ONE OF THE MOST IMPORTANT CHALLENGES OF OUR TIME IS TO MITIGATE THE HARMFUL IMPACTS OF PARTICULATE EMISSIONS (SOOT) FROM COMBUSTION ENGINES ON GLOBAL CLIMATE CHANGE AND TO REDUCE THE CONSUMPTION OF LIQUID PETROLEUM FUELS THAT POWER TRANSPORTATION SYSTEMS. A PROMISING CONCEPT IS TO MIX PETROLEUM FUELS WITH BIO-DERIVED FUELS. AN EVALUATION OF THE PERFORMANCE BENEFITS RESTS ON DIAGNOSTICS TO UNRAVEL THE COMPLEX RELATIONSHIPS BETWEEN SOOT FORMATION AND FUEL PROPERTIES. UNDER SOME CONDITIONS THE PRESENCE OF SOOT ITSELF IN THE COMBUSTION FIELD CAN INTRUDE ON THIS EFFORT. MEASUREMENTS THAT RELY ON DIGITAL VIDEO IMAGING OF THE FUEL BURNING PROCESS SUCH AS EMPLOYED IN THE FLAME EXTINGUISHMENT EXPERIMENT (FLEX) ARE VULNERABLE TO THIS CONCERN. FLEX WAS DEVELOPED TO UNDERSTAND MECHANISMS THAT CONTROL FLAME EXTINCTION AS IT RELATES TO CABIN FIRE SAFETY ABOARD MANNED SPACEFLIGHT THOUGH THE BROAD METHODOLOGIES ARE MORE WIDELY APPLICABLE TO COMBUSTION OF FUEL SYSTEMS IN COMBUSTION ENGINES. THE CONFIGURATION OF ISOLATED DROPLETS BURNING WITH NEAR SPHERICAL SYMMETRY WAS EMPLOYED TO ELUCIDATE THE MECHANISMS INVOLVED. THE MAIN DIAGNOSTIC WAS DIGITAL VIDEO IMAGING. FROM THIS INFORMATION QUANTITATIVE MEASUREMENTS OF THE DROPLET AND FLAME BOUNDARIES WERE MADE USING SUITABLE COMPUTER-BASED DATA EXTRACTION ALGORITHMS THAT REVEALED THE INFLUENCE OF AMBIENT GAS CONDITIONS AND LIQUID FUEL PROPERTIES ON FLAME EXTINCTION. FOR SOME OF THE FUELS EMPLOYED IN FLEX SOOT FORMATION WAS EVIDENT (I.E. N-HEPTANE DROPLETS BURNING IN AIR) WHICH OBSCURED PART OF THE DROPLET AND FLAME BOUNDARY THAT CAN COMPROMISE DATA ACCURACY. THE SUCCESS OF THE FLEX PROGRAM ASSUMES THE EXISTENCE OF EFFICIENT AND ACCURATE COMPUTER-BASED ALGORITHMS THAT CAN OVERCOME THE OBSCURATION INFLUENCE OF SOOT ON DROPLETS ARE ABLE TO TRACK DROPLETS IF THEY MOVE AND CAN ACCOUNT FOR DEVIATIONS FROM SPHERICITY DUE TO IGNITION DISTURBANCES. HOWEVER THIS IS NOT THE CASE. COMMERCIAL IMAGE ANALYSIS PACKAGES ARE LIMITED IN THEIR ABILITY TO DEAL WITH THE PRESENCE OF SOOT IN THE IMAGING FIELD WITHOUT SIGNIFICANT USER INPUT. FAILURE TO ADDRESS THIS PROBLEM IMPACTS NOT ONLY DERIVING FULL BENEFIT FROM THE FLEX EXPERIMENTS ALREADY CARRIED OUT BUT ALSO FOLLOW-ON STUDIES WHICH WOULD UTILIZE DIGITAL VIDEO IMAGING TO STUDY DROPLET COMBUSTION DYNAMICS OF SOOTING FUELS USED IN COMMERCIAL TRANSPORTATION SYSTEMS. IN THIS PROPOSAL WE ADDRESS THIS PROBLEM BE DEVELOPING A DIAMETER ESTIMATION REFINEMENT ALGORITHM THAT EMPLOYS CONCEPTS WHICH AUTOMATE DROPLET AND FLAME DIAMETER MEASUREMENTS FROM VIDEO IMAGES IN THE PRESENCE OF SOOT. THE ALGORITHM WILL BE USED TO REANALYZE CERTAIN FLEX DATA ON THE PSI SYSTEM - RESULTS FROM A PROOF-OF-CONCEPT PROGRAM ARE INCLUDED IN THE PROPOSAL FOR ILLUSTRATION - AND TO EXTRACT QUANTITATIVE DATA FROM NEW PROPOSED EXPERIMENTS TO STUDY THE INFLUENCE OF MIXTURE FRACTION ON BLENDS OF BIO-DERIVED FUELS WITH AN AVIATION FUEL: HYDROPROCESSED RENEWABLE JET FUEL DERIVED FROM ALGAE WITH JET-A (ALGAL FEEDSTOCKS HAVE POTENTIAL FOR LARGER YIELDS COMPARED TO OUTER SOURCES) FOR WHICH SOOT FORMATION IS EXPECTED. THE OUTCOME WILL BE A ROBUST CAPABILITY TO PROCESS DIGITAL VIDEO IMAGES THAT EFFICIENTLY AND PRECISELY EXTRACTS MEASUREMENTS FROM DIGITAL IMAGES EVEN IN THE PRESENCE OF SOOT AGGREGATES. THE RESULTS - DATA AND SOFTWARE - WILL BE FREELY AVAILABLE ON VARIOUS OUTLETS AS DISCUSSED IN THE PROPOSAL. THE PROJECT INCLUDES A TEAM WITH EXPERTISE IN DEVELOPING ALGORITHMS FOR IMAGE ANALYSIS (PROF. ANTHONY REEVES OF CORNELL'S ELECTRICAL AND COMPUTER ENGINEERING DEPARTMENT) AND EXPERIENCE IN DROPLET COMBUSTION EXPERIMENTATION (PROF. C. THOMAS AVEDISIAN OF CORNELL'S MECHANICAL AND AEROSPACE ENGINEERING (MAE) DEPARTMENT). THE PROJECT TEAM HAS SUPPLIES OF THE ALGAE-DERIVED AND JET FUEL SYSTEMS THAT WILL BE STUDIED (TERRAVIA INC; AND THE AIR FORCE).