Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636322
Title: Diffusion of microorganisms and micro-particles
Author: Cridland, J. V.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1980
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Abstract:
This thesis is concerned with the dispersal of motile micro-organisms, particularly that of Escherichia cola K12 W1485, from certain initial conditions, for example, a plane instantaneous source at x = 0 and t = 0. As a background to this study, a brief discussion of bacterial motion and diffusion measurements is presented, together with a survey of recent work on bacterial motion. A description is given of an apparatus which was constructed for the measurement of the intensity of light scattered, through an angle of 90° to the incident beam, by the bacteria as a function of position. The non-chemotactic dispersal of the bacteria E. coli has successfully been accomplished by recording the spatial distribution of the scattered light intensity. The diffusion of the fluorescent material fluorescein, was also recorded by determining the distribution of the fluorescent light through out the observation cell, and a comparison made with the dispersal of bacteria. The above spatial distribution of bacteria differed only slightly from those results obtained for the diffusion of fluorescein. This indicates that it is reasonable to describe the 'random' motion of an assembly of bacteria by a single motility coefficient; such coefficients have been calculated. However, possible reasons for the difference observed between the dispersal of bacteria and the diffusion of fluorescein are discussed; these include the influence of a distribution of motility coefficients, sedimentation, and particle size. In addition to the above measurements, non-random dispersal of the bacteria was also recorded and possible reasons for such observations discussed. Finally, the occurence of travelling bands is described and a qualitative comparison made with an analytical and a numerical solution to the equations said to describe such behaviour.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.636322  DOI: Not available
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