• Journal of the Korean GEO-environmental Society
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• v.12 no.1
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• pp.71-80
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• 2011

In period of rapid economic development, as doing river conservation work by using harmful materials environmental pollution has adversely effected humans, animals and plants frequently. For recovery of environmental pollution it needs a lot of time and cost. Therefore, in this study, in order to take an environment-friendly method which is also economical and durable both results of the laboratory model test and field test were compared and analyzed. According to the results of the laboratory model test, those methods such as concrete paving, asphalt paving, bentonite mat, stabilized soil method and mixed soil method have small amount of seepage, but on the other hand compaction soil, grassland and permeable materials have considerable amount of seepage. The results of field test show a similar tendency with laboratory test and have been satisfied to assess standard of domestic water permeability below $1.0{\times}10^{-7}cm/sec$ and unconfined compressive strength is also than 1.0MPa so it has been satisfied about standard. In conclusion, as compaction rate increased, as unconfined compression strength increased and coefficient of permeability decreased.

• Journal of the Korean GEO-environmental Society
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• v.12 no.9
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• pp.13-20
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• 2011

There are many mountains in Korean Peninsula, and those used for the construction of roads and railways sectors are forming slopes. Slope collapse occurs with falling rocks and landslide because of the relaxation of the thawing rocks. The heavy rain in summer can also significantly contribute to the process, and abnormal climate change is much more influential than before. Therefore, rockfall-related accidents in rainy season are easily accessible in media every year. There has been a lot of research on application of strengthening compensation of the sections in order to minimize casualties and property damage. Rockfall Protection Net, however, has not been focused on much in the field yet. This study highlights the need of Rockfall Protection Net, since it can segregate the falling rocks inside the net relatively safely. Although there has been a little doubt about the effectiveness of rockfall protection facilities, it is obvious that relevant studies dealing with the solidity of the net are necessary for the rockfall protection net to be capable of supporting rockfall energies. As a result, Expanded metal strength is much more durable compared to the PVC coating net, and it is regarded as an excellent alternative material for the Rockfall Protection Net. In this study, the applicability of Expanded Metal as the alternative of Rockfall Protection Net is verified experimentally.

• Korean Journal of Labor Studies
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• v.23 no.2
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• pp.1-45
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• 2017

This study aims at explaining organizational mechanisms of inequality that has been rising rapidly alongside the proliferation of irregular employment in the post-crisis Korean labor market. It argues that inequality is not sufficiently explained by individual gap in human capital or widespread marketization as such. Social categories into which each individual worker falls seems more important as a source of labor market inequality. Employment types that are composed of regular and irregular employment do not simply indicate the different economic meanings of employment contracts but have rather been institutionalized as a social category of status in the context of inequality over the past two decades. They are also often matched with other social categories such as gender that have created and reproduced greater labor market inequality. We pay attention to the organizational practice of dominant incumbents who make claims for advantages of return based on their exclusive accessibility to limited organizational resources and explain how that particular practice plays a role to increase relational inequality between those insiders who achieve advantageous returns and outsiders mostly irregular workers who are excluded from those resources because of the social categories that they belong to. In this study, we identify seniority based pay as the key organizational practice that justifies categorical differences within the workplace and examine how that particular practice contributes to organizational level segmentation and income ineqaulity.

• Journal of Chest Surgery
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• v.54 no.2
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• pp.99-105
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• 2021

Background: The number of heart transplantations (HTx) is increasing annually. Due to advances in medical and surgical support, the outcomes of HTx are also improving. Extracorporeal circulatory life support (ECLS) provides patients with decompensated heart failure a chance to undergo HTx. A medical approach involving collaboration among experienced experts in different fields should improve the outcomes and prognosis of ECLS-bridged HTx. Methods: From December 2003 to December 2018, 1,465 patients received ECLS at Samsung Medical Center. We excluded patients who had not undergone HTx or underwent repeated transplantations. Patients younger than 18 years were excluded. We also excluded patients who received an implantable durable left ventricular assist device before HTx. In total, 91 patients were included in this study. A multidisciplinary team approach began in March 2013 at our hospital. We divided the patients into 2 groups depending on whether they were treated before or after implementation of the team approach. Results: The 30-day mortality rate was significantly higher in the pre-ECLS team group than in the post-ECLS team group (n=5, 18.5% vs. n=2, 3.1%; p=0.023). The 1-year survival rate was better in the post-ECLS team group than in the pre-ECLS team group (n=57, 89.1% vs. n=19, 70.4%; p=0.023). Conclusion: We found that implementing a multidisciplinary team approach improved the outcomes of ECLS-bridged HTx. Team-based care should be adapted at HTx centers that perform high-risk HTx.

• Biomolecules & Therapeutics
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• v.30 no.6
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• pp.529-539
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• 2022

Rheumatoid arthritis (RA) is a multifactorial immune-mediated disease, the pathogenesis of which involves different cell types. T-cell activation plays an important role in RA. Therefore, inhibiting T-cell activation is one of the current therapeutic strategies. Cytotoxic T-lymphocyte antigen 4-immunoglobulin (CTLA4-Ig), also known as abatacept, reduces cytokine secretion by inhibiting T-cell activation. To achieve a homeostatic therapeutic effect, CTLA4-Ig has to be administered repeatedly over several weeks, which limits its applicability in RA treatment. To overcome this limitation, we increased the number of sialic acid-capped antennas by genetically engineering the CTLA4 region to increase the therapeutic effect of CTLA4-Ig. N-acetylglucosaminyltransferase (GnT) and α2,6-sialyltransferase (α2,6-ST) were co-overexpressed in Chinese hamster ovary (CHO) cells to generate a highly sialylated CTLA4-Ig fusion protein, named ST6. The therapeutic and immunogenic effects of ST6 and CTLA4-Ig were compared. ST6 dose-dependently decreased paw edema in a mouse model of collagen-induced arthritis and reduced cytokine levels in a co-culture cell assay in a similar manner to CTLA4-Ig. ST6- and CTLA4-Ig-induced T cell-derived cytokines were examined in CD4 T cells isolated from peripheral blood mononuclear cells after cell killing through irradiation followed by flow- and magnetic-bead-assisted separation. Interestingly, compared to CTLA4-Ig, ST6 was substantially less immunogenic and more stable and durable. Our data suggest that ST6 can serve as a novel, less immunogenic therapeutic strategy for patients with RA.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.661-666
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• 2022

This study presented the criteria for analyzing the corrosion of the powder extinguisher storage container according to the useful life, and conducted an experiment on the market area, the factory area, and the apartment building area to ensure proper performance at all times and drew the following conclusions.First, the experimental value for the degree of corrosion of external contact storage containers was found to be unsuitable in the factory area in 2014. In 2012, the experimental value for the degree of corrosion of external contact storage containers in apartment complexes was found to be inappropriate. Second, the experimental value for the dropout of the external paint in the storage container was found to be inappropriate in the factory area in 2014. In 2012, the experimental value of the degree of coating of the external paint storage container in the apartment building area was found to be inappropriate. It was analyzed that the useful life of the fire extinguisher is 10 years, and if it passes the sample test only once, it will be used for up to 13 years, but in fact, the difference varies greatly depending on the surrounding environment of the fire extinguisher place. Since the degree of corrosion of the storage container of the fire extinguisher from 8 years of the fire extinguisher's useful life is clearly decreased, it is judged that 5 years of the fire extinguisher is appropriate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.1-6
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• 1985

This experiment was designed to determine the effect of light quality on the appearance of photobleaching leaves during the cure of Burley Tobacco. The harvested and browned tobacco leaves were exposed to sunlight in pipe houses covered with 8 kinds of color vinyls (white, red, black, yellow, purple, orange, blue, green), and exposed to ultraviolet rays(20W x 3) and infrared rays (150W x 2) in curing chamber (1.2 x 1.2 x 1.2m). Photobleaching occured more at lower position leaf and after the leaves being browned when the curing was done in sunlight under a transparent vinyl. But photobleaching leaves were 5-6% of total cured leaves in sunlight under all kinds of color vinyl houses. It seems that photobleaching mainly induced by ultrabiolet rays of sunlight, and humidity too influenced. Yellow, orange and purple vinyl were durable and effective as shading material of color vinyls. since white and red vinyl tore easily in two monthes in strong sunlight and under black and blue vinyl houses curing period was longer than others.

