• 센서학회지
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• 제26권6호
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• pp.420-426
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• 2017

A colorimetric sensor was investigated to achieve a low-cost warning device for harmful gaseous formaldehyde (HCHO). The sensor is based on selective reactions between hydroxylamine sulfate and HCHO, leading to the production of sulfuric acid. The produced acid results in color-changing response through the acid-base reaction with dye molecules impregnated on a solid membrane substrate. For attaining this purpose, sensors were fabricated by drop-casting a dye solution prepared using different pH indicators on various commercially available polymer sheets, and their colorimetric responses were evaluated in terms of sensitivity and reliability. The colorimetric sensor using bromophenol blue (BPB) and nylon sheet was found to exhibit the best performance in HCHO detection. An initial bluish green of a sensor was changed to yellow when exposed to gaseous formaldehyde. The color change was recorded using an office scanner and further analyzed in term of RGB distance for quantifying sensor's response at different HCHO(g) concentrations. It exhibited a recognizable colorimetric response even at 50 ppb, being lower than WHO's standard of 80 ppb. In addition, the sensor was found to have quite good selectivity in HCHO detection under the presence of common volatile organic compounds such as ethanol, toluene, and hexane.

• 한국산업보건학회지
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• 제8권1호
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• pp.105-114
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• 1998

In this study, 108 thinners were analyzed to identify their composition. The purposes of this study were to provide the data for MSDS and worker exposure levels. Thinners were collected from manufacturing industries, distributors and users. Wide ranges of thinner components were found ; Toluene, xylene, and ethyl benzene were most often found. Next, MIBK, cellosolve acetate, butyl cellosolve, and butyl acetate were found in 20-40 thinners. Others, such as acetone, n-hexane, cyclohexane, heptane, methylcyciohexane, octane and nonane were also found. There were about 5-6 components in each thinner. In the view point of Industrial Hygiene, Benzene was the most important component of thinners, which procures leukemia. Benzene was found from 8 kinds of thinners out of the total 108 surveyed. Thus, Content of benzene in thinners must be evaluated when industrial hygiene surveys are performed. Aromatic hydrocarbons were identified from 71 kinds of thinners out of total 108 and their contents were 10-87%. Alkanes were not contained in automobile painting, spraying, degreasing, urethane and epoxy thinners but lacquer, enamel and coating thinners.

• Macromolecular Research
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• 제8권3호
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• pp.131-136
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• 2000

The synthesis of poly(2-ethynylpyridine) having glycidyl functionality was performed by the direct polymerization of 2-ethynylpyridine and epibromohydrin under mild reaction conditions without any initiator and catalysts. The polymerization proceeded well to give the resulting poly(2-ethynylpyridinium bromide) with a glycidyl functionality having relativity high molecular weight in high yields. The polymer structure was characterized by various instrumental methods to have the conjugated polymer backbone structure having glycidyl functionality. This ionic polymer was completely soluble in water, methanol, DMF, DMSO, and N,N-dimethylacetamide, but insoluble in THF, toluene, acetone, nitrobenzene, and n-hexane. This polymer system exhibited the UV-visible absorption around 300 and 520 nm and red photoluminescence spectrum around 725 nm.

• 환경생물
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• 제19권1호
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• pp.87-92
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• 2001

For the biological treatment of industrial wastewater containing high concentration of phenol, isolation and characterization of phenol - degrading bacterium were carried out. A bacterial strain P2 capable of degrading phenol was isolated from contaminated soils by enrichment culture technique and identified as the genus Rhodococcus by morphological, cultural, biochemical characteristics, and Biolog system. The optimal medium composition and cultural conditions for the growth and degradation of phenol by Rhodococcus sp. P2 were 0.1% of (NH$_4$)$_2$SO$_4$, 0.2% of KH$_2$PO$_4$, 0.25% of Na$_2$HPO$_4$ㆍ12$H_2O$, 0.2% of MgSO$_4$ㆍ7$H_2O$, and 0.008% of CaC1$_2$ㆍ2$H_2O$ along with initial pH 8.5 at 3$0^{\circ}C$. Rhodococcus sp. P2 could grow with phenol as the sole carbon source up to 1,800 ppm in batch cultures, but did not grow in medium containing above 2,000 ppm of phenol. When 800 ppm phenol was given in the optimal media, Rhodococcus sp. P2 completely degraded it within 24 h. Meanwhile, 1,800 ppm of phenol was degraded within 9 days. Rhodococcus sp. P2 could utilize toluene, n-hexane, xylene and benzene as sole carbon source .

