Refine your search:     
Report No.
 - 
Search Results: Records 1-16 displayed on this page of 16
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Nishiyama reservoir; Lead sources, inventory, and the influence of the Nagasaki atomic bomb

Katahira, Kenshi*; Moriwaki, Hiroshi*; Ishitake, Miho*; Kokubu, Yoko; Yamazaki, Hideo*; Yoshikawa, Shusaku*

Soil and Sediment Contamination, 22(8), p.1003 - 1012, 2013/07

 Percentile:100(Environmental Sciences)

The objective of this study was to reveal historical changes in environmental pollution, including the influence of the Nagasaki atomic bomb, based on heavy metal concentrations in sediment core samples. Lead isotope ratios were used to determine the sources of Pb. A sediment core was sampled from a reservoir about 3 km east of the hypocenter of the Nagasaki atomic bomb. It was reported in a previous study that this sediment core contained high activities of $$^{239+240}$$Pu and $$^{137}$$Cs at the 1945 layer as a result of the Nagasaki atomic bomb. Concentrations of heavy metals and the Pb isotope ratios in sediments were measured using ICP-MS. The results show a spiked peak in the Pb concentrations in the same layer as that of the $$^{239+240}$$Pu and $$^{137}$$Cs. It is thought that the spiked peak is due to the loading of Pb by the Nagasaki atomic bombing, and this is supported by further results showing that the Pb isotope ratios in this layer were different from those in other layers.

Journal Articles

Distribution of rare metal in sediment and evaluation of its environmental migration and behavior in modern history

Yamazaki, Hideo*; Yoshikawa, Shusaku*; Kokubu, Yoko

Reametaru Binran, 3, p.661 - 663, 2010/12

no abstracts in English

Journal Articles

Depositional records of plutonium and $$^{137}$$Cs released from Nagasaki atomic bomb in sediment of Nishiyama reservoir at Nagasaki

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Nagaoka, Shinji*; Mitamura, Muneki*; et al.

Journal of Environmental Radioactivity, 99(1), p.211 - 217, 2008/01

 Times Cited Count:13 Percentile:66.09(Environmental Sciences)

In a sediment core of Nishiyama reservoir at Nagasaki, depth profiles of $$^{240}$$Pu/$$^{239}$$Pu ratio, $$^{239+240}$$Pu and $$^{137}$$Cs concentrations were determined. Sediments containing plutonium and $$^{137}$$Cs, which were fallout deposited immediately after a detonation of Nagasaki atomic bomb, were identified in the core. Observed below the sediments were macroscopic charcoals, providing evidence for initial deposit of the fallout. This is the first entire depositional records of plutonium and $$^{137}$$Cs released from the Nagasaki atomic bomb together with those from atmospheric nuclear tests.

Journal Articles

Geographical distribution of plutonium derived from the atomic bomb in the eastern area of Nagasaki

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*

Journal of Radioanalytical and Nuclear Chemistry, 273(1), p.183 - 186, 2007/07

 Times Cited Count:5 Percentile:57.04(Chemistry, Analytical)

no abstracts in English

Journal Articles

Distribution of plutonium isotopes and $$^{137}$$Cs found in the surface soils of Nagasaki, Japan

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Mitamura, Muneki*; Yoshikawa, Shusaku*

Journal of Geosciences, Osaka City University, 50, p.7 - 13, 2007/03

no abstracts in English

Journal Articles

Geological distribution of plutonium isotopes of Nagasaki atomic bomb spread over Nagasaki and Kumamoto area

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*

KEK Proceedings 2006-5, p.36 - 40, 2006/11

no abstracts in English

Oral presentation

Geographical distribution of plutonium derived from the Nagasaki atomic bomb

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yoshikawa, Shusaku*; Yamazaki, Hideo*

no journal, , 

no abstracts in English

Oral presentation

Trace of "Black rain" originated from the Nagasaki atomic bomb in sediment of the Nishiyama reservoir at Nagasaki City

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Murakami, Akiko*; Inoue, Jun*; Yoshikawa, Shusaku*; Yamazaki, Hideo*; et al.

no journal, , 

no abstracts in English

Oral presentation

Origin of plutonium in sediments of the Nishiyama reservoir at Nagasaki city

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yoshikawa, Shusaku*; Yamazaki, Hideo*; Nagaoka, Shinji*

no journal, , 

no abstracts in English

Oral presentation

Plutonium in the Nishiyama area of Nagasaki city

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yoshikawa, Shusaku*; Yamazaki, Hideo*; Nagaoka, Shinji*

no journal, , 

no abstracts in English

Oral presentation

Plutonium and $$^{137}$$Cs derived from Nagasaki atomic bomb; The Sedimentation in Nishiyama reservoir for the last 60 years and the distribution in surface soil at present

Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Nagaoka, Shinji*

no journal, , 

In order to determine sedimentation of plutonium and $$^{137}$$Cs derived from Nagasaki atomic bomb for the last 60 years, we measured $$^{240}$$Pu/$$^{239}$$Pu ratio and Pu and $$^{137}$$Cs concentration in a sediment core collected at Nishiyama reservoir in Nagasaki city. A layer where plutonium and $$^{137}$$Cs deposited immediately after the detonation was specified in the core. Even at present, the plutonium and $$^{137}$$Cs from the atomic bomb are continuously being deposited together with those of the atmospheric nuclear tests. We also measured the ratios in soils collected at eastern part of Nagasaki prefecture and Kumamoto prefecture and so on to determine the detailed distributions of the plutonium. The ratios in soils collected in the Shimabara peninsula, Kumamoto city and Aso city were relatively lower than value of global fallout from atmospheric nuclear tests. It indicates that the atomic bomb plutonium was deposited between 2 km and about 100 km east from the hypocenter.

Oral presentation

The Evaluation of the long term environmental effects of the Nagasaki atomic bomb recorded in the Nagasaki Bay sediment core

Yamazaki, Hideo*; Bessho, Keisuke*; Nishida, Hironori*; Yoshikawa, Shusaku*; Murakami, Akiko*; Tsujimoto, Akira*; Fujiki, Toshiyuki*; Kokubu, Yoko; Magara, Masaaki; Nagaoka, Shinji*

no journal, , 

no abstracts in English

Oral presentation

Plutonium records in sediment core from Nagasaki Bay, Japan

Kokubu, Yoko; Magara, Masaaki; Usuda, Shigekazu; Shinohara, Nobuo; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Murakami, Akiko*; Tsujimoto, Akira*; Nagaoka, Shinji*

no journal, , 

Depth profiles of concentration of $$^{239+240}$$Pu and $$^{240}$$Pu/$$^{239}$$Pu ratio in the cores collected from the center of the Nagasaki Bay were determined to find depositional records of plutonium released from Nagasaki atomic bomb and other nuclear tests. The ratio in sediment at the depth of about 50 cm was higher than that of the global stratospheric fallout, which might show that the plutonium has come from the nuclear tests carried out around the Marshall Islands. Deposition of plutonium from the Nagasaki atomic bomb will be also reported in the presentation.

Oral presentation

Historical changes of environmental pollution based on concentrations of heavy metals and lead isotope ratios in bottom sediment core at Nagasaki-bay

Takasaka, Yuiko*; Katahira, Kenshi*; Moriwaki, Hiroshi*; Yamazaki, Hideo*; Kokubu, Yoko; Yoshikawa, Shusaku*

no journal, , 

Metal concentrations and lead isotope ratios in a bottom sediment core from Nagasaki-bay in Japan were measured by ICP-MS following the microwave extraction method. Before 1920s, metal concentrations in the sediment core samples were low and lead isotope ratios were near those of Japanese lead ore. From the middle of the 1930s, environmental pollution by heavy metals would become visible around Nagasaki-bay because the metal concentrations in the sediments increased and lead isotope ratios were changing. Spiked peaks for several metals in the sediment core samples were observed around 1960 when industry was developed rapidly. The amount of heavy metals released to the environment would have decreased by the law for the environmental pollution enforced in 1976. In this way, metal concentrations and lead isotope ratios in sediment core reflected the activations of industry and could reveal environmental changes for 100 years around Nagasaki-bay.

Oral presentation

The Evaluation of the environmental effect of the trace of the Nagasaki atomic bomb recorded in the sediments of Nagasaki bay and Nishiyama reservoir at Nagasaki

Yamazaki, Hideo*; Kawashima, Asami*; Kokubu, Yoko; Nagaoka, Shinji*; Tsujimoto, Akira*; Murakami, Akiko*; Yoshikawa, Shusaku*

no journal, , 

no abstracts in English

Oral presentation

Plutonium of Nagasaki atomic bomb deposited around Nagasaki, Japan

Kokubu, Yoko; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu*; Kimura, Takaumi; Yamazaki, Hideo*; Yoshikawa, Shusaku*; Nagaoka, Shinji*

no journal, , 

Plutonium isotopes were released from Nagasaki atomic bomb which exploded on August 9, 1945. The isotopes are interesting in research on environmental radioactivity, because evident information of the plutonium release provide opportunities to simplify understanding of environmental behavior of Pu. The Nagasaki area is one of the oldest areas that were contaminated with the artificial Pu in the world. As the isotopic composition of Pu depends on its origin, $$^{240}$$Pu/$$^{239}$$Pu ratio is a useful tool for the identification of the source of Pu. This paper is intended to report the $$^{240}$$Pu/$$^{239}$$Pu ratios in sediments and surface soils and distribution of the Pu from the atomic bomb.

16 (Records 1-16 displayed on this page)
  • 1