• The Journal of the Korea Contents Association
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• v.9 no.3
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• pp.353-360
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• 2009

The use of colorants as additives for foods and drinks is a significant factor to food consumers in determining the acceptability of processed foods. In recent years, the number of previously used artificial colorants/dyes suitable for food use has been drastically reduced as a result of toxicological studies. Therefore, the use of natural pigments such as anthocyanins and betacyanins that were known to have anticancer and antioxidant activities is increasingly required. In this study, the water-soluble plant pigments, anthocyanins and betacyanins, were easily extracted with a very simple method using a few organic solvents such as ethyl acetate, ethyl ether, and chloroform. After the extraction of them, these two major plant pigments could be also simply and rapidly separated and discriminated by a solely one-stepped agarose gel electrophoresis in a citrate buffer (pH 3.0).

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.32-40
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• 2018

The aim of this study was to determine the efficacy of a 3 tone plaque disclosing gel in assessing the risk of caries related to the population of Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus spp. quantified using a quantitative real-time polymerase chain reaction (qRT-PCR). 15 healthy children of ages 9 - 12 years were randomly examined. The 3 tone plaque disclosing gel was applied on teeth surfaces, which changed the color to pink or red, blue or purple and light blue. Plaque was divided into 3 groups based on staining. Genomic DNA from each sample was subjected to a qRT-PCR assay for quantitative detection of target bacteria. The Kruskal-Wallis test was conducted for correlation between the color of plaque and the number of bacterial species. The levels of S. mutans, S. sobrinus, and Lactobacillus spp. were significantly different in the plaque samples of the 3 groups (p < 0.05). The proportion of S. sobrinus to S. mutans showed correlation to the color of plaque. The different color-dyed plaque was related to the number of acidogenic bacteria. The 3 tone plaque disclosing gel could be used as one of the indicators to assess the clinical risk of caries associated with the population of S. mutans, S. sobrinus, and Lactobacillus spp.

• Elastomers and Composites
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• v.4 no.1
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• pp.70-78
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• 1969

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.215-216
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• 2003

대기환경에 대한 오존의 영향이 증대되면서 오존에 대한 관심이 증대되었다. 이에 따라 대기중 오존 농도를 정확히 측정할 수 있는 오존 측정기에 대한 관심도 고조되고 있는 실정이다. 오존을 측정하기 위한 방법은 분석하는 방법에 따라 Ion Chromatography, UV/Vis Spectrometer, Spectrofluorimeter, Spectrometer(reflection)방법 등을 들 수 있으며(Zhou and Smith, 1997, Geyh etal. 1997), 이들 중 Spectrometer(reflection)를 이용하는 방법이 비교적 간단하다. 이 방법은 대기 중 오존과 반응하여 색도가 변화하는 착색제를 사용하여 색도 변화를 관측하여 오존 농도를 평가하는 방법이다. (중략)

• Journal of agriculture & life science
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• v.45 no.1
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• pp.1-7
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• 2011

An experiment was conducted to test different heights of drainage level sensors in an irrigation management system for perlite bag culture of cucumber and paprika. The sensors were placed at 4, 8, 12, and 16 mm from the bottom of the container. Both cucumber and paprika did not show any significant difference in growth and yield among the treatments. However, placing the sensor at 4 mm seemed to be the best in order to prevent over-supply of water at the beginning of the day.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.306-310
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• 2010

Petroleum visible markers (dye) have been used to distinguish different fuel classes and to prevent illegal mixing. It is difficult to recognize the real color of visible marker when the small amount of petroleum product was mixed in another fuel oil. In this study, we determined the two wavelengths (370 nm, 645 nm) which detect all Korean petroleum visible marker using UV/Vis spectrophotometer. Then we analyzed the visible marker using high performance liquid chromatography (HPLC) in two wavelength detectors. Also, we optimized the analytic method for petroleum visible marker in illegal mixed fuel oil.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.372-375
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• 2009

반도체 봉지재란 실리콘 칩, 골드와이어, 리드프레임 등의 반도체 소지를 열, 수분, 충격으로부터 보호하기 위해 밀봉하는 재료로서 EMC(Epoxy Moding Compound)가 가장 많이 쓰인다. EMC는 기계적, 전기적 성능향상을 위한 무기재료로 실리카(Silica), 열에 의해 경화되어 3차원 경화구조를 형성하는 에폭시수지, 빠른 경화특성을 부여하기 위한 경화제로서의 페놀수지, 유기재료와 무기재료 사이의 결합력을 높이기 위해 커플링제, 카본블랙, 이형성 확보를 위한 왁스(Wax), 착색제(Colorant), 난연제(Flame Retardant)등의 첨가제로 구성되는 복합소재로써 본 연구에서는 에폭시의 유형에 따른 용융 실리카를 주충진재로 하여 각각의 봉지재의 첨가제를 기준으로 할 때 다양한 형태의 친환경 비할로겐계 반응형 난연제를 합성하는 기술을 개발하고 비 할로겐계 및 Sb 계 첨가형 난연제의 혼용 배합을 통해 친환경 EMC용 난연제의 제조기술을 개발하였다. 이들 EMC의 요구특성은 요구특성은 외부환경으로부터 칩 보호, 칩을 전기적으로 절연특성 유지, 칩의 작동시 발생되는 열의 효과적인 방출 특성 유지, 실장(Board Mounting)의 간편성 특성을 확보해야 하는 특성을 지니고 있어 이들 요구특성에 적합한 특성조사가 함께 이루어졌다.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.1-10
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• 2017

The present study aimed to evaluate the validity of resin infiltration in improving color stability after tooth whitening. Enamel samples were extracted from 40 healthy bovine upper incisors, and primary staining and whitening were performed. After that, specimens were randomly divided into 3 groups : resin infiltration group (n = 15, RI group), resin adhesive group (n = 15, RA group), and control group (n = 10). Secondary staining was performed on all samples. Coloration was assessed 5 times as follows: initial color, immediately after staining, after whitening, after resin application, and after secondary staining. Color was measured using a spectrophotometer and recorded by using the CIE $L^*a^*b^*$ color space. The color changes after primary staining for the RI, RA, and control groups were $12.16{\pm}3.50$, $12.16{\pm}3.38$, and $15.81{\pm}6.39$, whereas those after secondary staining were $15.21{\pm}7.19$, $15.93{\pm}4.31$, and $26.62{\pm}17.89$. Color changes after secondary staining showed a significant difference between the RI and control groups. In the within-group comparison between primary and secondary staining, there was no significant difference found in the RI group only (p = 0.26). The results suggest that Color stability after tooth whitening can be improved using resin infiltration.

• Applied Biological Chemistry
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• v.22 no.1
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• pp.39-41
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• 1979

Succeed to structural elucidation, the anthocyanins in the Korean restive Brassica juncea were quantitatively investigated. And obtained results were as follows: 1. The amount of total anthocyanins showed a little difference according to harvesting season, such as 175.5mg% in spring and 192.7mg% in autumn, as peonidin-3-glucoside. 2. By colored degree of leaf, the amount of total anthocyanins showed 290.2mg% in both side colored, 73.6mg% in one side colored and 40.0mg% in none colored as peonidin-3-glucoside. 3. The characteristic color of fresh Brassica juncea couldn't he detected with naked eyes within the limits of 40mg% of anthocyanin as peonidin-3-glucoside. 4. There were no differences with the harvesting season and the colored degree in the ratio of two kinds of anthocyanins, which was consisted of 57.3% of peonidin-3-glucoside and 44.7% of peonidin-3-galactoside.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.99-104
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• 2010

Platinum nanoparticles were added to a mixture of HEMA (2-hydroxyethyl methacrylate), NVP (N-vinyl pyrrolidone) and MMA (methyl methacrylate) in a mould at various concentrations. The resulting mixture was copolymerized by heating at $70^{\circ}C$ for 40 min, $80^{\circ}C$ for 40 min, and $100^{\circ}C$ for 40 min, respectively. The physical properties of contact lens were then measured. The oxygen transmissibility of $9{\sim}15{\times}10^{-9}$ cm/s mL $O_2$/mL ${\times}$ mmHg, water content of 34.22~35.52%, refractive index of 1.432~1.435, visible transmittance of 88.3~91.2% and tensile strength of 0.141~0.152 kgf were obtained. The addition of platinum nanoparticles to the polymer allowed the contact lens to have various colors without artificial coloring agents. The polymer materials satisfied the physical properties required to produce contact lenses, making the material suitable to be applied as a functional material for ophthalmological purposes.