{HEAD ~ The sparging} of the gas bubbles is {TAIL ~ the main mechanism} for mixing, catalyst suspension, and dispersion 
is
{ HEAD ~ The sparging } of the gas bubbles is { TAIL ~ the main mechanism } for mixing , catalyst suspension , and dispersion
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH