• Korea Journal of Cosmetic Science
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• 제2권1호
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• pp.21-31
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• 2020

The aim of this study is to develop a sunscreen stick formulation technology with excellent water resistance and washability. Consumers' needs for sunscreen products are diversifying. Water resistance and ease of washing are both important factors in sunscreen products. However, it is difficult to develop a sunscreen formulation that satisfies these two factors at the same time, because these two elements are in conflict. Fatty acid has a hydrophobic property against the water with low or neutral pH, but when it contacts with soapy water which has high pH, saponification occurs and the fatty acids become surfactants and can be dispersed in the water. Using the reaction characteristics of fatty acids, we can make sunscreen that is highly resistant to water or sweat, but is only selectively removed from soapy water. We found that the sunscreen stick containing fatty acids had better water resistance and washability than the sunscreen sticks without fatty acid. The sunscreen stick containing fatty acids showed a tendency to improve water resistance by scattering ultraviolet rays of long wavelength area by forming insoluble precipitation with divalent ions in tap water after immersion. In addition, an increase in the fatty acid content tended to also increase the ease of cleaning the sunscreen stick. Solid fatty acid was advantageous in improving water resistance than liquid fatty acid, but there was no difference between solid fatty acids and liquid fatty acid in washability. When it comes to stability, the sunscreen stick using liquid fatty acids maintained a high hardness and melting point, and showed no sweating. Based on this study, it is possible to develop an easy washable sunscreen stick formulation technology that has excellent water resistance but is selectively removed only in soapy water.

• 한국축산시설환경학회지
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• 제6권1호
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• pp.53-58
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• 2000

본 시험은 양축농가에서 환경오염으로 문제시되고 있는 우분뇨 액상구비를 혼파초지에 환원시 유거수내 BOD, COD 특성과 토양내 화학적 변화를 구명코자 축산기술연구소에서 무비구, 금비단용구, 우분뇨액비구(40, 60, 80톤/ha)를 두어 난괴법 5처리 3반복으로 시험한 결과는 다음과 같다. 무비구에서 유거수량이 1,469.4mm로 가장 많았으나 분뇨액비 60톤구에서는 1,278.1mm로 가장 적었다. 유거수내 BOD는 무비구에서 $19.84m{\ell}/{\;}{\ell}$로 가장 낮았으나 우분뇨 액비 수준이 증가함에 따라 높아지는 경향이었으며, 우분뇨액비 80톤구에서 $36.22m{\ell}/{\;}{\ell}$로 가장 높았다. 유거수내 CDO는 무비구에서 $21.28m{\ell}/{\;}{\ell}$로 가장 낮았으나 우분뇨 액비수준이 증가함에 따라 높아지는 경향이었으며, 우분뇨액비 80톤구에서 $37.51m{\ell}/{\;}{\ell}$로 가장 높았다. 토양의 화학성분중 유효인산 함량과 T-N은 금비구보다 우분뇨 액비 시용구에서 높게 나타났으나 우분뇨액비 수준간에는 차이가 적었다.

• 한국농공학회지
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• 제15권4호
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• pp.3137-3146
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• 1973

This study was to investigate the effects of compaction, compressive strength and Atterberg limits in accordance with the temperatures changes. It was conducted on four soils-KJ, JJ, MH, SS-at temperatures of -1, 1, 3, 5, 7, 10, 15, 19, $22^{\circ}C$. These tests were obtained the maximum dry density and the optimum moisture content of four soils in accordance with temperature changes by using distilled water and $CaCl_2$ 10% solution, and were put to the compressive strength tests on remolded specimens of soils compacted at the optimum moisture content. The result of the study can be summarized as follows; The maximum dry density increased with an increase in temperature, and the use of $CaCl_2$ 10% solution had higher maximum dry density than distilled water. The optimum moisture content decreased with an increase in temperature, and the use of $CaCl_2$ 10% solution had lower optimum moisture content than distilled water. The maximum compressive strength was shown high peak from $7^{\circ}C\;to\;15^{\circ}C$, and the use of $CaCl_2$ 10% solution had higher maximum compressive strength than distilled water. The liquid limit and plasticity index decreased with an increased in temperature. It is estimated that the use of $CaCl_2$ 10% solution can lower the minimum compacted temperature from $2^{\circ}C\;to\;4^{\circ}C$ in low temperature.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.60-68
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• 2002

Experiments have been conducted to investigate the effects of emulsified fuels on the spray characteristics and exhaust emissions in a diesel engine. Four different fuels were examined : diesel, emulsified fuels with water contents which were varied with 13, 15, and l7wt%. Characteristics of fuel spray were measured by an optical method, PLLIF(planar liquid laser induced fluorescence). Compared to diesel fuel, emulsified fuels which had relatively high kinematic viscosity showed smaller spray angle and longer spray tip penetration. The qualitative droplet distributions of emulsified fuels showed worse atomization process than that of diesel fuel. As the water contents were increased, PM and NOx could be reduced simultaneously. It was specially noted that the emulsified fuel with l7wt% water content was found to be the best in reducing rates, NOx 30% and PM 40%.

