• Journal of the Korean Wood Science and Technology
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• 제48권4호
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• pp.569-576
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• 2020

This study investigated the characteristics of microfibril angle(MFA) in order to see if there was any difference in pine tree lumber quality among the three mountain areas surrounding the Taebaek Mountains in Korea - Yeongdong (Goseong-gun), Yeongseo (Hongcheon-gun) and Yeongnam (Bonghwa-gun). Pine trees of each mountain area were divided into earlywood and latewood in relation to heartwood part (1959 ~ 1961, 3 annual rings) and sapwood part (2002 ~ 2004, 3annual rings), and measured at tangential section. The microfibril angle showed significant differences between mountain areas. In general, Goseong Mountain was found to have 37.35°, followed by Hongcheon Mountain 32.42° and Bonghwa Mountain 25.75°, in order. The sapwood part had larger angle than heartwood part; and earlywood, than latewood. Variation within a single annual ring tended to be smaller from earlywood toward latewood.

• 임산에너지
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• 제18권1호
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• pp.1-5
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• 1999

잦나무 조림목의 유용한 이용과 적합한 용도개발을 위한 수간내 재질변동을 조사하였다. 수고방향(수고 약 20m중 0.3, 1.3, 2.3, 5.3m부위)의 가도관장, 가도관폭, 마이크로피크릴경사각, 압축강도를 측정하고, 그들의 변동에 관하여 Duncan의 다중검정법에 의하여 조사하였다. 그 결과 가도관장, 가도관폭 및 압축강도는 대체로 유의차를 보이지 않았으나 마이크로피브릴경각은 유의차를 나타냈다. 그러나 마이크로피브릴경각은 수고에 따라 높아지거나 또는 낮아지는 등 일정한 경향을 보이지는 않았다.

• Journal of the Korean Wood Science and Technology
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• 제26권2호
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• pp.45-50
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• 1998

Tracheid length, microfibril angle, and compression strength were examined in south and north sides of Pinus koraiensis. The sample tree was 57 years old and had been planted in central Korea. Tracheid length on the south side of the tree ranged from 2.87 to 3.40mm and on the north ranged from 3.60 to 3.53mm and mean values were 3.15 mm for the south and 3.26mm for the north. Tracheid length was 0.11 mm longer on the north side than on the south. Microfibril angle on the south side ranged from $12.6^{\circ}$ to $20.3^{\circ}$ and that on the north from $6.8^{\circ}$ to $13.5^{\circ}$; mean values were $16.6^{\circ}$ on the south side and $9.6^{\circ}$ on the north. Microfibril angle was $7.0^{\circ}$ greater on the south side than on the north side. For compression strength on the south and north sides, significant difference at the 95% level was found only at l.3m above the ground level of the sample tree; for compression limit stress, significant difference at this level was found at 1.3 and 5.3m above the ground level. However, compression strength and compression limit stress were greater on the north side than on the south side.

• Journal of the Korean Wood Science and Technology
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• 제33권1호통권129호
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• pp.21-28
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• 2005

중부 지방의 조림지에서 생육된 30년생의 일본잎갈나무(낙엽송)에 대하여 지상고별로 원반을 채취해 수를 중심으로 남측과 북측 부위의 조재 및 만재에 대해 가도관 길이와 폭, 마이크로피브릴 경각 및 압축, 휨, 충격 강도를 조사했다. 가도관의 길이와 폭에 있어 남측과 북측간에는 측정된 대부분 부위에서 차이가 없는 것으로 나타났다. 남측과 북측간의 마이크로피브릴 경각과 강도 역시 측정된 대부분 부위에서 차이가 없는 것으로 나타났다. 남측과 북측 부위간의 접선방향 수축율과 강도에 차이가 드러나지 않은 것은 남측과 북측간의 마이크로피브릴 경각사이에 차이가 없는 점에 기인하는 것으로 생각되었다.

• 농업생명과학연구
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• 제45권1호
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• pp.9-14
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• 2011

Larix kaempferi is a tree with a major economic impact and is processed in large quantity every year in Korea. This study was carried out to collect basic data for the reasonable use of Larix kaempferi and to investigate the relation between anatomical properties and modulus of rupture (MOR) for heartwood and sapwood. As the length of earlywood tracheid and the radial wall thickness of earlywood tracheid and latewood tracheid increased, the modulus of rupture (MOR) increased, but decreased with increasing microfibril angle. Statistical analysis by the stepwise regression technique shows that the main factors affecting the modulus of rupture (MOR) of heartwood are the microfibril angle and the radial wall thickness of latewood tracheid, while those affecting MOR of sapwood are the length of earlywood tracheid and the microfibril angle.

