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Publications associées (66)

Well-Defined Ti Surface Sites in Ziegler-Natta Pre-Catalysts from 47/49Ti Solid-State Nuclear Magnetic Resonance Spectroscopy

Treatment of Ziegler-Natta (ZN) catalysts with BCl3 improves their activity by increasing the number of active sites. Here we show how Ti-47/49 solid-state nuclear magnetic resonance (NMR) spectroscopy enables us to understand the electronic structure of t ...

Washington2024

Room-temperature strength of the interfacial bond between silica inclusions and iron

Andreas Mortensen, David Hernandez Escobar, Alejandra Inés Slagter, Sergio Perosanz Amarillo

The strength of the interface between iron (Fe) and individual spherical silica (SiO2) inclusions of 5 +/- 1 mu m diameter is measured by means of in-situ micro-cantilever bending tests conducted under displacement control within a scanning electron micros ...

Oxford2023

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

Philippe Gillet, Marco Cantoni, James Badro, Susannah McGregor Dorfman, Farhang Nabiei, 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

The effect of alkali hydroxides and equilibration time on Al uptake by calcium silicate hydrates (C-S-H)

Sonya Barzgar

Cement production accounts for approximately 8% of man-made CO2 emissions. Lowering these CO2 emissions is currently one of the most important and urgent research topics within the cement community. To reduce these emissions, the Portland cement (PC) is pa ...

EPFL2021

Efficacy of SCMs to mitigate ASR in systems with higher alkali contents assessed by pore solution method

Karen Scrivener, Lionel Sofia, Marie Joshua Tapas

This study demonstrates the efficacy of supplementary cementitious materials (SCMs) to mitigate alkali-silica reaction (ASR) even when used in conjunction with cement of higher alkali contents (up to 1% Na2Oeq). The expansion of concrete prisms was studied ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Dissolved major and trace geochemical dynamics in Antarctic lacustrine systems

Tyler Joe Kohler

Clearwater Mesa Uames Ross Island, northeast Antarctic Peninsula) provides a unique opportunity to study solute dynamics and geochemical weathering in the pristine lacustrine systems of a high latitude environment. In order to determine major controls on t ...

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

Mn4+-Substituted Li-Rich Li1.2Mn0.43+Mnx4+Ti0.4-xO2 Materials with High Energy Density

Chunyang Zhang, Yong Yang

In this work, Li-rich Li1.2Mn0.43+Mnx4+Ti0.4-xO2 (LMMxTO, 0

2020

Deciphering Iron-Dependent Activity in Oxygen Evolution Catalyzed by Nickel-Iron Layered Double Hydroxide

Xile Hu, Lichen Bai, Seunghwa Lee

Nickel iron oxyhydroxide is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium. Whereas the presence of Fe ions is essential to the high activity, the functions of Fe are currently under debate. Using oxygen isotope labeling ...

WILEY-V C H VERLAG GMBH2020

Cracks, porosity and microstructure of Ti modified polymer-derived SiOC revealed by absorption-, XRD- and XRF-contrast 2D and 3D imaging

Jürgen Brugger, Helena Van Swygenhoven, Nicola Casati, Lorenz Hagelüken

Morphology, phase composition, cracks and porosity are investigated in monolithic Ti modified SiOC polymer-derived ceramics pyrolyzed at 1000°C and 1400°C using synchrotron X-ray full field absorption- contrast tomographic microscopy and scanning XRF- and ...

2020

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