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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
Editor in Chief :
Volume & Issues
Volume 25, Issue 4 - Dec 1997
Volume 25, Issue 3 - Sep 1997
Volume 25, Issue 2 - Jun 1997
Volume 25, Issue 1 - Mar 1997
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Enzymes of White-rot Fungi Cooperate in Biodeterioration of Lignin Barrier
Leonowicz, Andrzej ; Cho, Nam-Seok ; Wasilewska, Maria W. ; Rogalski, Jerzy ; Luterek, Jolanta ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 1~20
Preperation of Carbon Fiber from Acetosolve Lignin
Eom, Tae-Jin ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 21~26
Lignin viscous material was prepared from acetosolve lignin by phenolation and heat treatment. The yield of phenolation was about 160% with p-toluene sulfonic acid(2% of acetosolve lignin) as catalyzer. Phenolated lignin has a good spinnability and thermosetting property by
treatment with vaccum. Acetosolve lignin carbon fiber has
m diameter and
tensile strength. The yield of carbon fiber based on acetosolve lignin was 31%.
Relationship between Compression Strength Parallel to Grain and Anatomical Characters in Pinus densiflora S. et. Z.
Oh, Seung-Won ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 27~32
This study was carried out to find the relationship between anatomical characters and compression strength parallel to grain of Pinus densiflora S. et. Z., the representative conifer species in Korea. The results were as follows ; 1. The compression strength parallel to grain increased with the increase of tracheid length and wall thickness. The strength, however, decreased with the increase of height of uniseriate ray and microfibril angle. 2. The major factors affecting compression strength parallel to grain in heartwood were radial diameter of latewood tracheid and wall thickness of earlywood tracheid but length and tangential diameter of latewood tracheid were the important factors in sapwood.
Studies on Composites Using Wood and Nonwood Fibers - Effects of Polypropylene Fiber Length and Process Variables -
Lee, Phil-Woo ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 33~44
This study was executed to examine the effects of polypropylene fiber length and process variables of the composites made from wood fiber and nonwood fiber mixed formulations. As a nonwood fiber the polypropylene with 3 denier thickness of tow condition was selected and cut into each length of 0.5, 1.0, 1.5, 2.0 and 2.5cm to mix with wood fiber. And also western hemlock wood fiber for medium density fiberboard was prepared. First, to decide an adequate polypropylene mixing fiber length, the composites of 1.0g/
density were made from 10% polypropylene fiber by each of five lengths and 90% western hemlock fiber mixed formulations. Thereafter as the experiments of process variable, the composites applied with adequate polypropylene fiber length(1.5cm) were made from 4 density levels (0.6, 0.8, 1.0, 1.2g/
). 3 mixed formulations of wood fiber to polypropylene fiber(95 : 5, 90 : 10, 85 : 15), and 3 mat moisture contents(5, 10, 20%). According to the results and discussions it was concluded as follows ; The physical and mechanical properties were shown improved tendency. as polypropylene fiber length was increased in the range from 0.5 to 1.5cm, but shown decreasing tendency from 2.0 to 2.5 cm. Accordingly, it was shown that polypropylene fiber length is limited to 1.5cm or less length in mixing wood fiber and polypropylene fiber by turbulent air mixing process. As the densities of wood fiber-polypropylene fiber composites were increased, the physical and mechanical properties were clearly improved. Also they were shown significantly increasement statistically between densities respectively. In the mixed formulations, physical and mechanical properties were shown only slightly improvement, as they changed from 95 : 5 to 85 : 15 in wood fiber to polypropylene fiber. Despite of increasement of mat moisture content, mechanical properties were not improved significantly but physical properties were improved somewhat in wood fiber-polypropylene fiber composites.
Flavonoid Glycosides from Needles of Taxus cuspidata(Taxaceae)
Ham, Yeon-Ho ; Park, Wan-Geun ; Han, Sang-Sup ; Bae, Young-Soo ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 45~51
Study on the Application of Microwave-heating System for Making Bent-wood Furniture(II) - Bending Processing Properties of Carpinus laxiflora BL. by Microwave-heating -
So, Won-Tek ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 52~60
Hornbeam trees(Carpinus laxiflora BL.) are growing in Korea and have good characteristics such as relatively high density, fine texture, split- resistance, and white colour. However, they have seldom been used as manufacturing materials This study was carried out to evaluate the possibility of using hornbeam wood as bent, wood furniture materials. Softening methods were steaming and micro-wave heating. The specimens of
were used green or air-dried, and were steamed at
for 20min, or microwave heat ed f or 60 seconds. The bending processing conditions are showed in Table 3. The minimum solid-bending radii of air-dried wood were 40mm for steaming and 200mm for micro-wave heating, respectively. And that of green wood were 40mm for micro-wave heating. In conclusion, both of the steamed wood and micro-wave heated green wood showed very good solid bending processing properties, but micro-wave heated air-dried wood were not sufficient for bent-wood furniture.
Effect of Moisture Contents and Density of Paulownia tomentosa on Acoustical Properties
Yoo, Tae-Kyung ; Jung, Hee-Suk ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 61~66
Paulownia wood has been used as sound board for Korean traditional musical instruments such as Keomungo(Korean lute), Kayagum(twelve-stringed Korean harp) and Changgu(hour-glass shaped drum), etc. The acoustic properties of wood affected not only by dimensions but also by density and stiffness of wood. Due to inhomogeneity and hygroscopicity of wood. the acoustic properties of wood are inconsistent. To clarify the effect of moisture content and air dry density on acoustic properties, longitudinal vibration experiment was accomplished in 3 moisture content levels of 9.6, 11.1 and 12.5% and in 3 air dry density levels of 0.22, 0.25 and 0.28g/
. The results were as follows: As the moisture content increased, the fundamental frequency. specific dynamic Young's modulus and sound velocity decreased, but the internal friction increased so that loss of energy increased. The values in damping of sound radiation were rapidly decreased at 12.5%. It meant that the damping of internal friction was larger than damping of sound radiation at high moisture content. As the air dry density increased, the fundamental frequency, specific dynamic Young's modulus and sound velocity increased, but the internal friction and damping of sound radiation decreased so that loss of energy decreased. And acoustic converting efficiency was hardly influenced by increasing air drying density.
Drying Resistance of Some Softwoods Lumbers under Time Schedule
Jung, Hee-Suk ; Lee, Nam-Ho ; Lee, June-Ho ; Kwon, Ju-Yong ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 67~74
A relationship between drying resistance and moisture content was found for 24, 27 and 30mm thick boards, and 45, 51 and 57mm thick dimensions of Japanese larch. Dahurian larch and radiata pine in order to modify the kiln schedule by using time schedules. The amount of drying resistance for Dahurian larch lumber was the highest, and radiata pine lumber was the lowest, on the basis of the same moisture content range. Drying resistance increased curvilinearly as moisture content decreased, and was higher for thicker lumber than for thinner lumber, at a given moisture content. Combined drying resistance for the three board thicknesses and the three dimension thicknesses showed a comparatively strong for radiata pine and a Japanese larch, while a weak correlation for Dahurian larch as a function of two independent variables, thickness and moisture content of lumber, respectively.
The Beating Properties of High Yield Pulp Treated Ozone(I) - Fiber Length Distribution of Ozonenation Pulp for Beating -
Yoon, Seung-Lak ; Kojima, Yasuo ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 75~80
This research has been examined to measure the degree of the fiber damage of ozonenation high yield pulp in the beating process. Ozone treated the TMP(Thermomechanical Pulp) and CTMP(Chemithermomechanical Pulp) of spruce and the CTMP of birch has been beaten to be reached 200ml(freeness) of its content. It had been studied the forming of fiber distribution by treatment for long fiber, short fiber, fine with the above method. As ozone treatment time gets longer, the pulp has showed the tendency of increasing the fiber content of 28, 48mesh. Ozone treated fiber has been increased long fiber content by being added softness. By given longer ozone treatment time, the TMP and CTMP of spruce has showed the decreasing of fiber content. On the contrary, CTMP of birch has showed the increasing its fiber content. It had proved that the results of difference are rather closer to the species of tree than closer to the kinds of pulp. The fiber content of over 200mesh which has created in beating process demonstrates the decreasing of its fiber content by getting longer ozone treatment time. The softness of fiber can be extracted by the lignin of fiber surface that had been formed by ozone treatment. Thus we assume that the fiber in the process of beating obtains less physical damage.
Flavonoid Glycosides from Needles of Larix leptolepis(Pinaceae)
Kim, Jin-Kyu ; Park, Wan-Geun ; Bae, Young-Soo ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 81~87
Anatomical Comparisons of Compression, Opposite, and Lateral Woods in New Zealand Radiata Pine(Pinus radiata D. Don)
Eom, Young-Geun ; Butterfield, Brian G. ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 88~99
Variation of Oak Kraft Pulp Properties by Xylanase Treatment in C/D, P and Z Stage
Kim, Dong-Ho ; Paik, Ki-Hyon ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 100~109
The objectives of this study was to decrease pollutions of bleaching effluent and was to enhanced brightness of non-chlorine bleached pulps by xylanase treatments. Xylanase cloned Esherichacoli(E. coli) capable of each of endo, exo-xylanase and acetyl-esterase were obtained from Bacillus stearothermophillus. These xylanase was maintained high activity in alkali and high temperature. Especially endo-xylanase would be more active in
and pH 11. Xylanase pretreatment(X) of unbleached pulp increased brightness, and decreased the degree of delignification. The degree of increase in brightness of pulp due to xylanase pretreatment was similar to non-enzyme treated pulp, regardless of the amount of enzyme added. Therefore, the addition of xylanase of 2 unit was recommended when considering costs of enzyme. The pulp bleached XO sequence had higher brightness and lower Kappa no, than O bleached pulp, while pulp bleached XP sequence had similar brightness and Kappa no. with P bleached pulp. In XOC/D, XOZ and XOP bleaching sequences, brightness and degree of delignification were improved. The C/D and Z stage bleached pulp was good effect on rate of raise in brightness and Kappa no., but P stage bleached pulp had similar level in non-enzyme treated bleaching sequence.
Procyanidins from Lindera obtusiloba Bark
Lee, Sang-Keug ; Park, Wan-Geun ; Bae, Young-Soo ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 110~116
Variations in Properties and Qualities of Major Plantation-grown Softwoods in Korea(I) - Anatomical Properties of Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa -
Lee, Chan-Ho ; Park, Jung-Hwan ; Kim, Yong-Chae ;
Journal of the Korean Wood Science and Technology, volume 25, issue 2, 1997, Pages 117~126
In fast grown softwood, there are very large changes in material properties going outward from the pith to bark such as anatomical, physical and mechanical characteristics. Some of variations in anatomical properties with annual ring were then examined from Pinus koraiensis, Larix leptolepis, and Chamaecyparis obtusa, which are major softwoods of plantation in Korea. The large variations of annual ring width during young age of tree tended to stabilize after 25year through the transitional period in 17~23year. The ring density was 1.5~2.4 in 1~10year period, and 3.5~6.3 in 30~35year period, in which juvenile and mature wood were certainly assumed to be formed, respectively. Variations of tracheid length showed functional relationships with annual rings as logarithm. Demarcation between juvenile wood and mature wood could be 16~19year, which was determined from increase rate of tracheid length of 0.2%. Cell wall thickness increased with increase of annual ring even though large variations were observed as well. Variations of cell wall thickness within species were pronounced in latewood than earlywood. The increase of cell wall thickness from juvenile wood to mature wood was predominant in Larix leptolepis as 2.0times, and least in Chamaecyparis obtusa as 1.1 times. Cell diameters showed trends of increase during young age of 1~15year, and consistent afterward. The variations of cell diameter between radial and tangential direction were greater in latewood, and most pronounced in Chamaecyparis obtusa.