Browsing by Author "Johnson, Jason P."

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    Fine Particle (Nanoparticle) Emissions On Minnesota Highways
    (2001-05-01) Kittelson, David B.; Watts, Winthrop J.; Johnson, Jason P.
    This study examined the physical characteristics of combustion aerosols found on Minnesota highways. It emphasized the characterization of nanoparticles (less than 50 nm) with the goal of providing real-world data for the development of engine laboratory test methods. On-road particulate matter emissions ranged between 104 to 106 particles/cm3 with the majority of the particles by number being less than 50 nm in diameter. High-speed traffic produced high nanoparticle number concentrations and diesel traffic further increased number concentrations. At high vehicular speeds, particulate matter emissions increase because of higher engine load and fuel consumption. Measurements made at speeds less than 20 mph showed lower number but higher volume concentrations and larger particles. Measurements made 10-30 m from the highway in residential areas approached on-road concentrations with similar size distributions and high concentrations of nanoparticles. Lower concentrations and larger particles were observed in residential areas 500 to 700 m from the highway. Fuel specific and particle/mi emission rates were estimated from data collected on two different days. The particle/mi emissions were about an order of magnitude greater than published figures but mass emission rates compared well with published values. However, colder temperatures, different dilution and sampling conditions and different instrumentation could explain our increased estimates.
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    An On-Board Emissions and Performance Measurement System (OEPMS) for Measuring Carbon Monoxide Emission During Cold Starting
    (Minnesota Department of Transportation, 1999-05) Johnson, Jason P.; Kittelson, David B.
    This report describes the results of a project to develop an on-board emissions and performance measurement system (OEPMS) for the quantification of carbon monoxide (CO) emissions. Researchers measured emissions from a 1990, 2.5 liter TBI engine passenger automobile over a typical suburb-to-city commute in the Minneapolis/St. Paul metropolitan area. As a test of the OEPMS, researchers measured CO emissions during cold weather cold starts and commutes at temperatures characteristic of the area's winter weather. Open-loop and closed-loop emissions of CO were measured and compared. Additionally, the effectiveness of magnetic-type block heaters was examined. Tests with the OEPMS provided a wide range of results. The OEPMS proved very durable and easily adaptable for a wide variety of testing. The OEPMS holds promise for future research into fuels, emissions reducing technologies, regulations, and commute habits in real world situations.