• Food Science of Animal Resources
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• v.38 no.3
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• pp.487-497
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• 2018

Controlling of microorganisms in the industrial process is important for production and distribution of hatching and table eggs. In the previous study, we reported that chlorine dioxide ($ClO_2$) gas of a proper concentration and humidity can significantly reduce the load of Salmonella spp. on eggshells. In this study, we compared microbial reduction efficacy on egg's surface using hatching eggs and table eggs, internal quality of table eggs, and hatchability after both the conventional method (washing and UV expose, fumigation with formalin) and $ClO_2$ gas disinfection. Application of 40 ppm $ClO_2$ gas to the table and hatching eggs, respectively, reduced the aerobic plate count (APC) with no statistical difference compared with the conventional methods. Additionally, we didn't observed that any significant difference in albumin height, Haugh unit (HU), and yolk color, this result confirms that 40 ppm $ClO_2$ had no effect on the internal quality of the table eggs, when comparing with the UV treatment method. The hatchability of hatching eggs was not statistical different between formaldehyde fumigation and 80 ppm $ClO_2$ gas treatment, though the value was decreased at high concentration of 160 ppm $ClO_2$ gas. From these results, we recommend that $ClO_2$ gas can be used as a safe disinfectant to effectively control egg surface microorganisms without affecting egg quality.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.12
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• pp.1329-1336
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• 2007

This study was carried out to develop an efficient process abating high NO concentration. A hybrid process of selective catalytic reduction(SCR) and activated carbon fiber(ACF) adsorption was newly designed and tested. Used ACF in NO adsorption was regenerated by simultaneously applying heat and vacuum. The result of ACF regeneration was for superior in the desorption condition at $140^{\circ}C$ and vacuum 600 mmHg. A commercial catalyst was used at the conditions of reaction temperature at $300^{\circ}C$, $NH_3/NO$ mole ratio = 1.0 for SCR process. NO evolved from ACF regeneration reactor could be removed by SCR reactor up to 98%. But high concentration of NO was exhausted from SCR reactor for one minute when the flue gas of NO 300 ppm and deserted NO from ACF regeneration were simultaneously treated by the same SCR reactor. Therefore, it is necessary to use additional small sized SCR reactor or to increase $NH_3$ concentration for a short time along with NO concentration rather than to mix flue gas with the gas evolving from ACF regeneration at fixed $NH_3$ inlet concentration. The hybrid process of SCR and ACF showed high NO removal efficiency over 80% at any time courses. Through the repeated cycles, stable DeNOx efficiency was maintained, indicating that the hybrid process would be a good countermeasure to the spotaneously high NO concentration instead of increasing the SCR capacity.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.77.2-77.2
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• 2017

We investigate star formation activities of ~400 barred and unbarred faced-on late-type galaxies from the SDSS-IV MaNGA (Mapping Nearby Galaxies at APO) IFU survey. We find the star formation activities in gas-poor, barred galaxies are considerably suppressed than gas-rich, barred galaxies, while there is no difference among unbarred galaxies regardless of their HI gas content. The gas-poor and barred galaxies show the steeper difference of gradient in metallicity and age with respect to the stellar mass than gas-rich or unbarred galaxies, in that their centre is more metal-rich and younger. The results suggest that, combined with the gas contents available, the bar structure plays a significant role in quenching star formation in a galaxy by transporting/mixing gas via gas inflow.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1812-1814
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• 1998

Recently plasmas have been used to reduce the undesirable gases $SO_2$, NO, and $NO_2$. Especially bidirectional pulsed voltages were used to increase the efficiency of flue-gas reactors. The particle-Mesh model using NGP (Nearest-grid-point) and FEM (Finite Element Method) calculate the detailed space-time variations of the electric fields for the streamer and it makes the characteristics of reactor more clearly. In this simulation NO is considered a dominant gas.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.570-576
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• 2012

In this study, we investigated the characteristics of NO oxidation using un-divided electrolyzed seawater as oxidant. The concentration of available chlorine and the temperature of electrolyzed seawater are increased with electrolysis time in the closed-loop constant current electrolysis system. While NO gas flow through bubbling reactor which is filled with electrolyzed seawater, the oxidation rate of NO to $NO_2$ is increased with the concentration of available chlorine and the temperature. $NO_2$, generated by oxidation reaction, is dissolved in electrolyzed seawater and existed as $HNO_3{^-}$ ion.

• Journal of Welding and Joining
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• v.5 no.2
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• pp.17-26
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• 1987

In this study, the experiments were carried out for the purpose of establishment of the arc sparing method which reducing oxides or oxide film by using the inert gas as the carrier gas of atomizing particles. Main results obtained are as follows; 1. Oxides and oxide film which lower the adhesion strength are largely reduced by using the inert gas as the carrier gas of atomizing particles, and adhesion strength of coating film are improved. 2. The coating film characteristics appear to be no difference between the inert gas arc spraying in air environment and that in argon gas environment. 3. Inert gas arc spraying using argon as the carrie gas has higher reduction rate of composition element in coating film than compressed air spraying does.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.369.1-369.1
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• 2014

Au-functionalized $WO_3$ nanotubes were synthesized using ZnO nanowire templates. Transmission electron microscopy revealed the Au nanoparticles on the outer surface of a typical $WO_3$ nanotube ranged from 5 to 25 nm. The multiple networked Au-functionalized $WO_3$ nanotube sensors showed responses of 820-3, 924% in the $NO_2$ concentration range of 1-5 ppm at $300^{\circ}C$. These responses were approximately 5-12 fold higher than those observed for pristine $WO_3$ nanotube sensors over the same $NO_2$ concentration range. A model describing the gas sensing mechanism of Au-functionalized $WO_3$ nanotubes is discussed.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.237-239
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• 1994

The $NO_2$ gas-detection characteristics were investigated using the functional organic Langmuir-Blodgett(LB) film of Tetra-3-hexadecyl-sulphamoylcopperphthalocyanine(HDSM-CuPc). A surface pressure of 30mN/m was obtained as a proper one for a film deposition. A deposited film status was confirmed by electrical and optical methods such as UV/visible absorption spectra and current-voltage(I-V) characteristics. The $NO_2$ gas response experiments under 200ppm concentration show that there is not increment of electrical conductivity in room temperature and is identified by UV/visible absorption spectra. But There are some increments of electrical conductivity in $160^{\circ}C$.

• Korean Journal of Materials Research
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• v.20 no.11
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• pp.623-627
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• 2010

Semiconducting metal oxides have been frequently used as gas sensing materials. While zinc oxide is a popular material for such applications, structures such as nanowires, nanorods and nanotubes, due to their large surface area, are natural candidates for use as gas sensors of higher sensitivity. The compound ZnO has been studied, due to its chemical and thermal stability, for use as an n-type semiconducting gas sensor. ZnO has a large exciton binding energy and a large bandgap energy at room temperature. Also, ZnO is sensitive to toxic and combustible gases. The NO gas properties of zinc oxide-single wall carbon nanotube (ZnO-SWCNT) composites were investigated. Fabrication includes the deposition of porous SWCNTs on thermally oxidized $SiO_2$ substrates followed by sputter deposition of Zn and thermal oxidation at $400^{\circ}C$ in oxygen. The Zn films were controlled to 50 nm thicknesses. The effects of microstructure and gas sensing properties were studied for process optimization through comparison of ZnO-SWCNT composites with ZnO film. The basic sensor response behavior to 10 ppm NO gas were checked at different operation temperatures in the range of $150-300^{\circ}C$. The highest sensor responses were observed at $300^{\circ}C$ in ZnO film and $250^{\circ}C$ in ZnO-SWCNT composites. The ZnO-SWCNT composite sensor showed a sensor response (~1300%) five times higher than that of pure ZnO thin film sensors at an operation temperature of $250^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.36 no.3
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• pp.237-243
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• 1999

스크린 프린팅법을 이용하여 NOX 감지용 WO3 후막형 가스센서를 제조하였다. 본 실험에서는 감지막의 소성 온도에따른 감도변화 및 Ru을 첨가함으로써 감도의 증진을 중점적으로 조사하였다. 또한 NO2 50 ppm하에서 CO, H2, CH4 그리고 i-C4H10등의 가스에 대하여 cross sensitivity를 조사하였다. WO3 가스센서는 소성온도 50$0^{\circ}C$, 작동온도 30$0^{\circ}C$에서 최대감도를 얻었다. 순수한 WO3에 Ru(0.004 wt%)을 첨가시 NO2 및 NO 가스에 대한 감도가 크게 증진되었다. 그러나 순수한 WO3 센서는 Ru(0.004 wt%)이 첨가된 WO3 센서보다 더 우수한 cross sensitivity를 보였다.