الفهرس 
INTRODUCTION
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Abstract
The essential features of distinction the particles are the size, shape and surface roughness. The classical characterization of particles by using size analysis and geometric shape factors often cannot distinhguish statistically the valid differences between individual powders. By means of computer aided-image analysis on four different materials having the same particle size fraction (-315+250)um, eight parameters (which are used in estimating the surface roughness, shape and size of particles) have been determind. The tested materials are the spherical soda-lime-glass ballotini, ground ballotini, glass-sand and quartzite. A large numberr of particles from each material were analysed to examine the number of particles, which are suitable to obtain significant results of the parameters. The statistical analysis was exploited to proof whether there are significant differences between the measured parameter values of the materials examined and also to interpret the main differences between them.
Centrifugal experiments on the materials examined with different surface chemistry were carried out and the results indicated that the roughest particles have detachment forses larger than that of the other materials, as well as, the smoothest material has the lowest detachment force. Moreover, the forces required to detach the particles of ground ballotini were higher than of spherrical ballotini.