• Economic and Environmental Geology
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• v.51 no.2
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• pp.113-120
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• 2018

Radioactive cesium($^{137}Cs$) can be released into the environment through severe nuclear accidents such as the Chernobyl and Fukushima, The $^{137}Cs$ is one of major monitoring radionuclides due to its chemical toxicity, ${\gamma}$ radiation and long half-life($t_{1/2}=30.2yrs$). It has been known well that illite adsorb selectively and strongly the cesium due to frayed edge sites. The quantity of the FES in the illite could be controlled by weathering processes. Therefore, this study was modified illite samples through artificial weathering in the laboratory to increase sorption efficiency for cesium. Abundant interlayer cations(i.e., K, Ca) were eluted within 1 day, while Si and Al were gradually released from the crystal structure. In addition, broad peaks of XRD indicated the occurrence of chemical weathering. The cesium sorption distribution coefficients increased up to approximately 2 times after the weathering. These results suggested that sorption capacity of illite could be enhanced for cesium through artificial weathering under low temperature.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.241-249
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• 2007

This article addresses considerations, processes of drawing concepts and design approaches in compiling a corporate brochure set in the practice of editorial design. A well-made brochure does not simply refer to listings of the current state of a company and a fantastic visualization of their visions. It necessarily involves the utilization of strategic core keywords appropriate to the industry, proper and classy metaphors that fit the target, a certain harmony between direct and indirect narratives, and bringing all of these aspects under the hat of creative and purposeful design in a single brochure. Thus, it also calls for variety and changes to captivate the eye when leafing through brochures. 1. Does the brochure reflect accurate diagnoses on the position of the market environment, the industry and their needs? 2. Does it offer solutions to given tasks, does it claim to be able to solve problems a company may have, does it satisfy their expectations, and does it cover the topics in an in-depth manner? 3. Referring to questions 1 & 2, does it address existing cases of competitors, leading players and global trends? 4. Does it have an appropriate design language that can communicate intrinsic issues and global trends as well as appropriate rhetorical visual aids that stand out?

• Journal of Mushroom
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• v.2 no.3
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• pp.157-162
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• 2004

The objectives of this experiment were to study the growth and development of fruiting body of the two Ganoderma lucidum isolates on log of the soft wood Paraserianthes falcataria and the hard wood Shorea sp., and determination of organic germanium and crude ganoderic acid content of the fruiting body produced. The two Ganoderma lucidum isolates used were one Indonesian native (Indonesia isolate) and another isolate was purchased from Fungi Perfecti, USA (commercial isolate). The development and quality of the primordium and fruiting body of the mushroom, in general, were influenced by the isolates used. The types of wood, however, had no effect on the quality of the primordium and fruiting body produced. The Indonesian isolate produced better fruiting body compared to that of the commercial isolate. The development of fruiting body from primordium, however, was low for the two isolates tested. In general, only about one third of the primordium developed further into mature fruiting bodies, except for the commercial isolate grown on the soft wood medium in which more than 60% of the primordium developed into mature fruiting body. Apart from producing normal fruiting body, the commercial isolate also produced an abnormal one, which had a white mature pileus, whereas the normal one was brownish red. The organic germanium concentration of the fruiting body produced on the hard wood, in general, was higher than that of grown on the soft wood. The fruiting body from commercial isolate had higher organic germanium concentration compared to that of Indonesian isolate in both wood types. The two isolates used, however, had almost the same value of the crude ganoderic acid concentration in both types of wood tested. The Indonesian isolate had higher total yield of both organic germanium and crude ganoderic acid of the fruiting body produced compared to that of the commercial isolate.

• Journal of Radiation Protection and Research
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• v.30 no.3
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• pp.99-105
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• 2005

A model for evaluating radioactive contamination in the urban environment, named METRO-K, was developed as a basic step for accident consequence analysis in case of an accidental release. The three kind of radionuclides $(^{137}Cs,\;^{106}Ru,\;^{131}I)$ and the different chemical forms of iodine (particulate, organic and elemental forms) are considered in the model. The radioactive concentrations are evaluated for the five types of surface (roof, paved road, wall, lawn/soil, tree) as a function of time. Using the model, the contaminative impacts of the surfaces were intensively investigated with respect to with and without precipitation during the measurement periods of radionuclides in air. In addition, a practical application study was conducted using $^{137}Cs$ concentration in air and precipitation measured in an European country at the Chernobyl accident. As a result precipitation was an influential factor in surface contamination. The degree of contamination was strongly dependent on the types of radionuclide and surface. Precipitation was more influential in contamination of $^{137}Cs$ than that of $^{131}I$ (elemental form).

• Analytical Science and Technology
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• v.17 no.6
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• pp.514-519
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• 2004

Soil samples collected from around the BOMARC Missile Site were measured for their activity concentrations and isotopic ratios of Pu and Am isotopes with particle sizes. The activity concentrations of Pu and Am in the BOMARC soil were remarkably higher than the fallout levels, and the activities decreased nearly exponentially with an increasing particle size of the soil due to a decreasing surface area. The activity ratios of Pu-238 / Pu-239, 240, Pu-241 / Pu-239, 240 and Am-241 / Pu-239, 240 observed in the BOMARC soil were much lower than those attributed to the nuclear reprocess plants and the Chernobyl fallout. Also, the atomic ratio of Pu-240 / Pu-239 in the BOMARC soil was remarkably lower than the fallout value influenced by the nuclear weapons testing and the Chernobyl accident. The atomic ratio of Pu-240 / Pu-239 was so close to the value of the weapons grade Pu released from the crash of a B52 plane in the Thule of the Greenland, such that the Pu isotopes detected in the BOMARC soil could have originated from the weapons grade plutonium.

• Korean Journal of Child Education & Care
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• v.18 no.4
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• pp.175-185
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• 2018

Objective: The purpose of this study is to investigate the influence of teachers' demographic and sociological characteristics and the emotional support of the director and co-worker on the childcare efficacy of infant teachers. Methods: In this study, 169 Infant teachers of childcare centers have participated, where are located in Seoul and Gyeonggi-do Areas. The data was analyzed by using t-test and one way ANOVA to confirm the differences among groups, and also correlations analysis and multiple regression analysis were performed to analyze the interrelationship between variables and their effects. Results: Study outcome according to study subjects is as follows. First, we found a statistically meaningful difference in marital status and career by the differences of childcare efficacy depending on demographic and sociological characteristics of infant teachers. Second, childcare efficacy of infant teachers showed the most evident correlationship with co-workers support followed by the director's support. Third, the data also revealed that childcare efficacy of infant teachers was influenced by co-workers' support, their careers, marital status and their directors' support in order. Conclusion/Implications: In conclusion, higher levels of childcare efficacy were shown by the experienced and married early childhood teachers and the emotional support of co-workers has the greatest influence on their childcare efficacy.

• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.31-39
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• 2016

Background: It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. Materials and methods: A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. Results and discussion: A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. Conclusion: The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

• Journal of The Korean Association For Science Education
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• v.32 no.4
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• pp.775-788
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• 2012

This study was done at a scientific camp sponsored by Nara Women's University Secondary School, Japan. In this school, $10^{th}$ grade students from 4 East Asian countries: Korea, Japan, Taiwan, and Singapore, participated. We made a research on students' perceptions about nuclear energy. Sample populations include 77 students in total, with 12 Korean, 46 Japanese, 9 Taiwanese and 10 Singaporean students. Overall perceptions comparison about nuclear energy shows average values from the order of highest Korea, Taiwan, Singapore, and to lowest, Japan. We implemented a T-test to identify perception differences about nuclear energy, with one group that include 3 countries (Korea, Taiwan and Singapore) and another group that includes all the Japanese students. T-test results of perceptions about nuclear energy shows students from the 3 countries of Korea, Taiwan and Singapore having higher average than Japanese students. (p<.05). Korean average scores regarding overall perceptions about nuclear energy show as the highest in all 4 East Asian countries and also highest in all subcategories. On the contrary in Japan, they have lower and negative perceptions of nuclear energy. In spite of these facts, perceptions of Japanese students about nuclear energy seem lowest and negative mainly because of the recent Fukushima nuclear power plant disaster, caused by the tsunami and its subsequent damages and fears of radiation leaks, etc. This shows that negative information about future disasters and its resulting damages like the Chernobyl nuclear accident could influence more on people's risk perception than general information like nuclear energy-related technologies or the news that the plant is operating normally, etc. Even if the possibility of this kind of accident is very low, just one accident could bring abnormal risks to technology itself. This strong signal makes negative image and strengthens its perceptions to the people. This could bring a stigma about nuclear energy. This study shows that Government's policy about the highest priority for nuclear energy safety is most important. As long as such perception and decision are fixed, we found that it might not be easy to get changed again because they were already fortified and maintained.

• Journal of Radiation Protection and Research
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• v.33 no.1
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• pp.27-34
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• 2008

A Korean urban contamination model METRO-K (${\underline{M}}odel$ for ${\underline{E}}stimates$ the ${\underline{T}}ransient$ Behavior of ${\underline{R}}adi{\underline{O}}active$ Materials in the ${\underline{K}}orean$ Urban Environment, which is capable of calculating the exposure doses resulting from radioactive contamination in an urban environment, is taking part in a model testing program EMRAS (${\underline{E}}nvironmental$ ${\underline{M}}odelling$ for ${\underline{RA}}diation$ ${\underline{S}}afety$) oragnized by the IAEA (${\underline{I}}nternational$ ${\underline{A}}tomic$ ${\underline{E}}nergy$ ${\underline{A}}gency$). For radioactive contamination scenarios of Pripyat districts and a hypothetical RDD (${\underline{R}}adiological$ ${\underline{D}}ispersal$ ${\underline{D}}evice$), the predicted results using METRO-K were submitted to the EMRAS's Urban Contamination Working Group. In this paper, the predicted results for the contamination scenarios of a Pripyat district were shown in case of both without remediation measures and with ones. Comparing with the predictied results of the models that have taken part in EMRAS program, a feasibility for decision-making support of METRO-K was investigated. As a predicted result of METRO-K, to take immediately remediation measures following a radioactive contamination, if possible, might be one of the best ways to reduce exposure dose. It was found that the discrepancies of predicted results among the models are resulted from 1) modeling approaches and applied parameter values, 2) exposure pathways which are considered in models, 3) assumptions of assessor such as contamination surfaces which might affect to an exposure receptor and their sizes, 4) parameter values which are related with remediation measures applied through literature survey. It was indentified that a Korean urban contamination model METRO-K is a useful tool for dicision-making support through the participation of EMRAS program.