• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.6
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• pp.27-34
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• 2001

There are several electricity applied sterilizers such as using high frequency, ozone, high voltage, and so on. Those sterilizers feature "because of no chemical process and no secondly environmental pollution". At the power conversion part, ZVS and ZCS methods have been used that it results in reduced switching loss, miniaturized size, and lightened weight. Besides, the current in the propose device is smaller than that of existing method. Thus, it is expected that the cost of sterilization process, when quality of the device is measured by power consumption, will be reduce. Therefore, the purpose of this research is to solve the sterilization problems of existing powder with high voltage and field to and more economical and effective way, and to suggest mere improved sterilizer.

• Advances in materials Research
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• v.6 no.1
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• pp.1-12
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• 2017

The aim of the work was to evaluate the effect of ultraviolet-ozone ($UV-O_3$) irradiation with different times on the structure and thermal properties of hydroxypropyl methylcellulose (HPMC) in the form of a thin film to be used as bioequivalent materials according to their important broad practical and medical applications. HPMC thin films were exposed to $UV-O_3$ radiation in air at a wavelength of 184.9 nm.The beneficial effects of this treatment on the crystallinity and amorphousity regions were followed by X-ray diffraction technique and FTIR spectroscopy. Differential scanning calorimetry, thermogravimetric and differntial thermal analyses were used in order to study the thermal properties of HPMC samples following the process of photodegradation. The obtained results indicated that the rate of degradation process was increased with increasing the exposure time. Variations in shape and area of the thermal peaks were observed which may be attributed to the different degrees of crystallinity after exposing the treated HPMC samples. This meant a change in the amorphousity of the treated samples, the oxidation of its chemical linkages on its surface and its bulk, and the formation of free radical species as well as bond formation.

• Electrical & Electronic Materials
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• v.10 no.5
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• pp.425-433
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• 1997

BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and 82$0^{\circ}C$ and the highly condensed ozone gas pressure(PO$_3$) in vacuum chamber was varied between 2.0$\times$10$^{-6}$ and 2.3$\times$10$^{-5}$ Torr. Bi 2212 phase appeared in the temperature range of 750 and 795$^{\circ}C$ and single phase of Bi 2201 existed in the lower region than 785$^{\circ}C$. Whereas, PO$_3$dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with T$_{c}$(onset) of about 90 K and T$_{c}$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as CaCuO$_2$was observed in all of the obtained films.lms.

• Journal of Environmental Science International
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• v.15 no.3
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• pp.203-209
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• 2006

In predicting oxidants concentration, the most important fact is to select a suitable photochemical reaction mechanism. Sensitivity analysis of $O_3$ and other important photochemical oxidants concentrations was conducted by using CBM-IV model. The predicted oxidants concentration was considerably related with the initial concentration of formaldehyde, $[NO_2]/[NO],\;NO_x$, RH and RCHO. As the initial concentration of formaldehyde increased, concentration of $NO_2$ increased. $O_3$ concentration was proportional to the $[NO_2]/[NO]$ ratio. When the initial concentrations of RH and RCHO were high, photochemical reaction was more reactive, including more rapid conversion of NO to $NO_2$ and increased oxidants. Also, the sensitivities of ozone formation to rate constants, $K_l,\;K_2\;and\;K_3$ in the $NO_2$ photolysis were studied.

• Environmental Analysis Health and Toxicology
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• v.16 no.3
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• pp.139-142
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• 2001

Acetanilide is a High Production Volume Chemical, which is produced about 2,300 tons/year in Korea as of 1998 survey. Most is used as an intermediate for synthesis of pharmaceuticals and dyes, and the chemical is one of seven chemicals of which human and environmental risk are being assessed by National Institute of Environmental Research under the frame of OECD SIDS program. The Atmospheric Oxidation Program for Microsoft Windows (AOPWIN) is used to estimates the rate constant for the atmospheric, gas－phase reaction between photochemically produced hydroxyl radicals and organic chemicals. It is also used to estimates the rate constant for the gas－phase reaction between ozone and olefinic/acetylenic compounds. The rate constants estimated by the program are then used to calculate atmospheric half－lives for organic compounds based upon average atmospheric concentrations of hydroxyl radicals and ozone. AOPWIN requires only a chemical structure to make these predictions. Structures are entered into AOPWIN by SMILES (Simplified Molecular Input Line Entry System) notations. In this study, one of environmental fate/distribution of the chemical elements, photodegradation of acetanilide was estimated using AOPWIN model based on SMILES notation and chemical name data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1071-1074
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• 2002

This paper presents Bi thin films have been fabricated by atomic layer-by-layer deposition and co-deposition at an IBS method. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and $820^{\circ}C$ and the highly condensed ozone gas pressure$(PO_3)$ in vacuum chamber was varied between $2.0{\times}10^{-6}$ and $2.3{\times}10^{-5}Torr$. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$: and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, $PO_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.671-674
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• 2004

BSCCO thin films have been fabricated by epitaxy growth at an ultra-low growth rate. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and 820 $^{\circ}C$ and the highly condensed ozone gas pressure(PO3) in vacuum chamber was varied between $2.0{\times}10^{-6}$ and $2.3{\times}10^{-5}$ Torr. Bi 2212 phase appeared in the temperature range of 750 and 795 $^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785\;^{\circ}C$. Whereas, $PO_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.278-280
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• 2001

BSCCO thin films have been fabricated by co-deposition at an ultralow growth rate using ion beam sputtering(IBS) method. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and $820^{\circ}C$ and the highly condensed ozone gas pressure($PO_3$) in vacuum chamber was varied between $2.0{\times}10^{-6}$ and $2.3{\times}10^{-5}$ Torr. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$ and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, $PO_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.791-804
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• 2011

Numerical simulations were carried out to investigate the impact of PBL (Planetary boundary layer) scheme implemented in WRF on the result of meteorological fields and CMAQ modeling. 25-day period, representing high ozone concentration, was selected for the simulations. The three WRF domains covered East Asia region, Korean Peninsula and Seoul metropolitan area. The sensitivity of WRF-CMAQ modeling to the various PBL schemes was assessed and quantified by comparing model output and against observation from the meteorological and the air quality monitoring network within the domain. The meteorological variables evaluated included temperature, wind speed and direction over surface sites and upper air sounding sites. The CMAQ variables included gaseous species $O_3$ and $NO_x$ over monitoring stations. Although difference of PBL schemes implemented in WRF, they did not appreciably affect the WRF and CMAQ performance. There are partially differences between non-local and local mixing scheme, but are not distinct differences for the results of weather and air quality. It is suggested that impact of parameterization of vertical eddy diffusivity scheme in CMAQ also need to be researched in the future study.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.61-69
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• 1999

Contaminants such as fatty acids, triglycerides, resin acids and foam collected from a high yield sulfite weak liquor storage tank lowered the water surface tension and reduced inter-fibre bonding but also tended to benefit sheet opacity. Some common wet end additives such as defoamers and dispersants gave similar results. Lignosulfonate and naphthalene sulfonate showed little if any negative effect on both surface tension and sheet strength properties. Among the natural wood extractives. fatty acids were identified to be most detrimental followed by triglycerides and then resin acids. In order to alleviate the detrimental impact of these contaminants, membrane separation, air floatation and ozone treatment were carried out on paper machine white water samples. The effect of these treatments on removal of fatty and resin acids was quantified by a GC-Mass analysis. Reverse osmosis with a 1000 molecular weight cut off membrane failed to totally reject fatty and resin acids, but markedly reduced losses of sheet properties due to contaminants. Ozone treatment resulted in a significant increase of the surface tension and air floatation was considered to be a practical and useful method for removing fatty and resin acids from the machine white water.