• 한국임산에너지학회:학술대회논문집
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• 한국산림바이오에너지학회 1999년도 정기총회 및 학술연구발표회
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• pp.41-42
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• 1999

• Journal of the Korean Wood Science and Technology
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• 제36권4호
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• pp.66-76
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• 2008

최근 국내에서 급격히 그 수요가 증가하고 있는 낙엽송과 북미산 SPF(spruce-pine-fir) 규격재의 구조부재로서의 이용에 있어서 가장 간단하면서 많이 이용되는 파스너(fastener)인 못을 이용한 접합에 대해 그 전단성능을 검토하였다. 못접합은 특히 경골목구조(light frame construction)에서는 최적의 시공법으로 인식되고 있으며, 북미와 일본을 중심으로 못접합부에 대한 연구는 많이 진행되어 왔다. 현재 국내의 경골목구조와 기둥-보 공법에서 많이 이용되고 있는 구조부재(축재와 면재)의 못을 이용한 못접합부에 대해 그 전단성능의 기초적인 검토를 행하였다. 못접합부는 면재를 개입한 상태에서 주부재와 측면부재의 방향성에 따라 구분하여 주부재의 방향, 측면부재의 방향, 못의 종류에 따라 전단시험을 행하여 각각의 방향에 따른 못접합부의 전단성능을 비교 검토하였다. SPF 스터드재에 있어서는 낙엽송 집성재나 낙엽송 소재에 비해 못의 종류, 주부재와 면재의 방향성에 따른 전단성능의 차이가 현저하게 나타났다. 또한, 항복내력 및 최대내력과 접합계수와의 관계는 부재간의 배치상태에 따라 다르게 나타났다.

• 한국가구학회지
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• 제16권2호
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• pp.59-65
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• 2005

As physical condition of students improves, there is a need to develop human body-friendly desk and chair for students. In this study, desks and chairs were manufactured with curved veneer lamination under high frequency heating and pressing, using ten wood species such as Japanese red pine, Korean pine, pitch pine, Japanese larch, yellow poplar, black locust, oak, radiata pine, beech, and birch. The performance of these products were evaluated. The results obtained were summarized as follows; With high frequency heating, the turned lamination of veneers with full size sheet ($3{\times}6\;feet$) prepared by rotary lathe peeling was successfully applied for making the members of desk top, leg frames of desk and chair. Bending strengths of desk tops were relatively greater for yellow poplar, black locust and red pine, which were similar to those of beech and birch. Bending strengths of desk legs were classified into greater species group (red pine, yellow poplar, larch) and lower species group (radiata pine, Korean pine, pitch pine). Compressive strengths of chair legs in parallel direction to the lamination were greater in black locust and larch. On the other hand, differences between outer and inner gap at the top and drawer bottom of desk top were rather larger for the laminations of birch and beech, and less for those of yellow poplar and pitch pine, showing greater stability of open drawer space. In results, yellow poplar, larch, pitch pine and red pine showed good appearance and strength properties at the curved veneer lamination. Accordingly, it was believed that these domestic woods were able to substitute for birch which was being imported for the use of veneer-laminates type furniture.

• Journal of the Korean Wood Science and Technology
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• 제25권1호
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• pp.15-22
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• 1997

The effectiveness of presteaming for improving CCA treatability on refractory Japanese larch heartwood was investigated in this study. Presteaming was effective on improving treatability, and the extent of improvement was dependent on moisture contents of wood specimen and steaming conditions. Green wood showed higher average value in both preservative retention and penetration than dry wood, and steaming under pressure conditions also had higher treatability than steaming at atmospheric conditions. The degree of improvement for treatability was increased with the extension of steaming period. Treatability of dry wood pres teamed under pressure conditions more than 6 hours and green wood for 3 hours was similar to that enhanced by conventional incising. Presteaming green wood under pressure conditions more than 6 hours was more effective than conventional incising in improvement of CCA treatability, and resultant treatability satisfied a minimum value required for CCA-treated wood for being used at the regions of hazard class H3 and H4. In addition, an improvement of treatability by presteaming was due to an increase in permeability resulted from the degradation of hemicelluloses within aspirated pit membrane and cell wall, not the removal of extractives from pit membrane. The reduction in strength, measured as longitudinal compressive strength, due to pres teaming was related with the degradation of hemicelluloses, and was increased as steaming conditions were severe. The degree of strength reduction associated with presteaming treatment to obtain required treatability could be quantified from the relatively good relation between the increase in treatability and the decrease in strength.

• Journal of the Korean Wood Science and Technology
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• 제28권4호
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• pp.61-71
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• 2000

The effect of the treatment with CCFZ, FR-4, and PEG400 from butt end on the dimensional stability and bending properties was examined. Three softwood species such as red pine, Korean white pine and Japanese larch and three hardwood species such as poplar, alder and oak were investigated in this research. Shrinkage of red pine, Korean white pine, poplar, and alder treated with PEG400 decreased. However, there was no significant decrease of shrinkage in Japanese larch and oak. The decrease of shrinkage when moisture content changed from about 20% to 10% was larger than that at any other phase. In regard to the effect of treatment on bending properties, bending MOE and MOR of all specimens treated with PEG400 decreased significantly. Especially in the case of red pine, poplar, and alder treated with PEG400, bending MOR reduced 9%, 14%, and 12%, respectively. Reductions of MOR of the hardwood was also much larger than that of the softwood. However, in all species, treatment with CCFZ and FR-4 did not affect the change of bending MOE and MOR significantly. Comparing the large specimen which also included heartwood with the small specimen which included only treated sapwood, there was a difference in the change of bending MOE and MOR between them. The large specimens of Korean white pine, alder and Poplar, which had a relatively low proportion of sapwood(18~22%), showed the decrease of MOR by 11~13% more than that of small specimens, while red pine, Japanese larch and oak, which had a relatively high proportion of sapwood(35~40%), showed little decrease. It means that bending MOE and MOR of structural wood treated from butt end should be considered in terms of sapwood proportion as well as effect of treated chemicals.

• Journal of Forest and Environmental Science
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• 제33권4호
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• pp.315-321
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• 2017

This study was carried out to estimate the parameters of stem taper functions, to figure out the best taper model by species, and to compare with previous studies by species, targeting on the stemmed tree samples collected from the Korean red pine (Pinus densiflora), Korean white pine (Pinus koraiensis), and Japanese larch (Larix kaempferi ) stands in Gangwon and North Gyeongsang provinces of South Korea. The seven widely used models were applied in this study, and Muhairwe 1999 model for Korean red pine and Korean white pine and Kozak 2002 model for Japanese larch were evaluated as the best model for each species according to the fit statistics and the predicted stem form comparison. In addition, the predicted diameter was suitably fitted when comparing the previous studies, and the values were more appropriate following stem taper according to neiloid, paraboloid, and cone parts by species. Consequently, the estimation of this study was considered to represent the stem taper well. When comparing stem taper of three species, the diameter was largest in Korean white pine. Overall, the taper models of this study are judged to be useful for estimating stem form and volume computation of Korean red pine, Korean white pine, and Japanese larch.

• Journal of the Korean Wood Science and Technology
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• 제37권6호
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• pp.497-504
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• 2009

본 연구에서는 국산 잣나무, 일본잎갈나무, 신갈나무 및 산벚나무 Polyethylene glycol (PEG) 처리재의 초기 흡, 탈착과정에서 중량, 함수율 및 치수변화의 특성을 검토하였다. 각 수종의 무처리재와 PEG 1000, 2000, 4000 처리재는 상대습도 20%, 65% 및 98% 조건에서 1주일 동안 조습시켰다. 그 결과, 초기 흡, 탈착과정에서 PEG 1000과 2000으로 처리한 잣나무, 일본잎갈나무 및 산벚나무재의 중량은 크게 증감하였지만, 신갈나무재는 거의 변화가 없었다. PEG처리에 의한 함수율은 신갈나무재를 제외한 3 수종에서 상대습도의 변화에 의해 다소 높게 나타났으나, 모든 수종에서 PEG처리에 의해 치수변화를 예방할 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제35권4호
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• pp.1-8
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• 2007

목재의 방향별 내부수분이동계수와 표면방사계수를 측정하기 위하여 2.5 (방사방향) ${\times}$ 2.5 (접선방향) ${\times}$ 2.5cm (섬유방향)의 낙엽송 정육면체 시편을 제작하였다. 수분이동방향과 직교하는 단면을 제외한 나머지 4면을 파라핀테이프와 고무테이프를 이용하여 코팅한 후, 70, 50, $30^{\circ}C$의 3가지 온도조건과 30, 60%의 2가지 상대습도 조건에서 건조시키면서, 목재 내부와 표면에서의 수분이동을 평가하였다. 자유수 유동과 결합수 및 수증기의 확산에 의한 내부수분이동계수는 고온조건에서 크게 나타났으며, 섬유방향이 횡단방향에 비하여 6배, 횡단방향에서는 방사방향이 접선방향에 비하여 1.2배 정도 큰 값을 보였다. 표면방사계수는 온도가 상승하고, 표면함수율이 감소함에 따라 증가하였다. 본 연구 결과를 이용하여 비평형상태에서 낙엽송재 내 함수율 분포변화와 증발수분량을 예측할 수 있으리라 기대된다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.152.2-152
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• 1999

No Abstract, See Full Text

• 한국토양비료학회지
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• 제32권2호
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• pp.115-122
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• 1999

본 연구는 인공조림된 잣나무임분과 일본잎갈나무임분을 대상으로 1997년 6월에 요소 (N: $150kg\;ha^{-1}$)를 시용하고 1년간의 토양 및 토양수중 양분함량 변화를 조사하였다. 토양 pH는 시용 후 잣나무임분에서는 급격한 감소경향을, 일본잎갈나무임분에서는 완만한 증가경향을 보였으나 시간이 경과함에 따라 시용 전 농도수준으로 회복되고 있었으며, 전탄소, 전질소는 시용 후 증가 경향을 보이다. 일정한 값을 나타내고 있었다. 치환성 Ca, Mg는 시용 후 감소하는 경향을 보였으나 치환성 K는 증가하는 경향을 보였다. 일본잎갈나무의 토양수의 pH를 제외하고는 양임분 모두 토양수의 pH와 시용 후 감소하는 양이온중 Ca, $NH_4-N$, 음이온중 $NO_3-N$, $SO_4-S$, Cl 농도는 초기간계에서 증가하였으나, K, Mg, 농도는 시용 후 1~2개월 후부터 증가하기 시작하여 4개월 후에 최고 농도치를 나타내고 있었다. 시용 후 급격히 증가한 토양수중 각 용존원소 농도가시용 전과 같은 수준의 농도로 회복되는데에는 Ca, $NH_4-N$, $SO_4-S$, Cl에서 약 1개월, $NO_3-N$, K, Mg에서는 6~12개월로 용존원소에 따라 그 경향을 달리하고 있다.