Publications

2024

• Vulnerability and adaptation potential of high variable renewable energy penetration electricity systems tosocioeconomic scenarios of heating electrification and air conditioning adoption coupled to climate change : the case of France.
  
  • Delort Joan
  , 2024. The electricity generation sector is undergoing profound changes. In all european economies, thepenetration of variable renewable energies (VREs) is rising and is expected to reach important levels in the near future. These future mixes need to be able to provide secure and affordable electricity while subject to stringent ecological constraints. We investigate in this work two processes affecting the electricity generation sector: climate change, and electrification through heating electrification and air conditioning adoption. In particular, we ask how vulnerable is the electricity generation sector to these processes and how both these processes affect the optimal investment decisions in VRE capacity. Because climate change and the electrification potential are region-specific, we focus in the particular case of France. We show that an increase of the heating temperature sensitive demand favors wind penetration while the modification of the cooling demand along the extensive margin only has no effect in the case of France. We further show that climate change has no adverse impacts if impacts on the dispatchable producers are not accounted for, and that changes in demand are the driving factor of impacts on the optimal investment decisions. We finally show that socioeconomic change is potentially the driving force influencing vulnerability and investment decisions, but that socioeconomic and climate change impacts should be assessed jointly to issue relevant policymaking advice. Overall optimal mixes and associated costs change substantially with changing socioeconomic and climate conditions, with the former having a potentially greater impact than the latter. We suggest that further research focuses on producing more integratedassessments of potential future changes impacts on the electricity generation sector, by being exhaustive at the same time on the elements of the electricity generation sector considered and on the processes impacting them.
• Approaches for positioning the active medium in hybrid nanoplasmonics. Focus on plasmon-assisted photopolymerization
  
  • Chen Minyu
  • Marguet Sylvie
  • Issa Ali
  • Jradi Safi
  • Couteau Christophe
  • Fiorini-Debuisschert Céline
  • Douillard Ludovic
  • Soppera Olivier
  • Ge Dandan
  • Plain Jérôme
  • Zhou Xuan
  • Dang Cuong
  • Béal Jérémie
  • Kostcheev Sergei
  • Déturche Régis
  • Xu Tao
  • Wei Bin
  • Bachelot Renaud
  ACS photonics, American Chemical Society, 2024, 11 (10), pp.3933−3953. Over the past 20 years, hybrid plasmonics for nanoemitters of light or for nanoabsorbers, based on weak or strong coupling between metallic nanocavities and active media (emissive or absorbing entities), have given rise to important research efforts. One of the main current challenges is the control +of the nanoscale spatial distribution and associated symmetry of the active medium in the vicinity of the metallic nanoparticles. In this review, we first recall the main principles of weak and strong coupling by stressing the importance of controlling the spatial distribution of the active medium and present the main approaches developed for achieving this control. Nine different approaches are identified. We then focus our attention on one of them based on plasmonic photopolymerization and discuss the flexibility of this approach in terms of control of the spatial symmetry of the hybrid nanosystem metal−polymer nanoemitters and the resulting polarization dependence of the light emission. The different approaches are analyzed and compared with each other, and some future perspectives and challenges are finally discussed. (10.1021/acsphotonics.4c00868)
  DOI : 10.1021/acsphotonics.4c00868
• Spatial distribution of the photopolymerization induced by localized surface plasmons: impact of the morphology of the Au nanoparticles
  
  • Khitous Amine
  • Molinaro Céline
  • Abdallah Stephania
  • Chen Minyu
  • Marguet Sylvie
  • Laurent Guillaume
  • Vidal Loïc
  • Malval Jean-Pierre
  • Fiorini-Debuisschert Céline
  • Adam Pierre-Michel
  • Douillard Ludovic
  • Bachelot Renaud
  • Soppera Olivier
  Journal of Physical Chemistry C, American Chemical Society, 2024, 128 (31), pp.13097-13107. The analysis of the local distribution of the electric field, induced by localized surface plasmon resonance (LSPR), is crucial for selecting the morphology of gold nanoparticles (AuNPs) for specific applications. The reported study is based on an LSPR-induced near-field two-photon photopolymerization (NF2P) reaction. The initiation of NF2P is triggered by LSPR-enhanced near-field light, while in the far-field, oxygen inhibits this reaction. The spatial extent of the NF2P reaction is compared to the local electric field distribution depending on AuNP morphologies, established by numerical simulations. Overall, our results demonstrate that the photopolymerization is not only driven by the local near-field enhancement but also strongly depends on the topologies of nano-object, and the photopolymerization extension was more confined in anisotropic and sharp structures compared to isotropic ones. Additionally, we showcased its capability to confine polymerization reactions within nanoscale volumes with the possibility of controlling the localization of polymer lobes at a single triangle apex, for instance, via light polarization. (10.1021/acs.jpcc.4c03148)
  DOI : 10.1021/acs.jpcc.4c03148
• The Role of Tidal Mixing in Shaping Early Eocene Deep Ocean Circulation and Oxygenation
  
  • Ladant Jean-Baptiste
  • Millot‐Weil Jeanne
  • de Lavergne Casimir
  • Green J. A. Mattias
  • Nguyen Sébastien
  • Donnadieu Yannick
  Paleoceanography and Paleoclimatology, American Geophysical Union, 2024, 39 (7), pp.e2023PA004822. Abstract Diapycnal mixing in the ocean interior is largely fueled by internal tides. Mixing schemes that represent the breaking of internal tides are now routinely included in ocean and earth system models applied to the modern and future. However, this is more rarely the case in climate simulations of deep‐time intervals of the Earth, for which estimates of the energy dissipated by the tides are not always available. Here, we present and analyze two IPSL‐CM5A2 earth system model simulations of the Early Eocene made under the framework of DeepMIP. One simulation includes mixing by locally dissipating internal tides, while the other does not. We show how the inclusion of tidal mixing alters the shape of the deep ocean circulation, and thereby of large‐scale biogeochemical patterns, in particular oxygen distributions. In our simulations, the absence of tidal mixing leads to a relatively stagnant and poorly ventilated deep ocean in the North Atlantic, which promotes the development of a basin‐scale pool of oxygen‐deficient waters, at the limit of complete anoxia. The absence of large‐scale anoxic records in the deep ocean after the Cretaceous anoxic events suggests that such an ocean state most likely did not occur at any time across the Paleogene. This highlights how crucial it is for climate models applied to the deep‐time to integrate the spatial variability of tidally driven mixing as well as the potential of using biogeochemical models to exclude aberrant dynamical model states. (10.1029/2023pa004822)
  DOI : 10.1029/2023pa004822
• Physics of sport: Olympic swimming
  
  • Carmigniani Rémi Arthur
  , 2024. This manuscript reviews the main research subjects I have been conducting on “Physics of Sport” and particularly on Olympic swimming since I was appointed as a researcher at École des Ponts in the Laboratoire d’Hydraulique Saint-Venant in 2018. This work started with the launch of Sciences2024 research project, dedicated to solving problems identified with athletes to support them in their quest for medals at the Paris 2024 Olympic and Paralympic Games. It is funded by the ANR project NePTUNE and the Fondation Groupe EDF. Thisthesispresents4axesofresearchonOlympicswimming: thestudyofwaterresistance, the modeling of the velocity–stroke rate and coordination relationships, the measurement and modeling of starts and turns trajectories, and the prediction of racing conditions in open water. All this work is being conducted with the aim of benefitting the French athletes as they prepare for the Paris 2024 Olympic and Paralympic Games. This work is multi-disciplinary (artificial intelligence, computer vision, bio-mechanics, physiology, fluid mechanics, etc.), with a key discipline: physics. The first step is to observe, then understand and model, proposing the most basic and minimal law possible. This approach makes it possible to highlight important laws of sport, such as the speed-frequency relationship in paddle sports. While it’s true that athletes haven’t necessarily waited for physicists to help them perform, I hope that this work will enable us to better understand the mechanisms that have enabled the best (French) athletes to get close to their optimal performance, so that we can transfer it to future generations. The thesis is written in English so that it can be widely shared, and to provide an overview of the work carried out since 2018 for the Paris Games.
• Sea surface acidification events in the Andaman Sea associated with the last Toba volcanic activity
  
  • Alves Ana
  • Buisson Matthieu Paulhac
  • Louvat Pascale
  • Rollion-Bard Claire
  • Bassinot Franck
  • Gray William Robert
  • Paris Guillaume
  • Caron Benoît
  • Del Manzo Giulia
  • Le Friant Anne
  • Moreno Eva
  • Bartolini Annachiara
  Global and Planetary Change, Elsevier, 2024, 237, pp.104460. To date, little is known about the impact of super-eruptions on ocean biogeochemistry. Using boron isotopes ratios measured on planktonic foraminifera in the marine sediment core BAR94–25, we provide a high-resolution pH record in the Andaman Sea (North of Sumatra), spanning Marine Isotopic Stage 5 to 3. This transition encompasses the super-eruption of the Toba volcano, 74,000 years ago, making it possible to decipher the potential impact of the super-eruption emissions on the ocean pH for the first time. Our results show that inferred foraminiferal pH values generally follow those predicted by glacial-interglacial CO2 variations. However, several abrupt pH drops coincide with Toba ash deposition. This suggests the occurrence of acidification events possibly related to Toba volcanic sulphur emission episodes. These pH drops are followed by anomalous pH increases, possibly relating to localised increases in seawater alkalinity following the alteration of large ash deposits on land. (10.1016/j.gloplacha.2024.104460)
  DOI : 10.1016/j.gloplacha.2024.104460
• Temporal fragmentation of the energy demand in Europe: Impact of climate change on the maneuverability of energy system
  
  • Filahi Hajar
  • Omrani Hiba
  • Claudel Sandra
  • Drobinski Philippe
  Climate services, Elsevier, 2024, 34, pp.100469. The energy demand in Europe is projected to be affected by climate change in the future. The heating needs are expected to decrease while the cooling needs are expected to increase.The study investigates the impact of climate change on the temporal fragmentation of heating and to a lesser extent cooling needs and its implication on the energy power system. Ten bias-corrected and downscaled simulations from CMIP6 at 25 25 km2 horizontal resolution over Europe have been used to estimate change in heating and cooling energy needs under four anthropogenic scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5), using heating degree days (HDD) and cooling degree days (CDD) as proxies. Consistent with already published literature, here updated using the last CMIP6 simulation ensemble, the results show a large decrease of HDD over Europe and an increase of CDD under all scenarios. However, the study goes one step further by showing a fragmentation of the periods of heating needs during winter in the future which can potentially lead to a fragmentation of heating energy demand. In the worst-case scenario, periods of heating needs could be separated by up to 7 days, 9 times per winter. The cooling needs in summer are expected to be more frequent and last longer compared to the present climate. The fragmentation of temperature-sensitive energy needs for heating and to a lesser extent for cooling are expected to have an operational and economical impact on the balancing of the energy system. (10.1016/j.cliser.2024.100469)
  DOI : 10.1016/j.cliser.2024.100469
• Sonohydrothermal synthesis of zeolite A and its phase transformation into sodalite
  
  • Nzodom Djozing William'S
  • Valange Sabine
  • Nikitenko Sergey
  • Chave Tony
  Dalton Transactions, Royal Society of Chemistry, 2024, 2024. The sonohydrothermal (SHT) treatment is an innovative technique allowing the simultaneous coupling of low frequency ultrasound and hydrothermal conditions for the synthesis of materials. The aim of the present work was to investigate, for the first time, the synthesis of zeolite A and its formation mechanism under SHT conditions. The zeolite synthesis was carried out under sonohydrothermal conditions using a specially designed reactor that allows the application of ultrasonic irradiation at 20 kHz in an autoclave-type reactor heated up to 200 °C under autogenous pressure. The conversion kinetics of the amorphous hydrogel to zeolite A and its further conversion to sodalite were studied. Syntheses were performed in the SHT reactor at 80 and 100 °C, varying the synthesis time from 15 minutes to several hours. The required time to obtain fully crystalline zeolite A under sonohydrothermal conditions was only 25 minutes, highlighting a significantly improved crystallization rate compared to silent conditions (a 9.6-fold kinetic gain). In addition, the resulting zeolite A has smaller particles and a more homogeneous particle size distribution than the zeolite synthesized by hydrothermal treatment. These results can be explained by the sonofragmentation of the amorphous gel and the concomitant enhanced mass transfer of the building units at the interface between the crystallite surface and the solution resulting from the acoustic cavitation activity under SHT conditions. Compared to classical hydrothermal heating, a drastic kinetic increase of the transformation of zeolite A into the more stable sodalite phase was also observed under sonohydrothermal conditions. (10.1039/d4dt01943a)
  DOI : 10.1039/d4dt01943a