A supported membrane is {HEAD ~ a membrane cast} on a substrate, {TAIL ~ preferably a nonwoven fabric} 
on
A supported membrane is { HEAD ~ a membrane cast } on a substrate , { TAIL ~ preferably a nonwoven fabric }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL