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Concept

Acoustic wave

Publications associées (28)

Toward Band n78 Shear Bulk Acoustic Resonators Using Crystalline Y-Cut Lithium Niobate Films With Spurious Suppression

Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli

This work presents the study of suspended Y-cut Lithium Niobate shear bulk acoustic resonators for wide band filter applications in the frequency range of 3.5-4.5GHz. The resonators consist of a Lithium Niobate film with Aluminum top interdigitated electro ...

Institute of Electrical and Electronics Engineers2023

Acoustic Levitation apparatus (Robotics Practicals)

Mahmut Selman Sakar, Amit Yedidia Dolev, Lorenzo Francesco John Noseda, Bora Yalcin

The following data contain the information and files, which are required to recreate and build the experimental setup that is described in the Laboratory manual. Further details can be found in the associated publication “A graduate laboratory experiment t ...

Zenodo2023

A graduate laboratory experiment to study the dynamics of an acoustically levitated particle

Mahmut Selman Sakar, Amit Yedidia Dolev, Lorenzo Francesco John Noseda, Bora Yalcin

The comprehension of physical wave phenomena is imperative for students in the fields of engineering and basic sciences. Laboratory experiments that involve generation of acoustic waves can be used to explain advanced nonlinear wave phenomena. Acoustic lev ...

2023

Perfluorocarbon emulsion enhances MR-ARFI displacement and temperature in vitro: Evaluating the response with MRI, NMR, and hydrophone

Mohamed Farhat, Davide Bernardo Preso

Sonosensitive perfluorocarbon F(8)TAC(18)-PFOB emulsion is under development to enhance heating, increase thermal contrast, and reduce treatment times during focused ultrasound tumor ablation of highly perfused tissue. The emulsion previously showed enhanc ...

FRONTIERS MEDIA SA2023

Development of Thin Film Lithium Niobate Shear Bulk Acoustic Wave Resonators

Soumya Yandrapalli

RF MEMS piezoelectric acoustic resonators are the essential building blocks for RF filters used in RF front-end modules for wireless mobile communication due to their compact size in the MHz-GHz frequency range, high Quality factors and large relative band ...

EPFL2022

Partial discharge localization in power transformers using acoustic time reversal

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Hamidreza Karami, Florent Quentin Aviolat

The localization of partial discharges (PD) is important to monitor the conditioning of high voltage insulator materials. One of the key components in power grids is the high power transformer. Localization of PDs in these pieces of equipment can increase ...

Elsevier2022

Study on the Performances of AlScN based SAW/BAW Hybrid Resonators A Parametric Analysis of Acoustic Wave Resonators with Large Figure of Merit

Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli

In this study, we analyze a 3rd type of FBAR's fundamental mode by finite element method. We show the importance of the substrate's wave velocity and conductivity on the electromechanical coupling efficiency. Then we demonstrate that etching traditional SA ...

IEEE2021

Partial discharge localization using time reversal: application to power transformers and gas-insulated substations

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Amirhossein Mostajabi, Hamidreza Karami

A method for locating one or multiple partial discharge sources in a power transformer or a Gas-Insulated Substation, whereby the partial discharges emit electromagnetic and acoustic waves, the method comprising recording a signal corresponding to the wave ...

2021

A phenomenological extended-reaction boundary model for time-domain wave-based acoustic simulations under sparse reflection conditions using a wave splitting method

Jan Sickmann Hesthaven

In environmental acoustics and in room acoustics, many surfaces exhibit extended-reaction (ER) behavior, i.e., their surface impedance varies with the angle of the incident sound wave. This paper presents a phenomenological method for modeling such angle d ...

ELSEVIER SCI LTD2021

Electromagnetic Time Reversal: Theory, Application to Fault Location in Power Networks and Experimental Validation

Zhaoyang Wang

The time-reversal invariance is readily described and universally embodied in most laws of nature, either in a strict or in a soft sense. Based on this underlying physical principle, time-reversal theory has been theoretically and experimentally studied in ...

EPFL2020

Measurement and Modeling of Both Distant and Close Electric Fields of an M‐Component in Rocket‐Triggered Lightning

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Amirhossein Mostajabi

Simultaneous measurements of current and multiple‐station electric fields associated with a 5.4‐kA‐peak M‐component in rocket‐triggered lightning are presented in this study. A close‐range electric field measurement site was located northeast of the trigge ...

2020

Coupled-mode theory for stationary and nonstationary resonant sound propagation

Romain Christophe Rémy Fleury, Theodoros Koutserimpas

In this paper, we present a complete analytical derivation of the equations used for stationary and nonstationary wave systems regarding resonant sound transmission and reflection described by the phenomenological coupled-mode theory. We calculate the prop ...

2019

Measurements of ion velocity and wave propagation in a hollow cathode plume

Christopher Andrew Dodson

The mechanism responsible for the production of energetic ions in the plume of hollow cathodes for electric propulsion is still an open issue. These ions are of concern to cathode and thruster lifetime, particularly for cathodes operating at high (>20 A) d ...

IOP PUBLISHING LTD2019

Growth, Integration, and Functional Characterization of AlScN Thin Films for RF MEMS Devices

Fazel Parsapour

Mobile communication has grown explosively in recent years, leading to a strong demand for cheap, but high-performing bandpass filters with low insertion loss and smaller size. Surface acoustic wave (SAW) and thin film bulk acoustic wave (BAW) resonators r ...

EPFL2019

Non-reciprocal optical mirrors based on spatio-temporal acousto-optic modulation

Romain Christophe Rémy Fleury

Here, we investigate a scheme to realize free-space isolators and highly non-reciprocal mirrors with weak modulation imparted by an acoustic wave. We propose a strategy to dramatically break time-reversal symmetry by exploiting resonant interactions betwee ...

2018

Distributed analyses using distinct classes of Brillouin scatterings in optical fibres

Desmond Chow Ming Chia

Brillouin scattering is an interaction between light and sound in a material. This inelastic light scattering had been observed in the first optical fibres that were used in cross-continent communication. Via Brillouin scattering, the guided light wave in ...

EPFL2018

Scattering of SH-waves by an elliptic cavity/crack beneath the interface between functionally graded and homogeneous half-spaces via multipole expansion method

Alireza Ghafarollahi

In this study, based on multipole expansion method an analytical treatment is presented for the anti-plane scattering of SH-waves by an arbitrarily oriented elliptic cavity/crack which is embedded near the interface between exponentially graded and homogen ...

2018

Generation of acoustic helical wavefronts using metasurfaces

Juan Ramon Mosig, Hervé Lissek, Seyyed Hussein Seyyed Esfahlani

It has been shown that acoustic waves with helical wavefronts can carry angular momentum, which can be transmitted towards a propagating medium. Such a wave field can be achieved by using a planar array of electroacoustic transducers, forming a given spati ...

2017

Morphological component analysis for sparse regularization in plane wave imaging

Jean-Philippe Thiran, Yves Wiaux, Rafael Eduardo Carrillo Rangel, Adrien Georges Jean Besson, Dimitris Perdios, Marcel Arditi, Eric Bezzam

Classical ultrasound image reconstruction mainly relies on the well-known delay-and-sum (DAS) beamforming for its simplicity and real-time capability. Sparse regularization methods propose an alternative to DAS which lead to a better inversion of the ill-p ...

Ieee2016

Signal analysis of an actively generated cavitation bubble in pressurized pipes for detection of wall stiffness drops

Anton Schleiss, Giovanni De Cesare, Mohamed Farhat, Alexandre Jean Pachoud, Fadi Hachem

Due to the increasing production of volatile new renewable energies as solar and wind, storage hydropower plants have to operate under harsh operation conditions in order to stabilize the electricity grid. As a result, highly transient water pressures occu ...

Elsevier2016