• Applied Biological Chemistry
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• 제37권1호
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• pp.30-36
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• 1994

오미자(Schizandra Chinensis Bullion)를 simultanuous distillation 및 steam distillation으로 추출하여 정유의 관능적 특성을 조사하고, GC 및 GC-MS로 분석하여 47개 성분을 확인하였다. 오미자의 관능적 특성은 woody, camphorous하고 spicy, sour note이고 정유의 distillation extraction에 의한 수율은 0.64%, simultanous distillation extraction에 의한 수율은 0.88%이었다. 확인된 47개 성분 중에서 terpene계 화합물인 ${\alpha}-pinene$, camphene, limonene, ${\gamma}-terpinene$, p-cymene, ${\alpha}-ylangne$, ${\beta}-elemene$ 등이 많이 함유하고 있었다. 또 정유를 10개로 분획한 후 좋은 향기 특성을 갖고있는 4개의 분획물만을 선정하여 성분 분석하였다. 오미자 향기특성이 woody, camphorous하여 상쾌한 신맛을 느끼게 함으로 국산차 또는 음료용으로 개발전망이 밝다고 본다.

• Journal of Mechanical Science and Technology
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• 제19권11호
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• pp.2007-2015
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• 2005

A large-scale analysis to evaluate complex material and structural behaviors is one of interesting topic in diverse engineering and scientific fields. Also, the utilization of massively parallel processors has been a recent trend of high performance computing. The objective of this paper is to introduce a parallel process system which consists of general purpose finite element analysis solver as well as parallelized PC cluster. The later was constructed using eight processing elements and the former was developed adopting both hierarchical domain decomposition method and balancing domain decomposition method. Then, to verify the efficiency of the established system, it was applied for structural analysis of steam generator in nuclear power plant. Since the prototypal evaluation results agreed well to the corresponding reference solutions it is believed that, after reinforcement of PC cluster by increasing number of processing elements, the promising parallel process system can be utilized as a useful tool for advanced structural integrity evaluation.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.39-44
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• 2009

Geothermal energy is the heat contained in the earth and its internal fluids. Geothermal energy is stored as sensible or latent heat. Supplied by both internal and external sources, it represents a vast supply which is only started to be tapped for generation of electric power. In general, this is natural dry or wet medium to high enthalpy steam at temperatures above $150^{\circ}C$. For some time, binary systems employing substances with a lower boiling point than water in a secondary circuit have been used to generate vapor for driving turbines at a lower temperature level. The utilization of binary plants and the possibility of production from enhanced geothermal systems can expand its availability on a worldwide basis. The geothermal electricity installed capacity is approaching the 10,000GW threshold. Geothermal energy is not present everywhere, but its baseload capability is a very important factor for its success.

• 한국건축시공학회지
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• 제5권2호
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• pp.89-95
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• 2005

Various tests are performed with the recycled concrete including compressive strength, flexural strength, splitting tensile strength, bonding strength and chloride ion penetration test. The basic data obtained from the presented test could be accumulated for the purpose of utilization in concrete structure. Most of the strength tests show that strength decrease a little extent with increasing substitution ratio of recycled coarse aggregate except splitting tensile test for the concrete with $100\%$ recycled fine aggregate. But in case of the $50\%$ substitution of recycled coarse aggregate, compressive strength, flexural strength and bonding strength are almost equal to the normal concrete. Chloride ion penetration test shows that the penetration amounts of chloride ion becomes more in proportion to the substitution ratio of recycled aggregate. But most of the results show that the permeability of recycled concrete is proper to use. The results of present study nay imply that the use of recycled aggregate for steam curing concrete is possible but the substitution ratio of recycled aggregate should be determined through further studies.

• 한국수소및신에너지학회논문집
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• 제26권2호
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• pp.156-163
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• 2015

The fuel cells have been investigated in the applications of marine as the high efficient and eco-friendly power generating systems. In this study, modeling of IR Type molten carbonate fuel cell (Internal Reforming Type molten carbonate fuel cell) has been developed to analyze the feasibility of thermal energy utilization. The model is developed under Aspen plus and used for the study of system performances over regarding fuel types. The simulation results show that the efficiency of MCFC system based on NG fuel is the highest. Also, it is also verified that the steam reforming is suitable as pre-reforming for diesel fuel.

