• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.396-399
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• 2009

Thin-film transistors (TFTs) with an aluminum indium oxide (AIO) channel layer were fabricated via a simple and low-cost sol-gel process. Effects of annealing temperature and time were investigated for better TFT performance. The sol-gel AIO TFTs were annealed as low as $350^{\circ}C$. They exhibit n-type semiconductor behavior, a mobility higher than 19 $cm^2/V{\cdot}s$ and an onto-off current ratio greater than $10^8$.

• 한국자동차공학회논문집
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• 제19권2호
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• pp.105-110
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• 2011

Through this study, the performance evaluation on the addition of low-pressure loop EGR(Exhaust Gas Recirculation) in a 6.0 L commercial diesel engine was carried out using WAVE modeling and simulation. Since the key technology of advanced diesel engine combustion such as low-temperature combustion is to steadily supply high rates of EGR in a wide operating range, the current study could be effectively contribute to the design and development processes of up-to-date diesel engine systems as real-world reference data. The current simulation results show that the system in which low-pressure loop EGR is added shows almost 2.3 times increase in maximum EGR rate at 1000 rpm as well as almost 1.6 times increase at 2200 and 1600 rpm in comparison with an engine system employing high-pressure loop EGR only. Also, both turbocharger axis speed and charging pressure level did not deteriorate due to the addition of low-pressure loop EGR at 2200 and 1000 rpm, but they were fairly decreased at 1600 rpm.

• 한국수소및신에너지학회논문집
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• 제19권5호
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• pp.403-409
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• 2008

Polymer electrolyte membrane fuel cell (PEMFC) is very interesting power source due to high power density, simple construction and operation at low temperature. But it has problems such as high cost, improvement of performance, effect of temperature and initial start at low temperature. These problems can be approached to be solved by using experiment and mathematical method which are general principles for analysis and optimization of control system for heat and hydrogen detecting management. In this paper, insulation vessel and control system for stable operation of fuel cell at low temperature were developed for experiment. The constant temperature capability and the heating time at sub-zero temperatures with insulation control system were studied by using a heating bar of 60W class. PEMFC stack which was made by 4 cells with $50\;mc^2$ active area in each cell is a thermal source. Times which take to reach constant temperature by the state of insulation vacuum were measured at variable environment temperatures. The test was performed at two conditions: heating mode and cooling mode. Constant temperature capability was better at lower environment temperature and vacuum pressure. The results of this experiment could be used as basis data about stable operation of fuel cell stack in low temperature zone.

• 한국가스학회지
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• 제22권5호
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• pp.18-23
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• 2018

본 연구에서는 CNG자동차 인젝터의 외부 환경온도에 따른 인젝터의 분사량을 분석하고자 한다. 특히 냉간 시동시와 같은 조건에서 분사량의 변화를 측정하여 저온환경이 가스인젝터 성능에 미치는 영향을 파악하고자 하며, 가스 인젝터 내부의 스프링 특성을 다르게 하여 실험을 진행 하였다. 실험 장치는 연료 공급부, 유량 측정부, 온도 챔버와 인젝터 제어부로 구성하였다. 실험결과를 통해 저온환경일수록 가스인젝터의 초기 분사량이 증가하였으며, 스프링길이 증가에 따른 니들의 열리는 시간(무효분사시간)이 지연됨을 확인하였다.

• 대한기계학회논문집B
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• 제41권11호
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• pp.699-707
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• 2017

본 연구에서는 아홉 종류의 작동유체를 고려하여 저온 열원으로 구동되는 아임계 및 초월임계 유기 랭킨 사이클의 열역학적 성능 특성을 비교 해석한다. 터빈입구압력, 열원온도 및 작동유체가 열교환기 내 온도분포와 핀치포인트, 작동유체의 유량, 시스템 출력 및 열효율 등 시스템의 성능에 미치는 영향을 분석한다. 해석 결과는 작동유체의 압력이 아임계 영역에서 초임계 영역으로 높아지면 열교환기에서 열원과 작동유체 사이의 온도 불균일 정도가 감소하면서 시스템 출력이나 열효율 등은 증가하나 시스템의 단위출력당 터빈 크기는 작아짐을 보여준다.

• 전기전자학회논문지
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• 제18권3호
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• pp.420-426
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• 2014

본 연구에서는 저온유동성 성능검사 시스템 구현을 통해 디젤 차량용 통합형 연료필터의 성능을 평가한다. 저온유동성시험 장치의 시험조건은 경유(또는 등유)를 사용하고, 상온, -20 및 $-30^{\circ}C$ 에서 경유공급압력 $3.4kgf/cm^2$, 연료공급량 60 l/H, 설정전류 30 A 및 전압은 $13V_{dc}$를 사용한다. 시료시험으로 통합필터를 지그에 장착하고, 경유(또는 등유)를 일정압력과 유량으로 설정하여 챔버 탱크와 필터에 채운 후, 설정시간 동안 설정온도로 냉각한 후, 필터 전후에 따라 유압과 시동시간, 히터의 소모전류 및 전력을 측정한다.

• 한국분무공학회지
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• 제9권1호
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• pp.15-20
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• 2004

The post injection effect to enhance aftertreatment devices' performance is essential to meet future stringent emission standards by controlling exhaust gas temperature and emission pollutants. The test has been made with commercial common rail diesel engine by post injection manipulation, to optimize exhaust gas temperature while guarantee low fuel penalty. The optimization was done at 1500, 2000 and 2500[rpm] for 2, 4[bar] condition which show low exhaust gas temperature. The main purpose of this test is dedicated to understand mechanism of exhaust gas temperature rise while optimizing

• 한국자동차공학회논문집
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• 제11권6호
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• pp.59-64
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• 2003

Recently, as people pay attention to the environmental pollution, the emissions of diesel engine have been a serious problem. We carried out the performance evaluation test of Diesel Oxidation Catalysts (DOC) for HSDI diesel engine equipped vehicles. The DOC, basically coated with Pt catalyst, was manufactured with various washcoat materials. It was found that CO conversion efficiency depends on temperature, but THC conversion efficiency is dominated by temperature and space velocity. The THC and CO conversion efficiencies of aged catalysts were increased with additions of $ZrO_2$ and zeolite B in the washcoat. We found that DOC performance changes with coating techniques, even through it has same washcoat materials. The DOC coated by high temperature washcoat coating technology showed good conversion efficiency than low temperature washcoat coated DOC.

• 한국표면공학회지
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• 제52권6호
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• pp.306-309
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• 2019

Titanium (Ti) doped indium oxide (In₂O₃) films were deposited on glass substrates by RF magnetron sputtering and the films were rapid thermal annealed at 100, 200, and 300℃, respectively to investigate the influence of the rapid annealing on the opto-electrical performance of the films. The grain size of In₂O₃ (222) plane increased with annealing temperatures and their electrical resistivity decreased to as low as 8.86×10^-4 Ωcm at 300℃. The visible transmittance also improved from 77.1 to 79.5% when the annealing temperature increased. The optical band gap of the TIO films shifted from 4.010 to 4.087 eV with increases in annealing temperature from room temperature to 300℃. The figure of merit shows that the TIO films annealed at 300℃ had better optical and electrical performance than the other films prepared using lower-temperature or no annealing.

• 설비공학논문집
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• 제11권5호
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• pp.561-569
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• 1999

The effects of longitudinal heat conduction on the performance of heat transfer surfaces are investigated by using a single-blow method. In the transient testing method for determining the heat transfer characteristics, exponential inlet temperature variations are made by using screen-mesh heater with small time constant and low frontal velocities of the test section, and the experimentally determined inlet temperature profile is used as the inlet fluid temperature condition. The effects of longitudinal heat conduction are negligible only if $\gamma^\act<0.05\;and \;N_{tu}\le3$ and should be considered if $N_{tu}\le3$ The test results ate compared with the existing theoretical and experimental data and the validity of this technique is confirmed by the good agreement.