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dc.contributor.advisorStanley-Wood, N.G.
dc.contributor.authorZolfaghari, Mohammad Esmail*
dc.date.accessioned2010-06-30T09:05:17Z
dc.date.available2010-06-30T09:05:17Z
dc.date.issued2010-06-30T09:05:17Z
dc.identifier.urihttp://hdl.handle.net/10454/4353
dc.description.abstractWith the technological development in biologically orientated industries more and more natural products in powdered form are being handled and processed. Three differently comminuted liquorice rhizome products were classified into 23 narrow size fractions to investigate the particle and bulk characteristics of the material, and to study the influence of particle shape on powder flowability. The morphology of the fibrous particulate was investigated by using a Quantimet 720 Image Analyser. The perimeter (P), projected area (A), breadth (B), length (L), horizontal and vertical projected lengths (P V and Pi) and the horizontal and vertical Feret diameters (FV FH) were measured from which four dimensionless shape factors were evaluated, [P2/47rA, PHxPV/A, L/B, FV/FH]. The surface texture of the particles was measured by fractal analysis. The influence of particle shape and size on the mean flow rate, coefficient of flow variation and flow uniformity were measured using a specially designed inclined tube flowmeter. The failure properties of powdered liquorice when sheared under known normal compressive stresses were measured and from a series of yield loci the unconfined yield strength, major consolidation stress and effective angle of internal friction were obtained. The effects of particle shape and size on the angle of internal friction, wall friction, bulk and packed densities were. investigated and the experimental correlations expressed in terms of mathematical equations. These relationships, together with the failure function plots, indicate that comminuted liquorice powder behaves as a "simple" powder.en
dc.description.sponsorshipDarou-Pakhsh Pharmaceutical Companyen
dc.language.isoenen
dc.rights<a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>.en
dc.subjectComminuted liquorice rhizomeen
dc.subjectBulk characteristicsen
dc.subjectParticle characteristicsen
dc.subjectParticle shapeen
dc.subjectPowder flowabilityen
dc.titleThe morphological, flow and failure characteristics of fractionated natural bulk material. Evaluation of flowability of fractionated powdered liquorice using a specially designed flowmeter. The particle morphology was assessed by computer image analysis and the failure properties by shear cell testing.en
dc.type.qualificationleveldoctoralen
dc.publisher.institutionUniversity of Bradfordeng
dc.publisher.departmentPostgraduate School of Studies in Powder Technologyen
dc.typeThesiseng
dc.type.qualificationnamePhDen
dc.date.awarded1986
refterms.dateFOA2018-10-24T01:16:09Z


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