• 한국가구학회지
• /
• 제13권1호
• /
• pp.2-8
• /
• 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.

• Mycobiology
• /
• 제36권1호
• /
• pp.55-59
• /
• 2008

Gymnopilus spectabilis, a hallucinogenic mushroom belonging to the family Cortinariaceae, is found growing in dense clusters on stumps and logs of hardwoods and conifers. It contains the hallucinogenic alkaloid psilocybin and its strongly bitter taste makes it undesirable as an edible. In an effort to identify chemical constituents of Korean native wild mushrooms, 4,6-decadiyne-1,3,8-triol (1), ergosta-4,6,8(14), 22-tetraen-3-one (2), bisnoryangonin (3), and hispidin (4) were isolated from the methanolic extract of the fruiting bodies of G. spectabilis. Their structures were assigned on the basis of various spectroscopic studies. Compounds 3 and 4 displayed significant scavenging activity against the ABTS radical cation, DPPH radical, and superoxide radical anion, while 1 and 2 exhibited no antioxidant activity.

• 한국가구학회지
• /
• 제19권4호
• /
• pp.229-234
• /
• 2008

In a previous study, it was revealed that three major softwoods, Japanese pine, Korean pine and Japanese larch, heat-treated at $220^{\circ}C$, could produce high quality dark-colored boards. It is known that heat treatment decreases the hygroscopicity of wood. The hygroscopicity of major domestic softwoods and hardwoods heat-treated at $220^{\circ}C$ was investigated by a saturated salt solution method and compared with that of black and white charcoals. Equilibrium moisture contents of wood decreased with the increase of heat treatment time. Isotherm shapes of wood species were different from those of charcoals. Heat treatment decreases the equilibrium moisture contents of black locust more than those of Korean pine and Japanese larch. It was found that surface hardness of wood is improved by heat treatment to a certain extent, but a longer heat treatment causes thermal degradation, resulting in the decrease of the surface hardness.

• Journal of the Korean Wood Science and Technology
• /
• 제26권4호
• /
• pp.34-42
• /
• 1998

Three hardwood (ash, alder and black locust) and three softwood (Japanese red pine, radiata pine and Western hemlock) specimens were dried in microwave(MlW) oven and their drying rates were obtained. Their specific permeabilities were also measured by using a modified liquid permeability measuring device. The correlation between the M/W drying rates and permeabilities of six species were statistically analyzed. It was revealed that within a species there is a logarithmic relationship between the M/W drying rates and average moisture contents and that among species there is a linear relationship between the M/W maximum drying rates and the average specific permeabilities. A exception was Western hemlock, which was of low permeability and of high drying rate. A Me-time equation, which showed a good agreement with the actual data, was derived. Thus using this equation the moisture contents of wood and the drying end points of M/W drying could be predicted. Infrared images of the thermal distribution in wood were illustrated.

• Journal of the Korean Wood Science and Technology
• /
• 제44권1호
• /
• pp.48-56
• /
• 2016

이 연구에서는 환경부하가 적은 산림훼손지 생태복원용 단위격자틀을 개발하기 위하여 콘크리트와 국내산 침엽수 4종과 활엽수 3종을 각각 복합적층한 7종류의 목재-콘크리트 복합적층재를 제작하였고, 정적 휨 강도성능에 미치는 수종의 밀도의 영향을 조사하였다. 목재-콘크리트 복합적층재의 휨 탄성계수는 전반적으로 수종의 밀도에 비례하여 증가하였고, 대부분 콘크리트에 비해 높은 휨 탄성계수를 나타내어 복합적층에 의한 밀도감소와 탄성계수향상의 효과가 나타났다. 휨 탄성계수 실측치는 각 라미나의 탄성계수로부터 등가단면법을 이용하여 계산한 예측치보다 약간 낮은 값을 나타내었고, 그 차이는 10% 미만인 것이 확인되었다. 목재-콘크리트 복합적층재의 휨 비례한도 응력은 콘크리트보다 1.2-1.6배의 높은 값을 나타내었다. 목재-콘크리트 복합적층재의 휨 강도는 전반적으로 수종의 밀도에 비례하여 증가하였고, 복합적층에 의해 콘크리트의 그것보다 현저한 강도향상을 나타내어 목재-콘크리트 복합적층재는 환경부하가 적으면서 내구성을 지닌 생태복원용 재료로 응용가능 할 것으로 판단된다.

• Journal of the Korean Wood Science and Technology
• /
• 제10권3호
• /
• pp.52-67
• /
• 1982

우리나라산 유용 활엽수인 신갈나무, 층층나무, 들메나무, 박달나무, 거제수나무, 다릅나무, 찰피나무, 사시나무, 느릅나무, 고로쇠나무 등 10 수종의 해부학적 성질, 물리적 성질, 기계적 성질을 구명하므로서 가공 및 재질개량의 기초자료로 활용함과 동시에 활엽수중에 주 수종을 이루고 있는 참나무속의 형질과 이용율을 조사하여 참나무속의 이용 방향을 설정하기 위하여 실시되였다. 1. 활엽수재의 수고 부위별에 따른 연륜폭, 변재폭, 생재함수율은 수고 부위가 높아질수록 다소 감소하였으며 수종별 감소의 정도는 각각 상이하였고 시험결과는 Fig. 2.3,6과 같다. 2. 섬유장과 섬유폭은 수심에서 수피로 향하여 일정한 수령까지는 증대하였으나 그 이후는 고정 또는 체감하는 경향을 나타냈고, 수종별로 목재의 성숙 기간이 다소 달랐으며 시험결과는 Fig. 4, 5와 같다. 3. 비중, 수축율, 강도상수는 수종별로 상이하였으며 수축율과 강도상수는 비중이 큰 수종일수록 증대하였으며 시험결과는 Table 4~10과 같다. 4. 참나무속의 임목, 원목, 제재형질을 조사한 결과는 Tab1e 11~14와 같고, 원목과 제재품질은 대부분 저질품이였다. 원목 품질에 영향하는 형질별 순위는 굽음, 옹이 부후 순서이고, 제재 품질에 영향하는 형질별 순위는 옹이, 둥근모, 굽음의 순서였다. 5. 졸참나무 조제율은 67.9 %이고 신갈나무 조제율은 61.3%였다. 경급별에 따른 누적 조 조제율은 Fig.7 과 같고, 중경재 이상인 원목의 조제율은 졸 참나무가 58.6%이고 신갈나무는 51.5%였다. 조제된 원목의 재종별 구성은 대부분 중경재이였다. 6. 참나무속의 중경재 이상인 원목의 제재수율은 졸참나무가 38.5 %이고, 신갈나무는 35.2 % 였다. 중경재 이상인 원목을 일반용재로 이용할 경우 수종별 이용율은 졸참나무가 22.5%이고, 신갈나무가 18.1 %로서 대단히 적었다. 7. 참나무속은 임목, 원목 제재형질의 불량으로 인한 이용율의 저하로 일반용재의 개발 이용은 비합리적 일 것이고 경급별에 따라 대경제는 화장단판과, 중경재 이하인 원목은 갱목m 농기구m 팔프재 등의 선택적 이용을 기함이 바람직하다. 또한 벌채 시 임지에 폐잔되는, 임목재적의 약 29%나 차지하고 있는 지조재를 ��으로 이용하는 방안도 아울러 강주되어야 할 것이다.

• Journal of Forest and Environmental Science
• /
• 제13권1호
• /
• pp.114-133
• /
• 1997

우리나라산(産) 활엽수재 25과(科)45속(屬)78종(種)의 수종에 대하여 천공을 이루고 있는 구조를 주사전자현미경(SEM)을 사용하여 3차원적(次元的) 형태를 관찰하고, 이들의 미세한 천공구조의 본질을 조사하여 과(科), 속(屬), 종별(種別)로 고유의 특징을 구명하기 위하여 본 연구를 실시 하였으며 천공의 분류는 단천공(單穿孔), 계단천공(階段穿孔) 및 다공천공(多孔穿孔)(계단천공(階段穿孔) 이외의 다공천공(多孔穿孔))의 3가지로 구분하고 이것을 기초로하여 (1) 단천공(單穿孔)만을 갖는 수종(60종), (2) 계단천공(階段穿孔)만을 갖는 수종(5종), (3) 단천공(單穿孔)과 계단천공(階段穿孔)을 갖는 수종(4종), (4) 단천공(單穿孔)과 다공천공(多孔穿孔)을 갖는 수종(2종), (5) 계단천공(階段穿孔)과 다공천공(多孔穿孔)을 갖는 수종(5종), (6) 단천공(單穿孔), 계단천공(階段穿孔) 및 다공천공(多孔穿孔)을 갖는 수종(2종)의 6개의 그룹으로 분류 하였다. 그 결과 Betulaceae에 속하는 수종은 대부분이 계단천공(階段穿孔)을 나타내고 있으나 개서어나무에서는 단천공(單穿孔)이 출현하는 특징이 있으며, Fagaceae의 갈참나무에서는 단천공(單穿孔)의 천공연(穿孔緣)의 주연에 돌기물이 발생된 vesture천공이 관찰 되었다. 또한 계단천공(階段穿孔)의 상하의 bar가 서로 일치되고 있지않은 mismatching perforation plate가 물갬나무와 물오리나무에서 관찰되었으며 또한 계단천공의 bar사이에 벽물질이 남아 일부 또는 전부가 막혀 있거나 microfibrillar 모양의 substructure가 물박달나무와 계수나무에서 발견되었다.

• 한국산림과학회지
• /
• 제95권5호
• /
• pp.614-620
• /
• 2006

To study the chlorophyll contents and photosynthetic characteristics of 4 tree species of deciduous hardwoods; Betula platyphylla var. japonica, Zelkova serrata, Acer mono and Prunus sargentii were treated in 3 stages of shading; the full sun treatment, the medium shade treatment with 30% of transmittance comparing to full sun, the intense shade treatment with 8% of transmittance and their changes in chlorophyll contents and photosynthetic characteristics were examined and analyzed. Most hardwoods showed differences in the total chlorophyll contents in the order of May < September < July, however, that in Prunus sargentii increased progressively along with the lapse of time. Concerning the degree of shading, total chlorophyll contents increased in proportion to the level of shading. Betula platyphylla var. japonica and Prunus sargentii showed more than 2-3 times difference between the full sun treatment and the intense shade treatment. The changes in photosynthetic characteristics, the range of the light saturation point of the trees was $1,000{\sim}1,100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in May, before the shading was applied, and the intensity was shown in the order of Betula platyphylla var. japonica > Zelkova serrata > Acer mono > Prunus sargentii. The photosynthetic rate was $6.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}{\sim}27.1{\mu}mol{\cdot}CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of Betula platyphylla var. japonica > Prunus sargentii > Acer mono > Zelkova serrata that there were differences between species. Concerning the changes in light saturation point in each growth period after shading treatment, the light saturation point in the full sun treatment was found in the range of $560{\sim}1,100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and the level of intensity was shown in the order of May > July > September. The light saturation point decreased as the level of shading intensified and the level of changes in light compensation point in the full sun treatment for Betula platyphylla var. japonica and Prunus sargentii was shown in the range of $2.9{\sim}27.1{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of May > July > September, however, for Zelkova serrata and Acer mono was shown in the range of $3.9{\sim}11.7{\mu}mol{\cdot}CO_2{\cdot}m^{-2}{\cdot}s^{-1}$ in the order of July > May > September that there were differences between species.

• 한국가구학회지
• /
• 제23권2호
• /
• pp.163-168
• /
• 2012

Specimens of seven hardwood species were heat-treated at three temperature levels of 170, 190 and $210^{\circ}C$. Their FSP's were measured by the volumetric swelling method and compared with the control's. Within a species the FSP decreases as the temperature of heat treatment increases. The FSP's of the controls range from 26.1 to 29.6%, while those of the specimens heat-treated at $210^{\circ}C$ from 16.9 to 21.8%. There were no difference of basic density between the heat-treated and control specimens. The color indexes of ash and beech specimens were measured using a colorimeter. It was revealed that the temperature of heat treatment affected on the color more than the treatment time.

• 한국가구학회지
• /
• 제21권1호
• /
• pp.62-71
• /
• 2010

This study was carried out to investigate the physical and mechanical properties of 6 hardwoods before and after heat treatment in an effort to produce the high quality industrial lumber product. The object of the research was to design living products with heat treated woods. The results were as follows. Specific gravities of green woods were in range from 0.87 to 1.12. The specific gravities of never treated woods showed higher than those of the heat treated woods. The shrinkage of heat treated woods when green to air & oven dry was significantly low, compared to never treated woods. The compression strengths parallel to grain of heat treated woods showed higher than those of never treated woods. The moduli of rupture (MOR) of never treated and heat treated woods were $170.37N/mm^2~107.07N/mm^2$ and $122.78N/mm^2~61.27N/mm^2$ respectively. MORs of heat treated woods showed lower than those of never treated woods. The modulus of elasticity (MOE) of heat treated woods showed higher than those of never treated woods.