The first surface 930A is exposed to the moisture donating fluid, while the second surface {HEAD ~ 930B} is exposed to {TAIL ~ the moisture} accepting fluid 
The first surface 930A is exposed to the moisture donating fluid , while the second surface { HEAD ~ 930B } is exposed to { TAIL ~ the moisture } accepting fluid
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH