• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3060-3065
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• 2009

A series of wholly aromatic Poly(ether-ether-ester)s with flexible side chain was synthesized by direct polycondensation from ether linkaged triad diol and 2,5-dialkoxyterephthalic acid. The chemical structures and physical properties of these polymers were investigated by using $^1H$-NMR, FT-IR, DSC and TGA. As results of investigations, the inherent viscosities($\eta$inh) measured at $40^{\circ}C$ in 1,1,2,2-tetrachloroethane(TCE) were 0.45~0.86 dl/g and initial decomposition(Td) in TGA occurred at 378~418 $^{\circ}C$ in N2 gas. The majority of these polymers were soluble in organic solvents used in this experiments at elevated temperatures. Melting temperatures(Tm) decreased with increasing the length of the side chain and showed odd-even effects.

• Food Science and Preservation
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• v.19 no.6
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• pp.919-924
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• 2012

This study was conducted to investigate the antimicrobial activities and antioxidant activities of the Korean mistletoe extract and its solvent fractions (e.g. n-hexane, ethyl ether, ethyl acetate, butanol). Ethyl ether fraction against Bacillus cereus showed stronger activities than benzoic acid (2.5 mg/mL). The MIC of korean mistletoe extract and slovent fractions were in the range of 6.25-25 mg/mL. The MIC (6.25 mg/mL) of ethyl acetate fraction onto Staphylocossus aureus was the lowest among them. Ethyl ether fraction which showed the strongest antioxidant activities by DPPH (1,1-diphenyl-2-picryl-hydrazyl) and FRAP (ferric ion reducing antioxidant power) methods had the highest total phenolic contents. It is suggested that Korean mistletoe could be utilized as natural preservative material through the study of the active compounds from ethyl ether fraction.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.205-212
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• 1985

By using the Mass-Weighted-Cartesian coordinate method, the allosteric effect of 2,2'-bipyridyl crown(4) ether is studied. The vibrational modes of 235, 234, 188, and 178cm$^{-1}$ belong to the pore opening motion of crown ether and those of 168, 104, and 67cm$^{-1}$ belong to the rotational vibration motion of bipyridyl. Especially the mode appearing at 178cm$^{-1}$ shows a large allosteric effect by activation of the allosteric site.

• Natural Product Sciences
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• v.4 no.4
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• pp.245-252
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• 1998

The unique sulphated phenolics, gallic acid 3-methyl ether 5-potassium sulphate, isoferulic acid 3-potassium sulphate, and ellagic acid 4,4'-dimethyl ether 3-potassium sulphate have been isolated from the flowers of Tamarix amplexicaulis Ehrenb. (Tamaricaceae). The hitherto unknown natural phenolic acid, gallic acid 3-methyl ether, together with the known phenolic, gallic acid, gallic acid 4-methyl ether, isoferulic acid, ferulic acid, ellagic acid, and ellagic acid 4,4'-dimethyl ether have been also separated and characterized. The structures were established by conventional methods, including electrophoretic analysis and confirmed by ESI-MS, $^1H-\;and\;^{13}C-NMR$.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.19-22
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• 2024

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, we summarize the current status of Xenomai real-time framework and RTnet, which are essential for Linux operating systems to operate in real-time, and implement a real-time EtherCAT master system with these open sources. The real-time performance of the implemented EtherCAT master is evaluated according to Intel network controllers 82574L, I219, I210, and I225, respectively. The results show that the implemented EtherCAT master provides precise control performance for control frequencies from 1KHz to 8KHz and similar performance for I219, I210, and I225, and relatively slightly larger jitter for 82574L.

• 월간산업보건
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• s.308
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• pp.52-54
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• 2013

Phenyl glycidyl ether의 직업적 노출기준 TLV-TWA는 0.1 ppm($0.6mg/m^3$)으로 권고되고 있다. TLV-TWA는 동물실험에서 고환(정소) 독성, 비암 그리고 감작반응에 대한 위험도를 줄일 수 있다고 증명된 수준이다. 또한 사람에서의 감작반응이 보고되고 흰쥐에서 비암이 입증되어 경고표시(notation)로 SEN과 A3(동물에서 발암성 물질)를 권고하였다. Phenyl glycidyl ether와 다른 glycidyl ether에 노출된 근로자들에서 평균 6.5개월 후에 감작반응이 발견되어, 교차 감작반응의 가능성을 인지하여야 한다. Phenyl glycidyl ether를 흰쥐와 토끼에게 급성으로 피부에 도포한 결과 빠르게 흡수되어 조혈독성이 유발되는 것을 확인하여 피부(Skin) 경고표시의 타당성을 입증하였다.

• Fibers and Polymers
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• v.3 no.2
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• pp.49-54
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• 2002

Radical copolymerization behavior of 4'-vinylbenzo-15-crown-5, a vinyl monomer having a pendant 15-membared crown ether unit (VCE) with di(ethylene glycol) ethyl ether acrylate (DEGEEA) was carried out in toluene solution using 2,2-azobisisobutyronitrile (AIBN) as an initiator. The copolymers were characterized by means of FT-IR, $^1{H-NMR}$, and $^{13}{C-NMR}$ . The reactivity ratio of VCE and DEGEEA, determined by Fineman-Ross and Kelen-Tudos method, gave values 0.55 for VCE, and 0.11 for DEGEEA respectively.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.79-81
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• 1993

Synthetic routes are described for the introduction of hydroxyalkyl groups to the upper rim of calix[4]arene. Treatment of p-bromocalix[4]arene methyl ether 3 with n-BuLi followed by para-formaldehyde produced p-hydroxymethylcalix[4]arene methyl ether 4 in 60% yield. p-Acetylcalix[4]arene methyl ether 7, obtained by Friedel-Crafts acetylation of calix[4]arene methyl ether 6, was reduced with NaBH4 to produce p-(1-hydroxy ethyl)calix[4]arene methyl ether 8 in 67% yield.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.71-72
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.371-372
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• 2013