On the Magnetic Field Screening in Strong Crossed Electromagnetic Fields

In this paper, the effects of the quantum yield of free radicals in cryptochrome exposed to different electromagnetic fields were studied through the quantum biology. The results showed that the spikes characteristics was produced in the free radicals in cryptochrome, when it exposed to the applied magnetic field (ω = 50 Hz, B0 = 50 μT). The spikes produced by the electromagnetic field was independent of the changes of polar θ. When the frequency of the magnetic field increased, the spikes characteristics produced in unit time also increased. These results showed that the environmental electromagnetic field could affect the response of organisms to the geomagnetic field by influencing the quantum yield in the mechanism of free radical pair.It provided a basis for studying the influence of environmental electromagnetic field on biology, especially the navigation of biological magnetism.

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Stable Knots and Links in Electromagnetic Fields

Communications in Mathematical Physics ◽

10.1007/s00220-021-04219-3 ◽

2021 ◽

Author(s):

Benjamin Bode

Keyword(s):

Magnetic Field ◽

Electromagnetic Fields ◽

Quantum Fluids ◽

Closed Field ◽

Special Role ◽

Elastic Filaments ◽

Legendrian Links ◽

Field Lines ◽

Standard Contact ◽

The Magnetic Field

AbstractPersistent topological structures in physical systems have become increasingly important over the last years. Electromagnetic fields with knotted field lines play a special role among these, since they can be used to transfer their knottedness to other systems like plasmas and quantum fluids. In null electromagnetic fields the electric and the magnetic field lines evolve like unbreakable elastic filaments in a fluid flow. In particular, their topology is preserved for all time, so that all knotted closed field lines maintain their knot type. We use an approach due to Bateman to prove that for every link L there is such an electromagnetic field that satisfies Maxwell’s equations in free space and that has closed electric and magnetic field lines in the shape of L for all time. The knotted and linked field lines turn out to be projections of real analytic Legendrian links with respect to the standard contact structure on the 3-sphere.

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ELECTROMAGNETIC-GRAVITATIONAL CONVERSION CROSS-SECTIONS IN EXTERNAL ELECTROMAGNETIC FIELDS

Modern Physics Letters A ◽

10.1142/s0217732394003464 ◽

1994 ◽

Vol 09 (39) ◽

pp. 3619-3627 ◽

Cited By ~ 4

Author(s):

HOANG NGOC LONG ◽

DANG VAN SOA ◽

TUAN A. TRAN

Keyword(s):

Magnetic Field ◽

Electric Field ◽

Electromagnetic Fields ◽

Cross Sections ◽

Differential Cross ◽

Numerical Evaluation ◽

Differential Cross Sections ◽

Perturbation Techniques ◽

External Electromagnetic Fields ◽

The Magnetic Field

The classical processes: the conversion of photons into gravitons in the static electromagnetic fields are considered by using Feynman perturbation techniques. The differential cross-sections are presented for the conversion in the electric field of the flat condenser and the magnetic field of the solenoid. A numerical evaluation shows that the cross-sections may have the observable value in the present technical scenario.

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Sensitivity of Planaria to Weak, Patterned Electric Current and the Subsequent Correlative Interactions with Fluctuations in the Intensity of the Magnetic Field of Earth

J ◽

10.3390/j3010008 ◽

2020 ◽

Vol 3 (1) ◽

pp. 79-89

Author(s):

Victoria Hossack ◽

Michael Persinger ◽

Blake Dotta

Keyword(s):

Magnetic Field ◽

Electric Field ◽

Electric Current ◽

Electromagnetic Fields ◽

Linear Correlation ◽

Small Proportion ◽

Weak Electric Field ◽

Electric And Magnetic Fields ◽

The Magnetic Field ◽

Highly Evolved

Some species of fish show highly evolved mechanisms by which they can detect exogenous electric and magnetic fields. The detection of electromagnetic fields has been hypothesized to exist in humans, despite the lack of specialized sensors. In this experiment, planaria were tested in a t-maze with weak electric current pulsed in one arm to determine if the planaria showed any indication of being able to detect it. It was found that a small proportion of the population seemed to be attracted to this current. Additionally, if the experiment was preceded by a geomagnetic storm, the planaria showed a linear correlation increase in the variability of their movement in response to the presence of the weak electric field. Both of these results indicate that a subpopulation of planaria show some ability to respond to electromagnetic fields.

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Screen Elements Made of Perforated Steel Tape and their Application for Shielding Electromagnetic Fields

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.674.41 ◽

2016 ◽

Vol 674 ◽

pp. 41-47 ◽

Cited By ~ 1

Author(s):

Viktor Mironov ◽

Tarmo Koppel ◽

Mihails Lisicins ◽

Irina Boiko

Keyword(s):

Magnetic Field ◽

Electromagnetic Fields ◽

Three Dimensional ◽

Waste Products ◽

Field Source ◽

Low Weight ◽

Before And After ◽

Copper Composite ◽

The Magnetic Field ◽

Shielding Material

In the present work the methods for producing flat and three-dimensional shielding screens from the perforated steel tape are proposed. The possible application variants of mentioned screens are offered and analyzed. Main attention is given for producing one-layer and multi-layer screens with cellular structure due to its relatively low weight and technological elasticity – complex three-dimensional structures could be done successfully.Examples of produced shielding screens from the perforated steel tape for protection from electromagnetic fields in different frequency range are offered and tested. The efficiency of a shielding material was determined by measuring the magnetic field before and after applying the shielding material. Distribution of the magnetic field behind the shielding screen was determined by software vector mapping. Shielding efficiency was measured for 1) a three-layer perforated steel screen; 2) an one-layer perforated steel screen - shielding screen was placed in between the magnetic field source and the measurement point forming a two dimensional screen; 3) copper composite sprayed screen. During experimental investigation it was established, that a three-layer perforated steel screen application allowed the 27% reduction in the magnetic field, while one-layer perforated steel screen gave only 12% reduction. Copper composite sprayed screen reduced magnetic field by 15%.Recommendations for producing the multi-layer perforated steel screen accordingly to shielding efficiency are elaborated and laid down. The discussed material carries also ecological significance, since the material is produced by waste products (after stumping etc.). Therefore the production of such materials comes with reduced cost both in light of capital expenditures and ecological footprint.

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On Reactive Force in Thin Unclosed Conductor and Displacement Current

European Journal of Applied Physics ◽

10.24018/ejphysics.2021.3.5.100 ◽

2021 ◽

Vol 3 (5) ◽

pp. 7-10

Author(s):

Sergey A. Gerasimov

Keyword(s):

Magnetic Field ◽

Electric Current ◽

Electromagnetic Fields ◽

Momentum Density ◽

Linear Momentum ◽

The Self ◽

Displacement Current ◽

Reactive Force ◽

Self Force ◽

The Magnetic Field

The linear momentum density carried by electromagnetic fields creates the hidden force acting on the displacement current between ends of an unclosed conductor with alternative electric current. This force compensates the self-force exerted by the unclosed conductor with zero thin. The magnetic field produced by displacement current does not contribute to the force acting on the conductor. The unclosed conductor can move under action of the self-force. At small heights of cylindrical open conductor, the reactive force equivalent to the self-force becomes very large

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Electromagnetic Fields due to an Electron Avalanche

10.36227/techrxiv.14339756 ◽

2021 ◽

Author(s):

Debasish Nath

Keyword(s):

Magnetic Field ◽

Electromagnetic Fields ◽

General Expression ◽

Ionization Process ◽

Electron Avalanche ◽

Vector Potentials ◽

The Magnetic Field

<p>The present work has been able to relate the magnetic field produced to the basic physical ionization process and derive a general expression for the same starting from the fundamental retarded scalar and vector potentials (Leinard-Weichert potentials). <b></b></p>

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The Magnetic Field Screening with Nb-Ti

Proceedings of the Ninth International Cryogenic Engineering Conference, Kobe, Japan, 11–14 May 1982 ◽

10.1016/b978-0-408-01252-2.50034-0 ◽

1982 ◽

pp. 115-119 ◽

Cited By ~ 2

Author(s):

S. Sato ◽

M. Ikeuchi ◽

A. Iwata ◽

Y. Saji ◽

S. Kado

Keyword(s):

Magnetic Field ◽

Field Screening ◽

The Magnetic Field

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Position-based compensation of electromagnetic fields interference for electromagnetic locomotive microrobot

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406212466349 ◽

2012 ◽

Vol 227 (9) ◽

pp. 1915-1926 ◽

Cited By ~ 2

Author(s):

Jongho Choi ◽

Hyunchul Choi ◽

Semi Jeong ◽

Bang Ju Park ◽

Seong Young Ko ◽

...

