• Journal of Korean Home Economics Education Association
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• v.10 no.1
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• pp.1-16
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• 1998

The purpose of this study was to investigate the middle school and high school student's environmental consciousness and clothing behavior for environmental protection in their home, and to present the basic educational material for the reasonable clothing behavior which could help the environmental problems. This study was done by self-administered questionaires to the 439 middle school and high school students, and done from March to April in 1997. Frequencies, percentages, mean, and standard deviation were calculated. $\chi$$^2$-test, t-test, and F-test were done for group differences, and Duncan's multiple range test was followed. The results of this study were as follows ; 1. Environmental consciousness was higher at the middle school students, at good graded students, and at the good news receivers who watch or listen to the mass media frequently. And also environmental consciousness was higher at the students who separate and dispose waste practically and at those who realize the need of environmental education. 2. Those who purchase clothes reasonably in their home, practising the clothing behavior for environmental protection, were the middle school students, and the students sho watch or listen news frequently through the mass media. And those who manage clothes well in their home were the middle school students, metropolitan area residents, good news receivers, and residents in apartments. Those who separate and dispose waste well, those who have experienced much environmental education, those who know better the environmental protection marks which are attatched to the low pollution products and those who realize the need of environmental education seriously, were almost the same students who buy and manage clothes reasonably in their home, practising the clothing behavior for the environmental protection. And those who feel much more environmental education seriously were those who reuse clothes practically in their home. 3. As the students had the higher environmental consciousness level, the better they practised the clothing behavior for environmental protection in their home. The major sources of the students'knowledge and information about environment were from the mass medea, and then from school teachers.

• Nuclear Engineering and Technology
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• v.48 no.6
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• pp.1368-1375
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• 2016

A radiological safety assessment study was performed for the transportation of low level radioactive wastes which are temporarily stored in Korea Atomic Energy Research Institute (KAERI), Daejeon, Korea. We considered two kinds of wastes: (1) operation wastes generated from the routine operation of facilities; and (2) decommissioning wastes generated from the decommissioning of a research reactor in KAERI. The important part of the radiological safety assessment is related to the exposure dose assessment for the incidentfree (normal) transportation of wastes, i.e., the radiation exposure of transport personnel, radiation workers for loading and unloading of radioactive waste drums, and the general public. The effective doses were estimated based on the detailed information on the transportation plan and on the radiological characteristics of waste packages. We also estimated radiological risks and the effective doses for the general public resulting from accidents such as an impact and a fire caused by the impact during the transportation. According to the results, the effective doses for transport personnel, radiation workers, and the general public are far below the regulatory limits. Therefore, we can secure safety from the viewpoint of radiological safety for all situations during the transportation of radioactive wastes which have been stored temporarily in KAERI.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3298-3303
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• 2014

In order to recycle the waste bumper, techniques removing coated paint on a bumper is crucial. Chemical methods are known to be much more effective in removing the paint compared to physical methods. However, the chemical methods generally use toxic solvents and consequently cause environmental pollution. In this study, we tested a new method which combines the chemical and physical method to reduce the amount of solvent and increase the paint removal efficiency. We found that mechanical stirring increases the paint removal efficiency in soaking stage of solvent. When solid particles as a stress transfer media are incorporated into the solvent and high mechanical stirring is applied, the paint removal efficiency is very high. It was proved that the combined method can accomplish high level of the paint removal efficiency maintaining low amount of solvent consumed.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.565-573
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• 2018

Cyclotron for medical purposes generates nuclear reaction by accelerating protons in high speed, in order to produce radiopharmaceuticals, and unnecessary neutrons are generated through such nuclear reaction. Neutrons cause activation in the parts of cyclotron which then cause exposure to radiation for people working in the field. This study, in that regard, aims to analyze exposure level by finding out the degree of activation of aluminum body, silver body, and havar foil which are the parts of Targetry where the nuclear reaction takes place. The results of the experiment showed that aluminum body and silver body had no problems re-using them as the energy and half-life of activated nuclides were small and short, making the affect on the people working in the field extremely low. However for havar foil, its activated nuclides had a high level of energy which resulted in high level of affect to the people working in the field. The activation factors of the cyclotron were analyzed, and the results showed that the Havar foil was activated the most among the targetry parts, and greatly exposed workers due to regular replacement, and needed special management as radioactive waste.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.153-167
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• 1995

Recycling is receiving increasing social attention today as our nation begins to grapple with the significant problems caused by huge amount of municipal solid waste. The topic of recycling is not simple but extremely complicated. This study attempts to provide basic data and policy options for expanding and improving separated collection and recycling in public residential areas, through three case study of apartment housing areas in Taegu Metropolitan City. The main results of this study are summarized as follows. For the significant period of time, all three case areas had in common the extreme difficulty in establishing and operating the system of connecting public participation, collection and storage, transportation, and actual recycling of materials because of a variety of problems involved in this process. Both amounts of and prices for collected materials fluctuated considerably over time mainly due to monthly changes in recyclable home materials and the dynamic nature of recycling markets. Public questionnaire survey revealed the very high level of participation in separated collection, not only because almost all respondents well understood the necessity and importance of recycling, but because they also knew how to do separated collection. But overall activities were rated low and most respondents suggested the enlargement of public participation, the improvement of collection and storage facilities, and collection transportation networks. In particular, most respondents had little experience of using recycled Products and used mainly reproduced soap and bathroom tissue. Furthermore, they were considerably unsatisfied with low variety and quality of recycled products, their high prices and low availability in the market. Finally potential policy options and activities for improving separated collection and recycling are suggested.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.349-357
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• 2019

Controlled low strength material(CLSM) has been developed using variety of material such as excavated soil, industrial by-product and industrial waste. But theses research limited at laboratory test and failed at commercialization. So in this paper evaluates CLSM used excavated soil characteristics such as flowability, bleeding rate, early strength for following process and 28day strength for re-excavatability. Also, various mix proportion of CLSM by water-binder ratio and soil-binder ratio were evaluated in laboratory. And derive the optimized CLSM mix proportion for using at field application test by movable batch plant. After applying CLSM at trench, evaluate core sample strength and excavatability by shovel, pickax and excavator for verify re-excavation. Furthermore, measure the level change after casting CLSM to inspect subsidence stability. As results of these assessments, not only confirmed the characteristics of CLSM at field but the fillability around pipe and subsidence stability.

• Tunnel and Underground Space
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• v.21 no.5
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• pp.349-358
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• 2011

This paper introduces a new P wave arrival time determination algorithm of acoustic emission (AE) suitable to identify P waves with low signal-to-noise ratio generated in rock masses around the high-level radioactive waste disposal repositories. The algorithms adopted for this paper were amplitude threshold picker, Akaike Information Criterion (AIC), two step AIC, and Hinkley criterion. The elastic waves were generated by Pencil Lead Break test on a granite sample, then mixed with white noise to make it difficult to distinguish P wave artificially. The results obtained from amplitude threshold picker, AIC, and Hinkley criterion produced relatively large error due to the low signal-to-noise ratio. On the other hand, two step AIC algorithm provided the correct results regardless of white noise so that the accuracy of source localization was more improved and could be satisfied with the error range.

• Particle and aerosol research
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• v.15 no.1
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• pp.1-13
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• 2019

Current desulfurization and denitrification technologies have reached a considerable level in terms of reduction efficiency. However, when compared with the simultaneous reduction technology, the individual reduction technologies have issues such as economic disadvantages due to the difficulty to scale-up apparatus, secondary pollution from wastewater/waste during the treatment process, requirement of large facilities for post-treatment, and increased installation costs. Therefore, it is necessary to enable practical application of simultaneous SOx and NOx treatment technologies to remove two or more contaminants in one process. The present study analyzes a technology capable of maintaining simultaneous treatment of SOx and NOx even at low temperatures due to the electrochemically generated strong oxidation of the wet-pulse complex system. This system also reduces unreacted residual gas and secondary products through the wet scrubbing process. It addresses common problems of the existing fuel gas treatment methods such as SDR, SCR, and activated carbon adsorption (i.e., low treatment efficiency, expensive maintenance cost, large installation area, and energy loss). Experiments were performed with varying variables such as pulse voltage, reaction temperature, chemicals and additives ratios, liquid/gas ratio, structure of the aeration cleaning nozzle, and gas inlet concentration. The performance of individual and complex processes using the wet-pulse discharge reaction were analyzed and compared.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.110-120
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• 2005

For utilizing vitrification to treat low and intermediate level waste, industrial pilot plant was designed and constructed in October 1999 at Daejon, Korea through the joint research program among NETEC, MOBIS and SGN. More than 70 tests were performed on simulated IER, DAW etc. including key nuclide surrogate(Cs, Co); this plant has been shown to vitrify the target waste effectively and safely, however, some dust are generated from the HTF(High Temperature Filter) as a secondary waste. In case of long term operation, it is also concerned that pipe plugging can be occurred due to deposited dust in cooling pipe namely, connecting pipe between CCM(Cold Crucible Melter) and HTF. In this regard, we have developed the special complementary system of the off-gas treatment system to recycle the dust from HTF to CCM and to remove the interior dust of cooling pipe. Main concept of the dust recycling is to feed the dust to the CCM as a slurry state; this system is regarded as of an important position in the viewpoint of volume reduction, waste disposal cost and glass melt control in CCM. The role of DRS(Dust Recycling System) is to recycle the major glass components and key nuclides; this system is served to lower glass viscosity and increase waste solubility by recycling B, Na, Li components into glass melt and also to re-entrain and incorporate into glass melt like Cs, Co. Therefore dust recycling is helpful to control the molten glass; it is unnecessary to consider a separate dust treatment system like a cementation equipment. The effects of Dust Cleaner are to prevent the pipe plugging due to dust and to treat the deposited dust by raking the dust into CCM. During the pilot vitrification test, overall performance assessment was successfully performed; DRS and Dust Cleaner are found to be useful and effective for recycling the dust from HTF and also removing the dust in cooling pipe. The obtained operational data and operational experiences will be used as a basis of the commercial facility.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.847-870
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• 2023

The safe disposal of high-level radioactive waste requires accurate predictions of the long-term geochemical behavior of radionuclides. To achieve this, the present study was conducted to model geochemical behaviors of uranium (U), plutonium (Pu), and palladium (Pd) under different hydrogeochemical conditions that represent deep groundwater in Korea. Geochemical modeling was performed for five types of South Korean deep groundwater environment: high-TDS saline groundwater (G1), low-pH CO₂-rich groundwater (G2), high-pH alkaline groundwater (G3), sulfate-rich groundwater (G4), and dilute (fresh) groundwater (G5). Under the pH and Eh (redox potential) ranges of 3 to 12 and ±0.2 V, respectively, the solubility and speciation of U, Pu, and Pd in deep groundwater were predicted. The result reveals that U(IV) exhibits high solubility within the neutral to alkaline pH range, even in reducing environment with Eh down to -0.2 V. Such high solubility of U is primarily attributed to the formation of Ca-U-CO₃ complexes, which is important in both G2 located along fault zones and G3 occurring in granitic bedrocks. On the other hand, the solubility of Pu is found to be highly dependent on pH, with the lowest solubility in neutral to alkaline conditions. The predominant species are Pu(IV) and Pu(III) and their removal is predicted to occur by sorption. Considering the migration by colloids, however, the role of colloid formation and migration are expected to promote the Pu mobility, especially in deep groundwater of G3 and G5 which have low ionic strengths. Palladium (Pd) exhibits the low solubility due to the precipitation as sulfides in reducing conditions. In oxidizing condition, anionic complexes such as Pd(OH)₃^-, PdCl₃(OH)₂^-, PdCl₄^2-, and Pd(CO₃)₂^2- would be removed by sorption onto metal (hydro)oxides. This study will improve the understanding of the fate and transport of radionuclides in deep groundwater conditions of South Korea and therefore contributes to develop strategies for safe high-level radioactive waste disposal.