• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.3
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• pp.54-68
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• 2000

This study was tried to calculate the stumpage value using GIS technique. Before calculating this price the feasible areas to cut were divided from all forests. The stumpage value per $m^3$ was calculated by the method of calculating back from the market price, according to the working volume of logging unit and clearing a felling area using GIS. The distribution of the stumpage value for the coniferous stands was estimated from minimum 10,000 won to maximum 50,000 won, and for the deciduous stands the stumpage value was distributed from minimum 20,000 won to maximum 40,000 won. The total estimated selling price for the cutting available area (197.3ha) among this study area(250ha) except the cutting limited area was about 1.13 billions won. And the estimated selling price for the korean white pine stands was about 650 millions won, occupied 57% among the total selling price, and for the deciduous stands showed 383 millions won, occupied 34% of the total price, and for the japanese larch was 9.69 millions won, occupied 9% of the total price. But the rigida pine stands showed only 1.22 millions won.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.69-76
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• 2008

To estimate removal ability of harmful gas by charcoal, we carbonized Red oak (Quercus mongolica Fischer) wood and Larch (Larix leptoepis) bark at $300^{\circ}C$, $600^{\circ}C$ and $900^{\circ}C$ for 1 hour. Gas removal ratios was increased with carbonization temperature but there is no difference between wood and bark charcoal. In the case of bad smell and VOC gas, woody charcoal including bark charcoal carbonized at $300^{\circ}C$ showed low removal ratio, less than 50%, whereas woody charcoals which was carbonized at more than $600^{\circ}C$ reached almost 100% removal ratio to bad smell gas such as trimethylamine, methymercaptan, hydrogen sulfide, and to VOC such as benzene, toluene, xylene in $5{\ell}$ tedler bag with each gas of 100 ppm. It was thought that because charcoals carbonized at high temperature, for example, $600^{\circ}C$ or $900^{\circ}C$ have enough specific surface area to adsorb gas of 100 ppm. Moreover these charcoals rapidly removed almost gas in 10 minutes. However, acetylene, $SO_2$ and $NO_2$, charcoals which was carbonized more than $600^{\circ}C$ and which showed high removal ratio had low gas removal ratio of 40% at even 4 hours adsorption. It was concluded that adsorptive ability of woody charcoal was mainly influenced with carbonizing temperature, so that different charcoals carbonized at different temperature brings different gas removal ratio because these charcoals have not only different physical factor such as specific surface area but different chemical characteristic such as functional group, expected.

• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.40-47
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• 2016

Instead of metal connector generally used on the structural glued laminated timber rahmen joints, the GFRP reinforced laminated plates combining veneer and GFRP (Glass Fiber Reinforced Plastic) and bonded type GFRP rod were used as the connectors. As a result of moment resistance performance evaluation on the joint part applied with these connectors, the yield moment of specimen using the GFRP reinforced laminated plates and GFRP rod pin was measured 4 % lower in comparison to the specimen (Type-1) using the metal connectors, but the initial rotational stiffness was measured 29% higher. Also, the yield moment and rotational stiffness of the specimen using the GFRP-reinforced laminated plates and wood (Eucalyptus marginata) pin showed were measured 11% and 56% higher in comparison to the Type-1 specimen, showing the best performance. It was also confirmed through the failure shape and perfect elasto-plasticity analysis that it showed ductility behavior, not brittle fracture, from the shear resisting force by the pin and the bonding strength increased and the unification of member was carried out. On the other hand, in case of the specimen bonded with GFRP rod, it was impossible to measure the bonding performance or it was measured very low due to poor bonding.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.376-379
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• 2015

This study was conducted to evaluate the effects of different types and concentrations of organic nitrogen sources (${\small{L}}$-Glutamine and casein hydrolysate, CH) and plant growth regulators (auxins and cytokinins) on embryogenic tissue proliferation and somatic embryo production in L. kaempferi. Overall, the highest tissue fresh weight was obtained at either 2 or 4 weeks in culture when 1,000 mg/L ${\small{L}}$-Glutamine was added to the culture medium, which showed similar results with other treatments. In experiments with different types and concentrations of plant growth regulators on somatic embryo production, the highest production (426.3/90 mg tissue) was found when 0.2 mg/L IBA was added; however, no somatic embryos were induced following treatment with 0.2 mg/L BA or Kinetin. The effect of various concentrations of IBA on somatic embryo production was also tested. The best result (303/90 mg tissue) was obtained when plants were treated with 0.2 mg/L IBA; 1.0 mg/L IBA was also effective (281/90 mg tissue). The lowest result (109.3/90 mg tissue) was obtained with 5.0 mg/L IBA.

• Journal of the Korean Wood Science and Technology
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• v.34 no.6
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• pp.36-43
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• 2006

Using fluidized bed type fast pyrolysis system (capacity 400 g/h) bio-oils were produced from beech (Fagus sylvatica) and softwood mixture (spruce and larch, 50:50). The pyrolysis was performed for 1~2 s at the temperature of $470{\pm}5^{\circ}C$. Pyrolysis products consisted of liquid form of bio-oil, char and gases. In beech wood bio-oil was formed to ca. 60% based on dry biomass weight and the yield of bio-oil was 49% in soft wood mixture. The moisture contents in both bio-oils were ranged between 17% and 22% and the bio-oil's density was measured to $1.2kg/{\ell}$. Bio-oils were composed of 45% carbon, 47% oxygen, 7% hydrogen and lower than 1% nitrogen,which was very similar to those of original biomass. In comparison with oils from fossil resources, oxygen content was very high in bio-oils, while no sulfur was found. More than 90 low molecular weight components, classified to aromatic and non aromatic compounds, were identified in bio-oils by gas chromatographic analysis, which amounted to 31~33% based on the dry weight of bio-oils.

