A vision system examines droplets monitoring quality and a feedback signal to vary {HEAD ~ the material} in {TAIL ~ each droplet} 
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A vision system examines droplets monitoring quality and a feedback signal to vary { HEAD ~ the material } in { TAIL ~ each droplet }
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 TAIL