- Title Information
- Title
- Flagellated bacteria swimming in polymer solutions
- Name:
Personal
- Name Part
- Qu, Zijie
- Role
- Role Term:
Text
- creator
- Name:
Personal
- Name Part
- Breuer, Kenneth
- Role
- Role Term:
Text
- Advisor
- Name:
Personal
- Name Part
- Powers, Thomas
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Tang, Jay
- Role
- Role Term:
Text
- Reader
- Name:
Corporate
- Name Part
- Brown University. Engineering: Fluids and Thermal Sciences
- Role
- Role Term:
Text
- sponsor
- Origin Information
- Copyright Date
- 2018
- Physical Description
- Extent
- xii, 96 p.
- digitalOrigin
- born digital
- Note:
thesis
- Thesis (Ph. D.)--Brown University, 2018
- Genre (aat)
- theses
- Abstract
- The research is motivated by some previously-reported conflicting observations and explanations regarding the motility of flagellated bacteria swimming in polymer solutions. Three-dimensional real-time tracking microscopy is developed and applied to measure individual swimming behavior of E. coli over extended times. We first examine the swimming motility of wild type cells in Newtonian fluids of varying viscosity. Classical results showing the cells' "run and tumble" behavior are reproduced. We use the skewness of the swimming speed distribution to identify an extended flagellar bundling time associated with increased fluid viscosities and use Resistive Force Theory to argue that such variations are due to slower flagellar rotation rate at higher viscosity. In the next chapter, single particle microrheology is conducted to measure viscoelastic behavior in dilute polymer solutions. Statistical Particle Tracking Velocimetry is introduced as a method for resolving the particle motion observed using a high speed intensified camera and a standard epi-fluorescence microscope. In the final phase of the thesis, we examine the swimming behavior of both wild type and smooth swimming E. coli in non-Newtonian fluids (Methocel). A speed enhancement is observed for smooth swimmers, and is determined to be the result of shear-thinning effects. The swimming trajectory is observed to be straighter in solutions with increased polymer concentration, an effect we argue is due to the shear-induced normal stress acting on the cell body, reducing the cell body precession. In addition, we find evidence that the bundling time of the wild type swimmer is reduced with increased viscosity in non-Newtonian fluids. We argue that this phenomenon is partly due to the normal stress generated in the non-Newtonian fluid by the rotational shear flow around flagellar filaments.
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00832656")
- Topic
- Biophysics
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00910312")
- Topic
- Engineering
- Subject (fast)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00927999")
- Topic
- Fluid mechanics
- Language
- Language Term (ISO639-2B)
- English
- Record Information
- Record Content Source (marcorg)
- RPB
- Record Creation Date
(encoding="iso8601")
- 20180618
- Identifier:
DOI
- 10.26300/0emc-ej09
- Access Condition:
rights statement
(href="http://rightsstatements.org/vocab/InC/1.0/")
- In Copyright
- Access Condition:
restriction on access
- Collection is open for research.
- Type of Resource (primo)
- dissertations