Final size distribution

Using sands of narrow and wide size distributions suspended in various organic liquids, Capes and Sutherland (C7) have shown that large, compact agglomerates are formed if the amount of the bridging liquid is sufficient to occupy about 44-88% of the pore space in a densely compacted bed of sand particles. The final size distribution attained represents a balance between... 

Figure 10.22 Vesicle size selection by RNA added to a mixture of small ( 80 nm diameter) and large vesicles ( 160 nm) from 0.5 mM POPC-3.5% CTAB in 20 mM sodium phosphate buffer (pH 7.0). (a) The initial size distribution of the 1 1 mixture (b) the size distribution 4 min after RNA addition, during the selection process (c) the stable final size distribution after 15 min, with one peak for small diameters ( 90 nm) and a second peak indicating aggregates of large vesicles (> 1000 nm). As mentioned in the text, this process is reversible upon addition of RNAase (Thomas and Luisi, 2004.)...

Fig. 4.2.9 Histograms of the size distributions of the particles shown in Fig. 4.2.8. Original and final size distributions are shown by broken and solid lines, respectively. The diameter of an equivalent sphere having the same volume as a nonspherical particle was obtained with a Coulter counter. (From Ref. 9.)...

It was previously shown that the formation of a stable emulsion of methylene chloride in water was vital for the successful formation of individual microspheres [4,9]. Two main factors played an important role in the emulsification of methylene chloride in water and influenced the microsphere size the interfacial tension of the methylene chloride droplets in the surrounding aqueous phase and the forces of shear within the fluid mass. The former tends to resist the distortion of droplet shape necessary for fragmentation into smaller droplets whereas the latter forces act to distort and ultimately to disrupt the droplets. The relationship between these forces largely determines the final size distribution of the methylene chloride in water emulsion which in turn controls the final size distribution of the solid microspheres formed. 

The decisive parameters for the final size distribution are the average number of stress events A stress of each feed particle, the stress intensity and specific energy input E . The number of stress events refers either to the rapid flow between the surface of two approaching particles or to the particle capture between two beads in contact. It increases linearly with dispersion time t and rotational speed ca of the stirrer ... 

Evidence was found for a POPC matrix effect, in that the pre-added vesicles influenced the size distribution of the newly produced vesicles. The matrix effect leads to rapid formation of vesicle aggregates and control over the final size distribution, such that the mixed systems are more monodisperse than in the absence of the matrix, where the oleic acid vesicles grow in an uncontrolled way. This effect was more obvious at lower concentrations of oleic acid/oleate than at higher concentrations. 

Finally, Fig. 6 [72] shows again the linear growth rate curve of the previous figure (curve 1) the nucleation rate (curve 2) derived from the final size distribution and linear growth rate and the yield of faujasite against time derived from curves 1 and 2. This curve is sigmoid and was close to experimental points of yield against time. 

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