A shutter system could then be used to physically separate the non affected molecules taking advantage of {TAIL ~ this difference} in {HEAD ~ velocity} 
A shutter system could then be used to physically separate the non affected molecules taking advantage of { TAIL ~ this difference } in { HEAD ~ velocity }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD