On Meixner's edge condition for dielectric wedges

1977 ◽  
Vol 55 (22) ◽  
pp. 1970-1971 ◽  
Author(s):  
R. A. Hurd
Keyword(s):  
Electromagnetic Field ◽  
Electric Fields ◽  
Wedge Angle ◽  
Careful Examination ◽  
Edge Condition ◽  
First Case ◽  
Field Behaviour

It is pointed out that there is a difference between the electromagnetic field behaviour at the edge of a highly conducting wedge of angle greater than π (as predicted by Meixner) and the known field behaviour for a perfectly conducting wedge of the same angle. In particular, the perpendicular electric fields are infinite in the first case and finite in the latter. A careful examination of the theory suggests that Meixner's effect is real, but is only detectable in practical conductors if the wedge angle is very accurately machined.

scholarly journals Internal volumetric heat generation and heat capacity prediction during a material electromagnetic treatment process using hybrid algorithms

2018 ◽  
Vol 38 (1) ◽  
pp. 74-82
Author(s):  
Edgar García-Morantes ◽  
Iván Amaya-Contreras ◽  
Rodrigo Correa-Cely
Keyword(s):  
Inverse Problem ◽  
Heat Capacity ◽  
Electromagnetic Field ◽  
Heat Generation ◽  
Initial Conditions ◽  
Limited Range ◽  
First Case ◽  
Realistic Situation ◽  
Wide Range ◽  
Volumetric Heat Generation

This work considers the estimation of internal volumetric heat generation, as well as the heat capacity of a solid spherical sample, heated by a homogeneous, time-varying electromagnetic field. To that end, the numerical strategy solves the corresponding inverse problem. Three functional forms (linear, sinusoidal, and exponential) for the electromagnetic field were considered. White Gaussian noise was incorporated into the theoretical temperature profile (i.e. the solution of the direct problem) to simulate a more realistic situation. Temperature was pretended to be read through four sensors. The inverse problem was solved through three different kinds of approach: using a traditional optimizer, using modern techniques, and using a mixture of both. In the first case, we used a traditional, deterministic Levenberg-Marquardt (LM) algorithm. In the second one, we considered three stochastic algorithms: Spiral Optimization Algorithm (SOA), Vortex Search (VS), and Weighted Attraction Method (WAM). In the final case, we proposed a hybrid between LM and the metaheuristics algorithms. Results show that LM converges to the expected solutions only if the initial conditions (IC) are within a limited range. Oppositely, metaheuristics converge in a wide range of IC but exhibit low accuracy. The hybrid approaches converge and improve the accuracy obtained with the metaheuristics. The difference between expected and obtained values, as well as the RMS errors, are reported and compared for all three methods.

THERMODYNAMICS OF SOME SPECIAL FIELDS

1953 ◽  
Vol 31 (2) ◽  
pp. 329-336
Author(s):  
R. V. Krotkov ◽  
A. E. Scheidegger
Keyword(s):  
Free Energy ◽  
Electromagnetic Field ◽  
Internal Energy ◽  
Thermodynamic Functions ◽  
External Electromagnetic Field ◽  
Explicit Formulas ◽  
First Case ◽  
Quantized Fields

The free energy, internal energy, and entropy of two quantized fields are calculated, using the method introduced by Scheidegger and McKay. The two fields examined are those representing (a) an ensemble of mesons bound by an interaction with their source (a nucleon), and (b) an ensemble of electrons perturbed by an external electromagnetic field. The presence of a source in the first case is found to have no effect on the thermodynamic functions of the mesons, while an external electromagnetic field does affect the thermodynamic functions of the electrons. Explicit formulas in the latter case are given.

Solar Wind and Terrestrial Planets

2020 ◽  
Author(s):  
Edik Dubinin ◽  
Janet G. Luhmann ◽  
James A. Slavin
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Electric Fields ◽  
Interplanetary Space ◽  
Upper Atmosphere ◽  
Dipole Field ◽  
Terrestrial Planets ◽  
Solar Wind Interaction ◽  
Additional Energy ◽  
First Case

Knowledge about the solar wind interactions of Venus, Mars, and Mercury is rapidly expanding. While the Earth is also a terrestrial planet, it has been studied much more extensively and in far greater detail than its companions. As a result we direct the reader to specific references on that subject for obtaining an accurate comparative picture. Due to the strength of the Earth’s intrinsic dipole field, a relatively large volume is carved out in interplanetary space around the planet and its atmosphere. This “magnetosphere” is regarded as a shield from external effects, but in actuality much energy and momentum are channeled into it, especially at high latitudes, where the frequent interconnection between the Earth’s magnetic field and the interplanetary field allows some access by solar wind particles and electric fields to the upper atmosphere and ionosphere. Moreover, reconnection between oppositely directed magnetic fields occurs in Earth’s extended magnetotail—producing a host of other phenomena including injection of a ring current of energized internal plasma from the magnetotail into the inner magnetosphere—creating magnetic storms and enhancements in auroral activity and related ionospheric outflows. There are also permanent, though variable, trapped radiation belts that strengthen and decay with the rest of magnetospheric activity—depositing additional energy into the upper atmosphere over a wider latitude range. Virtually every aspect of the Earth’s solar wind interaction, highly tied to its strong intrinsic dipole field, has its own dedicated textbook chapters and review papers. Although Mercury, Venus, Earth, and Mars belong to the same class of rocky terrestrial planets, their interaction with solar wind is very different. Earth and Mercury have the intrinsic, mainly dipole magnetic field, which protects them from direct exposure by solar wind. In contrast, Venus and Mars have no such shield and solar wind directly impacts their atmospheres/ionospheres. In the first case, intrinsic magnetospheric cavities with a long tail are found. In the second case, magnetospheres are also formed but are generated by the electric currents induced in the conductive ionospheres. The interaction of solar wind with terrestrial planets also varies due to changes caused by different distances to the Sun and large variations in solar irradiance and solar wind parameters. Other important planetary differences like local strong crustal magnetization on Mars and almost total absence of the ionosphere on Mercury create new essential features to the interaction pattern. Solar wind might be also a feasible driver for planetary atmospheric losses of volatiles, which could historically affect the habitability of the terrestrial planets.

Vector E-Field Probe for Testing Industrial Applicators.

1994 ◽  
Vol 347 ◽  
Author(s):  
Georges Roussy ◽  
Jean-Marie Thiebaut ◽  
Kodjo Agbossou ◽  
Bernard Dichtel
Keyword(s):  
Electromagnetic Field ◽  
Electric Fields ◽  
Operating Conditions ◽  
Modulated Scatterer

ABSTRACTUsing the modulated scatterer technique allows us to measure the electromagnetic field in an applicator. The design of a new sensor modulated at 25 Hz is described. The operating conditions and the performance are presented.The sensor can be used for measuring high microwave electric fields up to 10 kV/m in an industrial applicator supplied by any industrial magnetron.

The Experimental Study on the Influence of Human Body to Measurement of High Voltage Power Frequency Electric Field

2013 ◽  
Vol 303-306 ◽  
pp. 482-488
Author(s):  
Kai Mao ◽  
Jin Gang Wang ◽  
Xu Dong Deng ◽  
Wei He ◽  
Zuo Peng Zhang
Keyword(s):  
Electromagnetic Field ◽  
Electric Field ◽  
Electric Fields ◽  
High Voltage ◽  
Human Body ◽  
Enhancement Factor ◽  
Electric Field Distribution ◽  
Field Distortion ◽  
Power Frequency ◽  
Frequency Electric Field

Based on the basic theory of electromagnetic field, the Electric Field Distortion (EFD) in power frequency electric field caused by induced current of human body has been analyzed. The enhancement factor of the electric field distortion is introduced to reduce the influences caused by human body in the measurement of high voltage electric fields. The Ansoft Maxwell is used to simulate and calculate the electric field distribution under the influence of the human body to have the value of enhancement factor. In addition, the enhancement factor has been corrected by experiment with the electromagnetic field analyzer EFA300. With the enhancement factor introduced in this paper, the measurement error can be reduced.

Local electric fields and molecular properties in heterogeneous environments through polarizable embedding

2016 ◽  
Vol 18 (15) ◽  
pp. 10070-10080 ◽  
Author(s):  
Nanna Holmgaard List ◽  
Hans Jørgen Aagaard Jensen ◽  
Jacob Kongsted
Keyword(s):  
Electromagnetic Field ◽  
External Field ◽  
Electric Fields ◽  
Molecular Properties ◽  
Heterogeneous Environments ◽  
Field Effects ◽  
Polarizable Embedding

Effective external field effects in spectroscopies of molecules in heterogeneous environments, i.e., the implications of the additional environment polarization induced by the probing electromagnetic field, can be significant and depart remarkably from the simple Onsager picture.

scholarly journals Radiation Problems Accompanying Carrier Production by an Electric Field in the Graphene

Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 205
Author(s):  
Sergei P. Gavrilov ◽  
Dmitry M. Gitman ◽  
Vadim V. Dmitriev ◽  
Anatolii D. Panferov ◽  
Stanislav A. Smolyansky
Keyword(s):  
Electromagnetic Field ◽  
Electric Field ◽  
Electric Fields ◽  
Strong Field ◽  
Numerical Study ◽  
Spectral Composition ◽  
General System ◽  
External Electromagnetic Field ◽  
Quantum Radiation ◽  
Quantized Electromagnetic Field

A number of physical processes that occur in a flat one-dimensional graphene structure under the action of strong time-dependent electric fields are considered. It is assumed that the Dirac model can be applied to the graphene as a subsystem of the general system under consideration, which includes an interaction with quantized electromagnetic field. The Dirac model itself in the external electromagnetic field (in particular, the behavior of charged carriers) is treated nonperturbatively with respect to this field within the framework of strong-field QED with unstable vacuum. This treatment is combined with a kinetic description of the radiation of photons from the electron-hole plasma created from the vacuum under the action of the electric field. An interaction with quantized electromagnetic field is described perturbatively. A significant development of the kinetic equation formalism is presented. A number of specific results are derived in the course of analytical and numerical study of the equations. We believe that some of predicted effects and properties of considered processes may be verified experimentally. Among these effects, it should be noted a characteristic spectral composition anisotropy of the quantum radiation and a possible presence of even harmonics of the external field in the latter radiation.

Physics-augmented deep learning for high-speed electromagnetic simulation and optimization

2021 ◽  
Author(s):  
Mingkun Chen ◽  
Robert Lupoiu ◽  
Chenkai Mao ◽  
Der-Han Huang ◽  
Jiaqi Jiang ◽  
...  
Keyword(s):  
Neural Network ◽  
Electromagnetic Field ◽  
Electric Fields ◽  
High Speed ◽  
Near Field ◽  
Physical Constraints ◽  
Simulation And Optimization ◽  
Field Distributions ◽  
The Neural Network ◽  
Nanostructure Arrays

Abstract The calculation of electromagnetic field distributions within structured media is central to the optimization and validation of photonic devices. We introduce WaveY-Net, a hybrid data- and physics-augmented convolutional neural network that can predict electromagnetic field distributions with ultra fast speeds and high accuracy for entire classes of dielectric photonic structures. This accuracy is achieved by training the neural network to learn only the magnetic near-field distributions of a system and to use a discrete formalism of Maxwell's equations in two ways: as physical constraints in the loss function and as a means to calculate the electric fields from the magnetic fields. As a model system, we construct a surrogate simulator for periodic silicon nanostructure arrays and show that the high speed simulator can be directly and effectively used in the local and global freeform optimization of metagratings. We anticipate that physics-augmented networks will serve as a viable Maxwell simulator replacement for many classes of photonic systems, transforming the way they are designed.

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