• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.1
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• pp.66-74
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• 2015

DIP(deinked pulp) was bleached by FAS, $Na_2S_2O_4$ and $H_2O_2$, which are widely used in DIP bleaching process, in order to improve optical properties of DIP, and the bleaching efficiencies of DIP and environmental loads of waste water were compared, depending on bleaching chemical dosages. With the application of different bleaching chemicals, some positive improvements were shown in optical and physical properties of bleached pulp. However, the physical properties of bleached DIP and their characteristics of wastewater were remarkably different, depending on dosages and bleaching reagents. DIP chemicals with FAS and $Na_2S_2O_4$ have higher improvement in optical and physical properties than $H_2O_2$. Also, environmental loads such as pH, turbidity, SCODcr and cationic demand were decreased in reductive bleaching process. Despite of higher effectiveness of reductive bleaching process, there were some environmental problems caused by sulfur ions from FAS and $Na_2S_2O_4$. With the method of sulfur ion controls, it would be more effective than $H_2O_2$ bleaching process.

• Journal of the Korean Wood Science and Technology
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• v.38 no.2
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• pp.140-148
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• 2010

This study was to investigate the enzymatic hydrolysis of cellulose using the cellulase from whole body of the native termite collected in Milyang-si, Kyungsangnamdo, Korea. In the results, optimal temperature and pH for the enzyme of native termites were $45^{\circ}C$ and pH 5.5 for both endo-${\beta}$-1, 4-glucanase and ${\beta}$-glucosidase. Enzyme activity of the termite enzyme was shown $8.8{\times}10^{-2}\;FPU/m{\ell}$. And the highest glucose hydrolysis rate of cellulose by the digestive enzyme from test termites was 24.5% based on the glucan, comparing 59.7% by commercial enzyme (only celluclast 1.5 L) at 1% (w/v) substrate and 36 hours in hydrolysis time. This hydrolysis rate by the digestive enzyme from test termites was comparatively high value in 41% level of the commercial enzyme. When cellulose was hydrolyzed by the digestive enzyme of the native termite, glucose hydrolysis was almost completed in 12 hours which was the considerably reduced time for cellulose hydrolysis. It was suggested that the quiet short reaction time for cellulose hydrolysis by the enzyme from native termite could be a very high advantage for development of hydrolysis cellulase for lignocellulosic biomass.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.572-579
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• 2017

Determination of the wood content in wood plastic composite (WPC) is crucial to form reliable WPC market. WPC with simple formulation consisting of only two components (wood flour and polypropylene) was examined using thermogravimetric analysis (TGA) and accelerator mass spectrometry (AMS) for determining wood content in the WPC. TGA method using derivative peak temperature (DTp) of polypropylene under low heating rate ($5^{\circ}C/min$) showed more reliable calibration curve and lower error factor compared to method of using the percentage of weight loss of wood flour. In addition, AMS using bio-based carbon content showed greater reliability for the determination of wood content in the WPC in comparison with the TGA method.

• Journal of the Korean Wood Science and Technology
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• v.51 no.6
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• pp.555-568
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• 2023

The diffusion strategies of wood culture were established using the analytic hierarchy process, to prepare a diffusion plan of wood culture and wood utilization in response to climate change due to global warming. 'Standardization of wood culture', 'Valuation of wood culture', and 'Habituation of wood culture' were set as three major implementation strategies and priorities were evaluated. As a result, it was analyzed in the following order: 'Development of systematic education programs for each age group for rational and efficient use of eco-friendly wood materials and development of wood education standard guidelines linked to the curriculum', 'Preparation of scientific basis data on human compatibility and eco-friendliness of wood to ensure the reliability of wood and wood products', and 'Establishment of monitoring and improvement plan through the designation as a model school'. Through this, it was determined that an educational environment, changes in public attitudes through publicity, and expanding opportunities to use wood and wood products were necessary for wood culture diffusion. The results of this study can be used as basic data to derive the diffusion strategies of wood culture and establish a roadmap and policy implementation strategy to revitalize wood culture.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.281-291
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• 2013

This study is design to provide basic directions that Korea can take in forestry negotiation of Korea- Vietnam FTA. Trade trends and characteristics of forestry sector are figured out and the competitiveness of main products are analyzed. The trade amount between Korea and Vietnam is $207,260 thousand. Korea exports nontimber products to Vietnam, while she mainly imports wood products. The average import value of wood products during recent five years accounts for 88% of all value from Vietnam. The export items are not various, and the export value is small. The amount of imports, however, which are mainly composed of low price wood products, is relatively big. The results of analysis say that three items of Korean forest products have competitiveness, while Vietnam has eleven items. According to the study it is recommended that a sawn wood and a plywood should be classified as sensitive products to minimize and to take a long term tariff reduction.

• Journal of the Korean Wood Science and Technology
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• v.50 no.6
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• pp.414-426
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• 2022

The Lauraceae family has commercial uses, such as in the food, pharmaceutical, and perfume industries. This study was conducted to investigate anti-asthmatic activity of essential oils from the seven species in the Lauraceae family. The essential oils were extracted from the leaves of seven species, and the chemical composition was investigated by gas chromatography-mass spectrometry. The major constituents of essential oils differed depending on the species, even if they belonged to the same family. The main constituents were camphor (89.09%) in Cinnamomum camphora, linalool (26.91%) in Cinnamomum cassia, 1,8-cineole (23.90%) in Cinnamomum japonicum, d-limonene (10.27%) and β-eudesmol (10.03%) in Lindera obtusiloba, δ-cadinene (13.85%) and α-phellandrene (11.57%) in Machilus japonica, cis-,trans-β-ocimene (13.80% and 12.06%) and elemol (11.46%) in Neolitsea aciculata, and cis-β-ocimene (37.94%) and sabinene (24.91%) in Neolitsea sericea. The anti-asthmatic activity of essential oils was investigated using the lipopolysaccharide-induced NCI-H292 cells. The relative expression levels of the pro-inflammatory cytokines [interleukin (IL)-1β and IL-6] and mucus gene (MUC5AC and MUC5B) were significantly reduced by essential oils from seven species in the Lauraceae family. Among the seven essential oils, the essential oil from L. obtusiloba had the most superior anti-asthmatic activity. These results suggest that the essential oil of L. obtusiloba leaves could be used as an agent to suppress mucus hypersecretion.

• The Korean Journal of Mycology
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• v.47 no.2
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• pp.173-179
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• 2019

Sawdust cultivation of Lentinula edodes has been increasing in Korea. Fourteen strains were used to develop the best varieties of L. edodes, and hybridization was carried out by monohybrid cross. The number of hybridized strains was 1,638 among 3,100 combinations. They were cultivated on sawdust medium, and fruiting bodies were formed in 364 strains. Among them, 65 strains were selected as superior candidate strains based on the shape and size of the fruiting bodies. Forty strains formed fruiting bodies without lamellae structure. The shape of the stipe was cylindrical (255 strains), thick to lower part (15 strains), and thick to upper part (94 strains). By the combinations of 2462 n1-10 and 3420 n1-10, 2462 n1, 2462 n2, 2462 n10, and 3420 n3 were selected as excellent monokaryotic strains. These strains were considered to be superior monokaryotic strains that could be used for hybrid breeding.

• Journal of Korean Society of Forest Science
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• v.110 no.1
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• pp.106-115
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• 2021

The aim of the study was to analyze the spatial characteristics of the main producing areas of nontimber forest products. We analyzed the spatial aggregations of the main producing area and their changes using the Moran's I index. We found that 45% of nontimber forest products were significanty spatially clustered. Additionally, in five major products, we observed that the main producing area has expanded and the degree of aggregation has also strengthened over the last ten years. The results of this study can be effectively used for forest policies, such as determining the location and size of the distribution centers of specific forest products.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.319-331
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• 2015

The marketing system of non-timber forest products has been criticized as it mainly depends upon private local dealers, having too many steps between producers and consumers, we believe, which makes it less efficient. Meanwhile, there were only a few empirical studies of how they are delivered to consumers. In order to devise and implement targeted forest policies efficiently, it is quite necessary to understand the distribution channel of them. We analyzed the distribution channel of chestnut, bitter persimmon, oak mushroom, and wild greens by data analysis, field and phone survey, and then drew an implication for improving the marketing system. First of all, the number of middle step has to be reduced and the direct transaction has to be expended. In addition, we need to have more active involvement of Forest cooperative in production sites, adding values by processing, and the upgrade of current marketing centers of non-timber forest products, which have been launched since 2004 by Korea Forest Service.

• Journal of the Korean Wood Science and Technology
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• v.51 no.4
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• pp.253-269
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• 2023

Oriented strand board (OSB) distributed in Korea was collected, and its mechanical properties were investigated according to the International Organization for Standardization (ISO), Japanese Industrial Standards, and Korean Design Standard. Ten types of OSBs were collected, including six types for walls and others for floors. The thickness swelling, moisture content, and density of each product satisfied the ISO standards. All products showed lower formaldehyde emission values than those of the SE0 grade. The internal bonding strengths of all products, except products B, H, and I, met the ISO standards. However, products A, B, C, F, and H did not satisfy the thickness swelling standard of the load-bearing OSB for use in dry conditions. Products D and G showed heavy duty load-bearing OSB for use in humid conditions in terms of internal bonding and bending strength after boiling. In the nail head pull-through force and lateral nail resistance tests, all products met the standards. In terms of the structural bending performance (four points), the six types of OSBs for walls satisfied the standard for bending strength and modulus of elasticity. All the products for flooring met the standard for bending strength but, except for product G, the products did not meet the standard for modulus of elasticity. Although the results of this study cannot represent the performance of all imported OSBs, considering the above results, the water resistance performance of seven types of OSB products did not meet the standard, and 10 types of products did not match the labeling grades.