• 분석과학
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• 제13권2호
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• pp.234-240
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• 2000

수질계의 부식산을 화학적 산화처리하기 위한 방법의 하나로 광산화공정을 도입하여 부식산의 특성 변화를 조사하였다. 광산화공정은 UV단독, UV/$TiO_2$ 및 UV/$H_2O_2$ 시스템을 실험하였다. UV 단독 조사시 TOC 제거율은 pH 7-9에서 가장 높았으며, 흡광도는 강알카리성 영역에서 감소율이 향상된 결과를 보였다. 각 시스템별로 처리도를 보면, UV/$TiO_2$ 시스템의 경우 $TiO_2$ 의 농도가 50ppm 일때 TOC 제거와 흡광도 감소의 효율이 높았으며 50ppm 이상을 투입해도 처리율에 변화가 없었다. UV/$H_2O_2$ 시스템에서는 과산화수소의 농도가 20mM이 최적의 주입농도로 조사되었으며, 그 이상 투입할 경우 TOC와 흡광도의 처리율이 저하되었다. 탄산이온을 첨가할 경우, TOC 제거율 및 UV 흡광도의 감소율 모두 감소하며, TOC 제거율이 흡광도 감소율에 비해 상대적으로 더 크게 나타났다.

• 한국물환경학회지
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• 제23권6호
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• pp.863-871
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• 2007

Spectroscopic characteristics of river water from four major watersheds in the Ulsan area were measured to examine their potential for estimating water quality parameters. The total 176 river samples were collected from 44 sites of small streams within the watersheds during the year 2006. Spectroscopic characteristics investigated included protein-like fluorescence (FLF) intensity, fulvic-like fluorescence (FLF) intensity, terrestrial humic-like fluorescence (TLF) intensity, UV absorbance at 254 nm, and UV absorbance difference at 220 nm and 254 nm. Protein-like fluorescence intensity showed linear relationships with biochemical oxygen demand (BOD), chemical oxygen demand (COD), total phosphorous (TP) concentrations of the samples with the correlation of 0.784, 0.779, and 0.733, respectively. Due to the UV absorption characteristics of nitrate at 220 nm, UV absorbance difference at 220 nm and 254 nm was selected to represent total nitrogen (TN) concentration. Exclusion of some samples with PLF intensity higher than 5.0 improved the correlation between the UV absorbance difference and TN as demonstrated by the increase of the correlation coefficient from 0.392 to 0.784. Instead, for the samples with PLF intensity lower than 5.0, the highest correlation of TN was achieved with UV absorbance at 254 nm. The results suggest that PLF intensity could be used as the estimation index for BOD, COD, and TP concentration of river water, and as the primary screening index for the prediction of TN using UV absorbance difference. Some BOD-based water quality levels among the river water were statistically discriminated by the PLF intensity. Low p-values were obtained from the t-tests on the samples with the first level and the second level (p=0.0003) and the samples with the second and the third levels (p=0.0413). Our combined results demonstrated that the selected spectroscopic characteristics of river water could be utilized as a tool for on-site real-time monitoring and/or the primary estimation of water quality.

• 산업기술연구
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• 제18권
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• pp.417-423
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• 1998

Experiments were performed to evaluate UV/VIS absorbance and TOC of humic acid solutions which were ozonated at different pH values. The optimum conditions for ozonation of humic acid from this study are pH 9 (buffered) and 0.84 ($H_2O_2/HA$, w/w) for $H_2O_2$ dosage.

• 한국염색가공학회지
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• 제13권5호
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• pp.10-10
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• 2001

The Purpose of this study was to investigate spectrophotometric characteristics of Korean knotweed extracts. The properties were evaluated by it′s extracting solvent, effect of metallic ion, variations of pH values and effect of light exposure. The results were as following; The highest absorbance was found in methanol extract of Korean knotweed, while the lowest absorbance was carbon tetrachloride extract. The UV-vis. spectra of Korean knotweed colors in several solvents showed hypsochromic shift of n-π/sup ＊/ transition with the polarity of solvent. Absorbance and peak of UV-vis. spectra of Korean knotweed colors became lower and broader by addition of metallic ion. The light stability in irradiation with xenon ]amp of the color solution with Cu were higher than those of Al and Fe. The UV-vis. spectra of Korean knotweed extracts in various pH values showed bathochromic shift under alkaline condition, and their peaks disappeared after 5 hours exposure.

• 한국염색가공학회지
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• 제13권5호
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• pp.298-305
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• 2001

The Purpose of this study was to investigate spectrophotometric characteristics of Korean knotweed extracts. The properties were evaluated by it's extracting solvent, effect of metallic ion, variations of pH values and effect of light exposure. The results were as following; The highest absorbance was found in methanol extract of Korean knotweed, while the lowest absorbance was carbon tetrachloride extract. The UV-vis. spectra of Korean knotweed colors in several solvents showed hypsochromic shift of $n->\pi^*$ transition with the polarity of solvent. Absorbance and peak of UV-vis. spectra of Korean knotweed colors became lower and broader by addition of metallic ion. The light stability in irradiation with xenon ]amp of the color solution with Cu were higher than those of Al and Fe. The UV-vis. spectra of Korean knotweed extracts in various pH values showed bathochromic shift under alkaline condition, and their Peaks disappeared after 5 hours exposure.

• 한국환경보건학회지
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• 제40권2호
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• pp.137-146
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• 2014

Objectives: Feasibility of electrochemical oxidation of the aqueous non-biodegradable wastewater such as cationic dye Rhodamine B (RhB) has been investigated in an electrochemical reactor with solid polymer electrolyte (SPE). Methods: Nafion 117 cationic exchange membrane as SPE has been used. Anode/Nafion/cathode sandwiches were constructed by sandwiching Nafion between two dimensionally stable anodes (JP202 electrode). Experiments were conducted to examine the effects of applied current (0.5~2.0 A), supporting electrolyte type (0.2 N NaCl, $Na_2SO_4$, and 1.0 g/L NaCl), initial RhB concentration (2.5~30.0 mg/L) on RhB and COD degradation and $UV_{254}$ absorbance. Results: Experimental results showed that an increase of applied current in electrolysis reaction with solid polymer electrolyte has resulted in the increase of RhB and $UV_{254}$ degradation. Performance for RhB degradation by electrolyte type was best with NaCl 0.2 N followed by SPE, and $Na_2SO_4$. However, the decrease of $UV_{254}$ absorbance of RhB was different from RhB degradation: SPE > NaCl 0.2 N > $Na_2SO_4$. RhB and $UV_{254}$ absorbance decreased linearly with time regardless of the initial concentration. The initial RhB and COD degradation in electrolysis reaction using SPE showed a pseudo-first order kinetics and rate constants were 0.0617 ($R^2=0.9843$) and 0.0216 ($R^2=0.9776$), respectively. Conclusions: Degradation of RhB in the electrochemical reactor with SPE can be achieved applying electrochemical oxidation. Supporting electrolyte has no positive effect on the final $UV_{254}$ absorbance and COD degradation. Mineralization of COD may take a relatively longer time than that of the RhB degradation.

• 대한화장품학회지
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• 제41권1호
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• pp.57-62
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• 2015

본 연구에서 우리는 유기자외선차단제와 왁스를 함유하고 Tween 80과 Span 80의 혼합계면활성제를 이용한 o/w 나노에멀젼에서 자외선 흡광도의 상승에 대해 연구하였다. Tween 80/Span 80 유화시스템에서 칸데릴라 왁스를 함유하고 PIC (Phase Inversion Composition) 방법으로 제조된 나노에멀젼의 입자는 50 nm 이하였다. Tween 80/Span 80/칸데릴라 왁스/유기자외선차단제의 농도를 4.5:0.5/3.0/2.0 wt%로 고정하고 다양한 유기자외선차단제를 각각 첨가하여 에멀젼을 제조한 결과, Parsol MCX와 Escalol 587에서 안정한 나노에멀젼이 형성되었다. 또한 동일 시스템에서 Parsol MCX와 칸데릴라 왁스의 비율은 2.0 미만일 때 안정한 나노에멀젼이 형성되었다. 자외선 흡수 효과는 Parsol MCX와 칸데릴라 왁스를 혼용하였을 때 높은 상승효과를 보였다.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2008년도 제39차 학술발표회
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• pp.25-26
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• 2008

일반적인 분산염료, Phthalimide계 중간체로 사용한 분삼염료, Diester계 커플러만 이용한 분산염료와 비교한 Diester계 치환기를 이용한 분산 염료들은 R/C조건과 EtOAc와 증류수로 층분리하여 증류수층의 UV-Vis absorbance은 떨어지고 용해성은 증가한다. 그리고 Thiopene ring만 가진 염료와 비교한 염료들은 같은 파장에서의 UV-Vis absorbance은 떨어져 용해도는 증가하고 Thiopene ring과 Azo group의 분해에 의한 화합물 때문에 단파장에서의 UV-Vis absorbance가 크게 증가하여 염색 폐수의 색도를 감소시킬 수 있다.

• 펄프종이기술
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• 제48권3호
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• pp.23-29
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• 2016

Effects of cationic polyvinylamine (PVAm) dry strength agent on effectiveness of optical brightening agent (OBA) during fine papermaking and the mechanism for brightness reduction of paper by PVAm was investigated by UV/Vis spectroscopy and turbidity measurement of OBA solution with PVAm. It was shown that PVAm reduced brightness of paper while opacity was not varied and tensile strength of paper was increased. Tetra-type OBA solution showed the peaks around the wavelength of 280 nm and 330 nm and the increase in the OBA concentration increased the UV absorbance in all wavelength. Addition of PVAm into the OBA solution decreased the UV absorbance at 280 nm. Turbidities of OBA and PVAm solutions were close to zero, respectively, while the turbidity value increased for the mixed solution of OBA and PVAm in various mixing ratios and the highest value was obtained when the mixing ratio of PVAm and OBA was 5:5, meaning that cationic PVAm formed complex with anionic OBA. In conclusion, cationic PVAm could form a complex with anionic OBA and that reduced UV absorbance, resulting in the reduced brightness of paper.

• 한방안이비인후피부과학회지
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• 제16권2호
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• pp.57-77
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• 2003

Objectives: The aim of this study was to investigate the depigmentation effects of Barley, Unpolished rice, Job's-tear. Metbods: We investigated that the extracts of Barley, Unpolished rice, Job's-tear inhibit activity of tyrosinase, the enzyme which convert ts 3-(3,4-dihydroxyphenyl) alanine to dopachrom in the biosynthetic process of melanin, the UV absorbance of the extracts in the UV-A region and UV-B region was measured by UV scanning, the effect of extracts on cell viability and melanin production in cultured B16 mouse melanoma cells were measured, and cytoprotective effects of extracts on PC12 cells injured by hydrogen peroxide measured by MTT assay. Results: The extracts of Barley, Unpolished rice, Job's-tear inhibited activity of tyrosinase in low density. The Barley, Job's-tear extracts not only showed inhibitory effects on melanin production in cultured B16 mouse melanoma cells, but also exhibited cytoprotective effects on PC12 cells injured by hydrogen peroxide in low density. Unpolished rice extract showed inhibitory effect on melanin production in cultured B16 mouse melanoma cells, but did not showed cytoprotective effect Barley, Unpolished rice, Job's-tear extracts did not showed an absorbance effect in the UV-A region and UV-8 region. Conclusions: These results suggest that Barley, Unpolished rice, Job's-tear inhibit melanin biosynthesis which is involved in hyperpigmentation and could be used as a whitening agent.