Morphological investigation of the microstructure, dimensions, and fractal geometry of diesel particulates

Lee, Kyeong O.; Cole, R. L.; Sekar, R.; Choi, Mijin; Kang, Jin Soo; Bae, Changseok; Shin, Hyun Dong

doi:10.1016/s1540-7489(02)80083-9

Cited by 166 publications

(115 citation statements)

References 10 publications

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“…The recognizable attributes of precursor nanoparticles are singlet particle morphology, a translucent response to the electron beam of the TEM, and a near absence of crystallinity or black opaqueness. Such particles appear very faintly in the TEM images (Lee et al 2002). Similar images were present in the micrograph from a commercial four-cylinder engine and but were thought to be artifacts of the sampling process (Park et al 2004).…”

Section: Morphology Of Engine Particulatessupporting

confidence: 52%

“…Twentythree not identified PAHs were found on the particle phase by GCMS. TEM micrographs first show faint images of precursorlike nanoparticles at light engine loads (Lee et al 2002). The recognizable attributes of precursor nanoparticles are singlet particle morphology, a translucent response to the electron beam of the TEM, and a near absence of crystallinity or black opaqueness.…”

Section: Morphology Of Engine Particulatesmentioning

confidence: 99%

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Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines

Dobbins

2007

Aerosol Science and Technology

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The formation of nanoparticles in laboratory hydrocarbon flames is reviewed in terms of particle morphology, chemical composition, and health hazards. The nascent nanoparticles in the nucleation mode have been widely reported in diverse laboratory flames, and are distinguished by their occurrence as singlet particles that form translucent images in transmission electron microscopy (TEM). Their sizes range from about 10 nm or more down to 2 to 3 nm, the limit of resolution of the TEM, and they possess a liquid-like quality. These particles are widely considered to be the precursor stage to the more readily observed carbonaceous aggregates consisting of chained primary particles that are opaque to the electron beam of the TEM. Nanoparticles sampled from the inverse diffusion flame and the particle effluent from diesel engines show a strong resemblance by GCMS analysis, and they contain many of the stabilomer PAHs and their isomers in the 200 to 302 atomic mass range. Many of these chemical species have high relative mutagenicities. Distinctive bimodal particle size distributions can be observed in both flame and engine samples. Recent TEM micrographs of diesel particulates show images of precursor-like nanoparticles, of as yet unknown chemical composition, that are formed in a diesel engine at many operating conditions.

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Section: Morphology Of Engine Particulatessupporting

confidence: 52%

Section: Morphology Of Engine Particulatesmentioning

confidence: 99%

Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines

Dobbins

2007

Aerosol Science and Technology

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“…Among them, the list of the TEFs proposed by Nisbet and LaGoy (1992) seems to better reflect the actual state of knowledge on the human health risk associated with inhalatory exposure to PAH mixtures. Thus, the TEFs reported in Nisbet and LaGoy (1992) were used in this study: BaPeq emission rates for each individual PAH were computed by multiplying the emission factor with the corresponding TEF value (Lee et al, 2002). Table 4 shows the total BaPeq emission factors for various size ranges and for each fuel.…”

Section: Pah Emissionsmentioning

confidence: 99%

Bioethanol–gasoline fuel blends: Exhaust emissions and morphological characterization of particulate from a moped engine

Seggiani

Prati

Costagliola

et al. 2012

Journal of the Air & Waste Management Association

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This study was aimed at evaluating the effects of gasoline-ethanol blends on the exhaust emissions in a catalyst-equipped fourstroke moped engine. The ethanol was blended with unleaded gasoline in at percentages (10, 15, and 20% v/v). The regulated pollutants and the particulate matter emissions were evaluated over the European ECE R47 driving cycle on the chassis dynamometer bench. Particulate matter was characterized in terms of total mass collected on filters and total number of particles in the range 7 nm-10 mm measured by electrical low-pressure impactor (ELPI). In addition, particle-phase polycyclic aromatic hydrocarbons (PAHs) emissions were evaluated to assess the health impact of the emitted particulate. Finally, an accurate morphological analysis was performed on the particulate by high-resolution transmission electron microscope (TEM) equipped with a digital image-processing/data-acquisition system. In general, CO emission reductions of 60-70% were obtained with 15 and 20% v/v ethanol blends, while the ethanol use did not reduce hydrocarbon (HC) and NO x emissions. No evident effect of ethanol on the particulate mass emissions and associated PAHs emissions was observed. Twenty-one PAHs were quantified in the particulate phase with emissions ranging from 26 to 35 mg/km and benzo[a]pyrene equivalent (BaPeq) emission factors from 2.2 to 4.1 mg/km. Both particulate matter and associated PAHs with higher carcinogenic risk were mainly emitted in the submicrometer size range (<0.1 mm). On the basis of the TEM observations, no relevant effect of the ethanol use on the particulate morphology was evidenced, showing aggregates composed of primary particles with mean diameters in the range 17.5-32.5 nm.Implications: Mopeds may contribute in a large share to air pollution in some major urban areas; therefore, efforts may be taken to reduce their emissions. The addition of ethanol into gasoline (up 20% v/v) leads to a significant reduction of CO emission at the exhaust of a catalyzed 4-S moped, whereas this does not reduce HC and NOx. No clear effects on particulate matter and associated PAHs emissions have been observed with ethanol addition, but particulate-phase PAHs were mainly found on submicrometer-size particles (<0.1 mm), which penetrate deeply into the human respiratory tract.

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“…Particle morphology not only influences the severity of adverse health effects (Madl and Pinkerton, 2009), but also conveys information on factors contributing to particle formation (Lee et al, 2002;Stachowiak et al, 2008).…”

Section: Particle Morphologymentioning

confidence: 99%

“…However, these spherical particles can aggregate and form new shapes. Lee et al (2002) reported that most diesel particles were amorphous in structure under low engine load conditions, whereas they displayed graphite structure under high loads. Lee et al (2002) explained these phenomena by the differences in dominant aggregation mechanisms.…”

Section: Particle Morphologymentioning

confidence: 99%

Particle Emissions From Rail Traffic: A Literature Review

Abbasi

Jansson

Sellgren

et al. 2013

Critical Reviews in Environmental Science and Technology

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Particle emissions are a drawback of rail transport. This work is a comprehensive presentation of recent research into particle emissions from rail vehicles. Both exhaust and non-exhaust particle emissions are considered when examining particle characteristics such as PM 10 , and PM 2.5 concentration levels, size, morphology, composition, as well as adverse health effects, current legislation, and available and proposed solutions for reducing such emissions. High concentration levels in enclosed rail traffic environments are reported and some toxic effects of the particles. We find that only a few limited studies have examined the adverse health effects of non-exhaust particle emissions and that no relevant legislation exists. Thus further research in this area is warranted.

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Morphological investigation of the microstructure, dimensions, and fractal geometry of diesel particulates

Cited by 166 publications

References 10 publications

Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines

Hydrocarbon Nanoparticles Formed in Flames and Diesel Engines

Bioethanol–gasoline fuel blends: Exhaust emissions and morphological characterization of particulate from a moped engine

Particle Emissions From Rail Traffic: A Literature Review

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