• 한국잡초학회지
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• 제18권1호
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• pp.54-62
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• 1998

본 실험은 식물생장조절제인 ABA와 IAA를 처리가 오존에 의한 가시적 피해 경감효과에 미치는 영향과, 항산화물질의 함량 및 항산화효소의 활성과의 관련성을 조사하기 위하여 담배품종 NC82를 공시하여, 파종후 60일 된 개체에 ABA와 IAA를 각각 $10^{-3}$M 및 $10^{-5}$M의 농도로 엽면처리한 후 0.3ppm의 농도로 하루 6시간씩 7일간 오존을 처리하여 다음과 같은 결과를 얻었다. 1. 담배에서 ABA와 IAA의 처리는 오존의 가시적 피해증상을 감소시키는 결과를 나타냈으며 오존 처리구에서는 모두 담배의 생육에는 큰 영향을 주지 않았으나 초장의 경우 IAA $10^{-3}$M의 처리구에서 다소 증가하였다. 2. 엽록소 함량은 오존처리후의 일수가 증가함에 따라 감소하는 경향을 보였으나 ABA와 IAA처리는 오존처리구에서 엽록소함량의 감소를 작게 하였다. 3. 오존에 3일간 처리한 담배는 산화형 ascorbate가 환원형 ascorbate 보다 높게 나타났으며 ABA와 IAA를 처리한 구에서는 오존 처리구보다 산화형 ascorbate가 낮게 나타났으나 7일간 오존을 처리한 구에서는 처리간에는 차이가 나타나지 않았다. 4. 3일간 오존 처리시 superoxide dismutase(SOD) 활성은 무처리구에 비하여 증가하였고 ABA 및 IAA $10^{-3}$M에서는 다른 처리구에 비하여 증가가 뚜렷하였으며, 7일간 처리에서도 SOD의 활성이 증가하였으나 식물생장조절제의 처리 효과는 나타나지 않았다. 5. Ascorbate peroxidase와 guaiac이 peroxidase 활성은 오존무처리구에서도 모두 증가하였으나, 7일간 처리시는 두 효소 모두 처리간에는 변화가 없었다.

• 한국산업보건학회지
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• 제28권2호
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• pp.200-210
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• 2018

Objectives: The purpose of this study is to assess the exposure to ozone and total volatile organic compounds(TVOCs) generated during welding work at a shipyard and recommend respiratory protective equipment(RPE) adequate against these hazards. Method: Ozone was collected for about 30 minutes at two-minutes intervals using a direct reading instrument, specifically an ozone analyzer(Serinus 10, Ecotech, Australia). TVOCs were collected for about 30 minutes at three-minute intervals using a portable GC (Alpha 115, Synspec BV, the Netherlands), and were determined simultaneously by area sampling at the welding plume closest to the welder's breathing zone. The total measurements were 162 for ozone($CO_2$ welding 47, TIG 60, stick 55), and 136 for TVOCs($CO_2$ 65, TIG 50, stick 21). Based on these measurements, a literature survey was conducted to assess the adequacy of RPE. Results: Relative to Korean OEL, measurements above STEL 0.2 ppm were 23.4% for $CO_2$, 63.3% for TIG and 14.5% for stick welding. There were significant differences(p=<0.0001) among welding types. Compared with ACGIH peak exposure of 0.4 ppm for ozone, which is not applied in Korea, $CO_2$ welding exceeded it by 10.6%, TIG by 40.0% and stick by 7.3%. Although it was not feasible to compare them directly since there are no Korean OEL, TVOCs had very high levels similar to the concentrations before moving into a new apartment and about 10-20 times the indoor air quality recommendations for some individual measurements. Conclusions: As ozone removal RPE has been recommended in welding environments for a long time(Lunau, 1967), this fact was demonstrated based on the results of the on-site work environment measurements(ozone and TVOCs). In conclusion, for all welding at a shipyard, gas/vapor and particulate combination RPE are recommended. If this is not possible, it should at least be present for TIG welding.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1652-1654
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• 2001

A comprehensive model of ozone generation in dielectric barrier discharges is presented. The model combines the physical processes in the microdischarges with the chemistry of ozone formation. It is based on an extensive reaction scheme including the major electronic and ionic processes. The importance of excited atomic and molecular states is demonstrated. Theoretical limits are given for the ozone production efficiency and the attainable ozone concentration. The most important parameters influencing the performance of ozonizers are identified.

• Journal of Ecology and Environment
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• 제32권3호
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• pp.149-158
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• 2009

American sycamore seedlings were grown in chambers with two different ozone concentrations ($O_3$-free air and air with additional $O_3$) for 45 days. Both the control and the $O_3$ chambers included non-fertilized and fertilized plants. After 18 days of $O_3$ fumigation, seedlings were placed in a clean chamber for 27 days. Seedlings under ozone fumigation showed a significant decrease in pigment contents and photosynthetic activity, and a significant increase in lipid peroxidation. Fertilization enhanced physiological damage such as the inhibition of photosynthetic activity and the increase of lipid peroxidation under ozone fumigation. During the recovery phase, the physiological damage level of seedlings increased with ozone fumigation. In addition, physiological damage was observed in the fertilized seedlings. Superoxide dismutase (SOD) and glutathione reductase (GR) activities of $O_3$-treated seedlings increased up to 33.8% and 16.3% in the fertilized plants. The increase of SOD activity was higher in the fertilized plants than in the non-fertilized plants. Negative effects of ozone treatment were observed in the biomass of the leaves and the total dry weight of the fertilized sycamore seedlings. The $O_3$-treated seedlings decreased in stem, root and total dry weight, and the loss of biomass was statistically significant in the fertilized plants. In conclusion, physiological disturbance under normal nutrient conditions has an effect on growth response. In contrast, in conditions of energy shortage, although stress represents a physiological inhibition, it does not seem to affect the growth response.

• 대한환경공학회지
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• 제22권10호
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• pp.1825-1832
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• 2000

유류화합물(디젤)로 오염된 불포화층 토양에 대한 현장오존복원공정의 기초연구로, 토양조건에 따른 오존의 이동과 분해, 디젤과의 반응경향을 조사하였다. 건조상태에서 유기물을 제거한 모래와 glass beads 충진컬럼에서 기상 오존의 분해를 조사한 결과 일차반응으로 가정시 반응 속도상수값(k)이 각각 $9.9{\times}10^{-3}s{^{-1}}$와 $4.3{\times}10^{-4}s{^{-1}}$로 나타나 모래의 경우 철 (Fe), 망간(Mn) 성분 등의 촉매작용으로 25배 가량 반감기가 짧은 것을 확인할 수 있었다. 디젤로 오염시킨 현장 토양과 모래를 컬럼에 충진하여 동일조건하에서 오존주입시 토양입자의 크기와 유 무기물의 함량 차에 의한 오존이동상에 지체효과 및 소모량의 차이를 관찰하였고, 50mL/min의 유속에서 공기만을 주입시 DRO(diesel range organic) 기준 초기 디젤총량($800{\pm}50mg/kg$)의 30%가 제거된데 비해 오존을 6mg/min으로 16시간 주입한 결과 각각 80% 이상이 제거되었다. 오존주입시간에 따라 컬럼의 유출 입부에 잔류하는 TPH(total petroleum hydrocarbon)와 DRO 중 aliphatic계열 8개 물질들의 농도를 비교/분석한 결과, 낮은 탄소수 물질들로의 전환과정을 거쳐 유체의 흐름에 따라 컬럼 밖으로 이동됨을 확인하였고, 토양내 수분함량은 오염 토양복원에 오존을 적용시 중요한 인자임을 확인하였다.

• Asian Journal of Atmospheric Environment
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• 제9권1호
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• pp.39-47
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• 2015

The emissions of ozone precursors, NOx and VOCs from a biogenic source and port-related sources (ship, shipping container truck, and cargo handling equipment) were estimated in Busan during 2013. Total biogenic isoprene emission in Busan during 2013 was estimated to be $4,434ton\;yr^{-1}$ with the highest emission (e.g., $28ton\;day^{-1}$) in summer using a BEIS method. Seasonal ozone production rates by isoprene ranged from 0.15 (winter) to 2.08 (summer) $ppb\;hr^{-1}$, contributing the predominant portion to ambient ozone levels. Total emissions of NOx and VOCs from ship traversing Busan ports were estimated to be 29,537 and $814ton\;yr^{-1}$, respectively, showing the significant contribution to total NOx emission in Busan. The emissions of ozone precursors were significantly different depending on ship tonnage and port location. Compared to the ship emission, the emissions of NOx and VOCs from the shipping container trucks in Busan were insignificant (2.9% for NOx and 3.9% for VOCs). Total NOx and VOCs emissions from the cargo handling equipment were estimated to be 1,440 and $133ton\;yr^{-1}$, respectively with the predominance of yard tractors.

• 상하수도학회지
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• 제24권5호
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• pp.595-601
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• 2010

It is evident that Korea will continue its battle with water shortage and alternative program are being taken into action. One of the main actions is reusing 1,800 tons of effluent of 357 sewage treatment plant located nationwide. Therefore this study supplemented ozone oxidation methods that would increase the efficiency of organic oxidation and coagulation. Through this method, fouling will be controled sufficiently by preventing membrane process in the system for advanced sewage treatment. In this study, ozone-coagulation-microfiltration membrane were used. The final removal efficiency of the pretreated water from the result of the ozone-coagulation were 50% of CODcr, 38% of TP and 11% of TOC respectively. Water quality treatment has decreased about 80% for TP. Ozone-coagulation-microfiltration membrane maintains the high flux while decreasing the number of organic matter and the membrane fouling, and reducing the TP. As a result, in order to reuse the water from the sewage, the ozone-coagulation-microfiltration membrane type must be considered in order to achieve the best efficiency.

• 한국염색가공학회지
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• 제8권1호
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• pp.43-55
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• 1996

When some disperse dye was decolored with oxidation power of ozone, the results in investigation of decoloration behavior with dye solution and its order of reaction and variation of TOC were as follow: 1. Order of decoloration for Some disperse dye is C.I. Disperse Blue 79>Blue 73> Red 343>Red 60>Blue 354>Yellow 42. 2. Velocity of decoloration for the all dyestuffs was the fastest when pH 3. 3. TOC was rapidly reduced between 10 min. and 20 min. 4. For the reduction of TOC ozone was needs many times as compared with decoloration of dyestuffs.

• 한국전기전자재료학회논문지
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• 제34권1호
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• pp.56-62
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• 2021

In this study, we created a DBD plasma device and a MnO2 catalyst mesh filter for evaluating ozone reduction of devices via the catalyst method. The DBD plasma device was manufactured by applying Ag paste to soda lime glass via the screen-printing method. The MnO2 catalyst mesh filter was manufactured by mixing MnO2 powder with binder with a 10% difference in concentration from 10% to 50% and then applying it using the dip-coating method. Finally, we sintered a MnO2 catalyst mesh filter in an electric furnace. We evaluated the characteristics of ozone generation according to the Ar gas flow of DBD plasma devices, the opening ratio, and ozone reduction performance of the MnO2 catalyst filters. Ozone reduction performance was approximately 20.4% at MnO2 10 wt%, 37.8% at MnO2 30 wt% and 50% at MnO2 50 wt%.

• Journal of Astronomy and Space Sciences
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• 제37권1호
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• pp.69-75
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• 2020

We analyze the observations of temperature and ozone measured by the Microwave Limb Sounder (MLS) during the period of 2005-2016, to investigate the vertical structures of temperature and ozone in the stratosphere and mesosphere during stratospheric sudden warming (SSW). We compute the height profiles of the correlation coefficients between 55 height levels of MLS temperature anomalies and compare them with the results of Whole Atmosphere Community Climate Model simulations for three major SSWs. We also construct the temperature and ozone anomalies for the events to investigate the changes in the temperature and ozone distributions with height. There seems to always be a relatively weak but broad negative correlation between the temperature anomaly at 10 hPa and temperature anomalies over the entire mesosphere during the period before SSW events. However, this pattern gets stronger in the lower mesosphere but becomes a positive correlation in the upper mesosphere and lower thermosphere after the onset of SSW. We also found that the temperatures from the simulations show a similar trend to the observational results but with smaller variations and the transition height from negative to positive correlation in the mesosphere is much lower in the simulation than in the actual observations.