• Journal of Adhesion and Interface
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• v.5 no.3
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• pp.10-17
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• 2004

We investigated the effect of stabilization processing parameters on the thermal shrinkage, thermal stability and microstructure of rayon fabrics stabilized under various conditions such as heating rate, stabilization temperature, atmosphere gas, and chemical treatment. The presence and absence of phosphoric acid treatment and the heating rate have most importantly influenced the thermal shrinkage and the weight change of rayon fabrics. Especially, the phosphoric acid treatment decreases the reduction of thickness, length, and weight of the fabrics by about 80%, 20%, and 26%, respectively, in comparison with the untreated counterparts, showing the protective effectiveness of the thermal shrinkage involved. The thermal stability of stabilized rayon fabrics is also affected by all the processing conditions used: stabilization temperature, phosphoric acid treatment, atmosphere gas, and heating rate. In addition, the surface and diameter of the stabilized fiber significantly depend on the treatment of phosphoric acid prior to stabilization process.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.748-753
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• 1999

In gelcasting process of the Si powder slurry mixed with acrylamide monomers, it was characterized the effects of chemical parameters such as monomers and additives(polymerization initiator, catalyst and dispersant), Si powder and humidity at drying on processing parameters such as viscosity and idle time as well as on shrinkage and mechanical strength of green bodies. Generally, idle time decreased as initiator and catalyst amounts were increased, but rather depended on initiator. Idle times of the slurries greatly decreased to less than 1/2 time of the premix solutions in which gelation was delayed at higher MBAM portion as a crosslinking monomer. And fluidity of the slurries became worse at greater than 0.6 wt % dispersant. The green bodies showed only less than 7% of linear shrinkage without crack and distortion when dried for longer than 300 hrs under 98% humidity. Typically, the dried bodies containing 40, 50 vol % of Si powder displayed 64 and 36 Mpa in average, respectively.

• Journal of the Korean Electrochemical Society
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• v.20 no.3
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• pp.49-54
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• 2017

We develop a ceramic composite separator prepared by coating $ZrO_2$ nanoparticles with a poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) copolymer on a polyvinyl alcohol (PVA) mechanical support prepared by electrospinning technique to improve thermal properties. The gurley number of the ceramic composite separator shows much lower value than that of a PE separator even though it possesses the polymeric coating layer with ceramic nanoparticles. In addition, the proposed sample shows higher electrolyte uptake than PE separator, leading to enhancing the ionic conductivity of the proposed sample and, by extension, the rate discharge properties of lithium ion batteries. Thermal stability of the ceramic composite separator is dramatically improved without any degradation in electrochemical performance compared to the performance of conventional PE separators.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.6
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• pp.259-265
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• 2011

This research was performed to stabilize heavy metals in mine tailing using fly ash and clay. Fly ash-clay-mine tailing system were investigated using XRD (X-ray diffractometer), XRF (X-ray fluorescence spectrometer), TG-DTA, SEM (Scanning Electron Microscope), Dilatometer and UTM with various mine tailing contents (~15 wt%). The fly ash used in this research was mainly composed of $SiO_2$ (33.01 wt%), $Al_2O_3$ (28.54 wt%), $K_2O$ (3.32 wt%), $Fe_2O_3$ (1.47 wt%), CaO(9.97 wt%). $SiO_2$ and $Al_2O_3$ composition of the clay was over 61 wt%. And the mine tailing have high composition of $SiO_2$ (26.91 wt%), CaO (24.25 wt%), $Fe_2O_3$ (22.97 wt%). Therefore, it was estimated that fly ash-clay-mine tailing have enough sintering characteristics. The shrinkage of specimens started at around $850^{\circ}C$ and changed little up to $1100^{\circ}C$, but increased markedly at above $1100^{\circ}C$. The shrinkage rate is strongly related to the decarbonization amount of coal fly ash. As the result of SEM, structure of the specimens with mine tailing addition showed more close than the one without mine tailing. Compressive strength of the specimens with mine tailing was highly increased to approximately 200~420 kgf/$cm^2$, it satisfied the first grade criterion for clay brick by KS L 4201. The specification of leaching characteristics of the sintered specimens were within the Korean regulation standard.

