• Journal of the Korean Wood Science and Technology
• /
• v.31 no.4
• /
• pp.1-7
• /
• 2003

Anatomical and physical characteristics of damaged wood by forest fire and sound wood of Pinus densiflora were examined. Granular substances were found in resin canals, epithelial cells and ray parenchyma cells of damaged wood, but the other distinctive marks of wood structure in damaged wood were not observed. Damaged wood showed slightly higher relative crystallinity in outermost growth ring than sound wood. Green moisture content and water absorptions both in tangential and radial sections of damaged wood were lower than those of sound wood. There were no significant differences in shrinkage, swelling and basic density between damaged and sound woods.

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.5
• /
• pp.539-547
• /
• 2012

To manufacture laminated wood with improved mechanical properties by providing uniform adhesiveness, the adhesive was applied and the plate adhesive was laminated on the wood surface. Then, after laminating the wood on the top part of the adhesivebond, it was heated and dried while the adhesive was stiffened using microwaves, and the test piece was manufactured by compressing it with the press machine for thirty minutes. The temperature and the water content were examined according to the heating time of the wood heated with the microwave, and testing was conducted on the shear strength and flexural strength of the wood. In addition, the microstructure of the adhesive bond between the wood was recorded to confirm the penetrabilityinto the wood structure for the adhesive. After the test was conducted, it was found that the test piece manufactured with wood that has its water content leveled with the microwave heating showed improved shear strength and bending strength compared to the standard test piece. With regard to adhesives, liquefied polyvinyl acetate resin and plate's PVB resin were found to have superior adhesive strength. Also, after filming the cellular microstructure, it was found that when the laminated wood is heated with microwaves, the infiltration of the adhesive into the inside of the wood becomes easy, which makes it effective for improving adhesiveness.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.4
• /
• pp.451-458
• /
• 2019

Jabon (Anthocephalus cadamba Miq.) is a fast-growing species that exhibits a lower natural resistance than that exhibited by the timber sourced from natural forests. Jabon's resistance to termite attack can be improved by impregnating its wood structure with poisonous organic materials. This study examined jabon's resistance to termite attack when impregnated with wood vinegar and an animal adhesive. The wood specimens were impregnated using sengon wood vinegar and an animal adhesive (8% and 10%, respectively) using a vacuum pressure machine. The specimens were tested for their resistance to subterranean and dry-wood termites according to Indonesian National Standard (SNI 7207-2014). The results denoted that jabon impregnated with wood vinegar and an animal adhesive concentration of at least 8% with the addition of 4% borate was effective to resist termite attacks. The impregnated jabon exhibited a lower weight loss and higher termite mortality when compared with those exhibited by the control specimens. Thus, the resistance class improved from class IV to class I.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.2
• /
• pp.88-94
• /
• 2006

The purpose of this study is to examine the relationship between antioxidant activities and chemical structures of various chalcones. Twenty-two chalcones were assessed for their radical scavenging activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Of 22 compounds tested, the most active on DPPH radical was 2',4-dihydroxy-3,3'5-trimethoxy-5'-propylchacone (4) (72.6% at 100 ppm). It was followed by 3',4'-dihydroxy-3,4,5-trimethoxy-6'-methylchalcone (6), 2',4,4'-trihydroxy-3-methoxy-5-propenylchalcone (7) and 2',4,4'-trihydroxy-3,5-dimethoxychalcone (13). Based on the results, we concluded that the scavenging activity is controlled by the number and the position of the substitution in the compound.

• Journal of Korean Society of Forest Science
• /
• v.81 no.4
• /
• pp.357-362
• /
• 1992

To understand water flow path in the cells of Robinia pseudoacacia and Pyrus ussuriensis and obtain color wood from them, this experiment was performed by penetrating 0.5% acidic fuchsin and 0.5% fast green solution into the living wood of them. A comparison was made of the wood structure and water flow path from Robinia pseudoacacia containing the ring-porous wood with tyloses, and Pyrus ussuriensis including solitary diffuse-porous wood with distinct fiber pits. The dye penetrated into vessel elements in the early wood of two growth rings from bark in Robinia pseudoacacia, but permeated all xylem in fonts ussuriensis. In Robinia pseudoacacia, the vessels of heart wood and intermediate wood were not stained because of tyloses.

• Proceedings of the KSFDT Conference
• /
• 2006.04a
• /
• pp.177-182
• /
• 2006

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.4
• /
• pp.71-77
• /
• 1998

To elucidate chemical structure of the wood extractive, wood meal of Larix leptolepis Gorden was extracted with 95% ethanol for 72 hours. The extract was fractionated with organic solvents such as n-hexane, chloroform, diethylether, and ethyl acetate. From the hexane somble fraction of the extractives, a new diterpene compound was isolated and identified as 6-acetoxymanool or 13-hydroxy-8(17), 14-labddienyl-6-acetate by IR, $^1H(^{13}C)$-NMR and Mass spectrometry.

• Journal of the Semiconductor & Display Technology
• /
• v.17 no.1
• /
• pp.1-5
• /
• 2018

Wood Polymer Composites(WPC) have attracted significant attention because of ecological and environmental concerns. However, the structure of Wood Flour containing many hydroxyl groups(-OH) reduces the interface adhesion to Phenol-formaldehyde(PF) and it decreases the mechanical properties of the PF/Wood Flour Composites. The present work involves the modification of Wood Flour using silanes reinforced with Phenol-formaldehyde to enhance the mechanical properties of the composites. The spectroscopic properties of the composites were analyzed using FT-IR, XPS(X-ray Photoelectron Spectroscopy) and the mechanical properties i.e., tensile strength, flexural strength and impact strength were studied. We confirmed the modification effect of silanes by spectroscopic analysis, and the mechanical properties of the composites using wood flour modified by silanes were significantly improved.

• Journal of architectural history
• /
• v.31 no.6
• /
• pp.7-16
• /
• 2022

Traditional Korean architecture and traditional ships maintained a close relationship with carpenters and tools because wood, the material, was common. This close relationship may have been from the time of ancient architecture and ancient ships. In previous studies, researchers proved the relationship between these two sides through historical records of traditional architecture and traditional ships. This study attempts to prove the structural association using existing remains. As a result, three structural similarities between traditional architecture and traditional ships could be found. First, the types of wood used are similar, and the tools and terms used are similar. Second, the method of distinguishing horizontal and vertical materials and the structure of wood and the method of forming wood are similar. Lastly, the ship carpenters mobilized for the construction of the palace mainly worked on long and curved materials such as the eaves and the ridge of a roof, because this was the work done when the ship was built. Therefore, it can be assumed that the roof structure they created resembles that of the ship.

• Journal of the Korean Wood Science and Technology
• /
• v.46 no.6
• /
• pp.681-691
• /
• 2018

The typical methods of mercury intrusion porosimetry (MIP) and capillary flow porometry (CFP) were used to evaluate the pore size of cross-section of wood and the effect of the pore structure on the permeability of wood was analyzed in this study. The results of this study were as followings: The pore size of wood measured by CFP was larger than that measured by MIP except for Lime tree, Korean red pine and Paulownia. Among the three pore types of porous materials defined by IUPAC (through pores, blind pores, and closed pores), only through pores are related to permit fluid flow. MIP measures the pore size of both through pores and blind pores, while CFP measures the pore size of only constricted through pores. Therefore, pore size measured by MIP was not related to gas permeability, however pore size measured by CFP had a proportional relationship with gas permeability.