• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.625-630
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• 2013

The friction behavior of a 60-${\mu}m$-thick anodic aluminum oxide (AAO) film having cylindrical nanopores of 45-nm diameter was investigated as a function of impregnated oil viscosity ranging from 3.4 to 392.6 cSt. Reciprocating ball-on-flat sliding friction tests using a 1-mm-diameter steel ball as the counterpart were carried out with normal load ranging from 0.1 to 1 N in an ambient environment. The friction coefficient significantly decreased with an increase in the oil viscosity. The boundary lubrication film remained effectively under all test conditions when high-viscosity oil was impregnated, whereas it was easily destroyed when low-viscosity oil was impregnated. Thin plastic deformed layer patches were formed on the worn surface with high-viscosity oil without evidence of tribochemical reaction and transfer of counterpart material.

• Clean Technology
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• v.14 no.1
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• pp.21-28
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• 2008

The properties of the dispersion of the red, green, and blue pigments were investigated for the manufacture of the millbase of LCD color filters. Their physical properties and viscosity were controlled to apply to the screen printing in order to substitute the existing photolithography method. The best dispersion properties were obtained with dispersant BYK-2000 and monomer EB-140. The millbase was pre-mixed at 500 rpm for 30 min, and dispersed at 4000 rpm for 5 - 6 hour by Torus Mill. The resulting particle sizes were $100{\sim}110\;nm$ for red, $50{\sim}70\;nm$ for green, and $60{\sim}80\;nm$ for blue. When the millbase viscosity was 200-300 cps in the low viscosity formulation, an efficient impact of the beads on pigments was achieved. The dispersion properties were confirmed from the rheological behavior and color characteristics.

• Composites Research
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• v.35 no.6
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• pp.412-418
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• 2022

Flame-retardant vinyl ester (VE) resin films were developed from the mixtures of brominated and non-brominated epoxy resins via esterification with methacrylic acid without reactive diluents. The films were used to fabricate carbon fiber (CF) prepregs via a hot melt impregnation process. The viscosity of VE resins suitable for film production was optimized by mixing low-viscosity bisphenol-A and high-viscosity brominated bisphenol-A epoxy precursors. Increasing the bromine content of the cured VE resin further increased the limited oxygen index (LOI) (39%), storage modulus (2.4 GPa) at 25℃ and residual carbonization (16.1%) values compared to non-brominated VE. Manual layup of as-prepared VE prepregs with subsequent curing led to the successful fabrication of CF-reinforced composites with high tensile and flexural strength. The results from the study hold high promise for a styrene-free, environmentally friendly VE composite process in the future.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.15-28
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• 2016

Water-in-oil emulsions including water-in-ester oil and water-in-silicone oil (W/O+S) have various advantages such as blocking moisture evaporation and forming air permeable membrane. However, their applications have been limited due to the poor stability under low viscosity condition. In this study, we investigated the effect of synergistic interaction between nonionic surfactant, micro-size particles and cationic surfactant on the stability of W/O+S formulation. The stability of W/O+S emulsions was changed as a function of cationic surfactant concentration where it increased at lower concentration and then started to decrease above a critical point. Finally, emulsion phase inversion occurred at a high concentration. The results suggest that W/O+S emulsions of low viscosity ranging from 2000 to 5000 cps can be stabilized under the conditions where a nonionic surfactant, micro-size particles and a cationic surfactant are used in the range of 1.0 ~ 4.0 wt%, 2.5 wt% and 0.1 ~ 0.5 wt%, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.1
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• pp.39-46
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• 2004

Waxy maize starches are inherently stable in soluble status and can be chemically modified to improve stability along with heat, acid and shear resistance. This study was carried out to investigate the effect of theological and sensory characteristics of the yellow layer cake made by adding different levels of waxy maize starch as a fat substitute for shortening. By increasing the substitution level of waxy maize starch for shortening, the specific gravity of cake batter increased and the viscosity decreased. The microstructures of cake crumb observed by the scanning electron microscope were not different significantly, and the size of air cells and fat particles also were not substantially decreased by increasing fat substitution level. The texture profile analysis using texture analyzer decreased by increasing the different substituting levels of waxy maize starch. Among various sensory properties, the color value of layer cake increased by increasing the level of waxy maize starch. However, the appearance, flavor, taste, texture and overall preference decreased.

• Journal of Energy Engineering
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• v.13 no.1
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• pp.20-27
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• 2004

In the study, the effect of low boiling point oxygenates in high viscous fuels on the exhaust emissions has been investigated for a single cylinder DI diesel engine. It was tested to estimated change of engine performance and exhaust emission characteristics for the base fuels and low boiling point oxygenates blended fuel which have six kinds of fuels and various mixed rates. The results of the study may be con eluded as follows By blending of various low boiling point oxygenated agents to lower grade fuels, significant improvements were simultaneously obtained in smoke, CO, PM, SOF and BSEC. Especially, these trends were remarkably obtained by retarding injection timing, by decreasing boiling point and increasing blending contents of additives in case of oxygenated agents rather than non-oxygenated agents. Also, it was revealed that when 20 vol.％ DMM added to high viscosity fuels and injection timing was retarded, Nox-smoke trade off relationship was much better than that of ordinary diesel fuel. Thus, lower grade fuels with high viscosity could be expected to be used efficiently and cleanly in diesel operation by blending low boiling point oxygenates.

• Journal of Conservation Science
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• v.25 no.2
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• pp.171-178
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• 2009

When we considered the superior ability of the semi-water soluble urethane 1st transcription and final epoxy products, the stability for moving historic sites depend on physical properties and the peel off state of separation media. In this paper, we synthesised three type of water-borne epoxy solution without using a surfactant, and investigated the peel off state, physical properties, and the state between urethane surface and epoxy surface after exfoliation. The life time of water-borne separation media is over the 60 days. When it is used the 30% solution of water-borne separation media, it made good separation of urethane pre-products surface and epoxy final product surface and no color change. The separation tension pressure is about 15~50 kg/$cm^2$ and there is no surface whitewash phenomenon. We suggest that this water-borne epoxy will be best material as separation media of low viscosity type.

• 보존과학연구
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• s.34
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• pp.20-29
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• 2013

Paper, textile and wood materials are mainly consisted of cellulose. Cellulose is high molecule and make up the strong crystalline structure by hydrogen bonds. In particular, the polymerization degree of cellulose are closely related to the strength of fiber, and the permanence. the useful life of fiber, also depends on the degradation of this substance. The viscosity of cellulose is considered to be an important indicator of fiber damage in high molecule polymers. The viscosity measurements with CED solution is used to measure the molecular weight and the degree of polymerization of cellulose. Cellulose viscosity of wood fibers is measured with TAPPI standard method T230. However, TAPPI standard method T230 is difficult to completely dissolving the cellulose of high molecular weight and large degree of polymerization, such as Korea traditional papers and fabrics made with mulberry, ramie, cotton fibers. In this study, The high viscosity of hanji and fabric was measured with TAPPI standard method T254. T254 method is that the cellulose specimen with the proper amount of weaker (0.167M CED) solution, and completely dissolved with the stronger (1.0M CED) solution. It was found that cellulose with high degree of polymerization was dissolved more easily in general CED method.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2006.05a
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• pp.170-174
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• 2006

근육 단백질과 우유 단백질간의 상호작용의 촉매제로써 TGase의 최적화를 위한 온도와 배양시간을 결정하고자 본 실험을 실시하였다. 돼지 등심에서 근원섬유 단백질을 추출하였고 배양온도는 4, $37^{\circ}C$로, 배양시간은 0, 0.5, 2, 4시간으로 설정하였다. 단백질의 열량분석, 점도, 겔 강도, 단백질 밴드의 변화를 측정하였으며, 그 결과 단백질 열량 변화는 각 단백질 별로 열량 변화 패턴이 상이하게 나타났으며 근원섬유와 카제인 염의 혼합액은 각각의 단백질의 피크와 유사하게 나타났고 배양시간과 온도에 따라 차이를 보여 $4^{\circ}C$에 비하여 $37^{\circ}C$에서 열량 변화가 크게 나타났다. 점도의 경우 배양하지 않은 것과 비교했을 때 $37^{\circ}C$에서 2시간 배양했을 때부터 유의적인 차이를 보이며 증가했으나 4시간 배양한 것과는 차이를 나타내지 않았다. 전기영동의 경우에도 $37^{\circ}C$에서 30분 배양한 처리구는 큰 변화를 나타내지 않았으나 2시간부터 저분자의 밴드가 소멸되고 고분자의 biopolymer를 형성되었다.

• Journal of the Society of Disaster Information
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• v.9 no.1
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• pp.56-64
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• 2013

The study examines the quiet pavement using fine-size aggregates and warm-mix technique to reduce traffic noise. In order to evaluate the quality of pavement, mix design and laboratory tests were carried out. Test results showed that using 10mm aggregates can reduce the cantabro loss compared with 13mm aggregates due to increase contact area between aggregates. Mixing and compaction temperatures of warm mix quiet pavement should be determined by gyratory compactor test because it is used high viscosity asphalt binder. Using warm-mix additive could reduce compaction temperature by about $15^{\circ}C$. Noise measurement and permeability tests were conducted at the test road for evaluation of the field performance. All of quiet pavements meet the standard of permeability and have sufficient porosity. Noise reduction of the quiet pavement using fine-size aggregates is more effective than that using 13mm aggregates. In particular, the effect of noise reduction was noticeable at low speeds.