Sedimentation image analysis

The basic idea of this method is the analysis of particles settling under gravity using a digital image acquisition system. A continuously operating CCD camera, with a frame grabber, tracks individual particles illuminated 

---

Fig. 4. Aggregate size distributions by electron microscope image analysis (D and centrifugal (Z9 sedimentations for N220 and N351 carbon blacks (8).

A new suspension array concept based on sedimentation and microscopic imaging was introduced by Moser et al. [98], Magnetic microbeads settle to the bottom of a microplate well by magnetic forces and form randomly ordered arrays, which are examined by fluorescence microscopy and automated imaging analysis. Each bead carries specific capture molecules and can be identified by a defined luminescent code. 

Other techniques, such as fight scattering and sedimentation, are also sensitive to particle shape. The direct observation of particles by a scanning electron microscope and distribution measurements by image analysis would appear to overcome many of the problems associated with the various other techniques, but problems of describing irregularly shaped particles remain. A universal particle size descriptor has not yet been developed. The technique adopted and the results obtained are most useful when empirical correlations with the end use can be made. 

The particles were deposited on the slides by in5>actation, sedimentation and diffusion. Subsequently, the samples were analyzed by scanning electron microscopy (SEM). Information on morphology and size distribution was obtained from image analysis, while the elemental composition of particles was determined by electron probe X-ray microanalysis (EPXMA). 

Verrecchia, E.P. (2004) Multiresolution analysis of shell growth increments to detect natural cycles. In Francus, P. (Ed.) Image Analysis, Sediments and Paleoen-vironments, Vol. 7, Developments in Paleoenvironmental Research. Dordrecht Kluwer Academic, pp. 273-293. 

Table V. Comparison of Diameter Values Measured by Flow FFF, Sedimentation FFF, and Image Analysis...

Figure I. The flow chart illustrates the advantages and flexibility of image analysis. Image acquiring, processing and measurements can be applied according to the purpose of the study and the sediment material available.

Provided that a statistical relationship between grey-seale and sediment composition can be established, image analysis can be used to infer fluxes of sediment components in records containing thousands of years. Ifa varved sediment is used, annual or perhaps even seasonal resolution can be obtained. Petterson et al. (unpublished) have inferred the annnal accumulation rate of minerogenic matter for 6400 years in Kassjon (Sweden). 

Krinsley, D. H., K. Pye, S. Boggs Jr. N. K. Tovey, 1998. Back-scattered Scanning Electron Microscopy and Image Analysis of Sediments and Sedimentary Rocks. Cambridge University Press, New York, 193 pp. 

Petterson, G., B. V. Odgaard I. Renberg, 1999. Image analysis as a method to quantify sediment components. J. Paleolim. 22 443—455. 

Folk, R. L, 1980. Petrology of Sedimentary Rocks. Hemphill Publishing Company, Austin, 182 pp. Francus, P., 1998. An image-analysis technique to measure grain-size variation in thin section of soft clastic sediments. Sed. Geol. 121 289-298. 

---