La connaissance de la source et du transport atmosphérique de l’aérosol marin est primordiale pour mieux comprendre un grand nombre de processus physico-chimiques régissant les propriétés de la basse troposphère. C’est dans ce cadre que s’inscrit cette thèse dont l’objectif principal concerne la modélisation de la génération et du transport des aérosols marins en zone côtière Méditerranéenne. Cette étude a permis notamment l’amélioration du modèle de transport MACMod à partir d’un travail sur les conditions aux surfaces frontières. Une formulation de la fonction source spécifique à la région méditerranéenne nord-occidentale a été déterminée et certains effets des transformations subies par les particules issues de la production primaire au cours de leur transport atmosphérique ont été analysés. De plus, dans le but de mieux tenir compte du cas des zones anthropisées pour les conditions aux limites du modèle, un travail sur l’implémentation du code CHIMERE sur la région méditerranéenne a été initialisé. Enfin, une dernière partie a été consacrée à l’adaptation du modèle MACMod à la prévision de la qualité de l’air et le suivi des concentrations de PM2.5 et PM10. / The knowledge of both the source and atmospheric transport of marine aerosols is needed for a better understanding of a large number of physicochemical processes that control the lower troposphere properties. In this context, the present work deals with the modelization of the generation and atmospheric transport of marine aerosols in the Mediterranean coastal zone. In particular, this study allowed improvement of the aerosol transport model MACMod on the basis of a specific work on the boundary conditions. A new formulation of the sea-spray source function has been determined for the northern Mediterranean and effects of the transformations of the sea-spray particles during their atmospheric transport were identified. In addition, to better take into account the influence of the anthropogenic zones for the boundary conditions, the implementation of the CHIMERE model on the study area was made. Finally, a last part of the thesis was dedicated to the use of the MACMod model for the air quality forecasting and the survey of the PM2.5 and PM10 concentrations.

Guided wave techniques have great potential for the structural health monitoring of plate-like components. Previous research has demonstrated the effectiveness of combining laser-ultrasonic techniques with time-frequency representations to experimentally develop the dispersion relationship of a plate; the high fidelity, broad bandwidth and point-like nature of laser ultrasonics are critical for the success of these results. Unfortunately, laser ultrasonic techniques are time and cost intensive, and are impractical for many in-service applications. Therefore this research develops a complementary digital signal processing methodology that uses mounted piezoelectric elements instead of optical devices. This study first characterizes the spatial and temporal effects of oil coupled and glued piezoelectric sources, and then develops a procedure to interpret and model the distortion caused by their limited bandwidth and finite size. Furthermore, it outlines any inherent difficulties for time and frequency domain considerations. The deconvolution theory for source function extraction in the time - and frequency domain under the presence of noise is provided and applied to measured data. These considerations give the background for further studies to develop a dispersion relationship of a plate with the fidelity and bandwidth similar to results possible with laser ultrasonics, but made using mounted piezoelectric sources.

This dissertation is composed of three parts of major contributions. In Chapter II, we discuss analytical study of contaminant transport from a finite source in a finite-thickness aquifer. This chapter provides analytical solutions of contaminant transport from one-, two-, and three-dimensional finite sources in a finite-thickness aquifer using Green's function method. A library of unpublished analytical solutions with different finite source geometry is provided. A graphically integrated software CTINT is developed to calculate the temporal integrations in the analytical solutions and obtain the final solutions of concentration. In Chapter III, we obtained solutions of groundwater flow to a finite-diameter horizontal well including wellbore storage and skin effect in a three-dimensionally anisotropic leaky aquifer. These solutions improve previous line source solutions by considering realistic well geometry and offer better description of drawdown near the horizontal well. These solutions are derived on the basis of the separation of the source and the geometric functions. The graphically integrated computer program FINHOW is written to generate type curves of groundwater flow to a finite-diameter horizontal well. The influence of the finite-diameter of the well, the wellbore storage, the skin effect, the leakage parameter, and the aquifer anisotropy is thoroughly analyzed. In Chapter IV, a general theory of groundwater flow to a fractured or non-fractured aquifer considering wellbore storage and skin effect is provided. Solutions for both leaky confined and water table aquifers are provided. The fracture model used in this study is the standard double-porosity model. The storage of the aquitard (the leaky confining layer) is included in the formula. A program denoted FINHOW2 is written to facilitate the calculation. Sensitivity of the solution to the confined versus unconfined conditions, fractured versus non-fractured conditions, and wellbore storage and skin effects is analyzed.

Il y a près d’une décennie, l'utilisation des supernovae de type Ia comme indicateurs de distances a permis de découvrir l'expansion accélérée de l'univers. Les expériences de seconde génération ont augmenté de manière significative la taille et la qualité des échantillons à grand décalage vers le rouge. Cependant, l'échantillon de référence des supernovae à faible décalage vers le rouge, nécessaire à la cosmologie restait très restreint. The Nearby Supernova Factory a mesuré, à l'aide d'un instrument spectro-photométrique dédié (the Supernova Integral Field Sepctrograph), près de 200 nouvelles supernovae de type Ia. Ma thèse de doctorat a été effectuée à l'Institut de Physique Nucléaire de Lyon et au Lawrence Berkeley National Laboratory dans le cadre du projet international the Nearby Supernova Factory et a pour but l'étalonnage spectro-photométrique du spectrographe à champ intégral. Afin d'atteindre la précision souhaitée, une attention particulière a été apportée à plusieurs aspects majeurs de la procédure d'étalonnage, incluant: la détermination de la réponse impulsionnelle de l'instrument en vue de l'extraction 3D de sources ponctuelles, l'estimation de la qualité photométrique d'une nuit, l'obtention de l'extinction atmosphérique par nuit sur un domaine de longueur d'onde étendu, sa modélisation en terme de composantes physiques et sa variabilité au cours d'une nuit donnée. Une chaîne d'étalonnage multi-standard a été mis en \oe{}uvre utilisant approximativement 4000 observations spectro-photométriques d'étoiles standards. J'exposerai également à la fin de ce manuscrit les résultats scientifiques préliminaires de la collaboration SNfactory. / Ten years ago, type Ia supernovae used as distances indicators led to the discovery of the accelerating expansion of the universe. Today, a second generation of surveys has significantly increased the high-redshift type Ia supernovae sample. The low-redshift sample was however still limiting the cosmological analysis using SNe. In this framework, the Nearby Supernova Factory has followed 200 nearby type Ia supernovae using the dedicated Supernovae Integral Field Spectrograph with spectro-photometric capacities. My PhD thesis has been carried out at the Institut de Physique Nucléaire de Lyon and at the Lawrence Berkeley National Laboratoryin the framework of the international cosmological project SNfactory. In order to reach the design spectrophotometric accuracy, attention has been focused on several key aspects of the calibration procedure, including: determination of a dedicated point spread function for 3D point source extraction, estimating the nightly photometric quality, derivation of the nightly sky extinction over the extended optical domain, its modeling in terms of physical components and its variability within a given night. A full multi-standards calibration pipeline has been implemented using approximately 4000 observations of spectrophotometric standard stars taken throughout the night over nearly 500 individual nights. Preliminary scientific results of the whole SNfactory collaboration will be presented at the end of this thesis.