When the vent is moved to a nonequilibrium position, it is located within one of the two cells and is not in {HEAD ~ direct relation} to {TAIL ~ the vent follower} 
to
When the vent is moved to a nonequilibrium position , it is located within one of the two cells and is not in { HEAD ~ direct relation } to { TAIL ~ the vent follower }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL