scholarly journals The Effect of Extremely Low Frequency Alternating Magnetic Field on the Behavior of Animals in the Presence of the Geomagnetic Field

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Natalia A. Belova ◽  
Daniel Acosta-Avalos
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Geomagnetic Field ◽  
Low Frequency ◽  
Alternating Magnetic Field ◽  
Magnetic Alignment ◽  
Resonance Model ◽  
Transduction Mechanisms ◽  
Alternating Magnetic Fields ◽  
The Magnetic Field

It is known that the geomagnetic field can influence animal migration and homing. The magnetic field detection by animals is known as magnetoreception and it is possible due to two different transduction mechanisms: the first one through magnetic nanoparticles able to respond to the geomagnetic field and the second one through chemical reactions influenced by magnetic fields. Another behavior is the magnetic alignment where animals align their bodies to the geomagnetic field. It has been observed that magnetic alignment of cattle can be disrupted near electric power lines around the world. Experimentally, it is known that alternating magnetic fields can influence living beings, but the exact mechanism is unknown. The parametric resonance model proposes a mechanism to explain that effect on living beings and establishes that, in the presence of a constant magnetic field, molecules associated with biochemical reactions inside cells can absorb resonantly alternating magnetic fields with specific frequencies. In the present paper, a review is made about animal magnetoreception and the effects of alternating magnetic fields in living beings. It is suggested how alternating magnetic fields can interfere in the magnetic alignment of animals and a general conclusion is obtained: alternating magnetic field pollution can affect the magnetic sensibility of animals.

scholarly journals The loss of energy in metal plates of finite thickness, due to eddy currents produced by alternating magnetic fields

1926 ◽  
Vol 111 (759) ◽  
pp. 604-614 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Eddy Currents ◽  
Finite Thickness ◽  
Metal Plate ◽  
The Self ◽  
Alternating Magnetic Field ◽  
Metal Plates ◽  
Alternating Magnetic Fields

The induction of eddy currents in metal plates which are subjected to alternating magnetic fields has been discussed by Clerk-Maxwell, J. J. Thomson and many others. When an alternating magnetic field is produced normal to the surface of a metal plate, eddy currents are induced at the surface of the plate, which gradually penetrate its interior, the current dying away as it penetrates more deeply into the metal. The diffusion of the currents into the plate depends upon the self-induction and resistance of the paths along which they flow, and can be calculated by the same kind of formula as is used for determining the conduction of heat through a metal slab.

The measurement of a weak alternating magnetic field in unshielded space

Metrologiya ◽  
2021 ◽  
pp. 46-59
Author(s):  
O. L. Sokol-Kutylovskii
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Induction ◽  
Geomagnetic Field ◽  
Gradient Methods ◽  
Alternating Magnetic Field ◽  
Geomagnetic Variations ◽  
Weak Magnetic Fields ◽  
Random Character

In connection with attempts to use various types of sensors for measuring weak magnetic fields in geophysics, magnetobiology, and medicine in an unshielded space, the problem of comparing the results of these measurements arose. The issues of measuring a weak alternating magnetic field by various magnetic induction sensors in an unshielded space in the absence of obvious geomagnetic variations are considered. It is shown that the amplitude of natural geomagnetic noise in a quiet geomagnetic field in the absence of geomagnetic variations has a random character; therefore, gradient methods for measuring a weak alternating magnetic field are limited from below by the level of natural geomagnetic noise. The influence of the size of sensors of a weak alternating magnetic field on the results of measurements of broadband random geomagnetic noise is noted.

scholarly journals Tumor therapy by fast moving magnetic nanoparticle under low-frequency alternating magnetic field

2015 ◽  
Vol 08 (02) ◽  
pp. 1550008 ◽  
Author(s):  
Yangyang Liu ◽  
Zhiyu Qian ◽  
Jianhua Yin ◽  
Xiao Wang
Keyword(s):  
Magnetic Field ◽  
Tumor Cells ◽  
Magnetic Nanoparticle ◽  
Tumor Therapy ◽  
Low Frequency ◽  
Alternating Magnetic Field ◽  
Nanoparticle Concentration ◽  
Field Frequency ◽  
A New Technique ◽  
The Magnetic Field

Magnetic nanoparticle plays an important role in biomedical engineering, especially in tumor therapy. In this paper, a new technique has been developed by using the rapid moving magnetic nanoparticle under a low-frequency alternating magnetic field (LFAMF) to kill tumor cells. The LFAMF system which was used to drive magnetic nanoparticles (MNPs) was setup with the magnetic field frequency and power range at ∼ 10–100 Hz and ∼ 10–200 mT, respectively. During the experiment, the LFAMF was adjusted at different frequencies and power levels. The experimental results show that the liver tumor cells (HepG2) mixed with MNPs (10 μg/mL) became partial fragments when exposed in the LFAMF with different frequencies (∼ 10–100 Hz) and power (∼ 10–200 mT), and the higher the frequency or the power, the more the tumor cells were killed at the same magnetic nanoparticle concentration. Conclusion: Tumor cells were effectively damaged by MNPs under LFAMF, which suggests that they had great potential to be applied in tumor therapy.

scholarly journals Study of the effect of low-frequency magnetic fields on biological objects

2011 ◽  
Vol 16 (4) ◽  
pp. 144-148
Author(s):  
M.M. Baran ◽  
R.V. Bubnov ◽  
T.O. Vojcekhovskaya ◽  
L.S. Gnatyuk ◽  
V.I. Zubchuk ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Ph Changes ◽  
Biological Objects ◽  
Water Ph ◽  
Environment Parameters ◽  
The Magnetic Field

One of the possible approaches on modeling of the magnetotherapeutic effects on biological objects is considered, using water as an example. Experimental data of the water pH changes depending on the effect of the magnetic field and the environment parameters are

Effects of Low-Frequency Alternating Magnetic Fields on the Human Body (Analytical Review)

2016 ◽  
Vol 5 (6) ◽  
pp. 65-75
Author(s):  
Коробенков ◽  
A. Korobenkov ◽  
Коробейников ◽  
S. Korobeynikov ◽  
Акрамова ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Biologically Active ◽  
Production Factor ◽  
Therapeutic Effects ◽  
Negative Effects ◽  
Frequency Magnetic Field ◽  
Analytical Review ◽  
Alternating Magnetic Fields

Domestic and foreign publications on the problem of low-frequency alternating magnetic fields effects on human being have been considered and analyzed in this review. The low-frequency magnetic field is biologically active factor whose effects and its result depend on many others factors, both external (magnetic fields’ frequency and intensity, exposure duration), and internal and individual ones, such as health of the person being subject to impact, nervous system’s state at the moment of exposure, the person’s nervous system excitability level, etc. The magnetic field may have either a positive (therapeutic) effects in certain modes and doses, and the negative one, adversely affecting person’s health (the negative effects, unfortunately, much more common and is considered as a harmful production factor and a factor of environmental pollution).

Horizontal Magnetic Dipole Embedded in a Two-Layer Conducting Medium

1972 ◽  
Vol 50 (6) ◽  
pp. 607-616 ◽  
Author(s):  
V. Ramaswamy ◽  
H. W. Dosso ◽  
J. T. Weaver
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Field ◽  
Magnetic Dipole ◽  
Low Frequency ◽  
Bottom Layer ◽  
Conducting Medium ◽  
Dimensionless Form ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field

The solutions for low-frequency fields of a horizontal magnetic dipole embedded within a two-layer conductor are derived. For convenience, the solutions are expressed in dimensionless form. The amplitudes and phases of the electric and magnetic fields along the surface of the bottom layer are calculated numerically and their dependence on the ratio of the conductivities of the two layers is investigated. Results indicate that, in general, the electric field induced by a subsurface horizontal magnetic dipole is more sensitive to the bottom-layer conductivity than is the magnetic field. Some of the results discussed in this paper are of interest in studying the seabed conductivity.

On the Dielectrophoretic and Magnetic Alignment of Magnetoactive Barium Hexaferrite-PDMS Nanocomposites

2017 ◽  
Author(s):  
Md Abdulla Al Masud ◽  
Noel D’Souza ◽  
Paris von Lockette ◽  
Zoubeida Ounaies
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Fields ◽  
Electric Field ◽  
Barium Hexaferrite ◽  
Magnetic Alignment ◽  
Hydrothermal Temperature ◽  
Duration Magnitude ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field

In this study, we demonstrate the electric and magnetic manipulation of nanoscale M-type Barium Hexaferrite (nBF) in polydimethylsiloxane (PDMS) to engineer a multifunctional nanocomposite with improved dielectric and magnetic properties. First, we synthesized the single crystal nBF via the hydrothermal synthesis route. The hydrothermal temperature, duration, and surfactant conditions were optimized to improve the magnetic properties of the nBFs, with further improvement achieved by post-annealing. The annealed nBFs were aligned dielectrophoretically (DEP) in the polymer matrices by applying an AC electric field. Under the influence of this electric field, nBFs were observed to rotate, align and form chains within the polymer matrix. Optical microscopy (OM) imaging was used to determine the electrical alignment conditions (duration, magnitude, and frequency) and these parameters were used to fabricate the composites. A Teflon setup with Indium Tin Oxide (ITO) coated Polyethylene Terephthalate (PET) was used, where the ITO coatings act as electrodes for the electric field-manipulation. To simultaneously apply the magnetic field, this Teflon setup is placed between two permanent magnets capable of generating a 0.6 T external magnetic field. Along with electric and magnetic fields, concurrent heating was applied to cure the PDMS and freeze the microstructure formed due to electric and magnetic fields. Upon completion of the curing step, parallel chain formation is observed under OM. The X-Ray Diffraction (XRD) results also confirm that the particles are magnetically oriented in the direction of the magnetic field within the chain. Vibrating Sample Magnetometry (VSM) measurements and dielectric spectroscopy are used to characterize the extent of anisotropy and improvement in dielectric and magnetic properties compared to random composites. We find that simultaneous electric and magnetic field alignment improves the dielectric properties by 12% compared to just magnetic alignment. We also observe 19% improved squareness ratio when both fields are applied. The possibility of simultaneous electrical and magnetic alignment of magnetic nanoparticles will open up new doors to manipulate and design particle-modified polymers for various applications.

scholarly journals New Magnetic Abrasive Finishing for Alumina Ceramic Plane Using Alternating Magnetic Fields

2019 ◽  
Vol 13 (6) ◽  
pp. 775-779
Author(s):  
Chaowen Dong ◽  
◽  
Yanhua Zou
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Diamond Particle ◽  
Alumina Ceramic ◽  
Alternating Magnetic Field ◽  
New Method ◽  
Magnetic Abrasive Finishing ◽  
Multi Stage ◽  
Abrasive Finishing ◽  
Alternating Magnetic Fields

In this paper, we propose a new plane magnetic abrasive finishing method, applicable to planes, that uses the alternating magnetic fields to solve problems such as the easy deformation and poor recovery of a magnetic brush in conventional magnetic abrasive finishing method. Compared with the magnetic brush used in conventional magnetic abrasive finishing, that in the new method can stably shape a workpiece under an alternating magnetic field. To determine the optimal finishing parameters, we focused on studying the effects of spindle rotational speed, size of diamond particle, and frequency of alternating magnetic field on the finishing surface. Then, according to the obtained optimal finishing parameters, multi-stage finishing experiments were performed with the new method. The results show that surface roughness can be improved from 230 nm Ra to 19 nm Ra in 60 min with the proposed method.

Wave propagation in a moving plasma. Part 2. Wave propagation along, and plasma motion normal to, the magnetic field

1974 ◽  
Vol 12 (2) ◽  
pp. 271-278
Author(s):  
D. N. Srivastava
Keyword(s):  
Magnetic Field ◽  
Wave Propagation ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Wave Band ◽  
Weak Magnetic Fields ◽  
Moving Plasma ◽  
The One ◽  
The Right ◽  
The Magnetic Field

This paper analyses the dispersion relation for a collisionless moving electron plasma, when the direction of motion is normal to the magnetic field and that of the wave propagation along the magnetic field. It is shown that, in strong magnetic fields, the one continuous allowed band of the left-handed wave (of the stationary plasma) splits into two, and the right-handed wave shows a second resonance besides the cyclotron resonance. In weak magnetic fields, the lefthanded wave develops a backward wave band, which shows resonance at its low frequency edge, and the right-handed wave also develops an extra band of propagation. The effect of the motion of the plasma, on waves of frequency much lower than the plasma frequency, is identical to a doppler shift, but, on those of frequency much higher than that, is negligible.

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