ED Mathématiques et Informatique
Variable-density Euler equations and ocean dynamics
by Théo FRADIN (IMB - Institut de Mathématiques de Bordeaux)
The defense will take place at 14h00 - Salle de conférence Institut de Mathématiques de Bordeaux UMR 5251 Université de Bordeaux 351, Cours de la Libération F-33405 TALENCE
in front of the jury composed of
- David LANNES - Directeur de recherche - Université de Bordeaux - Directeur de these
- Frédéric ROUSSET - Professeur des universités - Université de Paris-Saclay - Rapporteur
- Pascal NOBLE - Professeur des universités - INSA Toulouse - Rapporteur
- David GéRARD-VARET - Professeur des universités - Université Paris-Cité - Examinateur
- Marius PAICU - Professeur des universités - Université de Bordeaux - Examinateur
- Christophe LACAVE - Chaire de professeur junior - Université Savoie Mont Blanc - Examinateur
- Anne-Laure DALIBARD - Professeure des universités - Sorbonne Université - Examinateur
- Vincent DUCHêNE - Chargé de recherche - Université de Rennes - CoDirecteur de these
The various works presented in this thesis study mathematical models describing the dynamics of an idealized ocean. The main objective is to study the influence of the interplay between density variations, bottom topography and the free surface on this dynamics. We consider that this dynamics is described by the Euler equations, for which we look for regular solutions. It is expected that these solutions are defined on a finite time interval, and the main question, for which the different results gathered in the present thesis offer partial answers, is the dependency of the size of this interval with respect to physically relevant parameters. A first result proves that small density variations are compatible with the hydrostatic limit. A second considers large density variations, in the continuously stratified case, i.e. where the density is a decreasing function of height. This last assumption is usual in the study of geophysical flows, and we compare it in a theoretical and numerical study, with the rougher approximation of a two-layer flow.
ED Entreprise Economie Société
No Minor Threat: Emotions, Behaviour, and Economic Outcomes
by Niclas KNECHT (BSE - Bordeaux sciences économiques)
The defense will take place at 15h00 - Salle des Thèses 16 Av. Léon Duguit, 33600 Pessac
in front of the jury composed of
- Olivier BARGAIN - Professeur des universités - Université de Bordeaux - Directeur de these
- Jérôme WITTWER - Professeur des universités - Université de Bordeaux - CoDirecteur de these
- José DE SOUSA - Professeur des universités - Université Paris-Panthéon-Assas - Rapporteur
- Angela SUTAN - Professeure des universités - ESSEC Business School France - Examinateur
- Daniel MIRZA - Professeur des universités - Université de Tours - Rapporteur
This dissertation explores how exposure to threats—terrorism, natural disasters, and conflict—shapes critical socio-economic attitudes and political behavior. It aims to provide new insights into the malleability of social cohesion and democratic stability in response to short-term shocks. This thesis is organized into three chapters. The first chapter employs synthetic control methods to quantify the causal impact of terrorist attacks on international tourism, revealing persistent declines. The second chapter investigates the short-term plasticity of trust and hope through an online experiment, demonstrating that even brief exposure to threatening videos significantly reduces these attitudes, with heterogeneous effects by political orientation and social media usage. Finally, the third chapter combines a randomized video experiment in France with a German panel event study to examine how terrorist threats influence voting behavior, showing consistent increases in right-wing voting intentions and revealing systemic democratic vulnerabilities during electoral campaigns.
ED Sciences Physiques et de l'Ingénieur
Voltage reference in CMOS technology desensitized to the dose rate in a harsh radiation environment for the dismantling of nuclear power plants
by Maxime GUILLOT (Laboratoire de l'Intégration du Matériau au Système)
The defense will take place at 10h00 - Amphi J.P.DOM A0.85 Laboratoire de l'Intégration du Matériau au Système - Bat A31 351 Cours de la Libération, 33405 Talence Cedex, France
in front of the jury composed of
- Yann DEVAL - Professeur des universités - University of Bordeaux, CNRS, Bordeaux INP, IMS, UMR5218, F-33400 Talence, France - Directeur de these
- Véronique FERLET-CAVROIS - Chargée de recherche - European Space Agency - Rapporteur
- Stéphane BILA - Directeur de recherche - xlim - Rapporteur
- Noëlle LEWIS - Professeure - University of Bordeaux, CNRS, Bordeaux INP, IMS, UMR5218, F-33400 Talence, France - Examinateur
- François RIVET - Maître de conférences - University of Bordeaux, CNRS, Bordeaux INP, IMS, UMR5218, F-33400 Talence, France - Examinateur
- Thierry PARRA - Professeur - LAAS CNRS - Examinateur
- Geneviève MAZE-MERCEUR - Directrice de recherche - CEA/CESTA - Examinateur
As nuclear power plants age globally, their safe decommissioning has emerged as a critical industrial and environmental challenge. Dismantling operations expose electronic systems to intense radiation environments, necessitating good understanding of radiation effects on integrated circuits. While aerospace, aviation, and defense sectors have long addressed radiation hardening, the specific requirements of nuclear decommissioning remain largely unexplored. Ionizing radiation, including electromagnetic waves like X-rays and γ-rays, atomic particles, like heavy ions, and subatomic particles like protons and electrons generates electron-hole pairs in materials, triggering both immediate and cumulative parasitic effects that degrade circuit electrical characteristics. Common manifestations include threshold voltage shifts, elevated leakage currents, gain variations, and bit flips in digital circuits. Historical examples like the Telstar 1 satellite, which experienced severe radiation-induced malfunctions, underscore the severity of these challenges. Central to radiation tolerance analysis is the dose rate, the energy deposited per unit time in a material. This parameter governs the evolution of radiation damage, particularly in PN junctions, which generate parasitic currents under radiation exposure. This thesis addresses these challenges through radiation-hardening techniques specifically targeting dose rate effects. The primary approach employs guard rings, some metallic structures surrounding transistors to drain radiation-induced currents from PN junctions. Optimizing their topology is essential to mitigate radiation effects while minimizing circuit area and performance degradation. A key contribution of this work is the development of new voltage reference topologies serving as test vehicle for evaluating various hardening strategies. The design was validated by simulation, then it was manufactured and tested experimentally. This research establishes a foundation for developing robust electronics capable of operating in extreme radiation environments, representing a significant advancement toward electronics solutions tailored for nuclear decommissioning applications.