Keyword(s):

Magnetic Field ◽

Electromagnetic Field ◽

Electromagnetic Fields ◽

Electromagnetic Actuation ◽

Helmholtz Coils ◽

Compensation Algorithm ◽

Actuation System ◽

Electromagnetic Actuation System ◽

Propulsion Force ◽

The Magnetic Field

Recently, the locomotion of a microrobot wirelessly actuated by electromagnetic actuation systems has been studied in many ways. Because of the inherent characteristics of an electromagnetic field, however, the magnetic field of each coil in the electromagnetic actuation system induces magnetic field interferences, which can distort the desired electromagnetic field, preventing the microrobot from following the desired path. In this article, we used two pairs of Helmholtz coils and two pairs of Maxwell coils in a two-dimensional electromagnetic actuation system. Generally, the two pairs of Helmholtz coils generate the torque for the rotation of the microrobot and the two pairs of Maxwell coils generate the propulsion force of the microrobot. Both pairs of Helmholtz and Maxwell coils have to work to simultaneously align and propel the microrobot in a desired direction. In this situation, however, the electromagnetic fields produced by the Helmholtz coils can interfere with those produced by the Maxwell coils. This interference is closely dependent on the position of the microrobot in the region of interest inside the electromagnetic coils system. This means that the alignment direction and propulsion force of the microrobot can be distorted according to the position of the microrobot. Therefore, we propose a compensation algorithm for the electromagnetic field interference using the position information of the microrobot to correct the magnetic field interferences. First, the interference of an electromagnetic field obeying the Biot–Savart law is analyzed by numerical analysis. Second, a position-based compensation algorithm for the locomotion of a microrobot is proposed. Various locomotion tests of a microrobot verified that the proposed compensation algorithm could reduce the normalized average tracking error from 5.25% to 1.92%.

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CONTINUATION OF ELECTROMAGNETIC FIELDS—II

Geophysics ◽

10.1190/1.1440032 ◽

1969 ◽

Vol 34 (4) ◽

pp. 572-583 ◽

Cited By ~ 2

Author(s):

Amalendu Roy

Keyword(s):

Magnetic Field ◽

Electromagnetic Field ◽

Electromagnetic Fields ◽

Vertical Component ◽

Ground Surface ◽

Static Field ◽

Downward Continuation ◽

Displacement Current ◽

Grid Spacing ◽

The Magnetic Field

Given the values observed on a plane parallel to a horizontal ground surface, solutions are obtained for the continuation of dynamic electromagnetic fields upward in air or downward into a conducting earth. The upward (away from secondary sources) continuation integrals for the real and imaginary parts of any electromagnetic field component with arbitrary frequency and in a medium with arbitrary electrical and magnetic constants are derived and simplified to the case where the conductivity is zero. However, for frequencies normally used in electromagnetic prospecting, the effect of displacement current is negligible and one does not need to use the rigorous formulas derived, because adequate accuracy can be obtained by using the simpler static field formulas for continuation in a nonconducting medium such as air. The central problem in electromagnetic continuation is one of extrapolating the observed field from one medium to another through a physical boundary, namely, the air‐earth interface. From the magnetic field observed in air, one should be able to compute the same within the conducting earth. Conversely, from the electric field observed within the ground or on its surface, one should be in a position to calculate the same in air and also, of course, deeper into the ground. The continuity conditions for the vertical derivatives of the electromagnetic field components, which constitute the basis for continuing an electromagnetic field from one medium to another, are derived. Downward continuation formulas, suitable for practical use, are derived explicitly, through use of a Taylor expansion, for the vertical component of the magnetic field in air, this being the quantity which is commonly measured. Three‐dimensional downward continuation formulations to depths of one and two units of grid spacing and two‐dimensional continuation to a depth of one unit of grid spacing are derived under the assumption that the effect of displacement current can be neglected.

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