• 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.

• Journal of the Korean Wood Science and Technology
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• v.13 no.3
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• pp.27-33
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• 1985

Air-drying tests were carried out on green taun (Pometia pinnata f glabra) for 25-mm and 50-mm thickness to elucidate drying characteristics on air-drying rate, time and defects in spring and air-drying calendar. The results of this study were as follows: 1. The air-dried lumber for 25-mm thickness from an initial average moisture content (MC) of $58.3{\pm}3.5$ percent reached 30 percent MC in 17 days, 25 percent MC in 24 days, 20 percent MC in 38 days and 15 percent MC in 84 days. 2. The air-dried lumber for 50-mm thickness from an initial average MC of $59.6{\pm}5.0$ percent reached 30 percent MC in 39 days, 25 percent MC in 55 days and 20 percent MC in 84 days. 3. Air-drying calendar that could be useful in estimating drying times for each month developed by the use of climatological data for Suwon. Total number of effective air-drying days during a year were 243.5 days and the major determinant of the effect air-drying days was temperature. 4. The air-drying rates for 25-mm and 50-mm coated lumber were slight1y slower than those of uncoated lumber. The number and total length of both end checks and surface checks for end coated lumber were less severe than those of uncoated lumber.

• Journal of the Korean Wood Science and Technology
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• v.44 no.2
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• pp.184-190
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• 2016

Recently, wood is attracting attention as green building interior decoration material. When wood is used as building interior decoration material, excellent dimensional stability and thermal performance is required. In this study, superheated steam treatment process and thermal compression process were applied to flat sawn Pinus koraiensis wood panel in order to improve dimensional stability and thermal performance. According to results of this study, superheated steam treatment process and thermal compression process improve thermal performance and dimensional stability of wood, especially in tangential direction. The spring back in radial direction reduces the effect of thermal compression on dimensional stability of wood in radial direction.

• Geomechanics and Engineering
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• v.8 no.5
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• pp.649-661
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• 2015

This research provides insight on the laboratory investigation of the engineering properties of a lateritic soil modified with the mucilage of Opuntia ficus-indica cladodes (MOFIC), which has a history of being used as an earthen plaster. The soil is classified, according to AASHTO classification system, as A-2-6(1). The Atterberg limits, compaction, permeability, California bearing ratio (CBR) and unconfined compressive strength of the soil were determined for each of 0, 4, 8 and 12% addition of the MOFIC, by dry weight of the soil. The plasticity index, optimum moisture content, swell potential, unconfined compressive strength and permeability decreased while the soaked and unsoaked CBR increased, with increasing MOFIC contents. The engineering properties of the natural soil, which only satisfies standard requirements for use as subgrade material, became improved by the application of MOFIC such that it meets the standard requirements for use as sub-base material for road construction. The effects of MOFIC on the engineering properties of the soil resulted from bioclogging and biocementation processes. MOFIC is recommended for use as a modifier of the engineering properties of soils, especially those with similar characteristics to that of the soil used in this study, to be used as a pavement layer material. It is more economical and environment-friendly than conventional soil stabilizers or modifiers.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.539-550
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• 2016

The objective of this research was to evaluate physical and mechanical properties of three species of Styrax woods from North Tapanuli in Indonesia. The woods were more than 15 years old. Physical properties such as specific gravity, green moisture content, and volume shrinkage were determined by the procedures based on BS-373 standard for small clear specimen. Furthermore, mechanical properties, including modulus of rupture, modulus of elasticity, compression parallel to grain and hardness were also tested according to the standard. Along the stem direction, the edge section had better properties compared with those near the pith section. And the base section had also better properties than upper section. Based on the specific gravity, all of the Styrax woods in this research were classified into III-IV strength classes. A good dimensional stability was demonstrated by the value of the tangential and radial ratio which reached one. With the consideration of the mechanical properties, Styrax woods were suitable use for raw materials of light construction, furniture and handy craft.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.2
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• pp.156-161
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• 2001

This study was carried out to evaluate the effect of bulk fermentation on chemical, chromatic, and organoleptic characteristics of burley leaf tobacco. The pile of ferment processing was taken up 32 days under the conolitions of leaf moisture contents of $28\pm1%$, with a pressure of some 200kg/$m^2$ within a closed room (mean air temperature and relative humidity ; 20.5$^{\circ}C$ and 58.7%). The pile was opened up and reconstructed two times when the maximum inside temperature reached at $45~46^{\circ}C$. The nicotine content was decreased, but amomnia contents and pH were significantly increased by bulk fermentation. Otherwise, the contents of total nitrogen, total volatile base, organic acids, and fatty acids were not affected by same treatment. The value of L(black to white), a(red to green) and b(yellow to blue) in chromatic characteristics were significantly decreased by bulk fermentation. In sensory test of the cigarettes made by addition of the tormented tobacco leaves after toasting in proportion of 19-25%, no negative characteristics in irritation, taste, and preference were detected in comparison with normally processed cigarettes(19%, 2 years fermentation, toasting). The results suggest that bulk fermentation may be useful to increase the proportion of burley leaf tobacco in the cigarettes and to shorten the period of storage for aging.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.300-306
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• 2014

To recycle coal bottom ash(denoted here as CBA) generated from thermal power plants as a functional construction material, artificial soil(denoted as AS) containing CBA with dredged soil(denoted as DS) at a ratio(wt%) of 70 : 30 was manufactured by means of material engineering with sintering in a rotary kiln at $1125^{\circ}C$ using a green body formed via extrusion processing. The properties of the soil mechanics of the AS and the as-received CBA were analyzed and compared. Compaction testing results determined an optimum moisture content of the AS and CBA at 18%. During these tests, the maximum dry unit weights of the materials were similar, at 1.57 and 1.58 $t/m^3$, respectively. The compressive strength levels of the AS and CBA concrete specimens were 5.1 and 5.4 $t/m^3$, respectively, both of which increased after materials engineering processing. In a consolidation test, the compression index of the AS and CBA was found to be $0.114{\pm}0.001$ in both cases. The values were similar regardless of the materials engineering processes, but during the consolidation of AS, its coefficient was higher than that of the CBA materials.

• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.47-57
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• 2024

Solar energy is one of the most promising options for renewable energy and biomass is one of them. One of the main biomass sources, sugarcane bagasse, is produced annually in more than hundreds of nations worldwide exceeding 4.25 billion tons. To dry a 900-mm deep fixed bed of wet sugarcane bagasse, a solar air heater with a collector area of 2 m² was installed. Between October 10^th to 19^th in Gwangju, South Korea, a 9-day drying period, the solar collector received a total of 496,145 kJ of solar radiation. During this time, 54.5 kg of water was extracted from 133 kg of wet sugarcane bagasse (average green moisture content of 47.6%_w.b.). The estimated net heat from the evaporation of water removed during the dying period accounted for approximately 27% of the total solar radiation on the solar collector.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.357-364
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• 2014

This study aimed to determine effects of the use of water-retention additive, hydrophilic polymer, for extensive green roofs on growth of Juniperus chinensis var. sargentii and Euonymus fortunei 'Emerald and Gold' for woody plants, and Carex kobomugi and Carex pumila for herbaceous plants. Five different contents of hydrophilic polymer including 0% (Control), 1.0%, 2.5%, 5.0%, and 10% (polymer: medium (w/w), dry weight basis) were added to each of the container filed with a 100 kg of growth medium. Ten of plants were transplanted in each of square container ($1m(L){\times}1m(W){\times}0.3m$ (H)) built on the roof platforms in randomized complete block design in the $20^{th}$ of May, 2013. In results, excessively high volumetric soil water content, about 97-98%, was found in the substrate under elevated hydrophilic polymer concentration of at least 2.5%, during the entire growing period. The moisture content of the substrate containing 1.0% of hydrophilic polymer was higher about 20% in the range between 70% and 80%, compared tho that of Control substrate in the range between 50% and 60%, for 27 days after transplanting prior to abundant rainfall, indicating that the application of hydrophilic polymer to the extensive green roof substrate is effective to eliminate drought condition by retaining water in the substrate. Euonymus fortunei 'Emerald and Gold' and Carex kobomugi resulting in higher plant growth with 2.5% than those of the other treatment plants. Juniperus chinensis var. sargentii was observed the highest growth under 1.0% hydrophilic polymer treatement, and Carex pumila was founded the best growth with Control respectively. Plants that grown in both the 1.0% and 2.5% hydrophilic polymer survived all, while the plants that grown in the 5.0% and 10% hydrophilic polymer died after 3 months. These results suggest that advantage of the addition of hydrophilic polymer may be greater in drought-tolerant plants, but the mixture proportion of hydrophilic polymer should be determined according to the different features of the plant species being grown.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.890-895
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• 2021

This study investigated the quality characteristics and antioxidant activity of bread containing Codium fragile powder (CFP; 1, 3, 5%). As the CFP content increased, the fermentation expansion (%) of the dough significantly decreased (P<0.05). No significant difference (P>0.05) was observed in the moisture content (%) of bread as the CFP content increased, but the pH and weight significantly increased (P<0.05). The bread volume, specific volume, and baking loss significantly decreased (P<0.05) as the CFP content increased. The L, a and b Hunter colors on the bread crust showed a tendency to decrease (P<0.05) as the CFP content increased. Compared with the control, the bread crumb darkened and presented a green color as the CFP content increased. Compared with the control (DPPH, 4.10%, ABTS, 2.17%), the free radical scavenging activities of DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS [2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid] as antioxidant indices gradually increased (P>0.05) with the CFP content increased (DPPH, 9.77-18.63%, ABTS, 4.30-11.40%). Collectively, these results can make a compelling case for the functional development of CPP-containing bread due to its antioxidant properties. Furthermore, this study intends to contribute to the development of various processed seaweed foods by expanding the availability of CFP, which is easy to use and store for a long time.