varying either said partial pressure of {TAIL ~ reactants} or said coolant flow rate to maintain said sensed temperature to said {HEAD ~ highest temperature level} at said outlet side 
varying either said partial pressure of { TAIL ~ reactants } or said coolant flow rate to maintain said sensed temperature to said { HEAD ~ highest temperature level } at said outlet side
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH