• Journal of the Korean Wood Science and Technology
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• 제17권4호
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• pp.77-82
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• 1989

In this study the oxygen index method was used to compare the duration of flaming and the rate of weight loss at the level of 6 and 9mm panel thicknesses among solid wood, plywood, particleboard, and medium density fiberboard. The obtained results were as follows: 1. In 9mm-thick panels, the combustibility was the largest in lauan solid wood followed by medium density fiberboard. particleboard. and plywood. 2. Medium density fiberboard was burned more easily than plywood in 6mm-thick panels and the higher oxygen concentration was needed as the panel thickness increased. 3. The oxygen indices of 9mm-thick panels were 29.0 in lauan solid wood, 31.4 in medium density fiberboard, 33.0 in particleboard, and 33.4 in plywood and those of 6mm-thick panels were 28.3 in medium density fiberboard and 29.7 in plywood. 4. The rate of weight loss was the largest in lauan solid wood followed by medium density fiberboard, plywood, and particleboard.

• Journal of the Korean Wood Science and Technology
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• 제26권1호
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• pp.70-75
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• 1998

In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

• Journal of the Korean Wood Science and Technology
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• 제26권1호
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• pp.38-50
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• 1998

Laser cutting tests were conducted to investigate the laser cutting characteristics of solid woods such as 25mm-thick white oak(Quercus acutissima) and maple(Acer mono), and wood-based panels such as 15mm-thick medium density fiberboard and particleboard. Test variables were laser power, cutting speed, grain direction, and moisture content. Specific cutting energy was measured and the qualities of cut surface were estimated in constant laser power. Specific cutting energy of white oak was larger than that of maple, and specific cutting energy of medium density fiberboard was smaller than that of particleboard. For both white oak and maple, specific cutting energy of green wood was smaller than that of air-dried wood because weight loss of moisture evaporation in green wood was larger than that in air-dried wood. In laser-cut surface, wood cells were not deformed and damaged, but in circular saw-cut surface fibers were pushed out and cut, and wood cells were deformed severely. However, mechanical surface roughness of saw-cut surface was smoother than that of laser-cut surface because of the existence of undeformed cell cavity in laser-cut surface.

• Journal of the Korean Wood Science and Technology
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• 제23권2호
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• pp.26-31
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• 1995

Acetylcellulose(AC) was prepared with steam exploded wood(EXW) and EXW after delignification with sodium chlorite, pine (Pinus densiflora) and oak (Quercus mongolica) woods. The color of acetylated pine and oak exploded wood was brown, degree of substitution(D.S) of pine was 1.47~2.09, and this of oak was 1.49~2.29. The hemicellulose content of acetylated pine and oak exploded wood was 0~3.4% and 1.49~11.3%, individually. The degree of substitution of acetylated wood prepared from delignified EXW in the pine and oak wood was 0.50~0.71 and 0.70~0.88, individually. Hemicellulose content of acetylated EXW with sodium chlorite after delignification in the pine and oak wood was less than 1% and 0.6~2.5%. The color of acetylated wood after delignification was white. IR-spectra of acetylated pine and oak EXW after delignification were found that peaks at around 1740$cm^{-1}$ and 1200$cm^{-1}$ increase markedly, due to ester carbonyl group.

• Journal of the Korean Wood Science and Technology
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• 제11권2호
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• pp.27-40
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• 1983

최근(最近) 우리나라에서는 목재외(木材外)의 타계재료(他界材料)로의 건축(建築)이 이루어지고 있으므로 목조건축(木造建築)에 관한 연구(硏究)와 관심(關心)이 급속(急速)히 감소(減少)하고 있다. 이것은 국내(國內)에서의 목재생산(木材生産)이 극(極)히 저조(低調)하고 가격(價格)의 폭등(暴騰)으로 나타난 필연적(必然的)인 현상(現象)이라 하겠으나 목조건축(木造建築)이 아닌 타계재료(他界材料)로 시공(施工)한다고 하여도 목재(木材)는 꼭 쓰여지기 마련이다. 그러므로 주택(住宅)을 중심(中心)으로 각종건축물(各種建築物)의 구조(構造)를 이해(理解)함으로써 보다 합리적(合理的)인 목재이용(木材利用)을 꾀할 수 있을 것이다. 특히 목조주택(木造住宅)에 의존(依存)하고 있는 미국(美國)에서 경구조(輕構造)(light frame house construction) 또는 조립주택(組立住宅)(prefabricated house construction)에 의(依)한 목조주택건설(木造住宅建設)에 관(關)한 새로운 연구(硏究)가 착실(着實)하게 진행(進行)되어 큰 성과(成果)를 거두고 있어서 값 싼 주택(住宅)의 양산(量産)에 많은 도움을 주고 있음은 물론(勿論)이고 농용건축물(農用建築物)의 건설(建設)에도 크게 활용(活用)되고 있다. 더구나 8시간(時間)만에 한 채의 주택(住宅)을 건설(建設)할 수 있는 8시간건축(時間建設)(8 house construction)의 체계(體系)가 연구개발(硏究開發)되어 증가일로(增加一路)의 주택수요(住宅需要)를 메꾸어 나가고 있어서 우리나라에서도 부면(部面)에 관한 연구(硏究)가 추진(推進)되어야 할 것으로 믿는다.

• Journal of the Korean Wood Science and Technology
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• 제14권3호
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• pp.43-46
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• 1986

A stainless steel autoclave reactor, which is the property of Pacific Northwest Laboratories(PNL) and located in PNL, was acted for pyrolysis and gasification of sawdust, ricestraw, and ricehusk. The initial reaction temperature of this reactor was 300$^{\circ}C$, and up to 500$^{\circ}C$ to complete pyrolysis and gasification reaction. The maximum exerted pressure on this reactor was 800 psig. In order to examine the effect of catalyst on reaction temperature, $K_2CO_3$, and nickel/alkali carbonate catalyst mixture were also used. The experimental results obtained with this reactor indicated that good yields of methane-rich gas(exceeding 40% methane) can be produced. The product gas mixtures were also identified to be CO. $CO_2$, $C_2H_4$, and $CH_3CHO$ etc. by Gas Chromatography and Mass Spectrometer.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.80-84
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• 1991

Lignocellulosic biomass including acetosolv ricestraw and spruce lignin were liquefied and converted into liquid hydrocarbons by catalytic hydroliquefaction reaction. These experimental works were carried out in 1-liter-capacity autoclave using 50% tetralin and m-cresol solution respectively as soluble solvent and Ni. Pd. Fe and red mud as catalyst. $H_2$ gas was supplied into the reactor for escaltion of deoxhydroenolysis reaction. Catalyst concentrations were 1 % of raw material based on weight. The ratio between raw materials and soluble solvent are 1g and 10cc. The reaction conditions are 400-$700^{\circ}C$ of reaction temperature, 10-50 atms of reaction pressure. The highest yield of hydrocarbon, so called "product oil" showed 32% and 5.5% of lowest char formation when red mud was used as catalyst. The product oil yields from those of other catalysts were in the range of 20-29%. The influence of different initial hydrogen pressures was examined in the range d 30-50 atms. A minimum pressure of 35 atms was necessary to obtain a complete recovery of souble solvent for recycling.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.18-26
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• 1991

This study was carried out to examine not only the effect and the process of activation of aluminum sulfate for the manufacture of PB and MDF, but also application of the activation treatment to PB and MOF made with MDI adhesive. The results were as follows: 1. For the manufacture of PB, activating effect did not take place Because the low moisture content of 30% in the process of activation treatment made probably insufficient activation. It needs to examine higher moisture content for the uniform and enough activation same as that of MOF. 2. In the case of MOF, Activating effect was excellent, it showed not only better results of MOR 48%, MOE 29%, IB 60% than those of the control but also better dimensional stability. 3. Application of alum activation to the PB and MDF made with MDI adhesive yielded no effects. Maybe it was the reson that the curing mechanism of MDI is different. 4. Modifing the wood surface was the oxidation and wettability was not the variable limiting glueline performance. It is necessary to make a more study about activating reaction.

• 펄프종이기술
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• 제29권4호
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• pp.18-27
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• 1997

This study was performed to obtained the optimal delignified condition of exploded wood on the acid hydrolysis with sulfuric acid. Wood chips of pine wood(Pinus desiflora), oak wood(Quercus serrata) and birch wood (Betula platyphylla var. japonica) were treated with a high pressure steam (20-30kgf/$\textrm{cm}^2$, 2-6 minutes). The exploded wood was delignified with sodium hydroxide and sodium chlorite, and then hydrolyzed with sulfuric acid. The result can be summerized as follows ; In the exploded wood treated with sodium hydroxide, the optimal concentration of sodium hydroxide was 1% as content of lignin in the exploded wood. Lignin content of exploded wood treated with sodium chlorite was lower then that sodium hydroxide. The maximum reducing sugar yield of exploded wood treated with 1% sodium hydroxide was lower than non-treated exploded wood. In the case of sodium chlorite treated, the maximum reducing sugar yield was hgher than non-treated exploded wood. Sugar composition of acid hydrolysis solution was composed of xylose and glucose residue, and the rate of glucose residue was increased in high pressure condition.

• Applied Microscopy
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• 제29권3호
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• pp.275-280
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• 1999

Hypoxylon속은 자낭각을 지닌 갈색이나 진한 갈색의 목질, 또는 탄소질의 자좌를 형성하며, 자낭균류의 대표적인 목재 부후균으로 분류된다. 부후된 목재에서 발견된 국내 미기록종인 본 Hypoxylon moriforme를 국내에서는 최초로 발견하여 국내의 새로운 기록종으로 보고한다. Hypoxylon moriforme는 광학현미경, 주사전자현미경을 이용하여 미세구조학적으로 기술하였다. H. moriforme는 $7.5\sim9.0\times2.5\sim4.0{\mu}m$의 작은 자낭포자와 $75\sim130\times3\sim5{\mu}m$ 자낭을 가지고 있으며, 동북아시아에서 매우 다양하며 근접한 H. truncatum, 열대 및 아열대 지방에서 발견되는 유사한 H. bover 및 H. annulatum과 분류학적으로 비교, 동정하였다.