• Korean Journal of Weed Science
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• v.16 no.4
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• pp.292-300
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• 1996

This experiment was conducted to investigate the factor of phytotoxicity for herbicides(bensulfuron methyl, pyrazosulfuron-ethyl, dimepiperate, molinate) on flood direct-seeded rice. The phytotoxicity of herbicides was evaluated under controlled environment condition. Bensulfuron methyl and pyrazosulfuron-ethyl reduced more rice growth, especially root growth on low temperature(20/$11^{\circ}C$) than high temperature(30/$22^{\circ}C$) cultivations. The phytotoxicity of bensulfuron methyl and pyrazosulfuron-ethyl were increased relatively by non-nutrient and nutrient solution. cultivation, respectively. The rice applied bensulfuron methyl and pyrazosulfuron-ethyl with pH 3.5, 5.5, 7.5 and 9.5 solution became low growth rate on low pH of pH 3.5 and 5.5 solution cultivation. Bensulfuron methyl application with pH 5.5 and pH 7.5 solution, and pyrazosulfuronethyl application with pH 7.5 and 9.5 solution reduced rice growth inhibition. The root growth of rice seeded in 6cm depth of water solution applied herbicides was suppressed by bensulftuon methyl and pyrazosulfuron-ethyl, the growth of shoot was suppressed heavily by dimepiperate and molinate, in particular dimepiperate suppressed about the growth of 90%. The phytotoxicity of pyrazosulfuron-ethyl became high on light clay soil of non-fertilizer condition and sand loam soil of fertilizer condition, bensulfuron methyl became high on sand loam soil.

• Polymer(Korea)
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• v.37 no.2
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• pp.135-140
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• 2013

The stress relaxation of poly(methyl acrylate)-poly(acrylonitrile) copolymer samples was carried out in air, distilled water, pH 3, 7 and 11 solutions at various temperatures using a tensile tester equipped with a solvent chamber. The relaxation spectra of poly(methyl acrylate)-poly(acrylonitrile) copolymers were obtained by applying the experimental stress relaxation curves to the equation of relaxation spectrum derived from the Ree-Eyring and Maxwell model. The determination of relaxation spectra was performed from computer calculation using a Laplace transform method. It was observed that the relaxation spectra of these samples are directly related to the distribution of molecular weights and self-diffusions of flow segments.

• YAKHAK HOEJI
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• v.37 no.6
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• pp.555-560
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• 1993

Methyl 3-[(phenylsulfonyl)methyl]-1, 4, 8-trimethoxy-2-naphthoate(7) preparad by 3 steps was condensed with 5-ethyl-2-cyclohexen-1-one(8) to afford the teracyclic aromatic ring system compound 10, which was stepwise converted into the precursor of 11-Deoxy-$\beta$-rhodomycinone by means of various functional groups transformation.

• Bulletin of the Korean Chemical Society
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• v.11 no.5
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• pp.431-434
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• 1990

Template condensation reaction of diethylenetriamine, ethylenediamine, methylamine, and formaldehyde in the presence of Ni(II) or Cu(II) ion yields new saturated hexaaza macrobicyclic complexes $[Ni(C)]^{2+}\;and\;[Cu(C)]^{2+}$, where C is 8-methyl-1,3,6,8,10,13-hexaazabicyclo[11,2,1]hexad ecane. The macrobicyclic complexes contain one 1,3-diazacyclopentane ring and one methyl pendant arm in the ligand C and have square planar geometry with 5-6-5-6 chelate ring sequence. Synthesis, characterization, and the properties of the macrobicyclic complexes are described.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.302-307
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• 1992

The methanol extract of perilla leaves contained compounds to reduce the mutagenicity of aflatoxin B$_1$(AFB$_1$) in Salmonella typhimurium TA98 and 100. They were separated by solvent extractions and identified by GC and GC-MS as 2-ethoxy acetate, 1, 2, 3, 4-tetramethyl-cis-cyclobutene, two isomers of methyl 11, 14, 17-eicosatrienoate, 12-acetyl-9-octadecanoic acid, and phytol. The antimutagenicities of phytol and methyl 11, 14, 17-eicosatrienoate were dependent on the mutagens tested. Phytol reduced the mutagenicity of Trp-p-2 but not of AFB$_1$and methyl 11, 14, 17-eicosatrienoate reduced the activities both of the mutagens.

• Bulletin of the Korean Chemical Society
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• v.11 no.2
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• pp.144-149
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• 1990

Conformational free energy calculations using an empirical potential function (ECEPP/2) and the hydration shell model were carried out on the sulfonylurea herbicides of bensulfuron methyl (Londax) and metsulfuron methyl (Ally). The conformational energy was minimized from starting conformations which included possible combinations of torsion angles in the molecule. The conformational entropy of each conformation was computed using a harmonic approximation. To understand the hydration effect on the conformation of the molecule in aqueous solution, the hydration free energy of each group was calculated and compared each other. It was found that the low-free-energy conformations of two molecules in aqueous solution prefer the overall folded structure, in which an interaction between the carbonyl group of ester in aryl ring and the first amido group of urea bridge plays an important role. From the analysis of total free energy, the hydration and conformational entropy are known to be essential in stabilizing low-free-energy conformations of Londax, whereas the conformational energy is proved to be a major contribution to the total free energy of low-free-energy conformations of Ally.

• Archives of Pharmacal Research
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• v.13 no.3
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• pp.240-245
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• 1990

Asymmetric 2, 6-dimethyl-4-aryl-1, 4-dihydropyridine-3, 5-dicarboxylate with [N-(3, 4-methylenedioxybenzyl)-N-methyl] aminoethyl group as the ester moiety and related 1, 4-dihydropyridine derivatives were prepared and tested for the effects on vascular smooth muscles. 2-6-dimethyl-4-(3'-nitrophenyl)1-4-dihydropyridine-3, 5-dicarboxylic acid 3-[N-(3', 4-methylenedioxybenzyl-N-methyl] aminoethyl ester 5-methyl ester (11) and 2, 6-dimethyl-4-(3'-nitrophenyl)-1, 4-dihydropyridine-3, 5-icarboxylic acid 3-[N-2', 3'-methylenedioxybenzyl)-N-methyl] aminoethyl ester 5-ethyl ester (150 showed potent vasodilating activities $IC_{50}$($10_{-8}M$) was 2, 6 and 2.7 for 11 and 15, compared with 3.5 for nicardipine.

• Journal of the Korean Applied Science and Technology
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• v.24 no.3
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• pp.296-300
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• 2007

This paper presents applicability of photocatalytic decomposition of methyl mercaptan using $TiO_2$. A quartz reactor was used in order to elucidate reaction pathway in photocatalytic decomposition of methyl mercaptan. Experimental results showed that more than 99.9% of methyl mercaptan was decomposed within 30 minutes. It was found that the photocatalytic decomposition of methyl mercaptan followed pseudo first order and its reaction coefficient was $0.05min^{-1}$ During 30 minutes in the photocatalytic reaction, the concentration of methyl mercaptan, dimethyl disulfide, $SO_2$, $H_2SO_4$, COS, $H_2S$ were determined. These results showed that 64% of methyl mercaptan were compensated for the increase in sulfur after 30 minutes through the mineralization. The proposed main photocatalytic decomposition pathway of methyl mercaptan was methyl $mercaptan{\rightarrow}dimethyl$ $disulfide{\rightarrow}SO_2{\rightarrow}H_2SO_4$.

• Journal of the Korean Chemical Society
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• v.27 no.6
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• pp.441-448
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• 1983

A wide variety of vinylic bromides such as (Z)-1-bromopropene, 1-bromo-2-methylpropene, 2-bromo-3-methyl-2-butene, (E)-ethyl 2-methyl-3-bromo-2-propenoate, 1-bromo-cyclohexene has been found to react with ethyl acrylate, ethyl 3-butenoate, allyl cyanide, (E)-ethyl crotonate, ethyl 4-pentenoate, methyl 10-undecenoate and methyl methacrylate in the presence of triethylamine and a palladium acetate-triorthotolylphosphine catalyst. In general, 2,4-dienoic acid derivatives were obtained in good yield and stereochemistry of the products was determined. Using this method, four, five and eleven carbon-carbon extension with ethyl 3-butenoate, ethyl 4-pentenoate and methyl 10-undecenoate was also possible.

• Journal of the Korean Applied Science and Technology
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• v.16 no.1
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• pp.83-94
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• 1999

Glycoside fatty acid esters were synthesized by lipase-catalyzed glycosylation of fatty acids with methyl glycoside in solvent and solvent free process. Optimum condition of solvent process using 2-methyl-2-propanol were : moral ratio of methyl glycoside to fatty acid 1:3: initial concentration of methyl glycoside 50g/l:enzyme(immodilized lipase Novozym 435 from Candidia antarctica) content 1%(w/v) : desiccant content 9%(w/v); reaction temperature $60^{\circ}C$: reaction time 10hrs. The yield of 99% was obtained. Solvent-free process was carried out in total absence of solvent at $70^{\circ}C$ under reduced pressure, 5-20mmHg. To give meximum yield of 99% at the optimum condition of molar ratio of methyl glycoside to fatty acid 1:3, enzyme content 10%(w/w), and reaction time 10hrs. The glycosylation reactivity of different glycosylation agents were sequent to $Methyl-{\beta}-D-fructofuranoside$. $Methyl-{\beta}-D-glucopyranoside$. $Methyl-{\beta}-D-fructofuranosi$ de, and $Methyl-{\alpha}-D-glucopyranoside$.