• Polymer(Korea)
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• v.38 no.6
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• pp.791-800
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• 2014

4-Chlorobenzoyl (CB) group-attached multi-walled carbon nanotube (c-MWNT) was prepared via a direct Friedel-Crafts acylation of MWNT with 4-chlorobenzoic acid (CBA) in a $P_2O_5$/poly(phosphoric acid) medium. c-MWNT with a maximum chlorine content of 5.3 wt% (CB group content of 20.9 wt%) was obtained by controlling the amount of CBA during the reaction. Using a self-condensation polymerization of 4-chlorobenzenethiol (CBT) to poly(phenylene sulfide) (PPS), MWNT-g-PPS was prepared by adding c-MWNT of chlorine content of 5.3 wt% during the self-polymerization of CBT and removing homo PPS after polymerization in order to increase the interfacial interaction between PPS and MWNT. Thermal and surface properties of the MWNT-g-PPS were characterized. The results showed that PPS was formed on the surface of c-MWNT by the condensation of c-MWNT and CBT.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3304-3308
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• 2010

Condensation of 4-amino-5-mercapto-3-($\alpha$-naphthyl)-s-triazole (1) with cyanogen bromide gives 6-amino-3-($\alpha$-naphthyl)-s-triazolo[3,4-b]-1,3,4-thiadiazole (2) which on condensation with chloranil yields 3,9-di-($\alpha$-naphthyl)-6,14-dioxo-bis-(s-triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b]cyclohexane]-5a,6a-diene) (3). 3-($\alpha$-naphthyl)-s-triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b]quinoxaline (4) is obtained by a similar condensation of (2) with 2,3-dichloroquinoxaline. The reaction of (2) with $\alpha$-haloketones followed by bromination affords 7-aryl-3-($\alpha$-naphthyl)-imidazo[2,1-b]-1,3,4-thiadiazolo[2,3-c]-s-triazoles (5) and their 6-bromo analogues 6 respectively. The structures of all newly synthesized compounds were established on the basis of elemental analyses, IR, $^1H$-NMR. The antibacterial and antifungal activities of all newly synthesized compounds have also been evaluated.

• Korean Journal of Materials Research
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• v.5 no.5
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• pp.583-597
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• 1995

We investigated the effect of the oxygne partial pressure on the phase stability of B $i_{2}$S $r_{2}$Ca C $u_{2}$ $O_{8+x}$ and B $i_{2}$S $r_{2}$C $a_{2}$C $u_{3}$ $O_{10+x}$ at 82$0^{\circ}C$. As the oxygen pressure decreased, B $i_{2}$Sr/sb 2/CaC $u_{2}$ $O_{8+x}$ melted at 2.2$\times$10$^{-3}$ atm $O_{2}$. In the case of the B $i_{1.7}$P $b_{0.4}$S $r_{2}$C $a_{2}$ $O_{10+x}$, it started to decompose into theree phases of B $i_{2}$S $r_{2}$Cu $O_{6+y}$, $Ca_{2}$Cu $O_{3}$ and C $u_{4}$ $O_{3}$ and C $u_{4}$ $O_{3}$ at 8.0$\times$10$^{-3}$ atm $O_{2}$ and was completely decomposed at 4.3$\times$10$^{-3}$ atm $O_{2}$ B $i_{2}$S $r_{2}$C $a_{2}$C $u_{3}$ $O_{10+x}$ phase was not formed by the solid state reaction from the mixutre of $i_{2}$S $r_{2}$CaCu.sub 2/ $O_{8+x}$, $Ca_{2}$Cu $O_{3}$ and CuO down to 2.2$\times$10.sub -3/ atm O.sub 2/ but formed by the solidifciation of the formed from the mixture of the intermediate compounds in the Bi-Sr-Ca-Cu-O system and the fromation temperature of Bi.sub 2/S $r_{2}$C $a_{2}$Cu.$_{3}$ $O_{10+x}$ can be lowered by reducing oxygen partial pressure.e.e.ure.e.e.

• Natural Product Sciences
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• v.14 no.3
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• pp.161-166
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• 2008

A mixture of sixteen cerebrosides, which comprised four cerebroside molecular species (PL-1 ${\sim}$ PL-4) was separated from the roots of Paeonia lactiflora. The structures of cerebrosides were characterized as $1-O-{\beta}$-D-glucopyranosides of phytosphingosines, which comprised a common long-chain base, (2S,3S,4R,8E/Z)-2-amino-8-octadecene-1,3,4-triol with eight fatty acids or 2-hydroxy fatty acids of varying chain lengths ($C_{16}$, $C_{18}$, $C_{20-26}$) linked to the amino group. Aralia cerebroside and its 8Z isomer (PL-1), $1-O-{\beta}$-D-glucopyranosyl-(2S,3S, 4R,8E/Z)-2-[(2'R)-2'-hydroxytetracosanoylamino]-8-octadecene-1,3,4-triol (PL-2), $1-O-{\beta}$-D-glucopyranosyl-(2S,3S,4R, 8E/Z)-2-[(2'R)-2'-hydroxydocosanoylamino]-8-octadecene-1,3,4-triol (PL-3), and $1-O-{\beta}$-D-glucopyranosyl-(2S,3S,4R, 8E/Z)-2-[(2'R)-2'-hydroxytricosanoylamino]-8-octadecene-1,3,4-triol (PL-4) were identified as major components of these cerebroside molecular species. All the major cerebrosides were shown to be a mixture of geometrical isomers (8E and 8Z) of phytosphingosine-type glucocerebrosides possessing 2R-hydroxy fatty acids. In addition, three ${\beta}-sitosterol$ derivatives and adenosine were also separated. The structures of these isolates have been determined on the basis of chemical and spectroscopic evidence.

• Journal of the Korean Chemical Society
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• v.10 no.4
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• pp.166-174
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• 1966

The multistep mechanism of photosensitized curing reaction cinnamoylated photosensitive polymer is proposed from the energy level diagram of cinnamic acid and sensitizer, and from the fact that excess of sensitizer brings the sensitivity to a limiting value etc. Various factors which have effects on the ability of sensitizer are also discussed. The mechanism involves following steps: activation to the first excited singlet states of cinnamoyl group(C) and sensitizer(S) by their absorption of photon, their intersystem crossing to the lowest triplet state, bimolecular internal quenching by formation of excimer of sensitizer, triplet excitation energy transfer and intermolecular addition between cinnamoyl group in ground state and that in triplet state. The rate equation derived from this mechanism is $-\frac{d[C]}{dt} = \frac{K_1[C]}{K_2 + [C]}[\frac{I^c_{abs}}{K_3 + [S]} + \frac{K_4[C]}{(K_5 + [C])(K_6 + [S])}(I^s_{abs} + \frac{K_7I^c_{abs}[S]}{K_8 + [S]})]$ where $I^c_{abs}\;and\;I^s_{abs}$: the rates of absorption of photon by cinnamoyl group and sensitizer $K_n$: Constants. It is proved with the cinnamate of poly(glyceryl phthalate)(PGC) in the absence of sensitizer using the infrared analytical method and successfully applied for the experimental data reported on the effects of the degree of cinnamoyl esterification and the concentration of sensitizer upon the sensitivity.

• KSBB Journal
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• v.4 no.3
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• pp.288-292
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• 1989

Induction and culture of hairy roots from ginseng(Panax ginseng C. A. Meyer) roots discs by A. rhizogenes strain $A_4$ were studied. After 6-12 weeks infected with A. rhizogenes tumor and hairy roots emerged from the root discs. The ratio of hairy root induction on root discs was higher in 5-year old than in 3, 4, and 6-year old ginseng. On treatment with IAA, IBA, 2, 4-D and tryptophan, hairy roots formation showed a significant increase at 15-30mg/1 tryptophan treated. Subsequently, hairy roots were cultured on hormone-free RCM medium(pH 4.5, sucrose 30g/1).

• Journal of IKEEE
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• v.23 no.4
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• pp.1257-1264
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• 2019

A 3-GSymbol/s/lane transceiver, which supports the mobile industry processor interface (MIPI) C-physical layer (PHY) specification version 1.1, is proposed. It performs channel mismatch correction to improve the signal integrity that is deteriorated by using three-level signals over three channels. The proposed channel mismatch correction is performed by detecting channel mismatches in the receiver and adjusting the delay times of the transmission data in the transmitter according to the detection result. The channel mismatch detection in the receiver is performed by comparing the phases of the received signals with respect to the pre-determined data pattern transmitted from the transmitter. The proposed MIPI C-PHY receiver is designed using a 65 nm complementary metal-oxide-semiconductor (CMOS) process with 1.2 V supply voltage. The area and power consumption of each transceiver lane are 0.136 ㎟ and 17.4 mW/GSymbol/s, respectively. The proposed channel mismatch correction reduces the time jitter of 88.6 ps caused by the channel mismatch to 34.9 ps.

• The Korean Journal of Food And Nutrition
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• v.10 no.1
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• pp.110-116
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• 1997

Growth curves of seven strains of lactic acid bacteria isolated from Kimchi were graphed during cultivation at 1$0^{\circ}C$, 2$0^{\circ}C$, 3$0^{\circ}C$ and 4$0^{\circ}C$ in filter sterilized Chinese cabbage juice, and then lag time and generation time at each conditions were calcurated. At 3$0^{\circ}C$, the lag time of Leu. mesenteroides subsp. dextranicum was 168 min(minutes), Leu. mesenteroides subsp. mesenteroides 204 min, Leu. paramesenteroides 612 min, Lac. bavaricus 258 min, Lac. homohiochii 228 min, Lac. plantarum 270 min and Lac. brevis 264 min. And at this temperature, the generation times of Leu. mesenteroides subsp. dextranicum and Leu. mesenteroides subsp. mesenteroides were all 36 min, Lac. bavaricus 33 min, Lac. homohiochii 39 min, Lac. plantarum 66 min, Lac. brevis 42 min and Leu. paramesenteroides 162 min. As cultural temperature was lowed from 3$0^{\circ}C$ to 1$0^{\circ}C$, all strains showed remarkable prolongations in lag time and in generation time, and the prolongations were most conspicuous in Lac. plantarum. At 1$0^{\circ}C$, 2$0^{\circ}C$ and 3$0^{\circ}C$, both the lag time and the generation time of Leu. mesenteroides subsp. mesenteroides were shorter than those of Lac. plantarum. But at 4$0^{\circ}C$, this pattern was completely inverted. As a whole lower temperatures were more favorable for the growth of Leu. mesenteroides subsp. mesenteroides, while higher temperatures were for Lac. plantarum.

• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.680-686
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• 2002

The solidification/stabilization mechanism of each cementious material was investigated. It was found that when $C_3$S was hydrated , the Pb element could be transferred to the insoluble Ca[Pb(OH)$_3$.$H_2O$]$_2$and the Cr element to the CaCr $O_4$$H_2O$. The addition of heavy metal tends to delay the hydration until initial 7 days. The Pb element as also delayed the hydration and the Cr element was substituted for the ettringite. On the occasion of the hydration of $C_4$ $A_3$ $S^{S}$, the Pb and Cr ions were solidified/stabilized by the substitution into the ettringite and/or monosulfate. Leaching of the Pb, Cr and Zn elements in the solidified material was extremely little, indicating that heavy metals were effectively solidified/stabilized in the hydrated cementious materials. Solidification/stabilization of heavy metal ions in the industrial wastes such as the STS, BF and COREX sludge was investigated. In case of the mixing ratio of cement and slag was 3 : 7, leaching of hazardous heavy metal ions was very little, indications that the solidification and stabilization was very successful.l.

• 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.