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Concept

Entropie d'activation

Publications associées (21)

Bending and Stretching in a Narrow Ribbon of Nematic Polymer Networks

Harmeet Singh

We study the spontaneous out-of-plane bending of a planar untwisted ribbon composed of nematic polymer networks activated by a change in temperature. Our theory accounts for both stretching and bending energies, which compete to establish equilibrium. We s ...

SPRINGER2023

Hiding in Plain Sight: The Issue of Hidden Variables

Yimon Aye

Here we discuss "hidden variables", which are typically introduced during an experiment as a consequence of the application of two independent variables together to create a stimulus. With increased sophistication in modern chemical biology tools and relat ...

AMER CHEMICAL SOC2022

Reduction of PdO/Al2O3 in Liquid Cyclohexane Followed In Situ by ATR-IR, High-Energy XRD, and XAS

Oliver Kröcher, Davide Ferri, Thibault Xavier Florian Fovanna

Supported Pd-based catalysts used in heterogeneously catalyzed liquid phase processes often undergo an activation step through reduction of the oxide phase or of the oxidic passivation layer prior to reaction. An oxidized Pd/Al2O3 catalyst was reduced by u ...

AMER CHEMICAL SOC2021

Cu/Metal Oxide Hybrid Nanocrystals as Electrocatalysts for the CO2 Reduction Reaction

Seyedehbehnaz Varandili

The electrochemical CO2 reduction reaction (CO2RR) is envisioned to play a significant role in achieving carbon neutrality while contributing to storing renewable energies. Cu-based materials are among the most promising electrocatalysts. However, 16 diffe ...

EPFL2021

Catalytic Enantioselective Functionalizations of C-H Bonds by Chiral Iridium Complexes

Nicolai Cramer, Jin Fay Tan, Lukasz Piotr Wozniak, Adrien Jules Louis Madron Du Vigné, Qui-Hien Nguyen, Vitalii Smal

The development of catalytic enantioselective transformations, enabling the construction of complex molecular scaffolds from simple precursors, has been a long-standing challenge in organic synthesis. Recent achievements in transition-metal catalyzed enant ...

2020

Partial Hydrogenation of 2-Methyl-3-butyn-2-ol over Pd/ZnO: Effect of Reduction Temperature on Alloy Formation and Catalytic Response

Lioubov Kiwi

We have investigated the catalytic effect of the beta-phase PdZn alloy on selective gas-phase hydrogenation of 2-methyl-3-butyn-2-ol over Pd/ZnO using Pd/Al2O3 as a benchmark. Activation (in H-2) of Pd/ZnO to 973 K generated a beta-phase PdZn alloy (from X ...

AMER CHEMICAL SOC2020

Impact of alloy disorder on Auger recombination in single InGaN/GaN core-shell microrods

Benoît Marie Joseph Deveaud, Gwénolé Jean Jacopin, Georg Rossbach, Wei Liu

We study the influence of local inhomogeneities on carrier recombination dynamics in single InGaN/GaN core-shell microrods (MRs) by means of time-resolved microphotoluminescence (TRPL) at 10 K. At low carrier density (similar to 10(11) cm(-2)), the carrier ...

2019

Generation of Heteroatom Stereocenters by Enantioselective C-H Functionalization

Nicolai Cramer, Johannes Diesel

C-H functionalization has been established as an efficient way to generate molecular complexity. The formation of stereogenic carbon atoms by asymmetric C-H functionalization has seen tremendous progress over the past decade. More recently, the direct cata ...

2019

Design and characterization of variable stiffness structural joints

Gennaro Senatore

This paper presents design and characterization of a new type of structural joint which can vary its stiffness through actuation. Stiffness variation is employed to control the dynamic response of frame structures equipped with such joints. The joint is ma ...

2019

Catalyst design for the transformation of CO2 into value-added products

Felix Daniel Bobbink

The mass-utilization of fossil resources has led to a dramatic increase in carbon dioxide (CO2) production, most of which is released directly into the Earth's atmosphere, resulting in global warming. Efforts to contain CO2 emissions and to capture, store ...

EPFL2018

Rhodium(III)-Catalyzed Enantiotopic C-HActivation Enables Access to P-Chiral Cyclic Phosphinamides

Nicolai Cramer, Yang Sun

Compounds with stereogenic phosphorus atoms are frequently used as ligands for transition-metal as well as organocatalysts. A direct catalytic enantioselective method for the synthesis of P-chiral compounds from easily accessible diaryl phosphinamides is p ...

Wiley-Blackwell2017

Elevated temperature, micro-compression transient plasticity tests. on nanocrystalline Palladium-Gold: Probing activation parameters at the lower limit of crystallinity

Stefano Mischler, Johann Michler, Xavier Maeder

In this study, we probe the activation parameters and time-dependent plastic behavior of a nano crystalline Palladium-Gold alloy by means of elevated temperature micropillar compression experiments. All tests were conducted on a stable, displacement-contro ...

Pergamon-Elsevier Science Ltd2017

Activated Dissociation of HCl on Au(111)

We report zero-coverage reaction probabilities (S-0) for HCl dissociative adsorption on Au(111) obtained by the seeded molecular beam hot-nozzle method. For measurements at normal incidence with mean translational energies ranging from 0.94 to 2.56 eV (noz ...

Amer Chemical Soc2016

Reconstitution of [Fe]-hydrogenase using model complexes

Xile Hu, Matthew Wodrich, Dafa Chen, Tao Xu

[Fe]-Hydrogenase catalyses the reversible hydrogenation of a methenyltetrahydromethanopterin substrate, which is an intermediate step during the methanogenesis from CO2 and H-2. The active site contains an iron-guanylylpyridinol cofactor, in which Fe2+ is ...

Nature Publishing Group2015

A Deeper Look at Dataset Bias

Barbara Caputo, Tatiana Tommasi, Novi Patricia

The presence of a bias in each image data collection has recently attracted a lot of attention in the computer vision community showing the limits in generalization of any learning method trained on a specific dataset. At the same time, with the rapid deve ...

Springer Int Publishing Ag2015

Reactions of Grignard Reagents with Nitrous Oxide

Rosario Scopelliti, Kay Severin, Euro Solari, Alexander Tskhovrebov

The chemical activation of nitrous oxide (N2O) can be achieved by organocalcium, organosodium, and organolithium compounds. Grignard reagents, on the other hand, are believed to be inert. We demonstrate that this generalization is not correct. Some aliphat ...

American Chemical Society2014

Loading and release of internally self-assembled emulsions embedded in a magnetic hydrogel

László Forró, Andrzej Sienkiewicz, Katarzyna Pierzchala

We have investigated drug loading and release from thermosensitive gel emulsions with external triggering by an alternating magnetic field (AMF) for on-demand drug delivery. Superparamagnetic iron oxide nanoparticles dispersed in gel emulsions were used to ...

Amer Inst Physics2014

About the activation volume for cross-slip in Cu at high stresses

The experiment performed by Bonneville and Escaig, designed for the direct measurement of the activation parameters of cross-slip, has been repeated. A denser initial dislocation forest density is obtained with a higher predeformation stress compared with ...

2011

Exploring G-Protein Coupled Receptor Activation with Multiscale Molecular Simulations

Stefano Vanni

This thesis is devoted to the study of the activation mechanism of G-protein coupled receptors (GPCRs), one of the largest and most diverse protein families in mammalian genomes, by means of different computer-based simulation techniques. Using force field ...

EPFL2011

Mode-specific reactivity of CH4 on Pt(110)-(1×2): The concerted role of stretch and bend excitation

Rainer Beck, Régis Bisson, Marco Sacchi

The state-resolved reaction probability of CH4 on Pt(110)-(1×2) was measured as a function of CH4 translational energy for four vibrational eigenstates comprising different amounts of C-H stretch and bend excitation. State-specific reactivity is observed b ...

American Physical Society2010