88 research outputs found

    Numerical study of air-entraining and submerged vortices in a pump sump

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    Numerical detection of harmful vortices in pump sumps, such as an air-entraining vortex (AEV) and a submerged vortex (SMV), is crucially important to develop the drain pump machinery. We performed numerical simulations of the benchmark experiments of the pump sump conducted by Matsui et al. (2006 and 2016) using the OpenFOAM and compared the simulation results with the experimental data considering the effects of turbulence model, grid density and detection method of the vortices. We studied the threshold of the gas-liquid volume fraction of the VOF method and the second invariant of velocity gradient tensor to identify AEV and SMV. The methods proposed in the present paper were found to be very effective for the detection of the vortices, and the simulation results by RANS with the SST k-omega model successfully reproduced the experimental data. LES with the Smagorinsky model, however, was sensitive to the grid system and difficult to reproduce the experimental data even for the finest grid system having 3.7 million cells in the present study

    Identification of in vivo Essential Genes of Vibrio vulnificus for Establishment of Wound Infection by Signature-Tagged Mutagenesis

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    Vibrio vulnificus can cause severe necrotic lesions within a short time. Recently, it has been reported that the numbers of wound infection cases in healthy hosts are increasing, for which surgical procedures are essential in many instances to eliminate the pathogen owing to its rapid proliferation. However, the mechanisms by which V. vulnificus can achieve wound infection in healthy hosts have not been elucidated. Here, we advance a systematic understanding of V. vulnificus wound infection through genome-wide identification of the relevant genes. Signature-tagged mutagenesis (STM) has been developed to identify functions required for the establishment of infection including colonization, rapid proliferation, and pathogenicity. Previously, STM had been regarded to be unsuitable for negative selection to detect the virulence genes of V. vulnificus owing to the low colonization and proliferation ability of this pathogen in the intestinal tract and systemic circulation. Alternatively, we successfully identified the virulence genes by applying STM to a murine model of wound infection. We examined a total of 5418 independent transposon insertion mutants by signature-tagged transposon mutagenesis and detected 71 clones as attenuated mutants consequent to disruption of genes by the insertion of a transposon. This is the first report demonstrating that the pathogenicity of V. vulnificus during wound infection is highly dependent on its characteristics: flagellar-based motility, siderophore-mediated iron acquisition system, capsular polysaccharide, lipopolysaccharide, and rapid chromosome partitioning. In particular, these functions during the wound infection process and are indispensable for proliferation in healthy hosts. Our results may thus allow the potential development of new strategies and reagents to control the proliferation of V. vulnificus and prevent human infections

    Promotion of Secondary School Science Education Driven by Inquiry-Based Activity

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    This article reports fundamental researches organized for developing a novel teaching/learning system in secondary school science. A curriculum constructed by an effective integration of content-based and context-based curriculum arrangements is proposed for generating teaching/learning opportunities through various inquiry-based activities on the basis of previously acquired science knowledge and concepts. The science subjects, including physics, chemistry, biology and earth science, have different logics and methodologies of science, but those are completed by mutual interdependences. Therefore, various storylines that cover different leraning contents in science subjects can be developed. The inquiry-based activities along different storylines provide students with opportunities to correlate previous learnings in different science subjects and to experience various cognitive and scientific skills. Based on such findings of our basic researches, the merits of the science education system proposed in this study is discussed briefly.本研究は,科学研究費補助金基盤研究(A)(一般)(25242015)による

    Lesson Study Manual for Teacher Educators International Edition

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    1. 授業研究への誘い -本マニュアルの構成と見方 - … 1 2. なぜ教師教育者に授業研究が必要なのか … 3 3. 授業研究の手順 … 5  ステップ1 授業研究の組織を作る … 5  ステップ2 事前協議会を行う … 7  ステップ3 研究授業を実施し,観察する … 11  ステップ4 事後協議会を行う … 15  ステップ5 自分の授業を見直し,改善していく … 19  ステップ6 授業研究の仲間を増やし,拡げる … 20 4.おわりに … 22 5.よくあるQ&A … 23 執筆者・翻訳者一覧 … 2

    Active Learning Models in Science Classes

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    研究の第1年次に当たる本年は,理科におけるアクティブラーニング型授業の構造化に向けて,内化と外化の往還を取り入れた授業デザインとその実践に取り組み,具体的実践の蓄積を行った。小学校,中学校,高等学校それぞれで実践を行ったところ,1)学習内容の定着が図られる,2)発展的な内容や未習内容を生徒が主体的に理解することが可能である,3)協働的な学びの場面を加えることで理解の深化が図られる,4)どのような課題に取り組ませるのかといった課題の設定がカギである,5)アクティブラーニングであるか否かを判断するための要素を明らかにする必要がある,などの一定の成果と課題が明らかになった。The purpose of this study is to create active learning models in science classes. As the first-year research, the authors designed the classes which would include a round trip between externalization and internalization, and put them into practice. The designed models were adopted in elementary, junior high and senior high school classes. What have become clear are as the following; 1) Students’ acquisition of the learning contents can be promoted, 2) Students can understand advanced contents proactively, 3) Students’ learning can be deepened by adding collaborative activities, 4) The success or failure to active learning may depend on the quality of the tasks which students work on, 5) It is necessary to clarify the factors to determine active learning

    The Role of Science Education in the Construction of a Knowledge-Based Society

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    知識基盤社会における理科の役割は,科学的に探究する活動を通して得られた結果(情報)を活用し,それらの情報から導き出した自らの考えを表現する能力を高めることである。これまでに明らかになったことは,授業者が実験結果に対して関連付けることができる事項を明確にし,分析・解釈する視点を与えることが重要であるということである。今年度は,小学校,中学校,高等学校の理科で,パフォーマンス課題を取り入れた探究活動を行い,多くの授業者が共有できる方向性を考えた。実践の結果,以下のことが明らかになった。1)小集団での話し合いの質を高めるためには,話し合いの目的と方法を明示することが重要であること。2)そのために授業者の関わり方を引き続き検討する必要があること。3)パフォーマンス課題の設計には授業者がよりメタ認知を働かせることが必要であること。今後は,このような実践経験を広く共有すべきであると考えている。Science education should help students to utilize results and information through activities, to investigate scientifically, and to develop their abilities to express ideas they have derived from those results. We have learned that it is important for instructors to clarify which results from experiments relate to each other and to give students some clear perspectives for analyzing and interpreting them. This academic year, we investigated performance tasks at elementary, junior high, and senior high school levels. Through our research we have learned that to improve the quality of discussion in small groups, it is important to make the purpose and method clear. We also showed that instructors should monitor how they engage with students in the course of discussion and that they need to function meta-cognitive abilities more to design performance tasks

    The ASTRO-H X-ray Observatory

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    The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray
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