エアロゾル研究
Online ISSN : 1881-543X
Print ISSN : 0912-2834
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29 巻 , 2 号
選択された号の論文の9件中1~9を表示しています
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特集「エアロゾルプロセスを用いた微粒子材料の合成と環境エネルギー材料への応用」
若手論文特集
(研究論文)
  • 三木 裕介, 上田 紗也子, 三浦 和彦, 古谷 浩志, 植松 光夫
    29 巻 (2014) 2 号 p. 104-111
    公開日: 2014/07/08
    ジャーナル オープンアクセス
    Iron (Fe) is an essential element for marine phytoplankton growth. Long-range transport of atmospheric aerosols from the continent and subsequent deposition is an important process to supply Fe to the ocean. The mixing states with water-soluble materials are the significant factor for the dry and wet depositions of aerosol particles. In this study, we focused on water-insoluble Fe-containing particles and clarified the mixing states with water-soluble materials. We collected aerosol particles on the R/V Hakuho Maru in the mid-latitude over the North Pacific Ocean. Collected particles were analyzed using a transmission electron microscopy with a water dialysis method and an energy-dispersive X-ray (EDX) analysis. Particles larger than 0.5 μm in diameter during a dust event and no dust events (maritime and continental sample) were analyzed. The number fractions of water-insoluble material containing particles to total analyzed particles were 10% (maritime), 20% (continental) and 30% (dust event), respectively. Most of water-insoluble materials were mixed with water-soluble materials. Based on EDX analyses of water-insoluble materials in analyzed 3 samples, water-insoluble Fe-containing particles were found with other mineral components (Si or Al) and the number fractions of Fe-containing particles to total analyzed particles were 2% (maritime), 2% (continental) and 8% (dust events), respectively.
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(技術論文)
  • 並木 孝招, 関口 和彦, 王 青躍, 並木 則和, 東 賢一, 田村 一, 諏訪 好英, 鍵 直樹, 藤井 修二
    29 巻 (2014) 2 号 p. 112-118
    公開日: 2014/07/08
    ジャーナル オープンアクセス
    Degradation of volatile organic compound (VOC) gas by ultrasonic mist was investigated using a batch reactor under various experimental conditions. The experiments were conducted with or without hydrogen peroxide (H2O2) under 254 nm of UV irradiation. In the techniques with H2O2, VOC gas was removed by adsorption or reaction with OH radicals generated from H2O2 on the mist surface or inside it. Since 100% of toluene gas could be removed under all conditions by the adsorption or reaction with OH radicals on the mist surface, we evaluated the reactivity under the various experimental conditions by their reaction rates. The removal rate of toluene under UV/H2O2/mist condition was faster than that under UV/pure water/mist condition. Therefore, it is evident that H2O2 plays an important role in the generation of OH radicals and removal of gaseous VOC. Furthermore, in cases of 200 kHz of high frequency ultrasonic irradiation for the continuous generation of H2O2, sufficient removal rates were obtained not only under 200 kHz/UV/pure water/mist condition but also under 200 kHz/pure water/mist condition. Therefore, the results indicate that 200 kHz of ultrasound irradiation has a capability of continuous supply of H2O2, and a direct reaction with toluene by creating reactive cavities.
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(ノート)
  • 桜井 健治, 関口 和彦, 王 青躍, 古内 正美, 畑 光彦
    29 巻 (2014) 2 号 p. 119-123
    公開日: 2014/07/08
    ジャーナル オープンアクセス
    An inertial filter (INF) sampler can collect ultrafine particles (UFP) uniformly onto a 47 mmφ quartz filter with a low pressure drop (20–30 kPa) at 40 L/min. However, gas adsorption may influence chemical composition of UFP as a positive artifact during sampling period owing to very low mass concentration of UFP. In this study, we evaluated organic gas adsorption onto the quartz filter settled in the INF sampler during collection of atmospheric UFP in summer and winter to elucidate the influence of seasonal temperature and relative humidity. The filter samples collected by the INF sampler were analyzed for organic carbon (OC), elemental carbon (EC) by a thermal/optical carbon analyzer following the IMPROVE method.
    As a result, the artifacts of OC ranged from 33.0±11.7% in summer to 27.8±12.0% in winter, a large difference in the OC concentration was not observed between the seasons. The artifacts for each OC fraction showed that OC1 and OC4 were almost not adsorbed onto the filter but OC2 and OC3 were adsorbed about 40%, indicating that high boiling point components were adsorbed onto the filter at the high flow rate condition. From these results, it was thought that the gas adsorption was relatively low for the mass concentration of UFP and the INF sampler can be a useful device for UFP collection.
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