• 한국수소및신에너지학회논문집
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• 제14권1호
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• pp.17-23
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• 2003

$H_2$ permeation flux though a $100{\mu}m-thick$ Pd-Ru (6wt%) membrane was measured at various temperatures and pressures. The permeation flux followed the Sievert's law and thus the rate-limiting step of the hydrogen permeation was the bulk atomic diffusion step. The activation energy of the permeation flux was obtained at 17.9 kJ/mol and this value is consistent with those published previously. While no degradation of the permeation flux wasfound in the membrane exposed to the $O_2$ and $CO_2$ environments for 100 hours, the membrane exposed to $N_2$ environment for 100 hours showed the degradation in the $H_2$ permeation flux. The $H_2$ permeation was decreased as the exposure temperature to $N_2$, environment was increased. The $H_2$ permeation flux was fully recovered after the membrane was kept in the $H_2$ environment for certain time. The permeation flux degradation might be caused by the formation of metal nitride on the membrane surface.

• 공업화학
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• 제18권2호
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• pp.126-129
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• 2007

원할한 교통망 요구에 따라 도로의 확충이 요구되고, 산악지형이 많은 국토의 특성을 고려할 때 터널이 많이 요구된다. 이러한 터널 공사에서 많은 오염 물질은 천공, 발파, 버럭처리 숏크리트 과정에서 발생되었다. 특히 급기 팬만을 가동 할 경우 분진과 같은 오염물질은 발파 후 4 h이 지나도록 $5000{\mu}g/m^3$ 이상을 나타내었으며, 발파 직후에는 높은 분진 농도로 인하여 30 min 이상 작업을 중단할 수밖에 없었다. 또한 건식 집진기를 가동 할 경우에도 일정 시간 까지는 분진의 제거는 가능하였으나 발파 후 3 h이 지나면 집진 효율이 없는 것으로 나타났다. 본 논문 에서는 분진입자들의 거동과 분진제거장치의 사용에 대해 중점적으로 연구하였다. 또한 건식집진기와 습식집진기의 사용에 있어 각각에 대한 집진제거효율을 비교검토하는 것이 매우 중요하다 결론을 얻었다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4270-4274
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• 2011

A method is proposed for determining chromium content in the carbon steel pipes of a nuclear power plant (NPP) to evaluate wall thinning caused by flow-accelerated corrosion (FAC). A flat file was used to obtain filings samples. To assess sampling quality, a disk form of SRM 1227 was ground with the flat file, and the amount of Cr in the filings was determined by ICP-AES. The content of chromium in the filings of SRM 1227 was estimated as six times higher than the certified value due to the contamination of chromium in the file. To eliminate chromium contamination from the file, it was coated with WC-12Co using high-velocity oxygen-fuel (HVOF) spraying systems. After obtaining filings samples using the coated file, Cr content in four types of disk-form SRMs was determined by ICP-AES. The recoveries of Cr in the disk-form SRMs were in the range of 95.4-102.6%, with relative standard deviations from 0.43 to 3.0%. The Cr contents in the filings collected from the used outlet headers of the nuclear power plants using the flat file coated were in the range of 0.11-0.19%.

• 동아시아식생활학회지
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• 제19권5호
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• pp.798-802
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• 2009

시판되는 112점의 생식제품에서 대장균(Escherichia coli), 클로스트리디움 퍼프린젠스(Clostridium perfringens), 바실러스 세레우스(Bacillus cereus) 등의 오염 미생물을 분석하여 식품공전 기준 규격에 적합한지를 알아보았다. E. coli는 모든 생식제품에서 검출되지 않았다. C. perfringens는 11제품(9.8%)에서 검출되었고 $10^2$ CFU/g으로 기준 규격에 적합하였다. B. cereus는 25제품(23.3%)에서 검출되었고, 5제품에서 $10^2$CFU/g 이하, 7품에서 $10^2{\sim}10^3$ CFU/g, 13제품에서 $10^3{\sim}10^4$ CFU/g으로 검출되었다. 이 분리 세균은 전형적인 특성을 보이고 있었는데 TSC agar, MYP agar에서 검출된 균은 그람양성 및 간균이었으며, 생화학 테스트 결과 egg-yolk의 지질을 분해할 수 있는 lecithinase를 가지고 있는 것으로 확인되었다. 그러므로 유통되고 있는 생식 제품의 일부는 식품공전의 기준 규격을 초과하는 B. cereus가 검출되어 보다 더 철저한 세균 제어 관리가 필요하다고 사료된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.232-236
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• 2000

Multi-regression statistical analyses were applied for the water quality data of shallow alluvial ground water (n = 47) collected from the Youngdeok area, in order to quantitatively generalize the natural (non-anthropogenic) causes of regional water quality variation. Seven samples having the high contamination index ( $C_{a}$ > 3) reflect the striong effects by anthropogenic activity. Most of the alluvial groundwaters have acquired their quality primarily due to the dissolution of carbonate minerals. The results of multi-regression analysis show that chlorine is mainly derived from seawater effect. Sulfur isotopic compositions of dissolved sulfur and the S $O_4$/Cl ratio also enable us to discriminate the samples (n = 18) which are affected by atmospheric input of marine aerosol (sea-spray) and also by mixing between freshwater and seawater. Hydrogen and oxygen isotope data of the samples collected lie close to the local meteoric water line obtained from nearby Pohang city but has lower slope (5.45) on the $\delta$D-$^{18}$ O plot, indicating that alluvial groundwater was recharged from infiltrated meteoric water which has undergone some degree of kinetic evaporation. The estimated initial isotopic composition of the recharged water ($\delta$D = -74.8$^{0}$ /$_{00}$, $\delta$$^{18}$ O = -10.8$^{[-1000]}$ /$_{[-1000]}$ ) suggests that the alluvial ground water recharge largely occurs during summer storm events.s.s.

• 한국해양학회지
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• 제13권2호
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• pp.11-16
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• 1978

최근에 와서 유류오염과 더불어 중금속에 의한 해양오염, 특히 연안오염은 공공 관심의 대상이 되고 있다. 어떤 해역의 오염정도는 그 해역의 해수 및 그 해역에 서식 하는 유기체(Organisms)와 더불어 그 해역 퇴적물의 오염물질함량으로부터 파악할 수 있다. 진해만과 부산해역은 공업단지와 대도시가 인접해 있고 또 선박의 출입이 잦기 때문에 중금속에 의해 오염될 가능성이 많다. 그러나 이 해역에 대한 중금속의 오염조사현황을 보면 수질에 대한 조사는 수차(Kwak et al., 1974, 국립수산진흥원, 1975, 1977)에 걸쳐 행하여 졌으나 퇴적물에 대해서는 진해만에 대한 2회의 조사(Lee et al., 1974, Hyun, 1974)가 있었을 뿐이다. 본 조사에서는 진해만과 부산해역 퇴적물의 중금속 오염실태를 알아보기 위해 이를 해역의 퇴적물을 채취하고 퇴적물중 구리, 납, 아연, 니켈, 코발트, 철, 망간등 7가지 중금속의 함량을 측정하였다.

• 한국수산과학회지
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• 제40권5호
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• pp.288-292
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• 2007

Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often caused by pathogenic microorganisms originating from fecal contamination, such as Salmonella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefore, data on fecal coliforms are very important for evaluating the safety of fisheries in coastal areas. In this study, 2,226 sea water samples were collected from the southeast coast of Korea, and total and fecal coliforms were compared and analyzed. Total coliforms were detected in 76.5% of the samples and 71.4% of the total coliforms were fecal coliforms. At sea water temperatures above $20.0^{\circ}C$, total coliforms were found in 78.8% of the samples and fecal coliforms constituted 72.0% of the total coliforms. In sea water below $19.9^{\circ}C$, the respective values were 74.6% and 70.9%. These results suggest that temperature does not have a significant effect on the detection of fecal coliforms. When the salinity exceeded 30.0%o, total coliforms were found in 72.1% of the samples and fecal coliforms constituted 66.0% of these. At salinities below 29.9%o, the respective values for total and fecal coliforms were 90.4% and 85.2%. These results strongly suggest that the detection of fecal coliforms is proportional to the amount of precipitation.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5464-5468
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• 2011

본 연구는 채혈바늘에 의해 발생하는 2차 감염을 방지하기 위한 안전 랜싯(Lancet)을 설계 개발하고, 연속하여 채혈하는 경우에 쉽게 그리고 편리하게 사용할 수 있도록 무선 전동방식 채혈기의 설계 제작을 목적으로 한다. 안전랜싯은 채혈침과 보호캡이 일체형으로 설계되어 채혈 순간을 제외하고는 채혈침이 항상 보호캡 속에 있도록 하여 채혈바늘에 의한 사고를 방지하도록 하였다. 전동 채혈기는 충전건전지를 전원으로 하고 솔레노이드의 작동으로 랜싯을 타격하여 채혈하도록 설계되었으며, 연발타격 또는 단발타격의 기능을 선택하도록 설계 제작되었다. 또한 타격봉에 의한 충격력과 사용된 배터리의 수명 등이 측정되었다. 이 채혈기는 한방병의원의 사혈기로도 사용되도록 제작되었다.

• 한국환경농학회지
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• 제38권1호
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• pp.17-22
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• 2019

BACKGROUND: Soil contamination of As is a very sensitive environmental issue due to its adverse impact on human health and different characteristics with other heavy metals. With public awareness of As poisoning, there has been growing interest in developing guideline and remediation technologies for As-contaminated soil. The objective of this research was to evaluate the effectiveness of stabilizing amendments and soil dressing methods on the mobility of As in the contaminated rice paddy soils nearby mining area. METHODS AND RESULTS: Different amendments were mixed with surface and subsurface contaminated soils at a ratio of 3% (w/w) and monitored for five months. Three different extractants including 0.01M $CaCl_2$, TCLP, and PBET were used to examine As bioavailability in the soil and the concentration of As in rice grain was also measured with an inductively coupled plasma (ICP) spectroscopy. The results showed that all amendment treatments decreased As concentration compared to the control. Especially, coal mine drainage sludge (CMDS) treatment showed the highest efficiency of decreasing As concentration in the soil and rice grain. The values of Pearson correlation (r) between As concentrations in the soil and rice grain were 0.782, 0.753, and 0.678 for $CaCl_2$, TCLP, and PBET methods, respectively. Especially, $CaCl_2$ method was highly correlated between As concentrations of the soil and soil solution (r=0.719), followed by TCLP (r=0.706), PBET (r=0.561) methods. CONCLUSION: Stabilizing amendments can effectively reduce available As concentration in the soils as well as soil solution, and thereby potentially mitigating risks of crop contamination by As.

• 한국물환경학회지
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• 제38권6호
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• pp.275-281
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• 2022

To maintain water quality after water treatment, monitoring whether the quality of treated tap water quality changes is essential. However, current investigations are insufficient to prevent secondary contamination in drinking water supply systems. This study investigated Gyeonggi's e apartment where a red water problem occurred and monitored the water quality and corrosiveness of the overall water supply system to the apartment from June 2021 to April 2022. In a comparison of drinking water quality after water treatment and the influent of the reservoir, turbidity and heavy metal concentrations were increased and residual chlorine was decreased due to increases in temperature. Correlation analysis and principal component analysis (PCA) indicated that a low level of residual chlorine may cause the abscission of Mn²⁺ and Fe²⁺ through microorganism activation, which also causes a high level of turbidity. The corrosion index (LI) in the influent of the reservoir tank was increased due to Ca²⁺ and temperature. These results indicate that the corrosiveness of drinking water and the deterioration of drinking water quality were mainly increased between the drinking water treatment plant and the reservoir tank's influent. The findings provide clear evidence that it is essential to manage water supply systems and reservoir tanks to prevent the secondary contamination of drinking water.