• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.115_116
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• 2009

IEC 61850 based substation automation system mainly consists of a various of protective and control IEDs. In order to implement the system, All of them should require the performance verification of IEC 61850 communication services for the assurance of interoperability throughout the digital network. This paper shows a research result on the testing method of IEC 61850 control communication interface of IEDs according to IED IEC 61850 conformance test procedures.

• The Korea Journal of Herbology
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• v.20 no.2
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• pp.1-6
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• 2005

Objectives : The purpose of this study is to investigate genetic toxicity of Cervi pantotrichum Cornu herbal acupuncture solution(CPCHA). Methods : In this study, a series of investigation have been carried out to analyze the effects of Cervi pantotrichum Cornu herball acupuncture solution(CPCHA) on colony forming ability of NIH3T3cells, Hela cells and adrenorectal coloncell for genetic toxicity test. Results and Conclusions : From the above results, it is suggested that Cervi pantotrichum Cornu herball acupuncture solution(CPCHA) was limited 0.5-10ug/ml by test. Cervi pantotrichum Cornu herball acupuncture solution(CPCHA) did not exert the protective role to the genetic toxicity in kinds of cell lines used in this study. From these results, Cervi pantotrichum Cornu herbal aqua-acupuncture solution needs further study to prove it's function in cell culture system.

• Toxicological Research
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• v.31 no.1
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• pp.17-23
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• 2015

Excessive manganese (Mn) in the brain promotes a variety of abnormal behaviors, including memory deficits, decreased motor skills and psychotic behavior resembling Parkinson's disease. Hereditary hemochromatosis (HH) is a prevalent genetic iron overload disorder worldwide. Dysfunction in HFE gene is the major cause of HH. Our previous study has demonstrated that olfactory Mn uptake is altered by HFE deficiency, suggesting that loss of HFE function could alter manganese-associated neurotoxicity. To test this hypothesis, Hfe-knockout ($Hfe^{-/-}$) and wild-type ($Hfe^{+/+}$) mice were intranasally-instilled with manganese chloride ($MnCl_2$ 5 mg/kg) or water daily for 3 weeks and examined for memory function. Olfactory Mn diminished both short-term recognition and spatial memory in $Hfe^{+/+}$ mice, as examined by novel object recognition task and Barnes maze test, respectively. Interestingly, $Hfe^{-/-}$ mice did not show impaired recognition memory caused by Mn exposure, suggesting a potential protective effect of Hfe deficiency against Mn-induced memory deficits. Since many of the neurotoxic effects of manganese are thought to result from increased oxidative stress, we quantified activities of anti-oxidant enzymes in the prefrontal cortex (PFC). Mn instillation decreased superoxide dismutase 1 (SOD1) activity in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice. In addition, Hfe deficiency up-regulated SOD1 and glutathione peroxidase activities. These results suggest a beneficial role of Hfe deficiency in attenuating Mn-induced oxidative stress in the PFC. Furthermore, Mn exposure reduced nicotinic acetylcholine receptor levels in the PFC, indicating that blunted acetylcholine signaling could contribute to impaired memory associated with intranasal manganese. Together, our model suggests that disrupted cholinergic system in the brain is involved in airborne Mn-induced memory deficits and loss of HFE function could in part prevent memory loss via a potential up-regulation of anti-oxidant enzymes in the PFC.

• Corrosion Science and Technology
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• v.22 no.2
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• pp.123-130
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• 2023

This study aimed to evaluate corrosion resistance of steel coated with GI and Zn-Al-Mg alloy using cyclic corrosion test (CCT) with electrochemical polarization and impedance measurements. Results showed that the Zn-Al-Mg alloy coated steel had a much higher corrosion rate than GI coated steel in early stages of corrosion. With prolonged immersion, however, the corrosion rate of the Zn-Al-Mg alloy coated steel greatly decreased, mainly owing to a significant decrease in the cathodic reduction reaction and an increase in polarization resistance at the surface. This was closely associated with the formation of protective corrosion products including Zn₅(OH)₈Cl₂·H₂O and Zn₆Al₂(OH)₁₆CO₃. Moreover, when the steel substrate was locally exposed due to mechanical damage, the kinetics of anodic dissolution from the coating layer and the formation of protective corrosion products on the surface of the Zn-Al-Mg alloy coated steel became much faster compared to the case of GI coated steel. This could provide a longer-lasting corrosion inhibition function for Zn-Al-Mg alloy coated steel used in plant farms.

• Corrosion Science and Technology
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• v.6 no.1
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• pp.18-23
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• 2007

DLC coatings have been deposited onto substrate of STS 316L and Ti alloy using r.f. PACVD (plasma-assisted chemical vapor deposition) with a mixture of $C_{6}H_{6}$ and $SiH_{4}$ as the process gases. Corrosion performance of DLC coatings was investigated by electrochemical techniques (potentiodynamic polarization test and electrochemical impedance spectroscopy) and surface analysis (scanning electron microscopy). The electrolyte used in this test was a 0.89% NaCl solution of pH 7.4 at temperature $37^{\circ}C$. The porosity and protective efficiency of DLC coatings were obtained using potentiodynamic polarization test. Moreover, the delamination area and volume fraction of water uptake of DLC coatings as a function of immersion time were calculated using electrochemical impedance spectroscopy. This study provides the reliable and quantitative data for assessment of the effect of substrate on corrosion performance of Si-DLC coatings. The results showed that Si-DLC coating on Ti alloy could improve corrosion resistance more than that on STS 316L in the simulated body fluid environment. This could be attributed to the formation of a dense and low-porosity coating, which impedes the penetration of water and ions.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.3
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• pp.370-378
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• 2019

The hepatic ischemic model has recently been widely used for the epidemiological study of ischemic reperfusion injury. This study was carried out to investigate the protective effect of vanillin, which is known to have antioxidant and anti-inflammatory effects, against hepatic and renal injury using an ischemia-reperfusion rat model, and we also investigated the mechanism related to vanillins' protective effect. The test material was administered at a concentration of 100 mg/kg for 3 days, followed by ligation of the liver for 60 minutes to induce ischemia reperfusion. As control groups, there was a negative control, sham control and ischemia-reperfusion-only ischemia reperfusion control, and the controls groups were compared with the drug administration group. In the vanillin group, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were significantly inhibited compared with the AST and ALT activities of the ischemia-reperfusion group, and histopathological examination showed significant reduction of both inflammation and necrosis. The malondialdehyde (MDA) and superoxide dismutase (SOD) levels were significantly different from the ischemia-reperfusion group. In conclusion, vanillin showed a hepatocyte protective action by alleviating the cellular inflammation and cell necrosis caused by hepatic ischemia-reperfusion, and vanillin mitigated inflammatory changes in the kidney glomeruli and distal tubules. The protective effect is considered to be caused by vanillin's antioxidant function. Further studies such as on cell death and possibly vanillin's same effect on damaged tissue will be necessary for clinical applications such as organ transplantation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.350-366
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• 2016

Objectives: No 3D anthropometric analyses have been conducted for Korean children's faces for the purpose of designing respiratory protective devices. The aim of this study was to develop masks against yellow dust and fine particulates, particularly for children in Korea. Methods: This study utilized a 3D scanning method to obtain 16 facial anthropometric data from children, ages of 5 to 13 years old. A total of 144 boys and girls were recruited from the kindergarten, elementary schools and middle schools in Seoul. With facial dimensions obtained, cluster analysis was performed to categorize them into similar facial groups. For each cluster, an optimal mask was designed and manufactured using a 3D printer. In addition, lung function data were obtained from 62 subjects and compared with those of normal adults. The pulmonary physiological results were subsequently used to suggest a test method for mask certification. Results: Facial shapes were classified into tree clusters: small, medium, and large. The face width and length for the first group were small with high nosal protrusion. The face width and length for the second group were the largest among the three clusters. The third group had the largest angle of nose root - gnathion(n-prn-gn). Age was the most significant variable in the facial dimensions. Children's pulmonary physiological capacity was about 60% of adults' capacity. The results of fit test using the prototype masks developed showed very good fits for children. Conclusions: For Korean children, three mask sizes will be sufficient and practical for providing protection against yellow dust and fine particulates. Anthropometric data obtained using digitalized 3D face analysis can be very effective for designing respiratory devices. 3D images can be accurate and easily measured for multiple dimensions, particularly for curved areas of the face. It is imperative to adopt different test methods for certifying respiratory protective devices for children, since their pulmonary physiological capacity is inferior compared with that of adults.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.1
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• pp.53-62
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• 1990

This experiment was performed to clarify the effects of /sup 60/Co gamma irradiation on secretory function, amylase activity and contents of nucleic acids of parotid gland in rat. Experimental animals were divided into 6th hours, 3rd, 7th, 14th and 28th days after irradiation and control. The experimental animals are singly irradiated with 20Gy (2,000rad) through protective lead block. Secretory function of parotid gland was evaluted by uptake and clearance of /sup 99m/TcO₄. /sup 99m/TcO₄. 0.2μ ci/gm, was injected into peritonium in uptake groups. Rats were sacrified with cervical dislocation after 30 minutes and gland was excised. In the clearance group. pilocarpine nitrate (8㎎/㎏) was intraperitoneally injected at 30 minutes after /sup 99m/TcO₄ injection and rats were sacrified 30 minutes after pilocarpine injection. Radioactivity of excised parotid gland was measured by using of gamma counter and stimulation-secretion coefficients, uptake radioactivity divided by clearance radioactivity, was calculated. Amylase activity and contents of DNA and RNA were determined by spectrophotometry. The results obtained were as follows: 1. In the uptake test, the radioactivity of /sup 99m/TcO₄ per unit weight increase in experimental group except 6th hours group, compared with control groups and showed a peak at 3rd days after irradiation. 2. In the clearance test, the radioactivity of /sup 99m/cO₄per unit weight rose to a peak at 3rd days after irradiation and gradually recovered thereafter. 3. Stimulation-secretion coefficient of parotid gland decreased at 6th hours, 3rd and 7th days after irradiation, and gradually increased. 4. Amylase activity of parotid gland decreased in 3rd and 7th days group, and especially lowest in 3rd days after irradiation. 5. The contents of DNA showed no definite difference in all the experimental groups, but RNA was seemed to decrease with time after irradiation.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.592-596
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• 2004

Corrosion is never avoided in the use of materials with various environments. The underwater hull is normally protected against rusting by several coatings of anti-corrosive paint. The purpose of ICCP(Impressed Current Cathodic protection) system is to eliminate the rusting or corrosion, which occurs on metal immersed in seawater. The anode of ICCP system is controlled by an external DC source with converter. The function of anode is to conduct the protective current into seawater. The proposed algorithm includes the harmonic suppression control strategy and the optimum protection strategy and has tried to test the requirement current density for protection, the influence of voltage, the protection potential. This paper was studied the variation of potential and current density with environment factors, time and velocity, and the experimental results will be explained.

• The Korean Journal of Community Living Science
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• v.18 no.1
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• pp.39-53
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• 2007

The purpose of this study was to determine the characteristics of an experimental protective clothing material with regard to comfort and isolation from the hazardous heavy metals produced in municipal waste incineration. An analysis was conducted on the total concentrations of heavy metals in some parts such as surface, middle layer, and interior for the treated fabric, and the untreated one, and working clothes. We conclude that the processed fabric with charcoal for working clothes showed the least exposure to heavy metals of the three. Working clothes worn by workers during waste incineration were much more contaminated than the untreated and treated materials. The material of working clothes could be chosen according to the function with regard to its original chemical characteristics, which are the proper results of the dyeing process. The processed fabric material has high degrees of moisture regain, thermal insulation, water vapor penetration, and antibacterial function; consequently, it is much more comfortable to wear. The fabric material proposed in this research contributed much more to blocking heavy metal concentrations (such as Cd, Pb, Cu, Cr, Zn, Mn) than did the fabric of working clothes at present. Consequently, we strongly suggest that the material of working clothes be upgraded by adopting the above-mentioned charcoal-processed fabric. Materials of working clothes must be improved to increase comfort and prevent harmful gas, flying dust, and heavy metals from permeating the fabrics.