• YAKHAK HOEJI
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• v.37 no.1
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• pp.36-40
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• 1993

The 4-(2'-(N-(l-methyl-3'-carbamylphenyl)-n-propyl))aminoethyl)-l- hydroxy-2-pyridone which has isoelectronic and isosteric structural similarity with dobutamine without having the Catechol-O- Methyltransferase(COMT) vulnerable m-hydroxy group was synthesized via 12 synthetic steps.

• YAKHAK HOEJI
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• v.39 no.5
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• pp.569-571
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• 1995

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.504-511
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• 2008

Two kinds of nitroazobenzene derivatives: 4-{4'-(nitrophenylazo)phenoxy}alkanoic acids (NAAn, n = 2~8, 10, number of methylene units in the alkyl chain) and 4-{4'-(nitrophenylazo)phenoxy}alkanoyl chlorides (NACn, n = 2~8, 10) were synthesized, and their thermotropic liquid crystalline behaviors were investigated. NAA6 formed an enantiotropic nematic phase, while the remainders, except NAA2, showed monotropic nematic phases. Isotropic-nematic transition temperature ($T_{iN}$) and change of entropy (${\Delta}S$) at $T_{iN}$ for both of NAAn and NACn varied by the change of n, and pronounced odd-even effects of n were also observed. However, the $T_{iN}$ and ${\Delta}S$ values of NAAn were much higher than those of NACn. This fact may be attributed to the hydrogen bonding between carboxyl groups. Thermal properties and degree of order in the mesophase and the magnitude of the odd-even effects of both NAAn and NACn were significantly different from those reported for 4-(alkoxy)-4'-nitroazobenzenes. It was discussed in terms of the differences in the molecular anisotropy and the temperature-dependent flexibility of the substituted groups.

• Polymer(Korea)
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• v.25 no.6
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• pp.796-802
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• 2001

Novel monomer for polybenzimidazole was prepared and polymerized via aromatic nucleophilic substitution reaction. Thus, N-(4-fluorobenzoyl)-4-methoxy-N'-naphthyl-1,2-phenylenediamine was synthesized from the reaction of 4-methoxy-N-naphthyl-1,2-phenylenediamine and 4-fluorobenzoyl chloride. N-(4-fluorobenzoyl)-4-methoxy-N'-naphthyl-1,2-phenylenediamine was converted to 2-(4-fluorobenzoyl)-5-hydroxy-1-naphthylbenzimidazole by ring closure and demethylation reaction. Polymerization was done in N-cyclohexyl-2-pyrrolidinone (CHP) containing potassium car bonate. The resulting polymer was soluble in N-methyl-2-pyrrolidinone (NMP) and had inherent viscosity of 0.38 dL/g (NMP at $30^{\circ}C$). The glass transition temperature ($T_g$ ) of the polybenzimidazole was $270^{\circ}C$. The thermogravimetric analysis (TGA) thermograms of this polymer showed 5% weight losses at $550^{\circ}C$ in nitrogen and at $540^{\circ}C$ in air.

• Korean Journal of Crystallography
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• v.15 no.1
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• pp.35-39
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• 2004

Two new nickel vanadium borophosphate cluster compounds, $(NH_4)_{10}[Ni(H_2O)_5]_4[V_2P_2BO_{12}]_6{\cdot}nH_2O$ (1) and $(NH_4)_{3.5}(C_3H_{12}N_2)_{3.5}[Ni(H_2O)_6]_{1.25}{[Ni(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}nH_2O$ (2) have been synthesized and structurally characterized. Inter-diffusion methods were employed to prepare the compounds. The cluster anion $[(NH_4)\;{\supset}\;V_2P_2BO_{12}]_6$ is used as a building unit in the synthesis of new compounds containing $Ni(H_2O){^{2+}_5}$ in the presence of pyrazine and 1,3-diaminopropane. Compounds contain isolated cluster anions with general composition ${[Ni(H_2O)_5]_n[(NH_4)\;{\supset}\;V_2P_2BO_{12}]_6}^{-(17-2n)}$ (n = 2, 4). Crystal data: $(NH_4)_{10}[Ni(H_2O)_5]_4[V_2P_2BO_{12}]_6{\cdot}nH_2O$, monoclinic, space group C2/m (no. 12), a = 27.538(2) ${\AA}$, b = 20.366(2) ${\AA}$, c = 11.9614(9) ${\AA}$, ${\beta}$ = 112.131(1)$^{\circ}$, Z = 8; $(NH_4)_{3.5}(C_3H_{12}N_2)_b[Ni(H_2O)_6]_{3.5}{[Ni(H_2O)_5]_2[V_2P_2BO_{12}]_6{\cdot}nH_2O$, triclinic, space group P-1 (no. 2), a = 17.7668(9) ${\AA}$, b = 17.881(1) ${\AA}$, c = 20.668(1) ${\AA}$, ${\alpha}$ = 86.729(1)$^{\circ}$, ${\beta}$ \ 65.77(1)$^{\circ}$, ${\gamma}$ = 80.388(1)$^{\circ}$, Z = 2.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.3
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• pp.386-391
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• 1996

SiC particles (average size is 270 nm) of 0, 10, 20, 30, 40 vol% were dispersed in $Si_{3}N_{4}$, and $Si_{3}N_{4}/SiC$ nanocomposites were fabricated by hot press. After sintering, matrix phase, ${\alpha}-Si_{3}N_{4}$ was transformed to ${\beta}-Si_{3}N_{4}$, and second phase, ${\beta}-SiC$ was not changed. No grain boundary crystalline phase by adding of sintering additives was detected. Grain growth of $Si_{3}N_{4}$ was supressed with increasing of SiC contents, and then fine grain was occurred. The highest fracture strength was obtained at 10 vol% SiC, and fracture toughness was decreased, but hardness was linearly increased with SiC content.

• Bulletin of the Korean Mathematical Society
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• v.45 no.4
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• pp.739-748
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• 2008

In this paper, we obtain the general solution of a generalized cubic functional equation, the Hyers-Ulam-Rassias stability, and the stability by using the alternative fixed point for a generalized cubic functional equation $$4f(\sum_{j=1}^{n-1}\;x_j\;+\;mx_n)\;+\;4f(\sum_{j=1}^{n-1}\;x_j+mx_n\;x_j\;-\;mx_n}\;+\;m^2\sum_{j=1}^{n-1}\;(f(2x_j)\;=\;8f(\sum_{j=1}^{n-1}\;x_j)\;+\;4m^2{\sum_{j=1}^{n-1}}\;\(f(x_j+x_n)\;+\;f(x_j-x_n)\)$$ for a positive integer $m\;{\geq}\;1$.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.4
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• pp.49-57
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• 1992

Tungsten film was deposited on the TiN surface in a low pressure chemical vapor deposition reactor and chemical reaction mechanism between TiN surface and ($WF_{6}\;and\;SiH_{4}$ was studied. Interaction of ($WF_{6}\;or\;SiH_{4}$ with TiN surface and tungsten was deposited more easily. $WF_6$ reacted with TiN activated the TiN surface to form volatile TiF_4$ and tungsten nuclei were formed. ($SiH_{4}$ was dissociated on the TiN surface to form silicon nuclei. From RBS and AES analysis, we could not detect the impurities(such as Si or TiF$_x$)at the interface between tungsten and TiN. The adhesion at the W/TiN interface became poor when the deposition temperature was below 275$^{\circ}C$.

• Journal of Photoscience
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• v.11 no.3
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• pp.129-132
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• 2004

Photochemically stable dibenzoylmethane and curcumin were cleaved dramatically when they were irradiated in the presence of N,N-dimethylaniline in methanol with 300 nm UV light. Several products such as benzil, secondary product derived from 1,4-diphenyl-1,4-butanedione, and unidentified compound were observed from the photoreactions of dibenzoylmethane with N,N-dimethylaniline. It was also found that one of the primary fragments produced by irradiation of curcumin in methanol were coupled with N,N-dimethylaniline to give a new enone compound, i.e., 1-(4-dimethylaminophenyl)-4-(4-hydroxy-3-methoxyphenyl)-but-3-en-2-one, as the major product.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2235-2240
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• 2007

3-Aryloxy methyl-4-(N-pyrazin-2'yl carboxamido)-5-mercapto-1,2,4-triazoles (3a1-a14) were prepared starting from potassium dithio carbazinates (2a1-a14). These triazoles were then employed in the synthesis of 3-aryloxy methyl-4-(N-pyrazin-2'yl carboxamido)-5-hydrazino-1,2,4-triazoles (4a1-a14). All the newly synthesized compounds were characterized by analytical, IR, NMR spectral studies. The compounds were screened for their antibacterial, antifungal, anti-inflammatory and analgesic properties. Most of the compounds have shown significant antifungal activity while few have shown excellent anti-inflammatory and analgesic activity. An attempt is made to study the structure activity relationship (SAR).