Vectorial Impedance Identity for the Natural Dependence of Harmonic Fields on Closed Boundaries

1975 ◽  
Vol 53 (15) ◽  
pp. 1404-1407 ◽  
Author(s):  
O. A. Aboul-Atta ◽  
W. M. Boerner
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Electric Field ◽  
Inverse Scattering ◽  
Field Solution ◽  
Tangential Electric Field ◽  
First Time ◽  
Scalar Equations ◽  
Harmonic Electromagnetic Field ◽  
Exact Description

The exact description of the harmonic electromagnetic field solution at scattering surfaces is shown to require, in general, two impedances to relate the tangential electric field to the tangential magnetic field. The consequences lead to the generation of two independent surface vectors that are orthogonal, of equal norm, and have a realizable direction. They are used to describe the surface by two scalar equations. For the first time, the details of this vectorial impedance identity, the derivation of those two vectors, and the two scalar inverse scattering surface equations are shown.

On fluid motions induced by an electromagnetic field in a liquid drop immersed in a conducting fluid

1972 ◽  
Vol 51 (3) ◽  
pp. 585-591 ◽  
Author(s):  
C. Sozou
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Flow Field ◽  
Electric Field ◽  
Lorentz Force ◽  
Liquid Drop ◽  
Conducting Fluid ◽  
Uniform Electric Field ◽  
Tangential Electric Field ◽  
Set Up

The deformation of a liquid drop immersed in a conducting fluid by the imposition of a uniform electric field is investigated. The flow field set up is due to the surface charge and the tangential electric field stress over the surface of the drop, and the rotationality of the Lorentz force which is set up by the electric current and the associated magnetic field. It is shown that when the fluids are poor conductors and good dielectrics the effects of the Lorentz force are minimal and the flow field is due to the stresses of the electric field tangential to the surface of the drop, in agreement with other authors. When, however, the fluids are highly conducting and poor dielectrics the effects of the Lorentz force may be predominant, especially for larger drops.

Investigating flexible textile-based coils for wireless charging wearable electronics

2019 ◽  
Vol 50 (3) ◽  
pp. 333-345 ◽  
Author(s):  
Danmei Sun ◽  
Meixuan Chen ◽  
Symon Podilchak ◽  
Apostolos Georgiadis ◽  
Qassim S Abdullahi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Electromagnetic Field ◽  
Electric Field ◽  
Dimensional Stability ◽  
Screen Printing ◽  
Wearable Electronics ◽  
Wireless Charging ◽  
The Magnetic Field ◽  
Screen Printed

Smart and interactive textiles have been attracted great attention in recent years. This research explored three different techniques and processes in developing textile-based conductive coils that are able to embed in a garment layer. Coils made through embroidery and screen printing have good dimensional stability, although the resistance of screen printed coil is too high due to the low conductivity of the print ink. Laser cut coil provided the best electrical conductivity; however, the disadvantage of this method is that it is very difficult to keep the completed coil to the predetermined shape and dimension. The tested results show that an electromagnetic field has been generated between the textile-based conductive coil and an external coil that is directly powered by electricity. The magnetic field and electric field worked simultaneously to complete the wireless charging process.

A 4 × 4 array multichannel magnetic stimulation system using submillimeter sized planar square spiral coils: The spatial distribution of electromagnetic field

2022 ◽  
pp. 1-18
Author(s):  
Lei Tian ◽  
Limei Song ◽  
Yu Zheng ◽  
Jinhai Wang
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Spatial Distribution ◽  
Field Strength ◽  
Electric Field ◽  
Magnetic Stimulation ◽  
Spiral Coil ◽  
Average Magnetic Field ◽  
Stimulation System ◽  
Field Strengths

Multi-coil magnetic stimulation has advantages over single-coil magnetic stimulation, such as more accurate targeting and larger stimulation range. In this paper, a 4 × 4 array multichannel magnetic stimulation system based on a submillimeter planar square spiral coil is proposed. The effects of multiple currents with different directions on the electromagnetic field strength and the focusing zone of the array-structured magnetic stimulation system are studied. The spatial distribution characteristics of the electromagnetic field are discussed. In addition, a method is proposed that can predict the spatial distributions of the electric and magnetic fields when currents in different directions are applied to the array-structured magnetic stimulation system. The study results show that in the section of z = 2 μm, the maximum and average magnetic field strengths of the array-structured magnetic stimulation system are 6.39 mT and 2.68 mT, respectively. The maximum and average electric field strengths are 614.7 mV/m and 122.82 mV/m, respectively, where 84.39% of the measured electric field values are greater than 73 mV/m. The average magnetic field strength of the focusing zone, i.e., the zone in between the two coils, is 3.38 mT with a mean square deviation of 0.18. Therefore, the array-structured multi-channel magnetic stimulation system based on a planar square spiral coil can have a small size of 412 μm × 412 μm × 1.7 μm, which helps improving the spatial distribution of electromagnetic field and increase the effectiveness of magnetic stimulation. The main contribution of this paper is a method for designing multichannel micro-magnetic stimulation devices.

Influence of Electric Field and Temperature on Magnetic Field Induced Prolonged Changes of Electric Parameters of Silicon Systems

1995 ◽  
Vol 378 ◽  
Author(s):  
Vladimir M Maslovsky
Keyword(s):  
Magnetic Field ◽  
Diffusion Coefficient ◽  
Electric Field ◽  
Diffusion Activation Energy ◽  
Influence Of Temperature On ◽  
Electric Parameters ◽  
Generation Lifetime ◽  
Equilibrium Defects ◽  
First Time ◽  
Diffusion Activation

AbstractMagnetic field induced prolonged changes (MFIPC) of electric parameters of semiconductor systems is the phenomenon that has been recently established experimentally. In this work it is investigated for the first time the influence of electric field and temperature on duration of MFIPC of carrier generation lifetime in Si subsurface region and the influence of temperature on MFIPC of the MOS structure leakage voltage. The value of determined mobility of generated defects corresponds to the diffusion coefficient of vacancy -impurity complexes. These investigations of MFIPC of microstructure confirm that non-equilibrium defects reactions are limited by diffusion (in the absence of external electric field). It is shown that the corresponding diffusion coefficient is about 10−13 cm2s−1 and the magnitude of diffusion activation energy determined from these investigations is in the range 0.45–0.5 eV. This value is nearly the same as the diffusion coefficient of vacancy-impurity complex.

scholarly journals Recent Progress on Electromagnetic Field Measurement Based on Optical Sensors

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2860 ◽  
Author(s):  
Jun Peng ◽  
Shuhai Jia ◽  
Jiaming Bian ◽  
Shuo Zhang ◽  
Jianben Liu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Electric Field ◽  
Magnetic Fluid ◽  
Optical Sensors ◽  
Field Measurement ◽  
Faraday Effect ◽  
Optical Sensing ◽  
Piezoelectric Materials ◽  
Electrostatic Attraction

Electromagnetic field sensors are widely used in various areas. In recent years, great progress has been made in the optical sensing technique for electromagnetic field measurement, and varieties of corresponding sensors have been proposed. Types of magnetic field optical sensors were presented, including probes-based Faraday effect, magnetostrictive materials, and magnetic fluid. The sensing system-based Faraday effect is complex, and the sensors are mostly used in intensive magnetic field measurement. Magnetic field optical sensors based on magnetic fluid have high sensitivity compared to that based on magnetostrictive materials. Three types of electric field optical sensors are presented, including the sensor probes based on electric-optic crystal, piezoelectric materials, and electrostatic attraction. The majority of sensors are developed using the sensing scheme of combining the LiNbO3 crystal and optical fiber interferometer due to the good electro-optic properties of the crystal. The piezoelectric materials-based electric field sensors have simple structure and easy fabrication, but it is not suitable for weak electric field measurement. The sensing principle based on electrostatic attraction is less commonly-used sensing methods. This review aims at presenting the advances in optical sensing technology for electromagnetic field measurement, analyzing the principles of different types of sensors and discussing each advantage and disadvantage, as well as the future outlook on the performance improvement of sensors.

Effect of uniform electromagnetic field on the trajectory of a free jet in a resistant medium proportional to the velocity.

2015 ◽  
Vol 11 (1) ◽  
pp. 2909-2913
Author(s):  
Mercy Amaebi Orukari ◽  
Ngiangia, A. T
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Velocity Profile ◽  
Electric Field ◽  
Fluid Particle ◽  
Governing Equations ◽  
Free Jet ◽  
Resistant Medium ◽  
Uniform Electromagnetic Field

The effect of electromagnetic field in a resistant medium of a free jet was carried out. The solutions of the governing equations showed that increase in electric field also increases the  velocity profile of the fluid while increase in magnetic field decreases the velocity of the fluid particle. Increase in path angle beyond radian, shows improved location of objects in a resistant medium proportional to the velocity. 

scholarly journals Magneto-electrical orientation of lipid-coated graphitic micro-particles in solution

RSC Advances ◽  
2016 ◽  
Vol 6 (52) ◽  
pp. 46643-46653 ◽  
Author(s):  
Johnny Nguyen ◽  
Sonia Contera ◽  
Isabel Llorente García
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Static Magnetic Field ◽  
Time Varying ◽  
Micro Particles ◽  
First Time

We demonstrate, for the first time, confinement of the orientation of graphitic micro-flakes to a well-defined plane in solution by applying two perpendicular fields: a vertical static magnetic field and a horizontal time-varying electric field.

scholarly journals Schwinger mechanism in electromagnetic field in de Sitter spacetime

2018 ◽  
Vol 168 ◽  
pp. 03002 ◽  
Author(s):  
Ehsan Bavarsad ◽  
Sang Pyo Kim ◽  
Clément Stahl ◽  
She-Sheng Xue
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Electric Field ◽  
Pair Production ◽  
Production Rate ◽  
De Sitter ◽  
Sitter Spacetime ◽  
Constant Electromagnetic Field ◽  
Electric And Magnetic Fields ◽  
Schwinger Mechanism

We investigate Schwinger scalar pair production in a constant electromagnetic field in de Sitter (dS) spacetime. We obtain the pair production rate, which agrees with the Hawking radiation in the limit of zero electric field in dS. The result describes how a cosmic magnetic field affects the pair production rate. In addition, using a numerical method we study the effect of the magnetic field on the induced current. We find that in the strong electromagnetic field the current has a linear response to the electric and magnetic fields, while in the infrared regime, is inversely proportional to the electric field and leads to infrared hyperconductivity.

scholarly journals Measuring the dayside reconnection rate during an interval of due northward interplanetary magnetic field

2004 ◽  
Vol 22 (12) ◽  
pp. 4243-4258 ◽  
Author(s):  
G. Chisham ◽  
M. P. Freeman ◽  
I. J. Coleman ◽  
M. Pinnock ◽  
M. R. Hairston ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Interplanetary Magnetic Field ◽  
Line Length ◽  
Hf Radar ◽  
Plasma Convection ◽  
Ionosphere Plasma ◽  
Reconnection Region ◽  
Field Lines ◽  
First Time

Abstract. This study presents, for the first time, detailed spatiotemporal measurements of the reconnection electric field in the Northern Hemisphere ionosphere during an extended interval of northward interplanetary magnetic field. Global convection mapping using the SuperDARN HF radar network provides global estimates of the convection electric field in the northern polar ionosphere. These are combined with measurements of the ionospheric footprint of the reconnection X-line to determine the spatiotemporal variation of the reconnection electric field along the whole X-line. The shape of the spatial variation is stable throughout the interval, although its magnitude does change with time. Consequently, the total reconnection potential along the X-line is temporally variable but its typical magnitude is consistent with the cross-polar cap potential measured by low-altitude satellite overpasses. The reconnection measurements are mapped out from the ionosphere along Tsyganenko model magnetic field lines to determine the most likely reconnection location on the lobe magnetopause. The X-line length on the lobe magnetopause is estimated to be ~6–11 RE in extent, depending on the assumptions made when determining the length of the ionospheric X-line. The reconnection electric field on the lobe magnetopause is estimated to be ~0.2mV/m in the peak reconnection region. Key words. Space plasma physics (Magnetic reconnection) – Magnetospheric physics (Magnetopause, cusp and boundary layers) – Ionosphere (Plasma convection)

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