• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.1-12
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• 2008

A series of the studies on the applied physical properties of domestic species have been conducted last three years. Liriodendron tulipifera, Betula costata, Paulownia coreana were examined on sorption property, thermal property, electric property, acoustic property. Because the same apparatus and experimental procedures were used for all species, their results can be easily comparable. The experiments for sorption property were conducted with 80 mesh wood powder and resulted in their EMC's and sorption isotherms. The thermal conductivity and diffusivity, and electric resistance and volumetric electric resistivity were measured with a thermal-wire device and a high electric resistance meter. The differences of the thermal and electric properties between quarter-and flat-sawn specimens were observed, which was partially attributed to their anatomical differences. An acoustic measurement system was used to evaluate dynamic MOE and internal friction. This paper provides the useful fundamental data for designing a wood structure, correcting a portable resistance-type moisture meter, and acoustic properties of wood.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.184-191
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• 2004

Methanol extracts of fresh materials of 57 plants were screened for in vivo antifungal activity against Magna-porthe grisea, Corticium sasaki, Botrytis cinerea, Phyto-phthora infestans, Puccinia recondita, and Blumeria graminis f. sp. hordei. Among them, seven plant extracts showed disease-control efficacy of more than 90％ against at least one of six plant diseases. None of the plant extracts was highly active against tomato gray mold. The methanol extracts of Chloranthus japonicus (roots) (CjR) and Paulownia coreana (stems) (PcS) displayed the highest antifungal activity; the CjR extract controlled the development of rice blast, rice sheath blight, and wheat leaf rust more than 90％, and tomato gray mold and tomato late blight more than 80％. The PcS extract displayed control values of more than 90 ％ against rice blast, wheat leaf rust, and barley powdery mildew and more than 80％ against tomato gray mold. The extract of PcS also had a curative activity against rice sheath blight and that of CjR had a little curative activity against rice blast. On the other hand, the extract of Rumex acetocella roots reduced specifically the development of barley powdery mildew. Further studies on the characterization of antifungal substances in antifungal plant extracts are underway and their disease-control efficacy should be examined under greenhouse and field conditions.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.232-236
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• 1991

The efficacy of berberine sulphate, a fluorochrome having binding properties with both DNA and RNA, was investigated for the detection of mycoplasma-like organisms(MLOs) in jujube(Zizyphus jujuba), paulownia(Paulownia tomentosa), mulberry(Morus alba) trees and periwinkle (Catharanthus roseus) plant. When examined under fluorescence microscope, berberine sulphate-stained sections of diseased samples showed distinct MLO-specific fluorescent particles in the phloem area, while such fluorescence was absent in the healthy ones. This staining technique was proved to be a very accurate method for the diagnosis of MLO infections in woody and herbaceous plants. Furthermore, the cheap and easy procedure could be used to test a great number of samples on MLO infections with reliability and rapidity.

• Journal of the Korean Wood Science and Technology
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• v.19 no.1
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• pp.71-80
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• 1991

This study was carried out to investigate replaceable species with the conventional sounding board sitka spruce. by comparing the dynamic properties such as density, dynamic Young's modulus and internal friction Dynamic Young's modulus. internal friction of longitudinal and radial direction measured in free mass-free boundary condition for facile vibration analysis and measured by forced vibration method. Dynamical properties of four species were measured on squared plate specimen that the four edges were hung vertically by threads and driven magnetically through an iron piece glued on the specimen, by the use of condenser microphone as vibration transducer, and analyzed by FFT analyzer. The results obtained were as follows: 1. Chaldni method using aluminum powder was proper to identify the vibration mode in the plate vibration and it was possible to verify the resornance mode. 2. It was considered that it was necessary to investigate the influence of adhesive part on the plate vibration when the sounding board was made by two or three small board adhesion. 3. It was considered that plate vibration method, which was a superior to the vibration test of beam, was suitable for selecting suounding board because dynamic Young's modulus and internal friction show different order according to longitudinal and radial direction. 4. Paulownia tomentosa Thunb.) Steudel has been considered to be replaceable species with sitka spruce because it has high dynamic Young's modulus compared with low density, low internal friction, and K value of Paulownia tomentosa (Thunb.) Steudel is greater than that of sitka spruce.

• 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.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.215-220
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• 1984

Mulberry dwarf, paulownia witches' broom, jujube witches' broom, and sumach witches' broom are known to be associated with mycoplamalike organisms(MLO) in Korea. Simple microscopic detection of MLO infection in these plants was attempted. Periwinkle plant was also tested. Application of $0.2\%\;and\;0.4\%$ solution of Dienes' stain gave diagnoatic value for MLO-induced diseases of periwinkle and mulberry. Among the various plant parts examined, young herbaceous stem just below the apical part gave the best result. Density of staining reaction was proportional to disease severity. Longitudial sections were superior to transverse sections in confirming MLO infection by staining. Light source without blue filter was useful for increasing the color contrast between sieve tube and xylem vessel and for eliminating misinterpretation. Paulownia, jujube, and sumach samples gave no clear difference in staining reaction between healthy and diseased sections even when various modifications of Dienes' staining procedure were tried.

