231 research outputs found

    Isotopic fractionation of water during snow formation: Experimental evidence of kinetic effect

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    Deuterium excess(d-excess=δD-8・δ^(18)O), which is calculated using two water isotope ratios(δD and δ^(18)O), is an indicator of kinetic isotope fractionation. The d-excess value reflects the evaporation process from the ocean or ice-crystal growth. Consequently, d-excess records preserved in ice cores may provide a climatic history of ocean surface conditions at the vapor source area. J. Jouzel and L. Merlivat(J. Geophys. Res., 89, 11749, 1984) proposed an isotope model to analyze information from ice cores. That model includes kinetic fractionation during snow formation, depending on the degree of the supersaturation ratio of vapor. However, no experiment was conducted under the controlled supersaturation ratio. Experiments described herein measured the isotopic ratios of the vapor and artificial snow produced under a controlled supersaturation ratio to confirm the kinetic isotope effect experimentally. Results indicate a higher d-excess value for ice crystals at a higher vapor supersaturation ratio and provide experimental evidence for the kinetic effect during snow formation

    A comparison of dust concentration with high resolution analysis and visible strata in the Holocene and Last Glacial Maximum periods from the Dome Fuji ice core, East Antarctica

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    第3回極域科学シンポジウム 横断セッション「海・陸・氷床から探る後期新生代の南極寒冷圏環境変動」11月26日(月)、27日(火) 2階ラウン

    Climatic and atmospheric histories over the past 700,000 years from the Dome Fuji deep ice core, Antarctica

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    第3回極域科学シンポジウム 横断セッション「海・陸・氷床から探る後期新生代の南極寒冷圏環境変動」11月26日(月) 国立国語研究所 2階講

    Ice Core Records of Antarctic Warming Events in the Last Glacial Period

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    第3回極域科学シンポジウム 横断セッション「海・陸・氷床から探る後期新生代の南極寒冷圏環境変動」11月26日(月) 国立国語研究所 2階講

    General tendencies of stable isotopes and major chemical constituents of the Dome Fuji deep ice core (scientific paper)

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    Stable isotope compositions of water and major chemical constituents of the Dome Fuji ice core are analyzed and the data sets over the entire depth of the 2503-m core are presented in appropriate time resolution as consecutive series of average value in definite terms. These results based on the first stage analyses allow a temporal climatic dividing of the three glacial-interglacial cycles present in the records. A Comparison of the climatic and environmental characteristics of these climate stages is presented

    Evidence for a Two-stage Melting Transition of the Vortex Matter in Bi2Sr2Ca1Cu2O8+d Single Crystals obtained by Muon Spin Rotation

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    From muon spin rotation measurements on under- to overdoped Bi-2212 crystals we obtain evidence for a two-stage transition of the vortex matter as a function of temperature. The first transition is well known and related to the irreversibility line (IL). The second one is located below the IL and has not been previously observed. It occurs for all three sets of crystals and is unrelated to the vortex mobility. Our data are consistent with a two-stage melting scenario where the intra-planar melting of the vortex lattice and the inter-planar decoupling of the vortex lines occur independently.Comment: 9 pages and 3 figure

    Double primary malignancies associated with colon cancer in patients with situs inversus totalis: two case reports

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    Situs inversus totalis (SIT) is not itself a premalignant condition, however, rare synchronous or metachronous multiple primary malignancies have been reported. Herein we present a case of synchronous transverse and sigmoid colon cancers and a case of metachronous rectosigmoid colon and gastric cancers in patients with SIT

    A Case of Left Atrial Metastasis From Hepatocellular Carcinoma: Life-Saving Palliative Resection Using Cardiopulmonary Bypass

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    Hepatocellular carcinoma (HCC) with metastasis to the heart is uncommon. We report a rare case of left atrial metastasis of HCC which was resected palliatively as a live-saving procedure with the use of cardiopulmonary bypass. Despite chemoembolization, which was undertaken 11 times, cardiac metastasis occurred. Moreover, the right and left atria and left ventricle were involved simultaneously. The severe dyspnea improved dramatically after surgery. Following this, the patient underwent systemic chemotherapy and lived a life without recurrence of symptoms associated with mitral valve obstruction
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