• Korean Journal of Veterinary Service
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• v.37 no.2
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• pp.137-141
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• 2014

A captive mute swan (Cygnus olor) in the brooding period was found dead without any specific signs. On necropsy, the entire digestive tract was severely necrotized with loosely adherent pseudomembranes, and Clostridium perfringens (CP) colonies isolated from the intestinal contents were identified as CP type A by polymerase chain reaction. Microscopically, the intestine and the liver were necrotized and intralesional bacterial clusters were observed. In this case, there were no other mortalities, so the condition of a single bird, in particular, stress from incubation effort, could act as the predisposing factor for necrotic enteritis. In this study, we report a unique case of necrotic enteritis associated with incubation in a captive mute swan.

• Molecules and Cells
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• v.26 no.1
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• pp.18-25
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• 2008

Arsenic trioxide (ATO) can affect many biological functions such as apoptosis and differentiation in various cells. We investigated the involvement of ROS and GSH in ATO-induced HeLa cell death using ROS scavengers, especially N-acetylcysteine (NAC). ATO increased intracellular ${O_2}^{{\cdot}-}$ levels and reduced intracellular GSH content. The ROS scavengers, Tempol, Tiron and Trimetazidine, did not significantly reduce levels of ROS or GSH depletion in ATO-treated HeLa cells. Nor did they reduce the apoptosis induced by ATO. In contrast, treatment with NAC reduced ROS levels and GSH depletion in the ATO-treated HeLa cells and prevented ATO-induced apoptosis. Treatment with exogenous SOD and catalase reduced the depletion of GSH content in ATO-treated cells. Catalase strongly protected the cells from ATO-induced apoptosis. In addition, treatment with SOD, catalase and NAC slightly inhibited the G1 phase accumulation induced by ATO. In conclusion, NAC protects HeLa cells from apoptosis induced by ATO by up-regulating intracellular GSH content and partially reducing the production of ${O_2}^{{\cdot}-}$.

• Journal of Surface Science and Engineering
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• v.36 no.2
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• pp.148-154
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• 2003

Short ($\tau$=40 $mutextrm{s}$) and high-voltage ($U_{sub}$=2~8 kV) negative substrate bias pulses were used to assist pulsed magnetron sputtering DLC films deposition. Space- and time-resolved probe measurements of the plasma characteristics have been performed. It was shown that in case of high-voltage substrate bias spatial non-uniformity of the magnetron discharge plasma density greatly affected DLC deposition process. By Raman spectroscopy it was found that maximum percentage of s $p^3$-bonded carbon atoms (40 ~ 50%) in the coating was attained at energy $E_{c}$ ~700 eV per deposited carbon atom. Despite rather low diamond-like phase content these coatings are characterized by good adhesion due to ion mixing promoted by high acceleration voltage. Short duration of the bias pulses is also important to prevent electric breakdowns of insulating DLC film during its growth.wth.

• Journal of the Korean Society of Combustion
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• v.11 no.1
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• pp.1-10
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• 2006

Oil-fired power plant usually uses several burners and combustion air is supplied to each burner through the complicated duct which is called windbox. A windbox should be designed to supply combustion air to each burner uniformly but, due to the complicated duct shape, flow distribution in the windbox is unbalanced and non-uniform supplies of combustion air are induced by these unbalanced flows in the windbox. These flow patterns tend to make flame unstable, increase the formation of pollutants and lower the overall combustion efficiency. To prevent these disadvantages, flow patterns in the windbox should be investigated for the uniform flow distribution. In this study, computational simulation method was used to investigate the flow distribution in a windbox and measured the velocities at the exit of burners in a real windbox and model tests to compare with CFD results. The results show two significant flow patterns. One is that the flow rates of each burner are different from each other and this means that all burners operate in different conditions of air to fuel ratio. The other is that the flow distribution at the exit of each burner is not axi-symmetric although the burner shape is axi-symmetric. Additionally some modifications of windbox shape and installation of baffles were proposed to make the uniform flow in the windox.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.1
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• pp.51-55
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• 2000

Purpose : The purpose of this study is to setup a standard treatment protocol in surgical correction of skeletal malocclusion with Angle Class III patients. We asessed the soft tissue changes according to skeletal changes of patients who have undergone orthognathic surgery with bilateral split sagittal ramus osteotomy (BSSRO) and advancing genioplasty. Materials & Methods : The soft tissue change of 9 skeletal Class III patients was assessed after BSSRO and advancing genioplasty. The patient group was skeletal Class III who was surgically treated by BSSRO & advancing genioplasty. The average follow up period is 13 months with the range of 6 and 30 months. All patients have undergone preoperative and postoperative orthodontic treatment. The assessment was devided into two groups. One was antero-posterior relationship and the other was vertical relationship of dimensional changes of soft tissue after orthognathic surgery. Results : In antero-posterior dimensional changes after surgery, the percentage of soft tissue change in comparison to hard tissue was 89%. Vertical ratio after surgery, 86% soft tissue changes were assessed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.12
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• pp.77-82
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• 2015

Ozone is a powerful disinfectant and oxidizing agent, and it is used in a wide range of applications, such as waste water treatment, food processing, etc.. There is also a great potential of using ozone in new emerging medical applications, such as ozone dentistry and ozone oxygen therapy. For these purposes, simple, small, compact and efficient sources of ozone are needed. In this study, in order to increase the current-voltage range of the discharge and to avoid the overheating of the gas in the ozonizer we suggested ozonizer of injection needle and plate electrode type(INP Type) with the gas through the needle. A ozonizer of INP type have been investigated by focusing on ozone concentration and yield according to flow rates and Gap of two electrodes. The results of studies of ozone production for DC corona discharge in oxygen at atmospheric pressure about the ozonizer of INP type. The ozone concentration and the generation yield increased as the gap of two electrodes and gas flow were decreased. Also, when the gap of two electrodes and gas flow with no change, the ozone concentration and generation yield each have variation of direct proportion and inverse proportion with discharge voltage.

• KIEAE Journal
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• v.6 no.2
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• pp.11-18
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• 2006

In this research, Conducting an engineering properties experiment, this study examined basic properties of regional Hwangto. The results of experiments are as followings. 1) This study confirmed that a result of examining lime order for Hwangto and comparison of stimulants, this study confirmed that 28 day's strength promotion is found in case of calcium hydroxide(Ca(OH)2) and calcium chloride(CaCl2) stimulant. Finally, it is known the fact that lime highly improves the weak strength of Hwangtoh. 2) As XRD analysis for proving the strength manifestation principle of Hwangto by regions, CSH figure and CASH figure appeared in each regional Hwangto in all the strength areas. This result could be appeared through hydraulicity from reaction of alkali stimulant and water, and pozzolan reaction(CSH figure) and $Str{\ddot{a}}tlingite$ reaction(CASH figure) by silica (SiO2) ingredient and calcium hydroxide (Ca(OH)2) among ingredients of clay, and alumina(Al2O3). 3) In result of strength analysis, It is knowned that the Gyeongsangdo Hwangto is stronger than the Jeollado Hwangto in reactivity.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2141-2143
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• 2000

In this paper, high concentration yield multi-discharge type ozonizer (MDO) of new discharge type using superposed silent discharge was designed and manufactured, MDO can be consisted with 3 kind of multi discharge type ozonizer (MDO) in accordance with power supply method that supplying power, which has 180[$^{\circ}$] phase difference, to 3 electrodes and double gap. At the moment, discharge characteristics and ozone generation characteristics of each MDO were investigated in accordance with quantity of supplied gas, the number of MDO, and the shapes of each MDO. In result, ozone generation characteristics of 17185[ppm] and 783[g/kWh] were obtained, and when ozone of 17185 [ppm] was in contact with dyeing water waste, decolorization characteristics was excellent, so it confirmed that MDO could be used as water environment improvement facility.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2074-2076
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• 2000

In this paper, RFICP equipment is designed and manufactured with the aid of high frequency discharge to produce uniform plasma with high density and large diameter. And $SF_6$ gas is used to investigate plasma characteristics. The electron density and temperature, potential dependence of $SF_6$ plasma in accordance with its operating pressure, gas flux and input power are measured by the method of Langmuir probe. The etching characteristics of the plasma is researched in accordance with operating pressure, gas flux, input power to apply to Silicon Wafer which is used in the field of semiconductor process. The proposed RFICP equipment, in this paper, has relatively excellent etching characteristics, and is thought to be element of oxidization-sheath etching facility in semiconductor manufacturing process.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1862-1864
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• 2000

Recently diagnostic techniques have been investigated to detect a partial discharge(PD) associated with a dielectric material defect in a high-voltage electrical apparatus. Among the PD measuring method, detecting electromagnetic wave generated by PD is one of the most effective method because PD radiates wide frequency of electromagnetic wave up to UHF. From the above points of view, we have investigated the polarization and distance characteristics of electromagnetic wave radiated by an insertion of solid insulators between needle-plane electrodes in the air. According to the magnitude of applied voltage, the frequency spectrum of radiated electromagnetic waves were increased about under 100(MHz), compared with background noise. The electromagnetic wave magnitude is attenuated about 4$\sim$7.6[dB] at the point 3[m] away from PD.