A new method to identify the shape and the size of fibrils of asbestos by the diffraction patterns of the laser beam from the fibrils has been developed. The diffraction patterns from the fibrils are identified with reference shapes in the Multiplexed Matched Spatial Filter. The locations of the autocorrelation peaks on the back focal plane of an inverse Fourier transform lens show the shape, size and position of the fibrils simultaneously and instantaneously. This method of the measurement of the shape, size and position of the small fibrils is examined theoretically and experimentally.
Utilization of the two channel satellite infrared image was examined as a remote sensing method to determine the spatial distributions of atmospheric aerosols. In the analytical method presented in this paper, the image data of the difference in equivalent black body temperature Tbb observed by a two channel imager is used for the detection of aerosol areas. Theoretical calculations for the method show that the sign of the difference in Tbb for most types of aerosols is opposit to that for clouds and water vapor. The difference in Tbb for volcanic and oceanic aerosols are relatively large. This mothod is expected to be effective to distinguish the high concentration areas of aerosols from the optically thin clouds and irregular patterns of water vapor field as well as the variation of ground surface temperature. Applying this method to NOAA AVHRR data, the distributions of volcanic aerosols and that of forest fire aerosols were successfully determined.
Suspended particulate matters (SPM) were collected in Nov. 1989 and in Jan.1990 across a main road, Route 19 bypass in Kasugai, by using five hi-vol air samplers. Each sampler was calibrated beforehand by means of variance analytical method. Metallic elements of the SPM were analysed by ICP-AES.Contributions to SPM from six major sources (diesel engine, iron and steel industry, refuse incineration, oil combustion, soil and sea salt) were calculated by a chemical element balance (CEB) method using seven elements of elemental carbon, Na, Al, K, V, Fe and Zn. The result showed that the concentration of SPM does not decrease with a distance from the road edge, but has a maximum. According to the source contribution analysis by CEB method, the maximum SPM concentration is largely affected by resuspension of soil bust deposited on the neighboring minor roads. It was also found that the concentration estimated to be contributed by the diesel automobils decreases remarkably with the distance from the main road edge.
The inversion method to estimate the size distribution of particles with the extinction spectrum was described. We applied a singular value decomposition to this inversion method. When Junge and Log-normal types are assumed as particle size distribution function, those distribution types are inverted from the extinction spectra which are calculated by the size distributions and kernel functions. A good inverted solution was obtained, even if the effective digit of extinction intensity was reduced at least 2 (effective digits). It was found that the accuracy of this method was dependent on the division number of the analysis range for the radius and the wave length. The singular value decomposition to the light extinction is useful for the size distribution analysis.
Aerosol counting Characteristics of two types of coutinuous flow condensation nucleus counters (CNCs) were investigated. Three CNCs of each type (TSI, Model 3020 and 8010) were tested by using monodisperse NaCl aerosols ranging from 0.005 to 0.2 μm in diameter. Dependencies of indicated concentration on particle size and number concentration were investigated by inter-comparison with CNCs. When aerosol number concentration is less than 103 particles/ml, no significant difference in indicated concentration was observed among six CNCs. However, systematic differencies between the CNC types were observed over 103 particles/ml, where operational mode of the model 3020 changes from single counting mode to photometric mode. After compensation of the systematic differencies, no significant concentration dependency was observed. It was also observed that the model 3020 detected smaller particles than the model 8010. The detectable size was slightly different even for the same type of CNC. differencies.