• 한국정밀공학회지
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• 제28권10호
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• pp.1217-1223
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• 2011

In this paper, the dielectric barrier discharge plasma generator has been studied for producing of the high concentration ozone gas. Proposed plasma generator has the structure of extremely narrow discharge air gap(0.15mm) in order to realize the high electric field discharge. We investigate the performance of the dielectric barrier discharge plasma generator experimentally and the results show that the generator has very high ozone concentration characteristics of 13.7[wt%/$O_2$] at the oxygen flow rate of 1[${\ell}$/min] of each discharge cell. So, we confirmed that the proposed plasma generator is suitable for the high concentration ozone production facility of the eco-friendly ozone functional water cleaning system in the electronic components cleaning process.

• 대한환경공학회지
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• 제32권3호
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• pp.241-247
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• 2010

오존 접촉 반응기에서 용존 오존 농도 및 페놀 제거에 미치는 운전변수의 영향에 대해 실험실 규모 실험을 수행하였다. 반응기로 가스상 오존이 공급되고 일정한 시간이 경과한 후에 용존 오존 농도는 포화 농도에 도달하였으며 포화 농도의 크기는 운전 변수에 의해 영향을 받는 것으로 나타났다. 수용액내의 오존은 높은 pH 조건에서 불안정하므로 용존 오존 농도는 용액의 초기 pH값이 증가함에 따라 감소하였다. 일정한 유량의 기체가 반응기로 공급되는 조건에서 가스상 오존 농도의 크기는 용존 오존의 포화농도에 중요한 영향을 미치며 일정한 농도의 가스상 오존이 공급될 때 가스 유량은 용존 오존이 포화되는 속도에 영향을 주는 것으로 관찰되었다. 페놀 제거에 미치는 운전변수의 영향은 각 운전변수가 용존 오존 농도에 미치는 영향과 밀접하게 관련되어 있는 것으로 나타났다. 용존 오존은 높은 pH 조건에서 빠르게 분해되어 페놀과의 반응성이 높은 자유라디칼을 생성시키므로 pH가 증가함에 따라 페놀 제거가 향상되었다. 동일한 pH 조건에서 가스상 오존 농도 및 가스 공급량의 증가는 용존 오존을 증가시킴으로써 페놀 분해를 증진시키는 것으로 나타났다. 메탄올의 주입은 OH 라디칼을 소비시켜 페놀 분해를 방해하는 것으로 관찰되었다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권3호
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• pp.127-137
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• 2000

This study presents an analysis of the characteristics of vertical ozone distribution near the surface using ozonesonde data(l995 to 1998), plus surface ozone and meteorological data from the Pohang region. These features were examined in detail using three case studies. The first related to episodes of high surface ozone concentrations during the Spring season when the frontogenesis between the high and low pressure associated with the upper-level jet stream was found to be located near the surface. The second was a 5-day winter period(l3 -17 December, 1997) in the Pohang province when the hourly concentrations exceeded 90 ppb on several occasions owing to low-level jets(LLJs) induced by a nocturnal stable layer. Accordingly, this explains why the high surface ozone concentrations occurred at night as the ozone was transported across the zone by a strong wind speed( over 12.5 ms .1). The third case study was ozone enhancement due to photochemical reactions. In this case, the maximum concentration of ozone exceeded 60 ppb in the summer(23 -28 August, 1997). When an ozone peak appeared within the boundary layer, the occurrence frequency of a low-level jet due to the nocturnal stable layer was about 77%, similarly the occurrence frequency of a near-surface ozone peak relative to the appearance of an LLJ was about 76%. Accordingly, there is clearly a close correlation between the occurrence of LLJs and near-surface ozone peaks.

• 한국환경과학회지
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• 제24권8호
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• pp.993-1001
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• 2015

Comparing to the other air pollutants like $SO_2$, CO, the number of exceedance of the ozone national ambient air quality standard(NAAQS) and the ozone warning increased recently in Busan. The purpose of this study is to find out the preliminary symptoms for high ozone days in Busan area. In order to find out the preliminary symptoms, the hourly ozone data at air quality monitoring stations and the hourly meterological parameters at Busan regional meteorological 2007 to 2013 were used for the analysis. Averaged daily max ozone concentration was the highest(0.055 ppm) at Noksan and Youngsuri in the ozone season from 2007 to 2013. The horizontal distributions of daily max. ozone including all stations in Busan at high ozone days(the day exceeding 0.1 ppm of ozone concentration at least one station) were classified from two to five clusters by hierarchial cluster analysis. The meteorological variables showing strong correlation with daily max. ozone were the daily mean dew point temperature, averaged total insolation, the daily mean relative humidity and the daily mean cloud amount. And the most frequent levels were $19-23^{\circ}C$ in dew point temperature, $21-24 MJ/m^2$ in total insolation on the day before, $2.6-3.0 MJ/m^2$ on the very day, 67-80% in relative humidity and 0-3 in cloud amount.

• 한국대기환경학회지
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• 제19권5호
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• pp.611-619
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• 2003

Characteristics of the ozone concentrations in Seoul were analyzed for the data between May and September from 1996 to 2000. Observation data from 27 stations in Seoul are used. Among the results from 27 stations, representative results from 2 stations (City hall and Gwanak representing downtown and background areas of Seoul, respectively) are presented. The 24-hour average ozone concentrations of Gwanak (28.6 ppb) are higher than City hall (14.9 ppb). The 24-hour average ozone concentrations on Sunday are higher than other days at both sites. During weekday, the 24-hour average ozone concentrations on Wednesday are higher than other days. Although the mean of the I-hour daily maximum ozone concentrations at Gwanak is higher than City hall, the . ozone concentrations above 95th percentile at City hall are higher than Gwanak. As a result, the number of days on which the 1 - hour ozone concentration exceeding 100 ppb and 120 ppb at Gwanak (17 and 3) are lower than City hall (29 and 9). To sum up, both sites are VOCs limited region and the mean ozone concentration in Gwanak is higher because of the lower N0$_2$ concentration. But high ozone cases occur more frequently in City hall when conditions are right.

• 조명전기설비학회논문지
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• 제16권6호
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• pp.95-101
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• 2002

고농도의 오존발생에 영향을 주는 많은 변수들이 존재한다. 이러한 변수들은 오존발생장치 설계시 매우 중요한 요소가 되고 설계전에 반드시 고려되어야 할 것들이다. 오존발생장치 설계 후에도 고농도 오존발생에 크게 영향을 주는 주변변수들이 있다. 본 연구에서는 오존발생에 영향을 주는 많은 주변변수들중에서 입력산소가스의 유량과 여기에 첨가되는 첨가가스가 고농도의 오존발생에 미치는 영향을 조사하였다. 결과적으로, 입력산소가스의 유량을0.75[LPM］～2.00[LPM］으로 변화시키면서 오존농도를 측정한 결과 1.25［LPM］에서 71145［ppm］의 최대오존발생량을 보여주었다. 입력산소가스에 첨가되는 질소가스의 유량을 0.0［vol%］～6.4［vol%］으로 변화시켜가면서 발생되는 오존농도를 측정한 결과 첨가되는 질소가스량이 0.8［vol%］인 경우 최대 73135［ppm]의 오존을 얻을 수 있었다. 이것은 순수산소만을 입력가스로 사용했을 때보다 최대오존발생량이 3［%］가량 증가한 결과이다. 입력산소가스에 첨가되는 아르곤가스의 유량을 0.0[vol%］～6.4[vol％］으로 변화시켜가면서 발생되는 오존농도를 측정한 결과 첨가되는 아르곤가스량이 0.8［vol%］인 경우 최대 67288［ppm］의 오존을 얻을 수 있었다.

• 연구논문집
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• 통권33호
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• pp.99-109
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• 2003

Recently the utilization of the ozone dissolved de-ionized water(DIW-$O_3$) in semiconductor wet cleaning process and photoresist stripping process to replace the conventional sulfuric acid and hydro peroxide mixture(SPM) method has been studied. In this paper, we propose the water-electrode type ozone generator which has the characteristics of the high concentration and purity to produce the high concentration DIW-$O_3$ for the photoresist strip process in the semiconductor fabrication. The proposed ozone generator has the dual dielectric tube structure of silent discharge type and the water is both used to electrode and cooling water. Through this study, we obtained the results of the 10.3 wt% of ozone gas concentration at the oxygen gas of 0.5 [liter/min.] and the DIW-$O_3$ concentration of 79.5 ppm.. Through the photoresist stripping test using the produced DIW-$O_3$, we confirmed that the photoresist coated on the silicon wafer was removed effectively in the 12 minutes.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2001년도 학술대회논문집
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• pp.135-138
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• 2001

Recently, ozone is utilized In various fields and its needs are expanding. therefore, so many ozone generation methods have been reported in the latest years, its main purpose Is to get the high ozone concentration and to improve the ozone yield. One of them is a plate-type ozone generator. In this paper, the plate-type ozone generator is piled up many folds(3 and 5 electrodes). Ozone concentration and yield were investigated in accordance with power, quantity of supplied gas and gap spacing of plate electrodes.

• 한국대기환경학회지
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• 제15권4호
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• pp.441-455
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• 1999

Meteorological characteristics of three high-ozone episodes in the Greater Seoul Area, selected on the basis of morning-average wind direction and speed for the 1990~1997 period, were investigated. Three high-ozone episodes thus selected were seven days of July 3~9, 1992, nine days of July 21~29, 1994, and three days of August 22~24, 1994. Along with surface meteorological data from the Seoul Weather Station, surface and 850-hPa wind fields over the Northest Asia around the Korean Peninsula were used for the analysis. In the July 1992 episode, westerly winds were most frequent as a result of the influence of a high-pressure system in the west behind the trough. In contrast, in the July 1994 episode, easterly winds were most frequent due to the effect of a typhoon moving north from the south of Japan. Despite different prevailing wind directions in the two episodes, the peak ozone concentration of each episode always occurred when a sea-land breeze developed in association with weak synoptic forcing. The August 1994 episode, selected as being representative of calm conditions, was another typical example in which peak ozone concentration rose to 322 ppb under the well-developed sea-land breeze. All three high-ozone episodes were terminated by precipitation, and subsequent rises in ozone concentrations were also suppressed by a series of precipitation afterwards. In particular, two heavy rainfalls were the main reason why the August 1994 episode, with the highest and second-highest ozone concentrations during the 1990~1997 period, lasted for only a few days.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.201-204
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• 2002

A high accuracy ozone monitor using UV absorption method was developed for ambient ozone monitoring. The system was mainly composed of a high power pulsed xenon lamp as UV source, an optical spectrometer with a high sensitivity linear CCD array as UV detector and signal processing unit. The optical signal from the CCD array that provides unusually high response and excellent optical resolution for ozone concentration was converted to digital signal and the digital signal was displayed on screen using PC interface. The optical signal was propagated using optic fiber to reduce optical loss to increase the accuracy of the measuring system. This paper has been studied a interworking signalling protocol between two hybrid networks by analyzing Satellite B-ISDN architecture, DSS2 Layer 3 Signalling protocol, B-ISUP protocol, S-BISUP protocol stack and so on. Also in the paper, messages and primitives have been defined for B-ISDN's Connection Type, Ownership and each protocol in order to connect point-to-multipoint. The ozone sensing properties of the CCD ozone monitor was compared with those of the photo multiplier ozone monitor.