Earticle

This study aims to measure the current control waveform of an injector in real time using the developed monitoring system and verify its compliance with the manufacturer’s control waveform requirements. The measured operating waveforms include a peak current phase of 20A and a hold current phase of 10A. The injector of the engine was tested at 1500 RPM and 2000 RPM under conditions of normal fuel injection, small fuel injection, and large fuel injection. In this research, a real-time monitoring system was designed, incorporating an FPGA board and RS232 communication for PC interaction. This system is capable of measuring four channels simultaneously. Furthermore, it is expected that the system could measure up to 12 cylinders concurrently with the addition of more current probes while maintaining the same system configuration. The real-time collection of output waveforms using the developed monitoring system confirmed that the injector operates correctly and meets the manufacturer’s requirements.

In this study, the shape optimization of the injector according to fuel and tip was conducted through analytical techniques. As an analysis condition, a flow rate of 0.08 kg / s was applied to the inlet and the outlet was given a condition of 0 Bar. The working fluid for each fuel was applied. As a result of the analysis, it can be seen that the pressure and velocity of model with the modified tip become higher than that of the base model in diesel. Compared with the base model in the case of gasoline, the modified model of the tip was found to have more stable injection when the pressure inside the combustion chamber and the straightness of the fuel were observed. Finally, in case of LPG injector, the same modified tip as gasoline was found to be the more stable injection. On the basis of this study result, the shape parameters of the injector can be inferred.

기업의 위기관리에서 효율적인 커뮤니케이션 전략은 기업경쟁력 확보에 핵심적 요소로 부각되고 있다. 이에 따라, 본 연구는 최근 발생한 폭스바겐의 배기가스 유출 조작 사건과 이에 대한 폭스바겐사의 위기 대처 관리에 관한 사례 조사 (case study) 를 실시하여, 기업의 위기 커뮤니케이션이 더욱 효과적으로 실 행되기 위해서는 어떠한 요소들이 필요한지에 대해 모색해 보았다. 특히, 기업의 위기 커뮤니게이션 전략 에 자주 쓰이는 두 가지 이론, 이미지 회복 이론(Image Repair Theory)과 상황별 위기 커뮤니케이션 이 론(Situational Crisis Communication Theory)를 중심으로 폭스바겐사의 위기 대응 커뮤니케이션 전 략을 분석하였다. 이를 통해 기업의 위기관리 계획 수립 시 장애요소를 살펴보고 또한 기업의 위기 상황 에서 실제로 사용될 수 있는 실천적 커뮤니케이션 방법론을 제시하였다.

This exploratory case study analyzes the Volkswagen diesel crisis from a crisis communication perspective. The Volkswagen diesel case provides a unique opportunity to examine how a Fortune 500 company managed (or mismanaged) an intentional corporate misdeed, and to understand the shortcomings of existing crisis communication theories. In analyzing the case, this study adopted the theoretical frameworks from the two dominant crisis communication theories, namely Image Repair Theory and Situational Crisis Communication Theory. Our findings show Volkswagen’s systemic failure of crisis management and communication before and after the crisis erupted. The findings also suggest the scholarly need to further develop crisis communication theories in providing strategic implications for major crises such as the Volkswagen diesel case.

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions of diesel engines are recognized as main causes of the air pollution. CRDI (common rail direct injection) diesel engine is widely used for the sake of minimization on exhaust emission. Because biodiesel fuel is a renewable and alternative fuel for diesel engine, its usability is expanded. An commercial CRDI diesel engine used to commercial vehicle was fueled with diesel fuel and 5% biodiesel blended fuel (BDF 5%) with city mode in excess of 300 hours. The engine performance and exhaust emissions were sampled at 1 hour interval for analysis. To check the engine parts (valve, injector), the engine was inspected after test. It was concluded that there was no unusual deterioration of the engine, or any unusual changes in engine power and exhaust emissions in spite of operation of 300 hours with BDF 5%.

방산기술이 복제되거나 방해기술이 발달되어 그 가치와 효용이 낮아지는 것을 방지하고 부적절한 수출을 방지하기 위한 보호가 필요하여 2015년도에 방위산업기술보호법이 제정되었다. 방산기술이란 방위산업과 관련된 국방과학기술 중에 서 국가안보를 위하여 보호되어야 하는 기술을 의미한다. 그러나 현재 방산기술 보호체계 중에서 보호대상 기술의 식별 및 관리 체계의 기술식별 기준이 법규화 되어 있지 않다. 이에 본 연구에서는 델파이 설문을 통하여 141개 방산기술 중에서 고효율 내연기관 추진 기술과 관련 있는 디젤기관 요소기술 식별기준을 정립하고 방산기술 보호체계 중 보호대상 기술의 식별 및 관리 체계를 개선하였다. 연구결과로 디젤기관 요소기술 식별기준으로 작전 운용성, 내구성, 안전성, 계열화 및 모듈화 등을 정립하였다.

The Defense Technology Security Act was enacted in 2015 to protect the defense industrial technology from being duplicated or interfering technologies being developed, which prevents its value and utility from deterioration and prevents inappropriate export. Defense industrial technology refers to technology that should be protected for national security among the national defense science and technology related to the defense industry. However, technical identification criteria of identification and management system of protection technology are not regulated. Therefore, in this study, through the Delphi survey, diesel engine core technology identification criteria related to the high efficiency internal combustion engine propulsion technology among the 141 defense industrial technologies is established to improve the identification and management system of the technology to be protected among the defense industrial technology protection system. As a result of the study, operational operability, durability, safety, sequencing and modularization were established as diesel engine core technology identification criteria.

전통적인 화석 에너지 자원의 고갈과 환경오염 악화 등의 관점에서 볼 때 에너지 절약 및 배출가스의 저감은 동시에 해결해야 되는 문제로 대두되고 있다. 바이오연료는 대체연료의 하나로서 이러한 문제들을 효과적으로 해소할 수 있는 대안으로 떠오르고 있다. 따라서 본 연구에서는 커먼레일 터보과급디젤기관에 서 카놀라유 바이오디젤연료의 적용효과를 알아보기 위하여 실험적으로 고찰하였다. 실험에 사용된 연료 는 ULSD(초저황 디젤유), BD20(체적비로 20%인 카놀라유와 80% 디젤유 혼합) 및 PCO(순수한 카놀라 유)를 사용하였다. 카놀라유 바이오디젤연료의 혼합율이 증가함에 따라 입자상물질(PM)과 일산화탄소 (CO)는 크게 감소하였으며, 질소산화물(NOx)은 약간 증가하는 현상을 보였다.

With depletion of conventional fossil energy resources and increased pollution, energy-saving and emission reduction problems have to be solved. Biofuels are alternative fuels that can effectively reduce these problems. Therefore, in this study, the application characteristics of canola oil biodiesel in a CRDI Turbocharged Diesel Engine was experimentally investigated. The test fuels were denoted as ULSD (ultra low sulfur diesel), BD20 (20% canola oil blended with 80% ULSD by volume), and PCO (pure canola oil), respectively. By using canola oil biodiesel, the particulate matter (PM) and carbon monoxide (CO) emissions were considerably reduced with increased BMEP. The nitrogen oxide (NOx) emissions increased only slightly due to the inherent presence of oxygen in biodiesel.

The fuel used in this study, DMM is an oxygen additive containing 42.5% oxygen by weight and dissolved in diesel fuel, also known as methyl alcohol or Dimethoxymethane (CH3-O-CH2-O-CH3). DMM, which is a colorless liquid, shows chemical characteristics of gas-liquid and is also used as a diesel fuel component. In this study, five mixtures were added to the common diesel fuel at DMM addition rates of 2.5, 5, 7.5, 10 and 12.5% by volume. A single cylinder, four strokes, DI diesel engine was used as the test engine. Experimental data were also collected at 24 engine speed-load conditions operating in steady state. The purpose of this experiment was to study the effect of the addition ratio of oxidized fuel mixed in diesel fuel on engine power and exhaust performance. When compared with the common diesel fuel, the exhaust of Smoke was substantially reduced in all DMM mixing ratios. These results indicate that DMM can be an effective blend of diesel fuel and is an environmentally friendly alternative fuel. This study also shows that smoke and NOx emissions can be reduced at the same time through the application of oxygen fuel and EGR.

디젤엔진은 열효율이 높고 연비가 좋으며 CO, HC 및 CO2의 배출량이 낮은 등 가솔린 엔진보다 상당한 장점이 있다. 그러나 디젤엔진은 배기가스 중에 O2 농도가 높기 때문에 NOx 저감이 어렵고, 삼원촉매를 적용하기 어렵다. Urea-SCR과 LNT는 디젤엔 진에서 NOx를 연속적으로 저감하는데 활용 가능한 두 기술이다. 디자인 엔진에 Urea-SCR 시스템을 구현함으로써 2.5l 이상 엔진 에서 Euro-6의 강화된 NOx 기준을 충족시킬 수 있게 되었다. 본 연구에서는 엔진 회전속도, 부하, 촉매 방식 및 NH3/NOx 비율에 따른 NOx 저감 특성을 연구하여 NOx 저감을 극대화하는 조건을 제시하고자 한다. 또한 Euro-6 이상의 규제에 대응할 수 있도록 Urea-SCR에 대한 정밀한 실험 데이터를 제공하고자 한다.

Diesel engines have important advantages over its gasoline counterpart including high thermal efficiency, high fuel economy and low emissions of CO, HC and CO2. However, NOx reducing is more difficult on diesel engines because of the high O2 concentration in the exhaust, marking general three way catalytic converter ineffective. Two method available technologies for continuous NOx reduction onboard diesel engines are Urea-SCR and LNT. The implementation of the Urea-SCR systems in design engines have made it possible for 2.5l and over engines to meet the tightened NOx emission standard of Euro-6. In this study, we investigate the characteristics of NOx reduction with respect to engine speed, load, types of catalyst and the NH3/NOx ratio and present the conditions which maximize NOx reduction. Also we provide detailed experimental data on Urea-SCR which can be used for the preparation for standards beyond Euro-6.

본 연구에서는 광산의 운반 작업 시 발생하는 디젤 트럭의 탄소배출량을 도로 경사, 적재 여부, 탄소배출 국제표준을 고려하여 산정하는 기법을 제시하였다. 국내 석회석 광산을 대상으로 파쇄장, 적재장 사이의 왕복 경로를 결정하고 경로에 따른 배출계수의 변화를 확인하였다. 분석 결과 새로 개발된 기법은 운반 경로의 경사, 적재 여부에 따라변화하는 배출계수를 기존 방법보다 현실적으로 모사하였다. 동일한 조건에서 현장에서 사용하는 연식의 차량을 최신 연식으로 바꾼다고 가정하고 탄소배출량을 산정한 결과 배출량은 현재보다 4-6% 감소하였다. 개발한 기법은 다양한 범주의 차량, 오염 물질에 대하여 적용 가능하므로 제안한 방법은 차량 배기가스에 의한 온실가스 배출량을 예측하기 위하여 범용적으로 활용될 수 있다.

This study presents a method for calculating carbon-dioxide emissions of diesel trucks during haulage operations by considering road gradient, load capacity and emission standards. An underground limestone mine in Korea was selected as a study area to apply the method. In the study area, variations of emission factors were observed along haulage routes between a crusher and two loading points. The method could simulate the changes of emission factors reasonably with regard to road gradient and load capacity. Along the same haulage route, carbon-dioxide emission decreased by 4-6% with the change of current trucks to newer ones with improved emission standards. The suggested method can be used for the analysis with other vehicle types and greenhouse gases. Therefore, this method can be used for general estimation of greenhouse gas emissions.

The feature of asthma are airway inflammation (AI), reversible airway obstruction, and an increased sensitivity to bronchoconstricting agents, elevated airway hyperresponsiveness (AHR), excess production of Th2 cytokines, and eosinophil accumulation in the lungs. This study was performed to investigate if oral administration of Scutellaria baicalensis Georgi water extracts (SBG) have the antiasthmatic potential for the treatment of asthma. Asthmatic HI and AHR were induced by systemic sensitization to ovalbumin (OVA) with intratracheal instillation with 0.1 ㎎/mL of diesel exhaust particles (DEP) suspension once a week for 10 weeks in BALB/c mice. SBG was orally administered with the concentraion of 200㎎/㎏ 5 days a week for 10 weeks. Long-term SBG treatment suppressed the eosinophil infiltration into airways from blood,the asthmatic AI and AHR by attenuating the production of cytokine IL-4, IL-5 and IL-13, histamine and OVA-specific IgE. Our data suggest that SBG has inhibitory effects on AI and AHR in a mouse model of asthma, may act as a potential Th2cytokine antagonist, and may have a therapeutic effect on allergic asthma.

The objective of this study was to investigate the effect of crude ginseng total saponins (CGS) against airway inflammation (AI) and airway hyperresponsiveness (AH) induced by diesel exhaust particles (DEP) in mice. AI and AH were induced by the intratracheal instillation with 0.1㎎/㎖ of DEP suspension once a week for 10 weeks combined with ovalbumin (OVA) sensitization. Mice were also treated orally with 75㎎/㎖ of CGS, 5 days a week for 10 weeks. Oral CGS treatment decreased in the level of serum immunoglobulin (IgE) and histamine increased by DEP and OVA, and declined respiratory resistance. It also dropped an enhanced infiltration of eosinophils in the bronchoalveolar lavage fluid (BALF) of mice, and an increased T helper type 2 cell derived cytokine levels such as of interleukin (IL)-4, IL-13 and IL-5 in the BALF. However, it did not influence T helper type 1 cytokine such as interferon-gamma in the BALF. These results indicate that CGS may alleviate allergen-related AI and AH in mice and may play an important role in the modulation of asthmatic inflammation.

The aims of research of this paper are as follows; first of all, main contents of technical development are such as. 1. the burner system development for maximum efficiency of diesel particulate filter in low temperature emission gas, 2. the development of white fume reducing system by the second ejection in diesel, 3. the development of burner system for erasing of oxidation catalyzer of the most important role in diesel particulate filter, And the secondhand, expectation effect of this paper is such as. If the mass production of this development is successfully, this system is easy to applicable to small diesel vehicle stopping by low efficiency diesel particulate filter and is increased cost effective and adaptability by erasing oxidation catalyzer.

In this study, we investigated the effects of diesel-palm oil biodiesel-ethanol blends on combustion and emission characteristics in a 4-cylinder common rail direct injection (CRDI) diesel engine at low idling operations. The engine speed and engine load was 750 rpm and 40 Nm, while the main and pilot injection timing was respectively fixed at 2 °CA before top dead center (BTDC) and 20 °CA BTDC. The experimental results showed that the cylinder pressure increased with the increasing of palm oil biodiesel ratio from 20% to 100%. In addition, the peak value of cylinder pressure increased by 4.35% compared with pure diesel fuel when 5 vol.% ethanol oil added to diesel oil. Because the palm oil biodiesel and ethanol are the oxygenated fuel, the oxygen content played an important role in improving combustion. Based on the high oxygen content of biodiesel and ethanol, their mixing with diesel fuel effectively reduced PM emissions but increased NOx slightly, while CO and HC had no significant changes.

본 연구에서는 가변 압축비 조절기구가 부착된 단기통 4행정 수냉식 디젤 엔진(모델 : Farryman A 30 marine, TQ, UK) 에 바이오디젤 연료(BDF)를 적용하여 엔진의 성능변수와 배기가스 특성을 살펴보았으며 여러 가지 연료와 운전조건에 따른 비연료 소비율(SFC)과 매연 농도도 함께 조사하였다. 사용된 연료는 상업용 디젤유(DF)와 BDF100(BDF 100 %), 그리고 이들의 혼합유인 BDF20(BDF vol. 20 % + DF vol. 80%) 이며, 이 중에서 DF를 비교 기준 연료로 하였다. 실험조건으로는 압축비(CR)가 12:1, 14:1, 16:1 및 18:1 이며, 엔진 속도가 1000, 1500, 2000 및 2500 rpm 이다. 실험 결과, BDF의 SFC는 엔진 속도에 따라 DF에 비하여 1.3 ～ 3.7 % 증가하여 나타났으며, 매연 농도는 DF에 비하여 최대 45.7 % 감소하여 나타난 반면에, NOx 는 최대 38 % 까지 크게 나타났는데 이는 선행 연구결과인 12.0 % 정도를 훨씬 상회한다. 또한, 엔진 출력은 사용한 연료 종류에 따라 큰 차이를 보이지 않는 것으로 나타났다.

An experimental study on engine performance parameters and emission gas characteristics for bio-diesel fuels (BDF's) was performed by using of a specific engine; the type of single-cylinder, four-stroke, water-cooled diesel engine with variable compression ratio adjustment mechanism (the model Farryman A 30 marine, TQ, UK). Specific fuel consumptions (SFC) and soot tendency(smoke %) for various fuel and/or operation conditions were also examined. The BDF's used were prepared BD 20 and BD 100 together with the commercial diesel fuel (DF) for reference. The established conditions for experiment were 12:1, 14:1, 16:1 and 18:1 for compression ratio (CR), and 1000, 1500, 2000 and 2500 rpm for engine speed. It was found that SFC of BDF's is increased 1.3 ～ 3.7 % compared with DF according to the rpm's; for the smoke %, BDF's value is reduced significantly up to max. 45.7 % in comparison to that of DF; and while NOx is increased amazingly up to max. 38 %, which is too much than the previous results of around 12.0 %. Also, it does not seem that the engine's power output remains changed significantly according to the fuels used.

Diesel engine has the advantages of strong power, low fuel consumption and good durability, so it has been widely used in transportation, automobile, ship and other fields. However, the nitrogen oxides(NOx) and particulate matter(PM) emitted by diesel engines have become one of the main causes of air pollution. Especially during idling, the engine temperature is low, and there are more residual exhaust gases in the combustion chamber, resulting in the formation of more harmful emissions. In this study, performance of a single cylinder, four-stroke, direct injection (DI) diesel engine fueled with diesel–biodiesel mixtures has been experimentally investigated.

Many countries of the world has been devoting a lot of effort to reduce carbon emission. In order to reduce carbon emission, the high efficiency engine has been studied in the automotive industry. Of these, the spread and research of the diesel engine in Europe center are active. However the combustion characteristic of diesel engines have disadvantages of much NOx and soot emissions. In this study, the optimum regeneration point of the forced regeneration type DPF(Diesel Particulate Filter) that was equipped in medium-duty diesel vehicles using a mechanical fuel injection system have studied. DPF that is applied to the medium-duty diesel vehicle has a bent inlet pipe. The flow distribution characteristics of DPF according to the influence of the bent pipe have investigated. The flow distribution characteristics of DPF according to variation of the engine operating condition is considered to be useful data In order to decide the optimum regeneration point.