Methodology for measuring exhaust aerosol size distributions using an engine test under transient operating conditions

[EN] A study on the sources of variability in the measurement of particle size distribution using a two-stage dilution system and an engine exhaust particle sizer was conducted to obtain a comprehensive and repeatable methodology that can be used to measure the particle size distribution of aerosols emitted by a light-duty diesel engine under transient operating conditions. The paper includes three experimental phases: an experimental validation of the measurement method; an evaluation of the influence of sampling factors, such as dilution system pre-conditioning; and a study of the effects of the dilution conditions, such as the dilution ratio and the dilution air temperature. An examination of the type and degree of influence of each studied factor is presented, recommendations for reducing variability are given and critical parameter values are identified to develop a highly reliable measurement methodology that could be applied to further studies on the effect of engine operating parameters on exhaust particle size distributions. © 2011 IOP Publishing Ltd.The translation of this paper was funded by the Universidad Politecnica de Valencia, Spain.Desantes, J.; Bermúdez, V.; Molina, S.; Linares Rodríguez, WG. (2011). Methodology for measuring exhaust aerosol size distributions using an engine test under transient operating conditions. Measurement Science and Technology. 22(11):1-14. doi:10.1088/0957-0233/22/11/115101S1142211Dobbins, R. A. (2007). Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines. Aerosol Science and Technology, 41(5), 485-496. doi:10.1080/02786820701225820Davidson, C. I., Phalen, R. F., & Solomon, P. A. (2005). Airborne Particulate Matter and Human Health: A Review. Aerosol Science and Technology, 39(8), 737-749. doi:10.1080/02786820500191348McDonald, J. D., Barr, E. B., & White, R. K. (2004). Design, Characterization, and Evaluation of a Small-Scale Diesel Exhaust Exposure System. Aerosol Science and Technology, 38(1), 62-78. doi:10.1080/02786820490247623Brown, D. M., Wilson, M. R., MacNee, W., Stone, V., & Donaldson, K. (2001). Size-Dependent Proinflammatory Effects of Ultrafine Polystyrene Particles: A Role for Surface Area and Oxidative Stress in the Enhanced Activity of Ultrafines. Toxicology and Applied Pharmacology, 175(3), 191-199. doi:10.1006/taap.2001.9240Lighty, J. S., Veranth, J. M., & Sarofim, A. F. (2000). Combustion Aerosols: Factors Governing Their Size and Composition and Implications to Human Health. Journal of the Air & Waste Management Association, 50(9), 1565-1618. doi:10.1080/10473289.2000.10464197Kittelson, D. B. (1998). Engines and nanoparticles. Journal of Aerosol Science, 29(5-6), 575-588. doi:10.1016/s0021-8502(97)10037-4Dockery, D. W., Pope, C. A., Xu, X., Spengler, J. D., Ware, J. H., Fay, M. E., … Speizer, F. E. (1993). An Association between Air Pollution and Mortality in Six U.S. Cities. New England Journal of Medicine, 329(24), 1753-1759. doi:10.1056/nejm199312093292401Sem, G. J. (2002). Design and performance characteristics of three continuous-flow condensation particle counters: a summary. Atmospheric Research, 62(3-4), 267-294. doi:10.1016/s0169-8095(02)00014-5Ankilov, A., Baklanov, A., Colhoun, M., Enderle, K.-H., Gras, J., Julanov, Y., … Zagaynov, V. (2002). Intercomparison of number concentration measurements by various aerosol particle counters. Atmospheric Research, 62(3-4), 177-207. doi:10.1016/s0169-8095(02)00010-8Wiedensohlet, A., Orsini, D., Covert, D. S., Coffmann, D., Cantrell, W., Havlicek, M., … Litchy, M. (1997). Intercomparison Study of the Size-Dependent Counting Efficiency of 26 Condensation Particle Counters. Aerosol Science and Technology, 27(2), 224-242. doi:10.1080/02786829708965469Giechaskiel, B., Ntziachristos, L., & Samaras, Z. (2004). Calibration and modelling of ejector dilutors for automotive exhaust sampling. Measurement Science and Technology, 15(11), 2199-2206. doi:10.1088/0957-0233/15/11/004Cheng, M.-D., Storey, J. M., Wainman, T., & Dam, T. (2002). Impacts of venturi turbulent mixing on the size distributions of sodium chloride and dioctyl-phthalate aerosols. Journal of Aerosol Science, 33(3), 491-502. doi:10.1016/s0021-8502(01)00180-xHueglin, C., Scherrer, L., & Burtscher, H. (1997). An accurate, continuously adjustable dilution system (1:10 to 1:104) for submicron aerosols. Journal of Aerosol Science, 28(6), 1049-1055. doi:10.1016/s0021-8502(96)00485-5Lyyränen, J., Jokiniemi, J., Kauppinen, E. I., Backman, U., & Vesala, H. (2004). Comparison of Different Dilution Methods for Measuring Diesel Particle Emissions. Aerosol Science and Technology, 38(1), 12-23. doi:10.1080/02786820490247579Wong, C. P., Chan, T. L., & Leung, C. W. (2003). Characterisation of diesel exhaust particle number and size distributions using mini-dilution tunnel and ejector–diluter measurement techniques. Atmospheric Environment, 37(31), 4435-4446. doi:10.1016/s1352-2310(03)00571-5Liu, Z. G., Ford, D. C., Vasys, V. N., Chen, D.-R., & Johnson, T. R. (2007). Influence of Engine Operating Conditions on Diesel Particulate Matter Emissions in Relation to Transient and Steady-State Conditions. Environmental Science & Technology, 41(13), 4593-4599. doi:10.1021/es0616229Liu, Z. G., Vasys, V. N., & Kittelson, D. B. (2007). Nuclei-Mode Particulate Emissions and Their Response to Fuel Sulfur Content and Primary Dilution during Transient Operations of Old and Modern Diesel Engines. Environmental Science & Technology, 41(18), 6479-6483. doi:10.1021/es0629007Desantes, J. M., Bermúdez, V., Pastor, J. V., & Fuentes, E. (2004). Methodology for measuring exhaust aerosol size distributions from heavy duty diesel engines by means of a scanning mobility particle sizer. Measurement Science and Technology, 15(10), 2083-2098. doi:10.1088/0957-0233/15/10/019Lapuerta, M., Armas, O., & Gómez, A. (2003). Diesel Particle Size Distribution Estimation from Digital Image Analysis. Aerosol Science and Technology, 37(4), 369-381. doi:10.1080/02786820300970Wiedensohler, A. (1988). An approximation of the bipolar charge distribution for particles in the submicron size range. Journal of Aerosol Science, 19(3), 387-389. doi:10.1016/0021-8502(88)90278-9Wen, H. Y., Reischl, G. P., & Kasper, G. (1984). Bipolar diffusion charging of fibrous aerosol particles—II. charge and electrical mobility measurements on linear chain aggregates. Journal of Aerosol Science, 15(2), 103-122. doi:10.1016/0021-8502(84)90030-2Oh, H., Park, H., & Kim, S. (2004). Effects of Particle Shape on the Unipolar Diffusion Charging of Nonspherical Particles. Aerosol Science and Technology, 38(11), 1045-1053. doi:10.1080/027868290883324Matti Maricq, M. (2007). Chemical characterization of particulate emissions from diesel engines: A review. Journal of Aerosol Science, 38(11), 1079-1118. doi:10.1016/j.jaerosci.2007.08.001Katz, J. L. (1970). Condensation of a Supersaturated Vapor. I. The Homogeneous Nucleation of the n‐Alkanes. The Journal of Chemical Physics, 52(9), 4733-4748. doi:10.1063/1.1673706Burtscher, H. (2005). Physical characterization of particulate emissions from diesel engines: a review. Journal of Aerosol Science, 36(7), 896-932. doi:10.1016/j.jaerosci.2004.12.001Mamakos, A., Ntziachristos, L., & Samaras, Z. (2004). Comparability of particle emission measurements between vehicle testing laboratories: a long way to go. Measurement Science and Technology, 15(9), 1855-1866. doi:10.1088/0957-0233/15/9/02

Evaluación de nuevas metodologías para la medida de emisiones contaminantes reguladas y no reguladas

Con el objetivo de lograr una mejor comprensión de las emisiones contaminantes provenientes los Motores de Combustión Interna Alternativos, el trabajo de fin de Máster que se ha basado en la evaluación de distintas técnicas de medida que permitan obtener una mayor información sobre las propiedad físico-químicas de las emisiones contaminantes.Linares Rodríguez, WG. (2009). Evaluación de nuevas metodologías para la medida de emisiones contaminantes reguladas y no reguladas. http://hdl.handle.net/10251/12916Archivo delegad

Comparative study of regulated and unregulated gaseous emissions during NEDC in a light-duty diesel engine fuelled with Fischer Tropsch and biodiesel fuels

In this study, regulated and unregulated gaseous emissions and fuel consumption with five different fuels were tested in a 4-cylinder, light-duty diesel EURO IV typically used for the automotive vehicles in Europe. Three different biodiesel fuels obtained from soybean oil, rapeseed oil and palm oil, a Fischer Tropsch fuel and an ultra low sulphur diesel were studied. The test used was the New European Driving Cycle (NEDC), this allowed tests to be carried out on an engine warmed up beforehand to avoid the effect of cold starts and several tests a day. Regulated emissions of NOX, CO, HC and CO2 were measured for each fuel. Unburned Hydrocarbon Speciation and formaldehyde were also measured in order to determine the maximum incremental reactivity (MIR) of the gaseous emissions. Pollutants were measured without the diesel oxidation catalyst (DOC) to gather data about raw emissions. When biodiesel was used, increases in regulated and unregulated emissions were observed and also significant increases in engine fuel consumption. The use of Fischer Tropsch fuel, however, caused lower regulated and unregulated emissions and fuel consumption than diesel.Universidad Politecnica de Valencia (Spain), for granting financial support for the linguistic revision of this paper.Bermúdez, V.; Luján, JM.; Pla Moreno, B.; Linares Rodríguez, WG. (2011). Comparative study of regulated and unregulated gaseous emissions during NEDC in a light-duty diesel engine fuelled with Fischer Tropsch and biodiesel fuels. Biomass and Bioenergy. 35(2):789-798. doi:10.1016/j.biombioe.2010.10.034S78979835

Correction to: Comparative effectiveness and safety of non-vitamin K antagonists for atrial fibrillation in clinical practice: GLORIA-AF Registry

International audienceIn this article, the name of the GLORIA-AF investigator Anastasios Kollias was given incorrectly as Athanasios Kollias in the Acknowledgements. The original article has been corrected

Patterns of oral anticoagulant use and outcomes in Asian patients with atrial fibrillation: a post-hoc analysis from the GLORIA-AF Registry

Background: Previous studies suggested potential ethnic differences in the management and outcomes of atrial fibrillation (AF). We aim to analyse oral anticoagulant (OAC) prescription, discontinuation, and risk of adverse outcomes in Asian patients with AF, using data from a global prospective cohort study. Methods: From the GLORIA-AF Registry Phase II-III (November 2011-December 2014 for Phase II, and January 2014-December 2016 for Phase III), we analysed patients according to their self-reported ethnicity (Asian vs. non-Asian), as well as according to Asian subgroups (Chinese, Japanese, Korean and other Asian). Logistic regression was used to analyse OAC prescription, while the risk of OAC discontinuation and adverse outcomes were analysed through Cox-regression model. Our primary outcome was the composite of all-cause death and major adverse cardiovascular events (MACE). The original studies were registered with ClinicalTrials.gov, NCT01468701, NCT01671007, and NCT01937377. Findings: 34,421 patients were included (70.0 ± 10.5 years, 45.1% females, 6900 (20.0%) Asian: 3829 (55.5%) Chinese, 814 (11.8%) Japanese, 1964 (28.5%) Korean and 293 (4.2%) other Asian). Most of the Asian patients were recruited in Asia (n = 6701, 97.1%), while non-Asian patients were mainly recruited in Europe (n = 15,449, 56.1%) and North America (n = 8378, 30.4%). Compared to non-Asian individuals, prescription of OAC and non-vitamin K antagonist oral anticoagulant (NOAC) was lower in Asian patients (Odds Ratio [OR] and 95% Confidence Intervals (CI): 0.23 [0.22-0.25] and 0.66 [0.61-0.71], respectively), but higher in the Japanese subgroup. Asian ethnicity was also associated with higher risk of OAC discontinuation (Hazard Ratio [HR] and [95% CI]: 1.79 [1.67-1.92]), and lower risk of the primary composite outcome (HR [95% CI]: 0.86 [0.76-0.96]). Among the exploratory secondary outcomes, Asian ethnicity was associated with higher risks of thromboembolism and intracranial haemorrhage, and lower risk of major bleeding. Interpretation: Our results showed that Asian patients with AF showed suboptimal thromboembolic risk management and a specific risk profile of adverse outcomes; these differences may also reflect differences in country-specific factors. Ensuring integrated and appropriate treatment of these patients is crucial to improve their prognosis. Funding: The GLORIA-AF Registry was funded by Boehringer Ingelheim GmbH