• Journal of the Korean GEO-environmental Society
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• v.19 no.10
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• pp.21-26
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• 2018

Soil-water characteristic curve, which is called soil retention curve, is required to explore water flows in unsaturated soils, relative permeability of water in multi-phase fluids flow, and change to stiffness and volume of soils. Thus, the understanding of soil-water characteristic curves of soils help us explore the behavior of soils inclduing fluids. Biopolymers are environmental-friendly materials, which can be completely degraded by microbes and have been believed not to affect the nature. Thus, various biopolymers such as deacetylated power, polyethylene oxide, xanthan gum, alginic acid sodium salt, and polyacrylic acid have been studies for the application to soil remediation, soil improvement, and enhanced oil recovery. PAA (polyacrylic acid) is one of biopolymers, which have shown a great effect in enhanced oil recovery as well as soil remediation because of the improvement of water-flood performance by mobility control. The study on soil-water characteristic curves of sandy soils containing PAA (polyacrylic acid) has been conducted through experimentations and theoretical models. The results show that both capillary entry pressure and residual water saturation dramatically increase according to the increased concentration of PAA (polyacrylic acid). Also, soil-water characteristic curves by theoretical models are quite well consistent with the results by experimental studies. Thus, soil-water characteristic curves of sandy soils containing biopolymers such as PAA (polyacrylic acid) can be estimated using fitting parameters for the theoretical model.

• Journal of the Korean Society of Fashion and Beauty
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• v.3 no.3 s.3
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• pp.31-40
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• 2005

The reason that aromatherapy began to draw attention again as the alternative therapy is because the essential oils that are used for aromatherapy not only allow the human body to maintain homeostasis but also have an effect on curing a mental feeling of fatigue and because these efficacies and effects are proceeding with being proved scientifically. Also, with coming to be high in a voice of concern about severally side effects that the modern medicine and the synthetic chemistry have, the aromatherapy came to be paid attention as the replacement therapy that can substitute for and supplement this. In particular, at the time of requiring a study on a substance to substitute for this after having been announced in Japan for 1998 a risk of Zincpyrithione that is being used as a component of dandruff treatment, it is thought that the aroma oil that was known for having an anti-dandruff effect has a merit of being easy in a user's access, thus it will be effective in curing the symptom of dandruff. Accordingly, this study conducted the following experiment in a bid to examine whether the aroma oil has the anti-microbial effect on the actual malassezia. First of all, it measured the minimum concentration of aroma oil in which the growth of malassezia is inhibited, by carrying out MIC(Minimum Inhibition Concentration) test in terms of anti-microbial activity against Malassezia furfur KCTC 7744 while using oils of Patchouli, Rosemary, Lavender, and Tea tree among aroma oils that are being used for dandruff treatment. As a result of that, Tea tree oil has the most excellent anti-microbial activity, and the measurement result of anti-microbial activity was shown in order of Lavender oil>Rosemary oil>Patchouli oil. Next, it carried out the is actually eased by applying Tea tree oil directly to the scalp of dandruff. In consequence of the experiment, the massage of Tea tree oil indicated the result of relieving the symptoms of dandruff such as scale, itch, pain, inflammation, and sebum, and among these symptoms of dandruff, it was shown to be most effective in easing itch. Especially, this clinical experiment was indicated that the massage of Tea tree oil has the most effect on relieving itch of targets with a dry-skin type who had no experience of dandruff treatment.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.533-540
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• 2018

Graphene has been reported to be an excellent lubricant additive that reduces friction and wear when coated on the surface of various materials or when dispersed in lubricants as an atomic thin material with the low surface energy. In this study, alkyl functionalized graphene oxide (FGO) nanosheets for oil-based lubricant additives were prepared by using three types of alkyl chloride chemicals (butyl chloride, octyl chloride, and tetradecyl chloride). The chemical and structural properties of the synthesized FGOs were analyzed by Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), and transmission electron microscope (TEM). The synthesized FGOs were dispersed at 0.02 wt% in PAO-0W40 oil and its tribological characteristics were investigated using a high frequency friction/wear tester. The friction coefficient and the wear track width of poly alpha olefin (PAO) oil added with FGO-14 were tested by a ball-on-disk method, and the measured results were reduced by ~5.88 and ~3.8%, respectively compared with those of the conventional PAO oil. Thus, it was found that the wear resistance of PAO oil was improved. In this study, we demonstrated the successful functionalization of GO as well as the improvement of dispersion stability and tribological characteristics of FGOs based on various alkyl chain lengths.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.528-535
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• 2016

Two types of oleophilic acrylic prepolymers were prepared by the solution copolymerization of either ethyl acrylate (EA) or lauryl acrylate (LA) with hydroxy ethyl acrylate (HEA). For the formation of oil-absorbent materials, a mixed solution of the prepolymer and hexamethylene diisocyanate (HDI) as a cross-linker in toluene was applied to polypropylene knit velvet fabric through the conventional pad-dry-cure procedure. The gel fraction of the crosslinked resin, EA-HEA-HDI, increased with increasing feed ratio of HEA to total acrylate or HDI concentration. The oil absorbancy and retention ratio of the prepared materials were compared according to the add-on ratio of resin to fabric, and were assessed with n-decane, toluene, soybean oil, lubricant and bunker C oil as test oils. The optimal oil absorbancy of the materials were observed at around 6% of the add-on ratio for all these oils except for soybean oil. On the other hand, the oil retention ratio increased as the add-on ratio increased. Futhermore, heavier and more viscous oil generally showed higher oil retention ratios. In addition, the oil absorbancy of the materials treated with LA-HEA-HDI resin was higher than that treated with EA-HEA-HDI resin, which showed that the acrylic resins are more absorptive with increasing length of their side alkyl chain.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.189-199
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• 2015

In this study, we have investigated the stability of sunscreens based on the solubility of organic UV absorbers in the oil and sun protection efficacy of the products composed of a combination of organic UV absorbers to develop more stable and efficient sunscreen products. Results showed that the solubility of the organic UV absorber and stability were varied depending on the type, storage conditions and concentration of oil. It was also observed from the products in the emulsion type. Various UV absorbances were determined to the products composed of the combination of organic UV absorbers. In some combinations, a synergistic effect was observed to make an increase in absorbance compared to a single component. In other cases, specific synergistic effect was displayed only when combined with the particular component. In addition, the storage condition also affected the sunscreen efficacy. In conclusion, this study confirmed that there are various factors which could affect the UV-blocking efficiency of sunscreen products.

• Clean Technology
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• v.8 no.3
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• pp.119-128
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• 2002

In the present study the membrane filtration characteristics of a commercially available synthetic water-based cutting oil through two kinds of ultrafiltration membranes (HF1-45-CM50 and HF1-43-CM100) with molecular weight cut-offs of 50,000 and 100,000, respectively, have been investigated in detail. Among these membranes, the hydrophilic one (HF1-45-CM50) was found to show a satisfactory result for both the permeate flux and the permeability of oil components, whereas the permeate flux obtained with the hydrophobic membrane (HF1-43-CM100) appears to be significantly low, indicating that synthetic cutting oil was easily wetted on the hydrophobic membrane surface and induced more membrane fouling. The effect of material characteristics of the membrane on the filtration characteristics was found to be much more significant compared with the mean pore size of the membrane. Backflushing by nitrogen gas was applied to reduce the formation of a gel layer and membrane fouling. With the hydrophilic membrane, the backflushing was found to increase the permeate flux, whereas the backflushing resulted in a decrease in flux for the hydrophobic membrane. The flux recovery was observed to be highest when the membranes fouled with waste synthetic cutting oil were immersed into a cleaning solution for more than 72 hours and then backflushed by nitrogen gas.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.435-444
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• 2019

In this study, two types of nonionic saccharide biosurfactants, GP-6 and GP-7, were prepared from coconut oil and the structure of resulting products was investigated by FT-IR, $^1H-NMR$ and $^{13}C-NMR$ spectrophotometer. The interfacial properties of GP-6 and GP-7 were found to be excellent from interfacial property measurements such as critical micelle concentration, static and dynamic surface tensions, interfacial tension, emulsification power, wetting property and foam stability. Detergency test evaluated by using a Terg-o-tometer showed moderately good detergency compared to that of conventional surfactants used in detergent formulations. Biodegradability, acute oral toxicity, acute dermal irritation and acute eye irritation tests revealed that both surfactants possess excellent mildness and superior environmental compatibility indicating the potential applicability to detergent products formulations. In particular, GP-6 can be considered as a strong candidate in detergent formulations since it is more surface active, mild and readily biodegradable than GP-7.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.376-383
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• 2011

The CMCs of LA and LA3 nonionic surfactants obtained from the reaction between glycidol and lauryl alcohol were found to be $0.97{\times}10^{-3}mol/L$ and $1.02{\times}10^{-3}mol/L$ respectively and the surface tensions for 1 wt% surfactant were 26.99 and 27.48 mN/m respectively. Dynamic surface tension measurements using a maximum bubble pressure tensiometer showed that the adsorption rate of surfactant molecules at the interface between the air and the surfactant solution was found to be relatively fast in both surfactant systems, presumably due to the high mobility of surfactant molecules. The contact angles of LA and LA3 nonionic surfactants were 27.8 and $20.9^{\circ}$ respectively and the dynamic interfacial tension measurement by a spinning drop tensiometer showed that interfacial tensions at equilibrium condition in both systems were almost the same. Also both surfactant systems reached equilibrium in 2~3 min. Both surfactant solutions showed high stability when evaluated by conductometric method and the LA nonionic surfactant system provided the higher foam stability than the LA3 nonionic surfactant system. The phase behavior experiments showed a lower phase or oil in water (O/W) microemulsion in equilibrium with an excess oil phase at all temperatures studied. No three-phase region was observed including a middle-phase microemulsion or a lamellar liquid crystalline phase.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1370-1382
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• 2021

Previous studies have been conducted on domestic materials as a single extract. Research on complex mixtures for maximizing plant characteristics by individual extraction and potential interference with effects is insufficient. Therefore, this study confirmed the GC-MSD according to the extraction of essential oils for Agastache rugosa O. Kuntze(AR), Pinus densiflora Sieb. et Zuccarini(PD), Curcuma longa, Curcuma domestica(CC), Zingiber officinale Roscoe(ZR), Foeniculum vulgare Miller(FV), and Citrus medica L. var. sarcodactylis Swingle(CS). The cytotoxicity, antioxidant, and anti-inflammatory properties of the blending oil were confirmed to confirm its potential as a cosmetic material. As a result of analyzing GC-MSD aroma components, the main components were estragole of AR, à-Pinene for PD, Zingiberene for CC and ZR, Anethole from FV, and D-Limonene for CS. At a concentration of 100 uL/mL with no confirmed cytotoxicity, NO production was inhibited by 70.62%, DPPH radical scavenging activity was 64.03%, and ABTS radical scavenging activity was 89.55%. Through this, blended essential oil suggests the possibility of useful application as a raw material with antioxidant and anti-inflammatory effects in the cosmetic and food industries.

• Journal of the Korean Chemical Society
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• v.47 no.5
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• pp.479-486
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• 2003

In this study, poly(DL-lactide-co-glycolide) nanoparticles loaded with water-insoluble vitamins such as vitamin A (Retinol) and vitamin E acetate were prepared by the emulsification diffusion method. Polymer solution was prepared by the two water-miscible organic solvent, such as ethanol and acetone. Because of its biocompatible property, polyethyleneglycol-polypropyleneglycol diblock copolymer was used as surfactant and stabilizer. The influence of some preparative variables on the nanoparticle formation and on the loading efficiency of active agents, such as the type and concentration of stabilizing agent, the stirring methods, the water/oil phase ratio and the polymer concentration were investigated in order to control and optimize the process. After preparation of nanoparticles loaded with active agent, particle size and distribution were evaluated by the light scattering particle analyzer. The loading efficiency of active agents was evaluated by the UV-visible spectroscopy. As the results, particle size were 50-200 nm and dispersibility was monodisperse. The optimum loading efficiency of active agents was observed 50-60%. It was found that the appropriate of selections of binary solvent mixtures and polymeric concentrations in both organic and aqueous phases could provide good yield and favorable physical properties of PLGA nanoparticles.