Publications associées à Beam-induced oxidation of monomeric U(IV) species

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

Quantifying Photoinduced Polaronic Distortions in Inorganic Lead Halide Perovskite Nanocrystals

Majed Chergui, Giulia Fulvia Mancini, Andre Al Haddad, Thomas Charles Henry Rossi, Nicola Colonna, Dominik Kinschel, James Michael Budarz, Oliviero Cannelli, Michele Puppin, Ludmila Maria Diniz Leroy

The development of next-generation perovskite-based optoelectronic devices relies critically on the understanding of the interaction between charge carriers and the polar lattice in out-of-equilibrium conditions. While it has become increasingly evident fo ...

2021

Fe-57-Enrichment effect on the composition and performance of Fe-based O-2-reduction electrocatalysts

Jeremy Luterbacher, Benjamin Pierre Le Monnier

Pt-group metal (PGM)-free catalysts of the Me-N-C type based on abundant and inexpensive elements have gained importance in the field of oxygen reduction reaction (ORR) electrocatalysis due to their promising ORR-activities. Their insufficient stability, h ...

2021

Composition and Pressure Effects on Partitioning of Ferrous Iron in Iron-Rich Lower Mantle Heterogeneities

Marco Cantoni, Philippe Gillet, Farhang Nabiei, Susannah McGregor Dorfman, James Badro, Charles-Edouard Boukaré

Both seismic observations of dense low shear velocity regions and models of magma ocean crystallization and mantle dynamics support enrichment of iron in Earth’s lowermost mantle. Physical properties of iron-rich lower mantle heterogeneities in the modern ...

2021

Evaluation of materials for iodine and technetium immobilization through sorption and redox-driven processes

Daniel Teav Sun, Wendy Lee Queen

Radioactive iodine-129 (I-129) and technetium-99 (Tc-9(9)) pose a risk to groundwater due to their long half-lives, toxicity, and high environmental mobility. Based on literature reviewed in Moore et al. (2019) and Pearce et aL (2019), natural and engineer ...

ELSEVIER2020

Design guidelines for Al-12%Si latent heat storage encapsulations to optimize performance and mitigate degradation

Sophia Haussener, Selmar Rudolf Binder

We provide detailed insight into the growth kinetics of intermetallic layers formed at the interface of molten Al-12%Si with cylindrical encapsulations of 316L stainless steel. This knowledge is relevant for the design and operation of high-temperature lat ...

ELSEVIER2020

Role of Iron Sulfide Phases in the Stability of Noncrystalline Tetravalent Uranium in Sediments

Rizlan Bernier-Latmani, Luca Loreggian

Uranium (U) in situ bioremediation has been investigated as a cost-effective strategy to tackle U contamination in the subsurface. While uraninite was believed to be the only product of bioreduction, numerous studies have revealed that noncrystalline U(IV) ...

AMER CHEMICAL SOC2020

Factors influencing the hydration kinetics of ye'elimite; effect of mayenite

Mohsen Ben Haha, Karen Scrivener, Frank Bullerjahn

The aim of this study was to understand the origin of the variation in the hydraulic reactivity of ye'elimite systems. To this end, the hydration of two clinkers, one composed mainly of synthetic stoichiometric (C(4)A(3)(S) over bar) "Y" and the other of a ...

Pergamon-Elsevier Science Ltd2019

Contaminant loading and competitive access of Pb, Zn and Mn(III) to vacancy sites in biogenic MnO2

Jasquelin Peña, Louise Helene Soegaard Jensen

The scavenging properties of MnO2 are largely attributed to sorption on layer vacancy sites. However, co-occurrence of Mn(II, III) with MnO2 can change mineral reactivity by modifying its Mn(III) content or number of free vacancy sites. These processes are ...

2018

Corrosion mechanisms and durability models for historical tinplate food cans

Fabio Cova Caiazzo

Since the early of the 19th century, canning is one the most efficient ways to preserve foods. Tinplated steel has been used since the beginning for this purpose and it is still one of the most used materials for cans production because it combines the goo ...

EPFL2018

Bacterial iron reduction and biogenic mineral formation for the stabilisation of corroded iron objects

Julien Maillard, Arnaud Michel Gelb

Exploiting bacterial metabolism for the stabilisation of corroded iron artefacts is a promising alternative to conventional conservation-restoration methods. Bacterial iron reduction coupled to biogenic mineral formation has been shown to promote the conve ...

Nature Research2018

Forced Electrocodeposition of Silica Particles into Nickel Matrix by Horizontal Impinging Jet Cell

Hubert Girault, Véronique Amstutz, Desire Martial Koutouan Abro

The improvement of silica particle codeposition into a nickel electrodeposited composite coating (ECC) by a double face horizontal impinging jet cell (IJC) has been studied. The microstructure of coatings was examined by means of scanning electron microsco ...

2017

Virtual reading of a large ancient handwritten science book

Giorgio Margaritondo, Frédéric Kaplan, Fauzia Albertin, Alessandra Patera, Marco Stampanoni

We present a fundamental development step of a new technique to read and digitize ancient handwritten documents. Chemical analysis by x-ray fluorescence and x-ray tomography enabled us to decipher words and drawings from inside a closed, 200-pages 18 th ce ...

Elsevier2016

Probing the electronic and geometric structure of ferric and ferrous myoglobins in physiological solutions by Fe K-edge absorption spectroscopy

Majed Chergui, Ursula Röthlisberger, Ivano Tavernelli, Frederico Alves Lima, Marco Eli Reinhard, Thomas James Penfold

We present an iron K-edge X-ray absorption study of carboxymyoglobin (MbCO), nitrosylmyoglobin (MbNO), oxymyoglobin (MbO(2)), cyanomyoglobin (MbCN), aquomet myoglobin (metMb) and unligated myoglobin (deoxyMb) in physiological media. The analysis of the XAN ...

2014

Biomineralization in Newly Settled Recruits of the Scleractinian Coral Pocillopora damicornis

Anders Meibom, Melany Melissa Gilis, Isabelle Domart-Coulon, Jaroslaw Hubert Stolarski

Calcium carbonate biomineralization of scleractinian coral recruits is fundamental to the construction of reefs and their survival under stress from global and local environmental change. Establishing a baseline for how normal, healthy coral recruits initi ...

Wiley-Blackwell2014

Effects of Fe-enrichment on the equation of state and stability of (Mg,Fe)SiO3 perovskite

Susannah McGregor Dorfman

Fe-rich natural orthopyroxenes with compositions of (Mg0.61Fe0.38Ca0.01)SiO3 (Fe#38) and (Mg0.25Fe0.74Ca0.01)SiO3 (Fe#74) were studied at pressures up to 155 GPa and temperatures up to 3000 K. Single-phase orthorhombic GdFeO3-type perovskite was synthesize ...

Elsevier Science Bv2013

NMR Study of Ligand Exchange and Electron Self-Exchange between Oxo-Centered Trinuclear Clusters [Fe3(μ3-O)(μ-O2CR)6(4-R´py)3]+/0

André Merbach, Lothar Helm

The syntheses, single crystal X-ray structures, and magnetic properties of the homometallic mu(3)-oxo trinuclear clusters Fe-3(mu(3)-O)(mu-O2CCH3)(6)(4-Phpy)(3) (1) and F(e)3(mu(3)-O)(mu-O(2)CAd)(6)(4-Mepy)(3) (2) are reported (Ad = adamanta ...

American Chemical Society2011

Probing the Electronic Structure of the Hemoglobin Active Center in Physiological Solutions

Majed Chergui

Soft-x-ray absorption spectroscopy at the L2,3 edge of the iron center in bovine Hb and hemin under physiol. conditions is reported for the first time. Spectra of the same compds. in solid form are presented for comparison. Striking differences in the elec ...

2009