• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.15-21
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• 2006

The objective of this research is to develop the technique for carbonization of wood pellet and analyze a possibility for the utilization of carbonized wood pellet. The properties of wood pellet charcoals, such as density, yield, elemental composition, higher heating value, and methyleneblue adsorption, were analyzed. Wood pellet was made of sawdust of Hyunsasi-poplar, Japanese larch, Korean pine, Korean red pine, and Jolcharn-oak (serrate oak), respectively. The high density charcoal ($0.5{\sim}0.7g/cm^3$) was yielded from densified wood pellet. The carbon contents and calorific values of wood pellet charcoals were increased with the increase of carbonization temperature. The methyleneblue adsorptivity of wood pellet charcoal was similar to that of wood charcoal.

• Journal of the Korean Wood Science and Technology
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• v.16 no.3
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• pp.65-71
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• 1988

캐나다가 미국산 활엽수재의 가장 큰 수입국이며 수입된 일부 제재목과 수입원목으로 제조된 단판중 일부는 유럽으로 재 수출되고 있다. 수입 물량적인면에서 캐나다는 다른 국가와의 격차는 좁혀지더라도 미국산 활엽수재의 제1위 수입국의 위치를 당분간 유지할 것이다. 유럽에서의 제재목 수요가 1973년부터 1983년간의 10년간에는 급진적으로 증가 되었지만 1984년에 는 갑자기 감소되었다. 이와같은 현상은 과거 유럽 전통가구에 소재(素材)를 많이 사용했지만 현재는 소재(素材)를 적게 사용하고 단판이나 인쇄한 종이를 붙인 파아티클 보오드(PB)를 더욱 많이 사용하고 있기 때문이다. 현재 유럽지역에서는 가구의 크기를 줄이거나 가구에 사용되는 원자재의 비용을 줄임으로 제품의 가격을 싸게하여 소비자에게 보다 경쟁력있는 가격으로 제품을 공급할려고 하고 있으며 활엽수재의 가격이 너무 비싸 가구제조업체들은 소재(素材)를 다른 것으로 대체하고 보다 값싼 수종을 모든 지역에서 찾고 있는 중이다. 태평양 연안국가에서의 미국산 활엽수재의 수입 물량은 계속 증가되어 미국산 활엽수 총 수출 물량의 약 23% 정도 된다. 자유중국과 일본에서 미국산 활엽수재를 가장 많이 수입하고 있다. 자유중국은 주로 수출용 가구부품및 가구에 사용되는 red oak와 white oak 가 주 수종이고 가구는 미국으로 재 수출하고 있다. 일본은 주로 black cherry, yellow poplar와 cotton wood를 수입하는데 수입량의 약 67%는 대패질한 건조 가공품이다. 자유중국에서와는 달리 일본에서의 미국산 활엽수의 용도는 일본산 활엽수의 대체수종으로 허용되고 있다. 앞으로 일본에서의 미국산 활엽수재의 수요는 일본 국내시장의 요인에 의해 좌우될 것인데 한정된 물량의 일본산 활엽수재와 온대 활엽수재의 요구에 영향을 받을 것이다.

• Journal of the Korea Furniture Society
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• v.18 no.2
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• pp.143-146
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• 2007

This study was carried out to assess the dimensional stability of wood material treated by plastic processing for bentwood and compression wood. The evaluation method was different between two wood materials, but the treatments for them were very similar to each other. One of the main methods is heat treatment with sufficient water vapor. In bentwood, the used species were painted maple (Acer mono), bitter wood (Picrasma quassioides) and birch (Betula schmidtii). Steaming was the worst treatment method for dimensional stabilization of bentwood. The best results could be attained with PEG treatment for dimensional stabilization of bentwood. Dimensional stability of bitter wood was found to be conspicuous. However the steaming treatment at lower temperatures, i.e., about $130^{\circ}C$ was not suitable for dimensional stability of bentwood. In compression wood, the used specimen was Italian poplar wood (Populus euramericana). Two heat compressive pressing conditions, an open-press system and an air-tighten closed-press system, were used. The recovery rate was measured after boiling and/or absorbing in water to estimate the dimensional stability of heat compressed wood. The best dimensional stability of compressed wood in the air-tighten closed-press system was found to be better at $200^{\circ}C$ than $180^{\circ}C$. The best compression rate for dimensional stability was 73 percent.

• Plant Resources
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• v.8 no.1
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• pp.1-8
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• 2005

A type 3 metallothionein cDNA (PMT3a) from ozone-treated Populus alba${\times}$Populus glandulosa cDNA library has been isolated and characterized. A PMT3a cDNA is 459 nucleotides long and has an open reading frame of 201 bp with a deduced amino acid sequence of 66 residues (pI 4.94). The deduced amino acid sequence of PMT3a matched to the previously reported metallothionein genes. The deduced amino acid sequence of PMT3a showed the $86\%$ identity with P. balsamifera ${\times}$P. deltoides. Expression of PMT3a by the RT-PCR was increased 60 min than 30 min after drought treatment. The ozone treated poplar increased at 30 min in the early time and then decreased at 60 min.

• Journal of the Korean Wood Science and Technology
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• v.41 no.5
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• pp.456-465
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• 2013

Log cross sections of yellow poplar were dried in a radio frequency vacuum (RFV) dryer under alternating vacuum and release (AVR) process. The average moisture content (MC), temperature and vapor pressure at the volumetric center were monitored as functions of time. Three different log thicknesses (33, 60 and 75mm) were tested. The results show that the AVR process caused an increase in the drying rate when the moisture content was above fiber saturation point (FSP, about 30% MC) but that it had an inverse effect on the drying rate when the MC was below FSP. The effect of the AVR process on the drying rate decreased, and the severity of heart checks increased, with the increase in the thickness of the specimens.

• Journal of Korean Society of Forest Science
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• v.41 no.1
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• pp.19-25
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• 1979

The study was carried out to determine the frequency distribution of trees by diameter classes according to the method of Bruce and Reineke's alignment with the data of pitch pine (Pinus rigida Miller) and Italian poplar (Populus euramericana Guinier) which are prepared for the purpose of yield table construction. The results obtained are summarized as follows: 1. All through the tree species studied, when their diameters were larger, their distribution range became wider, while the percentage of their distribution frequency became lesser. 2. As for frequency percentage of trees in an average D.B.H. of stands, it became smaller when average D.B.H. of the stand is larger: the percentage of pitch pine stand is 36.2 and that of Italian poplaris 29.0. 3. In case of smaller D.B.H. under the average, the larger their D.B.H. became, the lesser the cumulative frequency percentages became.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.343-348
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• 1999

Populus euramericana has been identified as a possible species for use for phytoremediation of landfills. To identify the effects of waste leachate on the growth and physiological characteristics of Populus euramericana. four different treatments were applied to Populus euramericana seedlings: leachate solution (100% leachate). 25% dilution (75% leachate: 25% water. v/v), 50% dilution (50% leachate: 50% water. v/v) and control (100% tab water) were applied to Populus euramericana. Treatment with waste leachate significantly stimulated Populus euramericana height. diameter at root collar and biomass production relative to the water control. Chlorophyll contents. photosynthesis and transpiration of leachate irrigated-trees were significantly higher than those of water control. These results suggested that poplar could be a suitable species for phytoremediation in landfills because these species showed good growth performance and were capable of taking up waste leachate.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.206-214
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• 2011

Fifteen clones of poplars, 2 clones of willows, and yellow poplar were used to evaluate the effects of 5 treatments such as SCBLF (slurry composting and biofiltration liquid fertilizer), general slurry liquid fertilizer, chemical fertilizer, groundwater, and control (no treatment) on vitality, growth performance, and biomass production. Five cuttings for each tree species were planted in 3 replications. After planting cuttings, a coppice was induced by cutting off stems at 10cm above the ground. Data were collected for first growing season and trees were harvested at the end of October. Maximum mortality rate i.e. 96% was recorded in the cuttings treated with groundwater and minimum 92% with control (no treatment). In all tree species, sprouting of stump was not differ significantly among the treatments. Total nitrogen concentrations of leaves and stump sprouts were higher in the treatment of SCBLF than the control, 26.6% and 22.9%, respectively. Biomass production was highest in the stumps treated with chemical fertilizer, $1.98Mg\;ha^{-1}\;year^{-1}$, and lowest in control ($1.34Mg\;ha^{-1}\;year^{-1}$).

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.158-162
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• 2012

The acclimatization of in vitro propagated plants is an important step to produce vigorous plants for clonal forestry and in vitro micro-environment may affect the growth in ex vitro condition. To monitor in vitro environmental effects on the growth in ex vitro condition, several culture systems such semi-solid medium(SS), temporary immersion bioreactor(TIB) and continuous immersion bioreactor(CIB) culture types were tested to compare for the growth of acclimated plants of Liriodendron tulipifera. Results suggested that morphological characters, stomatal conductance, evapotranspiration and chlorophyll contents of acclimated plants were affected by the different of in vitro culture conditions. CIB type of culture was resulted to the lowest value in the biomass of acclimated plants. Net photosynthsis rate of CIB was the same level as those of SS and TIB. However, stomatal conductance, evapotranspiration and $CO_2$ partial pressure in the intercellular air space were lower than those of SS and TIB. The amounts of chlorophyll a, b and carotenoids were also lower than those of the other two culture systems. TIB, showing a little lower or higher value than SS in many growth character, is recommended rather than CIB to produce healthy yellow poplar plants in ex situ condition.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.372-380
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• 1989

The widely cultivated hybrid poplar Populus alba ${\times}$ P. glandulosa in Korea was transformed with Agrobacterium rhizogenes agropine type strain A4. Genetic transformation was confirmed by the presence of agropine. Alteration in growth rate of hairy roots was seen following changes in the dilution rate of medium and concentration of sucrose, suggesting that improved growth might be achieved by more precise manipulation of the nutrient medium. Plant regeneration occurred from transformed hairy roots on MS medium supplemented with 0.5 mg/l BAP. Transformed plantlets grown in vitro exhibited a more developed root system characterized by fast growth behavior in comparison to normal plantlets. This work demonstrates that the root transformation would be useful in improving plantlet establishment and growth through the effective root system.