Weight average diameters

For multiple turbines (/ in number) the sum of impeller blade widths X should be used for W, and the average impeller height X 67// should be used for Cin the equations which include these terms. With turbines having different diameters on the same shaft, a weighted average diameter based on the exponents of in the appropriate equations should be used. 

Average Particle Size (APS) is the weighted average diameter of a catalyst. 

NUMBER AND WEIGHT AVERAGE DIAMETERS CALCULATED USING MIE SCATTERING... 

The obtained weight average diameters can reasonably well follow the progress of the reaction as can be seen from Figure 6, where experimentally estimated weight average diameters are plotted with those theoretically predicted by a mathematical model for the batch emulsion polymerization of vinyl acetate.(6)... 

The chromatograms of the several injected PVAc samples were corrected for axial dispersion (8-11) and number and weight average diameters were estimated. The resulting distributions and diameter averages showed that the latex samples from the batch runs were "almost monodispersed (8). This was further supported by the fact that estimated average diameters were very close to the "peak" average diameters (Table III). 

SEC has been shown (7) to give satisfactory results for latexes with broad particle size distributions as well. The method is particularly useful (7) in the determination of distributions of small particles when specific turbidity would provide only a turbidity (or weight) average diameter. 

Turbidity measurements are simple, fast and reproducible. Specific turbidity can successfully follow the particle size evolution during the course of emulsion polymerization and can be translated into weight average diameters. A combination of an on-line spectrophotometer with an on-line densitometer (to obtain concentration) would provide the potential to estimate Dw on-line, as well. An on-line determination of PSD s, for small particles however, would seem quite difficult due to the high correlation of their parameters. One should bear in mind that the above conclusions have been validated only for poly(vinyl acetate) latexes the analysis is currently being extened to other systems, such as polystyrene and poly(methyl-methacrylate). 

From the observed values of the particle size analysis of each of the latex samples, the number and weight average diameters of the particles, the size distributions, and the standard deviations, S.D., of the average diameters were calculated. Knowing the rate of polymerization and the total number of particles in a system, the rate of polymerization per particle, Rpp, can also be calculated. The values are listed on Table III, where it can be seen that, in comparison with the other two recipes, the one with surfactant ratio of r = 0.207 has the following features. 

The above equations yield weight average diameters. m the evaluation of D becomes more difficult due to intensity of the maximum and broadening of the peak, been used for the size range 0.26 to 1.01 pm [108]. 

Samples A and C have wide distributions, as indicated by the number- and weight-average diameters determined by electron microscopy. This is reflected in the large disparity between electron microscopy results and the other techniques used. Closer agreement among the methods is seen for the narrow distribution sample 6. However, even in this case, the results are lower for electron microscopy for reasons of particle shrinkage in the beam. 

Particle diameters are expressed in terms of averages. The most important averages are the number-average diameter ( ) ), the volume-average diameter (Dv), and the weight-average diameter (D ), all of which may be calculated using ... 

Interestingly it has been found that the mixing order affects the resultant blend morphology of the PEI/PEsI/LCP blends as well. The weight-average diameter of the dispersed LCP domains (D) in the ternary blends at the identical blend composition is smaller when PEI and PEsI are premixed (D=ca. 5.56 im) than when LCP and PEsI are premixed (D=ca 6.03 im). In the case of binary blend without PEsI, D is measured to be ca 7.13 im. This experimental result indicates that PEsI is more compatible with LCP than with PEI. In other words, PEsI... 

The particle size distribution irt a commerical colloidal silica (Ludox ) has been determined by electron microscopy. by Deielic et al. (148). A weight-average diameter, (/ , determined from the particle size distribution curve by electron microscopy, was 20.0 nm, for example, which agreed within the 5% limit of experimental error with the particle diameters calculated from light-scattering data. 

Cationic latex particles with surface amino groups were prepared by a multi-step batch emulsion polymerisation. Monodisperse cationic latex particles to be used as the seed were synthesised first. Then the amino-functionalised monomer, aminoethylmethacrylate hydrochloride, was used to synthesise the final functionalised latex particles. Three different azo initiators were used 2,2 -azobisisobutyramidine dihydrochloride, 2,2 -azobisdimethyleneisobutyramidine dihydrochloride, and 2,2 -azobisisobutyronitrile. Hexadecyltrimethylammonium bromide was used as the emulsifier. The latices were characterised by photon correlation spectroscopy to study the mean particle diameters, transmission electron microscopy to deteimine the particle size distributions, and hence the number- and weight-average diameters and the polydispersity index. The conversion was determined gravimetrically, the surface density of the amino groups was detemiined by conductimetric titrations, and the... 

AS-SOLID TRANSPORT Calculation of weight average diameter from sieve analyses ... 

Determine rosebud coal the weight average diameter from the sieve analysis on the following Montana... 

The results (Fig. 5) are presented in a logarithmic graph of the retained percentage of solid versus the Krumbein parameter 0 (Krumbein, 1934). Afterwards the weighted average diameter d) of the particles has been calculated J = 5.3 10 m. 

On the other hand, the results of the CONTIN program seemed to be less sensitive to the noise level provided this was below 0.005 higher values resulted in an underestimated weight-average diameter as well as a largely overestimated width of the distribution. 

Oshinski et al. [54] suggested that the weight average diameter of a blend could be represented by ... 

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