• 한국안전학회지
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• 제13권4호
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• pp.206-212
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• 1998

The water permeation in protective coatings, which may greatly influence the corrosion protective property of these coatings, was studied using the electrochemical impedance spectroscopy technique. During the absorption of water in protective coatings immersed in electrolyte solution, the change of coating capacitance with concentration of electrolyte was determined from impedance measurements. When water absorption or desorption of coatings occured by exposing the coatings to electrolyte solutions of different concentration, increase in impedance caused by desorption of water was found to be higher in the case of thicker film. The amount of water absorbed in coatings changed with concentration of electrolyte. The water taken up in coatings from the solution of lower electrolyte concentration was deserted by contact with the solution of higher concentration. The uptake of water in protective coatings varied depending on the type of coating ingredient especially binder.

• 조명전기설비학회논문지
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• 제28권9호
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• pp.83-88
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• 2014

When DG interconnection into network is examined, details of the review are overvoltage, protective device malfunction, etc. In the case of protective device malfunction, replacing protective device into bi-directional protective device and installation NGR are the solution. Overvoltage at interconnection point occurs because the load is relatively less than DG output. When overvoltage at interconnection point occurs, DG interconnection is not permitted because this overvoltage affect other customers. Interconnection by installation new distribution line is one solution but it costs much money. Without installation new investment, change of NOP(Normal Open Point) position is a possible solution about DG interconnection into network.

• Journal of Yeungnam Medical Science
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• 제23권1호
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• pp.19-25
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• 2006

심실중격결손이나 심방중격결손과 같이 대동맥 차단시간이 길지 않은 질환에 있어서는 HTK용액의 심근보호효과가 냉혈심정지액과 비슷한 효과를 가짐을 알 수 있었다. 따라서 한번 투여로 2~3시간의 수술이 가능한 장점을 가진 HTK용액을 소아에서도 유용하게 사용할 수 있을 것으로 생각되며 향후 복잡심기형과 같은 긴 대동맥차단이 요구되는 소아환자의 안정성에 대해서는 더 많은 연구가 필요할 것으로 생각된다.

• 대한약침학회지
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• 제8권3호
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• pp.57-69
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• 2005

Objectives : Neurological disorders have been one of main therapeutic targets of acupuncture. The present study investigated the protective effects of Gwakhyangjeonggisan herbal acupuncture solution (GHAS). Methods : We performed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in glioblastoma cells, and did microarray analysis with cells exposed to reactive oxigen species (ROS) of hydrogen peroxide by 8.0 k Human cDNA, with cut-off level of 2-fold changes in gene expression. Results : MTT assay showed protective effect of GHAS on the glioblastoma cells exposed to hydrogen peroxide. When glioblastoma cells were exposed to hydrogen peroxide, 24 genes were downregulated. When the cells were pretreated with GHAS before exposure to hydrogen peroxide, 46 genes were downregulated. Many of the genes downregulated by hydrogen peroxide stimulation were decreased in the amount of downregulation or reversed to upregulation. Conclusions : The gene expression changes observed in the present study are supposed to be related to the protective molecular mechanism of GHAS in the glioblastoma cells exposed to ROS stress.

• Journal of Chest Surgery
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• 제27권10호
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• pp.815-823
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• 1994

This study was undertaken to hemodynamically determine the differences of myocardial protective effect between crystalloid and blood cardioplegic solution. Twenty nine children undergoing cardiac operations due to cyanotic congenital heart diseases were randomized into two groups receiving crystalloid or blood cardioplegia. Cardiac indices and other hemodynamic datum were examined postoperatively. Although there was no statistical differences between groups, postoperative stroke volume indices and left ventricular stroke work indices were slightly better with blood cardioplegia. We also found that postoperative left atrial pressures[p=0.0003], central venous pressures[p=0.004], and heart rates[p=0.014] were significantly lower with blood cardioplegia. The fact that relatively lower ventricular preloads [left atrial pressure and central venous pressure] were required to provide adequate cardiac output in blood cardioplegia group suggested superior myocardial protective effect of blood cardioplegic solution.

• Journal of Acupuncture Research
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• 제22권6호
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• pp.111-123
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• 2005

Objectives : Neurological disorders have been one of main therapeutic targets of acupuncture. The present study investigated the protective effects of Gwakhyangjeonggisan herbal acupuncture solution (GHAS). Methods : We performed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in glioblastoma cells, and did microarray analysis with cells exposed to reactive oxigen species (ROS) of hydrogen peroxide by 8.0 k Human cDNA, with cut-off level of 2-fold changes in gene expression. Results : MTT assay showed protective effect of GHAS on the glioblastoma cells exposed to hydrogen peroxide. When glioblastoma cells were exposed to hydrogen peroxide, 16 genes were upregulated. When the cells were pretreated with GHAS before exposure to hydrogen peroxide, 22 genes were upregulated. Most of the genes upregulated by hydrogen peroxide stimulation were reversed to downregulation by GHAS. Conclusion : The gene expression changes observed in the present study are supposed to be related to the protective molecular mechanism of GHAS in the glioblastoma cells exposed to ROS stress.

• 풍력에너지저널
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• 제14권3호
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• pp.43-53
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• 2023

To improve AEP, wind turbine blade lengths are increasing every year. As the length of blades increases, the blade tip speed also increases. Because of the increased tip speed, the impact energy between the leading edge and raindrops also increases. The increased impact energy is the primary factor contributing to erosion of the blade's leading edge. Blade leading edge erosion reduces aerodynamic performance, increases repair costs, and causes downtime. Therefore, numerous studies are being conducted on protective solutions and RET systems to prevent and delay erosion of the blade's leading edge. However, few institutions in Korea research protective solutions and RET systems. In this study, we aim to develop a laboratory-scale RET system. The developed RET system was based on the ASTM G73-10 standard. As a result of the RET, it was confirmed that the erosion tendency was similar to that of overseas institutions. In addition, the effectiveness of the RET system was verified by a maximum erosion rate of 0.0023 for an epoxy-based protective solution.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.67-68
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• 2002

The properties and mechanism of silicon protuberance and groove processing by diamond tip sliding using atomic force microscope (AFM) in atmosphere were studied. To control the height of protuberance and the depth of groove, the processed height and depth depended on load and diamond tip radius were evaluated. Nanoprotuberances and grooves were fabricated on a silicon surface by approximately 100-nm-radius diamond tip sliding using an atomic force microscope in atmosphere. To clarify the mechanical and chemical properties of these parts processed, changes in the protuberance and groove profiles due to additional diamond tip sliding and potassium hydroxide (KOH) solution etching were evaluated. Processed protuberances were negligibly removed, and processed grooves were easily removed by additional diamond tip sliding. The KOH solution selectively etched the unprocessed silicon area. while the protuberances, grooves and flat surfaces processed by diamond tip sliding were negligibly etched. Three-dimensional nanofabrication is performed in this study by utilizing these mechanic-chemically processed parts as protective etching mask for KOH solution etching.

• Journal of Chest Surgery
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• 제23권1호
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• pp.9-15
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• 1990

This study was designed to investigate the protective effect of chlorpromazine against the reperfusion injury of myocardium after high potassium cardioplegic arrest. Langendorff`s preparations of rat heart were infused with high potassium cardioplegic solution[St. Thomas Hospital Solution] at 25oC. Chlorpromazine [10-7Ｍ] increased the recovery of myocardial contractility[dp/dt], left ventricular pressure[LVP], and coronary flow rate of the reperfused heart. Both in control and experimental groups, the restoration of myocardial activity could not reach to the level of preplegic control. These results suggest that the etiologic factors of the reperfusion injury include the influence of high potassium cardioplegic solution and/or reperfusion itself, and that chlorpromazine protects myocardium from the reperfusion injury.

• 월간포장계
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• 통권354호
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• pp.68-73
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• 2022