• Title/Summary/Keyword: energy storage properties

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Studies on the Egg Storage Technology (계란비축을 위한 저장기법연구)

  • 김기성;유익종;강통삼
    • Korean Journal of Poultry Science
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    • v.16 no.4
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    • pp.233-238
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    • 1989
  • This experiment was carried out to establish effective egg storage technology by studying the physico-chemical properties of albumen and yolk during the cold storage. The results obtained were summarized as follows:1. Egg Yolk was gelated and whipping quality and whipping stability of albumen was decreased by the freezing storage. 2. NaCl was the best anti-freezer to prevent the gelation of egg yolk among various anti-freezer (NaCl, glucose, sucrose, amides). 3. Viscosity of egg yolk and albumen was increased and color was changed but changes of colorin albumen was slight during the storage at $-5^{\circ}C$ and $-20^{\circ}C$. 4. To store the 5% NaC1 added egg yolk -at $-5^{\circ}C$ was the best way to prevent the gelation of egg yolk and save the energy. 5. Emulsion capacity of egg yolk was decreased by the cold storage with the addition of NaCl.

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Stabilization of Physical Properties and Thermal Characteristic Analysis of Phase Change Material (상변화축열재의 물성안정과 열특성 분석)

  • 유영선;윤진하;손정익;김영중;강금춘;송현갑;장진택
    • Journal of Bio-Environment Control
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    • v.7 no.3
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    • pp.214-218
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    • 1998
  • This study was performed to stabilize the physical properties of Sodium Carbonate Decahydrate that was selected as a highly concentrative thermal energy storage medium. The addition of ARS(additives to prevent supercooling) showed to prevent the supercooling of Na$_{2}$CO$_{3}$.10H$_{2}$O, and the supercooling was decreased below $1.5^{\circ}C$ with ARS of 3 wt% and the addition of PSC(phase separation controller) of 1.5 wt% controlled the phase separation of Na$_{2}$CO$_{3}$ .10H$_{2}$O with the phase change cycles increased from 0 to 1,500, the phase change temperature and the latent heat has changed in the range of 30$\pm$1.$0^{\circ}C$ and 54$\pm$2.0Kcal.kg$^{-1}$ respectively.

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CO2 Capture & Separation in Microporous Materials: A Comparison Between Porous Carbon and Flexible MOFs (다공성 물질을 이용한 CO2 포집 및 분리: 다공성 탄소와 유연한 MOF 비교 연구)

  • Jung, Minji;Park, Seoha;Oh, Hyunchul;Park, Kwi-il
    • Korean Journal of Materials Research
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    • v.28 no.7
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    • pp.417-422
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    • 2018
  • The stereotype of flexible MOFs(Amino-MIL-53) and carbonized porous carbon prepared from renewable resources is successfully synthesized for $CO_2$ reduction application. The textural properties of these microporous materials are investigated, and their $CO_2$ storage capacity and separation performance are evaluated. Owing to the combined effects of $CO_2-Amino$ interaction and its flexibility, a $CO_2$ uptake of $2.5mmol\;g^{-1}$ is observed in Amino-MIL-53 at 20 bar 298 K. In contrast, $CH_4$ uptake in Amino-MIL-53 is very low up to 20 bar, implying potential sorbent for $CO_2/CH_4$ separation. Carbonized samples contain a small quantity of metal residues(K, Ca, Mg, S), resulting in naturally doped porous carbon. Due to the trace metal, even higher $CO_2$ uptake of $4.7mmol\;g^{-1}$ is also observed at 20 bar 298 K. Furthermore, the $CH_4$ storage capacity is $2.9mmol\;g^{-1}$ at 298 K and 20 bar. To evaluate the $CO_2$ separation performance, the selectivity based on ideal adsorption solution theory for $CO_2/CH_4$ binary mixtures on the presented porous materials is investigated.

One-Step β-Li2SnO3 Coating on High-nickel Layered Oxides via Thermal Phase Segregation for Li-ion Batteries

  • Seongmin Kim;Hanseul Kim;Sung Wook Doo;Hee-Jae Jeon;In Hye Kim;Hyun-seung Kim;Youngjin Kim
    • Journal of Electrochemical Science and Technology
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    • v.14 no.3
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    • pp.293-300
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    • 2023
  • The global energy storage markets have gravitated to high-energy-density and low cost of lithium-ion batteries (LIBs) as the predominant system for energy storage such as electric vehicles (EVs). High-Ni layered oxides are considered promising next-generation cathode materials for LIBs owing to their significant advantages in terms of high energy density. However, the practical application of high-Ni cathodes remains challenging, because of their structural and surface instability. Although extensive studies have been conducted to mitigate these inherent instabilities, a two-step process involving the synthesis of the cathode and a dry/wet coating is essential. This study evaluates a one-step β-Li2SnO3 layer coating on the surface of LiNi0.8Co0.2O2 (NC82) via the thermal segregation of Sn owing to the solubility limit with respect to the synthesis temperature. The doping, segregation, and phase transition of Sn were systematically revealed by structural analyses. Moreover, surface-engineered 5 mol% Sn-coated LiNi0.8Co0.2O2 (NC82_Sn5%) exhibited superior capacity retention compared to bare NC82 owing to the stable surface coating layer. Thus, the developed one-step coating method is suitable for improving the properties of high-Ni layered oxide cathode materials for application in LIBs.

Recent Developments in Ion-Exchange Nanocomposite Membranes for Energy Applications (에너지용 이온 교환 복합막 최근 연구 개발 동향)

  • Hwang, Doo Sung;Chung, Tiffany;Wang, Tongshuai;Kim, Sangil
    • Membrane Journal
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    • v.26 no.6
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    • pp.432-448
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    • 2016
  • In the last decade, various types of energy harvesting and conversion systems based on ion exchange membranes (IEMs) have been developed for eco-friendly power generation and energy-grid systems. In these membrane-based energy systems, high ion selectivity and conductivity properties of IEMs are critical parameters to improve efficiency of the systems such as proton exchange membrane fuel cells, anion exchange membrane fuel cells, redox flow batteries, water electrodialysis for hydrogen production, and reverse electrodialysis. This article suggests variable approaches to overcome trade-off limitation of polymeric membrane ion transport properties by reviewing various types of composite ion-exchange membranes including novel inorganic-organic nanocomposite membrane, surface modified membranes, cross-linked and pore-filled membranes.

Effects of Various Physicochemical Treatments on Volatiles and Sensory Characteristics of Irradiated Beef Bulgogi

  • Park, Jin-Gyu;Park, Jae-Nam;Han, In-Jun;Song, Beom-Seok;Kim, Jae-Hun;Yoon, Yo-Han;Byun, Myung-Woo;Park, Kyung-Sook;Lee, Ju-Woon
    • Food Science of Animal Resources
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    • v.31 no.2
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    • pp.200-206
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    • 2011
  • Off-flavor and lipid oxidation are possible defects of irradiated bulgogi. This study compared the effects of several physicochemical treatments on microbial safety, volatiles, lipid oxidation, and sensory properties of irradiated beef bulgogi. Samples were separately irradiated with 20 kGy after each treatment such as packaging (aerobic and vacuum), antioxidants (vitamin C + ${\alpha}$-tocopherol (0.0 and 1.0%, w/w)), charcoal teabags (0 and 0.5%), or different temperatures (room temperature, -20, and -70$^{\circ}C$). No bacterial growth was observed (p<0.05) after irradiation of more than 20 kGy during storage at $35^{\circ}C$. Volatiles created by irradiating bulgogi were toluene, heptane, and 1,3-bis(1,1-dimethylethyl)benzene. Irradiation offflavor, lipid oxidation, and deterioration of sensory quality induced by irradiation were effectively reduced (p<0.05) by all physico-chemical treatments tested.

Mechanical Stability Analysis to Determine the Optimum Aspect Ratio of Rock Caverns for Thermal Energy Storage (열에너지 저장용 암반 공동의 최적 종횡비 결정을 위한 역학적 안정성 해석)

  • Park, Dohyun;Ryu, Dongwoo;Choi, Byung-Hee;Sunwoo, Choon;Han, Kong-Chang
    • Tunnel and Underground Space
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    • v.23 no.2
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    • pp.150-159
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    • 2013
  • It is generally well known that the stratification of thermal energy in heat stores can be improved by increasing the aspect ratio (the height-to-width ratio) of the stores. Accordingly, it will be desirable to apply a high aspect ratio so as to demonstrate the good thermal performance of heat stores. However, as the aspect ratio of a store increases, the height of the store become larger compared to its width, which may be unfavorable for the structural stability of the store. Therefore, to determine an optimum aspect ratio of heat stores, a quantitative mechanical stability assessment should be performed in addition to thermal performance evaluations. In the present study, we numerically investigated the mechanical stability of silo-shaped rock caverns for underground thermal energy storage at different aspect ratios. The applied aspect ratios ranged from 1 to 6 and the mechanical stability was examined based on factor of safety using a shear strength reduction method. The results from the present study showed that the factor of safety of rock caverns tended to decrease with the increase in aspect ratio and the stress ratio of the surrounding rock mass was influential to the stability of the caverns. In addition, the numerical results demonstrated that under the same conditions of rock mass properties and aspect ratio, mechanical stability could be improved by the reduction in cavern size (storage volume), which indicates that one can design high-aspect-ratio rock caverns by dividing a single large cavern into multiple small caverns.

Studies on the Preservation of Korean Ginseng by Irradiation -Part II. Effect of Gamma Irradiation on the Physicochemical Properties of Ginseng Powder during the Storage- (방사선(放射線) 조사(照射)에 의(依)한 인삼저장(人蔘貯藏)에 관(關)한 연구(硏究) -제2보(第2報). 감마선(線) 조사(照射)가 인삼분말제품(人蔘粉末製品)의 저장중(貯藏中) 이화학적(理化學的) 특성(特性)에 미치는 영향-)

  • Sung, Hyun-Soon;Park, Myung-Han;Lee, Kwang-Seung;Cho, Han-Ok
    • Applied Biological Chemistry
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    • v.25 no.2
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    • pp.105-109
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    • 1982
  • The effect the physiochemical properties of red and white ginseng powder after $^{60}Co-{\gamma}$ ray irra diationduring the storage for 4 months at $25^{\circ}C$ was investigated. The storage periods and the treatment of irradation at various doses on ginseng powders has no significant effect on the proximate composition and color density of ginseng extract with 50% ethanol. No changes in the contents of saponin and its HPLC patterns were found during the storage. However, a little increase was found in the yield of 50% ethanol extract and Hunter's color value of powder. But generally it was found to be stable in the physicochemical properties of red and white ginseng powder by irradiation of the intensity during the storage.

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Electrodeposition of AuPt Alloy Nanostructures on a Biotemplate with Hierarchically Assembled M13 Virus Film Used for Methanol Oxidation Reaction

  • Manivannan, Shanmugam;Seo, Yeji;Kim, Kyuwon
    • Journal of Electrochemical Science and Technology
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    • v.10 no.3
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    • pp.284-293
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    • 2019
  • Herein, we report an electrode surface with a hierarchical assembly of wild-type M13 virus nanofibers (M13) to nucleate the AuPt alloy nanostructures by electrodeposition. M13 was pulled on the electrode surface to produce a virus film, and then a layer of sol-gel matrix (SSG) was wrapped over the surface to protect the film, thereby a bio-template was constructed. Blending of metal binding domains of M13 and amine groups of the SSG of the bio-template were effectively nucleate and directed the growth of nanostructures (NSs) such as Au, Pt and AuPt alloy onto the modified electrode surface by electrodeposition. An electrocatalytic activity of the modified electrode toward methanol oxidation in alkaline medium was investigated and found an enhanced mass activity ($534mA/mg_{Pt}$) relative to its controlled experiments. This bio-templated growth of NSs with precise composition could expedite the intention of new alloy materials with tuneable properties and will have efficacy in green energy, catalytic, and energy storage applications.

Synthesis and characterization of polymer electrolyte membrane for fuel cell including sulfonated bis (4-fluorophenyl) phenylphosphine oxide (술폰화된 비스(4-플루오로페닐) 페닐포스핀옥사이드를 포함한 연료전지용 고분자 전해질막의 합성과 특성분석)

  • Yoo, Eun Sil;Nahm, Kee Suk;Yoo, Dong Jin
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.176-183
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    • 2016
  • This study relates to a polymer electrolyte membrane for improved performance fuel cell, were researched with respect to properties required for driving a fuel cell. The bis(4-fluorophenyl)phenyl phosphine oxide was sulfonated using fuming sulfuric acid. Synthetic hydrophilic oligomer and the hydrophobic oligomer and the block copolymers were prepared via aromatic nucleophilic substitution polycondensation. A block copolymer structure and degree of sulfonation was analyzed by $^1H$-NMR and gel permeation chromatography(GPC) analysis. Thermal stability was confirmed by thermogravimetric analysis(TGA), block copolymer was stable at high temperature(>$200^{\circ}C$), The ion conductivity was measured in order to demonstrate the performance of fuel cell. Synthesis membrane was the increase of temperature was improved conductivity up to 58 mS/cm due to the influence of the developed ion clusters. The phase separation of the polymer was observed to make AFM analysis.