• Journal of Korean Society for Atmospheric Environment
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• v.12 no.1
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• pp.91-99
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• 1996

Ozone, sulfur dioxide, and nitrogen oxides were measured at Kosan, Cheju Island, Korea during the period of March 11 .sim. April 19, 1994. During the measurement period, the average SO$_{2}$ and NOx concentrations were about 0.97 ppb and 3.5 ppb, respectively. Average NO concentration was below the detection limit and thus the effect of NO during the period was negligible. The concentrations of SO$_{2}$ and Nox were lower than those at other urban area in Korea but higher than other remote areas in the world. Average $O_{3}$ concentration for the period was about 55 ppb, slightly higher than or comparable to those at remote marine areas in the world. Detailed analyses of trend of gaseous species concentrations show that the effects of local NO emission sources for NOx concentration were significant during the period, while those of local SO$_{2}$ emission sources were not high. Backward trajectory analysis results show that when SO$_{2}$ or $O_{3}$ concentration was higher than the average concentrations, the air parcels were transported from China.

• Journal of Environmental Science International
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• v.15 no.2
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• pp.133-139
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• 2006

Soil biofiltration is an environmentally-sound technology for elimination of VOCs, odorous and NOx compounds from a low concentration, high volume waste gas streams because of its simplicity and cost-effectiveness. This study was performed to evaluate effect of removal of gaseous NOx using a soil and a yellow soil. Over $60\%\;and\;48\%$ of NOx from a soil and a yellow soil was removed at the inlet NO concentrations of $423\~451$ppb, respectively. The bio-filter using a soil media was capable of purifying NOx with a different natural processes. Although some of the processes are quite complex, they can broadly be summarized as adsorption into soil pore water, and biochemical transformations by soil bacteria. When the filteration bio-reactor was applied to a soil and a yellow soil, effective NOx removal was obtained for several times and months. These results show that a soil biofilter can be of use as an alternative advanced NOx treatment system.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.24-30
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• 2010

In this study, numerical experiments were carried out to estimate the SCR De-NOx performance in DOC plus SCR systems. The SCR De-NOx phenomena are described by Langmuir-Hinshelwood reaction scheme. After validating the present approach by comparing the present results with the experimental results, such various parameters as space velocity, $H_2O$ concentration, $NO_2$/NOx ratio and relative volume of DOC are explored to increase the SCR De-NOx performance. The results indicate that SCR De-NOx performance largely depends on space velocity and $NO_2$/NOx ratio, especially below $200^{\circ}C$. SCR De-NOx performance is seriously affected by relative volume of DOC with SCR due to increasing in $NO_2$/NOx ratio at below $250^{\circ}C$.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.235-236
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• 2003

시멘트 업계에서 필연적으로 다량 배출되는 질소산화물(NOx)의 법적 규제치는 350ppm(산소 농도 13% 기준)이나 대부분의 시멘트 사업장에서 기준치를 초과하여 배출되고 있는 실정이다. 시멘트 산업은 석회소성로의 고온운전과 다량의 연료사용 등 시멘트 제조의 공정특성상 타 산업에 비해 많은 질소산화물을 배출하여 왔으나, 사업장 주변지역 환경에 질소산화물이 미치는 영향에 관한 연구가 전혀 이루어지지 않아 이에 대한 자료가 전무한 실정에 있다. (중략)

• Journal of the korean Society of Automotive Engineers
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• v.6 no.2
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• pp.47-54
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• 1984

The predictions of the mean effective pressure and the exhaust emission of NOx in hydrogen fueled spark ignition engine were studied. And the predictions were compared to the experimental results of D.B. Kittelson and H.S.Homan. The modeling was based on Otto cycle and the prediction of NOx was performed by extended Zeldovich mechanism. The differences between predictions and experimental results were 20 - 30% in the mean effective pressure and 10 - 20% in the concentration of NOx where the equivalence ratio .phi. was 0.6 - 0.8.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.368-370
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• 1999

고농도의 오존 농도를 예측ㆍ평가하기 위해서는 대상지역의 기상조건과 풍상쪽(up wind)으로부터의 오존ㆍ오존전구물질(precursor)의 중ㆍ장거리이동, VOCs 및 NOx의 배경농도 및 배출량과 관련된 VOC/NOx의 농도 특성을 파악하는 것이 필수적이다. 따라서 대상지역의 VOCs/NOx의 농도 특성에 따라 차후 고농도의 오존 생성을 예방하기 위한 오존전구물질의 저감대책이 결정되어지므로 대상지역의 광화학특성을 파악하는 것이 선행되어져야 한다.(중략)

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.518-524
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• 2013

In this study, we conducted a study on characteristics of exhaust gas emissions from boiler when water-bunker oil mixed by homogenizer was burned in boiler. The results showed that NOx concentration and CO concentration of the homogenized bunker oil was decreased by 19% and 54% compared to pure bunker oil pretreatment was not being performed. And, in the case of water-bunker A oil, the NOx concentration was decreased with increasing water mixing ratio in bunker A oil. In particular, the NOx concentration in exhaust gas of 20 %water-80 %bunker A oil decrease by 45 % compared with pure bunker-A. However, the CO concentration in exhaust gas of 20 %water-80 %bunker A oil shows irregular changes. This means that the mixing of water more than a certain amount can cause a decrease in combustion performance. From this result, it can be found that critical mixing ratio of water in bunker A oil for normal combustion is 15% in this study. Deposition amount of soot that is collected in the vicinity of the chimney was decreased with increasing water mixing ratio.

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.156-162
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• 2001

The effects of co-flow and the variation of the equivalence ratio on NOx emission were investigated experimentally for unconfined and confined partially premixed flames. The shape, length, temperature of flames and the concentration of burnt gas were measured. Two types of co-flow (parallel and swirling co-flow) were considered. For unconfined flames, flame with parallel co-flow is the longest and the next is flame without co-flow. Flame with swirl is the shortest. The length of swirling flame increases suddenly under certain value of equivalence ratio. EINOx is diminished by the decrease of equivalence ratio. It is found that the unconfining of flame enhances the emission of NOx. The EINOx of unconfined flame with parallel co-flow is less than that of flame without co-flow.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.715-719
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• 2000

It is reported that we are facing the serious environment pollution difficulties such as acid rain, green house effects, etc. The gaseous matter CO, NOx, SOx, VOCs which are regarded as main factors for these current pollutions are mainly emitted from power plants and vehicles. Therefore several leading countries are regulating the related laws strictly, especially exhaust emissions from a Diesel engine without an after treatment device. The Objective of this study is to find out NOx removal characteristics focused on emissions of a Diesel engine using radical at each engine speed and load. It is generated from outer air and put into a mixing chamber in the end of exhaust line. In addition, the optimum temperature condition to activate reaction by radical is experimentally carried out. Concentration of exhaust emissions is analyzed from the gas anlayzer(KaneMay) and FTIR to estimate by-products.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.937-942
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• 2000

The characteristics of spray combustion and dropsize of spray through twin-fluid atomizer was experimentally investigated. The distribution of flame temperature have an effect on the generation of NOx. To investigate there effects, flame temperature with different spray shape was observed. The spray shape was varied by various bluff-bodys. Mean temperature were measured by thermocouple respectively, and NOx concentration was measure by NOx analyser. Distribution of droplet sizes were measured by PMAS. The result showed that the flame with wide distribution has lower temperature and lower NOx emission compared with narrow.