• Journal of the Korean Wood Science and Technology
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• v.40 no.4
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• pp.237-243
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• 2012

Sound absorption capability and anatomical features of the organosolv pretreated Japanese larch and yellow poplar wood were estimated by stereoscopic observation and two microphone transfer function method. Sound absorption capabilities of organosolv treated wood, in the entire estimated frequency range (50~6,400 Hz), were higher than those of control specimen. Especially, the treated wood's absorption capabilities measured in the frequency range of 2~4 kHz were about two times higher than those of control specimen. By the organosolv pretreatment (at $70{\sim}120^{\circ}C$), the weight loss of wood occurred in less than 1% of total weight of wood and the porosity of wood increased slightly. In addition, it was presupposed that microstructural changes of wood occurred during organosolv pretreatment and this structural changes cause the increasing of the sound absorption capability of wood.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.243-249
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• 2017

This study was performed to find out the optimum adhesive conditions on manufacturing a cross-laminated timber (hereinafter CLT) with using domestic Korean Pine (Pinus koraiensis). The adhesive conditions including a applied amount of the glue and a Pressure are the one of the most important key factors on establishing CLT production process. The shear strength was examined with differing the adhesive conditions while using Phenol Resorcinol Formaldehyde Resin Adhesive (PRF resin). The optimum adhesive conditions was confirmed to be: glue spread of $250g/m^2$ and Pressure of 0.8 MPa respectively. The grain directions of glued specimens were also considered, perpendicularly bonded and parallelly bonded groups. Shear strength of the former group showed lower values than the latter group which is considered to be the effect of a rolling shear. Meanwhile the shear strength of both group satisfied the Korean Standard (KS F 3021) and the European Standard (EN 14080 and EN 16351). The results derived from this study can be used as the basic data for manufacturing the CLT with domestic Korean Pine. And additional researches for the other species including domestic Korean Larch and Pitch Pine is also now being performed.

• Journal of the Korea Furniture Society
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• v.21 no.6
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• pp.469-478
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• 2010

Fire resistance of new hybrid timber framed wall systems was evaluated in this study. These wall systems are composed of two major structural parts. One part is a heavy timber frame part designed to take charge of whole vertical load using heavy timber post and beam, and the other is an infill wall structure, designed to take charge of whole horizontal load and to provide an established level of fire resistance. A basic concept of this hybrid wall is adopted from a typical furniture structure with frame. A timber post and beam frame is constructed with Japanese Larch solid timber post(180mm by 180mm) and beam(180mm by 240mm). As infill wall systems, two types of walls are applied. One is a typical light timber framed wall with solid blocking and another is a structural insulated panel wall, in which polystyrene insulation is filled between two structural panels to make single structure. For all tested walls, two layers of 12.5mm thick type-X gypsum boards are used on fire exposed side. Prior to tests for hybrid walls, only infill walls are tested without heavy timber frame. All fire resistance tests are carried out in accordance with KS F 2257, and temperatures on several points within wall structure and unexposed wall surface are measured during fire tests. It is considered that the reinforcement of heavy timber frame is significantly efficient for improving the fire resistance of timber framed walls.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.407-419
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• 2014

The analysis of shape before and after heating, Surface moisture content, Moisture weight change and surface heat distribution by fixed type microwave heating in forms of flat veneer and veneer roll of Korean pine, pitch pine, larch and yellow poplar was conducted. The results were as follows: In case of flat veneer, the quality after microwave heating was comparatively good, but it was somewhat warped. These phenomena may be due to transformation by nonuniform drying stress and stronger effect of local irradiation on the veneers when heating veneer owing to the characteristics of fixed type microwave equipment. In case of the features of roll-shaped veneer heated by microwave, the quality after heating was comprehensively excellent. Especially there was no warping unlike flat veneer. Heat distribution and diffusion were also very stable for roll-shaped veneer and such heat distribution had much influence on surface moisture content and moisture weight loss. Accordingly, the veneer roll would show sufficient drying efficiency in fixed type microwave equipment through a scrutinized examination on generating power and irradiation time according to species and thickness of veneer.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.460-466
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• 2014

To evaluate wood charcoal as raw material for mineral water production, dissolution of inorganic ions from charcoal to water, pH and adsorption ability of chlorine in water were investigated as main variables. More potassium ion was dissolved in water as higher temperature manufactured charcoal but other ions showed no difference with different charcoal making temperatures. Highest dissolved cation was potassium followed by calcium and sodium. Among wood species, charcoal from Quercus variabilis and Platanus occidentalis showed significantly higher potassium content in water than that of larch, red pine and white pine. Other cations had similar pattern to the potassium but their difference was not apparent as much as potassium. pH value of water treated with charcoal was higher for wood charcoals from Platanus occidentalis (pH 8.5) and Quercus variabilis (pH 8.4) which contained higher inorganic cations. In chlorine removal in water by charcoal, all wood charcoals showed greater chlorine removal than that of the control, but softwood charcoals resulted in higher removal than those of hardwoods. There was no significant difference in the dissolution of cations and pHs between particle charcoal and whole charcoal. With easy of control, whole charcoal is better for mineral water making raw material than particle charcoal does.