• 한국대기환경학회지
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• 제9권4호
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• pp.288-294
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• 1993

Flue gas control systems for small-scale combustors must be designed to provide highly effective removal of three criteria pollutants (S $O_{2}$, N $O_{x}$ and particulate matter), and must be safe, reliable and small. These requirements make dry, regenerative clean-up process particularly attractive and this paper describes a new concept for integrated pollutant control : a filter comprised of layered, gas permeable membranes that act as an S $O_{2}$ sorbant, a N $O_{x}$ reduction catalyst and a particulate filter. A mixed metal oxide sorbent, Cu-Ce was used as a sorbent/catalyst and the activity was compared with Cu-7Al. The S $O_{2}$ removal eficiency of Cu-Ce was increased with temperature increase up to 500$^{\circ}$C and the catalytic activity for NO was higher than that of Cu-7Al. By the sulfation of Cu-Ce, the reduction activity was increased at the temperature higher than 350$^{\circ}$C. The regeneration of Cu-Ce was very fast and some amount of elemental sulfar was found.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.247-254
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• 2000

The base pressure of vacuum vessel of the KSTAR (Korea Superconducting Tokamak Advanced Research) Tokamak is to be a ultra high vacuum, $10^{-6}{\sim}10^{-7}Pa$, to produce clean plasma with low impurity containments. For this purpose, the KSTAR vacuum vessel and plasma facing components need to be baked up to at least $250^{\circ}C,\;350^{\circ}C$ respectively, within 24 hours by hot nitrogen gas from a separate baking/cooling line system to remove impurities from the plasma-material interaction surfaces before plasma operation. Here by applying the implicit numerical method to the heat balance equations of the system, overall temperature distributions of the KSTAR vacuum vessel and plasma facing components are obtained during the whole baking process. The model for 2-dimensional baking analysis are segmented into 9 imaginary sectors corresponding to each plasma facing component and has up-down symmetry. Under the resulting combined loads including dead weight, baking gas pressure, vacuum pressure and thermal loads, thermal stresses in the vacuum vessel during bakeout are calculated by using the ANSYS code. It is found that the vacuum vessel and its supports are structurally rigid based on the thermal stress analyses.

• 한국방재학회 논문집
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• 제1권1호
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• pp.157-163
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• 2001

본 연구의 목적은 청정실 내부에서 가상의 화재가 발생할 경우 화재 확산 및 연기의 전파 현상을 예측하기 위하여 실시하였다. 청정실 내의 화재로 인한 온도 및 속도분포의 해석은 유한체적법을 이용한 수치적 방법으로 해석하였으며 난류유동장의 계산은 표준 $k-{\varepsilon}$ 모델을 적용하여 실시하였다. 본 연구 결과는 화재발생 후 150초가 지난 후에는 화재가 완전히 성장한 것으로 나타났으며 이 경우 환기장치는 화재가 완전히 성장한 후에 정지하는 것으로 가정하였다. 연기의 질량분율은 온도 분포와 거의 유사한 것으로 나타났다. 따라서 청정실에서 화재가 발생할 경우 화재 성장이 60초 내에 전공간의 $20{\sim}30%$까지 확산되므로 내부에 있는 사람은 30초 이내에 대피하는 것이 바람직하다.

• 동력기계공학회지
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• 제17권6호
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• pp.5-10
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• 2013

Diesel engines have the advantages of good fuel efficiency and low emissions. Therefore, car makers have been developed various kinds of diesel engine management system to clean up emissions while improving fuel efficiency. One of them is the common rail system. In the common rail system, diesel fuel is injected into the combustion chamber at ultra high pressures up to 1,800 bar to ensure more complete combustion for cleaner exhaust gas, and highly precise multiple injection reduces NOx emission, combustion noise and vibration. Generally speaking, common rail system consists of booster pump, high pressure pump, common rail, injectors, control valves, and sensors. The high pressure pump receives low pressure fuel from the booster pump and supply high pressure fuel to injectors through the high pressure common injection rail. Therefore, high pressure pump has an important role in common rail system. In this paper, we have investigated the performance of high pressure pump of common rail system.

