J. Aerosol Sci., 1977, Vol. 8, p. 67. Pergamon Press. Printed in Great Britain.
BOOK REVIEW Fine Particles: Aerosol Generation, Measurement, Sampling and Analysis. Edited by B. Y. H. LIu, pp. xiii + 838, 15 x 23 cm. Facsimile from typescript, hard cover, author and subject indexes. £19, $34.50. Academic Press, London and New York, 1976. THIS book, produced in less than a year, contains 34 papers, 27 being from the Symposium on Fine Particles which was held in Minneapolis in May, 1975, and was reviewed in the Journal of Aerosol Science, 6 (6), 487, 1975. The 7 additional papers will be considered briefly. The first of these, by the Editor, reviews the standardisation and calibration of aerosol instruments at the Particle Technology Laboratory, University of Minnesota. This work is based on the Vibrating Orifice Generator which can produce clouds of monodisperse particles from 0.5 to 50 #m diameter. Various practical points about the use of this generator are discussed and its performance is made obvious by a number of electron micrographs. Smaller particles are obtained from the Electrical Mobility Classifier which segregates charged evaporated particles from a Collison spray in a cylindrical condenser; the lower limit of diameter is about 0.01/an. Takahashi and Kasahara, of the Institute of Atomic Energy, Kyoto University, report on the photo oxidation of SO2 in air; particle concentration by number was measured with a condensation nucleus counter and the effects of the presence of a foreign particle aerosol were studied. Phalen, Cannon and Esparzo (University of California, Battelle NW and Inhalation Toxicology Research Institute, Albuquerque) have made a comparison of the results from three different methods of sizing particles of cigarette smoke from a laboratory smoking machine. It was found possible to obtain electron micrographs of the particles by fixing them with methyl-2-cyano acrylate evaporated at 70°C. The count median diameter is given as 0.29 #m with tro = 1.4. Knutson of IIT, Chicago, presents a critical discussion of the electrical mobility method of particle size analysis. The crucial factors are particle mobility and charge which require to be known as functions of size. Chuan of Costa Mesa, California, a pioneer of the piezo weighing technique, describes 6 and 10 stage cascade impactors with a quartz crystal impaction plate in each stage. The beat frequency from each stage is fed to a control box which prints out the count in 2 sec. By a programmed, sequential interrogation of each stage, the tota~distribution is recorded in real time. Conversion to mass concentration is available. Fenton (ITT) studied the turbulent transport of 11 #m diameter particles (density 2.65g/cm 3) behind an obstacle in a wind tunnel with Reynolds numbers around 5000. The particle momentum eddy diffusion coefficient was about half the eddy diffusion coefficient of the air flow and the particle concentration diffusion coefficient was about 0.75 of the air flow coefficient. Gebhart and colleagues (Ges. fiir Strahlen- und Umweltforschung, Frankfurt/Main) give accounts of two light scattering instruments for measuring the particle size of homogeneous aerosols. One (LASS) deals with diameters from 0.05 to 0.7 #m, using light scattered near to 40 °. The other (LASI) goes from 0.7 to about 5/~m accepting light scattered between 2.5 ° and 5.5°. The book is a valuable source of information on the very latest ideas in aerosol technology and is likely to be an essential reference for several years to come. C. N. DAVIES
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