Electromagnetic energy

2021 ◽  
pp. 3-12
Author(s):  
Geoffrey Brooker
Keyword(s):  
Energy Density ◽  
Energy Flow ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Poynting Vector ◽  
Electromagnetic Energy

“Electromagnetic energy” takes a hard look at the reasoning by which energy density and energy flow (Poynting vector) are deduced from Maxwell's equations. What can be proved and what, lacking proof, can be usefully said? It is argued that the conventional division of energy into density and flow is unproven but does not mislead. Picture of a pillbox.

Investigation of energy conversion processes and wave activity related to dipolarization fronts observed by MMS

2021 ◽  
Author(s):  
Soboh Alqeeq ◽  
Olivier Le Contel ◽  
Patrick Canu ◽  
Alessandro Retino ◽  
Thomas Chust ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Energy Flow ◽  
Poynting Vector ◽  
Wave Activity ◽  
Electromagnetic Energy ◽  
Particle Measurements ◽  
Dipolarization Front ◽  
The Earth ◽  
Current Densities ◽  
Scale Properties

<p>In the present work, we consider four dipolarization front (DF) events detected by MMS spacecraft in the Earth’s magnetotail during a substorm on 23rd of July 2017 between 16:05 and 17:19 UT. From their ion scale properties, we show that these four DF events embedded in fast Earthward plasma flows have classical signatures with increases of Bz, velocity and temperature and a decrease of density across the DF. We compute and compare current densities obtained from magnetic and particle measurements and analyse the Ohm’s law. Then we describe the wave activity related to these DFs. We investigate energy conversion processes via J.E calculations and estimate the importance of the electromagnetic energy flow by computing the divergence of the Poynting vector. Finally we discuss the electromagnetic energy conservation in the context of these DFs.</p>

The Maxwell field, its adjoint field and the ‘conjugate’field in anisotropic absorbing media

1975 ◽  
Vol 13 (2) ◽  
pp. 299-316 ◽  
Author(s):  
Kurt Suchy ◽  
Colman Altman
Keyword(s):  
Electromagnetic Field ◽  
Differential Operator ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Poynting Vector ◽  
Maxwell Field ◽  
Absorbing Medium ◽  
Maxwell Operator ◽  
Physical Information ◽  
Absorbing Media

In absorbing media, where Maxwell's equations are not seif-adjoint, the adjoint field is introduced via the differential operator adjoint to the Maxwell operator. The concomitant vector can be made equal to the time averaged Poynting vector at a boundary with a non-absorbing medium. In general, the adjoint field represents an electromagnetic field in a medium other than the absorbing medium under consideration. To draw conclusions about the latter, a [conjugate field] in this medium is defined, using a conjugating transformation of the Maxwell operator and field. Relations between the conjugate and adjoint fields are established, allowing one to gather physical information about the first absorbing medium from the adjoint field.

Essentials of Electricity and Magnetism

2019 ◽  
pp. 3-42
Author(s):  
Richard Freeman ◽  
James King ◽  
Gregory Lafyatis
Keyword(s):  
Angular Momentum ◽  
Steady State ◽  
Electromagnetic Radiation ◽  
Electric Fields ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Electromagnetic Energy ◽  
Time Dependent ◽  
Time Varying ◽  
Electricity And Magnetism

A review of the basic elements of electricity and magnetism is presented with an introduction to Maxwell’s equations for steady-state in a vacuum. The modifications to these equations necessary to account for time varying sources are shown to produce to a causal unification of magnetic and electric fields. The application of Maxwell’s equations in the presence of matter leads to the concepts of electric and magnetic polarization of matter. Electromagnetic radiation arises directly from Maxwell’s time-dependent equations and the basic response of materials to this radiation is discussed. Finally, electromagnetic conservation laws are derived, including electromagnetic energy and linear and angular momentum.

Sumudu Applications to Maxwell's Equations

PIERS Online ◽  
2009 ◽  
Vol 5 (4) ◽  
pp. 355-360 ◽  
Author(s):  
Fethi Bin Muhammad Belgacem
Keyword(s):  
Maxwell’S Equations ◽  
Maxwell's Equations

Maxwell’s Equations versus Newton’s Third Law

2018 ◽  
Author(s):  
Glyn Kennell ◽  
Richard Evitts
Keyword(s):  
Electric Fields ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Simulated Data ◽  
Numerical Data ◽  
Transport Equations ◽  
Concentration Gradients ◽  
Third Law

The presented simulated data compares concentration gradients and electric fields with experimental and numerical data of others. This data is simulated for cases involving liquid junctions and electrolytic transport. The objective of presenting this data is to support a model and theory. This theory demonstrates the incompatibility between conventional electrostatics inherent in Maxwell's equations with conventional transport equations. <br>

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