• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.177-178
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• 2015

Recently, Advanced water treatment facilities with Ozone are being introduced owing to domestic water pollution. However, waterproofing/corrosion prevention construction method of concrete structure for existing advanced water treatment makes waterproofing/corrosion prevention materials and concrete deteriorated because of strong oxidation of ozone. it causes increase of maintenance cost and water quality degradation. Therefore, in this study, it will figure out problems of waterproofing/corrosion prevention construction method being applied to through existing studies.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.12
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• pp.614-621
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• 2001

In this Paper, the ozonizer is fabricated by piling plate-type electrodes up to minimize and reduce install space. Hereby ozone generation characteristics of piled plate-type ozonizer were investigated. Inverse-polarity voltage was generated by H.V neon transformer. And 2 H.V neon transformers were used to supply high voltage each 9 electrodes of plate-type ozonizer. According to the experiments, ozone concentration, generation and yield were proportionally increased tilth increasing the number of electrode. And the maximum increase effects of 246%, 245%, and 33% were obtained when the number of electrode were increased from 3 up to 9.

• Journal of the Korean Chemical Society
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• v.65 no.3
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• pp.185-196
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• 2021

For studying the reaction mechanism of the reactions related to NO in the ozone denitration reactions, the harmonic and anharmonic rate constants were calculated by the transition state (TS) theory and Yao and Lin (YL) method. According to above calculations, the reactions of NO with O₃ and NO₃ play an essential role, and the kinetic parameters considering anharmonic effect were fitted. Furthermore, the rate constants were up as temperature increasing, and the tendencies of high temperature were more gradual than the low temperature. The research will provide theoretical basis for the ozone denitration reactions.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.280-288
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• 1996

In the ozone evolution using $PbO_2$, which was electrodeposited on Ti plate at various conditions in electrolyte, the effects of lead dioxide structure on the current efficiency and surface structure changes of lead dioxide were investigated. Also the effects of oxygen transfer reaction on the ozone evolution were investigated by means of a $PbO_2$ electrodeposited on the platinum rotating disk electrode. In order to develope an electrode for ozone evolution, durability of lead dioxide and optimum current density were investigated. At the electrodeposited lead dioxide with the larger grain size and higher crystallinity, the efficiency for ozone evolution was higher. Optimum current density to electrodeposite lead dioxide with large grain size and high crystalinity was $50mA/cm^2$. Lead dioxide deposited in the presence of glycerin showed the best advantage of ozone evolution. Also lead dioxide electrodeposited at less than $10mA/cm^2$ or at more than $100mA/cm^2$ has poor performance of ozone evolution and poor adhesive strength to substrate. In the beginning of ozone evolution, surface structure of lead dioxide was changed and this change resulted in good effects on ozone evolution. Lead dioxide doped with other elements was favorable not to ozone evolution but to oxygen evolution, so it is speculated that ozone evolution has not intermediate stage of oxygen evolution and occurs competitively with oxygen evolution. When ozone was evolved at $0.7{\sim}0.8A/cm^2$, the current efficiency was highest.

• Journal of Korean Society on Water Environment
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• v.28 no.5
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• pp.704-716
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• 2012

This paper provides a detailed account of pilot testing conducted at South Lake Tahoe (California), the Ddukdo (Seoul) water treatment plant (WTP) and the Bokjung (Seongnam) WTP between February, 2010, and February, 2012. The objectives were first, to characterize the reactions of ozone with hydrogen peroxide (Peroxone) for Han River water following sand filtration, second to determine empirical ozone and hydrogen peroxide doses to remove a taste-and-odor surrogate 2-methylisoborneol (MIB) using an advanced oxidation process (AOP) configuration and third, to determine the optimum dosing configuration to reduce residual ozone to a safe level at the exit of the process. The testing was performed in a real-time plant environment at both low- and high seasonal water temperatures. Experimental results including ozone decomposition rates were dependent on temperature and pH, consistent with data reported by other researchers. MIB in post-sand-filtration water was spiked to 40-50 ng/L, and in all cases, it was reduced to below the specified target level (7 ng/liter) and typically non-detect (ND). It was demonstrated that Peroxone could achieve both MIB removal and low effluent ozone residual at ozone+hydrogen peroxide doses less than those for ozone alone. An empirical predictive model, suitable for use by design engineers and operating personnel and for incorporation in plant control systems was developed. Due to a significant reduction in the ozone reaction/decomposition at low winter temperatures, results demonstrate the hydrogen peroxide can be "pre-conditioned" in order to increase initial reaction rates and achieve lower ozone residuals. Results also indicate the method, location and composition of hydrogen peroxide injection is critical to successful implementation of Peroxone without using excessive chemicals or degrading performance.

• Journal of the Korean GEO-environmental Society
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• v.23 no.3
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• pp.23-29
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• 2022

In this study, we investigated the ozone nanobubble process in which nanobubble and ultrasonic cavitation were applied simultaneously to improve the dissolution and self-decomposition of ozone. To confirm the organic decomposition efficiency of the process, a 200 mm × 200 mm × 300 mm scale reactor was designed and phenol decomposition experiments were conducted. The use of nanobubble was 2.07 times higher than the conventional ozone aeration in the 60 minutes reaction and effectively improved the dissolution efficiency of ozone. Ultrasonic irradiation increased phenol degradation by 36% with nanobubbles, and dissolved ozone concentration was lowered due to the promotion of ozone self-decomposition. The higher the ultrasonic power was, the higher the phenol degradation efficiency. The decomposition efficiency of phenol was the highest at 132 kHz. The ozone nanobubble process showed better decomposition efficiency at high pH like conventional ozone processes but achieved 100% decomposition of phenol after 60 minutes reaction even at neutral conditions. The effect by pH was less than that of the conventional ozone process because of self-decomposition promotion. To confirm the change in bubble properties by ultrasonic irradiation, a Zetasizer was used to measure the bubbles' size and zeta potential analysis. Ultrasonic irradiation reduced the average size of the bubbles by 11% and strengthened the negative charge of the bubble surface, positively affecting the gas transfer of the ozone nanobubble and the efficiency of the radical production.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.2
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• pp.143-151
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• 2024

Ozone is a colorless, toxic gas that is produced when nitrogen oxides and hydrocarbons undergo a photochemical oxidation reaction in the sun's rays. Even at low concentrations, it affects the respiratory system, causing coughing and other harmful effects. It was confirmed that ozone was generated from nitrogen plasma among cosmetic raw materials, and it was found that the concentration of ozone decreased after 1 day. On the other hand, ozone was not detected in ozone-free plasma generated with argon gas. Therefore, we aimed to produce ozone-free cosmetics by utilizing ozone-free plasma. For efficient plasma processing, the non-sinking method was utilized to inject the plasma into layer separation mists, toners, and ampoules, and the stability was observed. It was found that the successful injection of plasma in the layer separation mist was higher than the other two formulations, but decreased sharply compared to the toner and ampoule. It was found that the ozone-free plasma used did not affect the stability of the layer separation mist, toner, and ampoule under low temperature (4 ℃), room temperature (25 ℃), and high temperature (37 ℃, 50 ℃) conditions. Therefore, this study suggests the importance of ozone-free plasma for cosmetic potential and stability of each formulation.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.7
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• pp.335-342
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• 2003

This paper presents a forward type high voltage pulse power supply for high voltage small current, which can be designed as a simple circuit configuration and managed easily using Power-MOSFET in the view of commercialization. According to the switching frequency, coupling factor(k) and duty ratio(D), the Principle of basic operation and the characteristics of the proposed pulse power supply are estimated. Simulation results have demonstrated the feasibility of the proposed pulse power supply. Also experimental results are presented to verify theoretical discussion with a lamp type ozonizer as a load. For studying the application at the part of environment of water, When ozonizer gas reacts with a colon bacillus, the sterilization characteristics of a colon bacillus according to the ozone concentration and response time have been investigated. This proposed pulse power supply will be able to be practically used as a pulse power supply in various environment improvement facilities like sterilization of colon bacillus, deodorization, and Nox gas elimination.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.12
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• pp.673-678
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• 2000

The dielectric barrier discharge(DBD) is a common method to create a nonthermal plasma in which electrical energy is used to create electrons with a high average kinetic energy. The unique aspect of dielectric barrier discharges is the large array of short lifetime(10ns) silent discharges created over the surface of the dielectric. A silent discharge is generated when the applied voltage exceeds the breakdown voltage of the carrier gas creating a conduction path between the applied electrode and grounded electrode. As charge accumulates on the dielectric, the electric field is reduced below the breakdown field of the carrier gas and the silent discharge self terminates preventing the DBD cell from producing a thermal arc. In fact, the most significant application of dielectric barrier discharges is to generate ozone for contaminated water treatment. Therefore, experiments were perfomed at 1∼2[bar] pressure using a coaxial geometry single dielectric barrier discharge for ozone concentrations and energy densities. The main result show that the concentration and efficiency of ozone are influenced by gas nature, gas quantity, gas pressure, supplied voltage and frequency.

• Journal of Environmental Science International
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• v.11 no.6
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• pp.497-506
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• 2002

A Photochemical-Trajectory model was used to understand the production of ozone in the atmospheric boundary layer. This model was composed of the trajectory and the photochemical models. To calculate trajectories of air parcels, winds were obtained from the three-dimensional nonhydrostatic mesoscale model (PSU/NCAR MM5V2), and the results were interpolated into constant height surfaces. Numerical integration in the trajectory model was performed by the Runge-Kutta method. The photochemical model consisted of chemical reactions and photodissociation processes. Chemical equations were integrated by the semi-implicit Bulirsch-Stoer method. We performed our experiments from 21 July to 23 July 1994 during the summer time for Seoul area. During the time of maximum ozone concentration in Seoul, four trajectories of air parcels which traveled from Inchon to Seoul were selected. Ozone concentrations estimated by two models are compared with observed one in Seoul area and the photochemical-trajectory model is better fitted than pure photochemical model. During the selected period, high ozone concentrations in Seoul area were more influenced by transferred pollutants from Inchon than emitted pollutants in Seoul.