi-gas optical sensor will be a very good candidate in many industrial and scientific fields where the need to measure the concentration of several gases is essential. Certain collaborations with the industry are considered for various applications, such as the measurement of gaseous emissions from internal combustion engines, the monitoring of the concentration of natural gas and the measurement of harmful gases in the atmosphere
Chamassi, Kaim. "Détecteur de gaz multi-espèces par mesure photo-acoustique à effet capacitif." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTS065.
The need of a sensitive, selective, stable and compact gas sensor is increasing due to public and military issues. Photoacoustic detection variant of tunable diode laser spectroscopy is a promosing solution. Current devices available on the market and developing are still cumbersome and unsuitable for being transported by a person. The goal of this thesis is to study and develop silicon capacitive micro-resonator in order to achieve a gas sensor based on photoacoustic spectroscpy. This original approach has never been proposed. It offers new perspectives and a solution to have very compact, sensitive, selective and stable gas sensor. First, theoretical study of capacitive micro resonators is done in order to set up modeling tools and determine the key optimization parameters. The performances are strictly linked to mechanical properties and viscous damping. A SOI process divided into two main steps is then developed in order to produce capacitive micro-resonator. Then, we demonstrate the approach by stable and reproducible methane and ethylene detection. Finally, we propose new micro-resonator adapted to photoacoustic spectroscopy without the constraints of capacitive transduction
Larbi, Allal. "Evaluation des proprietes capteur de gaz d'un polymere electroactif et automatisation du banc de mesures." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF2D199.
Roumanie, Marilyne. "Microréacteur pour la catalyse hétérogène. Applications : Stockage d'hydrogène dans les hydrocarbures. Filtre pour capteur gaz." Saint-Etienne, EMSE, 2005. http://www.theses.fr/2005EMSE0023.
This manuscript presents the design and the use of silicon microstructured reactor for heterogeneous catalysis and especially for the dehydrogenation of methylcyclohexane reaction. This reaction enables on one hand to store hydrogen and on the other hand to realise technological developments since it is endothermic and difficult to carry out. By consequence, a new microreactor obtained by DRIE was designed and capped with a Pyrex wafer. It bundles microheaters deposited by screen-printing and a high temperature metallic connection. It comprises either a catalyst coming from microtechnology, Pt film deposited by sputtering or a classic catalyst, platinum supported on alumina. For this last catalyst, the microreactor previously preoxidised is pretraited by oxygen plasma or liquid way so that the deposit to walls. The washcoat could be done in open microreactor by dip coating in the suspension or in closed microreactor under vacuum or by liquid circulation. After catalytic tests realised in a macroreactor, the Pt/Al₂O₃ catalyst was chosen to be inserted in the microreactor. The catalytic tests realised in a microreactor coupled with a mass spectrometer let to show the presence of hydrogen. In parallel, the microreactor was used as filter to improve gas sensor selectivity
Ghaddab, Boutheina. "Développement d’un capteur de gaz à base de couche hybride dioxyde d’étain / nanotubes de carbone." Thesis, Besançon, 2012. http://www.theses.fr/2012BESA2028/document.
The objective of this study is to develop a gas sensor based on a hybrid layer of SnO2/SWNTs inorder to improve the performance of “Conventional” chemical sensors basically made from tinoxide. First, in order to control the synthesis of the sensitive material, we validated the elaborationof a sensitive layer based on tin dioxide prepared using the sol-gel process. The synthesizedmaterial was deposited by the 'microdrop' technique on a micro-platform which simultaneouslyallows the heating of the sensitive layer whilst also measuring its conductance. The study of theelectrical responses of the gas sensor in the presence of benzene has allowed us to validate thepossibility of using our prepared tin sol for the realization of gas sensitive layers. In fact, it waspossible to detect benzene at traces with an optimal temperature of the sensing layer found to be420ºC.The second part of this study describes the synthesis of the hybrid sensor obtained by dispersingSWNTs in the tin-oxide based sol. The sensitive layers made by dip-coating from the carbonnanotubes modified tin sol have clearly shown the possibility of detecting various gases (ozoneand ammonia) at room temperature. This result is one the most important points of this work tothe extent that until now the chemical sensors based on tin dioxide only showed a high sensitivityto gases when they were operated at temperatures in the range of 350 - 400ºC. Concerning the twotarget gases tested in this work, the detection limit at room temperature was evaluated at 1 ppm inthe presence of NH3 and was lower than 20 ppb in the presence of ozone.The last part of this work has focused the optimization of the detection performance of thesensitive layers. In this case, the experimental study was oriented towards examination of theeffect of various parameters such as the amount of nanotubes in the hybrid material, thecalcination temperature of the sensitive layer, the sensor working temperature and also thephysico-chemical properties of the carbon nanotubes (synthesis method, diameter...) on thedetection efficiency of the sensing layers. The results obtained in terms of detection performancewere discussed in relation to the experimental parameters used
Larbi, Allal. "Evaluation des propriétés capteur de gaz d'un polymère électroactif et automatisation du banc de mesures." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37606986v.
Abdelghani, Aymen. "Capteur de gaz hyperfréquence à base de nanotubes de carbone, imprimé par technologie jet d’encre." Thesis, Limoges, 2018. http://www.theses.fr/2018LIMO0089/document.
In recent years, the development of gas sensors has grown rapidly for industrial, military and environmental applications to ensure safety and protection against harmful and toxic gases. These applications require sensitive, selective, low power and low cost sensors. The thesis work presented in this manuscript fits into this context. Its objective is the realization of a microwave sensor based on carbon nanotubes and manufactured by inkjet technology. The operating principle of the sensor is based on the frequency characterization of an RF resonator, one element of which is sensitive, thanks to the carbon nanotubes, to the presence of a surrounding gas. The manuscript addresses all the steps necessary for the realization of the sensor, namely: the design of the test devices, based on a theoretical study of their behavior, the characterization of the materials used, the fabrication on a flexible substrate by inkjet printing technique and finally the characterization of the gas sensor in terms of frequency behavior and sensitivity in the presence of gas
Donero, Laeticia. "Développement de micro-capteur et de nano-matériaux pour des applications de détection en milieu liquide." Thesis, Nantes, 2017. http://www.theses.fr/2017NANT4003/document.
This thesis is carried out within the framework of a partnership between two laboratories: IMN (Institute of Materials of Nantes), specialized in the elaboration of materials and IETR (Institute of Electronics and Telecommunications) specialized in microtechnologies and microsensors. The objective of this work is to develop original microsensors integrating nanomaterials, in order to obtain charge sensors with high sensitivities, especially in liquid media. The microsensors developed at the IETR are based on "bottom gate" and dual gate field effect transistors. Initially, we focused on the optimization of the technological process of the sensors to obtain the best electrical characteristics for our applications. Detection measurements using different pHs are explored. A second part of the project, carried out at the IMN, was the development of nanomaterials: carbon nanotubes and nanoporous carbon thin films. The studies have focused on the growth of carbon nanotubes deposited by PECVD and on the development of nanoporous layers. The last layers are obtained by depositing copper / carbon composite thin films by magnetron cathodic cosputtering followed by chemical etching of the copper. Subsequently, preliminary tests of integration of these carbon nanomaterials as well as of silicon nanowires were carried out to confirm the compatibility of the synthesis processes with the operation of the device
Blet, Vincent. "Etude d'un capteur à membrane gazeuse pour la détection d'espèces sensibles au pH." Vandoeuvre-les-Nancy, INPL, 1990. http://www.theses.fr/1990INPL031N.
Esnault, Benoît. "La transition du monopole à la concurrence sur les marchés du gaz naturel en Europe : l'importance stratégique du stockage souterrain." Dijon, 2000. http://www.theses.fr/2000DIJOE014.
