A cuvette has been used to exemplify one embodiment of the invention involving {HEAD ~ a flow} through {TAIL ~ system} 
through
A cuvette has been used to exemplify one embodiment of the invention involving { HEAD ~ a flow } through { TAIL ~ system }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL