• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.29-37
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• 2007

To evaluate the effect of carbonization temperature of charcoal on the heavy metal adsorption property, Quercus mongolica wood and Larix kaempferi bark powder (100~60 mesh) were carbonized at between 400 and $900^{\circ}C$ at intervals of $100^{\circ}C$. In the properties of carbonized materials which affect the adsorption ability, pH increased with increasing the carbonization temperature, so that the pHs of wood and bark charcoal carbonized at $900^{\circ}C$ were 10.8 and 10.4, respectively. Also, in both materials, the carbon content ratio became larger as the carbonization temperature was raised. At the same carbonization temperature, carbon content ratio of the bark charcoal tended to be greater than that of the wood charcoal. In case of iodine adsorption which indicates the adsorption property in liquid phase, the wood charcoal showed higher adsorption value than the bark charcoal. From the investigation of adsorptive elimination properties of the charcoals against 15 ppm Cd, Zn, and Cu, the higher the carbonization temperature, the greater elimination ratio was. In comparison, the wood charcoal presented higher elimination ratio than that of the bark charcoal. In the wood charcoals carbonized at higher than $500^{\circ}C$, especially, 0.2 g of the charcoal was enough to eliminated almost 100% of the heavy metal ions. Heavy metal ion elimination ratio of the charcoals depended on the kinds of adsorbates. The effectiveness of adsorbates in adsorptive elimination by the charcoals were in order of Cu > Cd > Zn. This is because the physicochemical interaction between the adsorbate and adsorbent affects their adsorption properties, it is considered that subsequent researches are needed to improve the effectiveness of heavy metal adsorption by the charcoals.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.51-62
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• 1999

The objective of this research is to develop paper sludge reinforced thermoplastic composites which incorporate the advantages of each component materials. The effects of paper sludge content(0, 10, 20, 30, 40----), mesh size(20~40, 60~80, less than 100mesh), and coupling agent(Epolene E-43 and Epolene G-3003) on the mechanical properties of paper sludge-polypropylene composites were investigated. Composite density increased with an increase in the paper sludge content. When paper sludge is incorporated into a polypropylene matrix, the flexural properties of the composite increase significantly with an increase in the paper sludge mixing ratio. Especially, flexural modulus was improved with increasing paper sludge content. The flexural strength of composites was improved, but flexural modulus reduced somewhat with decreasing paper sludge particle size. The flexural properties of paper sludge-polypropylene composites were improved by using coupling agents to enhance the bonding between reinforcing filler and matrix. Use of the epolene E-43 and G-3003 resulted in considerable improvement in the flexural strength over control specimens. The flexural strength of the G-3003 composite system is higher than that of the E-43 system. Generally, izod notched impact strength of paper sludge-polypropylene composite decreased slightly, whereas izod unnotched impact strength decreased significantly with increasing paper sludge contents. There was no effects of paper sludge particle size on impact strength of paper sludge-polypropylene composites. And izod unnotched impact strength of epolene E-43 composite system sharply decreased but that of G-3003 composite system was no tendency with increasing additive content.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.87-95
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• 2002

Three different species of green and air-dried Korean bamboos were carbonized by using three different types of kilns designated as special (800~1000℃), improved (600~700℃) and simple kiln (400~500℃), and the bamboo vinegars obtained from the carbonization processes were characterized. In the case of the special kiln, most of the bamboo vinegars obtained at the first recovery stage showed high values of specific gravity and also in content of organic acid and water-soluble tar. The bamboo vinegars obtained from the improved kiln showed various physical properties depending on their species. In the case of simple kiln, the bamboo vinegars obtained from air-dried bamboos and at temperatures below 80℃, showed a higher specific gravity and more water-soluble tar as well as total organic components than those obtained at 80~150℃. A good linear relationship (correlation coefficient of ca. 0.90) was obtained between the specific gravities and the sum of organic acids and water-soluble tars. Therefore, this correlation coefficient might be a good index to determine the quality of bamboo vinegars. The major chemical constituents of the bamboo vinegars were acetic acid and considerable amounts of phenols: guaiacol, ethyl guaiacol, syringol, and methyl syringol.

• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.467-478
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• 2016

This study was carried out to elucidate the distribution of vascular plants and their usefulness of Mt. Janggunbong (1,136 m) in Bonghwa-gun, Gyeoungsangbuk-do. The vascular plants, collected 15 times from 2006 to 2015, consisted a total of 462 taxa; 82 families, 279 genera, 397 species, 2 subspecies, 55 varieties, 8 forms. 10 taxa of the Korean endemic plants were recorded and 1 taxon of Critically Endangered Species (CR), 5 taxa of Vulnerable Species (VU) and 7 taxa of Least Concerned Species (LC), categorized by the Korean Forest Service as rare plants, were investigated in this region. Furthermore, Ⅳ, Ⅲ degrees of floristic regional indicator plants, designated by the Korean Ministry of Environment, were included 8 taxa and 14 taxa, respectively. Based on the usefulness, edible, pasturing, medicinal, ornamental, timber, stain, industrial, fiber and unknown usefulness plants included 352 taxa, 107 taxa, 71 taxa, 18 taxa, 8 taxa, 5 taxa, 3 taxa, 2 taxa and 111 taxa, respectively. In addition, 28 taxa of naturalized plants were observed.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.274-292
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• 2010

The flora of resource plants in Middle and Northern region of Yangsan-si were investigated for 7 times from March to Sept., 2009. The study indicated that, based on voucher specimens, the flora of this area consist of 427 taxa in total; 90 families, 256 genera, 376 species, 4 subspecies, 41 varieties and 6 forms. The resource plants in this area were categorized by their use into 9 groups inclusive of 1 unidentified group. Resources plants which were investigated in this area were 167 edible, 132 pasturing, 118 medicinal, 98 stainable, 52 ornamental, 15 timber, 6 fiber, 2 industrial taxa and 101 unknown resource plants, respectively. Also, there were remarkable plants such as 16 taxa of Korean endemic plants and 36 taxa of specific plants which were designated by the Ministry of Environment. Furthermore, 22 taxa of naturalized plants were observed in this investigated area where Urban Indexn UI) was 8.9%. Although the ecological status of investigated area was comparatively well conserved, the degree of (UI) was relatively high. Based on the results of this investigation, UI has been rapidly increased due to urbanization and construction of recreation objects in this area.

• Korean Journal of Plant Resources
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• v.21 no.5
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• pp.374-387
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• 2008

This study was carried out to investigate the distribution of the useful resources plants and the flora of the sand dune on South Coast and Jeju Island. The flora of sand dune on South Coast and Jeju Island was investigated from February to November in 2006. Vascular plants of this area consist of total 171 taxa; 1 forma, 18 varieties, 152 species, 130 genera, 51 families. The dominant species in the vegetations of the south coast sand dune were Calystegia soldanella, Ischaemum anthephoroides, Vitex rotundifolia, Carex pumila, Carex kobomugi. It corresponds to 11.1 % of totally 4,071 taxa appeared in Korea. Useful plants of this area were investigated 113 taxa. It corresponds to 66% of collected plants in this area under our study. Among the useful plants, there are 73 taxa of edible source, 61 taxa of medicinal source, 22 taxa of pasture source, 16 taxa of ornamental source, 7 taxa of fiber source, 1 taxa of timber source. Korean endemic plants were composed 1 taxa.

• Journal of the Korea Furniture Society
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• v.11 no.1
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• pp.45-51
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• 2000

It was thought that the stiffness of a coated specimen became lower than that of the solid wood because the stiffness of the dried film of coating material is lower than that of the solid wood. The authors were trying to compare the effect of lacquer varnish and rhus lacquer on the resonant frequency of the solid woods for the violin, spruce and maple. Vibration modal shape of coated specimens were same to those of solid woods, but the frequency became lower at each mode as were expected regardless of coat. frequency decrement of coated specimen was getting larger at upper mode in both European violin woods, however, rhus lacquer coated spruce specimens were less affected than lacquer varnish coated specimens.

• Journal of Environmental Policy
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• v.5 no.1
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• pp.25-43
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• 2006

This study is intended to develop an economic feasibility methodology of A/R CDM projects based on two project cases in China and Vietnam and to evaluate the project profitability from the view point of credit type selection between temporary CER (tCER) and long term CER (lCER) as well as from the aspect of CER prices by using indicators IRR, the year in which a single year profit is achieved and the year in which the accumulated deficit is cleared. For A/R CDM projects of industrial plantations, tCER is more suitable than lCER. Profitability of A/R CDM projects depend on the price of wood and CERs. In the case that the project participants take responsibility for replacement of credits to make the price of their CERs at higher levels, thus the project may not be feasible as a CDM project. However, minimum required tCER prices without replacement are 11US$/t $CO_2$, thus the project may be feasible under the future carbon market scheme.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.217-230
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• 2020

Global warming has increased interest in reducing greenhouse gas emissions. And a policy has effort to reduce energy consumption as a greenhouse gas reduction plan. In Korea, 25% of total energy is consumed in the building sector. In order to reduce energy consumption of buildings, it is possible to expand the utilization of wood as a structural material or thermal insulation materials with low thermal conductivity. It is also reported that when used as an interior finishing material, the energy consumption of the building is reduced by up to 7% by insulation performance. In this study, the heat transfer characteristics and the heat capacity were compared according to the three type of finishing materials(cement, paulownia coreana, medium density fiberboard) normally used as indoor finish materials. Through this study, most of the heat transfer volumes are transferred in the form of radiant heat, and the result was derived from the highest amount of energy and heat transfer in the use of paulownia coreana. When indoor finishing materials are used as wood, it is deemed that energy efficiency inside the building will be improved.

• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.341-348
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• 2010

Antifungal and antibacterial activities of wood vinegars were investigated in this study in order to apply for the natural fungicides and food preservatives. The antifungal activities of wood vinegars were measured as a hyphal growth inhibition rate using four plant pathogenic, four wood rot and one mushroom pathogenic fungi. Inhibition effect on the fungi growth was explicitly observed at the concentrations higher than 0.5% of unrefined wood vinegar and higher than 1.0% of refined wood vinegar, respectively, suggesting that unrefined wood vinegars showed the higher antifungal activities than that of refined wood vinegars. The highest inhibition effect on the fungi growth was shown in Libertella betulina which is a mushroom pathogenic fungus. In addition, the wood vinegars from Pinus densiflora showed the higher antifungal activities against the plant pathogenic and wood rot fungi than that from Quercus spp.. On the other hand, the antibacterial activities of wood vinegars were determined by a paper disc method using the three gram positive and five gram negative bacteria. The unrefined wood vinegars showed a prominent effect on the suppression of bacteria growth at the concentration of 10%, while the suppression of bacteria growth was not observed in the refined wood vinegars. These results also suggest that the unrefined wood vinegars showed the higher antibacterial activities than the refined wood vinegars. The antibacterial activities of wood vinegars against gram positive bacteria were higher than those of wood vinegars against gram negative bacteria. From these results, it can be inferred that the wood vinegars has the strong antimicrobial activities and can be applied as the natural fungicides and food preservatives.