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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Wood Science and Technology
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Journal DOI :
The Korean Society of Wood Science Technology
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Volume & Issues
Volume 24, Issue 4 - Dec 1996
Volume 24, Issue 3 - Sep 1996
Volume 24, Issue 2 - Jun 1996
Volume 24, Issue 1 - Mar 1996
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Comparative Anatomy of Diffuse-Porous Woods Grown in Korea(II) -Characteristics by Habit and Phenology-
Chung, Youn-Jib ; Lee, Phil-Woo ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 1~10
The frequency distribution diagrams of Korean diffuse-porous woods, 36 families, 75 genera, 145 species, 215 specimens in relation to habit and phenology were analyzed. As the habit character changes from shrub to tree, such quantitative features as vessel frequency, percentage of solitary vessels, length/diameter(L/D) ratio of vessel element decreased but tangential vessel diameter, fiber length/vessel element length(F/V) ratio increased. Qualitative features such as helical vessel wall thickening, diffuse distribution of longitudinal parenchyma, heterogeneous ray composition decreased, while alternate intervessel pits, libriform wood fiber, simple perforations increase. As the phenology character changes from evergreen to deciduous species, such quantitative features as percentage of solitary vessels, vessel element length and L/D ratio decreased but tangential vessel diameter, F/V ratio increased. Diffuse distribution of longitudinal parenchyma, heterogeneous ray composition, and crystals in qualitative features decreased, while alternate intervessel pits, libriform wood fiber, simple perforation of vessel element, ray width and ray height increased.
Assignment of the Allowable Design Values for Domestic Softwood Structural Lumber - Structural I-grade -
Oh, Sei-Chang ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 11~16
The purpose of this paper is to present a summary of assignment design values according to domestic softwood structural lumber grading rules. Allowable stresses for visually graded lumber were determined from basic data on small. clear specimens. The data corrected for variability such as natural defects and other factors. The procedure adopted by Japan was used for assigning allowable design values. Strength ratios in relation to each defect were taken from ASTM D 245-81. Korean pine(Pinus koraiensis S. et Z.), Korean red pine(Pinus densiflora S. et Z.), Japanese larch(Larix leptolepis Gordon) and Needle fir(Abies holophylla Max) were applied to this study. The calculated allowable stresses were same in Korean pine and Korean red pine. These values were highest in Japanese larch lowest in Needle fir. So, it is desirable for these species to be classified into different catagories Species Group. However, accurate comparison in design values on lumber grading rules among U.S., Japan and Korea was somewhat difficult. And full scale testing will be necessary for accurate determination of the correction factors to setting up design values.
Physical and Mechanical Properties of Sludge-Particle Board Manufactured by Composition Types and Composition Ratios from Mixed or Layered Paper Sludge and Wood Particle
Lee, Phill-Woo ; Yoon, Hyoung-Un ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 17~26
This research was accomplished to evaluate possibility of using paper sludge for the raw materials of wood based panel products. The experimental panels were manufactured by four mixed ratios, the proportion of paper sludge to wood particle: 20:80, 30:70, 40:60, 50:50% (oven dry weight basis) and by three composition types, sludge-particle mixed board, three layered sludge-particle board and three layered particle board. They were tested mechanical (bending strength and internal bond) and physical properties (water absorption, thickness swelling and linear expansion). From the results they were shown that bending strength of mixed and three layered sludge-particle board were decreased with increasing of composition ratios of sludge. And the mechanical and physical properties of the boards of three layered composition types have superior to those of mixed composition type. Although composition ratios of sludge increased, the internal bond strength and dimensional stability of sludge-particle board not decreased quantitatively. We concluded that the mechanical and physical properties of three layered sludge-particle board were similar w those of three layered particle-board (control) made by our laboratory design. Therefore, it was recognized that paper sludge can be used as potential raw material in particle-board manufacturing industry.
Analysis of Chemical Constituents of Saccharides and Triterpenoids in the Korean Native Mistletoes - I. Triterpenoids -
Ahn, Won-Yung ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 27~33
The aim of this research was to investigate the chemical components of C30 compounds, especially triterpenoids in Korean native mistletoes of Korthalsella japonicus Engler parasiting to Camellia japonica L., Viscum album var. coloratum (Kom.) Ohmi, to Quercus acutissima Carruth. and Loran-thus yadoriko Sieb. to Neolitsea sericea (BI.) Koidz. For the identification of triterpenoidal components, alkaline hydrolyzates of mistletoes meals were analyzed by TLC, GC, and GC/MS. The content of oleanolic acid and ursolic acid derivatives were highest in K. japonica. In V. album, there was no big difference between leaves and twigs in content. but oleanolic acid in leaves. and olean-12-en-
-ol and lup-20(29)-en-3-one in twigs were prominent. Similiar to V. album in L. yadoriki there was no difference between leaves and twigs in content, and both olean-12-en-
-ol, lup-20(29)-en-3-one and urs-12-en-
-ol in leaves, lup-20(29)-en-3-one in twigs were abundant. Triterpenoids as olea-12-en-
-ol, lupe-20(29)-en-3-one, 3-oxo-urs-12-en-24-oic acid, and
-A'-neogam-macer-22(29)-en-3-ol acetate were common in all samples tested. whereas ursolic acid only in P. japonicus and ursenol in L. yadoriki were detected. And P. japonicus had the largest number of triterpenoids and showed the highest in biological activity. So it is noted that Korean mistletoes tested in the study had three types of triterpenoid, oleanane, lupane, and ursane, irrespective of hosts, sampling positions and species.
Rotary Veneer Peeling of Some Softwoods and Its Veneer Drying
Jung, Hee-Suk ; Lee, Nam-Ho ; Yeo, Hwan-Myeong ; Lee, June-Ho ; Yoo, Tae-Kyung ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 34~47
Veneers of two nominal thicknesses, 1.5 and 2.5mm, were rotary peeled from Japanese larch (Larix leptolepis). Dahurian larch (Larix gmelinei) and Radiata pine (Pinus radiata) bolts unheated and heated in the water vat temperature of
by rising a final temperature at 10cm core of
to remain core diameter of 11.4cm. 1.5 and 2.5mm thick veneer cut from the heated Japanese larch were significantly thinner than those of the unheated bolt and 2.5mm thick veneer cut from the heated Dahurian larch were significantly thicker than that of the unheated bolt. 1.5mm thick Dahurian larch veneer and 1.5 and 2.5mm thick Radiata pine veneers showed insignificant difference between the unheated and heated bolts, respectively. Check distance on the loose side of 1.5mm thick veneer cut from the heated Radiata pine was significantly wider than that of the unheated bolt. However check distances on the loose side of 1.5 and 2.5mm thick Japanese larch and Dahurian larch veneers and 2.5mm thick Radiata pine veneers showed insignificant difference between the unheated and heated bolts. Also the depth of check on the loose side of three species showed insignificantly difference between the unheated and heated bolts. Arithmatic mean deviation(
) and maximum height(
) of the profile on the loose side of dried veneer by preheating the bolt compared with unheated bolts were different among apecies and between veneer thickness. The preheating treatment slightly affected qualities of these thin veneers such as 1.5 and 2.5mm. The yield of 2.5mm thick veneer from the heated radiata pine was significantly higher than that of the unheated bolt. However the yield of 2.5mm thick veneer for other two species and 1.5mm thick veneer for three species showed insignificant difference between the unheated and heated bolts. The yield of 2.5mm thick veneer for three species were higher than those of 1.5mm thick veneer. The average yields of green veneer of Japanese larch. Dahurian larch and Radiata pine were 57.1, 55.1 and 54.0 percent, respectively. Variables such as initial MC. drying time and veneer thickness had strong effect for Japanese larch veneer, less effect for Radiata pine veneer and nuch less effect on final MC for Dahurian larch veneer in jet drying. Correlation between the current MC and the drying time of Dahurian larch with low variation of initial MC was higher than those of Japanese larch and Radiata pine veneer with high variation of initial MC in high temperature drying. Thickness shrinkages of 2.5mm thick veneer for Japanese larch and Radiata pine were higher than those of 1.5mm thick veneers, but shrinkages of Dahurian larch veneer were similar between two nominal veneer thicknesses.
Evaluation on Relations between the Oxalic Acid Producing Enzyme, Oxaloacetase from Tyromyces palustris, and Wood Decaying Activity
Son, Dong-Weon ; Lee, Dong-Heub ; Oh, Jung-Soo ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 48~53
Brown rot fungus, Tyromyces palustris, has been reported to cause the loss of strength accelerated by oxalate, a non-enzymatic low molecular weight acid, with minute weight loss of decaying wood in early stage. The production of oxalate in relation to wood decaying and the presence of oxaloacetase. an oxalate producing enzyme, were identified during the process. Tyromyces palustris produced the largest amount of oxalate among brown rot fungi. In order to find out the cleavage of pulp fiber, we submerged pulp fiber in oxalate solution and the results showed that the number of short pulp fiber was highly increased, compared with control solution. The pH of decaying wood was decreased to 1.77 which was close to that of saturated oxalate solution, pH 1.2, Thus, the oxalate was thought to be accumulated in the decaying wood, The oxaloacetase which accelerates production of oxalate was derived from fungus, and the production of oxalate by the enzyme was determined by using on UV/Vis spectrophotometer. Therefore, the oxalate was found to be produced by oxaloacetase during decay. The oxalate may cause the acid-hydrolysis of cellulose and hemicellulose. The oxalate was thought to reduce the degree of polymerization and increase the enzyme activity, which resulted in rapid loss of strength in early stage-an identical feature of brown rot fungus.
Micromorphological Structures of the Vessel Wall Sculptures in Korean Hardwoods
Lee, Won-Yong ; Lee, Sung-Jae ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 54~67
Micromorphology of the vessel wall sculptures such as perforation plate, inter-vessel pits, vessel-ray pits, vessel-parenchyma pits, vestured pits, spiral thickening, and warts was observed in 78 species(45 genera, 25 families) of Korean hardwoods using a scanning electron microscopy. The SEM observation revealed the micromorphology of vessel wall sculptures which have not yet been described, and have confirmed findings already established at the light microscopical level.
Origin of Milled Wood Lignin : An Immunocytochemical Approaches in Combination with Transmission Electron Microscopy
Kim, Yoon-Soo ; Koh, Hong-Bum ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 68~74
Present work was undertaken to investigate the origin of milled wood lignin(MWL) in the wood cell wall using immunocytochemical techniques, which can provide the information on the localization of specific antigens(MWL in the present study) to be examined. Spruce MWL dissolved in DMSO and emulsified with Freund adjuvant was injected directly into the mouse spleen. The animals were boostered at two-week intervals after the initial immunization. Blood samples were purified in standard procedures. The characteristics of antibodies against MWL were tested by indirect ELISA. Visualization of MWL was carried out using conventional indirect immunogold-labelling methods on the ultrathin sections of spruce wood. Immuno-TEM observations showed that the immunogold probes were selectively attached to secondary cell walls of spruce wood. The most intense labelling was frequently observed in the S2 layer. In contrast, gold labelling in the lignin-rich regions, such as middle lamella and cell corner was not found. The immuno-TEM provides an indication that spruce MWL originates from the S2 layer.
Experimental Examinations on the Phenomenon of Transfer and Moisture Diffusion in Wood
Lee, Weon-Hee ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 75~80
The purpose of this study is to clarify the mechanism of moisture transfer depend on the thickness of the spruce(Picea sitchensis Carr.). Therefore, as the basic research of moisture transmission, the amount of moisture transmission and the moisture distribution in specimens and temperature of it's surfaces in vapor transmission process were investigated. The experiment was conducted in a steady state. and the moisture distribution was measured by knife cutting and weighing the specimens. The following conclusions were obtained ; 1. It can be found that distribution of moisture in the specimen can be approximated by two different straight lines intersecting at nine or ten percent moisture content. The amount of moisture movement defends on the gradient of moisture in the wood. 2. It is investigated that the wood surface moisture contents(MCs) are less for thinner specimens than for thick ones on the absorption side. On the other hand, the wood surface MCs are greater for thinner specimens than for thick ones on the desorption side. The main factor that affects the EMC of wood would be temperature when the relative humidity of atmosphere is constant. The specimen generate heat with the absorption and desorption process. In addition, the velocities of moisture transmission varied with the thicknesses of specimens. If the temperature of wood becomes greater, its MC decreases. Then the difference between surface MC and EMC of adsorption and desorption side becomes greater for thinner specimens. Therefore it is considered that the coefficients of moisture transfer decreases with the increases of the specimens' thicknesses.
Reduction in Mechanical Properties of Radiata Pine Wood Associated with Incipient Brown-Rot Decay
Kim, Gyu-Hyeok ; Jee, Woo-Kuen ; Ra, Jong-Bum ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 81~86
This study was performed to evaluate the reduction in bending properties of radiata pine sapwood associated with incipient brown-rot decay. Decayed bending specimens by Tyromyces palustris and Gloeophyllum trabeum for varoious periods were tested destructively. Brown-rot decay by T. palustris and G. trabeum caused serious reduction in bending properties at very early stages of decay, with about 30 percent decrease in bending strength observed for only 1~2 percent weight loss. In general, the reduction in bending properties caused by T. palustris was somewhat greater than that by G. trabeum. Work to maximum load was reduced most severely and rapidly from the onset of decay, while modulus of elasticity showed a much more moderate rate of reduction. Modulus of rupture was affected by decay to a greater extent than was modulus of elasticity. Since a relatively strong correlation between weight loss and bending strength was observed, the residual strength of decayed wood can be predicted by weight loss due to decay. The results of this study indicate that very early stages of brown-rot decay reduce the bending strength significantly. Thus, it is recommended that all load-bearing members in wooden structures, especially those that are periodically wetted, should be inspected regularly to prevent a sudden failure even though there are no definite signs of decay.
Analysis of Chemical Constituents of Saccharides and Triterpenoids in the Korean Native Mistletoes - II. Screening the Extractives of Korean Camellia Mistletoe (Pseudixus japonicus) for Cytotoxicity -
Kim, Pyoung-Su ; Ahn, Won-Yung ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 87~94
The Bending and Compression Strength Properties in Rhus verniciflua(I)
Byeon, Hee-Seop ; Shimada, Masahiro ; Fushitani, Masami ;
Journal of the Korean Wood Science and Technology, volume 24, issue 1, 1996, Pages 95~99
The bending and compression strength properties of two types Rhus verniciflua specimens, which made of no heat-treated wood and heat-treated wood for urushiol extraction, were measured. The heat-treated specimens were finger-jointed with either resorcinol-phenol or polyurethane resin adhesives, and the vertical type bending strength property was also measured in these specimens. The results obtained are as follows ; 1. The correlation coefficient between the compression strength and specific gravity in the specimens of no heat-treated and heat-treated wood was high. However there was no difference in compression strength property as affected by heat treatment. 2 The correlation coefficient between the bending strength and specific gravity in the specimens of no heat-treated and heat-treated wood was also high. However, there was no difference in bending strength property as affected by heat treatment. 3 The bending test showed high correlation between modulus of elasticity and modulus of rupture for the specimens made of no heat-treated and heat-treated wood. However, there was no difference in bending strength property between the specimens made of heat-treated and no heat-treated wood. 4. The efficiencies of bending strength test on the finger-jointed specimens of heat-treated wood with resorcinol-phenol and polyurethane resin adhesives were 0.85, 0.81. respectively.