• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.81-88
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• 2015

바이오매스는 유망한 신재생 에너지이다. 바이오매스는 액체 및 기체 연료로 전 환 할 수 있고, 다양한 공정을 통해 열 및 전력을 생산시키는데 사용된다. 바이오매스 가스화 공정은 바이오매스를 일산화탄소, 이산화탄소, 수소 및 메탄으로 이루어진 합성 가스로 전환시키는 기술이다. 바이오매스를 이용한 합성 가스 생산 및 활용은 세계적으로 늘어나는 에너지 필요성을 충족시킬 수 있는 대체에너지이다. 현재, 바이오매스 가스화의 주요 원료는 목질계 우드 칩을 주로 사용하고 있지만, 일반적으로 우드칩의 경우 수분을 다량 함유하고 있기 때문에 가스화 공정을 위해서는 별도의 건조처리를 필요로 한다. 우드칩의 건조에는 많은 에너지가 소요되고, 다량의 우드칩 건조에는 시간과 기상 및 공간적인 환경에 영향을 받는다. 본 연구에서는 미건조 우드칩의 가스화 공정을 위하여 미건조 우드칩에 숯을 각각 10, 30, 50 % 비율로 혼합하여 실험을 수행하였고, 실험결과 생산된 합성가스의 CO 농도 는 숯의 비율에 따라 14.9 ~ 25.6 % 증가되는 경향을 나타내었지만, 반대로 $CO_2$ 및 $CH_4$ 농도는 감소하였다. 이에 따라 합성가스 생산을 위한 미건조 우드칩과 숯의 최적혼합비율은 약 30 %로 판단되며, 발열량은 $1285.7kcal/Nm^3$, Gas yield는 $2.3Nm^3/kg$ 로 나타났다. 이에 적절한 숯의 혼합사용은 미건조 우드칩의 직접적인 가스화에 도움이 될 것으로 사료되며, 바이오매스 건조 공정에 필요한 에너지를 절약할 수 있을 것으로 판단된다.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.52-57
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• 2008

In this study, the effects of carbonization temperature on the physico-chemical properties of porous wood charcoal are studied by FT-IR and Raman spectroscopies. IR studies showed that cellulose and hemicellulose are mostly decomposed in the precarbonization stage at $500^{\circ}C$, while the decomposition reaction of relatively more stable lignin lasts up to $700^{\circ}C$. Above $900^{\circ}C$, the peak at $1575cm^{-1}$ disappears and a new peak at $1630cm^{-1}$, which seems to be related to the new carbon deposit phase, is evolved. The results of Raman studies, which show the red-shift of D-band and the increase in the relative intensity of D- to G-band, indicate that the size of the crystalline becomes smaller with increasing the carbonization temperature.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.84-92
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• 2008

Anatomical and physical characteristics of Pinus densiflora woods damaged by forest fire at Yangyang-gun, Kangwon-do were investigated in present study. Even though the bark was severly carbonized, no trace of carbonization in the xylem was found. The amount of resin exudation was different by the degree of fire damage. Green moisture content of sapwood in the damaged wood was lower than that in the sound wood, but vice versa in the heartwood. Green density of heartwood in the damaged wood was higher than that in the sound wood, but there was no significant difference in sapwood. Cambial activities were found stopped in the severely damaged wood but were identified in the lightly damaged wood. In safranine staining process, epithelial and ray parenchyma cell walls in the damaged woods showed darker hue than those in the sound wood. Granular substances were observed in the lumina of ray parenchyma and epithelial cells of the severely damaged wood. Relative crystallinity of the outermost growth ring in the severely damaged wood was slightly higher than that in the sound wood.

• Korean Journal of Medicinal Crop Science
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• v.11 no.2
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• pp.122-126
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• 2003

This study was conducted to investigate plant growth characteristics and anatomical studies of Korean mistel (Viscum album var. coloratum (Kom.) Ohwi). Parasite position was upper part that has a plenty of sunshine area 5 to 10m apart from the ground, regardless host tree. Stem developed two branch stems from the each basal stem, leaf was grown from the end stems as opposite. Fruit has a light yellow color and berry size was 7 to 8 mm long diameter and it contains seed. Floral bud differentiation initiated with forming rounded dome and arch-shaped floral apex at the beginning stage, and produced heart-shaped sepal following the differentiation of leaf primordia. Floral bud formation processed centeral part first and following bilateral sides were developed in order. Leaf was thick and stoma and guard cell were observed from the two or three inner layers from the epidermis. Mistletoe penetrated cork cambium of host plant and was growing by rooting on xylem. Korean mistel connected to host plant through parasitic organ, haustorium structurally and physiologically.

• Journal of the Korea Furniture Society
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• v.11 no.2
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• pp.73-78
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• 2000

This study was carried out to measure formaldehyde emission with the passing of two years from plywood, sliver-board and strand-board bonded with urea resins which were made of 6 f/U molar ratios. The urea resins were manufactured by six kinds of formaldehyde/urea molar ratio of 1.0, 1.2, 1.4, 1.6, 1.8 and 2.0. 1. The plywood with molar ratio of 1.0 satisfied the KS F3101 $F_2$ directly after manufacture. The plywood with molar ratio of 1.2 satisfied m 3 days. The plywood with molar ratio of 1.4 satisfied the $F_3$ in 3 days and the $F_2$ in 600 days. And the plywood with molar ratio of 1.8 and 2.0 satisfied the $F_3$ in 365 days, but didn't satisfy the $F_2$ in 730 days. 2. Sliver-board with molar ratio of 1.0 and 1.2 satisfied the KS F3104 $E_2$ right after manufacture. Sliver-board with molar ratio of 1.4 and 1.6 satisfied in 150 and 360 days, respectively. Sliver-board with molar ratio of 1.8 and 2.0 satisfied in 730 days. 3. Strand-board with molar ratio of 1.0 and 1.2 satisfied the KS F3104$ E_2$ directly after manufacture. Strand-board with molar ratio of 1.4 and 1.6 satisfied in 150 days. But Strand-board with molar ratio of 1.8 and 2.0 didn't satisfied in 730 days.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.6
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• pp.616-623
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• 2010

