Because of {HEAD ~ its proximity} to {TAIL ~ the floor} of the tubing 50, the apertures 51 are typically distributed more closely together than if the tubing were higher such as the tubing 19 in FIG 3 
to
Because of { HEAD ~ its proximity } to { TAIL ~ the floor } of the tubing 50 , the apertures 51 are typically distributed more closely together than if the tubing were higher such as the tubing 19 in FIG 3
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH