429 research outputs found

    ヒョウショウ タンサ レーダー ノ カイハツ オヨビ ゲンチ デノ ウンヨウ ジョウキョウ

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    南極大陸は基盤上の厚く広大な氷に象徴される大陸である.南極における種々の科学調査で氷床の厚さの把握が必要となるほか,地球上の大気-海洋-氷床システムの水循環・固定のメカニズムを考える上で,氷床の存在や消長にかかわる内部物理メカニズムの理解は欠かせない.国立極地研究所では,氷床探査を目的とした多種類のレーダーを長い間使用してきた.本報告では,ドームふじでの氷床深層掘削が本格化した1990年代以降を振り返り,この間の氷床探査レーダーの開発状況,仕様や,運用状況,主たる成果について記述する.特に,探査目的に応じて使用周波数を多周波とし,さらには電磁波の偏波面に依存する情報の活用を進めてきたことについて解説をする.また,近年は電力のみではなく位相情報の検知もできるレーダーの運用を開始したことについても述べる.将来の氷床探査での発展的な活用をにらみ,現状を説明する資料の提示を目的とする.Antarctica is a continent characterized by the huge ice mass above the bedrock. Better understanding the internal physical mechanism for existence and changes is essential to study how ice is fixed on the continent in water cycles in the atmosphere-ocean-ice system on the earth. The National Institute of Polar Research, Tokyo, has a long history of using ice sounding radar to study the ice sheet. This paper gives a brief history of the development, specifications, observations and major results. In particular, it explains the use of multiple frequencies and polarization planes. This paper also comments on the recent use of phase information in addition to power information. I hope that this document will be useful for future use of the radar

    Spatiotemporal variability of surface mass balance along the JARE traverse route for 1992-2018

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    The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

    The distribution and number of Leu-7 (CD57) positive cells in lung tissue from patients with pulmonary fibrosis.

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    Leu-7 positive lymphocytes, including natural killer cells, play an important role in the immune system's surveillance function to prevent the development of cancer. The incidence of lung cancer is significantly high in patients with end-stage pulmonary fibrosis. We hypothesized that the number of Leu-7 positive cells may be decreased in areas of severe pulmonary fibrosis. To demonstrate this, Leu-7 positive cells were immunohistochemically stained in 41 lung specimens obtained from patients with idiopathic pulmonary fibrosis and pulmonary fibrosis associated with collagen vascular disorders. The number of Leu-7 positive cells was evaluated according to the pathological findings. In pathologically normal lung, Leu-7 positive cells were mostly found within the capillaries of the septa and rarely in the alveolar space or the stroma. The number of Leu-7 positive cells was 0.69 +/- 0.15 in areas of advanced fibrosis (n = 41), 2.39 +/- 0.60 in areas that had newly developeing fibrosis (n = 41), 1.14 +/- 0.57 in bronchiolitis obliterans organizing pneumonia (n = 9), and 1.35 +/- 0.87 in diffuse alveolar damage (DAD) (n = 11). The number of Leu-7 positive cells in areas of newly developing fibrosis (2.39 +/- 0.60) was significantly higher than that in areas of established fibrosis (0.69 +/- 0.15, P &#60; 0.05). Our present study demonstrates a significant decrease in the number of Leu-7 positive cells in areas of advanced fibrosis. This evidence may partly explain the high incidence of lung cancer associated with pulmonary fibrosis.</p

    Turbine Characteristics of Wave Energy Conversion Device for Extraction Power Using Breaking Waves

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    A new type of wave energy converter which harnesses electricity from onshore breaking waves has been studied at Okinawa Institute of Science and Technology Graduate University (OIST) since 2014. This concept has been demonstrated at a coral beach on the Maldives since 2018. Wave energy conversion is possible when waves approaching the shore steepen due to decreased water depth resulting in wave breaks near the surface. A steepened wave reaches the critical velocity of 4~6 m/sec shoreward before it breaks. A rotating blade takes advantage of this breaking phenomenon to convert the wave energy into electricity. The work presented here includes an experimental and numerical investigation of a prototype model of the wave energy converter. The turbine having five blades of variable chord lengths, twist angles, and constant thickness profile from hub to tip was simulated under similar flow as well as testing conditions, to predict the turbine performance. A commercial computational fluid dynamic tool SolidWorks Flow Simulation 2018 was used for the simulations at various rotation speeds with a uniform inlet velocity. The modified k-ε with a two-scale wall function turbulence closure model was selected. The validation performed for different test cases showed that the present computational results match in good agreement with the experimental results. Additionally, details performance of the turbine running, and generator characteristics have been reported in this paper

    Asymmetrical membrane fluidity of bovine adrenal chromaffin cells and granules and effect of trichosporin-B-VIa

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    AbstractWe examined membrane fluidity of bovine adrenal chromaffin cells and chromaffin granules using cationic trimethylammonium derivative of diphenylhexatriene (TMA-DPH) as a fluorescence probe. After adding TMA-DPH to the suspension of chromaffin cells and that of granules, it first bound to the outer layer of the plasma membrane of the cells and that of the granule membrane, then gradually penetrated the inner layer of each membrane and distributed to both leaflets of the respective membranes. Accompanying increases in the ratio of incorporated probe on the cytoplasmic side of the chromaffin cell membrane, its fluorescence anisotropy gradually decreased. However, in chromaffin granules, the fluorescence anisotropy gradually increased with increases in the ratio of incorporated probe. These findings suggest that the inner layer of the plasma membrane and outer layer of the granular membrane are more fluid than the corresponding side of each membrane, which is suitable for the fusion between both membranes. We also examined the effect of trichosporin-B-VIa, a fungal ion channel forming α-aminoisobutyric acid-containing peptide, on the fluidity of chromaffin cells using TMA-DPH. The peptide decreased the fluorescence anisotropy and increased the fluorescence intensity in the concentration range that induced Ca2+ dependent catecholamine secretion, suggesting that a change in lipid dynamics of the lipid bilayer of the plasma membrane was induced by this peptide
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