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Concept

Schumann resonances

Related publications (22)

Lightning interaction with the ionosphere

Farhad Rachidi-Haeri, Marcos Rubinstein

Lightning discharges, including cloud-to-ground (CG) and intracloud (IC) lightning, are known to emit electromagnetic pulses (EMPs) in a wide frequency band ranging from few Hz up to hundreds MHz [1]. During the breakdown and ionization processes (mostly f ...

IET2023

Ionospheric Variations Induced by Thunderstorms in the Central Region of Argentina during the RELAMPAGO–CACTI Campaign

Farhad Rachidi-Haeri, Marcos Rubinstein

The ionosphere can be perturbed by solar and geomagnetic activity, earthquakes, thunderstorms, etc. In particular, electromagnetic pulses produced by thunderstorms can generate wave structures in the ionospheric plasma, which are known as atmospheric gravi ...

2023

A Correlation-Based Electromagnetic Time Reversal Technique to Locate Indoor Transient Radiation Sources

Farhad Rachidi-Haeri, Marcos Rubinstein, Zhaoyang Wang, Qi Li

To overcome the multipath interference in locating transient electromagnetic (EM) radiation sources in an indoor environment, we propose a criterion that calculates the correlation between back-propagated signals from observation points, to be used in EM t ...

Institute of Electrical and Electronics Engineers2021

Impact of Frequency-Dependent Soil Models on Grounding System Performance for Direct and Indirect Lightning Strikes

Farhad Rachidi-Haeri

The goal of this article is to investigate the effect of frequency-dependent soil models on the performance of grounding electrodes subjected to lightning strikes. Several soil models are examined while accounting for the variation of soil resistivity and ...

2021

An Efficient FDTD Method to Calculate Lightning Electromagnetic Fields Over Irregular Terrain Adopting the Moving Computational Domain Technique

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Wenhao Hou

We present an improved finite-difference time domain (FDTD) method based on the moving computational domain technique for the calculation of lightning-generated fields over large-scale irregular terrain. In the improved method, a spatial window moving alon ...

2020

LMA observations of upward lightning flashes at the Santis Tower initiated by nearby lightning activity

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Antonio Sunjerga, Amirhossein Mostajabi, Jacopo Grazioli, Nikola Besic

We present in this paper lightning current measurements, LMA (Lightning Mapping Array) data and fast antenna electric fields associated with upward flashes observed at the Santis Tower during summer of 2017. The LMA network consists of six stations that we ...

Elsevier2020

Electromagnetic and mechanical analyses of the ITER electron cyclotron Upper launcher steering M4 mirrors for the vertical displacement event

Timothy Goodman, René Chavan, Avelino Mas Sanchez, Matteo Vagnoni, Phillip Miguel Santos Silva

The mm-wave power exiting the eight In-Vessel waveguides inside the ITER Electron Cyclotron Upper Launcher is reflected by three fixed mirror sets and finally aimed by two independent steering mirrors to specific plasma locations. A design solution for bot ...

2020

High-Q surface electromagnetic wave resonance excitation in magnetophotonic crystals for supersensitive detection of weak light absorption in the near-infrared

Serguei Sekatski

The mid-infrared spectrum can be recorded from almost any material, making mid-infrared spectroscopy an extremely important and widely used sample characterization and analysis technique. However, sensitive photoconductive detectors operate primarily in th ...

OPTICAL SOC AMER2020

Role of higher order plasmonic modes in one-dimensional nanogratings

Ershad Mohammadi, Foziyeh Sohrabi

By theoretically investigating the optical behavior of one-dimensional gold nanogratings using Fourier Modal Method, we have shown that both integer and non-integer multiples of surface plasmon polariton wavelengths should be taken into consideration in sp ...

SPRINGER2019

The Propagation Effects of Lightning Electromagnetic Fields Over Mountainous Terrain in the Earth-Ionosphere Waveguide

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar

In this paper, a full-wave two-dimensional Finite-Difference-Time-Domain model is developed to evaluate the propagation effects of lightning electromagnetic fields over mountainous terrain in the Earth-ionosphere waveguide. In the model, we investigate the ...

2019

Nonlinear piezoelectric vibration energy harvester with frequency-tuned impacting resonators for improving broadband performance at low frequencies

Nico de Rooij, Danick Briand, Andres Felipe Vasquez Quintero, Robert Andrew Lockhart

The paper reports on a nonlinear frequency up-converting vibration energy harvester with enhanced broadband performance below 50 Hz, which is attained by leveraging vibro-impact interaction between two high-frequency piezoelectric generators and two low-fr ...

IOP PUBLISHING LTD2019

Dynamic pressure probe response tests for robust measurements in periodic flows close to probe resonating frequency

Jürg Alexander Schiffmann

A single-hole probe was designed to measure steady and periodic flows with high fluctuation amplitudes and with minimal flow intrusion. Because of its high aspect ratio, estimations showed that the probe resonates at a frequency two orders of magnitude low ...

IOP Publishing2018

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

Farhad Rachidi-Haeri, Marcos Rubinstein, Mario Paolone, Davide Pavanello, Mohammad Azadifar

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

Analysis of lightning electromagnetic field propagation in mountainous terrain and its effects on ToA-based lightning location systems

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Zhaoyang Wang, Keyhan Sheshyekani

In this paper, we analyze the propagation effects on lightning-radiated electromagnetic fields over mountainous terrain by using a three-dimensional (3-D) finite difference time domain (FDTD) method. We also discuss the time delay error in the time-of-arri ...

Amer Geophysical Union2016

Locating transient disturbance sources and modelling their interaction with transmission lines : use of electromagnetic time reversal and asymptotic theory

Gaspard Lugrin

This thesis deals with the application of electromagnetic time reversal to locating transient disturbance sources and the use of the asymptotic theory for the modelling of their interaction with transmission lines. We demonstrate that the time-of-arrival, ...

EPFL2016

Application of the time reversal of electromagnetic fields to locate lightning discharges

Farhad Rachidi-Haeri, Marcos Rubinstein, Nicolas Mora Parra

In this paper, we propose a new method for locating lightning discharges. The proposed method is based on the time reversal technique introduced for acoustics in the early 1990s. By analogy to the derivations in acoustics, equations for the focusing of ele ...

Elsevier2012

Microwave absorption in the frustrated ferrimagnet Cu2OSeO3

Helmuth Berger

The resonance properties of a new Cu2OSeO3 ferrimagnet have been investigated in a wide range of frequencies (17-142 GHz) at liquid helium temperature. The resonance data were used to plot the frequency-field curve of the ferromagnetic spectrum described i ...

2010

Comparison between seismic vulnerability models and experimental dynamic properties of existing buildings in France

Pierino Lestuzzi

Elastic fundamental frequency is a key-parameter of simplified seismic design and vulnerability assessment methods. Empirical relationships exist in codes to estimate this frequency but they miss experimental data to validate them accounting for national f ...

Springer Netherlands2010

Electromagnetic radiation from lightning return strokes to tall structures

Davide Pavanello

The study of the interaction of lightning electromagnetic fields with electrical systems and the design of appropriate protection strategies are generally based on statistical distributions of the lightning current measured at the channel base using either ...

EPFL2007

Chauffage de plasma par ondes électromagnétiques à la troisième harmonique de la fréquence cyclotron des électrons dans le tokamak TCV

Gilles Arnoux

The Tokamak à Configuration Variable (TCV) programme is based on flexible plasma shaping capabilities together with a powerful electron cyclotron wave (ECW) additional heating for studies of stability, confinement, transport, control and power exhaust. In ...

EPFL2005