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- 저자 : 이필우 ( Hee Suk Jung (검색결과 3 건)
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상수리나무 변재와 (邊材) 심재의 (心材) 열판건조에 (熱板乾燥) 관한 연구
정희석,이필우 ( Hee Suk Jung,Phil Woo Lee ) 한국산림과학회 1977 한국산림과학회지 Vol.36 No.1
Press drying was used on sapwood and heartwood of oak (Qercus acutissima Carruthers) to find profitable means of drying low grade logs. This study was designed to investigate the process of press drying considering core temperature, current moisture content, drying rate, drying time, final moisture content, dimensional change and drying defects. The drying tests were conducted using 1.5 centimeter thick material at platen temperature of 175℃ and pressure of 35psi. The results were summarized as fallows. 1. Core temperature was divided into three stages of drying characterized by initial heating period, plateau temperature, and period of rising core temperature. Plateau temperature of heartwood material was higher and longer than that of sapwood material. 2. The predicting equation for change in drying rate of sapwood material was log y=-2.7925-0.08llx as function of time. That of heartwood material was log y=-3.3382-0.0468x. 3. Sapwood material reduced the moisture content from 59 to 2.5 percent in 45minutes. Heartwood material reduced the moisture content from 64 to 3.3 percent in 55 minutes. 4. Shrinkage during press drying were 20.4 percent in thickness direction and 2.5 percent in width direction. Recovery on equilibrium conditioning at 65 percent relative humidity and temperature of 20℃. were 11.4 percent in thickness direction and 49.4 percent in width direction. 5. Heartwood material developed severe honeycombing and moderate checking. The sapwood material dried without honeycombing, checking and collapse. All material kept wood flat.
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이필우,정희석,엄영근 한국목재공학회 1987 목재공학 Vol.15 No.2
This study was executed to examine helical structure and other Features of Taxus cuspidata S. et Z. and Larix gmelinii var. principis-ruprechtii Pilger through photomicroscopic and scanning electron microscopic observation, and the obtained results were summarized as follows : 1. Tracheid transition from springwood to summerwood was abrupt and slightly gradual in Taxus cuspidata S. et Z. and summerwood width of Larix gmelznii var. principis-ruprechtii Pilger was wider than that of Taxus cuspidata S. et Z. 2. Normal vertical and horizontal resin canals and surrounding thick epithelial cells were present in Larix gmelinii var. principis-ruprechtii Pilger but not present in Taxus cuspidata S. et Z. 3. Instead of helical thickenings, helical checks were observed only in summerwood trachcids of Larix gmelinii var. principis-ruprechtii pilger. However, helical thickenings forming S, Z, and horizontal helix perpendicular to long axis of tracheid were observed in springwood and summerwood tracheids of Taxus cuspidata S. et Z, and these helical thickenings were considered as analogous to the innermost layer of secondary wall. 4. Unascriate and fusiform rays were appeared on tangential surface of Larix gmelinii var. principis-ruprechtii Pilger but only uniseriate ray was observed on tangential surface of Taxus cuspidata S. et Z. The fusiform rays of Larix gmclinii var. Principis-ruprechtii Pilger usually contained one horizontal resin canal but occasionally two observed in the tracheids of Larix gmelinii var. principis-ruprechtii Pilger but not observed in the tracheids of Taxus cuspidata S. et Z.
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이남호,이필우,정희석 한국목재공학회 1986 목재공학 Vol.14 No.2
Both the control arid heated specimen of oak, hornbean alder, poplar, red pine and pitch pine among domestic commercial species and taun imported were used for radial and tangential shrinkage and movement that occurred on changing the relative humidity of the atmosphere from 90 percent to 60 percent at 25℃. The results of this study were as follows. 1. The radial and tangential shrinkage of the. control and heated hornbean and oak wood, except alder, of high specific gravity showed greater than species with low specific gravity. The ratio of tangential to radial shrinkage was 1.46 for taun to 2.70 for alder. 2. Green volume specific gravity of the heated and soaked specimen of all species except poplar decreased 1.5 to 3.1 percent. Shrinkage of the heated specimen increased more than that of the control specimen, and antishrink efficiency of all timbers except alder had negative value. Shrinkage from green to airdry of treated specimens increased more than case of total shrinkage, and radial shrinkage of those specimen increased greater than tangential shrinkage. 3. The movement of the heating specimon for 120 hours decreased than those of the control and tire heating specimen for 240 hours. The movement of heating oak, poplar, red pine and pitch pine for 240 hours increased rather than those of the control specimen.
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