エアロゾル研究
Online ISSN : 1881-543X
Print ISSN : 0912-2834
ISSN-L : 0912-2834
22 巻 , 1 号
Spring
選択された号の論文の10件中1~10を表示しています
特集「エアロゾル技術の工業製品への応用」
研究論文
  • 大西 将徳, 酒井 敏
    2007 年 22 巻 1 号 p. 35-40
    発行日: 2007/03/20
    公開日: 2007/03/20
    ジャーナル フリー
    SPM and CO concentrations are low during the day time because the atmosphere is well mixed. In summer, solar radiation is twice as high as that in winter. So the atmospheric mixing during the day is stronger in summer than winter. However, in Kyoto, SPM and CO concentrations are not low in summer compared to winter. In order to reveal the reasons of these diurnal concentration variations, we estimated SPM and CO background concentrations using the data of the Atmospheric Environmental Regional Observation System in Kyoto. We conclude that SPM and CO diurnal concentration variations are caused by the following reasons; (a) SPM or CO concentrations decrease to SPM or CO background concentrations and (b) SPM background concentration is the highest in summer and is the lowest in winter and CO background concentration is almost constant through all seasons.
技術論文
  • 山本 勝
    2007 年 22 巻 1 号 p. 41-47
    発行日: 2007/03/20
    公開日: 2007/03/20
    ジャーナル フリー
    A moment method of the log-normal distribution is applied to evaporation of particles by introducing correction factors calculated from the error function. In the free-molecular regime, the improved moment method is tested for the evaporation and the sensitivity to time-integration scheme is examined. For the forward and backward Euler solutions, small time step size (<1 s for dv/dt = -10-10v2/3, where v is the particle volume and t is time) is required to accurately simulate the evaporation, since the difference from the exact one becomes larger with increasing the time step size. For large time step size (∼10 s) , the fourth order Runge-Kutta and simple exponential solutions agree well with the exact solution of the evaporation in the free molecular regime.
  • 小山 博已, 井川 誠司, 明星 敏彦, 奥山 喜久夫
    2007 年 22 巻 1 号 p. 48-53
    発行日: 2007/03/20
    公開日: 2007/03/20
    ジャーナル フリー
    We have developed a large annular-type differential mobility analyzer (DMA) , having outer electrode diameter of 100 mm to increase the sampling flow rate of size-classified aerosols up to 30 L/min. In order to calibrate this new DMA, three types of monodisperse polystyrene latex (PSL) particles with nominal diameter ranging from 28 to 100 nm were used as standard particles. PSL particles suspended in distilled water were aerosolized by a nebulizer and then introduced into the DMA. The mean diameters and standard deviations of these PSL particles were calculated by Ehara's method (Ehara, K. et al., Aerosol Sci. Technol., 32, 434-452 (2000) ) and compared with their nominal diameters and uncertainties. Nominal and measured diameters are in good agreement. These resutls indicate that this DMA is useful to classify large volume of nanometer-sized aerosols and for further measurements such as chemical analysis of particulate materials or inhalation experiments.
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