• Journal of the Korean Wood Science and Technology
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• 제46권5호
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• pp.511-526
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• 2018

본 연구에서는 국산 참오동나무재의 열처리에 의한 재질특성의 변화를 조사하였다. 비교를 위하여 은사시나무와 소나무재의 열처리 특성을 조사, 검토하였다. 세 공시수종의 목재시험편을 $160^{\circ}C$, $180^{\circ}C$, $200^{\circ}C$ 및 $220^{\circ}C$의 전기로 내에서 2시간 열처리 후, 재색변화($L^*a^*b^*$), 밀도, 중량감소율 및 셀룰로오스의 상대결정화도를 측정하였다. 재색변화 측정결과, 명도($L^*$)는 세 공시수종 목재 모두 $200^{\circ}C$ 이상에서 크게 감소하였다. 참오동나무재와 은사시나무재의 적-녹색도($a^*$)와 황-청색도($b^*$)는 열처리 온도증가에 따른 차이는 거의 없었으나, 소나무재의 $b^*$는 $200^{\circ}C$ 이후 감소하였다. 참오동나무재의 재색변화량(${\Delta}E^*$)은 $160^{\circ}C$ 열처리에서는 거의 없었고 $180^{\circ}C$ 이상에서 크게 나타났으나, 은사시나무와 소나무재는 $160^{\circ}C$에서도 재색변화가 크게 나타났다. 참오동나무재의 밀도는 $160{\sim}180^{\circ}C$ 열처리에서는 거의 변화가 없었고, 중량감소율은 참오동나무재가 가장 크게 나타났다. 열처리온도 증가에 따라 세 수종의 목재의 중량감소율과 상대결정화도는 증가하였으나 밀도는 다소 감소하였다. 결론적으로 참오동나무재는 색변화 온도, 중량감소율 및 상대결정화도 증가량이 비교수종 목재와 다른 특성을 나타났다.

• Journal of the Korean Wood Science and Technology
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• 제45권2호
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• pp.213-222
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• 2017

Heat treatment of wood is an attractive alternative environmentally-friendly treatment to add value of less valuable woods by improving color, dimensional stability, and natural durability. To improve the color properties of Korean white pine (Pinus koraiensis) and royal paulownia (Pauwlonia tomentosa), we treated the woods at $160^{\circ}C$, $180^{\circ}C$, $200^{\circ}C$, and $220^{\circ}C$ for 2 hours. Color change after heat treatment was evaluated using the CIE-Lab color system and survey was conducted to determine the consumer preferences towards color of heat-treated wood. Lightness ($L^*$) decreased with increasing temperature and the higher degree of change was obtained in royal paulownia. The red/green chromaticity ($a^*$) in both wood decreased after heat treatment at $160^{\circ}C$, and constantly increased after heat treatment at $180^{\circ}C$ to $220^{\circ}C$. Yellow/blue chromaticity ($b^*$) in Korean white pine tended to increase after heat treatment at $160^{\circ}C$, then decreased gradually afterwards. In royal paulownia, $b^*$ values linearly increased with increasing temperature. Overall color change (${\Delta}E^*$) increased with increasing temperature with higher degree obtained in royal paulownia. Samples with the clamps in both wood species showed lower degree of the change in $L^*$, $a^*$, b and ${\Delta}E^*$. The results of the consumer preferences test showed that the darker colors of heat-treated woods were more preferred by consumers compared to the lighter colors of untreated woods. Consequently, heat treatment could enhance the color properties of Korean white pine and royal paulownia woods for value added products.

• Journal of Forest and Environmental Science
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• 제21권1호
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• pp.16-23
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• 2005

강원대학교 구내림에서 오동나무 잎을 채취하여 아세톤-물(7:3, v/v)로 추출하고 n-hexane, methylene chloride, ethylacetate 및 $H_2O$ 등 네 개의 분획으로 분리한 후 에틸아세테트용성 분획물을 Sephadex LH-20으로 칼럼 크로마토그래피를 수행하였으며 용리용매는 메탄올 수용액과 에탄올-헥산 혼합액을 사용하였다. 그 결과 flavonoid류 화합물인 (+)-catechin, (-)-epicatechin, apigenin, luteolin, taxifolin과 phenolic acid류 화합물인 $\rho$-hydroxybenzoic acid, vanillic acid 및 $\rho$-coumaric acid를 단리 하였다. 단리된 화합물은 NMR 및 MS 스펙트럼을 이용하여 구조를 결정하였다.

• Journal of the Korean Wood Science and Technology
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• 제34권2호
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• pp.83-87
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• 2006

The leaves of Paulownia coreana Uyeki were extracted with acetone-$H_2O$ (7:3, v/v), concentrated under reduced pressure and fractionated successively with n-hexane, methylene chloride and ethyl acetate, leaving residual water soluble fraction. A portion of the resulting aqueous soluble powder was chromatographed on a Sephadex LH-20 column using aqueous methanol and ethanol-hexane as washing solvents. Three apigenin derivatives were isolated and identified as apigenin-7-O-${\beta}$-D-glucpyranoside, apigenin-7-O-${\beta}$-D-glucuronopyranoside and apigenin-7-O-[${\beta}$-D-glucuronopyranosyl($1{\rightarrow}2$)-O-${\beta}$-D-glucuronopyranoside] by spectroscopic methods including NMR and FAB-MS.

• Journal of the Korean Wood Science and Technology
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• 제34권2호
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• pp.78-82
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• 2006

The leaves of Paulownia coreana Uyeki were collected, extracted with acetone-$H_2O$ (7:3, v/v), concentrated under reduced pressure and successively fractionated using n-hexane, methylene chloride, ethyl acetate and water on a separatory funnel. A portion of the ethyl acetate soluble powder was chromatographed on a Sephadex LH-20 column using aqueous methanol and ethanol-hexane as washing solvents. Two isomeric phenylpropanoid glycosides were isolated and elucidated as verbascoside and isoverbascoside by NMR and MS spectrometers.

• Journal of the Korean Wood Science and Technology
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• 제35권2호
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• pp.96-101
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• 2007

Seeds of Paulownia coreana were collected, extracted with acetone-$H_2O$ (7 : 3, v/v), concentrated under reduced pressure and successively fractionated with n-hexane, methylene chloride, ethyl acetate and water on a separatory funnel. The $H_2O$ soluble fraction was chromatographed on a Sephadex LH-20 column using aqueous methanol and ethanol-hexane as washing solvents. Two isomeric phenylethanoid glycosides, verbascoside (1) and isoverbascoside (2), and one epimeric phenylethanoid glycoside, campneoside II (3), were isolated and their structures were elucidated on the basis of chemical and spectroscopical data.

• Journal of the Korean Wood Science and Technology
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• 제35권5호
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• pp.93-99
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• 2007

Paulownia coreana inner bark was collected, extracted in 70% acetone, concentrated under reduced pressure and sequentially fractionated using n-hexane, $CH_2Cl_2$, EtOAc and $H_2O$, then freeze dried to give brown powders. A portion of the EtOAc soluble powder was chromatographed on a Sephadex LH-20 column using a serious of aqueous methanol and ethanol-hexane mixture as eluting solvents. Two phenolic acid, $\rho$-courmaric acid and caffeic acid, two isomeric phenylethanoid glycosides, verbascoside and iso-verbascoside, and one epimeric phenylpropanoid glycoside, cistanoside F, were isolated and their structures were elucidated by spectroscopic analysis such as NMR and MS.

• Journal of the Korean Wood Science and Technology
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• 제40권4호
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• pp.229-236
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• 2012

본 연구는 감마선 조사가 소나무(Pinus densiflrora), 느티나무(Zelkovas serrenata), 오동나무(Paulownia tomentosa)의 세포벽 열화, 셀룰로오스 결정화도, 휨 강도에 미치는 영향을 구명하기 위해 수행되었다. 각 목재 시편들을 100 kGy 선량의 감마선 조사 후 주사전자현미경(scanning electron microscope; SEM) 관찰 결과, 목재 세포벽 열화는 관찰되지 않았으며 휨 강도 역시 현저한 변화가 나타나지 않았다. 감마선 조사에 의한 셀룰로오스 결정화도 역시 유의한 변화가 관찰되지 않았다. 이러한 감마선에 대한 목재의 높은 안전성은 감마선 조사 기술을 재질손상 없이 목재를 가해 중인 균류와 충류 구제를 위해 적용할 수 있음을 의미한다.

• Journal of the Korean Wood Science and Technology
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• 제14권4호
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• pp.40-46
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• 1986

국내산(國內産) 16수종재의 철오염(鐵汚染), 알칼리오염(汚染) 산오염(酸汚染), 태양광(太陽光)에 의한 변색을 측정한 결과를 요약하면 다음과 같다. 1. 철오염(鐵汚染)이 심(甚)한 수종(樹種)은 일본잎갈나무, 신갈나무, 느티나무, 왕버섯나무등 이었고, 적은 수종(樹種)은 참오동나무, 리기다소나무등 이었다. 2. 국내산수종(國內産樹種)은 알칼리오염(汚染)이 적은 평이었고, 알칼리오염(汚染)이 낮은 수종은 젓나무, 음나무, 현사시, 고로쇠나무, 리기다소나무, 신갈나무, 자작나무, 왕벗나무, 느티나무, 이태리포플러, 잣나무, 참오동나무 등이었다. 3. 산오염(酸汚染)이 심(甚)한 수종(樹種)은 본(本) 실험(實驗)에서 사용재중(使用材中)에는 나타나지 않았고, 낮은 수종은 리기다소나무, 오동나무, 잣나무, 신갈나무, 음나무, 고로쇠나무 등 이었다. 4. 태양광(太陽光)에 의한 변색은 본(本) 실험(實驗)에서 사용(使用)한 공시재중(供試材中)에는 변색의 정도가 높은편으로서 변색이 심(甚)한 수종은 일본잎갈나무, 고로쇠나무, 참오도나무, 이태리포플러, 소나무, 아까시나무, 젓나무, 현사시, 느티나무, 왕벗나무, 리기다소나무 등이었으며, 태양광에 의한 변색이 낮은 수종(樹種)은 오리나무로서 국내산재 16수종이 태양광에 의한 변색의 정도가 높은 것이 특징이었다. 일반적(一般的)으로, 한국산(韓國産) 수종(樹種)은 태양광(太陽光)과 철오염(鐵汚染)에 의한 정도가 높은 편이었고, 알칼리오염(汚染)과 산오염(酸汚染)에 의한 변색은 낮은 편에 속하였다.

• Journal of the Korean Wood Science and Technology
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• 제26권4호
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• pp.26-33
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• 1998

Acoustical properties of chestnut and paulownia woods have been determined in four film thicknesses of oriental lacquering and cashew varnishing on double surfaces of soundboard to elucidate effects of finishing. Accelerometer was attached to the specimen at one third position from one end, and specimen was hit by the impact hammer at one third position from opposite end. Data were processed by vibration analyzer. The ratio of axial-to-transverse sound velocity of untreated specimens of chestnut and paulownia were 3.25 and 5.34, respectively. Natural frequency, specific Young's modulus, acoustical coefficient, sound velocity, damping of sound radiation(DSR) and acoustical converting efficiency(ACE) decreased by oriental lacquering and cashew varnishing for both species. Damping of internal friction of chestnut decreased by oriental lacquering and cashew varnishing, but that of paulownia increased. Natural frequency. specific Young's modulus, acoustical coefficient, sound velocity, and DSR decreased with increased film thickness of both finishing materials. However, damping of internal friction and ACE showed irregular tendency with increased film thickness. Acoustical properties of cashew varnished chestnut specimen were better than those of oriental lacquered specimen. Acoustical properties of oriental lacquered paulownia specimen were better than those of cashew varnished specimen.