• Journal of Applied Biological Chemistry
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• 제64권1호
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• pp.57-61
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• 2021

Saikosaponin derivatives such as saikosaponins A, B1, B2, B3, B4, C, and D present in Bupleurum falcatum were analyzed by a high performance liquid chromatograph equipped with an evaporative light scattering detector, using different extraction solvents (water and 70% ethanol). The samples were injected into a YMC Pack Pro C18 column and separated using a gradient elution system with a mobile phase composed of acetonitrile and water at a flow rate of 1.1 mL/min. The content of saikosaponin derivatives was higher in 70% ethanol extract than in water extract. This study provides an efficient analytical method for determining the optimal conditions for extraction of saikosaponin derivatives, which can be used as a basis for development of functional foods and pharmaceutical products from B. falcatum.

• Toxicological Research
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• 제24권3호
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• pp.207-212
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• 2008

Pesticide residues play several key roles as environmental and food pollutants and it is crucial to develop a method for the rapid determination of pesticide residues in environments. In this study, a simple, effective, and sensitive method has been developed for the quantitative analysis of methoxyfenozide in water and soil when kept under laboratory conditions. The content of methoxyfenozide in water and soil was analyzed by first purifying the compound through liquid-liquid extraction and partitioning followed by florisil gel filtration. Upon the completion of the purification step the residual levels were monitored through high performance liquid chromatography(HPLC) using a UV absorbance detector. The average recoveries of methoxyfenozide from three replicates spiked at two different concentrations and were ranged from 83.5% to 110.3% and from 98.1% to 102.8% in water and soil, respectively. The limits of detection(LODs) and limits of quantitation(LOQs) were 0.004 vs. 0.012 ppm and 0.008 vs. 0.024 ppm, respectively. The method was successfully applied to evaluate the behavioral fate of a 21% wettable powder(WP) methoxyfenozide throughout the course of 14 days. A first-order model was found to accurately fit the dissipation of methoxyfenozide in water with and a $DT_{50}$ value of 3.03 days was calculated from the fit. This result indicates that methoxyfenozide dissipates rapidly and does not accumulate in water.

• Food Science and Biotechnology
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• 제17권2호
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• pp.430-433
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• 2008

A high performance liquid chromatography (HPLC) method has been successfully developed to identify and quantify major ginsenosides in Korean ginseng seeds and roots. Using gradient elution of acetonitrile and water without buffer, the 6 major ginsenosides ($Rb_1,\;Rb_2$, Rc, Rd, Re, and $Rg_1$) were identified. Compared with ginseng roots, the amount of ginsenoside Re and Rd in ginseng seeds were significantly higher than those in ginseng roots (p<0.05). In ginseng seeds, the content of protopanaxtriol (PPT) was higher than that of protopanaxdiol (PPD) and the ratio of PPT and PPD was approximately 2.2 : 1. However, the content of PPT was lower than that of PPD in ginseng roots. It should be mentioned that both content of PPT and PPD in ginseng seeds were much higher than those in ginseng roots.

• 한국산학기술학회논문지
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• 제18권3호
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• pp.687-693
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• 2017

본 연구는 제주조릿대 잎의 열수추출물과 에탄올추출물을 이용하여 항산화 효능과 세포독성에 의한 세포 생존율을 분석하였다. 제주조릿대 잎은 $95^{\circ}C$ 물과 70% 에탄올 용액으로 각각 추출하여 사용하였으며, 총 polyphenol함량, 총 tannin함량, 총 flavonoid 함량을 확인한 결과 총 polyphenol함량은 $95^{\circ}C$ 열수 추출물에서 26.6mg/g, 70% 에탄올추출물에서는 22.3mg/g으로 $95^{\circ}C$ 열수 추출물에서 더 높게 나왔으며, tannin함량 역시 $95^{\circ}C$ 열수 추출물 72.1mg/g, 70% 에탄올추출물에서 61.2mg/g로 $95^{\circ}C$ 열수 추출물이 더 높게 나왔다. 총 flavonoid 함량은 $95^{\circ}C$ 열수 추출물(17.8mg/g)보다 70% 에탄올추출물(25.4mg/g)에서 더 높게 나타났다. 또한 DPPH radical 소거능, ABTS radical 소거능을 측정한 결과 모두 각 추출물의 농도가 증가할수록 증가하였으며, DPPH radical 소거능에서 L-ascorbic acid는 500ppm에서 최대 소거율을 보인 후 농도가 증가함에도 더 이상의 변화는 나타나지 않았으나 제주조릿대 잎 추출물에서는 농도에 따른 증가를 볼 수가 있었다. ABTS radical 소거능에서 역시 유사한 현상을 나타냈으나 BHT와 같은 경우는 500ppm에서 최대 소거율을 보인 후 농도가 증가함에 따라 점점 떨어지는 것을 알 수 있었다. 그러나 제주조릿대 잎 추출물에서는 농도 의존적으로 증가하여 10000ppm의 농도에서는 90%이상의 소거율을 보였으며, $95^{\circ}C$ 열수 추출물에서 약간 더 증가함을 알 수 있였다. 그리고, 인간 섬유아세포주인 3T3(human skin fibroblast)를 이용하여 제주 조릿대 잎의 세포생존율 확인한 결과 $95^{\circ}C$ 열수 추출물은 세포생존율이 85.6~66.6%로 다소 낮아지는 반면 70% 에탄올추출물에서는 95.4~92.1%로 생존율이 더 높게 나타났다. 따라서 제주조릿대 잎 추출물은 향장소재 뿐만 아니라 천연 항산화제로서의 가능성이 있다고 판단된다.

• 유기물자원화
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• 제22권3호
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• pp.23-32
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• 2014

최근 들어 유기성폐기물의 혐기소화를 이용한 처리(에너지화)가 증가하고 있다. 이에 따라서 혐기소화 후 발생하는 혐기소화폐액의 처리방안에 대한 연구도 증가하고 있다. 그러나, 혐기소화폐액의 특성상 문제로 고액분리에 매우 어려움이 있다.이에 본 연구에서는 CST와 TTF를 이용하여 혐기소화폐액에 대한 응집에 따른 고액분리 특성을 파악하였다. 또한 이러한 문제를 해결하기 위하여 실험실수준의 멤브레인 필터프레스를 제작하고, 혐기소화폐액에 적용하였다. 고분자 응집제는 7192PLUS와 1T60가 가장 적합한 것으로 확인되었으며, 최소 7192PLUS (200 mg/L), 1T60 (100 mg/L)이상의 투입이 필요하였다. 탈수효율을 평가하기 위하여 탈수케이크의 함수율과 탈리여액의 입자성 고형물을 이용하였다. 결과적으로, 멤브레인 필터프스를 이용하여 고액분리 시 입자성 고형물의 제거효율은 97.4%로 높게 나타났으며, 탈수케이크의 함수율은 65%이하로 나타났다.

• 한국물환경학회지
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• 제37권4호
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• pp.306-314
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• 2021

The application of organic fertilizer could be accompanied by potential hazards to soil and humans due to trace metals. Livestock manure compost·liquefied fertilizer is a well-established approach for the stabilization of nutrients and the reduction of pathogens and odors in manures, which can be evaluated as compost·liquefied. In this study, the livestock manure compost·liquefied fertilizers produced at 333 liquid manure public resource centers and liquid fertilizer distribution centers were collected from May to December 2019. The nutrient content (nitrogen, phosphorus, and potassium), physicochemical properties, and heavy metal content were investigated. The livestock manure compost·liquefied fertilizer was measured using a mechanical maturity measurement device. The organic matter, arsenic, cadmium, mercury, lead, chromium, copper, nickel, zinc, E. coli (O157:H7), Salmonella, etc. of the livestock manure compost·liquefied fertilizers were analyzed. The average heavy metal content in the livestock manure compost·liquefied fertilizer was as follows: Cr 2.9 mg/kg (0.2~8.7 mg/kg), Cu 20.4 mg/kg (1.6~74.1 mg/kg), Ni 1.3 mg/kg (0.4~4.2 mg/kg), and Zn 79.8 mg/kg (3.0~340.7 mg/kg). Although large-scale organic fertilizer plants and resources recycling centers produce good organic (liquid) fertilizers with proper components, it is necessary to standardize livestock manure compost·liquefied fertilizer in order to facilitate efforts to turn livestock manure into useful resources.