• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.529-531
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• 2005

This paper proposes a compact pulse generator fur NOx removal application for diesel automotive. The rising time is important factor to increase NOx removal efficiency in pulsed corona discharge method. Manufacturing cost and compactness of the pulse power generator should be satisfied for automotive application. The proposed pulse power uses a low voltage thyristor, a pulse transformer with the function of saturated magnetic switch, and series connected general diodes as opening switch to satisfy that requirements. With 200 resistor load, the experiment results show that the output voltage is 21kV, the rising time is about 21ns, and the pulse width (FWHM) is about 42ns.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.1117-1122
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• 2001

This study is to investigate application to the load packing or block with photocatalystic which has the characteristics absorption and removal for NOx, which is mainly generated from plant or car, which can be resolved by actions of light. Therefor a basic study was carried out to maximize the photocatalystic block for elimination of NOx.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2001년도 추계학술대회 논문집
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• pp.419-420
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• 2001

최근 산업설비 및 기타 시설에서 배출되는 유해가스의 배출허용 기준이 계속 강화되고 있으며 그 중에서도 NOx는 SOx와 함께 대기오염의 주된 원인으로 작용하고 있다. 국내에서도 이들 유해가스를 제거하기 위한 플라즈마 적용기술이 활발히 연구되었으며, 일부 기술은 상용화 단계에 있다. NOx 제거에 있어서 펄스 코로나 방전에 의한 전자의 생성은 유입되는 가스 및 공기에 충돌하여 반응성이 큰 다량의 이온, 원자 및 radical(N, O, OH, $O_3$등)을 생성한다. (중략)

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2005년도 추계학술대회 논문집
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• pp.481-482
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• 2005

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2004년도 추계학술대회 논문집
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• pp.107-109
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• 2004

• 한국연소학회:학술대회논문집
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• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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• pp.117-128
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• 1999

The removal of nitrogen oxides(NOx) from $N_{2}/O_{2}$ gas using a pulsed corona discharge was investigated as a function of the reduced electric field(E/N) and the energy density(J/L). A kinetic model was developed to characterize the chemical reactions taking place in a pulsed corona discharge reactor. The model calculates the fractional concentrations of radical species at each pulse-on period and utilizes the radicals to remove NOx for the subsequent pulse-off period. Electron collision reaction data are calculated using ELENDIF program to solve Boltzmann equation for electron energy distribution function, and the subsequent chemical reactions are calculated using CHEMKIN-II program to solve stiff ODE(ordinary differential equation) problems for species concentrations. The corona discharge energy per pulse and the time-space averaged E/N were obtained by fitting the model to experimental data. The model calculation shows good agreement with the experimental data, and predicts the formation of other species such as $NO_{2}$, $O_{3}$ and $N_{2}O$.

• 한국응용과학기술학회지
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• 제30권3호
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• pp.451-460
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• 2013

NOx from the thermal power plants are NO and $NO_2$. This work investigated the chemical/physical characteristics and SCR efficiency of newly prepared catalysts including tungsten ($WO_3$), molybdenum ($MoO_3$) and antimony ($SbO_3$) based on vanadia($V_2O_5$) over titania($TiO_2$). As a result of the examination, the surface area of the catalysts promoted with additional metals was larger and the de-NOx efficiency also was enhanced with temperature. The most efficient catalytst was $V_2O_5/TiO_2-WO_3$(10%) at $200^{\circ}C$. Such a high efficiency could contribute to reduce the ammonia slip.

• 한국대기환경학회지
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• 제12권4호
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• pp.421-428
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• 1996

In this study, in order to make up its draw-back in Cu-ZSM-5 catalytic system, some of transition metals or alkaline earth metals were cocation-exchanged in Cu-ZSM-5. Among various cocation-ion-exchanged ZSM-5 catalysts, Mg/Cu-ZSM-5 has been found the most active and durable in NOx reduction even at high oxygen content as well as at the presence of water vapor. The role of Mg in ZSM-5 is supposed to prevent the dealumination of aluminum ions in super-cage even at harsh hydro-thermal conditions, and also it seems to stabilize the Cu ions in the structure. In order to prepare commercially available catalysts, Mg/Cu-ZSM-5 catalysts were wash-coated on the surface of honeycomb type monolith, and tested in terms of catalytic activities. As a result, it was found that the catalyst prepared bt the wash-coating showed satisfactorily high NOx conversion for the practical use in SCR process.

• Journal of Mechanical Science and Technology
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• 제15권11호
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• pp.1588-1598
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• 2001

The effects of recirculated exhaust gas on the characteristics of NOx and soot emissions under a wide range of engine loads were experimentally investigated by using a four-cycle, four-cylinder, sw irl chamber type, water-cooled diesel engine operating at three engine speeds. The purpose of this study was to develop the EGR-control system for reducing NOx and soot emissions simultaneously in diesel engines. The EGR system is used to reduce NOx emissions, and a novel diesel soot removal device with a cylinder-type scrubber for the experiment system was specially designed and manufactured to reduce soot contents in the recirculated exhaust gas to the intake system of the engine. The experiments were performed at the fixed fuel injection timing of 4$^{\circ}$ ATDC regardless of experimental conditions. It was found that soot emissions in exhaust gases were reduced by 20 to 70% when the scrubber was applied in the range of the experimental conditions, and that NOx emissions decreased markedly, especially at higher loads, while soot emissions increased owing to the decrease in intake and exhaust oxygen concentrations, and the increase in equivalence ratio as the EGR rate is elevated.

• Journal of Ceramic Processing Research
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• 제20권3호
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• pp.222-230
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• 2019

Microwave hydrothermal-assisted sol-gel method was employed to synthesize the Fe doped TiO2 photocatalyst. The morphological analysis suggests anatase phase nanoparticles of ~20 nm with an SBET area of 283.99 ㎡/g. The doping of Fe ions in TiO2 created oxygen vacancies and Ti3+ species as revealed through the XPS analysis. The reduction of the band gap (3.1 to 2.8 eV) is occurred by doping effect. The as-prepared photocatalyst was applied for removal of NOx under solar light irradiation. The doping of Fe in TiO2 facilitates 75 % of NOx oxidation efficiency which is more than two-fold enhancement than the TiO2 photocatalyst. The possible reason of enhancement is associated with high surface area, oxygen vacancy, and reduction of the band gap. Also, the low production of toxic intermediates, NO2 gas, is further confirmed by Combustion Ion Chromatography. The mechanism related NOx oxidation by the doped photocatalyst is explained in this study.