Publications associées à Surface diffusion of Ag on Pd(100) measured with specular helium scattering

Development of next-generation microfluidic systems for enhanced, faster, and cost-effective immunoassays for tissue diagnostics - Ac electrothermal flow & Acoustofluidics

The application of microfluidics in the field of surface-based assays and more specifically, the spatial molecular profiling of tumor tissues has gained a lot of interest, especially with the increased interest in personalized medicine and targeted therapy ...

EPFL2023

Atomic scale volume and grain boundary diffusion elucidated by in situ STEM

Johann Michler, Amit Sharma, Laszlo Pethö, Xavier Maeder

Diffusion is one of the most important phenomena studied in science ranging from physics to biology and, in abstract form, even in social sciences. In the field of materials science, diffusion in crystalline solids is of particular interest as it plays a p ...

Nature Portfolio2023

Diffusion timescale conundrum in contact metamorphism: Oxygen isotope and trace element profiles in dolomite

Lukas Baumgartner, Anders Meibom, Stéphane Laurent Escrig, Florence Bégué

Successful application of diffusion chronometry is based on detailed knowledge of diffusion parameters obtained from laboratory experiments, which also need to be upscaled to be applied to natural samples. While generally applicable, several examples of di ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Efficient AC electrothermal flow (ACET) on-chip for enhanced immunoassays

Martinus Gijs, Diego Gabriel Dupouy, Muaz Salama Abdelmonem Draz

Biochemical reaction rates in microfluidic systems are known to be limited by the diffusional transport of reagents, leading often to lowered sensitivity and/or longer detection times in immunoassays. Several methods, including electrically powering electr ...

ROYAL SOC CHEMISTRY2023

Oxidation of organic micropollutant surrogate functional groups with peracetic acid activated by aqueous Co(II), Cu(II), or Ag(I) and geopolymer-supported Co(II)

Urs von Gunten

Peracetic acid (PAA) in combination with transition metals has recently gained increasing attention for organic micropollutant abatement. In this study, aqueous Co(II), Cu(II), and Ag(I) were compared for their capacity to activate PAA. Co(II) outperformed ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Oxygen diffusion in garnet: Experimental calibration and implications for timescales of metamorphic processes and retention of primary O isotopic signatures

Anders Meibom, Stéphane Laurent Escrig

Knowledge of oxygen diffusion in garnet is crucial for a correct interpretation of oxygen isotope signatures in natural samples. A series of experiments was undertaken to determine the diffusivity of oxygen in garnet, which remains poorly constrained. The ...

MINERALOGICAL SOC AMER2022

Manifold Learning-Based Polynomial Chaos Expansions For High-Dimensional Surrogate Models

Ketson Roberto Maximiano Dos Santos

In this work we introduce a manifold learning-based method for uncertainty quantification (UQ) in systems describing complex spatiotemporal processes. Our first objective is to identify the embedding of a set of high-dimensional data representing quantitie ...

2022

Microfluidic study in a meter-long reactive path reveals how the medium’s structural heterogeneity shapes MICP-induced biocementation

Lyesse Laloui, Dimitrios Terzis, Ariadni Elmaloglou

Microbially induced calcium carbonate (CaCO3) precipitation (MICP) is one of the major sustainable alternatives to the artificial cementation of granular media. MICP consists of injecting the soil with bacterial- and calcium-rich solutions sequentially to ...

Nature Research2022

Hydrogen production on demand by redox-mediated electrocatalysis: A kinetic study

Hubert Girault, Sunny Isaïe Maye, Danick Reynard

Producing hydrogen from water using a redox mediator on solid electrocatalyst particles in a reactor offers several advantages over classical electrolysis in terms of safety, membrane degradation, purity and flexibility. Herein, vanadium-mediated hydrogen ...

ELSEVIER SCIENCE SA2021

Gold-in-copper at low *CO coverage enables efficient electromethanation of CO2

Michael Graetzel, Pengfei Ou, Xiaoyan Wang, Dan Ren, Yang Li, Jun Li, Ziyun Wang, Yongfeng Xie, Yi Xu, Yiping Wang

The renewable-electricity-powered CO2 electroreduction reaction provides a promising means to store intermittent renewable energy in the form of valuable chemicals and dispatchable fuels. Renewable methane produced using CO2 electroreduction attracts inter ...

Nature Research2021

First demonstration of real-time kinetic equilibrium reconstruction on TCV by coupling LIUQE and RAPTOR

Jean-Marc Moret, Olivier Sauter, Federico Alberto Alfredo Felici, Antoine Pierre Emmanuel Alexis Merle, Cristian Galperti, Francesco Carpanese

Kinetic equilibrium reconstruction (KER) in tokamaks is the solution of the free-boundary MHD equilibrium that best fits the external magnetic measurements and the internal plasma profiles as imposed from modeling and/or available internal measurements. In ...

IOP Publishing Ltd2020

Bimolecular charge transfer reactions at and through the liquid-liquid interface

Grégoire Clément Gschwend

Interfaces are ubiquitous in Nature. Among them, soft interfaces are essential constituents of biological tissues. Indeed, many electrochemical reactions and phenomena take place at these interfaces. In this respect, ITIES are an interesting model to study ...

EPFL2019

Two dimensional diffusion-controlled triplet–triplet annihilation kinetics

Pierre-François Marie Brevet, Hubert Girault, Astrid Johana Olaya Avendano, Grégoire Clément Gschwend, Morgan Kazmierczak

Diffusion controlled chemical reactions are usually observed in three dimensionalmedia. In contrast, planar bimolecular reactions taking place between reagents adsorbed at a soft interface are two-dimensional and therefore cannot be studied within the same ...

2019

Mechanism and Kinetics of Propane Dehydrogenation and Cracking over Ga/H-MFI Prepared via Vapor-Phase Exchange of H-MFI with GaCI3

Matthieu Bondil

In this study, the mechanism and kinetics of C3H8 dehydrogenation and cracking are examined over Ga/H-MFI catalysts prepared via vapor-phase exchange of H-MFI with GaCl3. The present study demonstrates that GaH cations are the active centers for C3H8 ...

2019

Dynamic wetting in pressure-infiltration of ceramic particle preforms by molten metal

Gionata Schneider

This thesis investigates the interaction between mechanically induced flow of a liquid metal into a porous solid, and kinetic effects at the triple line. The approach is experimental and focuses on metal-ceramic systems for which the literature gives value ...

EPFL2019

Prominent role of mesopore surface area and external acid sites for the synthesis of polyoxymethylene dimethyl ethers (OME) on a hierarchical H-ZSM-5 zeolite

Jeremy Luterbacher, Christophe Jean Baranowski, Oliver Kröcher, Florent Emmanuel Héroguel, Alimohammad Bahmanpour

H-ZSM-5 zeolite has been shown to be an active catalyst for the synthesis of polyoxymethylene dimethyl ethers (OME). However, we demonstrated – by passivation of the zeolite's external surface – that the reaction rate is limited due to severe internal diff ...

2019

Reactivity of Bioinspired Magnesium-Organic Networks under CO2 and O-2 Exposure

Klaus Kern, Magalí Alejandra Lingenfelder, Bart Willem Stel, Fernando Pablo Cometto, Daniel Eduardo Hurtado Salinas

Photosynthesis is the model system for energy conversion. It uses CO2 as a starting reactant to convert solar energy into chemical energy, i.e., organic molecules or biomass. The first and rate-determining step of this cycle is the immobilization and activ ...

2019

Automated Multiscale Approach To Predict Self-Diffusion from a Potential Energy Field

Berend Smit, Senja Dominique Barthel, Amber Kashan Mace

For large-scale screening studies there is a need to estimate the diffusion of gas molecules in nanoporous materials more efficiently than (brute force) molecular dynamics. In particular for systems with low diffusion coefficients molecular dynamics can be ...

2019

Importance of the advection scheme for the simulation of water isotopes over Antarctica by atmospheric general circulation models: A case study for present-day and Last Glacial Maximum with LMDZ-iso

Etienne Gabriel Henri Vignon

Atmospheric general circulation models (AGCMs) are known to have a warm and isotopically enriched bias over Antarctica. We test here the hypothesis that these biases are partly consequences of a too diffusive advection. Exploiting the LMDZ-iso model, we sh ...

2019

Dissolution-reprecipitation reaction of dolomite: investigation of self- and tracer-diffusion using SIMS mini-spot and NanoSIMS profiles

Lukas Baumgartner, Anders Meibom, Stéphane Laurent Escrig

Recrystallization of minerals due to fluid infiltration modifies their original chemical and isotopic signature. Such processes are sought after as they give access to timescales of geologic processes, which are commonly quantified using diffusion chronome ...

2019