{TAIL ~ Fluorescent emission} generally occurs in {HEAD ~ a time frame} of less than 10 nanoseconds 
{ TAIL ~ Fluorescent emission } generally occurs in { HEAD ~ a time frame } of less than 10 nanoseconds
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH