DOCSLIB.ORG

Ultrafine Particle-Particle and Particle-Ion Interactions in Aerosol Reactors by Girish Sharma

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ultrafine Particle-Particle and Particle-Ion Interactions in Aerosol Reactors by Girish Sharma Washington University in St. Louis Washington University Open Scholarship Engineering and Applied Science Theses & Dissertations McKelvey School of Engineering Spring 5-15-2020 Ultrafine arP ticle-Particle and Particle-Ion Interactions in Aerosol Reactors Girish Sharma Washington University in St. Louis Follow this and additional works at: https://openscholarship.wustl.edu/eng_etds Part of the Chemical Engineering Commons Recommended Citation Sharma, Girish, "Ultrafine arP ticle-Particle and Particle-Ion Interactions in Aerosol Reactors" (2020). Engineering and Applied Science Theses & Dissertations. 552. https://openscholarship.wustl.edu/eng_etds/552 This Dissertation is brought to you for free and open access by the McKelvey School of Engineering at Washington University Open Scholarship. It has been accepted for inclusion in Engineering and Applied Science Theses & Dissertations by an authorized administrator of Washington University Open Scholarship. For more information, please contact [email protected]. WASHINGTON UNIVERSITY IN ST LOUIS School of Engineering and Applied Sciences Department of Energy, Environmental, and Chemical Engineering Dissertation Examination Committee: Pratim Biswas, Chair Michel Attoui Richard Axelbaum Peng Bai Rajan Chakrabarty, co-advisor Ultrafine Particle-Particle and Particle-Ion Interactions in Aerosol Reactors by Girish Sharma A dissertation presented to The Graduate School of Washington University in partial fulfillment of the requirements for the degree of Doctor of Philosophy May 2020 Saint Louis, Missouri © 2020, Girish Sharma Table of Contents List of Figures .............................................................................................................................. vii List of Tables ............................................................................................................................. xvii Acknowledgements .................................................................................................................. xviii Abstract of the Dissertation ..................................................................................................... xxii Chapter 1. Introduction ............................................................................................................... 1 1.1 Background and Motivation ......................................................................................... 2 1.1.1 Synthesis of ‘good’ aerosols ................................................................................... 2 1.1.2 Measurement of 1-10 nm sized particles ............................................................... 4 1.1.3 Capture of ‘bad’ aerosols ....................................................................................... 8 1.2 Dissertation Outline ....................................................................................................... 9 1.3 References ..................................................................................................................... 10 Chapter 2. Collisional Growth Rate and Correction Factor for TiO2 Nanoparticles at High Temperatures in Free Molecular Regime ................................................................................. 17 Abstract ................................................................................................................................ 18 2.1 Introduction .................................................................................................................. 19 2.2 Methods ......................................................................................................................... 23 2.2.1 Experimental Set up ............................................................................................. 23 2.2.2 Analysis ........................................................................................................................ 27 2.3 Results and Discussion ................................................................................................. 31 2.3.1 Dilution Ratio .............................................................................................................. 31 2.3.2 Lognormal PSD of spherical TiO2 nanoparticles .................................................... 32 2.3.3 Collisional correction factor ( ) at different temperatures ................................... 34 2.4 Conclusions ................................................................................................................... 40 2.5 References ..................................................................................................................... 41 Chapter 3. Molecular dynamics trajectory calculations for collisional growth rates of titania nanoparticles during gas-phase synthesis at high temperatures ................................ 48 Abstract .................................................................................................................................... 49 3.1 Introduction .................................................................................................................. 50 3.2 Methodology ................................................................................................................. 54 ii 3.2.1 MD Trajectory Calculations ................................................................................ 54 3.2.2 Nanoparticle Equilibration and Collisions ......................................................... 57 3.3 Results and Discussions ............................................................................................... 58 3.3.1 Dipole Moment of Equilibrated Titania Nanoparticles ..................................... 58 3.3.2 Collisions of equally sized particles ..................................................................... 60 3.3.3 Collisions of unequally sized particles ................................................................ 63 3.3.4 Comparison with experiments and models ........................................................ 65 3.4 Conclusions ................................................................................................................... 67 3.5 References ..................................................................................................................... 68 Chapter 4. Role played by charge in early stages (1-10 nm) of TiO2 particle formation and growth in premixed flames ......................................................................................................... 73 Abstract ................................................................................................................................ 74 4.1 Introduction .................................................................................................................. 75 4.2 Methods ......................................................................................................................... 78 4.2.1 Experimental Set-up ............................................................................................. 78 4.2.2 Data inversion from Half-mini DMA .................................................................. 80 4.2.3 Experimental Plan ................................................................................................ 82 4.3 Results and Discussions ............................................................................................... 83 4.3.1 Blank Flame Ions (Ar v/s N2) ............................................................................... 83 4.3.2 Effect of diluent on particle charging (N2 v/s Ar) .............................................. 85 4.3.3 Effect of sampling height on particle charging .................................................. 87 4.3.4 Effect of precursor concentration on particle charging .................................... 91 4.4 Conclusions ................................................................................................................... 94 4.5 References ..................................................................................................................... 95 Chapter 5. Modeling Simultaneous Coagulation and Charging of Nanoparticles at High Temperatures Using the Method of Moments........................................................................ 101 Abstract .................................................................................................................................. 102 5.1 Introduction ................................................................................................................ 105 5.2 Model description ....................................................................................................... 107 5.2.1 Ion attachment coefficient .................................................................................. 107 5.2.2 Coagulation Coefficient ...................................................................................... 110 5.2.3 Solving for simultaneous coagulation and charging using MoM ................... 112 5.2.4 Charging terms of the GDE ............................................................................... 115 iii 5.2.5 Coagulation terms of the GDE........................................................................... 116 5.2.6 Ion Balance .......................................................................................................... 119 5.3 Simulation Results and Comparison with the MdM .............................................. 119 5.3.1
Load more

Recommended publications
  • Printer Emission Measurements at TSI Application Note PER-001
    PRINTER EMISSION MEASUREMENTS AT TSI APPLICATION NOTE PER-001 Health Risk from Laser Printer Emissions A recently published study in Australia [1] found that tiny particles released from some home and office laser printers are as dangerous to human health as inhaling cigarette smoke. Researchers found that nearly one-third of the 62 printers they tested emitted high levels of the ultrafine toner particles (diameter <100 nm). Several other evaluations by researchers in different parts of the world echo similar concerns [2-6]. Common office products, including printers, copiers and other electronic devices, can release gases and ultrafine particles into the indoor air. Such contaminants are easily inhaled into the smallest passageways of the lungs where they could pose a health concern. Symptoms such as asthma and pseudo allergic inflammations of the respiratory tracts, irritations of the skin and eyes, and headache and sick building syndrome have been linked to these emissions [7]. Particulate emissions from office machines must be characterized in order to establish a database for the evaluation of possible health risks and prevention measures. Printer Emission Measurements at TSI Objective The purpose of this study was to measure number concentration and size distribution of particulate emissions from a laser printer using TSI particle counting and sizing instruments. Methods Instruments Deployed TSI Model 3775 Condensation Particle Counter (CPC) for number concentration measurements. TSI Model 3936L85 Scanning Mobility Particle Sizer™ (SMPS™) spectrometer for particle size distributions. TSI Model 3321 Aerodynamic Particle Sizer® (APS) spectrometer for supermicrometer (diameter >1 m) particle measurements. Printer Used Figure 1: Phone booth office Leading brand laser printer (black & white copy only).
    [Show full text]
  • Association of PM2.5 and Ultrafine Particle Concentrations with Diesel Exhaust from Truck Traffic in Morgantown, WV
    i Association of PM2.5 and Ultrafine particle concentrations with diesel exhaust from truck traffic in Morgantown, WV Sonali Moon Problem Report Submitted to the Benjamin M. Statler College of Engineering and Mineral Resources at West Virginia University in partial fulfillment of the requirements for the degree of Master of Science in Industrial Hygiene Steven Guffey, PhD., CIH., Chair Michael McCawley, PhD. Xinjian "Kevin" He, PhD. Department of Industrial and Management Systems Engineering Morgantown, West Virginia 2015 Keywords: PM2.5, UFP, Diesel exhaust, Environmental parameters, Multivariate regression Copyright 2015 Sonali Moon ii ABSTRACT Diesel exhaust contains a number of toxic air contaminants and has been classified as a probable human carcinogen by the US Environmental Protection Agency (EPA, 1994). Diesel engines are a major source of fine-particulate matter ranging in size from coarse (PM10 <10 μm and PM2.5 <2.5 μm) to ultrafine (UFP <0.1μm). The microscopic nature of diesel exhaust particulates makes them readily respirable, contributing to a range of adverse health effects on the respiratory and immune systems of people exposed to it. These effects could be more severe in persons with asthma and other allergic diseases. Diesel exhaust particles account for a high percentage of the particles emitted in many towns and cities. Human exposure to traffic-generated diesel exhaust near roadways has also become a worldwide concern. Hence, it is essential to characterize on-road vehicle exhaust and their impacts on near-road air quality to determine the best methods to mitigate near-road particulate concentrations. Environmental parameters such as wind speed, wind direction, and precipitation also seem to affect the concentrations of PM2.5 and UFP.
    [Show full text]
  • Nanotoxicology: Toxicological and Biological Activities of Nanomaterials - Yuliang Zhao, Bing Wang, Weiyue Feng, Chunli Bai
    NANOSCIENCE AND NANOTECHNOLOGIES - Nanotoxicology: Toxicological and Biological Activities of Nanomaterials - Yuliang Zhao, Bing Wang, Weiyue Feng, Chunli Bai NANOTOXICOLOGY: TOXICOLOGICAL AND BIOLOGICAL ACTIVITIES OF NANOMATERIALS Yuliang Zhao, CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, The Chinese Academy of Sciences, Beijing 100049, & National Center for Nanoscience and Technology of China, Beijing 100190, China Bing Wang, CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, The Chinese Academy of Sciences, Beijing 100049 Weiyue Feng, CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, The Chinese Academy of Sciences, Beijing 100049 Chunli Bai National Center for Nanoscience and Technology of China, Beijing 100190, China The Chinese Academy of Sciences, Beijing 100864, China Keywords: Nanotoxicology, Nanosafety, Nanomaterials, Nanoparticles, Contents 1. Introduction 2. Target organ toxicity of nanoparticles 2.1. Respiratory System 2.1.1. Deposition of Nanoparticles in the Respiratory Tract 2.1.2. Clearance of Nanoparticles in the Respiratory Tract 2.1.3. Nanotoxic Response of Respiratory System 2.2. Gastrointestinal System 2.3. Cardiovascular System 2.4. Central Nervous System 2.5. Skin 3. Absorption,UNESCO distribution, metabolism and excretion– EOLSS of nanoparticles (ADME) 3.1. ADME of Nanoparticle Following Inhalation Exposure 3.1.1. Absorption and Retention of Nanoparticles Following Respiratory Tract Exposure 3.1.2. Translocation and Distribution of Nanoparticles Following Respiratory Tract Exposure SAMPLE CHAPTERS 3.1.3. Metabolism and Excretion of Nanoparticles in the Lung 3.2. ADME of Nanoparticle via Gastrointestinal Tract 3.3. ADME of Nanoparticles via Skin 4.
    [Show full text]
  • In Utero Ultrafine Particulate Matter Exposure Causes Offspring Pulmonary Immunosuppression
    In utero ultrafine particulate matter exposure causes offspring pulmonary immunosuppression Kristal A. Rychlika,1,2, Jeremiah R. Secrestb,2, Carmen Lauc, Jairus Pulczinskia,1, Misti L. Zamorad,1, Jeann Lealc, Rebecca Langleya, Louise G. Myatta, Muppala Rajue, Richard C.-A. Changf, Yixin Lib, Michael C. Goldingf, Aline Rodrigues-Hoffmannc, Mario J. Molinag,3, Renyi Zhangb,d, and Natalie M. Johnsona,2,3 aDepartment of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843; bDepartment of Chemistry, Texas A&M University, College Station, TX 77843; cDepartment of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843; dDepartment of Atmospheric Sciences, Texas A&M University, College Station, TX 77843; eDepartment of Epidemiology and Biostatistics, Texas A&M University, College Station, TX 77843; fDepartment of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843; and gDepartment of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093 Contributed by Mario J. Molina, December 6, 2018 (sent for review September 19, 2018; reviewed by Alexandra Noel and Tong Zhu) Early life exposure to fine particulate matter (PM) in air is predominance of T helper (Th) 2 cell-associated cytokine pro- associated with infant respiratory disease and childhood asthma, duction classically define the phenotypic response. This frame- but limited epidemiological data exist concerning the impacts of work has been extended to include an imbalanced Th17 and ultrafine particles (UFPs) on the etiology of childhood respiratory regulatory T cell (Treg) response (13). Knowledge on the disease. Specifically, the role of UFPs in amplifying Th2- and/or Th17- mechanisms of allergic inflammation has largely been derived driven inflammation (asthma promotion) or suppressing effector from murine models of asthma, which can replicate key features T cells (increased susceptibility to respiratory infection) remains unclear.
    [Show full text]
  • Characterization and Control of Occupational Exposure to Nanoparticles and Ultrafine Particles
    Chemical Substances and Biological Agents Studies and Research Projects REPORT R-777 Characterization and Control of Occupational Exposure to Nanoparticles and Ultrafine Particles Maximilien Debia Charles Beaudry Scott Weichenthal Robert Tardif André Dufresne Established in Québec since 1980, the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) is a scientific research organization known for the quality of its work and the expertise of its personnel. OUR RESEARCH is working for you ! Mission To contribute, through research, to the prevention of industrial accidents and occupational diseases, and to the rehabilitation of affected workers; To disseminate knowledge and serve as a scientific reference centre and expert; To provide the laboratory services and expertise required to support the public occupational health and safety prevention network. Funded by the Commission de la santé et de la sécurité du travail, the IRSST has a board of directors made up of an equal number of employer and worker representatives. To find out more Visit our Web site for complete up-to-date information about the IRSST. All our publications can be downloaded at no charge. www.irsst.qc.ca To obtain the latest information on the research carried out or funded by the IRSST, subscribe to Prévention au travail, the free magazine published jointly by the IRSST and the CSST. Subscription: www.csst.qc.ca/AbonnementPAT Legal Deposit Bibliothèque et Archives nationales du Québec 2013 ISBN: 978-2-89631-670-0 (PDF) ISSN: 0820-8395 IRSST – Communications
    [Show full text]
  • Deep Investigation of Ultrafine Particles in Urban Air
    Aerosol and Air Quality Research, 11: 654–663, 2011 Copyright © Taiwan Association for Aerosol Research ISSN: 1680-8584 print / 2071-1409 online doi: 10.4209/aaqr.2010.10.0086 Deep Investigation of Ultrafine Particles in Urban Air Pasquale Avino1*, Stefano Casciardi2, Carla Fanizza1, Maurizio Manigrasso1 1 DIPIA, INAIL (ex-ISPESL), via Urbana 167, 00184 Rome, Italy 2 DIL, INAIL (ex-ISPESL), via Fontana Candida 1, 00040 Monte Porzio Catone, Italy ABSTRACT This work describes the results of a study which started in 2007 to investigate the ultrafine particle (UFP) pollution in the urban area of Rome. The sampling site was located in a street with high density of autovehicular traffic, where measurements have shown that carbonaceous particulate matter represented an important fraction of aerosol pollution. UFPs have been classified by means of an electrostatic classifier. Monodisperse aerosol was either counted by ultrafine water-based condensation particle counter or sampled by means of a nanometer aerosol sampler. Samples collected were investigated using energy filtered transmission electron microscope in combination with energy dispersive X-ray spectroscopy and electron energy loss spectroscopy. Electron transmission microscope observations revealed that carbonaceous UFPs were present also as nanotube related forms. The rapid evolution of aerosol from autovehicular exhaust plumes was observed by highly time-resolved aerosol size distribution measurements. Keywords: Ultrafine particles; Energy Filtered Transmission Electron Microscope analysis; Health effects; Urban air; Carbonaceous aerosol. INTRODUCTION have indicated that about 50–70% of UFP mass consists of carbonaceous material (Puxbaum and Wopenka, 1984; Ultrafine particles (UFPs) are recently attracting Berner et al., 1996; Hughes et al., 1998; Chen et al., 2010; increasing attention due to their potential effects on human Zhu et al., 2010b).
    [Show full text]
  • The Health Effects of Ultrafine Particles
    Schraufnagel Experimental & Molecular Medicine (2020) 52:311–317 https://doi.org/10.1038/s12276-020-0403-3 Experimental & Molecular Medicine REVIEW ARTICLE Open Access The health effects of ultrafine particles Dean E. Schraufnagel1 Abstract Ultrafine particles (PM0.1), which are present in the air in large numbers, pose a health risk. They generally enter the body through the lungs but translocate to essentially all organs. Compared to fine particles (PM2.5), they cause more pulmonary inflammation and are retained longer in the lung. Their toxicity is increased with smaller size, larger surface area, adsorbed surface material, and the physical characteristics of the particles. Exposure to PM0.1 induces cough and worsens asthma. Metal fume fever is a systemic disease of lung inflammation most likely caused by PM0.1. The disease is manifested by systemic symptoms hours after exposure to metal fumes, usually through welding. PM0.1 cause systemic inflammation, endothelial dysfunction, and coagulation changes that predispose individuals to ischemic cardiovascular disease and hypertension. PM0.1 are also linked to diabetes and cancer. PM0.1 can travel up the olfactory nerves to the brain and cause cerebral and autonomic dysfunction. Moreover, in utero exposure increases the risk of low birthweight. Although exposure is commonly attributed to traffic exhaust, monitored students in Ghana showed the highest exposures in a home near a trash burning site, in a bedroom with burning coils employed to abate mosquitos, in a home of an adult smoker, and in home kitchens during domestic cooking. The high point-source production and rapid redistribution make incidental exposure common, confound general population studies and are compounded by the lack of global standards and national reporting.
    [Show full text]
  • Journal of BIOLOGICAL RESEARCHES ISSN: 08526834 | E-ISSN:2337-389X Volume 23 | No
    Journal of BIOLOGICAL RESEARCHES ISSN: 08526834 | E-ISSN:2337-389X Volume 23 | No. 2 | June | 2018 Original Article Influence of smoking rate on ultrafine particle emission of cigarette smoke Arinto Y.P Wardoyo1*, Dionysius J.D.H Santjojo1, Tintrim Rahayu2, Saraswati Subagyo3 1Department of Physics, Faculty of Mathematics and Natural Sciences, University of Brawijaya, Malang, Indonesia 2Department of Biology, Faculty of Mathematics and Natural Sciences, University of Islam Malang, Malang, Indonesia 3Research Institute of Free Radical and Shadding, Malang, Indonesia Abstract Ultrafine particles have been attached the attention for researchers due to their impacts on human health. Ultrafine particles can be emitted from burning process, such as forest burning, agriculture waste burning, cigarette, etc. In this study, ultrafine particles produced by cigarette smokes has been investigated as a function of smoking rate. The samples consisted of different types of Indonesia cigarette called Kretek cigarette. The quantification of emission factors was conducted by the burning of the cigarette samples, then the smoke that was sucked with a different flow rate using an adjustable pump. The flow rate was chosen to correspond as close as the variation of the rate that people smoke. The measurements of ultrafine concentrations were carried out using an ultrafine particle counter P-Trak TSI 8525 capable of measuring particles with the diameter in the range of 20 to 1000 nm. The results showed that the emission factor of ultrafine particles significantly depended on the smoking rate. A higher smoking rate produced higher average ultrafine particle emission factor. Keywords: Cigarette smoke, emission factor, smoking rate, ultrafine particle Received: 10 April 2018 Revised: 29 May 2018 Accepted: 6 June 2018 Introduction Cigarette smoke has been identified thousands of and the influencing factors.
    [Show full text]
  • Epa/Oppt/Ceb
    EPA/OPPT/CEB INTERNAL CEB INTERIM DRAFT - Do not quote or cite Revised May 2012 APPROACHES FOR ASSESSING AND CONTROLLING WORKPLACE RELEASES AND EXPOSURES TO NEW AND EXISTING NANOMATERIALS Chemical Engineering Branch (CEB) Economics, Exposure and Technology Division Office of Pollution Prevention and Toxics Environmental Protection Agency 1 EPA/OPPT/CEB INTERNAL CEB INTERIM DRAFT - Do not quote or cite Revised May 2012 PURPOSE This draft document revises and updates the previous approaches recommended by the Chemical Engineering Branch (CEB) of EPA's Office of Pollution Prevention and Toxics (OPPT) in its draft document dated June 2006, for assessing, monitoring, and controlling releases and exposures to new and existing nanomaterials1 in the workplace. (See Appendix A for information on the definitions and descriptions of nanomaterials.) The document focuses primarily on CEB’s methodology for evaluating Pre-Manufacture Notice (PMN) nanomaterials within OPPT’s New Chemicals Program (NCP). Because of the swiftly changing and challenging nature of nanotechnology, this document represents interim approaches that are based on the best available information to date in the specific areas that it addresses. The document addresses: I. Release and Exposure Assessment. II. Inhalation Monitoring. III. Engineering Controls IV. Personal Protective Equipment (PPE). The Appendices at the end of this document provide more details for specific topic areas and summarize some issues related to workplace release and exposure assessments for nanomaterials. Some special considerations for nanomaterials, including toxicity, routes of exposure, exposure metrics, and factors affecting exposure are provided in Appendix B. INTRODUCTION In the U.S., interim approaches and recommendations for release and exposure assessment as well as control approaches for minimizing workplace exposures to nanomaterials have been developed primarily by the National Institute for Occupational Safety and Health (NIOSH).
    [Show full text]
  • Chemical Multi-Fingerprinting of Exogenous Ultrafine Particles in Human Serum and Pleural Effusion
    ARTICLE https://doi.org/10.1038/s41467-020-16427-x OPEN Chemical multi-fingerprinting of exogenous ultrafine particles in human serum and pleural effusion Dawei Lu 1,2, Qian Luo3, Rui Chen4, Yongxun Zhuansun4, Jie Jiang5, Weichao Wang1,2, Xuezhi Yang1,2, ✉ ✉ Luyao Zhang1,2, Xiaolei Liu1,2, Fang Li3, Qian Liu 1,2,6 & Guibin Jiang1,2 1234567890():,; Ambient particulate matter pollution is one of the leading causes of global disease burden. Epidemiological studies have revealed the connections between particulate exposure and cardiovascular and respiratory diseases. However, until now, the real species of ambient ultrafine particles (UFPs) in humans are still scarcely known. Here we report the discovery and characterization of exogenous nanoparticles (NPs) in human serum and pleural effusion (PE) samples collected from non-occupational subjects in a typical polluted region. We show the wide presence of NPs in human serum and PE samples with extreme diversity in chemical species, concentration, and morphology. Through chemical multi-fingerprinting (including elemental fingerprints, high-resolution structural fingerprints, and stable iron isotopic fin- gerprints) of NPs, we identify the sources of the NPs to be abiogenic, particularly, combustion-derived particulate emission. Our results provide evidence for the translocation of ambient UFPs into the human circulatory system, and also provide information for understanding their systemic health effects. 1 State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. 2 College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China. 3 Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
    [Show full text]
  • Ultrafine Particles: a New Iaq Metric
    ULTRAFINE PARTICLES: A NEW IAQ METRIC APPLICATION NOTE ITI-068 By Peter A. Nelson TSI Incorporated Shoreview, Minnesota Overview Ultrafine Particles, A New Parameter Summary References Reprinted from INVIRONMENT® Professional August 1999, Volume 5, Number 8 Overview Today's indoor air quality (IAQ) professional is able to measure many parameters of the indoor air. However, even though the analytical capability may be better than it has ever been, it is still difficult or sometimes impossible to identify the root cause of the IAQ concerns or complaints. This difficulty begs the question, what are we missing? Do we need better sensitivity and resolution in commonly used techniques? Or, do we need an entirely different metric that is not now used? IAQ experts specializing in each of the IAQ parameters typically measured can identify technology extensions or measurement refinements that would add to our larger understanding of IAQ problems. But there are limited resources available to fund research in these areas. Particle technology is a recent area of attention for IAQ. Other research efforts mainly sponsored by the US Environmental Protection Agency (EPA) have the potential to significantly add to our understanding of the dynamics between health effects and airborne particles, especially ultrafine particles. If the current research is conclusive, ultrafine particles could become a significant indicator of the relative quality of indoor air and the presence of indoor pollutant sources. Comfort, temperature, and humidity have long been a source of IAQ concerns but these parameters are easily measured, instrumentation is readily available, and guidelines are well documented in ASHRAE Standards. One combination of comfort not commonly evaluated in the US is a draft index.
    [Show full text]
  • Ultrafine Aerosol Particle Sizer Based on Piezoresistive Microcantilever Resonators with Integrated Air-Flow Channel
    sensors Article Ultrafine Aerosol Particle Sizer Based on Piezoresistive Microcantilever Resonators with Integrated Air-Flow Channel Maik Bertke 1 , Ina Kirsch 2, Erik Uhde 2 and Erwin Peiner 1,* 1 Institute for Semiconductor Technology and Laboratory for Emerging Nanometrology (LENA), Technische Universität Braunschweig, Hans-Sommer-Str. 66/Langer Kamp 6a, 38106 Braunschweig, Germany; [email protected] 2 Fraunhofer Wilhelm-Klauditz-Institut (WKI), Bienroder Weg 54E, 38106 Braunschweig, Germany; [email protected] (I.K.); [email protected] (E.U.) * Correspondence: [email protected]; Tel.: +49-531-391-65332 Abstract: To monitor airborne nano-sized particles (NPs), a single-chip differential mobility particle sizer (DMPS) based on resonant micro cantilevers in defined micro-fluidic channels (µFCs) is intro- duced. A size bin of the positive-charged fraction of particles herein is separated from the air stream by aligning their trajectories onto the cantilever under the action of a perpendicular electrostatic field of variable strength. We use previously described µFCs and piezoresistive micro cantilevers (PMCs) of 16 ng mass fabricated using micro electro mechanical system (MEMS) technology, which offer a limit of detection of captured particle mass of 0.26 pg and a minimum detectable particulate mass concentration in air of 0.75 µg/m3. Mobility sizing in 4 bins of a nebulized carbon aerosol NPs is demonstrated based on finite element modelling (FEM) combined with a-priori knowledge of particle charge state. Good agreement of better than 14% of mass concentration is observed in a chamber test for the novel MEMS-DMPS vs. a simultaneously operated standard fast mobility particle sizer Citation: Bertke, M.; Kirsch, I.; Uhde, (FMPS) as reference instrument.
    [Show full text]