By forming the shield from silicon, {TAIL ~ its coefficient} of {HEAD ~ thermal expansion} substantially matches that of the nozzle array 
By forming the shield from silicon , { TAIL ~ its coefficient } of { HEAD ~ thermal expansion } substantially matches that of the nozzle array
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH