• 자원리싸이클링
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• 제27권3호
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• pp.93-99
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• 2018

본 연구에서는 디스플레이 산업의 백금 폐스크랩을 용해, 용매추출을 통하여 백금족 성분을 효율적으로 추출하고, 추출된 백금용액을 디젤자동차 배가스 정화촉매용 전구체 용액으로서 제조하고, 그 촉매활성을 실험하였다. 용액화학적 이론 연구를 통하여 백금 화학종의 수용액상 거동을 조사하였고, 화학종들의 존재영역 및 거동을 근거로 추출 및 분리 가능방안을 수립하였다. 전기화학적 방법에 의해 폐스크랩을 용해시킴으로써, 용해시간 단축 및 추출효율을 높였으며, 로듐 성분을 분리 제거, TBP에 의한 용매추출, 염산에 의한 탈거 공정을 거쳐 Pt-Chloride-$H_2O$ 계 백금용액을 용액을 제조하고, 이 용액을 원료로 액상 아민화 반응을 통해 아민산 백금용액을 제조한 다음, 카본블랙의 연소반응에 대한 촉매 활성을 실험함으로써, 백금족 폐스크랩으로부터 고부가 백금족 화합물의 제조가능성을 연구하였다.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.1-8
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• 2017

본 연구에서는 인휠 전기구동 시스템의 장점을 바탕으로 첨단능동안전지원 기술의 일종인 적응순항제어(Adaptive Cruise Control, ACC) 알고리즘의 고도화 방안을 제시한다. 본 연구에서 대상 차량은 전륜은 엔진에 의해, 후륜은 인휠모터에 의해 구동되는 4륜 하이브리드 구동계를 갖는 것을 특징으로 하는데, 이러한 구성은 기존 내연기관 차량을 개선하여 차량의 출력을 증가시키거나 4륜 하이브리드 형태로의 변화를 용이하게 하는 장점이 있다. 본 연구에서는 이러한 차량의 구성을 바탕으로 기본 상태에서는 엔진만을 이용하여 차간거리 제어를 수행하되, 젖은 노면 등 주행 환경에서 제어오차가 커지게 되면 후륜의 인휠모터를 구동하여 제어성능을 확보할 수 있는 ACC 알고리즘을 제안한다. 제안된 ACC 알고리즘은 상기와 같은 방법으로 ACC 제어성능을 최적화함과 동시에 기존 4륜 자동차가 갖는 장점을 그대로 유지하도록 한다. 또한 본 연구에서는 고정밀 동역학 SW를 기반으로 대상 인휠모터 및 인휠 하이브리드 구동계, 해당 구동계 기반의 ACC 제어시스템을 모델링하였으며, 이를 통해 시뮬레이션 환경을 기반으로 제안된 알고리즘의 검증 결과를 제시한다.

• Journal of Biosystems Engineering
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• 제12권1호
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• pp.45-52
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• 1987

엔진의 점화시기(點火時期)를 제어(制御)하는 데에 마이크로컴퓨터를 이용(利用)하고자 여러 종류(種類)의 제어장치(制御裝置)를 설계(設計) 제작(製作)하여 가동시험한 결과를 요약하면 다음과 같다. 가. 제어장치(制御裝置)의 제작시(製作時) 고압방전(高壓放電)에 의한 잡음(雜音), 서어지, 전자파(電磁波)로부터 디지탈회로와 컴퓨터의 기능(技能)이 교란되는 것을 방지하기 위하여는 고압회로(高壓回路)와 여타 회로와의 분리 및 고압회로의 기생발진 억제와 차폐가 완전하여야 할 것이며, 또한 양질의 점화용(點火用) 도선(導線)을 사용하여야 할 것으로 생각된다. 나. 본 실험의 범위내에서는(컴퓨터시스템) (써어보 기구에 의한 점화신호발생(點火信號發生) 및 제어(制御) - (트랜지스터 스위칭) - (고압회로) 로 구성(構成)시킨 점화시기제어장치가 컴퓨터 등의 기능교란을 일으키지 않고 가장 잘 작동(作動)되었다. 다. 본 실험의 결과(結果)를 기초(基礎)로 마이크로컴퓨터를 이용한 엔진의 최적점화진각제어(最適點火進角制御)에의 응용(應用)이 가능(可能)할 것으로 사료(思料)된다.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.42-49
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• 2014

The gasoline direct injection (GDI) system is considerably spreading in automotive market due to its advantages. Nevertheless, since GDI system emit higher particle matter (PM) due to its combustion characteristics, it is difficult to meet strengthened emission regulation in near future. For this reason, a combined GDI with MPI system, so-called, dual injection (DUI) system is being investigated as a supplemental measure for the GDI system. This paper focused on power and fuel consumption effect by injection mode strategy of DUI system in part load and idle engine operating condition. In this study, port fuel injectors are installed on 2.4 liters GDI production engine in order to realize DUI system. And, at each injection mode, DOE (design of experiment) method is used to optimize engine control parameters such as dual injection ratio, start of injection timing, end of injection timing, CAM position and so on. As a consequence, DUI mode shows slightly better or equivalent fuel efficiency compared to conventional GDI engine on 9 points fuel economy mode as well as MPI mode shows less fuel consumption than GDI mode during idle operation. Furthermore, DUI system shows improvement potential of maximum 2.0% fuel consumption and 1.1% performance compared to GDI system in WOT operating condition.

• 한국자동차공학회논문집
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• 제22권4호
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• pp.1-9
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• 2014

The vast stores of biomass available in the worldwide have the potential to displace significant amounts of petroleum fuels. Fast pyrolysis of biomass is one of several paths by which we can convert biomass to higher value products. The wood pyrolysis oil (WPO) has been regarded as an alternative fuel for petroleum fuels to be used in diesel engine. However, the use of WPO in a diesel engine requires modifications due to low energy density, high water contents, high acidity, high viscosity, and low cetane number of the WPO. One possible method by which the shortcomings may be circumvented is to co-fire WPO with other petroleum fuels. WPO has poor miscibility with light petroleum fuel oils; the most suitable candidates fuels for direct fuel mixing are methanol or ethanol. Early mixing with methanol or ethanol has the added benefit of significantly improving the storage and handling properties of the WPO. For separate injection co-firing, a WPO-ethanol blended fuel can be fired through diesel pilot injection in a dual-injection dieel engine. In this study, the performance and emission characteristics of a dual-injection diesel engine fuelled with diesel (pilot injection) and WPO-ethanol blend (main injection) were experimentally investigated. Results showed that although stable engine operation was possible with separate injection co-firing, the fuel conversion efficiency was slightly decreased due to high water contents of WPO compare to diesel combustion.

• Tribology and Lubricants
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• 제32권4호
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• pp.132-139
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• 2016

The piston of a marine diesel engine works under severe conditions, including a combustion pressure of over 180 bar, high thermal load, and high speed. Therefore, the analyses of the fatigue strength, thermal load, clamping (bolting) system and lubrication performance are important in achieving a robust piston design. Designing the surface profile and the skirt ovality carefully is important to prevent severe wear and reduce frictional loss for engine efficiency. This study performs flexible multi-body dynamic and elasto-hydrodynamic (EHD) analyses using AVL/EXCITE/PU are performed to evaluate tribological characteristics. The numerical techniques employed to perform the EHD analysis are as follows: (1) averaged Reynolds equation considering the surface roughness; (2) Greenwood_Tripp model considering the solid_to_solid contact using the statistical values of the summit roughness; and (3) flow factor considering the surface topology. This study also compares two cases of skirt shapes with minimum oil film thickness, peak oil film pressure, asperity contact pressure, wear rate using the Archard model and friction power loss (i.e., frictional loss mean effective pressure (FMEP)). Accordingly, the study compares the calculated wear pattern with the field test result of the piston operating for 12,000h to verify the quantitative integrity of the numerical analysis. The results show that the selected profile and the piston skirt ovality reduce friction power loss and peak oil film pressure by 7% and 57%, respectively. They also increase the minimum oil film thickness by 34%.

• 한국자동차공학회논문집
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• 제15권3호
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• pp.54-62
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• 2007

The knock characteristics in an engine were investigated under homogeneous charge compression ignition (HCCI) operation. Liquefied petroleum gas (LPG)and gasoline were used as fuels and injected at the intake port using port fuel injection equipment. Di-methyl ether (DME) was used as an ignition promoter and was injected directly into the cylinder near compression top dead center (TDC). A commercial variable valve timing device was used to control the volumetric efficiency and the amount of internal residual gas. Different intake valve timingsand fuel injection amounts were tested to verify the knock characteristics of the HCCI engine. The ringing intensity (RI) was used to define the intensity of knock according to the operating conditions. The RI of the LPG HCCI engine was lower than that of the gasoline HCCI engine at every experimental condition. The indicated mean effective pressure (IMEP) dropped when the RI was over 0.5 MW/m2and the maximum combustion pressure was over 6.5MPa. There was no significant relationship between RI and fuel type. The RI can be predicted by the crank angle degree (CAD) at 50 CA. Carbon monoxide (CO) and hydrocarbon (HC) emissions were minimized at high RI conditions. The shortest burn duration under low RI was effective in achieving low HC and CO emissions.

• 한국안전학회지
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• 제20권1호
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• pp.36-41
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• 2005

PCV(Positive Crankcase Ventilation) valve acts as a flow control valve to get a re-combustion of blow-by gas by having it flow from a crankcase to an inlet manifold suction tube. The blow-by gas of the crankcase should be eliminated or taken properly because it cause corrosion to critical parts, and contributes to increase crankcase pressure that can cause a drop in efficiency. The excessive stress and strain on the PCV valve that remove these harmful gas would be bring the difficult on the flow rate control and failure of the valve. Those condition inevitably induce the accident. Therefore, this study purpose is FEM evaluation of the stresses and deformation in the X3 PCV model according to the change of the differential pressure between inlet and outlet. From results, the maximum equivalent stresses increased linearly according to the increase of the differential pressure at the about 50mm from the inlet position and were under the yield strength of the valve. And the deformations were relatively small regardless of the in-outlet differential pressure variation.

• 한국자동차공학회논문집
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• 제25권2호
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• pp.157-166
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• 2017

The Fuel Cell Electric Vehicle(FCEV) is recently evolving into a new trend in the automobile industry due to its relatively higher efficiency and zero greenhouse gas(GHG) emission in the tailpipe, as compared to that of the conventional internal combustion engine vehicles. However, it is important to analyze the whole process of the hydrogen's life cycle(from extraction of feedstock to vehicle operation) in order to evaluate the environmental impact of introducing FCEV upon recognizing that the hydrogen fuel, which is used in the fuel cell stack, is not directly available from nature, but instead, it should be produced from naturally available resources. Among the various hydrogen production methods, ${\sim}54.1%^{8)}$ of marketed hydrogen in Korea is produced from naphtha cracking process in the petrochemical industry. Therefore, in this study, we performed a well-to-wheels(WTW) analysis on the hydrogen fuel cycle for the FCEV application by using the GREET program from the US Argonne National Laboratory with Korean specific data. As a result, the well-to-tank and well-to-wheel GHG emissions of the FCEV are calculated as 45,638-51,472 g $CO_2eq/GJ$ and 65.0-73.4 g $CO_2eq/km$, respectively

• 콘크리트학회논문집
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• 제28권6호
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• pp.647-653
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• 2016

본 연구에서는 FA (Fly Ash)를 20%치환한 배합에 대하여 TDFA (Tire Derived Fuel Ash)를 3.0~12.0%까지 중량 치환하면서 내구성 평가를 수행하였다. TDFA는 열병합발전소에서 열효율을 높이기 위해 폐타이어를 혼소시킨 뒤 발생한 산업부산물로서 국내에서 콘크리트에 적용한 연구는 없는 상태이다. 이를 위해 물-결합재를 50%, FA를 20% 치환한 Control 콘크리트를 제조하였으며, TDFA를 치환하면서 압축강도, 촉진 탄산화 시험, 촉진염해 시험, 공극구조평가를 수행하였다. 압축강도, 탄산화, 공극구조에서는 12%까지 TDFA를 FA와 치환해도 동등이상의 성능을 확보하였다. 특히 염해에 대해서는 TDFA의 치환률의 증가에 따라 뚜렷한 염화물 확산계수의 감소를 나타내어 최종적으로 75.3~70.9%까지 염화물 확산계수가 감소하였다. TDFA를 혼입한 콘크리트 배합시, 워커빌리티의 확보가 가능하다면 TDFA를 혼입한 콘크리트는 내구성 개선에 효과적일 것으로 판단된다.