• 제목/요약/키워드: energy storage properties

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감마선 조사된 꽁치과메기(semi-dried Cololabis seira)의 품질특성 (Quality Properties of gamma irradiated Kwamegi(semi-dried Cololabis seira))

  • 김덕진;이주운;조경환;육홍선;변명우
    • 한국식품과학회지
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    • 제32권5호
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    • pp.1128-1134
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    • 2000
  • 본 연구는 해풍에서 반건조된 꽁치(Cololabis seira)로 만든 과메기에 대한 감마선 조사에 의한 품질 특성을 평가하기 위해 수행되었다. 과메기의 가식부위를 준비하여, 진공포장하고, 3과 5 kGy에서 각각 감마선을 조사한 후 $5^{\circ}C$에 저장하였다. VBN및 TMA 함량은 조사직후 차이는 없었고, 저장 중 감마선 조사선량이 증가할수록 함량의 증가가 억제되는 것으로 나타났다. 조사직후 TBA는 모든 처리구에서 차이가 없었고 저장 중 증가하였으나, 감마선 조사에 의한 영향은 없었다. 휘발성 향기성분은 감마선 조사에 의해 전체적인 함량이 줄어들었다. 과메기의 물성은 감마선 조사구의 경우 저장 60일째에도 물성을 그대로 유지하였으나, 비조사구는 저장 중 연화되는 것으로 나타났다. 관능평가결과 조사직 후 감마선 조사구와 비조사구의 차이가 없었고, 감마선 조사구가 저장 60일째까지 관능적으로 품질이 유지되는 것으로 나타났다. 따라서 과메기에 대한 감마선 조사는 과메기의 품질을 유지시키는 효과적인 방법이라 할 수 있다.

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수소 분위기에서 고 에너지 볼 밀링으로 제조한 80Mg+14Ni+6TaF5합금의 수소와의 반응 속도와 수소 저장 용량 (Reaction Rate with Hydrogen and Hydrogen-storage Capacity of an 80Mg+14Ni+6TaF5 Alloy Prepared by High-energy Ball Milling in Hydrogen)

  • 박혜령;송명엽
    • 한국수소및신에너지학회논문집
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    • 제28권2호
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    • pp.137-143
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    • 2017
  • In the present study, Ni and $TaF_5$ were chosen as additives to enhance the hydriding and dehydriding rates of Mg. A sample with a composition of 80 wt% Mg + 14 wt% Ni + 6 wt% $TaF_5$ (named $80Mg+14Ni+6TaF_5$) was prepared by high-energy ball milling in hydrogen. Its hydriding and dehydriding properties were then examined. At the fourth cycle, the activated sample absorbed 3.88 wt% H for 2.5 min, 4.74 wt% H for 5 min, and 5.75 wt% H for 60 min at 593 K under 12 bar $H_2$. $80Mg+14Ni+6TaF_5$ had an effective hydrogen-storage capacity (the quantity of hydrogen absorbed for 60 min) of about 5.8 wt%. The sample desorbed 1.42 wt% H for 5 min, 3.42 wt% H for 15 min, and 5.09 wt% H for 60 min at 593 K under 1.0 bar $H_2$. Line scanning results by EDS for $80Mg+14Ni+6TaF_5$ before and after cycling showed that the peaks of Ta and F appeared at different positions, indicating that the $TaF_5$ in $80Mg+14Ni+6TaF_5$ was decomposed.

Electrochemical Properties of PPy/CNT Electrodes Prepared by Chemical Process for Ultracapacitor

  • Shin, Jeong-Gyun;Park, Soo-Gil
    • 전기화학회지
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    • 제10권2호
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    • pp.141-144
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    • 2007
  • Polypyrrole(PPy) was composite with MWNT to attain cycle stable by chemical method. We have been considered PPy is the ideal material for high energy density electrochemical capacitor due to pseudo capacitor reaction. In this study we found that increase in cycle life due to composite MWNT. Also PPy/MWNT composite material have resulted larger capacitance and exhibits better electrochemical behavior. The structural feature was investigated by using SEM and TEM. The PPy/CNT composite is not only a promising ultracapacitor material for energy storages but also has a good possibility because of its great capacitive properties, simple preparation and low cost.

