Дисертації з теми "Surveillance géochimique des gaz"
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Lafortune, Stéphane. "Apports de la géochimie des gaz rares à la surveillance des sites de séquestration géologiques de C02." Paris, Institut de physique du globe, 2007. https://tel.archives-ouvertes.fr/tel-00269264.
Lafortune, Stéphane. "Apports de la géochimie des gaz rares à la surveillance des sites de séquestration géologique de CO2." Phd thesis, Institut de physique du globe de paris - IPGP, 2007. http://tel.archives-ouvertes.fr/tel-00269264.
Afin d'être en mesure de respecter les engagements pris en matière de réduction des émissions atmosphériques, tout en permettant la poursuite raisonnée de l'exploitation des énergies fossiles, notamment pour les pays en plein développement économique, il est envisagé de stocker (séquestrer) le dioxyde de carbone produit au niveau de grandes plates-formes industrielles, dans des réservoirs géologiques, c'est-à-dire des roches poreuses et perméables. Bien qu'étant inspirée de nombreux exemples naturels, la séquestration géologique du dioxyde de carbone doit être étudiée en termes de faisabilité et d'intérêt, l'objectif étant de piéger durablement les gaz stockés.
Dans le cadre de ce doctorat, nous nous sommes concentrés sur la surveillance des sites de séquestration, afin d'être en mesure de contrôler la stabilité et l'efficacité des stockages géologiques dans le temps, et de détecter le plus rapidement possible les éventuelles fuites. Notre travail a consisté à développer une méthodologie de surveillance reposant sur l'étude des gaz rares. Nous avons été amenés à concevoir un nouvel outil pour l'analyse des gaz rares dissous dans des échantillons d'eau, la ligne Garodiox, puis à valider cet instrument sur l'étude d'un lac de cratère volcanique, le lac Pavin en Auvergne (France). Enfin, nous avons choisi d'illustrer la méthodologie de surveillance que nous proposons, à l'aide du contrôle de l'intégrité de l'accumulation naturelle de dioxyde de carbone de Montmiral, dans le département de la Drôme (France).
Les résultats obtenus soulignent la faisabilité et l'intérêt de la mise en place d'une telle méthodologie de surveillance au droit des sites de séquestration géologique du dioxyde de carbone.
Lacroix, Elodie. "Développements de protocoles méthodologiques pour le monitoring géochimique appliqué à la détection de fuite d'hydrogène (H₂) à l'aplomb des sites de stockage souterrain." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0342.
Combined with the energy transition, underground H₂ storage is a storage solution for the energy. The research project named "Rostock'H" integrating this thesis work associated the University of Lorraine and Ineris to develop geochemical monitoring methods in order to analyze the risks and opportunities. This project aims to study the risks and opportunities of H₂ storage in salt caverns. The next goal is to be able to store H₂ in a volume of up to 1,000,000 m³ between 300 and 1,400 m deep. The development of an underground storage site involves controlling pre, syn and post-operational risks by geochemical monitoring methods. Colorless and odorless, H₂ is a volatile and explosive gas. A particular attention is therefore paid to the risks of subsurface leakage from these storage sites and to the metrology associated with this detection. This thesis work had three main objectives: (i) to experiment in-situ and continuous monitoring methods from dissolved gas injections on a dedicated experimental site, (ii) to determine the potential impacts of a leak in “soils” and “aquifers” with a modeled analysis of the geochemical behavior of H₂ and associated parameters, (iii) to establish recommendations and a monitoring strategy for existing or future underground storage sites to prevent potential H₂ leakages. Composed of a semi-confined aquifer from 13 m deep, this experimental site in the Paris Basin has several wells and equipments reaching the saturated and unsaturated zones. Oxidizing, oxygenated and moderately mineralized, the waters of this aquifer have an initial chemical composition belonging to the calcium bicarbonate facies with a slight alteration in nitrates and sulphates. Several steps were necessary to simulate and model a potential leak: - Preparation of the site and choice of the metrological systems that will be deployed - Establishment of the initial state of the site through the definition of a geochemical baseline from measurements of the piezometric level, physico-chemical parameters, analyzes of ionic species and dissolved gas measurements in a dedicated well by combining of the Raman and infrared spectroscopies - Co-injection of dissolved He and hydrogeological tracers to validate the experimental protocol of the H₂ injection and to allow a first analysis of the aquifer dynamics - Co-injection of dissolved H₂ and tracers selected according to the adapted protocol linked to the experience feedback from the He injection - Post-injection monitoring to determine the impacts and the kinetics of return in the initial state of the aquifer using in particular the monitoring system of dissolved gases by optical sensors. An initial concentration of H₂ dissolved at 1.78 mg.L-1 was injected under surface conditions for 2.5 hours into the aquifer. The migration of the dissolved H₂ plume as well as other gases initially present in the aquifer was monitored both by continuous method (Raman and infrared spectroscopies) and discontinuous measurements (partial degassing). A dynamic of H₂ transfer in the water table was observed up to 20 m downstream from the injection well: 0.6 mg.L⁻¹ at 5 m, 0.17 mg.L⁻¹ at 7 m then 1.8*10⁻³ mg.L⁻¹ of H₂ at 10 and 20 m during the first week. Following the addition of H₂(aq), the physico-chemistry of the aquifer was modified with an increase of pH, a decrease of redox potential and of the O₂(aq) concentration. From continuous measurements by Raman spectroscopy (at 7 m downstream the injection well), a 2D model was established on the basis of a mixed H₂ diffusion/advection process, assuming a single-channel flow in the aquifer. The experimental results acquired in this thesis work validate, over the long term, the metrological choices applied, with a detection limit of H₂ in aquifer lowered to 0.02 mg.L⁻¹. These results thus confirm the feasibility of monitoring dissolved H2 in shallow aquifers and highlight the potential impacts of leakages from underground storage reaching the surface
Adisaputro, Didi. "Metrology and Monitoring of Gases Transfer (CO₂ and CH₄) Processes within the System of Geosphere and Biosphere." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0313.
This study is a continuation of our previous geochemical monitoring finding at the injection wells of Rousse 1 ( Total CCS pilot, Lacq- Rousse, France) where it was identified that the soil CO₂ mole fraction (χc) evolution in subsoil was negatively correlated with the level of the water table and the CO₂ sources were attributed to the CO₂-rich aquifers. However, it is still unclear whether this relationship exists in the forest ecosystem, representing a significant proportion of the CO₂ atmospheric budget. For this reason, this thesis focuses on monitoring the gas exchange and its main driver of the transport process between soil (-1 m), subsoil (-6 m), and biosphere. We developed and implemented an in-situ geochemical monitoring system for continuous monitoring of CO₂ mole fraction in the subsoil coupled with a micrometeorological monitoring system using a pre-established flux tower in the forest Ecosystem (Montiers, Lorraine Region, France). This soil gas measurement infrastructure combining borehole measurement with micrometeorological measurement offers great possibilities for long-term in-situ and continuous gas monitoring to derive the vertical distribution of CO₂. Thus, this infrastructure allowed the observation of the temporal dynamics in soil-gas CO₂ research. During the study periods, the ecosystem acted as a net carbon sink with a mean annual NEE, GPP, and Reco of -453±122 gC m-2y-1, -1468 ±109 gC m-2y-1, and 1052 ±88 gC m-2y-1 consecutively. The Carbon exchange, climate, and environmental drivers during the drought episodes were compared with long-term reference data recorded from 2014 to 2017. In contrast with some previous research where GPP and Reco parallelly decreased during the drought episodes, our site showed Reco is more sensitive to drought than GPP, resulting in a significant increase in Net Ecosystem exchange. Reco decreased by 20%, and 26% were found in Summer and Autumn (2018-2019) relative to the ref erence years (2014-2017). This study shows strong empirical shreds of evidence that wind turbulence plays a significant role in driving the deep soil CO₂ concentration. We hypothesize that this could be due to pressure pumping effects where it decreases the CO₂ molar fraction in the soil during high turbulence and increasing the CO₂ storage in deep soil during low turbulence. This study also demonstrates that permeability significantly reduced during wet periods diminishing molecular diffusion and advection. This study also revealed a strong biotic influence on CO₂ production. The δ¹³CCO₂ values in our site subsoil can be attributed to respiration and decomposition of the C3 plants. These biological origins of soil CO₂ are highly likely increases air density resulting in gravitational percolation that leads the CO₂ stored in a deeper layer of soil. The relationship of subsoil gases also emphasizes that biogenic components dominate the origins and controlling process of subsoil CO₂ while the geochemical process plays an insignificant role
Jeandel, Elodie. "Monitoring géochimique par couplage entre les gaz rares et les isotopes du carbone : étude d'un réservoir naturel." Phd thesis, Université Paris Sud - Paris XI, 2008. http://tel.archives-ouvertes.fr/tel-00399871.
Le développement d'outils de surveillance fiables pour s'assurer de la pérennité et de la sécurité des stockages est un préalable à la mise en œuvre des tels sites.
Dans ce cadre, une méthodologie de monitoring géochimique combinant la géochimie des gaz rares et des isotopes du carbone a été testée sur des analogues naturels et industriels.
Sur les analogues naturels de contextes géologiques variés, des comportements systématiques des paramètres géochimiques en fonction du confinement des sites ont pu être révélés, attestant de l'efficacité de ces outils en termes de détection des fuites et en tant que traceurs du comportement du CO2 dans les futurs sites de stockage.
De plus, une expérience de traçage géochimique sur un stockage de gaz naturel a démontré qu'il est possible d'identifier les processus physico-chimiques se déroulant dans le réservoir à l'échelle humaine, renforçant l'intérêt pour l'outil proposé et apportant des informations méthodologiques sur son utilisation.
Jeandel, Elodie. "Monitoring géochimique par couplage entre les gaz rares et les isotopes du carbon : étude d'un réservoir naturel." Paris 11, 2008. http://www.theses.fr/2008PA112318.
To limit emissions of greenhouse gases in the atmosphere, CO2 geological sequestration appears as a solution in the fight against climate change. The development of reliable monitoring tools to ensure the sustainability and the safety of geological storage is a prerequisite for the implementation of such sites. In this framework, a geochemical method using noble gas and carbon isotopes geochemistry has been tested on natural and industrial analogues. The study of natural analogues from different geological settings showed systematic behaviours of the geochemical parameters, depending on the containment sites, and proving the effectiveness of these tools in terms of leak detection and as tracers of the behaviour of CO2. Moreover, an experience of geochemical tracing on a natural gas storage has demonstrated that it is possible to identify the physical-chemical processes taking place in the reservoir to a human time scale, increasing interest in the proposed tool and providing general informations on its use
O, Burrola Francisco de la. "Étude pétrographique et géochimique intégrée du charbon et de shale à gaz du bassin Sabinas et de Chihuahua au Nord du Mexique : estimation des ressources en gaz méthane." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0233/document.
This comprehensive characterization study was performed using organic petrology and geochemistry conducted in the Sabinas basin and Chihuahua in northern Mexico. This information allowed a numerical modeling of gas formation, considering the thermal subsidence of coal and carbonaceous shales.The objectives of this thesis are: establish a characterization methodology for the studied rocks ; estimate potential gas generator and its regional distribution ; estimate the methane gas resources. For the development of this project, we conducted an intensive campaign representative sampling of coal, carbonaceous shales and coal gas "in situ". For the Sabinas basin were studied 97 samples and 114 samples in the basin of Chihuahua. The analyses carried out that were used on the samples analyzed allowed to characterize the kerogen and gas. The methodology used to cross petrographic and geochemical information to analyze the petroleum system by numerical modeling. Analyses were: Petrographic, reflectance %Ro, elemental analysis and immediate, Rock Eval6 ® (Bulk rock), isotopic analysis, [delta]13C, [delta]D, (coal gas), scanning electron microscopy, image analysis and analysis of macerals fluid inclusions. The analyzes that were used on the samples allowed to characterize the sample, the kerogen and gas. The methodology used to cross petrographic and geochemical information for analyze the oil system by numerical modeling. Analyses were: Petrographic, reflectance% Ro, elemental analysis and immediate, Rock Eval6 ® (Bulk rock), isotopic analysis, d13C, dD, (coal gas), scanning electron microscopy, image analysis and analysis of macerals fluid inclusions. A computer program was constructed to cross the information with the analysis of samples of artificial maturation experiments in the laboratory. This approach allowed estimation of methane gas resources generated by coal and carbonaceous shales. [...] In conclusion, between the two basins studied, the Sabinas basin, generates more gas for industrial exploitation. However, the rocks of the basin of Chihuahua unconventional types (shale gas) show good potential for hydrocarbon generation. The methodology used for the study of kerogen and gas in the two basins is in our opinion the most appropriate to meet the objectives proposed in this thesis. This allows to characterize the thermal evolution of coal, carbonaceous shale (shale gas), coal gas and hydrocarbon source rocks
Renard, Stéphane. "Rôle des gaz annexes sur l'évolution géochimique d'un site de stockage de dioxyde de carbone : application à des réservoirs carbonatés." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL025N/document.
Capture and geological storage of CO2 are an main option to limit GHEG emissions of industrial poles and power plants. The captured gases are not constituted by pure CO2 but contain a fraction (until 10 %) of other gases : Ar, N2, SOx and NOx. Most of these gases are highly reactive and could have a strong influence on physical and chemical conditions of the milieu and on the environmement if contamination of neighbour aquifers occurs by leakages. Several laboratory experiments investigated the reactivity of carbonated reservoir and cap rocks from the Aquitaine Basin as well as the reactivity of synthetic mineralogical blends in geologically relevant P-T conditions. The rocks, associated to brine, were altered in presence of various gaseous components at 100 bar and 150°C during one month : pure CO2, pure SO2, pure NO and a CO2 mixture containing fractions of Ar, N2, SO2 and O2. Each experiment was compared with a blank in which the initial gas was replaced with pure N2. Pure CO2 show a limited reactivity on the rocks. NO and SO2 show a intrinsic reactivity by disproportionations in aqueous or vapour phases implying a high alteration of rocks by compled acid – base and oxidation mechanisms. The gas mixture show also a double reactivity : SO2 is oxidized in sulphuric acid dissolving carbonates and clay minerals and O2 oxidizes all reduced mineralogical phases. These gases even in limited fractions control the reactivity of rocks. Their presence could change the behaviour of the rock toward gas and induce positive as well as negative transformations. Their implication must be checked for each geological storage as a function of gas composition, mineralogy and petrophysical
Bourry, Christophe. "Caractérisation physique et géochimique d'hydrates de gaz d'environnements géologiques différents : apport des techniques de Diffraction X Synchrotron et de Spectroscopie Raman : contribution à l'étude de leur origine, formation et stabilité sur les marges." Brest, 2008. http://www.theses.fr/2008BRES2043.
The knowledge of the occurrence of gas hydrates in the natural environment, their physical, chemical or thermodynamical properties is essential to prevent geohazards, to anticipate their role in climate change or to develop technologies to take advantage of this energy resource. To mis purpose, this work reports a physical and chemical characterization of four natural gas hydrates from African and Norwegian margins, and from the Sea of Marmara, for documenting their origin, formation and stability. Samples from African and Norwegian margins crystallize in type I structure. This observation is in agreement with their biogenic origin. On the other hand, hydrate samples from the sea of Marmara, characterized by a thermogenic origin, exhibit a type II structure. Raman spectroscopy was also used to investigate the dissociation processes of natural gas hydrates. These results indicate that there is no preferential dissociation of large small cages. Thermodynamical modeling let us evaluate the highly variable gas hydrate stability fields in sediments from the Hakon Most Mud Volcano, whereas it let us assert that only thermogenic gas hydrates can crystallize in the sea of Marmara. In a last chapter, geochemical data obtained from porewaters, gases, and gas hydrates collected during the Vicking cruise (2006) - HERMES Program - permitted to characterize the processes controlling the fluid circulation in the Hakon Mosby Mud Volcano where gas hydrates are present in great quantity
MATHIS, GAEL. "Outils de détection de rupture et de diagnostic : application à la surveillance de turbines à gaz." Rennes 1, 1994. http://www.theses.fr/1994REN10121.
Hermoso, Michaël. "Les perturbations environnementales au cours du Toarcien inférieur : apport de l'étude sédimentologique et géochimique de séries boréales et Ouest-Téthysiennes." Paris 6, 2007. https://hal.archives-ouvertes.fr/tel-01476891.
Grundman, Gaëlle. "Evaluation des potentiels en huile et gaz du Nord-Est de la Gaspésie (Québec, Canada) : approche géochimique et modélisation 2D du système pétrolier." Paris 6, 2013. http://www.theses.fr/2013PA066043.
Gaspé Peninsula (Québec, Canada) is made up of three distinct tectonostratigraphic domains: Cambro-Ordovician rocks, Siluro-Devonian rocks and Carboniferous. The objective of this study is to improve understanding of this petroleum system, through a geochemical approach coupled with a 2D modeling. Study of Rock-Eval 6 profiles of Siluro-Devonian bulk rocks suggests the presence of a significant amount of generated but not free petroleum products. To avoid overestimation of the oil potential, it appears necessary to analyze the kerogens. The study of kerogens extracts thus indicates that the Siluro-Devonian rocks have generated hydrocarbons without possibility to expel them. In addition, the kinetics parameters of thermal cracking of kerogens allowed the establishment of a decreasing curve of the HI, which can be compared to the curve measured in this study and enables to estimate the minimum height of eroded sediments during the last erosions that affected the northeastern Gaspé (4500 m). This estimated amount of erosion proved to be an important parameter during the numerical modeling. Thus, three scenarios were defined according to the thickness of eroded formations and assumptions of maximum burial, but also taking into account results on previous fission track analysis. If it is difficult to determine the best burial scenario that prevailed in the geological history of northeastern Gaspé, the convergence of results enable the establishment of the Cambro-Ordovician origin of the hydrocarbon, the provision of a reliable chronology of generation-expulsion-migration events, the estimation of the mass of hydrocarbons in play, and the location of accumulations over time
Taquet, Noémie. "Monitoring géochimique de la géosphère et l'atmosphère : application au stockage géologique du CO2." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0252/document.
This study is based on the problematic of gas exchanges at the interface between the geosphere, biosphere, hydrosphere and atmosphere through the geochemical monitoring of gas applied to CO2 geological storage sites. Concerning the "Metrological" aspect, we developed and implemented an in situ continuous geochemical monitoring station, based on coupling FTIR/ Raman spectrometry for measuring soil gas (O2, N2, CO2, CH4 and H2O) close to the injection wells of Rousse 1 (CCS Total pilot, Lacq-Rousse, France). We also developed protocols to identify and quantify CO2, CH4, SO2, H2S in the atmosphere (plume) by passive remote sensing FTIR. On the "Monitoring" and "Modelling" aspects, the continuous recording of soil CO2 concentration during more than 7 seasonal cycles indicate that CO2 concentration in the soil was anti-correlated with changes in piezometric level of the groundwater. This correlation was used to model the limits of natural variability of CO2 content in the soil, which is a key to CCS sites monitoring. The main fluctuations in soil CO2 content was assigned to a dissolution/release process of CO2 by the perched water table, acting as a CO2 pump. The CO2 concentration at the near surface (+ 1 m) would be governed by changes of the soil CO2 content. FITR remote sensing measurement of atmospheric gases allowed for the first time to perform an experimental 3D simulation of CO2 layers on the injection site. This type of experimental simulation is a first step for the monitoring of gases in the atmosphere
Nguyen, Ba Tong. "Mesures de traces de gaz par spectroscopie d'absorption par diodes lasers accordables. Application à la surveillance de l'environnement." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20201.
The need for trace gas analysis has increased in recent years due to an important concern of the public and industry on issues such as the control of emissions of air pollutants, environmental monitoring, health and security. It is therefore necessary to have the trace gas sensors able of high selectivity, sensitivity and a direct measurement in real time. The reliability of the measurement systems is also an important criterion, depending on the intended application, the need to move towards miniaturization of microsystems for the development of portable devices for on-site operations is also interesting.This thesis is in this context and focuses on the study and development of a sensitive, efficient and simple setup to make selective, in-situ and in real time measurements of trace gases. This system is based on quartz enhanced photoacoustic spectrocopy (QEPAS) which consists on the measurement of an acoustic wave generated by the non-radiative relaxation of the excited molecules after light absorption, with a quartz tuning fork (QTF). The operation of tunable laser sources, of QTF and different spectrophone configurations (combination of the micro-resonator and QTF) used in QEPAS technique are detailed. A model of the acoustic wave and the response of the sensor are also proposed. Two devices have been designed. The first one is a QEPAS prototype bench, dedicated to the measurement of ethylene with a DFB laser diode emitting at 3.32 µm. The second device is a new version of QEPAS sensor that is more compact than the currently existing devices and where it is possible to place any type of commercial laser diode. This compact bench is used for methane measurement with a DFB laser diode emitting at 3.26 µm
Baubestre, Claude. "Surveillance biologique et environnementale du risque professionnel lié aux effluents automobiles : étude dans deux garages municipaux parisiens." Paris 5, 1990. http://www.theses.fr/1990PA05P620.
Gonzalez, Cécile. "Quantification de l'acidification de l'océan par l'analyse géochimique des coraux profonds." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112009/document.
Ocean acidification is caused by the absorption of rising atmospheric CO2 by seawater andrepresents a major environmental issue. Since the beginning of the industrial era, seawater pH hasdecreased by 0.1 pH units and is already threatening calcifying organisms. Boron isotopes (11B) haveproved to be a powerful geochemical tool for the reconstruction of pH variations, but has not yet beenapplied to deep-sea corals (DSC). Accurate and precise measurements of boron isotopes in coralsand seawaters were performed in order to measure small pH variations.The technique of pH reconstruction based on boron isotopes (pH-11B) was used on two specimens of the DSC Madrepora oculata and Lophelia pertusa collected alive in the Norwegian Sea and spanning an age of 40 (3) and 67 (3) years, respectively. Acidification rates were calculated by applying a new pH-11B calibration obtained from the geochemical analysis M. oculata and L. pertusa samples cultured under different pCO2 conditions. The contribution of a biological-related vital effect on d11B was observed at macrometer scale, and a correction was finally suggested based on oxygen and carbon isotopes. Overall, the coral δ 11B-based reconstructions show a pH decrease in the Norwegian Sea since the 1940s, which seems to be related to the local hydrodynamics. The pH-11B technique was also applied to fossil DSC fragments from two “on-mound sediment cores” retrieved in the Siculo-Tunisian Strait with the aim to reconstruct the pH during the Last Glacial Maximum and the Holocene periods. Finally, well-preserved limestone samples from the stratigraphic sequence Nama (551-543 Ma) in Namibia were investigated for 11B to study the pH variations at the beginning of the Cambrian evolutive radiation
Ben, Baccar Mohamed Ennaceur. "Modélisation géochimique de la diagénèse minérale et de ses conséquences sur la porosité des réservoirs." Strasbourg 1, 1992. http://www.theses.fr/1992STR1A004.
Helli, Omar. "Multicapteurs de gaz pour la conception d'un nez électronique de surveillance de la pollution atmosphérique : application à la detection de NO2 et H2S dans une atmosphère humide chargée de CO2." Metz, 2003. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2003/Helli.Omar.SMZ0303.pdf.
Helli, Omar Lumbreras Martine. "Multicapteurs de gaz pour la conception d'un nez électronique de surveillance de la pollution atmosphérique Application à la detection de NO2 et H2S dans une atmosphère humide chargée de CO2 /." Metz : Université Metz, 2008. ftp://ftp.scd.univ-metz.fr/pub/Theses/2003/Helli.Omar.SMZ0303.pdf.
Huneau, Frederic. "FONCTIONNEMENT HYDROGEOLOGIQUE ET ARCHIVES PALEOCLIMATIQUES D'UN AQUIFERE PROFOND MEDITERRANEEN Etude géochimique et isotopique du bassin miocène de Valréas (Sud-Est de la France)." Phd thesis, Université d'Avignon, 2000. http://tel.archives-ouvertes.fr/tel-00323650.
Ding, Yi. "Application de la chimiluminescence de flamme et du courant d’ionisation à la surveillance de l’état de combustion pour une chaudière à gaz domestique." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLC039/document.
The variations of natural gas composition call for an automatic equivalence ratio regulation system for domestic gas boilers. Two potential techniques for this purpose are investigated, i.e. the flame chemiluminescence and ionization current. Equivalence ratio indicators are inferred from the chemiluminescence signal based on the experiments. The investigation proceeds by examining effects of the flameburner heat exchange on the chemiluminescence signal. The interference of several disturbing factors for the chemiluminescence signal characterization is also analyzed. The flame ionization current is investigated on a conical flame to understand the evolution of its intensity with the probe position and flame conditions. These changes are then attributed to modifications of the distance between the flame base and the burner rim. Finally a control loop is developed to demonstrate the feasibility of equivalence ratio self-regulation with the chemiluminescence signal
Roussel, Olivier. "Interet de la surveillance simultanee non invasive de l'hemodynamique et de la pression tele-expiratoire en gaz carbonique : valeur predictive sur la qualite de la perfusion tissulaire." Lyon 1, 1991. http://www.theses.fr/1991LYO1M112.
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
Kazantsev, Alexandre. "Perturbations d'amplitude du bruit ambiant au droit des hétérogéneités : étude de faisabilité pour l'exploration et la surveillance de réservoirs multi-fluide." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEM075/document.
This PhD work investigates the possible elastic mechanisms behind the ambient noise amplification above multi-phase fluid reservoirs. Three datasets are analysed above different reservoirs. The observed spectral signature is different in the gas storage and geothermal contexts. A non-supervised algorithm for amplitude spectrum classification is developed, allowing to extract and map the relevant attributes of a multi-phase fluid presence. As a first modelling step, a wavefield characterisation methodology is applied to determine the composition of the ambient noise. It reveals the presence of strong Rayleigh overtones. Numerical 2D elastic modelling is used to simulate the propagation of overtones across a reservoir within a realistic geological structure. The modelled reservoir response is too small compared to the real data. However, the small amplitude perturbations arising in the numerical simulations are successfully inverted for the position of the reservoir, in simple background models. The developed method could in theory be used for imaging small time-lapse amplitude variations (monitoring), despite the obstacles remaining to be overcome before a real-data application. Neither visco-elastic nor 3D effects are adressed. Thus this work does not exclude the possibility of strong reservoir-specific spectral anomalies
Kazantsev, Alexandre. "Perturbations d'amplitude du bruit ambiant au droit des hétérogéneités : étude de faisabilité pour l'exploration et la surveillance de réservoirs multi-fluide." Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEM075.
This PhD work investigates the possible elastic mechanisms behind the ambient noise amplification above multi-phase fluid reservoirs. Three datasets are analysed above different reservoirs. The observed spectral signature is different in the gas storage and geothermal contexts. A non-supervised algorithm for amplitude spectrum classification is developed, allowing to extract and map the relevant attributes of a multi-phase fluid presence. As a first modelling step, a wavefield characterisation methodology is applied to determine the composition of the ambient noise. It reveals the presence of strong Rayleigh overtones. Numerical 2D elastic modelling is used to simulate the propagation of overtones across a reservoir within a realistic geological structure. The modelled reservoir response is too small compared to the real data. However, the small amplitude perturbations arising in the numerical simulations are successfully inverted for the position of the reservoir, in simple background models. The developed method could in theory be used for imaging small time-lapse amplitude variations (monitoring), despite the obstacles remaining to be overcome before a real-data application. Neither visco-elastic nor 3D effects are adressed. Thus this work does not exclude the possibility of strong reservoir-specific spectral anomalies
Ambrosi, Philippe. "Amplitude et calendrier des politiques de réduction des émissions face aux risques climatiques : leçon des modèles intégrés." Paris, EHESS, 2004. http://www.theses.fr/2004EHES0106.
To date, climate change damages estimates are far from being reliable and non controversial. Therefor, this thesis compares - trough a family of optimal control integrated assessment models, RESPONSE - which CO2 mitigation policies are recommended for three more and more tangible proxies of climate risks : a set of constraints regarding magnitude and rate of global warming, a preference for current climate regime and an explicit modelling of climate change damages. Given the cascade of uncertainties from emissions to damages, results suggest to anticipate emissions reductions because abatements further delayed may induce significant regret in case of bad news about climate response or singularities in damages. Results also demonstrate that the eventuality of non-catastrophic threshods in damages is sufficient to increase earlier optimal abatements
Szenasi, Barbara. "Atmospheric monitoring of the CH4 emissions at the European scale." Electronic Thesis or Diss., université Paris-Saclay, 2020. http://www.theses.fr/2020UPASJ006.
Atmospheric mixing ratios of greenhouse gases have rapidly increased since the industrial revolution, mainly due to anthropogenic activities. Studies in the past decades have primarily targeted carbon dioxide (CO2), being the largest contributor to the global radiative forcing growth. Recently, the second largest contributor, methane (CH4), has received increasing scientific attention as it has a large mitigation potential. Due to its relatively short life-time of 8-10 years, mitigation efforts can be effective within relatively short time ranges. However, current estimates of CH4 emissions at both the global and regional scales are highly uncertain. This thesis aims at improving our understanding of CH4 emissions at the European scale by addressing various sources of uncertainties.This thesis presents the potential of emission uncertainty reduction by top-down atmospheric inversions of methane emissions. Emissions estimated by top-down approaches depend on the performance of chemistry-transport models (CTMs) and the precision of measurements. The potential of top-down approaches in our framework of CH4 emissions in Europe is explored by three studies, each focusing on different sources of uncertainties that must be specified in atmospheric inversions.In the first study, we focus on the performance of the chosen CTM by assessing errors in transport modelling and emissions used as input in the CTM. The second study targets other possible causes for misfits between measured and simulated atmospheric CH4 mixing ratios, as well as isotopic ratios δ13C and δ2H. Among others, we analyse whether misfits can be associated with isotopic source signatures or emissions used together as input in the transport model. This work demonstrates that information gained from isotopic measurements, in addition to measurements of CH4 mixing ratios, can be valuable for evaluating emission inventories and estimating emissions by atmospheric inversions.The potential of δ13C and δ2H measurements in atmospheric inversions is investigated by determining the instrument precision needed to detect signals of δ13C and δ2H from various CH4 sources. This is examined at the location of monitoring sites in the Integrated Carbon Observation System (ICOS) network. Our results indicate high precision requirements on instruments measuring δ13C and δ2H. However, they reveal that isotopic information, on top of mixing ratios, could improve discrimination of CH4 sources when implemented in atmospheric inversions of CH4 emissions. The work in this thesis offers insights into how inversion frameworks could be configured and what are the essentials to reliably estimate CH4 emissions at the European scale
Noel, Cécile. "Suivi de la biodégradation des hydrocarbures par le couplage des mesures géophysiques électriques du sol (polarisation provoquée) et des analyses des gaz (concentration du CO 2 et isotopie du carbone)." Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE2041/document.
Stimulated biodegradation is a depollution technique used to degrade hydrocarbons. Its monitoring is currently done thanks to very few expensive wells. This PhD research work proposes to improve bioremediation monitoring by combining geophysical electrical methods (induced polarization) and CO2 analyses (surface emissions and carbon isotopic ratio). These tools were tested at laboratory scale and then implemented on a pilot site under decontamination. Aerobic degradation of toluene in columns by a known bacterial strain (Rhodococcus wratislaviensis) was characterized by CO2 production, carbon isotopic fractionation and by an evolution of electrical complex resistivity of porous media, in correlation with microbiological and geochemical analyses. These results allowed to implement a monitoring at the site scale. The site is a gas station where gasoline and diesel leaked fifteen years ago. A trench supply oxygen to the water table in order to stimulate aerobic bacterial processes. Geophysical campaigns and CO2 analyses have been carried out since February 2014. The first results show a more conductive and chargeable area which corresponds to the contaminated zone defined by geochemical analyses in wells. Moreover in this area CO2 emissions have been measured with an isotopic signature typical of hydrocarbon biodegradation. These results show the interest of combining geophysical methods with gas analyses to monitor biodegradation and they have already allowed to provide a non-destructive and new methodology for in situ monitoring
Carette, Michel. "Etude expérimentale d'une source ionique par capture d'électrons d'atomes excités dans des états de Rydberg : application à la spectrométrie de masse de polluants atmosphériques." Aix-Marseille 1, 1999. http://www.theses.fr/1999AIX11065.
Tabau, Anne-Sophie. "Les interactions des contrôles international et communautaire de la mise en oeuvre du Protocole de Kyoto." Aix-Marseille 3, 2009. http://www.theses.fr/2009AIX32071.
The universality of climate change challenges and interdependance in the reduction of greenhouse gas (GHG) emissions called for a collective response in a multilateral framework. However, because of discrepancies on the appropriate desin for an international regime the European Community (EC) took the lead on the international stage in the negotiation and the application of the Kyoto Protocol. Thus, an international regime - a mixed agreement to which both the EC and its Member States are parties- and a regional regime in the framework of the European Union coexist. In both regimes, one of the core challenges remains to ensure the effective application of the law, which requires the set up of compliance control mechanisms. At the international level, an innovative observance procedure organizes a continuous monitoring which combines traditional techniques with more intrusive procedures. The system is also remarkable as regards the legal qualification of and reaction to non-compliance situations. For its part, the EC created a specific non-contentious mechanism and can make us of a reinforced jurisdictional armory and a reinforced sanctioning power. The EC's control mechanism should be able to take over the observance mechanism in order to reinforce the effectiveness of adopted rules. Through the study of these mechanism's interactions, this research aims at assessing the capacity of the control system as a whole to ensure the very credibility of the Protocol and the reliability of the international and European economic tools to reduce GHG emissions at least cost. Finally, the study allows envisaging the possible evolutions of the legal regime of the fight against climate change
Blottin, Benoît. "Le rôle des autorités de concurrence et des autorités de régulation sectorielle dans la surveillance de la libéralisation des marchés de l'énergie." Thesis, Paris 2, 2015. http://www.theses.fr/2015PA020085.
The opening to competition of the markets in gas and electricity has hardly produced the desired impact. To a large extent, the directives flowing from the third package have been transposed amongst the Member States. However, the effective implementation of a European energy is still facing several challenges ahead. With this nebulous background, supervision has become all-seeing, Argus-like. In fact, while competitions authorities and sectoral regulators are significantly stepping up theirs efforts so as to push forward the liberalization process towards the swift completion of the internal energy market, they seem, at times, to work against the grain of their original assignment. On the one hand, competition authorities appear to be increasingly willing to act as « builders » for the energy markets as they tackle market structures rather than harmful behaviours. Conversely, sectoral regulators, with their ever-strengthening powers, are more and more incited to track down and take sanctions against barriers to competition. Such bicephalous management has resulted in a confusion of roles which has not been alleviated by the « bridges »built between both types of regulators. At any rate, in the face of such a tangled web of competences, operators find themselves in markets that are not very conducive to competition and in a regulatory framework which is both volatile and complex, thereby paralysing the investments required to render such markets more dynamic. The system as it stands may still be improved and many would like to see it clarified. Although the prospect is not very realistic, some commentators have called for the merger of authorities. It appears nonetheless that reworking the supervision framework with a view to strengthening inter-regulation but also implementing actual European regulations is a route that has not yet been sufficiently explored
Rhino, Kévins. "Caractérisation, quantification et modélisation des processus de transfert et des interactions CO₂-eau-roche en milieu poreux non saturé en contexte de forage lors d'un stockage géologique." Thesis, Bordeaux 3, 2017. http://www.theses.fr/2017BOR30040/document.
Carbon storage is one of the most encouraging methods to decrease CO₂ concentration into the atmosphere. Carbon storage provides the longevity and the capacity needed to decrease CO₂ emissions toward the atmosphere. When dealing with storage on an industrial scale, carbonated reservoirs can be among the most suitable storage sites. However, these high depth injections are subject to leakage risks from the geologic trap itself or from the framework created by the establishment of the site. Two main types of leakage exist: brutal and diffusive leakage. In both cases, they are likely to endanger the environment and the population. Therefore, it is essential to develop tools that are able to anticipate any types of CO₂ leakage. Furthermore, it is also necessary to understand the reactive transport mechanism that take place when the leakage arrives in the shallow subsurface (vadose zone)and to see how the leakage can be buffered. This work deals with the characterization, the quantification and the modelling of transfer processes and CO₂-H₂O-CaCO₃ interactions into the vadose zone in a context of a leakage from a drilling well. This issue was first dealt through field experiment on the site of Saint Emilion. Then, the CO₂-H₂O-CaCO₃ interactions were studied through an experimental approach in laboratory. Two leakage experiments were performed on the site: a diffusive leakage and an ultra-diffusive leakage. They were performed as a sequel of former experiments carried on the pilot site. A comparison of all the leakage experiments revealed the necessity to use noble gases as precursor of the CO₂ arrival at the surface. Depending of the type of the leakage, helium can be a temporal precursor while krypton can anticipate the spread of the CO₂ gas plume. The higher the injection pressure, the more the gas migrates through advective flux. Moreover, a high injection pressure favors the existence of preferential paths in the vadose zone. The use of helium and carbon isotopes makes it possible to reveal the presence of a local aqueous phase within the porous media and to identify the origin of CO₂. The core scale experiments lead to the estimation of the buffering power of Oligocene limestone according to the rock facies. The permeability and the porosity influence the dissolution of the limestone. The reactivity of carbonates during a leakage depends on the pH of the aqueous phase, the flow rate that goes through the porous media, the water saturation and petrophysical characteristics of the carbonates
Lin, Xin. "Variabilité des concentrations atmosphériques de gaz à effet de serre et inversion des flux de méthane en Asie du Sud et de l’Est." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV076.
South and East Asia (SEA) is the world’s largest anthropogenic greenhouse gas (GHG) emitting region during the recent decades, yet estimates of regional GHG budgets remain uncertain either from bottom-up or top-down approaches. The aim of the thesis is to improve understanding of GHG budgets in SEA through atmospheric measurements from surface stations and regional inverse modeling. The first part of the thesis presents measurements of CO2, CH4, N2O, SF6, CO, and H2 from regular flask sampling at Hanle, Pondicherry and Port Blair, three new Indian stations established in the framework of the Indo-French collaboration. Time series of tracer concentrations are analyzed and related to variations in natural/anthropogenic fluxes and monsoon circulations in the Indian sub-continent, showing potential of these stations to constrain estimates of regional GHG fluxes. The second part of the study involves simulation of CO2 and CH4 using a zoomed version of the global chemistry transport model LMDzINCA, with a horizontal resolution of ~50km over SEA. Model performance is evaluated against observations from 30 surface stations in SEA and adjacent regions. The zoomed transport model shows the ability to reasonably reproduce CO2 and CH4 variabilities at stations, and improves model performance for CH4 compared to the standard model version within the zoomed region. Lastly, the CH4 emissions in SEA are retrieved for the year 2010 using atmospheric surface stations and a Bayesian inversion system PYVAR-LMDz-SACS with the zoomed model grids. Different setups of prior information are used in inversions to account for uncertainties in bottom-up inventories of anthropogenic emissions. Significant reduction in emissions compared to the prior estimates is found for East Asia (by 14–20%), particularly in North China (by 20–35%). The inverted CH4 budgets are sensitive to prior anthropogenic emissions in East Asia, especially in North China where coal mine hotspots dominate the budgets yet their representation is highly uncertain among different inventories
Caracausi, Antonio. "Noble gases as geochemical tracers of Earth's dynamic and evolution." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0339.
In my project, I used the nobles gases (He, Ne, Ar, Kr and Xe) to investigate natural processes occurring in different geodynamical contexts (i.e., subduction, continental collision, rifting), showing how the use of the noble gases is fundamental to constrain the origin of volatiles, and to investigate the Earth interior. Furthermore, I also used these volatiles to recognize the processes (water-gas-rock interaction) that occur during the fluids up rise from the Earth’s interior to the atmosphere and quantitatively constrain the extents of these processes. The results of my project are summarized in five main topics: 1) Insights into the degassing history of Earth’s mantle from high precision noble gas analysis of magmatic gas 2) Noble Gas and Carbon Isotope Systematics at the Seemingly Inactive Ciomadul Volcano (Romania): Evidence for Volcanic Degassing 3) Mantle‐Derived Fluids in the East Java Sedimentary Basin, Indonesia 4) Outgassing of Mantle Volatiles in Compressional Tectonic Regime Away From Volcanism: The Role of Continental Delamination 5) Continental degassing of helium in an active tectonic setting (northern Italy): the role of seismicity
Gaidi, Mounir. "Films minces de SnO2 dopés au platine ou au palladium et utilisés pour la détection des gaz polluants : analyses in-situ des corrélations entre la réponse électrique et le comportement des agrégats métalliques." Grenoble INPG, 1999. http://www.theses.fr/1999INPG0095.
