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Characterization of Floc Structure Using Cluster Analysis
Author(s) -
Nagel Manfred,
Ay Peter
Publication year - 1999
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/(sici)1521-4117(199910)16:5<229::aid-ppsc229>3.0.co;2-e
Subject(s) - cluster (spacecraft) , aggregate (composite) , pellet , scanning electron microscope , characterization (materials science) , materials science , cluster analysis , microtome , biological system , nanotechnology , chemical engineering , optics , composite material , computer science , physics , artificial intelligence , engineering , biology , programming language
This work is based on a numerical classification method (Forgy's method or c‐means clustering) to investigate floc structure, taking into account a physically well‐founded model. Two different kinds of morphologies, voluminous, irregularly shaped, fluffy flocs and dense, regularly shaped, compact, pellet‐like aggregates, are analyzed. These structures are embedded in glycol methacrylate and cut into thin sections by means of a motorized microtome. Scanning electron microscopic observations show that no serious damage to the aggregate structure due to the preparation technique is apparent. A sequence of image analysis steps reduces the total image information of the sections, taken by a light microscope, to a few pertinent measurements, applicable to cluster analysis. Thus a cluster‐cluster aggregation mechanism is confirmed experimentally. The floc structure is separated into two clusters. Cluster 1 consists of six microflocs and cluster 2 is made up of two sub‐units, which are again subdivided into six and three microflocs. The pellet‐like aggregate is assembled from ten particles. Further interpretation of aggregate growth history remains unconsidered owing to the expected errors. In a second paper more aspects concerning cluster analysis of flocs will be published.