Electromagnetism

Magnetostatics of anisotropic ellipsoids

by Carlos E. Solivérez

Electromagnetic field in Lyra manifold: a first order approach

by Cassius de Melo

Schwinger's principle and gauge fixing in the free electromagnetic field

by Cassius de Melo

How can one probe Podolsky Electrodynamics?

by Cassius de Melo

Classical Electrodynamics with Geometric Algebra

by Frank Witte

These are the incomplete lecture notes of an electrodynamics course heavilly using the geometric algebra of spacetime,... more These are the incomplete lecture notes of an electrodynamics course heavilly using the geometric algebra of spacetime, i.e. spacetime algebra.

The notion of electrical resistance

by Carlos E. Solivérez

A discussion of the validity of electrical resistance as a property of a piece of conductor when Ohm's Law is valid.... more A discussion of the validity of electrical resistance as a property of a piece of conductor when Ohm's Law is valid. An example calculation is worked out in detail: the electrical resistance of a sphere. A general derivation is then made illustrating that -in a completely general way, as the elementary formula states- the value of resistance depends on two geometrical factors: the length of the flux lines of electric field inside the conductor and its cross section. The first factor depends on the geometry of the full circuit, showing that resistance is, in general, not a localized property.

A model of the ball lightning

by Vladimir K. Ignatovich

The paper is published first in 1980 V.K.Ignatovich. Localised solutions of Maxwell equations in media with anomalous dispersion. JINR P4-80-103, Dubna, 1980. in Russian, then in Laser Physics., v.2, N.6., p.991-996 (1992); and JINR Communications E4-92-209, Dubna 1992. In arXiv I recently presented an updated version

The ball lightning is supposed to be a shock wave
of a point explosion frozen with electrostriction forces of... more The ball lightning is supposed to be a shock wave
of a point explosion frozen with electrostriction forces of the
internal strong laser discharge. The life time of the ball with
modest parameters is calculated.

Reflection of light from an anisotropic medium

by Vladimir K. Ignatovich

Coauthored with Filipp V. Ignatovich.
Anisotropic media are characterised by a vector and a parameter, related to this vector. With the help of dyadic representation of dielectric permittivity, we were able to give an explicit expression for plane waves and their polarisations in anisotropic media. It was done the first time since 170 years after Fresnel. But scientists know anisotropic media so badly, that they were unable to appreciate the new approach.
This paper was submitted to AJP and was rejected from there. Information about funny referee reports can be found here. It was already rejected from many journals. The last from Physica Scripta:on 12.12.2011by the board member:
"Too much of a mathematical exercise and too little physics for Physica
Scripta. Could be submitted to a journal for mathematical physics." Submitted to J.Phys.A

We present here a general approach to treat reflection and refraction of light of arbitrary polarization from single... more We present here a general approach to treat reflection and refraction of light of arbitrary polarization from single axis anisotropic plates. We show that reflection from interface inside the anisotropic medium is accompanied by beam splitting and can create surface waves.

A proposed experiment on ball lightning model

by Vladimir K. Ignatovich

The paper is submitted to Phys.Lett.A on 01.12.2010 and finally was accepted in August 2011.
Paper was rejected from Optics Letters because prof. A.Siegman said that he does not agree with our asertion that total reflection from active media is larger than unity. Phys.Rev.Lett. rejected as not interesting, refees of JETP rejected it because 1)It is not necessary to check Maxwell equations, and 2) such a simple idea is not for such a journal like JETP.

We propose an experiment for strong light amplification at
multiple total reflections from active gaseous media. We propose an experiment for strong light amplification at
multiple total reflections from active gaseous media.

A new planar electromagnetic sensor for quality monitoring of water from natural sources

by Mohd Amri Bin Md Yunus

M. A. Md Yunus, S. C. Mukhopadhyay, and G. Sen Gupta, "A new planar electromagnetic sensor for quality monitoring of water from natural sources," in ICST 2010. 4th International Conference on Sensing Technology, 2010, Lecce, Italy, 3-5th June 2010, pp. 554-559.

This paper introduces a novel sensor based on the combination of meander and interdigital planar electromagnetic... more This paper introduces a novel sensor based on the combination of meander and interdigital planar electromagnetic sensors for monitoring the level of contamination in water sources. Sensor modelling has been accomplished using COMSOL and the results are discussed herein. A series of experiments was conducted to determine the sensors characteristics and to observe the sensor response to materials involving distilled water
and nitrates-forms solutions with different concentrations. The work and improvement for future consideration are also discussed in this paper.

A Review of Material Properties Estimation Using Eddy Current Testing and Capacitive Imaging

by Mohd Amri Bin Md Yunus

M. A. Md Yunus, S. C. Mukhopadhyay, and G. Sen Gupta, "A Review of Material Properties Estimation Using Eddy Current Testing and Capacitive Imaging," Sensors & Transducers Journal, vol. 100, pp.92-115, January 2009.

The non destructive testing applications based on inductive (eddy current testing) and capacitive sensors are widely... more The non destructive testing applications based on inductive (eddy current testing) and capacitive sensors are widely used for imaging of material properties. The simple structure, safe to use, low cost, non contact application, good response at medium range frequency of the sensors make them preferable to be used in the industries. The aim of this study is to talk about the material properties estimation applications using eddy current testing and capacitive sensing. The basic operations of eddy
current testing and capacitive sensing with example of application in the non destructive testing are discussed. Next, the recent advancements of eddy current testing and capacitive testing in imaging technique are presented in this paper

Development of planar electromagnetic sensors for measurement and monitoring of environmental parameters

by Mohd Amri Bin Md Yunus

M. A. M. Yunus and S. C. Mukhopadhyay, "Development of planar electromagnetic sensors for measurement and monitoring of environmental parameters," Measurement Science and Technology, vol. 22, p. 025107, 18th January 2011.

Novel planar electromagnetic sensors designed, fabricated, and tested for environmental monitoring have been reported... more Novel planar electromagnetic sensors designed, fabricated, and tested for environmental monitoring have been reported in this paper. An intensive modelling of the sensors is also discussed. Experiments were conducted to obtain the impedance characterization for each sensor and the results were compared with the simulation results. The sensors have been tested to detect nitrates contamination in distilled water from two set of experiments. Firstly, two nitrates forms namely, sodium nitrates (NaN03) and ammonium nitrates (NH4NO3), each of different concentration between 5 mg and 20 mg dissolved in 1 litre of distilled water were used to observe the sensor response. Secondly, NaN03 and NH4NO3 were mixed in several different ratios dissolved in 1 litre of distilled water and the responses of
the sensors were observed. The best sensor has been determined based on the interpretation from both nitrates experiment results. Preliminary results show that the best sensor can very well detect the presence of nitrate added in distilled water and capable of distinguishing the concentration level. The work and improvement for future consideration are also discussed in this paper.

RESEARCH PAPER ON ELECTROMAGNETIC INTERFERENCE AND COMPATIBILITY

by Vikram Karve

A novel low-E field coil to minimize heating of biological samples in solid-state multinuclear NMR experiments

by Baudouin Dillmann

Selected for the front page of the Journal of Magnetic Resonance.

On the K-factor estimation for Rician channel simulated in reverberation chamber

by Emmanuel Amador

"Co-authored with Christophe Lemoine and Philippe Besnier", "published in IEEE transactions on Antennas and propagation"

Reverberation chambers were recently proposed to simulate Rician radio environment with controllable K-factor. The... more Reverberation chambers were recently proposed to simulate Rician radio environment with controllable K-factor. The K-factor is also a parameter that may tell how ideal may be a reverberation chamber when it is used for other more conventional purposes. This paper is dedicated to the problem of the correct estimation of K in a reverberation chamber given a set of data measured along a stirring process.

Quantifying stirred and unstirred components in reverberation chamber with appropriate statistics

by Emmanuel Amador

Lerideau G., Amador E., Lemoine C., Besnier P., IEEE International Symposium on EMC 2009, Austin, Texas, U.S.A.

Wireless devices have been massively developed in recent years, creating a real need to simulate controllable... more Wireless devices have been massively developed in recent years, creating a real need to simulate controllable multipath channels. Reverberation chamber is a well-known cavity for electromagnetic compatibility (EMC) testing and knows an increasing interest for wireless communication testing. In particular, it enables to generate various measurements distributions from Rayleigh to Rician. In order to estimate correctly direct and scattered components of a transmitted signal in RC, we propose two new methods leading to an accurate evaluation of the direct-to-scattered ratio (DSR).

Estimation fine du facteur K en chambre réverbérante pour l’évaluation de la directivité

by Emmanuel Amador

Christophe Lemoine, Emmanuel Amador, Jérôme Sol et Philippe Besnier, CEM 2010, Limoges, France. (Best paper award).

La directivité d’un objet sous test en chambre réverbérante à brassage de modes est habituellement inaccessible dans... more La directivité d’un objet sous test en chambre réverbérante à brassage de modes est habituellement inaccessible dans un tel environnement. Or, il est possible de montrer que le facteur K caractéristique des canaux de propagation de type Rice est directement relié à la directivité du système sous test. Son estimation étant délicate, nous avons développé une méthode statistique simple et adaptée à l’estimation du facteur K dans l’environnement de la chambre réverbérante.

Modélisation d’une chambre réverbérante basée sur la théorie des images: étude en régime pulsée

by Emmanuel Amador

Emmanuel Amador, Christophe Lemoine, Philippe Besnier et Alexandre Laisné, CEM 2010, Limoges, France.

Dans cet article, nous proposons un modèle de chambre réverbérante (CR) temporel basé sur la théorie des images (TI).... more Dans cet article, nous proposons un modèle de chambre réverbérante (CR) temporel basé sur la théorie des images (TI). Ce modèle très simple permet de simuler le comportement d’une chambre réverbérante en présence de signaux pulsés. Après une brève présentation du modèle, des résultats de simulations avec des impulsions de longueur différentes et différentes charges sont comparées à des mesures réalisées dans la CR de notre laboratoire.

Studying the Pulse Regime in a Reverberation Chamber with a Model Based on Image Theory

by Emmanuel Amador

Emmanuel Amador, Christophe Lemoine, Philippe Besnier and Alexandre Laisné, IEEE International Symposium on EMC 2010, Fort Lauderdale, Florida, U.S.A.

In this article, we propose a time-domain model of a reverberation chamber (RC). This very straightforward model based... more In this article, we propose a time-domain model of a reverberation chamber (RC). This very straightforward model based upon image theory (IT) allows to simulate the behavior of a reverberation chamber in the pulse regime. After a brief introduction of the model, results with different pulse lengths and different loading configurations are presented and compared to measurements made in the reverberation chamber of our laboratory.

Improved estimation of the K-factor for Rician channels emulation in a reverberation chamber

by Emmanuel Amador

Christophe Lemoine, Emmanuel Amador and Philippe Besnier, EuCAP 2010, Barcelona, Spain.

In many radio propagation environments, the time varying envelope of the received signal can be statistically... more In many radio propagation environments, the time varying envelope of the received signal can be statistically described by a Rician distribution. Recently, reverberation chambers have been proposed to simulate Rician radio environments with controllable K-factor. However, evaluation of Rician K-factor out of RC measurements must be analyzed very carefully. The paper provides an analytical formulation of both the estimation of K and the confidence interval associated with its estimation.