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In this paper we introduce an efficient algorithm for identifying conductive objects using induction data derived from eddy currents. Our method consists of first extracting geometric features from the induction data and then matching them…

Analysis of PDEs · Mathematics 2014-07-11 Habib Ammari , Junqing Chen , Zhiming Chen , Darko Volkov , Han Wang

Eddy currents induced in electrically conductive objects can be used to locate metallic objects as well as to assess the properties of materials non-destructively without physical contact. This technique is useful for material…

Applied Physics · Physics 2023-01-19 Lucy Elson , Adil Meraki , Lucas M. Rushton , Tadas Pyragius , Kasper Jensen

We consider an inverse problem of location identification of small conductivity inhomogeneity inside a conductor via boundary measurements which occurs in the EIT (Electrical Impedance Tomography). For this purpose, we derive topological…

Classical Physics · Physics 2013-08-20 Won-Kwang Park

The aim of this article is to elaborate and rigorously analyze a topological derivative based imaging framework for locating an electromagnetic inclusion of diminishing size from boundary measurements of the tangential component of…

Optimization and Control · Mathematics 2015-04-10 Abdul Wahab

Detection and imaging of an electrically conductive object at a distance can be achieved by inducing eddy currents in it and measuring the associated magnetic field. We have detected low-conductivity objects with an optical magnetometer…

Being able to characterise objects at low frequencies, but above the limiting frequency of the eddy current approximation of the Maxwell system, is important for improving current metal detection technologies. Importantly, the upper…

Analysis of PDEs · Mathematics 2022-09-28 P. D. Ledger , W. R. B. Lionheart

This paper is concerned with Eddy-Current (EC) nondestructive testing of conductive materials and focuses, in particular, on extending the well-known LinearSampling Method (LSM) to the case of EC equations. We first present the theoretical…

Numerical Analysis · Mathematics 2021-09-22 H. Haddar , M. K. Riahi

Eddy current stimulated thermography is an emerging technique for non-destructive testing and evaluation of conductive materials. However, quantitative estimation of the depth of subsurface defects in metallic materials by thermography…

Signal Processing · Electrical Eng. & Systems 2021-02-25 Qiuji Yi , Hamed Malekmohammadi , Gui Yun Tian , Stefano Laureti , Marco Ricci

Harmonic and transient eddy currents in a liquid metal positioned above an excitation coil are determined by measuring the voltage drop in a simple potential probe. The resulting spatio-temporal eddy current field is compared with the…

Fluid Dynamics · Physics 2009-05-13 Jan Forbriger , Vladimir Galindo , Gunter Gerbeth , Frank Stefani

We use a radio-frequency $^{85}$Rb alkali-vapor cell magnetometer based on a paraffin-coated cell with long spin-coherence time and a small, low-inductance driving coil to create highly resolved conductivity maps of different objects. We…

Instrumentation and Detectors · Physics 2016-05-25 Arne Wickenbrock , Nathan Leefer , John W. Blanchard , Dmitry Budker

A research of inductive conductometric cell is presented. An equivalent circuit and a mathematical model of inductive cell are given in the article. The model takes into account sample-coil capacity (i.e. capacity formed by the coil and the…

Instrumentation and Detectors · Physics 2013-05-01 Yury S. Semenov

Realistic applications in metal detection involve multiple inhomogeneous conducting permeable objects and the aim of this paper is to characterise such objects by polarizability tensors. We show that, for the eddy current model, the leading…

Analysis of PDEs · Mathematics 2018-09-25 P. D. Ledger , W. R. B. Lionheart , A. A. S. Amad

We present a new complete asymptotic expansion for the low frequency time-harmonic magnetic field perturbation caused by the presence of a conducting (permeable) object as its size tends to zero for the eddy current regime of Maxwell's…

Analysis of PDEs · Mathematics 2018-05-23 P. D. Ledger , W. R. B. Lionheart

We derive a mathematical model for eddy currents in two dimensional geometries where the conductors are thin domains. We assume that the current flows in the $x\_3$-direction and the inductors are domains with small diameters of order…

Analysis of PDEs · Mathematics 2007-05-23 Youcef Amirat , Rachid Touzani

The size estimates approach for Electrical Impedance Tomography (EIT) allows for estimating the size (area or volume) of an unknown inclusion in an electrical conductor by means of one pair of boundary measurements of voltage and current.…

Analysis of PDEs · Mathematics 2012-02-27 Giovanni Alessandrini , Antonio Bilotta , Antonino Morassi , Edi Rosset , Emilio Turco

A methodology to reduce the computational cost of time domain computations of eddy currents problems is proposed and implemented in a parallel computing environment. It is based on the modal decomposition of the current density and it is…

Computational Engineering, Finance, and Science · Computer Science 2024-07-18 Salvatore Ventre , Andrea Chiariello , Nicola Isernia , Vincenzo Mottola , Antonello Tamburrino

This paper proposes a novel approach to reconstruct changes in a target conductivity from electrical impedance tomography measurements. As in the conventional difference imaging, the reconstruction of the conductivity change is based on…

Computational Physics · Physics 2014-03-27 Dong Liu , Ville Kolehmainen , Samuli Siltanen , Anne maria Laukkanen , Aku Seppanen

The purpose of this paper is to propose a non-iterative method for the inverse conductivity problem of recovering multiple small anomalies from the boundary measurements. When small anomalies are buried in a conducting object, the electric…

Analysis of PDEs · Mathematics 2015-06-11 Ok Kyun Lee , Hyeonbae Kang , Jong Chul Ye , Mikyoung Lim

A simple model of eddy currents in which current is computed solely from magnetic forces acting on electrons proves accessible to introductory students and gives a good qualitative account of eddy current forces. However, this model cannot…

Physics Education · Physics 2007-05-23 P. J. Salzman , John Robert Burke , Susan M. Lea

Electrically conductive objects can be detected using the principle of electromagnetic induction where a primary oscillating magnetic field induces eddy currents in the object, which in turn produce a secondary magnetic field that can be…

Applied Physics · Physics 2022-12-06 L. M. Rushton , T. Pyragius , A. Meraki , L. Elson , K. Jensen
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