• Membrane Journal
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• v.16 no.2
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• pp.106-114
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• 2006

This study is concerned with preparation of chlorine resistant (CR) thin layer composite (TFC) membranes. The novel method for making CR membranes from commercially available RO membranes is based on sol-gel condensation of trialkoxyalkylsilane derivatives. The silane coupling agents used in this study have different number of alkyl carbon chain group (methyltriethoxysilane; METES and octyltriethoxysilane; OCTES). The OCTES composite membranes have a significant tolerance to chlorine compared to commercial polyamide RO membrane or METES composite membranes. The surface properties of membranes were examined to explain a significant difference of chlorine tolerance between OCTES composite membrane and the other two membranes. In this study, we tried several surface analyses to explain difference of chlorine tolerance. The element composition results of surface analysis by EDX confirmed that both silane fixed on polyamide firmly, The surface roughness and contact angle results showed long chain alkyl group of OCTES enhancing hydrophobicity considerably than METES. The hydrophobicity plays an important role in chlorine resistance of membrane.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.152-162
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• 2005

Coolant rubber hoses for automobile radiators can be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under the thermal and mechanical loadings. In this study, test analysis was carried out for evaluating the degradation and failure mechanisms of coolant hose materials. Two kinds of EPDM rubber materials applicable to the hoses were adopted: commonly-used ethylene-propylene diene monomer(EPDM) rubbers and EPDM rubbers with high resistance against electro-chemical degradation (ECD). An increase of surface hardness and a large reduction of failure strain were shown due to the formation of oxidation layer for the specimens which had been kept in a high temperature air chamber. Coolant ageing effects took place only by an amount of pure thermal degradation. The specimens degraded by ECD test showed a swelling behavior and a considerable increase in weight on account of the penetration of coolant liquid into the skin and interior of the rubber specimens. The ECD induced material softening as well as drastic reduction in strength and failure strain. However EPDM rubbers designed for high resistance against ECD revealed a large improvement in reduction of failure strain and weight. This study finally established a procedure for reliability analysis and evaluation of the degradation and failure mechanisms of EPDM rubbers used in coolant hoses for automobile radiators.

• Journal of the Korean Geosynthetics Society
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• v.18 no.2
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• pp.45-54
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• 2019

This paper describes the results of finite element analysis (FEA), in order to investigate a characteristics of pile pullout behavior according to the conditions of the relative density and fines content in original ground. In the FEA, a boundary elements and strength reduction factors ($R_{inter}$) on pile-soil interface were applied to simulate appropriately the shear behavior at the pile-soil interface, and then the reliability of numerical analysis method was verified by comparison of FEA results and previous experimental research(You et al., 2018). In addition, a the deformation characteristics at the pile-soil interface and determination method of $R_{inter}$ value was laid out. The results showed that the FEA, based on the analytical model applied in this study simulates appropriately the characteristics of the pile-soil interface by pullout model test of pile. In order to apply the suggested $R_{inter}$ value, it is necessary to consider the condition of the relative density and the fines content in ground.

• Journal of English Language & Literature
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• v.55 no.5
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• pp.907-936
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• 2009

Quite arguably, W. E. B. Du Bois is the first figure in the history of black nationalism who engaged most persistently and systematically with the dominant ideology of racism and white supremacy. It is not too much to say that, by contending with the Eurocentric but taken-for-granted concept of the 'Negro' in the turn of the century, Du bois has laid the theoretical and ideological cornerstone of postcolonialism today. But his concept of race varied over time and was even contradictory in the same writings. The early Du Bois defined race as something historically made rather than biologically given and determined. Yet he didn't utterly deny the significance of physical traits and skin color in constructing racial identity. His notion of the 'Negro' was not unambiguous, either. While drawing on the 'soul' of 'black folk' to undermine the Eurocentric dichotomy of white/mind and black/body, Du Bois argued that there is some kind of 'spiritual' differences between whites and blacks, differences that are essentially inherent and hereditary in the 'Negro.' Such essentialist notion of race and the 'Negro' was on the wane in the later Du Bois, especially after his encounter with Marxism. He came to think of race merely as a discourse of racism that can be subverted and even appropriated for anti-racist practices. Following the Marxist assumption that 'the color line' is a class conflict on the international level, Du Bois contended that the 'Negro' is an outcome of slavery which is in turn a subsystem of Western capitalism. He also argued that, since the 'Negro' is not a biological essence but a sociocultural formation, the identity of the 'Negro' can and must be reconstructed according to historical change. For Du Bois, therefore, the resistance against colonialism and capitalism became a resistance against racism. This is why his Pan-African movement shifted its gear from the American program in the initial phase to a truly 'Afrocentric' and socialist one.

