• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.514-523
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• 2017

Carbon catabolite repression is a crucial regulation mechanism in microorganisms, but its characteristic in Rhizopus is still unclear. We extracted a carbon regulation gene, cre, that encoded a carbon catabolite repressor protein (CRE) from Rhizopus stolonifer TP-02, and studied the regulation of CRE by real-time qPCR. CRE responded to glucose in a certain range, where it could significantly regulate part of the cellulase genes (eg, bg, and cbh2) without cbh1. In the comparison of the response of cre and four cellulase genes to carboxymethylcellulose sodium and a simple carbon source (lactose), the effect of CRE was only related to the concentration of reducing sugars. By regulating the reducing sugars to range from 0.4% to 0.6%, a glucose-containing medium with lactose as the inducer could effectively induce cellulases without the repression of CRE. This regulation method could potentially reduce the cost of enzymes produced in industries and provide a possible solution to achieve the largescale synthesis of cellulases.

• 한국세라믹학회지
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• 제31권8호
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• pp.893-901
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• 1994

In this study, AlN powder of fine particle size and of high purity was synthesized by the carbothermal reduction-nitridation of monodisperse, spherical Al(OH)3 which had been prepared by sol-gel method using Al(O-sec-C4H9)3 as the starting material. Depending on the mixing order and kinds of reducing agents, the optimum condition for the preparation of AlN was determined as follows. AlN single-phase was produced by the carbothermal reduction-nitridation of (1) Benzene-washed Al(OH)3 and the reducing agent, carbon, which was mixed in a ball mill: for 5 hours at 140$0^{\circ}C$ under NH3 atmosphere; (2) The mixture prepared by hydrolysis of alkoxide solution into which carbon had been dispersed beforehand: for 5 hours at 135$0^{\circ}C$ ; (3) Al(OH)3 Poly(furfuryl alcohol) composite powder: for 2.5 hours at 135$0^{\circ}C$; (4) The mixture of Al(OH)3 and polyacrylonitrile: for 5 hours at 140$0^{\circ}C$. Addition of CaF2 increased the nitridation rate when carbon or polyacrylonitrile was used as the reducing agent; but it had no effect on the nitridation rate when furfuryl alcohol was used as the reducing agent.

• 한국재료학회지
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• 제29권9호
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• pp.519-524
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• 2019

Spherical $Li_3V_2(PO_4)_3$ (LVP) and carbon-coated LVP with a monoclinic phase for the cathode materials are synthesized by a hydrothermal method using $N_2H_4$ as the reducing agent and saccharose as the carbon source. The results show that single phase monoclinic LVP without impurity phases such as $LiV(P_2O_7)$, $Li(VO)(PO_4)$ and $Li_3(PO_4)$ can be obtained after calcination at $800^{\circ}C$ for 4 h. SEM and TEM images show that the particle sizes are $0.5{\sim}2{\mu}m$ and the thickness of the amorphous carbon layer is approximately 3~4 nm. CV curves for the test cell are recorded in the potential ranges of 3.0~4.3 V and 3.0~4.8 V at a scan rate of $0.01mV\;s^{-1}$ and at room temperature. At potentials between 3.0 and 4.8 V, the third $Li^+$ ions from the carbon-coated LVP can be completely extracted, at voltages close to 4.51 V. The carbon-coated LVP exhibits an initial specific discharge capacity of $118mAh\;g^{-1}$ in the voltage region of 3.0 to 4.3 V at a current rate of 0.2 C. The results indicate that the reducing agent and carbon source can affect the crystal structure and electrochemical properties of the cathode materials.

• Carbon letters
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• 제1권1호
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• pp.17-21
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• 2000

Catalytic reduction and oxidation of NO over polyacrylonitrile based activated carbon fibers (PAN-ACF) under various conditions were carried out to develop removal process of NO from the flue gas. The effect of temperature, oxygen concentration and the moisture content for the reduction of NO with ammonia as a reducing agent was investigated. The reduction of NO increased with the oxygen concentration, but decreased with the increased temperature. The moisture content in the flue gas affects the reduction of NO as the inhibition of the adsorption of the other components and the reaction on the surface of ACE For the oxidation of NO to $NO_2$ over PAN-ACF without using a reducing gas, it showed the temperature and the oxygen concentration of the flue gas are the important factors for the NO conversion in which the conversion increased with oxygen concentration and decreased with the temperature increase and might be the alternative option for the selective catalytic reduction process.

• 한국항해항만학회지
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• 제47권3호
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• pp.134-146
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• 2023

'탄소저감' 문제는 전세계적으로 가장 중요한 이슈 중 하나라고 할 수 있다. 효율적인 탄소저감을 위해서는 배출량 감소는 물론, 흡수량을 늘리는 방법도 고려할 필요가 있다. 이에 최근 블루카본 바이오매스를 활용해 탄소흡수량을 늘리는데 많은 관심이 쏠리고 있다. 블루카본은 염생식물, 잘피 등 연안에 서식하는 식물과 갯벌 등의 퇴적물을 포함한 해양 생태계가 흡수하는 탄소를 말한다. 또한 블루카본 바이오매스는 블루카본과 관련된 생태계를 의미하며 이는 내륙 생태계보다 탄소흡수율이 높고, 포집 기간도 길어 탄소저감에 매우 효율적이라는 평가를 받고 있다. 하지만 국내에서는 아직까지 이에 대한 연구활동이 활발하지 않은 실정이며, 무엇보다도 블루카본 바이오매스 서식지 보존을 위한 공간계획과의 연계성이 부족하고, 관련 정책도 구체적으로 마련되어 있지 않은 실정이다. 이에 본 연구에서는 탄소저감 문제 해결에 적극적인 대응을 위하여 블루카본 바이오매스의 중요성을 인식하고, 서식지를 보존하여, 향후 이를 중심으로 한 국내 환경에 적합한 형태의 탄소저감형 해안도시를 조성할 필요가 있음을 제시하고자 한다.

• 한국조경학회지
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• 제51권6호
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• pp.75-87
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• 2023

본 연구는 조경·정원분야 기후변화 대응을 위한 역할로서 자연기반해법의 실증을 위한 실험적 설계를 제시하고, 탄소중립 사회를 위한 공간 전략적 방안과 문화 산업으로서의 역할을 제시하는 목적으로 진행되었다. 환경 보호와 탄소중립 사회 형성을 목표로 저 관리형 정원으로서의 탄소저감 효과를 위한 전략을 제시하고자 한다. 이를 위해 본 연구에서는 모델정원의 기능과 공간 요소, 탄소중립과 관련된 내용들을 보다 과학적인 데이터로 수집할 수 있도록 실질적 모델정원을 설계하고 조성하였다. 대상지는 국립세종수목원 내에 위치한다. 탄소저감 기능을 측정하는 실험구를 중심적으로 배치하며, 그 외 공간은 드라이가든과 커뮤니티 가든, 초화원 등으로 전시와 휴식을 할 수 있는 공간을 두었다. 실험구는 바이오차 부설 양, 식재밀도, 식재 수종에 따른 탄소저감 효과를 분석할 수 있게 타입을 구분하였다. 탄소저감을 위한 시설 적용과 시공 방식은 '지구를 위한 10가지 탄소정원 가꾸기'의 방식을 적용하였다. 대표적으로 빗물의 활용시설, 저탄소 인증 목재 활용, 인근지역 자재 사용을 적용하였다. 또한 각각의 시설 및 시공 방식에 따른 탄소저감 효과를 비교하여 제시하였다. 이 결과는 탄소중립 사회를 실현하기 위한 대응 방안을 모색하는 데에 중요한 기초 연구가 될 것으로 기대되며, 정원 산업 등 지속 가능한 발전이 필요한 다양한 분야에서의 참고가 될 것으로 기대한다.

• 한국대기환경학회지
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• 제28권5호
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• pp.556-570
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• 2012

The Low Carbon Path Calculator is an excel-based model to project greenhouse gas emissions from 2009 to 2050, which is based on the 2050 Pathways Calculator developed by the UK Department of Energy and Climate Change (DECC). Scenarios are developed to reduce GHG emissions in Korea at 50% based on 2005 levels by 2050 using a Low Carbon Path Calculator. They were classified in four different cases, which are high renewable, high nuclear, high CCS and mixed option scenarios. The objectives of this study are to compare scenarios in terms of GHG emissions, final energy, primary energy and electricity generation and examine the usefulness of that model in terms of identifying pathways towards a low carbon emission society. This model will enhance the understanding of the pathways toward a low carbon society and the level of the climate change policy for policy makers, stakeholders, and the public. This study can be considered as a reference for developing strategies in reducing GHG emissions in the long term.

• 한국운동역학회지
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• 제22권2호
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• pp.237-242
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• 2012

The purpose of this study was (a) to develop carbon nanotube-based shock absorbers for reducing potentially harmful impact forces and excessive foot pronation, and (b) to briefly determine how the effects of carbon nanotube-based shock absorbers on biomechanical variance during drop landing. A university student(age: 24.0 yrs, height: 176.2 cm, weight: 679.5 N) who has no musculoskeletal disorder was recruited as the subject. Hardness, specific gravity, tensile strength, elongation, 100% modulus, tear strength, split tear strength, compression set, resilience, vertical GRF, and loading rate were determined for each material. For each dependent variable, a descriptive statistics was used for different conditions. The property test results showed that tensile strength, tear strength, split tear strength, compression set, and resilience in carbon nanotube-based shock absorbers were greater than general Ethylene Vinyl Acetate(EVA). These indicated that resistance against variable strength in developed carbon nanotube-based shock absorbers were greater than general EVA. In vertical GRF of CNTC was less than those of EVA during drop landing and loading rate of CNTC was greater than EVA. It seems that the use of CNT can be a effective way of reducing and controlling shock from impact.

• 수산해양기술연구
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• 제48권4호
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• pp.360-369
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• 2012

The main purpose of this study is to analyse economic feasibility of low-carbon-oriented trawl gear. The results of benefit/cost analysis showed that use of the low-carbon fishing gear is economically feasible. Considering the fuel saving and relatively low $CO_2$ emission by reducing the resistance of gear, net present value by such gear improvement was estimated about 2,430~2,853 million won with the benefit-cost ratio 1.65~1.84 and the internal rate of return 29.18~30.48 percent. Development of low-carbon trawl gear would render significant contributions to reducing $CO_2$ emission in fishing operations and lead to reduce fishing costs due to fuel savings.

• Journal of Microbiology and Biotechnology
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• 제29권6호
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• pp.905-912
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• 2019

Bioethanol has attracted much attention in recent decades as a sustainable and environmentally friendly alternative energy source. In this study, we compared the production of bioethanol by Candida molischiana and Saccharomyces cerevisiae at different initial concentrations of cellobiose and glucose. The results showed that C. molischiana can utilize both glucose and cellobiose, whereas S. cerevisiae can only utilize glucose. The ethanol yields were 43-51% from different initial concentrations of carbon source. In addition, different concentrations of microcrystalline cellulose (Avicel) were directly converted to ethanol by a combination of Trichoderma reesei and two yeasts. Cellulose was first hydrolyzed by a fully enzymatic saccharification process using T. reesei cellulases, and the reducing sugars and glucose produced during the process were further used as carbon source for bioethanol production by C. molischiana or S. cerevisiae. Sequential culture of T. reesei and two yeasts revealed that C. molischiana was more efficient for bioconversion of sugars to ethanol than S. cerevisiae. When 20 g/l Avicel was used as a carbon source, the maximum reducing sugar, glucose, and ethanol yields were 42%, 26%, and 20%, respectively. The maximum concentrations of reducing sugar, glucose, and ethanol were 10.9, 8.57, and 5.95 g/l, respectively, at 120 h by the combination of T. reesei and C. molischiana from 50 g/l Avicel.