• Journal of the Korean Wood Science and Technology
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• 제51권3호
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• pp.222-237
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• 2023

Eucalyptus pellita is one of the fast-growing tree species and has become predominant in Indonesian forest plantations. Meanwhile, tree breeding programs with clone development are the best way to provide greater genetic advantages. A better understanding of genetic control on growth and basic density in E. pellita is important for increasing wood productivity and quality. In this study, growth characteristics (tree height, diameter, and volume), basic density and its genetic parameters (heritability, genetic gain and genetic correlation) were determined. The number of clones tested in both trials was 50, divided into 5 blocks, and 5 trees/plot. The results showed that there were significant differences in growth and basic density among clones. There was an interaction between genetics and the environment further indicating the existence of unstable clones. The high heritability was found in tree height (0.82-0.86), diameter (0.82-0.90), and basic density (0.91-0.93). This implies that E. pellita has good opportunities for genetic improvement to increase wood productivity and quality. In addition, the results of genetic correlations among growth characteristics (height, diameter, and volume) and basic density showed positive moderate to highly significant value. It is suggested that these characters may be used to the advantage of the breeder for bringing improvement in these traits simultaneously. Therefore, this study provides important information of the genetic improvement of wood quality in E. pellita in Indonesia.

• 한국산림과학회지
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• 제112권2호
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• pp.188-194
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• 2023

본 연구는 우리나라의 대나무림에 대한 탄소계정을 위하여 탄소배출계수 중 하나인 목재기본밀도를 도출하기 위하여 수행되어 졌다. 대나무는 전라남도와 경상남도에 주로 분포해 있으며, 계수 도출을 위한 표준목은 솜대, 왕대, 맹종죽 등 3수종별로 각각 101본씩을 선정하여 활용하였다. 목재기본밀도 도출은 KS F 2098 방법을 따랐다. 측정결과, 솜대의 목재기본밀도는 0.83 g/cm³, 왕대는 0.81 g/cm³, 맹종죽은 0.72 g/cm³로 각각 나타났다. 그렇지만, 우리나라는 대나무 분포 면적이 많지 않고, 맹종죽의 경우 일정 지역에 국한되어 생육하고 있다. 따라서 대나무에 적용할 수 있는 목재기본밀도는 하나로 통합하여 0.79 g/cm³로 확정하였다. 그리고 도출된 목재기본밀도에 대한 불확도를 평가한 결과, 1.61%로 낮은 불확도 값을 가져, 본 분석에서의 측정값에 대한 신뢰도를 확인할 수 있었다. 본 연구에서는 이번에 개발한 목재기본밀도와 기존의 바이오매스확장계수, 뿌리함량비 등을 이용하여 대나무 표준목에 대한 탄소저장량을 계산하고, 이를 확장시켜 ha단위까지 계산해 보았다. 이번 연구로 대나무의 재적을 이용하여 목재기본밀도 등 탄소배출계수 적용으로 탄소저장 및 흡수량 계산이 가능하게 되었다. 본 결과가 우리나라 탄소중립 정책 및 산림관리 방향에 도움이 되기를 기대한다.

• Journal of the Korean Wood Science and Technology
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• 제21권3호
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• pp.37-44
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• 1993

The collapse of four domestic Fagaceae species was observed in relation with their moisture content(MC), basic density, P (Percent of moisture content saturation of the wood) and Q (Percent of cell cavity volume containing water) and the variation of collapse phenomenon in the cross section of stem was also investigated. The results were summarized as follows : The values of collapse in each species were great in order of Quercus dentata, Quercus variabilis, Quercus aliena and Quercus mongolica and the values were higher in heartwood than in sapwood in all of specimen. MC, basic density, P and Q were important factors which affected on the occurance of collapse and the collapse phenomenon was decreased from pith to bark.

• Journal of the Korean Wood Science and Technology
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• 제24권3호
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• pp.12-17
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• 1996

This study was carried out to investigate some mechanical properties for wood rational utilization of heartwood and sapwood in radiata pine according to basic density, ring width and proportion of latewood which were grown in New Zealand. This result were summarized as follow: Heartwood showed 35.78(MPa) of the compression strength parallel to the grain while sapwood showed 42.08(MPa). The modulus of rupture in static bending was higher in sapwood showing 86.12(MPa) than in heartwood 72.99(MPa) Heartwood had 7.38(GPa) for the modulus of elasticity in static bending and sapwood 8.17(GPa). As the basic density and proportion of latewood increased: compression strength parallel to the grain, MOR and MOE in static bending had a tendency to increase. As ring width increased, the mechanical properties decreased.

• 한국산림과학회지
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• 제100권3호
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• pp.392-396
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• 2011

본 연구의 목적은 부트스트랩 시뮬레이션(Bootstrap simulation)을 이용하여 소나무의 목재기본밀도를 평가하고자 하였다. 소나무의 목재기본밀도는 생태형에 따라 강원지방소나무와 중부지방소나무의 자료로 구분하여 분석하였다. 비모수통계 방법의 하나인 부트스트랩 시뮬레이션 기법을 이용하여 추정된 목재기본밀도는 강원지방소나무에서 0.418($g/cm^3$), 중부지방소나무에서 0.464($g/cm^3$)으로 나타났다. 부트스트랩 시뮬레이션에서 100, 500, 1,000, 5,000번 반복 시행한 결과에 의하면, 모수 추정치의 95%신뢰구간은 일정한 수치로 나타난 반면에, 표본오차는 감소하는 경향으로 나타났다. 본 연구 결과로 제시된 목재기본밀도 추정치는 기존의 계수에 대한 단점을 보완하고, 신뢰성 높은 목재기본밀도 추정치로 적용이 가능할 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
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• 제16권3호
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• pp.22-37
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• 1988

In tendancy of manufacturing beam with laminating particleboard, it was thought that if the properties, especially mechanical properties, of particleboard be reinforced, the mechanical properties of particleboard-laminated beam would be also improved. So in this study the particleboard was reinforced with composing of wood particle and steel wire. This study was carried out to obtain the basic physical and mechanical properties of board composed of wood particle and steel wire, especially tensile strength and compressive strength which are the important factors of the lamina of beam, in order to estimate whether the board, composed of wood particle and steel wire could be to improve the properties of the particleboard- laminated beam. The results obtained were summarized as follows: 1. The board composed of wood particle and steel wire in accordance with lower board density took better thickness swelling. 2. The board with lower board density was improved in higher value of tensile strength with more steel wires in prescribed cross section area of the board. for example, the board of density 0.5 showing 140% improved value. 3. In compressive strength, the board with lower board density was also improved in hjgher value with more steel wires in prescribed cross section area.

• Journal of the Korean Wood Science and Technology
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• 제18권4호
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• pp.9-17
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• 1990

When manufacturing beam by laminating particleboards, the mechanical properties of particleboad-laminated beam would be also improved if the properties, especially mechanical properties of particleboad be reinforced. In this study, steel wires were used to reinforce particleboard. This study was carried out to obtain the basic mechanical properties of the board composed of wood particle and steel wires, focusing on bending strength which is the important factors in laminated beam and it was tried to estimate the relationship between the properties of the particleboard-laminated beam. and the proportion of steel wires to wood particles in particleboards. The result obtained can be summarized as follows: 1. The more steel wires used in boards, the higher value of modulus of rupture in bending was obtained, For example. the density 5 board composed of 14 numbers of steel wires showing 55% improved value than control board. 2. The board with lower density was also made better in higher value of elasticity, the density 0.5 board with 14 numbers of steel wires improved by 170%, the density 0.6 board by 86%, the 0.7 board by 37% and the 0.8 board by 26%. 3. The work to maximum load was improved with more steel wires. for example, the density 0.8 board with 14 numbers of steel wires improved by 31%.

• Journal of the Korean Wood Science and Technology
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• 제45권4호
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• pp.463-470
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• 2017

The objectives of this study are to obtain the basic knowledge of anatomical characteristics and wood properties of thinning trees of young teak (Tectona grandis L.F.) for fulfill the timber demand in Indonesia. Nine thinning trees of 5-year-old teak clone trees were used for analyzing the cell morphology and air-dry density. Vessel diameters in pore and outer pore zones were 165 and $90{\mu}m$, respectively. Mean value of fiber diameter, cell wall thickness, and fiber length in outer pore zone were $14.6{\mu}m$, $2.07{\mu}m$, and 1.04 mm, respectively. In addition, mean value of air-dry density was $0.55g/cm^3$. The measurement and values of vessel diameter, fiber diameter, cell wall thickness, fiber length and air-dry density in the experimental had lower than those in the older teak. Therefore, it could be suggested that the wood from thinning young teaks was not appropriate as construction material, but it could be used for furniture which do not need high of strength properties. Furthermore, since the measurements values of anatomical characteristics were still increasing from pith to bark, it could be suggested that 5-year-old teak clones are still in a juvenile phase. Positively significant correlations were found between air-dry density and cell wall thickness, indicating that cell wall thickness is strongly correlated with wood density of teak.

• 한국건설순환자원학회논문집
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• 제3권1호
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• pp.80-86
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• 2007

In this study we experimented setting time and basic properties as waste wood fiber and sodium silicate substitution rate to reuse waste wood fiber produced in construction field to wood chip board. To do this construction waste woods were crushed with the size less than 10mm, mixed with the rate of 1:2, 2.5, 3, and added sodium silicate with the rate of 0, 5% of cement content. The results are as follows. As the substitution rate of construction waste wood was increased delay of setting time was also increased, and the batch of adding 5% accelerator had a 13~17 hours faster setting time than non accelerator batch. The compressive strength was lower as wood substitution rate was higher, and as the specific gravity was higher, the strength was also higher. As wood substitution rate was higher, heat conductivity was lower, and as specific gravity was higher, heat conductivity also was higher.

• 한국세라믹학회지
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• 제47권4호
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• pp.308-311
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• 2010

Porous SiC samples were prepared with three types of wood (poplar, pine, big cone pine) by simply embedding the wood charcoal in a powder mixture of Si and $SiO_2$ at 1600 and $1700^{\circ}C$. The basic engineering properties such as density, porosity, pore size and distribution, and strength were characterized. The samples showed full conversion to mostly $\beta$-SiC with good retention of the cellular structure of the original wood. More rigid SiC struts were developed for $1700^{\circ}C$. They showed similar bulk density ($0.5{\sim}0.6\;g/cm^3$) and porosity (81~84%) irrespective of the type of wood. The poplar sample showed three pore sizes (1, 8, $60\;{\mu}m$) with a main size of $60\;{\mu}m$. The pine sample showed a single pore size ($20\;{\mu}m$). The big cone pine sample showed two pore sizes (10, $80\;{\mu}m$) with a main size of $10\;{\mu}m$. The bend strength was 2.5 MPa for poplar, 5.7 MPa for pine, 2.8 MPa for big cone pine, indicating higher strength with pine.