We have analyzed the role played in the sensing processes, by Pt and Pd metallic aggregates dispersed in SnO2 thin films used for the detection of various reducing gases such as CO, H2S or NOx. X-ray Absorption Spectroscopy (XAS) analysis has allowed us to follow in situ the evolution of the oxidation state of platinum aggregates. When they are incorporated in a very weak quantity, platinum particles change in a reversible manner, their oxidation state, according to the nature of the atmosphere. The oxidation state of particles depend strongly on their size (0,5 - 4,5 nm): under CO the smallest ones change from fully oxidized to a reduced state where Pt -O bondings have been removed and replaced by Pt-C. From the analysis of the electrical conductance evolution under controlled atmosphere, it has been possible to correlate the electrical reply under CO with the platinum reduction rate. An electronic interaction metal-SnO2 is shown to be at the origin of the conductance peak observed at low temperature. A comparative study of the electrical replies between SnO2 thin films doped with Pt or Pd, in the presence of CO, H2 and H2S, has allowed us to propose a model describing the mechanisms of the detection process involved in each case
Lin, Xin. "Variabilité des concentrations atmosphériques de gaz à effet de serre et inversion des flux de méthane en Asie du Sud et de l’Est." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV076.
South and East Asia (SEA) is the world’s largest anthropogenic greenhouse gas (GHG) emitting region during the recent decades, yet estimates of regional GHG budgets remain uncertain either from bottom-up or top-down approaches. The aim of the thesis is to improve understanding of GHG budgets in SEA through atmospheric measurements from surface stations and regional inverse modeling. The first part of the thesis presents measurements of CO2, CH4, N2O, SF6, CO, and H2 from regular flask sampling at Hanle, Pondicherry and Port Blair, three new Indian stations established in the framework of the Indo-French collaboration. Time series of tracer concentrations are analyzed and related to variations in natural/anthropogenic fluxes and monsoon circulations in the Indian sub-continent, showing potential of these stations to constrain estimates of regional GHG fluxes. The second part of the study involves simulation of CO2 and CH4 using a zoomed version of the global chemistry transport model LMDzINCA, with a horizontal resolution of ~50km over SEA. Model performance is evaluated against observations from 30 surface stations in SEA and adjacent regions. The zoomed transport model shows the ability to reasonably reproduce CO2 and CH4 variabilities at stations, and improves model performance for CH4 compared to the standard model version within the zoomed region. Lastly, the CH4 emissions in SEA are retrieved for the year 2010 using atmospheric surface stations and a Bayesian inversion system PYVAR-LMDz-SACS with the zoomed model grids. Different setups of prior information are used in inversions to account for uncertainties in bottom-up inventories of anthropogenic emissions. Significant reduction in emissions compared to the prior estimates is found for East Asia (by 14–20%), particularly in North China (by 20–35%). The inverted CH4 budgets are sensitive to prior anthropogenic emissions in East Asia, especially in North China where coal mine hotspots dominate the budgets yet their representation is highly uncertain among different inventories
Wang, Yilong. "The potential of observations of radiocarbon in atmospheric CO2 for the atmospheric inversion of fossil fuel CO2 emission at regional scale." Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV113.
Climate change has prompted nations, provinces, and cities to take actions to reduce anthropogenic sources of CO2 and other greenhouse gases. Accurate and consistent quantification of the emissions is required for both scientists and policymakers. Inventories of the CO2 emissions due to fossil fuel combustion are based on statistical data collected and reported by the emitters themselves and their quality is highly variable between countries. In principle, atmospheric measurements and inverse modeling could provide independent information to verify and evaluate these emissions. However, there are difficulties to separate the fossil fuel CO2 signal (FFCO2) from the signal of natural CO2 fluxes, in the atmospheric CO2 measurements from ground based continental networks. In this thesis, I aimed to improve the understanding of the potential of atmospheric 14CO2 measurements, one of the few tracers helping to separate FFCO2 from the signal of other CO2 sources, for the objective estimate of the fossil fuel emissions at national or provincial scales based on atmospheric inversion.I developed global inversion systems based on the global coarse-resolution (2.5°×3.75°) LMDZ atmospheric transport model, and on continental networks of atmospheric observations of CO2 and 14CO2, solving for the fossil fuel emissions at sub-continental / monthly scales in Europe and in China.In Chapter 2, I defined and quantified critical sources of modeling errors and their impact on the inversion of large-scale budget of the fossil fuel emissions when using a global inversion system and assuming FFCO2 data can be directly derived from 14CO2 measurements. The analysis highlighted the impact of ignoring the spatial distribution of the emissions and FFCO2 at a resolution higher than that of the transport model.In Chapter 3, I applied inversions with the system, assumptions and diagnostics of the modeling error from Chapter 2 in a series of Observing System Simulation Experiments to evaluate the skill of such an inversion system and of different virtual observation networks for estimating regional budgets of fossil fuel emissions in Europe. Results indicate that if assimilating continuous 2-week mean FFCO2 data from 17 existing 14CO2 European sites, the inversion would reduce the uncertainties in monthly fossil fuel emissions of western Germany by 30% compared to the assumed uncertainty in the inventories used as a prior knowledge in the Bayesian framework of the inversion. Using a larger network of 43 European sites that may be available in the future, up to 47% uncertainty reduction could be achieved for annual budgets of fossil fuel emissions for regions where the network would be the densest.In Chapter 4, I implemented a global isotopic inversion system that jointly assimilates atmospheric observations of CO2 and 14CO2 to simultaneously solve for fossil fuel emissions and natural CO2 fluxes over Europe and China. The purpose is to move beyond the assumption that variations in 14CO2 relate only to FFCO2 by accounting for non-fossil 14CO2 fluxes. The results confirm that 14CO2 data are useful to separate FFCO2 from the signal of natural fluxes at sites close to large emission regions, making 2-week mean 14CO2 data more efficient than daily CO2 data for estimating the emissions
Colin, Aurélia. "Contraintes sur les processus de dégazage des dorsales océaniques par la géochimie des volatils et la pétrologie des laves basaltiques." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL083N/document.
