A method 3, wherein said step of providing {HEAD ~ a flow} of gas across {TAIL ~ said opening} is performed inside of said oven region adjacent said opening 
A method 3 , wherein said step of providing { HEAD ~ a flow } of gas across { TAIL ~ said opening } is performed inside of said oven region adjacent said opening
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH