scholarly journals Extra low frequency magnetic fields of welding machines and personal safety

2018 ◽  
Vol 69 (6) ◽  
pp. 493-496 ◽  
Author(s):  
Hana Pačaiová ◽  
Milan Oravec ◽  
Miroslav Šmelko ◽  
Pavol Lipovský ◽  
Filip Forraj
Keyword(s):  
Magnetic Fields ◽  
Low Frequency ◽  
Personal Safety

Abstract The article is focused on the determination of the amplitude and the frequency parameters of the extra low frequency (ELF) field, created by the use of electro-technical devices.

Efficient determination of current densities induced in the human body from measured low-frequency inhomogeneous magnetic fields

2001 ◽  
Vol 29 (4) ◽  
pp. 211-213 ◽  
Author(s):  
Hans-Oliver Ruoß ◽  
Wolfgang Spreitzer ◽  
Shinichiro Nishizawa ◽  
Sven Messy ◽  
Michael Klar
Keyword(s):  
Magnetic Fields ◽  
Human Body ◽  
Low Frequency ◽  
Current Densities

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.

Natural and man-made low-frequency magnetic fields as a potential health hazard

1998 ◽  
Vol 168 (07) ◽  
pp. 767-791 ◽  
Author(s):  
N.G. Ptitsyna ◽  
G. Villoresi ◽  
L.I. Dorman ◽  
N. Iucci ◽  
Marta I. Tyasto
Keyword(s):  
Magnetic Fields ◽  
Health Hazard ◽  
Low Frequency ◽  
Potential Health ◽  
Potential Health Hazard

The characteristics and present state for Extremely Low Frequency-Magnetic Fields of metropolitan subway

2015 ◽  
Vol 14 (1) ◽  
pp. 7-15
Author(s):  
Dae-kwan Jung ◽  
◽  
Joon-sig Jung ◽  
Kyu-mok Lee ◽  
Hyung-kyu Park ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Present State ◽  
Low Frequency ◽  
Extremely Low Frequency

Occupational Exposure to Electric Shocks and Extremely Low-Frequency Magnetic Fields and Motor Neurone Disease

2020 ◽  
Author(s):  
Grace X Chen ◽  
Andrea’t Mannetje ◽  
Jeroen Douwes ◽  
Leonard H Berg ◽  
Neil Pearce ◽  
...  
Keyword(s):  
Occupational Exposure ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Population Based ◽  
Motor Neurone ◽  
Motor Neurone Disease ◽  
Cumulative Exposure ◽  
Spine Injury ◽  
Extremely Low Frequency ◽  
Electric Shocks

Abstract In a New Zealand population-based case-control study we assessed associations with occupational exposure to electric shocks, extremely low-frequency magnetic fields (ELF-MF) and motor neurone disease using job-exposure matrices to assess exposure. Participants were recruited between 2013 and 2016. Associations with ever/never, duration, and cumulative exposure were assessed using logistic regression adjusted for age, sex, ethnicity, socioeconomic status, education, smoking, alcohol consumption, sports, head or spine injury and solvents, and mutually adjusted for the other exposure. All analyses were repeated stratified by sex. An elevated risk was observed for having ever worked in a job with potential for electric shocks (odds ratio (OR)=1.35, 95% confidence interval (CI): 0.98, 1.86), with the strongest association for the highest level of exposure (OR=2.01, 95%CI: 1.31, 3.09). Analysis by duration suggested a non-linear association: risk was increased for both short-duration (<3 years) (OR= 4.69, 95%CI: 2.25, 9.77) and long-duration in a job with high level of electric shock exposure (>24 years; OR=1.88; 95%CI: 1.05, 3.36), with less pronounced associations for intermediate durations. No association with ELF-MF was found. Our findings provide support for an association between occupational exposure to electric shocks and motor neurone disease but did not show associations with exposure to work-related ELF-MF.

Magnetic Permeability and Relaxation Frequency in High Frequency Magnetic Materials.

2001 ◽  
Vol 674 ◽  
Author(s):  
M.I. Rosales ◽  
H. Montiel ◽  
R. Valenzuela
Keyword(s):  
High Frequency ◽  
Domain Walls ◽  
Magnetocrystalline Anisotropy ◽  
Low Frequency ◽  
Frequency Dispersion ◽  
Anisotropy Constant ◽  
Relaxation Frequency ◽  
Resonance Relaxation ◽  
Frequency Behavior

ABSTRACTAn investigation of the frequency behavior of polycrystalline ferrites is presented. It is shown that the low frequency dispersion (f < 10 MHz) of permeability is associated with the bulging of pinned domain walls, and has a mixed resonance-relaxation character, closer to the latter. It is also shown that there is a linear relationship between the magnetocrystalline anisotropy constant, K1, and the relaxation frequency. The slope of this correlation depends on the grain size. Such a relationship could allow the determination of this basic parameter from polycrystalline samples.

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