Effects of Low Frequency Magnetic Fields on Chick Embryos. Dependence on Incubation Temperature and Storage of the Eggs

1986 ◽  
Vol 41 (11-12) ◽  
pp. 1111-1116 ◽  
Author(s):  
Jukka P. Juutilainen
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Incubation Temperature ◽  
Low Frequency ◽  
Chick Embryos ◽  
The Difference ◽  
Incubation Temperatures ◽  
And Control ◽  
And Storage ◽  
The Magnetic Field

Abstract Chick embryos were exposed to sinusoidally oscillating 100 Hz magnetic fields during their first two days of development. The magnetic field strength was 1 A/m. Incubation temperatures of 36.3, 37.0, 38.0 and 38.5 °C were used and the duration of the storage of the eggs before incuba­tion was varied from 1 hour to 4 days. After the incubation, the embryos were examined for abnormalities. When the temperature was 36.3 or 37.0 °C and the eggs were stored for one day or less, the effect of the magnetic field was statistically significant. In these conditions, the percent­ age of abnormal control embryos was low, 8% in 36.3 °C and 5% in 37.0 °C. In the exposed groups the corresponding percentages were 23% (36.3 °C) and 25% (37.0 °C). However, higher temperature and storage of the eggs for 3 to 4 days increased the percentage of abnormal embryos in both the exposed and control groups. The difference between the exposed and control embryos was not significant in these conditions. The results demonstrate the importance of the handling of the eggs in this kind of experiments.

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 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

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.

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.

scholarly journals Testing the fossil field hypothesis: could strongly magnetised OB stars produce all known magnetars?

2021 ◽  
Author(s):  
Ekaterina I Makarenko ◽  
Andrei P Igoshev ◽  
A F Kholtygin
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Population Synthesis ◽  
Radio Pulsars ◽  
B Stars ◽  
Supernova Explosions ◽  
The Difference ◽  
Log Normal ◽  
Log Normal Distribution ◽  
The Magnetic Field

Abstract Stars of spectral types O and B produce neutron stars (NSs) after supernova explosions. Most of NSs are strongly magnetised including normal radio pulsars with B∝1012 G and magnetars with B∝1014 G. A fraction of 7-12 per cent of massive stars are also magnetised with B∝103 G and some are weakly magnetised with B∝1 G. It was suggested that magnetic fields of NSs could be the fossil remnants of magnetic fields of their progenitors. This work is dedicated to study this hypothesis. First, we gather all modern precise measurements of surface magnetic fields in O, B and A stars. Second, we estimate parameters for log-normal distribution of magnetic fields in B stars and found μB = 2.83 ± 0.1 log10 (G), σB = 0.65 ± 0.09 for strongly magnetised and μB = 0.14 ± 0.5 log10 (G), $\sigma =0.7_{-0.27}^{+0.57}$ for weakly magnetised. Third, we assume that the magnetic field of pulsars and magnetars have 2.7 DEX difference in magnetic fields and magnetars represent 10 per cent of all young NSs and run population synthesis. We found that it is impossible to simultaneously reproduce pulsars and magnetars populations if the difference in their magnetic fields is 2.7 DEX. Therefore, we conclude that the simple fossil origin of the magnetic field is not viable for NSs.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

PEMANFAATAN RADIASI ENERGI TEGANGAN 150 KV UNTUK LAMPU LED PENERANGAN JALAN

Jurnal Teknik ◽  
2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Mauludi Manfaluthy
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
High Voltage ◽  
Low Frequency ◽  
Energy Utilization ◽  
World Health ◽  
Electromagnetic Signals ◽  
Health Organization ◽  
The Magnetic Field ◽  
Low Frequency Waves

WHO (World Health Organization) concludes that not much effect is caused by electric field up to 20 kV / m in humans. WHO standard also mentions that humans will not be affected by the magnetic field under  100 micro tesla and that the electric field will affect the human body with a maximum standard of 5,000 volts per meter. In this study did not discuss about the effect of high voltage radiation SUTT (High Voltage Air Channel) with human health. The research will focus on energy utilization of SUTT radiation. The combination of electric field and magnetic field on SUTT (70-150KV) can generate electromagnetic (EM) and radiation waves, which are expected to be converted to turn on street lights around the location of high voltage areas or into other forms. The design of this prototype works like an antenna in general that captures electromagnetic signals and converts them into AC waves. With a capacitor that can store the potential energy of AC and Schottky diode waves created specifically for low frequency waves, make the current into one direction (DC). From the research results obtained the current generated from the radiation is very small even though the voltage is big enough.Keywords : Radiance Energy, Joule Thief, and  LED Module.

scholarly journals An 84-μG Magnetic Field in a Galaxy at Z=0.692?

2008 ◽  
Vol 4 (S254) ◽  
pp. 95-96
Author(s):  
Arthur M. Wolfe ◽  
Regina A. Jorgenson ◽  
Timothy Robishaw ◽  
Carl Heiles ◽  
Jason X. Prochaska
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Faraday Rotation ◽  
Large Scale ◽  
Dynamo Model ◽  
Magnetic Field Generation ◽  
Interstellar Gas ◽  
Splitting Technique ◽  
Average Value ◽  
The Magnetic Field

AbstractThe magnetic field pervading our Galaxy is a crucial constituent of the interstellar medium: it mediates the dynamics of interstellar clouds, the energy density of cosmic rays, and the formation of stars (Beck 2005). The field associated with ionized interstellar gas has been determined through observations of pulsars in our Galaxy. Radio-frequency measurements of pulse dispersion and the rotation of the plane of linear polarization, i.e., Faraday rotation, yield an average value B ≈ 3 μG (Han et al. 2006). The possible detection of Faraday rotation of linearly polarized photons emitted by high-redshift quasars (Kronberg et al. 2008) suggests similar magnetic fields are present in foreground galaxies with redshifts z > 1. As Faraday rotation alone, however, determines neither the magnitude nor the redshift of the magnetic field, the strength of galactic magnetic fields at redshifts z > 0 remains uncertain.Here we report a measurement of a magnetic field of B ≈ 84 μG in a galaxy at z =0.692, using the same Zeeman-splitting technique that revealed an average value of B = 6 μG in the neutral interstellar gas of our Galaxy (Heiles et al. 2004). This is unexpected, as the leading theory of magnetic field generation, the mean-field dynamo model, predicts large-scale magnetic fields to be weaker in the past, rather than stronger (Parker 1970).The full text of this paper was published in Nature (Wolfe et al. 2008).

scholarly journals Integral Equations for Problems on Wave Propagation in Near-Earth Plasma

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1395
Author(s):  
Danila Kostarev ◽  
Dmitri Klimushkin ◽  
Pavel Mager
Keyword(s):  
Magnetic Field ◽  
Integral Equations ◽  
Field Potential ◽  
Low Frequency ◽  
Fredholm Equation ◽  
Compression Waves ◽  
Parallel Component ◽  
Electric Field Potential ◽  
The Magnetic Field ◽  
Low Frequency Waves

We consider the solutions of two integrodifferential equations in this work. These equations describe the ultra-low frequency waves in the dipol-like model of the magnetosphere in the gyrokinetic framework. The first one is reduced to the homogeneous, second kind Fredholm equation. This equation describes the structure of the parallel component of the magnetic field of drift-compression waves along the Earth’s magnetic field. The second equation is reduced to the inhomogeneous, second kind Fredholm equation. This equation describes the field-aligned structure of the parallel electric field potential of Alfvén waves. Both integral equations are solved numerically.

Effect of Magnetic Fields on the Resistance and Microstructure of Al-Cu Alloy during Solidification Processing

2011 ◽  
Vol 287-290 ◽  
pp. 2916-2920
Author(s):  
Chun Yan Ban ◽  
Peng Qian ◽  
Xu Zhang ◽  
Qi Xian Ba ◽  
Jian Zhong Cui
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Turning Points ◽  
Probe Method ◽  
Solidification Processing ◽  
Ac Magnetic Field ◽  
Dc Magnetic Field ◽  
Cu Alloy ◽  
The Difference ◽  
Good Agreement

The resistance of Al-21%Cu alloy under no magnetic field, DC magnetic field and AC magnetic field from liquid to solid was measured by a four-probe method. The difference of resistance versus temperature curves (R-T curves) was analyzed. It is found that the R-T curves of Al-21%Cu alloy are monotone decreasing and have two obvious turning points. Under DC magnetic field, the liquidus and solidus temperatures of the alloy both decrease, while under AC magnetic field, the liquidus and solidus temperatures both increase. There is a good agreement between the microstructure of quenching sample and R-T curves. The mechanism of the effect of magnetic fields was discussed.

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