• Journal of the Korea Furniture Society
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• v.19 no.6
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• pp.447-451
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• 2008

This study was carried out to know the difference of vapor transmission on the thickness of Paulownia wood(Paulownia tomentosa). The behavior of moisture transmission of wood thickness direction is generally estimated by vapor permeability and vapor transmission resistance. In general, Paulownia wood is known to use of inside material for furniture making, because of the excellent ability of vapor adsorption and/or desorption. Quarter sawing Paulownia wood material is prepared and the thickness is 6.0mm, 7.0mm, 8.0mm, 9.0mm, 10.0mm, respectively. The measurement of vapor transmission were conducted by the "cup method" in accordance with JIS(Japanese Industrial Standard) Z-0208. The experiment was made in the condition of 49.8mmHg vapor pressure difference and $40^{circ}C$ at constant temperature. From the experiment results, it was considered that Paulownia wood is very stable on moisture variation and any other material conditions. In this experiment we found that the vapor permeability and vapor permeance was reduced with the increase of wood thickness to vapor direction and vapor transmission resistance and specific vapor transmission resistance was increased with the increase of wood thickness to vapor direction. Besides moisture contents of adsorption and desorption side were about 5 percent and 14 percent, respectively. Mean value was 9.5 percent and about 10 percent in dry oven method. Moisture gradient was reduced with the increase of wood thickness for a small moisture difference of adsorption and desorption side.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.61-66
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• 1997

Paulownia wood has been used as sound board for Korean traditional musical instruments such as Keomungo(Korean lute), Kayagum(twelve-stringed Korean harp) and Changgu(hour-glass shaped drum), etc. The acoustic properties of wood affected not only by dimensions but also by density and stiffness of wood. Due to inhomogeneity and hygroscopicity of wood. the acoustic properties of wood are inconsistent. To clarify the effect of moisture content and air dry density on acoustic properties, longitudinal vibration experiment was accomplished in 3 moisture content levels of 9.6, 11.1 and 12.5% and in 3 air dry density levels of 0.22, 0.25 and 0.28g/$cm^3$. The results were as follows: As the moisture content increased, the fundamental frequency. specific dynamic Young's modulus and sound velocity decreased, but the internal friction increased so that loss of energy increased. The values in damping of sound radiation were rapidly decreased at 12.5%. It meant that the damping of internal friction was larger than damping of sound radiation at high moisture content. As the air dry density increased, the fundamental frequency, specific dynamic Young's modulus and sound velocity increased, but the internal friction and damping of sound radiation decreased so that loss of energy decreased. And acoustic converting efficiency was hardly influenced by increasing air drying density.

• Journal of Environmental Science International
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• v.22 no.10
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• pp.1317-1325
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• 2013

Paulownia coreana is a medicinal, edible and industrial plant with the largest leaf, and is native to Korea. We evaluated the reducing power activities, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities (RSAs), nitrite scavenging activities (NSAs) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation RSAs by solvent extraction of P. coreana bark by using $50^{\circ}C$ hot water and $25^{\circ}C$ methanol. The antioxidative effect of P. coreana bark extract on corn seed oil was evaluated using the Rancimat test. The extraction yields on dry weight basis with 15 folds of hot water and methanol were 23.88% and 5.30%, respectively; further the flavonoid content in the hot water extract was over 2.5 times more than that in the methanol extract. The DPPH RSA of the methanol extract was substantially higher than that of the water extract, whereas the NSA of the water extract was higher than that of the methanol extract at pH 1.2. The ABTS RSAs of the two extracts were almost the same as that of ascorbic acid and 2,6-ditertiarybutyl hydroxytoluene. The two extracts of P. coreana bark in this study were found to slightly improve the oxidation stability of corn seed oil.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.15-21
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• 2003

Image processing technique was adapted for exploring the more convenient ways to investigate the drying characteristics of wood. The acquisition of information about drying characteristics is indispensable for the development or improvement of dry-kiln schedules. A small internal fan type wood dry kiln was combined with image-processing and data-acquisition systems to monitor continuously the formation of checks and moisture reduction during drying. All the images and data were analyzed to improve or estimate the dry-kiln schedules and predict the drying time which would be required to dry green wood to 10% moisture content in internal fan type kiln. Samples of 20 mm- and 50 mm-thick Metasequoia glyptostrobodies, Paulownia coreana Uyeki, Pinus densiflora Sieb. Et Zucc., Platanus occidentalis L., Quercus acutissima and Robinia pseudo-acacia were used to verify the potentiality of this technique.

• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.16-24
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• 2001

Conventional hot-air oven-drying method takes at least four hours to determine the moisture content of wood sample and this method is not always acceptable to wood industry. In this study samples of six different specifications from Paulownia coreana, Pinus densiflora and Quercus acutissima were dried in domestic microwave oven to their oven dry weights to investigate the possibility of rapid moisture content determination technique using microwave-oven drying method. Continuous heating time, cooling time and intermittent heating time were determined by each species and sample specifications. Temperatures of surface and center of samples were also measured during drying. Oven-drying times were reduced to 1/7~1/10 of conventional hot-air oven-drying method. Therefore microwave heating and drying techniques appear attractive for wood industry as a rapid moisture content determination method.

• Journal of Korean Society of Forest Science
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• v.58 no.1
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• pp.8-16
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• 1982

To study the comparison of aboveground biomass of paulownia coreana Uyeki of 6-year-old, located in Seongju of non-attacked forest and Ulsan of damaged forest by the air pollution were selected. Ten sample trees in Seongju district and seven trees in Ulsan selected taking account of DBH were measured for 16 trees in total within a $10{\times}10m$ experimental plot. The diagram of oven-dry weight distribution of stem, branch and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the two-variables, DBH and tree height, combined term were presented. IF the estimations are extended to a hectare area stand, it contains 47.49 tons of aboveground biomass in Seongju district and 19.05 tons of it in Ulsan. The annual net productions were 11.64 tons of above 2.29 kg/kg/yr in Ulsan and the efficiency of leaf to produce stem was 2.99kg/kg/yr in Seongju and 0.83kg/kg/yr in Ulsan.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.760-766
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• 2016

This study explored the effects of heating temperature and laminae thicknesses on the time required to heat the center of air-dried Paulownia tomentosa, Pinus sp., Abies sp., and Larix sp. laminae to $56^{\circ}C$, which is a minimum core temperature of wood packaging materials defined by ISPM 15 standard, and maintain for 30 minutes in dry heat treatment schedule. Heating times were different among wood species and were Pinus sp. ${\geq}$ Abies sp. > Paulownia tomentosa > Larix sp. in decreasing order. The differences in heating times of some species were significantly different statistically, but were not different enough in practical terms to warrant heating four species separately. Heating times decreased as heating temperature increased and followed approximately power-function relationship. Also, heating times increased linearly with increasing laminae thickness. These relationships make it possible to calculate intermediate heating times relative to experimentally observed heating times. The results of this study will serve as a guideline for heat sterilization of Chinese laminae species to meet heat treatment requirements for protection against invasive pests.

• (The)Study of the Eastern Classic
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• no.49
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• pp.137-160
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• 2012

This paper focuses on analyzing Eom Heun's grip on reality and attitudes through his literary works. He realized his time as a corrupted world that lack of morality. This actually was a criticism for the existing political force at that time, and he embodied it by using the image of wind, frost, mole cricket, ant, and so on. During that time, he tried to stick to his opinion on integrity. For that, he criticized men of the day who had an apathetic attitude. On the other hand, he praised pine and grass as an image of faith and fidelity. We may verify his world view by reading his literary works.

• Journal of agriculture & life science
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• v.51 no.4
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• pp.97-109
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• 2017

This study was conducted to investigate the effects of anti-inflammatory plant extracts on the in vitro rumen fermentation characteristics and methane emission. Anti-inflammatory plant extracts from Morus bombycis Koidz, Mallotus japonicus L., Morus alba L., Paulownia coreana Uyeki, Isodon japonicus Hara and Ginkgo biloba L. were used in the study. The ruminal fluid(5 mL), McDougall buffer(10 mL), timothy as a substrate(0.3 g) and each anti-inflammatory plant extract(5% of substrate) were dispensed anaerobically into 50mL serum bottle. The mixtures were incubated for 3, 9, 12, 24, 48 and 72h at $39^{\circ}C$ without shaking. Supplementation of the anti-inflammatory plant extracts did not effects characteristics(pH, digestibility of dry matter, glucose concentration, ammonia concentration, protein concentration, VFA) on rumen fermentation. Total gas was showed a different pattern depending on treatments. Carbon dioxide was significantly(p<0.05) higher in Morus alba and Isodon japonicus than in control at 48h. Methane was significantly(p<0.05) lower in treatment than in control at initial fermentation. However the more incubation time was increased, the more methane emission was higher in treatment than in control. The concentrations of polyphenol and flavonoid were higher in Ginkgo biloba. In conclusion, supplementation of the anti-inflammatory plant extracts did not effect on rumen fermentation and methane emission was decreased in initial fermentation.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.4
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• pp.1-15
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• 2023

This research intended to reveal the special characteristics of the vegetation structure and the tendency of change of -landfill slope districts, which are reclaimed land, through an investigationsinto the presently existent vegetation and plant community structure of the World Cup Park landfill slope district. For the analysis of changes in vegetation, this study compared the results of field surveys in 1999, 2003, 2005, 2007, 2008, 2012, 2016, and 2021. For the investigation into the plant community structure, a field investigation was carried out in 2021 with six fixed investigation districts designated in 1999 as subjects. To analyze the change in the plant community structure, the past data on the population, the number of the species, and the species diversity by the layer in 2021 were compared and analyzed in the landfill slope district, which is reclaimed land. The changes of the vegetation distribution and the power had been affected by typhoons (Kompasu). Above the plantation foundation, which had been dry and poor, Salix koreensis, marsh woody plants that had formed the community, decreased greatly. The Robinia pseudoacacia community, after the typhoon in 2010, decreased in the number of species and population. Afterward, it showed a tendency to rebound. Regarding the Ailanthus altissima-Robinia pseudoacacia-Paulownia tomentosa community, the number of the species and the population had shown a change similar to the Robinia pseudoacacia community. The Paulownia tomentosa and the Ailanthus altissima have been culled. The slope was predicted as a Future Robinia pseudoacacia forest. The Salix pseudolasiogyne community has been transitioning to a Robinia pseudoacacia forest. Only some enumeration districts, the Robinia pseudoacacia forests and the Salix pseudolasiogyne, had been growing. However, most had been in been declining. It was predicted that this community will be maintained as a Robinia pseudoacacia forest in the future. As these vegetation communities are the representative vegetation of the landfill slope districts, which is reclaimed land, there is a need to understand the ecosystem changes of the community through continuous monitoring. The results of this research can be utilized as a basic material for the vegetation restoration of reclaimed land.