• Journal of the Korean Wood Science and Technology
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• v.33 no.2 s.130
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• pp.24-28
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• 2005

Monte Carlo simulation was performed on theoretical models of plywood warp for southern yellow pine plywood originating from the United States. The objective of the investigation was to determine which plywood layers was more warp sensitive to veneers that were manufactured to an undesired thickness. This study found that for a balanced panel (a panel of equal target thickness for each of five layers) manufactured veneers of undesired thickness would experience minimal warp. The veneers of undesired thickness placed in the center of the plywood panel also provided a minimum change of plywood warp properties. The panel warp was very sensitive to surface veneers constructed with undesired thickness. Conversely, this study confirms that monitoring of veneer thickness and proper allocations within the plywood lay-up were critical.

• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.70-75
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• 1998

In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.439-445
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• 2010

Wood boring insects collected around bait logs of Pinus densiflora and Pinus koraiensis were 45 species from 4 families, which were composed of 21 species of Cerambycidae, 9 species of Curculionidae, 2 species of Rhynchophoridae, and 13 species of Scolytidae. Parasitic or predatory insects were 35 species from 15 families in 6 orders. Among the natural enemies, 2 parasitoids of Dolochomitus nakamurai and Echthus reluctator, and 2 predators of Trogossita japonica and Thanassimus lewisi, were observed frequently attacking a vector insect, Monochamus saltuarius, which has been known to transmit pine wood nematode. Bursaphelenchus xylophilus. Adults of D. nakamurai and E. reluctator emerged during early April and early May. Both parasitoids laid eggs on M. saltuarius prepupa and papa, which passed winter inside the pupal chamber. The general predators, T. japonica and T. lewisi, preyed actively during April and October, and attacted almost all of developmental stages of wood borers.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.71-80
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• 2003

The lignin degrading fungi were isolated from decayed woods and fruiting bodies gathered in forest area. Lignin degradation ability was investigated by Klason lignin of microbial treated pine wood. Among selected fungi, CJ-6 had 49.48% Klason lignin loss which was greater than 40.58% shown by Trametes versicolor that it is known as a typical lignin degrading fungus. Also, the biodegradation process and morphological features of degraded pine wood by selected fungi were observed with the scanning electron microscope. At the stage of 20 days incubation, mycelia invasion was observed without any failure of wood structure. At 60 days, wood decay was gone in some degree and one part of tracheid and ray wall was destroyed. At 100 days, tracheid wall was severely destroyed, and distinction between ray cell was difficult as cell wall was decayed much.

• Journal of the Korean Wood Science and Technology
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• v.27 no.4
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• pp.15-19
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• 1999

Three wood coffins of Chosun Dynasty period buried about 450 years ago were excavated in the sound condition in Andong area in the early 1998. The proprietors of wood coffins were grandparents, Mr. Myoung Jong Lee and Mrs. Mun, and their grandson, Mr. Eung Tae Lee, and the social standing of their family was known to belong to the nobility in those days by the clan genealogy. All the wood coffins investigated through light microscopy had same anatomical characteristics as follows: abrupt to somewhat abrupt tracheid transition from earlywood to latewood; normal longitudinal and horizontal resin canals with thin-walled epithelium; tylosoids in resin canals; bordered pits frequently in 1 row on radial walls of tracheids; 1 or 2 window-like pits per cross-field; uniseriate and fusiform rays; heterogeneous rays composed of body ray parenchyma cells and marginal ray tracheids or homgeneous rays composed of only ray tracheids; dentate ray tracheids; occasional trabeculae traversing tracheids in radial direction. Based on theses microscopic characteristics, all the wood coffins were identified to be Korean red pine (Pinus densiflora) or Korean black pine (Pinus thunbergii). Korean black pine growing naturally in coastal area might not be probable because the site of excavation, Andong area, was mountainous and inland area of Korea Thus, Korean red pine was thought to be the possible species for the wood coffins because of its natural distribution through the Korean Peninsula and the easy availability.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.323-326
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• 2005

This study aims to show the growing popularity in the use of wood in new residential construction and improvements to existing housing throughout Asia. Residents want wood in their house and we also have the problem to reduce carbon dioxide which we can solve by using wood. If well implemented in construction, we can expect Kyoto protocol reduce the average global temperature by 0.02$^{\circ}$C or even up to 0.28$^{\circ}$C by the year 2050. A survey of Korean and Japanese people was conducted targeting unique preferences that may exist between these two Nations. Initial findings showed that residents preferred wood in their homes and reductions in carbon dioxide was also a factor. It is important for architects and those interested in using wood to understand that there are many advantages to using wood materials for construction. From this point of view using wood to can produce appreciable effects such as cutting house maintenance costs, creating a natural home design, and building in a manner that is friendlier on the environment.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.116-125
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• 2017

In this study, natural extract of Ouercus mongolica by steaming explosion treatment were tested for antioxidant activity and safety. To determine the antioxidative properties of the hot water extracts, experiments were carried out by dividing into four groups (10 mice per group) of four-week-old B6C3F1 male mice from Air Logistics, Japan. As safety test, cell viability test, oral toxicity test were done. The activity of peroxidase was increased by more than 29% in the group treated with hydrothermal extract. From 4 kinds of safety tests, toxicity was not observed. From experimental results, natural extract of Ouercus mongolica by steaming explosion treatment showed superb safety and antioxidant effect.

• Korean Journal of Human Ecology
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• v.16 no.5
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• pp.979-986
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• 2007

The purpose of this study is to investigate the dyeability, and the hand of soybean/cotton blended fabric after dyeing with natural and synthetic dyes. Soybean/cotton blended fabrics dyed with extracted solution from turmeric, sappan wood, gardenia and synthetic dyes(weak-acid dyes, reactive dyes, direct dyes). The hand value of soybean/cotton blended fabrics dyed with 6 different dyes was measured using Kawabata Evaluation System. The results are as follows; 1. The K/S value of the soybean/cotton blended fabric dyed with sappan wood extracts was the highest. 2. The color fastness of the soybean/cotton blended fabric dyed with reactive dyes was excellent. The fastness to the light of the same fabric was much better than the other fabrics. 3. Linearity of load-extension and tensile energy of the soybean/cotton blended fabric dyed with sappan wood extracts showed very high. Shear stiffness of the soybean/cotton blended fabric dyed with weak-acid dyes was much higher than that of fabric of dyed with reactive dyes. Bending property of the fabrics dyed with natural colorants(sappan wood, gardenia) showed very high, but that the fabric dyed with reactive dyes was very poor. 4. In the primary hand value, stiffness and anti-drape stiffness of the fabric dyed with weak-acid dyes showed the highest. Fullness and softness of the fabric dyed with weak-acid dyes showed very low.

• 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.

• Journal of the Korean Wood Science and Technology
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• v.46 no.6
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• pp.703-712
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• 2018

The sound absorption property, hand feel, air permeability and pore size of 25 kinds of traditional Korean natural wallpapers (Hanji) were measured and analyzed in this study. The sound absorption rate of Hanji became larger with increasing of frequency beginning from 3.2 kHz, reached 2 times in frequency range of nearby 4 kHz. The sound absorption rate of Hanji was increased as the permeability was lowered and the pore size was decreased. The sound absorption property of Hanji wallpaper could be improved by manufacturing process such as super calendering process.