• 한국식품저장유통학회지
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• 제4권1호
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• pp.61-68
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• 1997

To enhance the utilization of garlic shoots as food material, the nutritional and volatile flavor com pounds were investigated for garlic shoots, both cold and warm region type garlic shoots. Proximate composition of cold and warm region type was as follows, respectively; crude protein 2%, crude lipid 0.4%, crude ash 1.1% and 1.5%, crude fiber 1.3% and 1.5%. The major fatty acids of 2 varieties of garlic shoots were linoleic, palmitic and linolenic acid, and their desaturation ratio of them was comparatively high, showing 73.7 and 66.8%, respectively. Free sugars were composed of glucose, sucrose, fructose, arabinose and sorbitol. In the total amino acid analysis, the major amino acids were glutamic acid and aspartic acid. The volatile flavor compounds of fresh garlic shoots extracted by hexane and Likens-Nikerson steam distillation apparatus were identified to be methyl-2-propenyl disulfide, diallyl disufide, propenyl propyl disulfide, di-2-propyl-trisulfide, 2-vinyl-1,3-dithiane, and 2-vinyl-4H-1,3-dithiin. Hexane was more effective than steam distillation for extraction of volatile components of garlic shoots.

• 대한기계학회논문집B
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• 제35권6호
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• pp.641-648
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• 2011

고온 발전용 연료전지인 MCFC의 연료극에서 방출되는 미반응 가스를 촉매연소의 열원으로 사용하고, 촉매연소 반응에 의해 발생한 열을 개질 반응에 필요한 공급열로 이용하는 통합형 촉매연소-개질 반응기에 있어서 MCFC의 운전 조건 변경에 따른 반응기의 열적 거동과 반응 특성을 실험적으로 연구하였다. 특히, 연료극에서 연료 이용률을 변동될 때 슬립가스의 조성이 바뀌는 것을 고려하여 촉매연소측에 공급해줄 혼합가스의 조성을 실험조건으로 설정하였다. 또한 개질측에서는 S/C(수증기/탄소)의 비를 운전조건의 변동 조건으로 설정하였다. 실험적으로 얻어진 데이터는 보다 현실적인 통합형 촉매연소-개질반응기를 설계하고 제작하는데 필요한 기본 자료로 활용될 수 있을 것이다.

• 한국수소및신에너지학회논문집
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• 제30권4호
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• pp.303-311
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• 2019

Reversible solid oxide fuel cell (RSOFC) has become a prospective device for energy storage and hydrogen production. Many studies have been conducted around the world focusing on system efficiency improvement and realization. The system should have not only high efficiency but also a certain level of simplicity for stable operation. External waste steam utilization was proved to remarkably increase the efficiency at solid oxide electrolysis system. In this study, RSOFC system coupled with waste steam was proposed and optimized in term of simplicity and efficiency. Ejector for fuel recirculation is selected due to its simple design and high stability. Three system configurations using ejector for fuel recirculation were investigated for performance of design condition. In parametric study, the system efficiencies at different current density were analyzed. The system configurations were simulated using validated lumped model in EBSILON(R) program. The system components, balance of plants, were designed to work in both electrolysis and fuel cell modes, and their off-design characteristics were taken into account. The base case calculation shows that, the system with suction pump results in slightly lower efficiency but stack can be operated more stable with same inlet pressure of fuel and air electrode.

• 한국유기농업학회지
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• 제10권1호
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• pp.35-47
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• 2002

양돈생산에 있어 영양소의 이용율을 증대시키는 것은 절대적으로 필요하다. 가공기술(예를 들면 분쇄, 펠렛팅, 스팀 프레이킹, 로스팅, 익스투르전 및 익스펜딩)의 발전과 더불어, 사료원료의 영양소 이용성이 크게 향상되어 왔다. 분쇄는 입자도의 감소와 함께 가장 널리 사용되는 가공방법이다. 익스펜더는 익스트루더와 유사한 구조이며 짧은 시간으로 고온고압의 과정을 거쳐 생산되어지는 과정이다. 이러한 가공은 펠렛 질을 향상시키기 위해 사용한다. 또한 사료원료의 익스펜딩은 성장 및 영양소 소화율의 향상을 보여준다. 사료 비용은 양돈 생산에 가장 큰 경제적 비중을 차지하기 때문에 영양소 이용률의 극대는 계속적으로 크게 관심이 되어질 것이다. 결국, 이러한 관심은 가축성장과 영양소 소화율에 있어 일률적인 향상을 주게 될 사료가공기술이 계속적으로 되어질 것이다.

• 한국수소및신에너지학회논문집
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• 제33권4호
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• pp.363-371
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• 2022

In this study, the operation characteristics of the internal reforming type molten carbonate fuel cell (MCFC) were studied using computational fluid dynamics (CFD) analysis according to the steam to carbon ratio (S/C ratio), operating temperature, and gas utilization. From the simulation results, the distribution of gas composition due to the electrochemical reaction and the reforming reaction was predicted. The internal reforming type showed a lower temperature difference than the external reforming type MCFC. As the operating temperature decreased, less hydrogen was produced and the performance of the fuel cell also decreased. As the gas utilization rate decreased, more gas was injected into the same reaction area, and thus the performance of the fuel cell increased.