• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.524-529
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• 2013

Recently, researchers have become interested in natural ester fluids, as they are an environmentally friendly alternative to mineral oils. Natural ester fluids are a natural resource made from plants; they have higher biodegradability, flash, and fire points, and a greater permittivity compared to conventional mineral oils. However, natural ester fluids also have a higher pour point, viscosity, and water content. These characteristics can hamper circulation and impair the electrical properties of an oil-filled transformer. A large amount of data has been accumulated over the years in regards to mineral insulating oil involving dielectric breakdown voltage and lightning impulse tests. However, natural ester fluids have not had their electrical properties sufficiently characterized. In this paper, we present an investigation into the characteristics of the electrical discharge development in natural ester fluids and in an oil-filled transformer near the pour points. The experiment results show that the electrical properties decreased according to a decrease in the ambient temperature and freezing time. It was found that the pour point and water content of natural ester fluids have a significant effect on the electrical properties.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1337-1345
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• 2018

The reliability of power transmission and distribution depends up on the consistency of insulation in the high voltage power transformer. In recent times, considering the drawbacks of conventional mineral oils such as poor biodegradability and poor fire safety level, several research works are being carried out on natural ester based nanofluids. Earlier research works show that sunflower oil has similar dielectric characteristics compared with mineral oil. BIOTEMP oil which is now commercially available in the market for transformers is based on sunflower oil. Addition of nanofillers in the base oil improves the dielectric characteristics of liquid insulation. Only few results are available in the literature about the insulation characteristics of nano modified natural esters. Hence understanding the influence of addition of nanofillers in the dielectric properties of sunflower oil and collecting the database is important. Considering these facts, present work contributes to investigate the important characteristics such as partial discharge, lightning impulse, breakdown strength, tandelta, volume resistivity, viscosity and thermal characteristics of $SiO_2$ nano modified sunflower oil with different wt% concentration of nano filler material varied from 0.01wt% to 0.1wt%. From the obtained results, nano modified sunflower oil shows better performance than virgin sunflower oil and hence it may be a suitable candidate for power transformer applications.

• 한국임상보건과학회지
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• 제4권4호
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• pp.730-736
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• 2016

Purpose. The aim of this study was to provide Aromatherapist with analysis of the effect of natural aroma essential oil on middle school students' self-concept. Methods. In total, 20 students were recruited to answer a self-administered questionnaire in pre and post. The questionnaire was composed of questions about general self-concept, class self-concept, achievement self-concept, ability self-concept, social self-concept, family self-concept, emotional self-concept, physical self-concept. The natural aroma essential oil program was operational in a 90-minute once a week for ten weeks. Results. As a result, the score of emotional self-concept(t=-2.60, p<.05) is higher than pre the experiment post experiment. Conclusions. This study is to get a basic data of natural aroma should be applied to improve self-concept of middle school students.

• 한국응용과학기술학회지
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• 제22권3호
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• pp.241-249
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• 2005

This experiment extracted the natural green-tea using ethanol and obtained the refined oil component after filterated green-tea extract. This study tested the antimicrobial effect as characteristics experiment, and analyzed refined oil component with pH-meter and GC/MS. In the result of this experiment, it obtained the next conclusions. In the first result of extraction experiment, it could know that extraction ratio of refined oil component appeared about 9.0%. In the second result of characteristics experiment, it could certificate that in case of increasing the refined oil component in concentration of 100ppm and above, and according to passage of cultivation time, the number of S-aureus and E-coli in microbe decreased less and less. But in case of blank test not adding the refined oil component, the number of microbe increased more and more. In these phenomena, it could certificate that refined oil component of green-tea appeared antimicrobial effect against microbe. In the third result of instrumental analysis, refined oil component of green-tea appeared about 7.6 in 1% distilled water solution with pH-meter, and the aromatic components of benzene, bonyl acetate, campene, ${\alpha},{\beta},{\gamma}$-pinnene etcs from refined oil component of green-tea was detected with GC/MS.

• 한국응용과학기술학회지
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• 제7권1호
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• pp.63-70
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• 1990

Influence of mixing ratio of blending oil (rice bran oil : RBD palm olein = 1 : 1, 1 : 4 mixture: w/w) and natural tocopherol, citric acid, and sodium polyphosphate on enhancement of oxidation stability of blending oil under the condition of tap water infulx(1 ml/min/200g oil) were compared by AOM test after heating these system at l80$^{\circ}C$. In addition, the effects of tocopherol, and synergist on oxidition stability were also tested with potato chips fried with blending oil(1 : 4 mixture). The result obtained were as followes; 1. The test of RBD palm olein addition of 50% and 80% against rice bran oil on oxidation stability showed that the higher the palm olein contents in blending oil, the higher the oxidation stability. 2. The test of oxidation stability, adding l00ppm, 200ppm and 400ppm of natural tocopherol in two different types of blending oils, A(1 : 1 mixture) and B(1 : 4 mixture), disclosed that blending oil B was more positively effective, and this trend was superior at 200ppm level particularly, Furthermore, oxidation stability was enhanced remarkably upon addition of 100ppm of natural tocopherol, and 50ppm of citric acid together with 50ppm, 100ppm and 200ppm of sodium polyphosphate in general. Especially, 200ppm of sodium polyphosphate addition induced the most synergetic effect on oxidation stability showing as much as 3 times compare to control. 3. The results of oxidation stability obtained by peroxide value on potato chips fried with blending oil (1:4 mixture} added tocopherol, citric acid and sodium polyphosphate and preserved at $60^{\circ}C$ revealed that addition of tocopherol and 50ppm of citric acid together with 200ppm of sodium polyphosphate treatment was the most synergistic coinciding with AOM test results.

• Journal of Plant Biotechnology
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• 제47권1호
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• pp.100-106
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• 2020

Coix lacryma-jobi (Hanjeli) is known to posses anti-microbial properties. Therefore, phytochemical compounds of C. lacryma-jobi have been studied to produce novel antimicrobial agents as treatments against antibiotic-resistant bacteria.The objective of this study was to determine the phytochemical composition and antibacterial activity of the C. lacryma-jobi oil against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The phytochemical composition of the oil was determined via gas chromatography mass spectrophotometry (GC-MS). Moreover, agar disk and agar well diffusion were employed to screen the antibacterial activity of the oil. An agar well diffusion test was implemented to determinate MIC's (minimum inhibitory concentrations). Dodecanoic acid, tetradecanoic acid, 2,3-dihydroxypropylester, 1,3-dioctanoin, N-methoxy-N-methyl-3,4-dihydro-2H-thiopyran6-carboxamide, propanamide, 5-Amino-1-(quinolin-8-yl)-1,2,3-triazole-4-carboxamide, and pyridine were identified in the C. lacryma-jobi oil. The MIC value of the oil was 0.031 g/L and the MBC of the oil was 0.125 g/L effective in all test bacteria. Dodecanoic acid displayed inhibitory activity against gram-positive and gram-negative bacteria. Therefore, our research demonstrated C. lacryma-jobi (Hanjeli) oil exhibited antibacterial activity against E. coli, S. aureus, and B. subtilis. These research suggest that C. lacryma-jobi root oil could be used for medicinal purposes; however clinical and in vivo tests must be performed to evaluate its potential as an antibacterial agent.

• Journal of Applied Biological Chemistry
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• 제58권2호
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• pp.105-108
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• 2015

This research is aimed at evaluating the potential abilities of the natural acaricide of F. suspense oil against Tyrophagus putrescentiae and Dermatophagoides spp. Based on the $LD_{50}$ values, in contact bioassay, F. suspense oil (8.19, 3.28, and $4.35{\mu}g/cm^2$) showed acaricidal effects against T. putrescentiae, D. farinae, and D. pteronyssinus, respectively. Fumigant toxicities of F. suspense oil showed similar patterns as those observed with contact toxicities. GC/MS analysis showed the major components of F. suspense oil to be ${\beta}$-pinene (45.88%), myrtenol (13.86%), (+)-${\alpha}$-pinene (13.09%), (-)-trans-pinocarveol (7.34%), sabinene (6.64%) and pinocarvone (4.13%). These findings indicate that F. suspense oil has potential as a natural acaricide.

