f) setting {HEAD ~ electric power supplies} in contact with {TAIL ~ the side surfaces} of said two elements, 
f ) setting { HEAD ~ electric power supplies } in contact with { TAIL ~ the side surfaces } of said two elements ,
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH