Publications associées à Mass-independent fractionation

The isotopic signature of U(V) during bacterial reduction

Marinella Mazzanti, Rizlan Bernier-Latmani, Margaux Camille Andréa Molinas, Radmila Faizova, Ashley Richards Brown

The two-step electron transfer during bacterial reduction of UVI to UIV is typically accompanied by mass-independent fractionation of the 238U and 235U isotopes, whereby the heavy isotope accumulates in the reduced product. However, the role of the UV inte ...

2024

Reliable uncertainties: Error correlation, rotated error bars, and linear regressions in three-isotope plots and beyond

Reto Georg Trappitsch

Correlated errors of experimental data are a common but often neglected problem in physical sciences. Various tools are provided here for thorough propagation of uncertainties in cases of correlated errors. Discussed are techniques especially applicable to ...

ELSEVIER2023

Mercury Isotope Fractionation during Dark Abiotic Reduction of Hg(II) by Dissolved, Surface-Bound, and Structural Fe(II)

Lorenz Schwab

Stable mercury (Hg) isotope ratios are an emerging tracer for biogeochemical transformations in environmental systems, but their application requires knowledge of isotopic enrichment factors for individual processes. We investigated Hg isotope fractionatio ...

Amer Chemical Soc2023

High-useful yield and new autoionizing state of resonantly ionized tungsten

Reto Georg Trappitsch

In order to measure tungsten isotopic composition in presolar stardust grains that contain a limited number of atoms, we developed a new three-photon three-color resonance ionization scheme using titanium:sapphire lasers and the Laser Ionization of Neutral ...

ROYAL SOC CHEMISTRY2022

Persistence of the isotopic signature of pentavalent uranium in magnetite

Rizlan Bernier-Latmani, Barbora Bártová, Zezhen Pan

Uranium isotopic signatures can be harnessed to monitor the reductive remediation of subsurface contamination or to reconstruct paleo-redox environments. However, the mechanistic underpinnings of the isotope fractionation associated with U reduction remain ...

2022

Phloem water isotopically different to xylem water: Potential causes and implications for ecohydrological tracing

Andrea Rinaldo, Paolo Benettin

The stable isotopes of hydrogen and oxygen in xylem water are often used to investigate tree water sources. But this traditional approach does not acknowledge the contribution of water stored in the phloem to transpiration and how this may affect xylem wat ...

WILEY2022

Precipitation fate and transport in a Mediterranean catchment through models calibrated on plant and stream water isotope data

Paolo Benettin

To predict hydrologic responses to inputs and perturbations, it is important to understand how precipitation is stored in catchments, released back to the atmosphere via evapotranspiration (ET), or transported to aquifers and streams. We investigated this ...

COPERNICUS GESELLSCHAFT MBH2022

Toward waste valorization by converting bioethanol production residues into nanoparticles and nanocomposite films

Xun Liao, Muhammad Farooq

A "waste-valorization" approach was developed to transform recalcitrant hydrolysis lignin (HL) from secondgeneration bioethanol production into multifunctional bio-based products. The hydrolysis lignin (HL) was extracted with aqueous acetone, yielding two ...

ELSEVIER2021

Aqueous-phase reactive species formed by fine particulate matter from remote forests and polluted urban air

Andrea Mario Arangio, Ting Zhang, Jing Li

In the aqueous phase, fine particulate matter can form reactive species (RS) that influence the aging, properties, and health effects of atmospheric aerosols. In this study, we explore the RS yields of aerosol samples from a remote forest (Hyytiala, Finlan ...

Copernicus Publications2021

Quantum kinetic energy and isotope fractionation in aqueous ionic solutions

Michele Ceriotti, Lu Wang

At room temperature, the quantum contribution to the kinetic energy of a water molecule exceeds the classical contribution by an order of magnitude. The quantum kinetic energy (QKE) of a water molecule is modulated by its local chemical environment and lea ...

ROYAL SOC CHEMISTRY2020

Tree water deficit and dynamic source water partitioning

Andrea Rinaldo, Paolo Benettin, Mitra Asadollahi

The stable isotopes of hydrogen and oxygen (delta H-2 and delta O-18, respectively) have been widely used to investigate tree water source partitioning. These tracers have shed new light on patterns of tree water use in time and space. However, there are s ...

