1,056 research outputs found

    Time trends in radiocaesium in the Japanese diet following nuclear weapons testing and Chernobyl:implications for long term contamination post-Fukushima

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    Estimation of time changes in radiocaesium in foodstuffs is key to predicting the long term impact of the Fukushima accident on the Japanese diet. We have modelled >4000 measurements, spanning 50 years, of 137Cs in foodstuffs and whole diet in Japan after nuclear weapons testing (NWT) and the Chernobyl accident. Broadly consistent long term trends in 137Cs activity concentrations are seen between different agricultural foodstuffs; whole diet follows this general trend with remarkably little variation between averages for different regions of Japan. Model blind tests against post-NWT data for the Fukushima Prefecture showed good predictions for radiocaesium in whole diet, spinach and Japanese radish (for which good long term test data were available). For the post-Fukushima period to 2015, radiocaesium in the average diet followed a declining time trend consistent with that seen after NWT and Chernobyl. Data for different regions post-Fukushima show a high degree of mixing of dietary foodstuffs between regions: predictions which assumed that only regionally produced food was consumed significantly over-estimated empirical data. Predictions of average committed effective internal doses from dietary 137Cs (2011 to 2061) in nonevacuated parts of the Fukushima Prefecture show that average internal dose is relatively low. This study focuses on average regional ingestion dose rates and does not attempt to make site specific predictions. However, the temporal trends identified could form a basis for site specific predictions of long term activity concentrations in agricultural products and diet both outside and (to assess potential re-use) inside currently evacuated areas

    Uber die Dopa-, Indophenol- und Peroxydasereaktion bei gonorrhoischen Eiterzellen

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    Kurz gefasst, zeigen die Dopa-, Iudophenol- und Peroxydasereaktionen einerseits in vielen Punkten eine sehr grosse Ahnlichkeit, weisen jedoch andereseits einige Unterschiede auf. Ich habe beobachtet, dass die Dopareaktion eine grosse Ahnlichkeit mit der Peroxydasereaktion hat, von der Indophenolreaktion aber in mancher Hinsicht abweicht. Besonclers ist die Reaktivierung der Indophenolreaktion durch gewisse MetallPulver und -salze im Gegensatz zu den anderen Reaktionen hervorzuheben. Zum Schlusse mochte ich Herrn Prof. Dr. S, Minami fur seine standige Leitung und Herrn Prof. Dr. T.Simizu fur seine freundlicLe Eilfe meinen herzlichsten Dank anssprechen . </p

    The Holistic Aspect of the Phenomenon of Entanglement

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    It is my aim to compare the conceptual and historical paths that led Bohr and Schrödinger to develop their positions with regard to the phenomenon of entanglement. For this purpose, the concept of holism and non-separability in relation to the views of Bohr and Schrödinger will be crucial for reconstructing their standpoints. The idea will be upheld that the concept of non-separability underlies the phenomenon of entanglement. Furthermore, I shall place emphasis on the divergences between Bohr and Schrödinger in spite of their shared holistic world view

    Removal of Radiocesium from Food by Processing: Data Collected after the Fukushima Daiichi Nuclear Power Plant Accident -13167

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    ABSTRACT Removal of radiocesium from food by processing is of great concern following the accident of TEPCO&apos;s Fukushima Daiichi Nuclear Power Plant accident. Foods in markets are monitored and recent monitoring results have shown that almost all food materials were under the standard limit concentration levels for radiocesium (Cs-134+137), that is, 100 Bq kg -1 in raw foods, 50 Bq kg -1 in baby foods, and 10 Bq kg -1 in drinking water; those food materials above the limit cannot be sold. However, one of the most frequently asked questions from the public is how much radiocesium in food would be removed by processing. Hence, information about radioactivity removal by processing of food crops native to Japan is actively sought by consumers. In this study, the food processing retention factor, F r , which is expressed as total activity in processed food divided by total activity in raw food, is reported for various types of corps. For white rice at a typical polishing yield of 90-92% from brown rice, the F r value range was 0.42-0.47. For leafy vegetable (indirect contamination), the average F r values were 0.92 (range: 0.27-1.2) after washing and 0.55 (range: 0.22-0.93) after washing and boiling. The data for some fruits are also reported

    Determination of U isotopic ratios in environmental samples by ICP-MS

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    Inductively coupled plasma mass spectrometry (ICP-MS) has been used for the determination of trace elements in a variety of materials. For uranium, the concentration of 238U can be measured with a detection limit of less than 0.1 ppt in a few minutes. However, because of the extremely low 234U concentrations in environmental materials, it is necessary to separate U from the matrices and to remove interfering elements from the sample solution for measurement of the 238U/234U ratio by ICP-MS. In this study, a simple and rapid separation method for U with an extraction chromatographic resin (TEVA resin) was developed for ICP-MS and the U isotopic ratios in phosphogypsum samples, collected in Spain, were measured. The resin efficiently retained U in 6 M HCl medium and more than 98% of the U was easily eluted with the first 30 mL of 0.1 M HNO3. The separated solutions were free from most of the matrix elements and the concentrations of U in the solutions ranged from 35 to 70 ppb. The 238U/234U isotopic ratios in the solutions were measured by ICP-MS. Moreover, due to the presence of a higher number of 235U atoms in comparison with 234U, the 238U/235U isotopic ratios were also determined with high precision by ICP-MS. The results obtained agreed well with the ratios measured by alpha-spectrometry. The method for this determination is more rapid than alpha-spectrometry, and is considered to be more suitable for environmental monitoring

    Concentration, Soil-to-Plant Transfer Factor and Soil-Soil Solution Distribution Coefficient of Selenium in the Surface Environment -9106

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    ABSTRACT Of the major radioactive selenium isotopes, Se-79, a beta emitter with a half-life of about 1.1 million years, is of special interest because it is one of the most important radionuclides for the long-term dose assessment of radioactive waste disposal. This radionuclide can reach human beings through several transfer paths in the environment. To predict Se-79 behavior from the environment to human beings, it would be useful to obtain the following information: stable Se concentration in environmental samples; soil-soil solution distribution coefficient (K d ); and soil-to-plant transfer factor (TF). In the present study, stable Se concentrations in river water, soil and crop samples collected in Japan, K d s and TFs were obtained. The results showed that geometric mean (GM) concentrations of river water, soil and crops were 0.057 µg/L (range: &lt;D.L.-1.17 µg/L), 0.43 mg/kg (range: 0.068-1.56 mg/kg-dry), and 0.015 mg/kg-dry (range: &lt;D.L.-0.24 mg/kg-dry), respectively. GMs of K d s for paddy field soil and upland field soil samples were 116 and 67, respectively, whereas GMs of TFs for brown rice and upland field crops were 0.066 and 0.024, respectively. Probably due to longer growing period and different water management in the paddy fields for brown rice compared to those for upland field crops, the TF would be high in brown rice

    The time-dependent transfer factor of radiocesium from soil to game animals in Japan after the Fukushima Dai-ichi nuclear accident

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    Since the Fukushima Dai-ichi accident, monitoring of tissues from hunted game animals ensures compliance with the standard food limits for radionuclides in Japan. We quantified the transfer of 137Cs from contaminated land to game animals using the Aggregated transfer factor (Tag = activity concentration in meat [Bq kg–1 fw]/amount in soil [Bq m–2]) of 137Cs for Asian black bear, wild boar, sika deer, green pheasant, copper pheasant and wild duck, collected between 2011 and 2015. Open data sources were used from Fukushima, Miyagi, Ibaraki, Tochigi, and Gunma prefectures. Our initially compiled data showed that the maximum reported 137Cs activity concentration in wild boar after the Fukushima Dai-ichi accident were lower than those reported after the Chernobyl accident. The geometric mean Tag values (m2kg–1 fw) of 137Cs in 2015 for Asian black bear, wild boar, sika deer and copper pheasant were similar (1.9–5.1) × 10–3 while those for green pheasant and wild duck were about 1 order of magnitude lower at (1.0–2.2) × 10–4. Effective half-lives were 1.2–6.9 y except for sika deer and copper pheasant where no decreases were found. In contrast to the Chernobyl accident, no seasonal change occurred in the meat 137Cs activity concentrations of the wild animals during the study period

    Studies on Silage-Making XVII : The Influence of Level of Fertilization to Forage Crops on the Quality of Silage

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    イタリアンライグラスに対して,10アールあたり窒素量を6kg(少肥),12kg(中肥または標肥),18kg(多肥),24kg(過肥)の4水準に施肥した場合,生草の成分ならびにこれでサイレージをつくった場合,その発酵的品質にどのような影響を与えるかを知るため実験を行なった. その結果の要約はつぎのようである. 1)いずれの生育期においても,粗タンパク質の含量は,単位面積あたりの窒素施肥量の多くなるにつれて高くなった. 2)窒素施肥量が高くなるにつれて,水溶性炭水化物の含量は低くなった. 粗タンパク質と可溶性炭水化物含量間には,負の相関,r=-0.85が見出された. 出穂初期の試料の窒索含量と還元糖含量間にも有意な負の相関r=-0.98が見出された. 3)カロチン含量は,窒素施肥量を多くするにつれて高くなった. 4)サイレージの発酵的品質は,少肥区サイレージ70点,中肥区サイレージ58点,多肥区サイレージ23点で,窒素施肥量が多くなるにつれて,品質の低下することが認められた. 5)サイレージの有機物の消化率は,区間に大きな差はなかったが,粗タンパク質の消化率は,窒素施肥量が多くなるにつれて,高くなった. 6)サイレージのカロチン含量は,多肥区サイレージが高かったが,埋蔵間の保存率は窒素施肥量の高いものが低かった. 7)簡易し好試験の緒果は,品質のよいものほど,単位時間あたりの乾物摂取量が高かった. 8)サイレージ養分としての単位面積あたりの養分収量は,施肥量の高いものほど,DCP,TDNの収量が高かった

    Changes in the soil to brown rice concentration ratio of radiocaesium before and after the Fukushima Daiichi nuclear power plant accident in 2011

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    Radiocaesium (RCs) mobility in soil is initially relatively high when the nuclide first comes into contact with soil, after which the mobile fraction decreases with time due to RCs fixation to soil particles (aging effect). Consequently, the RCs activity concentration in plants grown in soil was expected to decrease with time after the Fukushima Daiichi nuclear power plant accident in 2011. In this study, we collated data on concentration ratios (CR) of RCs between brown rice grain and paddy soil and compared CR values reported for periods before and after the accident. For this purpose, soil and rice data were collected after the accident specifically from paddy fields that did not have additional potassium fertilizer added (for remediation purposes). The geometric mean rice/soil CR of RCs for all types of soil was 1.2 × 10–2 in 2011 (n = 62) and by 2013 the value had declined to 3.5 × 10–3 (n = 32), which was similar to that for 1995–2007 of 3.4 × 10–3 (n = 120). The comparison suggests that the mean soil-to-rice grain concentration ratio had returned to that prevailing before the accident after less than three years. It was also confirmed that CR values for rice sampled from paddy fields were lower than those obtained from pot experiments
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