• Environmental Engineering Research
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• 제18권4호
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• pp.247-252
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• 2013

In this work, removal of phenol from aqueous solutions by activated red mud was investigated. Scanning electron microscopy and energy dispersive X-ray spectroscopy was used to observe the morphology and surface components of activated red mud, respectively. The effects of various parameters on the removal efficiency were studied, such as contact time, pH, initial phenol concentration, and adsorbent dosage. The removal percentage of phenol was initially increased, as the solution pH increased from 3 to 7, and then decreased above neutral pH. The removal percentage of phenol was decreased by increasing the initial phenol concentrations. Adsorption results show that equilibrium data follow the Freundlich isotherm, and kinetic data was well described by a pseudo-second-order kinetic model. Experimental results show that the activated red mud can be used to treat aqueous solutions containing phenol, as a low cost adsorbent with high efficiency.

• 대한화학회지
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• 제47권1호
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• pp.7-12
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• 2003

최근 연구 자료에 의하면 Tollen의 방법을 이용하여 만들어진 silver mirror substrate의 SERS 효과가 다른 substrate에 비해 상당히 뛰어난 효과가 있다는 것으로 보고되었다. 본 연구에서는 이러한 silver mirror substrate의 특성을 알아보기 위하여 환원제의 종류, 시간 및 열처리에 따른 silver mirror substrate의 변화를 조사하였다. 또한 이러한 변화가 phenol red의 SERS 증강에 미치는 영향 및 흡착 배향과 어떠한 상관관계가 있는 지에 대해서 연구하였다.

• 약학회지
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• 제20권1호
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• pp.41-43
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• 1976

The dissociation constant of phenol red indicator in mixed solvents was studied. Methanol and ethanol were employed as solvents and studied the changes of pK values of indicator according to the kind and concentration of organic solvent which is mixed into water solution. The effect of methanol solvent on pK is negligible at 40%, 60% and 80% mixing. While in the case of ethanol, the effect of above 40% mixing is not negligible.

• 센서학회지
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• 제18권5호
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• pp.365-371
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• 2009

In this study, we have fabricated a fiber-optic pH sensor which is composed of a light source, plastic optical fibers and a spectrometer. As an indicator, a phenol red is used, and a pH liquid solution is prepared by mixing of phenol red and various kinds of pH buffer solutions in these experiments. The emitting light from a light source is guided by plastic optical fibers to the pH liquid solution, and the optical characteristic of a light is changed in the pH liquid solution according to its color change. Therefore, we have measured the intensities and wavelength shifts of the modulated lights, which are changed due to the color variations of phenol red at different pH values, by using of a spectrometer for spectral analysis. Also, the relationships between the pH values of liquid solutions and the optical properties of modulated light according to the change of color of phenol red are obtained.

• 생명과학회지
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• 제33권7호
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• pp.549-554
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• 2023

한국 인삼은 수세기 동안 전반적인 건강 보조 식품으로 전통 한의학에 사용되어 왔다. 홍삼은 뿌리를 쪄서 건조시켜 만든다. 연질 홍삼은 새로운 가공 기술로 생산된 홍삼이다. 이 연질홍삼은 물리화학적 조성에서 생삼, 경질홍삼과 차이가 있는지 조사하였다. 인삼의 총 페놀 함량은 140℃에서 2.96 mg/g, 80℃에서 3.47 mg/g으로 평가되었다. 경질 홍삼과 연질 홍삼의 총 페놀은 160℃에서 각각 4.12 mg/g, 4.18 mg/g으로 평가되었다. 인삼, 경질 홍삼, 연질 홍삼의 총 페놀 함량은 통계적으로 유의한 차이를 보였다(p>0.05). 인삼, 경질 홍삼, 연질 홍삼의 총 플라보노이드 함량은 160℃에서 각각 2.62 mg/g, 3.97 mg/g, 3.83 mg/g으로 평가되었다. 샘플 중 연질 홍삼이 160℃로 총 산성 다당류가 가장 높았다. 두 홍삼 모두 산성 다당류 함량이 인삼보다 훨씬 높았다(49%-58%). 생삼, 경질 홍삼, 연질 홍삼에 있어 유의한 차이가 있었다(p<0.001). 연질 홍삼은 인삼보다 페놀 함량, 총 플라보노이드 함량, 총 당도 함량이 각각 25%, 49%, 45% 높았다.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1306-1310
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• 2006

Sphingomonas sp. strain SB5 could degrade carbofuran and carbofuran-7-phenol to a hydrolytic product, 2-hydroxy-3-(3-methlypropan-2-o1)phenol, and several red metabolites. However, the chemical structures of the red metabolites have largely remained unidentified. In this study, we identified the structure of one of the red metabolites as 5-(2-hydroxy-2-methyl-propyl)-2,2-dimethyl- 2,3-dihydro-naphtho[2,3-6]furan-4,6,7,9-tetrone by using mass spectrometric and NMR ($^1$H, $^{13}$C) analyses. It is suggested that the red metabolite resulted from condensation of some metabolites in the degradation of 2-hydroxy-3-(3-methlypropan-2-o1)phenol, a hydrolytic product derived from carbofuran. To our knowledge, this is the first paper to report a red metabolite in bacterial degradation of the insecticide carbofuran.

