• 한국수소및신에너지학회논문집
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• 제20권5호
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• pp.447-454
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• 2009

Electrolyzed reduced water was known as an alkaline solvent than piped water, natural water and mineral water etc. By means of reduction property, electrolyzed reduced water could dissolve a solute than other kinds of water without chemicals. In this study, serpentine dissolution in electrolyzed reduced water was investigated as a novel pre-treatment of serpentine which was a minerals for carbon dioxide sequestration. The elements (Ca, Si, Mg etc.) of serpentine were dissolved rapidly at early in the dissolvation then after some minutes the solubilities of serpentine elements showed stable state without abrupt changes. In spite of serpentine elements dissolution, chemical bondings and crystallographic structure of serpentine were not changed. It was explained that the dissolution mechanism of serpentine occurred from surface in electrolyzed reduced water and bulk structure sustained without collapse.

• 한국환경보건학회지
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• 제14권1호
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• pp.87-101
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• 1988

The effect of hepatic injury produced by CCL, was studied on rats receiving a low protein-high carbohydrate (7% casein), standard protein (20% casein) and a high protein diet (30% casein). The rats fed low protein diet are resistant to CCl$_4$ in its effects on the liver as judged by histology, serum enzymes(guanase, ALT) and the content of hepatic protein. On the other hand, the pretreatment of hydrocortisone before injection of CCl$_4$ to the rats fed a standard diet, slightly decreased both serum ALT and guanase activities. In the pretreatment of actinomycin D, the liver and serum guanase activities were significantly decreased. It indicates that the cause of increasing serum guanase is based on the alteration of membrane permeability and the result of accelerated enzyme synthesis in liver cells of CCl$_4$ intoxicated rats.

• 한국환경과학회지
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• 제18권10호
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• pp.1071-1077
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• 2009

A novel pretreatment technique was applied to the conventional Pt/alumina catalyst to prepare for the highly efficient catalyst for the preferential oxidation of carbon monoxide in hydrogen-rich condition. Their performance was investigated by selective CO oxidation reaction. CO conversion with the oxygen-treated Pt/Alumina catalyst increased remarkably especially at the low temperature below $100^{\circ}C$. This result is promising for the normal operation of the proton exchange membrane fuel cell (PEMFC) without CO poisoning of the anode catalyst. XRD analysis results showed that metallic Pt peaks were not observed for the oxygen-treated catalyst. This implies that well dispersed small Pt particles exist on the catalyst. This result was continued by high resolution transmission electron microscopy (HRTEM) analysis. Consequently, it can be concluded that highly dispersed Pt nanoparticles could be prepared by the novel pretreatment technique and thus, CO conversion could be increased considerably especially at the low temperatures below $100^{\circ}C$.

• 한국해양바이오학회지
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• 제2권4호
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• pp.257-262
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• 2007

Squid viscera oil was investigated by pretreatment method for enhancing the commercial value. Transeterification was performed to reduce rancidity of the oil, off-flavor was removed by using activated carbon adsorption. Analysis using ATD (Automatic Thermal Desorber) and GC/MG shows the efficacy of off-flavor removement. The rates of Transesterification employing inorganic catalyst and biocatalyst were tested, respectively. With stepwise addition of ethanol, the most efficiency of the reaction was achieved by inorganic catalyst. The efficiency of the reaction was estimated by acid value corresponding to rancidity of reaction product.

• Archives of Pharmacal Research
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• 제26권5호
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• pp.411-415
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• 2003

To investigate the mechanisms involved in hemin-induced febrile response, the rectal temperature of rats were measured after intracerebroventricular (i.c.v.) injections of hemin, with or without antagonists. Hemin ($10\mu\textrm{g}$) elicited a significant febrile response, which lasted from 30 min, to more than 6 h, after its administration, but this was not the case with biliverdin (i.c.v.) and bilirubin (i.c.v.). The hemin-induced febrile response was significantly inhibited by pretreatment with an inhibitor of tyrosine kinase (genistein), but not by pretreatment with an inhibitor of protein kinase C (chelerythrine) and a scavenger of iron (deferoxamine). These results suggest that tyrosine kinase is involved in the hemin-induced febrile response.

• Bulletin of the Korean Chemical Society
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• 제19권6호
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• pp.619-624
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• 1998

A simple and reproducible pretreatment method was developed for the determination of dioxins in milk sample. Liquid-liquid extraction (LLE) was used for the initial extraction of the analyte from milk. For the elimination of interferences coextracted from milk, acid treatment followed by multilayer silica gel, and then alumina column clean-up were performed. The clean extract could be obtained without carbon column or high performance liquid chromatographic (HPLC) clean-up procedure. Polychlorinated biphenyles (PCBS) and dioxins were separated on neutral alumina activated at 180 ℃ for 12 hours. The final extract was analyzed by HPLC and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The recovery of dioxins spiked in milk at 75-300 ppt level was 83.3-98.9% and their relative standard deviation was 4.1-14%.

• Toxicological Research
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• 제27권3호
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• pp.161-166
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• 2011

Carbon black, a particulate form of pure elemental carbon, is an industrial chemical with the high potential of occupational exposure. Although the relationship between exposure to particulate matters (PM) and cardiovascular diseases is well established, the cardiovascular risk of carbon black has not been characterized clearly. In this study, the cytotoxicity of carbon black to vascular smooth muscle and endothelial cells were examined to investigate the potential vascular toxicity of carbon black. Carbon black with distinct particle size, N330 (primary size, 28~36 nm) and N990 (250~350 nm) were treated to A-10, rat aortic smooth muscle cells and human umbilical vein endothelial cell line, ECV304, and cell viability was assessed by lactate dehydrogenase (LDH) leakage assay. Treatment of carbon black N990 resulted in the significant reduction of viability in A-10 cells at 100 ${\mu}g$/ml, the highest concentration tested, while N330 failed to cause cell death. Cytotoxicity to ECV304 cells was induced only by N330 at higher concentration, 200 ${\mu}g$/ml, suggesting that ECV304 cells were relatively resistant to carbon black. Treatment of 100 ${\mu}g$/ml N990 led to the elevation of reactive oxygen species (ROS) detected by dichlorodihydrofluorescein (DCF) in A-10 cells. Pretreatment of antioxidants, N-acetylcysteine (NAC) and sulforaphane restored decreased viability of N990-treated A-10 cells, and N-acetylcysteine, but not sulforaphane, attenuated N990-induced ROS generation in A-10 cells. Taken together, present study shows that carbon black is cytotoxic to vascular cells, and the generation of reactive oxygen contributes to the development of cytotoxicity. ROS scavenging antioxidant could be a potential strategy to attenuate the toxicity induced by carbon black exposure.

• 한국환경보건학회지
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• 제24권1호
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• pp.38-46
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• 1998

This study was to investigate the effects of carbon loadings, temperature and expansion ratio on the waterborne organic removal by the biologically active GAC fluidized bed on a laboratory scale. The raw water to be treated comes from midstream of Han river. BACFB(Biological Activated Carbon Fluidized Bed) process was very effective to remove the biodegradable fraction of dissolved organic matter. The more carbon weighed, the more DOC removed in a range from 16.7 to 133.3 g/l. DOC and UV$_{254}$ were removed more than 40% and 20% above 20$\circ$C respectively. Between 5$\circ$C and 10$\circ$C, DOC and UV$_{254}$ were eliminated about 30% and 15% respectively. In general, even if the temperature was higher, DOC removal was a little sensitive, probably influenced by GAC's residual adsorption capacity. UV$_{254}$ reduction was little fluctuated in accordance with water temperature. The gradual increase in expansion ratio from 10% to 75% didn't greatly affect on the removal of DOC and UV$_{254}$. The expansion ratio, therefore, is not a key factor over the critical expansion ratio.

• 한국환경농학회지
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• 제20권4호
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• pp.244-251
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• 2001

상수원수중 조류에 의해 발생하는 이취미물질인 2-MIB 및 Geosmin의 전처리방법에 따른 회수율 조사와 이들 물질의 효과적인 처리를 위한 회분식 실험에서의 제거효율을 조사한 결과는 다음과 같다. 전처리 방법에 따른 2-MIB 및 Geosmin의 회수율은 0.2 및 $2\;{\mu}g/L$ 농도에서 모두 시료채취량을 30 mL, 염석제인 NaCl를 9 g 주입하고, SPME syring주입 위치를 headspace로 하며, 흡착시간를 40분 이상으로 하였을 경우가 가장 높게 나타났으며, 최적전처리 조건에서의 회수율은 0.2 및 $2\;{\mu}g/L$ 농도에서 2-MIB의 경우 각각 약 85 및 95%, Geosmin의 경우 61 및 81%로 조사되었다. 회분식 실험에서의 2-MIB 및 Geosmin의 각 농도별 제거효율은 모든 흡착제에서 증류수를 사용하여 조제하였을 경우가 상수원수로 조제하였을 경우에 비해 높았고, 상수원수로 조제하였을 경우에는 농도에 따라서는 별 차이가 없었다. 흡착제의 종류에 따라 Freundrich 등온흡착식에 적응한 결과 흡착능력을 나타내는 K값은 제올라이트, 석탄계 활성탄 및 야자계 활성탄에서 2-MIB이 경우 각각 약 0.671, 1.811 및 1.340이었고, Geosmin의 경우 각각 약 0.613, 1.771 및 1.519로서, 2-MIB 및 Geosmin 모두 석탄계 활성탄 > 야자계 활성탄 > 제올라이트 순이었다.

• 한국산업보건학회지
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• 제9권2호
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• pp.135-144
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• 1999

The purposes of this study were to survey types of pretreatment methods adopted by industrial hygiene laboratories in Korea for extracting heavy metals in welding fume samples and to compare performances of two pretreatment methods, the acid extraction and the microwave digestion, in extracting heavy metals contained in the real workplace samples from various welding jobs including arc, argon, and carbon dioxide. A total of 25 analytical chemists in the industrial hygiene laboratories participating the quality control program directed by the Korea Industrial Safety Corporation were interviewed by telephone. For the purpose of comparing performance of extracting heavy metals from real workplace samples, a total of 53 welders from 21 workplaces located in Anyang, Uiwang, and Kunpo areas were sampled from the period of March 22, 1999 to April 20, 1999. It was found that the most frequently adopted method for samples from the quality control program was the acid extraction method(40%) followed by the NIOSH 7300 method(36%). The NIOSH method, however, was the dominant method(36%) for samples from workplace followed by the acid extraction method(28%). In this study, two extraction methods, the acid extraction and the microwave digestion, were compared in terms of recovery rate, accuracy, and precision for both manganese and chromium. Both methods produced comparable results for the samples prepared for the quality control program. In contrast, concentrations of two heavy metals determined from real workplace samples pretreated with the microwave digestion method were statis tically significantly higher, manganese(166%) and chromium (200%), than those of utilizing the acid extraction method. These findings were consistent regardless of types of welding techniques used. The results of this study clearly show the importance of verifying the analytical performances of extraction methods for heavy metals not only for the samples from the quality control program but also from the real world samples collected from welding jobs.