• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.957-966
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• 2020

This paper presents the virtual mass method to implement the prediction of total resistance for ice-going ship in floe ice region based on the combined method of CFD and DEM. Two ways of floe ice distribution are adopted for the analysis and comparison. The synthetic ice model test has been conducted to determine the optimal virtual mass coefficients for the two different floe ice distributions. Moreover, the further verification and prediction are developed in different ice conditions. The results show that, the fixed and random distributions in numerical method can simulate the interaction of ship and ice vividly, the trend of total resistance varying with the speed and ice concentration obtained by the numerical simulation is consistent with the model test. The random distribution of floe ice has higher similarity and better accuracy than fixed distribution.

• 한국표면공학회지
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• 제29권6호
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• pp.607-614
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• 1996

Yttrium(Y) coating was incorporated by ion-plating method either directly on the TiAl substrate or after pack aluminizing on TiAl to improve the oxidation resistance of TiAl alloy. After Y-coating, heat treatment at low oxygen partial pressure was carried out. Performance of various coating was evaluated by isothermal and cyclic oxidation tests. A simple Y-coating without pack aluminizing can give a detrimental effect on the. oxidation resistance of TiAl alloy, because it enhances formation of $TiO_2$. On the other hand, a composite coating of aluminide-yttrium has shown excellent oxidation resistance. A continuous protective $Al_2O_3$ scale is formed on the aluminized TiAl, and Y-coating improves $Al_2O_3$ scale adherence and substantially prevents depletion of Al in the aluminide-coating layer.

• Corrosion Science and Technology
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• 제11권5호
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• pp.165-172
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• 2012

The corrosion resistance of epoxy-coated carbon steel was evaluated. The carbon steel surface was subjected to different treatment methods such as steel grit blasting with different size, steel shot ball blasting and power tool treatment. To study the effect of the treatments, the topology of the treated surface was observed by optical 3D microscopy and a pull-off adhesion test was conducted. The corrosion resistance of the epoxy-coated carbon steel was further examined by electrochemical impedance spectroscopy (EIS) combined with hygrothermal cyclic testing. The results of EIS indicated that the epoxy-coated carbon steel treated with steel grit blasting showed an improved corrosion resistance compared to untreated epoxy-coated surfaces or surfaces subjected to shot ball blasting and power tool treatments.

• Clinical and Experimental Pediatrics
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• 제59권5호
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• pp.231-238
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• 2016

Purpose: Lipopolysaccharide-binding protein (LBP) is a 65-kDa acute phase protein, derived from the liver, which is present in high concentrations in plasma. Data regarding the association between circulating plasma LBP levels and obesity-related biomarkers in the pediatric population are scarce. We aimed to determine whether there was a difference in plasma LBP levels between overweight/obese and normal-weight adolescents and to assess the correlation of circulating LBP levels with anthropometric measures and obesity-related biomarkers, including insulin resistance, liver enzyme levels, and lipid profiles. Methods: The study included 87 adolescents aged 12-13 years; 44 were overweight/obese and 43 were of normal-weight. We assessed anthropometric and laboratory measures, including body mass index (BMI), blood pressure, insulin resistance, liver enzyme levels, and lipid profiles. Plasma LBP levels were measured using an enzyme-linked immunosorbent assay. Results: The mean age of the participants was $12.9{\pm}0.3$ years. Circulating plasma LBP levels were significantly increased in overweight/obese participants compared with those in normal-weight participants ($7.8{\pm}1.9{\mu}g/mL$ vs. $6.0{\pm}1.6{\mu}g/mL$, P<0.001). LBP levels were significantly and positively associated with BMI, systolic blood pressure, aspartate aminotransferase, alanine aminotransferase, total cholesterol, low density lipoprotein-cholesterol, fasting glucose and insulin, and insulin resistance as indicated by the homeostatic model assessment of insulin resistance (HOMA-IR) (all P<0.05). In multivariate linear regression analysis, BMI and HOMA-IR were independently and positively associated with plasma LBP levels. Conclusion: LBP is an inflammatory biomarker associated with BMI and obesity-related insulin resistance in adolescents. The positive correlation between these parameters suggests a potentially relevant pathophysiological mechanism linking LBP to obesity-related insulin resistance in adolescents.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.275-278
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• 2002

Conductive adhesives are commonly used for the interconnections of fine pitch, small packages like mobile applications. Since conductive particles connect mechanically with contact pads to give somewhat higher contact resistance, a metallurgical interconnection, which provides both fine pitch and low resistance, was studied using silver ball and indium which can be made at low temperatures. The connection resistance of the In-Ag metallurgical interconnection was lower than that of the Ni/Au-Ag mechanical interconnection and the former showed little dependency on the bonding load in contrast to the latter.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.586-593
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• 2007

Seed coating by a phenazine-producing bacterium, Pseudomonas chlororaphis O6, induced dose-dependent inhibition of germination in wheat and barley seeds, but did not inhibit germination of rice or cucumber seeds. In wheat seedlings grown from inoculated seeds, phenazine production levels near the seed were higher than in the roots. Deletion of the gacS gene reduced transcription from the genes required for phenazine synthesis, the regulatory phzI gene and the biosynthetic phzA gene. The inhibition of seed germination and the induction of systemic disease resistance against a bacterial soft-rot pathogen, Erwinia carotovora subsp. carotovora, were impaired in the gacS and phzA mutants of P chlororaphis O6. Culture filtrates of the gacS and phzA mutants of P. chlororaphis O6 did not inhibit seed germination of wheat, whereas that of the wild-type was inhibitory. Our results showed that the production of phenazines by P. chlororaphis O6 was correlated with reduced germination of barley and wheat seeds, and the level of systemic resistance in tobacco against E. carotovora.

• The Plant Pathology Journal
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• 제32권1호
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• pp.58-64
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• 2016

Bacterial wilt of tomatoes caused by Ralstonia solanacearum is a devastating disease that limits the production of tomato in Korea. The best way to control this disease is using genetically resistant tomato plant. The resistance degree to R. solanacearum was evaluated for 285 tomato accessions conserved in the National Agrobiodiversity Center of Rural Development Administration. These accessions of tomato were originated from 23 countries. Disease severity of tomato accessions was investigated from 7 days to 14 days at an interval of 7 days after inoculation of R. solanacearum under greenhouse conditions. A total of 279 accessions of tomato germplasm were susceptible to R. solanacearum, resulting in wilt and death in 70 to 90% of these plants. Two tomato accessions were moderately resistant to R. solanacearum. Only four accessions showed high resistance against R. solanacearum. No distinct symptom of bacterial wilt appeared on the resistant tomato germplasms for up to 14 days after inoculation of R. solanacearum. Microscopy of resistant tomato stems infected with R. solanacearum revealed limited bacterial spread with thickening of pit membrane and gum production. Therefore, these four resistant tomato germplasms could be used in tomato breeding program against bacterial wilt.

• 한국자원식물학회지
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• 제32권6호
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• pp.743-751
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• 2019

Sclerotinia rot, caused by Sclerotinia sclerotiorum, is a devastating disease that poses a serious threat to perilla production in Korea. Identifying effective sources of resistance offers long term prospects for improving management of this disease. Screening disease resistant genetic resources is important for development of disease-resistant, new cultivars and conduct related research. In the present study, perilla germplasm were screened in vitro against S. sclerotiorum using detached leaf method. Among 544 perilla accessions, two were highly resistant (IT226504, IT226533), five were resistant (IT226561, IT226532, IT226526, IT226441, and IT226589), five were moderately resistant (IT226525, IT226640, IT226568, IT220624, and IT178655), 16 were moderately susceptible, 31 were susceptible, and 485 were highly susceptible. The resistant accessions in this study could serve as resistance donor in the breeding of Sclerotinia rot resistance or subjected to selection procedure of varietal development for direct use by breeders, farmers, researchers, and end consumers.

• 한국재료학회지
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• 제22권12호
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• pp.643-649
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• 2012

Coatings composited with alumina and Perfluoro alkoxyalkane (PFA) resin were deposited on stainless steel plate (SUS304) to further improve corrosion resistance. Plate (ca. $10{\mu}m$) and/or nanosize (27~43 nm) alumina used as inorganic additives were mixed in PFA resin to make alumina-fluoro composite coatings. These coatings were deposited on SUS304 plate with wet spray coating and then the film was cured thermally. According to the amount and ratio of the two kinds of alumina having plate morphology and nano size, corrosion resistance of the film was evaluated under strong acids (HF, HCl) and a strong base (NaOH). The film prepared with the addition of 5~10 wt% alumina powders in PFA resin showed corrosion resistance superior to that of pure PFA resin film. However, for the film prepared with alumina content above 10 wt%, the corrosion resistance did not improve with the physical properties, such as surface hardness and adhesion. The film prepared with plate/nanosize (weight ratio = 1/2) alumina especially enhanced the surface hardness and corrosion resistance. This can be explained as showing that the plate and the nanosize alumina dispersed in PFA resin effectively suppressed the penetration of cations and anions due to the long penetration length and fewer defects that accompany the improved surface hardness under a serious environment of 10% HF solution for over 120 hrs.

• 한국화재소방학회논문지
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• 제26권6호
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• pp.64-71
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• 2012

60 MPa급, 100 MPa급 고강도 철근콘크리트 기둥에 대하여 횡구속력 보강공법(와이어로프)과 내화보강공법(Fiber-Cocktail) 적용 유무 및 하중비에 따른 내화성능을 평가하기 위하여 표준화재 재하조건에 내화실험을 실시하였다. 실험결과 60 MPa급 고강도 콘크리트 기둥의 경우 와이어로프를 적용함으로써 화재시 축방향의 연성이 향상되며, 내화성능은 23 % 이상 향상되는 것으로 나타났다. 또한 와이어로프를 적용할 경우 하중은 설계하중의 70 % 수준이 적정하다고 판단된다. 100MPa급 고강도 콘크리트 기둥에 와이어로프와 Fiber-Cocktail을 적용할 경우 띠철근만을 적용한 경우보다 내화성능이 4배 이상 향상되는 것으로 나타났으며, 100MPa급 고강도 콘크리트 기둥에 내화성능을 확보하기 위해서는 하중은 설계하중의 70 % 미만으로 설정하는 것이 적정하다고 판단된다.