• Ceramist
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• v.9 no.6
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• pp.24-29
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• 2006

Electron beam physical vapor deposition (EB-PVD) process has currently been applied to thermal barrier coatings (TBCs) for aircraft engines. Due to unique columnar structure, EB-PVD TBCs have advantages in resistances to thermal shock and thermal cycle for their applications, compared to films prepared by plasma spray By the EB-PVD equipment, we successfully obtained yttria-stabilized zirconia (YSZ) layer which has columnar and feather like structure including a large amount of nano size pores and gaps. The EB-PVD technique has been developed for coating functional perovskite type oxides such as (La, Sr)MnO3. Electrode properties have been improved by interface and structural control.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.449-455
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• 2005

Electron beam (EB) and ultraviolet (UV) curable monomers (AF-1 with mono functionality and AF-2 with tetra functionality) containing hydroxy and acrylate group for anti-fogging coating were synthesized and applied to EB and UV-curable coating systems. The synthesized reactive AF-1 and AF-2 monomers were first formulated into UV-curable system and the optimization of film properties for anti-fogging coating was investigated. The 5:17.5 ratio for AF-1 and AF-2 was found to be the best optimized formulation for anti-fogging coating without destroying the other essential properties such as hardness, solvent resistance, and adhesion. The optimized formulation was applied to the EB-curable system, and EB and UV-curable systems were compared. The results demonstrated that both EB and UV-cured films coated on PC sheet showed excellent anti-fogging properties; however, the EB-cured film exhibited better hardness, adhesion, and water repellent properties than the UV-cured film.

• Fashion & Textile Research Journal
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• v.15 no.3
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• pp.430-436
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• 2013

The purpose of this study investigates the effects of electron beam(EB) irradiation on the chemical and morphological properties of Hansan ramie fiber. Hansan ramie fibers were irradiated with electron beam doses of 0, 1, 3, 5 and 10kGy. The effect of electron beam irradiation on the chemical components of fibers as well as the surface chemical and morphological properties were investigated using chemical component analysis methods based on TAPPI standards, XPS, and SEM. The results indicate that the surface layers can be removed under suitable EB irradiation doses. Alcohol-benzene extraction and lignin content increases gradually with an increase in EB irradiation and reaching a maximum at an EB dose of 3kGy, and decreases at 10kGy. The surface chemical changes measured by XPS corresponded to the chemical composition analysis results. The C1 peak and the O/C ratio decreased with the removal of the multi-layer and primary layer by EB irradiation. The SEM images show the inter-fibrillar structure etched by EB irradiation up to 5kGy. At 10kGy, the surface structure of the ramie fiber shows highly aligned and distinctive striations in a longitudinal direction. The removal of these exterior layers of the fiber was confirmed by changes in surface morphology as observed in SEM images.

• Steel and Composite Structures
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• v.47 no.3
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• pp.383-393
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• 2023

Conventional reinforced concrete design codes assume ideal strain evolution in semi-deep beams with externally bonded fiber-reinforced polymer (EB-FRP) web strips. However, there is a strain interaction between internal stirrups and web strips, leading to a notable difference between code-based and experimental shear strengths. Current study provides an experiment-verified detailed numerical framework to assess the potential strain interaction under quasi-static monotonic load. Based on the observations, steel stirrups are effective only for low EB-FRP amounts and the over-strengthening of semi-deep beams prevents the stirrups from yielding, reducing its shear strength contribution. A notable difference is detected between the code-based and the study-based EB-FRP strain values, which is a function of the normalized FRP stress parameter. Semi-analytical relations are proposed to estimate the effective strain and stress of the components considering the potential strain interaction. For the sake of simplification, a linearized correction factor is proposed for the EB-FRP web strip strain, assuming its restraining effect as constant for all steel stirrup amounts.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.337-345
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• 2009

The purpose of this study is to investigate the shear strengthening effectiveness of the beams strengthened with near surface mounted (NSM) and external bonded (EB) CFRP strips. A total of nine concrete beams were made and tested. From this study, it was found that the shear stiffness and strength of the beams strengthened with NSM and EB strips were significantly improved compared to the control beam. Failure of the beam strengthened with NSM and EB strips was initiated by shear cracks, propagated diagonally to the adjacent epoxy grooves without crossing the epoxy and finally sudden diagonal crack connecting the point of application of load and flexural crack was occurred. For the beam strengthened combined with NSM and EB CFRP strips, the tensile strains in the NSM CFRP strips were observed in the range of 0.35% to 0.45% and strains with EB strips were measured about 0.3%.

• Journal of the Korean Electrochemical Society
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• v.7 no.3
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• pp.138-142
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• 2004

The polyaniline films of emeraldine base (EB) and leucoemeraldine base (LEB) form doped with cam-phorsulfonic acid (CSA) were prepared by casting the mixed solution of chloroform and m-cresol on ITO (indium tin oxide) electrode. By analyzing UV-vis spectra of the mixed solutions, the effects of the secondary doping by m-cresol were obtained. And the conductivity of polyaniline film was increased with increasing m-cresol content. As the results of analyzing cyclic voltammograms, it was known that the redox peak currents of polyaniline electrode prepared from LEB were larger and more reversible than those of polyaniline eleclrodes prepared from EB. The charge transfer resistances $(R_{ct})$ of polyaniline electrodes were reduced with increasing m-cresol content, showing smaller Rct for LEB/CSA than EB/CSA.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.193.2-193.2
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• 2014

열차폐 코팅(Thermal Barrier Coating)은 주로 항공기 엔진이나 화력발전용 터빈 등의 $1300^{\circ}C$ 이상의 고온에서 사용되는 부품에 적용되어 모재(내열합금)의 손상 방지 및 에너지 효율 향상을 위해 사용되고 있다. 열차폐 코팅의 경우 Plasma Spray 공법과 EB-PVD(전자빔 물리 증착법) 공법이 가장 많이 사용되고 있다. Plasma Spray에 의한 열차폐 코팅 공정은 생산 비용이 저렴하고 수평형 적층 구조를 통한 높은 열전도율을 가지는 장점이 있으며, EB-PVD 공정은 수직형 구조의 열차폐막을 통해 내열 충격성과 내열 사이클성이 양호하다는 장점이 있다. 본 연구에서는 열 사이클의 내구성이 뛰어난EB-PVD를 이용하여 열차폐 코팅 공정연구를 진행하였다. 본 연구소에서 사용하고 있는 EB-PVD 는 종래의 장치와는 달리 70 kW급 전자총 5기가 장착 되어 있으며, 각각 시편 가열용 전자총 2기 및 피코팅용 가열 전자총 3기로 구성되어 있다. 이런 구성을 통해 다양한 종류의 열차폐 박막과 높은 결정성과 치밀도를 가지는 박막 형성할 수 있을 것이다. 본 발표에서는 EB-PVD 공정 연구결과 및 향후 실용화를 위한 개발 연구 방향에 대해서 기술하였다.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.101-108
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• 2018

This study was conducted to establish optimized ${\beta}-glucan$ extraction method through enzymatic hydrolysis from Phellinus baumii and investigate ${\beta}-glucan$ contents and physicochemical properties. The optimal condition was obtained with the enzyme concentration of 0.66% (v/v), reaction time of 6.08 h ($R^2=0.9245$) and the ${\beta}-glucan$ contents from the Phellinus baumii extracts under the optimized condition was 1.9594 g/100 g. ${\beta}-Glucan$ yield (0.76-16.40%) of enzyme beta-glucan extract (EBE) was three fold higher than that of non-enzyme beta-glucan extract (NEBE). ${\beta}-Glucan$ purity (11.15-59.05%) of non-enzyme beta-glucan (NEB) and that of enzyme beta-glucan (EB) were higher than that of NEBE and that of EBE. ${\beta}-Glucan$ purity of EB (59.05%) and ${\beta}-glucan$ contents of EB (3.38 g/100 g) showed higher than those of others. Total sugar contents (0.61-1.17 mg/mL) showed that NEB and EB were higher than that of NEBE and EBE, EB had the highest total sugar content as 1.17 mg/mL, respectively. Protein contents (0.44-11.73 mg/mL) of NEBE and that of EBE were higher than that of NEB, that of EB. In FT-IR spectrum, the band at $890cm^{-1}$ of microcapsule was attributed to a ${\beta}-1,3-glucan$. The toxicities of ${\beta}-glucan$ from Phellinus baumii in both melanoma cell lines was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoli um bromide assay and ${\beta}-glucan$ from Phellinus baumii has no toxicity until $30{\mu}g/mL$. The effects of ${\beta}-glucan$ from Phellinus baumii on inhibition of cancer cell proliferation were detected by using a wound healing assay. The effect of NEB and EB were higher than NEBE and EBE, especially $30{\mu}g/mL$ of EB had the highest in both melanoma cell lines.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1286-1294
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• 2004

In a previous study by the current authors, hepatocellular carcinoma (HCC) was determined to be epidemiologically sex-dependent, and the incidence and multiplicity of HCC found to decrease in estradiol-3 benzoate (EB)-treated F344 rats. Therefore, to ascertain the anticancer mechanism of EB, a commercially available cDNA microarray, with a total of 14,815 cDNA rat gene clones, was used to determine the differentially expressed genes in nontreated livers, EB-treated livers, and diethynitrosolamine (DEN)-induced HCC. In the sequenced experiment, a total of 85 genes were differentially expressed at either two or more times the rate of the normal expression, where 33 genes were downregulated by EB, and 52 genes upregulated. Candidate genes were selected according to significant changes observed in the mRNA expression in the EB-treated livers compared with the nontreated livers, then these genes were filtered according to their different expression patterns in the DEN-induced tumors compared to the estrogen-treated livers. To confirm the microarray data, a real-time PCR analysis was performed for ten selected genes: the H-ras revertant protein 107 (H­rev107), insulin-like growth factor binding protein (lOFBP), parathyroid hormone receptor (PI'HR), SH3 domain binding protein (SH3BP), metallothionein, src-suppressed C-kinase substrate (SSeCK) gene, phosphodiesterase I, CD44, epithelial membrane protein 3 (EMP3), and estrogen receptor a (ERa). The SSeCK and phosphodiesterase I genes were both upregulated in the DEN-induced hepatocarcinomas, yet their possible carcinogenic functions remain unknown. Meanwhile, the other genes were downregulated, including the genes related to growth regulation (IOFBP, H-revI07, ER$\alpha$), adipogenesis inhibition (PTHR), and tumor suppression (metallothionein).

• Journal of the Korean Ceramic Society
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• v.42 no.2 s.273
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• pp.117-122
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• 2005

Electron Beam Physical Vapor Deposition (EB-PVD) is a typical technology for thermal barrier coating with Yttria Stabilized Zirconia (YSZ) on aero gas turbine engine. In this study EB-PVD method was used to fabricate dense YSZ film on NiO-YSZ as a electrolyte of Solid Oxide Fuel Cell (SOFC). Dense YSZ films of -10 $\mu$m thickness showed nano surface structure depending on deposition temperature. Electrical conductivities of YSZ film and electric power density of the single cell were evaluated after screen- printing $LaSrCoO_3$ as a cathode.