• 한국수소및신에너지학회논문집
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• 제22권6호
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• pp.925-933
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• 2011

The traditional feedstock for dimethyl ether (DME) has been natural gas obtained by pipeline from a nearby natural gas or oil field. This report focuses on other feedstock: Coal bed methane (CBM). The resource availability and suitability of CBM for DME manufacturing have been investigated. CBM in a short time has become an important industry, providing an abundant clean-burning fuel and also suggesting as a feedstock for gas industry. The use of CBM will have very little impact on the KOGAS' DME process design and economics up to 50 vol% of $CO_2$ in the CBM source. Many of the CBM sources in Asia are high in $CO_2$, but pose no difficulties for the KOGAS' DME plant. Since tri-reformer requires substantial $CO_2$ in its feed, no $CO_2$ removal from the CBM feed is needed. The $CO_2$ in the CBM means that less $CO_2$ needs to be recycled from the downstream in the process.

• 한국컴퓨터정보학회논문지
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• 제19권2호
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• pp.161-171
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• 2014

본 논문에서는 CFDRC 사의 상용 CFD 소프트웨어인 CFD-ACE+로 전산유체역학 기법을 적용하여 수치 해석을 수행하여 배연탈황 설비에서 Induced Draft Fan(I.D.Fan) 출구부터 Booster Up Fan(B.U.Fan) 입구까지 난류 유동장과 연소 유동 문제를 모사하여 배기가스 계통 설비의 유동 특성을 해석하였다. 배기가스가 I.D.Fan 출구 ~ B.U.Fan 입구 구간을 적정속도로 균일하게 유동하여 B.U.Fan로 균일하게 유입되도록 하며 압력손실이 적게 발생하도록 설계기준 보일러 부하와 최대연속 정격유량의 보일러 부하에서 이 구간의 안내깃을 검토하였다. 검토한 결과에 대해 CFD 해석을 수행하여 I.D.Fan 출구에서 안내깃을 제거하고 B.U.Fan 입구 전에 안내깃을 보강할 수 있도록 설계를 변경하였다. 배기가스 계통에 변경된 설계를 적용하여 수치모사한 결과에서 배연탈황 설비 내부의 배기가스 압력손실이 줄어들고 유속과 유선이 균일하게 유동할 수 있어 배연탈황 시스템의 효율이 향상한 것을 확인하였다.

• 청정기술
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• 제17권4호
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• pp.389-394
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• 2011

바이오가스로부터 이산화탄소와 질소를 제거하기 위한 흡착공정은 많이 논의되고 있다. 특히 흡착공정 중에서 압력변동흡착(Pressure swing adsorption)공정은 에너지소모가 적고 가격이 경제적이기 때문에 기체의 분리와 정제를 위한 공정으로 적절하다. 물리적 흡착을 사용하는 PSA공정은 흡착과 탈착이 가능하다. 각 cycle단계의 구성은 가압, 주입 및 흡착, 압력 균등화, 감압 및 세정으로 이루어져있다. 본 실험에서 PSA공정은 이산화탄소와 질소를 제거하기 위한 흡착제로 zeolite 13X와 carbon molecular sieve (CMS)로 구성되어 있으며, 혼합 가스의 농도는 $CH_4/CO_2/N_2$ (75:21:4 vol%)의 비율을 갖고 있다. 각각 zeolite 13X와 CMS는 선택적으로 혼합가스로부터 질소와 이산화탄소를 흡착하여 분리하고 제거한다. 또한 CMS의 경우는 빠르게 분산되는 이산화탄소의 처리량이 높다. 상부탱크, 하부탱크, 주입탱크의 가스 조성은 TCD 검출기를 이용하는 gas chromatography (GC)에 의해서 측정되었다.

• 한국식품위생안전성학회지
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• 제5권3호
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• pp.159-164
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• 1990

To detect and quantitation residual antibiotics and antibacterial agents in meats, we performed a biological assay employing the three microorganisms Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, and Bacillus cereus var. mycoides ATCC 11778 for the screening purpose and developed a Gas Chromatography-mass Spectrometry(GC/MS) analysis for the confirmation and quantiation. In the biological assay (paper disk method), three test solution are used depending on the character of the residual antibiotics and antibacterial agents, follow by a simple clean up procedure which includes homogenization with Mcilvaine buffer, defatting with includes homogenization with Mcilvaine buffer, defatting with hexane, extraction with chloroform, clean-up by Sep-Pak $C_{18}$ and Bakerbond SPE carboxylic acid column. The chloroform layer is used for the analysis of sulfa agents. macrolides antibiotics and antibacterial agents, Adsorbed materials in the Sep-Pak $C_{18}$ were also employed for th analysis of penicillins and tetracyclines. Effluents from the Sep-Pak $C_{18}$ were cleaned-up one more by Bakerbond 10 SPE COOH column and employed for the analysis of aminoglycosides. In the instrumental analysis by using the GC/MSD, residual antibiotics and antibacterial agent were quantitated by selected ion monitoring (SIM) mode after derivatization. A simultaneous analysis of six residual antibiotic and antibacterial agent such as oxytetracycline, penicillin, ampicillin, choliraphenicol and thiamphenicol was developed with simple cleanup procedures revealing good recovery and reproducibility. Also, simultaneous detection of macrolides antibiotics such as erythromycin, spiramycin, and oleandomycin was developed after acid hydrolysis due to their large molecular structures. Because of the high reproducibility and selectivity of these two methods, it is very desirable that the combination of the two methods be used in the bioassay for the screening of residual antibiotics and antibacterial agent and that GC/MSD analysis be used for the confirmation and quantitation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권4호
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• pp.1-6
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• 2020

Recently, ex-situ remediation technologies has been emerging to clean up contaminated soils mainly because the in-situ techniques have limited applicability and technical difficulties in relatively small contaminated sites. Accordingly, implementation of off-site treatment and disposal have been continuously increased in soil remediation and restoration projects in Korea. However, in many cases, reclaimed soil is still not properly recycled or reused. Therefore, there is an urgent need to document the current status of soil management practices in soil remediation projects in the nation. This study presents a survey of soil contamination status and remedial approaches in Korea based on soil cleanup projects completed in 2015 - 2019, and proposes the possible options of the recycling or reusing the reclaimed soils under compliance with related regulations. The results of the soil survey showed soil contamination was most severe in gas stations, industrial facilities, and military areas. The major types of pollution were related to the petroleum-contaminated site (TPH and BTEX) with 77.0% occurrence in all the contaminated sites. The reclaimed soils were mostly reused as a ground filling-up soils in industrial facilities (60.0%) and warehouses (37.0%).

• 한국축산식품학회지
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• 제29권4호
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• pp.482-486
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• 2009

The aim of this study was to optimize a simple, fast, and economical analysis procedure for the determination of 16 different pesticides in raw milk via GC/MSD. Analyses were performed via gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC/MSD-SIM) using Pentachloronitrobenzene as the internal standard. The modified sample preparation methodology was based on the Pesticide Analytical Manual (PAM) of the FDA concerning fat extraction, ACN-ether partitioning, and clean-up of the Sep-Pak florisil cartridge. The modified methodology for the determination of the 16 pesticides was validated. The range of LOQs of the 16 pesticides was likely three times lower than their Maximum Residence Levels (MRLs). The recoveries of most of the pesticides were acceptable at the fortification levels of 0.5 and 1.0 ${\mu}g/mL$ and their RSD (%) level was less than 20%. None of the 16 pesticides were detected in the selected raw milk samples.