• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.96-105
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• 2016

This study investigated thermal properties and activation energy ($E_a$) of torrefied oak wood powders treated with various torrefaction times (0, 5, 7.5, 10 min) by using non-isothermal thermogravimetric analysis at heating rates of 10, 20, $40^{\circ}C/min$ to check the feasibility of rapidly torrefied oak wood powders as a fuel. As the torrefaction time increases, onset of thermal decomposition temperature, lignin content, and the amount of final residue of torrefied oak wood powders were accordingly increased with reduced hemicellulose content. $E_a$ was determined by using Friedman and Kissinger models and respective R-square values were over 0.9 meaning very good availability of calculated $E_a$ values. The $E_a$ values of the samples were decreased with the increase of torrefaction time and the lowest $E_a$ value ob served in the torrefied oak wood powders treated for 7.5 min showed high feasibility of rapidly torrefied oak wood powder as a biomass-solid refuse fuel.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.807-819
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• 2020

The aim of this study was to investigate the anatomical characteristics of Quercus mongolica infested by oak wilt disease. To analysis the anatomical characteristics of the wood specimens infested by the oak wilt, the anatomical structures of an infected wood, a dead wood, and sound wood were observed at 10-year-old intervals from 10 to 50 annual rings using both an optical and a scanning electron microscope. The fiber length was measured in units of 5 annual rings from the pith, and the diameter of the vessel element and the ratio of the vessel including the tyloses were measured for each 10 annual ring. In the cross section, on the infected and dead wood specimens, mycelium was also observed with the tyloses in the vessel. There was no signification difference between the wood specimens in the fiber length and the vessel diameter of the vessel element. The fiber length was not difference after 20-30 annual rings which is a part of juvenile wood. The average of the vessel ratio including tyloses in the infected wood was the highest. Especially, the ratio of tyloses was the highest 40-50 annual rings in the infected wood and the dead wood. Therefore, the large difference between the infested wood by oak wilt and the sound wood was the ratio of tyloses. This result can be used as a basic data to utilize the infested wood.

• Journal of the Korean Wood Science and Technology
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• v.24 no.4
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• pp.87-92
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• 1996

When cutting 2.0cm-thick red oak and hard maple with an air-jet-assisted carbon-dioxide laser of 2kW output power, maximum feed speed at the point of full penetration of the beam decreased with increasing the angle between grain and cutting direction. Feed speed averaged 3.75 and 3.38 meters per minute for red oak and hard maple, respectively. Gray-level of laser-cut surfaces were analyzed by image analysis system. The highest gray level of laser-cut surface was obtained when red oak was cut parallel to grain by laser. Surface profiler was used to scan the sawn and laser-cut surfaces. Center line average roughnesses of laser-cut surfaces were higher than those of sawn surfaces. Scanning electron micrographs showed the cell walls which were melted by laser.

• Journal of the Korean Wood Science and Technology
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• v.17 no.3
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• pp.1-7
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• 1989

This study was performed to obtain the optimal condition that hydrolyzed exploded pine(Pinus densiflora), oak(Quercus serrata) and birch wood(Betula platyphylla var. japonica) by using sulfuric acid. The results obtained were summarized as follows: In hydrolysis of wood meal with sulfuric acid. maximum yield of sugar appeared that pine was 12 hours. oak and birch were 24 hours with 65% sulfuric acid. Futhermore, when wood meal and exploded woods were hydrolyzed with 65% sulfuric acid at $23^{\circ}C$ for 6 hours(primary hydrolysis), diluted to 3% and hydrolyzed again at $100^{\circ}C$ for 2 hours(secondary hydrolysis), the maximum sugar yield of wood meals were 6 hours. those of higher steam exploded pine wood was 3 hours. of lower steam exploded oak and birch woods were 6 hours. The sugar analyses of exploded wood showed that the amount of arabinose and xylose residue rapidly decreased. content of nemicelluose decreased with increase of steaming time and pressure.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.523-532
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• 2014

This study was done to evaluate the antioxidant effect of oak hot water extracts on the oxidative stress induced by reactive oxygen species (ROS). The cytotoxicity of $H_2O_2$-induced oxidative stress was performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for the cell viability according to the dose-dependent treatment. Oak extracts demonstrated a dose-dependent ability to inhibit $H_2O_2$-induced apoptosis in cultured tenofibroblasts, as assessed by MTT assay and FACS analysis. $H_2O_2$ increased the phosphorylation of extracellular regulated kinase1/2 (ERK1/2) and of c-Jun N-terminal kinase (JNK) and the production of reactive oxygen species (ROS). In contrast, treatment with oak extracts was decreased this activation of ERK1/2 and JNK, as confirmed by western blot analysis, and reduced the production of ROS, as verified by fluorescent microscopic and flow cytometry (FACS) analyses. These findings suggest that oak extracts, by suppressing JNK, ERK1/2, and intracellular ROS production, have a concentration-dependent antiapoptotic effect on achilles tenofibroblasts exposed to an oxidative stressor, and may have therapeutic potential.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.105-109
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• 2007

This study was carried out to investigate the biological effects oak wood vinegar. Antimicrobial activity was tested in five microbial species at the concentration of 5 to $50{\mu}l$ of oak wood vinegar by paper disc method. Growth of P. oleovoranse, P. vulgaris, E. coli, S. aureus and Prevotella intermedia was inhibited at a dose of as low as $50{\mu}l$ of oak wood vinegar. Antioxidant activities were measured by using DPPH radical scavenging and SOD-like activity. DPPH radical scavenging and SOD-like activities were 90% and 65% at the concentration of $25{\mu}l\;and\;50{\mu}l$ of oak wood vinegar, respectively. Stimulation of the macrophages RAW264.7 cells with lipopolysaccharide (LPS) resulted in increased production of nitric oxide (NO) in the medium. However, the oak wood vinegar showed marked inhibition of NO synthesis in a dose-dependent manner. This result suggest that oak wood vinegar plays significant role for activation of immune system in the pathogenesis of inflammatory diseases.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.3
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• pp.44-49
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• 2014

The mushroom cultured waste(MCW) from cork oak was evaluated as the raw material for bioethanol production. For enzymatic hydrolysis, cellulase cocktails (Celluclast 1.5L and Novozym 188) was used for polysaccharides to monosaccharides conversion. Compared with sound cork oak woodmeal, woodmeal from MCW showed higher cellulose to glucose conversion. To improve polysaccharides to monosaccharides conversion, pretreatment by sodium hydroxide was applied. Even though more xylan and lignin were removed in woodmeal of MCW than that of cork oak, concentration of glucose was higher from sodium hydroxide treated cork oak woodmeal (51.3 g/L) than treated MCW woodmeal (41.6 g/L).

• Journal of the Korean Wood Science and Technology
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• v.25 no.4
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• pp.68-74
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• 1997

This research was studied dissolving pulp for rayon production, which is not KP, SP methods but steam explosion and oxygen alkali treatment. The variation of characterization in wood cellulose after steam explosion and oxygen alkali treatment this follows. In the oxygen alkali treatment of exploded pine wood, yield of dissolving pulp was lower than steam-exploded oak wood, and we have obtained dissolving pulp that high purity cellulose, but degree of polymerization was inclined to decrease less than 200. In the case of steam-exploded oak wood, degree of polymerization was higher than steam-exploded pine wood but purity of cellulose was lower than its.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.851-860
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• 2015

The objective of this study was to manufacture the wood based roughage using lumber from thinning of oak and pitch pine (Pinus rigida). And the study also aimed to investigate a feed value evaluation of wood based roughages. To investigate the optimization condition of steam-digestion treatment for roughage, the wood chips of oak and pitch pine were steam-digestion treated at $160^{\circ}C$ under pressure 6 atm depending on treatment times (60 min, 90 min and 120 min) followed by the content of essential oils analyzed. The essential oil content of steam-digestion treated roughages for 90 min and 120 min were under 0.1 mL/kg. The evaluation of feed value was carried out from steam-digestion treated roughages for 90 min through feed chemical composition analysis, NRC (National research Council) modeling, ruminal degradability analysis and relative economic value analysis. The feed chemical compositions including DM (dry mater), CP (crude protein), EE (ether extract), NDF (neutral detergent fiber), ADF (acid detergent fiber), ADL (acid detergent lignin), NFC (nonfiber carbohydrate) in oak roughage were 95.4, 1.36, 3.11, 90.05, 83.85, 17.33, 6.50%, respectively, and in pitch pine roughage were 94.37, 1.33, 5.48, 87.89, 86.88, 30.56, 6.32%, respectively. Both roughages showed low level of protein and very high level of NDF. The TDN (total digestible nutrient) levels using NRC (2001) model in oak and pitch pine roughages were 40.55, 31.22%, respectively. The ruminal in situ dry matter degradability was higher in oak roughage (23.84%) than in pitch pine roughage (10.02%). The economic values of oak and pitch pine rough-ages were 235, and 210 \, respectively.

• The Korean Journal of Mycology
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• v.28 no.1
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• pp.38-40
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• 2000

Anamorph and teleomorph of Diatrype stigma on the bed-log inoculated with oak-mushroom (Lentinula edodes) in Korea were observed and identified. As the characters of anamorph of Diatrype stigma, conidia were hyaline, falcate or slightly curve, and $1{\sim}1.5{\times}12.5{\sim}17.5\;{\mu}m$, and conidia layer was confirmed under the bark. About teleomorph, perithecia $150{\sim}200{\times}450{\sim}500\;{\mu}m$, with ostiole ($30{\sim}40\;{\mu}m$, three- to four-sulcate). Size of ascus containing 8 ascospores was $5{\sim}6{\times}30{\sim}40\;{\mu}m$. Ascospores were hyaline to pale brown, $1.5{\sim}2{\times}5{\sim}7.5\;{\mu}m$ and mostly biguttulate.