• 공업화학
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• 제24권3호
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• pp.239-246
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• 2013

기존의 발포유리 제조공정의 원리는 원료유리분말을 거푸집에 담아 발포소성시키며, 발포소성 후에 발포체를 거푸집과 분리 후에 서냉 열처리를 하는 것이다. 이러한 이유로 기존의 발포유리 제조공정은 연속생산이 불가능하다. 본 연구에서는, 발포유리의 연속생산공정을 개발하기 위해서 거푸집을 사용하지 않는 대신, 원료유리분말을 가압성형하여 먼저 성형체를 만들고, 이 성형체를 발포시켜 발포유리를 생산하는 새로운 발포유리제조공정의 가능성을 타진하였다. 수화된 소다석회 유리분말을 사용하고 유리의 발포에 가장 핵심적인 발포제를 달리한 가압성형체를 발포소성시키는 실험 결과를 통해서, 거푸집을 사용하지 않고서도 발포유리의 연속생산공정이 가능할 수 있음을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1406-1409
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• 2003

There is a great demand for reducing the amount of material used in mass-produced plastics parts, for material cost constitutes a large percentage of the total cost of 60%. It may be noted that the price of plastics is directly rotated to the price of petroleum. Material reduction therefore decreases the amount of oil needed for the manufacture of plastics and thus help conserve this natural resource. Therefore microcellular foaming process(MCPs) was studied for solving this problems alternatively in 1980's at M.I.T Until now in MCPs carbon dioxide gas was mainly used for microcellular foaming. Besides, Talc was used for reducing the price of plastics. Consequently, we must certificate using the Talc in MCPs according to contents of the Talc.

• 한국물환경학회지
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• 제22권4호
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• pp.678-686
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• 2006

The feasibility of the high-hydrophilic biofilter was examined for application in rural wastewater treatment in Korea. The intermittent trickling biofiter was developed for wastewater treatment of media and examined instantaneous wetting water and immersional wetting water. Melamin foam absorbed 120 times it's weight in water and maintained wetting status than other materials. These characteristics are improvement for application in rural areas showing large variance of amount of influent. The biofilter process was effective in treating organic pollutants; mean removal efficiencies of $BOD_5$ and TSS were above 80%. The average SS concentrations of effluent was showed below $10mg/L^{-1}$ and meet guidelines in special regions, however, the average concentration of $BOD_5$ was about $20mg/L^{-1}$. The removals of T-N and T-P were relatively less effective and removal efficiencies were below 40%. It might meet the guidelines for T-P because of low levels of influent T-P concentration. However, the T-N concentration were too high and further treatment is required. The effluent concentration of $NH_4-N$ showed a significant reduction rate about 43.8%, but part of $NH_4-N$ was transformed to $NO_2-N$ and $NO_3-N$ inside the biofilter through nitrification process. The effluent concentration of org-P was removed about 78.8% of influent concentration by filtration. Considering stable performance and effective removal of pollutant in wastewater, low maintenance, and cost-effectiveness, the hydrophilic biofilter system was thought to be an effective and feasible alternative for decentralized rural areas.

• Composites Research
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• 제16권3호
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• pp.18-24
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• 2003

샌드위치 구조물들은 적은 무게의 첨가로 높은 강성(stiffness)을 요구하는 조선업에 널리 사용되어져 왔다. 국부하중 조건 하에서 샌드위치 구조물에 대한 디자인 변수들을 고려하는 것은 중요시되어졌다. 이 연구는 샌드위치 보의 강도에 대한 core층의 밀도, core층의 두께 그리고 face층의 두께 비율의 영향을 기술하였다. 이차원 탄성이론에 바탕을 둔 파손 하중은 AS4/3501-6 facing과 polyurethane foam core 샌드위치 보의 3점 굴곡 실험 결과와 잘 일치 하였다. 또한 그러한 파손 하중들은 face층의 비율의 변화와 함께 비교되었다. 파괴 mode들의 교차점으로 결정되어진 최적조건은 강도(strength)와 강성(stiffness)에 대한 샌드위치 빔의 최적 core 밀도의 값이 결정되었다. 추가적으로 강도에 대한 최적조건과 그렇지 못한 샌드위치 보에 대한 face 두께 비율 효과가 하중 길이에 따라 비교되었으며, 강도와 강성이 core/face무게 비율과 항께 검토하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.463-469
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• 2012

Solar thermochemical syngas and hydrogen production process bv redox system of metal oxide was performed under direct irradiation of the metal oxide on the SiC ceramic foam device using solar simulator. $CeO_2/ZrO_2$ nanotube has been synthesized by anodic oxidation method. 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. The produced syngas had the $H_2/CO$ ratio of 2, which was suitable for methanol synthesis or Fischer-Tropsch synthesis process. After ten cycles of redox reaction, $CeO_2$ was analyzed using XRD pattern and SEM image in order to characterize the physical and chemical change of metal oxide at the high temperature.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3177-3183
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• 2012

The carbon nanofibers (CNFs) used in this study were synthesized with an iron catalyst and ethylene as a carbon source. A concentration of 30 wt % iron(III) acetylacetonate was dissolved in resol type phenol resin and polyurethane foam was put into the solution. The sample was calendered after being cured at $80^{\circ}C$ in air for 24 h. Stabilization and carbonization of the resol type phenol resin and reduction of the $Fe^{3+}$ were completed in a high-temperature furnace by the following steps: 1) heating to $600^{\circ}C$ at a rate of $10^{\circ}C/min$ with a mixture of $H_2/N_2$ for 4 h to reduce the $Fe^{3+}$ to Fe; 2) heating to $1000^{\circ}C$ in $N_2$ at a rate $10^{\circ}C/min$ for 30 minutes for pyrolysis; 3) synthesizing CNFs in a mixture of 20.1% ethylene and $H_2/N_2$ at $700^{\circ}C$ for 2 h using a CVD process. Finally, the structural characterization of the CNFs was performed by scanning electron microscopy and a synthesis analysis was carried out using energy dispersive spectroscopy and X-ray photoelectron spectroscopy. Specific surface area analysis of the CNFs was also performed by $N_2$-sorption.

• 한국세라믹학회지
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• 제49권6호
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• pp.654-658
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• 2012

In this work, the properties of an organic-inorganic hybrid insulating material using an inorganic filler and polyurethane foam with different foaming conditions were investigated. At weight ratios of polyol and isocyanate of 1 to 1.2 good foaming properties were noted. In addition, an addition of 0.4 g of water, 0.1 g of surfactant, and 0.1 g of catalyst with respect to the composites of polyol at 5 g and isocyanate at 6 g showed the lowest apparent density and thermal conductivity. The pore size was smaller in the organic-inorganic hybrid foaming body with an increase in the $CaCO_3$ addition amount. Moreover, the apparent density and thermal conductivity were increased when the added amount of $CaCO_3$ increased. Increasing the amount of $CaCO_3$ powder is expected to improve the flame retardant capabilities; however, doing this tends to increase the apparent density and thermal conductivity.

• 한국화재소방학회논문지
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• 제30권6호
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• pp.1-8
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• 2016

유가의 상승과 환경의 문제로 차량중량의 감소에 의한 차량연비를 개선하기 위하여 가연물인 플라스틱과 직물 등의 사용이 획기적으로 증대되어 주차장에서 화재가 발생하면 2000년대 중반 이전에는 한 두 대가 연소되고 마는 것과는 달리 주차된 차량 전체가 연소하는 화재가 많이 발생하였다. 본 연구에서 차량에 사용되는 플라스틱 등 가연물의 량을 확인한 결과 한 대에 316.2 kg으로 차량 전체무게 1935 kg 대비 16.34%가 되어 과거대비 10배 이상의 증가가 있었다. 또한 주차장의 소화설비로 스프링클러를 설치 시 물분무설비의 원래 성능대로 살수밀도를 $20lpm/m^2$를 사용할 것과 필로티 주차장에 호스릴이산화탄소소화설비 대신 적응성이 있는 포, 분말, 강화액 설비를 사용할 것을 요구하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제26권1호
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• pp.61-66
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• 2013

Baculum elongatum has several peculiarities such as parthenogenesis, unique external features, changing body color, and dropping oviposition, which makes it a potential economically useful insect. Oviposition was performed by females without fertilization by the sperm of males. The oviposition period was $42.2{\pm}22.7$ days and the number of eggs per female was $109.5{\pm}70.5$ eggs. The hatch rate was 73.3% at $25^{\circ}C$ and 66.7% after low temperature treatment ($8^{\circ}C$ for 60 days). In nature, B. elongatum overwinters as an egg, but it can be assumed from the results that cold temperatures were not required for hatching. The hatch rate was 98.2% in the treatment using floral foam, fermented sawdust, and leaves. The developmental period was $100.9{\pm}4.2$ days for eggs, $55.3{\pm}4.6$ days for nymphs, and $49.7{\pm}16.0$ days for adults. The length of the eggs was $0.33{\pm}0.0$ cm and the lengths of the nymphs were clearly distinguishable according to the instar stage. Clover(Trifolium repens) was an excellent diet as it was similar to the host plant and could be used as an alternative diet. The rate of reaching adulthood for the insects was 66.7% on an artificial diet containing 25% acacia leaves. For sustainable mass rearing of nymphs or adults of B. elongatum, a natural diet could be used such as acacia (Robinia pseudoacacia), white oak (Quercus aliena), chestnut (Castanea crenata var. dulcis), and bush clover (Lespedeza bicolor), or an alternative diet such as clover or artificial diet.

• 대한기계학회논문집A
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• 제24권4호
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• pp.824-829
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• 2000

The industries use polymer materials for many purposes because they have many merits. But these materials' costs take up too much proportion in overall cost of products that use these materials as their major material. So it is very economical for polymer industries to reduce these costs. Microcellular foaming process appeared in 1980's to solve this problem and it proved to be quite successful. This process uses inert gases such as CO2, N2. As these gases are dissolved into polymer matrices. many properties are changed. Glass transition temperature is one of these properties. DSC, DMA are devices that measures this temperature, but these are not sufficient to measure the temperature of polymer containing gas. In this paper, we devised a new tester that uses magnetism. We used this device to acquire data of the change of glass transition temperature and made Cha-Yoon model that can predict the change of glass transition temperature. Using this model, the change of this temperature can be estimated as a function of weight gain of gas. Cha-Yoon model proved that Chow's model is inappropriate to predict the change of glass transition temperature of polymer matrices containing gas.