• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.282-289
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• 2014

After being laminated with a combination of glass fiber reinforced plastic and plywood, the GFRP laminated plate was densificated for 1 hour at $150^{\circ}C$ with pressure of $1.96N/mm^2$. A partial reinforced beam was produced by attaching the 5 GFRP laminated plates to the joint of glulam and the column. In addition, the column to beam joint was produced by using reinforced laminated wooden pin which was made of GFRP sheet and plywood, fiber glass reinforced cylindrical-LVL column. The joint was made of round log, glulam and drift pin as the reference specimen, and its moment resistance was evaluated. As a result, the strength performance of specimens with partial reinforced beams were 1.8 times stronger than the reference specimen on average. Furthermore, rupture was neither occurred on partial reinforced beam nor column. Toughness and stiffness of joints were also fine. The GFRP sheet reinforced laminated plate showed better reinforcement effect than GFRP textile reinforced one. GFRP sheet was inserted into each layer of laminate, and it showed good condition in rotation-angle and strength, therefore it is the most appropriate to reinforce the part of the beam.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.51-63
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• 2007

The biodeterioration behaviors of wooden parts in the Janggeongpanjeon built in 15 century were investigated according to the types of wood species, positions and parts of wooden column, and environmental conditions. It was found that a high differences of deterioration in the progressing levels of wood decay, according to the types of wood species, positions and parts of wooden column, and environmental conditions. The decay levels were high in the contacted areas with stone foundation which are about up to 8~40 cm above it, although it was shown the many of wooden parts of the round columns are still good condition. In the case of decay type, it was shown the brown-rot in many of the columns at outside of building which made of hardwoods. The decay in position of the columns was most serious in the directions of east-north, west-north and north. It was also indicated that the durability of Zelkova serrata was higher than other wood species of the round columns, while it was in inferior anti-insects.

• Journal of the Korean Wood Science and Technology
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• v.40 no.2
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• pp.141-146
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• 2012

The outer bark of Prunus sargentii was collected, air-dried and extracted with 70% aqueous acetone. Then it was successively partitioned with n-hexane, dichloromethane ($CH_2Cl_2$), ethyl acetate (EtOAc) and $H_2O$. From the EtOAc soluble fraction, four compounds were isolated by the repeated Sephadex LH-20 column chromatography. The isolated compounds were determined as (+)-catechin (1), (-)-epicatechin (2), taxifolin (3), and neosakuranin (4) by the spectroscopic analysis including $^1H$, $^{13}C$-NMR, and 2D-NMR spectrometers. The antioxidative activities on the isolated compounds and the separated fractions were evaluated by DPPH radical scavenging assay. The crude, EtOAc, and $H_2O$ soluble fractions indicated good antioxidative potential compared to the $CH_2Cl_2$ and n-hexane soluble fractions.

• Journal of the Korean Wood Science and Technology
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• v.38 no.5
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• pp.439-443
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• 2010

The 95% aqueous EtOH extract was obtanied from the fruiting body of Russula subnigricans. Repeated silica gel column chromatography and preparative TLC afforded one fatty acid and three chlorinated hydroquinone derivatives. They were identified as nonadecanoic acid (1), 2,6-dichloro-4-methoxyphenol (2), russuphelin A (3), and russuphelin E (4) on the basis of several spectral data (MS, $^1H$ and $^{13}C$-NMR, including HMBC).

• Journal of Korean Society of Forest Science
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• v.95 no.5
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• pp.511-515
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• 2006

From the EtOAc soluble fractions of Platanus orientals Linn leaves, (+)-catechin (1), (+)-epicatechin (2), (+)-gallocatechin (3), kaempferol (4), quercetin (5), kaempferol-3-O-${\alpha}$-L-rhamnopyranoside (6), quercetin-3-O-${\beta}$-D-glucopyranoside (7) and tyrosol (8) were isolated. The structures of the isolated compounds were characterized by NMR and MS spectrometers. The antioxidative activities of the isolated compounds and fractions were evaluated by DPPH free radical scavenging method and the results indicated that compounds 1, 2, 3, 4, 5 and EtOAc soluble fraction exhibited greater activities than ${\alpha}$-tocopherol and BHT, while compounds 6, 8 and other fractions showed low activity compared to the controls.

• Journal of Korean Association for Spatial Structures
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• v.19 no.1
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• pp.37-44
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• 2019

Yangjindang house, which is located in Sang-ju province of South Korea, is one of the special Hanok structures dated back to Joseon dynasty. This study aims to examine structural safety of the Yangjindang wood frame building considering dynamic parameters such as the natural frequency and damping ratio. The numerical model of the wood frame building is implemented using Midas Gen, especially the wood joint where column and beam were connected. The behavior of the actual frame building was compared with the modeling results. In addition, structure responses such as shear force, axial force, flexural moment and deflections were calculated and compared with the allowable limits. Numerical results show that, generally, despite of some local members shear failure, Yangjindang's structural response does not exceed the limitation according to current standards.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.8-14
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• 2011

Japanese larch glulam was used as structural members to develop a modern engineered wood jointing system using traditional post and beam structure. For the connections comprised of traditional joining and drift-pins, structural members are processed at a pre-cut factory. As a basic study to examine and increase the whole shear performance of portal frame, pin withdrawal test and moment resistance tests were conducted on each connection. The post and beam members with specified connectors showed good bearing performance in the wood members' joining system, column-base and beam-end. Moment rigidity was a bit better in a joint with higher slenderness ratio of drift-pin, but moment resistance performances, yield moment and maximum moment, were excellent in smaller one.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.104-112
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• 2011

There have been few reports on the constituents and biological activity of stem bark of $Acer$ $tegmentosum$, and no phytochemical and biological studies have been reported for stem wood of $A.$ $tegmentosum$. Two flavan 3-ols (1 and 2), three phenolic acid/alcohols (3~5), and two coumarins (6 and 7) were isolated from the stem wood of $A.$ $tegmentosum$ by repeated column chromatography. The structure of isolated compounds were identified as (+)-catechin (1), (-)-epicatechin (2), $p$-hydroxybenzaldehyde (3), syringic alcohol (4), $p$-tyrosol (5), scopoletin (6), and cleomiscosin A (7) on the basis of spectroscopic evidences such as $^1H$-NMR, $^{13}C$-NMR, 2D-NMR and MS spectrum. $p$-Hydroxybenzaldehyde (3), syringic alcohol (4), scopoletin (6), and cleomiscosin A (7) have not been reported from this plant so far. (+)-Catechin (1) and (-)-epicatechin (2) showed the higher 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than butylated hydroxyanisole (BHA) used as a positive control.

• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.53-59
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• 2001

The needles of torreya(Torreya nucifera S. et Z) were collected, extracted with acetone-$H_2O$(7:3, v/v), fractionated with hexane, chloroform and ethylacetate, and freeze dried to give some dark brown powder. The ethylacetate soluble mixture was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Most of the needle extractives were flavan and its methyl ether compounds such as (+)-catechin, (-)-epicatechin, (+)-gallocatechin, (-)-epigallocatechin, 3'-O-methyl-(+)-catechin and 3'-O-methyl-(-)-epicatechin including protocatechuic acid, one of benzoic acids. $^1H$- and $^{13}C$-NMR, NOE and CI-MS analyses were performed to elucidate the structures of the isolated compounds.

• Journal of the Korean Wood Science and Technology
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• v.31 no.1
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• pp.16-21
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• 2003

The methanol extractives from root bark of Ulmus davidiana var japonica nakai were fractionated with n-hexane, ethyl ether, ethyl acetate and waster, the water soluble fraction was also fractionated with silicagel column chromatograhy. The chemical structure of purifided compounds were identified with UV, IR, ¹H-NMR and ¹³C-NMR spectra and the antibacterial activities also were investigated. Two different antibacterial compounds (compound A and B) were fractionated with silicagel chromatography and TLC. Compounds B was identified as a catechin rahmnoside. The both of compounds had antibacterial activity on Staphylococcus aureus and Salmonella typhimurium.