{TAIL ~ Each} of the flow rates of the reactant gases is accurately controlled by {HEAD ~ conventional, commercially available mass flow controllers}, such as those from Tylan Corporation, in a manner well known in the art 
{ TAIL ~ Each } of the flow rates of the reactant gases is accurately controlled by { HEAD ~ conventional , commercially available mass flow controllers } , such as those from Tylan Corporation , in a manner well known in the art
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH