Publications related to Kinetic isotope effects for fast deuterium and proton exchange rates

129Xe Dynamic Nuclear Polarization Demystified: The Influence of the Glassing Matrix on the Radical Properties

Rolf Gruetter, Jean-Noël Hyacinthe, Andrea Capozzi, Thanh Phong Kevin Lê, Emma Linnea Wiström

129Xe dissolution dynamic nuclear polarization (DNP) is a controversial topic. The gold standard technique for hyperpolarized xenon magnetic resonance imaging (MRI) is spin exchange optical pumping, which received FDA approval in 2022. Nevertheless, the ve ...

2024

Deuterated TEKPol Biradicals and the Spin-Diffusion Barrier in MAS DNP

Dominik Józef Kubicki, David Lyndon Emsley, Yu Rao, Amrit Venkatesh, Federico De Biasi

The sensitivity of NMR spectroscopy is considerably enhanced by dynamic nuclear polarization (DNP). In DNP polarization is transferred from unpaired electrons of a polarizing agent to nearby proton spins. In solids, this transfer is followed by the transpo ...

Wiley-VCH Verlag GmbH2023

Long-Distance Coherent Propagation of High-Velocity Antiferromagnetic Spin Waves

Jean-Philippe Ansermet, Haiming Yu, Song Liu, Jilei Chen, Cheng Song, Rundong Yuan, Yao Zhang

We report on coherent propagation of antiferromagnetic (AFM) spin waves over a long distance (similar to 10 mu m) at room temperature in a canted AFM alpha-Fe2O3 owing to the Dzyaloshinskii-Moriya interaction (DMI). Unprecedented high group velocities (up ...

AMER PHYSICAL SOC2023

NMR Crystallography in the Big Data Era: New Methods and Applications Powered by Machine Learning

Manuel Cordova

Structure determination of materials is key to understanding their physical properties. While single-crystal X-ray diffraction is the gold standard for structures displaying long-range order, many materials of interest are polycrystalline and/or disordered ...

EPFL2023

The role of Zn in C-S-H atomic structure, nucleation and growth

Anna Morales Melgares

The most promising solution towards cementitious materials with a lower carbon footprint is the partial substitution of the clinker by supplementary cementitious materials (SCMs) such as fly ash, blast furnace slag, limestone and calcined clays. The produc ...

EPFL2023

Chiral magnetohydrodynamics with zero total chirality

Kohei Kamada, Jennifer Waltraud Schober

We study the evolution of magnetic fields coupled with chiral fermion asymmetry in the framework of chiral magnetohydrodynamics with zero initial total chirality. The initial magnetic field has a turbulent spectrum peaking at a certain characteristic scale ...

American Physical Society2023

Magnetic Resonance and Hyperpolarization Methods for Perovskite Photovoltaics

Aditya Mishra

Solid-state NMR can provide information about the atomic-level microstructure and dynamics in materials as it directly probes the local nuclear environment. In the last decade, halide perovskites have drawn intense interest because of their intriguing opto ...

EPFL2022

Characterization of Chemisorbed Species and Active Adsorption Sites in Mg-Al Mixed Metal Oxides for High-Temperature CO2 Capture

Berend Smit, Christopher Patrick Ireland, Kevin Maik Jablonka, Susana Garcia Lopez

Mg-Al mixed metal oxides (MMOs), derived from the decomposition of layered double hydroxides (LDHs), have been purposed as adsorbents for CO2 capture of industrial plant emissions. To aid in the design and optimization of these materials for CO2 capture at ...

AMER CHEMICAL SOC2022

Mechanistic studies of DNP and applications of hyperpolarized probes to study renal physiology and metabolism

Alice Radaelli

Dissolution dynamic nuclear polarization (dDNP) is a powerful technique that enhances the magnetic resonance signal of nuclear spins by several orders of magnitude. DNP relies on the principle of cross-relaxation by electron spins driven out of equilibrium ...

EPFL2021

Hyperpolarization of inorganic solids

Snaedis Björgvinsdóttir

Solid-state NMR can provide information about the atomic level structure and dynamics of materials. It directly probes symmetry and structure at nuclear sites, and is especially useful for investigation of disordered or amorphous solids that lack long rang ...

EPFL2020

Solid-state NMR spectroscopy

David Lyndon Emsley

Solid-state nuclear magnetic resonance (NMR) spectroscopy is an atomic-level method to determine the chemical structure, 3D structure and dynamics of solids and semi-solids. This Primer summarizes the basic principles of NMR spectroscopy as applied to the ...

SPRINGERNATURE2021

Scaling analyses for hyperpolarization transfer across a spin-diffusion barrier and into bulk solid media

Arthur César Pinon, David Lyndon Emsley, Bradley Floyd Chmelka

By analogy to heat and mass transfer film theory, a general approach is introduced for determining hyperpolarization transfer rates between dilute electron spins and a surrounding nuclear ensemble. These analyses provide new quantitative relationships for ...

2021

Regional Effects of Exchange Rate Fluctuations

Christian Pröbsting

We exploit differences across U.S. states' exposure to trade to study the effects of changes in the exchange rate on economic activity. Across states, trade-weighted exchange rate depreciations are associated with increased state exports, reduced state une ...

2020

Sensitivity Enhancements in Lithium Titanates by Incipient Wetness Impregnation DNP NMR

David Lyndon Emsley, Snaedis Björgvinsdóttir, Pierrick Berruyer, Pinelopi Moutzouri, Michael Allan Hope

Solid-state NMR spectroscopy is a widely used method for investigating structural and electronic properties of inorganic materials, but its use is often limited by low sensitivity. Here, we show how solvent-generated dynamic nuclear polarization can be use ...

2020

Exchange Rate Analysis by Nonlinear Time Series Method

Maria-Alexandra Paun

A financial data analysis using the time series method has been performed. At the same time a correct interpretation of daily exchange rates fluctuations, for Eur foreign currencies is presented. The fractal dimension evaluation has been performed using th ...

AMER INST PHYSICS2020

Watertable fluctuation-induced variability in the water retention curve: Sand column experiments

David Andrew Barry, Zhaoyang Luo

The soil water retention curve (WRC), describing the relation between the soil water content and its corresponding capillary pressure, relies not only on whether drying or wetting occurs but also on the pore scale water flow velocity. Here, we investigated ...

2020

Maximizing nuclear hyperpolarization in pulse cooling under MAS

Nicolas Luc Matthey, David Lyndon Emsley, Brennan James Walder

It has recently been shown how dynamic nuclear polarization can be used to hyperpolarize the bulk of proton-free solids. This is achieved by generating the polarization in a wetting phase, transferring it to nuclei near the surface and relaying it towards ...

Academic Press Inc - Elsevier Science2019

A Factor Two Improvement in High-Field Dynamic Nuclear Polarization from Gd(III) Complexes by Design

Anne-Sophie Chauvin, Marinella Mazzanti, Dominik Józef Kubicki, David Lyndon Emsley, Gabriele Stevanato, Georges Guévork Jean-Jacques Menzildjian

Gadolinium(III) complexes have recently been demonstrated to have potential as polarizing agents for high-field dynamic nuclear polarization (DNP) NMR spectroscopy. By tailoring the ligand design to reduce the zero-field splitting (ZFS), we demonstrate a q ...

2019

New Approaches to NMR Crystallography

Federico Maria Paruzzo

The first full protocol for nuclear magnetic resonance (NMR) crystallography (NMRX) using chemical shifts was developed a decade ago, and it combines experimental isotropic chemical shifts with crystal structure prediction (CSP) and with the calculation of ...

EPFL2019

Measurement of Proton Spin Diffusivity in Hydrated Cementitious Solids

David Lyndon Emsley, Brennan James Walder, Jayasubba Reddy Yarava, Federico Maria Paruzzo, Bradley Floyd Chmelka

The study of hydration and crystallization processes involving inorganic oxides is often complicated by poor long-range order and the formation of heterogeneous domains or surface layers. In solid-state NMR, H-1-H-1 spin diffusion analyses can provide info ...

2019