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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Wood Science and Technology
Journal Basic Information
Journal DOI :
The Korean Society of Wood Science Technology
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Volume & Issues
Volume 28, Issue 4 - Dec 2000
Volume 28, Issue 3 - Sep 2000
Volume 28, Issue 2 - Jun 2000
Volume 28, Issue 1 - Mar 2000
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Study on the Crystals in the Populus spp.(I) - Crystals in the Woods and Barks of Populus maximowiczii and Populuss nigra × maximowiczii
Lee, Kee-Young ; Kim, Jae-Kyung ; Kim, Nam-Hun ; Park, Wan-Geun ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 1~17
Crystals in the woods and barks of Populus maximowiczii and Populus nigra
maximowiczii were examined by light microscopy, scanning electron microscopy and soft X-ray. Populus examined had the wetwood and the heartwood of Populus showed higher moisture content than in adjacent sapwood. The crystals can be detected clearly by the soft X-ray due to their higher densities than the wood. Crystals in xylem wood of Populus were found mainly at heartwood. However, they were concentrated in specific areas such as in color-stained area or along the specific annual rings. Crystals showed the highest occurrence around the pith. Within a growth ring the amount of crystals in earlywood was more abundant than in latewood. Crystals were observed mainly at vessels and fibers although they occurred at all kinds of cells in heartwood. Crystals in the bark were scattered evenly both in inner bark and in outer bark. Populus nigra
maximowiczii showed higher frequency of leaf knots than Populus maximowiczii.
Effects of Finger Joint and Strength of Lamination on the Estimation of Strength Properties of Glulam
Kim, Gwang-Chul ; Lee, Jun-Jae ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 8~17
Structural glued laminated timbers were manufactured from Japanese larch(Larix leptolepis) lumber. The effect of various factors, such as finger joint, strength of lamination, on the strength properties of glulam was investigated. When only MOE of lamina was used as input variable for the estimation of strength properties of glulam, the deviations between actual and simulated results were increased with the number of lamination, because the effects of variance of lamina properties on the strength estimation of glulam were cumulated with the number of lamination. Therefore, to estimate the MOR of glulam more careful approach was needed. Besides, both MOE and MOR of lamination were used as input variable to compare the effect of input variable. In the case of finger jointed lamination was located in tension zone, MOE of glulam was some effected, because of the variation of MOE of lamination and the deficiency of information for knot. In the case of finger jointed lamination wasn't located in tension zone, more exact estimation was possible than the case of finger jointed lamination was located in tension zone. From the results, it was concluded that more exact estimation of strength properties of glulam could be obtained by considering effects of both finger joint and knot.
Warpinging and Budding Prediction Model of Wooden Hollow Core Flush Door due to Moisture Content Change (II) : Simple Method of LMC and MOE, and Monte Carlo Simulation for Calculating Reject
Kang, Wook ; Jung, Hee-Suk ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 18~27
Even the same materials are assembled in flush door skin panel, warping is not simply prevented under the changes of environmental conditions since wood and wood-based material have large variations in their physical and mechanical properties. The parameters such as linear movement coefficient(LMC), modulus of elasticity (MOE), required to predict warping could be estimated by oven drying method and dynamic method instead of American Society for Testing Materials(ASTM) procedure. The relationship between warping and LMC was curvilinear, while it between warping and MOE was linear. LMC had a larger effect on warping than MOE. Material propensity of skin panel such as hardboard and plywood showed normal distributions. The variation of material properties, however, was much larger in plywood than in hardboard. Monte Carlo simulation also indicated that rejection ratio of flush door due to the occurrence of warping could be predicted with consideration of the relationship of warping and parameters of probability distribution of MOE, LMC, and moisture content.
Development of Surface Improvement Technique of Japanese Larch Flooring Board(II)
Park, Sang-Bum ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 28~35
This paper deals with a coating technique for hardening surface layer of softwood(Larix leptolepis) flooring board to improve its surface properties such as hardness and abrasion resistance, Two coating methods were applied for surface hardening of the wood in this study. First, several functional monomers were added in UV-curing epoxy acrylate varnish. Secondly, unsaturated polyester varnish was used as under coat and acryl varnish including anti-abrasive agent was used as top coat. The hardness of the treated wood was similar to that of high density hardwood such as keruing by the first coating method. The abrasion resistance of the coated wood was greatly improved by the second method. Adhesion properties and impact resistance of the coated wood surface were also good. It was suggested that the well-coated softwood could be used as interior flooring board for heavy walking as substitute for hardwood.
Chemical Modification of Japanese Cedar with 2-Methacryloyloxyethyl Isocyanate
Han, Gyu-Seong ; Setoyama, Kouichi ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 36~41
This study was carried out to introduce functional groups onto wood by reacting with 2-methacryloyloxyethyl isocyanate(MOI). The effects of the catalyst and the reaction conditions(temperature and time) on the treatment were investigated. The evidence of bonding between wood and MOI were examined by infrared(IR) spectroscopy. The change in surface characteristics of MOI treated wood was examined by water contact angle measurement and X-ray photoelectron spectroscopy(XPS). Wood reacted quickly with MOI in the presence of di-n-butiltin dilaurate catalyst. Especially, the increase in weight percent gain(WPG) with increasing in reaction time was remarkable at the reaction temperature of over
. The IR spectrum of wood reacted with MOI showed a strong urethane absorption(1715
) but no isocyanate(2235
) absorption. It also showed a sharp olefinic C=C double bond absorption at 1635
. This means that an introduced methacrylate group becomes the starting point of further graft copolymerization with another vinyl monomers. The wood modified with MOI showed a gradual increase in contact angle with increasing in WPG, which means that the hydrophilic wood surface become quite hydrophobic. Also, it was cleared that most parts of the wood surface were modified with MOI by XPS analysis.
Pressure Treatment of Japanese Red Pine, Japanese Larch, and Ezo Spruce Round Posts with CCA
Kim, Gyu-Hyeok ; Kim, Jae-Jin ; Kim, Hyung-Jun ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 42~47
This study was designed to investigate the effect of treatment variables on CCA treatment of Japanese red pine (Pinus densiflora), Japanese larch (Larix leptolepis), and ezo spruce (Picea jezoensis) round posts. Variables included were duration of initial vacuum (30, 45, or 60 minutes) and maximum pressure applied (8.5, 10.5, or 14.0 kg/
), and maximum pressure was maintained until refusal point was reached. Regardless of wood species, extending the duration of initial vacuum more than 30 minutes did not affect treatability. Increasing pressure did not affect preservative penetration; however, preservative retention was affected by pressure levels, particularly at higher level (14.0 kg/
). Preservative penetration depth of Japanese red pine met a minimum requirement specified by Notification of Korean Forestry Administration (No. 1999-8) for hazard class H5 of CCA-treated wood. Penetration of preservative in both Japanese larch and ezo spruce was not deep because of shallow sapwood thickness of these species, so pretreatment such as incising should be considered if these species are treated with preservatives. Although retention in Japanese red pine was not significantly increased even with 14.0 kg/
, that of refractory Japanese larch and ezo spruce was significantly increased with the application of 14.0 kg/
. Effect of treatment variables on refusal time was unclear; however, it is cleared that the refusal time was shortened with the increase in sapwood thickness.
Thiamin Requirements for Vegetative Growth and Fruit Body Formation of Lentinula edodes
Shin, Gab-Gyun ; Meguro, Sadatoshi ; Kawachi, Shinsaku ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 48~54
The effects of thiamin on vegetative mycelial growth and fruit body formation of Lentinuia edodes were investigated in basal peptone-glucose liquid medium in relation to the uptake of thiamin. Thiamin was essential for fruit body formation, and the minimum requirements for thiamin were estimated to be approximately 10
/L. The vegetative mycelial growth was little influenced by the addition of thiamin in the range of 1.5
~1.5 mg/L. While the mycelium was successively transferred to fresh peptone-glucose-agar medium three times, the repression of mycelial growth was not significant. Even in cases using vitamin-free casamino acid or glutamic acid as a nitrogen source instead of peptone, a thiamin deficiency for mycelial growth did not occur as a result of transferring the mycelia to fresh media. Almost all of the thiamin contained in the media accumulated in the mycelia during the first 3 weeks of a 9-week incubation. These results suggest that only trace amounts of thiamin are required for vegetative mycelial growth in Lentinula edodes and that almost all thiamin added to a basal medium will be used for fruit body formation.
Culture Maturity of Lentinula edodes on Sawdust-Based Substrate in Relation to Fruiting Potential
Ohga, Shoji ; Min, Du-Sik ; Koo, Chang-Duck ; Choi, Tae-Ho ; Leonowicz, A. ; Cho, Nam-Seok ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 55~64
Culture maturity assessment can be used to control fruiting body flush timing. Culture maturity of sawdust-based substrate was evaluated by using oak mushroom, (Lentinula edodes (Berk.) Pegler). The influence of substrate water potential (
) on the growth and fruiting of three genotypes of L. edodes was also investigated. Glucosamine content revealed a peak at the fruiting body senescent stage. Glucosamine increased steadily to the sporophore senescent stage, and sharply declined at crop treatment. Lipid phosphate and ergosterol contents peaked at pinning and button break stages, respectively. Therefore lipid phosphate and ergosterol contents would be considered as the convenient measurement for judging culture maturity and fruiting potentials. The substrate pH values before inoculation and on the fruiting stage were varied from 6.3 to 4.0. This pH changes were detected as changes in color from bluish purple to yellow by direct bromphenol blue(BPB) spraying, and shown a good correlation with fruit body yield of the 1 st flush. Concerning water potential of the cultures, a slight reduction of water potential, -0.5MPa, stimulated mycelial and colony growths on liquid, agar and sawdust-based substrates. The water potential of well-colonized matured substrate was -0.7MPa and -4.0MPa, before and after the fruiting, respectively. Excellent water providing capacity (higher
) is expected to well-matured cultures with a high density of mycelial colonization. Also, the substrate water potential significantly affected by the interaction between genotypes and spawn run time.
Variation of Ergosterol Content in Lentinula edodes Culture
Koo, Chang-Duck ; Cho, Nam-Seok ; Kim, Je-Su ; Park, Jae-In ; Choi, Tae-Ho ; Min, Du-Sik ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 65~70
Ergosterol is an indicator chemical of fungi and involves in fungal cell growth as a major component in fungal cell membranes. Thus, this chemical can be used to estimate live fungal biomass within various solid substrates. Ergosterol content in liquid culture of Lentinula edodes had a linear relationship (r=0.98) with the hyphal mass of the fungus. This chemical content differed depending on the fungal strains, age of culture and water content levels of sawdust substrate. Ergosterol content was 0.13% in the 10 weeks old liquid culture while it was 0.10% in 20 weeks old one. The chemical content in the sawdust cultures of the fungus varied 0.015% to 0.042% depending upon strains and water content levels within sawdust substrate. Ergosterol content in the culture of a L. edodes strain, Sanrim 4, was higher by
/g dry substrate than those of strains, Mok-H and Sanrim 6. And the chemical contents in the sawdust cultures with 125% or 175% water, 297 to 425
/g dry substrate, were higher than those with 75% or 225% water, 148 to
/g dry substrate. We conclude that ergosterol analysis can estimate the fungal biomass within solid substrate such as logs and sawdust.
Effect of Coatings of Oxidized Starch on Properties of Linerboard
Ahn, Byoung-Kuk ; Ahn, Won-Yung ;
Journal of the Korean Wood Science and Technology, volume 28, issue 1, 2000, Pages 71~79
Two linerboards consisting of corrugated board were coated with oxidized starch solutions to investigate the change of their properties and analyze the effect of coating on them. The coating of linerboards with oxidized starch resulted in improvement in the properties related to corrugated board properties by increasing fiber bonding and rigidity. The improvement of ring crush strength by coating was greater in inside linerboard than in outside linerboard. Burst index of linerboards rapidly increased with an initial increase of coating weight, but as the coating weight further increased, there was no increase in burst index. Coating on linerboards with oxidized starch at low coating weight improved stiffness of them. There were no significant changes in tearing resistance of linerboards by coating of oxidized starch. The coating resulted in increase in air resistance and sizing degree of linerboards.