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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 33, Issue 6 - Nov 2005
Volume 33, Issue 5 - Sep 2005
Volume 33, Issue 4 - Jul 2005
Volume 33, Issue 3 - May 2005
Volume 33, Issue 2 - Mar 2005
Volume 33, Issue 1 - Jan 2005
Selecting the target year
Dimensions of Structural Elements in Fusiform Ray of Sitka Spruce (Picea sitchensis (Bong.) Carr.) Affecting Radial Permeability
Usta, Ilker ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 1~6
The anatomical structure of fusiform ray was examined by scanning electron microscopy (and microscopic images were analysed by image analyser) to explain the differences in radial fluid uptake between the extremes in the radial treatment data, i.e. between the selected trees of QCI (Queen Charlotte Islands in Rhondda, South Wales) and SO (South Oregon in Dalby, North-East England) planted in the UK. The ray structure of these two seed origins was examined microscopically and different patterns of ray composition were observed. The most important anatomical features influencing radial permeability were the nature of fusiform ray, and the condition of the resin canals, epithelial cells and intercellular spaces in particular.
The Mechanical Behavior and the Anatomical Changes of Wood due to Variation of Deflection Rates
Kang, Chun-Won ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 7~12
The objective of this study is to estimate the mechanical behavior in bending and the anatomical changes of wood under several deflection rates. Sample specimens of water-saturated Japanese cedar (Cryptomeria japonica) were stressed to rupture under several deflection rates. Mechanical properties of wood such as modulus of elasticity, modulus of rupture and stress at proportional limit, and anatomical changes affected by deflection rates were estimated. Microscopic observations on compression side of the test specimens when the specimen was loaded to rupture were carried out by the SEM (scanning electron microscopy). The results are summarized as follows: 1. The mechanical properties of wood were affected by variations of the deflection rates. The modulus of elasticity (MOE), modulus of rupture (MOR) and stress at proportional limit were in proportion to the logarithm of deflection rates. 2. The deflection of wood at rupture in bending increased as deflection rates decreased. 3. The variations of the microscopic deformations of sample specimens were closely related to the deflection of wood at rupture. In case of largely deflected wood by maximum bending load, severe and abundant microscopic deformations were observed.
Nondestructive Evaluation of Bending Strength Performances for Red Pine Containing Knots Using Flexural Vibration Techniques
Byeon, Hee-Seop ; Ahn, Sang-Yeol ; Park, Han-Min ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 13~20
This paper deals with flexural vibration techniques as a means of predicting bending strength properties for quarter-sawn and flat-sawn planes of red pine containing knots. Dynamic modulus of elasticity
was calculated from resonance frequency obtained from the flexural vibration induced by a magnetic driver in quarter-sawn and flat-sawn planes of red pine containing knots. The dynamic MOE were well correlated to bending strength properties. Their correlation coefficients ranged from 0.866 to 0.800 for the regression between dynamic MOE and static bending MOE or MOR. The difference of the values between quarter-sawn and flat-sawn was very small. These values were higher than correlation between percentage of total knot diameter to total width of red pine specimen
as well as
base upon ASTM D 3737 and static bending strength properties (correlation coefficient r = 0.448-0.704), and were similar to those between static bending MOE and bending MOR (r = 0.850). These results indicate that dynamic MOE obtained from resonance frequency induced by flexural vibration of magnetic driver is able to effectively use for predicting of static bending strength of red pine containing knots as well as static MOE.
CT Image Reconstruction of Wood Using Ultrasound Velocities I - Effects of Reconstruction Algorithms and Wood Characteristics -
Kim, Kwang-Mo ; Lee, Jun-Jae ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 21~28
For the proper conservation of wooden cultural properties, non-destructive evaluation (NDE) method, which can be used to quantitatively evaluate the internal state of wood members, are needed. In this study, an ultrasonic CT system composed of portable devices was attempted, and the capacity of this system was verified by reconstructing the CT images for two phantoms and two artificially defected specimens. Results from this study showed that the sizes of detected defects were enlarged and the shapes were distorted on the CT images. Also, the positions were shifted somewhat toward the surface of specimen, which is regarded due to the anisotropic property of wood. Compared to the filtered back-projection method, SIRT (simultaneous iterative reconstruction technique) method was determined to be more efficient as the algorithm of image reconstruction for wood. A new ultrasonic CT system is thought to be used as a NDE method for wood. However wood characteristics and wave diffraction within wood made it difficult to accurately evaluate the size, shape and position of defects. To improve the quality of CT image of wood, more research including the relationship between wood and ultrasound is needed, and wood properties should be taken into consideration on the image reconstruction algorithm.
CT Image Reconstruction of Wood Using Ultrasound Velocities II - Determination of the Initial Model Function of the SIRT Method -
Kim, Kwang-Mo ; Lee, Jun-Jae ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 29~37
A previous study verified that the SIRT (simultaneous iterative reconstruction technique) method is more efficient than the back-projection method as a CT algorithm for wood. However, it was expected that the determination of the initial model function of the SIRT method would influence the quality of CT image. Therefore, in this study, we intended to develop a technique that could be used to determine an adequate initial model function. For this purpose, we proposed several techniques, and for each technique we examined the effects of the initial model function on the average errors and the CT image at each iteration. Through this study, it was shown that the average error was decreased and the image quality was improved using the proposed techniques. This tendency was most pronounced when the back-projection method was used to determine the initial model function. From the results of this study, we drew the following conclusions: 1) The initial model function of the SIRT method should be determined with careful attention, and 2) the back-projection method efficiently determines the initial model function of the SIRT method.
Study on the Power Consumption Characteristics of Korean Domestic Species in Peripheral Milling with Image Analysis Technique
Lee, Hyoung-Woo ; Kim, Byung-Nam ; Kim, Kyung-Yong ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 38~44
Peripheral milling is one of the most important wood machining processes in wood industry. Power consumption characteristics of twelve Korean domestic species in peripheral milling were investigated in this study. Image analysis technique was applied to extract proper data from the power consumption profiles. Average power consumption increased as cutting depth increased and specific cutting power decreased as cutting depth increased. However, no significant relationship could be found between density and power consumption and between cutting depth and surface roughness.
Measurement of the Sound Absorption Coefficient of Fiberboard by Two Microphone Method
Kang, Chun-Won ; Park, Hee-Jun ; Jeong, In-Soo ; Kim, Gwang-Chul ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 45~49
The sound absorption coefficients of three types commercial fiberboard were experimentally measured under a relatively low frequency range of 50 to 1600 Hz by the two microphone transfer function method. The sound absorption coefficient of 30 mm thick fiberboard was higher than that of 18 mm thick fiberboard at the frequency range of 50 to 1.2 KHz. The sound absorption coefficient of medium density fiberboard was a little higher than that of low density fiberboard.
Effect of Wood Material Type on Biocide retention and Distribution Using Supercritical Fluid Impregnation
Kang, Sung-Mo ; Jung, Doo-Jin ; Koo, Ja-Oon ; Morrell, J.-J. ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 50~56
The effect of wood material type on biocide retention and distribution during supercritical fluid impregnation was assessed using three different wood types including solid wood, plywood and oriented strand board (OSB). The result revealed that biocide treatability differed with structural composition and permeability of the various materials. Low treatability of plywood might be attributed to interferences of glue line limiting fluid movement. OSB samples showed higher biocide retentions, resulting from the presence of interconnecting gaps permitting more open flow.
Effect of Adhesives and Finger Pitches on Bending Creep Performances of Finger-Jointed Woods
Park, Han-Min ; Oh, Seong-Won ; Byeon, Hee-Seop ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 57~65
Following our previous reports for finger-jointed woods with various finger profiles studied for the efficient use of small diameter logs and woods containing various defects, twelve types of finger-jointed woods glued with three kinds of adhesives and with two sizes of finger pitches were made with sitka spruce and red pine. The effects of the adhesives and finger pitches on bending creep performances of finger-jointed woods were investigated. The shape of creep curves differed among the used adhesives and finger pitches of finger-jointed woods for both tested species. Their creep curves showed a linear behavior beyond about one hour, and the N values fitted to power law increased with increasing finger pitches. The initial deformation increased with increasing finger pitches, regardless of the tested species and kinds of adhesives, whereas the effect of finger pitches on the creep deformation was not clear. For finger-jointed woods glued with polyvinyl acetate (PVAc) resin, creep failure occurred in 106 hours after the load was applied. And the difference of the creep compliance between finger-jointed woods glued with resorcinol-phenol formaldehyde (RPF) resin and aqueous vinyl urethane (AVU) resin was small. The ratios for creep performances of finger-jointed woods glued with RPF resin and AVU resin versus solid wood were higher in creep deformation than initial deformation for both species, and the difference between both adhesives was not found. The relative creep decreased with increasing finger pitches, and the marked differences was not found between RPF resin and AVU resin.
Physical Properties of Hybrid Poplar Flakeboard bonded with Alkaline Phenolic Soy Adhesives
Yang, In ; Kuo, Monlin ; Myers, Deland-J. ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 66~75
Soybean-based adhesives have recently been reconsidered as alternatives to petroleum-based adhesives due to the uncertainty of availability of petrochemical products and the increased demand for wood adhesives. This study was conducted to investigate the adhesive properties of alkaline phenolic soy (APS) resin for hybrid poplar flakeboard. The APS resin was formulated by crosslinking an alkaline soy flour hydrolyzate with lab-prepared PF resin in the soy hydrolyzate to PF resin weight ratios of 70/30, 60/40, and 50/50. The APS resins were used to fabricate homogeneous hybrid poplar flakeboards with different resin solid levels (5%, 7%, and 9%), press temperatures (175 and
), and press times of 8 and 10 minutes. The IB, wet MOR, and dimensional stability properties of board improved with increasing press time, press temperature, and PF level in APS resins. Increasing press time can be used to offset poor IB strength associated with a 9% resin solid level and the excessive moisture content in the mat. The following conditions were concluded to meet the requirements of the CSA standard for exterior-grade flakeboard: a 50% PF level, a 5% resin content, a
press temperature, and an 8 minute press time.
Degradation of Pentachlorophenol by Lignin Degrading Fungi and Their Laccases
Cho, Nam-Seok ; Cho, Hee-Yeon ; Pham, Hop-ThiBich ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 76~85
The degradation of pentachlorophenol (PCP) by lignin degrading fungi was performed. Several fungi, Abortiporus biennis, Cerrena unicolor and Trametes versicolor, were tested to evaluate the inhibitory effect of PCP on their growth. At the extremal concentration of PCP
, only C. unicolor showed relatively fast growth (60% within 14 days) in the comparison to the control culture. In the case of A. biennis and C. unicolor, when initial PCP concentration was
, about 88.2% and 79.5% of PCP degradation were achieved within 3 days, respectively. When 2,5-xylidine (0.2 mM) was added to the C. unicolor culture, as high as 98% of PCP degradation was achieved within just an hour after its addition. A. biennis removed 44% of PCP at the same condition. PCP was completely disappeared when laccase activities reached to maximum.
Studies on Biological Activity of Wood Extractives(XVI) -Antioxidant Components from the Bark of Rbus chinensis-
Lee, Yeon-Suk ; Park, Young-Ki ; Lee, Oh-Kyu ; Park, Il-Kwon ; Shin, Sang-Chul ; Kang, Ha-Young ; Choi, Don-Ha ; Choi, Tae-Ho ; Lee, Hak-Ju ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 86~91
Six compounds were isolated from the EtOAc and
fractions of the bark of Rhus chinensis by repeated column chromatography with
and Sephadex LH-20. The structures were determined by instrumental analysis using MS and NMR spectrophotometer as: gallic acid (1), methyl gallate (2), 6, 7-dimethoxycoumarin (3), orcinol-
-D-glucoside (4), scopoletin (5), semialactone (6). Among these compounds, 6,7-dimethoxycoumarin (3) was isolated from this plant for the first time. To measure the antioxidant activity, the DPPH radical scavenging activity test was performed. Gallic acid (1) showed the strongest activity, while orcinol-
-D-glucoside (4), semialactone (5) and scopoletin (6) had the low activities.
Optimization of in Vitro Cultivation of Inonotus Obliquus
Cho, Nam-Seok ; Shin, Yu-Soo ;
Journal of the Korean Wood Science and Technology, volume 33, issue 5, 2005, Pages 92~98
This study was performed to get the basic information concerned to the optimum culture condition of Inonotus obliquus. Several solid media, PDA, MEA and Czapek-Dox, and three liquid media were adopted for the in vitro cultivation. Some main features of the fungal morphological characteristics under cultivation conditions were observed and described. Preliminary results showed that appearance of the mycelial mat, hyphal size and substrate pigmentation differed according to the media. The PDA medium was the most favorable substrate for the growth on solid culture, followed by MEA and Czapek-Dox media. Concerned to the addition of amino acids, 5 amino acids, such as alanine, alginine, isoleucine, leucine and threonine, enhanced to the mycelial growth. Isoleucine was shown the best fungal growth. An important morphological hyphal structure for the fungus, the setae, was found in abundance and diverse its shape and size. In liquid culture, fresh potato broth was the best growth stimulant of the fungus, followed by Malt extract and potato broth. Addition of yeast extract to the liquid media had improved the biomass, but not laccase production.