著者
金子 友暁 横山 博史 佐藤 充 西川原 理仁 柳田 秀記
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
pp.22-00044, (Released:2022-05-25)
参考文献数
16

For a small axial fan in a duct, the effects of acoustic resonance occurring in the duct on the flow around the fan are focused on. To clarify the condition for the intense acoustic resonance, the effects of the rotational speed and duct width on the flow and acoustic fields around the fan were investigated by compressible flow simulations with a volume penalization method. The computational methods were validated by comparing the predicted static pressure rise and aerodynamic sound by the fan with those measured. The sound pressure level became most intense for a specific rotational speed, where the acoustic resonance occurs at the blade passing frequency in the upstream duct. Although the overall tendency of the increase in the static pressure coefficient was found for a higher rotational speed with the thinner momentum thickness around the blade surface, the static pressure coefficient drops at the rotational speed for the acoustic resonance. Moreover, the acoustic resonance became more intense for a narrower duct width. In this condition, flow disturbances occur near the wall of the bell-mouthed inlet of upstream duct due to the acoustic resonance, which prompts the inflow turbulence to the fan. To clarify the effects of the acoustic resonance on the flow around the fan, the computation with the artificially suppressed acoustic resonance was also performed and the predicted flow fields were compared with those with intense acoustic resonance for the same rotational speed and duct width. The incoming flow to the fan is confirmed to become more turbulent when the acoustic resonance occurs, which promotes the spreading of the tip vortices between rotor blades. As a result, the blade loading decreases and the turbulence in the blade wake leading to mixing loss becomes intense, causing the static pressure rise by the fan to decrease.

2 0 0 0 OA 芸術一家言

著者
谷崎潤一郎 著
出版者
金星堂
巻号頁・発行日
1924
著者
堂囿 俊彦
出版者
東京都立大学哲学会
雑誌
哲学誌 (ISSN:02895056)
巻号頁・発行日
no.60, pp.35-61, 2018-03-25

2 0 0 0 OA エイズに学ぶ

著者
玉城 英彦
出版者
日本民族衛生学会
雑誌
民族衛生 (ISSN:03689395)
巻号頁・発行日
vol.76, no.1, pp.1-2, 2010 (Released:2010-03-25)
著者
耳塚 寛明
出版者
日本教育社会学会
雑誌
教育社会学研究 (ISSN:03873145)
巻号頁・発行日
vol.80, pp.23-39, 2007-05-31 (Released:2018-07-01)
参考文献数
22
被引用文献数
8 4

The measurement of children’s academic achievements and the explanation of differences between social classes should not be dismissed by sociologists of education. Although inequality is a major theme of the field, the sociology of education has lacked empirical evidence on the structure of disparities in academic achievements. This is partly due to the difficulties involved in collecting sufficient data on academic achievement through schools.In and after 2002, studies were begun on the relationship between academic achievement and social class in Japan. At the time, schools were being heavily criticized within the context of the debate over falling children’s academic achievements. Some significant surveys were administered at that time, though they were small in number. However, they left some important issue to be solved. The first is that analyses of the determinants of academic achievement are inadequate for clarifying what factors will diminish class differences in achievement. The second concerns the reliability and validity of the variables collected. In particular, variables on the economic conditions of households are lacking. Finally, the surveys were conducted only in large cities.This paper examines the factors that affect children’s academic achievements, and the extent of the effect of such factors, through an analysis of the data of the Japan Education Longitudinal Study 2003 (JELS2003). JELS2003 was conducted in two areas: one a middle-sized city within the capital metropolitan areas, and the other a small local city. It also contains variables about the economic conditions of households.The major findings of the paper are as follows.1. In the small local city, the differences of academic achievement between social classes were relatively small.2. In the middle-sized city within the metropolitan area, children’s academic achievements were affected by the level of monthly educational expenses, level of educational expectations of the child, and income level of the family.Inequalities in children’s academic achievements in our society should be grasped in the context of the substitution of “parentocracy” for meritocracy.
著者
下鶴 大輔
出版者
Tokyo Geographical Society
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.98, no.6, pp.782-790, 1989-12-05 (Released:2009-11-12)
参考文献数
37
被引用文献数
4 1

2 0 0 0 OA 芭蕉全集

著者
松尾芭蕉 著
出版者
地平社
巻号頁・発行日
vol.上巻, 1948
著者
Kanako Ota Kazumasa Yamagishi Rie Kishida Tomomi Kihara Renzhe Cui Akiko Tamakoshi Hiroyasu Iso for the JACC Study group
出版者
Japan Atherosclerosis Society
雑誌
Journal of Atherosclerosis and Thrombosis (ISSN:13403478)
巻号頁・発行日
pp.63321, (Released:2022-05-18)
参考文献数
25
被引用文献数
3

Aim: In this study, we aimed to evaluate the association between age at menarche and risk of cardiovascular disease mortality. Methods: In total, 54,937 women aged 40-79 years old between 1988 and 1990 without a history of cardiovascular disease were eligible for analysis and were followed through December 2009. We used the Cox proportional hazards models to examine the association between age at menarche and risk of cardiovascular disease. Results: Compared with women with age at menarche of 15 years, the hazard ratios (95% confidence intervals) of stroke were 1.22 (0.85-1.75) for women with age at menarche of 9-12 years, 1.08 (0.85-1.36) for those of 13 years, 1.23 (1.02-1.47) for those of 14 years, 1.27 (1.07-1.50) for those of 16 years, 1.16 (0.95-1.41) for those of 17 years, and 1.39(1.16-1.68) for those of 18-20 years (P for trend=0.045). A similar pattern was observed for hemorrhagic stroke, ischemic stroke, and total cardiovascular disease. No such association was found for coronary heart disease. When stratified by age, for women aged 40-59 at baseline, the similar U-shaped association was observed. In contrast, for women aged 60-79 years at baseline, a significantly high hazard ratio was noted in the group of late age at menarche, but not in the group of early age at menarche. Conclusions: Both women with early and late age at menarche were determined to have higher risk of death from stroke and cardiovascular disease.
著者
DATT Ishan CAMARGO Suzana J. SOBEL Adam H. MCTAGGART-COWAN Ron WANG Zhuo
出版者
公益社団法人 日本気象学会
雑誌
気象集誌. 第2輯 (ISSN:00261165)
巻号頁・発行日
pp.2022-037, (Released:2022-05-13)
被引用文献数
3

A significant fraction of tropical cyclones develop in baroclinic environments, following tropical cyclogenesis “pathways” that are characterized by dynamical processes often associated with higher latitudes. This study investigates whether such storms are more likely to undergo subsequent extratropical transition than those that develop in more typical, non-baroclinic environments. We consider tropical cyclones globally in the period 1979-2011 using best-track datasets, and define the genesis pathway of each storm using McTaggart-Cowan's classification: non-baroclinic, low-level baroclinic, trough-induced, weak and strong tropical transition. In each basin, we analyze the total number and the fraction of storms that underwent extratropical transition, their seasonality, and storm tracks, according to their genesis pathways. The relationship between the pathways and extratropical transition is statistically significant in the North Atlantic and Western North Pacific, where the strong tropical transition and the trough-induced pathways have a significantly greater extratropical fraction compared to all other pathways, respectively. Latitude, longitude and environmental factors such as sea surface temperature and vertical shear were further analyzed to explore whether storms in these pathways happen to be in environments conducive to extratropical transition, or whether a “memory” of the genesis pathway persists throughout the storm life cycle. After controlling for genesis latitude, the relationship between the strong tropical transition and trough induced pathways, and extratropical transition occurrence remains statistically significant, implying a lasting effect from the pathway on the probability of an eventual extratropical transition.
著者
金澤 浩 浦辺 幸夫 岩本 久生 白川 泰山
出版者
日本理学療法士協会(現 一般社団法人日本理学療法学会連合)
雑誌
理学療法学Supplement Vol.35 Suppl. No.2 (第43回日本理学療法学術大会 抄録集)
巻号頁・発行日
pp.A0475, 2008 (Released:2008-05-13)

【目的】腱損傷や腱断裂の術後などでは腱組織の伸張性の改善が求められる.その際のリハビリテーションではストレッチングを用いる場合が多いが,ストレッチングによって生じる腱組織の伸張量は明確ではない.腱組織の伸張を目的としたストレッチングを効果的に実施しようとする場合,実施時間と腱組織の伸張量との関係を知る必要がある.本研究の目的は,下腿三頭筋をストレッチングし,アキレス腱伸張量とストレッチング時間との関係を調査してアキレス腱の伸張に有効なストレッチング時間を決定することである.【方法】対象は下肢に傷害の既往がなく,特別なスポーツ活動を行っていない健康な成人女性40名とした.方法は,まずデジタル超音波診断装置(EUB-6500,(株)日立メディコ)とリニア型プローブ(EUP-L54MA,(株)日立メディコ)を用い,安静立位の超音波画像上で右の腓腹筋内側頭の筋腱移行部を確認し,その位置の皮膚にマーカーを付けた.また,踵骨隆起の位置を確認して皮膚にマーカーを付け,二点間の距離をアキレス腱長とした.対象は足関節最大背屈角度に設定されたストレッチングボード上で立位をとった.ストレッチング終了直後,再び安静立位でアキレス腱長を測定し,ストレッチング前後のアキレス腱長を比較した.ストレッチング時間は,1分,2分,3分,5分,10分の5種類とした.1回のストレッチングの影響が最長で4日間持続するという報告があることから,各測定の間隔を5日以上とした.測定は同じ時間帯に行い,実施時間の順序は無作為に選択した.本研究は,医療法人エム・エム会マッターホルン病院倫理審査委員会の承認を得て行った.【結果】安静立位のアキレス腱長の平均は182.4±23.1mmだった.ストレッチング後,アキレス腱は,1分で3.3±1.5mm,2分で6.6±2.1mm,3分で6.8±0.4mm, 5分で7.1±0.5mm,10分で7.4±0.5mm伸張され,1分と2分では有意に伸張されたが(p<0.01),それより長い時間では伸張量に差は認められなかった.【考察】10分のストレッチングでアキレス腱は平均7.3mm伸張された.久保ら(2006)は,足関節底背屈0°で底屈方向への等尺性最大随意収縮時の腱組織の最大伸張量は20歳代で14.4mmだったと報告した.腱組織はストレッチングよりも筋収縮によってさらに伸張される可能性を示しており,腱損傷後などのリハビリテーションで段階的なストレッチングを実施する際に示唆を与えるかもしれない.アキレス腱伸張量とストレッチング時間との関係については,ストレッチングを3分以上行っても2分のアキレス腱長と差がなかったことから,腱組織の伸張を目的としたストレッチングは2分間で十分であると考えられた.【まとめ】本研究の結果,アキレス腱の伸張を目的としたストレッチングは2分で有効であることがわかった.
著者
六反 一仁
出版者
徳島大学
雑誌
挑戦的萌芽研究
巻号頁・発行日
2015-04-01

脳腸軸は、脳と腸の機能の維持に重要な役割を果たしている。研究代表者は、腸に定着するユニークな乳酸菌CP2305が脳腸相関を介して医学生の慢性ストレス反応を緩和することを見出した。本研究は、CP2305の生体内シグナルの解明を目指した。CP2305の菌体成分自身の作用を調べるため、殺菌洗浄したCP2305のストレス緩和作用を人体解剖実習ストレスと医師国家試験ストレスモデルで調べた。殺菌洗浄したCP2305も生菌と同じく、ストレスによる身体・精神症状を緩和して睡眠障害を改善することを見出した。これらの結果から、CP2305の菌体成分が腸上皮細胞の受容体を介して作用する可能性が示唆された。
著者
中原 啓太 籔脇 健司
出版者
一般社団法人 日本作業療法士協会
雑誌
作業療法 (ISSN:02894920)
巻号頁・発行日
vol.40, no.1, pp.52-60, 2021-02-15 (Released:2021-02-15)
参考文献数
32

要旨:本研究の目的は,地域在住高齢者の健康関連QOLに対して,作業参加,環境因子,運動量がどのように影響するか統計学的に検証することである.対象は,地域活動などに参加している高齢者105名とした.横断研究デザインを用い,先行研究に基づいて作成した仮説モデルを構造方程式モデリングで検討した.結果,最終モデルの適合度は基準を満たし,標準化係数は環境因子から作業参加が0.574,作業参加から健康関連QOLが0.574,運動量から健康関連QOLが0.312となり,全て有意となった.地域在住高齢者の健康関連QOLに対して,環境因子と因果関係にある作業参加を促進することが,運動量のみに焦点を当てるよりも強い影響を与えることが明らかとなった.
著者
小木曽 望 内海 智仁 室津 義定
出版者
一般社団法人 日本航空宇宙学会
雑誌
日本航空宇宙学会論文集 (ISSN:13446460)
巻号頁・発行日
vol.50, no.586, pp.458-465, 2002 (Released:2003-09-02)
参考文献数
12
被引用文献数
1 1

This study is concerned with a shape optimum design of a propeller blade operating in a low Reynolds number range, 1.0–2.0×105. The objective is to minimize the power-required under the constraints on the thrust and the angle of attack in terms of chord length and twist angle distributions where the power-required is evaluated by 3-D panel method. The profile drag is also considered in the optimization, because the effect cannot be ignored in a low Reynolds number range. For calculation efficiency, the profile drag coefficient is approximated by higher order polynomials in terms of Reynolds number and angle of attack. The effectiveness of the proposed method is demonstrated by the design of a propeller blade of a human-powered aircraft. Additionally, effect of the profile drag is discussed by comparing the designs with and without considering the profile drag.