Chromium nitride (CrN) samples with two different layer structures (multilayer and single layer) were coated on bipolar plates of polymer electrolyte membrane fuel cells (PEMFC) using the reactive sputtering method. The effects with respect to layer structure on corrosion resistance and overall cell performance were investigated. A continuous and thin chromium nitride layer (Cr0.48 N0.52) was formed on the surface of the SUS 316L when the nitrogen flow rate was 10 sccm. The electrochemical stability of the coated layers was examined using the potentiodynamic and potentiostatic methods in the simulated corrosive circumstances of the PEMFC under 80˚C. Interfacial contact resistance (ICR) between the CrN coated sample and the gas diffusion layer was measured by using Wang's method. A single cell performance test was also conducted. The test results showed that CrN coated SUS316L with multilayer structure had excellent corrosion resistance compared to single layer structures and single cell performance results with 25 cm2 in effective area also showed the same tendency. The difference of the electrochemical properties between the single and multilayer samples was attributed to the Cr interlayer layer, which improved the corrosion resistance. Because the coating layer was damaged by pinholes, the Cr layer prevented the penetration of corrosive media into the substrate. Therefore, the CrN with a multilayer structure is an effective coating method to increase the corrosion resistance and to decrease the ICR for metallic bipolar plates in PEMFC.

가막만은 여수반도 남단에 위치한 해역으로 동쪽으로 돌산도, 서쪽으로 고돌산반도 남똑으 로는 개도 등 여러 섬들로 둘러싸인 전형적인 반폐쇄적인 해역으로서, 납북방향의 길이가 약 15km, 동서방향으로 약 9km인 타원형 내만이며, 평균수심은 9m인 천해이다. 가막만의 퇴적물은 주로 silt와 clay로 구성되며 만전체적으로 세립질 퇴적상을 보인다. 지형특성에 따라 대체로 개의 수괴가 존재하 며, 만 내부의 북서쪽은 대형 웅덩이 형태의 지형을 보이며 생활하수가 유입되어 쌓이며 만내의 해수 유동에 의해 물질이 수렴되고 있다. 이처럼 영양염이 풍부하여 양식이 활발히 성행하고 있으며 북서쪽 내만역과 북동쪽 대경도를 중심으로 수하식 홍합양식과 피조개 양식, 만 중앙부에는 굴양식장이 산재 하며, 만 남쪽 입구에는 가두리 어류 양식이 이루어지고 있다. 따라서 해양환경 보전해역으로 지정되 어 있으나 분서 내만역을 중심으로 일부 해역은 생활하수와 양식부산물 등에 의해 부영양화가 진행되 어 고수온기 저층해수에 빈산소층이 형성되고 적조 발생등 다양한 환경문제를 일으킨다. 한편 중금속은 해수 중에 극미량으로 존재하고 있으며 유입시 분해되지 않는 특성을 가지고 있어 잔류성 오염물질로 분류되고 있다. 생물에 농축 될 뿐 아니라 먹이사슬에 의해 갈수록 축적 정도가 커 지며 하천이나 비, 대기 또는 직접적 유입 등 여러 경로로 환경 중으로 유입된다. 해양으로 유입된 중 금속은 수중의 생지화학적 과정에 의해서 입자화되어 퇴적물에 축적되어 저서생물에 영향을 미치게 된다. 가막만에 대한 중금속의 연구보고는 거의 없으며, 퇴적물은 해수보다 높은 농도로 존재 하기에 엄격 히 관리되어야 한다고 판단된다. 본 연구는 가막만을 대상으로 하여 3월과 8월 두차례에 걸쳐 조사하였으며, 3월 조사 결과 분포범위 와 평균값은 Cr이 4.31～75.63(평균 55.72) mg/kg, Cu가 1.87～37.30(평균 14.97) mg/kg, Zn이 26.31～ 148.98(평균 102.60) mg/kg, As는 5.05～9.98(평균 6.34) mg/kg, Pb는 10.58～33.37(평균 21.26) mg/kg, Al은 2.63~5.68(평균 4.01) %로 검출되었으며, Cd과 Hg는 검출되지 않았고, 8월 조사 결과 분포범위와 평균값은 Cr은 56.63～123.42(평균 91.39) mg/kg, Cu가 12.44～40.11(평균 22.98) mg/kg, Zn이 97.05～ 186.03(평균 133.84) mg/kg, As는 7.52～14.06(평균 9.75) mg/kg, Pb는 20.62～44.65(평균 28.87) mg/kg, Al은 0.95~4.36(평균 3.09) % 검출되었으며, Cd와 Hg는 검출되지 않았다.

This study was conducted to estimate the contents of heavy metals including lead, cadmium,arsenic and total mercury in alcoholic beverages in Korea. Concentration of Hg was analyzed by gold amalgamation method, using mercury analyzer, while concentration of Pb, Cd and As was analyzed by ICP-MS. Concentration (μg/kg) of heavy metal in fermented liquors were ; for Pb 9.9 ± 8.4(0~38.0), Cd 5.8 ± 4.9(0~5.4), As 28.6 ± 19.4(1~96.4),Hg 0.7 ± 1.2(0~10.6). Concentration (μg/kg) of distilled liquors were : for Pb 4.4 ± 5.7(0~29.3), Cd 2.0 ± 2.5(0~10.3),As 12.0 ± 17.0(0~95.6), Hg 0.2 ± 0.3(0~2.3). Concentration(μg/kg) of other liquors were ; for Pb 7.5 ± 5.1(0~13.7),Cd 5.8 ± 3.9(0.6~11.2), As 25.2 ± 39.0(0.5~103.3), Hg 0.3 ± 0.1(0.1~0.5). The present study showed that difference of the amount of constituent in a same category of food are not affect to the content of heavy metals among them. The residual levels of takju, yakju, sake, beer, fruit wine, soju, whiskey, brandy, general distilled liquor, liquor, other liquors are within the maximum levels, prescribed by Korea food code. It is given that heavy metal exposure of Pb,Cd, As, Hg from consumption of alcoholic beverages (takju, yakju, sake, beer, fruit wine, soju, whiskey, brandy, general distilled liquor, liquor, other liquors) are less than 0.03%, 0.06%, 0.01%, 0.01% (mean) in provisional tolerable weekly intake (PTWI) respectively, indicated by FAO/WHO.

상용원자로에서 발생하는 산화물 사용후핵연료의 부피감용과 재활용을 위하여 산화물을 금속으로 환원시 키는 공정에 대한 연구가 수행되어 왔다. 다양한 환원법 중에서, 한국원자력연구원은 LiCl-Li2O 용융염을 반 응매질로 사용하는 전해환원공정을 현재 개발 중이다. 파이로 공정의 전단부에 해당하는 전해환원 공정은 PWR 산화물 연료 주기를 소듐냉각 고속로의 금속연료 주기에 연결시켜 준다. 이 논문은 금속전환 공정을 개 발/개선하고, 용량 증대를 수행한 한국원자력연구원의 노력을 요약한다.

The emission characteristics of VOCs (Volatile Organic Compounds) from assembly metal product manufacturing industry (Korean standard industry classification code: 28) were studied. The sampling was carried out at 54 sites in Shiwha-Banwol industrial area with 3 M OVM (Organic Vapor Monitor) #3500 from August to October in 2008. The EPA 8020/8040 (10 chemicals) was used as a standard solution for the quantitative analysis with GC/FID. As the results, the VOCs concentration appeared to range from 0.9 ppb to 22,721.1 ppb, and the average concentration ratio of benzene : toluene : ethylbenzene : m,p-xylene : o-xylene : styrene appeared to be 0.005 : 1.000 : 0.198 : 0.096 : 0.057 : 0.110. Total VOC concentration of the "Manufacture of Structural Metal Products, Tanks, Reservoirs and Steam Generators" (KSIC code: 281) appeared to be seven times higher than that of "Manufacture of other fabricated metal products; metal working service activities" (KSIC code: 289).

Esterification reaction between succinic acid and 1,4-butanediol was kinetically investigated in the presence of nontoxic organometallic compound catalyst(ESCAT-100E) at 150-190℃. The reaction rates measured by the amount of distilled water from the reaction vessel. The Esterification reaction was carried out under the first order conditions respect to the concentration of reactants, respectively. The overall reaction order was 2nd. The linear relationship was shown between apparent reaction rate constant and reciprocal absolute temperature. By the Arrhenius plot the activation energy have been calculated as 376.13 kJ/mol under nontoxic organometallic compound catalyst and also apparent reaction rate constant, k' was found to obey first kinetics with respect to the concentration of catalyst.

