• Journal of the Korean Statistical Society
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• v.32 no.4
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• pp.313-335
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• 2003

Hourly ozone data are available for 73 stations in South Korea from January, 1988 to August, 1998. We are interested in detecting trends in both the mean levels and the extremes of ozone, and in determining how these trends vary over the country. The latter aspect means that we also have to understand the spatial dependence of ozone. In this connection, therefore, we examine in this paper the following features: determining trends in mean ozone levels at individual stations and combination across stations; determining trends in extreme ozone levels at individual stations and combination across stations; spatial modeling of trends in mean and extreme ozone levels.

• Korean Journal of Microbiology
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• v.25 no.2
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• pp.103-109
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• 1987

An ozone-sensitive mutant of Escherichia coli strain B, MQ 1844 is described. Its properties, including high sensitivity to ozone and radiation, inducible filamentation, extensive DNA degradation and impaired DNA synthesis following ozonation, are attributable to a mutation in ozrB, a gene which is cotransducible with malB. Based on differences in phenotypic expression as well as on the particular location of this gene on the bacterial chromosome, ozrB appears as distinct from the other ozone-or radiation-sensitivity genes previously described.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.4
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• pp.22-29
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• 2002

This research was conducted to investigate the morphological characteristics of fine fibers produced during beating process of high yield pulp treated with ozone and the distribution of lignin in the produced fine fibers. Thermomechanical(TMP) pulp and chemithermomechanical(CTMP) pulp of spruce and CTMP of white birch were beaten to reach 200$m\ell$ CSF, and then the fine fibers were observed using ultraviolet microscope. The fine fibers produced from TMP and CTMP of spruce using treated with ozone for 15 minutes were fragments of fiber surfaces or cell corners, and most of them contained lignin. However, lignin was not observed in the fibers after 15 minutes of ozone treatment. The fine fibers produced from CTMP of white birch were broken pieces or fragments of fiber surfaces or cell corners. The lignin was observed in the fibers until 5min of ozone treatment but no lignin was observed after 5 minutes of ozone treatment. Different morphological characteristics of TMP and CTMP explained both the different morphological characteristics and the distribution of lignin observed in the fine fibers produced from the beating process of TMP and CTMP treated with ozone.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.140-143
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• 2003

This research was to determine and compare the inactivation of total coliform as the indicator organism with chlorine, chlorine dioxide and ozone for drinking water treatment. The inactivation of total coliform was experimentally analyzed for the dose of disinfectant, contact time, pH, Temperature and DOC. The experiments for the characterization of inactivation were performed in a series of batch processes with the total coliform as a general indicator organism based on chlorine, chlorine dioxide and ozone as disinfectants. The nearly 2.4, 3.0, 3.9 log inactivation of total coliform killed by injecting 1mg/L at 5 minutes for chlorine, chlorine dioxide and ozone. For the inactivation of 99.9%, Disinfectants required were 1.70, 1.00 and 0.60 mg/L for chlorine, chlorine dioxide and ozone, respectively. The bactericidal effects of disinfectants were decreased as the pH increased in the range of pH 6-9. The influence of pH change on the killing effect of chlorine dioxide was not strong, but that on ozone and free chlorine was sensitive. The bactericidal effects of the disinfectants were increased as the temperature increase. The activation energies were 36,053, 29,822, 24,906 J/mol of chlorine, chlorine dioxide, ozone for coliforms. The inactivation effects were shown in the lowest order of chlorine, chlorine dioxide and ozone.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.3
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• pp.77-82
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• 1999

The delignification, and optical and strength properties were determined to compare the ozone treatment effect in hardwood and softwood CTMPs. During ozone treatment, the delignificantion was much higher in hardwood pulp than in softwood pulp . The optical and strength properties which were very dependent upon the lignin content in pulp were significantly improved in the case of hardwood pulp . The ozone treatment of high yield pulp was more effective in hardwood pulp than that of softwood pulp.

• Journal of the Korean earth science society
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• v.29 no.5
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• pp.428-436
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• 2008

This study observed the upper tropospheric ozone enhancement in the northern Atlantic for the Aerosols99 campaign in January-February 1999. To find the origin of this air, we have analyzed the horizontal and vertical fields of Isentropic Potential Vorticity (IPV) and Relative Humidity (RH). The arch-shaped IPV is greater than 1.5 pvus indicating stratospheric air stretches equatorward. These arch-shaped regions are connected with regions of RH less than 20%. The vertical fields of IPV and RH show the folding layer penetrating into the upper troposphere. These features support the idea that the upper tropospheric ozone enhancement originated from the stratosphere. Additionally, we have investigated the climatological frequency of stratospheric intrusion over the tropical north Atlantic using IPV and RH. The total frequency between the equator and $30^{\circ}N$ over the tropical north Atlantic exhibits a maximum in northern winter. It suggests that the stratospheric intrusion plays an important role in enhancing ozone in the upper troposphere over the tropical north Atlantic in winter and early spring. Although the tropospheric ozone residual method assumed zonally invariant stratospheric ozone, stratospheric zonal ozone variance could be caused by stratospheric intrusions. This implies that stratospheric intrusion influences ozone variance over the Atlantic in boreal winter and spring, and the intrusion is a possible source for the tropical north Atlantic paradox.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.12
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• pp.791-797
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• 1999

Recently the ozone generation system is well used for cleaning the contaminated water by using the strong oxidization effects of ozone. In this paper the concentration, yield and generation quantity of the ozone by the Surface-Silent Discharge According to the Length of Coaxial Electrode is described. The electrodes composed of 3 electrodes-2 gaps are coaxial type and the ozone generation tube were designed and fabricated from the point of view of the energy efficiency, stability and easy control. To investigate the ozone generation dependency on electrode length, a few discharge tubes with different lengths were fabricated. The experimental equipments were provided with cooling system and dehumidifier for the many testing conditions. The main results show that the concentration, yield and generation quantity of ozone are improved by decreasing gas temperatures and increasing electrode lengths.

• The Korean Journal of Ecology
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• v.20 no.4
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• pp.239-244
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• 1997

Hybrid poplar (Populus trichocarpa $\times$ P. deltoides) clones were fumigated with ozone. Fumigation was applied for 6 to 8 hours each day for approximately 3 months at ozone concentrations of 0.090 to 0.115 ppm using by open-top chambers. Growth and biomass of hybrid poplar seedlings were reduced by ozone exposure. Mean percentage of falling leaves in ozone-treated plant was 6 times higher than that of charcoal-filtered plant. Among physiological responses, rate of photosynthesis, stomatal conductance, transpiration and initial Rubisco activity were significantly lower in seedlings grown in ozone environment compared seedlings grown in charcoal-filtered air. All these physiological results supported that biochemical process to be a key feature to understand reduction in photosynthesis.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.24-28
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• 2001

The utilization of wastepaper as a papermaking raw material is everlastingly required for the environmental protection of earth. However the recycling of wastepaper for this purpose cause another problem such as the increasing of the load of wastewater treatment, lower strength properties of paper, and poor printability, etc. The interest in the development of the environmentally friendly deinking technology is increased continuously. Thus, our research team have tried to apply the ozone to the deinking of white ledger and ONP, and obtained the positive results which can be considered as an alternative method for the conventional deinking method. The purpose of this study is to investigate the mechanism of ozone deinking. Styrene acrylate and polystyrene were treated with ozone and measured the change of molecular weight with the GPC. The molecular weight distribution obtained with GPC showed only slight increase by the ozone treatment, and gel formation by the polymerization was observed. Therefore the removal of ink particles with ozone treatment seems to be facilitated by the increase of the brittleness and decrease of adhesive property.

• Journal of the Korean earth science society
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• v.27 no.7
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• pp.778-786
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• 2006

In Korea, the ozone profiles have been acquired by using ozonesonde at Pohang station of the Korea Meteorological Administration (KMA) since 1995. These ozone soundings were performed at 0500 UTC on a weekly basis (every Wednesday) in a clear sky. The ozonesonde is equipped with the model 5A ECC sensor, which is one of the most common ozonesonde systems. There have been no attempts to evaluate the Pohang ozonesonde profiles compared with satellite. This paper will provide the first evaluation results for the ozonesonde profiles against HALogen Occultation Experiment (HALOE) measurements over Korea. During 1995-2004 periods, a total of 450 and 188 ozone profiles were obtained from the ozonesonde measurements from HALOE measurements over Korea, respectively. Hence, a total of 34 coincident profile pairs are extracted. Among those total profiles, 26 profiles from ozonesonde are compared against nearly coincident HALOE measurements in time and space. For ozone profiles, the results of statistical analyses showed that the best agreement between two measurements occurs in the 20-25 km and 30-35 km region, where the mean and RMS percent differences are less than ${\pm}5$ and 14%, respectively. For temperature profiles, the mean and RMS percent differences in 20-25 km region are estimated to be about -0.1 and 1.7%, respectively. According to the scatter plots between two measurements, ozone data are strongly correlated each other above 20 km altitude range with more than 0.8 correlation coefficients. It is found that the altitude (pressure level) differences between two measurements would mainly lead to the discrepancy (over 40% below 18 km) below 20 km in ozone profiles.