• Journal of the Korean Applied Science and Technology
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• v.25 no.3
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• pp.291-298
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• 2008

Although the pyrimidine derivatives were obtained in low yields ranging from 8% to 20%, we reported the successful preparation of N,N-diaryl-pyrimidin-2-amine derivatives starting from the corresponding 2-aminopyrimidines (1a-1c), by direct palladium-catalyzed arylation using different arylbromides. The reasons of low yields are thought to be the electronic and steric effects by the neighboring aromatic systems. The absorption spectra and photoluminescent spectra of compounds (3a 3g and 4a-4c) were measured using dichloromethane on the concentration of 25 mM by UV vis spectroscopy and luminescent spectroscopy. Pyrimidine derivatives 4a, 4b, and 4c showed moderate emission maxima at 474 nm, 481 nm, and 367 nm, respectively, while other compounds showed very weak photoluminescence or no photoluminescence at all.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.582-587
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• 1997

The 6.7-dichloroquinoline-5,8-dione (I) was reacted with ethyl acetoacetate in the presence of sodium ethoxide to yield 6-(${\alpha}$-acetyl-${\alpha}$-ethoxycarbonyl methyl)-7-chloro-qui noline-5,8-dione(II). When this compound II was reacted with some arylamine (phenyl, p-toluyl, p-fluorophenyl, p-chlorophenyl. p-bromophenyl, p-iodophenyl, p-trifluoromethylphenyl, p-dimethylaminophenyl,indanyl), 1N-aryl-2-methyl-3-ethoxycarbonyl pyridino[2,3-f]-indole-4.9-dione(IIIa-I) were obtained via intramolecular cyclization.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.87-91
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• 1992

Twenty-six N-substituted-5-chloro-1,3-dimethylpyrazole-4-carboxamide were synthesized and their antifungal activity against Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea and Colletotricum gleosporiodes was compared. N-phenyl-5-chloro-l,3-dimethylpyrazole-4-carboxamides having electron releasing group at the meta position of phenyl ring demonstrated good fugicidal activity against R. solani.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.726-729
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• 2000

Though L $a_{1+x}$S $r_{2-x}$M $n_2$ $O_{7}$ n=2 R-P phases have been well known to have CMR effect, it was generally believed that n=1 phase was insulating. But recently monolayered perovskite $Ca_{2-x}$L $n_{x}$Mn $O_4$phase has been reported to show magnetoresistance. In this study, layered perovskite $Ca_{2-x}$L $n_{x}$Mn $O_4$ (x=0, 0.5, Ln=Pr, Nd, Sm, Gd) phases were synthesized by solid state reaction and their structures were refined by Rietveld method. The space groups of $Ca_2$Mn $O_4$, N $d_{0.5}$C $a_{1.5}$Mn $O_4$phases were refined as C2cb and Fmmm, respectively.y.ely.y.y.y.y.y.y.

• Journal of the Korean Magnetic Resonance Society
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• v.19 no.1
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• pp.18-22
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• 2015

The structural geometry of $[N(CH_3)_4]_2CdCl_4$ in a hexagonal phase is studied by $^1H$ MAS NMR, $^{13}C$ CP/MAS NMR, and $^{14}N$ NMR. The changes in the chemical shifts for $^{13}C$ and $^{14}N$ in the hexagonal phase are explained by the structural geometry. In addition, the temperature dependencies of the spin-lattice relaxation time in the rotating frame $T_{1{\rho}}$ for $^1H$ MAS NMR and $^{13}C$ CP/MAS NMR are measured.

• Bulletin of the Korean Chemical Society
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• v.6 no.3
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• pp.141-144
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• 1985

N-Arylation reaction of nitrogen-containing heterocycles such as pyridine, nicotinamide and 4,4'-bipyridine was studied. We prepared N-2,4-dinitrophenyl derivatives initially by reacting the above heterocycles with 2,4-dinitrochlorobenzene in ethanol, and then treated the N-2,4-dinitrophenylated heterocycles with various aniline derivatives, $XC_6H_4NH_2$(X = -H, p-$CH_3$, p-$C_2H_5$, p-Cl, p-CN, p-OH, p-$OCH_3$, o-Cl, m-$CH_3$) to yield the corresponding N-arylated compounds in fairly good yields. $H^1$-nmr patterns and peak assignments of the N-arylated products were described.

• Bulletin of the Korean Mathematical Society
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• v.58 no.4
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• pp.1031-1038
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• 2021

The main aim of this article is to study quantitative structure of finite simple exceptional groups F₄(2ⁿ) with n > 1. Here, we prove that the finite simple exceptional groups F₄(2ⁿ), where 2⁴ⁿ + 1 is a prime number with n > 1 a power of 2, can be uniquely determined by their orders and the set of the number of elements with the same order. In conclusion, we give a positive answer to J. G. Thompson's problem for finite simple exceptional groups F₄(2ⁿ).

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1093-1101
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• 2000

The object of this study was to develop new BNR process using fixed-biofilm which could be applied to retrofit the existing wastewater treatment plant or to introduce as tertiary treatment plant. To achieve complete denitrification from typical raw sewage in Korea, external carbon source must be supplied because $SCOD_{cr}/T-N(NH_4{^+}-N+NOx-N)$of raw sewage was lower than other countries. In this study, the ratio of $SCOD_{cr}/NH_4{^+}-N$ was 2.49 and the influent $NH_4{^+}$-N concentration during the experimental period was varied from 25 to 37 mg/L. To enhance nitrogen removal from the sewage, the two processes using fixed biofilm were adopted as R-Hanoxic/mid.settler/aerobic/anoxic/ aerobic) and R-2(aerobic/mid.settlerlanoxic/anoxic/aerobic), respectively. In the comparison of $NH_4{^+}$-N, T-N effluent quality and T-N removal efficiency in both processes without external carbon source, R-1 process was better than R-2 process for nitrogen removal from raw sewage. With respect to $SCOD_{cr}$/NOx-N ratio and total nitrogen removal in each anoxic reactor of two processes, R-1's was more effective than R-2's for distributing organic matters of raw sewage. In the both processes using fixed biofilm, the amount of required alkalinity to remove unit $NH_4{^+}$-N were 5.18 and 5.76($g{\cdot}CaCO_3/g{\cdot}NH_4{^+}-N_{removed}$), respectively and were lower than activated sludge BNR process(7.14).

• The Korean Journal of Soil Zoology
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• v.5 no.2
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• pp.85-96
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• 2000

Four new species of predatory nematodes belonging to the Actinolaimoidea, Dorylaimida are described. Neoactinolaimus gosungensis n. sp. is 2.2-2.4 mm long, b = 4.3-4.9; c = 10.7-11.2; species 60-62 ${\mu}{\textrm}{m}$ long and is distinguishable by low lip region, asymmetrical odontostyle and its wider lumen. Egtitus arcuatus n. sp. is 1.5-1.8 mm long, b = 3.6-4.2; c = 14-15 and is characterized by having dorsally arcuate odontostyle and presence of cardiac glands at base of oesophagus. Paractinolaimus tuberculantus n. sp. is 1.9-2.5 mm long, b = 3.3-4.0, c = 7.2-8.8, spicules 66-69 ${\mu}{\textrm}{m}$ long and is unique in having coiled body posture and a tubercle at the base of oesophagus. Carcharolaimus koriensis n. sp. is 1.7-1.9 mm long, b = 3.6-4.5, c = 65-76 and is characterized by having very thick body cuticle and larger odontostyle aperture.

• Applied Biological Chemistry
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• v.32 no.2
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• pp.154-161
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• 1989

1,3-Dimethyl-4-acyl-5-hydroxypyrazoles were treated with methyl isocyanate to give corresponding carbamates. They were 1,3-dimethyl-4-benzoyl-pyrazol-5-yl N-methylcarbamate(V), 1, 3-dimethyl-4-(2-chlorobenzoyl)-pyrazol-5-y1 N-methyl-carbamate(VI), and 1, 3-dimethyl-4-(2,4-dichlorobenzoy1)-pyrazol-5-yl N-methyl-carbamate(VII). The structures of the compounds were fully identified by UV, IR, $^{1}H-NMR$ and $^{13}C-NMR$. The synthesized carbamate compounds were tested for the phytotoxicity on the seed germination and the seedling growth of rice, radish, green-pea and turf grass. At 50ppm concentraction, the germination of seeds was not significantly affected. At higher concentraction, however, phytotoxic tendency on the seed germination and seedling growth was observed. In addition, these compounds were less phytotoxic to rice and turf seedlings as compared with radish and green pea seedlings.