• 한국환경과학회지
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• 제19권1호
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• pp.97-103
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• 2010

The biodegradable oil absorption resin was prepared by the suspension polymerization of the modified starch and 2-ethylhexyl acrylate (2-EHA). The highest oil-absorption capacity of B-PEHA prepared showed at the condition of the modified starch content of 10 g and ethyleneglycol dimethacrylate (EGDMA) of 0.133 wt%. Its maximum oil absorption capacity per g of oil absorber was chloroform 30.88 g, toluene 19.75 g, xylene 18.78 g, tetrahydofuran (THF) 15.96 g, octane 11.43 g, hexane 9.5 g diesel oil 12.80 g, and kerosene 13.79 g, respectively. The biodegradation of poly-2-ethylhexylacrylate (B-PEHA) determined by enzymatic hydrolysis showed approximately 17~20%. The results showed that the preparation of the biodegradable oil absorption resin is available using the modified starch.

• Advances in environmental research
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• 제2권2호
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• pp.143-153
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• 2013

This study investigated the concentrations of odourous compounds in air, leachate, stream and well in and around Taju-Bello dumpsite. Meteorological parameters (temperature, relative humidity, wind velocity) and six odour families comprising sulphur ($H_2S$), ammonia ($NH_3$), aromatic (benzene, toluene, ethylbenzene, styrene, p-xylene, m-xylene), aliphatic (hexane), oxygenated (formaldehyde, acetaldehyde) and halogenated (tetrachloroethene, trichloroethene, carbontetrachloride) compounds were measured. Meteorological parameters suggested low dispersal of pollutants at L1 with possible perspiration and suffocation from exposure to high temperature, relative humidity and low wind velocity. The trend of abundance of odourous compounds at studied locations is of the order dumpsite (L1) > leachate (L4) > 100 m away from dumpsite (L2) > 200 m away from dumpsite (L3) > stream (L5) > well (L6). $H_2S$, Oxygenated and aromatic compounds were the major contributors to odour strength in these locations. Correlation, factor and cluster analyses of the data revealed similarities of sources as biogenics and xenobiotics inherent in the wastes as the main sources of these odourous compounds.

• 한국식품영양과학회지
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• 제29권2호
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• pp.300-306
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• 2000

In the present studies, we assessed the stability of active components and toxicological safety of irradiated Angelica gigas Nakai(Danggui). In order to confirm the stability of active components in the ${\gamma}$-irradiated roots of Danggui, the quantitative analysis of decursin and decursinol angelate of ${\gamma}$-irradiated sample was carried out by high performance liquid chromatographic (HPLC) methods using reverse phase columns and normal phase columns. From the root of Danggui, decursin and decursinol angelate were isolated by a silica gel column chromatography(toluene : ether (1 : 1), Hexane : EtOAc(15 : 1)). And then the structures were confirmed in the 1H and 13C-NMR analysis. The HPLC chromatograms of decursin and decursinol angelate in ${\gamma}$-irradiated Danggui were similar with those of non-irradiated sample. In the examination of in vitro genotoxicity of the water extract from ${\gamma}$-irradiated Danggui using Salmonella reversion assay(Ames test) and micronucleus test in Chinese hamster ovary (CHO) cells, mutagenicity was not exhibited in the two assays with or without metabolic activation. These resutls suggest that active components in the ${\gamma}$-irradiated Danggui should be stable and that the safety of ${\gamma}$-irradiated Danggui could be revealed in further test in vivo.

• 한국산업보건학회지
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• 제32권4호
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• pp.371-380
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• 2022

Objectives: To ensure that employers handling petroleum compounds understand whether petroleum-based UVCB (unknown or variable composition, complex reaction products, or biological materials) substances contain hazardous substances and comply with the Occupational Safety and Health Act, petroleum-based UVCB substances were analyzed and the results from samples were compared with MSDS (Material Safety Data Sheet) contents. Methods: Twenty-one petroleum samples were analyzed using GC-MS (Gas Chromatography-Mass Spectrometry), targeting ten volatile organic compounds regulated by the Occupational Safety and Health Act. Results: The target chemicals were detected in 13 out of 21 samples. All 13 samples were in the naphtha (low boiling point naphthas (gasolines)) group. There were also naphtha group samples containing 2% benzene. Some naphtha samples used as solvents contained about 1% benzene. Conclusions: This study shows that naphtha group petroleum substances contain hazardous chemicals in many cases. In particular, if benzene, n-hexane, and toluene with low occupational exposure limits are contained above the limit concentration. Such information should be delivered in the article on MSDS legal regulations.

• 한국식품영양과학회지
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• 제31권3호
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• pp.506-510
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• 2002

본 연구는 불포화 인지질인 DLPC liposome에 도라지(Platycodon grandiflorum A. DC, PG)의 용매별 분획물 일정 량을 가하고, 산화제 benzoyl peroxide를 가한 후 시료의 항산화 작용을 비교 분석하였다. 도라지 용매별 추출물 중 ethylether 분획물인 PGMEE와 ethylacetate 분획물인 PGMEA는 $\alpha$-tocopherol의 경우 보다 훨씬 그 산화지수가 낮아두 분획물에 의한 강한 항산화력을 측정할 수 있었으며, 잘알려진 강력한 항산화제인 BHT(butylated hydroxytoluence)의 경우와 비슷한 항산화 효과를 나타내었다. 한편 PGMEE 분획층에 비타민 C를 일정량을 첨가함으로서 상호 보강 작용에 의한 항산화 상승효과를 본 결과, Vit C를 첨가하지 않았을 때보다 산화지수가 횔씬 낮아졌다. BHT 함유의 DLPC liposome의 경우도 Vit C에 의한 비슷한 추과를 나타내었다. 이상의 결과에 의하여 도라지의 PGMEE 분획층에는 BHT와 비슷한 강한 항산화 효과를 가진 물질의 존재가 분명하다고 사료되며 비타민 C 첨가로 인한 항산화 상승 효과도 본 연구결과에 의해 뚜렷이 알 수 있었다. 이와 같은 연구에 의해 여러 질병들의 원인이 될 뿐만 아니라 세포막 손상을 일으키는 활성 산소 또는 유리기의 생성억제 등 균형된 식생활을 통한 식품 섭취의 중요성이 매우크다고 인식되며 특히 식품으로서 애용되고 있는 도라지의 인지질 세포막에 미치는 항산화 효과가 식품으로서 약이 되는 기전 규명에 기초자료가될 것을 바라는 바이다.

• KSBB Journal
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• 제25권4호
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• pp.337-343
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• 2010

액체 이산화탄소를 반응용매로 사용하여 메탄올에 의한 효소 활성이 저해되는 것을 방지하고 친환경적이며 에너지 절감 효과가 우수한 바이오디젤 생산 방법을 제시하고자 유기용매 (t-butanol, acetone, chloroform, hexane, THF, cyclohexane, toluene)와 액체 이산화탄소 비교실험을 통해 액체 이산화탄소가 기타 유기용매와 같은 메탄올 저해를 방지하는 역할을 함으로써 반응 용매로서의 적합함을 확인하였다. 또한 동일이산화탄소를 이용한 초임계 이산화탄소와 비교 실험을 수행하여 초임계 이산화탄소를 이용한 바이오디젤 생산과 유사한 결과를 나타냄으로써 액체 이산화탄소를 이용한 바이오디젤 생산방법이 에너지절약형 친환경 바이오디젤 생산에 더욱 적합함을 확인할 수 있었다. 그리고 액체 이산화탄소상태에서 바이오디젤 생산의 최적화를 통해 고효율 효소는 novozym 435, lipozyme RM IM 및 lipozyme TL IM 중에서 1,3-위치 선택적 특이성을 가진 lipozyme TL IM이 가장 우수함을 확인할 수 있었다. 또한 경제적 최적 조건과 고전환율 최적조건을 도출하여 각각 88.3%, 99.7%의 높은 전환율을 얻었다. 본 연구를 통해 액체 이산화탄소가 메탄올에 의한 효소활성 저해를 방지하는 반응 용매로 적합하며, 지구 온난화의 주요요인인 이산화탄소를 이용할 뿐 아니라 비독성 용매로서 친환경적이며 초임계 이산화탄소 상태보다 에너지 절감효과가 우수하여 효소적 바이오디젤 생산 방법에 새로운 방안을 제시 할 수 있었다.