Microphysical properties of atmospheric soot and organic particles: measurements, modeling, and impacts

npj Climate and Atmospheric Science, Journal Year: 2024, Volume and Issue: 7(1)

Published: March 8, 2024

Abstract Atmospheric soot and organic particles from fossil fuel combustion biomass burning modify Earth’s climate through their interactions with solar radiation modifications of cloud properties by acting as condensation nuclei ice nucleating particles. Recent advancements in understanding individual microscopic composition have led to heightened interest microphysical properties. This review article provides an overview current advanced measurements offers insights into future avenues for studying these To quantify morphology ageing, fractal dimension ( D f ) is a commonly employed quantitative metric which allows characterize morphologies aggregates relation ageing factors like internal mixing state, core-shell structures, phase, heterogeneity. Models been developed incorporate diversity metrics aged particles, enabling assessment optical absorption radiative forcing effects. The are complex they influenced particle sources, process, meteorological conditions. Furthermore, soluble exhibit diverse forms can engage liquid–liquid phase separation sulfate nitrate components. Primary carbonaceous such tar balls warrant further attention due strong light absorbing properties, presence toxic constituents, small size, impact human health. Future research needs include both atmospheric modeling approaches, focusing on changes the structures ensembles, effects dynamics

Language: Английский

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Multi-platform observations and constraints reveal overlooked urban sources of black carbon in Xuzhou and Dhaka

Communications Earth & Environment, Journal Year: 2025, Volume and Issue: 6(1)

Published: Jan. 20, 2025

Language: Английский

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Mechanisms of soot-aggregate restructuring and compaction

Aerosol Science and Technology, Journal Year: 2022, Volume and Issue: 57(2), P. 89 - 111

Published: Oct. 25, 2022

Soot aggregates form as open, fractal-like structures, but aged atmospheric particles are often observed to be restructured into more-compact shapes due internal mixing ("coating"). This compaction has a major effect on the radiative properties of aggregates, and may also influence their aerosol-cloud interactions, toxicity, deposition in human lungs. Recent laboratory studies have presented conflicting arguments whether this occurs during condensation or evaporation coatings. In three-part study, we combine theory experiments explain these results. First, review surface-science literature identify explicit mechanisms for condensation-compaction well evaporation-compaction. We mechanism avoiding condensation, based heterogeneous nucleation kinetic barriers capillary formation. Second, soot-restructuring find clear evidence both condensation- evaporation-compaction, with being norm. Third, present new experimental results where forces anthracene coatings were "switched on" off" by using solid liquid phases coating addition removal. Consequently, demonstrate condensation-compaction, no compaction, same soot source. Overall, our study indicates that will typically undergo when coatings, while avoided through coagulation gas-to-particle formation highly viscous coatings.Copyright © 2022 American Association Aerosol Research

Language: Английский

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Effective density of inhaled environmental and engineered nanoparticles and its impact on the lung deposition and dosimetry

Particle and Fibre Toxicology, Journal Year: 2024, Volume and Issue: 21(1)

Published: Feb. 17, 2024

Airborne environmental and engineered nanoparticles (NPs) are inhaled deposited in the respiratory system. The dose of such NPs their deposition location lung determines impact on health. When calculating NP using particle inhalation models, a common approach is to use bulk material density, ρ

Language: Английский

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The Centrifugal Differential Mobility Analyser – concept and initial validation of a new device for measuring 2D property distributions

Aerosol Research, Journal Year: 2025, Volume and Issue: 3(1), P. 65 - 79

Published: Jan. 28, 2025

Abstract. Usually for the characterization of nanoparticles, an equivalent property is measured, e.g. mobility-equivalent diameter. In case non-spherical, complex-shaped one particle size not sufficient a complete characterization. Most methods utilized to gain deeper insight into morphology nanoparticles are very time-consuming and costly or have bad statistics (such as tandem setups TEM (transmission electron microscopy)/SEM (scanning microscopy) images). To overcome these disadvantages, prototype new compact device, Centrifugal Differential Mobility Analyser (CDMA), was built, which can measure full 2D distribution Stokes diameters by classification in cylinder gap through electrical centrifugal forces. An evaluation method determine transfer probabilities developed used this work compare measurement results with theory pure rotational behaviour (like Aerodynamic Aerosol Classifier) Dynamic Analyser). addition, ideal function derived using trajectory approach. This prerequisite obtaining from measurements inversion.

Language: Английский

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Dynamics of soot surface growth and agglomeration by enclosed spray combustion of jet fuel

Fuel, Journal Year: 2023, Volume and Issue: 342, P. 127864 - 127864

Published: March 2, 2023

Understanding the dynamics of soot formation and growth during combustion jet fuel is essential for mitigation aircraft engine emissions. Here, enclosed spray investigated its capacity to form with comparable characteristics that from engines. For this, microscopy, scanning mobility particle, X-ray diffraction & Raman spectroscopy measurements discrete element modeling (DEM) are employed along flame centerline at various Effective eQuivalence Ratios (EQR). The DEM-derived primary particle size distribution in excellent agreement those measured 5–63 cm height above burner (HAB) temperature volume fraction. At low EQR (1.46 1.59), surface stops residence time, t = 4–7 ms, resulting median diameters, d¯p, ∼ 14 nm. longer (high HAB), agglomeration takes over increasing diameter 16 88 or 145 nm 1.46 1.59, respectively, without altering d¯p having disorder graphitic band ratio, D/G 0.9 ± 0.01 a crystallite length, Lc 1.24 0.02 In contrast, 1.59 1.88, enhances growth, increases up 23 results more 0.8 1.47 Furthermore, inversely proportional determined largely by growth.

Language: Английский

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Toward Elimination of Soot Emissions from Jet Fuel Combustion

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(28), P. 10276 - 10283

Published: July 5, 2023

Soot from jet fuel combustion in aircraft engines contributes to global warming through the formation of contrail cirrus clouds that make up 56% total radiative forcing aviation. Here, elimination such emissions is explored N2 injection (containing 0–25 vol % O2) at exhaust enclosed spray nicely emulates soot emissions. It shown injecting containing 5 O2 enhances polyaromatic hydrocarbons (PAHs) adsorb on surface soot. This increases number density and volume fraction by 25 80%, respectively. However, further increasing concentration 20 or oxidation nearly eliminates combustion, reducing 87.3 95.4 98.3 99.6%, So, a judicious air just after engine can drastically reduce halve due aviation, as mobility, X-ray diffraction, Raman spectroscopy, nitrogen adsorption, microscopy, thermogravimetric analysis (for organic carbon ratio) measurements.

Language: Английский

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A review of quantification methods for light absorption enhancement of black carbon aerosol

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 924, P. 171539 - 171539

Published: March 9, 2024

Language: Английский

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Aerosols heat up the Himalayan climate

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 894, P. 164733 - 164733

Published: June 15, 2023

The impact of aerosols, especially the absorbing in Himalayan region is important for climate. We closely examine ground-based high-quality observations aerosol characteristics including radiative forcing from several locations Indo-Gangetic Plain (IGP), foothills and Tibetan Plateau, relatively poorly studied regions with sensitive ecosystems global importance, as well highly vulnerable large populations. This paper presents a state-of-the-art treatment warming that arises these particles, using combination new measurements modeling techniques. first-time analysis its kind, observations, satellite data, model simulations, which reveals efficiency (ARFE) atmosphere clearly high over IGP (80-135 Wm-2 per unit optical depth (AOD)), values being greater at higher elevations. AOD >0.30 single scattering albedo (SSA) ∼0.90 throughout year this region. mean ARFE 2-4 times here than other polluted sites South East Asia, owing to absorption (i.e., lower SSA). Further, observed annual aerosol-induced atmospheric heating rates (0.5-0.8 Kelvin/day), are significantly previously reported region, imply aerosols alone could account >50 % total (aerosols + greenhouse gases) surface demonstrate current models used climate assessments underestimate heating, Hindu Kush - Himalaya Plateau (HKHTP) indicating need more realistic representation properties, black carbon aerosols. significant, regionally coherent we observe altitudes significant factor contributing increasing air temperature, accelerated retreat glaciers, changes hydrological cycle precipitation patterns Thus, up climate, will remain key driving change

Language: Английский

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Process design for carbon black size and morphology

Carbon, Journal Year: 2023, Volume and Issue: 213, P. 118255 - 118255

Published: June 26, 2023

The structure (size and morphology) of carbon black (CB) largely determines its performance in tires, inks, batteries etc. Here, the impact CB process synthesis variables, i.e. temperature, T, precursor (i.e. acetylene) flow rate, Q, volume fraction, fv, on is elucidated by discrete element modeling (DEM) compared to experimental data literature. quantified mobility, dm, spherule or primary particle, dp, diameters, effective density, ρeff, fractal dimension, Df. Decreasing Q T enhances yield, surface growth agglomeration. This increases mean dm consistent with from laminar ethylene pyrolysis reactors. made at high less compact than that low having up 50% smaller ρeff 30% Df, excellent agreement also. Increasing fv (e.g. increasing rate) results aggregates (covalently-bonded particles) explaining commercial furnace data. These are quite 45% larger Df those black. So design diagrams generated present DEM simulations can be used guide optimization for various applications first principles.

Language: Английский

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