• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.117-123
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• 2006

Fumigant toxicity of 34 plant essential oils were tested against female adults of Culex pipiens pallens. Seven oils (basil, coriander, fennel, pennyroyal, peppermint, thyme red, thyme white) showed more than 60% mortality at 1 ${\mu}L\;L^{-1}$ air concentration and pennyroyal oil appeared to have the highest adulticidal activity. GC and GC-MS analysis of the seven essential oils and bioassay of their components revealed that pulegone (a major component of pennyroyal oil) and anethole (a major component of fennel and basil oil, $LD_{50}$, ${\mu}L\;L^{-1}$ air =0.49) showed higher adulticidal activities than others. In addition to the above two components, linalool ($LT_{50}$, min=0.91), camphor ($LT_{50}$, min=1.06), fenchone ($LT_{50}$, min=1.16), 1,8-cineole ($LT_{50}$, min=2.93), and geranyl acetate ($LT_{50}$, min=1.60) also showed higher adulticidal activity than empenthrin ($LT_{50}$, min=3.45).

• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.309-321
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• 2023

Chamaecyparis obtusa (C. obtusa) belongs to Cupressaceae and grows wild in southern area of Korea. C. obtusa has been used for furnitures because of the superior quality of the lumber and remaining branches and leaves were used for extraction of essential oil (C. obtusa oil). C. obtusa oil has numerous health effects, including anti-inflammation, antibacterial, deodorization, sedative effect. This study was performed to evaluate the effects of C. obtusa oil on anti-wrinkles, skin-barrier and moisturizing. First, DPPH and ABTS assay were conducted to evaluate antioxidant effect and C. obtusa oil showed significance scavenging activity on both radicals. And elastase activity was examined for anti-wrinkle effect. At the result, elastase activity was significantly reduced by C. obtusa oil. Next, real-time PCR was performed to evaluate gene expression. At the results, MMP-1 mRNA expression was significantly reduced by C. obtusa oil in HDF cells. In addition, filaggrin and HAS-2 mRNA expression significantly increased by C. obtusa oil in HaCaT cells. Taken together, these results indicate that C. obtusa oil has potential as a cosmetic material for anti-aging by enhancing anti-wrinkle, skin-barrier and moisturizing effects.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.467-470
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• 2005

지구온난화 현상과 화석연료의 고갈에 대한 두려움 때문에 재생에너지에 대한 관심이 지속적으로 증가하고 있다. 이에 따라 대체에너지, 합성가스, 화학 원료, 오일 등으로 전환할 수 있는 바이오매스 활용에 대한 연구도 활발히 진행되고 있다. 바이오매스의 열화학적 전환 공정에는 열분해, 연소, 가스화 등이 이용되고 있다. 특히 열분해는 syringol, levoglucosan, guaiacol등의 고부가가치 물질들을 생산하기에 적합한 기술로 인정받고 있다. 본 연구에서는 국내에서 쉽게 구할 수 있는 톱밥, 폐목재 등의 바이오매스의 열화학적 전환 특성을 분석하였다. 사용된 바이오매스의 열분해 특성은 열중량 분석기 및 열천칭 반응기를 통해 분석하였으며 이를 통해 유동충 반응기(지름 0.2m, 높이 2m)를 설계 및 제작하였다. 반응온도 및 산소 농도가 증가할수록 levoglucosan 등의 고부가가치 물질들의 수율이 낮아지며 페놀류가 급격히 증가함을 알 수 있었다. 회재 성분이 높은 왕겨의 바이오오일 수율은 톱밥보다 $30\%$이상 낮게 나타났다

• Clean Technology
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• v.19 no.3
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• pp.233-242
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• 2013

The influences of Ca and Fe based oxides as dechlorination sorbents on the product distribution, boiling point distribution of liquid product, concentration of Cl of the products from the pyrolysis of PVC containing combustible wastes were investigated. With Fe based oxides as the sorbents, the yield of liquid product remarkably decreased whereas the decrease of the boiling point distribution of the liquid product was not noticeable. This phenomenon indicated that Fe based oxides worked as catalysts with weak catalytic activity. With Ca based oxides as the sorbents, the yield of liquid product did not decrease and the boiling point distribution of liquid product did not change significantly, but the dechlorination performance of these was much better than that with Fe based oxides.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.1
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• pp.9-14
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• 2008

Formation of oil-in-water nano-emulsions has been studied in oil/hydrogenated lecithin/water systems by two shear different instrument. The influence of surfactant concentration on nano-emulsion droplet size and stability has been studied. Droplet size was determined by dynamic light scattering, and nano-emulsion stability was evaluated by measuring the variation of droplet size as a function of time. The results obtained showed that the breakdown process of nano-emulsions studied could be attributed to Ostwald ripening. An increase of nano-emulsion instability with increase in surfactant concentration was found in the droplet size in the range of 100~200nm, however, an decrease of instability was found in the droplet size in the range of 300~400nm.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.10 no.1
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• pp.37-44
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• 1998

In this study a new hybrid method is developed for solving flow-dominated transport problems accurately and effectively. The method takes the forward-tracking particle method for advection. However, differently from the random-walk Lagrangian approach it solves the diffusion process on the fixed Eulerian grids. Therefore, neither any interpolating algorithm nor a large enough number of particles is required. The method was successfully examined for both cases of instantaneous and continuous sources released at a point. Comparison with a surrounding 5-point Hermite polynomial method (Eulerian-Lagrangian method) and the random-walk pure Lagrangian method shows that the present method is superior in result accuracy and time-saving ability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.697-702
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• 2007

The lubricational characteristics about friction and wear has an important effect on the material quality of surface. Therefore, in the case of automobile engine oil which is used under severe running condition, or therefore, the seizure and anti-scuffing is very important. We have studied the lubricational characteristics of auto engine oil with additives using Falex wear test machine. We have obtained the studied result is as fellows. In order to more improved the surface roughness characteristics adding the P(phosphate) as additives is excellent at a low temperature. Adding the ZnDTP and Ca-phenate is excellent on the anti-wear and extreme pressure properties at the high load. Moreover, when the ZnDTP and P are added, the temperature properties is excellent because the stability is maintained in a high temperature.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.3
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• pp.283-294
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• 2020

In this study, in order to increase the utilization of Citrus junos seeds, which account for 13% of the weight ratio of Citrus junos ripened fruit, but are mostly discarded and not utilized, the efficacy of skin beauty of Citrus junos seed oil extracted by cold pressing was studied. Citrus junos seed oil was found to contain approximately 74% of unsaturated fatty acids consisting mainly of oleic acid and linoleic acid, and limonene, which is mainly contained in Citrus junos peel, contained a very low content of about 0.0187%. As a result of evaluating the DPPH radical scavenging activity of Citrus junos seed oil, 26% of DPPH radical scavenging ability was confirmed at 5% concentration of Citrus junos seed oil. To confirm the anti-inflammatory effect, as a result of testing RAW 264.7 cytotoxicity test and NO production for Citrus junos seed oil, NO production was suppressed by 53% at a concentration of 0.05% that does not show cytotoxicity. In addition, in the RBL-2H3 cytotoxicity and β-hexosaminidase release inhibitory efficacy test for anti-allergic efficacy confirmation, it was confirmed that β-hexosaminidas release was suppressed by 26% at a concentration of 0.05% that did not show cytotoxicity. Lastly, in the human skin application test result of O/W emulsion containing 5% of Citrus junos seed oil, it showed higher skin moisturizing effect than the control emulsion containing the same amount of caprylic/capric triglyceride. Therefore, it is thought that Citrus junos seed oil might be used as a excellent skin care material.

• Journal of Life Science
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• v.29 no.3
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• pp.332-336
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• 2019

Obesity is associated with an increased risk of many diseases including type 2 diabetes mellitus, hypertension, and hyperlipidemia. The flowers of Chrysanthemum boreale have been used as traditional medicines for the treatment of diseases such as obesity and type 2 diabetes mellitus. This study aimed to evaluate the effect of C. boreale Makino flower essential oil (CFEO) on adipocyte differentiation using preadipocyte cell line 3T3-L1. CFEO at concentrations between 0.1 and $5{\mu}g/ml$ did not affect 3T3-L1 cell viability. A CFEO concentration of between 0.1 and $1{\mu}g/ml$ significantly inhibited lipid accumulation during MDI-induced differentiation in 3T3-L1 cells in a dose-dependent manner, reaching a maximal level at $1{\mu}g/ml$ ($28.94{\pm}2.01%$; approximately 30% of control treated with MDI alone). Western blot analysis revealed that CFEO concentrations between 0.1 and $1{\mu}g/ml$ suppressed the activations of three adipogenic transcription factors in the MDI-stimulated 3T3-L1 cells: peroxisome proliferator-activated receptor ${\gamma}$; CCATT/enhancer binding protein ${\alpha}$; and sterol regulatory element binding protein-1. Moreover, the expressions of lipogenic enzymes, acetyl-CoA carboxylase, and fatty acid synthase were also inhibited by treatment with CFEO between 0.1 and $1{\mu}g/ml$. CFEO may therefore be a promising functional material for obesity prevention.

• Clean Technology
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• v.17 no.4
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• pp.314-324
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• 2011

Several amide derivatives have been used as additives for base oil of metal working fluids and pressure working oils. In this paper, a series of succinic acid alkyl half-amide derivatives were synthesized as over 97% yields by ring-opening reaction of succinic anhydride and several amines and were soluble in 100 N base oil within 1 wt% concentration. The structures of the synthesized amides were confirmed by $^1H$-NMR, FT-IR spectrum and GC analysis. Anti-corrosion properties of the amides in sea water were evaluated through ASTM D665 method and weight loss method. As the results of anti-corrosion properties, the properties of the amides with shorter alkyl chain and high concentration showed better performance than those with longer alkyl chain and low concentration. Also, the dialkyl amides showed better anti-corrosion properties than those of the monoalkyl amides. Inhibition efficiency% (IE%) was over 93% in the concentration of 40 ppm and corrosion rate (CR) was below 0.5 mm/year in the same concentration.