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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Wood Science and Technology
Journal Basic Information
Journal DOI :
The Korean Society of Wood Science Technology
Editor in Chief :
Volume & Issues
Volume 29, Issue 4 - Dec 2001
Volume 29, Issue 3 - Sep 2001
Volume 29, Issue 2 - Jun 2001
Volume 29, Issue 1 - Mar 2001
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Properties of Woodceramics Made from Thinned Logs of Cryptomeria japonica D. DON - Effect of steam injection and its time -
Oh, Seung-Won ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 69~75
This study was carried out to investigate the properties of woodceramics made from thinned logs of Cryptomeria japonica. In order to find the effect of steam injection time on the woodceramics fabricated with boards, boards were made with the non-steamed treatment and steamed treatment 1, 5, 10 min. at
. The percentage of weight loss was proportional to the increased density of board The reducing rate of length and thickness, however, decreased with increasing density of board. The rate of weight loss, length and thickness reduction in non-steamed board were slightly higher than those of steamed board. When the resin impregnation rate increased, the bending strength and compressive strength of woodceramics had a tendency to increase. The bending strength and compressive strength of woodceramics in non-steamed board was higher than those of steamed board. But there was little difference between dimensional and strength properties of woodceramics and steam injection time of board.
Mechanical Behaviour of Earlywood and Latewood under Longitudinal Compression Load
Kang, Chun-Won ; Juichi, Tsutsumi ; Jang, Sang-Sik ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 76~83
This study was carried out to clarify the mechanical behaviour of the earlywood and the latewood to the compressive load applied parallel to the grain. The results from the analysis of Japanese cedar wood (Cryptomeria japonica) were used to introduce a concept on stress-strain behaviour of the earlywood and the latewood. There was a significant differences in the mechanical behaviour of the earlyWood and the latewood. In the earlywood, the rate of cell wall upon annual ring was almost similar and the strain increased linearly with the stress increased. However, the rate of cell wall upon annual ring varied in the latewood and the strain of that increased curve-linearly with the stress increased. The longitudinal compression modulus of elasticity (MOE) variation by loading speed on latewood specimens and earlywood specimens shows no significant difference. The modulus of rupture (MOR) and MOE of latewood were about 4 times higher than those of earlywood.
A Morphological Comparison of Bamboo Zephyr Produced from Phyllostachys nigra var. henonis and Indonesian Gigantochloa apus
Kim, Yu-Jung ; Jung, Ki-Ho ; Park, Sang-Jin ; Roh, Jeang-Kwan ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 84~90
To investigate morphological characteristics of zephyr produced from two bamboo species, Phyllostachys nigra var. henonis and Gigantochloa apus, basic anatomic properties were examined by scanning electron microscopy and image analysis. According to SEM observation, zephyr from Phyllostachys nigra var. henonis was not of uniform in shape and showed macro crack between vascular bundle sheaths. This may be attributes to the sclerenchymatous fibers connected closely, thus resulting in difficult separation of intercellular layer. Zephyr from Gigantochloa apus was of uniform in shape, which may be caused by easy separation of intercellular layer of sclerenchymatous fibers having thin cell wall and large cell lumen. By image analysis in cross section of two species, the ratio of vascular bundle sheaths and cell wall ratio of sclerenchymatous fibers were examined. The ratio of vascular bundle sheaths in Phyllostachys nigra var. henonis was lower than that in Gigantochloa apus. However, cell wall ratio of sclerenchymatous fibers in Phyllostachys nigra var. henonis was higher than that in Gigantochloa apus.
Classification of Wood Surface Defects using Image Processing Technique
Lee, Hyoung-Woo ; Kim, Byung-Nam ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 91~99
In this study the possibility of classifying wood surface defects by image processing technique was investigated. An algorithm for the classification of wood surface defects, such as knot, check, and bark, on three Korean domestic species, Pinus densiflora, Quercus acutissima, and Carpinus laxiflora was also developed. Filtering was executed to separate dummies from the labels including real defect. Error rates in classifying knots on Pinus densiflora and Quercus acutissima were lower than 1% and error rates. In classifying check and bark in Quercus acutissima and Carpinus laxiflora could be lowered to below 13%.
Development of Databases for Domestic Species and Estimation of Part Yields through Rip-First Cutting Simulation
Lee, Hyoung-Woo ; Kim, Kwang-Nam ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 100~108
An understanding of potential lumber cutting yields may lead to increased utilization of the lower grades of lumber in wood industry. Computer simulations of rough-mill operations require a lumber database as input to give reasonable estimates of such yields. The lumber database must contain detailed information regarding the location and type of defects, and then all manufacturing sequences can be tested with the same raw material. However, no suitable lumber database with mapped defects exists for Korean wood industry. In this study lumber databases of Pinus densiflora S. et Z and Quercus acutissima which are the main Korean domestic species were developed to prepare for coming era of "utilization of domestic species" in the near future. These databases were put into lumber cut-up simulation model(gang-rip-first simulator) to investigate the part yields. Gang-rip first simulation showed average part yields of 44.75% and 63.10% for Quercus acutissima and Pinus densiflora lumber database developed, respectively. In most cases process set-up of fixed blade best feed showed the best part yields and the level of acceptable defects could not make significant differences in part yields.
Studies on Manufacture of Hanji(Korean Paper) Sludge·Wood Particle Composite - I. Physical Properties of Hanji(Korean Paper)Sludge·Wood Particle Composite
Lee, Phil-Woo ; Lee, Hak-Lae ; Son, Jung-Il ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 109~117
This research was carried out to develop the Hanji(Korean paper) sludge wood particle composite utilizing the waste sludges occurring from the making process of Hanji(Korean paper). In the research, four mixing ratios of white or black sludge to wood particle(10:90, 20:80, 30:70, and 40:60), three types of the resin adhesives(PMDI, urea and phenol resin) and three levels of the densities(0.60, 0.75 and 0.90) were designed to investigate the physical properties of Hanji(Korean paper) sludge wood particle composite. The linear expansion of Hanji(Korean paper) sludge wood particle composite was not always increased, compared to control boards. For thickness swelling, PMDI-bonded composites had the lowest value, and thickness swelling of composite was generally decreased with the increase of Hanji sludge. The water absorption of white sludge wood particle composite had no tendency, hut that of black sludge wood particle composite was decreased with an increase of mixing ratio of Hanji sludge.
Effect of Grain Angle on Bending Properties of Pinus densiflora
Kim, Jung-Hwan ; Lee, Weon-Hee ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 118~125
In this study, it was examined the characteristics of bending property of red pine(Pinus densiflora S, et Z.) related to slope of grain. At first, we have investigated the characteristics of wood species for bending property. At second, it was examined the relationships between grain angle and its related bending property. Specimens were made following to grain angle
, respectively. Dimension of wood materials was
. Microwave irradiation time for bending process was 30, 60, 90, 120 seconds. The result of this study were as follows ; 1. Grain angle of wood was closely related to Young's modulus on bending process. In the process of bending with various grain angle, wood bending was easily proceed on the high grain angle range. 2. However, the strength of bent wood was very weak when the grain angle was high. Therefore, it was considered suitable grain angle for bending was existed. 3. The characteristics of wood properties for wood bending were very different among wood species.
Formation and Preservative Effectiveness of Inorganic Substances in Wood Treated with Potassium Carbonate and Calcium Chloride
Yoon, Sun-Mi ; Lee, Jong-Shin ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 126~132
This research is carried out to investigate the formation and preservative effectiveness of inorganic substance, calcium carbonate(
), in wood. The specimens were prepared by the impregnation with saturated solutions of potassium carbonate(
) into the wood followed by precipitation in saturated solutions of calcium chloride(
) for 24h, 72h and 120h, and then they were leached in instrument flowing with water for 24h. The weight percent gains of
solution impregnated specimens reached approximately a maximum value (108.1%) by 72h precipitation in
solutions. Inorganic substances were observed to he produced in the lumina of tracheids of specimens. From these inorganic substances filling in the tracheids, characteristic X-rays of calcium(Ca-
) were detected by energy dispersive X-ray analyzer. Moreover, it was shown from a leaching treatment that these substances could not he leached easily from the specimens. Therefore, they were could he considered to be insoluble calcium carbonates. The weight losses of the prepared specimens were hardly occurred by test fungi attacks. Thus inorganic substances in specimens can be said to have preservative effectiveness.
Studies on Biological Activity of Wood Extractives(VI) - Flavonoids in heartwood of Prunus sargentii -
Lee, Hak-Ju ; Lee, Sung-Suk ; Choi, Don-Ha ; Kato, Atsushi ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 133~139
The structures of six flavonoids isolated from heartwood of Prunus sargentii(Rosaceae) were analyzed by Mass and NMR spectrometry. These flavonoids were grouped into dihydroflavonol, flavanone, and flavanone glycoside, and identified as follows : 3,3',4',5,7-pentahydroxyflavanone(taxifolin) as a dihydroflavonol, 5-hydroxy-7-methoxyflavanone(pinostrobin), 4',5,7-trihydroxyflavanone(naringenin), 3',4',5,7-tetrahydroxyflavanone(eriodictyol), 5,7-dihydroxyflavanone(pinoccmbrin) as a flavanone and 7-hydroxyflavanone 5-O-
-D-glucopyranoside(verecundin) as a flavanone glycoside.
Studies on Biological Activity of Wood Extractives(VII) - Antimicrobial and Antioxidation Activities of Extractives from the Heartwood of Prunus sargentii -
Lee, Sung-Suk ; Lee, Hak-Ju ; Choi, Don-Ha ;
Journal of the Korean Wood Science and Technology, volume 29, issue 2, 2001, Pages 140~145
Antimicrobial and antioxidative activities on heartwood extractives of domestic species were investigated to develop a natural fungicide or preservative. Six flavanones including pinostrobin, eriodictyol, naringenin, pinocembrin, taxifolin and verecundin were isolated from Prunus sargentii which has been selected due to its high antimicrobial and antioxidative activities among the tested species. According to the results of antifungal test, pinocembrin was evaluated as the highest antifungal compound among the test compounds, which showed 80% of hyphal growth inhibition rate. Antifungal activity of pinocembrin was similar to hinokitiol(
-thujaplicin), strong antimicrobial compound isolated from Thujopsis dolabrata. Naringenin followed pinocembrin in its antifungal activity. However, verecundin did not show any antifungal activity. No compound was effective in antibacterial activities. As a result of the measurement of free radical scavenging activity, antioxidative activities of taxifolin and eriodictyol were 2 times that of
-tocopherol, and antioxidative index of these compounds were even superior to that of
-tocopherol. In this regard, it could inferred that high antifungal and antioxidative activities of extractives of P. sargentii were derived from pinocembrin, taxifolin and eriodictyol, respectively.