WILEY2020

Non-crystalline tetravalent uranium species in the subsurface: formation and stability

Luca Loreggian

Uranium (U) contamination of ground and surface waters poses an acute hazard on the ecosystem and human health. Since the discovery of microbial U(VI) reduction, U bioremediation has been explored as a promising and cost-effective method compared to tradit ...

EPFL2019

Production and characterization of stabilized lignin

Masoud Talebi Amiri

Lignocellulosic biomass is a sustainable source of renewable carbon, and it is the most abundant form of terrestrial biomass. The three main constituents of lignocellulosic biomass are cellulose, hemicellulose, and lignin. The monomers from these biopolyme ...

EPFL2019

Ideas and perspectives: Tracing terrestrial ecosystem water fluxes using hydrogen and oxygen stable isotopes - challenges and opportunities from an interdisciplinary perspective

Paolo Benettin, Natalie Claire Ceperley, Jana Freiin von Freyberg

In this commentary, we summarize and build upon discussions that emerged during the workshop "Isotope-based studies of water partitioning and plant-soil interactions in forested and agricultural environments" held in San Casciano in Val di Pesa, Italy, in ...

Copernicus GmbH2018

Observation of enhanced ion particle transport in mixed H/D isotope plasmas on JET

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Martinus Gijs, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Bruno Emanuel Ferreira De Sousa Correia, Alessandro Pau, Pierre-Thomas Paul Brun, Cristian Sommariva, Henri Weisen, Michele Marin, Richard Pitts, Sun Hee Kim, Yann Camenen, Jan Horacek, Marco Wischmeier, Javier García Hernández, Mikhail Maslov, Miguel Fernández Ruiz, Nicola Vianello, Antonio José Pereira de Figueiredo, Federico Nespoli, Liang Yao, Dalziel Joseph Wilson, Yao Zhou, Robin Humphry-Baker, David Pfefferlé, José Pedro Rebelo Ferreira Marques, Davide Galassi, Ana Francisca Leal Silva Soares, Daniel Scott Alessi, Jonathan Marc Philippe Faustin, Arnout Lodewijk M Beckers, Julio Rodriguez, Jonnathan Cesar Hidalgo Acosta, Hamish William Patten, , , , , , , , ,

Accelerating path integral evaluation of equilibrium and kinetic isotope effects

Konstantin Karandashev

Investigating the effect of isotope substitution on equilibrium and kinetic properties of molecules has become an important tool for estimating the importance of nuclear quantum effects. In this work, we discuss calculating both equilibrium and kinetic iso ...

EPFL2018

Spruce tree-ring proxy signals during cold and warm periods

The strength and temporal rigidity of climate signals are important characteristics of proxy data used to reconstruct climate variability over pre-instrumental periods. Here, we assess the performance of different tree-ring proxies, including ring width, m ...

Bogucki Wydawnictwo Naukowe2017

Formation of N-nitrosodimethylamine during water disinfection with chloramine : insights into reaction mechanisms from isotope fractionation analyses

Stephanie Spahr

Disinfection processes such as chlorination, chloramination, and ozonation are a crucial measure to provide safe drinking water because they effectively inactivate pathogenic microorganisms. However, these processes can also lead to the formation of harmfu ...

EPFL2016

Mechanism of uranium reduction and immobilization in Desulfovibrio vulgaris biofilms

Rizlan Bernier-Latmani, Malgorzata Alicja Stylo

The prevalent formation of noncrystalline U(IV) species in the subsurface and their enhanced susceptibility to reoxidation and remobilization, as compared to crystalline uraninite, raise concerns about the long-term sustainability of the bioremediation of ...

Amer Chemical Soc2015

Reduction and immobilization of uranium in the subsurface : controls, mechanisms, and implications for in situ bioremediation

Malgorzata Alicja Stylo

Decades of uranium (U) mining, milling and military use left a legacy of U contamination around the world. The radioactivity and chemical toxicity of U at contaminated sites pose an acute and long-term hazard to human health and the surrounding environment ...

EPFL2015