巻号一覧
14 巻 (1979)
- 4 号 p. 225-
- 3 号 p. 145-
- 2 号 p. 81-
- 1 号 p. 1-
14 巻, 2 号
選択された号の論文の6件中1～6を表示しています
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古賀 妙子, 森嶋 彌重, 丹羽 健夫, 河合 廣, 西脇 安1979 年 14 巻 2 号 p. 81-88
発行日: 1979年
公開日: 2010/02/25
ジャーナル フリーThe fission track spark counting has been widely used for neutron monitoring by polycarbonate film. We have studied spark counting characteristics using polycarbonate detector films of different thickness and aluminized polycarbonate sheets of different aluminum thickness for an electrode, and observed the etch-pit sizes in relation to spark counting. Results obtained are as follows:
1. On spark counting of high density of etch-pits, round etch-pits seemed to be easily spark-punched and rod-like etch-pits remained unpunched.
2. The size of etch-pits due to uranium fission fragments appeared to be somewhat larger than due to thorium fission fragments. And the percentage of rod-like etch-pits to all etch-pits due to uranium fission fragments is smaller than that due to thorium fission fragments.
3. As the thickness of detector films decreases, percentage of round etch-pits to all etch-pits increased and spark counting efficiency increased. From our experiments, Makrofol KG of 10μm thick or Lumirror of 6μm thick appears to be suitable for routine use.
4. As the aluminum thickness of aluminized sheet electrode increases, spark counting efficiency increases slightly, range of spark counting plateau shortens, and multiple sparks occur at low voltage.抄録全体を表示PDF形式でダウンロード (2605K) -
丹羽 健夫, 古賀 妙子, 森嶋 彌重, 河合 廣, 西脇 安1979 年 14 巻 2 号 p. 89-93
発行日: 1979年
公開日: 2010/02/25
ジャーナル フリーBasic spark counting characteristics of cellulose nitrate films 13μm thick stripped off from the polyester bases of LR-115 Type II and LR-115 Type II Stripping made by KODAK-PATHÉ in France were investigated. Detector films irradiated with α-ray were etched with NaOH solution, sandwiched between copper and aluminized sheet electrodes, and the number of sparks was counted with a scaler. Results obtained were as follows:
1) Optimum etching condition was 26% NaOH solution at 50°C and etching time was 140min.
2) Sparking voltages were 600V for punching and 425V for counting.
3) Optimum thickness of polycarbonate sheet for a moderator was 20μm.
4) The relation between irradiation time and number of counts was linear up to about 1, 000/cm2.
LR-115 Type II Stripping B, which was sticked with thin LiBO2 layer on one side of the film, was also examined. It was irradiated with neutron produced from the reactor of Kinki University. Neutron fluence was estimated from spark counting of α-tracks produced by (n, α) reaction. The relation between spark counts and neutron fluence was linear between 2×108 and 4×109n/cm2.抄録全体を表示PDF形式でダウンロード (494K) -
西連寺 永康, 森脇 一成, 清水 雅美, 野口 邦和, 安齋 育郎, 池田 長生1979 年 14 巻 2 号 p. 95-104
発行日: 1979年
公開日: 2010/02/25
ジャーナル フリーPorcelain teeth, some of which contained uranium compounds for aesthetic purpose, have been widely used in dental clinics. Recently, the hazardous effects by uranium radiation were suggested.
In the present study, the authors carried out the determination of uranium concentrations of four major brands of porcelain teeth marketed in Japan using the fission track method, and the absorbed doses of oral tissues were calculated by the authors' introduced formula for calculation of alpha radiation.
Average uranium concentrations of the brands studied were determined 3.6ppm (0.33-10ppm, Japan), 18ppm (0.69-81ppm, Japan), 9.4ppm (2.5-14ppm, Japan) and 82ppm (11-205ppm, U. S. A.), respectively. The corresponding dose equivalents at the surface of oral mucosal membrane were 2.9rem y-1, 14rem y-1, 7.6 rem y-1 and 66rem y-1.抄録全体を表示PDF形式でダウンロード (1046K) -
本郷 昭三1979 年 14 巻 2 号 p. 105-109
発行日: 1979年
公開日: 2010/02/25
ジャーナル フリーBy using the risk factor given in ICRP publication 26 and an assumption of linear relationship between risk and dose, death rate and death number which correspond to radiation dose level and collective dose level of Japanese are estimated and they are compared with vital statistics of Japanese in 1975 to get out some ideas about radiation risk relative to the risks of everyday life.抄録全体を表示PDF形式でダウンロード (662K) -
The Consumption of Leaf Vegetables and Milk by Infants in Tokai Village住谷 みさ子, 根本 陽子, 大桃 洋一郎1979 年 14 巻 2 号 p. 111-113
発行日: 1979年
公開日: 2010/02/25
ジャーナル フリーSurvey on the consumption of leaf vegetables and milk by infants was carried out in Tokai village, which was one of the parameters used for the estimation of thyroid dose caused by iodine-131 released from stacks of nuclear facilities into the air. It was observed that unweaned babies had no leaf vegetables and were fed on milk only. The daily intake was estimated roughly as 1.1 liters. After weaning leaf vegetables consumption by infants increased with the age. On the contrary, milk consumption decreased with the age. The consumption of leaf vegetables and milk by each age group was as follows; 20g/d/p and 600ml/d/p for 0.5 to 1.5 years, 25g/d/p and 300ml/d/p for 1.5 to 3 years, 35g/d/p and 300ml/d/p for 3 to 5 years, and 50g/d/p and 300ml/d/p for 5 to less than 6 years old, respectively.抄録全体を表示PDF形式でダウンロード (318K) -
村田 幹生, 池沢 芳夫, 吉田 芳和1979 年 14 巻 2 号 p. 115-124
発行日: 1979年
公開日: 2010/02/25
ジャーナル フリーFor selecting good-performing masks and estimating the protection provided by the masks, the leakage has been measured for six types of half mask and three types of full-face mask as worn. The cloud of submicron sodium chloride particles was generated within a test hood in which the subject wore his mask. The air sampled from inside the mask with a miniature pump was assessed by a flame photometer. The leakage was measured under four simulated working conditions such as normal breathing, smiling, moving head, and talking.
The measured protection factors (defined as the ratio of the concentration of the test cloud outside the mask to that inside the mask) widely distributed from 10 to 3, 300 for the half masks and from 100 to 3, 300 for the full-face masks, depending on the persons and the working conditions. The values characterising the distribution of the protection factor for each mask are summarized.
Based on these values, the performance of each mask and the effects of working conditions on the protection are discussed.抄録全体を表示PDF形式でダウンロード (2298K)
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