• Journal of Korean Society for Atmospheric Environment
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• v.20 no.6
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• pp.773-781
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• 2004

Ceramic foams prepared from silica -clay were coated with TiO$_2$ and V$_2$O$_{5}$ catalysts for selective catalytic reduction of NOx with NH$_3$. The effects of V$_2$O$_{5}$ loading, reaction temperature, space velocity, and oxygen content on NOx reduction with NH$_3$ were mainly investigated. Also, the NOx reduction characteristics of V$_2$O$_{5}$ and V$_2$O$_{5}$ -TiO$_2$ filters were compared when sulfur dioxide exists. From the results, the optimal NOx reduction with the maximum reduction efficiency of 91 % could be performed under the condition with V$_2$O$_{5}$ loading 6.0 wt. %, reaction temperature 35$0^{\circ}C$, space velocity 6,000h$^{-1}$ , and oxygen content 5%. And, the V$_2$O$_{5}$ -TiO$_2$ filters have shown higher NOx reduction efficiency and acid resistance against sulfur dioxide than the V$_2$O$_{5}$ filters.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.1-7
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• 2005

In vehicle door system, weatherstrip seals protect passengers form noise, dust, rain and wind out of the vehicle. The higher efficient a weatherstrip is, the more durable it is in contact between the door and body frame. In this study, nonlinear finite element(FE) analysis is performed to obtain cauchy-stresses, displacements and reaction forces of the weatherstrip. Mechanical properties of the weatherstrip is obtained by uniaxial tension test. The MARC which is a commercial software for the nonlinear analysis of a flexible FE model is used. Twenty-one cases of the FE model are developed by using Ogden-foam formulation. In the results of nonlinear FE analysis, the most valuable deformation of the weatherstrip occurred when displacement control value reaches 7.2mm. Severe deformation is observed as the displacement control value become more increased. When the weatherstrip is designed, it would be considered that the displacement value of the weatherstrip has to be less than 7.2mm.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.78-82
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• 2023

The oxygen evolution reaction (OER) is the primary challenge in renewable energy storage technologies, specifically electrochemical water splitting for hydrogen generation. We report effects of Mo doping into Ni layered double hydroxide (Ni-LDH) microcrystal on electrocatalytic activities. In this study, Mo doped Ni-LDH were grown on three-dimensional porous nicekl foam (NF) by a facile solvothermal method. Homogeneous LDH structure on the NF was clearly observed. However, the surface microstructure of the nickel foam began to be irregular and collapsed when Mo precursor is doped. Electrocatalytic OER properties were analyzed by Linear sweep voltammetry (LSV) and Electrochemical impedance spectroscopy (EIS). The amount of Mo doping used in the electrocatalytic reaction was found to play a crucial role in improving catalytic activity. The optimum Mo amount introduced into the Ni LDH was discussed with respect to their OER performance.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.452-457
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• 2005

Foam-type MFI zeolite catalyst was prepared by dispersing fine ($-0.2{\mu}m$) particles of MFI zeolite on silicalite foam. Catalytic cracking of n-octane was investigated over the foam-type catalyst and Delplot method was employed to interpret product compositions for deducing reaction mechanism. The Si/Al molar ratio of dispersed MFI zeolite was estimated 25 and its dispersed amount of silicalite foam was 25 wt％. Since the apparent density of the foam type catalyst was very low $0.11g{\cdot}cm^{-3}$, the catalyst loading amount could be varied from 0.02 g to 0.5 g without concerning pressure drop, providing a wide variance in the residence time of the reactants and products. The conversion and olefin yield in the catalytic cracking of n-octane increased with the catalyst loading. The product composition was very simple and could be explained by applying the protolytic cracking mechanism when the catalyst loading was small. Higher loading of the catalyst brought about further reactions of cracked products, accumulating lower olefin and paraffin with low reactivity in product stream and resulting in complex product composition.

• Macromolecular Research
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• v.11 no.6
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• pp.488-494
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• 2003

We have fabricated gelatin-immobilized polyurethane foams (PUFG) by dipping polyurethane foam (PUF) in an aqueous solution containing gelatin and by subsequent reaction with glutaraldehyde after freeze-drying. Gelatin aqueous solutions of different concentrations were used as the dipping solutions to control the amount of immobilized gelatin. The average pore size of PUF decreased with an increase in gelatin concentration. It was found from the hepatocyte adhesion experiment that the amount of hepatocytes seeded on PUFG1, prepared by using a 1% aqueous gelatin solution, was higher than that on other PUFGs. The hepatocytes inoculated in PUFG1, were slightly aggregated as the incubation time increased. The cells inoculated in PUFG1 showed higher ammonia removal ability than those monolayer-cultured on a gelatin-immobilized polystyrene dish (PSG) after 1 and 4 days of incubation time. The inoculated cells exhibited higher albumin secretion relative to monolayer-cultured hepatocytes on PSG. Albumin secretion by hepatocytes seeded on PUFG1 was increased by the presence of serum and was further increased by both the presence of serum and cytokines. The results obtained from a 3-(3,4-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that PUFG can provide a better microenvironment for hepatocyte culture along with nutrition and metabolite transfer through the high porosity of PUF.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.260-266
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• 2012

Syngas and hydrogen from the $CeO_2/ZrO_2$ coated foam devices were investigated under simulated solar radiation. The $CeO_2/ZrO_2$ coated SiC, Ni and Cu foam device were prepared using drop-coating method. Syngas production step was performed at $900^{\circ}C$, and hydrogen production process was performed for ten repeated cycles to compare the CeO2 conversion in syngas production step, $H_2$ yield in hydrogen production step and cycle reproducibility. The produced syngas had the $H_2$/CO ratio of 2, which was suitable for methanol synthesis or Fischer-Tropsch synthesis process. In addition, syngas and hydrogen production process is one of the promising chemical pathway for storage and transportation of solar heat by converting solar energy to chemical energy. After ten cycles of redox reaction, the $CeO_2/ZrO_2$ was analyzed using XRD pattern and SEM image in order to characterize the physical and chemical change of metal oxide at the high temperature.

• Journal of the Korean Ceramic Society
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• v.51 no.6
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• pp.539-543
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• 2014

Foam type porous silicon carbide ceramics were fabricated by a polymer replica method using polyurethane foam, carbon black, phenol resin, and silicon powder as raw materials. The influence of the C/Si mole ratio of the ceramic slurry and heat treatment temperature on the porous silicon carbide microstructure was investigated. To characterize the microstructure of porous silicon carbide ceramics, BET, bulk density, X-ray Powder Diffraction (XRD), and Scanning Electron Microscope (SEM) analyses were employed. The results revealed that the surface area of the porous silicon carbide ceramics decreases with increased heat treatment temperature and carbon content at the $2^{nd}$ heat treatment stage. The addition of carbon to the ceramic slurry, which was composed of phenol resin and silicon powder, enhanced the direct carbonization reaction of silicon. This is ascribed to a consequent decrease of the wetting angles of carbon to silicon with increasing heat treatment temperature.

• Nano
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• v.13 no.11
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• pp.1850136.1-1850136.12
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• 2018

Three-dimensional (3D) mixed phases NiSe nanoparticles growing on the nickel foam were synthesized via a simple one-step hydrothermal method. A series of experiments were carried out to control the morphology by adjusting the amount of selenium in the synthetic reaction. Meanwhile, the as-prepared novel column-acicular structure NiSe exist three advantages including ideal electrical conductivity, high specific capacity and high cycling stability. It delivered a high capacitance of $10.8F\;cm^{-2}$ at a current density- of $5mA\;cm^{-2}$. An electrochemical capacitor device operating at 1.6 V was then constructed using NiSe/NF and activated carbon (AC) as positive and negative electrodes. Moreover, the device showed high energy density of $31W\;h\;kg^{-1}$ at a power density of $0.81kW\;kg^{-1}$, as well as good cycling stability (77% retention after 1500 cycles).

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.540-544
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• 2011

Novel phosphrous flame retardant tetramethylene bis(orthophosphorylurea) (TBPU) was synthesized by the reaction of diphosphoric acid with 1,4-butanediol and urea, and charaterized by Fourier transform infrared spectroscopy (FT-IR). As the amount of TBPU added in polyurethane foam (PUF) was increased, the flame retardancy of PUF was increased and the mechanical properties were not decreased. Also, in the flame resistance test after the reduced pressure storage, the flame retardancy of TBPU added PUF was retained. We could find out that the thermal resistance of TBPU added PUF increased compared to that of pure PUF.

• Composites Research
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• v.28 no.4
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• pp.191-196
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• 2015

In this study, the static analysis and experiment were carried out on DCB specimens manufactured with aluminum foam in order to investigate the fracture toughness at the adhesive joint of the structure bonded with adhesive. In case of static analysis, all specimen models were shown to have the maximum reaction force when the forced displacement proceeded as much as 5 mm. The maximum reaction forces became 0.25 kN, 0.28 kN and 0.5 kN respectively in cases of specimen thicknesses of 35 mm, 45 mm and 55 mm. Two specimens in case of static experiment were selected to verify these analysis results. The maximum reaction forces were shown when the forced displacement proceeded as much as 5 to 6 mm. The maximum reaction forces became 0.22 kN and 0.3 kN respectively in cases of specimen thicknesses of 35 mm and 45 mm. By comparing the derived results, it could be shown that there was not much difference between the data of analyses and experiments. Therefore, It is inferred that the study data can be secured with only analysis by no extra experimental procedure. It is thought that the mechanical properties at the structure bonded of DCB with the type of mode III can be analyzed systematically.