• 방사성폐기물학회지
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• 제20권3호
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• pp.279-296
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• 2022

The fundamental characteristics of groundwater colloids, such as composition, concentration, size, and stability, were analyzed using granitic groundwater samples taken from the KAERI Underground Research Tunnel (KURT) site by such analytical methods as inductively coupled plasma-mass spectrometry, field emission-transmission electron microscopy, a liquid chromatography-organic carbon detector, and dynamic light scattering technique. The results show that the KURT groundwater colloids are mainly composed of clay minerals, calcite, metal (Fe) oxide, and organic matter. The size and concentration of the groundwater colloids were 10-250 nm and 33-64 ㎍·L^-1, respectively. These values are similar to those from other studies performed in granitic groundwater. The groundwater colloids were found to be moderately stable under the groundwater conditions of the KURT site. Consequently, the groundwater colloids in the fractured granite system of the KURT site can form stable radiocolloids and increase the mobility of radionuclides if they associate with radionuclides released from a radioactive waste repository. The results provide basic data for evaluating the effects of groundwater colloids on radionuclide migration in fractured granite rock, which is necessary for the safety assessment of a high-level radioactive waste repository.

• 대한핵의학회지
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• 제21권2호
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• pp.183-190
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• 1987

In Raynaud's phenomenon, the authors measured finger blood flow after ice water exposure by analyzing the time activity curve of radionuclide angiography on both hands. The results were as follows: 1) The digital blood flow did not decrease after ice water exposure in normal subjects. 2) In the patients with Raynaud's phenomenon, there were two groups: the one had decreased digital blood flow after cold exposure, and the other had paradoxically increased digital blood flow after cold exposure. 3) There was no difference in the digital blood flow of hand in room temperature between the normal and the patients with reduced digital blood flow after cold exposure, but the digital blood flow of the hand in room temperature was markedly reduced in the patients with paradoxically increased flow after cold exposure. 4) In the static image the difference was not significant in comparision with the dynamic study, because it represents pooling of the blood in the vein rather than flow. 5) After the treatment with nifedipine, the digital blood flow increased. In conclusion, the radionuclide angiography was useful in measuring the digital blood flow in Raynaud's phenomenon, and further studies with various drugs is expected.

• 방사성폐기물학회지
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• 제20권3호
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• pp.321-338
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• 2022

The transport of radionuclides at oceanic scales can be assessed using a Lagrangian model. In this review an application of such a model to the Atlantic, Indian and Pacific oceans is described. The transport model, which is fed with water currents provided by global ocean circulation models, includes advection by three-dimensional currents, turbulent mixing, radioactive decay and adsorption/release of radionuclides between water and bed sediments. Adsorption/release processes are described by means of a dynamic model based upon kinetic transfer coefficients. A stochastic method is used to solve turbulent mixing, decay and water/sediment interactions. The main results of these oceanic radionuclide transport studies are summarized in this paper. Particularly, the potential leakage of ¹³⁷Cs from dumped nuclear wastes in the north Atlantic region was studied. Furthermore, hypothetical accidents, similar in magnitude to the Fukushima accident, were simulated for nuclear power plants located around the Indian Ocean coastlines. Finally, the transport of radionuclides resulting from the release of stored water, which was used to cool reactors after the Fukushima accident, was analyzed in the Pacific Ocean.

• 대한핵의학회지
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• 제35권1호
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• pp.43-51
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• 2001

목적: 이번 연구는 임상적으로 구내 건조증을 호소하는 환자에서 Tc-99m pertechnetate를 사용하여 역동적 타액선 신티그라피를 얻어 기능적 변수를 정량화 하고자 하였으며 그 결과를 정적 타액선 신티그라피와 비교하여 그 유용성을 비교하고자 하였다. 대상 및 방법: 임상적으로 구내 건조증을 호소하는 환자 26명의 52개의 이하선과 52개의 악하선을 대상으로 하였다. 각각의 환자에서 역동적 타액선 신티그라피와 정적 타액선 신티그라피를 얻었다. 비교를 위하여 10명의 정상 대조군에서 같은 방법으로 타액선 신티그라피를 획득하였다. 370 MBq Tc-99m pertechnetate를 정주한 다음 10분 후에 자극 전 정적영상을 획득하였고 이어서 20분간 역동적 영상을 획득하였는데 이때 최타 자극을 위해 레몬 주스를 사용하였다. 역동적 영상을 획득한 후에 정적영상을 다시 획득하여 재섭취 영상으로 하였다. 역동적 영상에서는 섭취율, 분비율 및 재섭취율과 같은 기능적 변수를 획득하여 정상과 비정상을 판별하였다. 마지막으로 정적영상과 동적영상의 결과를 비교하였다. 결과: 모든 증례에서 역동적 타액선 신티그라피에서 섭취율, 분비율 및 재섭취율을 성공적으로 획득할 수 있었다. 역동적 신티그라피에서 각각 52개의 이하선과 악하선 중 22개의 이하선과 22개의 악하선이 비정상으로 판독되었다. 정적 신티그라피에서는 다른 결과가 초래 되었는데 역동적 타액선 신티그라피의 결과를 참조하여 그 원인을 추정할 수 있었다. 결론: Tc-99m perechnetate를 사용한 역동적 타액선 신티그라피는 정적 신티그라피보다 타액선의 기능적인 평가에 더 유리하다고 생각되며 임상적으로 구강건조증이 있는 환자에서 타액선의 기능적인 변화를 평가하는데 유용하다고 생각된다.