• Journal of the Korean Wood Science and Technology
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• 제26권4호
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• pp.34-42
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• 1998

Three hardwood (ash, alder and black locust) and three softwood (Japanese red pine, radiata pine and Western hemlock) specimens were dried in microwave(MlW) oven and their drying rates were obtained. Their specific permeabilities were also measured by using a modified liquid permeability measuring device. The correlation between the M/W drying rates and permeabilities of six species were statistically analyzed. It was revealed that within a species there is a logarithmic relationship between the M/W drying rates and average moisture contents and that among species there is a linear relationship between the M/W maximum drying rates and the average specific permeabilities. A exception was Western hemlock, which was of low permeability and of high drying rate. A Me-time equation, which showed a good agreement with the actual data, was derived. Thus using this equation the moisture contents of wood and the drying end points of M/W drying could be predicted. Infrared images of the thermal distribution in wood were illustrated.

• Journal of the Korean Wood Science and Technology
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• 제35권2호
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• pp.23-28
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• 2007

Wood fuel must be dried before combustion to minimize the energy loss. Sawdust of Japanese red pine was dried in a direct contact thermal screw dryer to investigate the drying characteristics of sawdust as a raw material for bio-fuel. Average drying rate and energy efficiency was 1.4%/min and 69.23% at $100^{\circ}C$, respectively, and those at $120^{\circ}C$ was 2.1%/min and 71.03%, respectively.

• Journal of the Korean Wood Science and Technology
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• 제41권3호
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• pp.221-233
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• 2013

본 연구에서는 중심부분 엔드코팅처리가 소나무와 잣나무 중목구조부재의 고온저습건조에 미치는 영향을 알아보기 위해 수행되었다. 건조에 소요된 시간은 총 268시간 이었으며, 최종함수율은 소나무의 경우 정각기둥재와 원주기둥재 모두 9.2~10.8%, 잣나무 정각기둥재 15.0~22.0%, 원주기둥재 12.8~20.4% 범위로 조사되었다. 소나무재의 경우 함수율 분포가 균일한 반면, 잣나무재는 부분적으로 고함수율 부위가 존재하였다. 재면할렬은 잣나무가 더 많이 발생되었으며, 부분엔드코팅처리는 재면할렬 예방에 큰 효과가 없는 것으로 조사되었다. 내부할렬은 두 수종 모두에서 발생되었다. 표면경화율은 소나무재 3.7~9.1%, 잣나무재 20.9~35.8%로 경미한 크기의 잔류응력이 존재하였다.

• Journal of the Korean Wood Science and Technology
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• 제40권2호
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• pp.61-70
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• 2012

In this study the effect of heartwood-coating (HCO), vapor-dam (VD), bark-remaing (BR) and bark-remaining- coating (BRC) treatments were evaluated during air circulating oven-drying of hollowed round-post of Korean red pine. Hollowed round-post could be dried from the green condition to approximately 6% MC within 84 to 156 hours for the UC, HCO and VD specimens and it took 72 to 240 hours to about 8% MC, which is recommended as the indoor in-use MC. The temperatures in the hole of the Control (UC) and HCO specimens constantly showed a higher-leveled distribution pattern than those inside wood. The vapor pressure in the hole of the UC, HCO and BR specimens was higher than that inside wood and showed difference as highest value of about 20 mbar. The surface checks of all specimens were mild and were observed in increasing order of BRC, BR, UC, VD and HCO specimens.

• 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.

• Journal of the Korean Wood Science and Technology
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• 제47권4호
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• pp.498-508
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• 2019

This study was carried out to investigate the potential of Korean red pine (Pinus densiflora) inner bark extracts as an antidiabetic agent. The ethyl acetate soluble fraction of the bark extracts was chromatographed on a Sephadex LH-20 column to yield five compounds, which structures were elucidated by NMR spectroscopy. The isolated compounds were (+)-catehin, (-)-epicatechin, taxifolin, taxifolin-3'-O-${\beta}$-D-(+)-glucose and $\tilde{n}$-courmaric acid. The antidiabetic activity of the different fractions, including the crude extracts and isolated compounds, was evaluated by ${\beta}$-cells insulin secretion and glucose uptake in skeletal muscle cells. The insulin secretion was 128% for taxifolin at $25{\mu}g/mL$. However, the other samples had no effect on this test. For the glucose uptake activity assay, $1{\mu}M$ insulin and 2 mM metformin were used as controls. Both the crude extract and taxifolin showed relatively low activity values, but the other samples yielded glucose uptake values over 260%. ${\rho}$-courmaric acid showed the highest uptake (270%). The results confirmed that Korean red pine extracts may be used as a hypoglycemic agent.

• Journal of the Korean Wood Science and Technology
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• 제45권4호
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• pp.409-418
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• 2017

This work attempted to manufacture glued-laminated timber (Glulam) bonded with melamine-urea-formaldehyde (MUF) resin adhesives at various melamine contents from 20% to 50% under high frequency (HF) heating for a very short time. Two preparation methods were employed to prepare MUF resin adhesives with different melamine contents: one-batch method of synthesizing MUF resins in a single batch, and two-batch method of mixing urea-formaldehyde (UF) resin with melamine-formaldehyde (MF) resin that had been synthesized separately. As the melamine content increased, the gelation time and peak temperature of MUF resins decreased. The adhesion performance of plywood showed that the one-batch MUF resin adhesive with 50% melamine content only satisfied the standard requirement of water resistance. Thus, the one-batch MUF resin adhesive with 50% melamine content was applied for bonding wood lamina from four softwood species such as Japanese larch, Korean red pine, Korean pine and Japanese cedar to manufacture Glulam under HF heating. All Glulam samples bonded with the one-batch MUF resin adhesives with 50% melamine content except those from Korean Red Pine satisfied the requirement in water soaking or boiling water delamination test as an exterior grade Glulam. The presence of rosin in Korean Red Pine was believed to be responsible for its poor adhesion. These results showed that the one-batch MUF resin adhesives with 50% melamine content provided acceptable water resistance with exterior grade Glulam manufactured under HF heating.

