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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 32, Issue 6 - 00 2004
Volume 32, Issue 5 - 00 2004
Volume 32, Issue 4 - 00 2004
Volume 32, Issue 3 - 00 2004
Volume 32, Issue 2 - 00 2004
Volume 32, Issue 1 - 00 2004
Selecting the target year
Effect of Impregnation Ratio and Carbonizing Temperature on Surface Temperature of Woodceramics Made from Thinned Logs of Pinus densiflora S. et. Z.
Oh, Seung-Won ; Byeon, Hee-Seop ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 1~7
The change in surface temperature of woodceramics, made from thinned logs of Pinus densiflora, were investigated, by the impregnation ratio and carbonizing temperature. As the surface temperature of silicon rubber heater was going up, that of woodceramics also increase rapidly. In case of heaters surface temperature at 70
, the surface temperature of woodceramics was 53.9
when a sample was the impregnation ratio of 80%, while it was 54.2
when a sample was at 1,000
in carbonizing temperature, showing the highest. Also, it was found that woodceramics maintained heat for a long time because the descending velocity of their surface temperature was lower than that of the heater.
Studies on Biological Activity of Woad Extractives (XV) - Antimicrobial and antioxidative activities of extracts from diverse families-
Lee, Sung-Suk ; Lee, Hak-Ju ; Choi, Don-Ha ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 8~17
Antifungal, antibacterial, and antioxidative activities of ethanol extracts from 65 families 263 species were investigated to select tree species for the utilization of natural fungicide or preservative resources. The antifungal activities of extracts from wood, leaf and bark were measured as hyphal growth inhibition rate using four plant pathogenic and five wood rotting fungi. High inhibitory effect on the fungi growth was found in five species of Pinaceae (Pinus koraiensis; P. rigida, P. densiflora, P. banksiana. Cedrus deodara), three species of Cupressaceae (juniperus rigida, J. cbinensis, Cbamaecyparis obtusa) and three species of Leguminosae (Albizzia julibrisssin, Sophora japonica, Maackia amurensis), respectively. Antibacterial activities of ethanol extracts were determined by means of disc-agar plate diffusion method using three gram-positive and five gram-negative bacteria. The ethanol extracts, which showed prominent effect on the suppression of bacteria growth, were six species of Betulaceae (Carpinus tscbonoshii; C. coreana; C. laxiflora, Alnus birsuta; A. firma, Betula scbmidtii), five species of Fagaceae (Castanopsis cuspidata var. sieboldii; Quercus serrata, Q. mongolica, Q aliena, C crenata), four species of Euphorbiaceae (Aleurites fordii, Sapium sebiferum, S japonicum Mallotus japonicus) and three species of Elaeagnaceae (Elaeagnus umbellata, Elaeagnus glanbra, Elaeagnus macropbylla). According to these results, the extracts from Zelkova serrata, Pinus densiflora, Maackia amurensis, Cbamaecyparis obtusa and Juniperus cbinensis could be available for natural fungicide or food preservatives, because ethanol extracts from these species indicated excellent antifungal and antibacterial activities. In order to test antioxidative activities of ethanol extracts, free radical scavenging method was adopted with 1,1-diphenyl-2-picrylhydrohydrazyl (DPPH). Free radical scavenging activity was proved very high in the extracts of eight species of Rosaceae (Eriobotrya japonica, Prunus takesimensis, P yedoensis, P padus, P armeniaca var. ansu, Cbaenomeles sinensis, Stepbanandra incisa, Rosa multiflora) and five species of Ericaceae (Rhododendron mucronulatum; R. scblippenbacbii, R. yedoense var. poukbanense, Yaccinium bracteatum, V oldbami), resvectively. It turned out from this study that only six species among 48 species of Rosaceae showed less than 80% free radical scavenging activity. As a consequences, it could be deduced that the components effective on antioxidative activity commonly exist in Rosaceae plant family.
Vacuum Drying Characteristics Using Different Heating Methods for Douglas-fir Timber
Jung, Hee-Suk ; Eom, Chang-Deuk ; So, Bum-Joon ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 18~26
Timbers of 14 by 14 cm, 2.4 m long, were dried in a vacuum kiln to investigate vacuum drying characteristics using three types of heating methods, conduction heating with hot plate, the radio frequency (RF) heating and the combination of both (hybrid heating). Average drying rate is the highest for the hybrid heating and the lowest for the RF heating. Average specific energy is the highest for the RF heating and the lowest for conduction heating. Transverse moisture content distribution of dried timber revealed the convex profile for both conduction and the hybrid heating and moisture content increased from one face to the opposite face for the RF heating. Moisture content distribution along the length of timber increased from the end to the middle of timber length for conduction and the hybrid heating and decreased from the end to the middle of timber length for the RF heating. End- and surface checks for conduction heating were severer than the other heating methods. No internal check occurred in any heating methods. Drying characteristics of conduction heating showed in-between trend of the RF and the hybrid heating.
Biodegradation of 4-t-Octylphenol by Basidioradulum molare and Scbizopora paradoxa and Estrogenecity Reduction of its Metabolites
Lee, Soo-Min ; Ku, Bon-Wook ; Lee, Jae-Won ; Choi, Don-Ha ; Jeung, Eui-Bae ; Choi, In-Gyu ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 27~35
Recalcitrant 4-t-Octylphenol used as a surfactant was subjected to the biodegradation with wood rot fungi, Basidioradulum molare and Schizopora paradoxa. Two fungi were grown in the culture medium containing various concentrations of 4-t-Octylphenol in order to investigate their resistance against 4-t-octylphenol Schizopora paradoxa was reached to the full growth within 14 incubation days in the concentration of more than 200 ppm of 4-t-Octylphenol, while Basidioradulum molare showed the inhibitory mycelium growth as the concentration was increased Schizopora paradoxa and Basidioradulum molare biodegraded 95% and 36% of initial concentration of 4-t-Octylphenol at first incubation day, respectively. However, the biodegradation capability reached to more than 95% after 3 incubation days. During the biodegradation of 4-t-Octylphenol, the activity of manganese dependent peroxidase was induced by the addition of 4-t-Octylphenol in the culture medium of Schizopora paradoxa, but that of laccase was maximal before the addition. The reduction of estrogenecity was assayed by MCF-7 cell proliferation test and measurement of pS2 mRNA expression. The level of pS2 mRNA was decreased down to the level of baseline at first incubation day. Also, estrogenecity of 4--t-Ocrylphenol completely disappeared after treatment with supernatant by Scbizopora paradoxa and Basidioradulum molare from first incubation day of culture down to the levels of vehicle.
Flexural Analysis of Radiata Pine Plywood Plate for the Concrete Form by the Laminate Plate Theory
Nam, Jeong-Hun ; Son, Kyong-Wook ; Yoon, Soon-Jong ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 36~45
The plywood for concrete form is regarded as a laminate plate composed of orthotropic materials and the flexural analysis is conducted by applying the laminate plate theory, in which the four edges of the plate is assumed to be simply supported and the concentric point lateral load is applied. The results of flexural experiment are compared with the theoretical ones. Theoretically predicted results coincide with experimental ones up to the point of deflection less than 1/4 of plate thickness. In addition, when the plywood is regarded as an isotropic plate for simple analysis, the geometric average of the elastic modulus measured in the direction parallel to the face grain (
)and perpendicular to the face grain (
)could be used for the elastic modulus of isotropic plate.
High Temperature Drying of Pitch Pine Lumber
Yeo, Hwan-Myeong ; Shim, Sang-Ro ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 46~51
The objective of this study was to evaluate the applicability of high temperature drying to pitch pine (Pinus rigida) lumber, especially intended for use as lamina of structural glued laminated timber (glulam), to enhance the efficient utilization and provide added-value to that species. The high temperature schedule and drying procedures utilized were shown to be reasonable for drying glulam lamina due to the occurrence of small moisture gradients, minimal residual drying stress, and low warpage. Through preliminary tests, it was confirmed that residual resin at lamina surfaces did not adversely affect the gluing process. However, quantitative analysis of resin is required for developing a method to constrain the occurrence of pitch trouble with respect to decreasing long-term adhesive and finish durability of glulam in use after manufacturing. The final moisture content of high temperature dried lamina was much lower than target moisture content and discoloration was more severe than anticipated. In a further study, it will be necessary to determine the optimal drying conditions, such as temperature, humidity, drying time, and top load restraint level, which could best control discoloration, warpage, and moisture content of the lamina, while minimizing fuel expense.
Chemical Constituents of Stationary Cultured Mycelia of Inonotus obliquus
Shin, Yu-Soo ; Terazawa, Minoru ; Cho, Nam-Seok ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 52~57
Seven compounds were isolated from stationary cultured mycelia of Inonotus obliquus, of which several of them showed certain antitumor activities. Seven compounds were identified as lanosterol(l), inotodiol(2), trametenolic acid(3), 3
-hydroxylanosta-8,24-dien-21-al(B) and methyl trametenolate(C), respectively. The precursor compound of sclerotium obtained from shaking-cultured and stationary-cultured mycelia of Inonotus obliquus is lanosterol. Ergosterol and ergosterol peroxide were obtained by shaking-culture, and the substituted compounds of C-21 and C-22 of lanosterol were obtained by stationary culture.
Protease Activity from Fruit Body of Sarcodon aspratus
Cho, Nam-Seok ; Cho, Hee-Yeon ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 58~65
This study was performed to investigate the protease activity from fruit body of Sarcodon aspratus and its features. The specific protease activity was increased with the increasing purification steps, 2.62 times by desalting, 17 times by CMC column chromatography, 113.8 times by DEAE-Sephadex A-50 column chromatography, and 728.3 times by Sephadex G-75 column chromatography. Proteases were identified as two different enzymes having different isoelectric points at pH 4.35 (its recovery rate 8%) and pH 4.7 (its recovery rate 35%), Those proteases were purified by 3,025 folds and 3,257 folds in terms of specific activity. Two proteases having different isoelectric points had similar enzymatic properties. This protease was estimated to be 43,000 daltons of molecular weights by SDS-PAGE. This protease with optimum pH 4 was almost stable in the pH range of 4-7. Optimal temperature of protease activity was 40 to 50
, and the protease activity was completely inhibited at 70
for 30 min.
Effect of Distance between Finger Tip and Root Width on Compressive Strength Performance of Finger-Jointed Timber
Ryu, Hyun-Soo ; Ahn, Sang-Yeol ; Park, Han-Min ; Byeon, Hee-Seop ; Kim, Jong-Man ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 66~73
Three species of Italian poplar (Populus euramericana), red pine (Pin us densiflora) and oriental oak (Quercus variabilis) were selected for this study. They were cut so that the distances between each of tips and roots for a pair of fingers were 0, 0.15, 030 and 0.45 mm. Poly vinyl acetate (PVAc) and resorcinol-phenol resin (RPR) were used for finger-jointing. Compressive test parallel to the grain was conducted for the finger-jointed specimens. The results were as follows: The efficiency of compressive Young's modulus of finger-jointed timber to solid wood indicated low values, whereas the efficiency of compressive strength indicated high values of more than 90% in all species, especially, it was found that those of red pine indicated markedly high values of more than 97%. The efficiency of compressive displacement of Italian poplar finger-jointed timber was 2 times higher than solid wood, and it was 1.2 and 1.3 times higher than solid woods in red pine and oriental oak, respectively. Also, it was found that 0, the distance between each tip and root for the fingers, indicated the highest efficiency of compressive strength performance in Italian poplar finger-jointed timber, and for red pine and oriental oak finger-jointed timbers, the distances of 0.15 and 0.30 were found to indicate the highest efficiency.
Wood decay Detection by Non-destructive Methods
Son, Dong-Won ; Lee, Dong-Heub ;
Journal of the Korean Wood Science and Technology, volume 32, issue 4, 2004, Pages 74~81
The ultrasonic non-destructive method was used for wood decay test. The temperature change and moisture contents of wood were estimated how the ultrasonic wave velocity changes. The relationship between weight loss of wood decayed by T palustris and ultrasonic wave velocity was investigated. The non-destructive methods of different condition of logwood were estimated. Decay map of old wood was made by non destructive methods. Through these tests, we can accumulate the data to judge the degree of wood decay. The decay map of wood could be used for the analysis of old wood.