• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.49-54
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• 2009

This study aims to compare the profitability of using small diameter logs of Quercus species in terms of net profit (ratio), net income (ratio). The small logs of Quercus species could be used for the bed logs for shiitake mushroom and Phellinus linteus, sawdust, charcoal, and wood chip. The data of cost and revenue are collected by a face-to-face survey method from the associated factories. Our results show that the profitability for Phellinus linteus production is highest because its price has been formed high due to low market competition mainly resulted from capital service cost and production technique requirement. The next is followed by Shiitake mushroom, sawdust, wood chip, and charcoal. The study also reveals that profitability for long returning periods of investment is higher than that of short returning periods.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.6
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• pp.43-55
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• 2020

The study was performed in order to derive the management methods of revegetation space on embankment upper in the shoulder of expressway. The pilot study was conducted in 2013 on the test road section of the Jungbu Inland Expressway (Smart Highway) and continues to be monitored until 2020. In the test, three commonly used methods for weed control were applied. In the early two to three years, most of the methods were effective in controlling weeds. However, at the end of six years, weed suppression effects were different for each treatment. Vegetation coverage was 90% in the untreated control, 70-80% wood chip mulching method, 50-60% solidification method, and 20% sheet mulching method. The sheet method was found to be the most effective given the low vegetation coverage was effective in controlling weeds. The wood chip mulching method is promoting weed growth over time, and weeds are invading as the effect of soil hardening is reduced in the place where the soil hardener is treated. Among the methods applied in the test, mulching the sheet is the most effective, but it is important to use a durable sheet. In the future, it is necessary to find ways to control weeds on road shoulders, considering both economic and environmental aspects. For the proper management in the shoulder of expressway set target zone is needed. Clear standards for weed control on expressway should be established. And the technology to be applied must be durable for 3 years or more and must be able to suppress the amount of weeds to a level of 20% or less.

• New & Renewable Energy
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• v.9 no.4
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• pp.40-50
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• 2013

This study was performed to investigate the potential of torrefied tulip tree (TT) for the production of pellets. For this purpose, chemical composition and fuel characteristics of torrefied TT were examined. In addition, pellets were fabricated by using sawdust of torrefied TT chip, and durability of the pellet was measured. Lignin content of torrefied TT was higher than that of non-torrefied TT, and increased with the increases of torrefaction temperature and time. Fuel characteristics of torrefied TT were affected by torrefied conditions, and the characteristics were influenced more by torrefaction temperature than by torrefaction time. Higher heating value (HHV) and ash content (AC) of torrefied tulip tree increased with increasing torrefaction temperature, and the values were much higher than HHV and AC values of non-torrefied TT. Durability of pellets fabricated with $230^{\circ}C$- and $250^{\circ}C$-torrefied TT was higher than that of $270^{\circ}C$-torrefied TT, and the value exceeded the minimum requirement (-97.50%) of the 1st-grade pellet standard designated by Korea Forest Research Institute. Based on the results, torrefaction treatment of $250^{\circ}C/50min$ to TT might be a optimal condition for the production of TT pellets considering the mass balance and fuel characteristics of TT as well as the durability of the pellets. Thus, it is confirmed that torrefied TT can be used as a raw material for the production of bio-pellets.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.79-87
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• 2008

Many researchers have studied on rooftop greening that can be installed in abandoned spaces on a building roof. The most important issue in rooftop greening is the soil weight problem. The light greening materials are needed to solve this problem. Therefore, many alternative materials against the soil were investigated for rooftop greening. In this study, the waste wood chips and the waste paper slurry were evaluated as the lightweight vegetation foundation for rooftop greening. It also has a meaning for recycling of waste materials. The mixture ratio of waste wood chips to waste paper slurry for the board (the foundation of greening) was 60 to 40. The wet strength resin and the sizing agent were additionally added with different amount. After the forming of the board, physical and chemical properties were tested with the variation of wet strength resin and sizing agent. As the result of the test, the board with 15% of wet strength resin in the wet condition showed the highest strength. Futhermore, the moisture evaporation loss from the board surface with sizing agent was much lower than that from the board without sizing agent. Therefore, it was clear that the sizing agent was effective for water retention. The change of thickness in the wet condition was less than 1 mm, and it showed that the board is the predominant material on the dimensional stability. The average pH value of the board was ranged from 7.6 to 8.25.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.5
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• pp.60-67
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• 2011

Hemicelluloses pre-extracted from Korean mixed wood chip were investigated as a wet-end additive. Hemicelluloses dissolved in hot water and alkali solution were isolated by ethyl alcohol precipitation from pre-extractives. They showed molecular weight of 9,000 ~ 27,000 g/mol as revealed by size exclusion chromatography. The reduction of molecular weight through hot water extraction was caused by autohydrolysis. Chemical composition of the hemicelluloses were analyzed with high-performance liquid chromatography and UV-Vis spectroscopy. As the surface charge of isolated hemicelluloses were negative, the adsorption of hemicelluloses onto softwood unbleached kraft pulp fiber was promoted by poly-DADMAC. The physical properties of handsheets increased as the molecular weight of hemicellulose increased. On the other hands, the optical property decreased with hemicellulose adsorption.

• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.754-761
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• 2018

There is growing concern over the effects of global warning. In response, the power generation sector must consider a wider range of systems and fuels to generate power. One of the classes of solid fuels that is being increasingly developed is biomass. However, one of the most serious problems that biomass plants face is severe corrosion. To mitigate the problem, various approaches have been proposed in terms of additive utilization. This study is based on the results obtained during the co-combustion of wood chip and waste wood in a circulating fluidized bed boiler (CFBC boiler). The KCl concentration was reduced from 59.9 ppm to 3.9 ppm during the injection of ammonium sulfate, and NOx was reduced by 25.5 ppm from 30.6 ppm to 5.1 ppm. However, SOx increased by 110.2 ppm from 33.2 ppm to 143.4 ppm, and HCl increased by 71.5 ppm from 340.5 ppm to 412.0 ppm. Thus, we confirmed that the attitude of the superheater tube was reduced by 87 ~ 93%, and the injection of ammonium sulfate was effective in preventing high-temperature corrosion.

• Journal of the Korean Wood Science and Technology
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• v.36 no.1
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• pp.88-101
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• 2008

The aim of this study was to attempt the efficacy of antifungal activity of the wood extracts against Botrytis grey mold. Wood chip derived from Quercus mongolica was obtain from steam explosion process and extracted by hot water and methanol and ethanol. The conidial germination was maximum growth with the application temperature for 20 and $25^{\circ}C$. In pH test, we observed the maximum growth in pH 5.0 and 7.0. Antifungal activity was the best in the hot water extractives against Botrytis cinerea. The separation of the antifungal substances was performed using a silica-gel column (n-hexane : chloroform : ethyl acetate : formic acid = 12 : 17 : 8 : 0.2, v/v/v/v), TLC and UV-Spectrophotometer, and isolated 6 fraction group. The result of antifungal activity in 6 fraction group, fraction group I and fraction group II were the highest antifungal activity against grey mold with the present study. Three peaks in fraction group I and II were detected by HPLC and this compounds were suppose to effective of antifungal activity.

• Journal of Forest and Environmental Science
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• v.18 no.1
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• pp.61-72
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• 2001

The study was carried out to investigate the surroundings and benefit analysis on the planting investment of Thailand for securing a stable supply of timber through overseas planting, The results show that Thailand government is planing to increase the coverage of forest from 25% to 40%, encouraging planting over the country. More advantages and incentives are given in the investments in planting and wood-processing industries such as plywood, veneer, and chip & hard board, etc. In Thailand Eucalyptus species which are most popular in planting as they are lucratively used as a material of pulp. The Internal rate of return (IRR) in the study was ranged from 29.1 % to 59.3.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.5
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• pp.63-71
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• 2012

This study was carried out to investigate pulping properties of the forest biomass arising from the national forest management operation. The forest biomass was collected and classified into many groups according to their species and age. After the chips were made from the forest biomass, the measurement of chip size and chemical analysis were performed. To make the pulps from the forest biomass, the kraft pulping was applied and thereafter the physical and optical properties of kraft pulps were measured. The pulp fibers from the forest biomass had the similar mean fiber length, but their properties became different according to wood species and ages. Differently from the other species, kraft pulps from chestnut wood had the highest kappa number. Acacia, paulownia and chestnut woods made kraft pulps with lower tensile strength and brightness than the others. It could be concluded that acacia, paulownia and chestnut woods must be screened out in order to make a good quality of kraft pulps while being collected during Forest Management Operation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.87-96
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• 2010

This study was conducted to select environmentally-friendly and low-cost mulching material that could replace soil molding which can be used to restore vegetation in an abandoned coal mine area. To this end, we established 20 experimental plots (4m ${\times}$ 10m in size) on the steep, south west-facing slope of the abandoned coal mine area in Hwangji-Dong, Taebaek City, Gangwon Province in April 2006. We planted two-year-old 1,600 seedlings (at intervals of 0.6m ${\times}$ 0.8m) of drought-resistant tree species including Betula schmidtii, Betula platyphylla var. japonica, Amorpha fruticosa, and Quercus mongolica in the plots. After planting seedlings, mulching was applied by using five different kinds of material such as HWAP (Teracotem), peat moss, straw mats, wood chips, and control (no-mulching) and the effects of different mulching material on the survival rate and growth performance were compared. Three years after planting, the survival rate was the highest in wood chip mulching, followed by straw-mat, peat moss, HWAP, and control. The survival rate was the highest in Quercus mongolica, followed by Betula schmidtii, Betula platyphylla var. japonica, and Amorpha fruticosa. Meanwhile the height growth was the best in Betula platyphylla var. japonica, followed by Betula schmidtii, Quercus mongolica, and Amorpha fruticosa. The height growth of seedlings was the best in HWAP mulching, followed by peat moss, woody chips, straw mat, and control. From an economic point of view, wood chips are considered to be the best mulching material. The results showed that mulching without soil molding and/or mixing applications would be effective for restoring vegetation in an abandoned coal mine areas.