• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.36-36
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• 2017

• Journal of Environmental Science International
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• v.32 no.3
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• pp.197-204
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• 2023

This study aims to inactivate Artemia sp. (Zooplankton) in ballast water through the dielectric barrier discharge (DBD) plasma process. The DBD plasma process has the advantage of enabling direct electric discharge in water and utilizing chemically active species generated by the plasma reaction. The experimental conditions for plasma reaction are as follows; high voltage of 9-22 kV, plasma reaction time of 15-600 s, and air flow rate of 0.5-5.5 L/min. The results showed that the optimal experimental conditions for Artemia sp inactivation were 16 kV, 60 s, 2.5 L/min, respectively. The concentrations of total residual oxidants and ozone generated by plasma reaction increased with an increase of in voltage and reaction time, and the concentration of generated air did not increase above a certain amount.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1495-1506
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• 2023

For the safe disposal of high-level radioactive waste using Engineered Barrier Systems (EBS), bentonite buffer is used by its high swelling capability and low hydraulic conductivity. When the bentonite buffer is contacted to heated pore water containing ions by radioactive decay, chemical alterations of minerals such as illitization reaction occur. Illitization of bentonite indicates the alteration of expandable smectite into non-expandable illite, which threatens the stability and integrity of EBS. This study intends to provide a thorough review on the information underlying in the illitization of bentonite, by covering basic clay mineralogy, smectite expansion, mechanisms and observation of illitization, and illitization in EBS. Since understanding of smectite illitization is crucial for securing the safety and integrity of nuclear waste disposal systems using bentonite buffer, this thorough review study is expected to provide essential and concise information for the preventive EBS design.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.218-219
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• 2022

Among the Barrier Free (BF) certification evaluation items for public facilities, at which position the standard for the effective height of the stair railing handle should be calculated is not clearly determined. Because of this, not only the evaluation standards of the certification authority and the evaluation committee are different, but disputes are occurring between the ordering organization, the design company, and the construction company. Therefore, the stair railing installation standard laws for public facilities were analyzed and through a case study of institutions that obtained the BF certification, problems were analyzed. The results of problem analysis reveal the following. 1) The standards of the Ministry of Health and Welfare and the Ministry of Land, Infrastructure, and Transport were different. 2) The effective height calculation standard was ambiguous, and disputes occurred frequently. To solve this problem, we proposed improvement plans for calculating the height of the stair railing that can comply with laws while ensuring safety.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.27-28
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• 2021

For Barrier-Free certification, the floor and ground surfaces must be finished with materials that are not slippery, flat, and have low-impact in fallis. However, the BF Certification Act does not provide specific methods to meet these regulations. In performance-based design, the responsibility of proving the performance rests with the building owner and architect, so quantitative evaluation indexes are needed to select suitable materials. Furthermore, changes in performance after completion should be checked periodically in 'As-Is' conditions. There are various methods for slips, trips and falls risk assessment, causing confusion for users. In this study, the results of previous studies on the evaluation methods of slips, trips and falls were considered closely, and each quantitative evaluation index that can be used in the new construction and maintenance phase was presented.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.323-332
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• 2024

Circulating hydroponic cultivation has the advantage of reducing soil and water pollution problems caused by discharge of fertilizer components because the nutrient solution is reused. However, cyclic hydroponic cultivation has a low biological buffering capacity and can cause outbreaks of infectious root pathogens. Therefore, it is necessary to develop technologies or disinfection systems to control them. This study used dielectric barrier discharge plasma, which generates various persistent oxidants, to treat Fusarium oxysporum f. sp., a pathogen that causes wilt disease. Batch and intermittent continuous inactivation experiments were conducted, and the results showed that the total residual oxidant was persistent in intermittent plasma treatment at intervals of 2-3 days, and F. oxysporum was treated efficiently. Intermittent plasma treatment did not inhibit the growth of tomatoes.

• Journal of the Korean Society of Safety
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• v.38 no.3
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• pp.110-120
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• 2023

Following the Fukushima accident, portable equipment employed as accident mitigating systems have been installed and operated to reduce core damage and large early release frequencies. In addition, the establishment of an accident management strategy has gained importance. This study investigated the current status of portable equipment including the international portable equipment FLEX (diverse and flexible coping strategies), and domestic portable equipment multi-barrier accident coping strategy (MACST). Research on optimal utilization of MACST remains insufficient. As a preliminary study for establishing an optimal strategy, sensitivity studies were conducted to facilitate the priority of use on portable equipment, number of portable equipment, and dependency of operator actions based on a multi-unit probabilistic safety assessment model. The results revealed the conditions that reduced the multi-unit and site conditional core damage probabilities, indicating the optimal strategy of MACST. The results of this study can be used as a reference for establishing an optimal strategy that utilizes domestic safety equipment in the future.

• The Korean Journal of Pesticide Science
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• v.16 no.1
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• pp.11-20
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• 2012

As increasing the use of pesticides both in number and amount to boost crop production, consumer concerns over food quality and safety with respect to residual pesticides are also continuously increasing. However, there is still lacking of information that can effectively help to remove residual pesticides in foods. In recent years, contaminant removal by gas (or) glow discharge plasma (GDP) attracts great interests on environmental scientists because of its high removal efficiency and environmental compatibility. It was shown to be effective for the removal of some organophosphorus pesticides, phenols, benzoic acid, dyes, and nitrobenzene on solid substrate or in aqueous solution. This work mainly focuses on the removal of wide range of residual pesticides from fresh fruits and vegetables. As for preliminary study, the experiments were carried out to investigate whether GDP can be used as an effective tool for degrading target pesticides or not. With this objective, 60 selected pesticides drop wised onto glass slides were exposed to two types of GDP, dielectric barrier discharge plasma (DBDP) and low pressure discharge plasma (LPDP), for 5 min. Then, they were washed with 2 mL MeCN which were collected and used for determination of remaining concentration of pesticides using LC-MS/MS. Among selected pesticides, degradation of 18 pesticides (endosulfan-total was counted as one pesticide) by GDP could not be examined because control treatments, which were left in ambient environment, of those pesticides recovered less than 70% or even did not recover. However, majority of tested pesticides (42) were degraded by both types of GDP with satisfactory recovery (>80%) of control sample. Pesticides degradation ranged from 66.88% to 100% were achieved by both types of plasma except clothianidin which degradation in LPDP was 26.9%. The results clearly indicate that both types of gas discharge plasma are promising tools for degrading wide range of pesticides on glass substrate.

• Journal of Fisheries and Marine Sciences Education
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• v.20 no.2
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• pp.147-155
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• 2008

The purpose of this study was to identify the causal relationship developmental activity of the marine sports among the educational value and barrier's factors in a middle school teachers in Busan. Responses were collected from 352 questionnaires which participated in the survey chosen by convenient sampling from the middle school teachers who working the area of Busan. A total of 338 responses were used in data analysis; 14 questionnaires were excluded form data analysis because of incomplete or missing data. To conduct this study the multiple regression analysis was used by SPSS 10.0. The result of this study disclosed; first, The factors of educational value such as self-concept development, collaboration, human relationship, and emotional development were statistically causal relationship with the developmental activity of the marine sports. The other factors of creativity, leisure activity, and health were not statistically causal relationship with the development activity of the marine sports. Second, the barrier's factors of facility and weather were statistically causal relationship with the developmental activity of the marine sports. The other barrier's factors of safety accident, program, and participation expense were not statistically causal relationship with the developmental activity of the marine sports.

• Journal of Korean Society of Steel Construction
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• v.17 no.3 s.76
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• pp.263-270
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• 2005

This paper presents a program for protecting vehicles against side winds on highways. The present study consists of three processes. The first one involves giving a guideline for evaluating driving safety in high winds. The second one involves making a guideline for determining the necessity of wind protection system for a certain road area. A reasonable procedure is suggested based on the probability model of wind data on weather stations and the correction of local topographical conditions. The third one involves design of wind barriers. Both CFD analyses and wind tunnel tests were performed to find the proper type of wind barrier considering vehicle controllability, structural safety, economical efficiency as well as driver's visibility. Performance of the designed wind fences was verified from field tests. The performance of the four different types of wind barrier installed at the elevated bridge were tested and some of the results were provided.