• 멤브레인
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• 제32권4호
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• pp.218-226
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• 2022

대용량 화학 및 청정에너지의 운반체인 수소는 석유화학 산업 및 연료전지 등에서 많이 활용되는 중요한 산업용 기체이다. 특히 수소는 주로 증기개질 및 가스화를 통해 화석 연료에서 생성되며 부산물로 이산화탄소가 발생한다. 따라서 고순도 수소를 얻기 위해서는 이산화탄소를 제거해야 한다. 본 총설에서는 배러 단위[1 Barrer = 10^-10 cm³ (STP) × cm / (cm² × s × cmHg)]로 보고된 이산화탄소로부터 수소를 분리하는 프리스탠딩 고분자 분리막 및 혼합매질 분리막에 초점을 맞추었다. 최근 보고된 다양한 논문들을 분석하여 분리막의 구조, 형태, 상호 작용 및 제조 방법에 대해 논의하고 구조-물성 관계를 이해하여 향후 더 나은 분리막 소재를 찾는 데 도움이 되고자 한다. 다양한 분리막의 성능 및 특성 검토를 통해 수소/이산화탄소 분리에 대한 Robeson 성능 한계선을 제시하고, 가교, 혼합 및 열처리 등의 기술을 사용하여 분리 특성을 개선하는 다양한 혼합매질 분리막에 대해 논의하였다.

• 공업화학
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• 제21권3호
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• pp.272-277
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• 2010

현재의 값비싼 광생물반응기를 대체하기 위하여 비닐백을 소재로 한 보급형 광생물반응기를 개발하고자 본 연구를 실시하였다. 앞선 연구에서 Spirulina platensis NIES 39의 최적배양조건을 확립하였으며, 이를 토대로 하여 이산화탄소 고정화 연구를 실시하였다. 이산화탄소 농도 및 유속에 따른 성장은 10% $CO_2$, 0.1 vvm의 조건에서 가장 높은 2.677 g/L의 건조균체량을 나타냈으며, 이산화탄소 고정화량($F_{CO_2}$)은 4.056 g ${\cdot}{CO_2}$/L, 이산화탄소 고정화속도($R_{CO_2}$)는 0.312 g $CO_2$/L/day로 나타났다. 반면, 이산화탄소 고정화 효율($FE_{CO_2}$)의 경우 5% $CO_2$, 0.1 vvm의 조건에서 나타난 데이터에 비해서 그 절반 수준인 52.372%를 나타내었다. 그리고 빛의 유무에 따른 이산화탄소 주입효과를 알아본 결과, 빛이 있는 조건에서 약 3 h 주기로 10 min간 주입하는 조건이 가장 우수한 성장 및 이산화탄소 고정화를 한 것으로 나타났으며, 빛이 없을 때는 이산화탄소 주입이 무의미하다는 결론을 얻을 수 있었다.

• 한국건설관리학회논문집
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• 제13권4호
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• pp.78-88
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• 2012

지구 온난화의 주범인 온실가스 배출량을 규제하고자 하는 전 세계적인 기조에 따라 건설 분야에서도 이와 관련하여 다양한 노력이 시도되고 있다. 그 일례로 LCA (Life cycle Assessment) 방법론 도입을 통해 $CO_2$ 배출량을 정량적으로 측정하려는 연구가 활발하게 수행되고 있다. 그러나 일반 제조업에서 수행되고 있는 기존의 LCA 방법론은 다양한 자재의 투입과 복잡한 생산구조를 가지고 있는 건설업에 활용되기에는 많은 한계가 있다. 이에 본 연구는 보다 정확하고 세분화된 환경영향 평가를 도출할 수 있도록, 기존 LCA 방법론에 ABC원가관리방식을 도입한 Activity-based LCA 모델을 제안하였다. 이를 기반으로 대표적 온실가스인 $CO_2$의 주요 배출 Activity와 각각 배출량에 대한 정확한 예측이 가능하도록 하는 모델을 제시하였으며, 실제 시공 중인 건물의 커튼월 시스템 공정을 대상으로 하여 그 유용성을 검증하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.390-395
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• 2016

This study was conducted to investigate the effect of nocturnal light pulses (NLPs) on the feed intake and metabolic rate in geese. Fourteen adult Chinese geese were penned individually, and randomly assigned to either the C (control) or NLP group. The C group was exposed to a 12L:12D photoperiod (12 h light and 12 h darkness per day), whereas the NLP group was exposed to a 12L:12D photoperiod inserted by 15-min lighting at 2-h intervals in the scotophase. The weight of the feed was automatically recorded at 1-min intervals for 1 wk. The fasting carbon dioxide production rate ($CO_2$ PR) was recorded at 1-min intervals for 1 d. The results revealed that neither the daily feed intake nor the feed intakes during both the daytime and nighttime were affected by photoperiodic regimen, and the feed intake during the daytime did not differ from that during the nighttime. The photoperiodic treatment did not affect the time distribution of feed intake. However, NLPs lowered (p<0.05) the mean and minimal $CO_2$ PR during both the daytime and nighttime. Both the mean and minimal $CO_2$ PR during the daytime were significantly higher (p<0.05) than those during the nighttime. We concluded that NLPs lowered metabolic rate of the geese, but did not affect the feed intake; both the mean and minimal $CO_2$ PR were higher during the daytime than during the nighttime.

• 한국환경보건학회지
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• 제43권4호
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• pp.267-272
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• 2017

Objectives: The purposes of the study were to analyze the temporal variation of carbon dioxide ($CO_2$) and particulate matter (PM) in daycare centers and evaluate the appropriateness of the official test method of one-time measurement. Methods: Indoor air quality in 46 daycare centers in the Seoul Metropolitan Area was measured as specified in the official test method of Indoor Air Quality Management law. In addition, indoor air quality in the 46 daycare centers was measured over 37 days using a real-time monitor (AirGuard K). Results: The daily means of $CO_2$ and PM in the 46 daycare centers were $1042.74{\pm}134.45ppm$ and $67.60{\pm}18.25{\mu}g/m^3$, respectively. Indoor air quality in the daycare centers showed significant temporal fluctuation. Measurements for single days were significantly different from the 37-day average exposure. Relative error of short term exposure decreased with an increase in the number of sampling days. The noncompliance rate for $CO_2$ using the official testing method was 2.17%, and none exceeded the $PM_{10}$ standard of $100{\mu}g/m^3$. With monitoring over 37 days, the daily noncompliance rate for $CO_2$ was 50.4% and the daily noncompliance rate for PM was 13.8%. Conclusions: When the official test method evaluates the indoor air at daycare centers one day per year, the results may not represent actual indoor air quality over a longer period of time. Real-time monitoring devices could be an alternative for managing indoor air quality.

• Journal of Advanced Marine Engineering and Technology
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• 제28권3호
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• pp.500-508
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• 2004

The heat transfer coefficients during gas cooling process of carbon dioxide in a horizontal tube were investigated. The experiments are conducted without oil in the refrigerant loop. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater, and a gas cooler(test section). The water loop consists of a variable-speed pump, an isothermal tank, and a flow meter. The gas cooler is a counterflow heat exchanger by cooled water flowing in the annulus. The $CO_2$ flows in the horizontal stainless steel tube. which is 9.53mm in O.D. and 7.75mm in I.D. The gas cooler is 6 [m] in length. which is divided into 12 subsections, respectively. The experimental conditions considered in the study are following range of variables : refrigerant temperature is between 20 and $100^{\circ}C$. mass fluxes ranged from 200 to 400kg/($m^2$.s), average pressure varied from 7.5 to 10.0MPa. The main results were summarized as follows : The friction factors of $CO_2$ in the gas cooler show a relatively good agreement with those predicted by Blasius' correlation. The local heat transfer coefficient in the gas cooler has compared with most of correlations, which are the famous ones for forced convection heat transfer of turbulent flow. The results show that the local heat transfer coefficient of gas cooler agrees well with the correlation by Bringer-Smith except that at the region near pseudo critical temperature. while that at the near pseudo critical temperature is higher than the correlation.

• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.561-569
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• 2017

In this study, a synthetic amine made using the ethylene oxide-ammonia reaction was used as an absorbent to remove carbon dioxide. Existing absorbents were used in a mix in order to improve performance; however, because the ethylene oxide-ammonia reaction generates primary, secondary, and tertiary amines simultaneously, it has the merit that separate mixing of the absorbents was not needed. The performance of carbon dioxide absorption with the synthetic amine was compared to that of MEA. As a result of an experiment, it was determined that the $CO_2$ loading was 1.15 times better than that of MEA (a commonly used amine), while the cyclic capacity was 2.28 times higher. Because the heat of reaction was 1.10 times lower than for MEA, the synthetic amine showed superior performance in terms of absorption and regeneration.

• Korean Chemical Engineering Research
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• 제48권2호
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• pp.140-146
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• 2010

이산화탄소 포집기술 중 건식흡수제를 이용한 연소 후 이산화탄소 포집기술에 대하여 최신기술개발 현황에 대하여 자세히 기술하였다. $CO_2$ 포집에 있어서 건식흡수제 이용 기술의 장점으로는 조업온도의 폭이 크고, 에너지손실이 적으며, 폐수발생이 없고, 부식성이 적으며, 고체폐기물의 상대적인 천연성을 들 수 있다. 현재 한국과 미국에서는 건식흡수제의 성능 개선과 더불어 실제 연소배가스로부터 $CO_2$ 포집을 위한 공정 개발을 통해 포집비용을 줄이려는 연구가 지속적으로 이루어지고 있다. 건식흡수제는 가격이 싼 알칼리금속 계열의 화학흡수제, 아민을 실리카 지지체에 고정시킨 흡수제, 아민을 실리카 지지체에 공유결합시킨 흡수제, 기공성의 탄소에 아민의 기능성을 첨가시킨 흡수제, 아민고정 고분자지지체 흡수제, 금속유기구조체등의 연구가 이루어지고 있다. 포집비용을 대폭 줄이기 위하여 소재에 있어서도 혁신적인 성능 개선이 필요한 시점이다.

• 한국버섯학회지
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• 제2권2호
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• pp.45-48
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• 2004

The effect of $CO_2$ concentration (500, 3,000, $6,000{\mu}{\ell}/{\ell}$) on the mycelial growth and fruit body primordium formation of Ganoderma lucidum on nutrient agar medium was examined. Optimum $CO_2$ concentration for vegetative growth was above $3,000{\mu}{\ell}/{\ell}$. Fruit body initiation was accelerated at higher than $3,000{\mu}{\ell}/{\ell}$ $CO_2$ exposure but the maximum number and size of primordia, and primordium color were not influenced by $CO_2$ concentrations. Whereas each atypical fruiting structure forming stock culture showed different fruiting time under each concentration of $CO_2$ exposure.

• Toxicological Research
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• 제11권2호
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• pp.273-277
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• 1995

Several metabolic modulators on the generation of carbon monoxide (CO)from dichloromethane (DCM) was examined in adult female rats. It has been known that DCM is converted to CO by cytochrome P-450 or to carbon dioxide $(CO_2)$ by glutathione-dependent metabolic reaction. In rats treated with DCM (3 mmol/kg, ip) only, the carboxyhemoglobin (COHb) level reached a peak of approximately 10% 2 or 3 hr following the treatment. Disulfiram (300 mg/kg, ip) or allylsulfide (200 mg/kg, po), both known as a selective inhibitior for cytochrome P-450 2E1, blocked the increase in COHb concentratlons almost completely suggesting that the metabolic conversion of DCM to CO is mediated by the activity of this specific type of isozyme. YH439 (125 or 250 mg/kg, po), a potential hepatoprotective agent, decreased the COHb elevation as well indicating that this chemical is a potent inhibitor for 2E1. In rats treated with pyrazine (200 mg/kg, ip) 18 hr prior to DCM the peak COHb concentration was decreased by approximately 3 or 4%. However, pretreatment of rats with pyrazine either 24 or 48 hr before DCM increased the peak COHb concentration significantly compared to the rats treated with DCM only. The results in the present study strongly suggest that the generation of CO from DCM depends on the 2E1 activity and that the pharmacological and/or toxicological action of YH439 or pyrazine in animals or human is associated with its effect on this isozyme.