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Concept

Trioxyde d'uranium

Publications associées (24)

Atomic level insight into irradiation effects in nuclear fuel materials

Shaileyee Bhattacharya

Microstructural evolution during in-pile irradiation, radiation damage effects and fission products behavior in UO2 nuclear fuel are key issues in understanding and for the modeling of the performance as well as safety characteristics of nuclear fuels in t ...

EPFL2024

Design, synthesis, reactivity, and magnetic properties of uranium based oxide and nitride complexes

Luciano Barluzzi

The activation of small molecules is a paramount challenge in modern chemistry. The use of cheap and abundant molecules such as N2, H2, CO2, or CO as energy supplies or as precursors for fine chemicals production is highly desirable. In particular, the onl ...

EPFL2021

Systematic investigations of uranium carbide composites oxidation from micro- to nano-scale: Application to waste disposal

Nhât-Tân Vuong

The production of radioisotope beams at the ISOLDE (Isotope Separator OnLine DEvice) facility at CERN is achieved by irradiating target materials (e.g. uranium carbides and metal foils) with protons. The materials are usually operated at temperatures above ...

EPFL2021

Insights into the microbial reduction of pentavalent and hexavalent uranium species by Shewanella oneidensis MR-1

Margaux Camille Andréa Molinas

Decades of uranium-related activities such as ore mining, nuclear power generation, weapon manufacture, storage of nuclear wastes, have contributed to the release of U in the environment. U occurrence is concerning, since in surface environments, U is typi ...

EPFL2021

Synthesis, reactivity, and environmental relevance of uranyl(V) complexes

Radmila Faizova

Knowledge of fundamental chemical properties of all environmentally relevant uranium species is essential to understand environmental uranium mobility and develop novel remediation strate-gies. A myriad of uranium(VI) and uranium(IV) compounds has been stu ...

EPFL2020

Nanoscale mechanism of UO2 formation through uranium reduction by magnetite

Rizlan Bernier-Latmani, Thomas La Grange, Barbora Bártová, Zezhen Pan

Uranium (U) is a ubiquitous element in the Earth's crust at similar to 2 ppm. In anoxic environments, soluble hexavalent uranium (U(VI)) is reduced and immobilized. The underlying reduction mechanism is unknown but likely of critical importance to explain ...

Nature Research2020

Theoretical Investigation of the Electronic Structure and Magnetic Properties of Oxo-Bridged Uranyl(V) Dinuclear and Trinuclear Complexes

Marinella Mazzanti

The uranyl(V) complexes UO2(dbm)(2)K(18C6) (dbm = dibenzoylmethanate) and UO2(L)(L = 2-(4-tolyl)-1,3-bis(quinolyl)malondiiminate), exhibiting diamond-shaped U2O2 and triangular-shaped U3O3 cores respectively with 5f(1)-5f(1 )and 5f(1)-5f(1)-5f(1) ...

2019

The effect of iron binding on uranyl(V) stability

Rosario Scopelliti, Marinella Mazzanti, Radmila Faizova

Here we report the effect of UO2+⋯Fe2+ cation–cation interactions on the redox properties of uranyl(V) complexes and on their stability with respect to proton induced disproportionation. The tripodal heptadentate Schiff base trensal3− ligand allowed the sy ...

2018

Synthesis and Characterization of a Water Stable Uranyl(V) Complex

Rosario Scopelliti, Marinella Mazzanti, Anne-Sophie Chauvin, Radmila Faizova

We have identified a polydentate aminocarboxylate ligand that stabilizes uranyl(V) in water. The mononuclear [UO2(dpaea)]X, (dpaeaH2 = Bis(pyridyl-6-methyl-2-carboxylate)-ethylamine; X = CoCp2*+ or X = K(2.2.2.cryptand) complexes have been isolated from an ...

2018

Microbial communities associated with uranium in-situ recovery mining process are related to acid mine drainage assemblages

Rizlan Bernier-Latmani, Luiz Felippe De Alencastro, Pierre Rossi, Thomas Coral

A large fraction (47%) of the world's uranium is mined by a technique called “In Situ Recovery” (ISR). This mining technique involves the injection of a leaching fluid (acidic or alkaline) into a uranium-bearing aquifer and the pumping of the resulting sol ...

