• Journal of the Korean Wood Science and Technology
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• 제24권1호
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• pp.81-86
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• 1996

This study was performed to evaluate the reduction in bending properties of radiata pine sapwood associated with incipient brown-rot decay. Decayed bending specimens by Tyromyces palustris and Gloeophyllum trabeum for varoious periods were tested destructively. Brown-rot decay by T. palustris and G. trabeum caused serious reduction in bending properties at very early stages of decay, with about 30 percent decrease in bending strength observed for only 1~2 percent weight loss. In general, the reduction in bending properties caused by T. palustris was somewhat greater than that by G. trabeum. Work to maximum load was reduced most severely and rapidly from the onset of decay, while modulus of elasticity showed a much more moderate rate of reduction. Modulus of rupture was affected by decay to a greater extent than was modulus of elasticity. Since a relatively strong correlation between weight loss and bending strength was observed, the residual strength of decayed wood can be predicted by weight loss due to decay. The results of this study indicate that very early stages of brown-rot decay reduce the bending strength significantly. Thus, it is recommended that all load-bearing members in wooden structures, especially those that are periodically wetted, should be inspected regularly to prevent a sudden failure even though there are no definite signs of decay.

• 한국가구학회지
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• 제26권3호
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• pp.222-228
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• 2015

To evaluate the natural decay durability of valuable domestic softwoods which are used for preservative treatment in our country, we carried out decay test by European standard method. Of all test wood species, Japanese larch (Larix leptolepis) showed slightly high natural decay durability compared to other 4 wood species, Japanese red pine (Pinus densiflora), pitch pine (Pinus rigida), Japanese cedar (Cryptomeria japonica), and scots pine (Pinus sylvestris). However, all of evaluated domestic softwood species in this study caused high weight losses over about 30% in heartwood by test fungus, Poria placenta. We can hardly expect a good natural decay durability from these softwood species. According to the classification of the natural durability of European standard (EN 350-1), they are classified into "Not durable" or "Slightly durable". Therefore, if using these softwoods as exterior materials, we must do preservative treatment to ensure durability.

• Journal of the Korean Wood Science and Technology
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• 제43권1호
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• pp.112-121
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• 2015

국내에서 사용되고 있는 가압주입 처리용 구리 붕소 아졸화합물계의 목재 방부제 Copper Azole (CuAz)의 목재내 주입량별 부후 특성을 조사하였다. 여러 가지 주입량으로 CuAz-2 방부제를 가압주입한 시편을 이용하여 갈색부후균인 부후개떡버섯에 의한 방부효력시험을 실시한 후 질량감소율을 측정하였다. 또한, CuAz-2 처리 시편을 부후개떡 버섯으로 부후시킨 후 광학현미경과 전자현미경으로 부후 특성을 관찰하였다. 그 결과, 부후개떡버섯에 의한 무처리재는 40% 이상의 질량감소율을 보여주었고 실내 부후에 의한 CuAz-2 약제의 방부효력을 나타내는 값은 $1.79{\sim}3.32kg/m^3$이었다. CuAz-2의 주입량에 따라 횡단면, 방사단면, 접선단면에서의 목재조직은 무처리 시편과 비교하여 부후 정도가 다르게 나타났다. 횡단면에서는 조재와 만재부분에서 수직수지구, 방사조직의 부후가 많이 관찰되었고, 방사단면에서는 방사가도관, 방사유세포, 벽공 부분이 부후되어 파괴되었고, 접선단면에서는 방사조직, 수평수지구가 심하게 부후되었다. 따라서 본 연구에서 주입량에 따른 부후 현상이 크게 차이가 난 점 등을 고려하여, 현재의 CuAz-2 주입량에 대한 적정성 검토가 국내 환경에 대해서 이루어져야 할 것으로 생각된다.

• Journal of the Korean Wood Science and Technology
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• 제41권6호
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• pp.559-565
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• 2013

목재사용량의 증가에 따라 목재의 화재안전성에 대한 요구가 높아지고 있다. 실내 사용 목재의 난연처리에 무기인계를 약제로 사용함으로써 환경에 대한 부담을 줄이면서 난연성능을 향상 시킬 수 있다. 수용성 약제를 가압 주입하여 목재 내 깊숙이 침투시키면 목재의 고유기능을 유지하면서 난연성능을 부여 할 수 있다. 난연제의 용탈을 억제하여 장기간 성능을 유지할 수 있는 장점도 있다. 저자들은 액상규산나트륨을 주약제로 하고, 붕산 및 인계 약제를 보조약제로 하여 목재 내로 약액을 주입하는 공정을 개발하였다. 이들 약제는 난연성능 외에 방부 및 방충성능을 지니는 약제가 포함되어 있어, 난연성능과 함께 목재 사용 시 노출될 수 있는 부후환경에서의 내후성능을 방미효력과 방부효력으로 평가하였다.

• Journal of the Korean Wood Science and Technology
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• 제27권4호
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• pp.43-50
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• 1999

The safety-evaluation of ancient wood structures has been executed with only visual inspection. The application of NDE(nondestructive evaluation) is required because the visual inspection has many restrictions. Among many NDE techniques, the stress wave technique was used in this research. This study focused on evaluating the extent of decay in members of ancient structures, using stress wave nondestructive technique. For application of stress wave technique to ancient structures, the threshold time which divides members into categories according to degree of decay should be determined in advance. Stress wave timer (Metriguard Model 239A) was used in this study, specimens used in this research were the members obtained from six ancient structures. All specimens were identified as Hard Pine(Pinus densiflora S. et Z. or Pinus thunbergii P.) by microscope. Each member was tested with stress wave passing radially through the pith. In this study, the stress wave time of $12{\mu}s$/cm could distinguish between sound and decayed specimens with accuracy of 77.5 percent. Also, decayed specimens could be separated into moderate and severe categories by stress wave time of $20{\mu}s$/cm. Among the three decay location groups (exterior, mixed, interior), the exterior group could be classified into sound, moderate and severe decay with the greatest accuracy. Stress wave transit time was not sensitive to small decay pockets located in interior of the member.

• Journal of the Korean Wood Science and Technology
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• 제36권5호
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• pp.24-32
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• 2008

Artificial brown-rot decay was induced to two wood species, Pinus densiflora and Pinus radiata. A modified direct inoculation method was used and the decay indicators of mass loss and two compressive mechanical properties, maximum compressive strength (MCS) and compressive stiffness, were estimated over the period of 8 weeks of fungal exposure. Measurable mass loss occurred 2 weeks after the fungal attack, with 15% to 22% of the loss occurring 8 weeks after fungal exposure with Fornitopsis palustris and Gloeophyllurn trabeurn. Mechanical properties proved to be far more sensitive than mass loss detection: approximately five to six times by quantity. Of the two mechanical properties, MCS was more sensitive to and consistent with progressive brown-rot decay. An ultrasonic test was performed to determine the feasibility and accuracy of this method for nondestructive detection of brown-rot decay. The ultrasonic test is highly sensitive at qualitative detection of the early stages of brown-rot decay.

• Journal of the Korean Wood Science and Technology
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• 제36권2호
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• pp.73-78
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• 2008

Inorganic chemical treated wood was prepared by impregnation of calcium or magnesium chloride ($CaCl_2$ or $MgCl_2$) solution and immersion in saturated solution of ammonium fluoride ($NH_4F$) as a reactant in order to make an introduction of a refractory fluorides with fungicidal and insecticidal effects in wood. The weight percent gains (WPGs) were increased with increase in concentration of calcium chloride or magnesium chloride solution, and were higher in treatment with calcium chloride than with magnesium chloride. Inorganic substances were produced mainly in the lumina of tracheides. These substances were proved to be the calcium fluoride or magnesium fluoride by the energy dispersive X-ray analyzer in conjunction with a scanning electron microscope (SEM-EDX). The treated wood showed good decay resistance because the weight losses were hardly occurred by the test fungi such as Tyromyces palustris and Trametes versicolor. The fire resistance effect was superior to the treated wood compared with that of the untreated wood.

• 농약과학회지
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• 제6권1호
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• pp.1-8
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• 2002

Recent progress of several kinds of compounds which have been synthesized or isolated from natural fungi for screening or conducting test as agricultural fungicides as well as some formulations for wood stain and decay control have been reviewed in this paper in China. Comments were pointed for Chinas further research and development of fungicides as well as pesticides.

• Journal of the Korean Wood Science and Technology
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• 제23권2호
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• pp.77-82
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• 1995

With the aim to utilize pine wood(Pinus densiflora Sieb. et Zucc.) as an interior building materials, such as flooring material, monoethylene glycol(MEG) resin solution was impregnated into greenwood. Specimens of three different qualities, that is, normal wood, resinous wood and compression wood, were prepared. Distribution of resin element(phosphorus) in MEG resin solution-impregnated woods and preservative effectiveness against brown rot fungi(Tyromyces palustris and Serpula lacrymans) of these woods were investigated. The results were as follows: 1. The concentration of phosphorus into cell walls of resinous wood and compression wood was lower compared to that of normal wood. This shows that the quality of wood has an influence on the penetration of MEG resin solution into the wood. It was shown from a leaching test that MEG resin could be leached out easily from the cell walls. 2. The resinous wood and compression wood, even without MEG resin solution impregnation had high decay resistance. For normal wood, significant improvement of preservative effectiveness was observed after impregnation of MEG resin solution. It was shown that MEG resin was leached out from the woods after leaching test, resulting in the reduction of preservative effectiveness. From this result, suitability of MEG resin solution-impregnated woods as an interior materials was recognized.

• Journal of the Korean Wood Science and Technology
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• 제32권2호
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• pp.50-57
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• 2004

본 실험은 건조되지 않은 목재를 고온의 아마인유에 침지처리함으로써 목재건조와 동시에 발수효과를 얻고자 실시하였다.함수율 90% 이상의 소나무생재를 온도 150℃의 아마인유에서 6시간 침지처리하였을 때 목재함수율은 10%까지 떨어졌으며, 목재 축방향의 깊이에 관계없이 목재단면의 20%에 해당하는 아마인유가 침투하였다. 이때 목재의 강도적 손실은 발생하지 않는 것으로 나타났다. 목재표면의 천공처리는 목재의 내부할열방지에 효과적이었고, 아마인유의 깊은 침투를 유도할 수 있었다. 흡수성 시험 결과 처리재는 무처리재에 비하여 높은 발수효과를 나타냈다. 변색균 및 부후균에 대한 항균효력시험은 처리재 자체로서 균에 대한 독성 기작이 없었으나, 백색부후균 및 갈색부후균에 대해서는 무처리재보다 낮은 중량감소율을 나타내는 등 방부효력의 상승이 있었다.