• Title/Summary/Keyword: 동결특성

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Effects of Sucrose Immersion on the Rehydration Characteristics of Freeze Dried Mooks (전처리가 동결건조묵의 재수화 특성에 미치는 영향)

  • Youn, Kwang-Sup;Hwang, Jung-Shub
    • Korean Journal of Food Science and Technology
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    • v.33 no.4
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    • pp.395-400
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    • 2001
  • The objectives of this study are to establish efficient pretreatment concentration and rehydration process for the production of the high quality of freeze-dried Mook, a traditional gel food in Korea, as an instant food. Effect of immersion in sucrose solution as pretreatment before freeze-drying on the rehydration efficiency and quality characteristics was studied. The rehydration efficiency of non-treated Mook was the highest. The rehydration efficiency increased as the concentration of sucrose increased. The texture of rehydrated Mook treated in sucrose solution was decreased with increase in rehydration temperature. The Mook treated at 60% sucrose solution was somewhat similar to the market selling Mook in the quality and the treatment prevented color and texture degradation.

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Durability Characteristics of Limestone Powder added Concrete for Environment-Friendly Concrete (석회석미분말을 첨가한 친환경 시멘트콘크리트의 내구 특성)

  • Choi, Woo Hyeon;Park, Cheol Woo;Jung, Won Kyung;Jeon, Beom Joon;Kim, Gyu Seon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.5
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    • pp.59-67
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    • 2012
  • During the manufacturing of Portland cement, CO2 gas is also necessarily produced through both decarbonation of calcium carbonate and kiln burning. By partially replacing the Portland cement with limestone powder, which is an inert filler in a concrete mixture, CO2 consumption can be reduced in a construction field. This study is to investigate the fundamental durability characteristics of limestone powder added concrete. Experimental variable was the replacement ratio of limestone powder from 0% to 25% with 5% increment. Durability characteristics were investigated by resistance to freeze-thaw, alkali-silica reaction and de-icing chemical in addition to the properties of fresh concrete. From test results, it was observed that the addition of limestone powder did not significantly affect the resistance to freeze-thaw reaction and de-icing chemical. The addition of limestone powder reduced the occurrence potential of alkali-silica reaction by reducing an alkali content in Portland cement.

Absorption Characteristics of Persimmon Powder Depending on Temperature Changes and Drying Methods (건조방법과 온도변화에 따른 감 분말의 흡습특성)

  • 이원영;김종국
    • Journal of the East Asian Society of Dietary Life
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    • v.11 no.6
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    • pp.479-484
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    • 2001
  • The absorption characteristics of persimmon powder related to different drying methods and various storage temperatures was investigated. The physical properties of persimmon powder by different drying methods displayed the largest amount of porosity in the freeze-dried sample, and the smallest in hot air dried sample. Equilibrium moisture was reached in 6 days. Monolayer moisture contents were predicted to 0.09687~0.19712(freeze drying), 0.07820~0.18617(vacuum drying) and 0.07715~0.18056(hot air drying) g H2O/g solid respectively using the BET equation. BET equation for isothermal absorption curve showed over 0.95 R-square for all dried methods. Monolayer moisture contents were increased as storage temperature was incremented because water molecular movement was more active and there was a greater chance to clash with the absorption surface area.

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Review of the Study on Mechanical Properties of Rock Under the Polar Climate Condition (극지 암석의 역학적 특성 분석에 관한 연구 동향)

  • Ryu, Sung-Hoon;Song, Jae-Joon
    • Tunnel and Underground Space
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    • v.20 no.4
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    • pp.241-251
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    • 2010
  • The polar region is in the limelight for an academic worth as well as plenty of natural resources. The study on the polar region was reviewed for better understanding of the polar region and its rock properties. The antarctica has a windy and dry climate along with the lowest temperature on the earth. The thermal distribution according to depth in the area was reported: The freezing-thawing process was repeated in shallow depth, and the temperature falls down below zero under the specific depth. There is a great temperature difference between the atmosphere and rock. A research reported for the degree of weathering of the antarctic slope by using Schmidt hammer and Taffoni test. The rock specimens weathered by repeated freezing-thawing process were tested of the shore hardness and uniaxial compressive strength: The rock strength gradually decreased as the freezing-thawing process was repeated. The comprehensive mechanical properties of the polar region rocks and the relationship between the laboratory weathering test result and the real rock property change in the site remain as future research topics.