• Food Science and Biotechnology
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• 제18권2호
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• pp.390-395
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• 2009

Red radish seeds were irradiated at doses up to 8 kGy using electron beam (e-beam) and gamma ray ($\gamma$-ray). The seed viability and functional properties (carotenoid, chlorophyll, ascorbic acid, and total phenol) of sprouts grown from these irradiated seeds were evaluated. High germination percentage ($\geq$97%) was observed in seeds irradiated at $\leq$5 kGy, but the yield ratio and sprout length significantly decreased with increased irradiation dose. Irradiation at $\geq$6 kGy resulted in curling of the sprout roots. Sprouting enhanced the functional properties of red radish seeds as indicated by the increased carotenoid, chlorophyll, ascorbic acid, and total phenol contents during germination. However, radiation treatment hampered the growth of seeds resulting in underdeveloped sprouts with decreased carotenoid, chlorophyll, ascorbic acid, and total phenol contents. In general, e-beam and $\gamma$-ray irradiation of red radish seeds showed similar effects on the seed viability and functional properties of sprouts. Postharvest storage reduced the functional quality of sprouts.

• 한국식품영양과학회지
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• 제28권6호
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• pp.1316-1320
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• 1999

Antioxidative effect of ethanolic extracts of various tea materials(Camellia sinensis, Cassia tora, Lyc ium chinense, Polygonatum odoratum, Schizandrae chinensis) on red pepper seed oil was investigated. Ethanolic extracts were added to red pepper seed oil at a concentration of 0.05%(w/v). Two experimental conditions were employed : 50$\pm$0.1oC for 45 days and 150$\pm$3oC for 24 hours. Oxidation of red pepper seed oil was determined by measuring peroxide value and acid value. Electron donating ability(EDA) and total phenolic contents of each extract were also determined. The result showed that the extracts possess an antioxidative activities. The effectiveness of them was in the following order: C. sinensis>C. tora>P. odoratum>S. chinensis >L. chinense. Ethanolic extracts of C. sinensis showed substantially higher EDA value and total phenol contents than other tea materials. These results indicate that the antioxidative effect was strongly related with EDA and total phenol contents.

• 센서학회지
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• 제26권6호
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• pp.414-419
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• 2017

The optical characteristics of cresol red, phenol red, and neutral red immobilized in the thin film were investigated with absorbance measurement in order to find a sensing part of a fiber-optic pH sensor. Sol-Gel method with tetramethyl orthosilicate as a precursor was used to immobilize the pH indicators in the thin film. The absorbance spectra were measured when pH indicators were immobilized in the film and were dissolved in the buffer solution. Experimental results showed that the absorbance spectra could be changed when the pH indicator is immobilized in the thin film. As compared with other pH indicators, the neutral red exhibited similar absorbance spectra regardless of physical conditions and was sensitive over whole pH range between 4 and 11. In addition, the absorbance ratio of base peak to acid peak tended to increase in proportion to the increase in pH. Experimental results indicate that the neutral red is a good pH indicator for fabrication of a sensing part of the fiber-optic pH sensor.

• Food Science and Biotechnology
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• 제14권3호
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• pp.392-398
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• 2005

Fresh, and sun- and oven-dried red peppers were analyzed for volatile components. Also, their odor-active compounds were determined using gas chromatography-olfactometry (GC-O). More diverse volatile components, such as aldehydes, ketones, acids, and esters, were found in dried samples than in fresh ones. They included hexanal, ethyl acetate, ${\alpha}$-ionone, and ${\beta}$-ionone. Some Strecker aldehydes, 2-methyl butanal and 3-methyl butanal, were found only in dried red peppers. More hydrocarbons of high volatility and terpene-type components, such as ${\gamma}$-terpinene and aromadendrene, were detected only in fresh red peppers. A considerable amount of naphthalene was formed during sun-drying, whereas 2-furancarboxaldehyde, 1-methyl-1H-pyrrole and benzeneethanol were detected only in oven-dried red peppers. Characteristic odor of fresh ones could be attributed to 3-penten-2-o1, 2-methyl-2-butenal, 2-methoxy phenol, 2-hydroxy-methyl-benzoate, and 2-phenoxy ethanol, whereas some odorants, including 2-pentyl furan, naphthalene, hexyl hexanoate, and ${\alpha}$-ionone, could be responsible for distinctive odor property of sun-dried red peppers. 2-Furancarboxaldehyde, benzeneethanol, 4-vinyl-2-methoxy phenol, and unknown played important roles in odor property of oven-dried red peppers.