著者

Kojiro SUZUKI

出版者

THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES

雑誌

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN (ISSN:18840485)

巻号頁・発行日

vol.16, no.5, pp.412-419, 2018 (Released:2018-07-04)

参考文献数

15

被引用文献数

1 1

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A Mars orbiter/lander mission using a micro-satellite (less than 100 kg at Mars arrival) with a deployable membrane aeroshell for the orbit insertion by the aerocapture and the electric propulsion for the trajectory maneuver was considered. The aerodynamic heating environment during the atmospheric flight was investigated solving the thermo-chemical nonequilibrium axi-symmetric Navier-Stokes equations around the spacecraft with the flare-shaped aeroshell. To obtain the appropriate amount of deceleration at the atmospheric pass, the drag modulation technique, in which the aeroshell is timely jettisoned from the spacecraft, was assumed. The hypersonic wind tunnel experiment successfully demonstrated that the backward jettison works well without significant time delay and attitude disturbance. Finally the corridor width for the entry path angle was estimated considering the ability of the orbit insertion, the peak aerodynamic heating, and the capability of the electric propulsion to raise the periapsis altitude. The combination of a low ballistic coefficient flight with the membrane aeroshell and an electric propulsion works well to acquire a finite width of the entry corridor for the aerocapture.

著者

水庭 千鶴子 荒井 歩 國井 洋一 栗田 和弥 鈴木 貢次郎 MIZUNIWA Chizuko Ayumi ARAI Yoichi KUNII Kazuya KURITA Kojiro SUZUKI

出版者

東京農業大学

雑誌

東京農業大学農学集報 (ISSN:03759202)

巻号頁・発行日

vol.56, no.2, pp.171-182, 2011-09

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造園学において,「自然とのふれあい」や「ものづくり」は,造園の計画および設計,実際の施工等を学ぶための動機付けとして極めて重要な体験である。近年,生活環境の都市化に伴い,自然とのふれあいやものづくりの体験ができる機会は減少する一方である。このような現状の中,造園学を学ぶ学生の自然とのふれあいやものづくり体験の実態はいかなる状況であるのかを把握するために造園学を学ぶ大学生625人に対するアンケート調査を行った。その結果,自然とのふれあいに関しては,幼少期から学童期まで日常的に体験するような川魚,海洋生物等の採取,カブト虫等の昆虫採取,昆虫や植物の標本づくりは男子で5~6割,女子で7~8割はほとんど体験がなかった。ものづくり体験のうちの,ものづくり体験は,「2~3回程度の体験」を「体験無し」に含まれるとすると, 2割~5割の学生はものづくり体験がほとんどないことが明らかとなった。ケガの体験については,自然とのふれあいやものづくりの体験をほとんどしていないこともあり,カマで手を切ったり,重い石を落としたこと,脚立から落ちたり,木登りをしていて落ちたりしたことはほとんど体験がなかった。以上より,「自然とのふれあい」や「ものづくり」の体験の機会は,終戦後,空間の消失と共に減少してきたといわれていることが確認できた。これらの結果を踏まえ,造園科学科として2010年産より大学教育のカリキュラムへ動機付けの基礎となる「造園体験実習」の教科を新たに組み込む必要性が生じた。

著者

Shinji Naganawa Toshiaki Taoka Hisashi Kawai Masahiro Yamazaki Kojiro Suzuki

出版者

日本磁気共鳴医学会

雑誌

Magnetic Resonance in Medical Sciences (ISSN:13473182)

巻号頁・発行日

pp.mp.2017-0088, (Released:2017-09-29)

参考文献数

31

被引用文献数

9

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Purpose: Circumventricular organs (CVOs) lack a blood brain barrier and are also called “brain windows”. Among CVOs, the organum vasculosum of the lamina terminalis (OVLT) is an osmotic regulator involved in the release of vasopressin. In a previous study of healthy subjects, it was reported that contrast enhancement in the OVLT can be recognized in only 34% of 3 Tesla thin slice contrast-enhanced T1-weighted images. The purpose of this study was to evaluate the leakage of gadolinium contrast from the OVLT in healthy subjects using heavily T2-weighted three dimensional-fluid attenuated inversion recovery (3D-FLAIR) (HF) imaging.Methods: Eight healthy male subjects were included in this study. A standard dose (0.1 mmol/kg) of gadoteridol was intravenously administered. magnetic resonance cisternography (MRC) and HF were obtained before and 0.5, 1.5, 3, 4.5 and 6 h after the injection. Enhancement of the OVLT including the surrounding cerebral spinal fluid (CSF) was measured by manually drawing a rectangular region of interest (ROI) centered on the OVLT. The ROI was copied to the HF image and the signal intensity was measured. The signal intensity ratio (SIR) was obtained by dividing the signal intensity value of the OVLT ROI by that of the midbrain.Results: The differences between the mean SIR at pre-contrast and those at 0.5, 1.5, 3, 4.5, and 6 h were significant (P < 0.05). The mean SIR at 0.5 h was higher than those at all other time points (P < 0.05).Conclusion: Using HF imaging, enhancement around the OVLT was observed in all subjects at 0.5 h after intravenous administration of single dose gadoteridol.