Particle measurements

Now the relationship between v and A is given by the size distribution curve the value of A merely represents the lengths of the particles measured in terms of a particular, arbitrary, unit. Thus, if the size distribution curve remains of exactly the same shape during the grinding process, the values of... 

Stream scanning Brinkmann, Glimet, Goulter, Dantec, Erdco, Faley, Flowvision, Hiac/Royco, Kowa, Lasentec, Malvern, Met One, Particle Measuring Systems, Polytec, Procedyne, Rion, Spectrex 0.2-10,000 lm O.l-lOg (also on-line)... 

M depends not on the molecular sizes of the particles but on the number of particles. Measuring colligative properties such as boiling point elevation, freezing point depression, and vapor pressure lowering can determine the number of particles in a sample. 

Many particle-measuring methods use STORE S LAW to determine particle distributions. By suitable mcUiipulation(see below), we obtain an equation relating the Stokes diameter, M, with the particle density, Pj, and the liquid... 

Table I compares the measured values of extinction coefficients with the values calculated from theory at wavelengths of 25U, 280 and 350 nm. The lower values of extinction coefficients for the larger particles measured, using the online detector compared to the Beckman instrument, are due to the optical effects discussed above. The disagreement between the extinction coefficients calculated from Mie theory for non-absorbing spheres and the measured values from the Beckman instrument is very significant, particularly at 2 k and 280 nm.

Table III. Diameter Averages for Latex Particles Measured at...

Figure 12. Schematic representation of the setup for single particle measurements by electrostatic trapping (ET). Pt denotes two freestanding Pt electrodes (dashed region). A ligand-stabilized Pd cluster is polarized by the applied voltage and attracted to the gap between the Pt electrodes. (Reprinted with permission from Ref. [29], 1997, American Institute of Physics.)...

Figure 2 and Figure 3 show the size distribution of these ultrafine particles measured by separate single screens (EML), stacked single screen (USBM), and the mobility analyzer (UI). 

C. Orr and J. M. Dallavalle, Fine Particle Measurements, The Macmillan Company, New York, 1959. 

A 0.22-micrometer filter is recommended for CAA and dextrose solutions to remove particulate matter, air, and microorganisms. Because IVFE particles measure approximately 0.5 micrometers, IVFE should be administered separately and piggybacked into the PN line beyond the in-line filter. 

Bjerknes, R. and Bassoe, C.-F. (1983) Human leukocyte phagocytosis of zymosan particles measured by flow cytometry. Acta Pathol. Microbiol. Immunol. Scand. Sect. C. 91, 341-348. 

Table 6.3 Mean particle size d) of metallic and bimetallic particles measured by TEM and H2 and CO chemisorption properties of selected catalysts. (Reproduced from Reference 147].)...

Current particle sizing technology limits the smallest particle measurable to around 1 pm. A number of extrapolation methods have been suggested by Misra and White (5). Workers like Jones, Budz and Mullin (6) cautioned extrapolating to zero size and recommended the use of effective nucleation rate instead. It was thus decided not to extrapolate back to zero size but to find the effective nucleation rate basing on the smallest particle measurable. In contrast, the... 

When sources are studied, several things should be done to provide data needed for receptor-model applications. First, particles should be collected In at least two different size fractions corresponding to the division at about 2.5-ym dlam now used In many studies of ambient aerosols. In some cases. It may be desirable to have more size cuts. As noted above, compositions of particles from coal combustion change dramatically below about 0.5-pm dlam (44, 46). Above we Identified a minimum of about twenty elements that should be measured. Also, In order to develop adequate markers for sources that emit carbonaceous particles, measurements of organic compounds and other properties related to carbonaceous particles should be made. 

The uptake of water with increasing RH causes an increase in both mass and radius and a decrease in refractive index the net effect of all these factors is an increase in light scattering. This can be seen in Fig. 9.27, where the light scattering coefficient, bxai 6sp, for some ambient aerosol particles measured using an integrating nephelometer was found to increase with the liquid water content of the aerosols. 

TABLE 9.14 Average Elemental and Nitrate Concentrations of Particles Measured at Ducke Reserve in the Amazon Basin"... 

Similarly, Posfai et al. (1998) carried out AFM and TEM studies of aerosol particles collected over the North Atlantic Ocean. The size of the particles measured under the vacuum conditions of the TEM were smaller than those measured by AFM, due to evaporation of water from the particles. However, the TEM images also showed halos around the particles at the same diameters as the AFM measurements, suggesting that the particles under ambient conditions had an organic coating. This was supported by energy-dispersive X-ray spectrometry (EDS), which showed that these residues contained S, O, and C (although at least some of the C signal may have been due to the substrate). 

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