• Rapid Communication in Photoscience
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• v.1 no.2
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• pp.42-42
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• 2012

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1195-1198
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• 2013

Nickel hexacyanoferrate supported palladium nanoparticles (Pd-NiHCF NPs) were synthesized and studied for oxygen reduction reactions in direct methanol fuel cell. The NiHCF support was readily synthesized by a comixing of $Ni(OCOCH_3)_2$ and equimolar $K_3[Fe(CN)_6]$ solution into DI water under rigorous stirring. After the preparation of NiHCF support, Pd NPs were loaded on NiHCF via L-ascorbic acid reduction method at $80^{\circ}C$. Pd-NiHCF NPs were electrochemically active for oxygen reduction reaction in 0.1 M $HClO_4$ solution. X-ray absorption near edge structure analysis was conducted to measure the white line intensity of Pd-NiHCF to verify the OH adsorption. As a comparison, carbon supported Pd NPs exhibited same white line intensity. This study provides a general synthetic approach to easily load Pd NPs on porous coordination polymers such as NiHCF and can provide further light to load Pd based alloy NPs on NiHCF framework.

• Molecules and Cells
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• v.39 no.12
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• pp.855-861
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• 2016

Ginsenosides, which are the active materials of ginseng, have biological functions that include anti-osteoporotic effects. Aqueous ginseng extract inhibits osteoclast differentiation induced by receptor activator of NF-${\kappa}B$ ligand (RANKL). Aqueous ginseng extract produces chromatography peaks characteristic of ginsenosides. Among these peaks, ginsenoside Re is a major component. However, the preventive effects of ginsenoside Re against osteoclast differentiation are not known. We studied the effect of ginsenoside Re on osteoclast differentiation, RANKL-induced tartrate-resistant acid phosphatase (TRAP) activity, and formation of multinucleated osteoclasts in vitro. Ginsenoside Re hampered osteoclast differentiation in a dose-dependent manner. In an in vivo zebrafish model, aqueous ginseng extract and ginsenoside Re had anti-osteoclastogenesis effects. These findings suggest that both aqueous ginseng extract and ginsenoside Re prevent bone resorption by inhibiting osteoclast differentiation. Ginsenoside Re could be important for promoting bone health.

• Journal of Engineering Education Research
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• v.15 no.4
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• pp.101-108
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• 2012

The purpose of this study is to infer how is the effect of a governmental funding project to graduate schools by taking an example of World Class University Project's potential impact on the change of world university rankings in an international university ranking survey. Systematic results show that WCU contributes to improving academic peer reviews for both individual and institutional standings and discipline-based rankings. The potential effect of improving world rankings of participating universities could be ascribed to relatively higher weight of the survey to international peer review and invitation of world class scholars to the participating universities, which is a core device of the project. This implies a need to affirmatively utilize WCU foreign scholars over the course of facilitating international academic networking. The results should also be taken into consideration by universities and the government when developing evaluation systems and restructuring the project.

• Journal of the Korean association of regional geographers
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• v.19 no.4
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• pp.787-804
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• 2013

The purpose of this study is to explore the effect of 'World Cafe' conversations for collective intelligence. For this purpose, 'World Cafe' was applied to the class 'presentation and discussion' of university class. To explore the effect of 'World Cafe' conversations for collective intelligence I surveyed the responses of students participating in the class and analyzed results of the survey and class activities. The results are as follows: first, 82 percent of all students were actively involving in the class, second, topics were more discussed through World Cafe class than general discussion class. These results suggest 'World Cafe' class induced active participation of the students in class and have the effect producing the collective intelligence.

• Journal of the Korean Electrochemical Society
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• v.15 no.2
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• pp.109-114
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• 2012

The cathode catalyst layer in polymer electrolyte membrane fuel cells (PEMFCs) was fabricated with anodic aluminum oxide (AAO) template and its structure was characterized with scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The SEM analysis showed that the catalyst layer was fabricated the Pt nanowire with uniform shape and size. The BET analysis showed that the volume of pores in range of 20-100 nm was enhanced by AAO template. The electrochemical properties with the membrane electrode assembly (MEA) were evaluated by current-voltage polarization measurements and electrochemical impedance spectroscopy. The results showed that the MEA with AAO template reduced the mass transfer resistance and improved the cell performance by approximately 25% through controlling the structure of catalyst layer.

• Journal of Electrochemical Science and Technology
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• v.1 no.1
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• pp.19-24
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• 2010

Alloying degree is an important structural factor of PtRu catalysts for direct methanol fuel cells (DMFC). In this work, carbon supported PtRu catalysts were synthesized by reduction method using anhydrous ethanol as a solvent and $NaBH_4$ as a reducing agent. Using anhydrous ethanol as a solvent resulted in high alloying degree and good dispersion. The morphological structure and crystallanity of synthesized catalysts were characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM). CO stripping and methanol oxidation reaction were measured. Due to high alloying degree catalyst prepared in anhydrous ethanol, exhibited low onset potential for methanol oxidation and negative peak shift of CO oxidation than commercial sample. Consequently, samples, applying ethanol as a solvent, exhibited not only enhanced CO oxidation, but also increased methanol oxidation reaction (MOR) activity compared with commercial PtRu/C (40 wt%, E-tek) and 40 wt% PtRu/C prepared in water solution.

• Journal of Electrochemical Science and Technology
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• v.2 no.4
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• pp.204-210
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• 2011

Thin film electrodes have been intensively studied for active materials and current collectors to enhance the electrochemical performance. Here, porous structures of nickel-based oxide films, consisting of nickel oxide and copper (II) oxide, which was derived from the copper substrate during the annealing process, were deposited on metallic copper foils. The half-cell tests revealed excellent capacity retention after $80^{th}$ charge/discharge cycles. Some films showed an excess of the theoretical capacity of nickel oxides, which mainly originate from partially oxidized copper substrates during annealing. These results exhibit that both a preparation method of an active materials and partially oxidized current collectors could be important roles to apply thin film electrodes.

• Korean Journal of Comparative Education
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• v.28 no.4
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• pp.107-135
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• 2018

This study examines the contents and characteristics of 'Double First Class University Plan', which is conceived by Chinese government in 2015, following the current 211, 985 projects to develop comprehensively a group of elite Chinese universities and individual university departments into world class universities and disciplines by the end of 2050. For this study, we used the literature analysis method and collected various policy documents, research papers, newspapers and books published in China regarding this plan. First, this study looks at the development process, performance and limitations of 211, 985 projects. Second, it defines the concept of the world class university mentioned in China, and looks at the objectives and highlights of the plan. Finally, this study summarizes the characteristics of 'Double First Class University Plan' and the results such as focusing on the university's tradition and characteristic, cultivation and attraction of human resources, intensive financial support, and the introduction of a competitive system. Based on the results, this study proposes several implications such as establishing and implementing long-term and comprehensive higher education policies, inducing local government participation and support, focusing on fostering talents and developing disciplines, and putting emphasis on Korean characteristics in developing world class universities.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.613-619
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• 2011

Colloidal silver nanoparticles (AgNPs) have been commercialized as the typically stabilized form via the addition of a variety of surfactants or polymers. Herein, to examine the effects of stabilizing AgNPs in suspension, we modified the surface of bare AgNPs with four type of surfactants (NaDDBS, SDS, TW80, CTAB) and polymers (PVP, PAA, PAH, CMC). The modified AgNPs was applied to compare suspension stability and nanotoxicity test using Escherichia coli (E. coli) as a model organism. Modification of AgNPs surface using chemical stabilizer may be not related with molecular weight, but chemical structure such as ionic state and functional group of stabilizer. In this study, it is noteworthy that AgNPs modified with a cationic stabilizer (CTAB, PAH) were importantly toxic to E. coli, rather than anionic stabilizers (NaDDBS, SDS). Comparing similar anionic stabilizer, i.e., NaDDBS and SDS, the result showed that lipophilicity of chemical structure can affect on E. coli, because NaDDBS, which contains a lipophilic benzene ring, accelerated the cytotoxicity of AgNPs. Interestingly, none of the stabilizers tested, including biocompatible nonionic stabilizers (i.e., TW80 and cellulose) caused a reduction in AgNP toxicity. This showed that toxicity of AgNPs cannot be reduced using stabilizers.