Oxidation characteristics of benzene as a VOC were investigated using a fixed bed reactor system over transition metal catalysts. The transition metal catalysts were made by using transition metal nitrate reagent and various support materials such as γ-Al2O3, and TiO2. The parametric tests were conducted at the reaction temperature range of 200～500℃, benzene concentration of 2,000～3,000 ppm with space velocity of 10000 hr-1. The property analyses such as BET, SEM, TGA and the conversions of catalytic oxidation of VOC were examined. The experimental results showed that the BET surface areas of catalyst are 86.4∼167.7m2/g, the pore volumes are 0.049∼0.056cm3/g, and the average pore sizes of catalyst are 27∼44Å, which mean the meso pore. It was also found that the conversion of benzene oxidation reaction at 400∼500℃ with Cu/γ-Al2O3+TiO2 catalyst showed 90∼100%, which indicate that the transition metal catalyst with composite supports is very effective for the oxidation of benzene.

Inorganic oxide colloids dispersed in alcohol were applied to a stainless steel substrate to produce oxide coatings for the purpose of minimizing emissive thermal transfer. The microstructure, roughness, infrared emissive energy, and surface heat loss of the coated substrate were observed with a variation of the nano oxide sol and coating method. It was found that the indium tin oxide, antimony tin oxide, magnesium oxide, silica, titania sol coatings may reduce surface heat loss of the stainless steel at 300˚C. It was possible to suppress thermal oxidation of the substrate with the oxide sol coatings during an accelerated thermal durability test at 600˚C. The silica sol coating was most effective to suppress thermal oxidation at 600˚C, so that it is useful to prevent the increase of radiative surface heat loss as a heating element. Therefore, the inorganic oxide sol coatings may be applied to improve energy efficiency of the substrate as the heating element.

Esterification reaction between succinic acid[SA] and 1,4-butanediol [BD was kinetically investigated in the presence of organic metal catalysts (alkyl-silver oxide(ASO),CAT 100E) at 150~190℃. The reaction rates measured by the amount of distilled water from the reaction vessel. The esterification reaction was carried out under the first order kinetics with respect to the concentration of reactants and catalyst, respectively. The overall reaction order was 2nd. From the examination of relationship between apparent reaction rate constants and reciprocal absolute temperature, the activation energy has been calculate as 146.70 kJ/mol with ASO catalyst and 43.04 kJ/mol with CAT 100E catalyst.

한국고라니(Hydropotes inermis argyropus)는 우리나라의 고유종으로 가장 흔한 종의 하나이다. 이 종은 한반도 전역에 널리 분포하며 자연생태계에서 초식자로서 중요한 역할을 하는 것으로 알려져 있다. 따라서 고라니는 서식지의 질을 모니터링하는데 하나의 좋은 생물지표종으로 이용될 수 있을 것이다. 이 연구에서는 강원도 철원지역과 전라남도 동부지역에서 수집된 한국고라니의 서로 다른 3가지 조직(신장, 간, 지라)에서 5가지 중금속(Fe,

This study attempted to compare the litter decomposition rate of Arundinella hirta and Miscanthus sinensis var. purpurascens which collected from serpentine soil acting potentially toxic concentration of heavy metals and non-serpentine soil by using the m

본 연구의 목적은 중금속 흡착을 위한 방사선 그라프트 중합법에 의한 이온교환막의 성능 향상을 위한 것이다. 그라프트 체인의 이온교환기에 의해 체인이 막의 pore를 방해하여 투과유속이 크게 저하되는 문제를 해결하고자 그라프트 체인과 체인사이를 N-ethyleneglycoldimethacrylate계 가교제를 첨가하여 투과유속이 저하되는 문제를 해결하고자 했다. 이때 사용된 가교제는 길이가 서로 다른 ethylene glycol dimethacrylate (EDMA)와 diethylene glycol dimethacrylate (DDMA)를 사용하였다. GMA 막에 가교제가 첨가된 이온교환막에 술폰산기를 첨가한 막을 이용하여 중금속 이온(Pb2+) 흡착을 하였다. 술폰산기 밀도가 1.40 mmol/g인 EDMA막은 13.82 mg/g을 흡착하였고, 술폰산기 밀도가 2.14 mmol/g인 DDMA막은 17.37 mg/g의 흡착량을 보였다.

본 연구는 전자 및 반도체 산업의 각종 에칭공정에서 발생되는 중금속 함유 산성 폐에칭액을 NF 막분리법을 이용하여 에칭액 회수와 중금속 처리를 효율적으로 수행하기 위한 NF 막공정의 운전조건을 설정하기 위한 기본 자료를 확보하는데 있다. 이를 위해 3가지 종류의 상용 NF 막(General Electric Co. Duraslick NF-4040 막, Dow Co. Filmtec LP-4040 막 및 Koch Co. SelRO MPS-34 4040 막)을 대상으로 Pb+2 중금속을 함유한 모의 질산 폐에칭액의 회분식(dead-end) 막여과 실험을 수행하여 폐에칭액의 투과 플럭스와 Pb+2 중금속 이온의 총괄 배제도를 측정하여 폐에칭액 처리에 우수한 NF 막을 선정하였다. 실험결과 질산용액에의 막 보관기간이 길수록, 질산용액의 pH가 낮을수록 산에 의한 막의 손상이 심해졌으며, 질산에 의한 막의 손상은 SelRO MPS-34 4040 < Duraslick NF-4040 < Filmtec LP-4040 막의 순서로 심하게 일어났다. 또한 질산용액에의 막 보관기간이 길수록, 질산용액의 pH가 낮을수록 Pb+2 이온의 배제도가 낮아졌으며, 배제도 값은 Duraslick NF-4040 막의 경우에는 95% 수준의 초기 배제도 값에서 질산용액에의 4달 보관 후에는 20% 수준으로, SelRO MPS-34 4040 막의 경우에는 초기 85% 수준에서 4달 후 65% 수준으로, Filmtec LP-4040 막의 경우에는 초기 90% 수준에서 4달 후 10% 이하 수준으로까지 감소하였다. 3종류의 상용 NF 막 중 내산성 용도로 개발된 SelRO MPS-34 4040 막이 중금속 함유 산성 폐에칭액의 재생에 가장 적합하였다.

In this study, toluene catalytic oxidation was investigated using various metal components (Cu, Ce, Ni, La and Zr) supported on Used FCC zeolite for the application of the waste recycling and odor reduction. Among the metals, 5 wt% Cu/zeolite showed the best catalytic activity. 100 % conversion was achieved at 300℃ which was 50℃ lower than that of other metal components. As increasing the amount of doped Cu, the CuO was formed and the surface area and pore size were decreased. By the reduction treatment before toluene oxidation, the catalytic activity of the oxidation below 250℃ was improved. No decrease of conversion was observed during the continuos reaction at 300℃ for 48 h.

Chromated Copper Arsenate (CCA)-treated wood has been widely used in Korea since 1980s, but the release of chromium, copper, and arsenic from the wood has been reported to cause environmental contamination. This study was aimed at investigating the environmental impact of brook water and sediment from the construction of cylindrical wood piles around a brook (partially immersed in the water) and wood bridge structures over the brook. Ten water and ten composite sediment samples (including one control for each) were collected from sites where a large number of treated wood structures were installed. Samples were analyzed for total chromium, copper, and arsenic using atomic absorption spectroscopy. Water contamination was not observed in all samples, but metal concentrations in the sediment samples were elevated at most sites, indicating the accumulation of metals in the sediment. This study suggested that the use of CCA-treated wood by continuos contact with water can lead to marked leaching of metal components and may ultimately cause health effects on aquatic organisms living on or in the sediment.

Mg-Cu composites were successively fabricated using a combination of rapid solidification and extrusion processes. In addition, the microstructural variation of the composite was investigated by performing the extrusion repeatedly. It resulted that the composite formed an uniform and dense structure by the extrusion, and the microstructure became fine as the extrusion conducted repeatedly. The microstructural variation was known to be dependent on the number of extrusion and the area reduction ratio. The tensile strength was also measured as a function of the microstructural variation.