• The Korean Journal of Physiology
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• v.8 no.2
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• pp.75-78
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• 1974

It was planned to investigate, by observing incorporation of $[^3H]$ thymidine into liver cells, the influence of Panax Ginseng upon hepatic DNA synthesis in mice that received ACTH. Thirty male mice $(body\;weight:\;18{\sim}20\;g)$ were divided equally into the ginseng-ACTH and the saline-ACTH groups. Each animal of the ginseng-ACTH and the saline-ACTH groups received every day (subcutaneously) 0.05 m1/10 g body weight of ginseng extract (4 mg of ginseng alcohol extract in 1 ml of saline) and the same amount of saline, respectively, for 5 days. On the 5th experimental day, all animals received 0.01 unit of ACTH intraperitoneally one hour. after the last medication, and $1{\mu}Ci/g$ body weight of $[^3H]$ thymidine after one more hour. Five animals, at a time, of each group were sacrificed 1, 10, and 24 hours after thymidine administration, and their hepatic radioactivity was measured autoradiographically in terms of the % number of radioactive cells in 1,000 cell counts (Radioactive Index, R.1.). Following results were obtained: 1. The hepatic radioactive indices obtained from the saline-ACTH group 1, 10, and 24 hr after $[^3H]$ thymidine administration were $1.50{\pm}0.32,\;2.16{\pm}0.33\;and\;2.79{\pm}0.31\;(mean{\pm}S.D.)$, respectively. 2. The corresponding values obtained from the ginseng-ACTH group $(2.71{\pm}0.22,\;3.85{\pm}0.29,\;and\;5.06{\pm}0.31)$ were significantly higher than the values of the saline-ACTH group. It is inferred from the above results that the ginseng tends to prevent reduction in hepatic DNA synthesis caused by ACTH administration.

• Journal of Radiation Protection and Research
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• v.37 no.4
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• pp.202-207
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• 2012

The radioactivity inventory significantly affects all steps of decommissioning projects including planning, cost estimation, risk assessment, waste management and site remediation. The decommissioning project of the KRR-2 was completed in 2009 and a large amount of activated concrete waste was generated. The bioshield concrete, containing minute amount of impurity elements, was activated by neutron reaction during the operation of the reactor. A variety radionuclides was generated in the concrete, including $^3H$, $^{14}C$, $^{55}Fe$, $^{60}Co$ $^{63}Ni$, $^{134}Cs$, $^{152}Eu$ and $^{154}Eu$. In this paper, the comparison between the calculated results and previous measured results was carried out to estimate the inventory of the bioshield concrete of the KRR-2. The combined computer codes of MCNP5 and ORIGEN 2.1 for calculation of the distribution of neutron flux, cross-section and generation of radionuclides were used. The results were shown that 99.8% of the total radioactivity of $^3H$, $^{55}Fe$, $^{60}Co$ and $^{152}Eu$ in the bioshield concrete 12 years after shutdown. The effects on the variation of inventory were analysed depending on the operation periods and the cooling times in the bioshield concrete.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.73-80
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• 2019

Neutrons are generated by the nuclear reaction, which is absorbed into the concrete wall and causes the activation during cyclotron operation. The purpose of this study is to investigate the effect of neutron activation and radiative concrete on concrete type. This experiment used Monte Carlo simulation and RESRAD model. The results of the experiment showed that the higher the content of Fe in concrete, the greater the shielding rate. The effect of $^{56}Fe(n,\;2np)^{54}Mn$ reaction on workers is also increased. However, radioactive nuclides have low activity and have very low impact on workers. Radioactive concrete should be treated as general wastes with less than its self-disposal tolerance level, and it should be recycled to the surface such as road repair rather than landfill to minimize the effect of $^{14}C$.

• Journal of Radiation Protection and Research
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• v.36 no.3
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• pp.148-153
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• 2011

EMRAS-2 (Environmental Modelling for RAdiation Safety, Phase 2) is an international comparison program, which is organized by the International Atomic Energy Agency (IAEA), in order to harmonize the modelling of radionuclide behavior in the environment. To do so, the urban contamination working group within EMRAS-2 has designed the hypothetical scenarios for a specified urban area. In this study, the importance of contaminated surfaces composing an urban environment was analyzed in terms of dose rate using METRO-K, which has been developed to take a Korean urban environment into account. The contribution of contaminated surfaces to exposure dose rate showed distinctly a great difference as a function of specified locations and time following a hypothetical event. Moreover, it showed a distinct difference according to the existence of precipitation, and its intensity. Therefore, if an urban area is contaminated radioactively by any unexpected incidents such as an accident of nuclear power plants or an explosion of radioactive dispersion devices (RDDs), appropriate measures should be taken with consideration of the type of surface composing the contaminated environment in order to minimize not only radiation-induced health detriment but also economic and social impacts.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.857-862
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• 2020

In March 2011, a tsunami off Japan caused radioactive material that had seeped into the sea from the Fukushima nuclear accident to flow to the Pacific Ocean, causing pollution to sea life. For a comparative evaluation with the area surrounding the site of a nuclear power plant by the release of radioactive materials, an area 20 to 30 km away from the emergency protection plan area was selected as a comparative point considering weather conditions, population distribution, etc. In addition, the government intends to analyze the minimum detection radiation received by residents around the nuclear power plant and evaluate the effective dose. Analysis of tritium radiation from water samples showed that most of the samples were not detected and that 0.0014 % to 0.777 % of the annual legal standard of 1 mSv for the general public had little effect on the human body. Therefore, the measurement and analysis of water samples around the nuclear power plant site is expected to help relieve anxiety, such as exposure to the general public and neighboring residents due to radiation release.

• Membrane Journal
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• v.15 no.3
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• pp.198-205
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• 2005

Double-layered polymer films to assay the radioactive contamination were formulated using polysulfone (PSF) and cerium activated yttrium silicate (CAYS), consisting of a dense support layer and a CAYS-holding top layer prepared via the diffusion-induced phase inversion. As the vapor exposure process was omitted, the CAYS-holding layer showed a typical asymmetric structure, with CAYS being transfixed into the polymer network spread with large macropores. With the increase in vapor exposure time before immersion, morphology of the films transformed from asymmetric to sponge-like structures, with CAYS being localized in cellular structure. The border structure between the two layers reflects the phase inversion behavior of a cast solution during the coagulation. In the radioactive detection, the polymer phase in a film holding a sponge-like structure is so dense that the radionuclides, deposited on the film, could not filter through the phase, consequently resulting in the loss in the detection efficiency of the film.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.56-67
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• 2006

The reliability and failure mode effect analysis are effective means to achieve efficient and cost-reduction design for satellite development. The failure rate of COTS (Commercial-Off-The-Shelf) parts required for reliability analysis is not usually provided from the manufacturer. Space environment factors based on empirical data obtained from MIL-HDBK-217F can be applicable to the reliability calculation. As a radiation environment factor, the occurrence rate of SEL (Single Event Latch-up) is additionally incorporated for the failure rate prediction. In this paper, the statistical reliability analysis method for low-cost small satellite using COTS parts is suggested. This statistical reliability analysis was applied to HAUSAT-2 small satellite whose electronic boxes are consisted of many COTS parts to calculate the system reliability at the end of design mission life.

• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.357-366
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• 1993

Background: Lung clearance of inhaled $^{99m}Tc$-DTPA reflects alveolar epithelial permeability and it had been reported as more sensitive than conventional pulmonary function tests in detecting lung epithelial damage. However, measuring lung clearance of inhaled $^{99m}Tc$-DTPA by gamma camera may not always reflect alveolar epithelial permeability exactly because it is influenced by mucociliary clearance depending on the site of particle deposition. Moreover, this method takes much time and patient's effort because he has to sit or lie still in front of the camera for a prolonged period. Most of the absorbed DTPA is excreted in urine within 24 hours and the amount of excreted DTPA in urine during the first few hours after inhalation is influenced by absorption rate which is correlated with the alveolar-epithelial permeability suggesting that the urinary excretion, especially in first few hours, may be an alternate index for lung clearance. The purpose of this study was to evaluate the usefulness of ratio of excreted $^{99m}Tc$-DTPA in 2 hour and 24 hour urine as an index of alveolar-epithelial damage. Methods: Pulmonary function tests including diffusing capacity and lung clearance of $^{99m}Tc$-DTPA measured by gama camera ($T_{1/2}$) and 2hr/24hr urine excretion ratio (Ratio) of inhaled $^{99m}Tc$-DTPA in 8 normal subjects and 14 patients with diffuse interstitial lung disease were compared. Results: 1) In the normal control, there was significant negative correlation between the $T_{1/2}$ and the Ratio (r=-0.77, p<0.05). In patients with diffuse interstitial lung disease, there also was significant negative correlation between $T_{1/2}$ and Ratio(r=-0.63, p<0.05). 2) In diffuse interstitial lung disease patients, the $T_{1/2}$ was $38.65{\pm}11.63$ min which was significantly lower than that of normal control, $55.53{\pm}11.15$ min and the Ratio was $52.15{\pm}10.07%$ also signifantly higher than that of the normal control, $40.43{\pm}5.53%$ (p<0.05). 3) There was no significant correlations between $T_{1/2}$ or Ratio and diffusing capactiy of lung in both patients and controls (p>0.05). Conclusion: These results suggests that 2hr/24hr urine excretion ratio of inhaled $^{99m}Tc$-DTPA is a useful simple bedside test in assessing alveolar epithelial permeability and that it may be used as an additive follow-up test in patients with diffuse interstitial lung disease complementing conventional pulmonary function tests.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.151-156
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• 2012

$^{18}F$-fluorodeoxyglucose ($^{18}F$-FDG) causes a significant amount of radioactivity retention in kidneys and urinary tract and degrades image quality and diagnostic performance. Diuretics are used to perform tests and prevent the urinary tract retention of $^{18}F$-FDG. The purpose of the study is to investigate how the diuretics affect images and excretion rates of $^{18}F$-FDG. The study consists of a group using diuretics for patients with no primary tumors or transfer lesions in kidneys according to PET/CT images, a group using physiological saline and the control group injecting only $^{18}F$-FDG and SUVs are measured by configuring interested areas for each group. Also, SUVs are compared and evaluated depending on the lasix injection after basic inspection and injecting $^{18}F$-FDG for quantitative analysis. The study shows that images with decreased background radioactivity and increased urine excretion due to using diuretics. However, an opposite result that there is no change in the amount of radioactivity in urine appears. The study concludes that the diuretics may decrease background radioactivity in the images but may not affect the $^{18}F$-FDG excretion.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.41-46
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• 2011

Purpose: The result of exam using an imaging device is very closely related with the image quality. Moreover, this image quality can be changed according to the condition of image acquisition and evaluation method. In this study, we evaluated the image quality according to the difference of pre-set method in PET/CT image. Materials & Methods: PET/CT Discovery STe16 (GE Healthcare, Milwaukee, USA), Chest PET phantom (Experiment 1) and 94 NEMA phantom (Experiment 2) were used. Phantom were filled with $^{18}F$-FDG maintaining hot sphere and background ratio to 4:1. In the case of experiment 1, we set the radio activity concentration on 3.5, 6.0, 8.6 kBq/mL. In the case of experiment 2, we set the radio activity concentration on 3.3, 5.5, 7.7, 9.9, 12.1, 16.5 kBq/mL. All experiments were performed with the time-set method for 2 minutes 30 seconds per frame and the count-set method with one hundred million counts in 3D mode after CT transmission scan. For the evaluation of the image quality, we compared each results by using the NECR and SNR. Results: In the experiment 1, both the NECR and SNR were increased as radioactivity concentration getting increased. The NECR was shown as 53.7, 66.9, 91.4. and SNR was shown as 7.9, 10.0, 11.7. Both the NECR and SNR were increased in time-set method. But the count-set method's pattern was not similar with the time-set method. The NECR was shown as 53.8, 69.1, 97.8, and SNR was shown as 14.1, 14.7 14.4. The SNR was not increased in count-set method. In experiment 2, results of both the NECR and SNR were shown as 45.1, 70.6, 95.3, 115.6, 134.6, 162.2 and 7.1, 8.8, 10.6, 11.5, 12.7, 14.0. These results were shown similar patten with the experiment 1. Moreover, when the count-set method was applied, the NECR was shown as 42.1, 67.3, 92.1, 112.2, 130.7, 158.7, and SNR was shown as 15.2, 15.9, 15.6, 15.4, 15.5, 14.9. The NECR was increased but SNR was not shown same pattern. Conclusion: Increment of administered radioactivity improves the quality of image unconcerned with the pre-set method. However, NECR was not influenced by increment of total acquisition counts through simple increasing scan duration without increment of administered activity. In case of count-set method, the SNR was shown similar value despite of increment of radioactivity. So, the administered activity is more important than the scan duration. And we have to consider that evaluation of image quality using only SNR may not be appropriate.