Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kubota, Tomohiro; Kuroda, Hisao*; Watanabe, Mirai*; Takahashi, Akiko*; Nakazato, Ryoji*; Tarui, Mika*; Matsumoto, Shunichi*; Nakagawa, Keita*; Numata, Yasuko*; Ouchi, Takao*; et al.
Atmospheric Environment, 243, p.117856_1 - 117856_9, 2020/12
Times Cited Count：3 Percentile：15.82(Environmental Sciences)The dry and wet depositions of atmospheric ammonia (NH
) is one of the important pathways of nitrogen loads to aquatic ecosystems. Crop and livestock agriculture, one of the largest emitters of NH in Asian countries, are known to cause high spatial and seasonal variation of NH and influence the surrounding lake basin areas via its dry and wet deposition. However, the spatial characteristics of the NH concentration in basin scale are not completely understood for regulation in NH emission. Here we aim to clarify dominant factors of spatial and seasonal variations of the NH concentration in a eutrophic lake basin surrounded by agricultural areas in Japan. Passive sampling over various land use categories in the basin was conducted at 36 sites in total from October 2018 to January 2020. Interestingly, the observed NH concentration near the livestock houses were higher in winter than summer, which was inconsistent with knowledge of seasonal changes of current NH emission inventory based on temperature-driven volatilization process. Comparing monthly NH concentrations with various meteorological factors, we suggested the importance of seasonal advection of NH from high emission sources to which has been rarely paid attention by the previous past studies. As for this, should be considered for lake ecosystem management since deposition of NH is known to be closely related to the ecological processes such as phytoplankton blooming.
Irisawa, Keita; Nakagawa, Akinori; Onizawa, Takashi*; Kogawara, Takafumi*; Hanada, Keiji; Meguro, Yoshihiro
Proceedings of 15th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2013) (CD-ROM), 5 Pages, 2013/09
Times Cited Count：1 Percentile：60.76(Engineering, Environmental)Muraki, Keita*; Nakagawa, Takuya*; Kishimoto, Masahiko*; Abe, Hiroshi; Hiraki, Takeshi*; Uchida, Hirohisa*
no journal, ,
In this study, we examined the effect of electron irradiation on the surface of a hydrogen storage alloy in order to improve the initial activation. We measured the initial rate of hydrogen absorption in an electrochemical process, and found that the electron irradiation treatment in the atmosphere is more effective than that in the vacuum or helium gas. Based on results of surface analysis of the alloy by ESCA, we found the existence of non-stoichiometric oxides of rare earths. As well known, non-stoichiometric rare earth oxides such as CeO
and LaO has a high ability to dissociate covalent molecules like H
O. This paper demonstrates an effective surface treatment of electron irradiation, and the important catalytic actions of rare earth oxides in the surface to improve the initial activation of the alloy.
Katata, Genki*; Kubota, Tomohiro; Kuroda, Hisao*; Watanabe, Mirai*; Takahashi, Akiko*; Nakazato, Ryoji*; Tarui, Mika*; Matsumoto, Shunichi*; Nakagawa, Keita*; Numata, Yasuko*; et al.
no journal, ,
no abstracts in English
