• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.310-317
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• 2013

This research has been carried out to evaluate the durability characterization of larch wood used for woody erosion control dam. Wood deterioration and strength properties were analyzed according to installed position and duration. Optical and scanning electron microscope were used for examining wood deterioration, and an universal testing machine was applied for compression and shearing strength. As a result, deposited wood in water was maintained almost similar anatomical and physical properties compare to normal wood, even though it was used for seven years. In non-deposited wood which was installed on the side of the dam, heartwood did not show any significant change during seven years, while sapwood was significantly deteriorated in five years. Also, strength properties of sapwood were significantly decreased according to installed duration whereas, degree of decrease in heartwood were relatively smaller than that in sapwood.

• Journal of the Korean Wood Science and Technology
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• v.28 no.1
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• pp.1-17
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• 2000

Crystals in the woods and barks of Populus maximowiczii and Populus nigra ${\times}$ maximowiczii were examined by light microscopy, scanning electron microscopy and soft X-ray. Populus examined had the wetwood and the heartwood of Populus showed higher moisture content than in adjacent sapwood. The crystals can be detected clearly by the soft X-ray due to their higher densities than the wood. Crystals in xylem wood of Populus were found mainly at heartwood. However, they were concentrated in specific areas such as in color-stained area or along the specific annual rings. Crystals showed the highest occurrence around the pith. Within a growth ring the amount of crystals in earlywood was more abundant than in latewood. Crystals were observed mainly at vessels and fibers although they occurred at all kinds of cells in heartwood. Crystals in the bark were scattered evenly both in inner bark and in outer bark. Populus nigra${\times}$maximowiczii showed higher frequency of leaf knots than Populus maximowiczii.

• Journal of the Korea Furniture Society
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• v.18 no.2
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• pp.100-105
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• 2007

In this report, we describe the anatomical features of Gmelina arborea Roxb. belong to the genera of Verbenaceae native to Bangladesh and safranine penetration depth in radial and longitudinal directions. The wood of this species was characterized mostly by distinct growth ring boundaries, diffuse-porous, simple perforations, alternate non-vestured intervessel pits, and relatively short vessel elements and medium fibers. Thin to thick walled septate fibers with simple to minutely bordered pits are confined to the radial walls. Tyloses are common. They are paratracheal axial parenchyma vascicnetric and confluent. Rays not higher than 1milimeter are found, and larger rays commonly 4 to 5 seriate are dominantly present, as are multi seriate rays composed of a procumbent ray with 1 row of square or upright cells. Acicular crystals are present in ray cells. Another experiment was taken under consideration to observe the liquid penetration depth in longitudinal and radial directions using safranine. It was found that safranine penetrated easily in longitudinal direction and sapwood was more permeable than heartwood.

• Journal of the Korea Furniture Society
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• v.21 no.5
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• pp.413-423
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• 2010

The study has been carried to evaluate the wood color, a typical element of visual and decorative effect, for seven major domestic softwoods using L*a*b* and chrominance ($\Delta$E*ab). The result showed that the values of whiteness, redness, and yellowness were positive at both sapwood and heartwood and there were no wood having a small chrominance difference ranged 0~0.5. There was also no wood having a chrominance difference ranging 0.5~3.0. Ginkgo biloba, Pinus koraiensis, and Larix kaempferi wood showed a little different chrominance, Taxus cuspidata, Pinus densiflora for. erecta, and Pinus densiflora wood substantial different chrominance, Juniperus chinensis wood largest different chrominance. It is concluded that the study results could be utilized as a data base in areas of wood craft and furniture and could open a way to substitute foreign imported woods.

• Journal of the Korea Furniture Society
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• v.15 no.1
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• pp.1-7
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• 2004

Domestic oak trees of Quercus variabilis and Quercus serrata were harvested from several forest sites and their green moisture contents, green specific gravities and fiber lengths were compared. The green specific gravities of Quercus serrata trees showed differences between the forest sites at 5% significance level while those of Quercus variabilis didn't. In the radial direction the green specific gravities of Quercus variabilis gradually increased from pith to bark. There was no discrepancy of the green specific gravities between the sapwood and heartwood of Quercus variabilis. And no difference of fiber length was found between individual trees and tree heights for both species.

• Journal of the Korea Furniture Society
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• v.18 no.2
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• pp.111-119
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• 2007

An experiment was conducted to know the safranine impregnation distance from surface to inward using 6 different hardwood species. During impregnation, 3 parameters were applied-vacuum, pressure and soaking time. Only vacuum treatment did not increase the permeability of wood. Vacuum followed by pressure increased the penetration depth of safranine in radial, tangential and longitudinal direction. Longitudinal penetration was found easy to impregnate. Comparing with radial and tangential direction, radial penetration was found easy. There was a striking difference among sapwood and heartwood permeability. Safranine input depth was found highest in diffused porous wood rather than in ring porous wood. At increased vacuum and pressure, safranine penetration was found easy.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.27-32
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• 1997

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.

• Journal of the Korean Wood Science and Technology
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• v.21 no.3
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• pp.37-44
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• 1993

The collapse of four domestic Fagaceae species was observed in relation with their moisture content(MC), basic density, P (Percent of moisture content saturation of the wood) and Q (Percent of cell cavity volume containing water) and the variation of collapse phenomenon in the cross section of stem was also investigated. The results were summarized as follows : The values of collapse in each species were great in order of Quercus dentata, Quercus variabilis, Quercus aliena and Quercus mongolica and the values were higher in heartwood than in sapwood in all of specimen. MC, basic density, P and Q were important factors which affected on the occurance of collapse and the collapse phenomenon was decreased from pith to bark.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.98.2-99
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• 2003

Bacterial canker of sweet cherry (Prunus cerasus L.) was observed in farmers' orchard in Goesan, Chungbuk in 2003. Typical canker symptom occurred on the branches or twigs of sweet cherry in early spring and bacterial exudates oozed out of the cracked barks of diseased trees. Watersoaked brown symptom appeared on the leaves and severe infection caused thorough defoliation on the branches or twigs of sweet cherry. When cut the severely infected branches or twigs, irregular and rusty-colored symptoms in sapwood and heartwood were clearly found, indicating that they could serve as specific symptoms of bacterial canker of sweet cherry. The gram negative, aerobic bacterium isolated from the lesion produced fluorescent pigments on King's B agar medium but did not grow at 37$^{\circ}C$ The bacterium formed Levan-type colonies, and showed negative reactions in oxidase reaction, arginine dihydrolysis test, and pectolytic activity Based on the biochemical and pathological characteristics, the causal organism was identified as Pseudomonas syringae pv. morsprunorum. This is the first report on bacterial canker of sweet cherry in Korea.

• Journal of the Korean Wood Science and Technology
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• v.19 no.2
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• pp.30-39
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• 1991

Internal moisture gradients of 3cm-thick radiata pine (Pinus radiata) sapwood and meranti(Shorea spp.) heartwood were determined by using slicing method during drying and were predicted by Hart's Sorption Simulation. The shapes of internal moisture gradients. moisture contents and drying rates, which were obtained by the slicing method. were compared with those predicted by Sorption Simulation. After the 2nd fitting attempts. the differences between the gravimetric drying rates and the drying rates predicted by Sorption Simulation were less than 0.021%/hr for radiata pine and 0.043%/hr for meranti. The shapes of the internal moisture gradients predicted by Sorption Simulation were in good agreement with those obtained by the slicing method. It could be concluded that Sorption Simulation be an excellent tool to predict internal moisture gradients of wood.