Characterization of particles

The principle of inertial impaction is employed to sample aerosols aerodynamically for characterization of particle size and will be dealt with theoretically later in this chapter. 

Zdanowicz, C.M. Banic, C.M. Paktunc, D. Kliza-Petelle, D.A. 2006. Metal emissions from a Cu-smelter, Rouyn-Noranda, Quebec Characterization of particles sampled in air and snow. Geochemistry Exploration, Environment and Analysis, 6, 147-162. 

EPA. 1988d. Integrated approach to the characterization of particle and organic emissions from unvented kerosene space heaters. Research Triangle Park, NC U.S. Environmental Protection Agency, Office of Research and Development, Air and Energy Engineering Research Laboratory. EPA report no. EPA/600/D-88-251. 

Sexton K, Webber LM, Hayward SB, et al. 1986. Characterization of particle composition, organic vapor constituents, and mutagenicity of indoor air pollutant emissions. Environment International 12 351-362. 

Seeger, S., Wilke, O., Biicker, M. and Jann, O. (2006) Time and size-resolved characterization of particle emission from office machines with printing function. Proceedings of Healthy Buildings, Lisboa, Vol. 2, pp. 447-50. 

Elastic unshifted scattering Particles Tyndall (Hie) Characterization of particle distribution Information can be difficult to interpret for non-ideal particle systems... 

Photon Correlation Spectroscopy, Transient Electric Birefringence, and Characterization of Particle Size Distributions in Colloidal Suspensions... 

As shown before the total number of differential equations is K(N +1). In this study, K = 10 and N = 15. The choice of 10 is considered to be a reasonable number for the characterization of particle size fractions for design calculations. Therefore, the number of differential equations, 160, was not artificially reduced by taking only a few discrete cuts. However, the possibility of representing the particle behavior with one average size was explored. Different averages like mean surface, surface mean, volume mean, etc., were tried but, none proved to be applicable for this problem where heat transfer and devolatilization occur simultaneously. 

In this section we focus on four specific environmental problems coal combustion aerosol formation, dynamics of atmospheric aerosols, the chemical characterization of particles, and the role of aerosols in clean room technology or so-called microcontamination control. For the reader interested in an introduction to aerosol science, we recommend three texts [6-8]. 

Since the development of the equation, it has been tried to derive further information from it. Rees and Rue [129] determined the area under the Heckel plot. Duberg and Nystrom [137] used the nonlinear part for characterization of particle fracture. Paronen [138] deduced elastic deformation from the appearance of the Heckel plot during decompression. Morris and Schwartz [139] analyzed different phases of the Heckel plot. Imbert et al. [134] used, in analogy to Leuenberger and Ineichen [14], percolation theory for the compression process as described by the Heckel equation. Based on the Heckel equation, Kuentz and Leuenberger [135,140] developed a new derived equation for the pressure sensitivity of tablets. 

Guo, H. X., Heinamaki, I, and Yliruusi, J. (1999), Characterization of particle deformation during compression measured by confocal laser scanning microscopy,Int. J. Pharm., 186, 99-108. 

Sposito, G., Characterization of particle surface charge, in Environmental Particles, Buffle, J. and van Leeuwen, H.P., Eds., Lewis Publishers, Ann Arbor, MI, 1992, chap. 7. 

Walton, D.E., and Mumford, C.J. (1999). Spray-dried products characterization of particle morphology. TransIchemE, 77A, 21-38. 

Characterization of particle size. In Figure 12. a comparison is given between particle size determination by the analytical centrifuge, by electron microscope and by nitrogen adsorption on the carefully... 

As a result of its versatility, FFF in one form or another has been applied to the characterization of particles or molecules whose sizes range over five orders of magnitude from particles as small as 0.005 pm to as large as 500 pm [80]. The total mass range covered is over 15 decades. Most of the reported data are for aqueous suspensions non-aqueous suspensions have also been used [81]. 

A presumed application of this concept is for analytical or continuous micropreparative separation and characterization of particles according to their densities. This use can be suggested for the separation of biological cells and of inorganic or synthetic polymer particles. However, more extensive investigation is needed to make exact conclusions. 

Sposito, G. (1992) Characterization of Particle Surface Charge. In Environmental Particles, Vol. 1, J. Ruffle and H. P. van Leeuwen, Eds., Lewis, Chelsea, MI. 

An advantage of equivalent diameters is that they provide a unique characterization of particle size for the given method of measurement. In addition, the diameter gives information about the particle properties. For example, the equivalent surface diameter would give information about the surface area of the particle and the equivalent volume diameter would give information about the volume. Thus, if the density of the particles is known, the mass and properties important to pharmaceutical applications can be calculated. The numerical value for equivalent diameters derived from different geometric properties will only be identical in the case of perfectly spherical particles, and if the particle irregularity increases so will the differences between the different equivalent diameters. 

Following the progression of particle size analysis, so far we have gotten a perfect sample, uniquely characterized the particle size and done the statistical parameter estimates now we have the tools to look at actual data and methods of measurement. There are many methods for the characterization of particle size and shape however, in this section we will only include methods commonly used by researchers in tableting. The methods covered are microscopy, sieving, and laser diffraction. 

The detailed morphology (including overall particle shape, grain sizes and relative juxtapositions, and possible water inclusions) adopted by dried atmospheric particles probably depends on the temperature and the rate of evaporation. For these reasons, it cannot be certain that morphological features observed by TEM for particles dried by exposure to vacuum are the same as those adopted by particles dried by atmospheric processes. A critical need is the development of techniques capable of in situ characterization of particle morphology. Because the particles themselves are often no larger than 1 pm, the heterogeneity of their features occurs on the 10 to 100-nm scale. 

Brus LE (1983) A simple model for the ionization potential, electron affinity, and aqueous redox potentials of small semiconductor ciystalhtes. J Chem Phys 79 5566 Burtscher H, Kunzel S, Hughn C (1998) Characterization of particles in combustion engine exhaust. 

Raeymaekers B., Van Espen P. and Adams F. (1984) The morphological characterization of particles by automated scanning electron microscopy, Mikrochim Acta II 437—454. 

Hooton JC, German CS, Allen S, et al. Characterization of particle-interactions by atomic force microscopy effect of contact area. Pharm Res 2003 20(3) 508-514. 

As for all catalysts, well-characterized samples are necessary to be able to relate the catalytic performance to physico-chemical properties. Transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAFS) were used in this study to characterize the stabilized metal colloid. The necessity of such extensive characterization of particle size has been outlined by Harada et al. [6,7] showing that the formation of aggregates may be overlooked and misinterpreted as large metal particles when using TEM alone. The actual availability of the polymer stabilized surface has been probed by hydrogen/oxygen titration adopted from the description of Bernard et al. [8]. 

In this work we tried to create conditions to deposit MSA on the hydroxylated surface of a-alumina in dense silica layers. The surface-sensitive electrokinetic measurements, DRIFT, SIMS, and XPS, show that the coating grows by deposition of molecular units on the surface of the alumina, whereas TEM, XPS, and surface area measurements show that thick, nonporous silica coatings can be grown. Characterization of particles coated with submonolayer or thicker MSA give insights into the nature of the coatings and the deposition mechanism. 

Sommerfeld, M. and Qiu, H.-H., Characterization of particle-laden confined swirling flows by phase-Doppler anemometry and numerical calculation. Int. J. Multiphase Flows, 19, 1093-1127(1993)... 

Heinrich KFJ, ed. (1980) Characterization of Particles. NBS Spec. Pub. 533. US Government Printing OfFice, Washington, D.C. 

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