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.

Improvement of accuracy and stability in numerically solving hyperbolic equations by IDO (Interpolated Differential Operator) scheme with Runge-Kutta time integration

Yoshida, Hiroshi*; Aoki, Takayuki*; Utsumi, Takayuki*

Denshi Joho Tsushin Gakkai Rombunshi, A, 86(3), p.223 - 231, 2003/03

https://ci.nii.ac.jp/naid/110003311635

no abstracts in English

Development and validation of Multi-DimensionaI sodium combustion analysis code AQUA-SF

Takata, Takashi; Yamaguchi, Akira

JNC TN9400 2000-065, 152 Pages, 2000/06

JNC-TN9400-2000-065.pdf:6.26MB
JNC-TN9400-2000-065(errata).pdf:0.12MB

ln the liquid metal fast reactor (LMFR) using liquid sodium as a coolant, it is important to evaluate the effect of the sodium combustion on the structure, etc. Most of the previous analytical works are based on a zone model, in which the principal variables are treated as volume-average quantities. Therefore spatial distribution of gas and structure temperatures, chemical species concentration are neglected. Therefore, a multi-dimensional sodium combustion analysis code AQUA-SF (Advanced simulation using Quadratic Upstream differencing Algorithm - Sodium Fire version) has been developed for the purpose of analyzing the sodium combustion phenomenon considering the multi-dimensional effect. This code is based on a multi-dimensional thermal hydraulics code AQUA that employs SIMPLEST-ANL method. Sodium combustion models are coupled with AQUA; one is a liquid droplet model for spray combustion, and the other is a flame sheet model for pool combustion. A gas radiation model is added for radiation heat transfer. Some other models necessary for the sodium combustion analysis, such as a chemical species transfer, a compressibility, are also added. ln AQUA-SF code, bounded QUICK method in space scheme and bounded three-point implicit method in time scheme are implemented. Verification analyses of sodium combustion tests shown in the following have been carried out. (1)pool combustion test (RUN-D1) (2)spray combustion test (RUN-E1) (3)sodium leakage combustion test (Sodium Fire Test-II) (4)smaII-scale leakage combustion test (RUN,F7-1) ln each verification analysis, good agreements are obtained and the validity of AQUA-SF code is confirmed.

None

Oyamada, Kiyoshi*

JNC TJ1440 99-001, 82 Pages, 1999/03

JNC-TJ1440-99-001.pdf:2.52MB

no abstracts in English

None

Takase, Hiroyasu*; IMPEY*; EINCHCO*; *

PNC TJ1281 96-003, 163 Pages, 1996/03

PNC-TJ1281-96-003.pdf:6.76MB

None

None

Aoki, Kenji*; Hibiya, Keisuke*; Shiogama, Yukihiro*; Toida, Masaru*; Fukazawa, E.*; Okutsu, Kazuo*; *

PNC TJ1100 95-002, 195 Pages, 1995/03

PNC-TJ1100-95-002.pdf:16.41MB

None

Integration study (V) for performance assessment system of geological disposal

Yanagisawa, Ichiro*; Fusaeda, Shigeki*; Uzawa, Masayuki*; Kasai, Masao*; Ishihara, Yoshinao*; Ikeda, Yasuhiro*; Ezaki, Masahiro*

PNC TJ1214 94-007, 92 Pages, 1994/03

PNC-TJ1214-94-007.pdf:2.71MB

no abstracts in English

None

*

PNC TJ1604 93-003, 46 Pages, 1993/03

PNC-TJ1604-93-003.pdf:1.84MB

no abstracts in English

Numerical analysis of transient behavior of molten metals heated by electron beam

; Yokokawa, Mitsuo; Seki, Masahiro; Arisawa, Takashi

Heat Transfer in High Energy/High Heat Flux Applications, p.43 - 49, 1989/00

no abstracts in English

A Study on the water purification mechanism in the mill tailings pond in Ningyo-toge Environmental Engineering Center

Masunaga, Kosuke; Tokoro, Chiharu*; Ohara, Yoshiyuki

no journal, , 

In Ningyo-toge Environmental Engineering Center, water level of mill tailings pond is planned to be lowered to reduce overflow risks caused by heavy rain etc., as a part of remediation activities of the Uranium Mine. It is known that the concentration of Fe and As and other elements in the mine drainage are decreased by retaining in the pond. The aims of this study are to reduce the load of water treatment facility and to determine the efficient countermeasure method for remediation of the mill tailings pond. To accomplish these, purification mechanisms of Fe and As in the pond were investigated, referring other studies. Chemical composition of water drainage in the pond was estimated by the chemical equilibrium analysis with advection using PHREEQC. The result of the simulation was almost reproducible for Fe. For As, it was reproducible when taking into account of surface complexation to ferrihydrite in sediment in the bottom of the pond.