• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.296-302
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• 1991

Compression wood and opposite wood formed in a branch of Taxodium distichum Rich. is described and compared in qualitative and quantitative anatomical aspects. The qualitative features of compression wood appeared to differ from those of opposite wood in very gradual tracheid transition from earlywood to latewood, roundish tracheid shape on cross surface, tracheid tip distortion on radial surface, and existence of intercellular spaces and helical cavities. In quantitative features, compression wood tracheids showed shorter lengths than opposite wood. The ray density and the number of uniseriate rays were greater in compression wood than in opposite wood but the height of uniseriate rays in compression wood was smaller than in opposite wood.

• Journal of Animal Environmental Science
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• v.3 no.1
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• pp.27-34
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• 1997

This study was carried out to evaluate the feasibility of composting of swine manure with wood chips as a bulking agent. To evaluate the optimum blending ratio of wood chip to swine manure three levels of wood chip such as 100, 150, and 200% were blended on a volume basis with 100% of swine manure was used to determine the effect of wood chip compared with sawdust as a bulking agent on composting. The maximum temperature reached during composting was 70, 58, 48, 72$^{\circ}C$ at blending ratio of 100, 150, 200, and 50WC+50SD%, respectively. The bulk density of compost was increased extremely with increasing the blending level of wood chip. The C/N ratio of final compost ranged from 18.25 to 19.82 . Heavy metal contents in the final compost were in the range of 0.05∼0.16 mg/kg, 5,86∼10.95 $\mu\textrm{g}$/kg, and 295∼440 mg/kg for Cd, Hg, and Cu, respectively. It was concluded that the blending ratio of 200:100 of wood chip and manure by volume was satisfactory for swine manure composting.

• Journal of the Korean Wood Science and Technology
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• v.49 no.4
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• pp.315-327
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• 2021

Purpose of this study is reviewing the use method for the sawdust (sawmilling by-product) and rice husk (Agriculture by-product) by adding charcoal, an eco-friendly material. Mixed composite boards were manufactured with those materials with each density and mixing ratio, and bending performance was investigated. When the addition ratio of sawdust, rice husk and charcoal is 50:20:20 and the resin addition ratio is 10%, as the density of the prepared mixed board ranges from 0.5 g/cm³ to 0.7 g/cm³, the bending strength was 0.42~3.24 N/mm², dynamic modulus of elasticity was 94.5~888.4 N/mm², and the static modulus of elasticity was in the range of 31.4~220.7 N/mm². As the density increased, the bending performance increased, indicating that the density had a significant effect on the bending performance. In a board prepared by setting the density of 0.6 g/cm³, the addition ratio of sawdust to 50%, and the addition ratio of rice husk and charcoal at different ratios, the bending performance showed a tendency to decrease as the addition ratio of charcoal increased. The relationship between the addition ratio of rice husk and charcoal, bending strength, resonance frequency, and dynamic and static bending modulus showed a rather low correlation with the values of the coefficient of determination (R²) of 0.4562, 0.4310, 0.4589, and 0.5847, respectively. Thus, we found that the effect of the addition ratio on the bending performance was small.

• Journal of the Korea Furniture Society
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• v.17 no.2
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• pp.1-7
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• 2006

A chinese wood species called China Hongmu, is an excellent wood to make high quality furniture owing to attracting color, beautiful grain, and durability. Hongmu is not a tree or wood species name. The general designation in Hongmu group is a similar to one of its density, structure, color and use. Hongmu considers more than 30 hardwood species of Pterocarpus, Dalbergia, Diospyros, Millettia, and Cassia. According to the macrostructural characteristics and properties, Hongmu group can be classified into 8 groups which are Zitanmulei, Hualimulei, Heisuanzhimulei, Hongsuanzhimulei, Xiangzhimulei, Wumulei, Tiaowenwumulei and Jichimulei. In this paper, the growing areas, scientific names and identifiable characteristics of these Hongmu group species were introduced for help to identify China Hongmu and its products in the market as well.

• Journal of the Korea Furniture Society
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• v.18 no.2
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• pp.106-110
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• 2007

This study was performed to find potentialities of the leaves of gingko tree (Gingko biloba L.) as a raw material for particleboard (PB) manufacturing. Various amounts of the leaves were mixed with wasted wood particles to manufacture PB. Physical and mechanical properties, such as density, internal bond (IB) strength, and modulus of rupture (MOR) of manufactured PB were not much different from those of the control board. Formaldehyde emission values decreased with increasing the amount of leaves. Especially, the formaldehyde emission of PB made with 5 percent of leaves was decreased to 1.31 mg/l, which is about 36% lower emission than that of the control. From these results, the leaves of gingko tree may be considered as an additive of lowering formaldehyde emission in a functional PB manufacturing process.

• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.38-44
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• 2005

Peripheral milling is one of the most important wood machining processes in wood industry. Power consumption characteristics of twelve Korean domestic species in peripheral milling were investigated in this study. Image analysis technique was applied to extract proper data from the power consumption profiles. Average power consumption increased as cutting depth increased and specific cutting power decreased as cutting depth increased. However, no significant relationship could be found between density and power consumption and between cutting depth and surface roughness.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.853-856
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• 2006

It is known that cement production not only consumes large amount of energy but also contributes substantially to the green house gas emission. Therefore, there is a demand to develope a new technology to produce energy efficient and environmental conscious cements. The most recent, wood wool ceramic board is being applied in various building material field, for example thermal insulating and acoustic absorption material. This paper focused on improvement of the physical properties for wood wool ceramic board applied inorganic polymer binder. As the result of this experiment, what we could obtain better wood wool ceramic board's properties such as density, water contests, water resistance and band strength, was 0.46, $10{\sim}12%$, 1.9% and $40kgf/cm^2$. This result can be applicable to commercial wood wool ceramic board.

• Journal of the Korea Furniture Society
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• v.13 no.2
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• pp.29-38
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• 2002

Five type boxes, which are from brick, wood panel, charcoal-packed wood panel, plywood panel and charcoal-packed plywood panel, were prepared. Relationship of preservation characteristic of strawberry and change of relative humidity in the boxes were measured. Physical properties and industrial analysis of white charcoal used were also investigated. Physical Properties and industrial analysis showed that charcoal had: 1) $0.62-0.79g/cm^3$ of density, zero of refining degree and 8.6-9.4 of pH; and 2) 1.0-3.0% of moisture content, 1.9-2.9% of ash content, 3.9-5.0 of volatiles and 89.2-93.2% of fixed carbon, indicating high quality. During the experimental period, relative humidity was highest in the brick box and lowest in the charcoal-packed plywood panel box. Weight loss of strawberry was greatest in charcoal-packed wood Panel box and very little in brick box. In the boxes with charcoal, strawberry was preserved for 6 days without mold, but in brick box it was covered with mold in 3 days. From these results, it is suggested that charcoal-packed wood panel can be used for better ecomaterial.

• Journal of the Korean Wood Science and Technology
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• v.25 no.1
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• pp.50-55
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• 1997

This study was carried out to utilize old newspaper(ONP) and paper sludge more effectively, and also to elucidate the influences of pressing conditions on the medium density fiberboard(MDF) properties. MDFs were made from ONP and low grade of paper sludge by wet process with change of pressing time, temperature and pressure. MDFs of ONP were more affected by pressing conditions, especially pressing pressure, but temperature and pressing time were also important. According to mixing paper sludge to ONP tensile and bending strength of MDF were decreased, but density and dimensional stability were improved. These results indicated that some physical properties of MDF can be improved by paper sludge and it is possible to use it in MDF.

• Journal of the Korean Wood Science and Technology
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• v.26 no.4
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• pp.50-55
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• 1998

This study was carried out to develop low density board made of rice hull which needs proper use. Urea formaldehyde adhesive(UF) was used. The raw materials were the mixtures of the rice hulls from IllFum, DongGin, ChuChong, etc. The physical and mechanical properties of rice hull insulation board were examined. The results are as follows : For the thickness of 15mm of the low density rice hull board bonded with UF resin, proper manufacturing conditions were $171^{\circ}C$ of hot pressing temperature with thickness bar for optimum density, 12 percent of resin solid contents of rice hull ovendry weight, and 20 minutes of hot pressing time. These conditions meet Korean standards(KS 3201-1982) in relation to free formaldehyde emission, bending strength, water absorption and heat resistance.