This involves flowing a fluid over {TAIL ~ the surface} wherein the fluid contains {HEAD ~ positively charged ions} and electrons 
This involves flowing a fluid over { TAIL ~ the surface } wherein the fluid contains { HEAD ~ positively charged ions } and electrons
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH