• 한국식품저장유통학회지
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• 제18권4호
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• pp.502-507
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• 2011

돌산갓의 최적 절임조건을 조사하기 위하여 다양한 절임시간, 수세방법, 저장온도에 따른 돌산갓의 물리화학적 특성을 비교하였다. 또한, 최적조건에서 절임된 돌산갓을 50일 동안 저장하는 동안 유산균의 균수변화를 측정하였다. 절임돌산갓의 관능평가와 아삭거림의 결과로부터 장기간 보존을 위한 최적조건은 8시간 절임 후 염농도를 단계적으로 수세한 방법으로 나타났다. 절임돌산갓은 $4^{\circ}C$에서 저장되는 동안 유산균의 증가에 의해 pH가 감소하였다. 저장기간 동안 절단력은 천천히 증가하였으나, 염농도를 단계적으로 수세하였을 때는 절단력이 초기값과 비슷하게 유지되었다. 40일 저장된 절임돌산갓의 색변화는 관찰되지 않았으나 50일이 지나면서 갈변현상이 나타나 김치제조는 불가능 할 것으로 판단된다. 이들 결과들은 김치제조를 위한 절임돌산갓의 최적 절임조건과 저장기간으로 응용될 수 있을 것이다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.765-768
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• 2009

In this work, we prepared the activated multi-walled carbon nanotubes (Acti-MWNTs) with well developed physical surface structures, high specific surface area, and higher adsorption capacity by a physical activation process, in order to enhance the hydrogen storage capacity. The Acti-MWNTs' changes in the crystalline phase and in their lattice distortions were characterized by X-ray diffraction (XRD). The textural properties of the Acti-MWNTs were investigated by a nitrogen adsorption isotherms by Brunauer-Emmett-Teller (BET) equation and Harvath-Kawazoe (H-K) calculation, respectively. The hydrogen storage capacity of the Acti-MWNTs was investigated by BEL-HP at 298 K/100 bar. The hydrogen storage capacity of the Acti-MWNTs was improved with the physical activation, resulted from the formation of new hydrogen-favorable sites on the Acti-MWNT surfaces. In conclusion, the physical activation was one of the effective method to enhance the hydrogen storage capacity of the MWNTs.

• 전기화학회지
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• 제12권1호
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• pp.11-25
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• 2009

연료전지는 가까운 미래를 위한 핵심 청정 신에너지원 중의 하나로 기대된다. 그러나 고분자 연료전지에서 공기극은 느린 산소환원반응과 많은 백금 사용 때문에 상업화에 어려움을 겪고 있으며, 이것을 해결하는 것이 최근 당면 과제이다. 또한 연료극은 일산화탄소의 피독 현상과 전극의 안정성이 문제시 되고 있다. 본 총설에서는 고분자 연료전지를 위한 연료극, 공기극 전기화학 촉매의 이론적 접근을 통해 촉매를 설계하는 최근 연구 내용을 소개하려 한다. 촉매 설계는 합금 전기 화학 촉매를 통해 접근 했으며, 이는 electronic, geometric, lateral effects를 손쉽게 조절할 수 있게 한다. 이것은 계산되어진 d-band center의 함수에 의존하며, 촉매의 활성과 큰 관계를 가짐을 발견하였다. 본고에서 지향하는 촉매의 최종 방향은 이론적 접근을 통해서 촉매의 사용량을 줄이면서 효율적으로 사용하는 것이다.

• 한국수소및신에너지학회논문집
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• 제24권2호
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• pp.121-127
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• 2013

Tritium was attracted with high energy source in neutron fusion energy systems. A number of research was performed in tritium storage materials. The Korea was raised storage and delivery systems (SDS) of international thermonuclear experimental reactor (ITER) research. However, bottles of SDS would be important because of stability. The bottles have a welding zone, this zone will be vulnerable to hydrogen embrittlement. This zone have a high thermodynamic energy and heat deterioration. Therefore bottles were studied about hydrogen embrittlement to retain stability. The heat treatment of hydrogen was carried under pressure-composition-temperature (PCT) apparatus because of checking at real time. And then, mechanical properties were evaluated by tensile test and hardness test. In results of this study, hydrogen atmosphere condition is very important by tensile test and kinetics test. The samples were evaluated, that is more weak hydrogen pressure, increasing temperature and time. This results could be useful in SDS bottle designs.

• 한국수소및신에너지학회논문집
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• 제17권2호
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• pp.125-132
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• 2006

The alloys which compositions were represented by the formula, $Ti_{(0.22+X)}Cr_{(0.28+1.5X)}V_{(0.5-2.5X)}$ ($0{\leq}X{\leq}0.12$), had the total hydrogen storage capacity higher than 3 wt% and the effective hydrogen storage capacity higher than 1.4 wt%. Particularly, among all the tested alloys, the $Ti_{0.32}Cr_{0.43}V_{0.25}$ alloy exhibited the best effective hydrogen storage capacity of 1.65 wt%. Furthermore, the reversible bcc${\leftrightarrow}$fcc structural transition was observed with hydrogenation and dehydrogenation, which predicted the possibility of pressure cycling. EDS analysis revealed micro-segregation, which suggested the necessity of microstructure homogenization by heat treatment. The $Ti_{0.32}Cr_{0.43}V_{0.25}$ alloy was selected for heat treatment and for other related studies. The results showed that the total and the effective hydrogen storage capacity increased to 3.7 wt% and 2.3 wt%, respectively. The flatness of the plateau region was also greatly improved and heat of hydride formation was determined to be approximately -36 kJ/mol $H_2$.

