• Journal of the Korean Electrochemical Society
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• v.13 no.1
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• pp.34-39
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• 2010

This work investigated the effect of anode thickness on the anodic overpotential with $100\;cm^2$ class MCFC single cells. The hydrogen oxidation rate in the molten carbonate is sufficiently high, which may lead to weak relation of overpotential with anode geometrical area. The relation of anode surface area and overpotential was analysed in terms of anode thickness in this work. Steady state polarization, inert gas step addition (ISA), and reactant gas addition (RA) methods were employed to the two cells with 0.77 mm and 0.36 mm thickness of anode. The result represented that the anodic overpotential at the cells were identical. It implied that the anodic overpotential was independent on the electrode thickness within the tested range.

• Journal of Korea Technology Innovation Society
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• v.20 no.1
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• pp.205-238
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• 2017

Display industry in Korea has been rapidly developing over 20 years, now taking the top-class leading position in the world. Nevertheless, many previous studies have mainly focused on major panel set makers. To overcome the drawbacks, this study focuses on supplier companies in the upstream of display industry such as materials, components, and equipments sectors. The research method used in this study is an industry value chain perspective combined with architectural innovation approach. Display panel is produced through fabrication process and modular process, each having a different characteristics of process architecture. This research figured out that there are quite a different development characteristics between materials and components suppliers and equipment suppliers. The number and revenue of materials and components suppliers were quite larger than equipments suppliers. However, the former has been growing mainly in the field of modular process, having a very weak position in the field of fabrication process. On the contrary, equipments suppliers have been showing a continuously growing pattern in the field of fabrication process. The R&D expenditures between these two kinds of suppliers showed a similar pattern. The fabrication process of display panel production is characterized as a highly integral architecture characteristics, so as to be a strong barriers to local suppliers, resulting less development of materials and components suppliers in Korea.

• IMMUNE NETWORK
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• v.2 no.4
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• pp.248-255
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• 2002

Background: TAP1 and TAP2 are two ABC transporter genes located within the class II region of the human MHC. Their protein products form a heterodimer whose function is to transport peptides from the cytoplasm into the endoplasmic reticulum. This study was performed to examine the polymorphism of TAP genes and the distribution of HLA-TAP haplotypes in the Korean population through family analysis. Methods: The subjects used in this study were 50 healthy Korean families consisting of 233 individuals. TAP1 (codons 333 and 637) and TAP2 (codons 379, 565, 577, 651, 665, and 687) typings were carried out by the PCR-restriction fragment length polymorphism (RFLP) method. HLA-DRB1 and DQB1 genotyping results from a previous study were used for HLA-TAP haplotype analysis. Results: The number (gene frequency) of TAP1 and TAP2 alleles detected were 3 for TAP1 (A 81.5%, B 17.0%, and C 1.5%) and 8 for TAP2 (A1 32.0%, A2 12.5%, B 34.0%, Bky2 6.5%, C 7.0%, D 3.0%, E 4.5%, and G 0.5%). Eleven TAP1-TAP2 haplotypes were observed with $frequency{\geq}1%$, among which 4 haplotypes (A-B, B-A1, A-Bky2, and C-E) showed weak but significant positive linkage disequilibrium (P<0.05). When DRB1-DQB1 haplotypes were extended to TAP1 and TAP2 loci, much diversification of haplotypes was observed: 19 different DRB1-DQB1 haplotypes formed 58 different haplotypes extended to TAP1 and TAP2 loci. These results add more evidence to the view that recombination hotspot is present within and around TAP gene region. Conclusion: The allele frequencies of TAP1 and TAP2 genes and the distribution of TAP1-TAP2 and HLA-TAP haplotypes were studied in Koreans based on a family study.

• Journal of the Korean GEO-environmental Society
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• v.23 no.2
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• pp.5-12
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• 2022

In this study, a field test was conducted to present a test method for performance evaluation of a rock fall prevention fence, centering on the vertical drop test among the existing test methods of the rock fall prevention fence. A test to determine the support capacity of a rockfall prevention fence in Korea is usually conducted using a combination of wire mesh, poles, and wire rope, and the location of the impact of falling rocks has been conducted centered on the center of the wire mesh. However, in the case of domestic papers and test data, there is no data on direct hit of post. Therefore, the amount of displacement and weak section were analyzed when the impact on 100kJ class rock energy was hit on the post, centering on the Rockfall Protection fence (highway type No. 2).

• Toxicological Research
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• v.24 no.2
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• pp.151-159
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• 2008

Rhus verniciflua Stokes(RVS), one of traditional medicinal plants in Asia, was found to have pharmacological activities such as antioxidative and antiapoptotic effects, raising the possibility for the development of a novel class of anti-cancer drugs. Thus, potential genotoxic effects of RVS in three short-term mutagenicity assays were investigated, which included the Ames assay, in vitro Chromosomal aberration test, and the in vivo Micronucleus assay. In Ames test, the addition of RVS water extracts at doses from 313 up to 5000 mg/plate induced an increase more than 2-fold over vehicle control in the number of revertant colonies in TA98 and TA1537 strains for detecting the frame-shift mutagens. The similar increase in reversion frequency was observed after the addition of RVS ethanol extracts. To assess clastogenic effect, in vitro chromosomal aberration test and in vivo micronucleus assay were performed using Chinese hamster lung cells and male ICR mice, respectively. Both water and ethanol extracts from RVS induced significant increases in the number of metaphases with structural aberrations mostly at concentrations showing the cell survival less than 60% as assessed by in vitro CA test. Also, there was a weak but statistically significant increase in number of micronucleated polychromatic erythrocytes(MNPCEs) in mice treated with water extract at 2000 mg/kg while ethanol extracts of RVS at doses of up to 2000 mg/kg did not induce any statistically significant changes in the incidence of MNPCEs. Therefore, our results lead to conclusion that RVS acts as a genotoxic material based on the available in vitro and in vivo results.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.1
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• pp.35-43
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• 1997

Handling the emergency problems such as Chemobyl accident require real time prediction of pollutants dispersion. One-point real time sounding at pollutant source and simple model including turbulent-radiation process are very important to predict dispersion at real time. The stability categories obtained by one-dimensional numerical model (including PBL dynamics and radiative process) are good agreement with observational data (Golder, 1972). Therefore, the meteorological parameters (thermal, moisture and momentum fluxes; sensible and latent heat; Monin-Obukhov length and bulk Richardson number; vertical diffusion coefficient and TKE; mixing height) calculated by this model will be useful to understand the structure of stable boundary layer and to handling the emergency problems such as dangerous gasses accident. Especially, this simple model has strong merit for practical dispersion models which require turbulence process but does not takes long time to real predictions. According to the results of this model, the urban area has stronger vertical dispersion and weaker horizontal dispersion than rural area during daytime in summer season. The maximum stability class of urban area and rural area are 'A' and 'B' at 14 LST, respectively. After 20 LST, both urban and rural area have weak vertical dispersion, but they have strong horizontal dispersion. Generally, the urban area have larger radius of horizontal dispersion than rural area. Considering the resolution and time consuming problems of three dimensional grid model, one-dimensional model with one-point real sounding have strong merit for practical dispersion model.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.5
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• pp.429-438
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• 2003

The effects of fiber orientation on acoustic emission(AE) characteristics have been studied for the unidirectional and satin-weave, continuous glass-fiber reinforced plastic(UD-GFRP and SW-GFRP) tensile specimens. Reflection and transmission optical microscopy was used for investigation of the damage zone of specimens. AE signals were classified as different types by using short time fourier transform(STFT) : AE signals with high intensity and high frequency band were due to fiber fracture, while weak AE signals with low frequency band were due to matrix and interfacial cracking. The feature in the rate of hit-events having high amplitudes showed a process of fiber breakages, which expressed the characteristic fracture processes of individual fiber-reinforced plastics with different fiber orientations and with different notching directions. As a consequence, the fracture behavior of the continuous GFRP could be monitored as nondestructive evaluation(NDE) through the AE technique.

• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.330-342
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• 2020

Since the original report on ferroelectricity in Si-doped HfO2 in 2011, fluorite-structured ferroelectrics have attracted increasing interest due to their scalability, established deposition techniques including atomic layer deposition, and compatibility with the complementary-metal-oxide-semiconductor technology. Especially, the emerging fluorite-structured ferroelectrics are considered promising for the next-generation semiconductor devices such as storage class memories, memory-logic hybrid devices, and neuromorphic computing devices. For achieving the practical semiconductor devices, understanding polarization switching kinetics in fluorite-structured ferroelectrics is an urgent task. To understand the polarization switching kinetics and domain dynamics in this emerging ferroelectric materials, various classical models such as Kolmogorov-Avrami-Ishibashi model, nucleation limited switching model, inhomogeneous field mechanism model, and Du-Chen model have been applied to the fluorite-structured ferroelectrics. However, the polarization switching kinetics of fluorite-structured ferroelectrics are reported to be strongly affected by various nonideal factors such as nanoscale polymorphism, strong effect of defects such as oxygen vacancies and residual impurities, and polycrystallinity with a weak texture. Moreover, some important parameters for polarization switching kinetics and domain dynamics including activation field, domain wall velocity, and switching time distribution have been reported quantitatively different from conventional ferroelectrics such as perovskite-structured ferroelectrics. In this focused review, therefore, the polarization switching kinetics of fluorite-structured ferroelectrics are comprehensively reviewed based on the available literature.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.134-140
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• 2023

Activated carbon is a carbonaceous material mainly used as a gaseous or liquid adsorbent. As fire-related accidents occur consistently due to the accumulation of heat of adsorption and oxidation of volatile organic compounds, the explosive characteristics and thermal stability of powdered and granular activated carbon made from coal and coconut shells were evaluated. As a result of the particle size analysis, the powdered activated carbon was in the particle size range (0.4~3) ㎛, and thermal properties such as exothermic onset temperature and decomposition behavior were analyzed using a differential scanning calorimetry and a thermogravimetric analysis. As a result of the evaluation of the explosion hazards for dust, both coal-based and coconut-based powdered activated carbon are classified as St1 class with weak explosion, but this is a relative and does not mean that the explosion hazards is absolutely low. Therefore, it is necessary to establish countermeasures for reducing the damage.

• Reproductive and Developmental Biology
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• v.41 no.3
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• pp.57-63
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• 2017

Xenotransplantation is proposed as a solution to the problem of organ shortage. However, transplantation of xenogeneic organs induces an antigen-antibody reaction in ${\alpha}$-1,3-gal structure that are not present in humans and primates, and thus complement is also activated and organs die within minutes or hours. In this study, we used FasL gene, which is involved in the immune response of NK cell, and US11, which suppresses MHC Class I cell membrane surface expression, to inhibit cell mediated rejection in the interspecific immunity rejection, and also hDAF(CD55) was introduced to confirm the response to C3 complement. These genes were tranfeced into Korean native pig fetal fibroblasts using pCAGGS vector. And cytotoxicity of NK cell and human complement was confirmed in each cell line. The US11 inhibited the cytotoxicity of NK cell and, in addition, the simultaneous expression of US11 and Fas ligand showed excellent suppress to T-lymphocyte cytotoxicity, hDAF showed weak resistance to cytotoxicity of natural killer cell but not in CD8+ CTLs. Cytotoxicity study with human complement showed that hDAF was effective for reducing complement reaction. In this studies have demonstrated that each gene is effective in reducing immune rejection.