Role of advection in atmospheric ammonia; A Case study at a Japanese lake basin influenced by agricultural ammonia sources

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

https://doi.org/10.1016/j.atmosenv.2020.117856

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.

Measurements and numerical analysis of deformation of deep shaft excavated by short step sinking method

Nobuto, Jun*; Fukuda, Kazuhiro*; Sato, Toshinori; Kuroda, Hidetaka

Tonneru Kogaku Hokokushu (CD-ROM), 16, p.1 - 8, 2006/11

http://library.jsce.or.jp/jsce/open/00047/2006/16-0001.pdf

In this paper, we examine the mechanical behavior of shaft excavated by short-step sinking method, as part of the researches to verify the applicability of engineering technologies. Concretely, the shaft behavior during excavation is analyzed with FEM to estimate the deformation and stress state of rock mass and concrete lining support. Next, we actually measure rock mass deformation around the shaft and compare them with FEM analysis results. In addition, we apply inverse analysis method to short step sinking shaft in order to understand the shaft behavior better, and finally summarize the technological points to enhance the accuracy of inverse analysis method.

Winter transport and tidal current in the Tsugaru Strait

Onishi, Mitsuyo*; Isoda, Yutaka*; Kuroda, Hiroshi*; Iwahashi, Masayuki*; Sato, Chizuru*; Nakayama, Tomoharu*; Ito, Toshimichi; Iseda, Kenichi*; Nishizawa, Keisuke*; Shima, Shigeki*; et al.

Hokkaido Daigaku Suisan Kagaku Kenkyu Iho, 55(2), p.105 - 119, 2004/10

http://ci.nii.ac.jp/naid/110000954121

Transport variations and characteristics of tidal currents in the Tsugaru Strait (TS) are investigated using the ship-mounted ADCP data obtained during October 29, 1999 - March 31, 2000. The Tsugaru Strait connects the North Pacific Ocean (NPO) and Japan/East Sea (JES), and is a main output for Tsushima Warm Current (TWC) in the JES. The strong northeastwards mean current was found in the center of the strait, and counter flows exist near the Hokkaido and Honshu coasts. The estimated mean net eastward transport is 1.8 Sv (1Sv=10ms). In the TS, the transports of K1 and M2 across the strait are 0.72 Sv and 0.52 Sv, respectively. From the phase analysis, it is understood the K1 is progressive wave-like while the M2 is standing wave-like. We also find a significant barotropic fortnightly oscillation. The Mf tide is more energetic along the JES coast with the amplitude of 1-3cm, while the Mf tide amplitudes in the NPO are less than 1 cm. It is inferred that observed fortnightly oscillation may be generated by the difference of Mf tide amplitude between both sides of the TS.

10-, 25- and 60-day periodical current variations on the western shelf in Hidaka Bay

Kuroda, Hiroshi*; Isoda, Yutaka*; Onishi, Mitsuyo*; Iwahashi, Masayuki*; Sato, Chizuru*; Nakayama, Tomoharu*; Ito, Toshimichi; Iseda, Kenichi*; Nishizawa, Keisuke*; Shima, Shigeki*; et al.

Umi No Kenkyu, 12(2), p.195 - 214, 2003/03

https://ci.nii.ac.jp/naid/110003320248

Variabilities of the periodical current fluctuations on the shelf in Hidaka Bay were examined with use of ferry-mounted ADCP data obtained during 2000-2001. As the result of analysis, (1) three periodical variations around 10-, 25- and 60-day period are found, (2) the horizontal phase lag of these variations is little along the ship track, and the vertical phase lag is little at 10- and 25-day variations while several-day at 60-day variation, and (3) the 10-day variation shows coherent cross-correlation between current and wind.

Influence of precipitated hydride on the fracture behavior of zircaloy fuel cladding tube

Kuroda, Masatoshi*; Yoshioka, Kunihiko*; Yamanaka, Shinsuke*; Anada, Hiroyuki*; Nagase, Fumihisa; Uetsuka, Hiroshi

Journal of Nuclear Science and Technology, 37(8), p.670 - 675, 2000/08

https://doi.org/10.3327/jnst.37.670

no abstracts in English

Comparison between a steady-state fusion reactor and an inductively driven pulse reactor

*; Horiike, Hiroshi; Kuroda, Toshimasa*; Matsuzaki, Yoshimi; Shimomura, Yasuo; Sugihara, Masayoshi

JAERI-M 92-056, 53 Pages, 1992/04

JAERI-M-92-056.pdf:1.22MB

no abstracts in English