Formation of Deoxybenzoins and ${\beta}$-Keto Sulfides by the Reaction of ${\alpha}$-Stabilized Anion of Phosphonates with Nitriles

Kilsung Lee,Dong Young Oh Korean Chemical Society 1991 Bulletin of the Korean Chemical Society Vol.12 No.3

THE EFFECT OF CELL ASPECT RATIO AND FLOW RATE ON REVERSE ELECTRODIALYSIS SYSTEMS

Kilsung KWON,Byung Ho PARK,Daejoong KIM 한국신재생에너지학회 2014 AFORE Vol.2014 No.-

Addition of $\alpha$-Lithioalkana Phosphonates to Nitriles, Synthesis of $\beta$-Keto Phosphonate and Enamine Phosphonates

Kilsung Lee,Dong Young Oh Korean Chemical Society 1989 Bulletin of the Korean Chemical Society Vol.10 No.6

원통형 다공성 유리막을 이용한 전기삼투 펌프의 연구

권길섳(Kilsung Kwon),김대중(Daejoong Kim) 대한기계학회 2012 大韓機械學會論文集B Vol.36 No.6

본 논문에서는 원통형 다공성 유리막을 이용한 전기삼투 펌프의 실험적 연구를 수행하였고, 장시간 작동을 평가하였다. 전기삼투 펌프의 성능은 탈이온수와 1 mM 붕산염 완충액을 이용하여 최대유량, 최대전류, 그리고 최대압력으로 표현하였다. 최대유량, 최대전류, 그리고 최대압력은 모두 이론에서 예측하는 것과 같이 전압이 증가할 때 선형적으로 증가하였다. 최대유량을 유체의 펌핑면적과 적용 전압으로 나눈 표준화 유량을 사용하여 원통형 다공성 유리막을 이용한 전기삼투 펌프와 평면형 다공성 유리막을 이용한 전기삼투 펌프의 성능을 비교하였다. 표준화 유량은 원통형 다공성 유리막을 이용할 때 평면형 다공성 유리막보다 대략 1.5 배 높은 값을 가졌고, 이는 원통형 다공성 유리막과 평면형 다공성 유리막의 기하학적 부분의 차이에 의한 것으로 판단되었다. 표준화 유량 값을 이용하여 동일한 전기삼투 펌프 부피에서 두 다공성 막을 비교하면, 원통형 전기삼투 펌프는 평면형 전기삼투 펌프에 비해 최대 원주율만큼의 펌핑면적을 증가할 수 있으므로 5 배 높은 유량을 얻었다. 원통형 전기삼투 펌프의 내부 전극에서 전기분해에 의해 발생하는 가스들은 나피온 튜브를 통하여 효과적으로 배출되었고, 이로 인해 3 시간 이상의 작동에서 성능의 감소는 발생되지 않았다. In this study, we demonstrated the operation of an electroosmotic pump with cylindrical porous glass frits and evaluated its long-term operation. The performance of this electroosmotic pump was characterized in terms of maximum flow rate, current, and pressure using deionized water and 1 mM borate buffer. The maximum flow rate, current, and pressure linearly increase with voltage. The maximum flow rate is normalized by the pumping area and voltage for comparison of the performance between the electroosmotic pumps with cylindrical and planar frits. The normalized maximum flow rate of the cylindrical-type pump is higher than that of the planar-type pump because of their different geometries. The cylindrical-type electroosmotic pump has five times better performance than the planartype electroosmotic pump for a given pump package volume. It can operate stably for over 3 hours.

단위전류당 고유량 유기용매 이송을 위한 다공성 실리콘막 전기침투 펌프의 개발

권길성(Kilsung Kwon),김대중(Daejoong Kim) 대한기계학회 2010 大韓機械學會論文集B Vol.34 No.2

양극산화법과 DRIE 법으로 제작된 다공성 실리콘막을 이용하여 두 종류의 전기침투 펌프를 제작하였다. 펌프의 성능은 유기용매를 이용하여 유량과 단위전류당 유량으로 측정하였다. 두 종류 펌프 모두 기존의 다공성 유리막으로 제작된 전기침투 펌프보다 성능이 우월했다. 특히 DRIE 법으로 제작된 다공성 실리콘막은 유량과 단위전류당 유량이 모두 월등한 성능을 보였다. DRIE 법은 널리 알려진 방법이기에 이와 같이 제작된 펌프는 다양한 응용 분야에 비교적 쉽게 적용될 것으로 기대된다. Two types of electro-osmotic pumps were prepared: with anodized and DRIE porous silicon. The pump performance was characterized for both types in terms of flow rate and flow rate per current using organic solvents. Both types of electro-osmotic pumps showed a better performance compared to porous glass electro-osmotic pumps. The DRIE porous silicon electro-osmotic pump especially demonstrated an excellent flow rate and flow rate per current performance. The DRIE porous silicon electro-osmotic pump is expected to help in the development of electro-osmotic pumps and micropumps in general due to the recently widespread availability of DRIE processes.

Clinical and Polysomnographic Characteristics of Patients with Restless Legs Syndrome

James Kilsung Yang,moonsook lee 대한수면학회 2019 sleep medicine research Vol.10 No.1

Background and ObjectiveaaAlthough restless legs syndrome (RLS) symptoms are relatively clear, many people are suffering from RLS without proper care because RLS is often underdiag- nosed and misdiagnosed. Purpose of this study was to examine clinical and polysomnographic as- pects of RLS to better understand the disorder for future diagnosis. MethodsaaThis study enrolled 113 idiopathic untreated RLS patients, including 74 (65.5%) wom- en and 39 (34.5%) men. Restless legs syndrome rating scale (RLSRS) and RLS checklist were exam- ined. All patients underwent suggested immobilization test (SIT) and polysomnogram (PSG). ResultsaaRLS occurred in all age groups. It was the most prevalent in age groups of 50s and 60s. On average, RLS was diagnosed 12.5 years after the first occurrence of RLS symptoms. RLS oc- curred twice as often among women than that among men. Based on average RLSRS, 57.5% and 26.5% of patients belonged to severe and very severe categories, respectively. While symptoms were the most prominent between 8 PM and 4 AM, patients reported that calves were the main site of discomfort. Of all participants, 54.9% reported family history of RLS. RLS patients’ PSGs showed lower sleep efficiency (SE), total sleep time, and slow wave percentage with higher leg movement arousal index (LMAI), arousal index, and sleep latency (SL). RLSRS was positively correlated with LMAI (r = 0.221, p < 0.05), periodic leg movement during wake index-PSG (PLMWI-PSG) (r = 0.214, p < 0.05), and SL (r = 0.207, p < 0.05). RLSRS was also negatively correlated with SE (r = -0.222, p < 0.05). RLSRS was not correlated with PLMWI-SIT or PLMI. ConclusionsaaThe results suggest that the severity of RLS patients is related to SL, LMAI, PLM- WI-PSG, and SE. In order to effectively diagnose RLS, not only clinical characteristics, but also polygraphic characteristics such as SL, LMAI, PLMWI-PSG, and SE should be taken into account.

모자형 단면부재의 압궤특성에 관한 연구

이길성(Kilsung Lee),차천석(Cheonsuk Cha),양인영(Inyoung Yang) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

The purpose of this study was to develop lightweight hat shaped section side members which absorb the most of the energy during the front-end collision of vehicle. The hat shaped section members consist of the spot welded member which was utilized to an actual vehicle, the CFRP member and the hybrid member for lightweight of vehicle structural member. The spot welded member was made of SCP1 cold rolled steel sheet and the CFRP (carbon fiber reinforced plastics) member was made of CFRP prepreg sheet. The hybrid member was manufactured by combination of aluminum and CFRP. The hat shaped section members were tested under static axial loading by universal testing machine. Energy absorption capability and collapse mode of the members were analyzed and compared.

알루미늄 복합재료 혼성 구조부재의 에너지흡수 메커니즘

이길성(Kilsung Lee),양용준(Yongjun Yang),박준우(Junwoo Park),황우채(Woochae Hwang),김정호(Jungho Kim),서현경,양인경(Inyoung Yang) 한국자동차공학회 2007 한국자동차공학회 지부 학술대회 논문집 Vol.- No.-

Aluminum members under axial load absorb energy through sustained plastics deformation. However, CFRP (Carbon Fiber Reinforced Plastics) members absorb energy through uneven brittle failure. On the other hand, CFRP has higher specific stiffness and specific strength as compared to aluminum members. This study examines collapse characteristics of aluminum composite compound structural member. Since CFRP is an anisotropic material, its collapse characteristics change according to orientation. Therefore, CFRP collapse characteristics have been evaluated against orientation angle and thickness. Collapse mode of the combined CFRP aluminum member has been determined by orientation angle of the CFRP where it was steadily collapsed under high load. In addition, it was demonstrated that energy absorption is dependent upon orientation angle and thickness.

휴대용 고분자전해질막 연료전지의 산화제 공급을 위한 전기침투 현상 기반의 공기펌프의 개발

권길성(Kilsung Kwon),김대중(Daejoong Kim) 대한기계학회 2010 大韓機械學會論文集B Vol.34 No.7

본 논문은 고분자전해질막 연료전지의 공기 공급을 위해 전기침투현상에 기반을 둔 공기 공급 방법을 제안하고 이를 실험적으로 평가하였다. 작동 유체의 구동을 위해서 전기침투펌프를 낮은 주파수의 교류 전기장에서 사용하였다. 작동 유체는 유연한 막에 의해 막 밀봉하였고, 막의 움직임에 의해 연료전지 내로 공기를 공급하였다. 본 연구에서는 전기침투현상 기반 공기펌프를 사용하여 연료전지의 공기 공급을 성공적으로 설명하였다. 펌프의 출력은 연료전지에서 생성되는 출력을 초과하였지만, 본 논문에서는 펌프의 출력 당 연료전지의 출력비를 줄이기 위한 몇 가지 방법들에 대해 설명하였다. We propose an electroosmosis-based air delivery scheme for polymer electrolyte fuel cells and experimentally investigate its feasibility. An electroosmotic pump under a low-frequency AC electric field is used to displace initially a volume of pump working liquids. This working liquid is then pumped into a space enclosed by a flexible membrane and the movement of the membrane delivers air to a fuel cell. We successfully demonstrated the operation of a forced-convection fuel cell using this technique. In this preliminary study, however, the power consumption of the pump exceeds the power generated by the fuel cell. We conclude this paper with a discussion of several ways to reduce the pump-to-fuel cell power ratio.

적층구성이 CFRP 사이드부재의 압궤특성에 미치는 영향

이길성(Kilsung Lee),양인영(Inyoung Yang) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

This study is to investigate the collapse characteristics of CFRP(Carbon-Fiber Reinforced Plastics) side member on static tests. Currently, stacking condition related to the collapse characteristics of composite materials is being considered as an issue for the structural efficiency and safety of automobiles, aerospace vehicles, trains, ships even elevators during collision. In particular, CFRP composite materials have found wide applicability because of their inherent design flexibility and improved materials properties. The most important objective in designing automobiles is Currently to focus on environment-friendly aspect and safety performance aspect. In this study, CFRP side members with single-hat-section shaped were manufactured. The axial static collapse tests were performed for the members using universal testing machine, and the collapse mode and energy absorption capability were analyzed according to stacking condition.