• Journal of Plant Biology
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• v.30 no.3
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• pp.181-187
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• 1987

Copper inhibited PSII-mediated O2 evolution (H2OlongrightarrowDCIP, H2OlongrightarrowSiMo) but not PSImediated O2 uptake(DCIP. Asc.longrightarrowMV) in isolated Chinese cabbage chloroplasts. Copper toxicity on PSII-mediated O2 evolution was higher at alkaline condition than at acidic condition and was inhanced by light illumination after copper treatment. The increased toxicity by light illumination was not recovered by subsequent dark treatment. The inhibitory effect of copper on H2OlongrightarrowDCIP reaction was higher than that on H2OlongrightarrowSiMo reaction. This result suggests that there may be another inhibitory site of copper on PSII other than water oxidizing side of PSII.

• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.59-64
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• 2002

A facile and precise batch oxidation reaction system allows continuous monitoring of the oxidation rate and cumulated oxygen conversion of xylenes, and the side reactions to carbon monoxide and carbon dioxide may also be studied. The oxidation reaction can be analyzed precisely with the rate and amount of oxygen consumed. The reaction reveals that 4-carboxybenzaldehyde is an unstable intermediate of p-xylene oxidation as the reaction proceeds instantaneously from p-toluic acid to TPA (terephthalic acid). The alkali metals accelerate oxidation, even though they retard the reaction initially. The oxidation rate increases with decreasing water concentration. However, in the later part of reaction, the reactivity decreases a bit if the water concentration is very low. This retarding effect of water can be overcome partly by the addition of potassium. The oxidation of o-xylene, compared with the oxidation of p-xylene and m-xylene, proceeds quite fast initially, however, the oxidation rate of xylene isomers in the later stage of reaction is in the order of p-xylene > mxylene > o-xylene.

• Journal of Nutrition and Health
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• v.37 no.8
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• pp.669-674
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• 2004

The purpose of this study was to develop the antiallergic and hypoallergic fennented soybean foods without side effect. We manufactured Chungkukjang with addition of herbal (aloe, cinamon, licorice root) extract. Sensory evaluation was performed to evaluate the acceptability by the consumer. Clinical evaluation was performed with 10 atopic dermatitis (AD) patients who showed positive reaction with specific IgE and skin prick test. Cross-over study between nonnal Chungkukjang and Chungkukjang with aloe extract was performed. In sensory evaluation, Chungkukjang with aloe extract obtained best score overall. In clinical evaluation, 7 out of 10 AD patients showed positive reaction to soy-bean and 4 out of 10 AD patients showed positive reaction to normal Chungkukjang. 2 out of 10 AD patients showed positive reaction to Chungkukjang with aloe extract. In conclusion, Chungkukjang could be recommended as functional food with hypoallergic effect. As adding aloe extract to Chungkukjang, hypo allergic effect was increased.

• The korean journal of orthodontics
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• v.23 no.2 s.41
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• pp.199-216
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• 1993

The purpose of this study was to quantify the biologic effects of the tensile forces from helical springs across the maxillary incisors on the periodontal tissues of rats. 39 Sprague-Dawlely rats were divided into a control group(3 rats) and three experimental groups(36 rats)-group 1, pressured with a light force(50-75g), group 2, with a heavy force(250-300g) and group 3, with a hen force(250-300g) plus laser irradiation. Autoradiographic and histopathologic observations were performed in 12, 24, 48 and 96 hours after force application. The result were as follow : 1. Hyalinized zone of periodontal ligament began to appear at pressure side in 12 hours in group 2 and group 3 ; all decreased in 96 hours except in group 2. 2. Alveolar bone resorption began to appear in 12 hours in group 2 and group 3 ; Group 2 showed more resorption than group 1 and no difference to group 3. 3. Tearing of periodontal ligament and vascular dilatation began to appear at tension side in 12 hours in all groups ; Group 2 showed more changes than group 1 and no difference to group 3 ; Decrease began to appear in 96 hours. 4. New bone formation began to appear at tension side in 12 hours and increased more and more ; No differences were shown of groups 5. New capillary proliferation began to appear at pressure side in 12 hours ; The changes were the greatest in group 3, group 2, group 1, in that order. 6. Positive reaction of cells to $[^3H]-thymidine$ was the greatest in 24 hours of all groups and decreased with times i Group 2 showed more reaction than group 1 and no difference to group 3.

• Elastomers and Composites
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• v.40 no.1
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• pp.3-11
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• 2005

The ruling kinetics of epoxy resins with 3 different kinds or alkenylsuccinic anhydride (ASA) having C-8, C-12, and C-16 pendant side chain length with two different catalysts was studied by using differential scanning calorimetry (DSC). Nonisothermal and isoconversional method has been used for characterizing the effect of the pendant side chain length in the curing process. Results or nonisothermal method showed that there was no significant difference in the effect of the pendant side chain length of ASA. But isoconversional analysis showed that the value of the activation energy for the initiation reaction or C-8, C-12, and C-16 were $61.7{\sim}57.7kJ/mol$, $63.0{\sim}57.3 kJ/mol$, and $130.4{\sim}94.2 kJ/mol$, respectively, depending on the catalyst used. The values of activation energy for the initiation is different as reported value of 20 kJ/mol which indicating the difference in the effect of the pendant side chain length of ASA in the initial stage of the reaction.

• Journal of the Korean Chemical Society
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• v.50 no.4
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• pp.328-337
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• 2006

purpose of this study was to find out problems in experiments for electrolysis of an aqueous CuCl2 solution in high school science textbooks and to suggest an improved experiment considering students' capability of experimenting and laboratory safety in high schools. For this study, the experiments for electrolysis of an aqueous CuCl2 solution presented in 11 high school science textbooks were classified by their experimental methods. After high school chemistry teachers performed the experiments as presented in the high school science textbooks, an analysis was performed on problems of the experiments, and an improved experiment was devised. According to the results of this study, in the experiments for electrolysis of an aqueous CuCl2 solution using a U type tube and a U type tube with branch, reaction velocity of the electrolysis was slow, therefore, a side reaction was generated. In the experiment using a beaker, reaction of each electrode could not be observed separately. And in the experiment using an electrolysis instrument, it was difficult to identify property of the reaction product. In the improved experiment using a reaction vessel of ㅂshape, reaction velocity of the electrolysis was fast, reaction of each electrode could be observed separately, and the side reaction decreased. From these results, it was suggested that the improved experiment would help high school students understand scientific conception regarding electrolysis.

• Journal of the Korean Chemical Society
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• v.12 no.2
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• pp.55-60
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• 1968

Chlorination of aromatic derivatives under UV light and ${\gamma}$-ray irradiation was studied. Ethyl ${\alpha} ,{\beta} -dichloro-{\beta}$-phenyl propionate gave the p-chlorophenyl derivatives when chlorination was done under UV light. The same type of the product was obtained in the reaction where the mole ratio of the ester and chlorine was 1 to 2 and the chlorination was done under ${\gamma}$-ray irradiation. When the mole ratio of the ester and chlorine was 1 to 8, the chlorination reaction under ${\gamma}$-ray irradiation gave a poly-chlorinated derivatives which was identified as a side chain chlorinated p-chlorophenyl derivatives. Ethyl ${\alpha} ,{\beta} -dichloro-{\beta}$-(p-chlorophenyl) propionate gave the same type of the side chain chlorinated p-chloro derivatives by the chlorination under ${\gamma}$-ray irradiation, whereas ethyl ${\alpha} ,{\beta} -dichloro-{\beta}$-(o-chlorophenyl) derivatives gave o,p-dichlorophenyl derivatives. The identifications of the products were based on a radio thin layer chromatography and activation analysis of chlorine contents of product. The chlorination reaction was discussed in regards to the effect of phenyl substituents to the formation of reaction product and the procedures were described.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.6
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• pp.600-608
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• 2015

As a candidate for cheap oxygen carrier, $CaSO_4$ based oxygen carriers have been developing. However, research on reaction characteristics and side reaction of $CaSO_4$ based oxygen carrier is very limited. There are many possible reactions for main components of syngas from coal. In this study, we prepared three $CaSO_4$ based oxygen carriers ($CaSO_4$-$Fe_2O_3$/bentonite, $CaSO_4$-$K_2CO_3$/bentonite, $CaSO_4$-CaO/bentonite) and performed reduction tests by hydrogen. Cyclic reduction-oxidation tests up to $5^{th}$ cycle are also conducted using hydrogen as fuel. Reduction reactivity of those $CaSO_4$ based oxygen carriers were compared with that of NiO based oxygen carrier (OCN703-1100). Real weight change fractions of $CaSO_4$ based oxygen carriers were higher than theoretical oxyen transfer capacity and reactivity of these particles decreased with the number of cycle increased. To check possible side reaction of $CaSO_4$ based oxygen carriers, $CaSO_4$ decomposition tests were carried out and $SO_2$ was detected even at $700^{\circ}C$. Consequently, we could conclude that $CaSO_4$ based oxygen carriers decompose and release $SO_2$ and this reaction lead reactivity decay of $CaSO_4$ based oxygen carries.

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.81-89
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• 2008

Shear test procedure for concrete-dowel interaction was proposed along with determination of dowel support reaction factor or shear spring stiffness constant using the spreadsheet example. For this task, three AASHTO-type standard specimens were prepared to simulate behavior of the jointed concrete pavement. A side support system was adopted to minimize twisting of the test specimen which had been observed in a preliminary test. A typical elastic behavior of the dowel-concrete interaction was observed from several test loops of loading, unloading and reloading procedures. However load versus slab displacement represents to be nonlinear. Test results show that the dowel support reaction factor ranges from 550-880 GN/m3, which is 1.4-2.2 times greater than 407GN/m3 proposed by Yoder and Witczak. This is because less torsional distraction was occurred with the help of a side support system adopted in this experiment. The dowel support reaction factor or shear spring stiffness constant obtained from the procedures proposed in this paper may be used as a reference data for the structural analysis of jointed concrete pavement.

• 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.