著者

吉岡 勝廣 飯田 孝夫

出版者

日本保健物理学会

雑誌

保健物理 (ISSN:03676110)

巻号頁・発行日

vol.42, no.1, pp.53-62, 2007 (Released:2010-08-05)

参考文献数

39

被引用文献数

2 4

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We compared the periodic characteristics of the atmospheric radon concentration on the land and ocean, using data simultaneously measured at Oki Island in the Sea of Japan and Matsue, which is located 70km south of the island and on the Shimane peninsula. The radon concentration was the highest in the fall at Matsue and in the winter at Oki Island and the lowest during the summer at both locations. The frequency distributions and the annual periodic variations of the arriving pathways of the air masses and these radon concentrations at Matsue and Oki Island showed the same tendency. At Matsue, the monthly average of diurnal minimum of the radon concentration was highest in the winter that was three month late from the maximum season of the monthly average of all measurements. The monthly average of radon concentration at Matsue showed the positive correlation between the monthly occurrence times of temperature inversion. The annual periodic variation of the radon concentration at Oki Island depends on the long-term variation of the distribution of arriving pathways of the air masses.

著者

吉岡 勝廣

出版者

日本エアロゾル学会

雑誌

エアロゾル研究 (ISSN:09122834)

巻号頁・発行日

vol.17, no.4, pp.267-275, 2002-12-20 (Released:2008-03-27)

参考文献数

16

著者

久保 博尚 長瀬 通昭 板谷 芳樹 大森 丈治 吉岡 勝

出版者

The Japan Institute of Marine Engineering

雑誌

日本舶用機関学会誌 (ISSN:03883051)

巻号頁・発行日

vol.22, no.4, pp.263-270, 1987

被引用文献数

1

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Various attentions have been paid to improvement of propeller efficiency. Among these devices, the free rotating propeller (vane wheel) to be fitted additionally behind conventional main propeller is the most attractive one. However the design method, blade strength, etc. of the free rotating propeller are not specified.<BR>The authors designed the free rotating propeller for the ship by applying the momentum theory and the blade element theory that are used for designing the hydraulic machineries. In this report, the design accuracy is compared with full-scale measurements and as the results, the following conclusions are obtained.<BR>(1) The calculated revolutions and energy saving rate of the free rotating propeller show a similarity to those of measurements.<BR>(2) Measured energy saving rate is 6-8.5% at same speed condition.<BR>(3) The mean blade stress is 2.6kgf/mm<SUP>2</SUP> {25 MPa} and the fluctuation of blade stress for a rotation is 8.8kgf/mm<SUP>2</SUP> {86 MPa} in peak-to-peak value.<BR>(4) The pressure fluctuation caused by main propeller is reduced by 20% at the blade frequency components.

著者

飛田 宗重 高田 博仁 土肥 守 千田 圭二 小林 顕 関 晴朗 亀谷 剛 宮澤 幸仁 小野寺 淳一 鈴木 博義 今野 秀彦 吉岡 勝 會田 隆志 野村 宏

出版者

一般社団法人 国立医療学会

雑誌

医療 (ISSN:00211699)

巻号頁・発行日

vol.57, no.8, pp.503-507, 2003-08-20 (Released:2011-10-07)

参考文献数

6

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進行性核上性麻痺(progressive supranuclear palsy:PSP)は, いまだ病因不明で治療法未確立の難治性疾患であるが, 疫学調査を行うにも共通の登録基準さえ整備されていない状況にあった. 近年, 「神経疾患の予防・診断・治療に関する臨床研究班」(湯浅班)において, 疫学調査のための登録基準が提唱されたことを契機に, 東北ブロック政策医療神経筋疾患ネットワーク参加施設にてPSPの療養環境整備にむけた共同研究を施行した. 最初に剖検例を対象に登録基準の有用性について検討した. 病理学的に診断確定したPSP7例全例が登録基準を充たしていたが, PSPと鑑別を要する疾患群(MSA4例, PD8例, DLB4例, CBD1例)はいずれも登録基準を充たさず, 登録基準の有用性が示された. 次いで登録基準を用いて患者登録を行い, 療養環境について調査した. 今回の調査では, 入院療養への依存度が高く, 介護保険の利用が少ない実態が認められた. 重症化してから長期入院療養目的で国立医療機関へ紹介される症例が多い傾向を反映しており, 療養上の諸問題について検討した.

著者

吉岡 勝廣 湊 進

出版者

公益社団法人 日本アイソトープ協会

雑誌

RADIOISOTOPES (ISSN:00338303)

巻号頁・発行日

vol.53, no.7, pp.427-433, 2004-07-15 (Released:2011-03-01)

参考文献数

14

被引用文献数

3 3

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To study the relation between the terrestrial γ-ray dose rate and subsurface geology, the γ-ray dose rate has been surveyed at 213 points in Okinoshima, an island situated in the Japan Sea, with a γ-ray survey meter. The results of this observation are the mean value of terrestrial γ-ray dose rate at 213 points = 57.1 nGyh-1, the standard deviation =15.2 nGyh-1, the maximum value =107.2 nGyh-1, and the minimum value=23.1 nGyh-1. On the soil of the basement rock in Okinoshima, the terrestrial γ-ray dose rate of Oki-gneiss is 72±15 nGyh-1, which is about 1.6 times as big as the reported value for metamorphic rock and others are the same in the literatures. It is considered that the terrestrial γ-ray dose rate of Okigneiss has been more strongly affected by the granitic magma which has been interpenetrated in the process of this formation. In Okinoshima, it is suggested that the geological features of the basement rock remain in the surface soil, due to a good correspondence between the geographical distribution of terrestrial γ-ray dose rate and the subsurface geology. And then, in the relation between the terrestrial γ-ray dose rate and the atmospheric 222Rn concentration, the magnitude of 222Rn concentration is smaller than this of place on large land area. Because of a small land area in Okinoshima, this is caused that the land air is mixed with the sea air by the advection for a long time except the time from the sunset to around the midnight. It is suggested that the time and space change characteristic of the diffusion and mixture process is different in contrast to a place of large land area.