• Membrane Journal
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• v.32 no.6
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• pp.442-455
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• 2022

High-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) has been studied as an alternative to low-temperature PEMFC due to its fast activation of electrodes and high resistance to electrode poisoning by carbon monoxide. It is highly required to develop stable PEMs operating at high temperatures even doped by ion-conducting materials for the development of high-performance and durable HT-PEMFC systems. A number of studies have been conducted to develop polybenzimidazole (PBI)-based PEMs for applications in HT-PEMFC due to their high interaction with doped ion-conducting materials and outstanding thermomechanical stability under high-temperature operation. This review focused on the development of PBI-based PEMs showing high performance and durability. Firstly, the characteristic behavior of PBI-based PEMs doped with various ion-conducting materials including phosphoric acid was systematically investigated. And then, a comparison of the physicochemical properties of the PEMs according to the different membrane manufacturing processes was conducted. Secondly, the incorporation of porous polytetrafluoroethylene substrate and/or inorganic composites to PBI matrix to improve the membrane performances was studied. Finally, the construction of cross-linked structures into PBI-based PEM systems by polymer blending method was introduced to improve the PEM properties.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.1
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• pp.79-89
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• 2023

Development of efficient and stable electrocatalysts for oxygen evolution reaction (OER) under acidic conditions is desirable goal for commercializing proton exchange membrane (PEM) water electroyzer. Herein, we report iridium-doped hydrogenated titanate (Ir-HTO) nanobelts as a promising catalyst with a low-Ir content for the acidic OER. Addition of low-Ir (~ 3.36 at%) into the single-crystalline HTO nanobelts with large exposed {100} facets significantly boost catalytic activity and stability for OER under acidic conditions. The Ir-HTO outperforms the commenrcial benchmark IrO₂ catalyst; an overpotential for delivering 10 mA cm^-2 current density was reduced to about 25% for the Ir-HTO. Moreover, the catalytic performance of Ir-HTO is positioned as the most efficient electrocatalyst for the acidic OER. An improved intrinsic catalytic activity and stability are also confirmed for the Ir-HTO through in-depth electrochemical characterizations. Therefore, our results suggest that low-Ir doped single-crystalline HTO nanobelts can be a promising catalyst for efficient and durable OER under acidic conditions.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.89-96
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• 2018

The object of this study was to evaluate the change of antibody titers on virus strains after inoculation with commercial killed equine influenza (EI) vaccines in horses. Serum antibodies of 20 Thoroughbred yearlings were detected using hemagglutination inhibition test for 41 weeks. Second vaccination is inoculated 4 weeks after the initial vaccination. Most of antibody titers were not increased until 4 weeks after first vaccination. The highest titers were detected 6-10 weeks after vaccination. The titers were decreased slowly and maintained for 16 weeks after inoculation. We could barely detect the antibody 41 weeks after vaccination in most cases. Vaccine anergia were appeared in 3 horses (15%) but it depended on virus strains. A/Equine/La Plata/93(H3N8) strain that induce high and durable antibody responses was the most effective among three strains. This study presents the first comprehensive data on the endurance of antibody titers against EI. Our data also suggests that yearlings should be inoculated three times in order to maintaining optimal antibody titers against EI. We speculate the causes of anergia were vaccine break down or individual specificity. Further research is needed to investigate immunological unresponsiveness. This was the first study on strain of equine vaccine in Korea.