고온작동 수퍼커패시터용 이온성 액체 전해질에서의 흄드 실리카의 효과

김동원,정현영,Kim, Dong Won,Jung, Hyunyoung 한국재료학회 2018 한국재료학회지 Vol.28 No.1

The demand for energy storage devices capable of operating at high temperatures is increasing. In order to operate at high temperatures, a device must have excellent thermal stability and no risk of explosion. Ionic liquids are electrolytes that satisfy the above conditions, and studies on improving their performance have attracted great interest. Here, we report the results of a study on the fabrication of a supercapacitor that has a composite electrolyte prepared by dispersing fumed silica in an ionic liquid. The fumed silica filler exhibits improved ionic conductivity and lower interfacial resistance. In particular, the silica nanoparticles with diameters of 10 nm exhibit better electrochemical properties than fillers of other diameters and have excellent device performance of 33 times higher than the pristine ionic liquid at high temperatures. This study can be used to improve the electrolytes of electrochemical devices, such as the next generation battery or lithium ion battery.

멕켈 게실 천공에 의한 신생아 복막염 1례

김동원,김성신,박재옥,이도상,Kim, Dong Won,Kim, Seung Sin,Park, Jae Ock,Lee, Do Sang 대한소아소화기영양학회 2004 Pediatric gastroenterology, hepatology & nutrition Vol.7 No.1

저자들은 생후 22시간만에 보챔, 복부 팽만 등의 복막염 증세가 나타난 신생아에서 단순 복부 방사선 소견에서 기복을 확인하고 응급 수술을 시행하여 태생기에 발생한 멕켈 게실 천공으로 진단된 신생아 1례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다. Meckel's diverticulum is the most common malformation of gastrointestinal tract. Symptoms of Meckel's diverticulum usually arise within 2 years of life. The most common presentations include hemorrhage, perforation, diverticulitis and intestinal obstruction. Perforation of the Meckel's diverticulum in a neonate is uncommon but life threatening condition. We describe the first case of perforation of Meckel's diverticulum in a 1-day-old neonate who presented with abdominal distension without hemorrhage.

Enrichment of Magnesium Isotopes by Monoazacrown Bonded Merrifield Peptide Resin.

김동원,Kim, Dong Won Korean Chemical Society 2001 Bulletin of the Korean Chemical Society Vol.22 No.6

Magnesium isotope separation was investigated by chemical ion exchange with the 1-aza-12-crown-4 bonded Merrifield peptide resin using an elution chromatographic technique. The capacity of the novel azacrown ion exchanger was 1.0 meq/g dry resin. The heavier isotopes of magnesium were enriched in the resin phase, while the lighter isotopes were enriched in the solution phase. The single stage separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assys. The separation factors of $^{24}Mg^{2+}$-$^{25}Mg^{2+}$, $^{24}Mg^{2+}$-$^{26}Mg^{2+}$, and $^{25}Mg^{2+}$-$^{26}Mg^{2+}$ were 1.008, 1.019, and 1.006, respectively.

대체에너지기술개발 지원현황과 향후 추진계획

김동원,Kim, Dong-Won 대한석유협회 1989 석유와 에너지 Vol.1989 No.5

Chromatographic Enrichment of Lithium Isotopes by Hydrous Manganese(IV) Oxide

김동원,Kim, Dong Won Korean Chemical Society 2001 Bulletin of the Korean Chemical Society Vol.22 No.5

Separation of lithium isotopes was investigated by chemical ion exchange with a hydrous manganese(IV) oxide ion exchanger using an elution chromatography. The capacity of manganese(IV) oxide ion exchanger was 0.5 meq/g. One molar CH3COO Na solution was used as an eluent. The heavier isotope of lithium was enriched in the solution phase, while the lighter isotope was enriched in the ion exchanger phase. The separation factor was calculated according to the method of Glueckauf from the elution curve and isotopic assays. The single stage separation factor of lithium isotope pair fractionation was 1.021.

이종망간의 상호연동 거이트웨이 시스템을 위한 내부고속연동망

김동원,신현식,류원,이현우,전경표,배현덕,Kim, Dong-Won,Sin, Hyeon-Sik,Ryu, Won,Lee, Hyun-Woo,Jun, Kyung-Pyo,Bae, Hyeon-Deok 한국정보처리학회 1997 정보처리논문지 Vol.4 No.2

본 논문에서는 다양한 이기종 망간의 상호 연동을 통한 개방형정보통신서비스를 제공하기 위해 게이트웨이시스(Gateway System)으로 개발되고 있는 대용량 통신처리 시스템의 내부 고속 연동망의 구조를 제시한다. 주요제원으로는 32*32 입출력 체널의 공유버스 스위칭 대역폭은은 640MBPS로써 평형상태에서 각 채널별 약 20Mbps 정도의 대연폭 할당이 가능하여 전화망 뿐만 아니라 고속의 ISDN 및 인터네트 서비스 연동이 가능하다. 고속 연동망은 주된 스위칭 기능을 담당하는 중재교환부, 각 입출력 채널을 구성하는 가입자 입출력부, 이들 상호 연결하는 백플레인버스로 구성이 되고, 신뢰성 향상기 위하여 부하 분담 방식의 이중화 구성이 가능하다.또한망정합모들의 구현을 용이케 하고 연동망 프로토콜을 처리하는 부하를 감소하기 위해 고속 연동망 프로토콜을 전담 처리 가입자노드 어댑터를 개발하였다. This paper proprses the architeecture of an interconnection network for Advanced Information Communi-cation Procssing System(AICPS)developde for prividing open information communication servies on a variety of heterogeneous networks.The proposed Interconnection network,called High Speed Swiching Fabric(HSSF),has been designed by a common bus.It can handile 32 i/O channels,each of which uses serial communication method using 100Mbps TAXI.The switching bandwidth of the common bus is 640Mvps.Each I/O channel can be alloted about 20Mbps bandwidth in steady state,and therefore it's sufficient bandwidth is able to interwork with ISDN and Internet services, as well as PSTN. HSSF is composed of the switching board assembly,the subscriber,I/O board assemly,and the backplane board assembly.An attached node takes in the network adapter board assembly to adapt the high speed interworking protocol.For reliability,HSSF is duplicated with load-sharing method.

비활성 세라믹 분말이 고분자 전해질의 전기적, 기계적 특성에 미치는 영향

김동원,박정기,김창정,노광수,Kim, Dong-Won,Park, Jung-Ki,Kim, Chang-Jung,No, Kwang-Soo 한국재료학회 1993 한국재료학회지 Vol.3 No.3

폴리에틸렌 옥사이드(PEO)/리튬 삼불화메탄 술포네이트(${LiCF}_{3}{SO}_{3}$)착제에 평균 직경 $1{\mu}$m인 미세 세라믹 분말 ($\gamma -{LiALO}_{2}$)을 혼합하여 얻은 복합체 고분자 전해질의 특성을 형태학 및 기계적 성질의 관점에서 고찰하였다. 균일하게 분산된 세라믹 분말을 상온에서 고체 고분자 전해질의 전기적, 기계적 성질을 크게 향상시키는 것으로 관찰되었으며, 그 조성에 따라 그 특성이 변하였다. 본 연구에서 조사된 복합체 고분자 전해질의 경우, 상온에서 최대 이온 전도도를 나타내는 ${LiAlO}_{2}$의 최적 함량은 약 20%인 것으로 나타났다. The characteristics of composite polymer electrolytes obtained by adding a fine ceramic powder($\gamma-{LiAlO}_{2}$) with a diameter of $1{\mu}$m to a poly(ethylene oxide)/lithium trifluoromethane sulfonate (LiC$F_3$S$O_3$) complex are described in terms of morphological and mechanical behavior. The addition of uniformly dispersed ceramic powder greatly improves the electrical and mechanical properties of solid polymer electrolytes at ambient temperature. For the composite polymer electrolytes under this study, the optimum composition of the $\gamma-{LiAIO}_{2}$ in the composite for maximum ionic conductivity was found to be 20 wt%.

Effect of Metal Ions on the Degradation and Adsorption of Two Cellobiohydrolases on Microcrystalline Cellulose

김동원,장영헌,김창석,이남수,Kim, Dong Won,Jang, Yeong Heon,Kim, Chang Seok,Lee, Nam Su Korean Chemical Society 2001 Bulletin of the Korean Chemical Society Vol.22 No.7

To test the metal ion effect, hydrolysis experiments for two cellobiohydrolases (CBHⅠ and CBH Ⅱ) from Trichoderma reesei have been carried out in the presence of 10 mM metal ions, such as Cu++, Mn++, Ca++, Hg++, Ba++, Pb++, and Cd++. The addition of Mn++, Ba++, and Ca++(10 mM) during the hydrolysis of Avicel PH 101 caused an increase in the total reducing sugar (TRS) for CBH Ⅰ by 142, 135, and 114 percent, respectively. Those for CBH Ⅱ increased by 177, 175, and 115 percent, respectively. The Mn++ was the most stimulatory metal ion, whereas Hg++ was the most inhibitory metal ion. The adsorption experiments were performed to investigate how the influence of Mn++ and Hg++ on the hydrolysis is related to the adsorption of cellobiohydrolases on cellulose. The increase in TRS during hydrolysis by adding Mn++ caused an increase in adsorption affinity (Kad) and tightness (ΔHa). While, the decrease of TRS during hydrolysis by adding Hg++ caused a decrease in the adsorption affinity (Kad) and tightness (ΔHa). These results indicate the changes in the tightness and affinity of adsorption by adding metal ions play a crucial role in the degradation of the microcrystalline cellulose.

다중 코팅된 $Si_3N_4-TiC$ 세라믹의 특성

김동원,천성순,Kim, Dong-Won,Chun, Seong-Sun 한국재료학회 1991 한국재료학회지 Vol.1 No.1

화학증착법에 의해 $Si_3N_4-TiC$ 복합재료 위에 코팅된 TiC 박막은 TiN 박막에 비하여 우수한 미세구조와 열충격저항, 계면결합을 가지고 있는 것으로 나타났다. 화학증착법에 의한 TiN 박막은 TiC 박막에 비해 강철과의 마찰계수가 작고 화학적으로 안정하였다. 실험결과는 코팅된 절삭공구가 우수한 내 마모성을 갖고 있는 것으로 나타났다. 또한, 다중 코팅된 절삭공구는 단일 코팅된 공구보다 우수한 내 마모성을 보였다 TiC coating formed on $Si_3N_4-TiC$ composite ceramic by chemical vapor deposition (CVD) has an improved microstructures, better thermal shock resistance and interfacial bonding than TiN coating does. TiN coating formed by CVD, however, has lower friction coefficients against steels and better chemical stability. The experimental results indicate that the coated insert is superior to the uncoated one in flank and crater wear resistance. And the multilayer coating shows an improved wear resistance than the monolayer coating.

유가인상과 에너지절약

김동원,Kim, Dong-Won 대한석유협회 1990 석유와 에너지 Vol.1990 No.12