Durand-Viel, Laure. "Stratégies d'engagement et pouvoir de marché : une application au marché du gaz naturel." Paris 9, 2010. https://portail.bu.dauphine.fr/fileviewer/index.php?doc=2010PA090018.
This thesis is devoted to the analysis of commitment strategies in oligopolistic markets, with a particular focus on the European market for natural gas. The first chapter focuses on capacity investments in a bilateral relationship where the buyer-investor faces the threat of holdup. While some commitment is necessary to ensure investment, a too long commitment by the seller can lead to a lower investment level. The second chapter analyzes the strategic use of storage in a successive oligopoly and shows that while demand preemption through storage can be profitable, firms can however choose to commit not to use such a strategy. The third chapter provides a positive and normative analysis of gas release programs that aim at fostering competition in the downstream gas market by granting new entrants access to the incumbent's long-term contracts with foreign producers. Finally, the fourth chapter analyzes how real asset valuation methods based on spot market arbitrage can lead to suboptimal investment choices
Yoboue, N'Goran Pamela Marie Josephe. "Etude technologique pour l'amélioration des performances d'un capteur à gaz à oxyde métallique : développement d'une plateforme chauffante et intégration de couche sensible nanostructurée." Toulouse 3, 2010. http://thesesups.ups-tlse.fr/911/.
In recent years, the development of metal oxides gas sensors has experienced a considerable growth because of an interest more and more important in the protection of environment and people safety. Thanks to technological advances in microelectronics that promote better performances, low costs in terms of consumption and production, these sensors can be used for monitoring air quality in many fields such as transport, industry or housing environment. It is clear that metal oxide sensors sold today present mixed performances. Indeed, despite an interesting sensitivity with a detection threshold around the ppm, those sensors also have low selectivity and great instability, which limit their use to simple detectors. For that matter, these imperfections are the motor of many researches including development of new sensing materials but also new transducers. The goal of this thesis is to prove that it is possible to improve the performances of those metal oxide gas sensors especially on aspects of consumption (<80mW) with a remarkable mechanical stability and electrothermal stability up to 600°C. For that, our work consisted firstly to redefine a new design and then to optimize technological process to develop high-temperature microhotplate. Then we worked on the optimization of ink jet process as a new technological way to integrate nanoparticular sensitive materials; a way much more reproducibly than current deposition techniques. The first tests were conducted with ZnO nanoparticles and have shown promising results especially for flexible integration of various sensing materials for new multisensors
Woo, Heechul. "The selective low cost gas sensor based on functionalized graphene." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX050/document.
Recent advances in nanomaterials provided a strong potential to create a gas sensor with many advantages such as high sensitivity of single molecule detection, low cost, and low power consumption. Graphene, isolated in 2004, is one of the best promising candidate for the future development of nanosensors applications because of its atom-thick, two-dimensional structures, high conductivity, and large specific surface areas. Every atom of a monolayer graphene can be considered as a surface atom, capable of interacting even with a single molecule of the target gas or vapor species, which eventually results in the ultrasensitive sensor response.In this thesis work, graphene films were synthesized by Chemical Vapor Deposition (CVD) on the glass substrate. Raman spectroscopy was used to analyze the quality and number of layers of graphene. Atomic Force Microscope (AFM) and Scanning Electron Microscopy (SEM) were also performed to analyze the quality of graphene. After the characterization of graphene films, graphene based resistive devices (four identical electrodes are thermally evaporated directly onto the graphene film as metal electrodes) were fabricated. The electrical characterization has been carried out using Keithley-4200.Intrinsic device response was studied with different external condition changes (pressure, humidity, light illumination). The device was non-covalently functionalized with organometallic complex (Ru(II) trisbipyridine) and the its light exposure response was studied. The observed device response was reproducible and similar after many cycles of on and off operations. The theoretical and experimental approaches and the results obtained during the thesis are opening up a way to understand and fabricate future gas sensing devices based on the non-covalentely functionalized graphene
Chalabi, Habib. "Conception et réalisation d'une plate-forme multi-capteur de gaz conductimétrique…Vers le nez électronique intégré." Aix-Marseille 3, 2007. http://www.theses.fr/2007AIX30064.
