• Clean Technology
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• v.25 no.3
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• pp.256-262
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• 2019

Hydroxylammonium nitrate (HAN)-based liquid propellants are attracting attention as environmentally friendly propellants because they are not carcinogens and the combustion gases have little toxicity. The catalyst used to decompose the HAN-based liquid propellant in a thruster must have both low temperature activity and high heat resistance. The objective of this study is to prepare an Ru/alumina/metal foam catalyst by supporting alumina slurry on the surface of NiCrAl metal foam using a washing coating method and then to support a ruthenium precursor thereon. The decomposition activity of a HAN aqueous solution of the Ru/alumina/metal foam catalyst was evaluated. The effect of the number of repetitive coatings of alumina slurry on the physical properties of the alumina/metal foam was analyzed. As the number of alumina wash coatings increased, mesopores with a diameter of about 7 nm were well-developed, thereby increasing the surface area and pore volume. It was optimal to repeat the wash coating alumina on the metal foam 12 times to maximize the surface area and pore volume of the alumina/metal foam. Mesopores were also well developed on the surface of the Ru/alumina/metal foam catalyst. It was found that the metal form itself without the active metal and alumina can promote the decomposition reaction of the HAN aqueous solution. In the case of the Ru/alumina/metal foam-550 catalyst, the decomposition onset temperature was significantly lowered compared with that of the thermal decomposition reaction, and ${\Delta}P$ could be greatly increased in the decomposition of the HAN aqueous solution. However, when the catalyst was calcined at $1,200^{\circ}C$, the catalytic activity was lowered inevitably because the surface area and pore volume of the catalyst were drastically reduced and Ru was sintered. Further research is needed to improve the heat resistance of Ru/alumina/metal foam catalysts.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.107-110
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• 2000

• Proceedings of the Korean Fiber Society Conference
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• 1997.04a
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• pp.165-169
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• 1997

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2002.04a
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• pp.70-74
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• 2002

• 수도
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• s.4
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• pp.6-12
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• 1975

• 보존과학연구
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• s.7
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• pp.292-303
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• 1986

The purpose of this paper is to select the suitable resin as changed in environmental and ingredients, in the conservation of metallic objects. Disposal way of metallic objects were used to various resin and grease which will must be well selected in the nature of relics. The contents of this report are summed up as follows ; The resins of Incralac, Ruscoat, wash primer, Amerlock-400 wrer coated on the slice of ironware (5% saltspray test on the view of nature & Adherence). After the coating, add increasing speed to a corrosion rate, and then the adherence of resins were tested. In this study corrosion test, 0.10-0.25% Amerlock-400 jis proved to be a rare one of corrosion rate and 1.0-2.5% Wash primer is found to be a plenty one of corrosion area.

• Nuclear Engineering and Technology
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• v.16 no.2
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• pp.97-105
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• 1984

A method and computer code for the uncertainty analysis in the top event unavailability are developed and tested by combining Monte Carlo Method and Moments method with fault tree reduction technique. Using system fault trees and unavailability data selected in WASH-1400, the efficiency of the proposed method is tested and these results are compared with those obtained by Monte Carlo method. It is shown that the results are sufficiently good in accuracy and computation time is considerably reduced compared with those by Monte Carlo method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.9
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• pp.1491-1497
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• 1997

The purpose of this research is to improve the surface roughness of cast-iron pipe porduced by the centrifugal casting. A twin-fluid atomizer of mold-wash slurry is designed for this project. New atomizer is equipped with the existing manufacturing facility to produce pipes. Cast-iron pipes (.cent.125*L3000mm) are produced and the surface roughnesses of those are analysed by UBM. The average surface roughness of new products is 6.7.mu.m while the old products of sand-resin coating method have 17.0.mu.m of average surface roughness. The surface roughness of cast-iron pipe is improved very much than before.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.235-237
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• 2006

Non-photorealistic Rendering(NPR) is a method that can be used to simulate a wide range of materials used in visual arts. Currently, there is lack of availability for oriental-style rendering in 3D animation in contrast to the commonly available western-style rendering. In this paper, we combine the wash drawing technique and NPR to create an oriental-style shader for 3D animation. Our approach makes use of the Maya Embeded Language(MEL) to implement this new technique.

• Textile Coloration and Finishing
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• v.13 no.3
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• pp.165-171
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• 2001

In this study, UV/vis. spectra of color solution extracted from onion shell and dyeing properties of polyamide fibers such as wool, silk, and nylon were investigated. Also, the effect of mordanting on wash fastness and light fastness was Investigated. The amount of colors extracted was increased with extracting temperature and time. The wavelength of maximum absorption of onion shell extract corresponds to flavonol peak and quercetin peak. Also, spectra of color solution were shifted to longer wavelength at higher pH values. It appeared that the optimum condition of the dyeing of wool, nylon, and silk fabrics with onion shell extract was $60^\circ{C}$ , 30min, and pH 4.0 of dyed bath. Surface colors of the dyed fabrics were different according to the used mordants: Al and Cr mordanted fabrics were dyed in yellowish colors, Cu mordanted fabric in greenish color, Sn mordanted fabric in orange color, and Fe mordanted fabric in khaki color. The mordanting was effective at improving wash fastness and light fastness.