• Microbiology and Biotechnology Letters
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• v.51 no.1
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• pp.32-36
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• 2023

In this study, the effect of sodium hypochlorite on biofilm removal was evaluated using three bacterial strains; Aeromonas hydrophila, Streptococcus mutans, and Yersinia enterocolitica. For maximum biofilm removal in 10 min, sodium hypochlorite is required at 1.65, 0.83, and 0.41 g/l for A. hydrophila, S. mutans, and Y. enterocolitica, respectively. Resistance to sodium hypochlorite was increased by the biofilms of all three tested strains, while the change in bactericidal activity according to sodium hypochlorite concentration was strain-specific. Therefore, we aimed to determine the effective concentration of sodium hypochlorite required for hygiene, considering that higher concentrations are needed to remove biofilms than to kill cells.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.682-690
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• 2015

The bonding performance of two types of wood adhesives, namely phenol-resorcinol-formaldehyde (PRF) resin and melamine-urea-formaldehyde (MUF) resin for glued laminated timber manufactured by high frequency (HF) heating was evaluated. The HF heating system consists of HF oscillator with dielectric heating system for curing adhesives, and hydraulic press system for clamping glued laminated timber. The designed frequency and output power of the HF system was as 5 MHz and 60 kW, respectively. To verify dielectric heating mechanism under HF oscillation, the heat loss factors of laminae and adhesives were measured. The results show that it is possible to selectively heat adhesives for their curing due to the remarkably higher loss factor of the adhesives than those of wood laminae. The temperature of adhesive in the bonding line reached up to the set temperature within a few seconds by high frequency oscillating, which advanced the curing of adhesive afterwards. The bonding performance, such as shear strength of bonding line, water soaking delamination, and boiling water soaking delamination of PRF resin met the requirement of Korean Standard (KS), however the MUF resin did not meet the KS requirement of boiling water soaking delamination. These results indicate that the HF heating system is successful to manufacture glued laminated timbers with PRF resins to meet the bonding requirements.

• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.726-732
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• 2009

In order to compare and analyze the international competitiveness of Non-Timber Forest Products, the analyses of Revealed Comparative Advantage, Market Comparative Advantage, and Constant Market Share were performed in this study. From the result of data analysis from 2002 to 2006, most of items lost the international competitiveness. In the case of chestnut, however, the RCA and MCA indices recently has decreased, but still shows the competitiveness. As a Non-Timber Forest Products show a weak international competitiveness, Import is expected to increased according to the pending FTA and DDA negotiations of Korea/China. Therefore, In order to elevate the international competitiveness, reinforcement of policy support to durable technical development is required to lower the production cost and to heighten the added value.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.4
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• pp.32-42
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• 2012

Wood biomass including forest residues, waste wood, and construction residuals has been widely generated in Korea, but forest biomass from the National Forest Management Operation Project plays a big role in generating wood biomass. Unfortunately the promotion policy of woody energy organized by the Forest Service in Korea concentrates more on demand creation rather than on supply expansion. Therefore, in order to utilize insufficient wood resources effectively, it is greatly required to develop uses for maximizing their added value. In particular, more attention to the use of the second generation biomass has been paid in foreign countries because there is a threshold that the first generation biomass cannot produce enough biofuel without threatening food supplies and biodiversity. In Korea, wood pellets are regarded as the alternative clean fuels to oils and coals that emit green house gases into the atmosphere. However, using wood as pellet raw materials can not be an economic way because the value of wood disappears right after burning in the boiler in spite of its contribution to the decrease of carbon emission. Differently from wood pellets, kraft pulping process using woody biomass produces black liquor as a by-product which can be used to generate electricity, bioenergy and biochemicals through gasification. Thus, it can be more economical to make a torrefaction of lignocellulosic biomass such as low-quality wood and agricultural leftovers as raw materials of pellets.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.705-715
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• 2016

The main aim of this study was to investigate the potential of wood charcoal on removing furan compounds (5-hydroxymethylfurfural (5-HMF), furfural) known as fermentation inhibitors in sugar hydrolysates obtained from supercritical water treatment of lignocellulosic biomass. For this aim, model hydrolysate was prepared, and removal rates of sugars or furan compounds depending on wood charcoal concentration and treatment time were calculated and analyzed in comparison with the case of activated carbon. 0.5, 1, 2, 4, 8, or 12% (w/v) of wood charcoal or activated carbon was loaded into the model hydrolysate, containing glucose, xylose, 5-HMF, and furfural, and treatment was conducted for 1, 3, 6, 12, or 24 h. After treatment, removal rates of 5-HMF and furfural gradually increased as wood charcoal concentration or treatment time increased, and over 95% of 5-HMF and furfural were removed at 8% of wood charcoal concentration and 3 h of treatment time, while the loss of sugars (< 2%) was hardly observed. On the other hand, in the case of activated carbon treatment, removal rates of 5-HMF and furfural were over 95% at mild condition (activated carbon concentration: 8%, treatment time: 1 h), but over 10% of glucose and xylose were removed. Therefore, considering sugar production and further process applied sugar, the wood charcoal treatment of sugar hydrolysate was more effective for removing furan compounds and maintaining the sugar yield.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.162-168
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• 2015

The purposes of this study are estimating willingness to pay (WTP) of forest owners for the disaster insurance premium for forest products in Korea and investigating factors affecting their WTP. The result with contingent valuation method shows that forest owners' median WTP is $9,440\;KRW/ha{\cdot}yr$. Advanced forest managers including devoted forest managers and forestry successors are willing to pay more for insurance premium compared to non-advanced ones, and those who have experienced disaster in their own forest land have higher WTP than others. WTP of advanced forest managers appears to be 50% higher than that of non-advanced. These results imply that policy makers should consider advanced forest managers as a priority to introduce the insurance system.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.77-87
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• 2020

This study aims to suggest basic data for developing forest product in Jeongeup City by surveying and analyzing consumer awareness and purchasing behavior. A survey was conducted focusing on local tourist attractions in Jeongeup City, and the analysis was conducted on 234 people. Among the local specialty processed products that the survey participants had experience in purchasing, food was mainly tea, concentrate solution, liquor, snacks and fruit syrup/enzyme. The therapy was shown in order of soap, aroma oil, and lotion. It was found that the purchase cost was more than 10,000 won and less than 30,000 won. Major purchase uses were for direct use and gifts, and 56.8% of the customers were satisfied with the satisfaction of the products, which were found to be purchased because of their good quality, good gift, and good health functions. In the question of 11 kinds of forest products, the subjects were aware of bokbunja, balloon flower, wild flower, deodeok, bracken, durum, and mal, among which bokbunja and wild flower were recognized as the representative forest products of Jeongeup. A cluster of food and therapy product selection attributes was analyzed to find target consumers. As the group that is interested in forest products and values the safety and quality of products is highly recognized, the value of forest products should be increased in consideration of the quality and safety of forest products when developing products in the future.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.737-745
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• 2017

This study was carried out to investigate the changes in micro- and nanoscopic morphology of cellulose nanofibrils (CNFs) from various bioresources by investigating various mechanical milling systems. Mechanical milling in herbaceous bioresources was more effective than in woody bioresources, demonstrating lower energy consumption and finer morphology. The milling time to reach nanoscopic size was longer in woody bioresources than in herbaceous bioresources. Furthermore, at the same level of wet disk milling time, CNFs from herbaceous bioresources showed more slender morphology than those from woody bioresources. Tensile properties of nanopaper prepared from CNFs of herbaceous bioresources were higher than those of woody bioresources. The highest tensile strength was found to be 77.4 MPa in the nanopaper from Evening prim rose.

• Mycobiology
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• v.43 no.3
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• pp.297-302
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• 2015

Two white rot fungi, Ceriporia sp. ZLY-2010 (CER) and Stereum hirsutum (STH) were used as biocatalysts for the biotransformation of (-)-${\alpha}$-pinene. After 96 hr, CER converted the bicyclic monoterpene hydrocarbon (-)-${\alpha}$-pinene into ${\alpha}$-terpineol (yield, 0.05 g/L), a monocyclic monoterpene alcohol, in addition to, other minor products. Using STH, verbenone was identified as the major biotransformed product, and minor products were myrtenol, camphor, and isopinocarveol. We did not observe any inhibitory effects of substrate or transformed products on mycelial growth of the fungi. The activities of fungal manganese-dependent peroxidase and laccase were monitored for 15 days to determine the enzymatic pathways related to the biotransformation of (-)-${\alpha}$-pinene. We concluded that a complex of enzymes, including intra- and extracellular enzymes, were involved in terpenoid biotransformation by white rot fungi.

• Journal of the Korean Wood Science and Technology
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• v.14 no.4
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• pp.47-55
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• 1986