• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.819-820
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• 2008

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.497-498
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• 2011

• 대한미생물학회지
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• 제20권1호
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• pp.109-113
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• 1985

It was well known that B. pertussis cells possess protective antigen, histamine sensitizing factor, heatstable and labile toxin, hemagglutinin, agglutinogen and the others. Previous reports involving above antigenic properties of B. pertussis have been carried out for several years. However, leucocyte promoting property was not yet investigated. In this report, the results of studies on the leucocytosis, particulary the lymphocytosis, produced in mice by injecting pertussis vaccine were presented. Especially leucocyte promoting property and histamine sensitizing property of B. pertussis vaccine treated at various temperatures were compared. The relationship between the leucocyte promoting property and histamine sensitizing property was investigated. Results were as follows. 1. Although leucocytosis was significantly rised in both 0.5ml injection and 0.1ml injection of pertussis vaccine than in control, at the higher dose (0.5ml injection) an elevation in white cell count was more significant. The leucocyte responce to pertussis vaccine was greater following 0.5 ml injection than following 0.1ml injection. 2. Lymphocytosis was significantly rised in both 0.5ml injection and 0.1ml injection of pertussis vaccine than in control. At higher dose (0.5ml injection), an elevation in lymphocyte count was more significant. 3. Order of elevation in differential leucocyte counts was lymphocyte, polymorphonuclear leucocyte and monocyte. 4. The leucocyte response to pertussis vaccine was 2 fold greater following intravenous injection than following subcutaneous injection. 5. Decrease leucocyte promoting activity and histamine sensitizing activity resulted from exposure to temperature above $56^{\circ}C$. Histamine sensitizing activity of pertussis vaccine treated at various temperatures paralleled leucocyte promoting activity.

• 한국분무공학회지
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• 제11권4호
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• pp.228-233
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• 2006

There are two types of electric controlled fuel injection system in the gasoline engines of common vehicles. One is fuel return system and the other is fuel returnless system according to the methods of controlling injection pressures. It is important to understand the characteristics of these system in loaming and studying of engine, but it is very difficult without a special equipment in reality. The purpose of this paper is to develop the emulation system that can be compensated with the amount of injection fuel according to various driving conditions, battery voltage, cooling water temperature, and engine speed, may be appeared in real driving, and especially can analyze the difference between the electric signal controlling the amount of injection fuel and its result, and nullity injection duration. With the developed system, we can conveniently set various and completed driving condition and so can acquire the useful information such as non-uniformity rate and mass of injection fuel using waveform analysis and measurement modules. It must be a very useful and sophisticated system to instruct and learn the features and operating states of injection system, and to study f3r improving the performance of it.

• 청정기술
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• 제13권4호
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• pp.300-307
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• 2007

본 연구에서는 연료분출각의 변화에 따라 보염기(cylindrical stabilizer) 후류에 형성되는 확산화염의 화염 안정성, 재순환영역의 길이 및 온도, 보염기 후류의 난류강도 분포, 재순환영역의 연소가스 농도 등을 측정하고, 화염의 직접사진 및 슐리렌사진을 촬영하여 확산화염의 연소특성을 고찰하였다. 화염안정성은 연료분출각과 주류공기 유속의 영향을 받으며, 재순환영역의 길이와 온도는 연료분출각의 영향을 받았다. 재순환영역의 길이가 짧고 온도가 낮을수록 화염안정성이 양호하지만, 연료분출각의 변화에 따른 난류강도 분포에는 별로 차이가 없었다. 재순환영역 내 미연가스 농도가 높고 이산화탄소 농도가 낮은 경우, 화염안정성은 양호하지만 연소상태는 불량한 것으로 나타났다. 연소효율, 고부하 출력, 대기환경, 연료의 청정연소조건 등을 고려하여 적절한 연료분출각을 선정함으로써 양호한 연소조건을 유지할 수 있다.

• 전자공학회논문지A
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• 제33A권12호
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• pp.39-46
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• 1996

In AlGaAs/GaAs HBT the temperature dependence of DC parameters was investigated over the temperature range between 95K and 580K. The temperature dependence of DC parameters depends on the relative contribution of each of the current components suc as emitter-injection-current, base-injection-current, bulk recombination current, interface recombination curretn, thermal generation ecurrent and avalanche current due to impact ionization within the collector space charge layer in a specific temperature. In this paper we investigated the temperature effects on DC parameters such as V$_{BE,ON}$ current gain, input and output characteristics, V$_{CE, OFF}$, R$_{E}$, R$_{C}$ and analyzed the origins, and extracted the qualitativ econditions for a stable HBTs against the temperature variation. Finally, in order to keep HBTs stable with respect to the variation of temperature, the valance-band-energy-discontinuity at emitter-base heterojunction should be large enough to enhance the effect of carrier suppression at a relatively high temperature. In addition the recombination centers, especially around collector junction, should be removed and the area of emitter and collector junction should be identical as well.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3300-3305
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• 2007

Ignition delay of second injection of HSDI diesel engine was usually much shorter than that of first injection. It is due to the interaction between radicals generated during the combustion process, and mixed gas of second injection. In this paper, To analyze combustion phenomena of multiple injection mode in HSDI diesel engine effectively, two-dimensional flamelet combustion model was modified. To reduce calculation time, two-dimensional flamelet equations were only applied near stoichiometric region. If this region was ignited, species and temperature of other region were changed to the steady-state solutions of one dimensional flamelet equations. By this method calculation time for solving flamelet equations was reduced to 20 percents, thought the results were almost same. Modified flamelet combustion model was coupled to commercial CFD code interactively using user subroutine.

• Journal of Advanced Marine Engineering and Technology
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• 제25권3호
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• pp.644-654
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• 2001

In this paper, an electronic control unit of the automobile engine for optimal fuel injection an spark timing control has been designed and developed. This system includes hardware and software for a precise control of fuel injection and ignition timing. Especially, the crank angle sensor provides two separate signals: One is the position signal (POS) which indicates 180 degree pulses per revolution, and the other is the reference signal (REF) that represents each cylinder individually. Consequently, the developed engine control system has been able to control fuel injection and ignition timing more quickly and accurately. Through the experiment, it has been found that the fuel injection duration and the position of MBT have been influenced by coolant temperature, air flow rate and engine speed.

• 소성∙가공
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• 제20권2호
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• pp.173-178
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• 2011

Environmental Stress Cracking(ESC) is one of the most common causes of unexpected brittle failure of thermoplastic polymers. The exposure of polymers to liquid chemicals tends to accelerate the crazing process, initiating crazes at stresses that are much lower than the stress causing crazing in air. In this study, ESC of acrylonitirile butadiene styrene(ABS) was investigated as a function of the molding conditions such as injection velocity, packing pressure, and melt temperature. A constant strain was applied to the injection molded specimens through a 1.26% strain jig and a mixture of toluene and isopropyl alcohol was used as the liquid chemical. In order to examine the effects of the molding conditions on ESC, an experimental design method was adopted and it was found that the injection velocity was the dominant factor. In addition, predictions from numerical analyses were compared with the experimental results. It was found that the residual stress in the injection molded part was associated with the environmental stress cracking resistance (ESCR).

• Journal of Mechanical Science and Technology
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• 제17권9호
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• pp.1371-1379
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• 2003

The effects of change in injection pressure on spray structure in high temperature and pressure field have been investigated. The analysis of liquid and vapor phases of injected fuel is important for emissions control of diesel engines. Therefore, this work examines the evaporating spray structure using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 22 MPa to 112 MPa using a high pressure injection system (ECD-U2). Also, we conducted simulation study by modified KIVA-II code. The results of simulation study are compared with experimental results. The images of liquid and vapor phase for free spray were simultaneously taken by exciplex fluorescence method. As experimental results, the vapor concentration of injected fuel is leaner due to the increase of atomization in the case of the high injection pressure than in that of the low injection pressure. The calculated results obtained by modified KIVA-II code show good agreements with experimental results.