• 멤브레인
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• 제22권6호
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• pp.404-414
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• 2012

본 연구에서는 혼합기체 중의 $SO_2$ 제거를 위하여 폴리이서이미드 복합 중공사막을 이용하였으며, 지지체로 사용한 중공사막은 건-습식 상전이 법으로 제조하였다. PEBAX1657$^{(R)}$과 PEG를 혼합하여 제조한 용액을 지지체 표면에 코팅하여 복합막을 제조하였다. 중공사 복합막의 기체투과 특성을 확인하기 위하여 모듈을 제작하였고, 온도와 압력변화에 따른 $SO_2$, $CO_2$, $N_2$ 단일 기체투과를 실시하였다. 그 결과, 운전조건에 따라서 $SO_2$ 투과도는 220~1220 GPU를 나타내었으며, $SO_2/N_2$ 선택도는 100~506을 나타내었다. 그리고 혼합기체 분리거동을 관찰하기 위하여 $SO_2$, $CO_2$, $N_2$로 구성된 혼합가스를 이용하여 온도, 압력, 잔류부 유량을 변화시키면서 투과기체의 유량과 각 성분의 농도변화를 측정하였다. 그 결과, 압력과 온도가 증가할수록 $SO_2$ 제거효율이 높아지는 경향을 나타내었다.

• 자원리싸이클링
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• 제12권3호
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• pp.3-12
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• 2003

폐 탄탈륨 콘덴서에 함유된 탄탈륨 anode를 물리적인 방법으로 회수하고자 파쇄, 입도분리, 건식 자력선별 그리고 공기 분급 실험을 수행하였다. 단체분리를 위해 롤 크럿셔를 사용하여 폐회로 공정에서 8mesh 이하로 파쇄하면. 대부분의 탄탈륨 anode는 레진과의 단체분리는 이루어지나 일부 금속과의 단체분리가 되지 않은 상태로 남게된다. 파쇄된 시료를 8/10 mesh, 10/18 mesh, -18 mesh 로 분립한 결과, 금속물질은 8/10 mesh 입자에, 탄탈륨 anode는 +18 mesh에 주로 분포하며, -l8 mesh에는 레진의 함량이 71.5％로 레진이 탄탈륨 anode나 금속물질보다 미립화가 쉽게 이루어짐을 알 수 있었다. 자력선별에 의한 금속 물질의 분리효율은 원료의 입도에 따라 크게 차이가 있으나, 일부 금속물질이 약자성체이거나 탄탈륨anode와 단체분리가 이루어지지 않아 금속물질 제거율은 62.3%로 비교적 저조하였다. 탄탈륨 anode와 레진의 분리를 위한 입도별 공기 분급실험 결과, 각 입도별 최적 공기량은 각각 39㎥/h, 32㎥/h, 20㎥/h로 나타났다. 최적의 조건으로 회수한 탄탈륨 anode 생산율은 49.39wt.％, 각 성분의 함량은 97.47wt.% 탄탈륨 anode, 0.93wt.％ 레진. 1.51 wt.％ 금속으로 탄탈륨 anode 실수율은 94.45％이었다.

• 멤브레인
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• 제32권2호
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• pp.163-171
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• 2022

알코올의 탈수를 위하여 에너지 다소비 공정인 증류 공정을 투과증발 막 공정으로 대체하려는 연구가 많이 진행되어져 왔다. 대표적인 투과증발 막인 PDMS 분리막에 대한 시간의존적 분리 거동은 분리 메카니즘의 이해에 매우 중요하다. 따라서 본 연구에서는 50 wt% 에탄올-물 혼합용액에 대하여 50℃에서 막면적 1194 cm²인 PDMS/PSF 분리막 모듈의 시간의존적인 투과증발 분리 거동을 고찰하였다. 총 유속과 에탄올/물 분리계수는 투과증발 시간이 증가함에 따라서 초기에 증가하다가 다시 감소하였다. 초기 분리성능의 증가는 건조한 PDMS 분리막에 에탄올이 용해되는데 시간이 걸리기 때문이며, 후기 분리성능의 감소는 주입 탱크의 에탄올 농도가 시간에 따라서 감소하기 때문에 나타나는 현상이었다. 따라서 본 연구로부터 PDMS 분리막을 통한 에탄올의 투과는 용해-확산 메카니즘에 의해 발생된다는 것이 재확인되었다.

• 대한기계학회논문집A
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• 제29권2호
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• pp.228-231
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• 2005

In this paper, we present reusable quartz master fabricated by electron-beam lithography and dry etching process of quartz, and results of injection molding based on the reusable quartz master for the manufacturing of nano-scale information media. Since patterned structures of photoresist can be easily damaged by separation (demolding) process of nickel stamper and master, a master with photoresist cannot be reused in stamper fabrication process. In this work, we have made it possible of the repeated use of master by directly patterning on quart in nickel stamper fabrication process. We have designed and fabricated four different specimens including 100nm, 140nm 200nm and 400nm pit patterns. In addition, both intaglio and embossed carving patterns are fabricated for each specimen. In the preliminary test of injection molding, we have fabricated polycarbonate patterns with varying mold temperature. We have experimentally verified the fabrication process of the reusable quart master and possibility of quartz master as direct stamper.

• 대한기계학회논문집A
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• 제25권1호
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• pp.115-126
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• 2001

In this paper, through a series of comparative experiments, effects of two different cure processing methods, cocure and precure, on the mechanical properties of honeycomb core materials for aircraft applications are considered. Mass of moisture accumulated into the closed cells of the sandwich panel specimen from the measured mass of moisture diffused to the full saturation state into the elements(skin, adhesive layer, Nomex honeycomb), consisting the honeycomb sandwich specimen has been calculated. Water reservoir of 70$\^{C}$ was used to have specimens absorb moisture to see the influence of moisture absorbed into sandwich panel on its mechanical properties. For the repair condition holding for 2 hours at 177$\^{C}$(350℉) temperature, a pressure due to the vapor expansion in each cell of the sandwich panel, which may result in the local separation of the interface between laminated skin and the surface of the honeycomb, has been estimated by vapor pressure-temperature relation from the thermodynamic steam table and compared to the pressure from the ideal gas state equation. The bonding strengths of the laminated skins on the flat surface of the Nomex honeycomb have been compared by the flatwise tension test and climbing drum peel test performed at room temperature for dry, wet and wet-repair specimens, respectively.

• 한국잠사곤충학회지
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• 제39권1호
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• pp.22-29
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• 1997

Ultraviolet weavelength (UV) of 366 nm produced clearer fluorescent dolor than that of 254 nm for the inspection of silkworm cocoons. Fluorescent color of silkworm cocoons varied in color, appears no relationship with the natural color under the normal light. Uniformity of fluorescent color was improved by selection of blue or yellow line from wild types. Blue and yellow, located at the opposite poles on the color solid and L*a*b* color system, confirmed as pure standard of fluorescent color in the silkworm races for commercial white cocoons. the cocoons with blue fluorescence occupied as high as 1.7 to 8.6 times than those with yellow in the Japanese silkworm races. Fluorescence of silkworm cocoon was not affected by forced flow dry at 70$^{\circ}C$ for 6 hrs. While the Japanese races revealed no sexual difference in fluorescent color, sex-dependence of the color was common in the Chinese races for commercial white cocoon. The fluorescence of cocoon shell of Chinese races showed clear separation of blue of median color. Silkworm strain of Dc20 and Fc24 were sexualy segregated 98.8${\pm}$1.20%, 99.0${\pm}$1.00% by cocoon fluorescence, as that of 99.3${\pm}$0.44% by typical larval marking of sex-limited inheritance. Specific expression of cocoon fluorescence, applicable to breeding of simple discrimination of sex for Chinese races, inspected thoroughly on the surface and inner layer of cocoon shell.

• 한국의류학회지
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• 제28권9_10호
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• pp.1282-1291
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• 2004

Kenaf was cultivated and harvested in large quantity in Cheju Island and Chinju, Kyungsangnamdo. It was chemically rotted with 3% NaOH for 60 minutes at 100$^{\circ}C$, neutralized using 1% acetic acid, washed and dried, and obtained 40kg of dry kenaf fiber. Kenaf 15/rayon 85, flax 15/rayon 85, and rayon 100% yam was spun and the physical characteristics were measured. Plain weave and twill weave fabrics were made using each of the above yarns as the filling yam. Cotton 100% yam was used as the warp yam in all fabrics. Kenaf/rayon blend yarns were higher in tenacity and elongation, lower in yam uniformity, higher in the number of nep than the flax/rayon blended yams. Kenaf/rayon blend fabric had higher tenacity and elongation compared to the flax/rayon blend fabric Kenaf/rayon blend fabric was most stiff in both plain weave and twill weave fabrics whereas drape characteristics was dependent upon the fabric structure of the kenaf/rayon blend and flax/rayon blend. There were little differences between the kenaf/rayon blend fabric and the flax/rayon blend fabric in the Kawabata physical measurements and the PHVs. The only drawback of kenaf fiber was it's surface roughness and it is expected that it can be improved by enzyme retting and mechanical bundle separation.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.29-32
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• 2005

Recently, for the problem solution of demand and supply imbalance of fine aggregate due to the shortage of natural fine aggregate and the environment regulation on sea sand extraction in the construction field, the studies for the application of recycled fine aggregate using waste concrete are being progressed versatilely. The purpose of this study is to investigate quality of recycled fine aggregate manufactured by drying manufacturing system which is the manufacture method of high duality recycled fine aggregate, and to analyze on thehardened and durability properties of recycled concrete using it. Therefore it is to present the fundamental data for application and utilization of recycled concrete. The results of this study are as follows; Quality of recycled fine aggregate by drying manufacturing system is improved, and compressive strength, carbonation depth and chloride ion penetration depth of recycled concrete using high quality recycled fine aggregate are similar to those of normal concrete using natural and crashed sand. But, resistance to $H_{2}SO_{4}$ show decreased somewhat.

• Nuclear Engineering and Technology
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• 제40권7호
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• pp.581-592
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• 2008

In this study, a conceptual pyroprocess flowsheet has been devised by combining several dry-type unit processes; its applicability as an alternative fuel cycle technology was analyzed. A key point in the evaluation of its applicability to the fuel cycle was the recovery yield of fissile materials from spent fuels as well as the proliferation resistance of the process. The recovery yields of uranium and transuranic elements (TRU) were obtained from a material balance for every unit process composing the whole pyroprocess. The material balances for several elemental groups of interest such as uranium, TRU, rare earth, gaseous fission products, and heat generating elements were calculated on the basis of the knowledge base that is available from domestic and foreign experimental results or technical information presented in open literature. The calculated result of the material balance revealed that uranium and TRU could be recovered at 98.0% and 97.0%, respectively, from a typical PWR spent fuel. Furthermore, the anticipated TRU product was found to emit a non-negligible level of $\gamma$-ray and a significantly higher level of neutrons compared to that of a typical plutonium product obtained from the PUREX process. The results indicate that the product from this conceptual pyroprocessing should be handled in a shielded cell and that this will contribute favorably to retaining proliferation resistance.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2008년도 춘계학술발표대회 논문집
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• pp.144-148
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• 2008

The purpose of this study is to get a grasp on the current trend of apartment facilities by analyzing the bathroom facilities of the brand apartments, which are currently being sold in the metropolitan area. Twenty eight apartment complexes from top seven brand apartment, ranked by its construction ability in 2007, were selected as the subject of the study. Research was conducted by studying bathroom facilities of each complexes through e-catalogues in their web-site. The results of the analysis are as follows. Functional improvements as well as digital equipments were added to the basic facilities. Also in order to upgrade the quality of bathrooms, various and high-quality facilities and finishing materials were used as well as glass partitions for separation of dry and wet area, sunlight windows and so on. The conclusion reached to the fact that those various bathroom facilities need to be considered in the aspect of providing high quality living environment, not just supplying various bathroom to the future customer.