• 제목/요약/키워드: Pps

검색결과 399건 처리시간 0.029초

PPS시스템 이용 바이오디젤 혼합율에 따른 극미세입자 배출특성 비교 (Comparison of Nano-particle Emission Characteristics in CI Engine with Various Biodiesel Blending Rates by using PPS System)

  • 권지원;김민식;정명철;이진욱
    • 한국분무공학회지
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    • 제17권3호
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    • pp.134-139
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    • 2012
  • The main purpose of this study is to analyze and compare the nano-particle emission characteristics by 3-different biodiesel blending rates in a CI engine. Nano-particle number density emitted from various operating conditions of compression ignition engine can be investigated by using the PPS (Pegasor Particle Sensor) system. Namely, some particle charged through the corona discharge in real-time can be measured by PPS system. Under the steady state operation of the 2.0L CRDi diesel engine with different operating condition and biodiesel blending rates, the nano-particle number density was analyzed at the downstream position of DOC system. As this research result, more engine load speed and higher the concentration of biodiesel blending rate showed that the nano-particle number density decreases. Also we found that DOC system for clean diesel engine is effectively useful instrument to reduce diesel particulate matter as resource of nano-particle generation.

아세토페논을 함유한 Poly(phenylene sulfide)의 광가교에 의한 내열성과 인장인성 강화 (The Improvement of Thermal Stability and Tensile Toughness by the Photocrosslinking of Poly(phenylene sulfide) containing Acetophenone)

  • 장용준;장진호
    • 한국염색가공학회지
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    • 제24권4호
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    • pp.281-287
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    • 2012
  • Poly(phenylene sulfide) films containing acetophenone as a photoinitiator were photocrosslinked under UV irradiation using a continuous UV irradiator. The gel fraction of the irradiated PPS in 1-Chloro naphthalene reached 94.7% with increasing UV energy and the photoinitiator concentration in the film upto $200J/cm^2$ and 12wt% respectively. Solid state $^1C$ NMR analysis suggested that the crosslinking occurred between the phenylene chains in PPS, indicating that the acetophenone may the phenylene hydrogens and subsequently adjacent polymer radicals could be recombined to form the crosslinked structure. The crosslinking improved the thermal behavior of PPS such as loss of $T_g$ and $T_c$, higher melting point and lower melting enthalphy as well as significantly higher peak pyrolysis temperature as much as $63.5^{\circ}C$. Surprisingly the tensile toughness of the most crosslinked PPS increased by 842%, resulting from the substantial enhancements in tensile modulus, strength and strain as much as 76%, 236% and 240% respectively. Also dynamic mechanical measurement indicated that the distance between crosslinks in the crosslinked PPS reached 85.3 g/mol corresponing to a crosslink density of 0.012 mol/g.

Tunneling Layer의 두께 변화에 따른 유기 메모리의 특성

  • 김희성;이붕주;신백균
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.366-366
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    • 2013
  • 건식 박막증착 공정인 플라즈마 중합법을 이용하여 유기 재료인 Styrene을 절연 박막으로 제작하였다. 플라즈마 중합된 Styrene (ppS) 절연 박막의 정밀한 공정 제어를 위해 bubbler와 circulator를 이용하여 습식 공정과 비교하여도 절연 특성이 뛰어난 pps 절연 박막을 증착하고, 이를 활용하여 gate 전극으로 ITO, insulator layer로 pps, floating gate로 Au, tunneling layer로 ppMMA와 pps, semiconductor로 Pentacene, source/drain 전극으로 Au를 사용한 비휘발성 메모리 소자를 제작하였다. ppMMA와 pps의 서로 다른 tunneling layer의 두께 변화에 따른 비휘발성 메모리 특성 변화를 연구하였다.

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Characterization of PpsR, a Transcriptional Repressor of the Expression of Photosysem Gene, from Rhodobacter sphaeroides

  • Cho, Seung-Hyun;Kang, Sa-Ouk
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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    • pp.51-51
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    • 2002
  • PpsR from the facultative photohetrotroph Rhodobacter sphaeroides is involved in repression of photo system gene expression. SDS-PAGE analysis showed that some portion of PpsR is oxidized so that intra- or inter-disulfide bond is formed between the two cysteins in each subunit. The disulfide bond was reduced by dithiothreitol and the binding activity to puc promoter region was increased.(omitted)

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정전기 보호를 위한 n형 SCR 소자의 래치업 특성 (Latchup Characteristics of N-Type SCR Device for ESD Protection)

  • 서용진;김길호;이우선
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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    • pp.1372-1373
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    • 2006
  • An electrostatic discharge (ESD) protection device, so called, N-type SCR with P-type MOSFET pass structure (NSCR_PPS), was analyzed for high voltage I/O applications. A conventional NSCR_PPS device shows typical SCR-like characteristics with extremely low snapback holding voltage, which may cause latchup problem during normal operation. However, a modified NSCR_PPS device with proper junction/channel engineering demonstrates highly latchup immune current- voltage characteristics.

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고승압 소프트스위칭 양방향 컨버터의 PPS 제어기법 (PPS Control Method of High Gain Soft-Switching Bidirectional Converter)

  • 정현주;권민호;최세완
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2016년도 전력전자학술대회 논문집
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    • pp.211-212
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    • 2016
  • 본 논문에서는 비절연 고승압 소프트 스위칭 양방향 DC-DC 컨버터의 PWM Plus Phase Shift(PPS) 제어기법을 제안한다. 제안하는 컨버터는 기존의 하프브리지 양방향 컨버터의 2배의 승 강압비를 가지며 CCM에서 모든 스위치가 소프트스위칭을 성취한다. 또한, PPS 제어기법을 적용하여 스위치의 전압/전류정격을 최소화할 뿐 아니라 매끄러운 모드전환이 가능하다. 제안하는 양방향 컨버터의 3kW 시작품은 5.2배의 승 강압동작에서 최고효율 97.2%, 97.5%를 달성하였다.

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GPS의 IRIG-B 신호를 이용한 DFR TimeSync 시뮬레이터 개발에 관한 연구 (A Study on development of DFR TimeSync Simulator using IRIG-B signal of GPS)

  • 곽성환;권대윤;김석주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.737-738
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    • 2011
  • 전력 계통현상 분석장치(DFR)에서 시각동기에 대한 중요성이 부각됨에 따라 장치의 시각동기가 중요하게 대두되고 있다. 본 연구내용에서 보여주고자 하는 DFR TimeSync Simulator는 GPS 수신기로부터 IRIG-B 신호와 1PPS 신호를 수신하여 계통현상 분석장치의 사고발생 이벤트를 위한 절대시각을 제공하는 장치이다. 이 절대시각은 계통현상 분석장치의 정밀성 및 품질을 검증하는데 적용한다. 그리고 개발된 Simulator가 정확한 1PPS 신호를 산출해 내는지를 검증하기 위해 GPS 수신기의 1PPS 신호와 Simulator에서 출력되는 1PPS 신호의 파형을 비교 실험하여 정확도 및 신뢰성을 확인하였다.

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Feasibility Study on KSNP Adaption of French Digital Protection System

  • Koo, Jun-Mo;Lee, Young-Ryul;Jung, Ho-Chang;Chang, Ik-Ho;Han, Jai-Bok
    • Nuclear Engineering and Technology
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    • 제28권4호
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    • pp.359-365
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    • 1996
  • Upgrade of nuclear power plant I&C systems by using digital technology has been implemented to overcome the obsolescence of existing equipment and improve plant availability in many advanced countries. For upgrade of the Plant Protection System(PPS) based on conventional analog technology in the UCN 3&4 and YGN 5&6, French modernized Digital Integrated Protection System(DIPS) with proven technology is reviewed and evaluated for the adaptability into PPS. This paper contains the results of feasibility study for the design of digital PPS using French DIPS technology. Based on the results of evaluations, the system architecture of digital PPS is designed and described.

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장섬유강화 Nylon6/PPS 복합재료에 관한연구 (A study on the Long Fiber Reinforced Nylon6/PPS Composites)

  • 윤병선
    • 유변학
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    • 제8권2호
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    • pp.69-77
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    • 1996
  • 장섬유강화 열가소성 고분자 복합재료 (FRTP)의 난연성과 개선을 위하여 polyhenylene sulfide(PPS)를 첨가한 polyamide 6(PA6)/glass fiber (GF)의 FRTR를 제조하 였다. 고점성수지내에 보강섬유를 균일하게 분산시키고 함침성을 높임과 동시에 보강섬유의 손상을 방지하기 위하여 섬유상 수지와 보강섬유를 분섬비동장치에서 직접혼방시키고 이를 압축성형하는 독특한 공정을 도입하였다. 제조된 복합재료의 유변학적 특성 형태학적특성 인장 및 충격특성 열적특성, 난연성, 내약품성에 관한연구를 수행한 결과 복합재료와 기계적 특성을 약화시키지 않으면서도 난연성가 내약품성을 현격히 향상시킬수 있는 FRTP의 제조 가 가능함을 확인하였다.

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소아마비후 증후군 (Postpolio Syndrome)

  • 이동국
    • Annals of Clinical Neurophysiology
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    • 제5권2호
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    • pp.202-209
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    • 2003
  • Postpolio syndrome (PPS) refers to a constellation of neuromuscular and orthopedic symptoms and signs that have been noted to occur in patients with remote antecedent poliomyelitis. It has been increasingly recognized that individuals recovering from acute poliomyelitis develop new symptoms, most commonly weakness, fatigue, and pain that develops decades after initial disease in the region previously affected. Associated symptoms may include dysphagia, respiratory insufficiency, new muscular atrophy, dysarthria, muscle cramps, fasciculations, sleep abnormalities, and cold intolerance. Although the concepts of PPS was first described in the late 1800s, it was not until nearly 100 years later that the concept of PPS was more widely recognized and defined. This was due largely to the polio epidemic of the 1940s and 1950s that left many survivors in the world. The virtual epidemic of PPS that occurred among these polio survivors in the 1980s and 1990s has served as a catalyst to attract medical attention to this syndrome.

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