• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.267-270
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• 2010

This study was carried out to manufacture black charcoal board from domestic wood waste by using serum protein adhesive which is natural, environment-friendly and human-friendly. For the preparation of the serum protein adhesive, pig blood from slaughterhouse was centrifuged and serum was separated from corpuscles and concentrated to 30% by dry weight basis. The particle size of charcoal from domestic wood waste for this study was #6-60. Hot pressing schedule was $170^{\circ}C$ and 40kgf/$cm^2$ (1 min)-10kgf/$cm^2$ (2.5 min)-40kgf/$cm^2$ (5 min). The black charcoal board made by the addition of 13% serum protein adhesive on dry weight basis gave 41.76kgf/$cm^2$ of bending strength, 8.12kgf/$cm^2$ of internal bonding strength, and excellent gas adsorption and workability.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.215-222
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• 2002

As the GPS signals propagate from the GPS satellites to the receivers on the ground, they are delayed by the atmosphere. The tropospheric delay consists of two components. The hydrostatic (or "dry") component that is dependent on the dry air gasses in the atmosphere and accounts for approximately 90% of the delay. And the "wet" component that depends on the moisture content of the atmosphere and accounts for the remaining effect of the delay. The Zenith Hydrostatic Delay (ZHD) can be calculated from the local surface pressure. The Total Zenith Delay (TZD) will be estimated and the wet component extracted later. Integrated water Vapor (IWV) gives the total amount of water vapor that a signal from the zenith direction would encounter. Precipitable Water Vapor (PWV) is the IWV scaled by the density of water. The quality of this PWV has been verified by comparison with radiosonde data(at Osan). We processed data for JULY 2 and JULY 14, 1999 from four stations(Cheju, Kwangju, Suwon, Daegu). We found the coincidence between PWV of the estimations using GPS and PWV of pressing the radiosonde data. The average of the difference between PWV using GPS and PWV using radiosonde was 3.77 mm(Std. ＝ $\pm$0.013 mm) and 2.70 mm(Std. = $\pm$0.0011 mm) at Suwon & Kwangju.

• Journal of the Korean Ceramic Society
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• v.30 no.10
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• pp.845-851
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• 1993

Low firing temperature substrate were synthesized through tape casting and sintering of glass with cordierite composition and then their properties were investigated. Even though the dielectric properties and XRD patterns of substrates, obtained by tape casting and sintering at 900~100$0^{\circ}C$ for various periods, were similar to those of substrates obtained by dry pressing, the sinterability was enhanced. The substrates were thin and the size was 0.6$\times$50$\times$50mm. From the results of dielectric properties, the sinterability and X-ray diffraction pattern, the proper condition for cofiring process with conductor, Cu, was 90$0^{\circ}C$ for 1h. The properties of the substrate are as follows; the dielectric constant was 5.31(at 1MHz), the dissipation factor was 0.0028, the apparent porosity was 0.28% and the main crystalline phase was $\alpha$-cordierite.

• Journal of the Korean Ceramic Society
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• v.16 no.1
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• pp.13-20
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• 1979

High purity alumina has been extracted form low grade Korean alunite. Alunite ore was treated by 15% $NH_4OH$ solution, followed by 10% $H_2SO_4$ leaching and metallic impurities such as Fe and Ti were removed by solvent extraction method. Alumina prepared by the extraction process was 99.9% in purity. Hot Petroleum Drying Method has been employed for the preparation of uniformly fine alumina powder, using chemical reagent aluminum sulfate and ammonium aluminum sulfate extrated from Korea alunite. The sinterability of alumina powder prepared by Hot Petroleum Drying Method was shown to be improved in comparison with the one treated by other methods such as ball milling method, but dry pressing was difficult due to the agglomeration of calcined powder. The best slip of alumina powder prepared by Hot Petroleum Drying Method contained a lower soild content than the one treated by other methods. The alumina body formed by soild and drain casting with the former alumina powder showed a higher sintered density.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.28-28
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• 2003

고온가압소결(Hot Pressing) 된 다이아몬드 공구용 Co-Fe, Co-Ni계 금속본드의 상온 건식 미끄럼 마멸시험을 행하고, 조성에 따른 각 본드의 마멸 특성을 비교하고 마멸 기구를 규명하였다. 미끄럼 마멸시험은 pin-on-disk 형태의 마멸시험기를 사용하여 각 조성의 성분, 적용하중 그리고 마멸상대재를 변수로 상온, 대기 중에서 실시되었다. 마멸속도는 마멸시험 전후의 시편의 무게 감량을 이론밀도와 거리로 나누어 계산되었다. 마멸기구의 규명을 위하여 시험된 시편의 마멸면과 마멸단면을 SEM과 EDS를 이용하여 분석하였다. 시험 결과 Co-Fe system의 경우 그 마멸속도는 마멸상대재의 영향보다는 Fe 첨가에 따른 시편의 미세조직과 기계적 성질의 차이에 따라 크게 변화하였다. 그러나 Co-Ni system의 마멸속도는 마멸 상대재에 따라 크게 변화하는 것이 관찰되었다. $Al_2$O$_3$를 상대재로 마멸된 경우에는 마멸속도가 시편/상대재 접촉면에서 형성되는 산화층의 영향을 크게 받았고, glass bead(83% SiO$_2$)를 상대재로 한 경우에는 시편의 경도와 마멸속도는 서로 반비례하였다.

• Journal of the Korean Ceramic Society
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• v.34 no.4
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• pp.394-398
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• 1997

Mn-Zn ferrite powders were prepared by alcoholic dehydration, using coprecipitation method. Then the effects of organic dispersant and polymeric binder concentration on stability and casting of slurry were discussed. Citric acid, the organic dispersant and polyvinylacohol(PVA), the non-ionic binder, were selected as additives of slurry. With variation of concentration of water, citric acid and polyvinylalcohol(PVA), optimum forming conditions were determined from viscosity and density. To compare with dry process, density and microstructure of sintered body formed by uniaxial die pressing were observed.

• Journal of the Korean Wood Science and Technology
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• v.24 no.2
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• pp.15-19
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• 1996

To utilize the waste materials and develope wood adhesive from isolated bloods of slaughtered cow and pig and also to prevent water pollution, simple and rapid method of isolation and purification of plasma proteins from pig bloods with trichloroacetic acid(TCA) treatment was developed. Adding of TCA-precipitated blood powder to the phenol formaldehyde resin(PF) improved dry and wet strength of plywood and resulted in fast hot pressing times.

• Analytical Science and Technology
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• v.5 no.2
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• pp.217-222
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• 1992

An attempt was made to analyze green microstructure of AIN samples prepared by slip casting and dry pressing through Hg-porosimetry. Slip cast samples with narrow pore size distribation and high packing density showed higher sinterability and homogeneous distribution of second phase(s). Hg-porosimetry is and effective way to determine pore structure if "ink bottle" phenomenon does not occur. A comparison study with porosity measurement by quantitative microscopy showed that the effectiveness of Hg-porosimetry measurement could be extended to higher sintered density as long as pores remained open.

• Journal of the Korean Ceramic Society
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• v.42 no.12 s.283
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• pp.860-864
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• 2005

In this study, we fabricated honeycomb type Mixed-Gas Fuel Cell (MGFC) which has advantages of stacking to the axial direction and increasing volume power density. Honeycomb-shaped anode with four channels was prepared by dry pressing method. Two alternative channels were coated with electrolyte and cathode slurry in order to make cathodic reaction sites and the others were filled with partial oxidation (POX) catalyst to increase fuel conversion. Furthermore we employed the sol-gel technique which can increase cell performance and decrease carbon coking.

• Journal of the Korean Society of Food Culture
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• v.26 no.1
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• pp.39-52
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• 2011

This study examined the types and cooking methods for dasik (traditional pressed sweet), as recorded in 16 old Joseon dynasty (1392-1909) studies. The ingredients used in dasik during the Joseon dynasty were categorized into cereal powders, tree fruits, flower powders, root clods, dry-fish beef powders, and vegetables. In the early, middle, and late eras of the Joseon dynasty, $1^{st}$ set (two, five, and 70 kinds of dasik), $2^{nd}$ set (two, four, and 16 kinds of dasik) were prepared using cereal powders, and during the middle and late eras of the Joseon dynasty one and 22 kinds of dasik were prepared using tree fruits. During the late eras of the Joseon dynasty, seven kinds of dasik were prepared using flower powders, 11 kinds of dasik were prepared using root clods, 12 kinds of dasik were prepared using dry-fish beef powders, and two kinds of dasik were prepared using vegetables. The frequency of the ingredients were in the order of Huek-im (黑荏), Hwang-yul (黃栗), Jin-mal (眞末), Song-wha (松花), and Nok-mal (菉末) during the Joseon dynasty. To prepare dasik, the ingredients were mixed with honey, soy sauce, sesame oil, pepper, and water or ground and shredded to prepare for pressing and for abstract dasik, respectively. The appearance and taste of dasik varied, thereby resulting in nutrient supplementation, as the types of ingredients increased throughout the Joseon dynasty. This observation may be associated with the commercial industrial development that prevailed during the late Joseon dynasty. Further investigation will be conducted on the recipes and ingredients recorded in these old studies to develop a standardized recipe for the globalization of dasik.