• Title/Summary/Keyword: pressure injection

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Studies on the Development of Antihypertensive Agents from Korean Crude Drugs(II) -Influence of Euonymus japonicae Cortex on the Blood Pressure of Rabbits- (혈압강하제 국산 자원생약의 개발에 관한 연구(II) -사철나무(화두중(和杜仲)) 수피(樹皮)의 가토(家兎) 혈압(血壓)에 미치는 영향-)

  • Chung, Myung-Hyun;Park, Chung-Wan
    • Korean Journal of Pharmacognosy
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    • v.6 no.1
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    • pp.35-38
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    • 1975
  • Attempts were made to investigate the pharmacological actions of Euonymus japonicae Cortex which is used as a substitute of Eucommiae Cortex. Practically the influence of the alcohol extract of the bark on the blood pressure response of rabbit, was examined, and the results are as follows. 1) The intravenous injections of the alcohol extracts of the bark decreased the blood pressure of rabbits to 4.6 11.1 and 34.2 mmHg respectively. 2) The intravenous injection of 10 mg/kg of the alcohol extract after intravenous injection of atropine 4 mg/kg or that of propranolol 2 mg/kg did not give any notable change to the blood pressure. 3) The intravenous injection of 10 mg/kg of the alcohol extract slightly decreased the raised blood pressure caused by the administration of acetylcholine $10^{-8}g/kg\;and\;10^{-7}g/kg$.

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A Study on Engine Performance Characteristics with Scavenging Condition Variation in 2-Stroke Diesel Engine (2행정 디젤엔진의 소기조건 변화에 따른 엔진의 성능특성에 관한 연구)

  • Kim, Gi-Bok
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.3
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    • pp.259-264
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    • 2019
  • In this study, we experiment by making and designing of compression ignition diesel engine witch has air cooling, 2-cylinder and 2-strokes. Also, we make controller witch can control injection timing and period by arbitrary manual operation for change of injection timing. We also study experimentally in change about pressure and power of combustion chamber by increasing density of air which comes into cylinder because of increasing scavenging pressure. Through this, we confirmed that output change and scavenging pressure can develop performance of the engine by scavenging efficiency of a chamber and development of volume efficiency.

A Study on the Deflection of Large Mold for Injection Molding (대형 사출금형의 성형 시 발생하는 금형 휨에 관한 연구)

  • Hwang, Si-Hyun;Kim, Chul-Gyu;Shim, Soo-Kil;Jeong, Yeong-Deug
    • Design & Manufacturing
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    • v.8 no.1
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    • pp.1-4
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    • 2014
  • Large injection molds commonly have molding defects such as flashes and variation of product thickness. In this study, we conducted injection molding CAE analysis to find out the cavity pressure and structural analysis to find out mold deflection as input load conditions injection pressure obtained from injection molding analysis. As the results from CAE analysis, we found which element is the most effective on the mold deflection and we suggested a mold design to minimize the mold deflection.

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The Effect of Fuel Injection Timing on the Combustion and Emission Characteristics of a Natural Gas Fueled Engine at Part Loads

  • Cho, Haeng-Muk
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.7
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    • pp.1013-1018
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    • 2008
  • For a sequential port fuel injection natural gas engine, its combustion and emission characteristics at low loads are crucial to meet light duty vehicle emission regulations. Fuel injection timing is an important parameter related to the mixture formation in the cylinder. Its effect on the combustion and emission characteristics of a natural gas engine were investigated at 0.2 MPa brake mean effective pressure (BMEP)/2000 rpm and 0.26 MPa BMEP/1500 rpm. The results show that early fuel injection timing is beneficial to the reduction of the coefficient of variation (COV) of indicated mean effective pressure (IMEP) under lean burn conditions and to extending the lean burn limits at the given loads. When relative air/fuel ratio is over 1.3, fuel injection timing has a relatively large effect on engine.out emissions. The levels of NOx emissions are more sensitive to the fuel injection timing at 0.26 MPa BMEP/1500 rpm. An early fuel injection timing under lean burn conditions can be used to control engine out NOx emissions.

A Study on Plastic Injection Molding for Warpage Characteristics Evaluation of Mobile Phone Cover (모바일폰 커버의 휨특성 평가를 위한 사출 성형에 관한 연구)

  • Kim O. R.;Kim M. Y.;Lee S. H.;Kwon C. O.
    • Transactions of Materials Processing
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    • v.15 no.1 s.82
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    • pp.76-81
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    • 2006
  • In this study, warpage characteristics of mobile phone cover through injection molding process were investigated using design of experiments in injection molding process. Warpage in plastic injection molding has a significant effect on quality of product. Effects of injection time, packing pressure, packing time, mold temperature and melt temperature on the warpage of mobile phone cover were considered by numerical analysis and experiment with Taguchi method. The degree of warpage for the injection molded part was measured by using three dimensional coordinate measurement machine. It was shown that temperature control factor has more significant effect on the warpage of mobile phone cover than pressure control factor.

Linear Structural Analysis and Simple Tensile Test of Plastic Injection Molding Tensile Specimen (플라스틱 사출인장시편의 단순인장시험 및 선형구조해석)

  • Lee, D.M.;Han, B.K.;Lee, Sung-Hee
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.230-233
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    • 2006
  • In this study, the effects of residual stress induced by plastic injection molding process on the tensile behavior of plastic tensile test specimen were investigated. To manufacture plastic tensile test specimens, an injection mold based on the international standard system was designed and made. Cavity pressure and temperature sensors were installed inside of the presented mold to monitor pressure and temperature values during the cycle of injection molding. Injection molding simulation was performed with the same condition of experiment and linear structural tensile analysis was also performed with the initial condition of the residual stress. It was shown that the residual stress induced by injection molding has an effect on the experiment of tensile test and linear structural tensile simulation.

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Characteristics of Exhaust Emission by Impinging Spray of Diesel Engine (충돌분무에 의한 디젤기관의 배기 배출물 특성)

  • Jin, Y.S.;Kim, J.D.;Kim, Y.B.
    • Journal of Power System Engineering
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    • v.11 no.4
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    • pp.26-31
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    • 2007
  • Recently, study on the improvement of combustion performance for the diesel engine by using the impinging spray in the combustion chamber has been actively studied. The purpose of this study is to examine the variation of exhaust emission between the trial engine with impinging plate and the prototype engine in accordance with change of fuel injection timing and fuel injection pressure. The concentration of nitrogen oxide of trial engine decreased more than 50% compared to prototype engine. However, smoke of trial engine indicated very high concentration compared to prototype engine. The effect of fuel injection timing on the nitrogen oxide and smoke indicated different results, that is, the concentration of nitrogen oxide decreased as the degree of fuel injection start become slower, whereas the concentration of smoke decreased as the degree of fuel injection start become faster.

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A Study on the Deflection of Large Mold for Injection Molding (대형 사출금형의 성형시 발생하는 금형 휨에 관한 연구)

  • Hwang, Si-Hyun;Kim, Chul-Gyu;Shim, Soo-Kil;Jeong, Yeong-Deug
    • 한국금형공학회:학술대회논문집
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    • 2008.06a
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    • pp.99-102
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    • 2008
  • Large injection molds commonly have molding defects such as flashes and variation of product thickness. In this study, we conducted injection molding CAE analysis to find out the cavity pressure and structural analysis to find out mold deflection as input load conditions injection pressure obtained from injection molding analysis. As the results from CAE analysis, we found which element is the most effective on the mold deflection and we suggested a mold design to minimize the mold deflection.

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A Study on In-cylinder and Combustion Characteristics of GDI Engine using RCEM (급속 압축팽창 장치를 이용한 직접분사식 가솔린 기관의 실린더 내 분무 및 연소특성에 관한 연구)

  • 조규백;정용일
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.76-85
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    • 1999
  • GDI(Gasoline Direct Injection( engine technology is well known as a new technology since it can improve fuel consumption and meet future emission regulations. But the GDI has many difficulties to be solved, such as complexity of injection control mode, unburned hydrocarbon, and restricted power. A 2-D shape combustion chamber was adopted to investigate mixture formation and combustion characteristics of GDI engine. Spray and combustion experiments were performed by changing the injection timing. injection pressure an din-cylinder flow in Rapid Compression and Expansion Machine(RCEM).Through the experiments, the detailed characteristics of fuel spray and combustion was analyzed by visualizing the in-cylinder phenomena according to the change of injection condition, and the optimal fuel injection timing and fuel injection pressure were obtained.

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Effects of pilot injection timing on the Combustion and Emission Characteristics in a Common Rail Diesel Engine with Bio-diesel blended fuel (바이오디젤 혼합 연료에 커먼레일 디젤기관에서 예비 분사시기가 연소 및 배기 특성에 미치는 영향)

  • Yoon, Sam-Ki;Choi, Nag-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.2573-2578
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    • 2014
  • An experimental study was performed to investigate the characteristics of combustion pressure and exhaust emissions when the pilot injection timing and EGR rate were changed in a CRDI 4-cylinder diesel engine using bio-diesel blended fuel. The pilot injection timing and EGR rate have a significant impact on the combustion and emission characteristics of diesel engine. In this study, the pilot injection timing and EGR rate variation were conducted to 2000rpm of engine speed with fuel of bio-diesel blended rate 20%. In these experimental results, IMEP was shown maximum pressure at pilot injection timing BTDC$10^{\circ}$ combustion pressure and heat release rate were decreased in proportion to increase of EGR rate under the same pilot injection timing conditions. The NOx emission was decreased with increasing the EGR rate without influence on pilot injection timing. However, soot emission was reduced to a minimum at pilot injection timing BTDC$20^{\circ}$.