Journal of Aerosol Science最新文献

{"title":"Public health risk assessment and speciation of air-borne microorganisms in an office building","authors":"Abhaysinh R. Salunkhe,&nbsp;Swapnil Dudhwadkar,&nbsp;Neenu P. Raju,&nbsp;Shalini Tandon","doi":"10.1016/j.jaerosci.2024.106362","DOIUrl":"10.1016/j.jaerosci.2024.106362","url":null,"abstract":"<div><p>This study focuses on speciation of air borne microbes in an office building and health impacts of these microbes in terms of Quantitative Microbial Risk Assessment (QMRA), Hazard Quotient (HQ) and Hazard Index (HI). This is important in the wake of Sustainability Development Goal 3 (Public Health and well-being) specially when there is a lack of standards in terms of microbial air quality in office buildings where people spend 8–10 h indoors. Air borne bacterial and fungal species in different floors of the office building with varying occupancy and work profile were identified. The load of bacterial count on an average for the entire building was found to be 1917 CFU/m3. Overall, Gram-positive bacteria were predominant (&gt;53%). Based on V3–V4 sequencing <em>Staphylococcus scuiri</em> (causing UTIs) was the most abundant (93.7%) and other bacterial species found were <em>Lactobacillus hamsteri, Prevotella copri, Bacteroides plebeius Faecalibacterium prausnitzii, Bacillus coagulans</em> (gut commensals), <em>Shigella boydii</em> (causes bacillary dysentery), and <em>Propionibacterium acnes</em> (acne producing). Fungal load was 4000 CFU/m3. Based on ITS sequencing <em>Aspergillus</em> (45.6%) was the dominant fungus and other fungi found were <em>Cunninghamella</em>, <em>Lichtheimia, Fusarium,</em> and <em>Circinella Grammothele</em>, <em>Chondrostereum</em>, and <em>Pseudolagarobasidium</em>, <em>Candida</em> sp., <em>Chondrostereum, Sarocladium</em>. The QMRA of gram-negative air borne bacteria showed a high disease burden, well over the WHO benchmark values even though Hazard Quotient (HQ) and Hazard Index (HI) was found to be negligible. These findings can contribute to the development of guidelines for seemingly safe workplaces that may harbour disease-causing microbes and calls for an immediate attention from policy makers as it is a major cause of concern for public health.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"179 ","pages":"Article 106362"},"PeriodicalIF":4.5,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140277388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A nozzle design for mitigating particle slowing in the bow shock region during micro-cold spray of 8 YSZ films","authors":"Stephen G. Bierschenk ,&nbsp;Desiderio Kovar","doi":"10.1016/j.jaerosci.2024.106360","DOIUrl":"10.1016/j.jaerosci.2024.106360","url":null,"abstract":"<div><p>During micro-cold spray deposition, also referred to as the aerosol deposition method or vacuum kinetic spraying, performed with conventional nozzles, the particle impact velocities decrease drastically with particle size for fine particles &lt;500 nm in diameter due to slowing in the stagnation region. A new design for a nozzle that contains pressure relief channels is proposed that allows the pressure in the stagnation region downstream of the bow shock to be reduced. This reduced stagnation pressure results in less particle slowing compared to conventional nozzle geometries, particularly for smaller or less dense particles. The effects of the channel geometry on the particle impact velocity are systematically investigated by independently varying the channel parameters. Calculations show that the impact velocities for 100 and 200 nm yttria stabilized zirconia particles is increased by 111% and 31%, respectively, for a selected pressure relief channel nozzle when compared to a comparable conventional nozzle. Although impact velocities are increased, a tradeoff exists with this nozzle design in that the particle focusing in the nozzle is decreased and some of the particles may be removed from the aerosol by the channels. Experiments using a nitrogen as a carrier gas at ∼40 kPa upstream pressure show that, despite the loss of larger particles into the relief channels, the deposition efficiency is improved by 300% when depositing films from fine 8 YSZ powder with the pressure relief nozzle compared to a conventional nozzle.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"179 ","pages":"Article 106360"},"PeriodicalIF":4.5,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0021850224000272/pdfft?md5=ceeffe08c1491200afb7587ed06ae3ac&pid=1-s2.0-S0021850224000272-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140182176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle removal from solid surfaces via an impinging gas jet pulse: Comparison between experimental and CFD-DEM modeling results","authors":"Jens P. Metzger ,&nbsp;Carsten Mehring","doi":"10.1016/j.jaerosci.2024.106364","DOIUrl":"10.1016/j.jaerosci.2024.106364","url":null,"abstract":"<div><p>Computational and experimental studies are performed to investigate the influence of a gas jet pulse impinging perpendicularly onto a flat solid surface seeded with a monolayer of spherical particles. A numerical resuspension model is derived to predict particle release into the gas phase during jet impingement. To this end, discrete particles are immersed in a continuous gas phase modeled via Large Eddy Simulation to capture the effect of jet turbulence on the particle detachment process. Two-way coupling between particulate and gas phase is established via a near-wall particle drag model and a lift model. Direct particle–wall interactions are captured with adhesion, rolling friction and sliding friction models. To validate the overall modeling approach, numerical results are compared with resuspension experiments for monodisperse polystyrene particles placed on a glass slide. Simulations show that the particles preferentially mobilize by rolling, followed to a limited extend by lift off from the solid surface driven by aerodynamic forces and particle–particle collisions. Resuspension occurs in the first instants after jet impingement. Computational and experimental results for removal efficiency <span><math><mi>Γ</mi></math></span> are in good agreement in terms of the location of their <span><math><msub><mrow><mi>r</mi></mrow><mrow><mn>50</mn></mrow></msub></math></span> parameter, i.e., the radial position where 50% of the particles have been removed by the jet; both results show a linear dependence between the <span><math><msub><mrow><mi>r</mi></mrow><mrow><mn>50</mn></mrow></msub></math></span> value and the jet Reynolds number of the impinging jet. However, experimental <span><math><mrow><mi>Γ</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow></mrow></math></span> curves generally have a smooth sigmoidal shape whereas numerical results predict a sharp transition. Some model shortcomings are identified which lead to an underprediction of particle lift-off and which explain the observed differences. Furthermore, the experimental <span><math><mi>Γ</mi></math></span> curves nearly collapse onto each other when plotted over the predicted local wall-shear stress.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"179 ","pages":"Article 106364"},"PeriodicalIF":4.5,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0021850224000314/pdfft?md5=f5a796fa7134c18f73f7ae2d914a84c8&pid=1-s2.0-S0021850224000314-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140182122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling titanium dioxide (TiO2) nanoclusters using a 2D sectional method with molecular dynamics (MD) determined coagulation rates","authors":"Navneeth Srinivasan ,&nbsp;Gihun Shim ,&nbsp;Tomoya Tamadate,&nbsp;Shufan Zou,&nbsp;Li Li,&nbsp;Christopher J. Hogan Jr.,&nbsp;Suo Yang","doi":"10.1016/j.jaerosci.2024.106361","DOIUrl":"10.1016/j.jaerosci.2024.106361","url":null,"abstract":"<div><p>Accurate prediction of the particle size distribution (PSD) evolution of growing nanometer scale particles is important in designing gas-phase synthesis reactors for the production of nanomaterials. Towards improved predictions of growth, we model the evolution of the PSD of 1-4 nm TiO₂ particles from the decomposition of titanium tetraisoproxide (TTIP) using a two-dimensional (2D) sectional method, uniquely with coagulation rates derived from molecular dynamics (MD) trajectory calculations which account for detailed particle–particle interactions. The PSDs predicted by the 2D sectional method are compared to recent experimental measurements of PSDs in the 1-3 nm range in a flow tube reactor. The nucleation of particles is modeled based on prior mobility measurements of ions attributed to TTIP and their decomposition, with the specific nucleation rate here fitted as a fraction of base nucleation rate (<span><math><mi>k</mi></math></span>) derived from these prior measurements. In the 2D sectional model, we examine the influence of the initial (nucleated) particle charge distribution on the PSD, with different coagulation rate coefficients for neutral-charged and charged-charged particle collisions. With the MD-derived coagulation rate coefficients, we find that using nucleation rate coefficients between 0.005<span><math><mi>k</mi></math></span> and 0.03<span><math><mi>k</mi></math></span> leads to strong agreement between modeled PSD and measured PSD for a wide variety of experimental residence times, initial TTIP concentrations and temperatures. Increasing the charge fraction from 0% (uncharged) to 80% (bipolar) does not result in a significant change in the PSD, because the particles rapidly self-neutralize through coagulation based on the simulation results. The results with MD-derived coagulation rate coefficients are compared to those of the sectional method with classical kinetic theory of gases (KTG) rates with a constant enhancement factor to account for potential interactions. Through comparison, we find that the predictions from the classical KTG model consistently exhibit weaker coagulation rates than the MD-derived model during the PSD evolution.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"179 ","pages":"Article 106361"},"PeriodicalIF":4.5,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140182127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fate of inhaled electronic nicotine delivery systems (ENDS) puff constituents in the human respiratory tract","authors":"Bahman Asgharian ,&nbsp;Owen Price ,&nbsp;Scott Wasdo ,&nbsp;Jon Fallica ,&nbsp;Gladys Erives ,&nbsp;Cissy Li ,&nbsp;Raymond Yeager ,&nbsp;Susan Chemerynski ,&nbsp;Jeffry Schroeter","doi":"10.1016/j.jaerosci.2024.106363","DOIUrl":"https://doi.org/10.1016/j.jaerosci.2024.106363","url":null,"abstract":"<div><p>Published research on the fate of a puff from electronic nicotine delivery systems (ENDS) in the lungs is limited; more information would better inform human exposure and potential adverse outcomes from ENDS use. An ENDS puff is a mixture of multiple constituents in droplet and vapor form, including propylene glycol, vegetable glycerin, nicotine, water, and flavor chemicals. Understanding the complexity of the puff aids in developing mechanistic models that can account for the physical, physiological, and thermodynamic processes of the puff while traveling and depositing in lung airways. Previously, we developed a mathematical model to predict deposition and uptake of ENDS constituents in the oral cavity. In this study, we formulated the model for lung airways to extend to the entire respiratory tract and made adjustments to mechanisms such as phase change and nicotine protonation to study effects on droplet pH and nicotine evaporation. We conducted model simulations for two representative inhalation profiles relevant to ENDS users: mouth-to-lung and direct-to-lung inhalation. Simulation results showed that vapor uptake during ENDS use was the primary mechanism of the overall tissue dose for higher vapor pressure constituents. Nicotine protonation was unaffected by the ratio of propylene glycol to vegetable glycerin but changes to vanillin molarity impacted droplet pH and free nicotine fraction. The largest uptake and deposition occurred in the deep lung, where constituents more efficiently reach the arterial blood. Predicted total respiratory tract retention of higher vapor pressure constituents such as nicotine, propylene glycol, and benzaldehyde were 94–95%, whereas retention of lower volatility constituents such as vegetable glycerin and vanillin was 82–83%. Results also indicated regional uptake differences for the constituents evaluated in the two inhalation scenarios. Predictions from the ENDS deposition model can be linked to physiologically based pharmacokinetic (PBPK) models to determine the fate of puff constituents such as nicotine in other tissues and organs of the body and provides further basis for evaluating flavor chemicals and puff constituents based on user-specific exposure characteristics as well as internal dose to inform risk assessment of ENDS.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"178 ","pages":"Article 106363"},"PeriodicalIF":4.5,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140180417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular dynamics investigation of gold nanoparticle coalescence under realistic gas-phase synthesis conditions","authors":"P. Grammatikopoulos ,&nbsp;E. Toulkeridou","doi":"10.1016/j.jaerosci.2024.106356","DOIUrl":"10.1016/j.jaerosci.2024.106356","url":null,"abstract":"<div><p>Dependence of nanoparticle (NP) coalescence on various physical parameters (e.g., temperature, number of NPs, NP size, orientation, crystallinity, shape, or composition, etc.) is a very active field of investigation. However, most computational studies on NP coalescence to date are performed in vacuum, with only a handful of studies taking gas pressure into account and even fewer doing a systematic analysis. This is due to two reasons: first, many computational studies complement inert-gas condensation experiments, which typically happen at high vacuum. Second, a simulation set-up in vacuum is simpler and computationally less costly. Here we utilised classical molecular dynamics for a rigorous investigation of the effect (or lack of) of gas pressure, as well as of other parameters (namely temperature, angular momenta, and inert-gas species), on the early stages of coalescence between two metallic NPs. Our approach is relevant for both inert-gas condensation in high vacuum and aerosol synthesis in standard atmospheric conditions. Multiple linear regression analysis confirmed temperature as the key factor determining the degree of coalescence; relative angular momenta direction was revealed as yet another important contributor, whereas the effect of pressure was deemed insignificant for early coalescence stages. To shed light onto the sintering process we elaborate on interesting atomistic mechanisms. We aspire that our study may indicate potential strategies for both gas-phase synthesis methods.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"179 ","pages":"Article 106356"},"PeriodicalIF":4.5,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Health risk assessment and characterization of PM2.5 bound bioaerosols at the municipal solid waste landfill site of Nagpur, India","authors":"Pooja Kamdi ,&nbsp;Sakshi Patil ,&nbsp;Amit Bafana ,&nbsp;Asha Lalwani ,&nbsp;Anirban Middey ,&nbsp;Krishnamurthi Kannan ,&nbsp;Saravanadevi Sivanesan","doi":"10.1016/j.jaerosci.2024.106359","DOIUrl":"10.1016/j.jaerosci.2024.106359","url":null,"abstract":"<div><p>Landfill being the reservoir of organic waste, serves as the most important source in the generation and emission of bioaerosols in the environment, and these bioaerosols have a significant impact on the environment and public health. In India, there are limited studies on the characterization of culturable bacteria and fungi in the bioaerosols originating from landfills. Therefore, the present study aimed to quantify and identify the bioaerosols and study their characteristics at a landfill site in Nagpur, India. The study describes the seasonal variation of PM_2.5, PM_2.5-associated bacteria and fungi in the landfill air, their molecular identification, antibiotic resistance, pathogenicity, dispersion and health risk assessment during winter and pre-monsoon seasons at the landfill site and surrounding residential sites in upwind and downwind directions. The study showed PM_2.5 concentration was highest in the winter season (265.56 μg/m³) followed by the pre-monsoon season (173.1 μg/m³) at the landfill site. The culturable bioaerosol level was also significantly higher in winter (11056 CFU/m³) in comparison to pre-monsoon season (2244 CFU/m³) at the landfill site. Upon isolating and characterizing the microorganisms in the bioaerosols, some of the bacterial isolates, like <em>Bacillus, Staphylococcus gallinarum,</em> and <em>Streptomyces speibonae</em> were found to be resistant to chloramphenicol, netillin, nitrofurantoin, streptomycin etc. About 30% of the bacterial isolates were found to show β-hemolytic virulence activity. This indicated the presence of multi-drug resistant and potentially pathogenic bacteria in the bioaerosols over the landfill. The health risk assessment in adults indicated that the workers at the landfill site were at risk of bacterial aerosol in the winter season (hazard quotient i.e., HQ&gt;1). The impact of bioaerosols on children needs to be investigated in the further studies and regular monitoring of bioaerosols is suggested to avoid any morbidity. To the best of our knowledge, this is the first study on the characterization of microorganisms from the bioaerosols over an open landfill site in India.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"178 ","pages":"Article 106359"},"PeriodicalIF":4.5,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140046204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Operando gas- and particle-phase measurements of combustion cigarette smoke aerosols by vacuum ultraviolet photoionization mass spectrometry","authors":"Feng Zhao ,&nbsp;Zuoying Wen ,&nbsp;Xuejun Gu ,&nbsp;Weijun Zhang ,&nbsp;Xiaofeng Tang","doi":"10.1016/j.jaerosci.2024.106358","DOIUrl":"10.1016/j.jaerosci.2024.106358","url":null,"abstract":"<div><p>Cigarette smoke is a dynamically changing aerosol system and the operando measurement of its complex chemical compositions is challenging. In this work, the gas- and particle-phase components of combustion cigarette smoke aerosols, which usually have different adverse influences on environment and human health, have been separated and their individual compositions are measured online by using a novel vacuum ultraviolet (VUV) photoionization time-of-flight mass spectrometer. The gas-phase compositions are clearly identified and ascribed to low-mass volatile organic compounds (VOCs), while the particle-phase are more complicated and dominated with abundant semi- or non-volatile organics. The present results demonstrate that some compositions only present in gas- or particle-phase, but some can exist in both phases. In addition, the signals of the gas- and particle-phases increase with the puff number of smoking and their dynamical processes are discussed. The puff-by-puff increase of the gas-phase components is more obvious than that of the particle-phase, implying their different mechanisms involved in the smoking.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"178 ","pages":"Article 106358"},"PeriodicalIF":4.5,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140046206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the fuel spray characteristics in the near-nozzle region for a pressure swirl atomizer","authors":"S.K. Vankeswaram ,&nbsp;Milan Maly,&nbsp;Jan Jedelsky","doi":"10.1016/j.jaerosci.2024.106350","DOIUrl":"10.1016/j.jaerosci.2024.106350","url":null,"abstract":"<div><p>In the present study, an experimental investigation is carried out to analyze the Jet A-1 fuel spray characteristics in the near-nozzle region (NNR) of a swirl atomizer for varying injection pressures represented by the liquid Weber number. The droplet characteristics such as mean drop size, velocity components, and their spatial distributions are obtained using phase Doppler anemometer at two different axial locations (<em>Z</em> = 5 and 12.5 mm) from the orifice exit in the NNR. Interestingly, the droplet axial and radial velocities for all droplet sizes, in the hollow-region due to the momentum transfer from air entrainment process are independent of each other while in the core-region carrying the momentum from the liquid sheet are strongly coupled with each other. Upon further exploration of the effect of air entrainment, we discovered that the droplet velocities in the hollow region failed to follow the self-similarity particularly for the smallest drop size class. On the other hand, the drop size distribution in the core-region of the NNR is effectively predicted by gamma distribution, compared to the Rosin-Rammler distribution indicative of the ligament mediated breakup. The global mean drop size in the NNR is compared to various empirical correlations and theoretical models available in literature. We anticipate that the outcome of the current work will enhance the understanding of swirl injection spraying processes in engine fuel combustion and be of great utility for researchers engaged in spray modelling.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"178 ","pages":"Article 106350"},"PeriodicalIF":4.5,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140046202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of methods for characterizing the fine particulate matter emissions from aircraft and other diffusion flame combustion aerosol sources","authors":"Robert Giannelli ,&nbsp;Jeffrey Stevens ,&nbsp;John S. Kinsey ,&nbsp;David Kittelson ,&nbsp;Alla Zelenyuk ,&nbsp;Robert Howard ,&nbsp;Mary Forde ,&nbsp;Brandon Hoffman ,&nbsp;Cullen Leggett ,&nbsp;Bruce Maeroff ,&nbsp;Nick Bies ,&nbsp;Jacob Swanson ,&nbsp;Kaitlyn Suski ,&nbsp;Gregory Payne ,&nbsp;Julien Manin ,&nbsp;Richard Frazee ,&nbsp;Timothy B. Onasch ,&nbsp;Andrew Freedman ,&nbsp;Imad Khalek ,&nbsp;Huzeifa Badshah ,&nbsp;Scott Agnew","doi":"10.1016/j.jaerosci.2024.106352","DOIUrl":"10.1016/j.jaerosci.2024.106352","url":null,"abstract":"&lt;div&gt;&lt;p&gt;The U. S. Environmental Protection Agency in collaboration with the U. S. Air Force Arnold Engineering Development Complex conducted the VAriable Response In Aircraft nvPM Testing (VARIAnT) 3 and 4 test campaigns to compare nonvolatile particulate matter (nvPM) emissions measurements from a variety of diffusion flame combustion aerosol sources (DFCASs), including a Cummins diesel engine, a diesel powered generator, two gas turbine start carts, a J85-GE-5 turbojet engine burning multiple fuels, and a Mini-CAST soot generator. The VARIAnT research program was devised to understand reported variability in the ARP6320A sampling system nvPM measurements. The VARIAnT research program has conducted four test campaigns to date with the VARIAnT 3 and 4 campaigns devoted to: (1) assessing the response of three different black carbon mass analyzers to particles of different size, morphology, and chemical composition; (2) characterizing the particles generated by 6 different combustion sources according to morphology, effective density, and chemical composition; and (3) assessing any significant difference between black carbon as determined by the 3 mass analyzers and the total PM determined via other techniques. Results from VARIAnT 3 and 4 campaigns revealed agreement of about 20% between the Micro-Soot Sensor, the Cavity Attenuated Phase Shift (CAPS PM&lt;sub&gt;SSA&lt;/sub&gt;) monitor and the thermal-optical reference method for elemental carbon (EC) mass, independent of the calibration source used. For the LII-300, the measured mass concentrations in VARIAnT 3 fall within 18% and in VARIAnT 4 fall within 27% of the reference EC mass concentration when calibrated on a combustor rig in VARIAnT 3 and on an LGT-60 start cart in VARIAnT 4, respectively. It was also found that the three mass instrument types (MSS, CAPS PM&lt;sub&gt;SSA&lt;/sub&gt;, and LII-300) can exhibit different BC to reference EC ratios depending on the emission source that appear to correlate to particle geometric mean mobility diameter, morphology, or some other parameter associated with particle geometric mean diameter (GMD) with the LII-300 showing a slightly stronger apparent trend with GMD. Systematic differences in LII-300 measured mass concentrations have been reduced by calibrating with a turbine combustion as a particle source (combustor or turbine engine). With respect to the particle size measurements, the sizing instruments (TSI SMPS, TSI EEPS, and Cambustion DMS 500) were found to be in general agreement in terms of size distributions and concentrations with some exceptions. Gravimetric measurements of the total aerosol mass produced by the various DFCAs differed from the reference EC, BC and integrated particle size distribution measured aerosol masses. The measurements of particle size distributions and single particle analysis performed using the miniSPLAT indicated the presence of larger particles (≳150 nm) having more compact morphologies, higher effective density, and a composition ","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"178 ","pages":"Article 106352"},"PeriodicalIF":4.5,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0021850224000193/pdfft?md5=9bc2cc2d09a1d35cea764bb8dc336737&pid=1-s2.0-S0021850224000193-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140005732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}