• 한국수소및신에너지학회논문집
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• 제28권6호
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• pp.712-720
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• 2017

As Korean government has activated the renewable portfolio standard (RPS) since 2012, producers have been seeking and using the various renewable resources to meet the RPS quota. One of these efforts, Power Bio-Fuel oil demonstration project is being conducted to check the operability and compatibility with fossil fuel, Fuel oil (B-C) from 2014. The oil is a mixture of vegetable oil and animal fat or fatty acid ester of them and should satisfy some specification to use the power generation. The oil's quality and combustion characteristics are different from conventional oil, Fuel oil (B-C) in current power plant facility. In this study, it was investigated the storage stability and malodor intensity of Bio-Fuel oil.

• 한국자기학회지
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• 제2권2호
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• pp.163-168
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• 1992

포항 방사광 가속기 저장링용 시제품 2극전자석의 특성측정 및 보정결과에 대하여 기술 하였다. 전자석의 저장특성 측정을 위해 Hall probe mapping 기법과 rotating coil 기법과 rotating coil 기법을 동시에 사용하였다. 자장측정 결과로부터 2극전자석의 요구조건을 만족하도록 자극의 양 쪽 끝 부분을 수정하였다. 보정이 끝난 전자석은 2.0 GeV의 beam energy로 동작시킬 경우(1.058 Tesla) 약 99.7%의 효율을 얻었으며, 4극 이상의 다극 오차성분도 허용오차 범위 미만으로 포항 방사광 가속 기 저장링용 2극 전자석으로 적합함이 판명 되었다.

• 한국수소및신에너지학회논문집
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• 제33권3호
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• pp.209-218
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• 2022

Recently, research on the development of anion exchange membranes (AEMs) has received considerable attention from the scientific community around the world. Here, we fabricated a series of AEMs with branched structures with different alkyl spacers and conducted comparative evaluations. The introduction of these branched structures is an attempt to overcome the low ionic conductivity and stability problems that AEMs are currently facing. To this end, branched polymers with different spacer lengths were synthesized and properties of each membrane prepared according to the branched structure were compared. The chemical structure of the polymer was investigated by proton nuclear magnetic resonance, Fourier transform infrared, and gel permeation chromatography, and the thermal properties were investigated using thermogravimetric analysis. The branched anion exchange membrane with (CH₂)₃ and (CH₂)₆ spacers exhibited ionic conductivities of 8.9 mS cm^-1 and 22 mS cm^-1 at 90℃, respectively. This means that the length of the spacer affects the ionic conductivity. Therefore, this study showing the effect of the spacer length on the ionic conductivity of the membrane in the polymer structure constituting the ion exchange membrane is judged to be very useful for future application studies of AEM fuel cells.

• 한국수소및신에너지학회논문집
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• 제33권4호
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• pp.372-382
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• 2022

In this study, anion exchange membranes were prepared by synthesizing the main chain into a poly(arylene ether) (PAE) structure, and the structures capable of improving the physical and chemical stability of the membrane by introducing a heterocyclic quaternary ammonium functional groups were studied. The chemical structure and thermal properties of the prepared polymer were confirmed by ¹H-NMR, FT-IR, TGA, and DSC, and surface analysis was performed through AFM measurement. Additionally, dimensional stability and chemical properties was studied by measuring water uptake and swelling ratio, IEC and ionic conductivity. At 90℃, the quaternized poly(arylene ether) (QPAE)/1-methylpiperidine (MP) membrane exhibited the highest ionic conductivity of 27.2 mS cm^-1, while the QPAE/1-methylimidazole (MI) membrane and QPAE/1-methylmorpholine (MM) membrane exhibited values of 14.5 mS cm^-1 and 11.5 mS cm^-1, respectively. In addition, the prepared anion exchange membrane exhibited high chemical stability in alkaline solution.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.157.2-157.2
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• 2011

In this work, we prepared Mg nanoparticles loaded graphite oxide (Mg-G) as a function of Mg content in order to investigate hydrogen storage behaviors. The structure and morphology of the Mg-G samples were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The textural properties of the samples were evaluated using $N_2$/77 K adsorption isotherms. The hydrogen adsorption capacities were investigated at 298 K/10 MPa. As a result, the hydrogen adsorption capacities of the Mg-G were enhanced with increasing the Mg content. Therefore, it was found that the presence of Mg on graphite surfaces created hydrogen-favorable sites, resulting in enhancing the hydrogen adsorption capacity.