• KEPCO Journal on Electric Power and Energy
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• 제5권2호
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• pp.121-125
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• 2019

A YSZ electrolyte based ceramic supported Solid Oxide Cell (SOC) and a metal interconnect supported SOC was investigated under both fuel cell and co-electrolysis (steam and $CO_2$) mode at $800^{\circ}C$. The single cell performance was analyzed by impedance spectra and product gas composition with gas chromatography(GC). The long-term performance in the co-electrolysis mode under a current density of $800mA/cm^2$ was obtained using steam and carbon dioxide ($CO_2$) mixed gas condition.

• Bulletin of the Korean Chemical Society
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• 제11권3호
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• pp.214-220
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• 1990

We have studied the Infrared Multiphoton Dissociation (IRMPD) of 1-bromo-3-chloropropane by using the pulsed $CO_2$ laser. The product yields and the HCl/HBr branching ratios in IRMPD of $BrCH_2CH_2CH_2Cl$ are studied under the focused beam geometry as a function of buffer gas (He) pressure, laser energy, and photolysing wavelength. It is observed that the total dissociation yield has a laser energy dependence of 1.8-2.0 power order and the branching ratio is very slightly dependent on the pulse energy for the laser lines employed. The dependences of total dissociation yield and branching ratio on the buffer gas pressures show that the dissociation yield monotonically decreases and the branching ratio slightly decreases with the increase of the buffer gas pressure. The Energy-Grained Master Equation (EGME) was applied to explain the laser pulse energy and the buffer gas pressure(He) dependence of the dissociation yield and the branching ratio.

• Journal of the Korean Wood Science and Technology
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• 제52권1호
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• pp.31-46
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• 2024

Subterranean termite attacks on cajuput (Melaleuca cajuputi) seedling roots were widespread in several of Java's Perum Perhutani Forest Management Units. This attack was suspected to be related to the chemical components of the cajunput seedling roots. This study was conducted to determine the bioactivity of cajuput seedling root extract as an attractant for the subterranean termite Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae). The extraction process was performed according to ASTM D1108-96, and the extract was characterized using gas chromatography-mass spectrometry (GC-MS). Bioactivity testing of the extracts was carried out using attractiveness and no-choice feeding bioassays. The results showed that the average root extraction yield from cajunput seedlings was 4.94%. The attractiveness of the extract solutions at concentrations of 0.50%, 0.75%, and 1.00% were 45.33%, 62.00%, and 74.67%, respectively. The mortality rate of C. curvignathus termites ranged from 9.63% to 24.44%. Cajuput seedling root extract's lethal concentration 50 was 2.45% (non-toxic). GC-MS analysis showed that the extract contained linoleic acid, which has the potential to attract insects.

• 전기학회논문지P
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• 제59권2호
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• pp.212-217
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• 2010

When paper which was applied as insulation in oil-filled transformer was aged by thermal, its electrical, mechanical and chemical characteristics were changed and deteriorated. Therefore operating temperature was more higher, damage of paper was more quicker. Insulating paper which was generally made with cellulose was degraded, polymer of long length chain was decomposed as a monomer and CO, $CO_2$ gas and/or by-product such as furfural was produced from paper at the same time. In according with detection these gas and furfural by dissolved gas analysis(DGA) and high performance liquid chromatography(HPLC), we have investigated effects of CO, $CO_2$ gas and furfural on insulation of paper. Also we have analyzed for correlation between furfural and CO, $CO_2$ gas using linear regression method that was known as useful, credible statistical analysis.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.355-363
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• 2010

High purity hydrogen, 97-99 vol.%, with CO at just ppm levels was obtained in a fixed bed of iron oxide employing the steam-iron cycle operation with reduction at 823K and oxidation in a steam-$N_2$ mixture at 773K TGA experiments indicated that temperature of the reduction step as well as its duration are important for preventing carbon build-up in iron and the intrusion of $CO_2$ into the hydrogen product. At a reduction temperature of 823K, oxide reduction by $H_2$ was considerably faster than reduction by CO. If the length of the reduction step exceeds optimal value, low levels of methane gas appeared in the off-gas. Furthermore, with longer durations of the reduction step and CO levels in the reducing gas greater than 10 vol.%, carbidization of the iron and/or carbon deposition in the bed exhibited the increasing pressure drop over the bed, eventually rendering the reactor inoperable. Reduction using a reducing gas containing 10 vol.% CO and a optimal reduction duration gave constant $H_2$ flow rates and off-gas composition over 10 redox reaction cycles.

• 한국가스학회지
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• 제26권3호
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• pp.27-37
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• 2022

최근 ESS(전기저장장치)의 보급이 늘어나면서 ESS에 의한 지속적인 화재발생으로 인명 및 재산의 피해 또한 급증하고 있다. ESS에 활용되는 우레탄 샌드위치 패널에 제조에 있어 난연 성능의 향상이 필요한 실정이다. 본 연구에서는 연질 폴리우레탄 폼의 난연 특성을 구현하고자 제품의 물성을 변화시키는 이소시아네이트 관능기 파라미터의 변화로 인한 제품의 조직 치밀도가 화재성능에 미치는 영향을 연구하였다. 우레탄 조직의 치밀도를 변화시켜가며 제품을 제작하여 연소성능 시험, 가스유해성 시험, 연기밀도 시험을 진행하였다. 그 결과 총 방출열량은 이소시아네이트 관능기 그룹이 높은 경우 성능이 우수하고, 최대 열 방출율과는 상관이 없는 것을 확인하였다. 이소시아네이트 관능기 그룹의 값이 2.7이상에서 형상의 붕괴를 방지할 수 있었다. 가스유해성 시험에서는 이소시아네이트 관능기 그룹이 상대적으로 높아 조직이 치밀하면서 탄화 막 형성이 용이한 Char시스템용 난연제가 추가적으로 투입되어야 성능이 상승하였고, 연기밀도 시험에서는 이소시아네이트 관능기 그룹의 값이 2.75이상에서 성능이 증가되는 것을 확인하였다. 따라서 본 연구의 결과로 기존에 사용되던 저렴한 우레탄 샌드위치 패널을 대체할 난연제 개발에 기반을 마련할 수 있을 것으로 생각된다.

• 자원환경지질
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• 제55권3호
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• pp.281-293
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• 2022

연백, 연단, 밀타승으로 대표되는 납계열 안료의 대기환경에 따른 열화특성을 규명하였다. 자외선에 노출된 채색시편들은 모두 색차가 4~31로 어두워졌으나 성분에 변화는 없었다. CO₂는 시편의 색상 뿐 아니라 성분 변화에 큰 영향을 주지 못하였다. 반면 NO₂에 노출된 시편들은 색변화가 크게 나타나고 Lead nitrate(Pb(NO₃)₂)와 같은 2차 생성물이 확인되었다. 연백과 연단은 NO₂에 의한 색차가 각각 2와 10으로 시험 전에 비해 어두워졌으나 밀타승은 색차가 5이고 시험 전에 비해 밝게 변했다. 이를 통해 CO₂와 NO₂가 동일한 농도일 경우 CO₂에 비해 NO₂가 안료 보존에 영향력 있는 대기환경 인자임을 확인할 수 있다. 미세먼지에 존재하는 염의 영향을 보기 위해 5% NaCl(in distilled water)를 제조하여 염수 분무 시험을 실시하였다. 그 결과 연백, 연단, 밀타승 모두 시편 색변화와 함께 표면에 2차 생성물이 형성되었다. 이로 인해 아교도막이 박락되거나 hole이 형성되었으며, 생성물을 중심으로 색상이 변하였다. 또한 염수분무 후 XRD 피크 강도와 결정도가 함께 낮아진 것을 볼 수 있다. 염수분무 후 시료의 성분분석 결과 연백의 경우 Litharge가, 밀타승의 경우 Litharge와 Minium이 새로 형성되었다. 이를 통해 채색안료의 보존에 영향력 있는 대기환경 인자는 자외선, NO₂, 수용성 염임을 확인하였고 특히 납계열 안료 중 밀타승의 안정성이 다른 안료에 비해 낮은 것을 알 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.75.1-75.1
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• 2011

