• 한국전기전자재료학회논문지
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• 제26권1호
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• pp.33-37
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• 2013

The properties of LTCC green sheets formed by the MLS-22 powder of NEG Inc. were investigated for acrylic binders with different PVB and Tg in the variation of temperature. The elongation of the green sheets showed large variation depending on the temperature, and was rapidly decreased near the Tg of the sheets. With the increase of the ratio of plasticizer/binder (P/B), large elongation of the sheets was observed due to the decrease of the Tg. In the stacking process of the multilayer ceramic, the optimal control of the temperature is highly required depending on the Tg of the binder and the ratio of P/Buniform coating.

• 대한치과교정학회지
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• 제21권3호
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• pp.563-580
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• 1991

The purpose of this study was to investigate and compare the biomechanical properties of orthodontic rubber elastic materials. Latex bands, nylon-covered elastic threads and polyurethane-based elastic modules, delivering $205{\pm}10$ grams force at 30mm stretching state were selected and stored separately in 3 environments-air ($22{\pm}3^{\circ}C$), distilled water ($37{\pm}1^{\circ}C$), or natural saliva ($37{\pm}1^{\circ}C$). And, the amount of remaining force and permanent elongation of each sample were measured on Instron at interval of 1 hour, 6 hours, 12 hours, 24 hours, 1 week, and 2 weeks. So the data derived were analyzed statistically. The results were as follows: 1. Force decay and permanent elongation of all materials increased with time lapsed; elastic module, latex band and nylon-covered elastic thread in that order of the amount of force decay; elastic module, elastic thread, latex band in that order of the amount of permanent elongation. 2. Among environmental conditions, force decay and permanent elongation in natural saliva, most increased, and those in air, least increased. 3. There was a negative correlation between force decay and permanent elongation. 4. Force decay and permanent elongation were most affected by the material itself, time and environments in that order. 5. After 24 hours in saliva, the percentage of remaining force in elastic module was 51.9% (107.37grams); in latex band, 83.2%(172.62grams); in elastic thread, 85.0%(179.25grams). After 2 weeks in saliva, the percentage of remaining force in elastic module was 42.9%(88.75grams); in latex band, 74.5%(154.50grams); in elastic thread, 77.6%(163.75grams).

• 동력기계공학회지
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• 제18권5호
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• pp.106-114
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• 2014

For the purpose of development of polyurethane sealing material, polyurethane resins reinforced with CuO were prepared from polyol and MOAC(4,4'-Methylenebis(2-chlorobenzeneamine)). And the effects of compositions on the mechanical properties of the reinforced polyurethane resin were experimentally examined. The polyurethane resin got to be thermally decomposed at $260^{\circ}C$ and completely carbonized around $500^{\circ}C$. Tensile strength, elongation and hardness of the polyurethane resin increased with the content of MOCA. CuO was uniformly dispersed in the polyurethane resin by 1 minute's ultrasonic radiation. Tensile strength, elongation and hardness of the polyurethane resin reinforced with CuO increased with the content of CuO. Tensile strength and hardness of the reinforced polyurethane resin increased with particle size of the CuO, but elongation decreased. CuO showed higher tensile strength and hardness than any other additives, and lowest elongation.

• 펄프종이기술
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• 제40권3호
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• pp.59-64
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• 2008

The mechanical properties of WPC(wood plastic composite) should effected with the size of wood particle size and also characteristics of wood particles. In this paper, WPC were prepared with various size of wood particles and coupling agent and the mechanical properties were evaluated. The smaller size of wood particle were used for WPC, the higher properties of WPC in tensile strength and breaking elongation were obtained. The smaller amount of wood particle were used for WPC, the higher properties of WPC in tensile strength and breaking elongation were obtained.

• 한국의류학회지
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• 제22권6호
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• pp.609-609
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• 1998

This paper surveys the effect of rice straw ash solution to the physical properties of Sappan Wood dyeing fabrics. In the quantitative analysis of rice straw ash solution, the quantities of absorbed ingredients in fabrics were increased by bath pull treatment but the amount of absorption(K/S value) was increased by bath pH4.5 treatment. This is related to the metal ion. Among the metal ion, effect of Fe iou and Al ion were related. In case added extracted dye solution to mordants, the color dye solution became dark and increased reddish. The changes of mechanical properties of fabrics tensile resilience, bending rigidity(B), compressional resilience(RC) were increased. Generally mechanical properties were increased by rice straw ash solution treatment, specially bath pH9 treatment. Rice straw ash solution treatment of dyeing fabrics made the improvement in tensile strength and elongation and in the amount of absorption, dye ability, color fastness, mechanical properties, tensile strength, elongation.

• 한국의류학회지
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• 제22권6호
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• pp.699-705
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• 1998

This paper surveys the effect of rice straw ash solution to the physical properties of Sappan Wood dyeing fabrics. In the quantitative analysis of rice straw ash solution, the quantities of absorbed ingredients in fabrics were increased by bath pull treatment but the amount of absorption(K/S value) was increased by bath pH4.5 treatment. This is related to the metal ion. Among the metal ion, effect of Fe iou and Al ion were related. In case added extracted dye solution to mordants, the color dye solution became dark and increased reddish. The changes of mechanical properties of fabrics tensile resilience, bending rigidity(B), compressional resilience(RC) were increased. Generally mechanical properties were increased by rice straw ash solution treatment, specially bath pH9 treatment. Rice straw ash solution treatment of dyeing fabrics made the improvement in tensile strength and elongation and in the amount of absorption, dye ability, color fastness, mechanical properties, tensile strength, elongation.

• 한국식품과학회지
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• 제34권6호
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• pp.1023-1029
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• 2002

본 연구는 천연전분과 hydroxypropyl화 전분에 가소제를 0, 16, 33, 50, 66% 비율로 첨가하여 RVA점도를 측정하고 필름을 제조한 후 물성을 측정하여 두 물성 사이의 상관관계를 알아보고자 행하였다. 필름의 인장강도는 가소제의 함량이 높아질수록 감소하였고 신장율과 수증기투과도는 증가하였으며 glycerol이 sorbitol보다 큰 변화를 보이는 것으로 나타났다. Hydroxypropyl화 전분이 천연전분에 비해 강도는 떨어지나 신장율은 높아지는 것으로 나타났고 수증기투과도는 2배 큰 것으로 나타났다. 가소제를 혼합하여 필름의 물성을 측정한 결과 sorbitol은 유연성보다는 필름의 강도를 유지하는 역할을 그리고 glycerol은 필름의 신장율을 증가시키는 역할을 하는 것으로 나타났다. RVA물성과 필름 물성의 관계에서 가장 연관성이 높은 것은 peak viscosity, 인장강도, 수증기투과도인 것으로 판명되었고 peak viscosity와 인장강도, peak viscosity와 수증기투과도의 관계는 각각 직선적인 것으로 나타났다. 따라서 RVA 물성 중 peak viscosity를 활용하여 필름의 인장강도, 수증기투과도를 예측할 수 있다고 판단되었다.

• 수산해양기술연구
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• 제48권1호
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• pp.20-28
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• 2012

The monofilament with 0.304mm of diameter was produced using a polybutylene succinate (PBS) resin, and a gill net was made by it. We investigated the impact of heat setting temperature on the mechanical properties, knot state and height of gill net. Heat treatment was carried out using the high pressure steam machine for 20 minutes at temperature of $55^{\circ}C$, $60^{\circ}C$, $70^{\circ}C$ and $75^{\circ}C$. Before heat treatment, the strength and elongation of PBS monofilament were estimated to be $48.1kg/mm^2$, 23.8% at unknot, $37.6kg/mm^2$, 18.8% at single knot, $26.6kg/mm^2$, 22.9% at double knot in dry condition, respectively. The strength and elongation of PBS monofilament with double knot were decreased as heat setting temperature increased, and the decreasing rate of strength was showed to be higher than that of elongation. It was not found any differences in strength and elongation of PBS monofilament yarn with double knot at the $65^{\circ}C$ and $70^{\circ}C$ of heat setting temperature by 5% significance of T-test, but there was a significant difference at the $70^{\circ}C$ and $75^{\circ}C$ of heat setting temperature. The net's height and length from leg to leg appeared no differences at the $70^{\circ}C$ and $75^{\circ}C$ of heat setting temperature. In results, it was investigated that the PBS monofilament gill net with the maximized physical properties could be manufactured at $70^{\circ}C$ of heat setting temperature using a high pressure steam machine for 20 minutes.

• Current Research on Agriculture and Life Sciences
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• 제7권
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• pp.73-81
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• 1989

본 실험은 견직물의 염색시에 많이 사용되는 Acetic Acid, Sulphuric Acid 및 Formic Acid등의 산성화학약제 처리가 생사의 물리적 성질에 미치는 영향을 규명한 것으로서 그 결과는 다음과 같다. 생사의 강력(g/d)은 공시 3개약제 다같이 온도 및 pH 변화에 따른 차이를 인정할 수 없었다, 생사의 신도(%)는 Acetic Acid 및 Sulphuric Acid $40^{\circ}C$ pH 3에서 Formic Acid $80^{\circ}C$ pH 4에서 유의차 있게 저하되었다.

• 폴리머
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• 제26권4호
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• pp.468-476
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• 2002

순수한 PAN 섬유의 예비산화와 가수분해의 과정을 통하여 제조된 oxy-PAN은 염기와 산용액에 담그었을 때 신장과 수축 거동을 보임이 알려져 있다. 본 연구에서는, 염기 (NaOH) 용매에서 약 30%의 신장과 산 (HCl) 용매에서 30∼50%의 수축 거동을 관찰하였다. 기계적 특성에 대한 실험에서, oxy-PAN 섬유가 수축되었을 때 향상된 기계적 특성을 나타내었다. 이러한 거동과 기계적 특성은 인체의 근육과 선형 구동체의 그것들과 유사하였다. NaOH와 HCl 용액에서 oxy-PAN 섬유의 길이가 변화하는 중요한 요인으로는 친수화 또는 소수화 구조의 전환에 의한 영향이다. 다른 요인으로는 oxy-PAN 섬유와 용액간의 이온과 물의 교환, 이온의 농도차에 의한 삼투압 등이 영향을 준다. Oxy-PAN 섬유의 신장 및 수축과 기계적 특성에 영향을 미치는 여러 가지 요인들을 규명하기 위한 보다 많은 연구가 필요하지만, 본 연구실에서 제조된 oxy-PAN 섬유가 인공 근육 및 선형 구동체로 적용될 수 있는 충분한 가능성이 있음을 제시한다.