• Interaction and multiscale mechanics
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• 제2권2호
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• pp.109-128
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• 2009

Multiscale analysis is a stepwise procedure to obtain macro-scale material laws, directly amenable to structural analysis, based on information from finer scales. An essential ingredient of this mode of analysis is mathematical homogenization of heterogeneous materials at these scales. The purpose of this paper is to demonstrate the potential of multiscale analysis in civil engineering. The materials considered in this work are wood, shotcrete, and asphalt.

• Journal of the Korean Wood Science and Technology
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• 제31권4호
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• pp.16-23
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• 2003

전보에 이어 산벚나무(P. sargentii) 심재 에탄올 추출물로부터 4개의 페놀성 화합물을 단리하였으며 기기분석결과, isoflavone인 prunetin를 비롯하여 flavanone인 angophorol, sakuranetin 그리고 flavanone 배당체인 isosakuranin 으로 각각 동정하였다. 그러나 이들의 항균 및 항산화 활성을 조사한 결과 활성이 낮아 산벚나무 에탄올 조추출물의 높은 항균 및 항산화 활성은 이들 단리물질과는 무관한 것으로 사료되었다.

• Journal of the Korean Wood Science and Technology
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• 제31권4호
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• pp.63-70
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• 2003

송이(Tricholoma matsutake) 자실체의 메탄올(methanol, MeOH) 추출물로부터 4개의 화합물을 분리하였으며, 기기분석 결과 adenosine (9-𝛽-D-ribofuranosyladenine)을 비롯하여, methyl trans-cinnamate, ergosterol (ergosta-5, 7, 22-triene-3𝛽-ol) 및 ergosta-4, 6, 8 (14), 22-tetraen-3-one으로 각각 동정하였다.

• Journal of the Korean Wood Science and Technology
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• 제32권3호
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• pp.66-70
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• 2004

The antioxidant activities of six isoflavonoids isolated from Sophora japonica wood and bark were examined by DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging method. This study was focused on the relationship between antioxidant activity of isoflavonoids and their chemical structures. From the results of this study, it could be concluded that the hydroxyl groups that linked at ring B and ring A in isoflavonoids have importance in the antioxidant activity. Additionally, the absence of the 2,3-double bond on the isoflavonoid enhances its antioxidant activity.

• Current Research on Agriculture and Life Sciences
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• 제9권
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• pp.103-108
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• 1991

세포간층 lignin은 2차벽 lignin(end-wise-polymer)에 비해 축합도가 높으며 guaiacyl type의 phenol성 수산기등 말단기를 많이 갖는 2차벽 lignin보다 저분자량의 bulk polymer형 lignin이다.

• Journal of the Korean Wood Science and Technology
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• 제29권3호
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• pp.99-103
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• 2001

Three 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 4,4'-dimethoxy-, 4-ethoxy- and 4-ethoxy-4'-methoxy-2,3-trans-3,4-cis-(+)-leucorobinetinidin.

• Natural Product Sciences
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• 제3권2호
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• pp.127-134
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• 1997

Two new dimeric phenolic conjugates, 2,3-di-O-dehydrodigallicmonocarboxyl-$({\alpha},{\beta})$-$^4C_1$-glucopyranose and ellagic acid 3,3'-dimethylether-4-0-$SO_3K$ were isolated from the debarked heart wood of Tamarix tetragyna (Tamaricaceae) along with the known phenolic compounds, isoferulic acid, ferulic acid, gallic acid, gallic acid 4-methyl ether, syringic acid, ellagic acid 3,3'-dimethyl ether and ellagic acid. All structures were determined mostly by ESI-MS, ID and 2D-NMR spectroscopy.

• 한국가구학회지
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• 제25권4호
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• pp.345-352
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• 2014

This study was carried out to develop eco-friendly wood street lamp (EFWSL) by using wood resources stacked in the forests after tree tending operations which were mostly abandoned, but economical as renewable wood resources for developing the wood coated street lamps with the effects of cost reduction and their attractive appearances. This study has led to the development of key compact structures of street-lighting wood poles (shaft) using laminated timber. The core technique in this study is related with producing the more stable wood poles (shaft) with the hole inside than wood poles exposed under the natural environment through applicable process to protect the wood from bursting and splitting. We also comprehensively developed the method to conserve the timber durability of wood shaft and connect the wood shaft with groove, race way to be located in the groove, locking ring, current stabilizer connected to the groove and luminaire support arm, base and hand-hole which was partly used in combination with steel materials and wood. Also we increased the utilization of abandoned and stacked woods after thinning in the forests such as Pinus densiflora, Larix leptolepis, and Pinus koraiensis plantations by maximizing the value of these natural wood resources as main materials of eco-friendly street lightings with the effects of cost reduction and attractive appearances and also the expectation of advertising effects of street lightings developed in this study.

• Wind and Structures
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• 제29권3호
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• pp.177-194
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• 2019

While establishing adequate load paths in the light-frame wood structures is critical to maintain the overall structural integrity and avoid significant damage under extreme wind events, the understanding of the load paths is limited by the high redundant nature of this building type. The objective of the current study is to evaluate the system effects and investigate the load paths in the wood structures especially the older buildings for a better performance assessment of the existing building stock under high winds, which will provide guidance for building constructions in the future. This is done by developing building models with configurations that are suspicious to induce failure per post damage reconnaissance. The effect of each configuration to the structural integrity is evaluated by the first failure wind speed, amajor indicator beyond the linear to the nonlinear range. A 3D finite-element (FE) building model is adopted as a control case that is modeled using a validated methodology in a highly-detailed fashion where the nonlinearity of connections is explicitly simulated. This model is then altered systematically to analyze the effects of configuration variations in the model such as the gable end sheathing continuity and the gable end truss stiffness, etc. The resolution of the wind loads from scaled wind tunnel tests is also discussed by comparing the effects to wind loads derived from large-scale wind tests.

• Structural Engineering and Mechanics
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• 제78권3호
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• pp.319-332
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• 2021

The wood-concrete composite is an interesting solution in the field of Civil Engineering to create high performance bending elements for bridges, as well as in the building construction for the design of wood concrete floor systems. The authors of this paper has been working for the past few years on the development of the bonding process as applied to wood-concrete composite structures. Contrary to conventional joining connectors, this assembling technique does ensure an almost perfect connection between wood and concrete. This paper presents a careful theoretical investigation into interfacial stresses at the level of the two interfaces in composite wooden beam- reinforced concrete slab strengthened by external bonding of prestressed composite plate under a uniformly distributed load. The model is based on equilibrium and deformations compatibility requirements in all parts of the strengthened composite beam, i.e., the wooden beam, RC slab, the CFRP plate and the adhesive layer. The theoretical predictions are compared with other existing solutions. This research is helpful for the understanding on mechanical behaviour of the interface and design of the CFRP- wooden-concrete hybrid structures.