• Journal of Environmental Science International
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• v.23 no.4
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• pp.697-705
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• 2014

The exposed population of a vulnerable group to high ozone episodes (exceeding 60 ppb/8h) was estimated in Busan metropolitan city from 2000 to 2010. The frequency of high ozone days at monitoring sites and the number of the population aged over 65 were used to calculate the accumulated (total, seasonal, and yearly) number of the exposed older population (EOP) to high ozone episodes during the study period based on administrative areas, by interpolation and zonal mean methods in ArcGIS software. The older population in this city had increased significantly from 2000 to 2010 (representing over 10% of the total population in 2010). The vulnerable areas (e.g. the eastern area of the city) of the EOP to high ozone episodes were different from the areas with frequent high ozone episodes (e.g., the western area) due to the increase of the older population in particular areas. The difference was more significant in spring than in any other season, and in 2010 than in previous years (2000 and 2005).

• Journal of Sensor Science and Technology
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• v.13 no.1
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• pp.66-71
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• 2004

Pt-doped zinc oxide (ZnO:Pt) films were deposited by ultrasonic spray pyrolysis. Resistivity variation with Pt concentration was measured. The Pt distribution in ZnO:Pt films was studied through Auger Electron Spectroscopy (AES). The ZnO:Pt films were annealed in the ambient of air, water vapor and ozone, respectively. The variation in crystallographic properties and surface morphologies with respect to the annealing condition was observed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The resistivity variation of the films with the annealing condition was measured. Finally, Atomic Force Microscopy (AFM) measurements were carried out to study the effects of the annealing on the roughness of ZnO:Pt films.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.381-385
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• 2003

In this paper, a co-axial type ozonizer varied with discharge gap was designed and manufactured for investigating $\circled1$ discharge characteristics with variation of output voltage power supply, flow rate and gap $\circled2$ ozone generation characteristics with variation of flow rate, gap and discharge power. pure oxygen was used as process gas of the co-axial type ozonizer. In this paper, a double cylindrical type superposed silent discharge type ozonizer which internal electrode can be produced a vacuum has been designed and manufactured. Discharge and ozone generation characteristics have been investigated in accordance with output voltage of power supply, flow-rate, discharge power and vacuum of internal electrode.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.1
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• pp.73-79
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• 1986

This study is carried out to determine the concentration of the ozone and the factors affecting the variation of ozone concentration in the ambient air in Seoul. The one-hour average concentration of ozone $(O_3)$, sulfur dioxide $(SO_2)$, nitrogen oxides (NO and $NO_2$), suspended particulate (TSP), carbon monoxide (CO) and non-methane hydrocarbon (NMHC) at 5 sites in Seoul measured from September to October in 1983 and 1984 were analysed statistically along with meteorological data for the same period. The results were as follows; 1. The average concentrations of ozone at 5 sites during the period ranged from 3.3 to 9.1 ppb, they were below 20 ppb of the ambient air quality standard of Korea. 2. The maximum hourly concentration of ozone occurred between 2 and 3 p.m. in a day and concentration at night were very low but higher concentrations were observed at around 4 a.m. 3. The concentration ratio between NO and $NO_2$ in Seoul was relatively lower than that for the cities of foreign countries reported so far. 4. The ozone concentration has negative correlationships with the concentration of other primary pollutants$(SO_2, NO, NO_2, CO and NMHC)$ in simple regression analyses. 5. The ozone concentration was positively correlated to wind speed, temperature and insolation intensity but negatively correlated to relative humidity. 6. Stepwise multiple regression analysis of the ozone concentration to the pollutants and meteorological factors indicate that insolation intensity and $[NO_2]/[NO]$ were the primary influencing factors. 7. The three factors of insolation intensity, $[NO_2]/[NO] and NO_2$ concentration had a significant combined effect on the ozone concentration $(r^2 = 0.47-0.57)$.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2259-2261
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• 1999

In this paper, an ozonizer, which can generate individual and superposed silent discharge, using three-phase voltage has been designed and manufactured. The ozonizer consists of 3 electrodes(Central Electrode, Internal Electrode and External Electrode) and 2 gaps(gap between Central Electrode and Internal Electrode, gap between Internal Electrode and External Electrode). Ozone is generated according to voltage supplying method to each electrode by individual silent discharge and three-phase superposed discharge. The characteristics of ozone generation were investigated with variation of discharge power and the quantity of supplied gas($O_2$). In case of individual silent discharge, the maximum values of ozone concentration, ozone generation and ozone yield were obtained between internal electrode and external electrode, and its values were 2300[ppm], 570[mg/h] and 745[g/kWh] respectively. Each maximum values was 5039[ppm], 1773[mg/h] and 851[g/kWh] respectively, when three-phase superposed silent discharge was employed. Therefore, characteristics of ozone generation with three-phase voltage are improved compared with single-phase voltage because silent discharge is generated continuously.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.8
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• pp.311-315
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• 2016

