• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.145-157
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• 1999

Wood dust is created when machines are used to cut or shape wood materials. Industries of high risk of wood dust exposure are sawmills, dimension mills, furniture industries, and carpenters, etc. Health effects associated with wood dust exposure includes dermatitis, allergic respiratory effects and cancer. Health effects of wood dus t are mainly depend on the concentration, dust size and exposure time. This study were carried out to evaluate the concentration and particle size distribution of wood dust during working processes. The subjects of this study were 53 workers exposed to wood dust in 7 furniture factories and 5 musical instruments, and 5 sawmill factories. The average total wood dust concentrations measured by personal cascade impactor were $1.82{\pm}2.31mg/m^3$ in primary manufacture, $3.59{\pm}1.72mg/m^3$ in s econdary manufacture, $5.09{\pm}1.46mg/m^3$ in sanding operation. Mass median diameters of hardwoods dust were $3.36{\mu}m$ in primary manufacture, $4.25{\mu}m$ in secondary manufacture, $4.21{\mu}m$ in sanding operation. softwoods dust were $3.39{\mu}m$ in primary manufacture, $4.34{\mu}m$ in secondary manufacture. Particle size distributions showed a nearly the same pattern in each working processes. The sample concentration of all hardwood dust exceeded the Threshold Limit Value(TLV) and 20.8% of the softwood dust exceeded the Threshold Limit Value. The range of size distribution were $0.5-10{\mu}m$ in the soft and hardwood dust. The respirable dust of soft and hardwood took up 59% and above. Therefore new threshold limit value for wood dust should be needed in Korea. Also, it should be done for various studies on health effects related to occupational exposure of wood dust.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.618-630
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• 2020

Muna teakwood, especially from old stands, has been popular as raw material for timber industries in Indonesia for the past ten decades. Due to the scarcity of this wood, superior-grown seedlings of Muna teakwood have been developed and widely planted. Since there is no information on its characteristics, therefore, the aim of this research was to investigate wood characteristics of the 8-year-old superior-grown teak from Muna Island to ensure their proper utilization as raw material for wooden furniture. Wood discs and boards from basal area of three different trees were used as the samples. Macroscopic and microscopic anatomical characteristics were observed following the IAWA's list, while their physical-mechanical properties were measured following British Standard 373-57. Results showed that anatomical characteristics of this wood sample are similar to regular teakwood, but its heartwood portion is higher. Differences among trees are found in regards to wood texture, growth ring width, as well as early and latewood portion. The green moisture content was lower than that of fast-growing teak of a similar age. The wood is more stable than the old teakwood, but its specific gravity is lower. In general, mechanical properties of this wood were higher than those of the regular fast-growing teakwood, but lower than the old one. Based on its specific gravity, this superior Muna teakwood was categorized as a Strength Class of III. The wood is suitable enough for wooden furniture manufacturing.

• Journal of the Korea Furniture Society
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• v.20 no.1
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• pp.52-60
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• 2009

Joyangru, which is located in Woodo mountain in Chuncheon, Korea, was a gate tower of Monsogak. There are little historical records about Joyangru except of the 20th-century records. To study about Joyangru history, a dendrochronological analysis was conducted. We identified also the species of woods, We took 87 samples of wood elements for the species analysis and 13 samples for the dendrochronological analysis. We found 78 hard pines(Diploxylon), 4 Douglass-fir, 3 exotic hard pines(Pinus ponderosa type) and 1 Shorea sp.(Dipterocarpaceae). In the dendrochronological analysis, 2 floor flames were dated in 1887 (with complete sapwood) and 2 beams in 1884. We concluded that Joyangru was reconstructed just after 1888, most likely in 1890 together with Monsogak.

• Journal of the Korea Furniture Society
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• v.21 no.1
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• pp.17-25
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• 2010

Three buildings -Jibokjae, Hyubgildang and Palujung- are connected each other and consist of a library and reception complex for royal kings at Kyungbok Palace in Seoul. Jibokjae and Hyubgildang were known to have been moved from Changdok Palace in A.D. 1891. No construction records have been known for Palujung. In 2004, during repair of three buildings, a dendrochronological analysis was conducted to examine their building histories. We took 67 wood samples for dendrochronological analysis; 20 from Jibokjae, 37 Hyubgildang and 10 Palujung, respectively. The results showed that the felling dates of Jibokjae and Hyubgildang woods were A.D. 1877-1879/1880, indicating original construction of two buildings at early 1880s. Felling dates of Palujung were 1886-1889/1890, those of roof filling timbers 1890 and the connection part between Hyubgildang and Jibokjae 1886, confirming 1891's movement of Hyubgildang and Jibokjae and adding a new building, Palujung.

• Journal of the Korea Furniture Society
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• v.19 no.2
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• pp.111-115
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• 2008

An experiment was conducted to know ultra-pure distilled water penetration depth through large vessel, small vessel, latewood fiber and earlywood fiber in longitudinal direction of Castanea crenata. In heartwood, latewood fiber transported water more than large and small vessel. While in sapwood, small vessel conduction depth was found the highest. Penetration depth of water after 15.0 seconds, no significant difference was observed among earlywood fiber, latewood fiber and earlywood vessel. Whilst in heartwood, no statistical difference was observed among earlywood fiber, latewood fiber and earlywood vessel. At the beginning, the speed of water penetration was high and then gradually decreased.

• Journal of the Korea Furniture Society
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• v.19 no.2
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• pp.151-155
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• 2008

An experiment was conducted to observe the 5% CCFZ solution penetration depth through ray parenchyma and ray tracheid of Larix kapempferi. Moisture content was adjusted 28% for both sapwood and heartwood. Even though the moisture content was same, heartwood was 1.3 times less permeable than sapwood and the difference was found statistically significant. Due to anatomical differences between ray parenchyma and ray tracheid, ray parenchyma was about 1.3 times more permeable than ray tracheid. Penetration speed was high initially and it decreased rapidly in course of time.

• Journal of the Korea Furniture Society
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• v.18 no.4
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• pp.282-286
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• 2007

An experiment was conducted to compare the 1% safranine solution flow depth in radial and longitudinal direction of Prunus sargentii. Longitudinal flow of safranine solution was found higher than radial flow. Body ray parenchyma was found more permeable than marginal ray parenchyma and it was about 1.3 times higher. Intercellular space conducted safranine solution more than ray parenchyma. Vessel was found to be the main avenue for liquid conduction in longitudinal direction. Different anatomical features of ray, vessel and fiber affected the penetration depth of safranine solution. Moreover initial penetration depth was found to be high and thereafter decreased gradually.

• Journal of the Korea Furniture Society
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• v.18 no.4
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• pp.312-316
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• 2007

A study was conducted to know 99.5% ethyl alcohol penetration depth in radial and longitudinal direction of Castanea crenata. Alcohol penetration depth was found higher in longitudinal direction by about 12.47 times. In both earlywood and latewood, fiber conducted alcohol in higher depth than that of large and small vessel. Penetration depth of alcohol after 15.0 second of penetration in longitudinal direction, there was no significant difference among fiber in sapwood and heartwood, and vessel in sapwood. At the beginning of penetration the speed was high and then gradually decreased.

• Journal of the Korea Furniture Society
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• v.17 no.2
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• pp.49-56
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• 2006

This research was carried out to examine the FIR (far-infrared rays) emissivity and emission power of five types of flooring board by the mixing ratio of charcoal and loess, and the physical property of five types of injected flooring board by the amount of mixture. Type D was appeared the most high value of FIR emissivity and emission power. But there was a little difference among the five types of flooring board values. In physical properties, control type flooring board and injected flooring board showed a similar tendency. Among the domestic trees, all of hard wood seems to be used to surface wood for strong hardness flooring board. But a coniferous tree was not.

• Journal of the Korea Furniture Society
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• v.18 no.2
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• pp.138-142
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• 2007

Optical microscope was used to observe the difference of safranine penetration in Pinus densiflora, Pinus rigida, Pinus koraiensis and Larix kaempferi grown in Korea. It was found that Pinus koraiensis contained the highest number of ray parenchyma and ray tracheids. In longitudinal direction, latewood penetration was found higher than that of earlywood. The number of resin canals was found highest in Pinus koraiensis and lowest in Pinus rigida. The resin canal conducted safranine higher than longitudinal tracheids. In longitudinal direction, safranine diffused from longitudinal tracheid to ray parenchyma through the cross-field pits and from the longitudinal resin canal to ray parenchyma or longitudinal tracheid. Safranine diffused from longitudinal tracheid to its neighboring tracheid through bordered pit or ray parenchyma through the cross-field pits.