{HEAD ~ This cycle} of operation is repeated after {TAIL ~ each polymerization} run without opening the reactor 
is repeated after
{ HEAD ~ This cycle } of operation is repeated after { TAIL ~ each polymerization } run without opening the reactor
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH