• 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.

• 한국가구학회지
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• 제19권3호
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• pp.156-162
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• 2008

Three major domestic softwoods, Korean red pine, Korean pine and larch, were heat-treated at $220^{\circ}C$ and for various treatment times for color changing. A new heat treatment equipment was developed for this study and was revealed working well for changing the colors of the three softwoods. The color difference index of 15 was obtained after 8 hours for Korean red pine and Korean pine, and 10 hours for Larch. The correlations of brightness, redness and yellowness with treatment time were different between species.

• 한국가구학회지
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• 제21권5호
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• pp.413-423
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• 2010

The study has been carried to evaluate the wood color, a typical element of visual and decorative effect, for seven major domestic softwoods using L*a*b* and chrominance ($\Delta$E*ab). The result showed that the values of whiteness, redness, and yellowness were positive at both sapwood and heartwood and there were no wood having a small chrominance difference ranged 0~0.5. There was also no wood having a chrominance difference ranging 0.5~3.0. Ginkgo biloba, Pinus koraiensis, and Larix kaempferi wood showed a little different chrominance, Taxus cuspidata, Pinus densiflora for. erecta, and Pinus densiflora wood substantial different chrominance, Juniperus chinensis wood largest different chrominance. It is concluded that the study results could be utilized as a data base in areas of wood craft and furniture and could open a way to substitute foreign imported woods.

• Journal of the Korean Wood Science and Technology
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• 제25권1호
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• pp.8-14
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• 1997

Stress wave velocity, wave impedance, and stress wave elasticity of small, clear bending specimens of five domestic softwoods (Pinus densiflora, Pinus koraiensis, Chamaecyparis obtusa, Cryptomeria japonica, and Larix leptolepis) and four tropical hardwoods(Kempas, Malas, Taun, and Terminalia) were correlated with static bending modulus of elasticity(MOE) and modulus of rupture(MOR). The degree of correlation between stress wave parameters and static bending properties was dependent on wood species tested. Stress wave elasticity and wave impedance were better predictors for static bending properties than stress wave velocity for each species individually and for softwood or hardwood species taken as a group, even though elasticity and impedance were nearly equally correlated with static bending properties apparently. Based upon the correlation coefficient between stress wave parameters and static properties, stress wave elasticity and wave impedance were found as stress wave parameters which can be used for the purpose of the reliable and successful prediction of bending properties. The degree of correlation between static MOE and MOR was also different according to wood species tested. Static MOE was nearly as well correlated with MOR as was stress wave elasticity. The results of this research are encouraging and can be considered as a basis for further work using full-size lumber. From the results of this study, it was concluded that stress wave measurements could provide useful predictions of static bending properties and was a feasible method for machine stress grading of domestic softwoods and tropical hardwoods tested in this study.

• 한국가구학회지
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• 제10권1호
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• pp.43-49
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• 1999

The pH and buffering potential for water extract of seven hardwoods and three softwoods were determined. The pH values ranged from 3.81 to 5.51 for hardwoods and 4.08 to 5.49 for softwoods. The gelation time for a urea-formaldehyde resin for each woods was determined and found to be a range of one minute thirty seven seconds to two minutes thirty nine seconds. Results shows that gelation time of a urea-formaldehyde resin was directly correlated to the pH and inversely correlated with acid buffering potential for seven hardwoods and three softwoods aqueous extracts

• 한국가구학회지
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• 제19권4호
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• pp.229-234
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• 2008

In a previous study, it was revealed that three major softwoods, Japanese pine, Korean pine and Japanese larch, heat-treated at $220^{\circ}C$, could produce high quality dark-colored boards. It is known that heat treatment decreases the hygroscopicity of wood. The hygroscopicity of major domestic softwoods and hardwoods heat-treated at $220^{\circ}C$ was investigated by a saturated salt solution method and compared with that of black and white charcoals. Equilibrium moisture contents of wood decreased with the increase of heat treatment time. Isotherm shapes of wood species were different from those of charcoals. Heat treatment decreases the equilibrium moisture contents of black locust more than those of Korean pine and Japanese larch. It was found that surface hardness of wood is improved by heat treatment to a certain extent, but a longer heat treatment causes thermal degradation, resulting in the decrease of the surface hardness.

• Journal of the Korean Wood Science and Technology
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• 제35권6호
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• pp.91-99
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• 2007

소나무, 낙엽송, 리기다소나무, 잣나무 등 국내산 침엽수 목분을 기질로 진탕배양했을 때 갈색부후균인 Fomitopsis palustris로부터 분비된 당 분해성 균체 외 효소는 Endoglucanase (EG), $\beta$-glucosidase (BGL) 및 $\beta$-1,4-xylosidase (BXL)와 함께 결정형 셀룰로오스를 분해하는 Cellobiohydrolase (CBH)도 활성을 갖은 것으로 나타났다. 4주간 배양에서 변재는 심재에 비해 큰 효소활성을 나타냈으나, 배양기간을 증가시킴으로써 효소활성이 커지는 것으로 밝혀져 효소에 의한 목질바이오매스 분해의 경우 심변재 혼합처리도 가능할 수 있음이 시사되었다. 그리고, 균체 의 단백질을 SDS-PAGE로 분석한 결과, 대부분의 수종에서 나타나는 효소의 단백질 패턴은 거의 유사한 것으로 나타나 효소를 이용한 목질계 바이오매스 분해의 경구 수종별 혼합처리도 가능함이 시사되었다. F. palustris에 의해 분해된 목분(60 mesh 통과) 셀룰로오스의 결정화도 감소율은 4주 배양에서 약 4.2~20.4%, 8주 배양에서 약 12.9~28.9% 수준으로 나타났다.

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.46-54
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• 1996

This study was carried out to investigate the vacuum drying characteristics of 50mm- and 75mm- thick tree disks of some domestic softwoods for substituting the conventional hardwoods as the materials for wood crafts. Though the elapsed drying times from green to in-use moisture content(MC) were largely shortened by vacuum drying, the tree disks treated by EWS couldn't be dried to in-use MC, and so sapwood stains also were occurred severely. We suggest EWS treatment is undesirable for the species with very high sapwood portion or vacuum drying with hot water circulation heating system. Heart checks were slight, but sapwood checks, which have never been trouble in drying process of tree disks, were severe. For the reasonable explanation it is suggested MC differences between sapwood and heartwood were large and most of tree disks had already no barks before drying test. Ginkgo was vacuum-dried with very slight drying defects such as heart checks, sapwood checks. V-cracks and sapwood stains. In Korean red pine and pitch pine V-cracks were severely occurred. And it was found the special feature that most of these defected tree disks contained several V-cracks within one tree disk. It can be considered as the causes that the region of sapwood was defected by the several checks at the early drying stage because of the steep MC gradient along the radial direction, and then at the later drying stage the drying stresses due to differential shrinkage were concentrated on these brittle spots.

• Journal of Forest and Environmental Science
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• 제28권4호
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• pp.268-277
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• 2012

Among the domestic softwoods, technical value of Pinus koraiensis small diameter logs which have comparatively low applicability was evaluated and sensitive characteristics and physical characteristics were investigated and analyzed for examining if it can be utilized as the interior decoration material. For the sensitive characteristics of Pinus koraiensis, wood figure, wood grain, wood color and odor were evaluated and for the physical characteristics, growth-ring width and latewood percentage, abrasion, density, shrinkage, swelling, absorption, roughness and hardness were evaluated. Then, the possibility to be developed as the interior decoration material was found. As the result of evaluating sensitive characteristics and physical characteristics of domestic Pinus koraiensis, wood figure, wood grain, color and scent clearly were judged to have excellent visual factor as the interior decoration material. And, physical characteristics were also judged to be excellent, so it is judged to be developed as the interior decoration material. Therefore, as the result of various forms of design pattern with domestic Pinus koraiensis small diameter logs, several patterns of interior decoration can be developed by characteristics of each side and colors of heartwood and sapwood. And, in the future, it can be applied to furniture design or interior decoration material for the proper use. Especially, it is considered to contribute to wood applying industry through the study on the quality of domestic small diameter logs which have low applicability.

• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.55-59
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• 2003

The fixation and leaching characteristics of chromated copper arsenate (CCA Type C) and chromium- copper-fluoride-zinc (CCFZ) in domestic softwood (Japanese red pine, Korean pine, and Japanese larch) sapwood were investigated using the expressate method to follow chromium fixation and the American Wood-Preservers' Association (AWPA) leaching procedure to determine leaching properties after fixation. The rates of fixation were affected by preservative types; CCA was fixed much faster than CCFZ for all species evaluated. There were definite differences in the fixation rates of different species, with Korean pine requiring shorter to fix than the other species evaluated. Chromium fixation was greatly enhanced by elevated temperatures, and fixation time can be estimated according to fixation temperatures applied. The percentage of arsenic and zinc leached from domestic softwoods was relatively high compared to chromium and copper, indicating that there is still a relatively high unfixed arsenic and zinc components after complete chromium fixation in CCA-and CCFZ-treated samples, respectively.