• Bulletin of the Korean Chemical Society
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• v.19 no.7
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• pp.743-746
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• 1998

The Belousov-Zhabotinskii (BZ) reaction, which is composed of a bromate-organic acid-metal catalyst and an acidic solution is a commonly employed chemical oscillating reaction system. Cyclohexanedione (CHD) has been used as an initial organic substrate in oscillation systems. We studied each system of 1,4-CHD/BrO3-/Ce4/H+ and 1,3-CHD/BrO3-/Ce4+/H+ oscillating reactions, and studied the control of oscillating characters in a CHD/BrO3-/Ce4+/H+ batch system using a mixed substrate of 1,4-CHD and 1,3-CHD under a fixed total CHD concentration. In the mixed reactions, 1,4-CHD was used as a main substrate and small amounts of 1,3-CHD were used in order to vary the oscillatory behaviours by changing the mixing amount ratio of two substrates.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.217-222
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• 2012

The synthesis of dimethyl carbonate(DMC) is a promising reaction for the use of naturally abundant carbon dioxide. DMC has gained considerable interest owing to its versatile chemical reactivity and unique properties such as high oxygen content, low toxicity, and excellent biodegradability. In this study, the synthesis of DMC through the transesterification of ethylene carbonate(EC) with methanol was investigated by using ionic liquid and metal oxide catalysts. The screening test of different catalysts revealed that choline hydroxide ([Choline][OH]) and 1-n-butyl-3-methyl imidazolium hydroxide([BMIm][OH]) had better catalytic performance than metal salts catalysts such as MgO, ZnO and CaO. The effects of reaction parameters such as reaction temperature, MeOH/EC mole ratio, and carbon dioxide pressure on the reactivity of [Choline][OH] catalyst were discussed. High temperature and high MeOH/EC mole ratio were favorable for high conversion of EC. However, the yield of DMC showed a maximum when carbon dioxide pressure was 1.34 MPa, and then it decreased for higher carbon dioxide pressure. Zinc chloride($ZnCl_2$) was used as co-catalyst with the ionic liquid catalyst. The mixed catalyst showed a synergy effect on the EC conversion and DMC yield probably due to the acid-base properties of the catalysts.

• Korean Journal of Materials Research
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• v.22 no.6
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• pp.316-320
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• 2012

$Co_3O_4$, $Al_2O_3$ and $Co_3O_4$/$Al_2O_3$ mesoporous powders were prepared by a sol-gel method with starting matierals of aluminum isopropoxide and cobalt (II) nitrate. A P123 template is employed as an active organic additive for improving the specific surface area of the mixed oxide by forming surfactant micelles. A transition metal cobalt oxide supported on alumina with and without P123 was tested to find the most active and selective conditions as a heterogeneous catalyst in the reaction of styrene epoxidation. A bBlock copolymer-P123 template was added to the staring materials to control physical and chemical properties. The properties of $Co_3O_4$/$Al_2O_3$ powder with and without P123 were characterized using an X-ray diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), a Bruner-Emmertt-Teller (BET) surface analyzer, and $^{27}Al$ MAS NMR spectroscopy. Powders with and without P123 were compared in catalytic tests. The catalytic activity and selectivity were monitored by GC/MS, $^1H$, and $^{13}C$-NMR spectroscopy. The performance for the reaction of epoxidation of styrene was observed to be in the following order: [$Co_3O_4$/$Al_2O_3$ with P123-1173 K > $Co_3O_4$/$Al_2O_3$ with P123-973 K > $Co_3O_4$-973 K>$Co_3O_4$/$Al_2O_3$-973 K > $Co_3O_4$/$Al_2O_3$ with P123-1473 K > $Al_2O_3$-973 K]. The existence of ${\gamma}$-alumina and the nature of the surface morphology are related to catalytic activity.

• Journal of the Korean Ceramic Society
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• v.44 no.6 s.301
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• pp.325-330
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• 2007

High porous AlO(OH) gel is used in precursor of ceramic material, coating material and porous catalyst. For use of these, not only physiochemical control for particle morphology, pore characteristic and peptization but also studies of synthetic method for preparation of high porous AlO(OH) gel were required. In this study, high porous AlO(OH) gel was prepared through the aging and filtration process of aluminum hydroxides gel precipitated by the hydrolysis reaction of $Na_2CO_3$ solution and $Al_2(SO_4)_3$ and $Na_2SO_4$ mixed solution. In this process, optimum synthetic condition of AlO(OH) gel having excellent pore volume as studying the effect of hydrolysis pH on gel precipitates has been studied. Hydrolysis pH brought about numerous changes on crystal morphology, surface area, pore volume and pore size. Physiochemical properties of gel were investigated as using XRD, TEM, TG/DTA, FT-IR and $N_2$ BET method.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.260-265
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• 2006

An experimental study on the catalytic reformer adopted in the auxiliary power unit system of solid oxide fuel cell was conducted. A 3-fluid nozzle, by which liquid fuel such as diesel, water and air are sprayed and uniformed mixed, was designed and used in this study. An electrically heated monolith inserted in the reformer was used for the vaporization of fuel and water in the transient state of reformer. The reformer uses the partial oxidizing reaction at the catalyst and the supply of water prevents the flame combustion in the spraying zone and lessens the deactivation of catalyst. The result showed that the reforming of liquid fuel can be started by the electrically heated monolith and the 3-fluid nozzle can give the uniform mixing of fuel, water and air. It was also found that the reformer fueled by n-hexadecane can make the reformate, at best, containing $H_2$ at 15.5% and CO at 11.5% that are used as fuel in the solid oxide fuel cell.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.4
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• pp.288-294
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• 1993

Flue gas control systems for small-scale combustors must be designed to provide highly effective removal of three criteria pollutants (S $O_{2}$, N $O_{x}$ and particulate matter), and must be safe, reliable and small. These requirements make dry, regenerative clean-up process particularly attractive and this paper describes a new concept for integrated pollutant control : a filter comprised of layered, gas permeable membranes that act as an S $O_{2}$ sorbant, a N $O_{x}$ reduction catalyst and a particulate filter. A mixed metal oxide sorbent, Cu-Ce was used as a sorbent/catalyst and the activity was compared with Cu-7Al. The S $O_{2}$ removal eficiency of Cu-Ce was increased with temperature increase up to 500$^{\circ}$C and the catalytic activity for NO was higher than that of Cu-7Al. By the sulfation of Cu-Ce, the reduction activity was increased at the temperature higher than 350$^{\circ}$C. The regeneration of Cu-Ce was very fast and some amount of elemental sulfar was found.

• Journal of Industrial Technology
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• v.38 no.1
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• pp.15-19
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• 2018

In this study, hyaluronic acid (HA) was electro-spun to fabricate nanofibrous membranes for support materials. Because HA is very hygroscopic, it is difficult to obtain enough viscosity to apply electrospinning method. Therefore, we mixed HA with polyethylene oxide (PEO) to obtain proper viscosity and added adipic acid (ADH) to promote cross-linking of PEO/HA during electrospinning. The morphology of PEO/HA membrane was optimized according to PEO/HA concentration ratio and spinning rate. Finally, we fabricated gold-nanoparticle-embedded PEO/HA membranes and their catalyst activities were evaluated in tetramethylbenzidine (TMB) oxidation.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4371-4376
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• 2011

In this work, we investigate the growth behavior of silicon oxide nanowires via a solid-liquid-solid process. Silicon oxide nanowires were synthesized at $1000^{\circ}C$ in an Ar and $H_2$ mixed gas. A pre-oxidized silicon wafer and a nickel film are used as the substrate and catalyst, respectively. We propose two distinctive growth modes for the silicon oxide nanowires that both act as a unique solid-liquid-solid growth process. We named the two growth mechanisms "grounded-growth" and "branched-growth" modes to characterize their unique solid-liquid-solid growth behavior. The two growth modes were classified by the generation site of the nanowires. The grounded-growth mode in which the grown nanowires are generated from the substrate and the branchedgrowth mode where the nanowires are grown from the side of the previously grown nanowires or at the metal catalyst drop attached at the tip of the nanowire stem.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.54-57
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• 2007

Urea-formaldehyde (UF) resin was formulated similarly to plywood resin in the laboratory. The synthesized UF resin adhesive was mixed with extender, filler and acid catalyst. The mixture contained 56.1% total solids and 43.9% water. The mixes was used to bond five Com-Ply types using Korean wood species. The Com-Ply made were tested for shear strength and wood failure according to KS F 3101 ordinary plywood as well as for bending strength per KS F 3104 particleboard. The performance test results showed good strength properties for all Com-Ply types made in this study. This result represented that the UF resin adhesive mix was adequate for bonding Com-Ply with domestic wood species.

• Journal of Fashion Business
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• v.16 no.1
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• pp.41-51
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• 2012

Polyester is mainly used as a bedding filler material. PLA fiber as an eco-friendly material for substituting polyester has a low melting temperature and therefore a hardening process is impossible. This study is to develop the oil for feather touch that can treat at the melting temperature of PLA. The slippery and soft aminosilicone emulsion, and the bulky epoxysilicone emulsion were used. They had proper viscosity and particle size for flexibility and elasticity. When using methoxy aminosilane [$H_2NSi(OCH_3)_3$] as an aminosilane and [$Zn(OCOCH_3)_2$] as a catalyst, the hardening reaction was fast and effective. Feather touch process were treated by 2 steps. At first step, aminosilicone emulsion, epoxysilicone emulsion and methylaminosilane were mixed and homogenized, and at second step, 5% blened solution of the first step, Zn catalyst 1%, distilled water 94% were treated at PLA fiber. After treatment the static friction coefficient and dynamic friction coefficient were reduced to 23.5-60.8% and 30.0-61.3% respectively, and the laundry and sun light fastnesses have not shown any decrease.