• Elastomers and Composites
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• v.41 no.1
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• pp.10-18
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• 2006

Influence of low molecular weight polybutadiene (liquid PB) treated with maleic anhydride on properties of a silica-filled SBR compounds was studied. Silica dispersion was improved by adding liquid PB. The liquid PB treated with maleic anhydride (liquid MAPB) was found to be more effective for the improvement of silica dispersion than the liquid PB without maleic anhydride (liquid NPB). Viscosity of the SBR compound decreased by adding the liquid PB. The crosslink density decreased with increase of the liquid PB content and the cure rate became slower with increasing the liquid PB content. Considering the experimental results, it was believed that addition of small amount of the liquid PB (less than 5 phr) was desirable to improve properties of silica-filled SBR compounds.

• Elastomers and Composites
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• v.38 no.1
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• pp.65-71
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• 2003

Influence of low molecular weight styrene-butadiene rubber (liquid SBR) on properties of a silica-filled styrene-butadiene rubber (SBR) compounds was studied. Viscosity of the silica-filled SBR compound decreased by adding the liquid SBR. The crosslink density decreased and the cure rate became slower as the liquid SBR content increased. The modulus and tensile strength decreased while the elongation at break became longer by increasing the liquid SBR content. The abrasion losses were nearly the same irrespective of the liquid SBR content. This might be due to the improvement of silica dispersion by adding the liquid SBR. Considering the experimental results, it was believed that addition of small amount of the liquid SBR (less than 5 phr) was desirable to improve properties of silica-filled SBR compounds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.119-119
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• 2009

선택적 액상증착(Selective Liquid Phase Deposition)을 이용하면, 기존의 열에 의한 손상 없이 섭씨 50도 이하의 낮은 온도로 실리콘 산화물을 증착시킬 수 있다. 형성된 액상증착 실리콘 산화물은 조직이 매우 치밀하며 표면이 매우 고르게 형성됨을 확인하였다. 뿐만 아니라, 액상증착 실리콘 산화물의 누설 전류 또한 매우 낮음을 확인하였다. 또한 형성된 박막에 다양한 온도 하에서 열처리하여 산화막의 특성 변화를 관찰하였으며, 열처리 후에도 박막의 표면 거칠기나 누설전류의 변화가 미미한 것을 확인하였다. 이것은 액상증착 실리콘 산화물이 열처리 유무와 관계없이 집적회로에서 좋은 절연소재로 사용될 수 있는 가능성을 내포한다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1485-1489
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• 2005

The dropwort was fermented by steeping with brown sugar, fructose syrup or oligosaccharide at room temperature for 2 month, and then stored at cold room for 6 months. The dropwort extracts prepared with three different sugars showed more than $50^{\circ}$Brix, below pH 4.0 and about $0.7\%$ titratable acidity. The dropwort extract with brown sugar showed $1.6{\times}10^6$ viable cell counts and $21.2\%$ reducing sugar. Formation of $CO_2$ gas was superior to the dropwort fermented with brown sugar or oligosaccharide. The dropwort extract with fructose syrup indicated $9.0{\times}10^3$ viable cell counts and $50.1\%$ reducing sugar. Microorganism present in fermented dropwort extract was effectively pasteurized by the addition of $3\%$ citric acid and heat-treatment at $85^{\circ}C$ for 15 min, resulting in the less production of $CO_2$ gas. The dropwort extracts prepared with brownsugar, fructose syrup or oligosaccharide was suitable for the standardization that required for plant extract in Korea Food Codex.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1052-1060
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• 1999

Tire and raw material of tire, i.e., SBR were degraded using pyrolysis process. The yield of pyrolytic oil was increased and that of gas was decreased with increase of operating temperature in pyrolysis. And the yield of pyrolytic oil was increased and that of gas and char was decreased with increase of heating rate. The maximum oil yields of SBR and tire were 86% and 55% each at $700^{\circ}C$ with a heating rate of $20^{\circ}C/min$. The number average molecular weight ranges of SBR and tire were 740~2486, 740~1719, and the calorific value of SBR and tire was 39~40 kJ/g. The oil components were consisted of mostly 50 aromatic compounds. The particle size was decreased and the surface area was increased with increase of operating temperature, and the BET surface area was $47{\sim}63m^2/g$. The optimum condition of pyrolysis was the temperature of $700^{\circ}C$ with heating rate of $20^{\circ}C$, and the reactor was continuously purged with inert gas to sweep the evolved gases from the reaction zone.

• Food Industry And Nutrition
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• v.7 no.3
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• pp.39-43
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• 2002

본 연구에서는 전통적으로 한방에서 성장 촉진을 위하여 사용된 녹각, 우슬, 구기자, 두충, 오미자 및 용안 등의 한약재 추출물과 액상칼슘을 각각 첨가하여 4구간의 빵을 제조하여 품질 특성을 비교 분석하였다. 빵의 물성을 측정한 결과, strength, hardness는 한약재 추출물과 액상칼슘의 첨가량이 많을수록 높아지는 경향을 나타냈었으며 cohesiveness, springiness, gumminess 및 brittleness는 감소하는 경향으로 나타났다. 빵의 내부와 표면의 색도(L,a,b)는 첨가량에 따라 차이가 있었으며 저장 4일째에 각각 변화 정도의 차이가 있었다. $37^{\circ}$ 에서 4일간 저장 후 일반세균은 무첨가구 $15\times10^3CFU/g$에 비하여 한약재 추출물 및 액상칼슘 첨가량이 많은 구간에서는 급격히 감소하여 보존성이 높게 나타났다. 관능적 특성은 실험구간에 따른 유의적 차이는 크게 나타나지 않았으며, 각각의 실험구간에 따른 칼슘함량을 비교 분석한 결과. 한약재 추출물과 액상칼슘이 많은 구간에서 높게 나타나는 경향이었다. 이상의 결과를 바탕으로 성장촉진 한약재 및 액상칼슘을 기능성 소재로서 제빵에 활용 가능할 것으로 생각된다.

• Journal of the Korean Geosynthetics Society
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• v.10 no.3
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• pp.19-24
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• 2011

In the preceding study, the possibility of liquefaction according to the liquefaction evaluation methods was predicted in Saemangeum reclamation area for tide embankment, Jeollabuk-do, Korea. The risk of liquefaction was also expected when foundations and underground structures were built at a depth within 10m below ground surface, and meticulous care was required in the design of them in the future. This study considered the effect of the embedded depth for foundation design regarding liquefaction based on the various earthquake data from literatures. On the basis of the results of this study, an alternative consideration in foundation design for liquefaction was proposed for the Saemangeum area.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.91-100
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• 2011

This study presents the estimation for the possibility of liquefaction according to the liquefaction evaluation methods in Saemangeum reclamation area for tide embankment, Jeollabuk-do, Korea. Liquefaction estimation is performed by cyclic triaxial tests and seismic response analysis using earthquake records of the long- and short-term. This area appears to have greatly potential of liquefaction from the grain-size distribution curve of the dredged and reclaimed soil in the area. Because the liquefaction can occur in this area if the foundations or buried structures are built at a depth within 10m below ground surface, the meticulous care is required in the design of them in the future.

• Journal of Energy Engineering
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• v.10 no.1
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• pp.49-54
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• 2001

최근 자동차용 청정 연료로서의 이용 가능성으로 주목받는 디메틸에테르를 액상 혼합 반응기에서 직접 합성 가스로부터 합성하였다. 메탄올 함성촉매와 감마알루미나의 혼성촉매를 사용한 결과, $H_2$/CO=1일 때, 메탄올 함성 촉매와 탈수촉매의 비가 8:2인 경우, 가장 높은 메탄옥 환산 생산량을 보였다. 또한 공간속도의 변화에 따른 디메틸에테르, 메탄올, 이산화탄소, 메탄 등 각 생성물에 대한 선택도의 변화는 거의 없이 일정하였다. 메탄옥 합성 반응 촉매만을 사용한 경우, 생성물 중 각 성분의 선택도는 반응가스의 공간속도에 따라 달라졌는데, 반응가스의 공간속도가 작아지면 생성물 중 디메틸에테르의 선택도는 변화가 없었으나, 이산화탄소의 발생량이 많고 메탄올의 생성이 적어졌다. 동일한 반응 조건에서 액상 반응과 시강 반응을 비교한 결과, DME 수율이 액상의 경우가 더 높았다.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.185-193
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• 2020

There have been many studies on the calcination of oyster shells in the perspective of recycling of resources. The quicklime made by the calcination of oyster shells is used either as it is or after reacting with water to transform to liquid lime before being used. However, the liquid lime made from calcined oyster shells show slightly different properties from that of limestone. In this study, to compare these properties of oyster shell with those of limestone, the samples were calcined and reacted with water at various temperatures to transform to a liquid lime and filtered using 150 ㎛ sieves to calculate the transform rate to liquid lime. The calcined limestone was transformed to liquid lime at all temperatures, but calcined oyster shell did not show any transformation at 30℃ and 50℃ under the experimental conditions of this study, and rather increased the weight for the remaining after filtration due to the presence of Ca(OH)₂ produced by the reaction with water, Even at 90℃, the transformation rate of calcined oyster shell to liquid lime was lower than that of limestone. This difference in oyster shell can be explained partly by the preventing calcined one from reacting with water by conchiolin which is protein found in the prismatic and pearl layers of oyster shell. Conchiolin is also known to be stable and does not decompose even at high temperature. However, even the calcined chalk layer without conchiolin shows lower transformation rate than that of calcined limestone, probably due to the small amount of Na in oyster shell, which may cause additional reaction including eutectic melt during calcination process.