Jet impingement cooling apparatuses having non-uniformly sized jet orifices for producing an array of impingement jets that impinge a target surface are disclosed. Certain embodiments of the method involve bringing the gas mixture into contact with a liquid solvent or reagent for the acid gases in a first turbulent contactor and subjecting the gas mixture and liquid to turbulent mixing conditions. Approximately the same total net current flow is delivered during active discharge pulses as during the stimulation pulses, but in the opposite direction and optionally at a lower amplitude. The ball screw mechanism is made of a feed screw supported in a screw hole of a nut member so as to be capable of screw-fed rotation.