• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.1973-1978
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• 2014

Here, we present a facile method to synthesize Pt nanoparticles (NPs) and graphene composite materials (Pt/G) via vacuum filtration. Anodic aluminum oxide (AAO) templates were used to separate Pt/G composite and liquid phase. This method can be used to easily tune the mass ratio of Pt NPs and graphene. Pt NPs, graphene, and carbon nanotubes (CNTs) as building blocks were characterized by a variety of techniques such as scanning electron microscopy, UV-Vis spectroscopy, and Raman spectroscopy. We compared the electrocatalytic activities of Pt/G with Pt NP and CNT films (Pt/CNT) by cyclic voltammetry (CV), CO oxidation, and methanol oxidation. Pt/G was much more stable than pure Pt films. Also, Pt/G had better electrochemical activity, CO tolerance and methanol oxidation than Pt/CNT loaded with the same amount of Pt NPs due to the better dispersion of Pt NPs on graphene flakes without aggregation. We further synthesized Au@Pt disk/G and Pt nanorods/G to determine if our synthetic method can be applied to other NP shapes such as nanodisks and nanorods, for further electrocatalysis studies.

• Journal of the Korean Society for Heat Treatment
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• v.19 no.4
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• pp.200-207
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• 2006

In addition to the basic properties of the base and top coating agents, corrosion resistance of non-chrome magni 565 coating and characteristics of coating film when coated to steel substrate were studied. The system had a good wettability at room temperature. Moreover, both the contact angle and surface tension were affected little by the viscosity of coating agent and surface roughness of the steel substrate. And the samples coated with optimal conditions showed a great corrosion resistance in salt spray test with 1500 hours or longer of initial appearance time of rust. The coating film was composed of overlapping layer of zinc and aluminium flakes, and the thickness of base coat increased with an increase of base coat viscosity. Based on the C-F peaks of 1,1-Difluoroethaen homo-polymer, it was thought that the base coat was an inorganic polymer bond layer. Meanwhile, the top coat showed C-F peaks of polytetrafluoroethylene with C-H peaks of phenol in FT-IR analysis. From the lower weight loss of base coat in TG analysis, it was thought that cross linking density of base coat was larger than that of top coat. It was thought that the small exothermic reactions observed in DSC curves were due to the thermosetting resins contained in the coating agents. Compared to the non-coated specimen, the coated sample showed more higher polarization resistance and corrosion potential with lower corrosion current density.

• 보존과학연구
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• s.37
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• pp.43-51
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• 2016

A wooden rice chest in National Museum of Korean Contemporary History was colored by black lacquer but it was degraded and fallen apart partially. The condition of the paint of front and left sides were relatively fine, but the coat of the top, back and right sides were exfoliated. The legs at the bottom of the chest were severly degraded and turned whitish. After condition checking flakes and deterioration of film, the conservation treatment was undertaken with cleaning surface. Wet cleaning was conducted that area had lots of dust area. Apply watery animal glue to degraded lacquer layers. The legs were exfoliated a lot, so applied watery animal glue several times. Other side of rice chest except Gaepan, that was not felt sense of difference, colored centrally Gaepan.

• Journal of Powder Materials
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• v.24 no.6
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• pp.457-463
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• 2017

Nanosized $Gd_2O_3:Eu^{3+}$ red phosphor is prepared using a template method from metal salt impregnated into a crystalline cellulose and is dispersed using a bead mill wet process. The driving force of the surface coating between $Gd_2O_3:Eu^{3+}$ and mica is induced by the Coulomb force. The red phosphor nanosol is effectively coated on mica flakes by the electrostatic interaction between positively charged $Gd_2O_3:Eu^{3+}$ and negatively charged mica above pH 6. To prepare $Gd_2O_3:Eu^{3+}$-coated mica ($Gd_2O_3:Eu/mica$), the coating conditions are optimized, including the stirring temperature, pH, calcination temperature, and coating amount (wt%) of $Gd_2O_3:Eu^{3+}$. In spite of the low luminescence of the $Gd_2O_3:Eu/mica$, the luminescent property is recovered after calcination above $600^{\circ}C$ and is enhanced by increasing the $Gd_2O_3:Eu^{3+}$ coating amount. The $Gd_2O_3:Eu/mica$ is characterized using X-ray diffraction, field emission scanning electron microscopy, zeta potential measurements, and fluorescence spectrometer analysis.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.123-129
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• 2015

There are two kinds of cartons for beverage packaging, one is aseptic brick (AB) type and the other is gable top (GT). In this study, AB and GT were used as a raw material of recycled paper to investigate the recyclability at their varied blending ratios. Fiber consistency at pulping decreased as the blending ratio of AB increased. As a result, a lot of fines were generated from AB and flakes from GT increased because shear force in pulper decreased. Bulk of handsheets was more than $2.0cm^3/g$, and ISO brightness decreased as the blending ratio of AB increased. The best condition to recycle beverage cartons is to discriminate each cartons separately because of differences in the composition. However, there are problems such as the limit of the collection system and social costs. Therefore, it is assumed that the blending ratios of AB should be adjusted at less than 20% for effective recycling of beverage cartons.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.482-483
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• 2011

Graphene is a good candidate for the future nano-electronic materials because it has excellent conductivity, mobility, transparency, flexibility and others. Until now, most graphene researches are focused on the nano electronic device applications, however, biological application of graphene has been relatively less reported. We have fabricated a deoxyribonucleic acid (DNA) conjugated graphene field-effect transistor (FET) and measured the electrical transport characteristics. We have used graphene sheets grown on Ni substrates by chemical vapour deposition. The Raman spectra of graphene sheets indicate high quality and only a few number of layers. The synthesized graphene is transferred on top of the substrate with pre-patterned electrodes by the floating-and-scooping method [1]. Then we applied adhesive tapes on the surface of the graphene to define graphene flakes of a few micron sizes near the electrodes. The current-voltage characteristic of the graphene layer before stripping shows linear zero gate bias conductance and no gate operation. After stripping, the zero gate bias conductance of the device is reduced and clear gate operation is observed. The change of FET characteristics before and after stripping is due to the formation of a micron size graphene flake. After combined with 30 base pairs single-stranded poly(dT) DNA molecules, the conductance and gate operation of the graphene flake FETs become slightly smaller than that of the pristine ones. It is considered that DNA is to be stably binding to the graphene layer due to the ${\pi}-{\pi}$ stacking interaction between nucleic bases and the surface of graphene. And this binding can modulate the electrical transport properties of graphene FETs. We also calculate the field-effect mobility of pristine and DNA conjugated graphene FET devices.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.30-38
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• 2015

In cold-climate regions, deicing agents is used for smooth traffic on the road due to freezing and snowdrift in winter. The use of de-icing salts has resulted in the accelerated scaling damage of concrete with salt damage under freezing and thawing condition. Scaling is the deterioration of concrete where in the paste-mortar structure delaminates in flakes from the surface of the concrete. Due to such damage, concrete pavement causes various problems such as early deterioration according to the decrease in the thickness of cover concrete and user's stability issues. Accordingly, various tests and evaluation methods have been suggested in order to evaluate these phenomena in other countries. However, there have been no regulations for the evaluation method in South Korea, and related studies are also very rare. Therefore, in this study, the evaluation methods proposed by each institution and country were investigated and the experiments were performed according to each regulation, followed by the comparison and analysis of the results. Furthermore, this study aims to suggest the optimized experimental method adopted to domestic field through the discussion of such experimental methods and results.

• The Korean Journal of Food And Nutrition
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• v.28 no.6
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• pp.973-987
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• 2015

This study was conducted to investigate the eating habits and food preferences of elementary school children belong to multi-cultural families and ordinary families. The data were obtained by interview based on questionnaire from November to December in 2012. The subjects of multi-cultural families and ordinary families were 99 and 376 children, respectively. In comparison with eating habits, the ordinary children showed higher scoring in the items of eating proteins, green and yellow vegetables, and fruits or fruit juice than those of multi-cultural children. The ordinary children ate less midnight-meals than those of multi-cultural children (p<0.05). Furthermore, the ordinary children ate kimchi more frequently than the multi-cultural children. It was significantly different (p<0.05) on the items of 'eating-out types' dietary habits between two groups. Education of mothers correlated with the ordinary children's eating habits more than multi-cultural families. In the investigation of the food preference to Korean foods, 'beef and radish soup', 'pumpkin porridge', and 'wheat flakes noodles' were more preferred by children of ordinary families than by those of multi-cultural families (p<0.05). To conclude, nutritional education for their parents should be done and maintained to keep a right eating habit of children of multi-cultural families even at home.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.37-40
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• 1984

A simple and low cost autogenous-type extruder with a capacity of about 400kg/hr for rice bran-oil stabilization was developed. Specific energy consumption of the extruder was 0.060-0.070 KWH/kg of rice bran during extrusion. Rice bran was easily extruded to form flakes or pellets with an increase of bulk density. And also the desired extrusion temperature of $95^{\circ}C{\;}to{\;}150^{\circ}C$ could be easily obtained without any water addition when the rice bran was properly parametered with feed rate. The moisture content of bran was reduced and peroxidase was significantly inactivated after extrusion. The rice bran stabilized by the extrusion process was excellent in storage stability without considerable increase in free fatty acids.

• Korean Journal of Human Ecology
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• v.5 no.2
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• pp.9-21
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• 2002

This study was investigated traditional food utilization actual conditions of Gwangju and Chollanamdo. Frequency of main meal ice plain white rice, boiled rice and cereals, bean-mixed rice, gruel Dakjuk, winter squash porridge, sesame porridge, noodles by noodles cut out with a kitchen knife, noodles with assorted mixtures, soup with dough flakes order frequency much have. Soup ate much beanpaste soup, soup cooked with dried radish leaves, seaweed soup, broth by power-pot soup, hot shredded beef soup, loach soup order. Pot stew soybean paste stew and kimchi stew, beef casserole bean curd beef casserole and small octopus beef casserole often eat. Kimchi ate much cabbage kimchi, radish kimchi, radish cube kimchi, dish of dried slices of radish by sesame leaf dish of dried slices of radish, pickled garlics, Maneuljjong dish of dried slices of radish order. Salted sea foods that eat often were salted anchovies, tiny salted shrimps, Gejang order, and soy sauce were toenjang, korean hot pepper paste, bean-paste soup prepared with around fermented soy beans order, and laver fried kelp, tangle fried kelp, green perilla leaf fried kelp order to fried kelp, and it was bean sprouts, bracken herbs, fragrant edible wild aster herbs order to herbs. It is Ssukgatmuchim, squid debt saliva, Jabanmuchim's order that season, hard-boiled food is beef boiled in soy sauce, mackerel radish hard-boiled food, order of bean curd hard-boiled food, panbroiling ate often by order of Kimchi panbroiling, red pepper anchovy panbroiling, pork panbroiling. Steamed dish is egg steamed dish, fish steamed dish, steamed short-ribs order, fried fish egg speech, by Gimchijeon, Pajeon order, meat roasted with seasoning ate often by laver meat roasted with seasoning, hair-tail meat roasted with seasoning, mackerel meat roasted with seasoning order. Minced raw meat are small octopus raw that live, beef dish of minced raw beef, Hongeohoe order, rice cake is cake made from g1u1ions rice, Seolgitteok, songpyon order, dessert ate often by fermented rice Punch, cinnamon flavored persimmon punch, Kangjung order.