2018

First-principles calculations of momentum distributions of annihilating electron-positron pairs in defects in UO2

Julia Anna Wiktor

We performed first-principles calculations of the momentum distributions of annihilating electron-positron pairs in vacancies in uranium dioxide. Full atomic relaxation effects (due to both electronic and positronic forces) were taken into account and self ...

Iop Publishing Ltd2017

Biogenic non-crystalline U(IV) revealed as major component in uranium ore deposits

Rizlan Bernier-Latmani

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U-(VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U-(IV) ...

Nature Publishing Group2017

Resistive Switching Element and Use Thereof

Giovanni De Micheli, Yusuf Leblebici, Pierre-Emmanuel Julien Marc Gaillardon, Davide Sacchetto, Shashi Kanth Bobba, Tugba Demirci

A bipolar resistive switching device including an electrically conductive bottom electrode, a stack of transition metal oxides layers, a number of transition metal oxide layers being equal or greater than 2, the stack including: at least one MOx layer, at ...

2016

Investigation of the water exchange mechanism of the Plutonyl(VI) and Uranyl(VI) ions with quantum chemical methods

François Rotzinger, Antonio Prlj

The water exchange reactions of PuO2(OH2)(5) and UO2(OH2)(5) were investigated with density functional theory (DFT) and wave function theory (WFT). Geometries and vibrational frequencies were calculated with DFT and CPCM hydration. The electron ...

Taylor & Francis2015

Long-term in-situ oxidation of biogenic uraninite in an alluvial aquifer: impact of dissolved oxygen and calcium

Rizlan Bernier-Latmani, Daniel Scott Alessi, Elena Suvorova Buffat, Harish Veeramani

Oxidative dissolution controls uranium release to (sub)oxic pore waters from biogenic uraninite produced by natural or engineered processes, such as bioremediation Laboratory studies show that uraninite dissolution is profoundly influenced by dissolved oxy ...

Amer Chemical Soc2015

Heterometallic Fe-2(II)-U-V and Ni-2(II)-U-V Exchange-Coupled Single-Molecule Magnets: Effect of the 3d Ion on the Magnetic Properties

Marinella Mazzanti, Lucile Sylvie Danielle Chatelain

Uranium-based compounds have been put forward as ideal candidates for the design of single-molecule magnets (SMMs) with improved properties, but to date, only two examples of exchange-coupled 3d-5f SMM containing uranium have been reported and both are bas ...

Wiley-Blackwell2015

Validation of Two Monte Carlo Codes for LWR Burnup Calculations

Mathieu Hursin, Damar Canggih Wicaksono, Hakim Ferroukhi

This paper presents an assessment conducted at the Paul Scherrer Institut (PSI) of two Monte Carlo-based codes, namely Monteburns and Serpent, for LWR depletion calculations. First, a validation of predicted spent fuel compositions is presented on the basi ...

2014

Speciation and reactivity of uranium products formed during in situ bioremediation in a shallow alluvial aquifer

Rizlan Bernier-Latmani, Daniel Scott Alessi, Elena Suvorova Buffat

In this study, we report the results of in situ U(VI) bioreduction experiments at the Integrated Field Research Challenge site in Rifle, Colorado, USA. Columns filled with sediments were deployed into a groundwater well at the site and, after a period of c ...

Amer Chemical Soc2014

Electron energy loss spectroscopy investigation through a nano ablated uranium dioxide sample

A lamella of uranium dioxide (similar to 10 x similar to 10 x similar to 0.02-0.20 mu m) was produced by focused ion beam for transmission electron and electron energy loss spectroscopy (EELS) examinations. This sample allows quantitative analysis of the E ...

Elsevier Science Bv2013

Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

Jean-Claude Bünzli

The current interest in functionalized calixarenes with phosphorylated pendant arms resides in their coordination ability towards f elements and capability towards actinide/rare earth separation. Uranyl cation forms 1: 1 and 1: 2 (M : L) complexes with a t ...

2012