These ring compounds are maintained in {TAIL ~ a concentration} of between 0.01 and 4.0 grams per liter of {HEAD ~ solution} in the bath 
These ring compounds are maintained in { TAIL ~ a concentration } of between 0.01 and 4.0 grams per liter of { HEAD ~ solution } in the bath
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH