Publications associées à Relaxation (physics)

Valence can control the nonexponential viscoelastic relaxation of multivalent reversible gels

Gels made of telechelic polymers connected by reversible cross-linkers are a versatile design platform for biocompatible viscoelastic materials. Their linear response to a step strain displays a fast, near-exponential relaxation when using low-valence cros ...

Amer Assoc Advancement Science2024

Testing Theories of the Glass Transition with the Same Liquid but Many Kinetic Rules

Matthieu Wyart, Carolina Brito Carvalho dos Santos

We study the glass transition by exploring a broad class of kinetic rules that can significantly modify the normal dynamics of supercooled liquids while maintaining thermal equilibrium. Beyond the usual dynamics of liquids, this class includes dynamics in ...

Amer Physical Soc2024

Scaling Description of Dynamical Heterogeneity and Avalanches of Relaxation in Glass-Forming Liquids

Matthieu Wyart, Ali Tahaei

We provide a theoretical description of dynamical heterogeneities in glass-forming liquids, based on the premise that relaxation occurs via local rearrangements coupled by elasticity. In our framework, the growth of the dynamical correlation length e and o ...

American Physical Society2023

A Low Power 35 GHz HEMT Oscillator for Electron Spin Resonance Spectroscopy

Giovanni Boero, Nergiz Sahin Solmaz, Alessandro Valentino Matheoud

This paper presents a low power microwave oscillator designed as sensor for electron spin resonance (ESR) spectroscopy. Low power consumption is necessary for low temperature operation. Additionally, lower power consumption allows for a lower microwave mag ...

IEEE2021

In vivo macromolecule signals in rat brain 1 H‐MR spectra at 9.4T: Parametrization, spline baseline estimation, and T 2 relaxation times

Lijing Xin, Cristina Ramona Cudalbu, Bernard Lanz, Veronika Rackayová, Dunja Simicic

Purpose Reliable detection and fitting of macromolecules (MM) are crucial for accurate quantification of brain short-echo time (TE) 1H-MR spectra. An experimentally acquired single MM spectrum is commonly used. Higher spectral resolution at ultra-high fiel ...

Wiley2021

Non-exponential magnetic relaxation in magnetic nanoparticles for hyperthermia

Ferenc Simon, Bence Gábor Márkus

Magnetic nanoparticle based hyperthermia emerged as a potential tool for treating malignant tumours. The efficiency of the method relies heavily on the knowledge of magnetic properties of the samples; in particular, knowledge of the frequency dependent com ...

2021

Nanodiamond Relaxometry-Based Detection of Free-Radical Species When Produced in Chemical Reactions in Biologically Relevant Conditions

Mayeul Sylvain Chipaux

Diamond magnetometry is a quantum sensing method involving detection of magnetic resonances with nanoscale resolution. For instance, T1 relaxation measurements, inspired by equivalent concepts in magnetic resonance imaging (MRI), provide a signal that is e ...

AMER CHEMICAL SOC2020

Phase transitions, screening and dielectric response of CsPbBr3

Dominik Józef Kubicki

Cesium-lead-bromide (CsPbBr3) is the simplest all inorganic halide perovskite. It serves as a reference material for understanding the exceptional solar cell properties of the organic-inorganic hybrid halide perovskites and is itself discussed as an altern ...

Royal Society of Chemistry2020

Cerebral Gray and White Matter Involvement in Anorexia Nervosa Evaluated by T1, T2, and T2*Mapping

Tobias Kober, François Lazeyras, Nurten Ceren Askin

BACKGROUND AND PURPOSE Changes in the brain composition of anorexics could potentially be expected, opening the door to new imaging approaches where quantitative and qualitative MRI have a role. Our purpose was to investigate anorexia-related brain dehydra ...

WILEY2019

Model-assisted identification of solid oxide cell elementary processes by electrochemical impedance spectroscopy measurements

Jan Van Herle, Stefan Diethelm, Arata Nakajo, Priscilla Caliandro

Electrochemical Impedance Spectroscopy (EIS) is extensively used to characterize Solid Oxide Cells (SOCs) to extract information on the elementary loss mechanisms. However, these individual mechanisms usually overlap in the frequency domain, requiring dedi ...

2019

Excited-state band mapping and momentum-resolved ultrafast population dynamics in In/Si(111) nanowires investigated with XUV-based time- and angle-resolved photoemission spectroscopy

Michele Puppin, Matthias Wolf

We investigate the excited state electronic structure of the model phase transition system In/Si(111) using femtosecond time-and angle-resolved photoemission spectroscopy (trARPES). An extreme ultraviolet 500 kHz laser source at 21.7 eV is utilized both to ...

AMER PHYSICAL SOC2019

Energy Relaxation and Thermal Diffusion in Infrared Pump-Probe Spectroscopy of Hydrogen-Bonded Liquids

Michele Ceriotti

Infrared pump-probe spectroscopy provides detailed information about the dynamics of hydrogen-bonded liquids. Due to dissipation of the absorbed pump pulse energy, thermal equilibration dynamics also contributes to the observed signal. Disentangling this c ...

AMER CHEMICAL SOC2019

Ultrafast Broadband Fluorescence Up-conversion Study of the Electronic Relaxation of Metalloporphyrins

Majed Chergui, Andrea Cannizzo, Olivier Christian Bräm

We present a systematic study of the ultrafast fluorescence with broadband detection and similar to 110 fs resolution of 5,10,15,20-tetraphenylporphin (TPP) and 2,3,7,8,12,13,17,18-oc-taethylporphin (OEP), with open 3d-shell metals. We also revisit the cas ...

AMER CHEMICAL SOC2019

Identification of Solid Oxide Cell Elementary Processes by Electrochemical Impedance Spectroscopy

Priscilla Caliandro

The energy sector is undergoing several transformations in an effort to tackle climate change, driving society towards reducing energy consumption and more sustainable energy conversion. In this context, electrochemical devices such as Solid Oxide Cell (SO ...

EPFL2018

Kinetic Monte Carlo approach to nonequilibrium bosonic systems

Timothy Chi Hin Liew, Hugo Pierre Alexandre Flayac

We consider the use of a kinetic Monte Carlo approach for the description of nonequilibrium bosonic systems, taking nonresonantly excited exciton-polariton condensates and bosonic cascade lasers as examples. In the former case, the considered approach allo ...

Amer Physical Soc2017

Simulating Energy Relaxation in Pump-Probe Vibrational Spectroscopy of Hydrogen-Bonded Liquids

Michele Ceriotti

We introduce a nonequilibrium molecular dynamics simulation approach, based on the generalized Langevin equation, to study vibrational energy relaxation in pump probe spectroscopy. A colored noise thermostat is used to selectively excite a set of vibration ...

Amer Chemical Soc2017

Bulk diffusive relaxation mechanisms in optically excited topological insulators

Helmuth Berger, Arnaud Magrez, Alberto Crepaldi, Philippe Bugnon

The possibility to inject spin currents in topological insulators (TIs) by ultrashort optical pulses has stimulated intense studies of their out-of-equilibrium electronic properties. However, a comprehensive description of the electronic relaxation dynamic ...

Amer Physical Soc2017

Water Exchange on [Ln(DO3A)(H2O)2] and [Ln(DTTA–Me)(H2O)2]− Studied by Variable Temperature, Pressure, and Magnetic Field NMR

Lothar Helm, Shima Karimi

Water exchange kinetics of [Ln(L)(H2O)2]x complexes (Ln = Pr, Nd, Dy, Tm, and Yb; L = DO3A and DTTA–Me) were studied by 17O NMR spectroscopy as a function of temperature, pressure, and frequency and by 1H nuclear magnetic relaxation dispersion. Water excha ...

American Chemical Society2016

A nA Crystal - Less Oscillator for Internet of Things

Maher Kayal, François Krummenacher, Mathieu Yves Hervé Coustans

This work presents an ultra-low power oscillator designed to target different contexts, such as crystal-assisted time keeping, reference oscillator to optimize the always on domain of a microcontroller or wake-up timer. This oscillator enables ultra-low po ...

Ieee2016

Effects of elevated temperature on the shear response of PET and PUR foams used in composite sandwich panels

Thomas Keller, Mário Alexandre De Jesus Garrido

Composite sandwich panels comprising fibre reinforced polymer (FRP) skins and lightweight material cores are being increasingly used in civil engineering. In several applications, such as fa ades, roof structures and bridge decks, these panels may experien ...

Elsevier2015