• Journal of the Korean Wood Science and Technology
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• 제45권2호
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• pp.202-212
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• 2017

This study was to establish the interrelation between chemical compositions and near infrared (NIR) spectra for the classification on distinguishability of domestic gymnosperms. Traditional wet chemistry methods and infrared spectral analyses were performed. In chemical compositions of five softwood species including larch (Larix kaempferi), red pine (Pinus densiflora), Korean pine (Pinus koraiensis), cypress (Chamaecyparis obtusa), and cedar (Cryptomeria japonica), their extractives and lignin contents provided the major information for distinction between the wood species. However, depending on the production region and purchasing time of woods, chemical compositions were different even though in same species. Especially, red pine harvested from Naju showed the highest extractive content about 16.3%, whereas that from Donghae showed about 5.0%. These results were expected due to different environmental conditions such as sunshine amount, nutrients and moisture contents, and these phenomena were also observed in other species. As a result of the principal component analysis (PCA) using NIR between five species (total 19 samples), the samples were divided into three groups in the score plot based on principal component (PC) 1 and principal component (PC) 2; group 1) red pine and Korean pine, group 2) larch, and group 3) cypress and cedar. Based on the chemical composition results, it was concluded that extractive content was highly relevant to wood classification by NIR analysis.

• 임산에너지
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• 제22권3호
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• pp.49-56
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• 2003

목재의 탄화과정 산물인 목탄과 목초액의 농업적 이용의 일환으로 고추 생육 및 토양미생물에 미치는 영향을 조사하였다. 목탄과 목초액을 토양에 처리할 경우 토양을 중성으로 개량하는데 효과적이고 토양의 이화학적성질이 유용 미생물이 생육하기에 적합한 환경조건으로 변화되어 토양내 유용미생물의 밀도 증가로 나타났다. 고추의 생육에 있어서도 탄화물 처리로 고추모의 길이, 직경생장 및 고추 결과 수가 증가되었다. 특히 결과 수에서는 목탄 1kg, 목초액 1000배액 및 세균처리에 의하여 대조구보다 약 50% 정도의 증수 효과를 나타냈다. 고추모의 길이 및 줄기직경 증가는 노지에서 여러 가지 환경 변화 요인에 대한 저항성을 갖게 하여 최종 수확량의 증대로 나타날 것으로 사료된다. 고추 탄저병균에 대한 길항성 실험에서는 목초액 농도 2배, 10배에서는 곰팡이가 사멸되었고, 100배, 1000배 희석농도에서는 대조구보다 성장 속도가 둔화되었다.

• 한국응용곤충학회지
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• 제15권1호
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• pp.7-16
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• 1976

본 보고는 불개미 (Formica rufa truncicola var. yessoensis Forel: red wood ant, Polydomous ant)가 어떤 일정한 지역의 삼림애 한정되어 서식하기 때문에 그의 서식지에 있어서의 서식의 제한인자인 생태학적 환경요인을 구명함으로서, 다른 지역의 송림에 이식하여, 실제로 송충의 천적으로 이용할 수 있는 기초자료가 될 수 있으므로. 자연서식지(A구)이 있어서의 불개미 집(소)의 분포와 밀도를 조사하는 동시에, 토양의 물리 및 화학적성질, 식물의 분포와 밀도, 소나무의 입목도와 울패도, 조소와 지주식물, 지표면의 습도 그리고 이식시험한 결과 등을 종합한 것이며 그의 결과를 요약하면 다음과 같다. 1. 자연서식지에 있어서 불개미의 집(소)은 주로 산록부와 산복부이 분포하여 서식밀도가 높으나 산정부에는 불개미가 전혀 서식하지 못하였다. 2. 자연서식지(A구)에 있어서의 불개미의 경제밀도는 $2.85/m^2$이고 단위밀도는 $1.95/m^2$로서 실제로 송충의 발새오가 피해를 완전히 억제하고 있으므로 경제적 이용효율이 높은 것으로 사료된다. 3. 불개미의 자연서식지는 10-20년생 소나무가 밀생하여 임목도와 울패도가 높은 송림의 지표면에 임간나지가 많고 쇠풀과 화본과 잡초인 새류가 부분적으로 군생하는 반면에 잔디가 적었다. 4. 불개미는 자연서식지의 산록부가 산복부에서 주로 새류와 소나무 등을 지주식물로 이용하여 조소하였다. 5. 자연서식지에 있어서 습도에 따르는 불개미의 분포한계선은 5월부터 9월까지(활동기)는 산복부의 $76\%$선이고 10-11월(월동기)까지는 $72\%$선이었다. 6. 불개미의 자연서식지는 지표면에 유기물과 수분등의 함량이 많은 반면에 Ca와 Mg의 함량이 적고, 미사와 세사 및 점토가 많은 반면에 조사가 현저히 적었다. 7. 불개미를 자연서식지와 환경조건이 비슷한 비서식지의 송림에 분군이식하면 증식과 정착이 가능하다는 것을 알 수 있었다.