Polydispersed particles incorporation

Other data indicate that bronchodilator particles that are <5.6 pm are more efficacious than larger particles. Rees et al. (49) incorporated terbutaline crystals into standard MDIs and generated polydisperse aerosols characterized by three different MMADs 5.6, 9.1, and 13.6 pm. In 10 patients with asthma, they found that only the smallest aerosol (5.6 pm) significantly improved the FEVj, sG, and MEFjq. Since the two other aerosols had no significant bronchodilating ef-... 

Usually, the viscosity of a latex is not appropriate for its intended end use, and must be increased by the incorporation of a water-soluble viscosity modifier. Particle-particle interaction in latexes strongly affects viscosity behaviour (147). At higher solids contents, the viscosity rapidly inaeases. Alternatively, smaller particles (at the same solids content) have less distance between particles, and as a result, a higher latex viscosity. Latex viscosity is also a function of the particle size distribution, such that high solids latexes may be produced as polydisperse or bimodal distribution latexes, in which smaller particles fill the interstices between the larger ones. The formation of... 

Particles bigger in diameter than the column can be incorporated with tilt. If a tilted particle occurs, it may be preferentially at the end of a stack where there is more space. This might favour the cubatic structure as shown schematically in Figure 4b rather than long columns. We have observed that the particles with different dimensions separate in different columns (not shown in the micrographs in the paper). In such case, whole columns with bigger particles are tilted to obtain a column width, W, that is smaller than D, the diameter of particle in the stack. One such example is shown schematically in Figure 4b. These different structures for a polydisperse... 

The second type of calibration standard is a batch ofpolydisperse particles with a known size distribution and a carefully determined concentration. For these polydisperse standards, the cumulative concentration at any selected size should not differ from the specified value by more than 10%, except for a certain population of particles that has only a few particles. This type of calibration can be carried out by incorporating data from another particle characterization technology. For example, by comparing the pulse-height distribution from an optical particle counter with the size distribution obtained using an aerod5Uiamic... 

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