Semiconducting oxide gas sensors often bases on structures unstable over time and presents always low gas selectivity. Thus this work describes the development of new generation gas microsensors. The different elements of the device have been studied and improved. In particular, a new micro-hotplate with platinum resistance could be achieved by using a numerical approach based on the finite element method. Good control of technological processes has enabled the development of a multi-sensors technology involving four cells on one chip. A WO3 sensitive layer was able to be integrated into this system and electrical and thermographic characterizations of devices have been enabled to validate functioning and good stability of structures. Preliminary tests in controlled gaseous atmosphere have provided good overall performances in term of sensibility and selectivity. This work is encouraging first stage for electronic nose realisation
Chalabi, Habib. "Conception et réalisation d'une plate-forme multi-capteur de gaz conductimétriques...Vers le nez électronique intégré." Phd thesis, Université Paul Cézanne - Aix-Marseille III, 2007. http://tel.archives-ouvertes.fr/tel-00265932.
Hijazi, Mohamad. "Capteur de gaz SnO2 fonctionnalisé fonctionnant à température ambiante, sensible et sélectif pour la détection d’ammoniac." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEM030/document.
One of the major challenges in the modern era is how we can detect the disease when we are still feeling healthy via noninvasive methods. Exhaled breath analysis is offering a simple and noninvasive tool for early diagnosis of diseases. Molecularly modified SnO2 sensors seem to be promising devices for sensing polar gases such as ammonia. SnO2 surface functionalization was performed in order to obtain sensitive and selective ammonia gas sensor that operates at room temperature. The first step of functionalization is the covalently attachment of 3-aminopropyltriethoxysilane (APTES) film on SnO2 in vapor or liquid phases. The characterization performed by the Infrared Spectroscopy and X-ray Photoelectron Spectroscopy, show that more APTES were grafted by hydrous liquid phase silanization. The second step was the functionalization of APTES modified SnO2 with molecules having acyl chloride of end functional groups molecules such as alkyl, acid and ester groups. Pure SnO2 and APTES modified SnO2 sensors did not show any significant sensitivity to ammonia (0.2-100 ppm) at 25 °C. On the contrary, acid and ester modified sensors are sensitive to ammonia between 0.2 and 10 ppm at room temperature. However, ester modified SnO2 was more selective than acid modified sensor regarding the ethanol and carbon monoxide gases. Ammonia variates the attached molecular layer’s dipole moment which leads to change in SnO2 conductance. Working at ambient temperature is also one of the advantages of these sensors in addition to the selectivity to ammonia regarding other gases such as ethanol, carbon monoxide and acetone
Derouiche, Nadir. "Propriétés électriques de films de polypyrroles dopé, action des gaz, utilisation en capteur de NH#3." Clermont-Ferrand 2, 1990. http://www.theses.fr/1990CLF21240.
RAMIREZ-SALGADO, JOEL. "Contribution à l'étude des électrodes à gaz dans un capteur potentiométrique à CO2 de deuxième espèce." Université Joseph Fourier (Grenoble), 2001. http://www.theses.fr/2001GRE10113.
CHAMBON, LAURE. "Etude d'un micro-systeme capteur de gaz multimembranes mecanismes d'interactions physico-chimiques gaz-oxydes semiconducteurs metalliques dans des conditions atmospheriques ; traitement du signal associe." Clermont-Ferrand 2, 1997. http://www.theses.fr/1997CLF21968.
Acuautla, Meneses Monica Isela. "Development of ozone and ammonia gas sensors on flexible substrate." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4337/document.
