Arakaki Takemitsu

写真a

Title

Professor

Researcher Number(JSPS Kakenhi)

80343375

Current Affiliation Organization 【 display / non-display

  • Concurrently   University of the Ryukyus   Graduate School of Engineering and Science   Chemistry, Biology and Marine Science   Professor  

  • Duty   University of the Ryukyus   Faculty of Science   Chemistry, Biology and Marine Science   Professor  

  • Concurrently   University of the Ryukyus   Graduate School of Engineering and Science   Marine and Environmental Sciences   Professor  

Study abroad experiences 【 display / non-display

  • 1991.08
    -
    1996.12

    Duke University  

External Career 【 display / non-display

  • 2005.06
    -
    2010.12

    University of the Ryukyus, Faculty of Science, Department of Chemistry, Biology, and Marine Science, Marine Chemistry, Associate Professor  

  • 2011.01
     
     

    Dept. of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus  

Research Interests 【 display / non-display

  • Environmental Chemistry

  • Atmospheric Chemistry

  • Photochemistry

  • 光化学

  • 環境化学

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Research Areas 【 display / non-display

  • Environmental Science/Agriculture Science / Environmental dynamic analysis

Published Papers 【 display / non-display

  • Source apportionment of black carbon aerosols by isotopes (<sup>14</sup>C and <sup>13</sup>C) and Bayesian modeling from two remote islands in east Asian outflow region

    Uchida M.

    Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms ( Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms )  538   64 - 74   2023.05 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Aerosol Proteinaceous Matter in Coastal Okinawa, Japan: Influence of Long-Range Transport and Photochemical Degradation.

    Li X, Zhang Y, Shi L, Kawamura K, Kunwar B, Takami A, Arakaki T, Lai S

    Environmental Science & Technology ( Environmental Science and Technology )  56 ( 8 ) 5256 - 5265   2022.04 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Heterogeneity and potential aquatic toxicity of hydrogen peroxide concentrations in selected rivers across Japan.

    Sunday MO, Jadoon WA, Ayeni TT, Iwamoto Y, Takeda K, Imaizumi Y, Arakaki T, Sakugawa H

    Science of the Total Environment ( Science of the Total Environment )  733   139349   2020.09 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

     View Summary

    Hydrogen peroxide (H2O2) is a reactive oxygen species formed in natural water. It is reportedly toxic to aquatic organisms with a predicted no-effect concentration (PNEC) of about 380 nM. In this study, a countrywide investigation of H2O2 concentrations in selected rivers across Japan was conducted to identify rivers that pose toxicity concerns. Twelve rivers with a total catchment area of 13,646 km(2) were selected from different prefectures. Spatial and temporal variation studies showed that the H2O2 concentrations (avg. 320 nM, n = 111) varied by two orders of magnitude (range 212929 nM) across the rivers. The Yamato River in Osaka and Nara prefectures and the Kokubu River in Chiba Prefecture had the highest concentrations at 276669 nM and 2362929 nM, respectively. >75% of the data from the two rivers were either close to or exceeded the PNEC. Most of the results for the other rivers were less than the PNEC. There was a clear seasonal variation in the H2O2 concentrations, with the highest values obtained in summer because of high solar irradiation. The H2O2 concentration had the highest positive correlation (r = 0.61, p < 0.01, n = 111) with the product of dissolved organic carbon and solar radiation intensity, which suggests that these two factors in combination are important in determining the H2O2 concentrations in river water. It was also observed that bigger rivers had lower H2O2 concentration and vice-versa. This shows that the size of a river may influence its H2O2 concentration. This study is the first countrywide survey of H2O2 concentrations in different rivers and evaluation of their relationship with the PNEC. The data provide insight on the factors influencing the concentrations of H2O2 in river water.

  • Preparation of standard materials of aerosol particles for X-ray fluorescence analysis using a small chamber sampling unit

    Nakano K.

    X-Ray Spectrometry ( X-Ray Spectrometry )  47 ( 6 ) 450 - 458   2018.11 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

  • Long-Term Monitoring of Metal Elements in the Total Suspended Particle Aerosols Simultaneously Collected at Three Islands in Okinawa, Japan

    Itoh, A. Y. Oshiro, S. Azechi, Y. Somada, D. Handa, Y. Miyagi, K. Nakano, A. Tanahara, T. Arakaki

    Asian Journal of Atmospheric Environment   12 ( 4 ) 326 - 337   2018.10 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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Academic Awards 【 display / non-display

  • Excellence in Reviewing

    2016.07   Elsevior (Chemosphere)  

    Winner: Arakaki Takemitsu

Grant-in-Aid for Scientific Research 【 display / non-display

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SDGs 【 display / non-display

  • 水の酸化処理技術
    大気エアロゾルと台風の勢力