• 한국정밀공학회지
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• 제19권10호
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• pp.212-220
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• 2002

The finishing process for die and mold manufacturing is very important because it influences the final quality of products. Injection molds need higher quality surface than general purpose dies and molds. Conventional polishing can not make mold surface down to nanometer roughness efficiently because of their loading and glazing. This paper focused on the development of fixed abrasive pad using water swelling mechanism of polymer binder network. Self-conditioning was recognized as the long term polishing stabilization tool without any loading or glazing because water makes fixed abrasives free by swelling of the pad. Consequently, stable nano-polishing process has been applied on the injection mold, from the experimental results with polished surface roughness of Ra 15.1nm on STD-11 die steel.

• 생약학회지
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• 제27권3호
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• pp.274-281
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• 1996

Ulmus parvifolia has been used as a traditional folk medicine to treat the carbuncle in deep skin. In this study, the effect of water extract of root bark of Ulmus parvifolia (WUP) on the carbuncle, pain, inflammation and hypersensitivity was evaluated in animal models. The administration of WUP significantly decreased the size of Staphylococcus aureus ($10^8$ cells/mouse)-induced carbuncle, and also exhibited analgesic activity in the HAc-induced writhing syndrome at doses of 50-500 mg/kg. It also showed significant anti-inflammatory activity in the carageenin- and complete Freund's adjuvant-induced inflammation. In the histamine-induced anaphylaxis, it decreased the percent of mortality by protecting mice treated with Bordetella pertussis. In the immune responses in the mice sensitized and challenged with sheep red blood cells, the Arthus reaction determined by swelling of foot pad at 4 h after challenge, HA titer, HY titer and PFC which can be used to evaluate the humoral immune response were significantly suppressed by oral administration of WUP at doses of 100 and 200mg/kg. The cellular immune responses in the same mice such as delayed type hypersensitivity determined by swelling of foot pad at 24 h after challenge and RFC were also significantly suppressed in the same manner.

• 대한화학회지
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• 제45권3호
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• pp.230-235
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• 2001

양 밀단에 methacryl기를 함유한 polydimethylsiloxane(PDMS)을 가교제로 하여 poly(N-isopropylacrylamide)(PNIPAAm)을 합성하여 PDMS를 함유한 PNIPAAm을 얻었다. IR, DSC를 이용하여 그것들의 성질을 조사하였으며 DSC 조사결과 PNIPAAm과 PDMS는 각각 분리된 상으로 존재하는 것이 확인되었으며, PNIPAAm의 $T_g$는 PDMS의 함량이 증가하면 약간씩 감소하였다. 또한 온도에 따른 팽윤도를 조사한 결과 PDMS의 함량이 증가하면 팽윤도는 감소하였으나 lower critical solution temperature(LCST)는 큰 변화가 없었다. 수팽윤된 중합체의 DSC 측정결과도 LCST는 PDMS의 함량에 영향을 받지 않는 다는 것을 확인하였다.

• 한국식품과학회지
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• 제16권2호
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• pp.201-205
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• 1984

생강전분의 몇 가지 물리화학적 성질을 옥수수 가교 전분과 비교 검토하였다. 생강전분은 아밀로스 함량이 23.5%, 물결합 능력이 99.1%이었고 B형의 X-ray 회절도를 보였다. 생강 전분의 광투과도는 $70^{\circ}C$ 이후에 증가하였고 옥수수 가교 전분의 swelling power와 용해도는 $90^{\circ}C$까지 아주 낮은 값을 보였으며, 알카리에 대하여도 안정하였다. 아밀로그라피에 의한 생강전분 (7%)의 초기 호화온도는 $81.5^{\circ}C$ 이었고, 옥수수 가교전분과 같이 안정한 Paste를 보였다.

• 한국식생활문화학회지
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• 제36권5호
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• pp.484-491
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• 2021

This study investigated the effect of dry heat treatment (DHT) on the physicochemical properties of hard type (HR) and floury type (FR) rice to improve the processing aptitude of rice flour. The rice flour was heated at 130℃ for 0, 2 and 4 hours, and the color value, water absorption index (WAI), water soluble index (WSI), swelling power, solubility, pasting properties, particle shape and the X-ray diffraction were measured. After DHT, the L value of rice flour decreased, and the b value increased. The WAI, WSI, swelling power and solubility of HR and FR increased with the increase of treatment time. The cold viscosity and setback increased, while breakdown decreased. Cracks and lumps formed with fine particles were observed. The X-ray diffraction pattern was A-type, while the diffraction intensity decreased. According to the results of the two-way analysis of variance (ANOVA) test, the hydration and pasting properties were significantly different between HR and FR and were affected by DHT time. The results suggest that the properties of modified rice flour by DHT can be used in the food industry.

• Journal of the Korean Wood Science and Technology
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• 제50권1호
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• pp.59-67
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• 2022

Dietary fiber is considered a feed ingredient with high nutritional value in the broiler feed industry. Pine chips contain a large amount of dietary fiber and require some modification for use as broiler feed. In this study, pine chips were subjected to steam explosion under different severity factor (Ro) conditions to improve the chemical and physical properties of dietary fiber. The highest water-holding capacity, oil-holding capacity, and swelling capacity were found for Ro 4.0, followed by Ro4.5 and 3.5. The optimal condition for the steam explosion was determined to be Ro 4.0 (reaction temperature of 210℃, and reaction time of 6.0 min). Under these conditions, the water-holding capacity, oil-holding capacity, and swelling capacity of steam-exploded pine chips were 8.3 g/g, 6.5 g/g, and 5.0 mL/g, respectively. This study may contribute to the application of lignocellulose and related products in the broiler feed industry.

• 폴리머
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• 제25권4호
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• pp.545-557
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• 2001

Hydroxypropyl cellulose (HPC)를 이용하여 제조한 메탄올의 유방성 용액에 두 종류의 aliphatic dicarboxylic acid chlorides (succinyl chloride 와 suberoyl chloride)를 첨가하여 주형시킴에 의해 cholesteric 질서를 지닌 가교필름들을 제조하였다. 가교필름의 cholesteric pitch의 온도의존성과 물과 메탄올중에서의 가교필름의 팽윤거동을 검토하였다. 필름들은 cholesteric 액정상의 특징적인 지문조직을 나타내었으며 이들의 pitch는 HPC 자체와 동일하게 온도가 상승함에 따라 증가하였다. 그러나 모든 가교시료들은 주어진 온도하에서 HPC가 나타내는 pitch에 비해 대단히 크며 가교제의 농도 및 길이의 증가에 의해 증가하였다. 가교시료들은 두 용매중에서 이방성 팽윤을 나타냈다. 이방성 팽윤의 정도는 용매와 가교제의 종류에 다소 의존하나 검토된 가교제의 농도에는 거의 의존하지 않았다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.493-496
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• 2000

The extraction efficiencies of panaxynol and panaxydol according to extraction temperature were the highest at $80^{cdot}C$ among 65, 80, $95^{cdot}C$ with soxhlet and increased with shaking method when temperature increased from $25^{cdot}C$ to $45^{cdot}C$. The amounts of panaxynol and panaxydol were determined by gas chromatography. In time dependence of extracted amounts of panaxynol and panaxydol using shaking method, the efficiencies of panaxynol and panaxydol were increased during 12 hour. The effect of water swelling on panaxynol and panaxydol extraction efficiency using soxhlet and shaking methods, the efficiencies of panaxynol and panaxydol were decreased as swelling time was increased.

• 한국가구학회지
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• 제10권1호
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• pp.95-102
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• 1999

The objective of this paper was the development of boards made from waste newspapers. The boards were produced from particle ONP(old newspaper) to reduce energy consumption in the board production process. ONP boards bonded with polyurethan adhesives(PU) were produced on a laboratory scale, and their physical and mechanical properties were examined. The average density of the ONP was $0.48g/cm^3$, and the densities of the boards were $0.50-0.90g/cm^3$. Therefore, th compaction ratios of the boards were in the range of 1.04-1.88. The results obtained were as follows: 1) An increase in board density results in a corresponding improvement in bending properties. 2) An increase in board density results in increased thermal conductivity. 3) In this research, ONP board can be used only for interior applications. To gain exrerior applications, the dimensional stability properties(thickness swelling and water absorption) need to be improved.

• 한국식품과학회지
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• 제17권1호
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• pp.33-36
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• 1985

쌀보리(송학, 영산 및 진안56호) 전분의 물 결합능력, 아밀로스 함량, 상대적 결정도, Swelling Power및 가열에 따른 호화도의 변화는 품종간에 뚜렷한 차이를 보이지 않았다. 그러나 아밀로그람 특성값 및 알카리에 의한 점도 증가 양상은 품종마다 독특한 경향을 보였다. 송학전분은 아밀로그람에 의한 호화온도가 가장 낮았으며, 알카리 호화에 대하여 저항성이 큰 경향을 보였다.