Pub Date : 2021-03-15DOI: 10.3769/RADIOISOTOPES.70.95
S. Toyoda
Electron spin resonance dating is based on the principle that natural radiation creates paramagnetic defects in minerals. The method has been applied to various minerals starting from calcite of speleothems. As quartz is one of the most common minerals on the surface of the Earth, many applications are available on various geological events occurring on the Earth. The present review article summa-rizes the recent research results and directions of electron spin resonance dating of quartz.
{"title":"Paramagnetic Defects in Crystalline Quartz and Its Applications to Electron Spin Resonance Dating","authors":"S. Toyoda","doi":"10.3769/RADIOISOTOPES.70.95","DOIUrl":"https://doi.org/10.3769/RADIOISOTOPES.70.95","url":null,"abstract":"Electron spin resonance dating is based on the principle that natural radiation creates paramagnetic defects in minerals. The method has been applied to various minerals starting from calcite of speleothems. As quartz is one of the most common minerals on the surface of the Earth, many applications are available on various geological events occurring on the Earth. The present review article summa-rizes the recent research results and directions of electron spin resonance dating of quartz.","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82311811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-15DOI: 10.3769/RADIOISOTOPES.70.173
Shoma Fukuda, S. Sueoka, T. Tagami
Thermochronometric studies (e.g., fission-track thermo chronometry) on major orogenic belts, such as collision zones and/or cratons have been successfully conducted since 1970s. However, such studies in arc-trench systems were limited so far. According to the development of thermochronology in three decades, the applicability for these regions has been identified. Thus, recent thermochronomet ric studies in an island arc setting have been proceeding. This paper introduces the concept and the current status of thermochronometric studies for mountain building process on arc-trench settings, especially these case studies in island arcs.
{"title":"Thermochronometric Studies of Mountains in Island Arc Settings Based on Fission-track Method: A Review","authors":"Shoma Fukuda, S. Sueoka, T. Tagami","doi":"10.3769/RADIOISOTOPES.70.173","DOIUrl":"https://doi.org/10.3769/RADIOISOTOPES.70.173","url":null,"abstract":"Thermochronometric studies (e.g., fission-track thermo chronometry) on major orogenic belts, such as collision zones and/or cratons have been successfully conducted since 1970s. However, such studies in arc-trench systems were limited so far. According to the development of thermochronology in three decades, the applicability for these regions has been identified. Thus, recent thermochronomet ric studies in an island arc setting have been proceeding. This paper introduces the concept and the current status of thermochronometric studies for mountain building process on arc-trench settings, especially these case studies in island arcs.","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81889566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-15DOI: 10.3769/RADIOISOTOPES.70.63
Ichio, N. Nihei, A. Hirose, N. Kobayashi, Muneo Kanno, M. Mizoguchi
We performed consecutive field trials of rice cultivation to monitor radiocesium contamination in harvested rice from 2012, in the Iitate Village in Fukushima Prefecture, where people were forced to be evacuated due to high level of radioactive contamination caused by the disaster at the Fukushima Dai-ichi Nuclear Power Plant of Tokyo Electric Power. The early year results (2012–2013)1, 2) showed the radiocesium concentration in the brown rice was reduced depending on the decontaminated level of paddy soil and on the exchangeable K content of the soil. This report of later year results (2015–2019) showed further more than 80% reduction of 137Cs concentration in the brown rice and straw at KCl fertilized paddy soil, in spite of little reduction of 137Cs concentration of the soil. The transfer factor of 137Cs from soil to brown rice reduced from 0.0022 in 2015 to 0.0003 in 2019 and that to straw reduced from 0.0262 in 2015 to 0.0028 in 2019, respectively. Exchangeable positive ions of the soil were also analyzed. Multiple regression analyses of all data of transfer factor in 2015 to 2019 to year (ageing) and exchangeable K ion as variables shows that the main causal factor is year (ageing) with some supportive effect of increase of exchangeable K ion. This implicates that radiocesium in soil was gradually transformed to a form more difficult to be absorbed by rice, that is, 137Cs immobilization or fixation on clay minerals by ageing, not only in early years after the accident (2011–2015), but also in later years (2015–2019). This implication was supported by comparative analysis of exchangeable 137Cs of dry soil of 2017, 2018 and 2019.
{"title":"Annual Reduction of Transfer Factor of Radiocesium from Soil to Rice Cultivated in a KCl Fertilized Paddy Field from 2015 to 2019","authors":"Ichio, N. Nihei, A. Hirose, N. Kobayashi, Muneo Kanno, M. Mizoguchi","doi":"10.3769/RADIOISOTOPES.70.63","DOIUrl":"https://doi.org/10.3769/RADIOISOTOPES.70.63","url":null,"abstract":"We performed consecutive field trials of rice cultivation to monitor radiocesium contamination in harvested rice from 2012, in the Iitate Village in Fukushima Prefecture, where people were forced to be evacuated due to high level of radioactive contamination caused by the disaster at the Fukushima Dai-ichi Nuclear Power Plant of Tokyo Electric Power. The early year results (2012–2013)1, 2) showed the radiocesium concentration in the brown rice was reduced depending on the decontaminated level of paddy soil and on the exchangeable K content of the soil. This report of later year results (2015–2019) showed further more than 80% reduction of 137Cs concentration in the brown rice and straw at KCl fertilized paddy soil, in spite of little reduction of 137Cs concentration of the soil. The transfer factor of 137Cs from soil to brown rice reduced from 0.0022 in 2015 to 0.0003 in 2019 and that to straw reduced from 0.0262 in 2015 to 0.0028 in 2019, respectively. Exchangeable positive ions of the soil were also analyzed. Multiple regression analyses of all data of transfer factor in 2015 to 2019 to year (ageing) and exchangeable K ion as variables shows that the main causal factor is year (ageing) with some supportive effect of increase of exchangeable K ion. This implicates that radiocesium in soil was gradually transformed to a form more difficult to be absorbed by rice, that is, 137Cs immobilization or fixation on clay minerals by ageing, not only in early years after the accident (2011–2015), but also in later years (2015–2019). This implication was supported by comparative analysis of exchangeable 137Cs of dry soil of 2017, 2018 and 2019.","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"115 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85983459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-15DOI: 10.3769/radioisotopes.70.85
Y. Nagahama, Saki Kato, Osamu Sakata, Norio Nagashima, S. Miyake, Terumitsu Yoshida, Rie Ishii
{"title":"Radioactivity Survey of Total Diet and Boxed Lunches in Saitama Prefecture from 2016 to 2018","authors":"Y. Nagahama, Saki Kato, Osamu Sakata, Norio Nagashima, S. Miyake, Terumitsu Yoshida, Rie Ishii","doi":"10.3769/radioisotopes.70.85","DOIUrl":"https://doi.org/10.3769/radioisotopes.70.85","url":null,"abstract":"","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84990055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-15DOI: 10.3769/RADIOISOTOPES.70.55
N. Linh, N. A. Sơn, M. Furuta, T. Kume
The effects of low-energy X-ray irradiation were investigated as an intervention strategy for the disinfection of fungi-contaminated woodblocks. Fungi were isolated from the woodblocks of the Nguyen dynasty of Vietnam and Cladosporium sp. was identified as the most radiation-resistant strain in the woodblock. The dose rates of the F1 (1-mm-aluminum filtered) and F0 (non-filtered) X-rays at the surface of the woodblock were 1.14 and 4.64 kGy/h, respectively. At the middle (8.5 mm from the surface) of the woodblock, the doses of the F1 and F0 X-rays decreased to 76% and 20% of the surface doses, respectively. The F1 X-rays were useful for irradiating the inside of the woodblock; the concentration of the fungi at the middle decreased by more than 4 log fractions at 6.2 kGy and the fungi were eliminated with a surface dose of 8.3 kGy. Furthermore, the contaminated fungi in the woodblock were disinfected by both-side irradiation with F1 X-rays delivering a dose of 10 kGy at a dose uniformity of 1.04.
{"title":"Disinfection of Woodblocks of the Nguyen Dynasty of Vietnam by Low-Energy X-rays","authors":"N. Linh, N. A. Sơn, M. Furuta, T. Kume","doi":"10.3769/RADIOISOTOPES.70.55","DOIUrl":"https://doi.org/10.3769/RADIOISOTOPES.70.55","url":null,"abstract":"The effects of low-energy X-ray irradiation were investigated as an intervention strategy for the disinfection of fungi-contaminated woodblocks. Fungi were isolated from the woodblocks of the Nguyen dynasty of Vietnam and Cladosporium sp. was identified as the most radiation-resistant strain in the woodblock. The dose rates of the F1 (1-mm-aluminum filtered) and F0 (non-filtered) X-rays at the surface of the woodblock were 1.14 and 4.64 kGy/h, respectively. At the middle (8.5 mm from the surface) of the woodblock, the doses of the F1 and F0 X-rays decreased to 76% and 20% of the surface doses, respectively. The F1 X-rays were useful for irradiating the inside of the woodblock; the concentration of the fungi at the middle decreased by more than 4 log fractions at 6.2 kGy and the fungi were eliminated with a surface dose of 8.3 kGy. Furthermore, the contaminated fungi in the woodblock were disinfected by both-side irradiation with F1 X-rays delivering a dose of 10 kGy at a dose uniformity of 1.04.","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91023545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-15DOI: 10.3769/RADIOISOTOPES.70.73
S. Fukano, 深野重男
{"title":"Calculation of Effective Dose Transmission of 60Co, 65Zn, 124Sb, 187W, 184Re and 196Au Produced by Operation of the Clinical Linear Accelerator","authors":"S. Fukano, 深野重男","doi":"10.3769/RADIOISOTOPES.70.73","DOIUrl":"https://doi.org/10.3769/RADIOISOTOPES.70.73","url":null,"abstract":"","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"8 1","pages":"73-83"},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79381732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-15DOI: 10.3769/RADIOISOTOPES.70.1
M. Kowatari, 古渡意彦, Y. Tanimura, 谷村嘉彦, P. Kessler, S. Neumaier, A. Röttger
For proper environmental radiation monitoring, a method to simultaneously determine ambient dose equivalent rate and radioactivity concentration in the air by using a newly developed scintillation spectrometer, namely a CeBr 3 spectrometer was investigated. The performance of the proposed method, including energy dependence, angular dependence and the linearity of the spectrometer (i.e. the dose rate dependence of its re-sponse), was verified by a series of measurements, conducted according to the procedure of inter-comparison of detectors used for early warning network performed by the European Radiation Dosimetry Group (EURADOS). Measurement results show that the proposed method is suitable for environmental radiation monitoring pur-poses. After thorough tests, the investigation on obtaining activity concentration in air from the pulse height spectrum of γ-ray was demonstrated in the laboratory by using a point-like sealed 133 Ba source to simulate an artificial increase of ambient dose equivalent rate due to a radioactive cloud containing 131 I and 133 Xe. The photon fluence rate was obtained from the pulse height spectrum by using the unfolding method, and the activ ity concentration in air for radionuclides of interest could be estimated from the obtained photon fluence rate by applying the conversion coefficient evaluated via a Monte Carlo calculation.
{"title":"Study on Method for Simultaneous Determination of Ambient Dose Equivalent Rates and Activity Concentration in Air for Environmental Radiation Monitoring","authors":"M. Kowatari, 古渡意彦, Y. Tanimura, 谷村嘉彦, P. Kessler, S. Neumaier, A. Röttger","doi":"10.3769/RADIOISOTOPES.70.1","DOIUrl":"https://doi.org/10.3769/RADIOISOTOPES.70.1","url":null,"abstract":"For proper environmental radiation monitoring, a method to simultaneously determine ambient dose equivalent rate and radioactivity concentration in the air by using a newly developed scintillation spectrometer, namely a CeBr 3 spectrometer was investigated. The performance of the proposed method, including energy dependence, angular dependence and the linearity of the spectrometer (i.e. the dose rate dependence of its re-sponse), was verified by a series of measurements, conducted according to the procedure of inter-comparison of detectors used for early warning network performed by the European Radiation Dosimetry Group (EURADOS). Measurement results show that the proposed method is suitable for environmental radiation monitoring pur-poses. After thorough tests, the investigation on obtaining activity concentration in air from the pulse height spectrum of γ-ray was demonstrated in the laboratory by using a point-like sealed 133 Ba source to simulate an artificial increase of ambient dose equivalent rate due to a radioactive cloud containing 131 I and 133 Xe. The photon fluence rate was obtained from the pulse height spectrum by using the unfolding method, and the activ ity concentration in air for radionuclides of interest could be estimated from the obtained photon fluence rate by applying the conversion coefficient evaluated via a Monte Carlo calculation.","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87373436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-15DOI: 10.3769/RADIOISOTOPES.70.19
S. Horii, A. Kuwana, M. Hachinohe, S. Kusaba
To confirm the contamination by radiocaesium, the concentrations of 137 Cs and 133 Cs of Japanese persim mon fruits and soils were measured in several orchards. Over 3 years, the 137 Cs concentration tended to decrease in many orchards, and there was no significant difference in the transfer factor. Additionally, 5 to 7 years after the accident, the effect of above-ground contamination seemed to be decreasing, and radiocaesium contamination by roots was likely negligible. The 133 Cs concentration in the soil was similar in all orchards; however, the 133 Cs concentration of fruits in one orchard was higher than that in the other orchards.
{"title":"Differences in Fallout-Derived 137Cs and Naturally-Derived 133Cs Transfer to Fruit in Persimmon Tree","authors":"S. Horii, A. Kuwana, M. Hachinohe, S. Kusaba","doi":"10.3769/RADIOISOTOPES.70.19","DOIUrl":"https://doi.org/10.3769/RADIOISOTOPES.70.19","url":null,"abstract":"To confirm the contamination by radiocaesium, the concentrations of 137 Cs and 133 Cs of Japanese persim mon fruits and soils were measured in several orchards. Over 3 years, the 137 Cs concentration tended to decrease in many orchards, and there was no significant difference in the transfer factor. Additionally, 5 to 7 years after the accident, the effect of above-ground contamination seemed to be decreasing, and radiocaesium contamination by roots was likely negligible. The 133 Cs concentration in the soil was similar in all orchards; however, the 133 Cs concentration of fruits in one orchard was higher than that in the other orchards.","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77584219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-15DOI: 10.3769/radioisotopes.70.41
N. Kano, T. Morohashi, Naoto Miyamoto
{"title":"Estimation of Environmental Behavior in Recent Years Based on the Viewpoint of Tritium (T) Concentration and Oxygen, Hydrogen Stable Isotope Ratios (δ18O, δD) in Precipitation","authors":"N. Kano, T. Morohashi, Naoto Miyamoto","doi":"10.3769/radioisotopes.70.41","DOIUrl":"https://doi.org/10.3769/radioisotopes.70.41","url":null,"abstract":"","PeriodicalId":20809,"journal":{"name":"Radioisotopes","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86739434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}