means for delivering {HEAD ~ the energy} from {TAIL ~ the source} to the inner surface of the tubular portion 
from
means for delivering { HEAD ~ the energy } from { TAIL ~ the source } to the inner surface of the tubular portion
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH