Do permanent magnets really harm our body?
1. Harm of magnetic field: magnetic fields can promote human blood circulation, and there is no statistic indicating that the magnetic field is harmful to the human body, so we do not need to worry about harms of magnetic field.
2. Whether or not magnetic field harms human body depends on the strength of magnetic field. Generally strength of magnetic field less than 3000 Gauss (magnetic field units) does no harm to human body. Magnetic field strength over 3000 Gauss may harm human body. However such harm of magnetic field to human body is so little that it can be ignored. According to test, the harms magnetic field do on people is only one-fifth of TV.
"High temperature magnet" --- ferrite magnets VS neodymium iron boron magnets
Ferrite permanent magnets and neodymium magnets are different in the following ways:
1. NdFeB magnets are highly temperature-resistant, usually can stand 80 degrees, and demagnetization occurs when the operating temperature exceeds 80 degree.
2. Stability of ferrite magnets is excellent. It is oxide itself, and very stable, while Nd-Fe-B magnet is alloy, and prone to oxidation, so coating is necessary.
3. Performance of neodymium permanent magnets is better than that of ferrite.
4. Price of ferrite is much more favorable than that of NdFeB.
Application of pushing and pulling forces of magnets in rail transport
There being two different types of magnetic force:
pulling and pushing force, there are two different corresponding application types of magnetic floating trains: a: railway based on repulsion force generated by superconducting electromagnets on trains and coil forces of rails; b railway based on pulling forces of permanent magnet, which means installing magnets at the bottom and tops of the train and equip the T-rail with reaction plate and induction steel plates on bottom and arm parts to control the electric current through magnets, and keep a distance of 10 mm between the magnet and guides (error of plus or minus 2 mm) and to maintain the gravity balance of rail steel and vehicles, so that the vehicles runs suspending on the tracks.
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