The Experts below are selected from a list of 1914 Experts worldwide ranked by ideXlab platform
Alan W Gertler - One of the best experts on this subject based on the ideXlab platform.
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exhaust particle size distribution measurements at the tuscarora Mountain Tunnel
Aerosol Science and Technology, 2002Co-Authors: Mahmoud Abuallaban, W Coulomb, Alan W Gertler, J A Gillies, William R Pierson, C F Rogers, John C Sagebiel, Leland TarnayAbstract:On-road particle size distributions were measured at the Tuscarora Mountain Tunnel on the Pennsylvania Turnpike in May 1999. The data were obtained using a scanning mobility particle sizer. The nucleation modes of the size distributions contained most of the particles on a number concentration basis and exhibited peak diameters ranging from 11 to 17 nm. This observation is consistent with previous calculations and measurements, indicating that significant numbers of ultrafine aerosol particles can be expected in close proximity to busy motorways. The experiment provided 4 case studies for which the Tunnel inlet data could be used to correct data obtained at the outlet, allowing for estimates of particle production within the Tunnel. Exhaust particle production rates per vehicle kilometer were estimated; the results are presented with the caveat that the measurements were affected by ambient dilution. The 4 case study nucleation mode sizes varied inversely with ambient temperature. The light-duty vehicle c...
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Apportionment of NMHC tailpipe vs non-tailpipe emissions in the Fort McHenry and Tuscarora Mountain Tunnels
Atmospheric Environment, 1996Co-Authors: Alan W Gertler, William R Pierson, Eric M. Fujita, David N. WittorffAbstract:Measurements of on-road emissions of non-methane hydrocarbons (NMHCs) were made in the Fort McHenry Tunnel (Baltimore) and Tuscarora Mountain Tunnel (Pennsylvania) during the summer of 1992. Measurements were made during 11 one-hour periods in the Fort McHenry Tunnel and during 11 one-hour periods in the Tuscarora Mountain Tunnel. The observed light-duty fleets were quite new, with a median model year of approximately 1989. Speciated NMHC values were obtained from analyses of canister and Tenax samples, and light-duty speciated emission factors were calculated for the two Tunnels. Fuel samples were collected in the area around the Tunnels for use in constructing headspace and liquid fuel profiles for the chemical mass balance (CMB) receptor model. Profiles of tailpipe emissions were obtained from the literature. The CMB was used to apportion tailpipe from non-tailpipe emissions. Non-tailpipe sources were found to constitute approximately 15% of the light-duty NMHC emissions. The Federal automotive emission-rate models, MOBILE4.1 and MOBILE5, underpredicted non-tailpipe emissions, assigning approximately 9% and 6.5%, respectively, to non-tailpipe sources. In terms of total absolute emissions, MOBILE5 predictions were approximately a factor of 2 greater than MOBILE4.1 predictions. Both MOBILE4.1 and MOBILE5 underestimated the NMHC emissions in the Fort McHenry Tunnel and overpredicted the NMHC emissions in the Tuscarora Mountain Tunnel. In all cases, the MOBILE models underestimated the absolute value of the non-tailpipe emissions. The ability of the MOBILE models to account for observed emissions when conditions are more variable than those studies in the Fort McHenry and Tuscarora Mountain Tunnels is still an open question.
David N. Wittorff - One of the best experts on this subject based on the ideXlab platform.
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Apportionment of NMHC tailpipe vs non-tailpipe emissions in the Fort McHenry and Tuscarora Mountain Tunnels
Atmospheric Environment, 1996Co-Authors: Alan W Gertler, William R Pierson, Eric M. Fujita, David N. WittorffAbstract:Measurements of on-road emissions of non-methane hydrocarbons (NMHCs) were made in the Fort McHenry Tunnel (Baltimore) and Tuscarora Mountain Tunnel (Pennsylvania) during the summer of 1992. Measurements were made during 11 one-hour periods in the Fort McHenry Tunnel and during 11 one-hour periods in the Tuscarora Mountain Tunnel. The observed light-duty fleets were quite new, with a median model year of approximately 1989. Speciated NMHC values were obtained from analyses of canister and Tenax samples, and light-duty speciated emission factors were calculated for the two Tunnels. Fuel samples were collected in the area around the Tunnels for use in constructing headspace and liquid fuel profiles for the chemical mass balance (CMB) receptor model. Profiles of tailpipe emissions were obtained from the literature. The CMB was used to apportion tailpipe from non-tailpipe emissions. Non-tailpipe sources were found to constitute approximately 15% of the light-duty NMHC emissions. The Federal automotive emission-rate models, MOBILE4.1 and MOBILE5, underpredicted non-tailpipe emissions, assigning approximately 9% and 6.5%, respectively, to non-tailpipe sources. In terms of total absolute emissions, MOBILE5 predictions were approximately a factor of 2 greater than MOBILE4.1 predictions. Both MOBILE4.1 and MOBILE5 underestimated the NMHC emissions in the Fort McHenry Tunnel and overpredicted the NMHC emissions in the Tuscarora Mountain Tunnel. In all cases, the MOBILE models underestimated the absolute value of the non-tailpipe emissions. The ability of the MOBILE models to account for observed emissions when conditions are more variable than those studies in the Fort McHenry and Tuscarora Mountain Tunnels is still an open question.
William R Pierson - One of the best experts on this subject based on the ideXlab platform.
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exhaust particle size distribution measurements at the tuscarora Mountain Tunnel
Aerosol Science and Technology, 2002Co-Authors: Mahmoud Abuallaban, W Coulomb, Alan W Gertler, J A Gillies, William R Pierson, C F Rogers, John C Sagebiel, Leland TarnayAbstract:On-road particle size distributions were measured at the Tuscarora Mountain Tunnel on the Pennsylvania Turnpike in May 1999. The data were obtained using a scanning mobility particle sizer. The nucleation modes of the size distributions contained most of the particles on a number concentration basis and exhibited peak diameters ranging from 11 to 17 nm. This observation is consistent with previous calculations and measurements, indicating that significant numbers of ultrafine aerosol particles can be expected in close proximity to busy motorways. The experiment provided 4 case studies for which the Tunnel inlet data could be used to correct data obtained at the outlet, allowing for estimates of particle production within the Tunnel. Exhaust particle production rates per vehicle kilometer were estimated; the results are presented with the caveat that the measurements were affected by ambient dilution. The 4 case study nucleation mode sizes varied inversely with ambient temperature. The light-duty vehicle c...
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Apportionment of NMHC tailpipe vs non-tailpipe emissions in the Fort McHenry and Tuscarora Mountain Tunnels
Atmospheric Environment, 1996Co-Authors: Alan W Gertler, William R Pierson, Eric M. Fujita, David N. WittorffAbstract:Measurements of on-road emissions of non-methane hydrocarbons (NMHCs) were made in the Fort McHenry Tunnel (Baltimore) and Tuscarora Mountain Tunnel (Pennsylvania) during the summer of 1992. Measurements were made during 11 one-hour periods in the Fort McHenry Tunnel and during 11 one-hour periods in the Tuscarora Mountain Tunnel. The observed light-duty fleets were quite new, with a median model year of approximately 1989. Speciated NMHC values were obtained from analyses of canister and Tenax samples, and light-duty speciated emission factors were calculated for the two Tunnels. Fuel samples were collected in the area around the Tunnels for use in constructing headspace and liquid fuel profiles for the chemical mass balance (CMB) receptor model. Profiles of tailpipe emissions were obtained from the literature. The CMB was used to apportion tailpipe from non-tailpipe emissions. Non-tailpipe sources were found to constitute approximately 15% of the light-duty NMHC emissions. The Federal automotive emission-rate models, MOBILE4.1 and MOBILE5, underpredicted non-tailpipe emissions, assigning approximately 9% and 6.5%, respectively, to non-tailpipe sources. In terms of total absolute emissions, MOBILE5 predictions were approximately a factor of 2 greater than MOBILE4.1 predictions. Both MOBILE4.1 and MOBILE5 underestimated the NMHC emissions in the Fort McHenry Tunnel and overpredicted the NMHC emissions in the Tuscarora Mountain Tunnel. In all cases, the MOBILE models underestimated the absolute value of the non-tailpipe emissions. The ability of the MOBILE models to account for observed emissions when conditions are more variable than those studies in the Fort McHenry and Tuscarora Mountain Tunnels is still an open question.
Leland Tarnay - One of the best experts on this subject based on the ideXlab platform.
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exhaust particle size distribution measurements at the tuscarora Mountain Tunnel
Aerosol Science and Technology, 2002Co-Authors: Mahmoud Abuallaban, W Coulomb, Alan W Gertler, J A Gillies, William R Pierson, C F Rogers, John C Sagebiel, Leland TarnayAbstract:On-road particle size distributions were measured at the Tuscarora Mountain Tunnel on the Pennsylvania Turnpike in May 1999. The data were obtained using a scanning mobility particle sizer. The nucleation modes of the size distributions contained most of the particles on a number concentration basis and exhibited peak diameters ranging from 11 to 17 nm. This observation is consistent with previous calculations and measurements, indicating that significant numbers of ultrafine aerosol particles can be expected in close proximity to busy motorways. The experiment provided 4 case studies for which the Tunnel inlet data could be used to correct data obtained at the outlet, allowing for estimates of particle production within the Tunnel. Exhaust particle production rates per vehicle kilometer were estimated; the results are presented with the caveat that the measurements were affected by ambient dilution. The 4 case study nucleation mode sizes varied inversely with ambient temperature. The light-duty vehicle c...
Eric M. Fujita - One of the best experts on this subject based on the ideXlab platform.
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Apportionment of NMHC tailpipe vs non-tailpipe emissions in the Fort McHenry and Tuscarora Mountain Tunnels
Atmospheric Environment, 1996Co-Authors: Alan W Gertler, William R Pierson, Eric M. Fujita, David N. WittorffAbstract:Measurements of on-road emissions of non-methane hydrocarbons (NMHCs) were made in the Fort McHenry Tunnel (Baltimore) and Tuscarora Mountain Tunnel (Pennsylvania) during the summer of 1992. Measurements were made during 11 one-hour periods in the Fort McHenry Tunnel and during 11 one-hour periods in the Tuscarora Mountain Tunnel. The observed light-duty fleets were quite new, with a median model year of approximately 1989. Speciated NMHC values were obtained from analyses of canister and Tenax samples, and light-duty speciated emission factors were calculated for the two Tunnels. Fuel samples were collected in the area around the Tunnels for use in constructing headspace and liquid fuel profiles for the chemical mass balance (CMB) receptor model. Profiles of tailpipe emissions were obtained from the literature. The CMB was used to apportion tailpipe from non-tailpipe emissions. Non-tailpipe sources were found to constitute approximately 15% of the light-duty NMHC emissions. The Federal automotive emission-rate models, MOBILE4.1 and MOBILE5, underpredicted non-tailpipe emissions, assigning approximately 9% and 6.5%, respectively, to non-tailpipe sources. In terms of total absolute emissions, MOBILE5 predictions were approximately a factor of 2 greater than MOBILE4.1 predictions. Both MOBILE4.1 and MOBILE5 underestimated the NMHC emissions in the Fort McHenry Tunnel and overpredicted the NMHC emissions in the Tuscarora Mountain Tunnel. In all cases, the MOBILE models underestimated the absolute value of the non-tailpipe emissions. The ability of the MOBILE models to account for observed emissions when conditions are more variable than those studies in the Fort McHenry and Tuscarora Mountain Tunnels is still an open question.