Nowadays the emerging of new applications in the micro and nanotechnology field required to reduce fabrication costand to improve electronic devices with properties such as flexibility, portability, lightweight, and low cost. Traditional methods involve expensive and long production steps, and chemical vapor deposition. The purpose of this work is to present the conception and characterization of flexible ammonia and ozone sensors fabricated by photolithography and laser ablation processes. The flexible platform is composed of Kapton substrate with interdigitated Ti/Pt electrodes for gas detection and a micro-heater device. The circuit patterns were realized by photolithography and laser ablation. Photolithography is a well-known and reliable patterning process used on rigid substrate. The application of laser ablation process not only reduces fabrication time, but also represents an excellent viable alternative instead of chemical processes. ZnO thin films deposited by drop coating have been used as sensitive materials due to their excellent properties in the gas detection. The gas sensing condition and the performances of the devices are investigated for ozone and ammonia at different gas concentrations and different thin film thicknesses. In order to test a deposit methodology used in large scale industrial production, an ultrasonic spray deposition was done. The sensor provides a wide range of detection from 5 ppb to 500 ppb for ozone and from 5 ppm to 100 ppm for ammonia. Their best sensibilities were obtained at 200°C for ozone and 300 °C for ammoniac with good repeatability, stability and fast response/recovery time
Moudakkir, Salah. "Etude physico-chimique de l'oxyde d'étain SnO2. Aptitude à la réalisation d'un capteur passif sensible aux traces de gaz réducteurs dans l'air." Tours, 1998. http://www.theses.fr/1998TOUR4016.
Madrolle, Stéphanie. "Méthodes de traitement du signal pour l'analyse quantitative de gaz respiratoires à partir d’un unique capteur MOX." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT065/document.
Non-invasively taken, exhaled breath contains many volatile organic compounds (VOCs) whose amount depends on the health of the subject. Quantitative analysis of exhaled air is of great medical interest, whether for diagnosis or for a treatment follow-up. As part of my thesis, we propose to study a device to analyze exhaled breath, including these VOCs. This multidisciplinary thesis addresses various aspects, such as the choice of sensors, materials and acquisition modes, the acquisition of data using a gas bench, and then the processing of the signals obtained to quantify a gas mixture. We study the response of a metal oxide sensor (MOX) to mixtures of two gases (acetone and ethanol) diluted in synthetic air (oxygen and nitrogen). Then, we use source separation methods in order to distinguish the two gases, and to determine their concentration. To give satisfactory results, these methods require first to use several sensors for which we know the mathematical model describing the interaction of the mixture with the sensor, and which present a sufficient diversity in the calibration measurements to estimate the model coefficients. In this thesis, we show that MOX sensors can be described by a linear-quadratic mixing model, and that a dual temperature acquisition mode can generate two virtual sensors from a single physical sensor. To quantify the components of the mixture from measurements on these (virtual) sensors, we have develop supervised and unsupervised source separation methods, applied to this nonlinear model: independent component analysis, least squares methods (Levenberg Marquardt algorithm), and a Bayesian method were studied. The experimental results show that these methods make it possible to estimate the VOC concentrations of a gas mixture, accurately, while requiring only a few calibration points
Tetelin, Angélique. "Caractérisation et modélisation de la réponse transitoire d'un capteur d'humidité à couche sensible polymère." Bordeaux 1, 2003. http://www.theses.fr/2003BOR16016.
This work presents the characterization and modelling of the transient response of a capacitive humidity sensor. The sensitive layer of the sensor consists in a benzocyclobutene (BCB) polymer film. Analytical physical and behavioural models of the sensor were developed on the basis of the theory of sorption and diffusion of gases in polymers, and on the study of the capacitive structure of the sensor. These models were validated by experiments and numerical simulations. They allow the prediction of the transient response of the sensor when exposed to the specific humidity conditions of human breath for medical application. They also provide strategies to shorten the response time of the sensor. Finally, these models were used to predict moisture diffusion in BCB adhesive films for wafer-level MEMS packaging
Lefevre, Nathalie. "La pression partielle de gaz carbonique : developpement d'un capteur et analyse de la distribution dans l'ocean pacifique equatorial." Paris 6, 1994. http://www.theses.fr/1994PA066171.
Guillet, Nicolas. "Etude d'un capteur de gaz potentiométrique. Influence et rôle des espèces oxygénées de surface sur la réponse électrique." Grenoble INPG, 2001. http://tel.archives-ouvertes.fr/tel-00001580.
Halfaya, Yacine. "Optimisation, fabrication et caractérisation d’un capteur de gaz à base d’hétérostructure AlGaN/GaN HEMT pour des applications automobiles." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0312.
The work of the thesis focuses on the development of a new type of gas sensors based III-Nitride semiconductor materials (gallium nitrides). These materials have many advantages that could be used to develop sensitive and selective NOx sensors for the control of pollution emitted by diesel exhaust line. To limit the polluting gases emitted by internal combustion engines in general and diesel in particular (NO, NO2, NH3, CO, ...), different European standards have been established. To meet these standards, anti-pollution systems (consisting of particle filters, catalysts, NOx sensors, ... etc) are used. NOx sensors currently used in automobiles are based on a solid electrolyte. Their operation is based on the measurement of the oxygen concentration. This enables an estimate of the total concentration of NOx gas (indirect measurement) after filtering NOx from O2 and decomposing NOx into O2. These sensors do not detect NH3 at the outlet of the exhaust line, and do not give accurate information on the relationship between NO and NO2 (lack of selectivity) which is important factor for an optimal functioning of selective catalyst (SCR performance improvement). Hence there exists a need for a more efficient and selective in particular gas sensor to improve the control systems, post-treatment and diagnosis. Our approach is to use a HEMT (High Electron Mobility Transistor) transistor based on gallium nitride with a combination of a functional layer instead of the gate. The interaction of the gas molecules with the functional layer gives a signature (output signal variation) specific for each type of gas that helps to improve the selectivity. The project contains two parts: the optimization of the chosen structure and the optimization of the functional layer in order to achieve selective detection between various gaseous pollutants. This technology is interesting for development of gas sensors through the possibility of detection low voltage variations and the possibility of operating in harsh environments. The thesis is part of OpenLab "Materials and Processes" in a collaboration between Georgia Tech-CNRS laboratory and the PSA Peugeot-Citroen Group
Halfaya, Yacine. "Optimisation, fabrication et caractérisation d’un capteur de gaz à base d’hétérostructure AlGaN/GaN HEMT pour des applications automobiles." Electronic Thesis or Diss., Université de Lorraine, 2016. http://www.theses.fr/2016LORR0312.
The work of the thesis focuses on the development of a new type of gas sensors based III-Nitride semiconductor materials (gallium nitrides). These materials have many advantages that could be used to develop sensitive and selective NOx sensors for the control of pollution emitted by diesel exhaust line. To limit the polluting gases emitted by internal combustion engines in general and diesel in particular (NO, NO2, NH3, CO, ...), different European standards have been established. To meet these standards, anti-pollution systems (consisting of particle filters, catalysts, NOx sensors, ... etc) are used. NOx sensors currently used in automobiles are based on a solid electrolyte. Their operation is based on the measurement of the oxygen concentration. This enables an estimate of the total concentration of NOx gas (indirect measurement) after filtering NOx from O2 and decomposing NOx into O2. These sensors do not detect NH3 at the outlet of the exhaust line, and do not give accurate information on the relationship between NO and NO2 (lack of selectivity) which is important factor for an optimal functioning of selective catalyst (SCR performance improvement). Hence there exists a need for a more efficient and selective in particular gas sensor to improve the control systems, post-treatment and diagnosis. Our approach is to use a HEMT (High Electron Mobility Transistor) transistor based on gallium nitride with a combination of a functional layer instead of the gate. The interaction of the gas molecules with the functional layer gives a signature (output signal variation) specific for each type of gas that helps to improve the selectivity. The project contains two parts: the optimization of the chosen structure and the optimization of the functional layer in order to achieve selective detection between various gaseous pollutants. This technology is interesting for development of gas sensors through the possibility of detection low voltage variations and the possibility of operating in harsh environments. The thesis is part of OpenLab "Materials and Processes" in a collaboration between Georgia Tech-CNRS laboratory and the PSA Peugeot-Citroen Group
Djizanne, Djakeun Hippolyte. "Stabilité mécanique d'une cavité saline soumise à des variations rapides de pression : Application au stockage souterrain de gaz naturel, d’air comprimé et d’hydrogène." Palaiseau, Ecole polytechnique, 2014. https://theses.hal.science/tel-01130986/document.
Salt caverns used for the underground storage of large volumes of natural gas are in high demand given the ever-increasing energy needs. The storage of renewable energy is also envisaged in these salt caverns for example, storage of compressed air and hydrogen mass storage. In both cases, salt caverns are more solicited than before because they are subject to rapid injection and withdrawal rates. These new operating modes raise new mechanical problems, illustrated in particular by sloughing, and falling of overhanging blocks at cavern wall. Indeed, to the purely mechanical stress related to changes in gas pressure variations, repeated dozens of degrees Celsius of temperature variation are superimposed; causes in particular during withdrawal, additional tensile stresses whom may lead to fractures at cavern wall; whose evolution could be dangerous. The mechanical behavior of rock salt is known: it is elasto-viscoplastic, nonlinear and highly thermo sensitive. The existing rock salt constitutive laws and failures and damages criteria have been used to analyze the behavior of caverns under the effects of these new loading. The study deals with the thermo mechanics of rocks and helps to analyze the effects of these new operations modes on the structural stability of salt caverns. The approach was to firstly design and validate a thermodynamic model of the behavior of gas in the cavern. This model was used to analyze blowout in gas salt cavern. Then, with the thermo mechanical coupling, to analyze the effects of rapid withdrawal, rapid injection and daily cycles on the structural stability of caverns. At the experimental level, we sought the optimal conditions to the occurrence and the development of cracks on a pastille and a block of rock salt. The creep behavior of rock salt specimens in triaxial extension also was analyzed
Gao, Jing. "Etude et mise au point d'un capteur de gaz pour la detection sélective de NOx en pot d'échappement automobile." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2011. http://tel.archives-ouvertes.fr/tel-01016361.
Maulion, Geoffrey. "Conception, fabrication et caractérisation de composants photoniques innovants appliqués à la détection de gaz." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS063/document.
For about a decade, gas detection has known a tremendous interest, due to several reasons: environmental issues, public health, people and building safety, etc... This trend, triggered a spectacular and sustainable need of gas detection means improvement and development, which has grown with both standards sophistication and scope extension. As a matter of fact, the number of research projects related to this particular topic increased: PEPS ANR project, begun in 2010, is one of them. This research project, which is the acronym of Pellet Photonique Sensor, aim at developing a photonic multigas detection system based on thermo-optical effect, thanks to the combination of on one hand, catalitic nanopowders which react selectively with the target gas (hydrogen or carbon monoxide) and on the other hand, an high sensitive to refractive index variations planar photonic component. This thesis manuscript mostly treats of the photonic component design (choice and optimization)
Wannebroucq, Amélie. "Synthèse de matériaux moléculaires et héterojonctions, de l'intérêt des matériaux ambipolaires dans les capteurs de gaz conductimétriques." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCK047/document.
The molecular semiconductors have enabled the production of electronic devices such as field effect transistors, diodes and other heterojunctions. The ambipolar materials, capable of carrying both positive charges and negative, result in devices with special properties. The purpose of this thesis is to synthesize new ambipolar materials develop original electronic devices, especially for applications in the field of gas sensors. We are interested in molecules capable to lead to thin films with low temperature techniques known as solution processing, particularly metallo-phthalocyanines