• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.409-410
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• 2017

본 연구는 편백 에션셜 오일을 이용하여 치아우식증과 치주질환을 예방하기 위한 효과적인 구강양치액을 연구개발하고자 수행되었다. Streptococcus mutans에 대한 항미생물 효과 및 치면세균막 형성에 미치는 영향을 실험실연구(in vitro)와 전임상연구(preclinical observations)를 통해 조사하였다. 편백에센셜오일은 실험실 연구결과 S. mutans 성장 억제효과와 항미생물 효과를 보였고, 전임상시험 결과 자원자들의 치면세균막 지수가 감소하였다. 편백 에센셜 오일은 뛰어난 항미생물 효과와 치면세균막 억제를 보이는 것으로 나타났다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.99-103
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• 2010

Waxes, or long-chain hydrocarbons, may be obtained naturally from animals, vegetables, and mineral waxes, or may be synthesized. The oil-wax gels are widely applied to lots of cosmetics such as lipsticks. For example, the lipstick texture is strongly dependent on the glossiness of the oil-wax gels. Extensive research has been carried out to investigate the lattice structure of wax mixture in pure solvents (hydrocarbons) and defined mixtures. However, only a limited amount of work has been published on the lattice structure of wax matrixes in undefined mixtures. The objective of this study was to investigate the relationship between the lattice structure of ceresin wax and different wax mixtures and the glossiness of oil-wax gels. Recently visual factors such as the glossiness of skin are generally known as the words to express the beauty. The mechanism of glossiness has been suggested to understand the changes that occur in the lattice structure of the wax matrixes when they are forming gels and also the effects of the nature of solvent. The present work investigates the lattice structure of the wax matrixes and glossiness of oil-wax gels obtained from ceresin and microcrystalline wax as well as of the gels formed by different waxes in solvent.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.248.1-248.1
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• 2010

수송용 바이오연료로써 바이오디젤의 보급 활성화에 따른 원료인 식물성 기름의 가격 상승 및 수급 불안정성 문제를 해결하고자 그동안 활용되지 않았던 폐유지를 바이오디젤 생산 원료로 사용하여 바이오디젤 생산 단가를 낮추고 원료의 수급 안정성도 확보하려는 시도가 이루어지고 있다. 폐유지의 경우 대부분 유리지방산 함량이 높아 염기 촉매를 적용하는 방법으로는 비누의 생성으로 전환이 힘들며 산 촉매를 적용하여 유리지방산을 에스테르화하는 공정을 필요로 한다. 에스테르화 반응에서는 반응 부산물로 물이 생성되며, 생성된 물은 바이오디젤 생산 반응을 저해하고 역반응을 유도하며 촉매의 활성을 감소시킨다. 본 연구에서는 고유리지방산 함량 오일의 에스테르화 반응에서 수분의 영향을 검토하였다. 산 촉매로 액상 촉매인 황산과 고체 산 촉매인 Amberlyst-15를 사용하였다. 초기 수분 함량이 0, 1, 2, 5, 10, 20%로 증가하였을 때, 지방산 메틸 에스테르 함량이 크게 감소하였으며, 1%의 수분 함량에서도 반응이 크게 저해받는 것으로 나타났다. 따라서 고유리지방산 함량 오일의 에스테르화 반응에서 수분에 의한 저해가 중요한 변수라는 것을 알 수 있다. Amberlyst-15는 황산보다 수분의 영향에 의해 지방산 메틸 에스테르 함량이 빠르게 감소하였다. 이는 다공성의 Amberlyst-15에서 생성된 물이 반응물질들이 active site에 접근하는 것을 방해하였기 때문인 것으로 생각된다. 황산을 사용하였을 경우에는 오일 대 메탄올 몰비를 1:3에서 1:6으로 증가시킴으로써 정반응 속도가 증가하여 수분에 대한 영향이 감소하는 현상이 나타났다. 에스테르화 반응 종료 12시간 후에 바이오디젤과 메탄올 내에 수분 함량을 분석한 결과 12%의 수분이 바이오디젤 층에 존재하며 88%의 수분은 메탄올 층에 존재하였다. 반응 중에 생성된 수분을 제거하기 위해, 에스테르화 반응 30분 후에 물을 포함하는 메탄올과 촉매 층을 새 메탄올과 촉매로 교환하는 2단계 반응을 수행함으로써 지방산 메틸 에스테르 함량을 향상시킬 수 있었다. 반응 초기에는 황산이 Amberlyst-15보다 높은 활성을 보였지만, 시간이 지날수록 두 촉매 사이의 에스테르화 성능 차이는 감소하였다. 따라서 2단계 에스테르화 반응이 수분의 저해작용을 줄이는 한 가지 대안으로 제안될 수 있다. 또한 에스테르화 반응에서 물의 저해 작용을 줄이기 위해 앞으로 투과증발막의 적용 또는 물에 저해작용을 받지 않는 구조의 촉매 사용을 검토할 필요가 있다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.731-736
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• 2021

Oil fences effectively prevent the spread of oil spilled in the sea, thereby reducing the damage to the marine environment. However, the fence is damaged by oil and structures at the accident site and is discarded. When incinerated disposal method for discarded fences, fine dust, and harmful materials are generated. Moreover, as a part of the damaged fence is dumped into the sea, it may cause secondary environmental pollution, such as microplastics. Therefore, in this study, durability was measured using the most common solid foam type oil fences. As a result, the reduction rate of after five days of contact was 13 % in seawater and 3 % in oil, affected by temperature changes. Thus, the durability of the fence should be improved because it is exposed to seawater and oil and affected by wind, light, and waves depending on the weather conditions. Therefore, we suggest a method to improve the oil fence inspection to strengthen the durability of the fence's fabric part.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1533-1546
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• 2023

Nanoemulsion is an emulsion with a particle size of about 20 ~ 200 nm and has the advantage of having a transparent or translucent appearance and improving the skin permeability of an effective material with a small particle size, so it is applied in various fields. In this study, eight oils with different types of HLB and 16 oils with different types of required HLB were selected to investigate the effect of the required HLB and the type on the formation of nanoemulsion. The surfactants used at this time were Polysorbate 60 (HLB 14.9), Sorbitan state (HLB 4.7), PEG-60 hydrogenated castor oil (HLB 14.0), which were mixed with Polysorbate 60 and Sorbitan state, fixed with HLB 14.0, and Polysorbate 60 and PEG-60 hydrogenated castor oil, respectively. The formation of nanoemulsion was different depending on the type of oil, and oil with an ester structure showed a relatively excellent nanoemulsion formation ability. In particular, it was confirmed that a stable nanoemulsion was formed without a significant change after Cetyl ethylhexanoin was produced in a small size of 40 nm or less on average. In addition, it was found that using a mixture of Polysorbate 60 and Sorbitan stearate has a superior nanoemulsion formation ability than using PEG-60 hydrogenated castor oil or Polysorbate 60 alone.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.115-122
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• 2008

The effects of characteristic condition number on the convergence of preconditioned Euler equations were investigated. The two-dimensional preconditioned Euler equations adopting Choi and Merkle's preconditioning and the temperature preconditioning are considered. Preconditioned Roe's FDS scheme was adopted for spatial discretization and preconditioned LU-SGS scheme was used for time integration. It is shown that the convergence characteristics of the Euler equations are strongly affected by the characteristic condition number, and there is an optimal characteristic condition number for a problem. The optimal characteristic condition numbers for the Choi and Merkle's preconditioning and temperature preconditioning are different.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.274-284
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• 1994

Phase Inversion Temperature (PIT) measurements showed that the addition of polar components such as oleyl alcohol and oleic acid to the system comprising n-dodecylpentaoxyethylene monoether ($C_{12}E_5$), nonpolar oil (n-hexadecane) and water produced large reductions in the PIT. The PIT was lowered as the additive-to-surfactant ratio in the surfactant films in the microemulsion phase was increased. Another dramatic effect of additive was the manner in which it affects the volume of the microemulsion phase at the PIT of the oil and water solubilization characteristics. Microemulsion phase volume was increased rapidly with decreasing PIT, i.e., with increasing amounts of additive in the system. Also with a decrease in PIT, the solubilization parameters of both oil and water in the microemulsion phase were strikingly increased. Even though soil removal data were not available for the conditions where our results obtained, PIT measurement seems a useful starting point for estimating conditions when middle-phase microemulsion formation and its associated high solubilization of oil can be expected.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.4
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• pp.319-326
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• 2011

In order to investigate the potential of Nigella sativa (N. sativa) oil as an active ingredient for whitening cosmetics, we prepared N. sativa oil. We measured its inhibitory effects on mushroom tyrosinase activity, cellular tyrosinase activity, and melanin synthesis inhibitory activity in B16 melanoma cells. N. sativa oil and its components showed inhibitory activity against mushroom tyrosinase and melanin synthesis. In a melanin synthesis inhibition assay using mouse B16-F10 melanoma cell, it reduced melanin production up to 86 % at a concentration of 10 mg/mL without cytotoxicity. In the study on the melanogenic protein expressions by using RT-PCR and Western blot, N. sativa oil and its components inhibited expression of tyrosinase protein, which is a well-known key protein on melanogenesis, and tyrosinase expression was gradually decreased in a dose-dependent manner. Therefore, this result suggests that N. sativa oil could be used as an active ingredient for whitening cosmetics.

• Journal of Energy Engineering
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• v.18 no.3
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• pp.203-211
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• 2009

Vapor pressure of HFC-404a and polyol ester system were measured at 56 points from 263.15 to 323.15 K and from 0 to 90 mass %polyol ester. It was found that below 273.15 K, the effect of the polyol ester on the vapor pressure was negligible up to 30 mass % polyol ester. The vapor pressure of the system significantly decreased as the mass fraction of polyol ester increased over 50 percent. Raoult's model and Flory-Huggins model were tested for data reduction. Empirical vapor pressure equations were obtained in terms of temperature and mass fraction of polyol ester.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.6-10
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• 2012

The main objective of this work was studying the influence of paraffin oil(PO) on the adhesion properties at low temperature in styrene-butadiene-styrene(SBS) copolymer and crumb rubber(CR) modified asphalt. The temperature susceptibility of SBS/CR asphalt and PO/SBS/CR/asphalt blends were measured by penetration and softening point. Adhesion properties at low temperature and dispersion of modifiers in PO/SBS/CR/asphalt blends were evaluated by universal test machine and florescence microscopy, respectively. The adhesion properties of PO/SBS/CR/asphalt blends at low temperature increased in the proportion of SBS contents with both 5 and 10 wt % of paraffin oil. Results showed that the maximum tensile adhesion strength and toughness energy at $-20^{\circ}C$ were obtained when PO and SBS contents were 10 wt % and 6 wt %, respectively. The addition of PO is effective for enhancing the flexibility of SBS/CR/asphalt blends and leads to the increase of toughness at low temperature.