• Journal of the Korean Wood Science and Technology
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• 제24권1호
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• pp.11-16
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• 1996

The purpose of this paper is to present a summary of assignment design values according to domestic softwood structural lumber grading rules. Allowable stresses for visually graded lumber were determined from basic data on small. clear specimens. The data corrected for variability such as natural defects and other factors. The procedure adopted by Japan was used for assigning allowable design values. Strength ratios in relation to each defect were taken from ASTM D 245-81. Korean pine(Pinus koraiensis S. et Z.), Korean red pine(Pinus densiflora S. et Z.), Japanese larch(Larix leptolepis Gordon) and Needle fir(Abies holophylla Max) were applied to this study. The calculated allowable stresses were same in Korean pine and Korean red pine. These values were highest in Japanese larch lowest in Needle fir. So, it is desirable for these species to be classified into different catagories Species Group. However, accurate comparison in design values on lumber grading rules among U.S., Japan and Korea was somewhat difficult. And full scale testing will be necessary for accurate determination of the correction factors to setting up design values.

• 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.

• 한국조경학회지
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• 제27권4호
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• pp.50-58
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• 1999

This study was carried out to investigate the growth characteristics and propagation methods of L. obtusiloba as a woody landscape plant. The results are obtained as follows: L. obtusiloba was dioecious shrub and shaped with bush type. Leaves were ovate, obtuse, cordate, 7.05 cm long, 7.20 cm wide, and petiole 2.0 cm long. Flowers of L. obtusiloba were diclinous. Soil acidity ranged from pH 4.06 to 5.53 with the lowest at the Mt. Soo-Ri. Mt. Soo-Ri located near factory district, which was considered to damaged by environmental deteoration. While soil organic matter was highest at Mt. Soo-Ri, inorganic nutrients were low. L. obtusiloba grows in the area with low soil acidity and low content of inorganic. Therefore it seemed to be tolerant to air pollution. L. Obtusiloba was high seed germination rate in the plug box and its shoots were longer than seeding box and softwood cutting of L. obtusiloba showed the rooting rate of 50% at 5,000ppm on June 23. To develop a mass propagation method of Korean native L. obtusiloba through an axillary bud culture as a woody landscape plant, about 2∼3 cm shoots induced from explant were subcultured to new media contained different growth regulators. Shoots multiplied most effectively on a WPM containing 1.0 mg/l BA, producing 5.5 shoots with a shoot length of 2.5 cm per shoot explant.

• Journal of the Korean Wood Science and Technology
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• 제21권3호
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• pp.61-66
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• 1993

24mm-thick specimens from three species of plantation-grown softwood were press dried under two platen pressures of 1.75kgf/$cm^2$ and 3.50kgf/$cm^2$ to obtain drying information regarding to drying rate, thickness shrinkage and drying defects. The influence of platen pressure on drying fare in range of moisture content (30 to 10 percent) increased for pitch pine and larch, but reduced for korean white pine at higher pressure. Thickness shrinkage was increased at the higher pressure, and estimated thickness shrinkage at final MC of 10 percent became unrealistically greater for specimens containing higher final moisture content under the great influence of compressive strain. The effects of pressure on the amount of surface checks and honeycombing were different from species used. These species should have applied lower temperature than 177$^{\circ}C$ in this study to reduce surface checks and honeycombing.

• 한국약용작물학회지
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• 제12권4호
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• pp.285-288
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• 2004

꾸지뽕나무의 대량번식을 위한 상토와 생장조절제 처리에 따른 삽목 번식에 관한 시험을 수행한 바, 삽목상토는 미풍화토에서 양호하여 숙지삽과 녹지삽에서 각각 56.9%, 62.3%의 발근율을 보였고, 생장조절제는 IBA 100 ppm처리에서 발근이 양호하여 숙지삽에서 57.9%, 녹지삽에서는 89.2%의 발근율을 보였다.

• Journal of the Korean Wood Science and Technology
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• 제22권4호
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• pp.37-42
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• 1994

The adsorption of water vapor and equilibrium moisture content(EMC) of the specimens for four softwood species dried by conventional- and high temperature method and equilibrated to 15% of the target EMC condition at 25$^{\circ}C$ were determined by oven drying method and with moisture meters. The amount of adsorption for high temperature dried red pine was significantly higher than that of conventional kiln dried wood, while those of eastern white pine, eastern hemlock and Norway spruce were not significantly different between drying methods. EMCs of these four species determined by oven drying method and with capacitive admittance moisture meter were not significantly different between drying methods. EMC of high temperature dried red pine determined with resistance moisture meter was significantly higher than that of conventional kiln dried wood. But EMCs of other species did not show significant difference between drying methods. EMCs of conventional and high-temperature dried wood determined with electronic moisture meters, especially in the case of the capacitive-admittance moisture meter measurement, were lower than that determined by oven drying method.

• 한국가구학회지
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• 제14권2호
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• pp.21-29
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• 2003

This study was carried out to investigate characteristics of plywood overlaid with softwood veneers densified by resin impregnation and compression. The resin impregnability of Korean pine veneer under atmospheric pressure soaking was greater than that of larch, and impregnability of melamine resin was slightly greater than phenolic resin. It was suggested that resin impregnation ratio was affected by density and thickness of veneer. The largest melamine resin impregnation ratio of 50.7% was obtained with 1.26mm thick Korean pine veneer, and the lowest phenolic resin impregnation ratio of 11.7% with 3.41mm thick larch veneer. Therefore, it was suggested that the vacuum-pres sure-soak treatment is required at thick larch veneer. In densifying resin-impregnated veneers, densification ratio from 13.4 to 31.2% was obtained by high pressure from 15.6 to $20.8kgf/cm^2$. Impregnation of melamine resin also showed relatively greater at densification than that of phenolic resin. So it showed the degree of densification of about 20% or greater. It was seemed that adhesive bonding strength of plywood(base panel) which was directly pressed and overlaid with resin-impregnated veneer was affected by resin tackiness after resin impregnation followed by semi-drying. In laboratory scale, melamine resin impregnation was more favorable for the development of adhesive bonding strength owing to moisture control.

• 한국습지학회지
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• 제17권2호
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• pp.124-129
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• 2015

하천의 복원을 위한 기초자료로 사용하고자 인간의 간섭에 의한 훼손이 없거나 적은 10개의 자연하천을 군집생태학적 방법으로 조사하여 통계적으로 분석하였다. 그 결과 신갈나무군락과 소나무군락, 사시나무군락, 굴참나무군락, 산벚나무군락 등 총 29개의 식물군락으로 확인되었다. 하천식생은 계곡 계반림과 하변림으로 나누어졌다. 계곡 계반림은 경사가 급하고 물에 의한 영향이 적어 경목림이 우점하였고, 하변 연목림은 버드나무류로 대변되었다. 하천 선택시 자연성이 기준이 되어 인간의 간섭이 많은 하류보다 중 상류에 위치한 조사지가 많았고, 그에 따라 출현군락의 92%(44 plot)는 경목림이었고, 8%(4 plot)는 연목림이었다. 전층을 이용한 PCA 분석에서는 신갈나무군락 그룹과 산벚나무군락 그룹, 소나무군락 그룹, 산벚나무군락과 소나무군락 혼합 그룹, 기타군락 그룹으로 크게 5개의 그룹으로 나누어졌다. 교목층을 이용한 PCA 분석은 신갈나무군락 그룹, 산벚나무군락 그룹, 기타군락 그룹으로 크게 3개의 그룹으로 나누어졌다. 하천변에 출현한 식물군락은 경목림과 연목림으로 나누어졌으며, 이를 통해 하천제방권 및 고수위권은 신갈나무, 소나무, 사시나무, 굴참나무와 산벚나무 등의 종을 식재하는 것이 적합하고, 고수부지권 및 저수위권은 버드나무속 식물을 식재하는 것이 적합할 것으로 판단된다. 식재될 목본에 따른 초본의 선택은 통계분석에서 같은 그룹에 속해있고, 높은 빈도로 출현하는 종으로 하는 것이 적합하다고 판단된다.

• 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.

• Journal of the Korean Wood Science and Technology
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• 제32권2호
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• pp.82-89
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• 2004

선행 연구에서 보존 균주에 대하여 우수한 목재 방미효력을 나타내는 2종의 플루오르화합물계 약제(RNF-3, RNF-4)를 선발하였다. 본 연구에서는 이들 약제의 실용화 가능성을 검토하기 위하여 야외 분리 균주를 이용한 목재 방미효력 시험 및 침엽수 제재목 생산 현장에서의 야외 시험을 실시하였다.플루오르와 구리 성분을 함유한 합성 약제 RNF-3은 PDA 배지 상에서 16종의 분리 균주에 대하여 높은 생장 억제 효력을 발휘하였다. 또한 소나무, 잣나무 및 라디에타소나무 시험편에서도 농도 2% 이상 처리에서 분리 균주의 생장이 이루어지지 않음으로써 목재 방미효력 또한 우수한 것으로 밝혀졌다. 한편 플루오르 성분만을 함유한 RNF-4의 경우에는 농도 2% 이상 처리에서도 PDA 배지 및 목재 시험편에서 균사의 생장이 이루어짐으로써 RNF-3에 비하여 분리균에 대한 효력이 떨어지는 것으로 나타났다. 라디에타소나무 판재를 이용한 현장 야외 시험에서도 농도 2%의 RNF-3 수용액에 침지 처리한 처리구는 균류에 의한 표면오염이 발생하지 않고 건전한 외관을 유지하고 있어 높은 목재 방미효력이 인정되었다. 이들 결과로부터 RNF-3은 침엽수 제재목의 표면오염 방지를 위한 국산 목재 방미제로써 사용이 가능할 것으로 판단되었다.