Publications associées à Théorème d'Earnshaw

Laser Doppler Vibrometer measurements of the 3D pressure field for the estimation of the radiation force produced by an acoustic standing-wave levitator

Acoustic levitation devices use powerful ultrasonic standing waves to levitate objects in mid-air. We have created a system and method to measure the full harmonic content of the acoustic field accurately. Our study revealed that levitated particles alter ...

Elsevier Science Sa2024

Spatiotemporal energy‐density distribution of time‐reversed electromagnetic fields

Farhad Rachidi-Haeri, Marcos Rubinstein, Hamidreza Karami, Elias Per Joachim Le Boudec, Nicolas Mora Parra

Time reversal exploits the invariance of electromagnetic wave propagation in reciprocal and lossless media to localize radiating sources. Time-reversed measurements are back-propagated in a simulated domain and converge to the unknown source location. The ...

2024

Principles and Test Result of Novel Full Passive Magnetic Levitation Motor with Diamagnetic Disk

Hannes Bleuler

This paper proposes a novel full passive magnetic levitation motor without active magnetic suspension. It has a magnetic levitation unit and a motor unit. The Halbach array permanent magnets and a pyrolytic graphite (PG) disk realize the full passive magne ...

IEEE2021

Experimental verification of X-point potential well formation in unfavorable magnetic field direction

Basil Duval, Holger Reimerdes, Christian Gabriel Theiler, Joaquim Loizu Cisquella, Marco Wischmeier, Mirko Wensing, Cedric Kar-Wai Tsui, Claudia Colandrea, Hugo De Oliveira, Sophie Danielle Angelica Gorno

Recent TCV experiments confirm the predicted formation of an electric potential well, below the magnetic X-point, in configurations with unfavorable

B_t

field direction (ion

\nabla B

drift away from the divertor), that substantially reshapes the typica ...

Elsevier2020

Speed and Stability Limits for High-Speed Bearingless Disc Drives

Yves Perriard, Douglas Martins Araujo, Juan Patricio Tomás Peralta Fierro

Increasing material costs and emerging applications have steered research trends towards compacter and therefore faster drives. The arising challenges of miniaturization have made contactless magnetic levitation increasingly attractive, which offer practic ...

IEEE2018

Spin Diffusion in Dynamic Nuclear Polarization Nuclear Magnetic Resonance

Arthur César Pinon

Dynamic Nuclear Polarization (DNP) is currently one of the most efficient ways of enhancing sensitivity in solid-state Nuclear Magnetic Resonance (NMR) experiments. The DNP protocol consists in doping a sample with a small amount of paramagnetic species, t ...

EPFL2018

Realization of a Diamagnetically Levitating Rotor Driven by Electrostatic Field

Hannes Bleuler, Yuanping Xu, Qingwen Cui, Ryosuke Kan, Jin Zhou

In this paper, a novel configuration of frictionless diamagnetic levitation combined with electrostatic glass motor is presented. A 12.5 mm diameter disc shaped rotor comprised of pyrolytic graphite and glass is fabricated. The rotor disc is levitated stab ...

Institute of Electrical and Electronics Engineers2017

Stabilization of electrodynamic bearings with active magnetic dampers

Qingwen Cui

Electrodynamic Bearings (EDBs) are a kind of passive magnetic bearings that exploits the interaction between the induced eddy currents in a conductor and a magnetic field to provide re-storing forces. They have been regarded as an appealing alternative to ...

EPFL2016

Transverse spin penetration length in metallic spin valves

Jean-Philippe Ansermet

A semiclassical description of diffusive spin transport in spin valves, which takes into account the transverse components of spin accumulation, is used to calculate the second harmonic voltage response to a low-frequency current. The description is applie ...

American Institute of Physics2013

Diamagnetic thresholds for sawtooth cycling in tokamak plasmas

Federico David Halpern

The cycling dynamics of the internal kink mode, which drives sawtooth oscillations in tokamak plasmas, is studied using the three dimensional, non-linear magnetohydrodynamic (MHD) code XTOR-2F [H. Lütjens and J.-F. Luciani, J. Comput. Phys. 229, 8130 (2010 ...

American Institute of Physics2011