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