The spindle speed is {HEAD ~ a function} of the desired mean thickness of the photoresist, the barometric pressure and {TAIL ~ the relative humidity} 
The spindle speed is { HEAD ~ a function } of the desired mean thickness of the photoresist , the barometric pressure and { TAIL ~ the relative humidity }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL