• Title/Summary/Keyword: High temperature drying (HD)

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Effect of Reserve Air-Drying of Korean Pine Heavy Timbers on High-temperature and Low-humidity Drying Characteristics (예비천연건조가 잣나무 중목구조부재의 고온저습건조 특성에 미치는 영향)

  • Lee, Chang-Jin;Lee, Nam-Ho;Park, Moon-Jae;Park, Joo-Saeng;Eom, Chang-Deuk
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.1
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    • pp.49-57
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    • 2014
  • The pre-air-drying of Korean pine before the high-temperature and low-humidity drying was shown to be effective in uniform moisture content distribution and prevention of surface check. Our results suggest that initial moisture content of the timber also plays important role in high-temperature and low-humidity drying method. The pre-air-drying also helps in the reduction of surface checks in Korean pine when compared to the Korean pine dried by only high-temperature and low-humidity. End-coating was not effective in the prevention of twist, shrinkage, case hardening and internal checks. The pre-air-drying reduces the internal tension stresses which occur during high-temperature and low-humidity drying thus decreasing case hardening and also preventing internal checks. The pre-air-drying decreases the moisture content and causes shrinkage which leads to increased twist in the Korean pine.

Physiology Activity of Barley Leaf Using Different Drying Methods (건조방법을 달리한 보리 잎의 생리활성)

  • Park, Soo-Jin;Lee, Jea-Soon;Hoe, Young-Hoi;Moon, Eun-Young;Kang, Myung-Hwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.12
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    • pp.1627-1631
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    • 2008
  • This study was to analyze the physiology activity of barley leaf extract using different drying methods. Yield of RL (raw leaf) and barley leaves dried did not show significant difference by various drying methods. There was no significant difference in total phenolic content by dry method. However, total flavonoid content was high in HD (dried after heat treatments) barley leaf after RL. There was no significance in barley leaf dried by SD (dried in the shade), FD (vacuum freeze dried) and MW (dried by microwave) after the microwave. Superoxide dismutase-like activity was high over 90%: $95.6{\pm}0.3%$ in RL, $94.9{\pm}0.7%$ in HD barley leaf, $92.0{\pm}1.3%$ in SD barley leaf, $91.5{\pm}0.4%$ in FD barley leaf, and $92.5{\pm}0.2%$ in MW barley leaf using the microwave. Significantly higher antioxidant activity was shown as compared to the control group of sesamol ($88.426{\pm}0.802%$), tocopherol ($88.8{\pm}0.6%$), and BHT ($86.6{\pm}0.8%$). Also, except for RL and MW barley leaf, all showed over 80% peroxyl radical scavenging activity and over 90% inhibition rate of xanthine oxidase. The results of this study show that total phenolic content and total flavonoid content by dry method were dependent on the drying temperature with no impact on antioxidant activity.

Effect of End-coating Around Pith of Heavy Timbers of Red Pine and Korean Pine on High-temperature and Low-humidity Drying Characteristics (중심부분 엔드코팅처리가 국산 소나무와 잣나무 중목구조부재의 고온저습건조 특성에 미치는 영향)

  • Lee, Chang-Jin;Lee, Nam-Ho;Eom, Chang-Deuk;Shin, Ik-Hyun;Park, Moon-Jae;Park, Joo-Saeng
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.3
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    • pp.221-233
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    • 2013
  • This study was performed to identify the effect of end-coating around pith of heavy timbers of Red pine and Korean pine on high temperature and low humidity drying characteristics. Total drying times were 268 hours, and ranges of final moisture content was investigated that Red Pine 9.2% to 10.8% MC for square and round timber, in case of Korean Pine 15.0% to 22.0% MC for square timber, 12.8% to 20.4% MC for round timber. Moisture content distribution of Red Pine was a uniform, but part of high moisture content was found in Korean Pine. In case of Korean pine, the surface checks were occurred more severe than in case of Red pine, and end-coating treatment were investigated to be ineffective on surface check. The internal checks were only formed on the two timbers. The value of the case hardenings was investigated that the ranges 3.7% to 9.1% for Red pine. In case of Korean pine, on the other hand, the case hardenings presence a few as 20.9% to 35.8%.