{TAIL ~ First coal solvation} involves formation of free radicals which are stabilized by {HEAD ~ hydrogen} 
{ TAIL ~ First coal solvation } involves formation of free radicals which are stabilized by { HEAD ~ hydrogen }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD