• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.18-18
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• 2012

전 세계적으로 이산화탄소 배출량 저잠을 위해 모든 산업분야에서 연구개발의 중점을 두고 있다. 그의 일환으로 자동차 산업에서는 EU규제에 따라 리사이클이 가능한 소재 개발이 요구되고 있으며, 그중 많은 양이 사용되고 있는 PU Foam의 대체 재료 개발이 시급한 실정이다. 기존 자동차의 흡음재로 주로 사용되고 있는 PU Foam 소재는 통기성이 부족할 뿐만 아니라 연소 시 인체에 유해한 HCN Gas를 발생시키고, 한번 성형된 부품은 Recycle 및 Re-Use가 불가능하다는 단점이 있다. 또한 장시간 사용시 황변 발생과 악취가 발생하는 등으로 최근 대두되고 있는 자동차 내장재 감성품질 향상 측면에 한계를 나타내고 있다. 이러한 Low Melting 성능을 가지는 PET 부직포 소재의 한계를 극복하기 위하여 저융점 성능의 Elastic Fiber의 개발과 함께 고탄성 복합부직포 소재의 개발을 통해 높은 변형률과 우수한 복원력을 나타내는 환경친화형 열가소성 탄성체(Thermoplastic Elastomer) 개발을 추진하고 있다. 고탄성 복합부직포는 자동차 내장재 성형 시 열을 가하더라도 Elastomer 자체의 탄성 발현을 통해 초기의 Bulky성을 유지할 수 있으며, Recycle 및 Re-use가 가능하여 환경 친화적인 측면에서도 큰 장점을 갖고 있다. 자동차용 흡음 내장재뿐만 아니라 각종 수송용 차량의 경량화 및 쾌적성 향상을 위한 용도로써 자동차 내장용 PU Foam의 57% 이상을 차지하고 있는 Seat Cushion재 등의 대체가 가능하며, 다양한 산업분야에서 사용되고 있는 PU Foam의 대체로 다양한 용도 전개가 가능할 것으로 예상된다. 본 연구에서는 PU Foam의 대체 재료로 각광받고 있는 Elastic PET를 개발하여 자동차 내장재로의 적용 가능성을 검토하였다.

• Journal of Energy Engineering
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• v.24 no.1
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• pp.132-136
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• 2015

The objective of this study is to investigate the effect of biodiesel blending on spray and combustion characteristics. In order to this, blended fuels containing 0, 5, 20, 50, 100% biodiesel in weight fraction was injected via common rail to constant volume combustion chamber. As a result, spray cone angle decreased and the Sauter mean diameter increased because of the higher dynamic viscosity and density of biodiesel, however, it does not seemed that spray penetration was affected by these factors considerably. In the combustion experiment, ignition delay of biodiesel was shorter than that of diesel due to higher cetane number. And the peak value of heat release rate increased and the end of combustion was advanced owing to higher combustion efficiency cause by the characteristic of oxygenated fuel.

• Fire Science and Engineering
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• v.32 no.6
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• pp.46-54
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• 2018

A total of 19 elevators for evacuation were installed in the Lotte World Tower and it is planned to operate the shuttle using the manual key from five refuge floors to the 1st floor in an emergency. In the event of a fire or other disaster, it is necessary to conduct intensive analysis to determine how much RSET reduction could be achieved using the evacuation elevator compared to the existing evacuation plans. When the optimal transportation sharing ratio by the evacuation elevators was 40% at the Lotte World Tower, the RSET of the evacuation scenario in parallel with the elevators in the entire building was calculated to be 1 hour and 2 minutes. The RSET of a conventional evacuation scenario (Walking along the stairs without using the elevators) was calculated to be 1 hour 29 minutes, therefore, the former evacuation scenario were found to have a shortening effect of approximately 27 minutes compared to the latter. On the other hand, to maintain this effect, each part of the evacuation route using the elevator must have the capability to protect the evacuee from any hazards caused by fires, such as smoke, flame, and radiant heat during the evacuation. Moreover, the evacuation route should be continuous from the residence position of the elevator user to the final evacuation site, and be recognized easily.

• Journal of the Korean earth science society
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• v.45 no.3
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• pp.192-202
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• 2024

Ocean reanalysis data are extensively used in ocean circulation and climate research by integrating observational data with numerical models. This approach overcomes the spatial and temporal limitations of observational data and provides high-resolution gridded information that considers the physical interactions between ocean variables. In this study, I extended the previously produced 12-year (2011-2022) Northwest Pacific regional ocean reanalysis data to create a long-term reanalysis dataset (K-ORA22E) with a horizontal resolution of 1/24° spanning 30 years (1993-2022). These data were analyzed to diagnose long-term ocean climate change in the Korean marginal seas. Analysis of the K-ORA22E data revealed that the axis of the Kuroshio extension has shifted northward by approximately 6 km per year over the past 30 years, with a significant increase in sea surface temperature north of the Kuroshio axis. Among the waters surrounding the Korean Peninsula, the East Sea exhibited the most significant temperature increase. In the East Sea, the temperature increase was more pronounced in the middle layer than in the surface layer, with the East Korea Warm Current showing a rate two to three times higher than the global average. In the central Yellow Sea, where the Yellow Sea Bottom Cold Water appears, temperatures increased over the long-term, but decreased along the west and south coasts of the Korean Peninsula. These spatial differences in long-term temperature changes appear to be closely related to the heat transport pathways of warm water from the Kuroshio Current. High-resolution regional ocean reanalysis data, such as the K-ORA22E produced in this study, are essential foundational data for understanding long-term variability in the Korean marginal seas and analyzing the impacts of climate change.

• Food Science and Preservation
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• v.9 no.4
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• pp.434-440
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• 2002

The growth characteristics of 5. coli O157:H7 CDFI, A. sobria CDF3 and S. aureus CDF2 isolated from surface of carcass were investigated to improve hygienic quality of beef. The total count of carcass surface before washing was higher than that of after washing. Total count of after cooling decreased about 10$^1$∼ 10$^2$/㎠ compare with before cooling. Total count of carcass surface after transfer increased regardless seasons. The growth E. coli O157:H7 CDF1 occurred at pH 4 and 6% NaCl but A. sobria CDF3 and S. aureus CDF2 did not grow at the same conditions. Although the growth of E. coli O157:H7 CDF1 and S. aureus CDF2 was inhibited by 0.3％ lactic acid, but A sobria CDF3 did not grow in TSB containing 0.3％ lactic acid. E. coli O157:H7 CDF1 grew rapidly after 3 days incubation at 10$\^{C}$ but did not grow at 4$\^{C}$. But A. sobria CDF3 grew rapidly after 3 days incubation at 4$\^{C}$. E. coli O157:H7 CDF1 and A. sobria CDF3 were destroyed by heat treatment for 3 min at 60$\^{C}$. S. aureus CDF2 did not detect after heat treatment for 2 min at 70$\^{C}$.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.383-393
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• 2008

Purpose: Cancer specific killing can be achieved by therapeutic gene activated by cancer specific promotor. Expression of sodium iodide symporter (NIS) gene causes transportation and concentration of iodide into the cell, therefore radioiodine treatment after NIS gene transfer to cancer cell could be a form of radionuclide gene therapy. luciferase (Luc) gene transfected cancer cell can be monitored by in vivo optical imaging after D-luciferin injection. Aims of the study are to make vector with both therapeutic NIS gene driven by AFP promoter and reporter Luc gene driven by CMV promoter, to perform hepatocellular carcinoma specific radiodiodine gene therapy by the vector, and assessment of the therapy effect by optical imaging using luciferase expression. Materials and Methods: A Vector with AFP promoter driven NIS gene and CMV promoter driven Luc gene (AFP-NIS-CMV-Luc) was constructed. Liver cancer cell (HepG2, Huh-7) and non liver cancer cell (HCT-15) were transfected with the vector using liposome. Expression of the NIS gene at mRNA level was elucidated by RT-PCR. Radioiodide uptake, perchlorate blockade, and washout tests were performed and bioluminescence also measured by luminometer in these cells. In vitro clonogenic assay with 1-131 was performed. In vivo nuclear imaging was obtained with gamma camera after 1-131 intraperitoneal injection. Results: A Vector with AFP-NIS-CMV-Luc was constructed and successfully transfected into HepG2, Huh-7 and HCT-15 cells. HepG2 and Huh-7 cells with AFP-NIS-CMV-Luc gene showed higher iodide uptake than non transfected cells and the higher iodide uptake was totally blocked by addition of perchlorate. HCT-15 cell did not showed any change of iodide uptake by the gene transfection. Transfected cells had higher light output than control cells. In vitro clonogenic assay, transfected HepG2 and Huh-7 cells showed lower colony count than non transfected HepG2 and Huh-7 cells, but transfected HCT-15 cell did not showed any difference than non transfected HCT-15 cell. Number of Huh-7 cells with AFP-NIS-CMV-Luc gene transfection was positively correlated with radioidine accumulation and luciferase activity. In vivo nuclear imaging with 1-131 was successful in AFP-NIS-CMV-Luc gene transfected Huh-7 cell xenograft on nude mouse. Conclusion: A Vector with AFP promoter driven NIS and CMV promoter driven Luc gene was constructed. Transfection of the vector showed liver cancer cell specific enhancement of 1-131 cytotoxicity by AFP promoter, and the effect of the radioiodine therapy can be successfully assessed by non-invasive luminescence measurement.