• 제목/요약/키워드: 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
    • 한국제4기학회지
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    • 제17권2호
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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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    • 제35권5호
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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.

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

  • 김종현;허선화;김형천;조명란;임승영;이상보;강대일
    • 한국대기환경학회지
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    • 제33권2호
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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.

Lepista nuda의 고체배양 (Solid-culture of Lepista nuda)

  • 이상선;최경진
    • 한국균학회지
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    • 제23권2호통권73호
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    • pp.105-113
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    • 1995
  • 한국교원대학교 주변의 아카시아림 및 상수리나무와 아카시아의 혼합림에서 민자주방망이버섯(L. nuda)을 채집하여 균사를 순수분리하였다. 분리된 균사와 농진청 균이과에서 분양 받은 균사를 시료로 수종의 기질에 따른 균사의 성장을 나무 건중량과 탄산가스 발생량으로 측정하였다. 이 결과 아카시아, 뽕나무, 느티나무 순으로 균사의 성장을 나타냈다. 아카시나무 톱밥, 조 및 옥수수를 이용한 고형발효를 한 결과 균사의 성장에 관련된 성장곡선은 그렸으나, 자실형성을 하지 못하였다. 그러나, 앞으로 유망한 식용버섯으로 다른 수종의 나무에 자라는 균사를 얻었으며, 자실체 형성을 위하여서는 많은 연구가 필요하다.

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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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    • 제29권3호
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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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    • 제4권1호
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    • pp.23-30
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    • 1972
  • 감마선 중합에 의한 목재와 프라스틱의 복합체 제조에 있어서, 각종 목재들에 대한 단량체의 침투량과 침투속도를 검토하였으며, 중합에 있어서는 국산 목재를 주로 하여 이에 각종 단량체 및 그 혼합물, 방사선의 조사량, 조사율, 이에 따르는 중합속도 등을 검토하여 다음과 같은 결과를 얻었다. 1) 단량체 침투에 있어서, 침투속도나 침투량은 모두 포플라에서 컸다. 2) 목재내에서의 단량체의 중합속도는 비닐 아세테이트-메찔메타아크릴레이트-스타이렌의 순서이며 필요한 전 조사량은 조사율 4$\times$$10^4$rad/hr에서 3~15Mrad의 범위었다. 따라서 중합속도의 관점에서 볼때 비닐아세테이트나 메찔메타아크릴레이트가 좋은 단량체 이다. 3) 단량체와의 결합에 있어서 리기다송, 육송등이 중합속도로 보아 효과적인 목재이다. 4) 목재 내부에서 단량체는 비교적 낮은 조사율인 2.1$\times$$10^4$rad/hr에서 더 용이하게 중합되었다.

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

  • 황원중;김남훈
    • 임산에너지
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    • 제18권2호
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    • pp.70-77
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    • 1999
  • 간벌 소경재의 새로운 용도개발을 위한 기초연구로서 국내산 주요 침·활엽수 4수종의 알칼리팽윤 특성을 조사하였다. 그 결과, 4수종 모두 알칼리 처리후 밀도가 증가하였으며 그 정도는 활엽수재가 더 크게 나타났다. 알칼리처리에 의해 접선방향의 팽윤이 현저한 반면 방사방향의 팽윤은 작았고, 섬유방향은 오히려 감소하는 경향이 있었다. 알칼리 팽윤후 수축율은 활엽수재가 더 컸으며, 특히 기건상태까지의 수축율은 방사방향과 접선방향간에 수축육의 차이가 거의 없이 등방적으로 수축하는 특징을 보여주었다.

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

  • 박원규;정현민
    • 한국가구학회지
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    • 제20권4호
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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
    • 한국가구학회지
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    • 제19권2호
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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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Polyethylene glycol처리과정 중 목재 치수안정성의 경시적 평가 (Estimation of dimensional stability of woods with time by Polyethylene glycol treatment)

  • 권구중;김남훈
    • 한국가구학회지
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    • 제13권1호
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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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