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An experimental study of respiratory aerosol transport in phantom lung bronchioles

The transport and deposition of micrometer-sized particles in the lung is the primary mechanism for the spread of aerosol borne diseases such as corona virus disease-19 (COVID-19). Considering the current situation, modeling the transport and deposition of drops in human lung bronchioles is of utmos...

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Autores principales: Mallik, Arnab Kumar, Mukherjee, Soumalya, Panchagnula, Mahesh V.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: AIP Publishing LLC 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7684681/
https://www.ncbi.nlm.nih.gov/pubmed/33244213
http://dx.doi.org/10.1063/5.0029899
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author Mallik, Arnab Kumar
Mukherjee, Soumalya
Panchagnula, Mahesh V.
author_facet Mallik, Arnab Kumar
Mukherjee, Soumalya
Panchagnula, Mahesh V.
author_sort Mallik, Arnab Kumar
collection PubMed
description The transport and deposition of micrometer-sized particles in the lung is the primary mechanism for the spread of aerosol borne diseases such as corona virus disease-19 (COVID-19). Considering the current situation, modeling the transport and deposition of drops in human lung bronchioles is of utmost importance to determine their consequences on human health. The current study reports experimental observations on deposition in micro-capillaries, representing distal lung bronchioles, over a wide range of Re that imitates the particle dynamics in the entire lung. The experiment investigated deposition in tubes of diameter ranging from 0.3 mm to 2 mm and over a wide range of Reynolds number (10(−2) ⩽ Re ⩽ 10(3)). The range of the tube diameter and Re used in this study is motivated by the dimensions of lung airways and typical breathing flow rates. The aerosol fluid was loaded with boron doped carbon quantum dots as fluorophores. An aerosol plume was generated from this mixture fluid using an ultrasonic nebulizer, producing droplets with 6.5 µm as a mean diameter and over a narrow distribution of sizes. The amount of aerosol deposited on the tube walls was measured using a spectrofluorometer. The experimental results show that dimensionless deposition (δ) varies inversely with the bronchiole aspect ratio ([Formula: see text]), with the effect of the Reynolds number (Re) being significant only at low [Formula: see text]. δ also increased with increasing dimensionless bronchiole diameter ([Formula: see text]), but it is invariant with the particle size based Reynolds number. We show that [Formula: see text] for 10(−2) ⩽ Re ⩽ 1, which is typical of a diffusion dominated regime. For Re ⩾ 1, in the impaction dominated regime, [Formula: see text] is shown to be independent of Re. We also show a crossover regime where sedimentation becomes important. The experimental results conclude that lower breathing frequency and higher breath hold time could significantly increase the chances of getting infected with COVID-19 in crowded places.
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spelling pubmed-76846812020-11-24 An experimental study of respiratory aerosol transport in phantom lung bronchioles Mallik, Arnab Kumar Mukherjee, Soumalya Panchagnula, Mahesh V. Phys Fluids (1994) ARTICLES The transport and deposition of micrometer-sized particles in the lung is the primary mechanism for the spread of aerosol borne diseases such as corona virus disease-19 (COVID-19). Considering the current situation, modeling the transport and deposition of drops in human lung bronchioles is of utmost importance to determine their consequences on human health. The current study reports experimental observations on deposition in micro-capillaries, representing distal lung bronchioles, over a wide range of Re that imitates the particle dynamics in the entire lung. The experiment investigated deposition in tubes of diameter ranging from 0.3 mm to 2 mm and over a wide range of Reynolds number (10(−2) ⩽ Re ⩽ 10(3)). The range of the tube diameter and Re used in this study is motivated by the dimensions of lung airways and typical breathing flow rates. The aerosol fluid was loaded with boron doped carbon quantum dots as fluorophores. An aerosol plume was generated from this mixture fluid using an ultrasonic nebulizer, producing droplets with 6.5 µm as a mean diameter and over a narrow distribution of sizes. The amount of aerosol deposited on the tube walls was measured using a spectrofluorometer. The experimental results show that dimensionless deposition (δ) varies inversely with the bronchiole aspect ratio ([Formula: see text]), with the effect of the Reynolds number (Re) being significant only at low [Formula: see text]. δ also increased with increasing dimensionless bronchiole diameter ([Formula: see text]), but it is invariant with the particle size based Reynolds number. We show that [Formula: see text] for 10(−2) ⩽ Re ⩽ 1, which is typical of a diffusion dominated regime. For Re ⩾ 1, in the impaction dominated regime, [Formula: see text] is shown to be independent of Re. We also show a crossover regime where sedimentation becomes important. The experimental results conclude that lower breathing frequency and higher breath hold time could significantly increase the chances of getting infected with COVID-19 in crowded places. AIP Publishing LLC 2020-11-01 /pmc/articles/PMC7684681/ /pubmed/33244213 http://dx.doi.org/10.1063/5.0029899 Text en © 2020 Author(s) Published under license by AIP Publishing. 1070-6631/2020/32(11)/111903/12/$30.00 All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle ARTICLES
Mallik, Arnab Kumar
Mukherjee, Soumalya
Panchagnula, Mahesh V.
An experimental study of respiratory aerosol transport in phantom lung bronchioles
title An experimental study of respiratory aerosol transport in phantom lung bronchioles
title_full An experimental study of respiratory aerosol transport in phantom lung bronchioles
title_fullStr An experimental study of respiratory aerosol transport in phantom lung bronchioles
title_full_unstemmed An experimental study of respiratory aerosol transport in phantom lung bronchioles
title_short An experimental study of respiratory aerosol transport in phantom lung bronchioles
title_sort experimental study of respiratory aerosol transport in phantom lung bronchioles
topic ARTICLES
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7684681/
https://www.ncbi.nlm.nih.gov/pubmed/33244213
http://dx.doi.org/10.1063/5.0029899
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