The first reaction chamber is arranged in {HEAD ~ continuous fluid communication} with {TAIL ~ the downstream conduit} and has a preselected first effective surface area 
with
The first reaction chamber is arranged in { HEAD ~ continuous fluid communication } with { TAIL ~ the downstream conduit } and has a preselected first effective surface area
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH