• 센서학회지
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• 제21권6호
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• pp.402-407
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• 2012

We report a Fabry-Perot interferometer (FPI)-based multi-channel micro-spectrometer used for multi-gas measurement in the spectral range of $3-5{\mu}m$ and its gas sensing performance. The fabricated infrared (IR) spectrometer consists of two parts: an FPI on the top side for selective IR filtering and a $V_2O_5$-based IR detector array on the bottom side for the detection of the filtered IR. Experimental results show that the FPI-based multi-channel gas sensor has reliability and selectivity for simultaneously detecting environmentally harmful gases such as $CH_4$, $CO_2$, $N_2O$ and CO in the spectral range of $3-5{\mu}m$. The fabricated FPI-based multi-channel gas sensor also demonstrated that a reliable and selective detection of gas concentrations ranging from 0 to 500 ppm is feasible. In addition, the electrical characteristics demonstrate a superior response performance in regards to the selectivity in the multi-target gases.

• 신재생에너지
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• 제5권2호
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• pp.9-14
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• 2009

Automobile Shredder Residue (ASR) is very appropriate in a gasification melting system. Gasification melting system, because of high reaction temperature over than $1,350^{\circ}C$, can reduce harmful materials. To use the gasification processes for hydrogen production, the high concentration of CO in syngas must be converted into hydrogen gas by using water gas shift reaction. In this study, the characteristics of shift reaction of the high temperature catalyst (KATALCO 71-5M) and the low temperature catalyst (KATALCO 83-3X) in the fixed - bed reactor has been determined by using simulation gas which is equal with the syngas composition of gasification melting process. The carbon monoxide composition has been decreased as the WGS reaction temperature has increased. And the occurrence quantity of the hydrogen and the carbon dioxide increased. When using the high temperature catalyst, the carbon monoxide conversion ratio ($1-CO_{out}/CO_{in}$) rose up to 95.8 from 55.6. Compared with average conversion ratio from the identical synthesis gas composition, the low temperature catalyst was better than the high temperature catalyst.

• 한국생산제조학회지
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• 제19권2호
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• pp.301-305
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• 2010

Cutting procedures where qualities are determined by various demand factors largely influences shipbuilding productivity. Particularly, defects in cutting shapes and cutting surface results in delay for post shipbuilding stages such as in welding and assemblage lines which could become factors for reduced economic viability of the project. Existing cutting procedures utilize fossil fuels such as propane or ethylene as the main fuel component and these methods applied particularly to ship plate cutting gives relatively slow cutting speed and generates large quantities of harmful and sometimes poisonous polluting fumes of which warrants an urgent need to look for alternative cutting methods. Recent introduction of hydrox gas generated by electrically dissociating water into hydrogen and oxygen components to be utilize as an alternative cutting fuel has resulted not just in visible improvement on cutting quality and speed over the existing methods but it has also been welcomed as an environmentally friendly clean fuel source. This paper has been prepared to serve as the basis for accommodating this environmentally friendly hydrox gas cutting method into actual working environment by observing and recording hydrox gas cutting thermal characteristics.

• 센서학회지
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• 제27권1호
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• pp.13-20
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• 2018

Gas sensors based on metal oxide semiconductors are used in numerous applications including monitoring indoor air quality and detecting harmful substances like volatile organic compounds. Nanostructures, for example, nanoparticles, nanotubes, nanodomes, and nanofibers have been widely utilized to improve gas sensing properties of metal oxide semiconductors, and this increases the effective surface area, resulting in participation of more target gas molecules in the surface reaction. In the recent times, 1-dimensional (1D) metal oxide nanostructures fabricated using anodic oxidation have attracted great attention due to their high surface-to-volume ratio with large-area uniformity, reproducibility, and capability of synthesis under ambient air and pressure, leading to cost-effectiveness. Here, we provide a brief overview of 1D metal oxide nanostructures fabricated by anodic oxidation and their gas sensing properties. In addition, recent progress on thin film-based anodic oxidation for application in gas sensors is introduced.

• 한국자동차공학회논문집
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• 제1권2호
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• pp.34-41
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• 1993

In order to reduce harmful substances such as particulates and nitric oxides emitted from diesel engine, man kinds of methodology like high pressure spray of diesel fuel oil, exhaust gas recirculation, emulsified fuel usage and dual fuelling have been studied. Dual fuelling of a diesel engine with hydrogen which is well-known as the clean fuel and has excellent combustibility is expected to be effective in reducing harmful substances from diesel engine. This experimental study was conducted to investigate the effect of premixed hydrogen with intake air on the performance and particulate emission characteristics using a single cylinder, prechamber type diesel engine. As a result, it was clarified that a hydrogen-premixed diesel engine can be operated in the state of lower particulate emission and slightly aggravated fuel economy, compared with the conventional diesel engine.

• International Journal of Precision Engineering and Manufacturing
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• 제7권3호
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• pp.24-29
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• 2006

Pressurized gas pipelines are subject to harmful effects from both the surrounding environment and the materials passing through them. Reliable assessment procedures, including fracture mechanics analyses, are required to maintain their integrity. Currently, integrity assessments are performed using conventional deterministic approaches, even though there are many uncertainties to hinder rational evaluations. Therefore, in this study, a probabilistic approach was considered for gas pipeline evaluations. The objectives were to estimate the failure probability of a corroded pipeline in the gas and oil industries and to propose limited operating conditions for different types of loadings. To achieve these objectives, a probabilistic assessment program was developed using a reliability index and simulation techniques, and applied to evaluate the failure probabilities of a corroded API-5L-X52 gas pipeline subjected to internal pressures, bending moments, and combined loadings. The results demonstrated the potential of the probabilistic integrity assessment program.

• 동력기계공학회지
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• 제3권3호
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• pp.44-53
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• 1999

This study is concerned with the emission characteristics of kerosene fan heater, which is burned with kerosene and water droplets simultaneously in the burner, in order to prohibit the emissions of harmful exhaust gas and reduce smell caused by incomplete combustion, and the addition of water droplets to the conventional kerosene fan heater was performed by ultrasonic atomizer. For the investigation of this study, the measurement of exhaust gas components and exhaust gas temperature was carried out by using an automatic combustion gas analyser and $NO_x$ analyser, and the measurement of consumption weight of oil and water was obtained by using electric digital balance. Consequently, according as the water percent weight ratio of about $21{\sim}23%$ was supplied for this study, it was found that the combustion-generated $NO_x$ and CO emissions were reduced very largely, but the emissions of $O_2\;and\;CO_2$ and the temperature of exhaust gas were not changed.

• 한국정밀공학회지
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• 제22권10호
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• pp.158-166
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• 2005

Pressurized gas pipeline is subject to harmful effects both of the surrounding environment and of the materials transmitted in them. In order to maintain the integrity, reliable assessment procedures including tincture mechanics analysis etc are required. Up to now, the integrity assessment has been performed using conventional deterministic approaches even though there are many uncertainties to hinder a rational evaluation. In this respect, probabilistic approach is considered as an appropriate method for gas pipeline evaluation. The objectives of this paper are to estimate the failure probability of corroded pipeline in gas and oil plants and to propose limited operating conditions under different types of leadings. To do this, a probabilistic assessment program using reliability index and simulation techniques was developed and applied to evaluate failure probabilities of corroded API-5L-X52/X60 gas pipelines subjected to internal pressure, bending moment and combined loading. The evaluation results showed a promising applicability of the probabilistic integrity assessment program.

• 대한조선학회 특별논문집
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• 대한조선학회 2008년도 특별논문집
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• pp.126-132
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• 2008

Cutting procedures whose qualifies are determined by various variables largely influences shipbuilding productivity. Particularly, defects in cutting shapes and cutting surface results in delay of the post shipbuilding stages such as welding and assemblage process. Because cutting procedures are influenced by various numbers of requirements according to the plate thickness, cutting precision can be maintained when the cutting conditions are appropriate. Existing cutting procedures utilize fossil fuels such as propane or ethylene as the main fuel component. Especially, when fossil fuel is applied to thick plate cutting, this process gives relatively slow cutting speed and generates large quantities of harmful polluting fumes. Recently, hydrogen-oxygen mixed gas generated by electrically dissociating water into Hydrogen and oxygen components is welcomed as an alternative fuel source. Also recent results report that alternative cutting fuel improves the cutting Dualities and speed. This paper presents that cutting characteristics and optimum cutting condition of hydrogen-oxygen mixed gas.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.818-823
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• 2001

Because the exhaust emissions from automobiles are increased, our environment is faced with very serious problems related to the air pollution in these days. In particular, the exhaust emissions of diesel engine are recognized main cause which influenced environment strong. Lots of researcher have been attempted to develop various alternative fuel on purpose to reduce these harmful emissions. In this study, the potential possibility of esterfied rice bran oil which is a kind of biodiesel fuel was investigated as an alternative fuel for diesel engine. And, we tried to analysis not only total hydrocarbon but hydrocarbon components from $C_1$ to $C_6$ in exhaust gas using gas chromatography to seek the reason for remarkable reduction of exhaust emission. Individual hydrocarbon$(C_1\simC_6)$ as well as total hydrocarbon of biodiesel fuel is reduced remarkably than that of diesel fuel in this experiment.