Sodium diffusion in hard carbon studied by small- and wide-angle neutron scattering and muon spin relaxation

Oishi, Kazuki*; Igarashi, Daisuke*; Tatara, Ryoichi*; Kawamura, Yukihiko*; Hiroi, Kosuke; Suzuki, Junichi*; Umegaki, Izumi*; Nishimura, Shoichiro*; Koda, Akihiro*; Komaba, Shinichi*; et al.

Journal of Physics; Conference Series, 2462, p.012048_1 - 012048_5, 2023/03

https://doi.org/10.1088/1742-6596/2462/1/012048

Impacts of freeze-thaw processes and subsequent runoff on Cs washoff from bare land in Fukushima

Igarashi, Yasunori*; Onda, Yuichi*; Wakiyama, Yoshifumi*; Yoshimura, Kazuya; Kato, Hiroaki*; Kozuka, Shohei*; Manome, Ryo*

Science of the Total Environment, 769, p.144706_1 - 144706_9, 2021/05

https://doi.org/10.1016/j.scitotenv.2020.144706

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.

On-site background measurements for the J-PARC E56 experiment; A Search for the sterile neutrino at J-PARC MLF

Ajimura, Shuhei*; Bezerra, T. J. C.*; Chauveau, E.*; Enomoto, T.*; Furuta, Hisataka*; Harada, Masahide; Hasegawa, Shoichi; Hiraiwa, T.*; Igarashi, Yoichi*; Iwai, Eito*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2015(6), p.063C01_1 - 063C01_19, 2015/06

https://doi.org/10.1093/ptep/ptv078

The J-PARC E56 experiment aims to search for sterile neutrinos at the J-PARC Materials and Life Science Experimental Facility (MLF). In order to examine the feasibility of the experiment, we measured the background rates of different detector candidate sites, which are located at the third floor of the MLF, using a detector consisting of plastic scintillators with a fiducial mass of 500 kg. The gammas and neutrons induced by the beam as well as the backgrounds from the cosmic rays were measured, and the results are described in this article.

Ground-state properties of the one-dimensional attractive Hubbard model with confinement; A Comparative study

Hu, J.-H.*; Wang, J.-J.*; Xianlong, G.*; Okumura, Masahiko*; Igarashi, Ryo; Yamada, Susumu; Machida, Masahiko

Physical Review B, 82(1), p.014202_1 - 014202_12, 2010/07

https://doi.org/10.1103/PhysRevB.82.014202

We revisit the one-dimensional attractive Hubbard model by using the Bethe-ansatz-based density-functional theory and density-matrix renormalization method. The ground-state properties of this model are discussed in details for different fillings and different confining conditions in weak-to-intermediate coupling regime. We investigate the ground-state energy, energy gap, and pair-binding energy and compare them with those calculated from the canonical Bardeen-Cooper-Schrieffer approximation. We find that the Bethe-ansatz-based density-functional theory is computationally easy and yields an accurate description of the ground-state properties for weak-to-intermediate interaction strength, different fillings, and confinements.

Partial order of frustrated Potts model

Igarashi, Ryo; Ogata, Masao*

Journal of Physics; Conference Series, 200, p.022019_1 - 022019_4, 2010/02

https://doi.org/10.1088/1742-6596/200/2/022019

Next-generation quantum many-body simulation project toward petaflops computing; Density matrix renormalization group method on massively parallel computer

Yamada, Susumu; Imamura, Toshiyuki*; Okumura, Masahiko; Igarashi, Ryo; Machida, Masahiko

no journal, , 

no abstracts in English

Parallel solver for large eigenvalue problems on density matrix renormalization group method

Yamada, Susumu; Imamura, Toshiyuki*; Okumura, Masahiko; Igarashi, Ryo; Machida, Masahiko

no journal, , 

no abstracts in English

Parallelization strategy for density matrix renormalization group toward peta-flops parallel computer

Yamada, Susumu; Imamura, Toshiyuki*; Okumura, Masahiko; Igarashi, Ryo; Machida, Masahiko

no journal, , 

no abstracts in English

Ground state phase diagram of the asymmetric spin tube up to 6 legs

Igarashi, Ryo; Okumura, Masahiko; Yamada, Susumu; Machida, Masahiko

no journal, ,