At the object level . Permissions allowed or denied at the object level apply to the entire object. For example, you can set an object-level permission on an OU object that allows a particular group, such as Account Operators, to create child objects in the OU. At the property level .
Ball mills are used in chemistry and in industry to grind hard solids to a very fine powder. They are very similar to rock tumblers. Basically, the idea is to rotate a container filled with heavy metal balls that crush the substance that you want to grind.
Most of the boron that is mined is eventually refined into boric acid or borax. Boric acid is used in a number of applications including insecticides, flame retardants, antiseptics, and to create other compounds. Borax is a powdered material used in detergents, cosmetics, and enamel glazes. Boron is used in the manufacture of glass and ceramics.