Concept

Vibrations of a circular membrane

Publications associées (18)

Optothermal shaping of lamb waves with square and spiral phase fronts

Romain Christophe Rémy Fleury, Janez Rus, Aleksi Antoine Bossart

We introduce a Lamb-wave medium with tunable propagation velocities, which are controlled by a two-dimensional heating pattern produced by a laser beam. We utilized it to demonstrate that waves in an appropriately designed medium can propagate in the form ...

2024

From thin plates to Ahmed bodies: linear and weakly nonlinear stability of rectangular prisms

Edouard Boujo, Giuseppe Antonio Zampogna

We study the stability of laminar wakes past three-dimensional rectangular prisms. The width-to-height ratio is set to W/H = 1.2, while the length-to-height ratio 1/6 < L/H < 3 covers a wide range of geometries from thin plates to elongated Ahmed bodies. F ...

CAMBRIDGE UNIV PRESS2023

Space-time wave packets with reduced divergence and tunable group velocity generated in free space after multi-mode fiber propagation

Tobias Kippenberg, Maxim Karpov, Hao Song, Xinzhou Su

Previously, space-time wave packets (STWPs) have been gen-erated in free space with reduced diffraction and a tunable group velocity by combining multiple frequency comb lines each carrying a single Bessel mode with a unique wave num-ber. It might be poten ...

Washington2023

Quantitative Analysis of Nanorough Hydrogenated Si(111) Surfaces through Vibrational Spectral Assignment by Periodic DFT Calculations br

Christophe Ballif, Stefaan De Wolf, Jakub Holovsky

In this work, we use periodic density functional theory(periodic DFT) to rigorously assign vibrational spectra measured on nanorough wet-processed hydrogenated Si(111) surfaces. We compare Si(111)-(1x1) surfaces etched by dilute HF and NH4F, featuring two ...

AMER CHEMICAL SOC2022

Thermal transport beyond Fourier, and beyond Boltzmann

Michele Simoncelli

Crystals and glasses exhibit fundamentally different heat conduction mechanisms: the periodicity of crystals allows for the excitation of propagating vibrational waves that carry heat, as first discussed by Peierls in 1929, while in glasses the lack of per ...

EPFL2021

Raman spectroscopy and lattice dynamics calculations of tetragonally-structured single crystal zinc phosphide (Zn3P2) nanowires

Anna Fontcuberta i Morral, Elias Zsolt Stutz, Jean-Baptiste Leran, Mahdi Zamani, Simon Robert Escobar Steinvall, Rajrupa Paul, Mirjana Dimitrievska

Earth-abundant and low-cost semiconductors, such as zinc phosphide (Zn3P2), are promising candidates for the next generation photovoltaic applications. However, synthesis on commercially available substrates, which favors the formation of defects, and cont ...

2020

Evidence for Marginal Stability in Emulsions

Matthieu Wyart, Jie Lin

We report the first measurements of the effect of pressure on vibrational modes in emulsions, which serve as a model for soft frictionless spheres at zero temperature. As a function of the applied pressure, we find that the density of states D(omega) exhib ...

American Physical Society2016

Experimental mode shape determination of a cantilevered hydrofoil under different flow conditions

Mohamed Farhat, Eduard Egusquiza

The first three mode shapes of a cantilevered NACA0009 hydrofoil were experimentally investigated in air and under different flow conditions in a cavitation tunnel. First and second bending modes and first torsion mode were determined in resonance conditio ...

Professional Engineering Publishing2016

Method and apparatus for a photoacoustic probe using a multimode fiber

Demetri Psaltis, Christophe Moser

This invention is a method and apparatus to pick up a photoacoustic signal purely via optical means and via an endoscope. The photoacoustic endoscope invention relies only on optical excitation and detection methods. A light focus spot generates a photoaco ...

2015

Electroacoustic absorption: towards room equalization in the low-frequency range

Hervé Lissek

The occurrence of standing waves in room dramatically affects the sound rendering in the low-frequency range ([20-200 Hz]), and solutions of the state-of-the-art are incapable to damp such modes over the whole low-frequency band. This talk will present a n ...

2015

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