• Journal of Veterinary Science
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• v.24 no.6
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• pp.85.1-85.13
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• 2023

Background: A recent increase in the occurrence of canine skin and soft tissue infections, including otitis externa and pyoderma, caused by antimicrobial-resistant Staphylococcus pseudintermedius and S. schleiferi has become a significant public and veterinary health issues. Objective: We investigated the virulence potentials associated with the occurrence of canine otitis externa in S. pseudintermedius and S. schleiferi. Methods: In this study, the prevalence of genes encoding leukocidins, exfoliative toxins, and staphylococcal enterotoxins (SEs) was investigated using previously characterized S. pseudintermedius (n = 26) and S. schleiferi (n = 19) isolates derived from canine otitis externa. Susceptibility to cathelicidins (K9CATH and PMAP-36) and hydrogen peroxide (H₂O₂) was also examined in both staphylococcal species. Results: A high prevalence of genes encoding leukocidins (lukS/F-I, lukS1/F1-S, and lukS2/F2-S), exfoliative toxins (siet, expB, and sset), and SEs was identified in both S. pseudintermedius and S. schleiferi isolates. Notably, S. pseudintermedius isolates possessed higher number of SE genes, especially newer SE genes, than S. schleiferi isolates harboring egc clusters. Although no significant differences in susceptibility to K9CATH and H₂O₂ were observed between the two isolate groups, S. pseudintermedius isolates exhibited enhanced resistance to PMAP-36 compared to S. schleiferi isolates. Conclusions: These findings suggest that high a prevalence of various toxin genes together with enhanced resistance to cathelicidins may contribute to the pathogenicity of S. pseudintermedius and S. schleiferi in canine cutaneous infections.

• Journal of the Korean Geotechnical Society
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• v.36 no.7
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• pp.15-28
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• 2020

As the skin friction of an embedded pile is produced by the cement paste injected into the borehole, the skin friction cannot be evaluated by the end of initial driving test, which is conducted before the cement paste is cured. In addition, the total resistance of an embedded pile may not be properly evaluated during the restrike test if the base resistance is not fully mobilized because of the insufficient driven energy. The objective of this study is to suggest a new load-settlement curve of embedded piles by combining the results of the end of initial driving and restrike tests. Test piles are installed at fields by using the embedded pile method, and the results of the dynamic pile tests are analyzed using CAse Pile Wave Analysis Program (CAPWAP) after the end of initial driving and restrike tests are conducted. A new load transfer curve, which combines the behaviors of the pile base at the end of initial driving and of the pile shaft at the restrike, is suggested, and a new load-settlement curve is obtained. Subsequently, the resistances of the test piles are evaluated using the combined load-settlement curve, and compared with the results from the end of initial driving and restrike tests. The results showed that the resistances, which are evaluated using the combined load-settlement curve, may overcome the underestimation of the resistance because of the insufficient driven energy. In addition, the resistance resulted from the combined load-settlement curve may be more similar to that from the static load test because the suggested load transfer curve is closer to the behavior of the embedded pile compared to the results of end of initial driving and restrike tests. Therefore, this study demonstrates that the combined load-settlement curve may be effectively used for the evaluation of the bearing capacity of embedded piles.

• Proceedings of the Korean Geotechical Society Conference
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• 1994.09a
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• pp.87-93
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• 1994

Factors which affect the capacity and the soil plug condition of an open-ended pile can be broadly divided into three categories:i.e., pile conditions, soil conditions and penetration methods. It has been found that the relative density and the horizontal stress have much effects on the soil plug behavior than other soil conditions. Also, it has been found that the pile diameter is the most important factor among pile conditions. However, a few investigations have been performed to account for both soil conditions and pile conditions. In this paper, a number of calibration chamber tests have been conducted with three different sized open-ended model piles. The model pile was driven into siliceous sand, with varying soil conditions, to clarify coupled effects of pile diameter and soil conditions on the plug behavior, the capacity, and the load trasfer mechanixm of soil plug. The model piles are composed of two stainless steel pipes so as to measure the plug capacity, the tip resistance, and the outside skin friction. separately.

• IMMUNE NETWORK
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• v.15 no.2
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• pp.58-65
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• 2015

Melanoma is the most aggressive skin cancer and its incidence is gradually increasing worldwide. Patients with metastatic melanoma have a very poor prognosis (estimated 5-year survival rate of <16%). In the last few years, several drugs have been approved for malignant melanoma, such as tyrosine kinase inhibitors and immune checkpoint blockades. Although new therapeutic agents have improved progression-free and overall survival, their use is limited by drug resistance and drug-related toxicity. At the same time, adoptive cell therapy of metastatic melanoma with tumor-infiltrating lymphocytes has shown promising results in preclinical and clinical studies. In this review, we summarize the currently available drugs for treatment of malignant melanoma. In addition, we suggest cytokine-induced killer (CIK) cells as another candidate approach for adoptive cell therapy of melanoma. Our preclinical study and several previous studies have shown that CIK cells have potent anti-tumor activity against melanomas in vitro and in an in vivo human tumor xenograft model without any toxicity.

• Journal of Engineering Education Research
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• v.21 no.1
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• pp.77-89
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• 2018

The chromosomes of all the world are the same in all 24 pairs, but the key, skin color and appearance are different. Also, it is the resistance of adult disease, diabetes, cancer. In 1953, Watson, Crick of Cambridge University experimentally discovered a DNA double helix structure, and in 1962, They laureates the Nobel Prize. In 1964, Temin, University of Wisconsin, USA, experimentally identified the ability to copy gene information from RNA to DNA and received the Nobel Prize in 1975. In this paper, we analyzed 24 pairs of DNA chromosomes using mathematical matrices based on the combination order sequence of four groups, and designed the Taegeuk pattern genetic code for the first time in the world. In the case of normal persons, the middle Yin-Yang taegeuk is designed as a block circulant Jacket matrix in DNA, and the left-right and upper-lower pairs of east-west and north-south rulings are designed as pair complementary matrices. If (C U: A G) chromosomes are unbalanced, that is, people with disease or inheritance become squashed squirming patterns. In 2017, Professor Michel Young was awarded a Nobel by presenting a biological clock and experimentally explained the bio-imbalance through a yellow fruit fly experiment.This study proved mathematical matrices for balanced and unbalanced RNA.

• The Korean Journal of Pain
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• v.10 no.1
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• pp.73-76
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• 1997

Background : Epidural anesthesia is now accepted as a popular technique for pain relief and anesthesia. However, accidental dural puncture may occur during placement of the epidural needle. This study was undertaken to evaluate difference of the epidural depth between parturients and non-parturients. Method : Eighty non-parturients receiving epidural anesthesia were assigned to group I, and eighty parturients whose body weight had not yet increased over 15 kg from pregnancy were assigned to group II. With patients in lateral decubitus position, 18 guage Tuohy needle was punctured by approaching at $L_{3-4}$ interspace. Epidural space was identified using loss-of-resistance to air technique. Result : Epidural depth was 4.18 cm and 4.25 cm in group I and group II respectively. There was no significant statistical difference in body mass index(BMI) and ponderal index(PI) (p<0.05), nor in epidural depth between the two groups. Conclusion : Epidural needle need not be placed deeper in parturients than in nonparturients.