An electrical bias is applied across {HEAD ~ the gap} between {TAIL ~ the belt} and the overcoated ohmic layer 
between
An electrical bias is applied across { HEAD ~ the gap } between { TAIL ~ the belt } and the overcoated ohmic layer
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH