• Transactions of the Korean hydrogen and new energy society
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• v.25 no.4
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• pp.344-354
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• 2014

Activated charcoal supported nickel molybdenum carbide (carburized Ni-Mo/AC) catalysts were prepared by wet-impregnation followed by temperature-programmed carburization using 20% $CH_4/H_2$ gas. The effects of pH and initial Ni/Mo mole ratio during wet-impregnation step on the characteristics of the carburized Ni-Mo/AC catalysts were investigated using ICP, XRD, XPS, BET and $CO_2$-TPD techniques, and correlated with the catalytic activity of the carburized Ni-Mo/AC in methane dry reforming reaction. Comparison of the results of methane dry reforming reaction kinetics with the results of characterization of the carburized Ni-Mo/AC catalyst showed that the catalytic activity in methane dry reforming reaction was higher at higher initial Ni/Mo mole ratio or at lower pH(3~natural value). This phenomenon was related to the crystal size of metallic Ni in the carburized Ni-Mo/AC catalyst.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.280-282
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• 2011

Silica-gold composite particles were prepared by wet chemical route including impregnation method. Obtained composite particles were characterized using FE-SEM, and XPD.

• Korean Journal of Materials Research
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• v.11 no.10
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• pp.846-850
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• 2001

In the present study, nano-size powders of ternary ferrites, $Ni_{0.5}Zn_{0.5}Fe_2O_4$, as the potential catalysts of $CO_2$decomposition, were prepared by the wet processing of hydrothermal synthesis and coprecipitation method, and the catalyzing effects of impregnation of the noble metals, Pt and Pd, onto $Ni_{0.5}Zn_{0.5}Fe_2O_4$for the $CO_2$decomposition were investigated. XRD results of the synthesized ferrites showed a typical spinel structure of ferrite and the particle size was very small as about 6~10 nm. BET surface area of the ternary ferrites was not affected by the impregnation of Pt and Pd. The reactivity of the $CO_2$decomposition to carbon was improved by the impregnation of the noble metals of Pd and Pt. The effect of Pd-impregnation on the $CO_2$decomposition rate was higher than Pt-impregnation.

• Design & Manufacturing
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• v.14 no.4
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• pp.11-16
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• 2020

In this study, forming of carbon composite parts was performed using an injection/compression molding process. An impregnation of matrix is determined by ability of wet and flow rate between the matrix and reinforcement. The flow rate of matrix passing through the reinforcements is a function of permeability of reinforcement, a viscosity of matrix and pressure gradient on molding, and the viscosity of the matrix depends on the mold temperature, molding pressure and shear strain of matrix. Therefore, compression molding experiment was conducted using a heating mold in order to confirm the possibility of matrix impregnation. The impregnation of the matrix through the porosities between the woven yarns was confirmed by the cross-sectional SEM image of compression molded parts. An injection molding process was also performed at a short cycle time, high molding pressure and low mold temperature than those of compression experiment conditions. Deterioration of impregnation on the surface of molded parts were caused by these injection conditions and it could be the reason of decreasing the maximum tensile strength. In order to improve impregnation of matrix on the surface, injection/compression molding and insert-over molding were applied. As a result of applying injection/compression molding and insert-over molding, it was shown that the improvement of impregnation on the surface and the maximum tensile strength was increased about 2.8 times than the virgin matrix.

• Journal of Species Research
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• v.12 no.3
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• pp.203-211
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• 2023

Five ciliate species of Euplotes were isolated from fresh and coastal water during a sampling survey to identify unrecorded ciliates in South Korea. Their morphology was investigated using live observation, protargol and "wet" silver nitrate staining methods. Brief descriptions and microphotographs of each species and a comparison with related species are provided. Euplotes focardii is characterized by an average size of 65×47 ㎛ after protargol impregnation, 6 dorsal and 3 ventral ridges and dorsal argyrome pattern of double-eurystomus type. Euplotes nobilii shows an average size of 34×20 ㎛ after protargol staining, 6 dorsal and 3 ventral ridges and dorsal argyrome pattern of double-patella type. Euplotes octocarinatus, the only freshwater species described in the present study, is characterized by an average size of 66×46 ㎛ after protargol impregnation, 6 dorsal and 3 ventral ridges and dorsal argyrome pattern of double-patella type. Euplotes petzi has an average size of 43×30 ㎛ after protargol staining, a macronucleus hook-shaped and dorsal argyrome pattern in double-patella type. Euplotes raikovi is characterized by an average size of 40×24 ㎛ after protargol staining, 6 dorsal and 3 ventral ridges and dorsal argyrome pattern of double-patella type.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.2
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• pp.129-136
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• 2017

Characteristics of $ZrO_2$ felt supported Cu/Zn catalysts have been investigated for the production of hydrogen via methanol steam reforming. Cu and Zn in different weight percent were loaded using wet impregnation over $ZrO_2$ felt support. The catalysts were characterized with BET and FE-SEM. The performance of these synthesized catalysts were investigated at SCR=1.5, $GHSV=2000h^{-1}$, temperature=$300{\sim}400^{\circ}C$, and pressure=2.5~19.5 barA. The results showed that the $Cu^{32.5}Zn^{7.5}ZrO_2$ catalyst was most active in terms of methanol conversion and hydrogen production. The methanol conversion in steam reforming of methanol was 84.6% at 19.5 barA and furnace $400^{\circ}C$ over $Cu^{32.5}Zn^{7.5}ZrO_2$ catalyst. The catalysts prepared using $ZrO_2$ felt show higher reactor temperature than the pellet type catalyst at same furnace temperature.

• Journal of Species Research
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• v.11 no.4
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• pp.278-286
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• 2022

During a field survey of Korean marine ciliates, we collected Pleuronema marinum from a brackish water sample. It is characterized by the presence of a contractile vacuole in mid-body, rather than the subterminal/ terminal contractile vacuole as in other congeners. The cells were examined in vivo and based on protargol and 'wet' silver nitrate impregnation. In addition, the nuclear 18S rRNA gene was sequenced using a single cell. The Korean population morphologically and molecularly resembles a Chinese population of P. marinum. Historical review of the species concludes that 1) two or more species have been assigned into P. marinum, 2) the position of contractile vacuole (e.g., in mid-body) is a valid character state, and 3) P. marinum is probably a rare species. Here we provide a monographic treatment of P. marinum to clarify the issue and for further studies of relevant species. Considering there are about 40 nominal species and complex nomenclatural acts in the genus Pleuronema, further studies should provide descriptions based on protargol and 'wet' silver impregnation with marker gene(s).

• The Journal of Engineering Research
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• v.3 no.1
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• pp.215-222
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• 1998

The effect of La and Si addition of the thermal stabilization of $\gamma-alumina$ powers have been studied. Reagent grade $La(NO_3)_3{\cdot}6H_2O$ and $Si(OC_2H_5)_4$ were used as starting materials. These additives were introduced by wet impregnation method. Both La and Si additives suppressed the sintering of alumina and were found to be good thermal stabilizers of $\gamma-alumina$. Especially, Si drastically suppressed the phase transition of alumina at high temperatures. The major mechanisms for the thermal stabilization of alumina were seemed to be new phase formation and retardation of surface diffusion by addition of La or Si into alumina matrix.

• Journal of Conservation Science
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• v.6 no.2 s.8
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• pp.126-140
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• 1997

There were some cases in the past that waterlogged wooden finds were neglected and damaged severely because adequate methods of conservation processing could not be found. However, since a wooden ship unearthed in Anapji of Kyongju was processed by poly(ethylene glycol) (PEG) impregnation method in 1975, most of waterlogged wooden finds have been processed by diverse scientific methods. Most commonly-used conservation processing methods of waterlogged wooden finds in Korea are PEG impregnation method, alcohol-ether-resin method and vacuum freeze-drying method. New methods developed recently in Europe and Japan such as sucrose method, sugar-alcohol method and higher alcohol method are also being studied here. The most important task in conservation processing of waterlogged wood is to find good impregnation materials suitable to Korean climate and environments and develop their application methods. For efficient conservation processing, it is important to know the natures of finds and impregnation materials and relation between impregnation and drying condition. To achieve it, many experiments and studies are needed.

• Journal of the Korean institute of surface engineering
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• v.50 no.6
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• pp.523-530
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• 2017

In this study, we developed the h-BN interphase for ceramic matrix composites (CMCs) through a wet chemical coating method, which has excellent price competitiveness and is a simple process as a departure from the existing high cost chemical vapor deposition method. The optimum condition for nitriding an h-BN interphase using boric acid and urea as precursors were derived, and the h-BN interphase coating through a wet method on a carbon preform of 2.5 D was conducted to apply the optimum conditions to the CMCs. In order to control the coating property via the wet coating method, four parameters were investigated such as dipping time of the specimen in the precursor solution, the ratio of boric acid and urea in the precursor, the concentration of solution where the precursor was dissolved, and the cycle of dipping and dry process. The CMCs was fabricated through polymer impregnation and pyrolysis (PIP) processes and a three-point flexural strength test was conducted to verify the role of the coated h-BN interphase.