• 제목/요약/키워드: Lee Don-Hwa

검색결과 114건 처리시간 0.028초

Low Spin-Casting Solution Temperatures Enhance the Molecular Ordering in Polythiophene Films

  • Lee, Wi Hyoung;Lee, Hwa Sung;Park, Yeong Don
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권5호
    • /
    • pp.1491-1494
    • /
    • 2014
  • High-crystallinity poly(3-hexylthiophene) (P3HT) thin films were prepared by aging the precursor solutions, prepared using a good solvent, chloroform, at low temperatures prior to spin-casting. Lower solution temperatures significantly improved the molecular ordering in the spin-cast P3HT films and, therefore, the electrical properties of field-effect transistors prepared using these films. Solution cooling enhanced the electrical properties by shifting the P3HT configuration equilibrium away from random coils and toward more ordered aggregates. At room temperature, the P3HT molecules were completely solvated in chloroform and adopted a random coil conformation. Upon cooling, however, the chloroform poorly solvated the P3HT molecules, favoring the formation of ordered P3HT aggregates, which then yielded more highly crystalline molecular ordering in the P3HT thin films produced from the solution.

p-Toluenesulfonic Acid 촉매를 이용한 1,4-Sorbitan 제조

  • 임근길;류화원;이종일;박돈희;김인홍;이광연;김해성
    • 한국생물공학회:학술대회논문집
    • /
    • 한국생물공학회 2001년도 추계학술발표대회
    • /
    • pp.894-897
    • /
    • 2001
  • This experiment was to determine the optimum conditions for D-sorbitol cyclization in the presence of p-toluenesulfonic acid(p-TSA) as acid catalyst before the esterification of sorbitol with fatty acids. The optimum conditions of hydration reaction to obtain maximum yield of 1,4-sorbitan were at $130^{\circ}C$, 200mmHg reduced pressure, after l50min and l%(w/w) p-TSA. In this condition the yield of 1,4-sorbitan was approximately 90%.

  • PDF

Enzymatic Synthesis of Sorbitan Methacrylate: Effect of Acyl donor and Molar ratio

  • Lee, Hye-Jin;Jeong, Gwi-Taek;Lee, Kyoung-Min;Ryu, Hwa-Won;Kim, Do-Man;Park, Don-Hee;Kim, Hae-Sung
    • 한국생물공학회:학술대회논문집
    • /
    • 한국생물공학회 2005년도 생물공학의 동향(XVI)
    • /
    • pp.296-299
    • /
    • 2005
  • Sugar polymers have been considered as biomaterial. Biomaterials are widely utilized for a medical applications in direct contact with living tissue Clearly, biomaterials must be carefully and microscopically fabricated for optimal acceptance within the living organism in both functional and structural senses. In this study, the enzymatic synthesis of sorbitan methacrylate from 1,4-sorbitan via the manipulation of an immobilized biocatalyst (Novozym 435) and acryl donors (methacrylic acid and vinyl methacrylate) was evaluated.

  • PDF

LLM을 적용한 명리학의 삼합모델링에 관한 연구 (A syudy for Myungrihak's Samhab Modeling using LLM)

  • 이옥화;조성제
    • 한국정보전자통신기술학회논문지
    • /
    • 제5권2호
    • /
    • pp.89-95
    • /
    • 2012
  • 본 논문은 삼합의 수리적 함수를 동반한 새로운 기법의 연구를 적용하여, 역학(易學) 데이터 모델링을 제작하는데 목적이 있다. 그 목적은 삼합의 새로운 연결고리의 연구가 요구되는데, 이것을 LLM이라고 한다. 그러므로 삼합을 작성할 때, 수기(手記)에 의하지 않고, LLM방식으로 제작함으로서, 현장에서의 편리성을 확보할 수 있다.

Characteristics of One- & Two-Stage Biofiltration System : Removal of Volatile Organic Compounds

  • Jeong, Gwi-Taek;Lee, Gwang-Yeon;Lee, Kyoung-Min;Cha, Jin-Myeong;Ryu, Hwa-Won;Park, Don-Hee
    • 한국생물공학회:학술대회논문집
    • /
    • 한국생물공학회 2005년도 생물공학의 동향(XVII)
    • /
    • pp.281-286
    • /
    • 2005
  • Biofiltration is a biological process which is considered to be one of the more successful examples of biotechnological applications to environmental engineering, and is most commonly used in the removal of odoriferous compounds. In this study, we have attempted to assess the efficiency with which both single and complex odoriferous compounds could be removed, using one- or two-stage biofiltration systems. The complex gas removal scheme was applied with a 200 ppm inlet concentration of ethanol, 70 ppm of acetaldehyde, and 70 ppm of toluene with EBCT for 45 seconds in a one- or two-stage biofiltration system. The removal yield of toluene was determined to be lower than that of the other gases in the one-stage biofilter. Otherwise, the complex gases were sufficiently eliminated by the two-stage biofiltration system.

  • PDF

Implementing Expanded Rapid Human Immunodeficiency Virus Testing in Public Health Centers in Seoul, 2015

  • Kang, Cho Ryok;Bang, Ji Hwan;Cho, Sung-Il;Lee, Young Hwa;Oh, Myoung-don;Lee, Jong-Koo
    • Infection and chemotherapy
    • /
    • 제50권4호
    • /
    • pp.346-349
    • /
    • 2018
  • In 2015, rapid human immunodeficiency virus (HIV) testing was implemented in all 25 public health centers in Seoul. During March and December 2015, 20,987 rapid HIV tests were performed, of which 116 (0.5%) were positive. Compared to those of the period before application of the rapid HIV test in place of conventional enzyme immunoassay method, the number of HIV tests performed and the number of positive results increased by sevenfold and twofold, respectively. In conclusion, expansion of the provision of rapid HIV tests in public health centers increased the number of voluntary HIV tests.

B형 트리코테센 곰팡이 독소 데옥시니발레놀에 의한 인체 장관 상피세포 염증성 인터루킨 8유도에서의 PKR과 EGR-1의 상호 역할 규명 (Role of PKR and EGR-1 in Induction of Interleukin-S by Type B Trichothecene Mycotoxin Deoxynivalenol in the Human Intestinal Epithelial Cells)

  • 박성환;양현;최혜진;박영민;안순철;김관회;이수형;안정훈;정덕화;문유석
    • 생명과학회지
    • /
    • 제19권7호
    • /
    • pp.949-955
    • /
    • 2009
  • 점막 상피는 외부 인자를 감지하는 최전선의 인식부위로서 외부스트레스 자극을 하부의 반응 신호로 전달하는 주요 세포이다. 리보솜독성 반응을 유발하는 데옥시니발레놀 (DON) 및 그 관련 곰팡이 독소는 푸자륨 곰팡이 오염에 의한 식중독성 소화기 염증성 질환과의 연관성이 알려 져 있다. 본 연구의 목적은 DON이 상피세포 감지 신호 전달 분자로서 PKR과 EGR-1이 관련 되고 이들이 상피세포에서의 염증성 사이토가인 인터루킨 8의 생성에 관련 된다는 가정 하에서 연구를 수행 하였다. PKR 발현의 세포내 작용 억제는 DON에 의해 유도되는 인터루킨 8의 생성을 감소시켰다. 또한 DON에 의한 IL-8 전사 활성화는 PKR 억제에 의하여 장관 상피세포에서 감소하였다. PKR 저해제의 처리는 EGR-1 promoter 활성, mRNA, 단백질 유도 등을 감소를 유발하였으며 MAP kinase (ERK1/2, p38, JNK)는 변화가 적거나 오히려 PKR 저해제의 전처리에 의하여 항진 되었다. 결론적으로 DON에 의해 자극된 감지신호인 EGR-1은 자체적으로 또는 PKR 신호를 경유하여 인터루킨8의 생산을 항진하는데 주요한 기능을 하였다. 이를 통하여 향후 리보솜 독성 반응과 관련된 소화기 염증유발의 주요한 기전을 제공하고 있다.

수도권 전압안정도 향상을 위한 100MVA STATCOM 위치선정 연구 (The Site Selection of 100MVA STATCOM for Voltage Stability Enhancement in Korean Metropolitan Area)

  • 장병훈;김수열;한정열;최돈근;송화창;이병준
    • 전기학회논문지
    • /
    • 제56권9호
    • /
    • pp.1543-1548
    • /
    • 2007
  • This paper reports a study on determination of the adequate location of 100 MVA STATCOM regarding the transfer capability enhancement on the metropolitan interface as well as the economy in system operation. The base case in the study was established considering a scenario of the energy support to North Korea from the KEPCO (Korea Electric Power Corporation) system through a HVDC interconnection. In the base case, the energy support was approximately modeled with a load of 1500 MW, and by the load addition, the system was weakened in terms of voltage stability and transfer capability. After a thorough investigation on the case, the location of the STATCOM was decided to compensate the reactive deficit of the modified system and to maximize the operational benefit which can be estimated by FV analysis.

Support Vector Machine Based Bearing Fault Diagnosis for Induction Motors Using Vibration Signals

  • Hwang, Don-Ha;Youn, Young-Woo;Sun, Jong-Ho;Choi, Kyeong-Ho;Lee, Jong-Ho;Kim, Yong-Hwa
    • Journal of Electrical Engineering and Technology
    • /
    • 제10권4호
    • /
    • pp.1558-1565
    • /
    • 2015
  • In this paper, we propose a new method for detecting bearing faults using vibration signals. The proposed method is based on support vector machines (SVMs), which treat the harmonics of fault-related frequencies from vibration signals as fault indices. Using SVMs, the cross-validations are used for a training process, and a two-stage classification process is used for detecting bearing faults and their status. The proposed approach is applied to outer-race bearing fault detection in three-phase squirrel-cage induction motors. The experimental results show that the proposed method can effectively identify the bearing faults and their status, hence improving the accuracy of fault diagnosis.

IEC 61850 기반의 디지털 변전소를 위한 통신 드라이버에 관한 연구 (A Study on Communication Driver for Substation Automation based on IEC 61850)

  • 이일화;최철환;한진희;전태영;신용학
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
    • /
    • pp.111-113
    • /
    • 2006
  • Substation automation is one of the key issues for the enhancement of the power industrial foundation. IEC 60850 is an international standard specifying communication network and systems in substation. It supports interchangeability and interoperability of equipments from different vendors. ACSI(Abstract communication service interface) specifies basic communication structure for substation and IEDs. It supports communication as well as various services without proper protocols. For actual communication, MMS(Manufacturing Message Specification : ISO 9506) is used to map ACSI services. Solutions for the development of communication driver based don IEC 61850 are proposed in this paper.

  • PDF