• Title/Summary/Keyword: wood turnery

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Microwave-Vacuum Drying of Short Roundwoods and Wood Turneries (단척 통나무와 선반가공목의 마이크로웨이브-진공 건조)

  • Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.29 no.4
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    • pp.25-32
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    • 2001
  • A microwave vacuum (MW/V) dryer was developed for drying short roundwoods, from which woodcraft souvenirs in Korean market are mostly made, and which were hardly dried without defects in a conventional kiln. It consisted of three 1.5 kW magnetrons of 2,450 MHz, a vacuum pump, a load cell of 100 kg and a cavity of $580{\times}580{\times}1,360\;mm^3$. A computer program was developed to switch on or off the magnetrons according to drying schedules, those were based on microwave injection time or the average of wood temperatures. To evaluate the new MW/V dryer the roundwood specimens of rigida pine, poplar and birch were dried. Their log diameters and lengths ranged from 125 to 25 em and from 25 to 50 cm, respectively. In spite of the presence of minor drying defects, the MW/V drying is found to be an effective method for drying short roundwoods. Wooden turneries made of red alder and ash logs were also MW/V dried from green to 4%MC without any degradation. The rates of the MW/V drying were examined for three different lengths of poplar logs.

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Acacia mangium Willd. - A Fast Growing Tree for Tropical Plantation

  • Hegde, Maheshwar;Palanisamy, K.;Yi, Jae Seon
    • Journal of Forest and Environmental Science
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    • v.29 no.1
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    • pp.1-14
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    • 2013
  • Acacia mangium is an evergreen fast-growing tropical tree, which can grow up to 30 m tall and 50 cm thick, under favorable conditions. It is a low-elevation species associated with rain forest margins and disturbed, well-drained acid soils. It is native to Papua, Western Irian Jaya and the Maluku islands in Indonesia, Papua New Guinea and north-eastern Queensland in Australia. Due to its rapid growth and tolerance of very poor soils, A. mangium was introduced into some Asian, African and western hemisphere countries where it is used as a plantation tree. A. mangium has good quality wood traits, such as a comparatively low proportion of parenchymatous cells and vessels, white and hard wood, and high calorific value. Therefore, it is useful for a variety of purposes, such as furniture, cabinets, turnery, floors, particleboard, plywood, veneer, fence posts, firewood, and charcoal. It is also being used in pulp and paper making because it has good pulp traits, with high yields of pulp, quality of kraft, and produces paper with good optical, physical and surface properties. Because there are significant provenance differences in growth rate, stem straightness, heartwood formation and frequency of multiple leaders, the productivity and quality also varies depending upon environmental conditions, so genetic improvement programmes have been undertaken in countries like Australia, India, Indonesia, Malaysia, the Philippines, Taiwan and Thailand. The programme includes provenance identifications and testing, plus tree selection and clonal multiplication, establishment of seed orchards and hybridization. The phenology, reproductive biology, fruit characteristics, silvicultural practices for cultivation, pest and diseases problems, production of improved planting stock, harvesting, wood properties and utilization have been discussed in this paper.

Species Identification of Ancient Wood Excavated from Capital Area in Sabi Era, Baekje (백제 사비기 목제유물의 수종 식별과 분석)

  • Han, Sang-Hyo;Park, Won-Kyu
    • 보존과학연구
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    • s.25
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    • pp.197-226
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    • 2004
  • This study was made to identify species of archaeological wood products excavated from three sites(Kwunbuk-ni, Gungnamgi, Wanggung-ni) of Sabi Era, Baekje. These sitesare presumably considered as capital areas of Sabi Era, Baekje. Total of 220 specimens were identified into five softwoods and eighteen hardwoods. Pinus densiflora(or Pinusthunbergii) and Quercus spp. are the most common and occupied 32%, 28% of totalspecimen, respectively. The others are follows : Torreya nucifera(1%), Abiesholophylla(3%), Cryptomeria japonica(4%), Thuja spp.(2%), Chamaecyparisobutusa(2%), Salix spp.(1%), Platycarya strobilacea (3%), Alnus spp.(1%), Carpinusspp.(0.5%), Castanea crenata(9%), Zelkova serrata (6%), Celtis spp.(0.5%), Prunusspp.(2%), Rhus verniciflua(1%), Rhus trichocarpa(0.5%), Meliosma oldhamii(1%),Hovenia dulcis(1%), Kalopanax pictus(0.5%), Cornus walteri(0.5%), Styrax japonica(1%),Fraxinus rhynchophylla (0.5%), F. sieboldiana(1%).Most of the identified species have been growing in this area until nowadays. However,a few species(Cryptomeria japonica, Thuja spp. Chamaecyparis obutusa, Torreyanucifera) didn’t grow natively around this area at that time. Two species(Cryptomeriajaponica, Chamaecyparis obutusa) are endemic species of Japan, indicating international trade or exchange of woods between Baekje Kingdom and Japan in 6-7th century. Torreyanucifera grows in limited areas in Korea (south of $35^{\circ}$10′N), however, is widely distributed in the southern Japan. Quercus spp. was identified the most in implements of Baekje and Pinus densiflora(orPinus thunbergii) was in the second place. Zelkova serrata was mainly used for raw materials of turnery products, e.g., wooden container. This species produces one of the hardest woods as 0.7 in specific gravity. It indicates that iron technologies have reached some high level in Sabi Era, Beakje.

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