Since ships are exposed to noise and vibration for a long time in seas isolated from land, the stress of workers is high, requiring studies on the improvement of the problem. In addition, the health of crew members on fishing vessels, unlike commercial ships, carrying out fishing activities is closely related to fishing performance. However, considering that most of IMO's guidelines apply to merchant ships, provisions should be made for vibration in accommodation areas of fishing vessels. Accordingly, this study, applying the revised ISO 20283-5:2016 standard and through experiment, investigated the vibration characteristics of the accommodation area for each operating conditions of a 1000-ton trawler fishing vessel. Within the scope of the study and the full-ahead mode, the vibration was highest in the engine control room (4.17mm/s) while the acceptable standard was satisfied sufficiently in all conditions. Application of the merchant vessel vibration standard to fishing vessel is expected to improve the working environment of fishing vessel crew members.

Despite its advantages such as safety, unnecessary pretreatment, and decontamination of waste with complex geometry, conventional ultrasonic decontamination technology has been only used to remove loose contaminants, oil and grease, not fixed contaminants due to the limitations in increasing the intensity in the high frequency range. Thus, ultrasound has been used as an auxiliary method to accelerate chemical decontamination of radioactive wastes or chemicals were added to the solution to increase the decontamination efficiency. The recently developed high-intensity focused ultrasound (HIFU) decontamination technology overcomes these limitations by combining multiple frequencies of ultrasonic waves in a specific arrangement, making it possible to remove most fixed contaminants, including radioactive micro particles less than 1 micrometer within half an hour. KEPCO NF and EnesG developed mobile HIFU decontamination equipment and successfully demonstrated the decontamination effect on various radionuclides found in nuclear power plants by treating radioactive metal waste to the level below free release criteria. The mobile HIFU decontamination equipment used in the demonstration can be operated anywhere where water is supplied, including controlled area in nuclear power plants, and is expected to be used widely for decontamination and free release of metal radioactive wastes.

Recently, the International Maritime Organization is strengthening regulations for ships operating in polar regions. Hence, insulated multi-core tubes as components for vessels operating in extreme cold need to be investigated in various aspects. Furthermore, the demand for research on electric propulsion vessels is also increasingly growing. Thus, to utilize a 4-core insulated multi-core tube with glass wool as insulation, which was previously developed for ships operating in polar regions, as a water-cooled electrical cable, this study conducted an experiment on the temperature change when water at normal temperature 25℃ was supplied as a coolant under the overcurrent varied from 10A to 25A. As a result, the temperature increase of the core in 10A condition was 3.3℃, but it increased to 13.05℃ in the 25A condition. This showed that a temperature difference of approximately 9.75℃ occurred according to the overcurrent load. However, the coolant inlet and outlet temperatures were relatively uniform around 1℃ in all conditions. This suggests that increasing the residence time by proper control of the coolant flow in the future could achieve a higher cooling effect.

본 연구는 고삼 물추출물과 주 성분인 마트린의 유전 독성 유발능을 마우스 간세포 및 혈구세포에서 체내 단세포전기영동 시험법을 사용하여 평가하였다. OECD TG 489 에서 정하고 있는 체내 알카리코멧 시험법(in vivo alkanine Comet assay)을 수컷 마우스를 사용하여 수행하였다. 고삼 물추출물의 투여 용량은 한계 용량을 포함하도록 체중 대비 1,000와 2,000 mg/kg으로 하였다. 마트린의 세 투여용량은 50, 100, 200 mg/kg으로 정하였고, 최고 투여용량은 용량 설정시험을 통하여 설정하였다. 음성대조물질과 시험물질은 경구로 3회 투여하였고, 양성대조물질(ethyl methanesulfonate, EMS)은 2회 투여하였다. 마지막 투여 후 3-4시간 내에 간 조직과 혈액을 채취하였고 단세포전기영동을 알카리 조건에서 수행하였다. 코멧 시험 결과, 고삼 물추출물과 마트 린에 의한 체중의 변화가 관찰되지 않았으며, 간세포와 혈구세포에서 통계적으로 유의성 있는 유전자 손상을 유발 하지 않았다. 따라서, 본 연구조건에서 고삼 물추출물과 마트린은 유전독성 유발능이 없는 것으로 사료된다.