Carbon Materials as Catalysts

  • Lim, Seong-Yop;Jung, Doo-Hwan;Yoon, Seong-Ho;Mochida, Isao
    • Carbon letters
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    • 제9권1호
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    • pp.47-60
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    • 2008
  • Understanding the exact structure and surface characteristics of carbon materials is very important for design, synthesis, and utilization of the best carbon form with particular functions and high performance for practical applications such as selective adsorption adsorbents, energy storage materials, catalysts or catalyst supports, etc. This review paper focuses on carbon surface properties and the interaction between gaseous or liquid substances and carbon surface. Catalytic functions of carbon materials are reviewed including recent progress in synthesis and applications of nano-carbons.

천부 지열에너지로서의 지하 열에너지 저장 기술 동향 (Status of Underground Thermal Energy Storage as Shallow Geothermal Energy)

  • 심병완;이철우
    • 자원환경지질
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    • 제43권2호
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    • pp.197-205
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    • 2010
  • 최근 급격한 기후변화가 세계적 또는 국지적으로 발생하고 있으며, 지구온난화에 대한 대책으로 $CO_2$ 저감 기술들이 중요한 해결책으로 여겨지고 있다. 이 기술들에 대한 한 방법으로서 대체에너지를 개발하고 있는 대부분의 국가에서 천부 지하 열에너지 저장 (UTES: underground thermal energy storage)은 신뢰성 있는 냉난방 기술로 적용되어 왔다. 천부의 토양이나 암반, 대수층내 지하수 및 지하공간내 저장된 유체 등의 열 에너지원을 이용하는 지열 시스템은 일반적으로 열에너지의 회복과 저장의 개념을 기반으로 한다. 아직 국내에서는 이러한 기술 개발이 기초적이지만 지속적인 연구들을 수행한다면 보다 친환경적이며 경제성 및 효율이 높은 시스템을 개발할 수 있을 것으로 본다. 국내 지반은 대수층이 전국적으로 분포하고 있으므로 수리지열학적 특성을 활용한 고효율의 시스템 개발이 용이하다. 그러나 UTES에 대한 이해 부족 및 제도적 문제들로 다양한 시스템이 개발되지 못하고 국내에는 90% 이상이 단편적인 폐회로형 지열시스템으로 보급되고 있다. 비효율적인 지열시스템의 보급 확산을 방지하기 위해서는 지반의 수리 지열학적 특성을 반영한 선진화된 UTES 시스템들을 개발할 필요가 있다. 개선된 시스템 보급을 위하여 국제적인 협력이 필수적이며, 지속적인 UTES 연구를 통하여 천부 지열시스템의 효율을 개선시킬 수 있다.

Polyethylene Glycol의 분자량 및 NCO index의 변화에 따른 Hydrophilic Reactive Hotmelt Polyurethane의 물성 변화 (Effect of Polyethylene Glycol Molecular Weight and NCO Index on Properties of the Hydrophilic Reactive Hotmelt Polyurethane Adhesives)

  • 한영철;김덕한;오경석;신현정;양정한;정한모
    • 한국염색가공학회지
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    • 제30권2호
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    • pp.90-97
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    • 2018
  • Hydrophilic reactive hot-melt polyurethane adhesive(HRHA) using a hydrophilic polyol having different molecular weight and NCO index was synthesized. This HRHA was synthesized using Polyethylene glycol(PEG) as a hydrophilic polyol, Polypropylene glycol(PPG) and Polycaprolactone diol(PCL) as hydrophobic polyols, and Methylene diphenyl diisocyanate(MDI) as an isocyanate. The changes in IR spectrum, viscosity and thermal properties of HRHA with different PEG molecular weights and NCO index were investigated, and the tensile strength and elongation of the HRHA casting film and the peel strength, moisture permeability and water pressure of the HRHA coated fabric were confirmed. In this experiment, as the molecular weight of PEG and NCO index increased, the adhesive strength, tensile strength, elongation and moisture permeability was increased but viscosity and Tg was decreased.

Modified Silica with Cellulose/Starch by Gel-Adsorption Method as Reinforcing Materials for SBR Latex

  • Li, Xiang Xu;Cho, Ur Ryong
    • Elastomers and Composites
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    • 제53권1호
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    • pp.6-12
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    • 2018
  • Styrene-butadiene Rubber (SBR) Latex composites, incorporated with cellulose/starch-silica hybrids synthesized by gel-adsorption method, were filled into rubber by the latex compounding method. The structure morphology, mechanical properties, and thermodynamic properties of gel-silica hybrids were characterized. The states of hybrids which used as fillers were also characterized by SEM. As the fillers ratio increased, the difference for storage modulus of samples had been morphology by rubber process analyzer (RPA). Then, as more fillers ratio was filled into the matrix, the best tensile strength result, and the largest modulus value were also proved by UTM and RPA. As for thermal stability, increase in the ratio of fillers led to higher initial decomposition temperature, which was also proved by TGA. The swelling ratio of samples has also been characterized. From the results of all the tests, cellulose-silica hybrid showed the best results as a filler, and the best filling ratio of this hybrid is about 10 phr, which has the best storage modulus and great tensile strength.

The Quality of Modified Atmosphere Packaged Meat from Lambs Slaughtered at 50 and 100 Days of Age

  • Tanski, Zenon;Stanislaw, Milewski;Bozena, Zaleska
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권3호
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    • pp.428-434
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    • 2012
  • The aim of this study was to determine the quality of modified atmosphere (MA) packaged meat from Pomeranian rams slaughtered at 50 and 100 days of age. Determined: chemical composition, physicochemical and sensory properties of meat, and the fatty acid profile of intramuscular fat. Meat from 100-d-old lambs was characterized by a significantly higher content of dry matter, total protein and crude fat, a darker color and higher physiological maturity ($p\leq0.01$). Meat from younger lambs was marked by a better water-holding capacity ($p\leq0.05$), a lower energy value and higher concentrations of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). An increase in the content of dry matter, total protein and ash, and energy value was noted in MA-stored meat. Meat pH decreased over MA storage and the sensory properties deteriorated. The studied meat remained safe from microbial contamination during storage.

Electrochemical Properties of Binary Electrolytes for Lithium-sulfur Batteries

  • Kim, Hyung-Sun;Jeong, Chang-Sik
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3682-3686
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    • 2011
  • The electrochemical properties of lithium-sulfur batteries with binary electrolytes based on DME and DOL, TEGDME and DOL mixed solvent containing $LiClO_4$, LiTFSI, and LiTF salts were investigated. The ionic conductivity of 1M LiTFSI and $LiClO_4$ electrolytes based on TEGDME and DOL increased as the volume ratio of DOL solvent increased, because DOL effectively reduces the viscosity of the above electrolytes medium under the same salts concentration. The first discharge capacity of lithium-sulfur batteries in the DME and DOL-based electrolyte followed this order: LiTFSI (1,000 mAh/g) > LiTF (850 mAh/g) > $LiClO_4$ (750 mAh/g). In case of the electrolyte based on TEGDME and DOL, the first discharge capacity of batteries followed this order: $LiClO_4$ (1,030 mAh/g) > LiTF (770 mAh/g) > LiTFSI (750 mAh/g). The cyclic efficiency of lithium-sulfur batteries at 1M $LiClO_4$ electrolytes is higher than that of batteries at other lithium salts-based electrolytes. Lithium-sulfur battery showed discharge capacity of 550 mAh/g until 20 cycles at all electrolytes based on DME and DOL solvent. By contrast, the discharge capacity of batteries was about 450 mAh/g at 1M LiTFSI and LiTF electrolytes based on TEGDME and DOL solvent after 20 cycles.