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.
Physico-Chemical Aspects of Grinding: a Review of Use of Additives. H. EL-SHALL. Montana College of Mineral Science and Technology, Butte, MT 59701 (U.S.A.) and P. SOMASUNDARAN. Henry Krumb School of Mines, Columbia University, New York, NY 10027 (U.s.A.) (Received August 20, 1982;in revised form August 1,1983) SUMMARY.