• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.44-49
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• 2003

This study was carried out to evaluate the weathering durability of waterborne preservative (AAC, ACQ, CCA, CuAz) treated Japanese red pine (Pinus densiflora S. et Z.) sapwood samples by accelerated weathering, and to find out the factor of stability. When considered the color changes, weight losses, surface degradation, and microstructure changes due to weathering, ACQ-, CCA-, and CuAz-treated samples were durable against weathering; the weathering durability of AAC-treated samples was poor and similar to untreated controls. The lignin content in aqueous extracts collected from ACQ-, CCA-, and CuAz-treated samples during weathering was lower than that from untreated and AAC-treated ones. From these findings, we might concluded that weathering durability of ACQ-, CCA-, and CuAz-treated samples was enhanced by the fixation of preservative component(s) onto the lignin structure, which is very susceptible to weathering.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.57-62
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• 2003

The Mechanical and drying characteristics of Pinus densiflora wood, which was damaged by forest fire, and sound wood were examined. There were no significant differences in axial compressive properties, shearing strength and impact bending absorbed energy between damaged and sound woods. But the bending properties of damaged wood were slightly higher than those of sound wood. The green moisture content of sapwood in damaged wood was lower than that in sound wood, but oven-drying rate was similar in both woods. Number of initial check in damaged wood was smaller than that in sound wood, and inner check in damaged and sound woods was not observed. Consequently, it is considered that mostly damaged wood by forest fire can be used for wood material after removing the bark.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.488-496
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• 2000

This study was carried out to investigate the characteristics of longitudinal permeability and hydraulic resistance, and to compare the longitudinal permeability ($K_E$) calculated by the Hagen-Poiseuille's law (Siau, 1971) and the longitudinal permeability (K) measured in sapwood of Acer mono stem. The volume flow rate (Q) in a vessel was $0.80{\times}10^{-4}cm^3/sec$ and the hydraulic resistance ($R_S$) to viscous flow through a vessel was, on average, $1.37{\times}10^{10}dyn{\cdot}sec{\cdot}cm^{-3}{\cdot}cm^{-2}$. The average value of volume flow rate ($Q_N$) through the cross section of sapwood was $0.32cm^3{\cdot}sec^{-1}{\cdot}cm^{-2}$, and the average resistance ($R_{SN}$) was $3.59{\times}10^6dyn{\cdot}sec{\cdot}cm^{-3}{\cdot}cm^{-2}$. The values of K decreased as the diameter of stem increases, which was attributable to variations in the number of vessel per unit area rather than in vessel diameter, and to different resistances in the conducting tissues of each part of the stem. The average value of K measured at breast height was 31% of average value of $K_E$. The $K/K_E$ ratios were 100% in 4 to 6 year-old stems and more than 90% in 7 to 27 year-old stems. The $K/K_E$ ratio decreased as the age of stems increases, and was not more than 20% in near-ground parts of stem.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.288-299
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• 1996

This is the basic study to investigate the amount of transpirational water loss in thrifty mature Quercus mongolica stand by the heat pulse method. The differences of heat pulse velocity by direction and depth, differences of heat pulse velocity by dominant, codominant and suppressed trees, diurnal changes of heat pulse velocity due to the change of leaf water potential, vapor pressure deficit and radiation, and sap flow path way in sapwood by dye penetration were measured in stems. Finally the amounts of daily and annual transpiration in stand were calculated by the heat pulse velocity. The results obtained were summarized as follows : 1. Relationship between heat pulse velocity(V) and sap flow rate(SFR) was obtained as a equation of SFR=1.37V. 2. The sap flow rate was high in the order of dominant, codominant, and suppressed trees. The daily heat pulse velocity changed with radiation, temperature and vapor pressure deficit. 3. The heat pulse velocity showed the similar diurnal variation as the leaf water potential change. 4. The heat pulse velocity showed the highest value in May(4.0cm/hr in average), the lowest one in July(2.9cm/hr in average). 5. The heat pulse velocity in the same stem presented the highest value in the northern direction, medium in western, and the lowest in southern and eastern. 6. The heat pulse velocity in stem was highest in 0.5cm, medium in 1.0cm, and lowest in 1.5cm depth from the surface of stem. 7. The sap flow path way in stem showed sectorial straight ascent pattern in four sample trees. 8. The amount of sap flow(SF) was presented as a equation of $SF=1.37A{\cdot}V$(A: the cross-sectional area of sapwood, V: heat pulse velocity), and especially SF was larger in dominant tree than codominant and suppressed trees. 9. The amount of daily transpiration was 5.6ton/ha/day, and its composition ratio was 72% at day and 28% at night. 10. The amount of stand transpiration per month was largest in May(168ton/ha/month), lowest in July(125ton/ha/month). The amount of stand transpiration per year was 839ton/ha/year.

• Journal of Forest and Environmental Science
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• v.14 no.1
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• pp.1-13
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• 1998

In this paper, it has been discussed on the relation between the anatomical features of woods and the penetration of methyl methacrylate monomer system into major Korean tree species, especially the Pinus koraiensis, Larix leptolepis, Quercus mongolica and Tilia amurensis. 1. There was some differences in penetration of polymers among different tree species, but generally the penetration of ring porous woods seems to be larger than that of diffuse porous woods and it was very difficult to penetrate to Larix leptolepis, especially to the that of heart wood. 2. The penetration on transeverse surface was relatively easy but radial and tangential impregnation were somewhat hard and differences between them were negligible. 3. The penetration of sapwood was larger than that of heartwood and its differences varied according to the existence of tyloses or contents in vessel. 4. Generally the polymer penetration of earlywood was larger than that of latewood in ring porous woods, but on the contrary, penetration of earlywood was small than that of latewood on diffuse porous woods. 5. Vessel diameter of wood had nearly no relation to polymers penetration. This seems to come from the reason that effective vessel diameter varies with the existence of tyloses or contents in vessel. 6. The penetration of ray tracheids was larger than that of ray parenchyma cells in softwoods, but penetration of hardwood rays seems to be small in comparison with softwood ray parenchyma cells. 7. Specific gravity and annual ring width had no relation to the penetration of polymer.

• Journal of the Korea Institute of Building Construction
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• v.11 no.3
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• pp.256-264
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• 2011

By implementing an analysis on the liquid flame proof agent infiltration of microwave-heated wood under soaking conditions (room temperature soaking, heat soaking), its correlation with wood temperature, and the structure of wood and permeating components after soaking in flame proof agent, which was carried out as basic research in order to improve the fire resistance performance of the wood itself, it is found that the infiltration increases as the microwave heating time increases, while for heat soaking, it is found that high infiltration as well as the stable permeability of flame proof agent is achievable. Also, when the wood temperature is more than $80^{\circ}C$, the infiltration by the flame proof agent increased, and a very even infiltration of flame proof agent was observed, which implies that the liquid flame proof agent has a dependency on temperature change of the wood as a condition to penetrate into the wood. As a result of fine structure analysis, the flame proof agent transfer between cells through pits was considered as a cause to increase the infiltration of flame proof agent, and it is also shown that for heat soaking among the permeating component analysis, as the crystallized flame proof agent around the heartwood and sapwood inner pits increases, the flame proof agent can penetrate into the the heartwood part.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.12-19
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• 2017

Yellow-hearted pine (YHP; Pinus densiflora for. erecta Uyeki) is one of the Red pine species and has extremely narrow growth ring and high ratio of heartwood growing in Korea. It has been used for valuable wooden constructions as palace and temple for royal family since the Joseon Dynasty period. However, scientific information on the wood properties of YHP is still very lacking. This study was carried out to investigate natural durability of YHP to fungi and termites attack. Examination of anti-fungal and anti-termite properties of YHP was performed at indoor condition using brown-rot fungi (Fomitopsis palustris), white-rot fungi (Trametes versicolor), and termite (Reticulitermes speratus). The results showed that weight loss of the heartwood in YHP after fungi and termite test was much lower than those of the sapwood in YHP. Furthermore, the highest mortality of termite was obtained from the heartwood of YHP. Consequently, it is clearly revealed that the heartwood of YHP has excellent durability against brown- and white-rot fungi and termite.

• Journal of Forest and Environmental Science
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• v.7 no.1
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• pp.1-6
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• 1990

This study was performed to investigate the variation of tracheid length, ray spacing per mm and ray height of major coniferous woods (Picea jezoensis, Abies sachaliensis, Pinus koraiensis, Pinus sylvestris and larix gmelini)grown at Sivelian forest of USSR. The results of the study are as follows: 1. The averaged mean values of tracheid length are respectively $3550{\mu}$ on Pinus koraiensis, $3440{\mu}$ on Abies sachaliensis and Larix gmelini, $2900{\mu}$ on Picea jezoensis, and generally this values of Sivelian coniferous wood are more longer than Korean samewood. 2. The tracheid length on sapwood is more larger than heartwood and this values on latewood are also larger than earlywood. 3. The averaged mean values of ray height are respeetively 14.5 on Larix gmelini, 13.5 on Picea jezoensis and Pinus sylvestris, 9.7 on Pinus koraiensis, and this values of Sivelian coniferous wood are more larger than Korean samewood. 4. Ray height is comparatively small near the pith and tend to be increased to bark of wood. 5. The avereged values of ray spacing per mm are respectily 7.9-8.3 on Larix gmelini and Picea jezoensis, 7.1 on Abies sachaliensis, and 6.1-6.2 on Pinus koraiensis and Pinus sylvestris.

• Journal of the Korean Wood Science and Technology
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• v.33 no.6 s.134
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• pp.87-94
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• 2005

This study was carried out to investigate the effect of soil types and soil properties on wood preservative leaching. Radiata pine (Pinus radiata Don.) sapwood stakes, which had been treated with 2.0%(w/v) CCA, were leached for 12 weeks by a common laboratory method in four different soils and for 14 days by the AWPA standard leaching method in water. The physical and chemical properties of the four soils were determined, and the percent leaching of the individual component of CCA was correlated with the various soil properties. The data show that leaching of preservative chemicals from treated wood exposed to soil is influenced by the type of soil. The preservative leaching was greater when wood was exposed to water than when the wood was in contact with water-saturated soil. The greatest chromium, copper and arsenic leaching from CCA-treated stakes were observed in the sandy loam, loam, and sand, respectively, and the least amount of leaching of CCA components occurred in the silty loam. The leaching of preservative components from treated wood is extremely complex and appears to be influenced differently by the soil properties. The extent of copper leaching from CCA treated wood appears to be related to exchangeable Mg and sum of bases. There is a reasonably good relationship between chromium leaching and exchangeable Mg, and between arsenic leaching and exchangeable K, soil Ni, Mn, Fe, Cr, or Cu content. Since this study was conducted based on laboratory leaching method using small cross-sectional dimensions; thus, data obtained from this experiment should not be used to predict leaching characteristics from commercial-size wood used in real situation. Accordingly, further studies are necessary using outdoor ground-contact leaching.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.15-20
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• 2011

The pine wilt disease is one of the most serious forest diseases that kill the pine trees, and the study on the invasion and movement of the pine wood nematode within the tree is very important for understanding the inhabitation of pine wood nematode. In this relation, the microscopic observation was carried out to study the place of inhabitation and movement of pine wood nematode within the infested wood. In result, the rays were mainly infested by pine wood nematode and showed dark discoloration due to their necrosis in cross, radial and tangential surface. Also, the intensive damage was found in the resin canals. On the other hand, some traumatic resin canals in tangential band were identified in the sapwood near the cambium. In the ray, the pine wood nematode occurred more commonly in the ray parenchyma cell and fusiform ray with horizontal resin canal than in the ray tracheid and uniseriate ray without horizontal resin canal, respectively. The pine wood nematode was thought to move from ray to tracheid through the large natural opening, window-like pit, in the cross-field, neither through the small natural opening, bordered pit, in the tracheid nor through the tracheid wall by creating a bore hole.