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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 35, Issue 6 - Nov 2007
Volume 35, Issue 5 - Sep 2007
Volume 35, Issue 4 - Jul 2007
Volume 35, Issue 3 - May 2007
Volume 35, Issue 2 - Mar 2007
Volume 35, Issue 1 - Jan 2007
Selecting the target year
Micromorphological Characteristics of Frost Rings in the Secondary Xylem of Pinus radiata
Lee, Kwang Ho ; Kim, Jong Sik ; Singh, Adya P. ; Kim, Yoon Soo ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 1~8
Frost ring formed in the secondary xylem of Pinus radiata was examined using various microscopic techniques. Cell walls in a frost ring were poorly developed, lacking in the proportion of wall components. Formation of secondary cell wall was imperfect and thickness of secondary wall was varied. Cytochemical examinations provided the evidence that the synthesis of structural polysaccharides and lignin was inhibited, resulting in the malformation of secondary cell walls. Judging by the highly irregular nature of the cell wall, it appears that cellulosic/hemicellulosic framework was affected and the template for lignification by frost.
Cell Wall Structure of Various Tropical Plant Waste Fibers
Abdul Khalil, H.P.S. ; Siti Alwani, M. ; Mohd Omar, A.K. ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 9~15
A comparative study of the structure and organization of the primary and secondary walls in different types of tropical plant waste fibers was carried out using transmission electron microscopy (TEM). The thickness of each layer was also measured using Image Analyzer. TEM micrographs haveconfirmed that cell wall structure of all six types of tropical plant waste fibers (empty fruit bunch, oil palm frond, oil palm trunk, coir, banana stem and pineapple leaf) has the same ultrastructure with wood fibre. The fibers consisted of middle lamella, primary and thick secondary wall with different thickness for different types of fibers. The secondary wall was differentiated into a
layer, a unique multi-lamellae
Alkali-Swollen Morphology of Native Cellulose Fibers
Kim, Nam-Hun ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 16~22
The behavior of ramie fibers and some wood elements in the early stage of alkali swelling was examined. When the fibers were treated with alkali solution, they significantly shrank in length and swelled in wall thickness. Ramie fibers showed a shrinkage averaging 23% in length and a swelling averaging 92% in width in 100 seconds treating time. Dimensional changes showed different fashion in each element of woods. The tracheids of latewood especially in Pinus densiflora and Larix kaempferi woods swelled intensively and showed balloon swelling, but in the case of Cryptomeria japonica, it was hardly observed. The swelling morphology of libriform fibers was similar to that of tracheids. The walls of vessel elements and parenchyma cells also swelled considerably in thickness but, no balloon swelling was found in both elements. The differences of swelling in different elements can be interpreted in terms of the differences of organization and/or chemical components of the cell walls.
Experimental Study on the Direct Contact Thermal Screw Drying of Sawdust for Wood-Pellet Fuel
Lee, Hyoung-Woo ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 23~28
Wood fuel must be dried before combustion to minimize the energy loss. Sawdust of Japanese red pine was dried in a direct contact thermal screw dryer to investigate the drying characteristics of sawdust as a raw material for bio-fuel. Average drying rate and energy efficiency was 1.4%/min and 69.23% at
, respectively, and those at
was 2.1%/min and 71.03%, respectively.
Radial and Circumferential Variations in Hygroscopicity and Diffusion Coefficients within a Tree Disk
Kang, Wook ; Chung, Woo Yang ; Eom, Chang Deuk ; Han, Yeon Jung ; Yeo, Hwan Myeong ; Jung, Hee Suk ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 29~38
This study was undertaken to investigate the variation of equilibrium moisture content (EMC) in transverse direction and three different directional (longitudinal, radial, and tangential) linear movements, and diffusion coefficients within a tree disc of Korean red pine (pinus densiflora). The EMC gradually increased in heartwood from pith. Therefore, the chemical components might differ even in heartwood and the radial variation in EMC might have a close relationship with the cellulose content within a cross section. The specific gravity increases gradually from pith and the porosity has not direct influence on the variation of EMC within a tree disk. Both the radial and tangential diffusion coefficients exhibited clear trend of increase from pith. The EMC change (
) and tangential diffusion coefficient were close to be axisymmetrical but others were deviated from axisymmetry. The diffusion coefficient decreases with decreasing an activation energy and specific gravity, The diffusion coefficient increased with increasing
and hygroscopicity of wood might be inversely proportional to the activation energy, The fJEMC may depend on the chemical constituents of cellulose, hemicellulose and lignin. As the number of sorption sites and sorption capacity of wood increase, therefore, it might be assumed that the hygroscopicity of wood increases while activation energy decreases. Modeling physico-mechanical behavior of wood, the variations should be considered to improve the accuracy.
Physico-mechanical Properties and Formaldehyde/TVOC Emission of Particleboards with Volcanic Pozzolan
Kim, Sumin ; An, Jae-Yoon ; Kim, Jin-A ; Kim, Hee-Soo ; Kim, Hyun-Joong ; Kim, Hak-Gyeom ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 39~50
The purpose of this study was to investigate the physico-mechanical properties and characteristics on reduction of formaldehyde and total volatile organic compound (TVOC) emission from particleboard (PB) with added volcanic pozzolan. Pozzolan was added as a scavenger at the level of 1, 3, 5, and 10 wt.% of urea formaldehyde (UF) resin for PB manufacture. The moisture content, density, thickness swelling, water absorption and physical properties of PBs were examined. Three-point bending strength and internal bond strength were determined using a universal testing machine. Formaldehyde and TVOC were determined by desiccator and 20L small chamber methods. With increasing pozzolan content the physical and mechanical properties of the PBs were not significantly changed, but formaldehyde and TVOC emissions were decreased. Because pozzolan has a rough and irregular surface with porous form, it can be used as a scavenger for PBs at a content up to 10 wt.% without any detrimental effect on the physical and mechanical properties.
Utilization of Pyrolysis Oil from Pine Wood as Thermosetting Wood Adhesive Resins
Kim, Jae-Woo ; Myers, Deland J. ; Brown, Robert C. ; Kuo, Monlin ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 51~60
In this study, the possibility of using pyrolysis oil as wood adhesives was explored. Especially, adhesives were formulated by reacting pyrolysis oil and formaldehyde and also partially replacing phenol with pyrolysis oil in phenol-formaldehyde (PF) adhesive and soy hydrolizate/PF adhesive formulation. The pine wood was fast pyrolyized and the oils were obtained from a series of condensers in the pyrolysis system. The oils from each condenser were first reacted with formaldehyde to explore potential use of the oil itself as adhesive. The lap-shear bond strength test results indicated that the oil itself could be polymerized and form bonds between wood adherends. The oils from each condenser were then mixed together and used as partial replacement of phenol (25, 33, and 50% by weight) in phenol-formaldehyde adhesive. The bond strength of the oil containing PF adhesives was decreased as percent phenol replacement level increased. However, no significant difference was found between 25 and 33% of phenol replacement level. The oil-contained PF resins at 25, 33, and 50% phenol replacement level with different NaOH/Phenol (Pyrolysis oil) molar ratio were further formulated with soy hydrolizate to make soy hydrolizate/pyrolysis oil-phenol formaldehyde adhesive at 6:4 weight (wt) ratio and used for fiberboard manufacturing. Surface internal bond strength (IB) of the boards bonded with 33% replacement at 0.3 NaOH/Phenol (Pyrolysis oil) molar ratio performed better than other replacement levels and molar ratios. Thickness swelling after 24 hr cold water soaking and after 2 hr in boiling water was increased as % replacement of pyrolysis oil increased.
Characteristics of Non-plasticizer PVAc Resin for Wood Products
Kim, Sumin ; Kim, Hyun-Joong ; Choi, Youn Mee ; Jang, Sung-Wook ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 61~68
The applicable scope of adhesives in the current society is broad and currently, several types of PVAc resin are sold in the market for adhesives. PVAc resin is primarily used for wood works and paper adhesion. However, the PVAc resin itself has the disadvantages that its viscosity is highly temperature- dependent and the work condition and viscosity get worse at the low temperature in the winter seasons. Although phthalate-based plasticizer is used to complement these disadvantages, adhesion strength and heat-resistance are weakened by adding the phthalate-based plasticizer and in the winter period, the amount of quantity should be increased. Also in a high-density product, it worsens the work condition by causing a rise of viscosity and delays curing and in a low-density product, it worsens the storage stability by causing separate precipitation. In addition to these, the phthalate-based plasticizer as a material of causing environmental hormones is currently restricted in the advanced countries for its amount of use and also in the domestic market, it is necessary to prepare for the situation. This study has not only eliminated the disadvantages of PVAc resin emulsion without adding a phthalate-based plasticizer of causing these problems, but also synthesized the PVAc resin for timber adhesion that is excellent in woodwork, thermal-resistance, water-resistance, storage stability, and adhesion performance. As the result, it has proven an excellent performance in thermal resistance, water resistance, storage stability, and minimum film forming temperature.
Influence of Hwangto on the Mechanical Properties of Wood Flour Reinforced High Density Polyethylene (HDPE) Composites
Lee, Sun-Young ; Doh, Geum-Hyun ; Kang, In-Aeh ; Wu, Qinglin ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 69~78
The mechanical properties of wood flour, Hwangto (325 and 1,400 mesh per 25,4 mm) and coupling agent-reinforced HDPE composites were investigated in this study. Hwangto and maleated polyethylene (MAPE) were used as an inorganic filler and a coupling agent, respectively. The addition of Hwangto and MAPE to virgin HDPE also increased the Young's modulus in the smaller degree. The addition of wood flour and Hwangto to virgin HDPE increased the tensile strength, due to the high uniform dispersion of HDPE by high surface area of Hwangto in HDPE and wood flour. MAPE also significantly increased the tensile strength. When wood flour was added, there was no notable difference on the tensile properties, in terms of Hwangto particle size. Hwangto also improved the flexural modulus and strength of reinforced HDPE composites. With different particle sizes of Hwangto, there was no considerable difference in flexural modulus and strength of reinforced HDPE composites. The addition of Hwangto showed slightly lower impact strength than that of wood flour. However, the particle size of Hwangto showed no significant effect on the impact strength of reinforced composites. In conclusion, reinforced HDPE composites with organic and inorganic fillers provide highly improved mechanical properties over virgin HDPE.
Prevention of Mold Growth on CCA-treated Radiata Pine Lumber by Incorporation of Moldicide into the CCA Solution
Kang, Sun-Mi ; Kim, Gyu-Hyeok ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 79~84
Surface mold fungi growing on CCA-treated wood could be inhibited effectively by the incorporation of moldicide into treating solution. In this study, moldicides compatible with the CCA solutions from various commercial moldicides were screened, and then their optimum concentrations for controlling surface mold on CCA-treated radiata pine sapwood were examined through both the laboratory and the field trials. Among nine commercial moldicdes tested, two substituted isothiazolinones, moldicide A containing 2-n-octyl-4-isothiazoline-3-one and moldicide B containing 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, were chemically compatible with CCA solution. The optimum concentration to be incorporated into 2% CCA treating solution was determined to be 0.001% for moldicide A and 0.003% for moldicide B.
Production of Mn-Dependent Peroxidase from Bjerkandera fumosa and Its Enzyme Characterization
Jarosz-Wilkolazka, Anna ; Luterek, Jolanta ; Malarczyk, Elzbieta ; Leonowicz, Andrzej ; Cho, Hee-Yeon ; Shin, Soo-Jeong ; Cho, Nam-Seok ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 85~95
Manganese dependent peroxidase (MnP) is the most ubiquitous enzyme produced by white-rot fungi, MnP is known to be involved in lignin degradation, biobleaching and oxidation of hazardous organopollutants. Bjerkandera fumosa is a nitrogen-unregulated white-rot fungus, which produces high amounts of MnP in the excess of N-nutrients due to increased biomass yield. The objective of this study was to optimize the MnP production in N-sufficient cultures by varying different physiological factors such as Mn concentration, culture pH, and incubation temperature. The growth of fungus was optimal in pH 4.5 at
-unregulated white-rot fungus produces high amounts of MnP in the excess N-nutrients. The fungus produced the highest level of MnP (up to
as N source at 1.5 mM
concentration, pH value of 4.5 at
. Purification of MnP revealed the existence of two isoforms: MnPl and MnP2. The molecular masses of the purified MnPl and MnP2 were in the same range of 42~45 kDa. These isoforms of B. fumosa strictly require Mn to oxidize phenolic substrates. Concerned to kinetic constants of B. fumosa MnPs, B. fumosa has similar Km value and Vmax compared to the other white-rot fungi.
Phenylethanoid Glycosides from Seeds of Paulownia coreana
Si, Chuan-Ling ; Bae, Young-Soo ;
Journal of the Korean Wood Science and Technology, volume 35, issue 2, 2007, Pages 96~101
Seeds of Paulownia coreana were collected, extracted with acetone-
(7 : 3, v/v), concentrated under reduced pressure and successively fractionated with n-hexane, methylene chloride, ethyl acetate and water on a separatory funnel. The
soluble fraction was chromatographed on a Sephadex LH-20 column using aqueous methanol and ethanol-hexane as washing solvents. Two isomeric phenylethanoid glycosides, verbascoside (1) and isoverbascoside (2), and one epimeric phenylethanoid glycoside, campneoside II (3), were isolated and their structures were elucidated on the basis of chemical and spectroscopical data.