{TAIL ~ Stable operations} have been observed with {HEAD ~ a maximum gas holdup} as high as 0.72 
{ TAIL ~ Stable operations } have been observed with { HEAD ~ a maximum gas holdup } as high as 0.72
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH