Publications associées à Structure interne de la Terre

New tools for phase segmentation and denoising of analytical STEM data for enhanced chemical sensitivity, applied to Earth mantle research

This thesis is dedicated to developing innovative methodologies that improve elemental quantification in scanning transmission electron microscopy (STEM) using energy-dispersive X-ray spectroscopy (EDXS). The primary motivation stems from a geochemistry pr ...

EPFL2023

Dissipative magnetic structures and scales in small-scale dynamos

Jennifer Waltraud Schober

Small-scale dynamos play important roles in modern astrophysics, especially on galactic and extragalactic scales. Owing to dynamo action, purely hydrodynamic Kolmogorov turbulence hardly exists and is often replaced by hydromagnetic turbulence. Understandi ...

OXFORD UNIV PRESS2023

Microstructure observations in compacted clays subjected to thermal loading

Lyesse Laloui, Melis Sütman, Roba Houhou

The response of clayey materials to thermal variation has been the subject of extensive studies, given the wide range of engineering applications which involve subjecting soils to substantial temperature fluctuations. A number of hypotheses have been propo ...

2021

Relation between Inner Structural Dynamics and Ion Dynamics of Laser-Heated Nanoparticles

Christoph Bostedt

When a nanoparticle is irradiated by an intense laser pulse, it turns into a nanoplasma, a transition that is accompanied by many interesting nonequilibrium dynamics. So far, most experiments on nanoplasmas use ion measurements, reflecting the outside dyna ...

American Physical Society2021

PyFrac: A planar 3D hydraulic fracture simulator

Brice Tanguy Alphonse Lecampion, Haseeb Zia

Fluid driven fractures propagate in the upper earth crust either naturally or in response to engineeredfluid injections. The quantitative prediction of their evolution is critical in order to better understandtheir dynamics as well as to optimize their cre ...

2020

van der Waals Epitaxy of Earth-Abundant Zn3P2 on Graphene for Photovoltaics

Anna Fontcuberta i Morral, Roland Logé, Cyril Cayron, Elias Zsolt Stutz, Jean-Baptiste Leran, Shreyas Sanjay Joglekar, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Nicolas Philippe Laurent Humblot

Earth-abundant semiconducting materials are a potential solution for large-scale deployment of solar cells at a lower cost. Zinc phosphide (Zn3P2) is one such Earth-abundant material with optoelectronic properties suitable for photovoltaics. Herein, we rep ...

2020

Effects of composition and pressure on electronic states of iron in bridgmanite

Arnaud Magrez, Philippe Gillet, Susannah McGregor Dorfman

Electronic states of iron in the lower mantle's dominant mineral, (Mg,Fe,Al)(Fe,Al,Si)O-3 bridgmanite, control physical properties of the mantle including density, elasticity, and electrical and thermal conductivity. However, the determination of electroni ...

MINERALOGICAL SOC AMER2020

Growth and characterisation of earth-abundant semiconductor nanostructures for solar energy harvesting

Simon Robert Escobar Steinvall

Zinc phosphide (Zn3P2) is a compound semiconductor based on earth-abundant elements with functional properties ideal for solar cell applications. Cheap, abundant, and renewable energy sources are increasingly imperative due to the imminent threat posed by ...

EPFL2020

Microbial-induced carbonate precipitation applicability with the methane hydrate-bearing layer microbe

Alexandra Clarà Saracho

Production of methane gas from the methane-hydrate-bearing layer below the deep-ocean floor is expected to be crucial in the future of energy resources worldwide. During the methane gas-production phase from the methane hydrate with the depressurisation me ...

ELSEVIER SCI LTD2020

Ab Initio Molecular Dynamics Investigation of Molten Fe-Si-O in Earth's Core

James Badro

Silicon and oxygen are potential light elements in Earth's core because their stronger affinity to metal observed with increasing temperature posits that significant amounts of both can be incorporated into the core. It was proposed that an Fe-Si-O liquid ...

AMER GEOPHYSICAL UNION2019

A Reassessment of of the geochemical and isotopic fidelity of biogenic carbonates

Anders Meibom, Jaroslaw Hubert Stolarski, Arthur Adams, Deyanira Graciela Cisneros Lazaro, Jinming Guo, Tarek Axel Vennemann

Oxygen isotope compositions of calcite foraminifera tests are considered to be a robust palaeotemperature proxy at earth-surface conditions, where diffusion is slow. Recrystallization of tests during diagenesis may be optically identified and is often the ...

2019

Reply to Comment by Jennings et al. on "Investigating Earth's Formation History Through Copper and Sulfur Metal-Silicate Partitioning During Core-Mantle Differentiation"

James Badro

Recognizing existing materials that can act as proxies for Earth's building blocks, and understanding the accretionary pathway taken during Earth's growth, persist as outstanding issues in need of resolution. In Mahan, Siebert, Blanchard, Badro, et al. (20 ...

AMER GEOPHYSICAL UNION2019

On Linear Learning with Manycore Processors

Martin Jaggi

A new generation of manycore processors is on the rise that offers dozens and more cores on a chip and, in a sense, fuses host processor and accelerator. In this paper we target the efficient training of generalized linear models on these machines. We prop ...

IEEE COMPUTER SOC2019

Synthesis and Application of Transition Metal Oxides as Oxygen Evolution Catalysts

Laurent Liardet

Nowadays, mankind is facing an important energy challenge. Depletion in fossil fuels reserves and increasing energy demand, coupled with the problematic greenhouse effect induced by massive anthropogenic release of carbon dioxide into the atmosphere, are d ...

EPFL2019

Mitigating tip vortex cavitation by a flexible trailing thread

Mohamed Farhat, Ali Amini

Tip Vortex Cavitation (TVC) is a major issue in design and operation of axial hydraulic machines. We investigate the capacity of a flexible trailing thread in alleviating TVC by analyzing the flow-induced motion. For this purpose, a nylon thread with three ...

AMER INST PHYSICS2019

Solvent-induced surface hydroxylation of a layered perovskite Sr3FeCoO7−δ for enhanced oxygen evolution catalysis

Xile Hu, Fang Song, Jun Gu, Xiang Xu, Kongliang Xu

Efficient oxygen evolution reaction (OER) catalysts made of earth abundant elements are essential for the cost-effective generation of solar fuels. Surface modification is a novel strategy to enhance the activity of OER catalysts, however, it is commonly d ...

Royal Society of Chemistry2018

Investigating Earth's Formation History Through Copper and Sulfur Metal-Silicate Partitioning During Core-Mantle Differentiation

James Badro

Identifying extant materials that act as compositional proxies for Earth is key to understanding its accretion. Copper and sulfur are both moderately volatile elements; however, they display different geochemical behavior (e.g., phase affinities). Thus, in ...

AMER GEOPHYSICAL UNION2018

Core-Shell Structure of Organic Crystalline Nanoparticles Determined by Relayed Dynamic Nuclear Polarization NMR

David Lyndon Emsley, Arthur César Pinon, Jasmine Viger-Gravel

The structure of crystalline nanoparticles (CNPs) is determined using dynamic nuclear polarization (DNP) enhanced NMR spectroscopy experiments. The CNPs are composed of a crystalline core containing an active pharmaceutical ingredient (compound P), coated ...

AMER CHEMICAL SOC2018

Composition of the low seismic velocity E ′ layer at the top of Earth's core

James Badro

Using ab initio simulations on Fe-Ni-S-C-O-Si liquids, we constrain the origin and composition of the low-velocity layer E′ at the top of Earth's outer core. We find that increasing the concentration of any light element always increases velocity and so a ...

2017

Coupled 3D Dislocation Modeling at Nano- and Micro-Scales

Jaehyun Cho

The performance of crystalline materials varies depending on the considered scale. To understand the size dependence of materials properties, the interaction and evolution of defects are essential. As such, the role played by dislocations is crucial for mo ...

EPFL2017