A first plurality of ventilation apertures are formed in the substrate and the metallic material, and {HEAD ~ the first plurality} of {TAIL ~ ventilation apertures} are configured to permit a fluid to pass through the substrate and the metallic material 
A first plurality of ventilation apertures are formed in the substrate and the metallic material , and { HEAD ~ the first plurality } of { TAIL ~ ventilation apertures } are configured to permit a fluid to pass through the substrate and the metallic material
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD 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