scholarly journals Biological Effects of a Low-Frequency Electromagnetic Field on Yeast Cells of the Genus Saccharomyces Cerevisiae

2021 ◽  
Vol 21 (2) ◽  
pp. 34-41
Author(s):  
K Sladicekova ◽  
M Bereta ◽  
J Misek ◽  
D Parizek ◽  
J Jakus
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electromagnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Biological Effects ◽  
Low Frequency ◽  
Growth Dynamics ◽  
Yeast Cells ◽  
Magnetic Flux Density ◽  
Time Points

Abstract Background: Although the scientific community is extensively concerned with the effects of the EMF, the unambiguous explanation of its effects on living structures is still lacking. Goals: The goal of the study was to evaluate the effect of a low-frequency (LF) electromagnetic field (EMF) on the growth and multiplication of the yeast Saccharomyces cerevisiae. Methods: Yeast cells were exposed to a frequency of 900 Hz and a magnetic flux density of 2.3 mT. The duration of each experiment was 8 hours, in the beginning of the measurement the value of frequency, rms (root mean square) value of electric current (2 A), and magnetic flux density were fixed set on the exposure device. A paired experiment was performed, a sample exposed to EMF, and a sample shielded from the field. Subsequently, samples were taken every two hours, the number of cells was recorded, and then the concentration of the yeast cells was evaluated at time points. The time points reflected the exposure time of the samples exposed to EMF. Results: The results indicate that LF EMF at given parameters has an inhibitory effect on the growth and multiplication of yeast cells. Conclusion: Exposure to EMF can cause the differences in growth dynamics between cells exposed to the field and the unexposed ones.

scholarly journals Modification ofS. cerevisiaeGrowth Dynamics Using Low Frequency Electromagnetic Fields in the 1-2 kHz Range

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ján Barabáš ◽  
Roman Radil ◽  
Ivona Malíková
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electromagnetic Fields ◽  
Proliferative Response ◽  
Low Frequency ◽  
Growth Dynamics ◽  
Magnetic Flux Density ◽  
Wild Type ◽  
Frequency Range ◽  
Ambient Conditions ◽  
Resonance Theory

This paper details our further experiments pertaining to the influence of low frequency electromagnetic fields (LF EMF) on the growth dynamics of two wild-typeSaccharomyces cerevisiaestrands. We opted to explore frequencies beyond the usual 50–60 Hz range, motivated by the ion parametric resonance theory and several studies which discovered and recorded endogenous biosignals in variousSaccharomyces cerevisiaestrands in the 0.4–2.0 kHz frequency range, most probably stemming from microtubules. Both yeast strands used in our experiments have been subjected to continuous 66-hour session of LF EMF exposure (frequencies 1.2, 1.4, 1.6, 1.8, and 2.0 kHz; average magnetic flux density 2.43 mT) under identical ambient conditions. Experiment results indicate a frequency-dependent proliferative response of both yeast strands.

scholarly journals The influence of conductive passive parts on the magnetic flux density produced by overhead power lines

2019 ◽  
Vol 32 (4) ◽  
pp. 555-569
Author(s):  
Slavko Vujevic ◽  
Tonci Modric
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Biological Effects ◽  
Research Work ◽  
Power Lines ◽  
Magnetic Flux Density ◽  
Human Beings ◽  
Overhead Power Lines ◽  
The Magnetic Field

There has been apprehension about the possible adverse health effects resulting from exposure to power frequency magnetic field, especially in the overhead power lines vicinity. Research work on the biological effects of magnetic field has been substantial in recent decades. Various international regulations and safety guidelines, aimed at the protection of human beings, have been issued. Numerous measurements are performed and different numerical algorithms for computation of the magnetic field, based on the Biot- Savart law, are developed. In this paper, a previously developed 3D quasistatic numerical algorithm for computation of the magnetic field (i.e. magnetic flux density) produced by overhead power lines has been improved in such a way that cylindrical segments of passive conductors are also taken into account. These segments of passive conductors form the conductive passive contours, which can be natural or equivalent, and they substitute conductive passive parts of the overhead power lines and towers. Although, their influence on the magnetic flux density distribution and on the total effective values of magnetic flux density is small, it is quantified in a numerical example, based on a theoretical background that was developed and presented in this paper.

Low-Frequency Magnetic Localization of Capsule Endoscopes with an Integrated Coil

2021 ◽  
Vol 6 (1) ◽  
pp. 38
Author(s):  
Samuel Zeising ◽  
Rebecca Seidl ◽  
Angelika Thalmayer ◽  
Georg Fischer ◽  
Jens Kirchner
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Eddy Currents ◽  
Low Frequency ◽  
Magnetic Sensors ◽  
Video Frame ◽  
Magnetic Flux Density ◽  
Field Source ◽  
Localization Method

Wireless capsule endoscopy is a promising and less invasive alternative to conventional endoscopy. A patient swallows a small capsule with an integrated camera to capture a video of the gastrointestinal tract. For accurate diagnosis and therapy, the capsule position in terms of the travelled distance must be known for each video frame. However, to date, there is no reliable localization method for endoscopy capsules. In this paper, a novel magnetic localization method is proposed. A coil as a magnetic field source is integrated into a capsule and fed with a low-frequency alternating current to prevent static geomagnetic field interference. This alternating magnetic field is measured by twelve magnetic sensors arranged in rings around the abdomen. The coil and the capsule batteries were designed based on the geometry and power supply of a commercially available endoscopy capsule and simulated by COMSOL Multiphysics software. In this way, the coil position and orientation were determined with an accuracy below 1 mm and 1°, respectively. As an analytic model for the magnetic flux density of the coil in that setup, a modified dipole model was derived. It was used to show that the batteries help to increase the amplitude of the magnetic flux density. The model is valid when signals below 100 Hz are applied, and no eddy currents are generated within the batteries. It is concluded that the magnetic flux density generated by the developed coil would be measurable with state-of-the-art magnetic sensors.

Electromagnetic Field Modelling Using FEM of the Active Part of Oil-Immersed Transformers

2016 ◽  
Vol 856 ◽  
pp. 184-189 ◽  
Author(s):  
Emil Mechkov ◽  
Raina Tzeneva ◽  
Valentin Mateev ◽  
Ivan Yatchev
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electromagnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Field Distribution ◽  
Active Part ◽  
Magnetic Flux Density ◽  
Field Modelling ◽  
Element Method

The electromagnetic field of the active part of oil-immersed transformers 160kVA and 630kVA has been modelled in the present paper. Finite element method and ANSYS program have been employed for the field modelling. Based on the created model, the field distribution with values of the magnetic flux density has been obtained, as well as the Joule losses have been calculated. Two variants of the model - with and without tank are studied and compared.

scholarly journals Reduction of Magnetic Flux Density of Parallel Overhead Power Lines by Optimization of Phase Wires Hanging Order

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Andrii Vitaliyovich Dymerets ◽  
Dmitro Anatoliyovich Revko ◽  
Oleksii Vasyliovich Krasnozhon ◽  
Andrii Vasiliovich Krasnozhon
Keyword(s):  
Magnetic Fields ◽  
Magnetic Flux ◽  
Flux Density ◽  
Low Frequency ◽  
Power Lines ◽  
Magnetic Flux Density ◽  
Safe Level ◽  
Electric And Magnetic Fields ◽  
Efficiency Comparison ◽  
Overhead Power Lines

Overhead power lines are one of the largest sources of the low-frequency magnetic fields. Such magnetic fields occur the harmful effects on human health and other biological objects. The current size of the security zones doesn’t provide a safe level of the magnetic flux density outside them. Therefore, the task of reducing the magnetic flux density value of the overhead power lines outside the security zone is urgent. Some overhead power lines have sections where two lines pass parallel to each other at a short distance. For such lines the method of phase wires hanging order optimization can be applied. For efficiency comparison of different hanging orders was chose two types of electricity pylons: portal (PB330-7) and triangular (P330-3). The cases both lines done by the same pylons were investigated. Analyze of different hanging orders efficiency was performed by mathematical simulation using MATLAB software. The magnetic flux density computation inside the security zone and outside it was done by a specialized simplified methodology of power lines electric and magnetic fields calculation. It is shown that in case of identical phase wires hanging order and the same currents direction of two parallel lines there is a significant increasing of magnetic flux density value at the border of the security zone and outside it for both types of the electricity pylons. It is determined that with a certain hanging order it is possible to achieve a significant reduction of the magnetic flux density value. For lines with electricity pylons of a portal type (PB330-7) the most efficient is the mirror order. It allows to obtain a decreasing of magnetic flux density more than 30 percent at the security zone border and more than 50 percent outside it. For pylons of a triangle type (P330-3) the most efficient is the nonsymmetrical order. It provides the decreasing of magnetic flux density up to 20 percent. In case of opposite currents direction, the most efficient is the same hanging order for both types of electricity pylons. It is shown that optimal phase wires hanging order allows to decrease the magnetic flux density value outside the security zone border, to reduce the distance to border of the area with safe level of the magnetic flux density, to increase the phase current value at which the magnetic flux density value reaches the safe level within the security zone.

Numerical Simulation of Distribution Characteristics of Electromagnetic Field for Round Billet with Mold Electromagnetic Stirring

2015 ◽  
Vol 1095 ◽  
pp. 927-933
Author(s):  
Xing Li ◽  
Zhou Hua Jiang
Keyword(s):  
Electromagnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Three Dimensional ◽  
Electromagnetic Stirring ◽  
Magnetic Flux Density ◽  
Ansys Software ◽  
Current Frequency ◽  
Round Billet ◽  
Circle Center

A three-dimensional mathematical model of mold electromagnetic stirring (M-EMS) for round billet was established. Based on Maxwell’s equations, the distribution of electromagnetic field was solved by ANSYS software. Different process parameters’ influence on magnetic flux density and electromagnetic force (EMF) was studied. The results show that the magnetic flux density reaches the maximum at the stirrer center in the axis direction and increases with the increasing distance from the circle center on the cross section of the stirrer center. The tangential EMF is symmetric about the circle center and reaches the maximum at the edge of round billet. Both the magnetic flux density and the tangential EMF increase with the increasing current intensity. With the increasing current frequency, the magnetic flux density decreases, while the tangential EMF increases in the applied range of current frequency for M-EMS.

Numerical Simulation of High Frequency Electromagnetic Field in Soft Contact Continuous Casting Mold

2012 ◽  
Vol 482-484 ◽  
pp. 1534-1537
Author(s):  
Peng Tian ◽  
Xing Juan Wang ◽  
Li Guang Zhu ◽  
Yue Kai Xue ◽  
Wei Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Electromagnetic Field ◽  
Magnetic Flux ◽  
Continuous Casting ◽  
Flux Density ◽  
Three Dimensional ◽  
Current Strength ◽  
Magnetic Flux Density ◽  
Continuous Casting Mold ◽  
Power Frequency

Based on electromagnetic theory, a billet model electromagnetic continuous casting of physical and mathematical were established. The three-dimensional mold for billet electromagnetic field was calculated by finite element method of ANSYS three-dimensional numerical simulation. Then the distribution of the electromagnetic field inside the crystal was gotten. At the same time, the influence of the power frequency and current strength on the intensity and distribution of the magnetic field were simulated. The result shows that the maximum of the electromagnetic flux density lies in the center of induction coil (steel surface in the center of the coil), and the magnetic flux density gradually reduces along the casting direction; the magnetic flux density increases while the power frequency is increasing; the magnetic flux density increases with the increasing of the current intensity.

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