http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
멜라민 화합물을 이용한 산화 그래핀 도핑 및 특성 평가
김수민,김현,김소양,한종훈,Kim, Sumin,Kim, Hyun,Kim, So Yang,Han, Jong Hun 한국재료학회 2019 한국재료학회지 Vol.29 No.11
In this paper, nitrogen-doped reduced graphene oxide(rGO) is obtained by thermal annealing of nitrogen-containing compounds and graphene oxide (GO) manufactured by modified Hummers' method. We use melamine as a nitrogen-containing compound and treat GO thermally with melamine at over $800{\sim}1,000^{\circ}C$ and 1 ~ 3 hr under Ar atmosphere. The electrical conductivity of doped rGO is measured by 4-point probe method. As a result, nitrogen contents on rGO are found to be in the range of 2.5 to 12.5 at% depending on the doping conditions after thermal annealing. The main doping site on graphene oxide is changed from pyridinic-N and pyrrolinic N to the graphitic site as the heat treatment temperature increases. The electrical conductivity of doped rGO increases as the N doping content increases. As the thermal treatment time increases, the change of both total doping contents and doping sites is slight and the surface resistance is remarkably reduced, which is caused by healing effects of doped graphene oxide at high temperature.
2단 실린더형 싸이클론의 물 및 오일 액적 제거 성능 분석 연구
김수민,김학준,김명준,한방우,우창규,김용진,Kim, Sumin,Kim, Hak-Joon,Kim, Myungjoon,Han, Bangwoo,Woo, Chang Gyu,Kim, Yong-Jin 한국입자에어로졸학회 2017 Particle and Aerosol Research Vol.13 No.3
A novel two stage cylindrical cyclone was developed for a 3 phase separator in shale oil production industry. The cyclone performance was compared with a cone type cyclone and multi cyclone at the same experimental condition using water and oil mists generated by a humidifier and atomizer at the flow rate 1 to $2m^3/min$. The removal efficiency of total suspended water droplets by the novel cyclone, calculated using inlet and outlet concentrations measured by an optical particle counter, was 99% which is higher than 90% of oil droplet removal efficiency at $2m^3/min$. It might be due to the evaporation of small water droplets during the tests. The water and oil droplet removal performance of the novel cyclone based on the quality factor which is a function of pressure drop and removal efficiency was the highest among three cyclones. The results indicate that the cyclone could be an economical device to remove water and oil mists from shale gas generation processes where a huge three phase separator is commonly used.
김수민,송건탁,김정,Kim, Sumin,Song, Guntak,Kim, Jeong F. 한국막학회 2021 멤브레인 Vol.31 No.4
In this work, we tested commercial organic solvent nanofiltration (OSN) membranes using both in-house dead-end and crossflow systems. Four different crosslinked polyimide Duramem (DM) OSN membranes with various MWCO (molecular weight cut off) values were tested in organic solvents such as ethanol, N,N-dimethylformamide, acetone and acetonitrile. The membranes exhibited more reliable and reproducible performance in the crossflow system, and the performance changed significantly depending in the physical properties of the testing solvent. This is due to the initial stabilization period via pressure-induced compaction phenomenon, which can be vastly different between membrane samples. Hence, to obtain reliable and reproducible results, crossflow system is the preferred choice. 본 연구에서는 Dead-end와 Crossflow 시스템을 사용하여 유기용매 나노여과(Organic Solvent Nanofiltration, OSN) 상용분리막의 성능을 분석하였다. 가교된 polyimide 소재 기반의 Duramem (DM) OSN 분리막의 성능을 ethanol, dimethylformamide (DMF), acetone, acetonitrile 용매에서의 성능을 분석하였다. 네 종류의 분획분자량 성능을 갖는 DM 분리막의 성능을 평가하였을 때 dead-end보다 Crossflow에서 조금 더 정확하고 신뢰성 높은 결과를 얻을 수 있었으며, 동일한 분리막이더라도 용매의 특성에 따라 투과도와 선택도 차이가 크게 난다는 것을 확인할 수 있었다. 이는 압밀화현상으로 인한 초기 안정화 기간의 차이 때문인 것으로 판단되며 분리막마다 안정화기간이 다르므로 신뢰성 높은 결과를 얻기 위해선 Crossflow 시스템을 활용하는 것이 더 적합한 것으로 보인다.
ESG 압력이 기업의 혁신활동에 미치는 영향: 규제 및 규범적 압력의 효과를 중심으로
김수민(Sumin Kim),박재민(Jaemin Park),봉강호(Kang Ho Bong) 한국경영학회 2023 經營學硏究 Vol.52 No.4
Recently, with the emphasis on ESG management worldwide, social pressure on ESG management is increasing. ESG is driven by two contradictory pressures: ‘responsibility required from society’ and ‘voluntary participation of companies’, and ESG activities are sustainable, if the two pressures work together. From the view of maximizing social benefit, it is necessary to identify the optimal pressure level. Therefore, this study aims to empirically examine the relationship between regulatory · normative ESG pressure and corporate innovation activities from the perspective of institutional theory. Innovation as an ESG activity enables companies to achieve revenue generation through ESG activities, enabling sustainable ESG activities. As a result of the analysis, it was confirmed that regulatory ESG pressure had an inversed U-shape relationship with innovation activities, and normative ESG pressure had a U-shape relationship.
김수민(Sumin Kim),이동민(Dongmin Lee),문정훈(Junghoon Moon) 한국가금학회 2018 韓國家禽學會誌 Vol.45 No.1
Recently, the Korean government has been trying to conserve the genetic resources of native chicken. Although the production aspect is important, consumers should also value the native chicken in order for this market to grow. As certification systems are used to inform consumers about the value of a product, this study aims to investigate certification systems for chicken in France. Two regions were selected: Alsace and Bresse. We conducted a value-chain analysis of activities related to native chicken in each of these two regions, including hatching, breeding, slaughtering and processing, distributing, and marketing activities. We found that various certification systems were used not only to inform consumers about the value of the native chicken but also to protect biodiversity. Also, geographical indication, one kind of certification system, was utilized to establish higher quality based on the characteristics of each region. Implications pertinent to a domestic certification system for Korean native chickens were suggested.
김수민(Sumin Kim),김태훈(Tae-Hoon Kim),차희령(Hee-Ryoung Cha),이정구(Jung-Goo Lee) 한국자기학회 2024 韓國磁氣學會誌 Vol.34 No.2
Nd-Fe-B 희토류 영구자석은 1983년 개발된 이후로 지금까지 상용자석 중 가장 높은 자기적 특성을 가지고 있어 수많은 산업 분야에서 핵심 소재로 적용되어 왔다. 특히 전기/하이브리드 자동차의 보급에 따른 전기모터의 소형화, 경량화, 고효율화에 대한 요구는 고특성 Nd-Fe-B 영구자석의 의존도를 더욱 증대시켰다. 하지만 2025년 네오디뮴(Nd)에 대한 수요가 공급을 넘어설 것으로 예측되고 있으며, 희토류 원소 보유국의 자원전략화 등으로 인한 희토류 공급/가격 리스크를 고려하였을 때 Nd-Fe-B 자석에 대한 의존도를 낮추는 방향으로 가야만 한다. 이에 대한 해결책으로 Nd 대신 세륨(Ce), 란타넘(La), 사마륨(Sm)과 같이 자원이 풍부하거나 시장에 과공급 되어있는 희토류 원소를 적극적으로 사용할 필요가 있다. 따라서 본 글에서는 Nd를 Ce, La 등의 경희토류 원소로 대체하는 ‘Nd-저감형 희토류 영구자석’과 Nd를 완전히 배제하는 Sm-Co, Sm-Fe(-N) 등과 같은 ‘Nd-free 희토류 영구자석’ 소재의 제조 기술과 연구 동향에 대해 다루고, 이 소재들의 상용자석으로서의 가능성을 살펴보고자 한다. Since the development of Nd-Fe-B based rare-earth permanent magnet in 1983, it has become indispensable materials in various industries, owing to their unparalleled magnetic properties among commercial magnets. Especially, the proliferation of electric/hybrid vehicles and demands for downsizing, lightweighting, and high efficiency of electric motors have further increased the reliance on high-performance Nd-Fe-B permanent magnets. However, it is predicted that the demand for neodymium (Nd) will surpass the supply by 2025, and considering the risks of rare earth supply/price due to the resource strategies of rare earth-rich countries, it is necessary to reduce the dependence on Nd-Fe-B permanent magnets. As a viable solution, active utilization of rare earth elements such as cerium (Ce), lanthanum (La), and samarium (Sm), which are abundant or oversupplied in the market, instead of Nd, is needed. Therefore, we will discuss the manufacturing technology and research trends of ‘Nd-reduced rare earth permanent magnets’ replacing Nd with Ce, La, and ‘Nd-free rare earth permanent magnets’ such as Sm-Co, Sm-Fe(-N), and explores their potential as commercial magnets.