In {HEAD ~ one embodiment, phenolic resins}, pyrolyzable binders, or other sources of {TAIL ~ carbon} are used 
In { HEAD ~ one embodiment , phenolic resins } , pyrolyzable binders , or other sources of { TAIL ~ carbon } are used
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH