{HEAD ~ Particularly the fibrillating gas} is {TAIL ~ a gaseous material} such as air, nitrogen, steam, etc 
{ HEAD ~ Particularly the fibrillating gas } is { TAIL ~ a gaseous material } such as air , nitrogen , steam , etc
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH