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Landwehr KR, Mead-Hunter R, O'Leary RA, Kicic A, Mullins BJ, Larcombe AN. Respiratory Health Effects of In Vivo Sub-Chronic Diesel and Biodiesel Exhaust Exposure. Int J Mol Sci 2023; 24:ijms24065130. [PMID: 36982203 PMCID: PMC10049281 DOI: 10.3390/ijms24065130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/01/2023] [Accepted: 03/03/2023] [Indexed: 03/30/2023] Open
Abstract
Biodiesel, which can be made from a variety of natural oils, is currently promoted as a sustainable, healthier replacement for commercial mineral diesel despite little experimental data supporting this. The aim of our research was to investigate the health impacts of exposure to exhaust generated by the combustion of diesel and two different biodiesels. Male BALB/c mice (n = 24 per group) were exposed for 2 h/day for 8 days to diluted exhaust from a diesel engine running on ultra-low sulfur diesel (ULSD) or Tallow or Canola biodiesel, with room air exposures used as control. A variety of respiratory-related end-point measurements were assessed, including lung function, responsiveness to methacholine, airway inflammation and cytokine response, and airway morphometry. Exposure to Tallow biodiesel exhaust resulted in the most significant health impacts compared to Air controls, including increased airway hyperresponsiveness and airway inflammation. In contrast, exposure to Canola biodiesel exhaust resulted in fewer negative health effects. Exposure to ULSD resulted in health impacts between those of the two biodiesels. The health effects of biodiesel exhaust exposure vary depending on the feedstock used to make the fuel.
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Affiliation(s)
- Katherine R Landwehr
- Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, WA 6845, Australia
- Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, WA 6009, Australia
| | - Ryan Mead-Hunter
- Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, WA 6845, Australia
| | - Rebecca A O'Leary
- Department of Primary Industries and Regional Development, Perth, WA 6151, Australia
| | - Anthony Kicic
- Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, WA 6845, Australia
- Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, WA 6009, Australia
- Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, Perth, WA 6009, Australia
- Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth, WA 6009, Australia
| | - Benjamin J Mullins
- Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, WA 6845, Australia
| | - Alexander N Larcombe
- Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, WA 6845, Australia
- Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, WA 6009, Australia
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Landwehr KR, Hillas J, Mead-Hunter R, King A, O'Leary RA, Kicic A, Mullins BJ, Larcombe AN. Biodiesel feedstock determines exhaust toxicity in 20% biodiesel: 80% mineral diesel blends. Chemosphere 2023; 310:136873. [PMID: 36252896 DOI: 10.1016/j.chemosphere.2022.136873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 10/04/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
To address climate change concerns, and reduce the carbon footprint caused by fossil fuel use, it is likely that blend ratios of renewable biodiesel with commercial mineral diesel fuel will steadily increase, resulting in biodiesel use becoming more widespread. Exhaust toxicity of unblended biodiesels changes depending on feedstock type, however the effect of feedstock on blended fuels is less well known. The aim of this study was to assess the impact of biodiesel feedstock on exhaust toxicity of 20% blended biodiesel fuels (B20). Primary human airway epithelial cells were exposed to exhaust diluted 1/15 with air from an engine running on conventional ultra-low sulfur diesel (ULSD) or 20% blends of soy, canola, waste cooking oil (WCO), tallow, palm or cottonseed biodiesel in diesel. Physico-chemical exhaust properties were compared between fuels and the post-exposure effect of exhaust on cellular viability and media release was assessed 24 h later. Exhaust properties changed significantly between all fuels with cottonseed B20 being the most different to both ULSD and its respective unblended biodiesel. Exposure to palm B20 resulted in significantly decreased cellular viability (96.3 ± 1.7%; p < 0.01) whereas exposure to soy B20 generated the greatest number of changes in mediator release (including IL-6, IL-8 and TNF-α, p < 0.05) when compared to air exposed controls, with palm B20 and tallow B20 closely following. In contrast, canola B20 and WCO B20 were the least toxic with only mediators G-CSF and TNF-α being significantly increased. Therefore, exposure to palm B20, soy B20 and tallow B20 were found to be the most toxic and exposure to canola B20 and WCO B20 the least. The top three most toxic and the bottom three least toxic B20 fuels are consistent with their unblended counterparts, suggesting that feedstock type greatly impacts exhaust toxicity, even when biodiesel only comprises 20% of the fuel.
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Affiliation(s)
- Katherine R Landwehr
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia.
| | - Jessica Hillas
- Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia
| | - Ryan Mead-Hunter
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia
| | - Andrew King
- Fluid Dynamics Research Group, School of Civil and Mechanical Engineering, Curtin University, Perth, Western Australia, Australia
| | - Rebecca A O'Leary
- Department of Primary Industries and Regional Development, Perth, 6151, Western Australia, Australia
| | - Anthony Kicic
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia; Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia; Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth, 6009, Western Australia, Australia
| | - Benjamin J Mullins
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia
| | - Alexander N Larcombe
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, 6009, Western Australia, Australia
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Landwehr KR, Hillas J, Mead-Hunter R, King A, O'Leary RA, Kicic A, Mullins BJ, Larcombe AN. Toxicity of different biodiesel exhausts in primary human airway epithelial cells grown at air-liquid interface. Sci Total Environ 2022; 832:155016. [PMID: 35381248 DOI: 10.1016/j.scitotenv.2022.155016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/25/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
Biodiesel is created through the transesterification of fats/oils and its usage is increasing worldwide as global warming concerns increase. Biodiesel fuel properties change depending on the feedstock used to create it. The aim of this study was to assess the different toxicological properties of biodiesel exhausts created from different feedstocks using a complex 3D air-liquid interface (ALI) model that mimics the human airway. Primary human airway epithelial cells were grown at ALI until full differentiation was achieved. Cells were then exposed to 1/20 diluted exhaust from an engine running on Diesel (ULSD), pure or 20% blended Canola biodiesel and pure or 20% blended Tallow biodiesel, or Air for control. Exhaust was analysed for various physio-chemical properties and 24-h after exposure, ALI cultures were assessed for permeability, protein release and mediator response. All measured exhaust components were within industry safety standards. ULSD contained the highest concentrations of various combustion gases. We found no differences in terms of particle characteristics for any of the tested exhausts, likely due to the high dilution used. Exposure to Tallow B100 and B20 induced increased permeability in the ALI culture and the greatest increase in mediator response in both the apical and basal compartments. In contrast, Canola B100 and B20 did not impact permeability and induced the smallest mediator response. All exhausts but Canola B20 induced increased protein release, indicating epithelial damage. Despite the concentrations of all exhausts used in this study meeting industry safety regulations, we found significant toxic effects. Tallow biodiesel was found to be the most toxic of the tested fuels and Canola the least, both for blended and pure biodiesel fuels. This suggests that the feedstock biodiesel is made from is crucial for the resulting health effects of exhaust exposure, even when not comprising the majority of fuel composition.
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Affiliation(s)
- Katherine R Landwehr
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia.
| | - Jessica Hillas
- Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia
| | - Ryan Mead-Hunter
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia
| | - Andrew King
- Fluid Dynamics Research Group, School of Civil and Mechanical Engineering, Curtin University, Perth, Western Australia, Australia
| | - Rebecca A O'Leary
- Department of Primary Industries and Regional Development, Perth 6151, Western Australia, Australia
| | - Anthony Kicic
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia; Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia; Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth 6009, Western Australia, Australia
| | - Benjamin J Mullins
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia
| | - Alexander N Larcombe
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia
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Landwehr KR, Hillas J, Mead-Hunter R, Brooks P, King A, O'Leary RA, Kicic A, Mullins BJ, Larcombe AN. In Vitro primary human airway epithelial whole exhaust exposure. MethodsX 2021; 8:101561. [PMID: 34754823 PMCID: PMC8563817 DOI: 10.1016/j.mex.2021.101561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/23/2021] [Indexed: 11/06/2022] Open
Abstract
The method outlined in this article is a customization of the whole exhaust exposure method generated by Mullins et al. (2016) using reprogrammed primary human airway epithelial cells as described by Martinovich et al. (2017). It has been used successfully to generate recently published data (Landwehr et al. 2021). The goal was to generate an exhaust exposure model where exhaust is collected from a modern engine, real-world exhaust concentrations are used and relevant tissues exposed to assess the effects of multiple biodiesel exposures. Exhaust was generated, gently vacuumed into a dilution chamber where it was diluted 1/15 with air and then vacuumed into an incubator containing the primary cell cultures for exposure. Exhaust physico-chemical properties including combustion gas concentrations and particle spectra were then analyzed using a combustion gas analyzer and a Universal Scanning Mobility Particle Sizer. 24 h after exposure, cellular viability and mediator release were measured using Annexin-V/PI staining and meditator multiplexing kits respectively. This method was generated to test biodiesel exhaust exposures but can be easily adapted for any type of engine exhaust exposure or even potentially other respirable environmental exposures such as woodsmoke. The main customization points for this method are:Exhaust generated by a diesel engine equipped with EURO VI exhaust after treatment devices including diesel particulate filter and diesel oxidation catalyst. The generated exhaust was diluted 1/15 with air to replicate real world exposure concentrations. Used primary human airway epithelial cells obtained from bronchoscope brushings from multiple volunteers and reprogrammed to allow multiple, comparative exposures from the same individual.
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Affiliation(s)
- Katherine R Landwehr
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, Western Australia 6845, Australia.,Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, Western Australia 6009, Australia
| | - Jessica Hillas
- Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, Western Australia 6009, Australia
| | - Ryan Mead-Hunter
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, Western Australia 6845, Australia
| | - Peter Brooks
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Andrew King
- Fluid Dynamics Research Group, School of Civil and Mechanical Engineering, Curtin University, Perth, Western Australia, Australia
| | - Rebecca A O'Leary
- Department of Primary Industries and Regional Development, Perth, Western Australia 6151, Australia
| | - Anthony Kicic
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, Western Australia 6845, Australia.,Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, Western Australia 6009, Australia.,Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, Perth, Western Australia 6009, Australia.,Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Benjamin J Mullins
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, Western Australia 6845, Australia
| | - Alexander N Larcombe
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth, Western Australia 6845, Australia.,Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth, Western Australia 6009, Australia
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Landwehr KR, Hillas J, Mead-Hunter R, Brooks P, King A, O'Leary RA, Kicic A, Mullins BJ, Larcombe AN. Fuel feedstock determines biodiesel exhaust toxicity in a human airway epithelial cell exposure model. J Hazard Mater 2021; 420:126637. [PMID: 34329109 DOI: 10.1016/j.jhazmat.2021.126637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/02/2021] [Accepted: 07/10/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Biodiesel is promoted as a sustainable replacement for commercial diesel. Biodiesel fuel and exhaust properties change depending on the base feedstock oil/fat used during creation. The aims of this study were, for the first time, to compare the exhaust exposure health impacts of a wide range of biodiesels made from different feedstocks and relate these effects with the corresponding exhaust characteristics. METHOD Primary airway epithelial cells were exposed to diluted exhaust from an engine running on conventional diesel and biodiesel made from Soy, Canola, Waste Cooking Oil, Tallow, Palm and Cottonseed. Exhaust properties and cellular viability and mediator release were analysed post exposure. RESULTS The exhaust physico-chemistry of Tallow biodiesel was the most different to diesel as well as the most toxic, with exposure resulting in significantly decreased cellular viability (95.8 ± 6.5%) and increased release of several immune mediators including IL-6 (+223.11 ± 368.83 pg/mL) and IL-8 (+1516.17 ± 2908.79 pg/mL) above Air controls. In contrast Canola biodiesel was the least toxic with exposure only increasing TNF-α (4.91 ± 8.61). CONCLUSION This study, which investigated the toxic effects for the largest range of biodiesels, shows that exposure to different exhausts results in a spectrum of toxic effects in vitro when combusted under identical conditions.
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Affiliation(s)
- Katherine R Landwehr
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia.
| | - Jessica Hillas
- Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia
| | - Ryan Mead-Hunter
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia
| | - Peter Brooks
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia
| | - Andrew King
- Fluid Dynamics Research Group, School of Civil and Mechanical Engineering, Curtin University, Perth, Western Australia, Australia
| | - Rebecca A O'Leary
- Department of Primary Industries and Regional Development, Perth 6000, Western Australia, Australia
| | - Anthony Kicic
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia; Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia; Centre for Cell Therapy and Regenerative Medicine, The University of Western Australia, Perth 6009, Western Australia, Australia
| | - Benjamin J Mullins
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia
| | - Alexander N Larcombe
- Occupation, Environment and Safety, School of Population Health, Curtin University, PO Box U1987, Perth 6845, Western Australia, Australia; Respiratory Environmental Health, Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth Children's Hospital, Nedlands, Perth 6009, Western Australia, Australia
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Landwehr KR, Hillas J, Mead-Hunter R, O'Leary RA, Kicic A, Mullins BJ, Larcombe AN. Soy Biodiesel Exhaust is More Toxic than Mineral Diesel Exhaust in Primary Human Airway Epithelial Cells. Environ Sci Technol 2019; 53:11437-11446. [PMID: 31453689 DOI: 10.1021/acs.est.9b01671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
As global biodiesel production increases, there are concerns over the potential health impact of exposure to the exhaust, particularly in regard to young children who are at high risk because of their continuing lung development. Using human airway epithelial cells obtained from young children, we compared the effects of exposure to exhaust generated by a diesel engine with Euro V/VI emission controls running on conventional diesel (ultra-low-sulfur mineral diesel, ULSD), soy biodiesel (B100), or a 20% blend of soy biodiesel with diesel (B20). The exhaust output of biodiesel was found to contain significantly more respiratory irritants, including NOx, CO, and CO2, and a larger overall particle mass. Exposure to biodiesel exhaust resulted in significantly greater cell death and a greater release of immune mediators compared to both air controls and ULSD exhaust. These results have concerning implications for potential global health impacts, particularly for the pediatric population.
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Affiliation(s)
- Katherine R Landwehr
- Occupation, Environment and Safety, School of Public Health , Curtin University , P.O. Box U1987, Perth , Western Australia 6845 , Australia
- Respiratory Environmental Health, Telethon Kids Institute , Perth Children's Hospital , Nedlands, Perth , Western Australia 6009 , Australia
| | - Jessica Hillas
- Respiratory Environmental Health, Telethon Kids Institute , Perth Children's Hospital , Nedlands, Perth , Western Australia 6009 , Australia
| | - Ryan Mead-Hunter
- Occupation, Environment and Safety, School of Public Health , Curtin University , P.O. Box U1987, Perth , Western Australia 6845 , Australia
| | - Rebecca A O'Leary
- Department of Primary Industries and Regional Development , Perth , Western Australia 6151 , Australia
| | - Anthony Kicic
- Occupation, Environment and Safety, School of Public Health , Curtin University , P.O. Box U1987, Perth , Western Australia 6845 , Australia
- Respiratory Environmental Health, Telethon Kids Institute , Perth Children's Hospital , Nedlands, Perth , Western Australia 6009 , Australia
- Department of Respiratory and Sleep Medicine , Perth Children's Hospital , Nedlands, Perth , Western Australia 6009 , Australia
| | - Benjamin J Mullins
- Occupation, Environment and Safety, School of Public Health , Curtin University , P.O. Box U1987, Perth , Western Australia 6845 , Australia
| | - Alexander N Larcombe
- Occupation, Environment and Safety, School of Public Health , Curtin University , P.O. Box U1987, Perth , Western Australia 6845 , Australia
- Respiratory Environmental Health, Telethon Kids Institute , Perth Children's Hospital , Nedlands, Perth , Western Australia 6009 , Australia
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Caley MJ, O'Leary RA, Fisher R, Low-Choy S, Johnson S, Mengersen K. What is an expert? A systems perspective on expertise. Ecol Evol 2013; 4:231-42. [PMID: 24558579 PMCID: PMC3925425 DOI: 10.1002/ece3.926] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 09/12/2013] [Accepted: 11/24/2013] [Indexed: 11/11/2022] Open
Abstract
Expert knowledge is a valuable source of information with a wide range of research applications. Despite the recent advances in defining expert knowledge, little attention has been given to how to view expertise as a system of interacting contributory factors for quantifying an individual's expertise. We present a systems approach to expertise that accounts for many contributing factors and their inter-relationships and allows quantification of an individual's expertise. A Bayesian network (BN) was chosen for this purpose. For illustration, we focused on taxonomic expertise. The model structure was developed in consultation with taxonomists. The relative importance of the factors within the network was determined by a second set of taxonomists (supra-experts) who also provided validation of the model structure. Model performance was assessed by applying the model to hypothetical career states of taxonomists designed to incorporate known differences in career states for model testing. The resulting BN model consisted of 18 primary nodes feeding through one to three higher-order nodes before converging on the target node (Taxonomic Expert). There was strong consistency among node weights provided by the supra-experts for some nodes, but not others. The higher-order nodes, “Quality of work” and “Total productivity”, had the greatest weights. Sensitivity analysis indicated that although some factors had stronger influence in the outer nodes of the network, there was relatively equal influence of the factors leading directly into the target node. Despite the differences in the node weights provided by our supra-experts, there was good agreement among assessments of our hypothetical experts that accurately reflected differences we had specified. This systems approach provides a way of assessing the overall level of expertise of individuals, accounting for multiple contributory factors, and their interactions. Our approach is adaptable to other situations where it is desirable to understand components of expertise.
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Affiliation(s)
| | - Rebecca A O'Leary
- Australian Institute of Marine Science, UWA Oceans Institute Crawley, WA, 6009, Australia
| | - Rebecca Fisher
- Australian Institute of Marine Science, UWA Oceans Institute Crawley, WA, 6009, Australia
| | - Samantha Low-Choy
- School of Mathematical Sciences, Queensland University of Technology GPO Box 2434, Brisbane, Qld, 4001, Australia
| | - Sandra Johnson
- School of Mathematical Sciences, Queensland University of Technology GPO Box 2434, Brisbane, Qld, 4001, Australia
| | - Kerrie Mengersen
- School of Mathematical Sciences, Queensland University of Technology GPO Box 2434, Brisbane, Qld, 4001, Australia
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Mead-Hunter R, Bergen T, Becker T, O'Leary RA, Kasper G, Mullins BJ. Sliding/rolling phobic droplets along a fiber: measurement of interfacial forces. Langmuir 2012; 28:3483-3488. [PMID: 22260243 DOI: 10.1021/la2046838] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Phobic droplet-fiber systems possess complex geometries, which have made full characterization of such systems difficult. This work has used atomic force microscopy (AFM) to measure droplet-fiber forces for oil droplets on oleophobic fibers over a range of fiber diameters. The work adapted a previous method and a theoretical model developed by the authors for philic droplet-fiber systems. A Bayesian statistical model was also used to account for the influence of surface roughness on the droplet-fiber force. In general, it has been found that the force required to move a liquid droplet along an oleophobic filter fiber will be less than that required to move a droplet along an oleophilic fiber. However, because of the effects of pinning and/or wetting behavior, this difference may be less than would otherwise be expected. Droplets with a greater contact angle (~110°) were observed to roll along the fiber, whereas droplets with a lesser contact angle (<90°) would slide.
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Affiliation(s)
- Ryan Mead-Hunter
- Fluid Dynamics Research Group, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia
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O'Leary RA, O'Brien B. Assessing demand for intensive care services: the role of readmission rates. Crit Care 2012. [PMCID: PMC3363932 DOI: 10.1186/cc11121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Cooper TF, Berkelmans R, Ulstrup KE, Weeks S, Radford B, Jones AM, Doyle J, Canto M, O'Leary RA, van Oppen MJH. Environmental factors controlling the distribution of symbiodinium harboured by the coral Acropora millepora on the Great Barrier Reef. PLoS One 2011; 6:e25536. [PMID: 22065989 PMCID: PMC3204971 DOI: 10.1371/journal.pone.0025536] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 09/06/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The Symbiodinium community associated with scleractinian corals is widely considered to be shaped by seawater temperature, as the coral's upper temperature tolerance is largely contingent on the Symbiodinium types harboured. Few studies have challenged this paradigm as knowledge of other environmental drivers on the distribution of Symbiodinium is limited. Here, we examine the influence of a range of environmental variables on the distribution of Symbiodinium associated with Acropora millepora collected from 47 coral reefs spanning 1,400 km on the Great Barrier Reef (GBR), Australia. METHODOLOGY/PRINCIPAL FINDINGS The environmental data included Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data at 1 km spatial resolution from which a number of sea surface temperature (SST) and water quality metrics were derived. In addition, the carbonate and mud composition of sediments were incorporated into the analysis along with in situ water quality samples for a subset of locations. Analyses were conducted at three spatio-temporal scales [GBR (regional-scale), Whitsunday Islands (local-scale) and Keppel Islands/Trunk Reef (temporal)] to examine the effects of scale on the distribution patterns. While SST metrics were important drivers of the distribution of Symbiodinium types at regional and temporal scales, our results demonstrate that spatial variability in water quality correlates significantly with Symbiodinium distribution at local scales. Background levels of Symbiodinium types were greatest at turbid inshore locations of the Whitsunday Islands where SST predictors were not as important. This was not the case at regional scales where combinations of mud and carbonate sediment content coupled with SST anomalies and mean summer SST explained 51.3% of the variation in dominant Symbiodinium communities. CONCLUSIONS/SIGNIFICANCE Reef corals may respond to global-scale stressors such as climate change through changes in their resident symbiont communities, however, management of local-scale stressors such as altered water quality is also necessary for maintenance of coral-Symbiodinium associations.
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Affiliation(s)
- Timothy F. Cooper
- Australian Institute of Marine Science, Oceans Institute, University of Western Australia, Crawley, Australia
| | - Ray Berkelmans
- Australian Institute of Marine Science, Townsville, Australia
| | | | - Scarla Weeks
- Centre for Spatial Environmental Research and Coral Reef Ecosystems Lab, University of Queensland, St. Lucia, Australia
| | - Ben Radford
- Australian Institute of Marine Science, Oceans Institute, University of Western Australia, Crawley, Australia
| | - Alison M. Jones
- Centre for Environmental Management, Central Queensland University, Rockhampton, Australia
| | - Jason Doyle
- Australian Institute of Marine Science, Townsville, Australia
| | - Marites Canto
- Centre for Spatial Environmental Research and Coral Reef Ecosystems Lab, University of Queensland, St. Lucia, Australia
| | - Rebecca A. O'Leary
- Australian Institute of Marine Science, Oceans Institute, University of Western Australia, Crawley, Australia
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12
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Cooper TF, Ulstrup KE, Dandan SS, Heyward AJ, Kühl M, Muirhead A, O'Leary RA, Ziersen BEF, Van Oppen MJH. Niche specialization of reef-building corals in the mesophotic zone: metabolic trade-offs between divergent Symbiodinium types. Proc Biol Sci 2011; 278:1840-50. [PMID: 21106586 PMCID: PMC3097838 DOI: 10.1098/rspb.2010.2321] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 11/01/2010] [Indexed: 11/12/2022] Open
Abstract
The photobiology of two reef corals and the distribution of associated symbiont types were investigated over a depth gradient of 0-60 m at Scott Reef, Western Australia. Pachyseris speciosa hosted mainly the same Symbiodinium C type similar to C3 irrespective of sampling depth. By contrast, Seriatopora hystrix hosted predominantly Symbiodinium type D1a or D1a-like at shallow depths while those in deeper water were dominated by a Symbiodinium C type closely related to C1. The photosynthesis/respiration (P/R) ratio increased consistently with depth at the two sampling times (November 2008 and April 2009) for P. speciosa and in November 2008 only for S. hystrix, suggesting a reduction in metabolic energy expended for every unit of energy obtained from photosynthesis. However, in April 2009, shallow colonies of S. hystrix exhibited decreased P/R ratios down to depths of approximately 23 m, below which the ratio increased towards the maximum depth sampled. This pattern was mirrored by changes in tissue biomass determined as total protein content. The depth of change in the direction of the P/R ratio correlated with a shift from Symbiodinium D to C-dominated colonies. We conclude that while photobiological flexibility is vital for persistence in contrasting light regimes, a shift in Symbiodinium type may also confer a functional advantage albeit at a metabolic cost with increased depth.
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Affiliation(s)
- Timothy F Cooper
- Australian Institute of Marine Science, UWA Oceans Institute (M096), 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
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13
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Fakiola M, Mishra A, Rai M, Singh SP, O'Leary RA, Ball S, Francis RW, Firth MJ, Radford BT, Miller EN, Sundar S, Blackwell JM. Classification and regression tree and spatial analyses reveal geographic heterogeneity in genome wide linkage study of Indian visceral leishmaniasis. PLoS One 2010; 5:e15807. [PMID: 21209823 PMCID: PMC3013125 DOI: 10.1371/journal.pone.0015807] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 11/24/2010] [Indexed: 11/18/2022] Open
Abstract
Background Genome wide linkage studies (GWLS) have provided evidence for loci controlling visceral leishmaniasis on Chromosomes 1p22, 6q27, 22q12 in Sudan and 6q27, 9p21, 17q11-q21 in Brazil. Genome wide studies from the major focus of disease in India have not previously been reported. Methods and Findings We undertook a GWLS in India in which a primary ∼10 cM (515 microsatellites) scan was carried out in 58 multicase pedigrees (74 nuclear families; 176 affected, 353 total individuals) and replication sought in 79 pedigrees (102 nuclear families; 218 affected, 473 total individuals). The primary scan provided evidence (≥2 adjacent markers allele-sharing LOD≥0.59; nominal P≤0.05) for linkage on Chromosomes 2, 5, 6, 7, 8, 10, 11, 20 and X, with peaks at 6p25.3-p24.3 and 8p23.1-p21.3 contributed to largely by 31 Hindu families and at Xq21.1-q26.1 by 27 Muslim families. Refined mapping confirmed linkage across all primary scan families at 2q12.2-q14.1 and 11q13.2-q23.3, but only 11q13.2-q23.3 replicated (combined LOD = 1.59; P = 0.0034). Linkage at 6p25.3-p24.3 and 8p23.1-p21.3, and at Xq21.1-q26.1, was confirmed by refined mapping for primary Hindu and Muslim families, respectively, but only Xq21.1-q26.1 replicated across all Muslim families (combined LOD 1.49; P = 0.0045). STRUCTURE and SMARTPCA did not identify population genetic substructure related to religious group. Classification and regression tree, and spatial interpolation, analyses confirm geographical heterogeneity for linkages at 6p25.3-p24.3, 8p23.1-p21.3 and Xq21.1-q26.1, with specific clusters of families contributing LOD scores of 2.13 (P = 0.0009), 1.75 (P = 0.002) and 1.84 (P = 0.001), respectively. Conclusions GWLS has identified novel loci that show geographical heterogeneity in their influence on susceptibility to VL in India.
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Affiliation(s)
- Michaela Fakiola
- Cambridge Institute for Medical Research and Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Anshuman Mishra
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Madhukar Rai
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Shri Prakash Singh
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Rebecca A. O'Leary
- Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia, Subiaco, Australia
| | - Stephen Ball
- Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia, Subiaco, Australia
| | - Richard W. Francis
- Cambridge Institute for Medical Research and Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
- Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia, Subiaco, Australia
| | - Martin J. Firth
- Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia, Subiaco, Australia
| | - Ben T. Radford
- Australian Institute of Marine Science, The UWA Oceans Institute, The University of Western Australia, Crawley, Australia
| | - E. Nancy Miller
- Cambridge Institute for Medical Research and Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Shyam Sundar
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Jenefer M. Blackwell
- Cambridge Institute for Medical Research and Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
- * E-mail:
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14
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Wilson SK, Depczynski M, Fisher R, Holmes TH, O'Leary RA, Tinkler P. Habitat associations of juvenile fish at Ningaloo Reef, Western Australia: the importance of coral and algae. PLoS One 2010; 5:e15185. [PMID: 21151875 PMCID: PMC2998428 DOI: 10.1371/journal.pone.0015185] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 10/28/2010] [Indexed: 11/18/2022] Open
Abstract
Habitat specificity plays a pivotal role in forming community patterns in coral reef fishes, yet considerable uncertainty remains as to the extent of this selectivity, particularly among newly settled recruits. Here we quantified habitat specificity of juvenile coral reef fish at three ecological levels; algal meadows vs. coral reefs, live vs. dead coral and among different coral morphologies. In total, 6979 individuals from 11 families and 56 species were censused along Ningaloo Reef, Western Australia. Juvenile fishes exhibited divergence in habitat use and specialization among species and at all study scales. Despite the close proximity of coral reef and algal meadows (10's of metres) 25 species were unique to coral reef habitats, and seven to algal meadows. Of the seven unique to algal meadows, several species are known to occupy coral reef habitat as adults, suggesting possible ontogenetic shifts in habitat use. Selectivity between live and dead coral was found to be species-specific. In particular, juvenile scarids were found predominantly on the skeletons of dead coral whereas many damsel and butterfly fishes were closely associated with live coral habitat. Among the coral dependent species, coral morphology played a key role in juvenile distribution. Corymbose corals supported a disproportionate number of coral species and individuals relative to their availability, whereas less complex shapes (i.e. massive & encrusting) were rarely used by juvenile fish. Habitat specialisation by juvenile species of ecological and fisheries importance, for a variety of habitat types, argues strongly for the careful conservation and management of multiple habitat types within marine parks, and indicates that the current emphasis on planning conservation using representative habitat areas is warranted. Furthermore, the close association of many juvenile fish with corals susceptible to climate change related disturbances suggests that identifying and protecting reefs resilient to this should be a conservation priority.
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Affiliation(s)
- Shaun K Wilson
- Science Division, Department of Environment and Conservation, Marine Science Program, Kensington, Western Australia, Australia.
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15
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McKinnon AD, Trott LA, Brinkman R, Duggan S, Castine S, O'Leary RA, Alongi DM. Seacage aquaculture in a World Heritage Area: the environmental footprint of a Barramundi farm in tropical Australia. Mar Pollut Bull 2010; 60:1489-1501. [PMID: 20598717 DOI: 10.1016/j.marpolbul.2010.04.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 04/30/2010] [Accepted: 04/30/2010] [Indexed: 05/29/2023]
Abstract
The fate of aquaculture wastes from a seacage farm within a pristine mangrove environment was studied. Seasonal and tidal differences were most important in determining water quality within receiving waters and obscured any nutrient enrichment effect by the farm. Farm wastes added significantly to the N budget status of the creek system, but overall water quality conformed to Queensland EPA Water Quality standards. Mangrove trees throughout the creek system contained (15)N signatures traceable to aquaculture feeds, but the footprint of the farm itself was best indicated by the ratio of Zn:Li in sediments. The creek became hypoxic (<2 mgl(-1)) during wet season low tides. Consequently, we recommended monitoring of water-column oxygen concentrations to warn of hypoxic conditions threatening to fish health, as well as Zn:Li ratios in sediment accumulation zones to determine the area of influence of the farm.
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Affiliation(s)
- A David McKinnon
- Australian Institute of Marine Science, P.M.B. No. 3, Townsville M.C., Queensland 4810, Australia.
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16
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Cleaver AL, Beesley AH, Firth MJ, Sturges NC, O'Leary RA, Hunger SP, Baker DL, Kees UR. Gene-based outcome prediction in multiple cohorts of pediatric T-cell acute lymphoblastic leukemia: a Children's Oncology Group study. Mol Cancer 2010; 9:105. [PMID: 20459861 PMCID: PMC2879253 DOI: 10.1186/1476-4598-9-105] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 05/12/2010] [Indexed: 02/07/2023] Open
Abstract
Background Continuous complete clinical remission in T-cell acute lymphoblastic leukemia (T-ALL) is now approaching 80% due to the implementation of aggressive chemotherapy protocols but patients that relapse continue to have a poor prognosis. Such patients could benefit from augmented therapy if their clinical outcome could be more accurately predicted at the time of diagnosis. Gene expression profiling offers the potential to identify additional prognostic markers but has had limited success in generating robust signatures that predict outcome across multiple patient cohorts. This study aimed to identify robust gene classifiers that could be used for the accurate prediction of relapse in independent cohorts and across different experimental platforms. Results Using HG-U133Plus2 microarrays we modeled a five-gene classifier (5-GC) that accurately predicted clinical outcome in a cohort of 50 T-ALL patients. The 5-GC was further tested against three independent cohorts of T-ALL patients, using either qRT-PCR or microarray gene expression, and could predict patients with significantly adverse clinical outcome in each. The 5-GC featured the interleukin-7 receptor (IL-7R), low-expression of which was independently predictive of relapse in T-ALL patients. In T-ALL cell lines, low IL-7R expression was correlated with diminished growth response to IL-7 and enhanced glucocorticoid resistance. Analysis of biological pathways identified the NF-κB and Wnt pathways, and the cell adhesion receptor family (particularly integrins) as being predictive of relapse. Outcome modeling using genes from these pathways identified patients with significantly worse relapse-free survival in each T-ALL cohort. Conclusions We have used two different approaches to identify, for the first time, robust gene signatures that can successfully discriminate relapse and CCR patients at the time of diagnosis across multiple patient cohorts and platforms. Such genes and pathways represent markers for improved patient risk stratification and potential targets for novel T-ALL therapies.
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Affiliation(s)
- Amanda L Cleaver
- Division of Children's Leukaemia and Cancer Research, Telethon Institute for Child Health Research, Perth, Australia
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17
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Mullins BJ, Braddock RD, Agranovski IE, Cropp RA, O'Leary RA. Observation and modelling of clamshell droplets on vertical fibres subjected to gravitational and drag forces. J Colloid Interface Sci 2005; 284:245-54. [PMID: 15752809 DOI: 10.1016/j.jcis.2004.10.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2004] [Accepted: 10/13/2004] [Indexed: 11/15/2022]
Abstract
Extensive experimental investigation of the wetting processes of fibre-liquid systems during air filtration (when drag and gravitational forces are acting) has shown many important features, including droplet extension, oscillatory motion, and detachment of drops from fibres as airflow velocity increases, and also movement or flow of droplets along fibres. A detailed experimental study of the processes was conducted using stainless steel filter fibres and H2O aerosol, which coalesce on the fibre to form clamshell droplets. The droplets were predominantly observed in the Reynolds transition flow region, since this is the region where most of the above features occur. The droplet oscillation is believed to be induced by the onset of the transition from laminar to turbulent flow as the increasing droplet size increases Reynolds number for the flow around the droplet. Two-dimensional flow in this region is usually modelled using the classical Karman vortex street, however there exist no 3D equivalents. Therefore to model such oscillation it was necessary to create a new conceptual model to account for the forces both inducing and preventing such oscillation. The agreement between the model and experimental results is very good for both the radial and transverse oscillations.
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Affiliation(s)
- Benjamin J Mullins
- School of Environmental Engineering, Faculty of Environmental Sciences, Griffith University, Nathan QLD 4111, Australia.
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