• Title/Summary/Keyword: wood structures

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Spatial Distributions of Chromium, Copper, and Arsenic Concentrations in Soils Near Three Log Structures and a Sound Barrier, All Constructed with CCA-treated Wood (CCA 처리 목재로 지은 세 개의 통나무 구조물과 방음벽 주변 토양에서 크롬, 구리 및 비소의 공간적 분포)

  • Kim, He-Kap;Song, Byeong-Yeol;Koo, Jin-Hoi
    • Journal of Soil and Groundwater Environment
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    • v.13 no.2
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    • pp.12-20
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    • 2008
  • This study was conducted to investigate the spatial distributions of chromated copper arsenate (CCA) metals in soils around three log structures and a sound barrier, all built with CCA-treated wood. Sixty-six surface and 35 profile soil samples were collected around the wood structures in addition to 13 background soil samples. The concentrations of chromium, copper, and arsenic in the soil samples collected in the vicinity of the structures were higher than those in the background samples, except in the case of one structure. The concentrations in the surface soils adjacent to the 3-year-old structures seemed to be higher than those in the soils adjacent to the 8-year-old ones. Although the lateral distributions of the metals varied with the structures, chromium and arsenic appeared to show concentration gradients within 20-60 cm and 40-100 cm, respectively. Copper seemed to be the least mobile, displaying concentration gradients only within 20 cm. Even though there were no explicit vertical concentration gradients for any of the metals according to the profile soil sample analysis, chromium and copper seemed to show concentration gradients only up to 5 and 10 cm, respectively, whereas arsenic showed gradients up to 35 cm. At study sites, it was evident that heavy metals leached into soil from CCA-treated wood were confined to neighboring areas both laterally and vertically, and that any plausible ecological impact may occur only within a small range.

Study on the Relationship between the Structure and Antioxidant Activities of Chalcones

  • Park, Youngki;Lee, Hak-Ju;Lee, Wi Young;Ahn, Jin-Kwon;Hwang, Byung-Ho
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.2
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    • pp.88-94
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    • 2006
  • The purpose of this study is to examine the relationship between antioxidant activities and chemical structures of various chalcones. Twenty-two chalcones were assessed for their radical scavenging activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Of 22 compounds tested, the most active on DPPH radical was 2',4-dihydroxy-3,3'5-trimethoxy-5'-propylchacone (4) (72.6% at 100 ppm). It was followed by 3',4'-dihydroxy-3,4,5-trimethoxy-6'-methylchalcone (6), 2',4,4'-trihydroxy-3-methoxy-5-propenylchalcone (7) and 2',4,4'-trihydroxy-3,5-dimethoxychalcone (13). Based on the results, we concluded that the scavenging activity is controlled by the number and the position of the substitution in the compound.

Quercetin Glycosides from Bark of Maple (Acer komarovii Pojark.)

  • Kwon, Dong-Joo;Bae, Young-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.2
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    • pp.171-176
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    • 2009
  • The chemical constituents of Acer komarovii Pojark. which belongs to Aceraceae has never been reported. The bark of A. komarovii was extracted with 70% aqueous acetone, and the concentrated extract was successively partitioned with n-hexane, dichloromethane, ethyl acetate and $H_2O$. From the ethyl acetate soluble fraction, four compounds were isolated by the repeated Sephadex LH-20 and RP C-18 column chromatography. From the results of spectroscopic methods including FAB-MS, 1D and 2D NMR, the structures of the compounds were determined as quercetin (1), guaijaverin (2), hirsutrin (3) and hyperin (4). These compounds (1-4) have not been reported in this tree yet.

Phenolic Compounds from the Bark of Acer barbinerve Max.

  • Kwon, Dong-Joo;Bae, Young-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.2
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    • pp.164-170
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    • 2009
  • The bark of Acer barbinerve was extracted with 70% aqueous acetone and the organic extracts were concentrated to small volume using rotary evaporator and then fractionated successively with n-hexane, dichloromethane, ethyl acetate and water. The chromatographic separation of ethyl acetate soluble fraction led to the isolation of five phenolic compounds. By means of spectroscopic method, the structures of these compounds were identified to methyl gallate (1), methyl gallate-4-O-${\beta}$-D-glucose (2), (+)-catechin (3), (-)-epicatechin (4) and (-)-epicatechin-3-O-gallate (5). These compounds (1-5) have not been reported in this plant yet.

Stilbenoids of Korean Pine (Pinus koraiensis) Inner Bark

  • Kwon, Dong-Joo;Bae, Young-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.5
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    • pp.474-479
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    • 2009
  • Pinus koraiensis inner bark was collected and extracted with 95% ethanol. The extracts were concentrated and then sequentially fractionated using n-hexane, $CH_2Cl_2$, EtOAc, and $H_2O$ to be freeze dried. A portion of EtOAc fraction (6.6 g) was chromatographed on a Sephadex LH-20 column using aqueous methanol to isolate (+)-catechin (1), (-)-epicatechin (2), and trans-pinostilbenoside (3). Resveratrol (4) and trans-pinostilbene (5) were isolated by column chromatography using EtOH-hexane mixture after purification with aqueous methanol. The structures of these stilbenosides and flavans were characterized by spectroscopic tools using NMR and MS.

Ellagitannins from Bark of Juglans mandshurica

  • Kwon, Dong-Joo;Bae, Young-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.5
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    • pp.480-485
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    • 2009
  • Juglans mandshurica bark was collected and extracted with 70% aqueous acetone. The extracts were concentrated and then sequentially fractionated using n-hexane, $CH_2Cl_2$, EtOAc, and $H_2O$ to be freeze dried. A portion of $H_2O$ fraction was chromatographed on a Sephadex LH-20 column using aqueous methanol to isolate (S)-2,3-HHDP-D-glucopyranoside (1). Some of EtOAc fraction was also treated on a Sephadex LH-20 column using aqueous methanol and EtOH-hexane mixture to purify pedunculagin (2). The structures of these two epimeric ellagitannins were elucidated by spectroscopic tools, NMR and MS.

New Flavan 3,4-Diol Derivatives from the Heartwood of Robinia Pseudoacacia

  • Bae, Young-Soo;Ham, Yeon-Ho;Kim, Jin-Kyu
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.4
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    • pp.25-28
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    • 2000
  • Two flavan 3,4-diol derivatives were isolated from the heartwood of Robinia pseudoacacia and characterized by spectroscopic methods including $^1H$ and $^{13}C$ NMR and positive FAB-MS. The structures were identified as 2,3-trans-3,4-cis-3,4,7,3',4',5'-hexahydroxy flavan, one of isomeric leucorobinetinidins, and 4'-methoxy-2,3-trans-3,4-cis-3,4,7,3',5'-pentahydroxy flavan.

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Fatigue behavior of circular hollow tube and wood filled circular hollow steel tube

  • Malagi, Ravindra R.;Danawade, Bharatesh A.
    • Steel and Composite Structures
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    • v.19 no.3
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    • pp.585-599
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    • 2015
  • This paper presents the experimental work on fatigue life and specific fatigue strength of circular hollow sectioned steel tube and wood filled circular hollow section steel tube. Burning effect was observed in the case of circular hollow sectioned steel tube when it is subjected to Maximum bending moment of 19613.30 N-mm at 4200 rpm, but this did not happen in the case of wood filled hollow section. Statistical analysis was done based on the experimental data and relations have been built to predict the number of cycles for the applied stress or vice versa. The relations built in this paper can safely be applied for design of the fatigue life or fatigue strength of circular hollow sections and wood filled hollow sections. Results were validated by static specific bending strengths determined by ANSYS using a known applied load.

A Study on the Reduction Characteristics of Floor Impact Sound Insulation Due to the Ceiling Frame Structures in Apartment Houses (공동주택의 천장틀구조 변화에 따른 바닥충격음 차음특성 연구)

  • 정환욱;기노갑;송민정;김선우
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.8
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    • pp.573-580
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    • 2002
  • Generally the ceiling frame of apartment house is made of wood. But the wood frame has several problems due to the natural properties such as distortion by shrink, low fire resistance and material loss in the construction field. And it has some defections in sound insulation performance. Therefore it is necessary to develop a new method that can be used as a ceiling frame. This study aims to analyze and to compare the sound insulation characteristics against the floor impact sound between wood ceiling frame and M-bar frame which is made of steel. The results of this study are like these. M-bar frame is more effective than wood ceiling frame in sound insulation. And sound absorbing or sound insulation materials which can be Put on gypsum board are helpful to improve floor impact sound insulation performance.

Extractives from Fruits of Amorpha Fruticosa (I)

  • Lee, Hyun-Jung;Lee, Hak-Ju;Kwon, Yeong-Han;Choi, Don-Ha;Paik, Ki-Hyon
    • Journal of the Korean Wood Science and Technology
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    • v.31 no.6
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    • pp.8-14
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    • 2003
  • This study was carried out identify extractives of Amorpha fruticosa. In this study, one flavonoid glycoside, one ester and two rotenoids were isolated from fruits of A. fruticosa. The structures were determined as: kaempferol 7-O-α-L-rhamnopyranoside (I), methyl 3, 4, 5-trihydroxybenzoate (methyl gallate, II), tephrosin (III) and dalbinol (IV), respectively, on the basis of spectroscopic data.