천마(Gastrodia elata Blume)는 난초과 다년생 기생식물로 곰팡이균과 공생하는 독특한 생활방식을 가진다. 천마의 지하근은 고혈압, 뇌졸중, 백혈병, 두통 특히 신경쇠약치료 등에 쓰이는 약용식물이다. 본 연구는 지구온난화가 천마의 생태적 반응에 미치는 영향을 알아보기 위해 보통의 야외 대기환경과 같은 대조구, 대조구보다 온도를 약 2℃ 상승시킨 온도상승구, 온도와 함께 대조구보다 CO2 농도를 약 2배 증가시킨 CO2+온도상승구에서 참나무 원목, 뽕나무버섯균, 종마를 함께 파종하고, 재배하여 생식기관과 지하근의 생물량을 비교 관찰하였다. 그 결과, 꽃대 수는 온도상승구> 대조구> CO2+온도상승구 순으로 적었다. 꽃대 길이는 온도상승구> 대조구> CO2+온도상승구 순으로 짧았다. 화서 길이는 대조구> 온도상승구> CO2+온도상승구 순으로 짧았다. 생식기관의 무게는 온도상승구> 대조구> CO2+온도상 승구 순으로 가벼웠다. 지상부의 생물량은 온도상승구> 대조구> CO2+온도상승구 순으로 낮았다. 생산된 근경의 수는 온도상승구> 대조구> CO2+온도상승구 순으로 적었다. 근경의 생물량은 온도상승구> 대조구> CO2+온도상승구 순으 로 낮았다. 이러한 결과는 온도만 올라간 환경조건에서는 천마의 생육은 활발하여 생산량이 증가하지만, 지구온난화조 건인 온도와 CO2 농도가 동시에 상승하는 조건에서는 천마의 생육이 불량하게 됨을 의미하는 것이다. 따라서, 천마의 성마와 종마 생산량을 높이기 위해서는 재배지의 적정지온 20~25℃를 유지하고, 높은 CO2 농도에 노출되지 않도록 하여야 할 것이다.

This study was performed to investigate how changing the period of light and dark influences the vegetative growth and the photosynthesis of Doritaenopsis Queen Beer ‘Mantefon’. Clones of Dtps. Queen Beer ‘Mantefon’ at 4-month-old stage were grown in a closed-plant factory system with four different light/dark cycles; 06/06 h, 08/08 h, 10/10 h, and 12/12 h. Temperature and relative humidity were set at 28oC and 80%, respectively, with a photosynthetic photon flux density of 160 ± 10 μmol·m-2·s-1. Repetitive measurements showed that the leaf length and the leaf width were the longest under 12/12 h closely followed by 10/10 h. The fresh weight and the dry weight of leaves and roots were the heaviest at 10/10 h treated samples. Different CO2 uptake patterns were observed from different light/dark cycles. Under 10/10 h and 12/12 h treatments, the CO2 uptake started at early dark period. When the light/dark cycles were shortened to 06/06 h and 08/08 h, the CO2 uptake started at the middle of dark period. Total CO2 uptake amounts were the highest under 12/12 h treatment followed by 10/10 h, 06/06 h, and 08/08 h treatments. Quantitative measurements showed that the vegetative growths under 10/10 h treatment were comparable with that of 12/12 h treatment. These studies indicated that manipulating light/dark can modify the photosynthesis patterns and vegetative growth of Dtps. Queen Beer ‘Mantefon’, resulting in the reduction of the production period.

본 논문에서는 주류공정의 고농도 CO2 제거를 위한 스크러버의 CO2 흡수 성능평가를 진행하였다. Lab-scale 실험을 통해서 설계인자인 액가스비(18 L/m3), 공탑속도(0.14 m/s)를 산정하였다. 설계인자를 기반으로 제작한 5 m3/min 급 CO2 흡수 반응기로 실험한 결과, 풍량이 1, 2, 3, 4, 5 m3/min 증가시 CO2 제거율은 98.47%, 96.46%, 92.95%, 89.71%, 85.49%로 감소하는 경향을 보였다. 또한 스크러버를 사용하기 전 후의 에너지 개선율(5.4%) 평가 및 에너지 절감량(11.5 TOE/year), 온실 가스 감축량(6.5 TC/year)를 산정하였다.

The objective of this study was to determine the effect of moisture contents (40, 50, 60%) and CO2 gas injection (0 and 800 mL/min) on physicochemical properties of extruded soy protein isolate (SPI). The expansion ratio and specific length at 40 and 50% moisture contents with CO2 gas injection increased while piece density decreased. On the contrary, the expansion ratio and specific length of extruded SPI at 60% moisture content with CO₂ gas injection decreased while piece density increased. Extruded SPI with CO2 gas injection had small cell size and higher amount of cell than extruded SPI without CO2 gas injection. The water holding capacity and nitrogen solubility index increased with CO2 gas injection increased while the integrity index and the springiness and cohesiveness decreased. In conclusion, extruded SPI with CO2 gas injection showed better expansion properties and cell formation than extruded SPI without CO2 gas injection.

아민 흡수제를 이용한 CO2 포집용 충전탑 기술의 문제점으로 제기되고 있는 범람, 거품, 과다한 재생 에너지 등을 해결하기 위하여 최근 접촉막 기술이 주목받고 있다. 연구자들 대부분은 고분자 분리막을 이용하여 접촉막 기술을 개발 하고 있으며, 장기 운전 시 팽윤 현상에 의한 성능저하 문제가 제기되고 있다. 세라믹은 고분자 소재에 비해 화학적, 열적안정성이 뛰어나기 때문에 아민 흡수 제에 대한 팽윤 현상을 방지할 수 있다. 본 연구에서는 세라믹 중공사 접촉막의 기공구조 제어 기술을 개발하고, CO2 포집 특성을 분석하였다.

Pebax 의 hard amide block 은 우수한 기계적 특성과 선택도를 제공하고 soft ether block 은 높은 투과도를 제공한다. 특히 ether block 은 CO2 의 투과도를 촉진시킨다. 또한 Pebax 기준으로 PEGDA 를 첨가하였을 때 첨가되는 PEGDA 분자량이 증가함에 따라 CO2/N2 선택도가 증가하는 것으로 알려졌다. 본 연구에서는 Pebax-2533 / PEGDA 혼합 막과 PES 지지체를 사용한 Pebax-2533 / PEGDA / PES 복합 막을 제조하여 비교한다. 제조된 막의 특성은 FT-IR, TGA, DSC, SEM 분석으로 확인하였으며 막의 CO2, N2 기체에 대한 투과도와 선택도 또한 확인하였다.

Carbon membranes can be applied to several process steps in natural gas, biogas or flue gas treatment. The significant more expensive inorganic membranes must have a higher separation performance compared to the polymeric membranes. Because of its resistance to solvents, pressure and temperature inorganic membranes have a chance in the marketplace. The predominant transport mechanism is molecular sieving (MSCM). Graphitic carbon do have lattice plane distances in the range of small gas molecules. Different steps in the production process allowed controlling the size of pores. High separation factors in gas mixtures were achieved. Reproducibility in the fabrication process is an unsolved problems. Carbon membranes showed a robust performance also in presence of impurities like H2O and H2S.

Carbon dioxide recovery by vacuum stripping at low temperatures (below 100°C) could be a promising technology to substitute the desorption process in conventional aqueous amine absorption process. We prepared composite membranes by coating hydrophobic silicalite-filled PDMS layers on porous PE supports and used as new membrane strippers for CO2 recovery to prevent typical pore wetting problem of hydrophobic PTFE porous membranes. CO2 fluxes were measured under various operation conditions, such as different vacuum pressures, stripping temperatures, CO2 loadings, types of amine solutions and operation time. The composite membranes showed excellent long-term stability in vacuum stripping process when compared with porous PTFE membranes.

바이오가스를 98% 이상의 고순도 메탄가스로 정제하여 자동차연료나 도시가스로 활용한다면 경제적으로 매우 큰 효과를 기대할 수 있다. 본 연구에서는 음 식물쓰레기 처리시설에서 발생하는 바이오가스를 정제하여 98% 이상의 고순도 메탄가스를 95% 이상 분리 회수하는 분리막 정제 시스템 개발을 하고자 하였다. 분리막 공정 설계에 필요한 데이터를 확보하기 위하여 분리막 모듈의 이산화탄소/메탄 혼합기체 분리시험을 수행하였으며, 다양한 운전조건에서 얻어진 실험결과를 바탕으로 공정설계를 수행하였다. 최종 생산되는 메탄 순도 98%, 이산화탄소 순도 95% 이상을 만족하는 운전 조건에서 메탄, 이산화탄소 회수율과 이에 필요한 각 단의 막면적과 비율을 확인하였다.

Recently, Graphene Oxide (GO) has extensively studied as a membrane material due to its 2D structure and high CO2 sorption property, however, GO membrane still has challenging issues; low gas permeability to apply to practical system and low stability under dry condition. In this study, we introduced GO as a nanofiller in CO2-philic polymer matrix because GO has molecular sieving property and 2D structure. First, we mixed two kinds of PEO-containing polymers by controlling the ratio of free volume in polymer networks to increase the permeability, and then, we added GO in the mixed polymer matrix for improving the CO2/N2 selectivity. Finally, we fabricated GO-incorporated mixed matrix membranes with high CO2/N2 separation performance beyond the upper bound. High long-term stability and high CO2/N2 selectivity were also achieved in mixed gas system.

기체분리용 기능소재에 대한 세계적인 시장의 요구가 증가함에 따라 광범위한 연구개발이 진행되고 잇다. 본 연구는 둘 이상의 기체혼합물에서 높은 이산화탄소 포집성능을 목적으로 하는 복합막의 제조이다. Isocyanate와 SI-PEG, 소 량의 촉매를 사용하여 코팅액을 제조한 뒤 PAN지지체 위에 코팅하여 복합막을 제조하였다. SEM기기를 활용하여 복합막의 코팅층을 확인하였고 Bubble flowmeter를 사용하여 기체투과특성평가를 실시하였다. 기체복합막의 두께는 3 um 이하로 고른 분포를 보이며, 50 GPU의 이산화탄소 투과값과 질소에 대한 이산화탄소 선택도는 15의 결과를 보였다.

심냉법을 이용한 산소 제조 기술은 지난 한 세기 동안 사용되어 왔으나 에너지 효율의 문제가 제기 되고 있으며, 최근에는 이온전도성 분리막을 이용한 산소 제조 기술이 효율적으로 산소를 제조할 수 있는 대안으로 대두되고 있다. 이 온전도성 분리막을 산소 연소 공정에 적용하기 위해서는 높은 산소투과능과 이산화탄소에 대한 내성이 필요하다. Ba0.5Sr0.5Co0.8Fe0.2O3-δ와 같이 기존에 잘 알려진 조성의 분리막은 높은 산소 투과성능을 나타내지만 이산화탄소에 대한 내성이 낮다. 이를 개선하기 위해 본 연구에서는 이산화탄소 내성을 가지는 Sm0.3Sr0.7Cu0.2Fe0.8O3-δ과 Ce0.8Sm0.2O2-δ으로 이상 분리막(dual phase)을 제조하였다. 제조된 분리막의 특성을 분석하고, 헬륨 및 이산화탄소 조건에서 산소투과 실험을 진행하였다.

The gas separation through membrane is considered as a promising solution for the stabilization of greenhouse gas level of atmosphere attributed from CO2. The separation process of membrane allows low energy requirement, low cost, and ease of operation. However, conventional polymeric membranes generally suffer from the trade-off between permeability and selectivity, which remains as one of the most important challenges for commercialization. Mixed matrix membranes (MMMs), consisting of a polymer matrix and porous nano-filler, are considered to be a promising solution to overcome the trade-offs in polymeric membranes. Herein the porous nano-structures were fabricated to enhance the permselectity of CO2 separation membranes. The MMM which were fabricated with prepared porous nano-filler showed permeability improvement without significant selectivity loss.

Graphite fibers are materials with a high specific modulus that have attracted much interest in the aerospace industry, but their high manufacturing cost and low yield are still problems that prevent their wide applications in practice. This paper presents a laser-based process for graphitization of carbon fiber (CF) and explores the effect of laser radiation on the microstructure of CF. The obtained Raman spectra indicate that the outer surface of CF evolves from turbostratic structures into a three-dimensional ordered state after being irradiated by a laser. The X-ray diffraction data revealed that the growth of crystallite was parallel to the fiber axis, and the interlayer spacing d002 decreased from 0.353 to 0.345 nm. The results of scanning electron microscopy revealed that the surface of irradiated CFs was rougher than that of the unirradiated ones and there were scale-like small fragments that had peeled off from the fibers. The tensile modulus increased by 17.51% and the Weibull average tensile strength decreased by 30.53% after being irradiated by a laser. These results demonstrate that the laser irradiation was able to increase the graphitization degree of the CFs, which showed some properties comparable to graphite fibers.

The effects of Postharvest CO2 treatment on the quality and shelf life of oyster mushroom packaged with oriented polypropylene (OPP) film bag were investigated. On the day of harvest, the ‘Gonji-7ho’ oyster mushroom grown by bottle cultivation of Jangheung County, Korea transferred to a laboratory in Wanju County and were cooled in a cold room at 3°C for 1 day and then treated with 30% or 50% CO2 for 3 hours at 3°C. After the CO2 treatment, 400 g of oyster mushroom were sealed into 20 μm thick OPP film bag (width: 29 cm, length: 24 cm) used in the actual farmhouse. The package gas composition, hardness, color change, off-flavor index, browning index, and overall quality were evaluated during storage at room temperature (RT) for 6 days and at 3°C for 21 days. As a result, During storage at RT, the concentration of carbon dioxide in the bag of 30%, 50% CO2 were higher than untreated and shelf-life of oyster mushroom at 50% CO2 was reduced 1 day due to off-flavor while 30% CO2 or untreated was 2 days. During storage at 3°C, the concentration of carbon dioxide in the bag was kept low at 30%, 50% CO2 treatment compared to untreated, the respiration of oyster mushroom at 30, 50% CO2 were lower than untreated during initial 7 days storage at 3°C, but ethylene production were not different. The hardness of oyster mushroom at 30% CO2 was higher, the lightness (L* value) of stem surface was higher, the yellowness (b* value), browning index was lower and odor index was lower than untreated or 50% CO2. 30% CO2 treated oyster mushroom packaged with OPP film bag kept 4.2~16.2% O2 and 4.2~15.5% CO2 concentration in the bag during storage at 3°C, and showed highest overall quality index. Marketable shelf-life was assessed 10 days for untreated, 17 days for 30% CO2, and 16 days for 50% CO2, respectively.

In order to compare greenhouse gases emission from different animal manures and to explore how different animal manures effect on soil mineralization, three kinds of materials, cattle, goat and chicken manure were amended to soil for 14 days incubation as CtS (cattle manure-amended soil), GS (goat manure-amended soil) and ChS (chicken manure-amended soil). Cumulative NH3 emissions in all treatments were rapidly increased until day 7 and then it was slightly increased in three manure-amended soils but maintained in control until day 14. GS had the highest NH3 emission at 0.14 mg kg-1 during the entire experimental period. Emissions of CO2 were highly increased by 7.8-, 9.0- and 12.4-fold in CtS, GS and ChS, respectively, compared to control at day 14. A significant increase of N2O emission in all treatments occurred within 5 days and then it was slightly increased until day 14. N2O emission was 2-fold higher in all manure-amended soils than that of control. Compared to day 1, inorganic N (NH4 + plus NO3 --N) content was highly increased in all four treatments at day 14. The increase rate was the highest in CtS treatment. Net N mineralization was increased by 4.0-, 2.4- and 2.9-fold in CtS, GS and ChS, respectively, compared to control. These results indicate that increase of NH3, CO2 and N2O gas emissions was positively related to high N mineralization.

CO2농도와 온도의 상승으로 인한 지구온난화가 진행되었을 때 광, 수분 그리고 유기물 구배에 따른 멸종위기식물인 황근의 생육과 생태적 지위폭의 변화를 알아보았다. 대조구(야외)와 처리구(CO2 + 온도 상승구)로 나누어 각각 광, 수분 그리고 유기물구배를 두어 재배하였다. 그 연구결과, 황근은 낮은 광량보다 높은 광량을 선호하나, 광량이 787±77.76μmol m-2s-1을 넘어가면 높은 광량이라 하더라도 생육이 어려웠다. 또한 유기물이 없거나(0%) 너무 많은 토양(20%)에서는 생육이 어려웠다. 그러나 수분 구배에 따른 경향이 보이지 않았다. 황근의 고사율은 대조구보다 처리구에서 광량이 높은 조건을 제외한 모든 구배에서 높았다. 이는 CO2와 온도가 상승하면 광에 대한 내성범위가 좁아진다는 것을 의미한다. 대조구와 처리구를 비교하였을 때, 수분구배에 따른 경향은 보이지 않았다. 유기물구배에서 는 대조구보다 처리구에서 모두 고사율이 낮았는데, 이는 유기물에 대한 내성의 범위가 넓어진 것을 의미한다. 황근의 생태적 지위폭은 처리구가 대조구보다 광 구배에서 30.1% 좁아졌으며, 수분 구배에서 8.6% 그리고 유기물 구배에서 30% 넓어졌다. 따라서 CO2농도와 온도의 증가로 인한 지구온난화가 진행되면, 황근의 생육은 광량에 의해서 제한될 것으로 판단된다.

This study presents a sustainable design method to optimize the embodied energy and CO2 emission complying with the design code for reinforced concrete column. The sustainable design method effectively achieves the minimization of the environmental load and energy consumption whereas the conventional design method has been mostly focused on the cost saving. Failure of reinforced concrete column exhibits compressive or tensile failure mode against an external force such as flexure and compression; thus, optimization analyses are conducted for both failure modes. For the given sections and reinforcement ratios, the optimized sections are determined by optimizing cost, embodied energy, and CO2 emission and various aspects of the sections are thoroughly investigated. The optimization analysis results show that 25% embodied energy and 55% CO2 emission can be approximately reduced by 10% increase in cost. In particular, the embodied energy and CO2 emission were more effectively reduced in the tensile failure mode rather than in the compressive failure mode. Consequently, it was proved that the sustainable design method effectively implements the concept of sustainable development in the design of reinforced concrete structure by optimizing embodied energy consumption and CO2 emission.