Search Results 1-20 of 618

  • Influence of Deposition of Atmospheric Nitrogen Compounds to the Surface Chlorophyll-a Concentration over Japan Sea  [in Japanese]

    TAKETANI Fumikazu , AITA Maki N. , SEKIYA Takashi , YAMAJI Kazuyo , IKEDA Kohei , MATSUMOTO Kazuhiko , HONDA Makio C. , KANAYA Yugo

    … <p>The sensitivity of ocean phytoplankton (chlorophyll-a concentration) to deposition of atmospheric inorganic nitrogen compounds over Japan Sea was investigated using a 3-D lower trophic-marine ecosystem model (COCO-NEMURO) combined with an atmospheric regional chemical transport model (WRF-CMAQ). … The monthly mean values for the wet and dry deposition of inorganic nitrogen compounds including gases (HNO<sub>3</sub> …

    Earozoru Kenkyu 36(1), 46-54, 2021


  • Nitrous Oxide Emissions from a Sugarcane Field with Green Manure and Chemical Fertilizer Applications in Okinawa, Japan

    MAEDA Tabito , SUGIHARA Soh , NISHIGAKI Tomohiro , MIYAMARU Naoko , YOSHIDA Koichi , YAMAMOTO Akinori , TOYOTA Koki , TANAKA Haruo

    … <p>The objective of this study was to evaluate N<sub>2</sub>O emissions during the first three months after different nitrogen (N) source treatments involving green manure and chemical fertilizer in a sugarcane field in Okinawa, Japan. … We regularly measured N<sub>2</sub>O flux and soil inorganic N (NH<sub>4</sub><sup>+</sup>-N and NO₃<sup>−</sup>-N), and also recorded environmental data. …

    Japan Agricultural Research Quarterly: JARQ 55(1), 17-27, 2021


  • Recent advances in the understanding of ecosystem processes at eddy covariance CO<SUB>2</SUB> flux sites in East Asian forest ecosystems: a review

    Shih-Chieh CHANG , Taku M. SAITOH , SHIBATA Hideaki , Satoshi N. SUZUKI

    flux sites in East Asia to clarify these ecosystem processes and attributes. … Since the establishment of AsiaFlux in 1999, the number of flux tower sites has grown to 110 sites, spanning a large geographic extent in East Asia and covering diverse ecosystems embedded in large climatic gradients. …

    Journal of Agricultural Meteorology 77(1), 52-65, 2021


  • Molecular dynamics simulation of amine groups formation during plasma processing of polystyrene surfaces

    Michlíček Miroslav , Hamaguchi Satoshi , Zajíčková Lenka

    … To model favorable conditions for the incorporation of primary amine groups, we assumed the plasma treatment as the flux of NH2 radicals and energetic NH3 ions, and the plasma polymerization as the flux of cyclopropylamine molecules and energetic argon ions. … It is shown in both the simulation and the experiment that the polystyrene treatment by the bipolar pulsed N2/H2 plasmas with an applied voltage of about ±1 kV formed a nitrogen-rich layer of a thickness of only a few nm. …

    Plasma Sources Science and Technology 29(10), 105020, 2020-10-30


  • Dissolved and Particulate Organic Matter Dynamics Relative to Sediment Resuspension Induced by the Tidal Cycle in Macrotidal Estuaries, Kyushu, Japan

    Takasu Hiroyuki , Uchino Koji , Mori Koichiro

    … Although dissolved organic carbon (DOC) comprises more than half of the riverine flux of organic carbon to the ocean, the influence of sediment resuspension induced by the tidal cycle on DOC dynamics is largely unknown. … This study examined the dynamics of POC, particulate organic nitrogen (PON), DOC, humic-like and protein-like fluorescent dissolved organic matter (DOM) in relation to the tidal cycle in the Chikugo and Hayatsue River Estuaries, Kyushu, Japan. …

    Water 12(9), 2561, 2020-09-13


  • Effect of low C/N crop residue input on N2O, NO, and CH4 fluxes from Andosol and Fluvisol fields

    秋山 博子 , 山本 昭範 , 内田 義崇 , 星野 裕子 , 多胡 香奈子 , 王 勇 , 早津 雅仁

    … We investigated N2O, NO, and CH4 fluxes after low C/N crop residue (cabbages and potatoes) inputs to lysimeter fields for two years using with automated flux monitoring system. … Nitrogen application rates were 250 kg N ha−1 of synthetic fertilizer and 272 kg N ha−1 of cow manure compost for cabbage, and 120 kg N ha−1 of synthetic fertilizer and 136 kg N ha−1 of cow manure compost for potato, respectively. …

    Science of The Total Environment = Science of The Total Environment (713), 136677, 2020-04-15


  • Nanowire crystals of tantalum nitride grown in ammonium halide fluxes at high pressures

    Gaida Nico Alexander , Sasaki Takuya , Liu Zheng , Niwa Ken , Hirozawa Masaki , Ohsuna Tetsu , Hasegawa Masashi

    … Scanning TEM–EDX elemental analyses showed that the nanowire crystals were composed of tantalum and nitrogen with small amounts of oxygen. … The presence of the melted ammonium halides combined with supercritical ammonia acting as a reactive flux at high pressure and temperature played a significant role in the nanowire crystal growth. …

    Applied Physics Letters 116(12), 123102, 2020-03-24


  • Dry deposition flux of atmospheric nitrogen into the Kuroshio region  [in Japanese]

    Iwamoto Yoko , Kamezaki Kazuki , Hattori Shohei , Miura Kazuhiko , Uematsu Mitsuo

    <p>黒潮域の基礎生産におよぼす大気起源窒素の影響を調査するため、2015年秋季の黒潮域において採取した大気試料中の無機態窒素成分の濃度から、同海域への大気起源窒素の乾性沈着フラックスを推定した。大気エアロゾル中で、硝酸は主に粗大粒子、アンモニウムは主に微小粒子として存在し、アジア大陸からの気塊が到達した期間に高い濃度が観測された。エアロゾルの乾性沈着による窒素沈着フラックスは、平均で …

    Abstracts of Annual Meeting of the Geochemical Society of Japan 67(0), 11, 2020


  • Evaluation of Stabilized Si Double-crystal Monochromator with Liquid-nitrogen Cooling System and High Flux KB Focusing Mirror Optics  [in Japanese]

    Yumoto Hirokatsu , Yamazaki Hiroshi , Takeuchi Tomoyuki , Koyama Takahisa , Suzuki Motohiro , Kawamura Naomi , Mizumaki Masaichiro , Ohashi Haruhiko

    従来と比較して 100 nm × 100 nm あたり20倍の集光フォトン数が期待できる KB 配置型ミラー集光光学系を構築した。本光学系は垂直方向に関して光源の直接縮小投影を用いるため、不安定性の原因となりえる光路中の液体窒素冷却シリコン二結晶分光器について、熱的安定性に寄与する機器を改良した。高真空型集光ミラー姿勢調整装置を BL39XU 第2実験ハッチに導入し、集光性能を評価した。結果、2. …

    SPring-8/SACLA Research Report 8(1), 167-171, 2020



    OTANI Sosuke , YASHIKI Tomoya , UEMURA Kenta , TOKUDA Kunihiro , FUJISHIMA Kohei , ENDO Toru

    <p> 本研究では大阪市を流れる淀川河口に位置する泥質干潟において小潮と大潮時に24時間の連続調査を行い,水質の時間変動や流入,流出による物質収支を定量化するとともに,対象干潟の優占種であるヤマトシジミの物質収支への寄与を明らかにすることを目的とした.本干潟の形態別の炭素・窒素・リン濃度の経時変化より,炭素とリンは溶存無機態の割合が高く,窒素は懸濁態の割合が高い特徴があり,本干潟はTN …

    Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) 76(2), I_925-I_930, 2020


  • Active control of coaxial jet flames under different fuel compositions through manipulation of mixing process with miniature jet actuators

    SAIKI Yu , KURODA Masahiro , NAKURA Kasumi , ISHINO Yojiro

    … In the present study, methane (CH<sub>4</sub>) is diluted by nitrogen (N<sub>2</sub>) or carbon dioxide (CO<sub>2</sub>) with various dilution rates to mimic biogas with different ratios of combustible and non-combustible components. … of the miniature jets even for the different fuel dilution rates, which affect the momentum flux ratio of the coaxial jet. …

    Journal of Thermal Science and Technology 15(1), JTST0011-JTST0011, 2020


  • Experimental and theoretical discussion on step-out characteristics of high temperature superconducting induction/synchronous motor

    Nakamura T. , Sekiguchi D.

    31st International Symposium on Superconductivity (ISS2018) 12–14 December 2018, Tsukuba, Ibaraki, Japan

    Journal of Physics: Conference Series (1293), 2019-10-15


  • Enhancement of Saturated Boiling Heat Transfer by Using Coated Surfaces  [in Japanese]

    OHKUBO Hidetoshi , HIROTANI Toshiki , MOROKUMA Takayuki , AGUI Haruka

    <p>本研究では, 大気圧下での飽和液体窒素へのプール沸騰熱伝達に及ぼす表面被覆層の影響を実験的に検討した.被冷却物体として,直径25 mm の銅球を用いた.銅球表面の被覆層として,氷層および霜層を用い,これらの厚さを変化させた.得られた結果として,冷却曲線と沸騰熱伝達特性に対する氷層の影響が顕著であることが確認できた.また,霜層を被覆層として用いた場合,遷移沸騰領域の熱流束が著しく増 …

    Transactions of the Japan Society of Refrigerating and Air Conditioning Engineers 36(4), 283, 2019


  • Continuous Combustion Behaviors of Aluminum-Oxygen-Nitrogen Gas-Solid TwoPhase Flow  [in Japanese]

    Seki Shoma , Kobayashi Yoshinari , Takahashi Shuhei

    … A powder feeder was designed and developed, and the combustion behaviors of aluminum powder-oxygen-nitrogen solid-gas two-phase flow were investigated. … The radiative heat flux from a flame was increased due to the increased oxygen concentration, thereby extending the flame-propagation limit and then achieving the steady combustion at high flow rates.</p> …

    The Proceedings of the Thermal Engineering Conference 2019(0), 0185, 2019




    <p> 内湾底層の有機汚濁につながることが懸念されるカキ養殖から沈降する有機物の化学組成,起源,および酸素消費能を評価した.調査対象とした南三陸町志津川湾のカキ養殖場内では場外と比較し有機炭素沈降フラックスが平均8倍程度増加していた.養殖場内の沈降有機物は,酸素消費活性および藻類由来マーカー脂肪酸の割合がともに沈降有機物の潜在的起源であると考えられるカキ排泄物や付着物と比較し小さかった …

    Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research) 75(7), III_289-III_298, 2019


  • Enhancement of natural-convection boiling heat transfer by using frost layer  [in Japanese]

    MOROKUMA Takayuki , OHKUBO Hidetoshi , UTAKA Yoshio , HIROTANI Toshiki , SUGINO Taiyo

    … In this study, we investigated the influence of roughness and thermal conductance of a boiling surface on the pool boiling heat transfer to saturated liquid nitrogen at atmospheric pressure. … As a result, it is confirmed that the critical heat flux and the heat transfer coefficient of transition-nucleate boiling ware increase when the frost layer is used as the thermal resistance layer. …

    The Proceedings of the Symposium on Environmental Engineering 2019.29(0), J404, 2019


  • High-Power Amorphous Motor with Sm-Fe-N-based Bonded Magnet  [in Japanese]

    Deguchi Kenta , Enomoto Yuji , Tokoi Hirooki

    … <p>We have developed a high-efficiency (IE5 class), 11kW axial-flux permanent magnet motor (AFPM) with ferrite magnets and amorphous cores. … In particular, Sm-Fe-N (Samarium-Iron-Nitrogen) magnets are used in rotors to improve the torque. …

    IEEJ Transactions on Industry Applications 139(12), 1015-1021, 2019


  • Atmospheric deposition flux of inorganic nitrogen into the Eastern Indian Ocean during boreal autumn  [in Japanese]

    Iwamoto Yoko , Kawamoto Katsuhiro , Taketani Fumikazu , Kanaya Yugo , Noguchi―Aita Maki , Sekiya Takashi , Yamaji Kazuyo

    <p>南アジア地域の人為活動に起因する大気起源窒素化合物が海洋生態系に与える影響を理解するため、東部インド洋を対象とした学術研究船白鳳丸KH-18-6次航海において採取されたエアロゾルに含まれる窒素化合物を計測した。エアロゾル中の窒素化合物のうち、硝酸イオンは主に粗大粒子、アンモニウムイオンは主に微小粒子として存在し、ITCZの南北で明瞭な濃度差が観測された。ITCZの北側に当たるベン …

    Abstracts of Annual Meeting of the Geochemical Society of Japan 66(0), 71, 2019


  • Development of the Coal Co-Firing Technology with Ammonia and Numerical Evaluation of the Boiler Performance  [in Japanese]

    ITO Takamasa , ZHANG Juwei , ISHIHARA Sakiko , ISHII Hiroki , SUDA Toshiyuki , FUJIMORI Toshiro

    … Another is the inflection of the local heat flux on the boiler wall. … Ammonia was well decomposed into the nitrogen and hydrogen in such a strong reduction zone. … The second issue related to the heat flux on the boiler wall was discussed by the numerical analysis. …

    Journal of the Combustion Society of Japan 61(198), 304-308, 2019


  • Development of Superconducting RF Cavities toward Higher Performance  [in Japanese]

    UMEMORI Kensei

    … Recently, new technologies, so-called Nitrogen doping and Nitrogen infusion, have been proposed and an improvement in cavity performance was achieved. … Nitrogen doping realizes a drastic reduction in surface losses and has become the new standard for CW accelerators. … Nitrogen infusion is another attractive technology. …

    TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan) 54(4), 267-274, 2019


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