Publications associées à Vitesse de dérive (électricité)

An experimental study on the upper part-load elliptical vortex instability in a Francis turbine

François Avellan, Elena Vagnoni, Arthur Tristan Favrel, Andres Müller, Ali Amini

This paper presents preliminary results of an experimental study on the occurrence and development of the upper part-load instability in a reduced-scale Francis turbine. The study includes draft tube pressure measurements, high-speed flow visualization, an ...

IOP PUBLISHING LTD2021

Theory and Computation of Hall Scattering Factor in Graphene

Samuel Poncé, Feliciano Giustino

The Hall scattering factor, r, is a key quantity for establishing carrier concentration and drift mobility from Hall measurements; in experiments, it is usually assumed to be 1. In this paper, we use a combination of analytical and ab initio modeling to de ...

AMER CHEMICAL SOC2020

Lorentz Force from a Current-Carrying Wire on a Charge in Motion under the Assumption of Neutrality in the Symmetrical Frame of Reference

Marcos Rubinstein, Antonio Sunjerga

It is commonly assumed that a wire conducting an electric current is neutral in the laboratory frame of reference (the rest frame of the lattice of positive ions). Some authors consider that the wire is neutral only in a symmetrical frame of reference, in ...

2018

Implementation of drift velocities and currents in SOLEDGE2D-EIRENE

Davide Galassi, Nicolas Mellet, Eric Serre

In order to improve cross-field transport description, drifts and currents have been implemented in SOLEDGE2D-EIRENE. The derivation of an equation for the electric potential is recalled. The resolution of current equation is tested in a simple slab case. ...

Elsevier2017

Room-Temperature Negative Differential Resistance in Graphene Field Effect Transistors: Experiments and Theory

Mihai Adrian Ionescu, Arnaud Magrez, Antonios Bazigos, Laurent Syavoch Bernard, Pankaj Sharma

In this paper we demonstrate experimentally and discuss the negative differential resistance (NDR) in dual-gated graphene field effect transistors (GFETs) at room temperature for various channel lengths, ranging from 200 nm to 5 mu m. The GFETs were fabric ...

Amer Chemical Soc2015

Modulation Doping of GaAs/AlGaAs Core-Shell Nanowires With Effective Defect Passivation and High Electron Mobility

Anna Fontcuberta i Morral, Federico Matteini, Fauzia Jabeen, Alberto Casadei, Sonia Conesa Boj, Francesca Amaduzzi

Reliable doping is required to realize many devices based on semiconductor nanowires. Group IIIV nanowires show great promise as elements of high-speed optoelectronic devices, but for such applications it is important that the electron mobility is not comp ...

American Chemical Society2015

Mobility Measurement in Nanowires Based on Magnetic Field-Induced Current Splitting Method in H-Shape Devices

Jean-Michel Sallese, Didier Bouvet, Farzan Jazaeri, Lucian Barbut

This work investigates a new method to measure mobility in nanowires. Based on a simple analytical approach and numerical simulations, we bring evidence that the traditional technique of Hall voltage measurement in low dimensional structures such as nanowi ...

Institute of Electrical and Electronics Engineers2014

Integrated Hall Magnetic Angle Sensors

Radivoje Popovic

A magnetic angle sensor is a matched combination of a permanent magnet, affixed to a rotating shaft, and a magnetic field sensor. The magnet part of the angle sensors is configured so as to create either a magnetic field with an angle-dependent component p ...

Soc Microelectronics, Electron Components Materials-Midem2014

Basic investigations of electrostatic turbulence and its interaction with plasma and suprathermal ions in a simple magnetized toroidal plasma

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Christian Gabriel Theiler, Joaquim Loizu Cisquella, Fabio Avino, Nicola Vianello, Sébastien Jolliet, Fabio Riva, Kyle Gustafson, Alexandre Dominique Bovet

Progress in basic understanding of turbulence and its influence on the transport both of the plasma bulk and of suprathermal components is achieved in the TORPEX simple magnetized torus. This configuration combines a microwave plasma production scheme with ...

IOP Publishing Ltd2013

A case study on spatial and temporal hydraulic variability in an alpine gravel-bed stream based on the hydromorphological index of diversity

Anton Schleiss, Walter Gostner, Piotr Parasiewicz

Physical heterogeneity is a major topic in river sciences because it is known to be a key factor for ecological integrity. In this paper, we investigated the hydraulic enviroment in an alpine gravel-bed stream with an unaltered hydrological regime. The stu ...

John Wiley and Sons2013

Controlling edge states in the Kane-Mele model via edge chirality

Oleg Yazyev, Gabriel Albert Autes

We investigate the dependence of band dispersion of the quantum spin Hall effect (QSHE) edge states in the Kane-Mele model on crystallographic orientation of the edges. Band structures of the one-dimensional honeycomb lattice ribbons show the presence of t ...

Wiley-V C H Verlag Gmbh2013

Impact Ionization and Carrier Multiplication in Graphene

Yusuf Leblebici, Luca Pirro

We develop a model for carrier generation by impact ionization in graphene, which shows that this effect is non-negligible because of the vanishing energy gap, even for carrier transport in moderate electric fields. Our theory is applied to graphene field ...

American Institute of Physics2012

The Hydro-Morphological Index of Diversity : a Planning Tool for River Restoration Projects

Walter Gostner

Contemporary river engineering must guarantee effective long-term flood protection while also improving stream ecology. Nowadays, river engineering projects must aim at optimizing hydromorphological heterogeneity, as this is an acknowledged basic condition ...

EPFL2012

Impact Load Measurements in an Erosive Cavitating Flow

Ayat Karimi, Jean-Pierre Franc

Impact load measurements were carried out in a high-speed cavitation loop by means of a conventional pressure sensor flush-mounted in the region of closure of the cavity where maximum damage was observed. The sensor was dynamically calibrated by the ball d ...

2011

Two-dimensional Vlasov simulation of electron plasma wave trapping, wavefront bowing, self-focusing, and sideloss

Stephan Brunner

Two-dimensional Vlasov simulations of nonlinear electron plasma waves are presented, in which the interplay of linear and nonlinear kinetic effects is evident. The plasma wave is created with an external traveling wave potential with a transverse envelope ...

American Institute of Physics (AIP)2011

On A Class Of Mean Field Solutions Of The Monge Problem For Perfect And Self-Interacting Systems

Philippe Choquard

The Monge problem (Monge 1781; Taton 1951), as reformulated by Kantorovich (2006a, 2006b) is that of the transportation at a minimum "cost" of a given mass distribution from an initial to a final position during a given time interval. It is an optimal tran ...

2010

Multiscale Computational Methodology Applied to Hydroacoustic Resonance in Cavitating Pipe Flow

Nicolas Ruchonnet

The present work is a contribution to the physical analysis and numerical simulation of the pressure surges in hydraulic machinery and connected conduit systems. Localized hydrodynamic instabilities including cavitation are prone to interact with the entir ...

EPFL2010

Direct use of discrete complex image method for evaluating electric field expressions in a lossy half space

Abdolhamid Shoory

A modelling technique is proposed for direct use of the discrete complex image method (DCIM) to derive closed-form expressions for electric field components encountered in the electric field integral equation (EFIE) representing a lossy half space problem. ...

2010

Divertor power deposition and target current asymmetries during type-1 ELMS in ASDEX Upgrade and JET

Richard Pitts

Analysis of the type-l ELM power load asymmetries using infra-red thermography and target current measurements is performed ASDEX Upgrade Upper Single Null and JET DOC-L type-I ELMy H-Mode discharges with 'normal' and,reversed' field direction, i.e. with t ...

2007

High electron mobility lattice-matched AlInN/GaN field-effect transistor heterostructures

Nicolas Grandjean, Jean-François Carlin, Eric Feltin, Marcel Py, Marcus Gonschorek

Room temperature electron mobility of 1170 cm(2)/V s is obtained in an undoped, lattice-matched, Al0.82In0.18N/GaN field-effect transistor heterostructure, while keeping a high (2.6 +/- 0.3)x10(13) cm(-2) electron gas density intrinsic to the Al0.82In0.18N ...

2006