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Despite this doctrine , there exist numerous service in-house studies , books , articles , and frequent seminars that identify a perceived gap . The use of poisonous chemicals ( such as mercury and cyanide ) banned in developed countries remains prevalent in many parts of Africa , with the chemical either being used directly in large mines or illegally imported and sold to small miners by companies that service large mines . With respect to Internet access , upgraded cable systems can carry data up to several hundred times faster than transmission using dial-up modems over ordinary telephone lines , and a hundred times faster than ISDN ( integrated services digital network ) telephone lines . Eleven years experience servicing third party contracts performing depot level maintenance on ship board weapon systems and a helicopter flight simulator for Department of Defense heavy military systems world wide . The DC-DC Converters plug into a backplane , making servicing quick and easy .