共查询到20条相似文献,搜索用时 46 毫秒
1.
Y. Inomata M. Aoyama T. Tsubono D. Tsumune Y. Kumamoto H. Nagai T. Yamagata M. Kajino Y. T. Tanaka T. T. Sekiyama E. Oka M. Yamada 《Journal of Radioanalytical and Nuclear Chemistry》2018,318(3):1587-1596
Distributions of radiocaesium (134Cs and 137Cs) derived from the Tokyo Electric Power Company (TEPCO) Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident in the North Pacific Ocean in the summer of 2012 were investigated. We have estimated the radiocaesium inventory in the surface layer using the optimal interpolation analysis and the subducted amount into the central mode water (CMW) by using vertical profiles of FNPP1-134Cs and mass balance analysis as the first approach. The inventory of the 134Cs in the surface layer in the North Pacific Ocean in August–December 2012 was estimated at 5.1?±?0.9 PBq on 1 October 2012, which corresponds to 8.6?±?1.5 PBq when it was decay corrected to the date of the FNPP1 accident, 11 March 2011. It was revealed that 56?±?10% of the released 134Cs into the North Pacific Ocean, which was estimated at 15.3?±?2.6 PBq, transported eastward in the surface layer in 2012. The amount of 134Cs subducted in the CMW was estimated to be 2.5?±?0.9 PBq based on the mass balance among the three domains of the surface layer, subtropical mode water, and CMW. 相似文献
2.
In some tea tree planting areas within 300 km from the TEPCO’s Fukushima Daiichi Nuclear Power Plant (FNPP), it was found
that newly emerged tea plant leaves for green tea contained two radiocesium species (cesium-134 and cesium-137). In this study,
using processed green tea leaves for drinking, extraction ratios of radiocesium under several brew conditions were observed.
When 90 °C water was used, 50–70% of radiocesium was extracted into the water, while 54–60% of radiocesium was extracted with
60 °C water. A part of radiocesium would be removed from leaves if the leaves were washed with 20 and 60 °C water before brewing,
and the efficiencies were 11 and 32%, respectively. Newly emerged camellia leaves were used to simulate the radiocesium removal
ratio from raw tea leaves by washing and boiling; radioactivity concentration was decreased to 60% of the original concentration
with washing and 10 min boiling. From these results, it was found that almost half of the radiocesium would not be removed
from raw or processed tea leaves. The values obtained in the present study could be used for internal radiation dose estimation
from tea leaves. 相似文献
3.
Michio Aoyama Daisuke Tsumune Yasunori Hamajima 《Journal of Radioanalytical and Nuclear Chemistry》2013,296(1):535-539
Impact of the TEPCO Fukushima-Daiichi NPP accident, FNPP1, to the North Pacific Ocean occurred through two pathways, namely direct release and atmospheric deposition to wide ocean surface. We collected more than 100 seawater samples in the North Pacific Ocean in April and May 2011 by seven commercial ships as VOS. Since the sample volume was 2 l each, we measured radiocaesium activity at Ogoya Underground Facility to obtain reliable activity. 137Cs was detected at all stations and 134Cs was detected at most of the stations in the North Pacific Ocean. The 137Cs activity ranged from around 1 to 1,000 Bq m?3 with activity ratios of 134Cs/137Cs close to 1 which is a signature of radiocaesium originated from the FNPP1 accident. At east of the International Date Line north of 40°N in the Pacific Ocean in April 2011, the 134Cs activity ranged from 2 to 12 Bq m?3. 相似文献
4.
Effective atomic numbers, effective electron densities for photon mass energy absorption and kerma values of soft tissue and some thermoluminescence dosimeter containing boron are calculated in the energy range from 1 keV to 20 MeV. It is investigated that the variation of effective atomic numbers, effective electron densities and kerma with energy. The TL dosimeters studied are compared with the soft tissue for calculated values. In addition, dopant effect on the effective atomic numbers and electron densities for photon mass energy absorption and kerma values of the TL dosimeter containing boron is presented. Effect of the concentrations of the element H on effective electron density of the soft tissue is discussed. 相似文献
5.
S. F. Chiu P. C. Wang P. F. Kao J. B. Lin D. B. Lin C. Y. Chen 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(3):873-882
Hair samples from junior high school students in metropolitan areas of Taichung, Taiwan were tested for a total of 13 elements,
Al, Ag, Br, Cl, Cr, Fe, K, La, Mn, Na, Sc, Se, and Zn by instrumental neutron activation analysis (INAA) to establish seasonal
variations, gender and environmental exposures. The seasonal variations of hairs in 39 healthy students (18 males and 21 females;
age 13.3 ± 0.4 years; height, 158.0 ± 4.1 cm; weight, 53.4 ± 5.7 kg) were collected at 1.5-month intervals for 1 year starting
from late August, 2008. The concentrations of the above elements varied from 103 to 10−2 μg g−1 at different sampling times. A quantified index of agreement (AT) was introduced to help classify the elements. A smaller
AT indicated highly consistent quantities of specific metals in the hair while a larger AT indicated increased fluctuation,
i.e., less agreement. The different ATs in various hair samples were discussed. The concentrations of these elements are compared
with the data in the literature. 相似文献
6.
7.
Vanadium levels in marine organisms of Onagawa Bay in Japan 总被引:1,自引:0,他引:1
M. Fukushima H. Suzuki K. Saito A. Chatt 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(1):85-89
Vanadium in marine organisms from Onagawa Bay in Miyagi, Japan, was determined by an instrumental neutron activation analysis
(INAA) method using anti-coincidence gamma-ray spectrometry at the Dalhousie University SLOWPOKE-2 Reactor (DUSR) facility
in Canada. Seaweeds, cultivated oysters, plankton, and four different species of sea squirt were collected from Onagawa Bay
during 2005–2008. Vanadium levels around 20 μg g−1 (dry weight) were found in Japanese tangle and hijiki seaweeds. One species of sea squirt (Ciona savignyi) contained 160–500 ppm of V and it was highest among the four species of sea squirts studied. Protein-bound V species were
separated by gel permeation chromatography (GPC) and the element determined by inductively coupled plasma atomic emission
spectrometry (ICP-AES). 相似文献
8.
L. Popov 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(2):897-902
Methods for routine assessment of 3H and 14C content in gaseous releases from ventilation stacks of Kozloduy Nuclear Power Plant (Bulgaria) were developed. Technique
for correction of incomplete desorption of tritium from exposed silica gel was proposed. The distribution and the concentrations
of both nuclides in various chemical forms were constantly monitored for a period of 1 year. The results for annual normalized
gaseous discharges were assessed for the fifth unit at 173 GBq/(GW.a) for 3H and 369 GBq/(GW.a) for 14C, while for the sixth unit—3H—98 GBq/(GW.a) and 14C—289 GBq/(GW.a). 相似文献
9.
M. Manolopoulou S. Stoulos A. Ioannidou E. Vagena C. Papastefanou 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(1):155-159
Fallout from the Fukushima Nuclear Accident has been monitored for about 1 month in Thessaloniki, Northern Greece. Three different
radionuclides, one short-lived, one relatively long-lived and one long-lived fission product were identified in air, precipitation,
soil, grass and milk samples. The 131I, 137Cs and 134Cs activity concentrations in air reached 497, 145 and 126 μBq m−3, respectively on 4 April, 2011. The external exposure dose rate to humans of the order of 14.4 pSv per day due to 137Cs deposited on the ground was very small compared to the normal background level. The accumulated dose equivalent to the
adult thyroid from inhaled 131I varied from 0.4 to 3.5 nSv per day was insignificant and there was not any problem for the Greek population and no preventive
measures were needed to be provided against the nuclear accident according to the Greek Atomic Energy Commission, the official
agent of the Greek Government. Some special radioecological aspects in the air-grass-cow-milk-man pathway for 131I were particularly studied. 相似文献
10.
Eun Hee-Chul Yang Hee-Chul Kim Hyung-Ju Kim Sung-Jun Lee Keun-Young Seo Bum-Kyoung 《Journal of Radioanalytical and Nuclear Chemistry》2021,328(2):627-635
Journal of Radioanalytical and Nuclear Chemistry - Activated carbon wastes from the air cleaning system in a nuclear facility contain a long half-life value of 14C (5700 years). This 14C... 相似文献
11.
Chunguang Wang Zishou Zhang Kancheng Mai 《Journal of Thermal Analysis and Calorimetry》2011,106(3):895-903
β-nucleated PP/PET blends were prepared using nano-CaCO3 supported β-nucleating agent (β-NA), PP as matrix, and PET as dispersion phase. The effects of preparation methods, PET content, and melting temperature
on the non-isothermal crystallization behavior and the melting characteristic and polymorphic composition of PP in the blends
were investigated by differential scanning calorimeter (DSC) and wide angle X-ray diffraction (WAXD). The results indicated
that the PP crystallized predominantly in β-modification in the presence of β-NA. However, efficiency of β-NA for PP crystallization decreased with addition of PET and increasing PET contents. The β-nucleation of β-NA for PP crystallization in the blends was dependant on the preparation methods. The high β-nucleation and high β-PP content were obtained for PP/PET blend prepared at the temperature of 265 °C and added the β-NA into the blend at the temperature of 180 °C. However, the addition of β-PP or β-NA into blends at 265 °C decreased the β-nucleation, and no β-PP was formed because the β-NA mainly dispersed on the PET dispersion phase or at the interface between PP and PET. 相似文献
12.
S. M. Whitney E. Alvarez D. Haas K. Jackman S. Wilson S. Biegalski 《Journal of Radioanalytical and Nuclear Chemistry》2008,276(3):857-861
Graduate students in the Mechanical Engineering department at the University of Texas at Austin have designed and modeled
a fast neutron prompt-gamma activation analysis facility as part of a new course introduced in the graduate program titled
“The Design of Nuclear Systems.” The students were responsible for creating a design concept as well as implementing and modeling
the concept to ensure its safety and functionality. The purpose of the class was to give graduate students the independence
to create a project of their own vision, but to do so in a collaborative and formal manner as will be necessary in their future
work. The fast neutron PGAA facility was successfully designed and computational models have been analyzed to display benefits
of the fast neutron facility compared to the thermal neutron PGAA facility that also exists at The University of Texas at
Austin. 相似文献
13.
Y. J. Park B. C. Song M. I. Chowdhury K. Y. Jee 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(3):585-594
A neutron induced prompt γ -ray spectrometry (NIPS) facility has been developed at the Nuclear Chemistry Research Division,
of the Korea Atomic Energy Research Institute (KAERI) with the aim of analyzing the major components of various elements in
aqueous samples. The facility is equipped with a 252Cf neutron source and a γ-γ coincidence setup with two n-type coaxial HPGe detectors based on NIM spectrometric modules in
association with data acquisition and spectral analysis systems. The development of the system, its set-up and the calibration
of detection efficiency up to 8 MeV using a set of radionuclides and the (n,γ) reactions of chlorine are described in the
paper.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
Abdullah M. Noh Yusoff M. Amin Rosli H. Mahat D. A. Bradley 《Radiation Physics and Chemistry》2001,61(3-6):497-499
Using a deuterium UV source, we have investigated the response of a number of commercially available thermoluminescence (TL) dosimeters (TLDs) to UV radiation (UVR), including LiF : Mg, Cu, P (TLD-100 H), CaF2 : Dy (TLD-200), CaF2 : Mn (TLD-400), Al2O3 (TLD-500), 7LiF : Mg, Cu, P (TLD-700 H) and CaSO4 : Dy (TLD-900). The intrinsic method was used to detect UVR, while trap depth and frequency factors were estimated using the initial rise method. We have studied TL intensity as a function of exposure time, observing high sensitivity of TLD-500 to UVR. Conversely, TLD-400 displays weak sensitivity to these same radiations. Although TLD-900 and TLD-200 are both less sensitive to UVR than TLD-500, they each provide a linear response to UVR. The possible use of these phosphors as UV dosimeters has been further appraised, examining thermal fading effects and fading due to light exposure. 相似文献
15.
A. Okubo J. Zheng M. Yamada T. Aono T. Nakanishi H. Kaeriyama M. Kusakabe 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(2):291-297
An analytical method for the determination of 239Pu and 240Pu in marine particle samples by sector field high-resolution ICP-MS was developed. The method was applied for large and small
particle samples (particle diameter: >70 μm and 1–70 μm, respectively, collected with a large volume in situ filtration and
concentration system at different depths in the water column off Rokkaho, Japan, where the spent nuclear fuel reprocessing
plant of Japan Nuclear Fuel Ltd. has started test operation since March 2006. 相似文献
16.
A. Aboulkas K. El Harfi A. El Bouadili M. Nadifiyine 《Journal of Thermal Analysis and Calorimetry》2010,100(1):323-330
Investigations into the pyrolytic behaviours of oil shale, poly (ethylene terephthalate) (PET) and their mixture have been
conducted using a thermogravimetric analyzer. Experiments were carried out dynamically by increasing the temperature from
298 to 1,273 K with heating rates of 2–100 K/min under a nitrogen atmosphere. Discrepancies between the experimental and calculated
TG/DTG profiles were considered as a measurement of the extent of interactions occurring on co-pyrolysis. The maximum degradation
temperature of each component in the mixture was higher than those the individual components; thus an increase in thermal
stability was expected. The kinetic processing of thermogravimetric data was carried out using Flynn–Wall–Ozawa (FWO) method. 相似文献
17.
Cieszykowska Izabela Jerzyk Katarzyna towska Magorzata Janiak Tomasz Birnbaum Grayna 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):1029-1037
Journal of Radioanalytical and Nuclear Chemistry - Electrochemical dissolution of pressed into discs and sintered metallic molybdenum powder with the mass of 712 ± 10 mg... 相似文献
18.
G. Prasad T. Ishikawa M. Hosoda A. Sorimachi S. K. Sahoo N. Kavasi S. Tokonami M. Sugino S. Uchida 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(3):1385-1390
Radon and thoron concentration in the outdoor environment are affected by the magnitude of the exhalation rate that can vary
diurnally and seasonally. This paper presents measurement results of radon and thoron exhalation rates and gamma-ray dose
rate in different season at same location points in Gunma Prefecture Japan. Exhalation rates were measured by the MSZ instrument
which is based on the accumulation method. Three measurement points Katashina Village, Midori City and Takasaki City were
selected for measurement. Soil water saturation and soil temperature were measured to investigate their relationship with
exhalation rate. The diurnal variation of exhalation rate may be correlated with soil temperature but no clear relationship
was found between them. The gamma-ray dose rate do not vary significantly at the same places even in different season. The
average radon exhalation rates were 11 ± 2, 2 ± 1, 5 ± 3 and 11 ± 4 mBq m−2 s−1 for spring, summer, autumn and winter, respectively. Those for thoron were 1,100 ± 100, 120 ± 30, 250 ± 80 and 860 ± 140 mBq m−2 s−1. Thus there was a variation of radon and thoron exhalation rate with different seasons. The radon and thoron exhalation rates
in the summer and autumn surveys are higher than those in the spring and winter surveys which were affected by rainfall. It
indicates that water saturation is an influential factor for radon and thoron exhalation rates. 相似文献
19.
Journal of Radioanalytical and Nuclear Chemistry - Four different grain size fractions (0.2–0.5, 0.5–1, 1–1.8, 1.8–2 mm) of red brick and cement mortar samples at... 相似文献
20.
Ma Zhili Wang Yanfei Liu Mouwu Luo YiGe Xie Xiaoqing Xiong Zeng 《Journal of Radioanalytical and Nuclear Chemistry》2019,319(3):1093-1101
Journal of Radioanalytical and Nuclear Chemistry - Radiocarbon and radiocesium were measured on litter fractions (LF) collected on November 19th, 2011 at 40 km NW of the FDNPP. The 137Cs... 相似文献