• 제목/요약/키워드: Egr3

검색결과 137건 처리시간 0.032초

건설기계의 배출가스 저감을 위한 대형 프로판 전용 엔진 개발 (Development of Large-sized Propane Engine for Emission Reduction of Construction Machinery)

  • 김용래;박철웅;장형준;최영;정문용;한명훈;정동훈
    • 한국가스학회지
    • /
    • 제27권3호
    • /
    • pp.91-97
    • /
    • 2023
  • 오래된 디젤 엔진을 탑재하고 있는 노후화된 건설용 기계 및 차량들은 보통 수명이 길기 때문에 최신의 배기 규제와는 동떨어진 수준의 유해한 배출가스를 계속 배출하고 있다. 따라서 이러한 구형 디젤 엔진을 최신 배기 규제를 만족하는 엔진으로 대체할 수 있다면 대기질 개선에 도움이 될 것으로 기대되는데, 건설 현장에서 손쉽게 구할 수 있는 프로판 연료를 적용한 엔진이 적합한 대안이 될 수 있다. 따라서 본 연구에서는 6.8리터 CNG 엔진을 베이스로 프로판 전용 엔진을 개발하였으며, 가스 전용 인젝터, 배기가스재순환(EGR), 강화된 촉매 등의 기술이 적용되었다. 그 결과 동급의 디젤 엔진 출력 및 토크를 확보하는 한편 최신 배출가스 규제인 Stage-V 수준에서 질소산화물은 절반 수준에 해당하는 배출가스 성능을 달성하였다.

High Glucose Induces Connective Tissue Growth Factor Expression and Extracellular Matrix Accumulation in Rat Aorta Vascular Smooth Muscle Cells Via Extracellular Signal-Regulated Kinase 1/2

  • Ha, Yu Mi;Lee, Dong Hyup;Kim, Mina;Kang, Young Jin
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제17권4호
    • /
    • pp.307-314
    • /
    • 2013
  • Connective tissue growth factor (CTGF) is a potent pro-fibrotic factor, which is implicated in fibrosis through extracellular matrix (ECM) induction in diabetic cardiovascular complications. It is an important downstream mediator in the fibrotic action of transforming growth factor ${\beta}$ ($TGF{\beta}$) and is potentially induced by hyperglycemia in human vascular smooth muscle cells (VSMCs). Therefore, the goal of this study is to identify the signaling pathways of CTGF effects on ECM accumulation and cell proliferation in VSMCs under hyperglycemia. We found that high glucose stimulated the levels of CTGF mRNA and protein and followed by VSMC proliferation and ECM components accumulation such as collagen type 1, collagen type 3 and fibronectin. By depleting endogenous CTGF we showed that CTGF is indispensable for the cell proliferation and ECM components accumulation in high glucose-stimulated VSMCs. In addition, pretreatment with the MEK1/2 specific inhibitors, PD98059 or U0126 potently inhibited the CTGF production and ECM components accumulation in high glucose-stimulated VSMCs. Furthermore, knockdown with ERK1/2 MAPK siRNA resulted in significantly down regulated of CTGF production, ECM components accumulation and cell proliferation in high glucose-stimulated VSMCs. Finally, ERK1/2 signaling regulated Egr-1 protein expression and treatment with recombinant CTGF reversed the Egr-1 expression in high glucose-induced VSMCs. It is conceivable that ERK1/2 MAPK signaling pathway plays an important role in regulating CTGF expression and suggests that blockade of CTGF through ERK1/2 MAPK signaling may be beneficial for therapeutic target of diabetic cardiovascular complication such as atherosclerosis.

커먼레일 디젤엔진의 운전조건이 나노크기 입자상 물질 배출특성에 미치는 영향에 관한 실험적 연구 (Experimental Investigation of Nano-sized Particulate Matter Emission Characteristics under Engine Operating Conditions from Common Rail Diesel Engine)

  • 이형민;명차리;박심수
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제34권4호
    • /
    • pp.508-514
    • /
    • 2010
  • 본 논문은 커먼레일 디젤엔진의 정속운전시 배출되는 나노크기의 입자상 물질을 분석하는데 초점을 두었다. 디젤산화촉매 후단에서 나노입자상 물질의 개수농도 저감수준은 크지 않았으나 매연여과장치 후단에서 분석한 결과 1,000배 정도 저감되는 결과를 확인하였다. 고속 고부하 조건에서는 매연여과장치의 자연재생 효과로 인해 입자상 물질은 증가하였다. 연료분사시기를 BTDC $6^{\circ}CA$ 에서 ATDC $4^{\circ}CA$까지 지각시킨 결과 입자상 물질의 개수농도는 감소하였지만 최지각 조건인 ATDC $9^{\circ}CA$에서는 증가하는 결과를 확인하였다. EGR 적용시 핵화모드 입자상 물질은 저감되는 경향을 보였으며 축적모든 입자는 증가하였다.

유전알고리즘을 이용한 대형 디젤 엔진 운전 조건 최적화 (Optimization of Heavy-Duty Diesel Engine Operating Parameters Using Micro-Genetic Algorithms)

  • 김만식
    • 한국자동차공학회논문집
    • /
    • 제13권2호
    • /
    • pp.101-107
    • /
    • 2005
  • In this paper, optimized operating parameters were found using multi-dimensional engine simulation software (KIVA-3V) and micro-genetic algorithm for heavy duty diesel engine. The engine operating condition considered was at 1,737 rev/min and 57 % load. Engine simulation model was validated using an engine equipped with a high pressure electronic unit injector (HEUI) system. Three important parameters were used for the optimization - boost pressure, EGR rate and start of injection timing. Numerical optimization identified HCCI-like combustion characteristics showing significant improvements for the soot and $NO_X$ emissions. The optimized soot and $NO_X$ emissions were reduced to 0.005 g/kW-hr and 1.33 g/kW-hr, respectively. Moreover, the optimum results met EPA 2007 mandates at the operating point considered.

대형 디젤기관에서 매연가스 예측에 관한 연구 (Study on Smoke Prediction in Heavy-duty Diesel Engine)

  • 백두성;이종선
    • 한국산학기술학회논문지
    • /
    • 제9권4호
    • /
    • pp.865-870
    • /
    • 2008
  • 대형디젤 기관에서 매연배기가스에 대한 배기가스 재순환장치의 영향을 KIVA-3V 전산유체해석코드를 통해서 수치 해석적으로 연구했다. 지배방정식으로 RNG k-$\varepsilon$ 난류 모델을 이용했고, 무화, 벽 침투 그리고 매연 등의 물리적인 현상을 나타내기 위해서 TAB, Wave, Watkins-Park, Nagle-Strickland 모델이 적용되었다.

한국공업화과정(韓國工業化過程)에서의 광물자원(鑛物資源)의 수급구조변화(需給構造變化)와 경제성장(經濟成長)에 있어서의 역할(役割) (The Changing Patterns of Demand-Supply and Role of Mineral Resources in Economic Growth during Industrialization of the Republic of Korea)

  • 윤석규
    • 자원환경지질
    • /
    • 제18권1호
    • /
    • pp.65-92
    • /
    • 1985
  • A total of 12 mineral commodities significant in domestic output, economy and/or strategy of the Republic of Korea are chosen to examine the structural changes in production and demand-supply of these minerals during the last two decades of her industrialization. These include iron and manganese ores as the raw materials for iron and steel making, copper, zinc and tungsten ores among other non-ferrous metallic minerals, limestone (cement), kaolin, talc, pyrophyllite and graphite among other non-metallic minerals, and anthracite coal as the only domestic source of fossil energy. These are reviewed historically in time-series based on the statistical data which are tabulated and graphed in terms of domestic output, export, import, apparent demand-supply, its increasing rate, and self-sufficiency rate of each commodity. The increasing rates of demand-supply (IRDS) of some more important commodities are compared with those of Gross Domestic Production (GDP) and Economic Growth Rate (EGR) to evaluate how the IRDS contributed to the GDP and EGR. The major results revealed are as follows: Among the 12 commodities, the domestic output of 8 commodities appeared to have grown with steady upward trends: they are ores of lead, zinc and tungsten, limestone (cement), kaolin, talc, pyrophyllite and anthracite coal. Two commodities, ores of iron and copper, continued with unchanging or slightly declining trends and varied fluctuations, in spite of their cardinal importance to the heavy industry and strategy of Korea. The remaining two, graphite and manganese ore, have gradualy declined in domestic output in which the former has still enough resource potential but the latter has not and virtually ceased its domestic output. Trade patterns for mineral commodities in the Republic of Korea during the last two decades have changed greatly, being marked by a shift from mineral-exporting to mineral importing, mainly because of increasing consumption of mineral raw materials for industrialization rather than beceuse of decreasing output of domestic mineral commodities in quantity. In terms of trade patterns, the 12 commodities concerned in this study can be classified into the following four groups. The 1st group - ores of lead and tungsten have only been exported without imports. The 2nd group - amorphous graphite, and pyrophyllite have mainly been exported but partly been imported. The 3rd group - kaolin, talc and crystalline graphite have equally been exported and imported, but quantity of imports have rapidly been increased with time. The 4th group - ores of iron, manganese and zinc have shifted from exports to imports during the industrialization, particularly owing to the initiation of iron and steel making by the Pohang Iron and Steel Company in the middle 1970' s and the new establishment of the Onsan Zinc Refinery in the late 1970' s. All of the 12 commodities under considerations were far above 100% in self-sufficiency rate before or in the early 1960' s. Recently, however, most of them have been declined to below 100% except for those of limestone (cement) and pyrophyllite. It is particularly serious to identify that the self-sufficiency rates of the three important metallic minerals, iron, copper and manganese ores in 1982 appeared to be 5.1%, 0.5%, and 0.01%, respectively. The average self-sufficiency rate of the total domestic minerals produced in 1982 was 14.4% (in value) for that year. Mining industry appeared to be extremely high in its intermediate demand rate whereas its intermediate input rate to be quite low indicating that mineral raw materials have been exerted strong forward linkage effects upon the other industries rather than backward linkage effects. In comparing the curves of increasing rates of demand-supply of several major minerals - iron ore, manganese ore, copper ore, limestone (cement), kaolin, and anthracite coal - with those of Gross Domestic Production and Economic Growth Rate drawn on every graph, it is clearly shown that the curves of increasing rates of demand-supply comprise around 6 to 7 periods of cycles which roughly harmonious with those of the curves of GDP and EGR, except for the curve of anthracite coal of which the configuration seems to have resulted from the (artificial) government's mineral policy rather than from economic free market mechanism. The harmonic feature of these curves well suggests that the increasing rates of demand-supply of major minerals have been significantly contributed to the GDP and EGR. In addition, the wider amplitudes of the iron, manganese and copper curves than those of the limestone (cement) and kaolin curves indicate that the contribution of the former, metallic commodities, has been greater than that of the latter, non-metallic commodities.

  • PDF

Comprex 압력파 과급기의 작동 및 응용 (Working principle & application of comprex pressure wave super charger)

  • ;채재우역
    • 오토저널
    • /
    • 제7권4호
    • /
    • pp.24-31
    • /
    • 1985
  • 본 논문은 Comprex압력파 과급기(Pressure-wave Supercharger;이하 PWS)의 공기 역학적인 원 리에 대해 기술하였으며, 또 기체 동력학적인 현상들이 별도의 제어장치없이도 우수한 운전성과 낮은 연료소모율, 적은 배기 배출물을 형성하는 차량들에 대해 기계적으로는 간단하면서도 완벽 한 boosting장치를 만들어 내는데 어떻게 사용될 수 있는지를 설명하였다. 근본적인 목적은 종 래의 turbo charger와 동일이지만 Comprex PWS는 현재 응용되고 있는 승용차가 요구하는 여러 가지면, 즉 1) 부하변동에 대한 충진공기압의 빠른 응답성 2) 엔진속도 전영역에 걸친 높은 boost 효과 3) 배기배출물특성을 좋게할 수 있는 배기가스 재순환(EGR)효과 등에서 종래의 것과 구별된다. 따라서 PWS의 중요한 특징들을 기술하였으며 마지막으로 최근 자동차용 Diesel Engine에의 몇 가지 예를 보았다.

  • PDF

Profilin-1 과발현에 의한 난소암 세포 성장 및 이동 저해 효능 연구 (Overexpression of Profilin 1 Inhibited Ovarian Tumor Cell Growth and Migration)

  • 이승훈
    • 생명과학회지
    • /
    • 제27권1호
    • /
    • pp.1-7
    • /
    • 2017
  • 비정상적 액틴의 재구성은 암세포의 대표적 특성이다. Thymosin ${\beta}_{10}$ (TB10)과 Profilin-1 (PFN-1)은 액틴중합조절에 필수적인 단백질이다. 이전의 연구에서 본 연구진은 TB10이 F-actin의 구조를 파괴하여 난소 암 세포의 사멸을 일으킨다는 사실을 보고하였으나 그 기전에 대하여 보고 된 바는 아직까지 없다. 본 연구에서는 TB10에 의하여 PFN-1의 발현이 조절되며, PFN-1의 난소 암 저해 유전자로서의 새로운 기능을 보고하였다. 우선 난소암세포주인 SKOV3 세포에서 TB10에 의하여 발현이 조절되는 단백질들을 전기영동법과 liquid chromatography-mass spectroscopy (LC-MS/MS) 방법을 통하여 분석하였다. 그 결과 PFN-1이 TB10에 의하여 발현이 급격히 증가되는 단백질로 동정되었으며, 이 PFN-1을 난소 암 세포주인 SKOV3에 과발현 시켰을 때 암세포의 증식과 이동을 저해하고 암세포 사멸을 유도하였다. 또한 이 결과는 PFN-1에 의하여 Erk 신호전달기전이 저해되고 부수적으로 Elk-1과 Egr-1의 발현이 저해 됨으로써 유도될 가능성을 보여준다. 결론적으로, PFN-1이 난소암세포의 성장과 이동을 저해함과 동시에 세포사멸을 일으키므로 난소 암 치료에 유용하게 이용될 가능성이 높다.

파일럿 분사가 저온 디젤 연소에 미치는 영향 (Effects of Pilot Injection on Low Temperature Diesel Combustion)

  • 한상욱;배충식
    • 한국자동차공학회논문집
    • /
    • 제20권3호
    • /
    • pp.141-147
    • /
    • 2012
  • A direct injection diesel engine with large amount of exhaust gas recirculation was used to investigate low temperature diesel combustion. Pilot injection strategy was adopted in low temperature diesel combustion to reduce high carbon monoxide and hydrocarbon emissions. Combustion characteristics and exhaust emissions of low temperature diesel combustion under different pilot injection timings, pilot injection quantities and injection pressures were analyzed. Retarding pilot injection timing, increasing pilot injection quantity and higher injection pressure advanced main combustion timing and increased peak heat release rate of main combustion. As a result of these strategies, carbon monoxide and hydrocarbon emissions were reduced. Soot emission was slightly increased with retarded pilot injection timing while the effect of pilot injection on nitrogen oxides emission was negligible under low combustion temperature condition. Spatial distribution of fuel from the spray targeting visualization was also investigated to provide more insight into the reason for the reduction in carbon monoxide and hydrocarbon emissions.

MCF-7 세포주에서$\gamma$선에 의한 세포신호 전달 관련 유전자의 발현 양상의 분석 (Signal Transduction-related Gene Expression Analysis in MCF-7 followed by $\gamma$-radiation)

  • 박지윤;황창일;박웅양;김진규;채영규
    • 환경생물
    • /
    • 제21권1호
    • /
    • pp.52-55
    • /
    • 2003
  • There is considerable evidence that ionizing radiation (IR) mediates checkpoint control, repair and cell death. In this study, we have used a high density microarray hybridization approach to characterize the transcriptional response of human breast carcinoma MCF-7 cell line to ${\gamma}$-radiation, such as 4 Gy 4 hr, 8 Gy 4 hr, and 8 Gy 12 hr. We found that exposure to ${\gamma}$-ray alters by at least a $log_2$ factor of 1.0 the expression of 115 known genes. Of the 66 genes affected by ${\gamma}$-radiation, 49 are down-regulated. In our results, the cellular response to irradiation includes induction of the c-jun and EGR1 early response genes. The present work has examined potential cytoplasmic signaling cascades that transduce IR-induced signals to the nucleus. 40S ribosomal protein s6 kinase modulates the activities of the mitogen activated protein kinase (MAPK) and c-Jun $NH_2$-terminal kinase (JNK1) cascades in human monocytic leukemia (U937/pREP4) cells. 14-3-3 family members are dimeric phosphoserine -binding proteins that participate in signal transduction and checkpoint control pathways.