• Journal of the Korean Wood Science and Technology
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• 제36권4호
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• pp.77-83
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• 2008

국내에서 생장한 주요 침엽수 3종(소나무, 잣나무, 리기다소나무)의 수간 내 마이크로피브릴 경사각(microfibril angle, MFA)의 축방향 및 방사방향 변이를 요오드 침적법에 의해 조사하였다. 각 수종의 MFA의 평균값은 소나무 $16.4^{\circ}$, 잣나무 $14.4^{\circ}$, 리기다소나무 $26.2^{\circ}$로 리기다소나무가 가장 크게 나타났다. 공시 수종의 MFA는 약 15~20 연륜까지 감소하다가 그 후 거의 안정된 경향을 보여 주었고 만재부의 MFA는 조재부의 MFA보다 다소 작은 경향이 있었다. 공시재료의 수고에 따른 MFA의 차이는 기부 부분에서 다소 크게 나타났으며 수고가 증가함에 따라 MFA는 감소하는 경향이 있었으나 리기다소나무 조재부는 예외였다. 따라서 MFA는 국내산 주요 침엽수재의 미성숙재와 성숙재를 구분하는 지표의 하나로 이용이 가능할 것으로 생각되었다.

• 한국가구학회지
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• 제10권2호
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• pp.55-61
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• 1999

This research was carried out to investigate the fundamental properties such as the structure of annual ring, density distribution, compressive strength with parallel to grain, relative crystallinity, and microfibril angle of Gumgangsong(Pinus densoflora for. erecta Uyeki). The wood specimens, Gumgangsong and Sonamu(Pinus densiflora S. et Z.), for this experiment were prepared at Ulijingoon Sokwangri and Kyungpook university's forest in Kyungpook province, respectively. Average annual ring width is $2.0mm{\pm}0.3$ in heartwood of Gumgangsong. The respectively of heart wood was over 60 percent in Gumgangsong and 20~50 percent in Sonamu. Heartwood density were ranged from 0.5 to $0.8{\;}g/cm^3$ in Gumgangsong and from 0.4 to $0.5{\;}g/cm^3$ in sonamu. Compressive strength in Gumgangsong and Sonamu was about $30{\pm}5MPa$ and $25{\pm}5MPa$, resepectively. But the relative crystallinity and microfibril angle of two species were not different clearly. From these results of Gumgangsong and Sonamu, therefore, it was considered the main difference factors for both species were annual ring width and heartwood percentage.

• Journal of the Korean Wood Science and Technology
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• 제41권5호
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• pp.399-405
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• 2013

This study demonstrates the utilization of light microscopy and Fast Fourier Transform-Peak Finding (FPF) method for microfibril angle (MFA) measurement from unstained sections of red pine (Pinus densiflora). To obtain an image with optimal contrast and resolution for MFA measurement, effects of numerical aperture (NA) of condenser lens and color filters were investigated. About 60% of NA of the maximum condenser NA produced an image with optimal contrast, but a color filter with short wavelength range (DAPI) created images with improved resolution. Manual angle measurement and the FPF method were applied to the image with optimal contrast for MFA measurement. The experimental results from the FPF method were considered to be more repeatable and less subjective than those from the manual angle measurement.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.27-32
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• 1997

This study was carried out to find the relationship between anatomical characters and compression strength parallel to grain of Pinus densiflora S. et. Z., the representative conifer species in Korea. The results were as follows ; 1. The compression strength parallel to grain increased with the increase of tracheid length and wall thickness. The strength, however, decreased with the increase of height of uniseriate ray and microfibril angle. 2. The major factors affecting compression strength parallel to grain in heartwood were radial diameter of latewood tracheid and wall thickness of earlywood tracheid but length and tangential diameter of latewood tracheid were the important factors in sapwood.

• Journal of the Korean Wood Science and Technology
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• 제46권4호
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• pp.323-337
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• 2018

Merkusii pine wood (Pinus merkusii) was extensively planted throughout Indonesia, where it is only indigenous in northern Sumatera, by the Dutch during colonial times. The demand for this wood species, especially in the domestic market, has increased notably, despite its limited durability regarding decay resistance. The purpose of this study was to investigate the occurrence of juvenile and mature wood on merkusii pine and to analyze its radial features from pith to bark based on density, shrinkage, static bending in modulus of rupture and modulus of elasticity, fiber length, microfibril angle, and durability. A segmented modeling approach was used to find the juvenile-mature transition. The graveyard test was performed to characterize the termite resistance from pith to bark of merkusii pine. The maturations were estimated to start at radial increments of 15 cm from the pith by fiber length and of 12 cm from the pith by microfibril angle. The projected figures for the proportion of juvenile wood at breast height were around 65%. The results also indicate that the pine wood was $0.52g/cm^3$ in density, 1.45 in coefficient of anisotropy, which indicates its good stability, 7597 MPa in modulus of elasticity, and 63 MPa in modulus of rupture. Natural durability against subterranean termite of the merkusii pine wood was rated to be grade 4 to 0 from pith to bark. However, after being treated by Entiblu and Enborer preservatives, its rating increased to grade 10 to 9.