Search Results 1-20 of 698

  • Reconstruction of radiocesium levels in sediment off Fukushima: Simulation analysis of bioavailability using parameters derived from observed 137Cs concentrations

    青山 道夫 , Yutaka Tateda , Kazuhiro Misumi , Daisuke Tsumune , Michio AOYAMA , Yasunori Hamajima , Jota Kanda , Takashi Ishimaru , Tatsuo Aono

    … Since the radiocesium in the sediment off Fukushima was suggested as a possible source for the transfer of this radionuclide through the benthic food chain, we conducted numerical simulations of 137Cs in sediments off the Fukushima coast by using a model which incorporates dynamic transfer processes between seawater and the labile and refractory fractions in sediment particles. …

    Journal of environmental radioactivity (214-215), 106172, 2020-04

    IR 

  • Evaluation of a Linear Model considering the Influence of Fine Bubbles for Measuring Suspended Sediment Concentration and Particle Size Distribution by Ultrasonic Waves  [in Japanese]

    古川 仁志 , 奥村 裕史 , 田井 秀一 , 小林 力

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 119(374), 119-124, 2020-01-22

  • A New Species of <i>Semicytherura</i> (Crustacea: Ostracoda: Cytheroidea) from Obitsu River Estuary (Central Japan) and Its Microhabitat

    Nakao Yuriko , Tsukagoshi Akira

    … nov. individuals were collected from muddy sand bottoms in tidal creeks, possess some carapace-features comparable to those of interstitial and infaunal ostracods, and were observed to crawl in detritus rich fine-grained sediment in the laboratory, we concluded that this new species is an infaunal species.</p> …

    Species Diversity 25(1), 1-9, 2020

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  • Habitat changes and population dynamics of fishes in a stream with forest floor degradation due to deer overconsumption in its catchment area

    Nakagawa Hikaru

    … Mass consumption of forest floor vegetation by deer creates denuded slopes and increases sediment inputs into adjacent rivers. … During my 11 years of observation, characteristics of stream habitats changed from a predominantly coarse substrate to a fine substrate. …

    Conservation Science and Practice 1(8), 2019-08

    IR 

  • SEDIMENT TRANSPORTATION AND SAND BAR DEFORMATION OWING TO TIDAL CURRENTS IN SITTAUNG RIVER ESTUARY, MYANMAR

    AHMED T. S. , EGASHIRA S. , HARADA D. , YOROZUYA A.

    水工学論文集 Annual journal of Hydraulic Engineering, JSCE 64, I_1027-1032, 2019

  • EROSION RATE OF BED SEDIMENT BY MEANS OF ENTRAINMENT VELOCITY  [in Japanese]

    原田 大輔 , 江頭 進治 , AHMED T. S. , 片山 直哉

    水工学論文集 Annual journal of Hydraulic Engineering, JSCE 64, I_967-972, 2019

  • STUDY ON INFLUENCE OF ROADS ON DEBRIS FLOWS OCCURRED DUE TO 2018 JULY HEAVY RAIN  [in Japanese]

    NAKATANI Kana , HASEGAWA Yuji , KASAHARA Takuzo , KAIBORI Masahiro , SATOFUKA Yoshifumi

    <p> 平成30年7月豪雨では西日本各地で土砂災害が多発し,山裾まで開発が進んだ扇状地の住宅地で発生した土石流により人的・物的被害が生じた.山間部では,谷出口から延びる渓流や流路が扇状地の直上で暗渠化されることが多い.平成30年7月豪雨により兵庫県神戸市や広島県広島市の住宅地で発生した土石流では,暗渠が土砂等で閉塞したことで,暗渠が接続した道路上を土砂・水が移動して,住宅地に広く被害を …

    Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) 75(1), 403-413, 2019

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  • Damage characteristics of debris flow disasters caused by heavy rain in Hiroshima City in August 2014  [in Japanese]

    UCHIYAMA Shoichiro , SUGAI Toshihiko

    2014(平成26)年8月20日に広島県広島市で発生した土石流災害について,無人航空機(UAV)撮影とSfM写真測量により土砂堆積量を計測し,地質による被害特性の差異を明らかにした。 人的被害は,谷出口から平均132mの範囲で発生し,これは建物被害域よりも小さかった。建物被害域は,ホルンフェルス地域よりも花崗岩地域のほうが範囲が大きかった。また,ホルンフェルス地域では,建物が土石流を停止させる働き …

    Journal of Japan Society for Natural Disaster Science 38(S06), 57-79, 2019

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  • Influx and distribution of submerged aquatic plants in Lake Biwa Canal water system  [in Japanese]

    Kimisato ODA , Katsue FUKAMACHI , Shozo SHIBATA

    <p>琵琶湖疏水は,2015 年に重要文化的景観の選定を受けた岡崎地域を代表する都市水系である。重要な水生生態系として琵琶湖疏水をとらえ,これらの基盤となる沈水植物の流入と分布を調査した。琵琶湖疏水内の85 区画で調査を行い,この調査では11 種の流入および8 種の沈水植物が確認された。被度と底質の分布を用いてnMDS による分析を行ったところ,疏水分線では泥底質とオオカナダモが,疏水 …

    Journal of the Japanese Society of Revegetation Technology 45(1), 51-56, 2019

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  • Hjulström's Diagram: Understanding the Formation of Detritus Sediment Strata Associated with Stream Water  [in Japanese]

    HIROKI Yoshihisa

    <p>流水による砕屑物からなる地層の形成を理解する上で非常に重要なユールストロームダイアグラムを解説した.ユールストロームダイアグラムは今から約80年前の1939年に発表されたダイアグラムであるが,水中における砕屑物の堆積を理解するのに,今でも有効である.このダイアグラムは堆積や侵食が起こるときの流速と堆積物の粒径との関係を示している.地層は流速が変化する中で,異なる粒径の粒子が堆積す …

    Education of Earth Science 71(3), 97-107, 2019

    J-STAGE 

  • Characteristics of Tosufloxacin crystals and crystal casts observed in urine sediment of infants  [in Japanese]

    NAGATA Katsuhiro , TANAKA Yoshi , MATSUMOTO Masami , HASHIMOTO Aya , YAMAGUCHI Fumina , NAKAGAWA Shizuyo , YANAIDA Yoshitame , IINUMA Yoshitsugu

    <p>トスフロキサシン(Tosufloxacin; TFLX)は,小児への適用を取得しているニューキノロン系抗菌薬である。我々は形態的にTFLX結晶と考えられた針状結晶について,その特徴を検討した。研究期間中,10例の小児例を経験し,その尿沈渣像は,褐色の細い針状結晶がウニ様または束状であった。また,針状結晶が入り込んだ結晶円柱を8例に認め,結晶円柱の多くは上皮円柱でもあった。円柱の多 …

    Japanese Journal of Medical Technology 68(4), 751-757, 2019

    J-STAGE  Ichushi Web 

  • CHARACTERISTICS OF SEDIMENT TRANSPORT IN SWASH ZONE ACCORDING TO GRANULARITY OF BOTTOM SEDIMENT  [in Japanese]

    OCHI Masashi , WADA Kyouka , MIYATAKE Makoto , SASSA Shinji

    <p> 著者らが過去に実施した画像計測法および漂砂移動可視化実験において,底質混合粒径の粒度分布を変化させた場合の適用性を検証した後,底質の粗粒化に伴う漂砂濃度や地下水変動の計測結果から,底質を構成する粒度分布が縦断地形変化へ及ぼす影響を評価した.その結果,画像解析による漂砂計測は,異なる粒度分布においても適用可能であることを確認した.また,漂砂移動可視化実験より,底質が粗配合の場合, …

    Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) 75(2), I_463-I_468, 2019

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  • A LABORATORY STUDY ON MIXED-SEDIMENT TRANSPORT DUE TO INUNDATION FLOW  [in Japanese]

    SUZUKI Takayuki , COX Daniel T.

    <p> アメリカ,オレゴン州立大学が有する小型アクリル水槽(長さ7m,幅15.5cm,高さ35cm)を用いて,波高4.7cmの押し波を作用させ,陸上遡上波による中砂,粗砂,細礫の混合率を変化させた混合砂の移動特性を把握する目的の実験を行った.本研究では,細礫(<i>d<sub>50</sub></i> = 4.05mm)の移動動態に着目し …

    Journal of Japan Society of Civil Engineers, Ser. B3 (Ocean Engineering) 75(2), I_337-I_342, 2019

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  • EXPERIMENTAL STUDY ON THE INFLUENCE OF SPATIAL VARIATION OF CLAY ON THE TOPOGRAPHY CONSISTING OF MIXED SOIL  [in Japanese]

    AKAHOSHI Rei , CHO Yong-hwan , WATANABE Mikiya , NAKAMURA Tomoaki , MIZUTANI Norimi

    <p> 干潟保全の重要な因子とされる細粒分の動的特性解明の一環として,砂粘土混合土から成る地形の変動に着目した水理模型実験を実施し,波浪条件と粘土含有率による混合土砂地形の変動特性と,粘土の空間分布が混合土砂の漂砂特性に与える影響を検討した.その結果,粘土を含む混合土砂では,地形形成過程において粘土の粘着力の影響により,地形変動を遅延させる効果があった.また,比較的高い粘土含有率条件下 …

    Journal of Japan Society of Civil Engineers, Ser. B3 (Ocean Engineering) 75(2), I_193-I_198, 2019

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  • Common occurrence of calcic plagioclase in granitoids from Mt. Kaizuki area, central Japan

    Hong Mei , ENAMI Masaki , TSUBOI Motohiro , ASAHARA Yoshihiro

    … <p>Calcic plagioclase with anorthite (An) content of up to 91% commonly occurs in coexistence with the sodic phase (An<sub><40–50</sub>) in the Cretaceous Kaizuki–yama (Mt. Kaizuki) granitoid body that intrudes into the Mino belt of the Jurassic accretionary sediment complex in central Japan. … The calcic parts rarely show fine and nebular texture with sodic domains; …

    Journal of Mineralogical and Petrological Sciences 114(4), 201-213, 2019

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  • Characteristics of Flood Flow with Active Sediment Transport in the Sozu River Flood Hazards at the Severe Rainfall Event in July 2018

    Harada Daisuke , Nagumo Naoko , Nakamura Yousuke , Egashira Shinji

    … <p>This study reveals the characteristics of flood flow with active sediment transport that caused the Sozu River flood disaster in July 2018. … The results of field surveys revealed that the basin contains steep mountains and flat areas, facilitating the rapid transport of sediment produced in the mountains to downstream areas during the disaster. … Two-dimensional numerical simulations of flood flow with sediment transport are conducted to realize the flood flow characteristics. …

    Journal of Disaster Research 14(6), 886-893, 2019

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  • Retentive primary Sr isotopic ratio of source rock to sediment and sedimentary rock through multistage sedimentary cycles: Case study of stream sediments in Awajishima Island  [in Japanese]

    Ohta Atsuyuki , Minami Masayo

    … Twenty-three fine stream sediments (<180 μm) in Awajishima Island were used for the study. … Stream sediment is presumed to consist of clastics supplied from respective lithologies according to their exposed areas. … However, <sup>87</sup>Sr/<sup>86</sup>Sr of stream sediment is not comparable to the values calculated from exposed areas of lithologies and isotopic data of parent rocks. …

    Chikyukagaku 53(2), 59-70, 2019

    J-STAGE 

  • Sediment Toxicity Testing with the Amphipod <i>Grandidierella Japonica</i> and Effects of Sediment Particle Size Distribution

    Hiki Kyoshiro , Nakajima Fumiyuki , Tobino Tomohiro , Wei Nan

    … is an organism well-suited to sediment toxicity testing in Japan, where no other sentinel amphipod species are found. … in Japan, we performed 10-day whole sediment toxicity tests of six estuarine sediment samples collected from estuaries and tidal rivers flowing into Tokyo Bay. …

    Journal of Water and Environment Technology 17(2), 117-129, 2019

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  • Study on Behavior of Turbid Water around Dredged Navigation Channel at River Mouth  [in Japanese]

    NAKAGAWA Yasuyuki

    … <p>Field measurements were carried out in the port of Niigata to elucidate sediment transport processes around navigation channel and turning basin in the port at river mouth. … The measurements include salinity, suspended sediment concentration and in-situ mud density at several monitoring points along the navigation channel in the port. …

    JAPANESE JOURNAL OF MULTIPHASE FLOW 33(1), 12-19, 2019

    J-STAGE 

  • Spatial distribution of hydrogen sulfide and sulfur species in coastal marine sediments Hiroshima Bay, Japan

    Asaoka Satoshi , Umehara Akira , Otani Sosuke , Fujii Naoki , Okuda Tetsuji , Nakai Satoshi , Nishijima Wataru , Takeuchi Koji , Shibata Hiroshi , Jadoon Waqar Azeem , Hayakawa Shinjiro

    Marine Pollution Bulletin (133), 891-899, 2018-08

    IR 

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