An exhaust emission control system for an internal combustion engine is disclosed. The pressure relief device may include, inter alia, rupture disks assemblies and explosion panel assemblies. A versioning data structure is created for the memory segment. In some cases, the base station may configure the wireless communication device’s antenna port mode via radio resource control signaling. Typically, each transition between transmission mode and mute mode operation requires that the device undergoing the transition receives a warning that the transition is to occur. Moreover, in a flue gas treating process, the amount of ammonia injected in the denitration step ) andor the amount of ammonia at a point downstream of the denitration step are determined so as to be on such an excessive level that ammonia or ammonium salt will remain in the flue gas introduced into the desulfurization step ).