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Nonlinear deformation and localized failure of bacterial streamers in creeping flows

We investigate the failure of bacterial floc mediated streamers in a microfluidic device in a creeping flow regime using both experimental observations and analytical modeling. The quantification of streamer deformation and failure behavior is possible due to the use of 200 nm fluorescent polystyren...

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Autores principales: Biswas, Ishita, Ghosh, Ranajay, Sadrzadeh, Mohtada, Kumar, Aloke
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4997318/
https://www.ncbi.nlm.nih.gov/pubmed/27558511
http://dx.doi.org/10.1038/srep32204
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author Biswas, Ishita
Ghosh, Ranajay
Sadrzadeh, Mohtada
Kumar, Aloke
author_facet Biswas, Ishita
Ghosh, Ranajay
Sadrzadeh, Mohtada
Kumar, Aloke
author_sort Biswas, Ishita
collection PubMed
description We investigate the failure of bacterial floc mediated streamers in a microfluidic device in a creeping flow regime using both experimental observations and analytical modeling. The quantification of streamer deformation and failure behavior is possible due to the use of 200 nm fluorescent polystyrene beads which firmly embed in the extracellular polymeric substance (EPS) and act as tracers. The streamers, which form soon after the commencement of flow begin to deviate from an apparently quiescent fully formed state in spite of steady background flow and limited mass accretion indicating significant mechanical nonlinearity. This nonlinear behavior shows distinct phases of deformation with mutually different characteristic times and comes to an end with a distinct localized failure of the streamer far from the walls. We investigate this deformation and failure behavior for two separate bacterial strains and develop a simplified but nonlinear analytical model describing the experimentally observed instability phenomena assuming a necking route to instability. Our model leads to a power law relation between the critical strain at failure and the fluid velocity scale exhibiting excellent qualitative and quantitative agreeing with the experimental rupture behavior.
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spelling pubmed-49973182016-08-30 Nonlinear deformation and localized failure of bacterial streamers in creeping flows Biswas, Ishita Ghosh, Ranajay Sadrzadeh, Mohtada Kumar, Aloke Sci Rep Article We investigate the failure of bacterial floc mediated streamers in a microfluidic device in a creeping flow regime using both experimental observations and analytical modeling. The quantification of streamer deformation and failure behavior is possible due to the use of 200 nm fluorescent polystyrene beads which firmly embed in the extracellular polymeric substance (EPS) and act as tracers. The streamers, which form soon after the commencement of flow begin to deviate from an apparently quiescent fully formed state in spite of steady background flow and limited mass accretion indicating significant mechanical nonlinearity. This nonlinear behavior shows distinct phases of deformation with mutually different characteristic times and comes to an end with a distinct localized failure of the streamer far from the walls. We investigate this deformation and failure behavior for two separate bacterial strains and develop a simplified but nonlinear analytical model describing the experimentally observed instability phenomena assuming a necking route to instability. Our model leads to a power law relation between the critical strain at failure and the fluid velocity scale exhibiting excellent qualitative and quantitative agreeing with the experimental rupture behavior. Nature Publishing Group 2016-08-25 /pmc/articles/PMC4997318/ /pubmed/27558511 http://dx.doi.org/10.1038/srep32204 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Biswas, Ishita
Ghosh, Ranajay
Sadrzadeh, Mohtada
Kumar, Aloke
Nonlinear deformation and localized failure of bacterial streamers in creeping flows
title Nonlinear deformation and localized failure of bacterial streamers in creeping flows
title_full Nonlinear deformation and localized failure of bacterial streamers in creeping flows
title_fullStr Nonlinear deformation and localized failure of bacterial streamers in creeping flows
title_full_unstemmed Nonlinear deformation and localized failure of bacterial streamers in creeping flows
title_short Nonlinear deformation and localized failure of bacterial streamers in creeping flows
title_sort nonlinear deformation and localized failure of bacterial streamers in creeping flows
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4997318/
https://www.ncbi.nlm.nih.gov/pubmed/27558511
http://dx.doi.org/10.1038/srep32204
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