The efficiency of manure treatment was investigated in terms of the pH, BOD, COD, SS, T-N and TP with a variation in the injection amount of PAC, polymer and ozone. The wastewater flow rate to the AOF is of $7.4m^3/hr$ with a reaction time of 30 minutes. The amount of PAC and polymer changed by 30, 35, 40 ml/min, and 30, 40, 50 ml/min, respectively. The amount of ozone injected varied from 110, 125, and $150kg-O_3/hr$. The optimum manure treatment performance was found for a PAC of 35 ml/min for the COD and SS, with polymer of 30 ml/min, and ozone injection of $150kg-O^3/hr$. A substantially optimum dose for each PAC, polymer, and ozone was also found to exist.

• Journal of Environmental Science International
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• v.7 no.4
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• pp.493-500
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• 1998

An experimental study was conducted to Indentify the dlrpct denitrification of ammonium nitrogen In culture water by ozone. During the experimnet period, pH was 7.8-8.8. pH was grdually lower after ammonium nitrogen was reacted with ozone under Br . In addition, it can be tmown that the culturing water was improved greatly form the inverstigation of T-N by biofilm and ozonation. As the results of a variation of recirculation rate, denitrification of ammonium nitrogen was in increased in proportion to the recirculation rate. But Nitrification of microorganism was opposite to the recirculation rate. With the increasing injected ozone in ozonation tank uner 21 clrculation/day(6.71 /min), dinitrification of ammonium nitrogen was Increased lineraly in propotion to the Increasing of injected ozone concentration.

• Journal of Environmental Science International
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• v.19 no.3
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• pp.261-267
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• 2010

The variation of assimilable organic carbon(AOC) concentration at each condition of ozonation was investigated using a model water and drinking water resource. AOC concentration of model raw water and drinking water resource tended to increase at low ozone dose. The maximum AOC concentration was detected when the residual ozone begin to be measured. Also, the AOC concentration increase at pH 8 compared to both pH 6 and 7 while that for pH 9 decreased rapidly. The removal characteristics of trihalomethane formation potential(THMFP) by ozonation was also investigated. Unlike the trend of AOC, the THMFP concentration never increased by ozonation but decreased even at low ozone dosage. From these results, the ozone dosage would be effective to simultaneously decrease both AOC and THMFP.

• Textile Coloration and Finishing
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• v.8 no.1
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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.

• The Journal of Korean Society for Radiation Therapy
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• v.21 no.2
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• pp.75-82
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• 2009

Purpose: Measure the ozone level in the treatment room while treating a patient so want to know the degree of contamination caused by ozone occurrence. Materials and Methods: Use the linear accelerator (Clinac 21EX, Varian, USA) with the ozone meter (series-200, aeroQual, New Zealand) and water phantom (Wellhofer, IBA, Germany) is irradiated the radiation so that measured the ozone generation level according to MU, dose-rate, SSD, field size, energy, delay time and put the ozone meter in the treatment room actually while treating a patient so measured the daily ozone level variation. Results: While irradiating the radiation, degree of ozone contamination wasn't affected by the energy but mostly in case of electron beam, ozone level was higher than photon beam. The higher dose-rate (0.016~0.025 ppm/hr), the farther SSD (0.018~0.030 ppm/hr), the wider field sizes (0.016~0.025 ppm/hr), the more MU (0.018~0.046 ppm/hr), it occurred high ozone level. Ozone decrement according to delay time changed the background level (0.016 ppm/hr) after elapsed time of 10 minutes from irradiating radiation. And daily ozone occurrence level in the treatment room was below ozone standard level 0.1 ppm/hr (average:0.06 ppm/8 hr) but it could confirm that ozone generation level was included the level (max:0.038 ppm/hr) above 0.02 ppm/hr which patient could perceive. Conclusion: Through ozone level according to variation of certain conditions, actually in the treatment room ozone generation level didn't damaged to patients or workers. Commonly peoples think that ozone was harmful gas but it thought that small amount of ozone generation level while treating a patient was beneficial in the treatment room through air purge action of pathogenic germ or virus sterilization.