Numerous configurations are within the scope of the present invention, including {TAIL ~ elongate chambers}, {HEAD ~ some} of which can be formed of a long, relatively narrow pipe 
of
Numerous configurations are within the scope of the present invention , including { TAIL ~ elongate chambers } , { HEAD ~ some } of which can be formed of a long , relatively narrow pipe
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH