Publications associées à Signal carré

Optothermal shaping of lamb waves with square and spiral phase fronts

Romain Christophe Rémy Fleury, Aleksi Antoine Bossart, Janez Rus

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

Generalised Kerr Microcomb Physics in Synchronously Driven Systems

Miles Henry Anderson

In this thesis, the generation of microcombs under complex, non-trivial, and/or higher-order cavity conditions is explored, both in theory & simulation, and in practical experimentation. Pulse-driving of microresonators is investigated for the generation ...

EPFL2023

Zero dispersion Kerr solitons in optical microresonators

Tobias Kippenberg, Junqiu Liu, Wenle Weng, Miles Henry Anderson, Alexey Tikan

Solitons are shape preserving waveforms that are ubiquitous across nonlinear dynamical systems from BEC to hydrodynamics, and fall into two separate classes: bright solitons existing in anomalous group velocity dispersion, and switching waves forming 'dark ...

Nature Research2022

On the reconstruction of the attenuation function of a return-stroke current from the Fourier Transform of finite-duration measurements

Farhad Rachidi-Haeri, Marcos Rubinstein

A correct representation of the lightning current is crucial when the electromagnetic field radiated to a point of interest has to be computed. Based on the engineering models of Transmission Line type, such representation involves the knowledge of the ret ...

2022

Analytical Expressions for Lightning Electromagnetic Fields With Arbitrary Channel-Base Current—Part I: Theory

Marcos Rubinstein

The article provides analytical expressions for the electromagnetic fields generated by a lightning return stroke characterized by a channel-base current with arbitrary time waveform, in presence of either a perfectly conducting or a lossy ground, assuming ...

2021

Quantum interference effects of out-of-plane confinement on two-dimensional electron systems in oxides

Emmanouil Frantzeskakis, Ji Dai

It was recently discovered that a conductive, metallic state is formed on the surface of some insulating oxides. First observed on SrTiO3 (001), it was then found in other compounds as diverse as anatase TiO2, KTaO3, BaTiO3, ZnO, and also on different surf ...

2020

Importance of Taking Into Account the Soil Stratification in Reproducing the Late-Time Features of Distant Fields Radiated by Lightning

Marcos Rubinstein, Antonio Sunjerga, Farhad Rachidi-Haeri, Qi Li, Mi Zhou

In this paper, we present an analysis of the propagation effect along a lossy ground on the characteristics of lightning-generated electric fields, using simultaneous observations of lightning currents and radiated fields measured at nine different distanc ...

2019

Tokamak plasma edge studies by microwave short-pulse reflectometry and backscattering

Pedro Andres Molina Cabrera

Moving towards an increased understanding of the dynamic processes in the edge of tokamak plasmas requires continuous innovation in diagnostic capabilities, pushing the envelope in both spatial and temporal dimenstions. Plasma density and rotation, and the ...

EPFL2019

No time for drifting: Comparing performance and applicability of signal detrending algorithms for real-time fMRI

Dimitri Nestor Alice Van De Ville, Frank Scharnowski, Yury Koush, Rotem Roza Kopel

As a consequence of recent technological advances in the field of functional magnetic resonance imaging (fMRI), results can now be made available in real-time. This allows for novel applications such as online quality assurance of the acquisition, intra-op ...

2019

Peta-pico-Voltron: An open-source high voltage power supply

Samuel Rosset, Samuel Schlatter

We present the design (hardware + software) of “Peta-pico-Voltron”, a low-current high voltage power supply for electrostatic actuators. Developed primarily for dielectric elastomer actuators, it offers a low-cost solution to generate user controllable vol ...

2018

High sensitivity field asymmetric ion mobility spectrometer

Jürgen Brugger, Giovanni Boero, Alessandro Valentino Matheoud, Mario Andres Chavarria Varon, Philippe Marmillod

A high sensitivity field asymmetric ion mobility spectrometer (FAIMS) was designed, fabricated, and tested. The main components of the system are a 10.6 eV UV photoionization source, an ion filter driven by a high voltage/high frequency n-MOS inverter circ ...

