• Composites Research
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• v.29 no.1
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• pp.40-44
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• 2016

Nuclear fuel cladding used in a nuclear power plant must possess superior oxidation resistance in the coolant atmosphere of high temperature/high pressure. However, as was the case for the critical LOCA (loss-of-coolant accident) accident that took place in the Fukushima disaster, there is a risk of hydrogen explosion when the nuclear fuel cladding and steam reacts dramatically to cause a rapid high-temperature oxidation accompanied by generation of a huge amount of hydrogen. Hence, an active search is ongoing for an alternative material to be used for manufacturing of nuclear fuel cladding. Studies are currently aimed at improving the safety of this cladding. In particular, ceramic-based nuclear fuel cladding, such as SiC, is receiving much attention due to the excellent radiation resistance, high strength, chemical durability against oxidation and corrosion, and excellent thermal conduction of ceramics. In the present study, cladding with $SiC_f/SiC$ protective films was fabricated using a process that forms a matrix phase by polymer impregnation of polycarbosilane (PCS) after filament-winding the SiC fiber onto an existing Zry-4 cladding tube. It is analyzed the oxidation and microstructure of the metal cladding with $SiC_f/SiC$ composite protective films using a drop tube furnace for thermal shock test.

• Journal of the Society of Disaster Information
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• v.12 no.1
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• pp.1-9
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• 2016

Local wall thinning elbow due to the water flow is one of the main degradation phenomenon in carbon steel pipe of plant system. The API579 code of FFS (fitness for service) used in the chemical plant gives a guideline to protect local wall thin problem in a straight pipe, but it does not include an elbow. In this study, the locally wall thinned elbow, which is considered an extrados or intrados wall thinned elbow, was carried out considering in-plane or out-plane bending using FEM (finite element method) analysis, and some of results were also compared with the experimental data. The results could give the structure integrity assessment to protect the local wall thinned elbow.

• Economic and Environmental Geology
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• v.50 no.5
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• pp.415-422
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• 2017

This study focuses on the sustainable development and intelligence information society, analyzing the results of science and technology forecasts from Korea and Japan for 2040-2050. Future geological environment and disaster technologies are presented, such as base geology, geophysical geological disaster, weather adjustment, $CO_2$ reduction, environmental disaster, and smart ecocity developments. For the future technologies in energy and resources technology, space resources development and nuclear fusion will be realized by 2040 and 2050. Moreover, new material and resource technologies will be applied to replace existing energy and mineral resources by 2040. Japan has introduced intelligent information viewpoints and presented new technologies.

• Journal of IKEEE
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• v.22 no.4
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• pp.1079-1087
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• 2018

Recently, computer vision field based deep learning artificial intelligence has become a hot topic among various image analysis boundaries. In this study, flames are detected in fire images using the Faster R-CNN algorithm, which is used to detect objects within the image, among various image recognition algorithms based on deep learning. In order to improve fire detection accuracy through a small amount of data sets in the learning process, we use image augmentation techniques, and learn image augmentation by dividing into 6 types and compare accuracy, precision and detection rate. As a result, the detection rate increases as the type of image augmentation increases. However, as with the general accuracy and detection rate of other object detection models, the false detection rate is also increased from 10% to 30%.

• Journal of the Korean Society of Radiology
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• v.14 no.6
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• pp.755-762
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• 2020

This study is desinged to examine the effects of Taheebo(Tabebuia avellanedae) extract on the prostate of male rats as a natural radiation protection agent. Taheebo extract is well known to inhibit cell growth for the cell lines of breast and prostate cancer. In this study, the X-ray 7 Gy was irradiated in the prostate of male rat to identify radiation protection effects by Taheebo Extracts, 1, 7, and 21 Days later, hematological changes, external toxicity assessments(LDH), antioxidant enzyme(SOD) activity changes and tissue change were observed. IR+TH group showed greater lymphocyte levels than the irradiation group, which is believed to affect the hematopoietic immune system's resilience. As a results of the external toxicity assessment, Taheebo extract's toxicity is maximum 18.128±5.16%, minimum 13.6945±4.43%. Taheebo is considered to be of little toxicity. The composition of prostate cell nuclei and cytoplasm in Control and TH group was honogeneous, whereas the cell nucleus cohesion in the prostate in irradiation group and inflammatory reactions in cytoplasm were shown. IR+TH group showed less inflammatory reactions of cytoplasm in the prostate than in the radiation irradiation group, but showed a cohesive phenomenon of cell nuclei. It is judged that Taheebo extract has radiation protection against prostate cells.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.313-320
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• 2021

This study evaluates the radiation protection effects of Schizonepeta tenuifolia water extract on white rat by gender. Schizonepeta tenuifolia contains polyphenol and flavonoid, which are typical substances that remove free radical. Thus, to determine the effectiveness of radiation protection, the Schizonepeta tenuifolia water extract was administered to Sparaqu-Dawely (SD) rat males and females for two weeks, followed by hematological analysis, analysis of changes in the length of the small intestine villi length, and SOD activity evaluation. The male rat in ST+IR group showed a slightly greater recovery of platelets than the IR group. The ST+IR group also showed a higher platelet recovery capability than the IR group. lymphocyte showed that male and female rat ST+IR groups have higher resilience than IR groups likewise platelet. After irradiation, the villi length of the male rat and female rat decreased less in ST+IR group than in the IR group, indicating that the villi length of all genders was less damaged. This result confirmed that the Schizonepeta tenuifolia water extract had a radiation protection effect.

• Journal of radiological science and technology
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• v.46 no.1
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• pp.23-28
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• 2023

The purpose of this study is to see the radiation protection effect of the oral injected Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts on the small intestine and uterus of female SD Rat as a natural radiation protection agent. The experimental group was divided into four groups: Normal Control group (NC group), Injected Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts group (DZ group), irradiated group after injecting Dendranthema zawadskii var. latilobum (Maxim.) Kitam. extracts (DZ+IR group). The whole body of SD Rat was irradiated with gamma-ray 10Gy, and the administration of oral Dendranthema zawadskii var. latilobum (Maxim.) Kitam. Extract was 2 cc (71.56 mg/day/kg) once a day for 2 weeks. For this study, chages in blood cell levels, SOD assay, small intestine and uterus were observed. In the 21st white blood cell level, the DZ+IR group recovered to a normal level, and the IR group didn't. The IR group villus length was lower than other groups on Day 1. IR group was partially recovered, and DZ+IR group was recovered like the NC group on Day 21. In the case of the first-day endometrium, the IR group was thin and the boundary was cloudy, and the DZ+IR group was thicker and the boundary was clearer than the IR group. Day 21 IR group still did not recover, and DZ+IR group recovered like NC group. This is believed to have radiation protection effects in the blood cells and small intestine and uterus of the irradiated female SD Rat, and is expected to be useful for the study of natural radiation protection materials.

• Journal of Science and Technology Studies
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• v.15 no.1
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• pp.45-67
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• 2015

This essay aims to search for the reason of why, even after Fukushima nuclear disaster, Korean citizens did not try to seek out the possibility of another energy option. Firstly, we single two counter-concepts, the configuration of risk communication and scientific citizenship, out from the measure of frequency of co-occurrence key-terms and the analysis of survey on the citizens' scientific perception each. Secondly, we try to interpret the meaning of qualitative data, and finally, we draw out the result as follow. Korean government have driven out the pro-nuclear policy, and in this course have made full use of the discourse of there-is-no-alternative-option. We need to take an attention to the reason of why the discourse can circulate freely in society. From one data, we find out that the configuration of risk communication guarantee government's success. But we also should look at the another side, the scientific citizenship. From another data, we find out that the upstream scientific citizenship, the momentum of preparing alternative, has not been mature, and it is reason of why the discourse have an strong influence.

• Hwankyungkyoyuk
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• v.18 no.1 s.26
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• pp.120-133
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• 2005

This study investigated the changes of consciousness and ambivalent attitudes about the important environmental issues among the teachers who enrolled the environmental education training. Experimental and control groups were composed with 47 and 30 person, respectively. Environmental issues were constructions of sea-wall, nuclear power plant and dam. Cronbach alpha of the self-developed questionnaire was $0.6909{\sim}0.8992$. Score were made with 5 Likert scales for consciousness, and with semantic differential half scale for ambivalent attitudes. Almost teachers(94.0% and 97.1%) have above 10 years teaching career. Strangers in environmental program were 53.2%. After environmental training, teachers' consciousness was significantly changed to negative about the construction of sea-wall for the farm field and industry complex area(p=0.019), and about the construction of dam for disaster like flood(p=0.026), and for adverse effects of citizen by fog(p=0.042). They were also significantly changed to negative about the construction of nuclear power plant for economical energy(p=0.004)', no-emission of greenhouse gases(p=0.033)', 'alternative energy(p=0.000)', 'destruction of ecology(p=0.052)' and 'social fear(p=0.009)'. The consciousness of teachers who have the experience of environmental training, were significantly changed to negative about the construction of nuclear power plant. Scores of teachers' ambivalent attitudes were made lower in experimental than control group about the construction of sea-wall and nuclear power plant. After education training, they were made lower so much as -10.0% in control, but higher much as +4.4% in experimental, and severely higher much as 86.5% in teachers who had experienced the environmental training about construction of sea-wall. Their scores were made lower so much as -3.3% in control, but much as -6.4% in control.

• Journal of Radiation Protection and Research
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• v.48 no.3
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• pp.131-143
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• 2023

Background: This study examined the detection limit of thyroid screening monitoring conducted at the time of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011 using a Monte Carlo simulation. Materials and Methods: We calculated the detection limit of a NaI(Tl) survey meter to measure ¹³¹I accumulation in the thyroid gland of children. Mathematical phantoms of 1- and 5-year-old children were developed in the simulation of the Particle and Heavy Ion Transport code System code. Contamination of the body surface with eight radionuclides found after the FDNPP accident was assumed to have been deposited on the neck and shoulder area. Results and Discussion: The detection limit was calculated as a function of ambient dose rate. In the case of 40 Bq/cm² contamination on the body surface of the neck, the present simulations showed that residual thyroid radioactivity corresponding to thyroid dose of 100 mSv can be detected within 21 days after intake at the ambient dose rate of 0.2 µSv/hr and within 11 days in the case of 2.0 µSv/hr. When a time constant of 10 seconds was used at the dose rate of 0.2 µSv/hr, the estimated survey meter output error was 5%. Evaluation of the effect of individual differences in the location of the thyroid gland confirmed that the measured value would decrease by approximately 6% for a height difference of ±1 cm and increase by approximately 65% for a depth of 1 cm. Conclusion: In the event of a nuclear disaster, simple measurements carried out using a NaI(Tl) scintillation survey meter remain effective for assessing ¹³¹I intake. However, it should be noted that the presence of short-half-life radioactive materials on the body surface affects the detection limit.