The composition of mantle volatiles is related to the origin of Earth's volatiles and to the past and present volatile fluxes to the atmosphere. Although this reservoir is naturally sampled during volcanic eruptions, most of the volatiles are lost to the atmosphere during this event, thus the composition of mantle volatiles is still uncertain. We try here to precise the processes of degassing below mid-oceanic ridges to correct the lava compositions for degassing.The He-Ne-Ar-CO2 analyses of basaltic glasses sampled along the Galapagos Spreading Center, in the area of influence of the Galapagos hotspot, show that the volatile composition of lavas is fully explained by a Rayleigh distillation of a unique source distinct from the plume source. These results imply that the plume degasses at depth or is heterogeneous.Several volcanic glasses from Mid-Atlantic ridge and East Pacific Rise have been imaged by X-rays microtomography. The mechanisms of vesicle nucleation and growth appear to be different below the two ridges. A step of convection at the magma body margin has been evidenced by the petrologic study of the glasses. Imaged vesicles have been subsequently opened under vacuum by laser ablation and analysed (CO2, 4He, argon isotopes). We observe, depending on the samples, either a single composition for all bubbles, or variations in composition between bubbles consistent with a trend of equilibrium degassing in an open system. The trends of degassing allow extrapolating locally to the volatile composition of the mantle source, which is heterogeneous. We also studied the heterogeneity of 40Ar/36Ar ratios in magmatic chambers using the laser opening method, which lowers the contribution of atmospheric gases compared to the classical crushing method
Wang, Yilong. "The potential of observations of radiocarbon in atmospheric CO2 for the atmospheric inversion of fossil fuel CO2 emission at regional scale." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV113/document.
Climate change has prompted nations, provinces, and cities to take actions to reduce anthropogenic sources of CO2 and other greenhouse gases. Accurate and consistent quantification of the emissions is required for both scientists and policymakers. Inventories of the CO2 emissions due to fossil fuel combustion are based on statistical data collected and reported by the emitters themselves and their quality is highly variable between countries. In principle, atmospheric measurements and inverse modeling could provide independent information to verify and evaluate these emissions. However, there are difficulties to separate the fossil fuel CO2 signal (FFCO2) from the signal of natural CO2 fluxes, in the atmospheric CO2 measurements from ground based continental networks. In this thesis, I aimed to improve the understanding of the potential of atmospheric 14CO2 measurements, one of the few tracers helping to separate FFCO2 from the signal of other CO2 sources, for the objective estimate of the fossil fuel emissions at national or provincial scales based on atmospheric inversion.I developed global inversion systems based on the global coarse-resolution (2.5°×3.75°) LMDZ atmospheric transport model, and on continental networks of atmospheric observations of CO2 and 14CO2, solving for the fossil fuel emissions at sub-continental / monthly scales in Europe and in China.In Chapter 2, I defined and quantified critical sources of modeling errors and their impact on the inversion of large-scale budget of the fossil fuel emissions when using a global inversion system and assuming FFCO2 data can be directly derived from 14CO2 measurements. The analysis highlighted the impact of ignoring the spatial distribution of the emissions and FFCO2 at a resolution higher than that of the transport model.In Chapter 3, I applied inversions with the system, assumptions and diagnostics of the modeling error from Chapter 2 in a series of Observing System Simulation Experiments to evaluate the skill of such an inversion system and of different virtual observation networks for estimating regional budgets of fossil fuel emissions in Europe. Results indicate that if assimilating continuous 2-week mean FFCO2 data from 17 existing 14CO2 European sites, the inversion would reduce the uncertainties in monthly fossil fuel emissions of western Germany by 30% compared to the assumed uncertainty in the inventories used as a prior knowledge in the Bayesian framework of the inversion. Using a larger network of 43 European sites that may be available in the future, up to 47% uncertainty reduction could be achieved for annual budgets of fossil fuel emissions for regions where the network would be the densest.In Chapter 4, I implemented a global isotopic inversion system that jointly assimilates atmospheric observations of CO2 and 14CO2 to simultaneously solve for fossil fuel emissions and natural CO2 fluxes over Europe and China. The purpose is to move beyond the assumption that variations in 14CO2 relate only to FFCO2 by accounting for non-fossil 14CO2 fluxes. The results confirm that 14CO2 data are useful to separate FFCO2 from the signal of natural fluxes at sites close to large emission regions, making 2-week mean 14CO2 data more efficient than daily CO2 data for estimating the emissions
Humez, Pauline. "Traçage des intrusions de CO2 dans les aquifères d'eau douce par les méthodes multi-isotopiques." Electronic Thesis or Diss., Paris, ENMP, 2012. http://www.theses.fr/2012ENMP0049.
This study deals with the impact of CO2 leakages out of geological storage into overlying freshwater aquifers. Compared to other existing studies, the major added value of this study lies, on the one hand, in the research of new monitoring tools and isotopic approach in the context of CCS aiming at early and sensitive detection of CO2 leakage and, on the other hand, in the application of these tools at the (limited) laboratory scale as well as at field scale. In order to test these tools, solid and liquid materials were sampled out of the major strategic drinking water Albian aquifer in the Paris Basin (France). We have then precisely characterized and used them within a batch experiment. This experiment yields interesting results which help understanding and constraining precisely the water-rock-CO2 interactions as well as the isotopic responses. A real scale application of the method was then performed in Norway. It was an opportunity to develop this isotopic program and to track the isotopic evolution composition, while differentiating the natural processes and the system response tothe CO2 injection. When applied to the detection of CO2 leakage context, the two case studies open the way for choosing the “best” isotopic tools as indirect indicators of CO2 presence in these specific systems. The efficiency of these isotopic tools comes from the recording of the CO2 footprint all along the water-rock-CO2 interactions. Using such tools imposes a rigorous methodology, which is tackled inthis manuscript. Furthermore, future application will require adapting to the specifics of a proposed site
Gouhier, Mathieu. "Application du radar Doppler (VOLDORAD) à l'étude de la dynamique des éruptions Stromboliennes de l'Etna." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2008. http://tel.archives-ouvertes.fr/tel-00731252.
Humez, Pauline. "Traçage des intrusions de CO2 dans les aquifères d'eau douce par les méthodes multi-isotopiques." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2012. http://pastel.archives-ouvertes.fr/pastel-00797525.
Brisville, Anne-Claire. "Évaluation, surveillance et soutien de la fonction respiratoire chez des veaux clonés en période néonatale." Thèse, 2010. http://hdl.handle.net/1866/5287.
High morbidity and mortality decrease the efficiency of somatic cell nuclear transfer. The main abnormalities observed in neonatal cloned calves are skeletal malformations, enlarged umbilical vessels, respiratory problems and weakness. This retrospective study involved 31 cloned calves. The objectives of this study were to describe the respiratory problems suffered by cloned calves during neonatal period, to assess their evolution, and to determine the possible causes. Secondary objectives were to describe the techniques used to assess and support respiratory function and the calves’ response. Respiratory problems affected 22 calves. Tachypnea, hypoxemia and hypercapnia were the most frequently observed signs. Arterial blood gas analyses and chest radiographs were precious to identify and assess respiratory problems. Intranasal oxygen and mechanical ventilation were efficient to limit mortality due to respiratory failure to 18% (4/22). It is plausible that more than one disease affect cloned calves. Delayed resorption of pulmonary fluid, persistent pulmonary hypertension and surfactant deficiency, or a combination of these factors, are among the most probable pathological entities.