• Journal of environmental and Sanitary engineering
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• v.24 no.2
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• pp.31-39
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• 2009

In this research, I carried out the adsorption and removal test of Pb, Ni, Co and Cu ions using organic substances spread out any where in the nature which can be obtained easily from our neighbor-such as Paulownia coreana, Pinus densiflora, Juniperus chinesis, Quercus dentata, Magnolia kobus, Platanus occidentalis, Gingko biloba, Diospyros kaki leaves. As the result of the research to find the best optional condition for the adsorption and removal, shows that the adsorption and removal ratio of Pb ion by a Paulownia coreana raw leaves is 99% at $70^{\circ}C$, those of Ni ion and Co ion by Magnolia kobus formalin treatment leaves are 79% at $70^{\circ}C$, 97% at $40^{\circ}C$ respectively. And that of Cu ion by Platanus occidentalis treatment leaves is 97% at $50^{\circ}C$ in mixed solution. As the result of comparing the removal ratio by raw leaves and formalin treatment leaves, the removal ratio of treatment is 30~90% more effective than raw leaves in most cases. And I concluded Pb > Cu > Co > Ni ion in multiple solution and Co > Ni > Cu >Pb ion in single solution after testing adsorption and removal ratio of mixed solution separately as time goes by. In general, the reactions were completed within first 5 minutes. The test result of measuring the hydrolysable tannin content of each leaf shows that an overcup Quercus dentata is 11.36%, a Diospyros kaki is 10.81% and the rest of them are 2.49~4.12% in raw leaves cases. In treatment leaves cases, an overcup Quercus dentata is 3.23% and the others are less than 1%.

• 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 Environmental Science International
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• v.16 no.10
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• pp.1139-1146
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• 2007

The vascular plants in the Mt. Manduk was listed 560 taxa composed of 110 families, 345 genera, 488 species, 1 subspecies, 67 varieties and 4 forms. Based on the list of the rare plants by the Forest Research Institute, 4 taxa were recorded in the studied areas; Lilium distichum (Preservation priority order; No. 159), Tricyrtis dilatata (No. 97), Aristolochia contorta (No. 151) and Prunus yedoensis (No. 110). Based on the list of Korean endemic plants, 12 taxa were recorded; Cephalotaxus koreana, Carex okamotoi, Lilium amabile, Populus tomentiglandulosa, Salix purpurea var. japonica, Pseudostellaria multiflora, Prunus yedoensis, Stewartia koreana, Forsythia koreana, Paulownia core ana, Weigela subsessilis and Aster koraiensis. Based on the list of approved for delivering overseas of plants, 7 taxa were recorded; Carex okamotoi, Lilium distichum, Aristolochia contorta, Vaccinium oldhami, Paulownia coreana, Asperula lasiantha and Saussurea seoulensis. Specific plants by floral region were total 32 taxa; Prunus yedoensis in class V, Wistaria floribunda in class IV, 5 taxa (Girardinia cuspidata, Spiraea salicifolia, Acer palmatum, Stewartia koreana, Asperula lasiantha) in class III, 3 taxa (Potentilla dickinsii, Viola tokubuchiana var. takedana and Caryopteris incana) in class II and 22 taxa (Pinus koraiensis, Hosta capitata, Chloranthus japonicus, Salix glandulosa, Juglans mandshurica, etc.) in class I. The naturalized plants in the surveyed sites were 14 families, 36 genera, 44 species, 2 varieties, 46 taxa and naturalization rate was 8.2% of all 560 taxa of vascular plants. Wild plants disturbing ecosystem like Ambrosia artemisiifolia var. elatior have been increasing. Therefore, continuous control and conservation measures are needed on the ecosystem of Mt. Manduk.

• Korean Journal of Agricultural Science
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• v.28 no.2
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• pp.125-131
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• 2001

Trametes versicolor(CV5) selected as a white-rot fungus with strong lignin degrading activity, in the previous paper, was investigated on a properties of degradation of wood lignin. Lignins of hardwoods, especially oak(Querous acutissima carruth) an paulownia (Paulownia coreana Uyeki) were considerably delignified by the CV5, however, softwoods used in this experiment were not delignified. Bavendamm's reaction was positive with several phenols on agar plates for the confirmation of a phenoloxidase secreted Through the morphologies of decayed wood chip observed with the aid of scanning electron microscopy, it was found that the hypha of CV5 penetrated the ray cells and vessels caused separation of the wood cellulose.