• Transactions of the Korean hydrogen and new energy society
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• v.26 no.6
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• pp.507-515
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• 2015

HI decomposition reaction requires a catalyst for the efficient production of hydrogen as a key reaction for hydrogen production in sulfur-iodine thermochemical water-splitting (SI) cycle. As a catalyst used in the reaction, the performance of platinum catalyst is excellent. While, the platinum catalyst is not economical. Therefore, studies of a nickel catalyst that could replace platinum have been carried out. In this study, the characteristics of the catalytic HI decomposition on the amount of loaded nickel (Ni = 0.1, 0.5, 1, 3, 5, 10 wt%) were investigated. As the supported Ni amount increased up to 3 wt%, HI decomposition was found to increase in linear proportion. However, the conversion of $Ni/Al_2O_3$ catalyst loaded above 3 wt% was not linear. It was thought that the different HI decomposition characteristics was caused in the size and metal dispersion of Ni particles of catalyst. The physical property of catalyst before and after HI decomposition reaction was characterized by BET, chemisorption, XRD and SEM analysis.

• Journal of the Korean Chemical Society
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• v.34 no.1
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• pp.102-107
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• 1990

The reaction of thiazoline-azetidinone (7) with $I_2$ in $CH_2Cl_2-H_2O$ gave directly 3-iodo-3-methylcepham (4). A phase transfer catalyst considerably increased the reaction rate. Similar to the hydrolysis of thiazoline-azetidinone (7) under a weak acidic condition, thiazole (10) was given as major product in the treatment with 0.1 eq. of iodine. The difference between cyclization reaction and hydrolysis could be explained in terms of solvents, the amount of iodine and the nature of thiazoline-azetidinones (7).

• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.326-331
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• 2017

Castor oil can be used as a useful raw material for chemical industries such as intermediates of surfactants through hydrogenation reaction. In this study, effects of the preparation method and pretreatment condition on the nickel catalyst for the hydrogenation of castor oil were investigated. The nickel catalyst was supported on the silica carrier by the precipitation method with different Ni contents, solution pH values, and precipitants. Repeated pretreatments of oxidation and reduction cycles were then carried out. The activity of the nickel catalyst was measured by comparing the iodine value of the castor oil. The dispersion of nickel on the catalyst was analyzed by X-ray diffraction (XRD), $N_2$ adsorption-desorption, and transmission electron microscopy (TEM). The activity of nickel catalyst was also compared by CO oxidation experiments. The redispersion of nickel occurred on the silica by repeated oxidation and reduction cycles, and this effect contributed to promoting the castor oil hydrogenation activity.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.3
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• pp.301-308
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• 2006

The present work explores the effect of carbon-supported platinum catalyst on the HI decomposition using gas adsorption analyzer, thermogravimetry, X-ray diffractometry, scanning electron microscopy, and gas chromatography. For this purpose, three types of activated carbon (C), Pt/C-1 wt.%, and Pt/C-5 wt.% were prepared. The HI gas conversion is crucially influenced by the amount of Pt on the carbon support. The more the amount of Pt was, the higher results in the HI gas conversion. For three types of catalysts, HI conversion increased with increasing the decomposition temperature but with decreasing the space velocity. The increase of HI conversion with temperature was more pronounced in activated carbon than that in Pt/C. From EDX result, it was found that the activated carbon comprised higher amount of iodine than the Pt/C after the decomposition reaction. This implies that the HI conversion is closely related to the amount of Iodine.

• Journal of the Korean Applied Science and Technology
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• v.21 no.4
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• pp.359-363
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• 2004

Reaction conditions and catalysts were investigated for direct $CF_3I$ synthesis. Optimum reaction temperature was determined by pyrolysis of $CF_3H$ and catalytic reactions. Reactions with changing oxygen concentration were performed. As a result, yield of $CF_3I$ increased with decreasing oxygen concentration. Catalytic activity was changed with the weight ratio of the used metal salts. This result was stemmed from the change in the pore size of activated carbon by the metal salts. The optimum reaction conditions were: $600^{\circ}C$, space velocity of $45hr^{-1}$, and with 7wt% KF/AC catalyst.

• The Korean Journal of Nuclear Medicine
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• v.12 no.1
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• pp.37-40
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• 1978

Labelling auflatoxines, the potential carcinogenic compounds, by radioactive iodine has been studied. The auflatoxine-$B_1$, which is known to be the most abundant components of auflatoxines in the nature, was labelled by radioactive iodine-125 through an acid catalyst chloroamine-T procedure. The radiochemical yield was amounted to 63.6%. The chemical structure of the labelled product was proved to be 6-iodo 5-methoxy coumarine structure of auflatoxine-$B_1$ molecule by means of I.R. and N.M.R. spectroscopy. The labelled product was orally administered in a test animal (Rat) and examined the accumnulation of radioactivity in the body at the definite time interval. The accumnulation of the radioactivity was pronounced at the blood and the liver. There was no indication of the decomposition of auflatoxine-$B_1-^{125}I$ in the organs of the test animal.

• Journal of the Korean Applied Science and Technology
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• v.10 no.2
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• pp.57-63
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• 1993

This study investigated the reaction and variation of fatty acid composition of soybean oil when it is partially hydrogenated until its iodine value(IV) shifts from 134 to 110. Experment was conducted under he outlined reactiion conditions of temperatures(170, 190 and $210^{\circ}C$), pressure(1.3, 2.8 and 4.2atm) and nickel(Ni) catalyst concentraons(0.005, 0.01, 0.05, and 0.1%) with a fixed agitation(350rpm). Further investigation was also made to see the effect of added lecithin on hydrogenation. When reaction temperature was gradually raised and catalyst concentration increased, the content of linolenic acid progressively decreased while the increase amount of stearic acid reduced(P<0.05). On he other hand when pressure gradually increased, the contents of stearic acid and linolenic acid increased(P<0.05). Meanwhile when lecithin was added, reaction time increased by two to six times more than when no addition was made.

• Journal of the Korean Chemical Society
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• v.12 no.1
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• pp.35-38
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• 1968

Radio iodination of various aromatic derivatives (aniline, toluene, iodobenzene, acetanilide, benzene, benzoic acid) were achieved at low temperature by a chloroamine-T procedures in presence of polar solvent(dioxane). Organic base (piperidine) was used as the catalyst. Iodine replacement reaction had occured on the aromatic or alicyclic ring by this reaction, and the kind and ratio of iodinated products were proved to be different from those of usual iodide reaction in organic solvent at low temperature. The reactivity of various aromatic or alicyclic compounds towards the present iodination system was evaluated and the scope and limitation of the present procedures in the preparation of radio pharmaceuticals were discussed.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.41-46
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• 1995

Changes of fatty acid composition and reaction rate were investigated according to reaction condition during partial hydrogenation reaction of soybean oil until its iodine value decreased from 134 to 110. The reaction conditions were varied in the range of from $170^{\circ}C$ to $210^{\circ}C$ of temperature, from 1.3 atm to 4.2 atm of pressure and from 0.005% to 0.1% of nickel concentration as catalyst. Lecithin was added in soybean oil to investigate the change of reaction rate. The result of addition of lecithin showed that reaction rate decreased to from 2 to 6 times in comparison with non-additive system.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.687-692
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• 1997

During the hydrogenation of rapeseed oil, reaction kinetics and physicochemical characteristics with catalysts (UP9900, DM3, Nysosel 222) were determined. Hydrogenation reaction rates for the UP 9900, Nysel DM3 and Nysosel 222 were $1.6{\pm}0.1\;({\times}10^{-2}),\;1.2{\pm}0.1\;(10^{-2}),\;1.2{\pm}0.1\;(10^{-2})$, respectively. The selectivities for the linoleic acid and oleic acid were determined to be $0.9{\sim}1.5\;and\;39{\sim}44$ at 20 min. From these results, the use of catalysts was shown to be non-selective. Trans isomer content in Nysosel 222 was 32% when the reduction rate of iodine value was 38%, that in Nysel DM3 was 28% at the reduction rate of 45%. UP9900 showed no influence on the trans isomer content. Below the melting point of $35^{\circ}C$, oleic acid and trans isomer acid were increased. On the other side, over the melting point of $35^{\circ}C$, oleic acid was decreased and trans isomer acid was constant. And this tendency was also appeared at the reduction rate of iodine value of 38%.