• Title/Summary/Keyword: Woods

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Reconstruction of Vegetation During $9^{th}$ Century in Southern Korea: Anatomical and Dendrochronological Analysis of Waterlogged Woods Excavated at Cheonghea-jin Fort

  • Han, Sang-Hyo;Park, Won-Kyu;Kim, Yo-Jung;Jung, Suk-Bae
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.117-122
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    • 2003
  • This study is conducted to examine the woods that were excavated at Jangdo Island. The Jangdo site is located in a small island some 180 meters away from the main island of Wando, Jeollanam-do in southern Korea. This site is known as Cheong-Hea Jin fort for the marine King Jang Bogo during the early 9$^{th}$ century. Total of 101 specimens were collected in three groups; small-size piles, log fences (Mok-check) and logs from a well. The species of the group of piles consisted of Quercus spp. (43%), Pinus densiflora (29%), Pinus koraiensis (5%), Alnus japonica (3%), Fraxinus spp. (3%), Styrax obassia (3%), Juglans spp. (2%), Zelkova serrata (2%), Platycarya strobilacea (2%), Celtis spp. (2%), Torreya nucifera (2%), Quercus myrsinaefolia (2%), and Cinnamomum spp. (2%). The species of Mok-check and logs from the well were identified as all Pinus densiflora. The species composition indicated that the climate around A. D. 9th-10th century in southern Korea was similar to the present.. The wooden fences were also examined for tree-ring analysis. The ages of woods were 50∼60 years. We made two site chronologies. The chronologies indicated that southeastern and southwestern fences were repaired frequently. The results could not give the absolute dates due to lack of reference chronologies in this period.

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Effect of Humidity Conditions on Bending Creep Performance of Finger-Jointed Woods

  • Park, Han-Min;Byeon, Hee-Seop
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.5
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    • pp.7-15
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    • 2007
  • To evaluate the durability of finger-jointed woods according to change of humidity conditions, four types of finger-jointed woods glued with different kinds of adhesives and finger pitches were made with Sitka spruce, and the effect of humidity conditions on creep performances was investigated. The shape of creep curves differed among humidity conditions, and the inclination of creep curves was greatest in 85%RH, and lowest in 65%RH. Their creep curves showed a linear behavior beyond approximately one hour, regardless of humidity conditions. The A values of the creep curves fitted to power law increased with increasing relative humidity, whereas the A' values were in order of 30 > 85 > 65%RH unlike the A values. The initial deformation increased with increasing relative humidity, whereas the creep deformation unlike the initial deformation was in order of 85 > 30 > 65%RH, and it was found that the creep deformation of finger-jointed woods indicated the smaller amount in air-dry moisture content rather than in a low moisture content less than 30%RH. Finger-jointed woods with 6.8 mm (L) pitch had the greater creep amount than in those with 4.4 mm (S) pitch in all humidity conditions. The difference of creep amount between both adhesives in all humidity conditions was small. Relative creep at 240 hr was greatest as 62.2~71.9% in 85%RH, and the values indicated 2.1~2.6 times that of 30%RH and 3.0~3.6 times that of 65%RH and were equal or slightly greater than that of solid spruce.

A Study on Emission Characteristics of Air Pollutants from the use of Solid Fuel (고체연료 사용에 따른 오염물질 배출특성 조사연구)

  • Kim, Jong-Hyeon;Heo, Sun-hwa;Kim, Hyung-Chun;Jo, Myeong-ran;Lim, Seungy-oung;Lee, Sang-Bo;Kang, Dae-il
    • Journal of Korean Society for Atmospheric Environment
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    • v.33 no.2
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    • pp.77-86
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    • 2017
  • Globally, use of affordable fuels such as briquettes, woods and wood pellets has increased. Organic pollutants emitted from non-point sources using solid fuels may have contributed to air pollution in urban environment. In this study, we utilized simulated incinerator proposed by U.S. EPA and investigated concentrations of PM, $PM_{10}$, $PM_{2.5}$, OC/EC, CO, $SO_x$, $NO_x$, VOCs and PAHs emitted while cooking meat and fish using briquettes, woods and wood pellets, and developed emission factors. As a result, wood combustion produced more air pollutants than the others. Particulate matter emission factors for woods and wood pellets were 13.54 g/kg and 9.15 g/kg, respectively. Total VOCs emission factors for briquettes, woods and wood pellets were 36.12mg/kg, 46.13mg/kg and 18.26mg/kg, respectively. Additionally, total PAHs emission factors for briquette, woods and wood pellets were 0.44 mg/kg, 18.84mg/kg and 101.62mg/kg, respectively.

Solid-culture of Lepista nuda (Lepista nuda의 고체배양)

  • Lee, Sang-Sun;Choi, Kyoung-Jin
    • The Korean Journal of Mycology
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    • v.23 no.2 s.73
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    • pp.105-113
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    • 1995
  • The mycelia of Lepista nuda were isolated from the different basidiocarps, collected from the forests of Robinia pseudo-acaciae and mixed forests of R. pseudo-acaciae and Quercus serrata. On the different woods, the growths of mycelia collected were compared with those transferred from Applied Mycology Division, RDA. Also, the measurements of dry weight loss, as growth of mycelia, were correlated to the productions of carbon dioxide on the different wood substrates. The growth of mycelia was observed to be best on the woods of R. pseudo-acaciae; followed by the growth on the woods of Morus alba. The growth rate of mycelia appeared to be various, depending on the different kinds of wood substrates. The soild-cultures of the mycelia on the sawdust of the R. pseudo-acaciae woods and the grains of sorghum and corn were conducted, but the basidiocarps were not obtained from these. Therefore, this mycelium collected was believed to be important as new mushroom utilizing the different woods resources instead of Q. serrata.

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Anatomical Comparison of Compression, Opposite, and Lateral Woods in New Zealand Rimu (Dacrydium cupressinum Lamb.)

  • Eom, Young-Geun;Butterfield, Brian G.
    • Journal of the Korean Wood Science and Technology
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    • v.29 no.3
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    • pp.1-13
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    • 2001
  • Compression, lateral, and opposite woods in the stem and branch of rimu (Dacrydium cupressinum Lamb.), a softwood species indigenous to New Zealand, were described and compared in the anatomical aspects. Qualitatively, growth rings were wide in the compression wood, intermediate in the lateral wood, and narrow in the opposite wood. Tracheid transition from early wood to late wood was very gradual in the compression wood but was more abrupt in both the lateral and opposite woods. When viewed transversely, compression wood tracheids showed a roundish outline except at the growth ring boundary but lateral and opposite wood tracheids were angular to rectangular in outline. Intercellular spaces were occasionally detected in the compression wood except in the late wood at the growth ring boundary but were absent from both the lateral and opposite woods. Slit-like extensions of the bordered pit openings caused by the location of pit apertures within short and narrow helical grooves were observed in the compression wood tracheids but not in the opposite or lateral wood tracheids. In the compression wood tracheids, fine striations in the form of fine checks or grooves were observed on the lumen surfaces and the innermost $S_3$ layer of secondary wall was absent. In the tracheids of lateral and opposite woods, the $S_3$ layer was sometimes absent but occasionally highly developed. Cross-field pits in the compression wood appeared to be piceoid due to slit-like pit apertures but those in the lateral and opposite wood tracheids showed cupressoid to taxodioid. Quantitatively, compression wood tracheids were somewhat shorter than those of opposite or lateral wood in stem but not different from the opposite or lateral wood tracheids in branch. The walls were thicker in the compression wood than in the lateral or opposite wood. Uniseriate rays in the compression wood were fewer than in the lateral or opposite wood.

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A Study on the Preparation of Wood Plastic Combinations (II). Monomer Impregnations and Gamma-ray Induced Polymerizations

