• 한국과학교육학회지
• /
• 제20권3호
• /
• pp.364-370
• /
• 2000

본 연구에서는 산성비, 오존층, 온실 효과에 대한 학생들의 개념을 조사하였다. 고등학교 1학년 137명을 대상으로 세 가지 개념과 이들 사이의 관계에 대한 생각을 주관식 검사를 통해 알아보았다. 학생들의 응답을 분석한 결과, 학생들은 산성비의 정의, 온실 효과와 지구 온난화의 구분, 온실 효과의 증가 억제 방법 등에 대하여 잘 이해하지 못하는 것으로 나타났다. 또한 오존층을 온실 효과와 혼동하고 있었다. 산성비의 증가, 오존층의 파괴, 온실 효과의 증가 사이에 인과 관계가 있다고 생각하는 학생들이 많았다.

• 조명전기설비학회논문지
• /
• 제29권3호
• /
• pp.54-60
• /
• 2015

There are 5 purification plants with the adopted advanced water purification treatment process in Korea. Annual operating costs were 8,990 million won including purchase cost of oxygen and power usage charges. We need research to optimize, in the future, when considering the direction of domestic water treatment continues to adopt advanced water treatment process. In this paper, calculate the optimal operating costs by injected the oxygen gas, used power cost. approximately 25% of the operating costs can be reduced when injected the ozone gas is 1.0ppm than 2.0ppm, the necessary amount of oxygen is increased then power is lower. so operating costs are decided according to oxygen costs. On the other hand, high ozone concentration 2.0ppm, the necessary power is increased then amount of oxygen is lower. Therefore, in the case of G purification plant, the controlling factor of the input ozone concentration 2ppm, PID control operation by setting the concentration of over 10Wt% is efficient. The installed capacity is the more little the more better when considering on Ozone injection rate in the process of water treatment.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 전문대학교육위원
• /
• pp.88-91
• /
• 2004

In order to improve ozone generation, we experimentally investigated the silent discharge plasma and ozone generation characteristics of a multi-discharge type ozonizer. Ozone in a multi-discharge type ozonizer is generated by superposition of a silent discharge plasma, which is simultaneously generated in separated discharge spaces. A multi-discharge type ozonizer is composed of three different kinds of superposed silent discharge type ozonizers, depending on the method of applying power to each electrode. We observed that the discharge period of the current pulse for a multi-discharge type ozonizer can be longer than that of silent discharge type ozonizer with two electrodes and one gap.Hence, ozone generation is improved up to 17185 ppm and 783 g/kwh for the superposed silent discharge type ozonizer for which an AC high voltages with a 180 phase difference were applied to the internal electrode and the external electrode, respectively, with the central electrode being ground

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 1999년도 Pre-symposium of the 10th ISWPC Recent Advances in Paper Science and Technology
• /
• pp.375-380
• /
• 1999

In order to improve the optical properties of high yield pulp, bleached chemi-thermo-mechanical pulp (BCTMP) was produced from CTMP of Betula maximowicziana Regel by two staged ozone-hydrogen peroxide bleaching. This pulp was used for the evaluation of the improvement of optical properties, chemical characteristics of lignin in fiber, and the relationship between lignin and optical properties in fiber cell wall. By hydrogen peroxide treatment, the brightness was improved, but the post color number (PC No.) was not. There was little improvement on optical properties by ozone treatment, but his could be solved by using two staged ozone-hydrogen peroxide bleaching. The hydrogen peroxide treatment did not make nay change on chemical characteristics of lignin in cell wall, but by ozone treatment, it was found that the non-aromatic conjugated structure was existed in the surface of cell wall, but this could be removed by hydrogen peroxide treatment in two staged ozone-hydrogen peroxide treatment. Therefore, the optical properties was significantly improved due to the removal of non-aromatic conjugated structure.

• 한국대기환경학회지
• /
• 제29권4호
• /
• pp.390-406
• /
• 2013

In Korea, photochemical air pollution has drawn public attention as one of the major environmental issues since 1990s. To abate ozone and air pollution, new legislation was enacted and regulation was reinforced in conjunction with basic researches. As a result, the air quality has been much improved in terms of primary pollutant such as CO and the occurrence of extremely high ozone concentration. In Seoul, on the other hand, concentrations of ozone and exeedance hours of its national standard have increased since 2005, which is intimately coupled with $NO_2$ variations. It indicates the need for further research at long-term bases to improve our understanding on complex processes determining ozone concentrations. In this paper, the characteristics of ozone variation was analyzed with 13-year measurement data obtained in Seoul. In addition, the previous studies and their main results were summarized that have been performed in association with photochemical air pollution in Korea over the last three decades.

• 한국식품영양과학회지
• /
• 제28권1호
• /
• pp.67-73
• /
• 1999

In order to increase the enzymatic activity of malt used as a source of traditional processing foods, the enzymatic activities of various barley were examined and the effects of ozone and light illumination treatment on the enzymatic activities of amylase, amylase, and glucanase in malt during man ufacture were also examined. Barley didn't show amylase activity prior to soaking, but the activity of barley increased quickly after soaking. Glutinous barley showed the highest amylase activity among Duru barley, Ol barley, two rowed barley and naked barley. Naked barley showed the lowest activity. The amylase activity was the highest in Duru barley and decreased in the order of in glutinous barley, naked barley and two rowed barley. It was showed that the enzymatic activity of malt was higher than that of control when malt was soaked for 24hr at the concentration of 0.3ppm of ozone. The enzymatic activity of malt treated with light illumination was higher than that of control. The bud and root of light illuminated malt was much stronger than that of control. The root of light illuminated malt was much shorter than that of control. In addition, light illuminated malt showed a little green color which matches the demand of consumer. These studies demonstrated that both ozone and light illumination treatment increased the enzymatic activity of malt to result in high quality of malt manufacture.

• Environmental Engineering Research
• /
• 제10권3호
• /
• pp.144-154
• /
• 2005

The use of ozone gained acceptance in the production of ultrapure water because of its powerful oxidizing ability. Ozone is currently used to deactivate microorganisms and remove organic contaminants. However, interest also exists in using radical species, which arc stronger oxidants than ozone, in such processes. One means of producing radical species is by corona discharge. This work investigates the use of a novel pulseless corona-discharge system for the removal of organic substances in ultrapure water production. The method combines corona discharge with electrohydrodynamic spraying of oxygen, forming microbubbles. Experimental results show that pulseless corona discharge effectively removes organics, such as phenol and methylene blue, in deionized water. The corona-discharge method is demonstrated to be comparable to the direct use of ozone at a high-applied voltage. The results also show that a minimum applied voltage exists for operation of the corona-discharge method. In this work, the minimum applied voltage is approximately 4.5 kV. The kinetic rate or phenol degradation in the reactor is modeled. Modeling results show that the dominant species of the pulseless corona-discharge reactor are hydroxyl radical and aqueous electron. Several radical species produced in the pulseless corona-discharge process are identified experimentally. The. major species are hydroxyl radical, atomic hydrogen species, and ozone.

• 대한방사선치료학회지
• /
• 제21권2호
• /
• pp.75-82
• /
• 2009

목 적: 방사선 치료 시 치료실 내에서 발생하는 오존량을 측정하여 오존 발생으로 인한 오염 정도를 알아보고자 한다. 대상 및 방법: 선형가속기(Clinac 21EX, Varian, USA)와 오존 측정기(series-200, aeroQual, New Zealand)를 이용하여 water phantom (Wellhofer, IBA, Germany)에 방사선을 조사하여 MU, 선량율, 선원-표면간 거리(SSD), 조사야, 에너지, 경과 시간에 따라 발생되는 오존량을 측정 분석하였으며, 실제 환자치료 시 치료실 내에 오존 측정기를 위치하여 일일 오존 변화량을 측정하였다. 결 과: 방사선 발생 중 생성되는 오존의 오염도는 에너지에 따른 영향을 크게 받지 않지만 대체로 광자선보다 전자선 조사 시(0.016~0.028 ppm/hr) 많이 발생하였다. 또한, Dose-Rate가 높을수록(0.016~0.025 ppm/hr), SSD가 멀어지고(0.018~0.030 ppm/hr), 조사야가 넓어지고(0.016~0.025 ppm/hr), MU가 많을수록(0.018~0.046 ppm/hr) 오존 농도가 높아졌다. 시간 경과에 따른 오존의 감소량은 방사선을 조사한 후 10분이 경과된 후부터 background 농도(0.016 ppm/hr)로 변화하였다. 그리고 방사선 치료실 내의 일일 발생하는 오존의 농도는 실내의 오존 허용기준인 0.1 ppm/hr (측정 평균 0.06 ppm/8 hr) 이하이지만, 냄새에 민감한 환자들이 감지할 수 있는 수준인 0.02 ppm/hr 이상의 농도(최대: 0.038 ppm/hr)를 포함하는 것을 확인할 수 있었다. 결 론: 일정한 조건의 변화에 따른 오존 농도를 통하여 실제 치료실 내 오존 발생량은 환자나 작업종사자에 대해 유해한 작용을 미치는 수준은 아니었다. 흔히 오존을 해로운 기체라고 생각하지만 방사선 치료 시 발생되는 미량의 치료실 내 오존은 오히려 병원성 세균이나 바이러스 살균 등의 공기 정화 작용을 함으로써 치료실 내 이로운 오존의 역할을 할 것이라 사료된다.

• Asian Journal of Atmospheric Environment
• /
• 제5권4호
• /
• pp.205-215
• /
• 2011

Ozone ($O_3$) is a main component of photochemical oxidants and a phytotoxic air pollutant. Although the current levels of tropospheric $O_3$ in East Asia could adversely affect productivity of forest tree species, risk assessments of $O_3$ impact were limited. In this paper, we summarize the methodology of risk assessment of $O_3$ on forest tree species based on our two previous studies, risk assessments of $O_3$ impact on the growth of Fagus crenata by Watanabe et al. (2012) and on the annual carbon absorption of three representative conifers, Cryptomeria japonica, Pinus densiflora and Larix kaempferi by Watanabe et al. (2010). $O_3$ sensitivity of each tree species obtained from an experimental study, $O_3$ exposure and atmospheric N deposition based on field monitoring and vegetation survey were integrated by geographic information system method. Based on the results, we conclude that the area with high risk of $O_3$ impact does not necessarily correspond to the area with high $O_3$ exposure. The varieties of tree habitat, tree sensitivity to $O_3$ and annual carbon absorption among the tree species, and N deposition-induced change in the $O_3$ sensitivity of F. crenata are raised as the factors of discordance between areas with high risk and those with high $O_3$ exposure. In the last part of this paper, we discuss the present uncertainty and perspectives of risk assessment for the future studies on the impact of $O_3$ on forest tree species in East Asia.

• 멤브레인
• /
• 제18권4호
• /
• pp.354-361
• /
• 2008

자연유기물을 처리하는 혼합 오존-세라믹 한외여과 수처리 시스템에서 막의 운전조건과 처리수의 화학적 조성이 세라믹 막의 투과플럭스에 미치는 영향을 연구하였다. 오존주입량, 막간압력 그리고 교차흐름속도를 포함한 운전조건의 영향을 관찰한 결과, 막의 투과플럭스는 오존주입량과 교차흐름속도가 증가할수록 그리고 막간압력이 감소할수록 증가하였다. 오존주입으로 인한 막오염의 감소는 교차여과에서 오존기체방울에 의해 발생하는 오염물질의 물리적인 역수송보다는 촉매 금속산화물로 이루어진 세라믹막 표면에서 발생하는 오존과 자연유기물간의 화학반응에 의한 영향에 더욱 의존할 수 있음을 확인하였다. 그러나 이와 같은 막오염의 감소는 상대적으로 높은 막간압력을 적용 시 줄어드는 경향을 나타내었다. 모델 자연유기물을 이용하여 실험한 결과, 높은 pH에서는 칼슘의 첨가로 인해 투과플럭스가 급격하게 감소하였으나 상대적으로 낮은 pH에서는 투과플럭스 감소에 대한 칼슘의 효과는 저하되었다. 혼합 오존-세라믹만 시스템에서 연속적인 오존주입은 세라믹막 표면에서 발생하는 촉매오존산화에 의한 자연유기물의 분해로 운전 초기 막의 투과플럭스의 감소 후 궁극적으로는 막의 투과플럭스를 회복시킬 수 있음을 확인할 수 있었다.