• Carbon letters
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• 제7권4호
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• pp.245-248
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• 2006

Thin films of carbon-nano materials (CNMs) of different morphology have been successfully deposited on ceramic substrate by CVD at temperatures $800^{\circ}C$, $850^{\circ}C$ and $900^{\circ}C$ using plant based oils in the presence of transition metal catalysts (Ni, Co and Ni/Co alloys). Based on the return and insertion loss, microwave absorption properties of thin film of nanocarbon material are measured using passive micro-Strip line components. The result indicates that amongst CNMs synthesized from oil of natural precursors (mustered oil - Brassica napus, Karanja oil - Pongamia glabra, Cotton oil - Gossipium hirsuta and Neem oil - Azadirachta indica) carbon nano fibers obtained from neem's seed oil showed better microwave absorption (~20dB) in the range of 8.0 GHz to 17.90 GHz.

• 대한화장품학회지
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• 제39권1호
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• pp.65-73
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• 2013

립 메이크업 제품은 음식물과 함께 체내로 유입되므로 안전성에 대한 필요성이 다른 화장품보다 크다. 또한 합성 안료인 타르계 색소에 대한 안전성 문제가 지속적으로 부각되고 있는 상황에서 천연색소에 대한 요구가 점점 증가되고 있으며, 많은 종류의 천연 색소가 개발되고 있다. 하지만 립메이크업 제품에 합성색소 대신 천연색소를 이용하기에는 여러 가지 문제점이 있다. 대부분 천연 색소는 안토시아닌 계통의 친수성 물질로 구성되어 있지만, 기존의 입술 화장료는 오일과 왁스로 이루어진 무수상태의 유분산 제형이 대부분이기 때문이다. 따라서 립메이크업 제품은 상기에서 설명한 바와 같인 무수제형이기 때문에 수용성인 천연색소를 사용할 경우에 색상발현도가 낮고 불안정하여 제형에서 색소가 분리되기 쉽다. 또한 천연색소는 pH, 열 및 일광 등에 의해 쉽게 변하는 단점이 있는데, 무수제형에서는 이에 대한 조절이 쉽지 않아 안정도에 문제점을 가지고 있다. 따라서 본 연구에서는 천연색소를 사용하여 인체에 안전하면서 색상 표현력이 우수한 립메이크업 조성물에 대하여 연구를 수행하였고, 천연색소를 유중폴리올 에멀젼에 포집하여 색소의 안정도를 확보하였으며, 수분증발 시 생기는 건조함이 없는 우수한 보습력을 갖는 립메이크업 제품을 제조하였다.

• 약학회지
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• 제36권2호
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• pp.93-109
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• 1992

The purpose of this experiment was to investigate both the immunomodulatory effect of evening primrose(EP) oil and the effects of EP oil on immunoregulation by cyclophosphamide in mice. EP oil at doses of 0.1, 0.2 and 0.4 ml/kg were orally administered to ICR male mice once daily for 28 consecutive days. Cyclophosphamide was injected intraperitoneally to ICR mice with a single dose of 5 mg/kg at 2 days before secondary immunization. Mice were sensitized and challenged with sheep red blood cells(S-RBC). Immnune responses were evaluated by humoral and cellular immune responses and non-specific immune response. The results of this study were summarized as follows; (1) The humoral immune responses such as hemagglutination titer(HA), hemolysin titer(HY), Arthus reaction and plaque forming cell(PFC) were significantly enhanced in the low dose EP oil administered groups(0.1 and 0.2 ml/kg). However, in the high dose EP oil administered group(0.4 ml/kg) the responses were significantly lowered. (2) In the case of cellular immune responses, delayed type hypersensitivity reaction(DTH) was significantly decreased in EP oil whereas rosette forming cell(RFC) was remarkably enhanced. (3) Activities of natural killer cells and phagocyte were generally enhanced in EP oil. In addition, serum albumin and globulin were also increased.