1.

論文(リポジトリ)

論文(リポジトリ)
Wang, Yishu ; Reeder, T. ; Karaki, Y. ; Kindervater, J. ; Halloran, T. ; Maliszewskyj, N. ; Qiu, Yiming ; Rodriguez, J. A. ; Gladchenko, S. ; Koohpayeh, S. M. ; Nakatsuji, S. ; Broholm, C.
出版情報: Science Advances.  7  2021-06-16.  American Association for the Advancement of Science
URL: http://hdl.handle.net/20.500.12000/48586
概要: Ferromagnetically interacting Ising spins on the pyrochlore lattice of corner-sharing tetrahedra form a highly degenerate manifold of low-energy states. A spin flip relative to this “spin-ice” manifold can fractionalize into two oppositely charged magnetic monopoles with effective Coulomb interactions. To understand this process, we have probed the low-temperature magnetic response of spin ice to time-varying magnetic fields through stroboscopic neutron scattering and SQUID magnetometry on a new class of ultrapure Ho_2Ti_2O_7 crystals. Covering almost 10 decades of time scales with atomic-scale spatial resolution, the experiments resolve apparent discrepancies between prior measurements on more disordered crystals and reveal a thermal crossover between distinct relaxation processes. Magnetic relaxation at low temperatures is associated with monopole motion through the spin-ice vacuum, while at elevated temperatures, relaxation occurs through reorientation of increasingly spin-like monopolar bound states. Spin fractionalization is thus directly manifest in the relaxation dynamics of spin ice. 続きを見る
2.

論文(リポジトリ)

論文(リポジトリ)
前之園, 唯史 ; 石田, 憲 ; 佐伯, 智史 ; Maenosono, Tadafumi ; Ishida, Akira ; Saeki, Toshifumi
出版情報: Fauna Ryukyuana.  60  pp.1-2,  2021-06-09.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/48545
概要: The record of Shinobium trapezoideum from Iriomote Island was previously based only on unpublished information. The presence of a voucher specimen with previously unpublished information, deposited in the Ryukyu University Museum, Fujukan (RUMF), is here documented. 続きを見る
3.

論文(リポジトリ)

論文(リポジトリ)
戸篠, 祥 ; 谷本, 都 ; Toshino, Sho ; Tanimoto, Miyako
出版情報: Fauna Ryukyuana.  60  pp.3-7,  2021-06-09.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/48546
概要: 立方クラゲ綱の一種ミツデリッポウクラゲTripedalia cystophora Conant, 1897が沖縄島から採集された. 本種はカリブ海や南米, アフリカ, 東南アジア, オーストラリア, ハワイの亜熱帯や熱帯の浅海域に生息し, 日本では紀伊半島沿岸や九州東岸から報告がある. 本報告はミツデリッポウクラゲの琉球列島からの初記録となる.<br />A cubozoan jellyfish, Tripedalia cystophora, was collected from the Ryukyu Archipelago, Okinawa Prefecture, southern Japan. Tripedalia cystophora is widely distributed throughout subtropical and tropical waters in the Pacific and Atlantic oceans. This species has been reported from the coast of Kii Peninsula and eastern Kyushu in Japan. This study represents the first record of this species from the Ryukyu Archipelago, Okinawa, southern Japan. 続きを見る
4.

論文(リポジトリ)

論文(リポジトリ)
下瀬, 環 ; 今井, 秀行 ; Shimose, Tamaki ; Imai, Hideyuki
出版情報: Fauna Ryukyuana.  60  pp.9-15,  2021-06-09.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/48547
概要: 八重山諸島の石垣島で, 2018年12月16日にゴマサバScomber australasicusの成魚が水揚げされた. ゴマサバは沖縄島から記録があるものの, 八重山諸島からは初記録であるため, ここに報告する. また, サバ属Scomb erとグルクマ属RastrelligerからなるScombriniの臀鰭棘数を観察したところ, 近年普及している図鑑での数値と異なる結果が得られたので, これについても考察した.<br />A single adult specimen of Scomber australasicus was collected from Ishigaki-jima Island, Okinawa, Japan, on 16 December 2018, which represents the first specimen-based record from the Yaeyama Islands. In this paper, the number of anal-fin spines in the tribe Scombrini is also discussed. 続きを見る
5.

論文(リポジトリ)

論文(リポジトリ)
中島, 淳 ; 鹿野, 雄一 ; Nakajima, Jun ; Kano, Yuichi
出版情報: Fauna Ryukyuana.  60  pp.17-20,  2021-06-09.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/48548
概要: 2014年に石垣島においてタイワンコオイムシ1個体を採集した. これは石垣島初記録であると同時に, 国内からの56年ぶりの再発見となる. その形態的特徴を報告するとともに, 本標本の3Dモデルを作成して公開した.<br />We collected a single specimen of Diplonychus rusticus (Fabricius, 1781) from Ishigaki-jima Island, Okinawa Prefecture, Japan, in 2014. This is the first record from Ishigaki-jima Island, and the first rediscovery from Japan in 56 years. The morphological features of the specimen are described, and a 3-D model of the specimen has been made public online. 続きを見る
6.

論文(リポジトリ)

論文(リポジトリ)
河合, 上総 ; Kawai, Kazusa
出版情報: Fauna Ryukyuana.  60  pp.25-30,  2021-06-09.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/48565
概要: ヤエヤマサソリLiocheles australasiae (Fabricius, 1775)を中琉球に属する座間味島より記録したので, ここに報告する. 本種のこれまでの確実な国内分布は南琉球のみであったが, 今回中琉球での生息を確認した . 今回採取したのは生体1個体と脱皮殻1個体で, 双方共メスであった.<br />The confirmed distribution of Liocheles australasiae (Fabricius 1775)(Scorpiones: Hormuridae) in Japan has been limited to the southern Ryukyus, but this study confirmed that L. australasiae inhabits Zamami-jima Island, central Ryukyus, Japan. A live individual and an exuvia collected were both female. 続きを見る
7.

論文(リポジトリ)

論文(リポジトリ)
上野, 大輔 ; 伊勢戸, 徹 ; Uyeno, Daisuke ; Iseto, Tohru
出版情報: Fauna Ryukyuana.  60  pp.25-30,  2021-06-09.  Ryukyu University Museum, Fujukan — 琉球大学資料館 (風樹館)
URL: http://hdl.handle.net/20.500.12000/48566
概要: 沖縄県宮城島の沿岸にて採集されたオオイワガニGrapsus tenuicrustatus (Herbst, 1783) (イワガニ科) の鰓室から, 寄生性等脚類の1種カニヤドリエビヤドリムシKepon grapsi (Nobili, 19 05) (エビヤドリムシ科) の雌成体が発見されたので報告する. 本報告は, 本種の沖縄県初記録であり, 本邦沿岸からは2例目の報告となる. また, 今までに琉球列島より報告されているエビヤドリムシ科の記録についても取り纏めた.<br />The bopyrid isopod, Kepon grapsi (Nobili, 1905), is recorded based on an adult female specimen from the branchial chamber of the common intertidal shore crab, Grapsus tenuicrustatus (Herbst, 1783) (Grapsidae), collected from Ukun Beach, Miyagi Island, Okinawa Islands, southern Japan. This discovery represents the first record of K. grapsi from Okinawa Prefecture. A list of bopyrid species recorded from the Ryukyu Islands is also provided. 続きを見る
8.

論文(リポジトリ)

論文(リポジトリ)
Huang, Yongyi ; Yona, Atsushi ; Takahashi, Hiroshi ; Hemeida, Ashraf Mohamed ; Mandal, Paras ; Mikhaylov, Alexey ; Senjyu, Tomonobu ; Lotfy, Mohammed Elsayed
出版情報: Sustainability.  13  2021-05-30.  MDPI
URL: http://hdl.handle.net/20.500.12000/48787
概要: Electric vehicle charging station have become an urgent need in many communities around the world, due to the increase of using electric vehicles over conventional vehicles. In addition, establishment of charging stations, and the grid impact of household photovoltaic power generation would reduce the feed-in tariff. These two factors are considered to propose setting up charging stations at convenience stores, which would enable the electric energy to be shared between locations. Charging stations could collect excess photovoltaic energy from homes and market it to electric vehicles. This article examines vehicle travel time, basic household energy demand, and the electricity consumption status of Okinawa city as a whole to model the operation of an electric vehicle charging station for a year. The entire program is optimized using MATLAB mixed integer linear programming (MILP) toolbox. The findings demonstrate that a profit could be achieved under the principle of ensuring the charging station’s stable service. Household photovoltaic power generation and electric vehicles are highly dependent on energy sharing between regions. The convenience store charging station service strategy suggested gives a solution to the future issues. 続きを見る
9.

論文(リポジトリ)

論文(リポジトリ)
Mochida, Keiji ; Nonaka, Daisuke ; Wamulume, Jason ; Kobayashi, Jun
出版情報: International Journal of Environmental Research and Public Health.  18  2021-05-21.  MDPI
URL: http://hdl.handle.net/20.500.12000/48707
概要: Child mortality due to malaria and diarrhea can be reduced if proper treatment is received timely at healthcare facilities, but various factors hinder this. The present study assessed the associations between the use of public healthcare facilities among febrile/diarrheal children in rural Zambia and supply-side factors (i.e., the distance from the village to the nearest facility and the availability of essential human resources and medical equipment at the facility). Data from the Demographic and Health Survey 2018 and the Health Facility Census 2017 were linked. Generalized linear mixed models were used to assess the associations, controlling for clustering and other variables. The median distances to the nearest facility were 4.5 km among 854 febrile children and 4.6 km among 813 diarrheal children. Children who were over 10 km away from the facility were significantly less likely to use it, compared to those within 5 km (fever group: odds ratio (OR) = 0.36, 95% confidence interval (CI) = 0.20–0.66; diarrhea group: OR = 0.30, 95% CI = 0.18–0.51). The availability of human resources and equipment was, however, not significantly associated with facility use. Poor geographic access could be a critical barrier to facility use among children in rural Zambia. 続きを見る
10.

論文(リポジトリ)

論文(リポジトリ)
Huang, Yongyi ; Masrur, Hasan ; Shigenobu, Ryuto ; Hemeida, Ashraf Mohamed ; Mikhaylov, Alexey ; Senjyu, Tomonobu
出版情報: Energies.  14  2021-05-21.  MDPI
URL: http://hdl.handle.net/20.500.12000/48765
概要: This article proposes a plan to replace real-time power with constant power from the grid to reduce costs and reduce the impact of the micro-grid on the main grid at the same time. Most of the peak electricity consumption periods of universities or some enterprise institutions are during the daytime. If solar energy can be used reasonably at this time, it can provide a good guarantee of peak power. In this study, a grid-linked solar-plus-storage micro-grid was used to supply power to a university located in Okinawa, Japan. The non-dominated sorting genetic algorithm II (NSGA-II) was used to optimize the model size, and the loss of power supply probability (LPSP), life cycle cost (LCC), and waste of energy (WE) were taken as the optimization indicators. For this study, three scenarios were considered where the first scheme (Case 1) was a comparison scheme, which used a PV battery and real-time power from the infinity bus. Both the second and third cases used constant power. While Case 2 used constant power throughout the year, Case 3 used daily constant power. The optimal solutions for the power supply units were grouped into three cases where Case 1 was found to be the most expensive one. It was found that the costs of Cases 2 and 3 were 62.8% and 63.3% less than Case 1. As a result, the waste of energy was found to be more significant than Case 1: 70 times and 60 times, respectively. On the contrary, Case 1 had 15.2% and 16.7% less carbon emissions than Case 2 and Case 3, respectively. This article put forward the idea of constant power supply growth at the financial markets, which breaks the traditional way in which the power supply side follows the user’s consumption. While reducing costs, it reduces the impact on large-scale power grids and can also ensure the reliability of campus microgrids. 続きを見る