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.
Types and Uses of a Grinding Machine. The grinding machine is a type of tool that is utilized for grinding work pieces. It basically use an abrasive wheel as the cutting tool. The rough surface of the abrasive wheel shreds off small portions of the work piece as required. It is also known as a grinder.