  • Pyun, Hyung-Chick;Kim, Jae-Rok;Lee, Kyung-Hee
    • Nuclear Engineering and Technology
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    • v.4 no.1
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    • pp.23-30
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    • 1972
  • A study on the preparation of wood-plastic combinations by gamma-ray induced polymerization is carried out. In monomer impregnation, the rates and amounts are determined for various woods. The polymerization rates of various monomers and monomer mixtures impregnated mainly domestic woods are studied varying the total gamma-dose and gamma-dose rates. The obtained data indicate that; 1) in impregnation of monomer, populus deltoides is the fastest in rate, and the most impregnated in amount 2) the general trends of polymerization of monomers ill woods is in the order of vinyl acetate--methyl metacrylate--styrene, ranging from 3 to 15 Mard of total does in rate of 4$\times$10$^4$rad/hr., thus vinyl acetate or methyl metacrylate is suitable monomer in view of polymerization rate, 3) the successful woods in combination with monomer are pinus rigida and pinus densiflora in view of polymerization rate, 4) the monomers in woods are more easily polymerized under the conditions of moderately lower does rate, 2.1$\times$10$^4$rad/hr.

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Utilization of Domestic Small Timbers -Shrinkage and Swelling of Alkali-Treated Woods- (간벌재 및 소경재의 이용개발에 관한 연구 -알칼리 처리 목재의 수축팽윤성-)

  • 황원중;김남훈
    • Journal of Korea Foresty Energy
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    • v.18 no.2
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    • pp.70-77
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    • 1999
  • The behaviors of alkali swelling in four major Korean woods were examined as a function of concentration cf alkali solution. Density of alkali-treated woods increased highly with increasing alkali concentration in both softwoods and hardwoods. Wood samples swelled in dimension during alkali swelling, and thereafter they shrank highly by water washing and air drying. The air-dried wood samples after alkali treatment showed almost isotropic shrinkage in tangential and radial direction.

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Species and Tree-Ring Analysis of Coffin Woods Excavated from Mundangdong, Gimcheon, Korea (김천 문당동 유적 출토관재의 수종과 연륜연대)

  • Park, Won-Kyu;Jeong, Hyun-Min
    • Journal of the Korea Furniture Society
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    • v.20 no.4
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    • pp.274-280
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    • 2009
  • The purpose of this study was to identify the species of coffin woods excavated at Mundangdong in Gimcheon and to date this coffin by using tree-ring method. All coffin woods were identified as red pines, most possibly, Pinus densiflora S. et Z. Tree-ring dating provided absolute years of 3 among 19 coffins. Both I-9 and II-22 coffins were estimated to be made in the mid-seventeenth century, and I-65-1 in the mid-sixteenth century. Others possessed too few rings to be dated.

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Dendrochronological Dating of Coffin Woods from Hoamdong, Chungju, Korea

  • Park, Won-Kyu;Kim, Sang-Kyu;Han, Sang-Hyo
    • Journal of the Korea Furniture Society
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    • v.19 no.2
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    • pp.130-136
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    • 2008
  • The objective of this study was to date coffin woods of a grave of husband and wife, using the tree rings, which were excavated from Hoamdong, Chungju city in the central area of South Korea. The species of coffin woods was Japanese Red Pine (Pinus densiflora S. et Z.), one of the major conifers growing in Korea. The husband coffin was dated as A.D. 1628. Due to the absence of bark in the wife's coffin, the number of sapwood rings was estimated to obtain the cutting date. The cutting date of wife's one was estimated to be A.D. 1651${\pm}$10. The Jeogori Jacket for women, which was found in the husband coffin, indicates that the husband died earlier than the wife, as the tree-ring dates suggested.

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Estimation of dimensional stability of woods with time by Polyethylene glycol treatment (Polyethylene glycol처리과정 중 목재 치수안정성의 경시적 평가)

  • 권구중;김남훈
    • Journal of the Korea Furniture Society
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    • v.13 no.1
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    • pp.2-8
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    • 2002
  • This study was carried out to investigate the reasonable condition for better dimensional stability in woods by polyethylene glycol(PEG) treatment. Eight species grown in Kangwon-do were used for this study. Three species of softwoods(Pinus densiflora, Pinus koraiensis, Larix kaempferi) and two species of hardwoods(Prunus sargentii, Populus tomentiglandulosa) treated with 30% aqueous solution of PEG 1000 showed good dimensional stability under the treatment for 1 day. The dimensional stability of Betula davurica, Quercus mongolica and Quercus variabilis woods increased with increasing treatment time. From the above results, it was concluded that PEG penetration and dimensional stability were affected by characteristics of wood species such as density and structure.

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