Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically "hard" materials, which do. Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferrite that are subjected to special processing in a powerful magnetic field during manufacture, to align their internal microcrystalline structure, making them very hard to demagnetize. To demagnetize a saturated magnet, a certain magnetic field must be applied, and this threshold depends on coercivity of the respective material. "Hard" materials have high coercivity, whereas "soft" materials have low coercivity.
Jeff Andersen on 30 Aug 16For many students, the college experience includes game days watching athletes wearing the school colors take the field or court. But in today's environment of rising costs, soaring student debt and declining enrollment, college and university leaders are sometimes finding they have to explain the need for what has become an "arms race" among athletic departments. The argument might be made that much of the money that is required to keep college athletic teams going comes from ticket sales and outside sources such as alumni contributions. The other side of that coin is that some of the cost is borne by students, even those with no interest in sports. In the case of private institutions, it is up to school officials to decide whether the expense is worthwhile. The public has an obvious and greater role in the determination of the role and funding of sports in state institutions.
