An abbreviation of mister, a title used before the surname in theory, though not generally in practice, above some undefined social level, too old to be addressed as “Master”, not a knight or of some higher rank, and, in Britain though not in the United States, not entitled to be addressed as “Dr.”
Mr is sometimes used in front of words such as `President' and `Chairman' to address the man who holds the position mentioned. Mr. President, you're aware of the system. see also Messrs. Mauritania (in Internet addresses)
Magneto-resistive heads detect the magnetic flux of a platter by using a sliver of a special material whose resistance changes according to the strength of an applied magnetic field; MR heads are more sensitive than TFI heads, allowing higher areal densities