Electric fields induced by low frequency magnetic fields in inhomogeneous biological structures that are surrounded by an electric insulator

1990 ◽  
Vol 11 (3) ◽  
pp. 235-249 ◽  
Author(s):  
C. Polk ◽  
J. H. Song
Keyword(s):  
Magnetic Fields ◽  
Electric Fields ◽  
Low Frequency ◽  
Electric Insulator ◽  
Biological Structures

Analysis of human brain exposure to low-frequency magnetic fields: A numerical assessment of spatially averaged electric fields and exposure limits

2013 ◽  
Vol 34 (5) ◽  
pp. 375-384 ◽  
Author(s):  
Xi-Lin Chen ◽  
Stefan Benkler ◽  
Nicholas Chavannes ◽  
Valerio De Santis ◽  
Jurriaan Bakker ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Human Brain ◽  
Electric Fields ◽  
Low Frequency ◽  
Exposure Limits ◽  
Numerical Assessment ◽  
Brain Exposure

scholarly journals Propagation of ULF waves through the ionosphere: Inductive effect for oblique magnetic fields

2004 ◽  
Vol 22 (4) ◽  
pp. 1155-1169 ◽  
Author(s):  
M. D. Sciffer ◽  
C. L. Waters ◽  
F. W. Menk
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Fields ◽  
Low Frequency ◽  
Shielding Effect ◽  
Ulf Waves ◽  
High Latitudes ◽  
Wave Fields ◽  
Faraday’S Law ◽  
Background Magnetic Field

Abstract. Solutions for ultra-low frequency (ULF) wave fields in the frequency range 1–100mHz that interact with the Earth's ionosphere in the presence of oblique background magnetic fields are described. Analytic expressions for the electric and magnetic wave fields in the magnetosphere, ionosphere and atmosphere are derived within the context of an inductive ionosphere. The inductive shielding effect (ISE) arises from the generation of an "inductive" rotational current by the induced part of the divergent electric field in the ionosphere which reduces the wave amplitude detected on the ground. The inductive response of the ionosphere is described by Faraday's law and the ISE depends on the horizontal scale size of the ULF disturbance, its frequency and the ionosphere conductivities. The ISE for ULF waves in a vertical background magnetic field is limited in application to high latitudes. In this paper we examine the ISE within the context of oblique background magnetic fields, extending studies of an inductive ionosphere and the associated shielding of ULF waves to lower latitudes. It is found that the dip angle of the background magnetic field has a significant effect on signals detected at the ground. For incident shear Alfvén mode waves and oblique background magnetic fields, the horizontal component of the field-aligned current contributes to the signal detected at the ground. At low latitudes, the ISE is larger at smaller conductivity values compared with high latitudes. Key words. Ionosphere (ionosphere-magnetosphere interactions; electric fields and currents; wave propagation)

scholarly journals Modulation of Cellular Response to Different Parameters of the Rotating Magnetic Field (RMF)—An In Vitro Wound Healing Study

2021 ◽  
Vol 22 (11) ◽  
pp. 5785
Author(s):  
Magdalena Jedrzejczak-Silicka ◽  
Marian Kordas ◽  
Maciej Konopacki ◽  
Rafał Rakoczy
Keyword(s):  
Magnetic Field ◽  
Wound Healing ◽  
Magnetic Fields ◽  
Electric Fields ◽  
Metabolic Activity ◽  
Cellular Response ◽  
Healing Process ◽  
Low Frequency ◽  
Rotating Magnetic Field

Since the effect of MFs (magnetic fields) on various biological systems has been studied, different results have been obtained from an insignificant effect of weak MFs on the disruption of the circadian clock system. On the other hand, magnetic fields, electromagnetic fields, or electric fields are used in medicine. The presented study was conducted to determine whether a low-frequency RMF (rotating magnetic field) with different field parameters could evoke the cellular response in vitro and is possible to modulate the cellular response. The cellular metabolic activity, ROS and Ca2+ concentration levels, wound healing assay, and gene expression analyses were conducted to evaluate the effect of RMF. It was shown that different values of magnetic induction (B) and frequency (f) of RMF evoke a different response of cells, e.g., increase in the general metabolic activity may be associated with the increasing of ROS levels. The lower intracellular Ca2+ concentration (for 50 Hz) evoked the inability of cells to wound closure. It can be stated that the subtle balance in the ROS level is crucial in the wound for the effective healing process, and it is possible to modulate the cellular response to the RMF in the context of an in vitro wound healing.

Practical High Resolution Microscopy

1968 ◽  
Vol 26 ◽  
pp. 302-303
Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Resolving Power ◽  
Careful Attention ◽  
Electron Microscopes ◽  
The Relationship ◽  
High Resolution Microscopy ◽  
New Facilities

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.

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