• Bulletin of the Korean Chemical Society
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• v.29 no.11
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• pp.2161-2168
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• 2008

• YAKHAK HOEJI
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• v.16 no.2
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• pp.90-96
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• 1972

The author tried to isolate the Vibrio parahaemolyticus from Han River water and river fishes, to investigate the route of contamination by way of marine product and to make clear the survival ability in various kinds of food. The results are as follows: 1. Twenty eight strains of V. parahaemolyticus were identified among 312 samples in Han river from March to August. 2. V. parahaemolyticus was detected in the margenic content of Cyprinus and Anguilla. 3. 9 strains of K-3 type, 5 strains of K-11 type, 8 strains of K-8 type, 6 strains of K-32 type and 1 strain of K-52 type were clarified through K-antiserum reaction.

• YAKHAK HOEJI
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• v.39 no.1
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• pp.41-47
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• 1995

An efficient and stereoselective synthetic route to the trisubstituted hydroxy cyclopentane as an useful synthetic intermediate for carbaprostacyclin is described. Pd(0)-mediated intramolecular alkylation of allylic carbonate has been employed as a key reaction.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.271-275
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• 2003

Easy and efficient synthetic route of novel 4'-C methyl branched carbocyclic nucleosides is described. The installation of alkyl and aryl groups at 4'-position of carbocyclic nucleosides were successfully made via sequential [3,3]-sigmatropic rearrangement and ring-closing metathesis (RCM) starting from simple ketones such as acetol. Adenine and uracil were coupled via Pd(0) catalyzed reaction, followed by desilylation to give novel compounds 13 and 14, respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.181-181
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• 2005

• Bulletin of the Korean Chemical Society
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• v.7 no.6
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• pp.442-444
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• 1986

Starting with the readily available p-tert-butyl-calix[4]arene 2, tert-butyl groups are removed by $AlCl_3$-catalyzed de-alkylation reaction, and the calix[4]arene 3 formed is converted to the tetraacetate 4. This compound undergoes Fries rearrangement to yield p-acetylcalix[4]arene 6, which seems to be an attractive starting material for the introduction of functional groups. As a preliminary experiment p-(1-hydroxyethyl)calix[4]arene 7 is prepared by LiAlH$_4$ reduction of 6.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.489-492
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• 1995

A new synthetic route to chiral liquid crystal dopant, 4-[2-(7S-methylnonanyl)oxy-5-pyrimidinyl]phenyl(2S,3S)-2-chloro-3-methylpentanoate (1), starting from 4-nitrophenylacetic acid is described. The key intermediate methylthiopyrimidine compound (8) has been synthesized from 4-nitrophenylacetic acid by Vilsmyer-Haack reaction followed by the formation of pyrimidine ring, and then converted to chiral ester (1) by the replacement of nitro group by (2S,3S)-2-chloro-3-methylpentanoic acid 2 through the formation of diazonium salt.

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.165-167
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• 1987

Reaction of 5-(2-thianthreniumyl)thianthrene perchlorate with sodium naphthalenide in the presence of benzenethiol in tetrahydrofuran at -$78^{\circ}C$ proceeded via a formation of a sulfuranyl radical to give thianthrene (66%), 2-phenylthiothianthrene (33%), phenyl 2-(2-thianthrenylthio)phenyl sulfide (traceable amount), and some unknowns, along with naphthalene and very small amount of 1,4-dihydronaphthalene.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.437-442
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• 2016

A new route for PBT (Poly butylene terephthalate) production from recycled PET (Poly ethylene terephthalate) has been explored. The route consists of glycolysis of PET (Poly ethylene terephthalate) wastes using 1,4-butandiol into BHBT oligomers and polycondensation of the oligomers into PBT oligomer. This process uses post-consumer or post-industrial recycled PET and converts it into high-end PBT type engineering thermoplastic via a chemical recycling process. Zink acetate was used as a catalyst for both glycolysis and polycondensation. Two types of reactor for the glycolysis, batch and semi-batch reactor, were investigated and their performances were compared. Semi-batch reactor removes ethylene glycol (EG) and THF (tetrahydrofuran) during the reaction. Amounts of EG and THF generated during the glycolysis reaction were measured and used as criteria for the reactor performance. Performance of semi-batch reactor was shown to be better than that of batch reactor. Optimum reaction condition for the semi-batch reactor was BD/PET ratio of 4, and reaction temperature of $220^{\circ}C$, giving high EG yield (max 91%) and low production of THF. In addition, it was confirmed that the molecular weight of PBT oligomer increases in accordance with the progress of the polycondensation reaction.

• Journal of the Korean Ceramic Society
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• v.49 no.4
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• pp.287-294
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• 2012

Ceramic Matrix Composites (CMCs) represent a class of non-brittle refractory materials for harsh and extreme environments in aerospace and other applications. The quasi-ductility of these structural materials depends on the quality of the interface between the matrix and the fiber surface. In this study, a manufacture route is described where in contrast to most other processes no additional fiber coating is used to adjust the fiber/matrix interfaces in order to obtain damage tolerance and fracture toughness. Adapted microstructures of uncoated carbon fiber preforms were developed to permit the rapid infiltration of molten alloys and the subsequent reaction with the carbon matrix. Furthermore, any direct reaction between the melt and fibers was minimized. Using pure silicon as the reactive melt, C/SiC composites were manufactured with an aim of employing the resulting composite for friction applications. This paper describes the formation of the microstructure inside the C/C preform and resulting C/C-SiC composite, in addition to the MAX phases.