• Bulletin of Food Technology
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• v.26 no.3
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• pp.188-194
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• 2013

글로벌동향브리핑(GTB)에서는 100여명의 국내 외 과학기술 전문가가 농림 수산, 생명과학, 보건 의료 등 19개 주제로 해외 과학기술동향을 소개하고 있다. 이를 바탕으로 식품분야의 최신 해외과학기술 주요동향을 요약하여 재정리 하고자 한다. 농수축산물을 포함하여 대다수의 식품은 좋은 음식으로서의 기능 뿐 아니라, 다양한 용도로 활용된다. 점차 이러한 연구가 많아지고 있으며 활용의 범주가 바이오리파이너리, 에너지 생산 외에도 의학, 화학산업 등으로 다양하다. 이번 호에서는 지난해부터 발표된 식품의 새로운 용도가 발견된 결과를 다루고자 한다.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.489-492
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• 2002

고분자/금속 복합재료는 현대 전자산업에 중요한 역할을 하고 있다. 그러나 이들간의 계면은 고분자의 수축 또는 계면 안정성의 저하로 인하여 박리가 일어나게 된다. 즉, 계면의 접합이 떨어지게 되면 전기 화학적인 반응이 계면에서 발생하여 드러난 금속부위는 산화되고 산소가 환원될 때 발생하는 OH기와 같은 라디칼들에 의해 금속과 고분자 사이의 결합이 파괴되어 금속표면으로부터의 고분자의 박리가 발생한다. (중략)

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.237-237
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• 1994

혈압강하작용은 oxyindole계 분획에서 제일 강력하였으며, 다음이 hetero-yohimbine계 분획이며, 극성 alkaloid계 분획이 제일 약하였다. 특히, oxyindole계 및 hetero-yohimbine계는 epinephrine의 승압작용을 길항하지 아니하였으므로 이들의 혈압강하작용은 혈관의 수축작용을 길항하는 기전과는 무관함을 알 수 있었다. 반면에 화학적으로는 hetero-yohimbine계 분획에서 hirsuteine, corynantheine 및 hirsutine을 분리하였고 극성 alkaloid 분획에서는 3$\alpha$-dihydrocadambine을 분리 동정하였으며 전자 3종의 alkaloid는 열(10$0^{\circ}C$)에 안정하고 후자는 불안정함을 확인하였다.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.205-206
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• 2003

Poly(ethylene 2,6-naphthalene dicarboxylate) (PEN)는 주사슬에 PET의 벤젠링 대신에 나프탈렌링을 가지고 있어서 PET보다 분자사슬이 훨씬 더 강직하여 보다 좋은 기계적 물성과 치수안정성을 가진 소재로 알려져 있다. 또한 PEN섬유는 열수축률과 탄성률이 레이온 섬유에 가장 근접해 있고 PET보다 높은 유리전이 온도를 가짐으로써 열안정성이 우수하며 화학적 안정성 또한 뛰어나므로 타이어 코드용 섬유로 널리 알려져 있다. (중략)

• Polymer Science and Technology
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• v.21 no.5
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• pp.426-434
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• 2010

• Ceramist
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• v.4 no.3
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• pp.18-28
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• 2001

세라믹스 부품의 실형상 제조기술은 실형상 성형기술과 더불어 반응소결기술의 발달에 의하여 거의 수축율이 제로인 기술로 발달하고 있다. 분말사출성형으로 대표되던 실형상 성형기술도 젤 캐스팅과 열경화 몰딩과 같은 화학적 성형기술의 도입에 따라 플라스틱과 같이 쉽게 부품을 성형할 수 있는 상태에 도달하고 있다. 특히, 나노분말의 실형상 성형은 화학적 방법에 의해서만 가능할 것으로 예상된다.