公共衛生學系;Department of Public HealthWANG, CHIU-SENCHIU-SENWANGGANATRA, C., P.C., P.GANATRAGEBREYES, K.K.GEBREYES2008-07-302018-06-292008-07-302018-06-291980http://ntur.lib.ntu.edu.tw//handle/246246/80910Deposition velocities were experimentally determined for aerosols of saline droplets moving in a physical model of the human airways consisting of the first two generations of bifurcations. The aerosols were generated from aqueous solutions containing 0.9 and 1.35﹪ NaCl (by weight) by a Collison nebulizer. The size distributions of the saline droplets were approximately lognormal, with a geometric standard deviation of 1.7 The mass median diameters were 1. 04 and 1.23 μm for 0.9 and 1.35﹪ saline droplets. The constant flow rate through the trachea was 255 cm /sec and the relative humidity of the stream was 99.7﹪ at 22℃. The first bifurcation consisting of the trachea and the two main bronchi, was placed horizontally, while the two second bifurcations were placed in planes normal to the first bifurcation. Because the saline droplets were not monodispersed, larger droplets tended to deposit on the lower edges of the main bronchi. The average deposition velocities on the lower edge were 1.4 × 10 cm/sec for 1. 35﹪ saline droplets and 1.0 × 10 cm/sec for 0.9﹪ saline droplets. The average deposition velocity on the inner edges of the main bronchi was 3.25 × 10 cm/sec. for both 0.9 and 1.35﹪ saline droplets. These results show that the deposition is nonuniform and that the degree of nonuniformity depends to a great extent on the droplet size. 　These factors should be taken into consideration in aerosol therapy. #B0180011en-US微粒肺部沈積DEPOSITION OF INHALED PARTICLESjournal article