Typically, coke-oven gas is obtained from a battery comprising a number of narrow, vertical chambers, or ovens (0.5m wide, 5m high and 12m long) built of silica brick that are separated by heating ducts, such that heat is transmitted to the coal through both sides of the chamber walls.
ISO keyboard symbol for âControlâ. In computing, a Control key is a modifier key which, when pressed in conjunction with another key, performs a special operation (for example, +); similar to the Shift key, the Control key rarely performs any function when pressed by itself.
Simply defined, the term access control describes any technique used to control passage into or out of any area. The standard lock that uses a brass key may be thought of as a simple form of an access control system. Over the years, access control systems have become more and more sophisticated.