• Bulletin of the Korean Chemical Society
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• v.3 no.4
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• pp.162-165
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• 1982

The rate constants of the nucleophilic addition of thioglycolic acid to the derivatives $(H,\;p-CH_3,\;p-CH_3O,\;p-Cl,\;p-NO_2)$ of ${\beta}$-nitrostyrene were determined by ultraviolet spectrophotometry. The rate equations which can be applied over a wide pH range were obtained. Therefrom a reaction mechanism was proposed. Above pH 8.5 sulfide anion adds to the double bond (Michael type addtion). However, below pH 8.5, the neutral molecule and $HSCH_2COO^{\theta}$ add to the double bond.

• Journal of the Korean Chemical Society
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• v.15 no.3
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• pp.159-163
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• 1971

The relative viscosities ${\eta}_r$ of a series of homologous tetraalkylammonium chlorides $Me_4NCl,\;Et_4NCl,\;Pr_4NCl\;and\;Bu_4NCl$ in a series of isopropanol-water mixtures have been determined at $30^{\circ}C$ using Ubbelohde-type viscometers. The viscosity data have been interpreted in terms of viscosity A-and B-coefficients calculated from the Jones-Dole equation, ${\eta}_r=1+AC^{1/2}+BC$. The results indicate that the structure-breaking effect of chloride ion is maximum at 0.l~0.15 mole fraction isopropanol, while the size effect(Einstein effect) of the larger $R_4N^+$ ions is maximum at 0.2~0.25 mole fraction. The results also indicate that in aqueous and water-rich solutions the larger $R_4N^+$ ions (e.g. $Pr_4N+, Bu_4N^+$) appear to be excellent structure-formers and that the viscosities of solutions is not strongly affected by the electrostriction effect of chloride ion.

• Bulletin of the Korean Chemical Society
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• v.2 no.4
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• pp.125-129
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• 1981

The addition reactions of cysteine without blocking amino and carboxyl groups to substituted and unsubstituted ${\beta}$-nitro-styrene derivatives were investigated. ${\beta}$-Nitrostyrene(1a), p-methyl-${\beta}$-nitrostyrene(1b), 3,4,5-trimethoxy-$[\beta}$ -nitrostyrene(1c), $[\varpi}$-3,4-methylenedioxy-${\beta}$ -nitrostyrene(1d), o-, m- and p-chloro-${\beta}$ -nitrostyrene (1e, 1f, 1g) and o-, m- and p-methoxy-${\beta}$-nitrostyrene (1h, 1i, 1j) easily undergo addition reactions with cysteine to form S-(2-nitro-1-phenylethyl)-L-cysteine(3a), S-[2-nitro-1-(p-methyl)phenyl-ethyl]-L-cysteine(3b), S-[2-nitro-1-(3',4',5'-trimethoxy) phenylethyl]-L-cysteine(3c), S-[2-nitro-1-($[\vatpi}$ -3',4'-methylenedioxy)phenylethyl]-L-cysteine(3d), S-[2-nitro-1-(o-chloro)phenylethyl]-L-cysteine(3e), S-[2-nitro-1-(m-chloro)-phenylethyl]-L-cysteine(3f), S-[2-nitro-1-(p-chloro)phenylethyl]-L-cysteine(3g), S-[2-nitro-1-(o-methoxy)phenylethyl]-L-cysteine(3h), S-[2-nitro-1-(m-methoxy)phenylethyl]-L-cysteine(3i) and S-[2-nitro-1-(p-methoxy)phenylethyl]-L-cysteine(3j), respectively. The structure of adducts were confirmed by means of UV-spectrum, IR-spectrum, molecular weight measurement and elemental analysis. The various factors effecting the yield of cysteine adducts to ${\beta}$-nitrostyrene derivatives were also studied.

• Journal of the Korean Chemical Society
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• v.23 no.5
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• pp.307-313
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• 1979

Seven new hydrazine derivatives were prepared from N-Aryllsufonylbenzimidoyl chloride. These were: ${\beta}-({\alpha}-Benzenesulfonamidobenzal)hydrazine\;(II),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)dimethylmethylenehydrazine\;(III),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)phenylhydrazine\;(VII),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-4-nitrophenylhydrazine\;(VIII),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-2,4-dinitrophenylhydrazine\;(IX),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)dimethylhydrazine\;(X),\;{\beta}-({\alpha}-Benzenesulfonamidobenzal)-p-methylphenylhydrazine\;(XI)$. The structure of these derivatives were identified by elemental analysis, spectral data and other chemical methods. In general, it was found that the yields of these reactions were significantly improved in polar solvent and by the electron attracting substituents in phenylhydrazine.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.361-372
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• 1994

Vanadium containing MFI type zeolites have been prepared hydrothermally or by the impregnation method with $NH_4VO_3$ solution after dealumination of HZSM-5. Incorporation of vanadium into the framework of zeolite has been demonstrated by XRD, DTA, FT-IR and ESR analyses. Upon $NH_4VO_3$ impregnation and calcination of dealuminated zeolite, vanadium substitution into the framework could be performed like a hydrothermally synthesized zeolite. Vanadium in zeolite is able to pass redox cycles at high temperatures, and it is shown that vanadium is probably fixed and atomically dispersed in the structure of zeolite. The catalytic benzene hydroxylation, hexanes and alcohols oxidation were used for evaluating the properties of vanadium incorporated MFI zeolite.

• Journal of the Korean Chemical Society
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• v.26 no.6
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• pp.407-413
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• 1982

The rate constants of the nucleophilic addition of cysteine to 3,4-methylenedioxyphenylmethylene malononitrile were determined by UV Spectrophotometry and a rate equation which can be applied over wide pH range was obtained. On the basis of rate equation, it may be concluded that the rate constants were dependent upon only the concentration of hydroxide ion above pH 9.0, however, below pH 6.0, the reaction were initiated by the addition of neutral cysteine molecule to carbon-carbon double bond and at pH 7.0~9.0, the addition of a neutral cysteine molecule and it's anion occurred competitively.

• Journal of the Korean Chemical Society
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• v.25 no.6
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• pp.390-393
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• 1981

Eight new compounds were prepared by the addition reaction of thioglycolic acid to ${\beta}$-nitrostyrene and its derivatives. s-[2-Nitro-1-phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-methyl)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-methoxy)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-chloro)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-bromo)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(p-nitro)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(3-methoxy-4-ethoxy)phenylethyl]-thioglycolic acid; s-[2-nitro-1-(3,4,5-trimethoxy)phenylethyl]-thioglycolic acid; The structure of these compound were identified by elemental analysis, UV, IR and NMR spectral data.

• Journal of Broadcast Engineering
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• v.9 no.4 s.25
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• pp.384-390
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• 2004

In this paper we compare the performance of 4 different algorithms for converting the sampling frequency of an audio from 44.1KHz to 48KHz. The algorithms considered here include the basic polyphase method. sine function based method. multi-stage method. and B-spline based method. For a fair comparison, the sampling rate converters using the 4 algorithms are redesigned under a high fidelity condition. Then, their H/W complexities are compared in terms of the computational complexity and the memory size. As a result, it is shown that the basic polyphase method and sine function based method outperform the other two in terms of the computational complexity, while the B-spline based method requires less memory than the others.

• Bulletin of the Korean Chemical Society
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• v.4 no.2
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• pp.92-95
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• 1983

The addition products of glutathione to ${\beta}$ -nitrostyrene derivatives were synthesized. ${\beta}$ -Nitrostyrene (1a), p-methyl-${\beta}$-nitrostyrene (1b), 3,4,5-trimethoxy-${\beta}$-nitrostyrene (1c), o-, m- and p-chloro-${\beta}$-nitrostyrene (1e, 1f, 1g) and o-, m- and p-methoxy-${\beta}$-nitrostyrene (1h, 1i, 1j) undergo addition reactions with glutathione to form S-(2-nitro-1-phenylethyl)-L-glutathione (5a), S-[2-nitro-1-(p-methyl)phenylethyl]-L-glutatione (5b), S-[2-nitro-1-(3', 4', 5'-trimethoxy)phenylethyl]-L-glutathione (5c), S-[2-nitro-1-(o-chloro)phenylethyl]-L-glutathione (5e), S-[2-nitro-1-(m-choro)phenylethyl]-L-glutathione (5f), S-[2-nitro-1-(p-chloro)phenylethyl]-L-glutathione (5g), S-[2-nitro-x-(o-methoxy)-phenylethyl]-L-glutathion e(5h), S-[2-nitro-x-(m-methoxy)phenylethyl]-L-glutathion e (5i), and S-[2-nitro-1-(p-methoxy)phenylethy])-L-glutathione (5j), respectively. The structure of adducts were identified by UV and IR-spectra, molecular weight measurement, and elemental analysis.

• Journal of the Korean Chemical Society
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• v.31 no.4
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• pp.369-372
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• 1987

Five N-(2-acetyl-2-benzoyl-1-phenylethyl) piperidine derivatives (2a-2e) were synthesized from piperidine, benzoylacetone and benzaldehyde derivatives. Five ${\beta}$-acetyl-${\beta}$-benzoylstyrene derivatives (3a-3e) were synthesized from their adducts of piperidine derivatives. The structures of these compounds were confirmed by means of elemental analyses, ir and nmr spectra.