Aerosol Science and Technology最新文献

{"title":"Development of the Reiss theory for binary homogeneous nucleation of aerosols","authors":"M. S. Veshchunov","doi":"10.1080/02786826.2023.2279527","DOIUrl":"https://doi.org/10.1080/02786826.2023.2279527","url":null,"abstract":"AbstractThe Reiss theory for binary homogeneous nucleation in binary gas mixtures is critically analysed and further developed. Based on the analysis of phase space trajectories in the supercritical zone of the phase transition, carried out within the framework of the theory of two-dimensional dynamical systems and supplemented by the flux matching condition at the boundary of the critical zone, it is shown how the theory should be modified. The proposed modification is equivalent to the earlier modifications by Langer and Stauffer, based on additional trial assumptions (ansatz) for solving the steady state equation for the non-equilibrium size distribution function, but reveals and substantiates the approximation underlying their approach. The extension of the Reiss theory to binary vapours in inert carrier (atmospheric) gases is justified.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"3 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135819207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Volatile propellant droplet evaporation measurements in metered dose inhaler sprays","authors":"Daniel J. Duke, Harry N. Scott, Anesu J. Kusangaya, Alan Kastengren, Jan Ilavsky, Brandon Sforzo, Benjamin Myatt, Phil Cocks, Stephen Stein, Paul Young, Damon Honnery","doi":"10.1080/02786826.2023.2271079","DOIUrl":"https://doi.org/10.1080/02786826.2023.2271079","url":null,"abstract":"ABSTRACTMany aerosol products rely on the rapid vaporization of volatile propellants to produce a fine spray. In the simplest case, these are binary mixtures of propellant and a delivered product which undergo a flash-evaporation process leaving only the less volatile product in the resultant droplet. In more complex applications such as pressurized metered-dose inhalers, the non-propellant component may contain dissolved or suspended drug which precipitates or dries to form a matured particle. The size and morphology of the particles depends strongly on the time-history of the droplet as the propellant evaporates. However, measuring the dynamic evaporation processes which occur in dense sprays containing millions of droplets is challenging. In this paper, we demonstrate a novel application of Ultra Small Angle X-ray Scattering to measure the bulk composition of volatile HFC134a–ethanol sprays, and compare the obtained results with simple evaporation models in a dry nitrogen environment. The data reveal that diffusion-limiting processes inside the droplet are equally important as external convection and mixing-limited factors in determining evaporative timescales.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Additional informationFundingThis work was supported by the Australian Research Council under Grants LP190100938 and DP200102016, and by Kindeva Drug Delivery.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135569816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Effects of ventilation rate and social distancing on risk of transmission of disease: A numerical study using Eulerian-Lagrangian method","authors":"Wonseok Oh, Ryozo Ooka, Hideki Kikumoto, Sihwan Lee","doi":"10.1080/02786826.2023.2271954","DOIUrl":"https://doi.org/10.1080/02786826.2023.2271954","url":null,"abstract":"ABSTRACTThis study utilized the Eulerian-Lagrangian method to investigate the risk of transmission of disease by tracking particles generated through coughing. The effects of ventilation rates (0.5, 5.0, and 10 ACH) and social distancing (0.9 and 1.8 m) were examined in a small office room using a displacement ventilation system. Numerical simulations considered different particle sizes (1, 5, 10, 20, 40, and 80 μm) to understand particle behavior and transmission routes. The airflow resulting from human coughing was validated with experimental data. Results showed that at a social distance of 0.9 m, increasing the ventilation rate led to a higher fraction of particles directly inhaled by susceptible individuals, potentially causing droplet and airborne transmission. However, maintaining a social distance of 1.8 m and a ventilation rate of 10 ACH significantly reduced the fraction of inhaled particles. Larger particles tended to deposit on floors and surfaces, while smaller particles remained suspended in the air. Higher ventilation rates increased particle deposition on the body surface of susceptible individuals, whereas increasing social distance reduced particle deposition. These findings highlight the importance of appropriate ventilation rates and social distancing in reducing the risk of infection transmission. Maintaining a social distance of 1.8 m combined with increased ventilation effectively reduced the fraction of inhaled particles. Larger particles were more likely to deposit on surfaces, emphasizing the need for regular disinfection. Understanding the dynamics of infectious particles and implementing effective ventilation and distancing measures can help mitigate the spread of infectious diseases in indoor environments.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementsThis research was supported by JSPS KAKEHI (Grant Number 21K18763).Supplementary informationThe supplementary information includes Appendix A, Appendix B, and Appendix C.Supplementary data for this article is available online at the provided DOI: https://doi.org/10.1080/02786826.2023.2271954.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135888083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Comparing respiratory aerosol emissions between children and adults during sustained phonation","authors":"Mahender Singh Rawat, Mehtap Agirsoy, Dinushani Senarathna, Byron D. Erath, Tanvir Ahmed, Sumona Mondal, Andrea R. Ferro","doi":"10.1080/02786826.2023.2261715","DOIUrl":"https://doi.org/10.1080/02786826.2023.2261715","url":null,"abstract":"AbstractRespiratory aerosols arise due to bronchial fluid film bursting within the pulmonary tract, the vibration of the vocal folds during phonation, and articulation of the tongue/lips/teeth. We expect respiratory aerosol emission rates to be lower in children than adults due to the smaller size of their laryngeal structure, reduced sub-glottal pressure created during speech, and reduced number of alveoli. However, few studies have evaluated respiratory aerosols for children. We recruited 50 participants from three age categories: children aged 6−11 years, children aged 12−18 years, and adults ( >18 years). We investigated particle emissions for three different 5 s sustained vocalizations of /a/ or /pa/ at 262 Hz, as well as for running speech and breathing. The particle generation rate ranged from 0 to 488 particles/s. Children aged 6−11 years produced fewer particles (mean 12 ± SD 9 particles/s) than children aged 12−18 years (23 ± 19 particles/s) and adults (70 ± 73 particles/s). Taking a deep breath before vocalizing /a/ resulted in higher aerosol emission rates than the baseline case. The particle number size distributions for all vocalizations and age groups consistently showed two modes at ≈0.6 μm and ≈2 μm. Children had a slightly smaller primary mode location and larger secondary mode location than adults. Superemitters (statistical outliers) were found in all groups. Experiments repeated over time revealed large intrapersonal variability indicating additional variables (e.g., environmental, physiological, behavioral) may significantly influence emission rates. The lower respiratory aerosol emission rates for children indicate a need to consider population demographics when predicting airborne disease transmission risks.KEYWORDS: airborne particlesrespiratory emissionCOVID-19aerosolsbioaerosolstransmissionsuperemitterDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Additional informationFundingThis work was supported by the National Science Foundation [CBET:2029548] and the Clarkson University COVID-19 Special Solicitation.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135824019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Estimating Viscosity of Individual Substrate-Deposited Particles from Measurements of Their Height-to-Width Ratios","authors":"Felipe A. Rivera-Adorno, Jay M. Tomlin, Matthew Fraund, Erick Morgan, Michael Laskin, Ryan Moffet, Alexander Laskin","doi":"10.1080/02786826.2023.2270503","DOIUrl":"https://doi.org/10.1080/02786826.2023.2270503","url":null,"abstract":"AbstractAirborne particles alter the radiative forcing of climate and have further consequences on air visibility, atmospheric chemistry, and human health. Recent studies reported the existence of highly viscous semi-solid and even solid amorphous organic aerosol (OA) particles. Particle viscosity has an impact on the heterogeneous chemistry, gas-particle partitioning, and ice nucleation properties. Consequently, variations in particle viscosity must be considered when predicting the atmospheric impact of OA. Here we use scanning electron microscopy (SEM) and scanning transmission X-ray microscopy (STXM) to estimate the viscosity of individual particles deposited on substrates based on their characteristic height-to-width ratios, which are affected by changes in morphology upon deposition. The height-to-width ratios obtained from SEM and STXM exhibit a strong correlation, demonstrating that both imaging approaches can be applied separately for viscosity assessment of the substrate-deposited particles. While these metrics are largely qualitative, this method enables rapid assessment of particle viscosity ranges, distinguishing between semi-solid (>1010 Pa·s), viscous (104-108 Pa·s), and liquid (10°-101 Pa·s) particles within ensembles of ambient particles collected for microscopy studies.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementsThis work was supported by the U. S. Department of Energy’s (DOE) Atmospheric System Research program, Office of Biological and Environmental Research (OBER), award DE-SC0021977. The SEM imaging for this project was performed at the Life Science Microscope Facility at Purdue University. The STXM imaging was performed at beamline 5.3.2.2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. We thank Mr. Mark Carlsen, instrumentation specialist from Purdue’s Jonathan Amy Facility for Chemical Instrumentation, for assembling the drying system used for particle generation and collection.Author contributionsF.R. and A.L. devised the project. F.R., J.T., M.F., R.M. conducted STXM measurements. F. R. and E.M. conducted laboratory experiments, collected samples of particle standards, performed SEM measurements, analyzed and integrated all datasets. M.L. provided geometry derivations. F.R. and A.L. wrote the manuscript with contributions from all coauthors. The authors report there are no competing interests to declare.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136079766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Probing the pH dependence of brown carbon formation: Insights from laboratory studies on aerosol particles and bulk phase solutions","authors":"Kevin T. Jansen, Margaret A. Tolbert","doi":"10.1080/02786826.2023.2267649","DOIUrl":"https://doi.org/10.1080/02786826.2023.2267649","url":null,"abstract":"AbstractLight-absorbing organic aerosol (brown carbon, BrC) can have a significant impact on the radiative balance of the Earth’s atmosphere. However there are still substantial uncertainties regarding the formation, composition, and radiative properties of BrC. In this study, we conducted laboratory experiments to investigate the pH dependence of BrC formation in both aerosol particles and bulk phase solutions. Using glyoxal, ammonia, and ammonium salts, we generated precursor solutions under varying bulk pH conditions ranging from 0.69 to 8.43. Drying the solutions either in the bulk or aerosol phase resulted in BrC formation. The resulting organic material was analyzed to determine its chemical composition and optical properties. Under the set of conditions investigated here, neutral to basic conditions of relevance to cloud water favored BrC formation for both aerosols and bulk solutions. In contrast, BrC products were formed under acidic conditions only in the aerosol phase. Due to rapid equilibration with the gas phase and evaporative losses of water, the aerosols probed here likely had extremely low pH values, well below the bulk pH of 0.69. By achieving such acidic conditions in the aerosol phase, new acid-catalyzed pathways are possible to form BrC. These findings indicate brown carbon formation is favored at both high and very low pH, and further point to the importance of using aerosol samples in studies of pH dependent chemistry of relevance to the atmosphere.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136352956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"The Filtration Efficiency of Surgical Masks for Expiratory Aerosol and Droplets Generated by Vocal Exercises","authors":"Alicja Szczepanska, Joshua Harrison, Brian Saccente-Kennedy, Justice Archer, Natalie A. Watson, Christopher M. Orton, William J. Browne, Ruth Epstein, James D. Calder, Pallav L. Shah, Declan Costello, Bryan R. Bzdek, Jonathan P. Reid","doi":"10.1080/02786826.2023.2267689","DOIUrl":"https://doi.org/10.1080/02786826.2023.2267689","url":null,"abstract":"AbstractTransmission of an airborne disease can occur when an individual exhales respiratory particles that contain infectious pathogens. Surgical face masks are often used to reduce the amount of respiratory aerosol emitted into the environment by an individual while also lowering the concentration of particles the individual inhales. Respiratory aerosol generation is activity-dependent with high person-to-person variability. Moreover, mask fit differs among people. Here, we measure the efficacy of surgical masks (EN14683 Type IIR) in reducing both aerosol (0.3 – 20 μm diameter) and droplet (20 – 1000 μm diameter) emission during breathing, speaking and five speech and language therapy tasks performed by a human cohort. When participants wore a surgical face mask, measured particle number concentrations at the front of the mask were always lower than that for breathing without mitigation in place. For breathing and speaking, the through-mask filtration efficiencies were 80% and 87%, respectively, while for voice therapy tasks the through-mask filtration efficiencies ranged from 89% (“Hey!”) to 95% (/a::/). Size-dependent through-mask filtration efficiencies were high (80 – 95%) for particles 0.5 – 2 μm diameter, with masks filtering a greater fraction of larger particle sizes. For particle sizes >4 µm diameter, filtration efficiencies of surgical face masks for all tested respiratory tasks were ∼100%. Surgical face masks significantly reduced the number of particles emitted from all respiratory activities. These results have implications for developing effective mitigations for diseases transmission through inhalation.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. ACKNOWLEDGEMENTSThe authors acknowledge funding from the Engineering and Physical Sciences Research Council (EP/V050516/1). B.R.B. acknowledges the Natural Environment Research Council (NE/P018459/1). B.R.B. and A.S. acknowledge funding from the European Research Council (Project 948498, AeroSurf). J.H. acknowledges funding from the EPSRC Centre for Doctoral Training in Aerosol Science (EP/S023593/1). Fortius Surgical Centre, Marylebone, London, is acknowledged for the generous provision of space to conduct the measurements. We thank all our volunteer participants for their contribution to this study.Data AvailabilityData underlying the figures are publicly available in the BioStudies database (https://www.ebi.ac.uk/biostudies/) under accession ID S-BSST1187.The analysed data are provided in Supplemental Information available online.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136294797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Impact of Test Methodology on the Efficacy of Triethylene Glycol (Grignard Pure) against Bacteriophage MS2","authors":"Katherine M. Ratliff, Lukas Oudejans, John Archer, Worth Calfee, Jerome U. Gilberry, David Adam Hook, William E. Schoppman, Robert W. Yaga, Lance Brooks, Shawn Ryan","doi":"10.1080/02786826.2023.2262004","DOIUrl":"https://doi.org/10.1080/02786826.2023.2262004","url":null,"abstract":"AbstractThe COVID-19 pandemic has raised interest in using chemical air treatments as part of a strategy to reduce the risk of disease transmission, but more information is needed to characterize their efficacy at scales translatable to applied settings and to develop standardized test methods for characterizing the performance of these products. Grignard Pure, a triethylene glycol (TEG) active ingredient air treatment, was evaluated using two different test protocols in a large bioaerosol test chamber and observed to inactivate bacteriophage MS2 in air (up to 99.9% at 90 minutes) and on surfaces (up to 99% at 90 minutes) at a concentration of approximately 1.2 – 1.5 mg/m3. Introducing bioaerosol into a TEG-charged chamber led to overall greater reductions compared to when TEG was introduced into a bioaerosol-charged chamber, although the differences in efficacy against airborne MS2 were only significant in the first 15 minutes. Time-matched control conditions (no TEG present) and replicate tests for each condition were essential for characterizing treatment efficacy. These findings suggest that chemical air treatments could be effective in reducing the air and surface concentrations of infectious pathogens in occupied spaces, although standard methods are needed for evaluating their efficacy and comparing results across studies. The potential health impacts of chronic exposure to chemicals should also be considered, but those were not evaluated here.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementsThe authors gratefully acknowledge members of the EPA Project Team, the members of Jacobs Technology, Inc. (JTI) supporting the EPA Homeland Security and Materials Management Microbiology lab and the JTI Aerosol Science Team, Adam Burdsall and Marc Carpenter for internal technical reviews of this manuscript, and Ramona Sherman and for quality assurance support.DisclaimerThe EPA, through its Office of Research and Development, directed the research described herein conducted through contract 68HERC20D0018 with Jacobs Technology, Inc. It has been subjected to the Agency's review and has been approved for publication. Mention of trade names, products or services does not convey official EPA approval, endorsement, or recommendation.Declaration of InterestsThe authors report there are no competing interests to declare.Data AvailabilityThe data that support the findings of this study are openly available at https://doi.org/10.23719/1528421.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135044326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"The volatility of pollen extracts and their main constituents in aerosolized form via the integrated volume method (IVM) and the volatility basis set (VBS)","authors":"Kevin Axelrod, Chiranjivi Bhattarai, Palina Bahdanovich, Vera Samburova, Andrey Y. Khlystov","doi":"10.1080/02786826.2023.2265954","DOIUrl":"https://doi.org/10.1080/02786826.2023.2265954","url":null,"abstract":"The volatility of organic aerosol in the atmosphere is an important quality that determines the aerosol/gas partitioning of compounds in the atmosphere and thus influences their ability to participate in gas-phase reactions in the atmosphere. In this research, the volatility of biological aerosols, specifically water-soluble pollen extracts and their chemical constituents, are studied for important thermodynamic properties such as saturation vapor concentration and latent heat of vaporization. The integrated volume method (IVM) was applied to characterize these properties for various free amino acids and saccharides in pollen, and the volatility basis set (VBS) approach was utilized to obtain a distribution of the mass fraction of pollen extracts with respect to saturation vapor concentration. Our results indicate that among seven compounds tested with the IVM, proline, γ-aminobutyric acid, and fructose had semivolatile saturation vapor concentrations of 17.5 ± 2.2, 14.7 ± 0.8, and 4.4 ± 0.5 μg m−3, respectively. Additionally, our VBS measurements indicate that aspen pollen extract contains a greater semivolatile mass fraction (up to 8.5% of total water-soluble mass) than lodgepole pine pollen (up to 2.2%), indicating that different pollen species may contribute to the total atmospheric semivolatile organic compound (SVOC) and low volatile organic compound (LVOC) budget differently. Depending on estimates of several factors, fluxes and concentrations of SVOCs and LVOCs from pollen could be comparable to other sources such as biomass burning and ambient urban emissions, though further research is needed to better constrain the contribution of pollen and other bioaerosols to organic compounds in the atmosphere.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135346720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Optimization of sampling conditions to minimize sampling errors of both PM _2.5 mass and its semi-volatile inorganic ion concentrations","authors":"Thi-Cuc Le, Pallavi Gajanan Barhate, Kai-Jing Zhen, Manisha Mishra, David. Y. H. Pui, Chuen-Jinn Tsai","doi":"10.1080/02786826.2023.2265454","DOIUrl":"https://doi.org/10.1080/02786826.2023.2265454","url":null,"abstract":"ABSTRACTThe accurate measurement of PM2.5 and its inorganic matters (IMs) is crucial for compliance monitoring and understanding particle formation. However, semi-volatile IMs (SVIMs) like NH4+, NO3− and Cl− tend to evaporate from particles, causing sampling artifacts. The evaporation loss occurs due to many factors making the quantitative prediction difficult. This study aimed to investigate the evaporation loss of SVIMs in PM2.5 under different sampling conditions. In the field tests, when a normal single Teflon filter sampler (STF), which is like a Federal Reference Method (FRM) sampler, was used to sample PM2.5 at ambient conditions, a significant SVIM evaporation loss was observed, resulting in negative biases for total IMs (-25.68 ± 3.25%) and PM2.5 concentrations (-9.87 ± 4.27%). But if PM2.5 was sampled by a chilled Teflon filter sampler (CTF) at 4 0C following aerosol dehumidification so that relative humidity (RH) was controlled to within the 10-20% range (RHd), evaporation loss was minimized with a bias of < ±10% for both total IMs and PM2.5 based on the reference data. When RHd is below 10%, both IMs and PM2.5 are under-measured, but only PM2.5 is over-measured when RHd is >20%. A model considering predictable saturation ratios for NH4+, NO3− and Cl− under various pressure drop, temperature and RH conditions was developed to predict accurately the actual concentrations of PM2.5 and its SVIMs for the STF. Additionally, the ISORROPIA-II model predicted SVIMs effectively for the CTF. In summary, using the CTF at optimized sampling conditions can achieve accurate measurement of both SVIMs and PM2.5 concentrations simultaneously.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementsThis work was supported by the Ministry of Science and Technology, Taiwan (contract MOST 111-2221-E-A49-057-MY3), the Ministry of Education, the Higher Education Sprout Project of National Yang Ming Chiao Tung University, and the Academic-Industry Research Hub of People and Earth (AIR HoPE).Disclosure statementThe authors report there are no competing interests to declare.","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135346718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}