• 폴리머
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• 제37권5호
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• pp.592-599
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• 2013

Polyacrylonitrile(PAN) 고분자 용액으로부터 전기방사된 고분자 나노섬유를 다양한 농도의 KOH 용액을 이용하여 다공성 나노탄소섬유를 제조하였으며, 그에 따른 세공 구조 및 이산화탄소 흡착 특성을 평가하였다. PAN 용액으로부터 제조된 활성나노탄소섬유는 KOH 활성화 농도가 증가함에 따라 섬유 직경이 감소하였으며, 표면의 산소관능기가 증가하는 경향을 보였다. 또한 질소 흡착에 따른 세공특성을 분석한 결과 KOH 활성화 농도 증가에 따라 활성나노탄소섬유의 비표면적이 증가하고, 미세공은 4 M KOH로 활성화한 나노탄소섬유가 가장 많았으며, 중간세공은 8 M KOH로 활성화한 활성나노탄소섬유가 가장 많았다. 또한 0, $25^{\circ}C$에서 KOH 활성화제의 농도가 BET 및 XPS에서 나타난 것처럼 이산화탄소 흡착을 강화시키도록 세공 및 표면 특성에 영향을 주었다.

• 자원리싸이클링
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• 제30권1호
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• pp.77-82
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• 2021

철강 산업에 있어서 CO2 배출량 감소는 중요한 이슈이며, CO2 배출 감소를 위해 코크스를 일부 대체할 수 있는 탄재 연료의 연구는 필요하다. 한편, 바이오매스 연료는 고정 탄소를 일부 함유하고 있으며, 반탄화 공정을 통해 연료내 탄소의 함량을 증가시킬 수 있다. 바이오매스 연료 중 커피박은 약 55 mass%의 탄소를 함유하고 있으며, 국내에서 연간 약 27만 ton이 매립 또는 소각되고 있다. 또한, 연간 커피 소비량의 증가로 인한 재활용 공정에 관한 연구가 필요하다. 본 연구에서는 반탄화 공정을 통한 커피박 내 고정 탄소의 농도에 미치는 온도의 영향을 연구하였다. 또한, 반탄화 커피박의 용해 실험을 통해 금속 샘플 내 탄소 농도와 용해 효율에 대한 코크스와 혼합비의 영향을 조사하였다.

• 한국미생물·생명공학회지
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• 제24권4호
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• pp.404-407
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• 1996

The effects of carbon sources on vancomycin production were investigated using Nocardia orientalis CSVC 3300. Among carbon sources tested, glucose, maltose and fructose were effective for the production of vancomycin. Glucose was favored for growth, but decrease the production of vancomycin at the concentration above 7.5%. In comparison, maltose did not decrease the production of vancomycin up to the concentration of 20%. When the mixture of glucose and maltose was used in the ratio 1:3 to 1:4, the highest production of vancomycin was achieved. When glucose concentration was set at 3.0%, catabolite repression could not be observed up to total sugar concentration of 16.0%. Fermentation was carried out using commercial hydrolyzed starch composed of glucose, maltose, maltotriose and maltotetraose, The initial glucose concentration was set at 3.0% and subsequent oligosaccharide consumption was monitored by checking their supernatant with HPLC. During initial cultivation for 38 hour, glucose was the sole carbon source leading to rapid growth. After cell growth stopped, the maltose and glucose concentrations increased due to degradation of maltotriose and maltotetraose, but glucose level was maintained at around 3.0%. After 70 hour fermentation, maltose slowly converted to glucose, and vancomycin production continued during the period.

• 한국가구학회지
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• 제23권4호
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• pp.381-387
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• 2012

Utilization of underground floor is becoming the main issue of our society to maximize and diversify the potential of recent urban space. It has brought about the changes of underground floor. Recently there are lots of huge bookstores in these underground floor. Bleach, adhesive and ink used for manufacturing books pollute indoor air in bookstore. Therefore, the purpose of this study is to analyze indoor air quality in these large bookstores. Concentrations of carbon dioxide and formaldehyde in three large bookstores in Seoul were measured by presence and type of books and distance of main entrance which is well-ventilated. According to the data, space that places lots of volumes measured higher concentration of formaldehyde than that of non-existence books. Children's book section was measured more concentration of formaldehyde than other book section. Closer main entrance near outside, lower concentration of formaldehyde was measured. Concentration of carbon dioxide was affected by the number of people in bookstore.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.131-135
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• 2002

Acetobacter xylinum KJ1 efficiently producing bacterial cellulose(BC) in shaking culture was isolated from a rotten grape. The strain was used to investigate optimum operating conditions for increasing BC production and factorial design model was employed for the optimization. The results of experiments were statistically analyzed by SAS program. Reciprocal effects of each factors(carbon source concentration, shaking speeds(rpm), oxygen pressure, and CSL concentration) and culture condition of BC production were examined by getting regression equation of the dependent variable. Comparisons between experimental results and predicted results about BC concentration were done in total 24 experiments by combination of each factors using SAS program, and the correlation coefficients of BC concentration and BC yield were 0.91 and 0.81, respectively. The agitated cultures were performed in various operation conditions of factors which affected considerably to BC production in jar fermentor. The results showed that BC concentration was 11.67g/ L in 80 hours cultivation under the condition of carbon source concentration shaking speeds(rpm) : oxygen pressure: CSL concentration = 4% : 460rpm : 0.28 : 6%. On the other hand BC yield was 0.42g/g in 80 hours cultivation under the condition of carbon source concentration shaking speeds(rpm) : oxygen pressure: CSL concentration = 4% : 564rpm : 0.21 : 2%. The BC production could be enhanced up to more than 65.3% by factorial design. The result of a verifying experiment under the optimal conditions determined by the factorial design to the BC production showed that the model was appropriate by obtaining BC concentration of 11.02g/L in the optimum condition

• 대한공간정보학회지
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• 제18권1호
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• pp.129-134
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• 2010

저탄소 녹색성장은 국내외적으로 중요한 정치적 이슈가 되고 있으며, 한국정부는 최근 저탄소 녹색성장을 위한 비젼을 발표하였다. 이런 관점에서 탄소배출 추정은 도시계획에 있어서 중요한 요소가 되고 있다. 탄소저감 계획을 수립하기 위하여 본 연구에서는 과거 40년 동안 진주시의 탄소배출 추정과 토지이용변화의 상호추이변화를 분석하였다. 토지적성평가 데이터베이스와 항공영상의 영상처리자료는 과거 40년간의 토지이용변화를 분석하는데 유효한 정보를 주었으며, 신주거지 개발에 의한 토지이용변화는 급격한 인구집중과 탄소배출증가를 가져왔다. 앞으로 저탄소 녹색성장을 위한 도시관리계획에 있어서 토지이용변화에 따른 탄소배출 증가를 계획수립 시 반드시 고려해야하며, 향 후 토지이용과 연료소비추정이 포함된 정확한 탄소배출 추정모델개발에 대한 추가적인 연구가 필요하다고 사료된다.

• Environmental Engineering Research
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• 제13권2호
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• pp.98-104
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• 2008

In this study, chromate and cetylperidinium chloride (CPC) removal from artificial wastewater was monitored by using micellar enhanced ultrafiltration (MEUF) and activated carbon fibre (ACF) adsorption hybrid processes. For the efficient chromate removal, molar concentration of the CPC should be five times that of chromate and it should be at least one critical micelle concentration (CMC). The MEUF was found to be effective in the chromate removal while ACF in the CPC adsorption to produce chromate and CPC free effluents. The chromate and CPC removal was 99.8% from MEUF-ACF process. Effluent chromate concentration was exponentially correlated with molar ratio of CPC to chromate and pH.

• 한국대기환경학회지
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• 제29권1호
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• pp.56-63
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• 2013

This study was aimed at developing and evaluating a diffusive sampling method using a barium hydroxide solution as an absorbent for measuring carbon dioxide ($CO_2$) in ambient air. The collected $CO_2$ concentration was calculated by the change of conductivity resulted in the reaction of $CO_3{^{2-}}$ and $Ba^{2+}$ in aqueous solution. The sampling rate for the diffusive sampler was determined 0.218 mL/min, as obtained from the slope of the linear correlation between the $CO_2$ mass collected by the diffusive sampler and the time-weighted $CO_2$ concentration with the active sampling method. The unexposed blank sampler sealed in aluminium foil-polyethylene laminated packets has remained stable during at least one-month storage period. A good correlation was observed between the diffusive sampler and active sampler with a coefficient of determination of 0.956. This diffusive sampler would be suitable for the indoor $CO_2$ concentration monitoring.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.497-502
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• 2003

This study intends to provide the analytical and experimental damping characterization of carbon nanotube/epoxy composites. A constitutive model based on continuum mechanics is employed to describe epoxy and the perfectly bonded and partially bonded nanotubes. An interfacial stick-slip between the nanotubes and epoxy is considered to characterize the damping of the composites. For experimental estimation, beam-type specimens are prepared with a variation of nanotube concentration from 0.5% to 2% in weight. An ultrasonic agitation method is employed for enhancing the nanotube dispersion within epoxy. Damping of the composites is characterized in terms of the strain and the nanotube concentration. Results show that the nanotube concentration significantly affects the damping characteristics of the nanocomposites. A good correlation is found between the analytical prediction based on the stick-slip and the experimental measurements.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.172-175
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• 2008

In the last five years, 45 people died and 104 were wounded because of carbon monoxide poisoning accident. CO poisoning accident is higher than any other gas accident in the rate of deaths/incidents. Most of these CO poisoning accidents were caused by defective exhaust tube in the old gas boiler and multi-use facility. In this study, the spread of CO gas released from leakage hole of exhaust tube was analyzed by computational flow modeling and concentration measuring test. CO gas leaked form exhaust tube in a building was highest concentrated near the ceiling and formed the circular currents along the walls. Through these experiments and simulation, the reasonable installation location of CO alarm was made certain and suggested.