Coal gasification is considered as one of the most prospective technologies in energy field since it can be utilized for various products such as electricity, SNG (Synthetic Natural Gas or Substitute Natural Gas) and other chemical products. Among those products from coal gasification, SNG is emerging as a very lucrative product due to the rising prices of oil and natural gas, especially in Asian countries. The process of SNG production is very similar to the conventional IGCC in that the overall process is highly dependent on the type of gasifier and coal rank. However, there are some differences between SNG production and IGCC, which is that SNG plant requires higher oxygen purity from oxygen plant and more complex gas cleanup processes including water-gas shift reaction and methanation. Water-gas shift reaction is one of the main process in SNG plant because it is a starting point for the latter gas cleanup processes. For the methanation process, syngas is required to have a composition of $H_2$/CO = 3. This study reviewed various considerations for water-gas shift process in a conceptual design on an early stage like a feasibility study for a real project. The factors that affect the design parameters of water-gas shift reaction include the coal properties, the type of gasifier, the overall thermal efficiency of the plant and so on. Water-gas shift reaction is a relatively proven technology compared to the other processes in SNG plant so that it can reduce technological variability when designing a SNG project.

• 핵의학기술
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• 제12권1호
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• pp.74-77
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• 2008

The radiopharmaceuticals are routinely injected to blood vessel for acquiring PET image. For this reason, It is imperative that they undergo strict quality control measures. Especially, Sterility test is more important than any other quality control procedures. According to the FDA guideline, It requires filter integrity test used in the processing of sterile solutions. Among several methods, we can decide to use bubble point test. We usually use vented GS-filters (Millipore co., USA) which are sterilizinggrade (0.22 um pore size) and are placed upper site on product vial. After the synthesis of $^{18}F$-FDG, solutions wet the membrane in filter and then go into the product vial. By all synthesis steps have finished, we can observe the presence of the bubbles in the product vial. Since we have started this study, we have never found any bubbles in the product vial. Because the maximum pressure intensity of the filter which has set by manufacturer is up to 5 bars, but helium gas pressure is up to 1 bar in our module system. So, we can make 5 bars pressure using helium gas bombe and increase pressure up to 5 bars step by step. However, it does not happen to anything in vial.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.222-222
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• 2011

Plastic product is increasing by the growth of its demand and most of refused plastics are incinerated or reclaimed. However, the refused plastic is not easily decomposed and has the environmental problem with its various toxic gas in case of incineration. Therefore, many countries such as USA, Japan, Germany and other developed industrial countries as well as Korea are interested in studying the recyclable resource of refused plastic. The macromolecular waste pyrolysis has the advantage of collecting of raw materials in high price and can at least get fuel gas or oil with high heat capacity. It also discharges low waste gas and low toxic gas including SOx, NOx and HCl heavy metals. However, pyrolyzed oil includes enough excess unsaturated hydrocarbons to form tar, which can cause the nozzle of engines to plug when pyrolyzed oil is used as fuel. Activated carbon was proven to have prominent adsorption capability among the other adsorbents that were mainly composed of carbon. This study examined the possibility of application in activated charcoal of its solid formation by analysing the feature of pyrolysis which is one of the chemical recycling methods and getting chemical analysis of the product and activated energy. Analyze the element of the oil produced by pyrolysis using GC-MS. The experiment of tar adsorption using fly-ash showed that fly-ash improved the optical intensity of pyrolyzed oil and decreased oxygen compounds in the pyrolyzed oil.