Recently, interests in indoor air quality (IAQ) have been increased; however, a number of researchers have mainly focused on anthropogenic volatile organic compounds (AVOC) emitted from building materials. Therefore, the properties of natural VOC (NVOC) and anthropogenic VOC (AVOC) emitted from wood-based panels was investigated in this work. VOCs emitted from these panels were sampled through Tenax TA/Cabotrap and analyzed by GC-MS and GC-FID. Comparisons were made concerning TVOC, NVOC, and composition ratios of NVOC. It was revealed that TVOC emission rates of midium density fiber (MDF) were the highest. Besides, it was found that emissions of NVOC from wood-based panels were much higher than those of anthropogenic AVOC except for plywood of Oceania timber. It was also observed that the composition ratio of NVOC emitted from plywood of Pinus radiata was the highest as 65% of TVOC. Major NVOC components were monoterpene compounds such as $\alpha$-pinene, $\beta$-pinene, d-limonene, camphene and $\alpha$-terpinene. It was concluded that the composition rates of VOCs emitted from building materials were clearly different according to the raw materials and manufacturing methods.

• Conservation Science in Museum
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• v.7
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• pp.43-51
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• 2006

From the low swamp remains in Sinchang-dong, Gwangju, a number of wooden lacquerware along with various wooden artifacts were excavated. These excavated lacquerware have deteriorated and weak wooden parts and the lacquer layer come off from the wooden parts; they are very likely to peel off and crack. Therefore, we impregnated the lacquerware in PEG#4000 40% solution that was effective for vacuum freeze drying and finished freeze-drying below 0°…. We compared the weight of wood and lacquerware right after the freeze-drying with the weight after leaving them in a airtight space with 60% RH (relative humidity). The comparison results showed no change in weight; thereby we confirmed controlling the finishing temperature during freeze-drying could control the moisture in wood after drying and it could stabilize wood against the change in moisture in the atmosphere. according to the analysis of the lacquer fragment, the base layer was pasted on the wooden surface with mixed black pigment and the upper layer was pasted three or four times with the mixture of lacquer and black pigment; or it was pasted without the black base coating.

• The Korean Journal of Mycology
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• v.14 no.1
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• pp.43-47
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• 1986

Among the representative phenolic compounds in relation to lignin derivatives and protein synthesis inhibitors, the most effective inducer for the extracellular polyphenol oxidase (PO) of Lentinus edodes JA01 was gallic acid and ferulic acid for Pleurotus ostreatus. Optimum concentration of these inducers was 2.0 mM and 1.0 mM, respectively. Addition of gallic acid after two days culture had the best effect on production of PO enzyme of L. edodes JA01 and for P. ostreatus, and addition of ferulic acid after three days culture had the best effect. Also, in case of L. edodes JA01, polyphenol oxidase activity was parallel to growth curve, whereas the maximum enzyme activity of P. ostreatus was shown at exponential growth phase and declined thereafter.

• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.9-15
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• 2001

This study deals with shear strength test for Pinus densiflora and Pinus radiata treated at above $100^{\circ}C$ by heat steam. Treatment conditions of this experiment were operated at regular intervals of $20^{\circ}C$ at temperatures up to $200^{\circ}C$ for 5, 10, 20 and 30 minutes by using the steam-explosion apparatus. It was examined, at high temperatures, degradation of some compounds from wood composition could lead to reduced the shear strength through heat steaming processes and play a large part in the plastic process of solid wood materials. It could be estimated that the shear strength of woods were gradually reduced by heat steaming time. Remarkable reduction of shear strength of woods was observed with increasing steaming temperatures above 10 minutes steaming time. Furthermore, this phenomenon shows a tendency to increase with higher temperatures. Therefore, it was considered that the softening by steaming treatment at high temperatures is necessary for the improvement on the wood processing ability.

• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.48-53
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• 1996

Brown rot fungus, Tyromyces palustris, has been reported to cause the loss of strength accelerated by oxalate, a non-enzymatic low molecular weight acid, with minute weight loss of decaying wood in early stage. The production of oxalate in relation to wood decaying and the presence of oxaloacetase. an oxalate producing enzyme, were identified during the process. Tyromyces palustris produced the largest amount of oxalate among brown rot fungi. In order to find out the cleavage of pulp fiber, we submerged pulp fiber in oxalate solution and the results showed that the number of short pulp fiber was highly increased, compared with control solution. The pH of decaying wood was decreased to 1.77 which was close to that of saturated oxalate solution, pH 1.2, Thus, the oxalate was thought to be accumulated in the decaying wood, The oxaloacetase which accelerates production of oxalate was derived from fungus, and the production of oxalate by the enzyme was determined by using on UV/Vis spectrophotometer. Therefore, the oxalate was found to be produced by oxaloacetase during decay. The oxalate may cause the acid-hydrolysis of cellulose and hemicellulose. The oxalate was thought to reduce the degree of polymerization and increase the enzyme activity, which resulted in rapid loss of strength in early stage-an identical feature of brown rot fungus.