American Institute of Physics2017

Analytical Time-Domain Solution of Plane Wave Propagation Across a Viscoelastic Rock Joint

Lyesse Laloui, Jian Zhao, Yang Zou

The effects of viscoelastic filled rock joints on wave propagation are of great significance in rock engineering. The solutions in time domain for plane longitudinal ( P-) and transverse ( S-) waves propagation across a viscoelastic rock joint are derived ...

Springer Verlag2017

Analysis of lightning-ionosphere interaction using simultaneous records of source current and 380 km distant electric field

Mario Paolone, Marcos Rubinstein, Mohammad Azadifar, Farhad Rachidi-Haeri, Wolfgang Schulz, Davide Pavanello, Dongshuai Li

We present simultaneous current and wideband electric field waveforms at 380 km associated with upward lightning flashes initiated from the Santis Tower, Switzerland. To the best of our knowledge, the dataset presented in this study includes the first simu ...

Elsevier2017

An experimentalist's guide to the matrix element in angle resolved photoemission

Simon Karl Moser

Angle resolved photoemission spectroscopy (ARPES) is commonly known as a powerful probe of the one-electron removal spectral function in ordered solid state. With increasing efficiency of light sources and spectrometers, experiments over a wide range of em ...

Elsevier Science Bv2017

Time-Resolved Nonlinear Coupling between Orthogonal Flexural Modes of a Pristine GaAs Nanowire

Anna Fontcuberta i Morral, Gözde Tütüncüoglu, Federico Matteini

We demonstrate nonlinear coupling between two orthogonal flexural modes of single as-grown GaAs nanowires. The resonant frequency of one mode can be shifted over many line widths by mechanically driving the other mode. We present time-domain measurements o ...

American Chemical Society2016

On Lightning Electromagnetic Field Propagation Along an Irregular Terrain

Mario Paolone, Marcos Rubinstein, Mohammad Azadifar, Farhad Rachidi-Haeri, Zhaoyang Wang, Stefan Metz, Davide Pavanello, Dongshuai Li, Qilin Zhang

In this paper, we present a theoretical analysis of the propagation effects of lightning electromagnetic fields over a mountainous terrain. The analysis is supported by experimental observations consisting of simultaneous records of lightning currents and ...

Institute of Electrical and Electronics Engineers2016

Duration of Purkinje cell complex spikes increases with their firing frequency

Michele Giugliano

Climbing fiber (CF) triggered complex spikes (CS) are massive depolarization bursts in the cerebellar Purkinje cell (PC), showing several high frequency spikelet components (+/- 600 Hz). Since its early observations, the CS is known to vary in shape. In th ...

Frontiers Research Foundation2015

Elasto-Dynamic Behavior of a Two-Dimensional Square Lattice With Entrained Fluid II: Microstructural and Homogenized Models

Alessandro Spadoni, Vladimir Dorodnitsyn

This paper presents a detailed study of the pressure waves and effective mechanical properties of a closed-cell cellular solid with entrained fluid. Plane-harmonic-waves are analyzed in a periodic square with a finite-element model of a representative-volu ...

Asme2014

Fast prediction and evaluation of gravitational waveforms using surrogate models

Jan Sickmann Hesthaven

We propose a solution to the problem of quickly and accurately predicting gravitational waveforms within any given physical model. The method is relevant for both real-time applications and in more traditional scenarios where the generation of waveforms us ...

American Physical Society2014

A General Family of Morphed Nonlinear Phase Oscillators with Arbitrary Limit Cycle Shape

Auke Ijspeert, Mostafa Ajallooeian, Jesse van den Kieboom

We present a general family of nonlinear phase oscillators which can exhibit arbitrary limit cycle shapes and infinitely large basins of attraction. This general family is the superset of familiar control methods like PD-control over a periodic reference, ...

Elsevier Science Bv2013