• Title/Summary/Keyword: surface ozone concentration

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One-Plate Type Hybrid Plasma Discharge Device with Heating Element (히터 일체형 하이브리드 단판형 플라즈마 방전소자)

  • Choi, Woo Jin;Choi, Eun Hye;Sung, Hyeong Seok;Kwon, Jin Gu;Lee, Seong Eui
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.4
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    • pp.320-326
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    • 2019
  • Recently, the application of atmospheric plasma technology in air filtration is increasing. Sterilization by an atmospheric plasma device is very effective. However, ozone gas, which is generated during atmospheric plasma formation, poses a hazard to human health. To reduce the ozone gas during plasma discharge, we fabricated a one-plate hybrid plasma discharge device with a heating element, which can decompose ozone gas effectively by a simple heating action. In this study, we evaluated the plasma discharge characteristics and ozone concentrations with various Ar flow rates and temperatures. With increasing Ar gas flow rate, the ozone concentration and spectrum intensity increased till an Ar gas flow rate of 60 sccm, and decreased thereafter. When discharged in high temperature, the ozone concentration and spectrum intensity decreased. Further, to evaluate the state of the treated surface under various plasma discharge and heating conditions, we measured the variation in the contact angles on the surface. Regardless of the temperature, the contact angle increased with increasing discharge voltage. However, the contact angle increased when discharged at high temperature.

Measutements of the ground-level ozone in a rural area of Chongwon, Korea (충북 청원군에서 관측된 지표면 부근의 오존)

  • 윤마병;정용승
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.1
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    • pp.85-93
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    • 1995
  • Measurements of ground level ozone concentrations were made in a rural area of Chongwon (Choongbook Province) from June 1993 to July 1994. High values frequently exceeding 100 ppb (ambient air qualyty standard of Korea) were recorded. High ozone concentrations in the boundary layer were primarily correlated with the several meteorological parameters in warm seasons: pressure, radiation, temperature, precipitation and wind velocity. The annual average concentration of ozone at Chongwon was 17ppb, and this value was relatively higher than those for other cities in Korea. O$\_$3/ concentrations were observed to increase when the ridge of a surface anticyclone was passing over the region, and maximum values(.geq.100 ppb) were observed on the rear sides of high pressure centers and in the warm sectors of cyclones(well head of cold fronts). The ozone concentrations had a negative correlation with the concentration of primary pollutants(e.g., total hydrocarbons).

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On Characteristics of Surface Ozone Concentration and Important Meteorological Parameters in Pusan, Korea (부산 지역의 오존 농도 특징과 기상 인자에 관한 연구)

  • 전병일;김유근;이화운
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.1
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    • pp.45-56
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    • 1995
  • We considered that characteristics of surface ozone continuous and important meteorological parameters from the data measured 7 air quality continuous monitoring stations during 2 years (1990, 1993) in pusan. The diurnal ozone variation showed a primary peak near 1500LST and a secondary peak of the DP(double peaked) pattern. The episode day was defined when an ozone peak higher than 60 ppb was observed at least one station. The frequency of episode day was 100 (298 hours, 69 days). The frequency of the episode day was higher at Meongryundong and Daeyeondong than other sites and highest in August under control of pacific subtropical high. The high temporatant meteorological parameters accompanying the high episode days. The favorable synoptic environment accompanying ozone episode was distributed to 7 different pattern. These pattern can be taken as a nesessary but not an absolute indicator for predicting the occerrence of an episode.

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On Characteristics of Surface Ozone Concentration and Temporal.Spatial Distribution in Kwangyang-Bay (광양만권의 오존농도 특성과 시.공간적 분포)

  • Ha, Hoon;Lee, Sang-Deug;Lee, Joong-Ki;Park, Chan-Oh;Mun, Tae-Ryong
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.5
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    • pp.642-652
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    • 2006
  • In order to understand the characteristics of surface ozone concentration and high $O_3$ concentration days, regional data from seven air quality monitoring stations which were operated by local governments were analyzed Regional characteristics of $O_3$ concentration were analyzed with the data of $O_3$ concentration and the characteristics of $O_3$ generation and weather conditions by the selection of the days in which the concentration was higher than 80 ppb. In the case of daily variation, the lowest $O_3$ concentration was shown in all regions from 7am to 8am and the highest around at 4 pm. The monthly variation of mean $O_3$ concentration and ${\Delta}O_3$ values revealed a reducing pattern in July and August following the peak in June, and again a gradual increasing trend in September and October. The result shows that the amount of ozone is dependent on photochemical reaction. The days of $O_3$ generated more than 80 ppb in the region of Gwangyang-bay were 544 days(1,760 hrs). The frequency of occurrence in the region revealed a strong pattern with the order of Samil-dong, Jinsang, and Gwangmu-dong stations in the Gwangyang region. However, Tein-dong, which is the nearest station to air pollution material generation source, showed the lowest frequency in the study area. Consequently, the meteorological parameters which can easily generate the high concentration of $O_3$ in the region of Gwangyang-bay are characterized as follows; atmospheric temperature which is higher than $19^{\circ}C$, relative humidity with the range of $60{\sim}85%$, the less average wind velocity than 5 m/s, cloud cover which is less than 5/10, and the more duration of sunshine than 8 hours.

A Study on the Bleaching Properties of Silk Fabric Using Vapor Type Ozone Treatment (기상 오존처리법을 이용한 견직물의 표백성에 관한 연구)

  • Kim, Jung-Min;Lee, Mun-Soo
    • Fashion & Textile Research Journal
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    • v.6 no.4
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    • pp.511-514
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    • 2004
  • We studied on the bleaching properties of silk fabric by vapor type ozone processing using ozone's strong oxidation instead of 28% $H_2O_2$ chemical treatment. When vapor type ozone processing was directly treated to fabrics retaining water to 50~70% pick up ratio, high concentration ozone was generated 14,000ppm(168 mg/h) approximately and finally its bleaching improved. The fabric's bleaching effect was improved because vapor type ozone generated the highest decomposition to oxidation of surface and inter molecules. The experiment revealed that fabric's bleaching was improved by change of the pick-up ratio of vapor type ozone processing. However, tensile strength and elongation were reduced by increase of time, and the time that was assumed as the most optimized time to minimize the reduction of fabric's tensile strength and elongation as well as maximizing the fabric's bleaching was 30 minutes.

A Study on the Softness Properties of Polyester Fabric Using Vapor Type Ozone Treatment (기상 오존처리법을 이용한 폴리에스테르직물의 유연성에 관한 연구)

  • Lee, Mun-Soo;Kwon, Yoon-Jeong
    • Fashion & Textile Research Journal
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    • v.3 no.4
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    • pp.362-366
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    • 2001
  • We studied on the softness properties of polyester fabric by vapor type ozone processing using ozone's strong oxidation instead of 25% NaOH chemical treatment. When vapor type ozone processing was directly treated to fabrics retaining water to 40% pick up ratio, high concentration ozone was generated oxidation of 3~4% approximately in polyester fabrics and finally its softness improved. The fabric's softness effect was improved because vapor type ozone generated the highest decomposition to oxidation of surface and inter molecules. The experiment revealed that fabric's softness was improved by change of the time of vapor type ozone processing. However, tensile strength and elongation were reduced by increase in time, 60 minute was assumed as the most optimized time to minimize the reduction of fabric's tensile strength and elongation as well as maximizing the fabric's softness.

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Spatial-temporal variations in surface ozone concentrations in Busan metropolitan area (부산지역 오존농도의 시·공간 분포 변화)

  • Kang, Yoon-Hee;Kim, Yoo-Keun;Hwang, Mi-Kyeong;Jeong, Ju-Hee;Kim, Hyunsu;Kang, Min-Seong
    • Journal of Environmental Science International
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    • v.28 no.2
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    • pp.169-182
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    • 2019
  • Temporal and spatial variations in surface ozone concentrations in Busan were investigated by using observation data from urban air quality sites during 2001-2016. The annual ozone concentrations showed a significant increasing trend of $+0.40ppb\;yr^{-1}$ in this period, with a more rapid increase of $+0.81ppb\;yr-1$ since 2010. For the monthly analysis, the increase in ozone concentration was the greatest in August ($+0.68ppb\;yr-1$). These ozone trends were due mainly to rising temperature ($+0.05^{\circ}C\;yr^{-1}$) and weak decreasing precipitation ($-6.42mm\;yr^{-1}$). However, the extreme weather events (heat wave, localized heavy rain, etc.) lead to an increase in short-term variability of ozone since 2010. The relatively low ozone concentrations in the downtown area were caused by high NOx emissions from mobile sources. The increases in ozone concentrations were observed at most of the air quality monitoring sites due to the reductions in anthropogenic emissions of NOx during 2001-2015. However, in the southern coastal area, lower rates of increase in ozone concentrations were observed by $-0.10{\sim}0.25ppb\;yr^{-1}$ due to the significant NOx emitted by ships in the Busan port and Busan new port.

Optimal Conditions for the Growth of Soybean Sprouts by Ozone Water Watering (오존수 살수(撒水)에 의한 콩나물의 성장조건 최적화)

  • 김일두;김순동
    • Journal of the East Asian Society of Dietary Life
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    • v.11 no.3
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    • pp.219-224
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    • 2001
  • This study was conducted to investigate the optimal conditions for the growth of soybean sprouts by ozone water watering. Optimal conditions for ozone water watering of soybean sprouts during cultivation at 2$0^{\circ}C$ were evaluated with ozone concentration(0.1~O.5 ppm) and watering frequency(1~9 times) by response surface methodology. The optimal conditions for growth of soybean sprouts were ozone concentrations of 0.20~0.32 ppm, ozone treatment frequency of 3.0~4.4 times. Germination rates, hypocotyl weights and hypocotyl lengths in the soybean sprouts cultivated under the optimal conditions increased by 13.3, 10.1 and 11.9%, respectively, whereas root weights decreased by 89.0%.

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The Characteristics of the Complex Discharge Type Ozonizer using Applied Voltage of a Inverse-Polarity and a Screw Type Electrode (역극성 전압인가와 나사형 전극을 이용한 복합방전형 오존발생기의 특성)

  • Song, Hyun-Jig
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.9
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    • pp.80-85
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    • 2011
  • In this paper, complex discharge type ozonizer with a screw type electrode has been designed and manufactured for environmental improvement using low power and high efficency ozoniazer. The complex discharge type ozonizer is equipped with three electrodes{central electrode(CE), internal electrode(IE) and external electrode(EE)}. Ozone of the complex discharge type ozonizer is generated by superposition of silent discharge and surface discharge in discharge space as a screw type CE and IE are respectively applied to AC high voltage of inverse-polarity has $180[^{\circ}]$ phase difference, EE is common electrode. In this time, when oxygen has been used as supplied gas, the maximum values of ozone concentration, ozone generation and ozone yield were obtained as 8,334[ppm], 3,249[mg/h] and 65.3[g/kwh].

The effect of iron ions on the reducing of natural organic matter and THMFP in ozonation (오존 처리 시 철 2가 이온이 자연유기물질과 트리할로메탄 저감에 미치는 영향)

  • Kwak, Yeonwoo;Lee, Seulki;Jang, Gyuhwan;Hong, Seongho
    • Journal of Korean Society of Water and Wastewater
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    • v.33 no.6
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    • pp.447-456
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    • 2019
  • This study focused on natural organic matter and trihalomethane removal by ozonation with various ferrous concentration in surface water. Ozonation is more affected by injection concentration than reaction time. dissolved organic carbon removal rates in ozonation increased with the increase in ferrous concentration. The highest removal was obtained at 6 mg/L of ferrous concentration. When 1 mg/L of ferrous was added with 2 mg/L of ozone concentration, it was found to be a rapid decrease in specific ultraviolet absorbance at the beginning of the reaction because ferrous acts as a catalyst for producing hydroxyl radical in ozonation. As ozone concentration increased, trihalomethane formation potential decreased. When 2 mg/L of ozone was injected, trihalomethane formation potential was shown to decrease and then increase again with the increase in ferrous concentration.