エアロゾル研究
Online ISSN : 1881-543X
Print ISSN : 0912-2834
ISSN-L : 0912-2834
21 巻 , 3 号
Autumn
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「機能性プラズマの科学とその先端応用技術」
研究論文
  • 金丸 真広, 横山 奈津子, 足立 元明
    2006 年 21 巻 3 号 p. 233-238
    発行日: 2006/09/20
    公開日: 2007/03/15
    ジャーナル フリー
    A new electrospray pyrolysis method (named ac electrospray pyrolysis) is developed where droplets with a diameter smaller than 0.3 μm are formed through the breakdown of droplets by an ac voltage. The effectiveness of electrospray pyrolysis is demonstrated through the ZnS particle synthesis from the zinc nitrate and thiourea/ethyl alcohol solution. The amount of particles generated by the ac electrospray pyrolysis were about 10 times that by the conventional dc electrospray method at a given condition (the gas flow rate : 2 L/min, the furnace temperature : 873 K, the feeding rate of solution : 45 ∼ 38.5 mL/h) . SEM photographs showed that the particles prepared by ac voltage were agglomerated and the average size of the primary particles was almost the same as that of particles produced with dc voltage. X-ray diffraction patterns showed that particles produced by ac electrospray were ZnS.
  • 森川 敦史, 東野 達, 笠原 三紀夫
    2006 年 21 巻 3 号 p. 239-246
    発行日: 2006/09/20
    公開日: 2007/03/15
    ジャーナル フリー
    Hourly time scale variation of modified components in individual Asian dust (Kosa) particles was analyzed with double thin film methods combined with time-series samplings. Kosa particles were collected with an impactor at Yasaka, Tango, Kyoto. 3 ∼ 4 days' samplings were run during springtime in 2003 (Run.1) and 2004 (Run.2) , and each one Kosa event could be observed. Several time-series samplings were performed every 3 ∼ 6 hours from the beginning of the Kosa episode. Double thin film methods were utilized to determine the mixing state of sulfate and nitrate, and that of nitrate and chloride in individual aerosol particles. Particles containing SO42- was detected in 25 ∼ 45 % of the coarse particles (50 % cut-off aerodynamic diameter : D50 ≥ 1.2 μm) collected onto each impactor stage at the first Kosa sampling in Run.1. The percentage decreased drastically 6 hours later and particles containing NO3- became the dominant species in the modified components. The latter result held for the samples in Run.2 irrespective of the sampling time. Meteorological condition and the results of the simultaneously performed bulk sample analysis in Run.1 implied sulfate in the Kosa particles was formed by the absorption of gaseous SO2 and the subsequent oxidation in high humidity condition. Percentage of the modified particles roughly decreased with time and that of the particles containing both Cl- and NO3- indicated similar pattern. In each sample, particles containing both SO42- and NO3- were hardly detected, which suggests that formation of nitrate and that of sulfate is exclusive.
  • 李 相権, 鄭 鎭度, 大谷 吉生
    2006 年 21 巻 3 号 p. 247-254
    発行日: 2006/09/20
    公開日: 2007/03/15
    ジャーナル フリー
    Environmental tobacco smoke consists of 85 % of sidestream cigarette smoke and 11 % of exhaled mainstream smoke. In order to prevent non-smokers from passive smoking, exposure to the exhaled mainstream smoke as well as to the sidestream smoke has to be taken into account. In the present work, in order to elucidate the washout characteristics of inhaled smoke from the lung, smoking patterns were measured for the subjects with various vital capacities by using newly devised anemometer, and the particle concentrations and size distributions in the exhaled air were measured with SMPS (Scanning Mobility Particle Sizer, TSI Model 3936) and ELPI (Electrical Low Pressure Impactor, DEKATI Model 24317). As a result, (1) vital capacities of smokers do not affect the inspiration pattern of cigarette smoke, (2) exhaled air from a subject who is breathing room air contains particles with a bimodal distribution, (3) residual particles in the lung are washed out after 20 times of deep breathing, (4) human lung constantly generates particles with a median size smaller than 0.01 μm at the concentration of about 1.6 × 104 cm-3, (5) smoke exhaled from the lung has a bimodal distribution with the concentration of about 2.5 × 107 cm-3, (6) after smoking, complete washout of residual smoke in the lung requires normal breathing for 20 min.
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