• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.306-315
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• 2010

The stress laminated timber, which could be manufactured by small dimension lumber on construction site, has high possibilities for bridges in remote area, such as recreation forest or forest road, because those bridges may be short span and low frequency in use. The stress laminated timber has merits of easiness for preservative treatment and transportation because it is manufactured with small dimension lumber. This study was carried out to analyze performances of stress laminated timber manufactured with preservative treated domestic pitch pine for developing structural design data for stress laminated timber bridges for vehicular traffic. Perpendicular to grain compressive performance by preservative treatment and bending performance by bored holes of pitch pine lumber was analyzed. Then, the effects of bending performance by pre-stress pressure, distance of bolts, number of laminations and planning were analyzed. Conclusively, planning of lumber was not necessary for manufacturing stress laminated timber, and 80% of bending stiffness criteria was maintained as pre-stress pressure was higher than 3.0 kg/$cm^2$. However, further researches are needed to define the effects of bolt distances and number of laminations. The results of this research would be basic data for design stress laminated timber bridges for vehicular traffic in Korea.

• Journal of the Korean Wood Science and Technology
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• v.33 no.6 s.134
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• pp.87-94
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• 2005

This study was carried out to investigate the effect of soil types and soil properties on wood preservative leaching. Radiata pine (Pinus radiata Don.) sapwood stakes, which had been treated with 2.0%(w/v) CCA, were leached for 12 weeks by a common laboratory method in four different soils and for 14 days by the AWPA standard leaching method in water. The physical and chemical properties of the four soils were determined, and the percent leaching of the individual component of CCA was correlated with the various soil properties. The data show that leaching of preservative chemicals from treated wood exposed to soil is influenced by the type of soil. The preservative leaching was greater when wood was exposed to water than when the wood was in contact with water-saturated soil. The greatest chromium, copper and arsenic leaching from CCA-treated stakes were observed in the sandy loam, loam, and sand, respectively, and the least amount of leaching of CCA components occurred in the silty loam. The leaching of preservative components from treated wood is extremely complex and appears to be influenced differently by the soil properties. The extent of copper leaching from CCA treated wood appears to be related to exchangeable Mg and sum of bases. There is a reasonably good relationship between chromium leaching and exchangeable Mg, and between arsenic leaching and exchangeable K, soil Ni, Mn, Fe, Cr, or Cu content. Since this study was conducted based on laboratory leaching method using small cross-sectional dimensions; thus, data obtained from this experiment should not be used to predict leaching characteristics from commercial-size wood used in real situation. Accordingly, further studies are necessary using outdoor ground-contact leaching.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.112-121
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• 2015

In this study, Copper Azole (CuAz), a domestically available wood preservative for pressure treatment, was employed to perform an experimental research on its infiltration and decay properties in Japanese Red Pine. Test specimens were pressure-injected with CuAz-2 preservative to measure its preservative effectiveness, and then its impact on weight and mass losses. Furthermore, wood specimens were treated with CuAz-2 preservatives of various concentration levels before they were decayed with brown-rot-fungi in order to observe decay properties on light microscope (LM) and field emission scanning electron microscope (FE-SEM). As a result, untreated specimen by Fomitopsis palustris showed the mass loss of more than 40%, and the value of preservative effectiveness of CuAz-2 by indoor decay was $1,73-3.32kg/m^3$. The concentration levels of CuAz-2 preservative were shown to cause significant variations in terms of decay progresses in the cross section, radial section, and tangential section. By contrast, untreated specimens had underwent serious decays in early wood, late wood, longitudinal resin canals, and ray, which led to vertical destruction of wood texture. As for the radial section, ray tracheid, ray parenchyma cell, and window like pits were decayed and destroyed. In the case of tangential section, uniseriate rays and vertical resin canals were seriously decayed. In conclusion, this study indicates that the adequacy of the current CuAz injection amount should be reviewed in the domestic environment because there are significantly different decays at different decay conditions.

• Korean Journal of Agricultural Science
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• v.7 no.1
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• pp.33-37
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• 1980

To clarify the influence of ethylene on flowering and senescence of carnation flowers and the treatment of the floral preservative solution for reducing their ethylene production, bud-cut carnations (Dianthus caryophyllus L. cv. Coral) were sprayed with/without 500 ppm ethephon [(2-chloroethyl) phosphonic acid] and then held in distilled water or preservative solution (5% sucrose+50 ppm $AgNO_3$+300 ppm 8-hydroxyquinoline). 1. Ethylene inhibited to bloom carnation flowers because of causing sleepiness. 2. Carnation flowers were led to senescence after a lot of ethylene was produced by them. Therefore, ethylene seems to act as a trigger of senescence in carnation flowers. 3. The features of senescence in carnation flowers were different in accordance with the amount of ethylene produced by the flowers. 4. Exposure to ethylene decreased fresh weight, flower diameter, and water uptake of carnations. 5. The floral preservative extended vase life markedly by inhibiting ethylene production of cut flowers. The flowers exposed to lots of ethylene, however, were not restored even though they were held in the preservative solution.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.2
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• pp.111-115
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• 2007

It is inevitable to use germicidal agents like parabens, imidazolidinyl urea, phenoxyethanol and chlorphenesin to preserve the cosmetics. Although effective in reducing microblological contamination, chemical preservatives are irritative, allergenic and even toxic to human skin. So it is needed to decrease or eliminate usage of preservatives in cosmetic products Glycerin, butylene glycol (BG), prorylene glycol (PG), and dipropylene glycol (DPG) are widely used in cosmetics as skin conditioning agent or solvents. At high concentrations, they have antimicrobial activities, but deteriorate product quality like sensory feeling or safety. The purpose of study is to evaluate the effects of polyols on antimicrobial and preservative efficacy and confirm whether using adjusted polyols can decrease the contents of preservatives without deterioration of the quality of cosmetics. Effects of common polyols on antimicrobial activities of general preservatives were measured. BG and PG significantly (p < 0.05) increased activities of preservatives, but glycerin influenced little. It was inferred from the regression analysis of the results with S. aureus that adding 1% of PG increased activities of preservatives up to $2.1{\sim}8.4 %$ and BG improved activities of preservatives up to $1.8{\sim}8.4 %$. The challenge test results for oil in water lotions and creams showed that BG and PG improved the efficacy of preservative systems up to 40 % at a range of $5.5{\sim}9.9 %$, but glycerin had little effect on it. The measured rates of improvement were analogous to the inferences from regression analysis. It can be concluded that is possible to reduce total chemical preservatives up to 40 %, consequently improve the safety and sensory quality of cosmetics with the precision control of polyols. Added to that, using this paradigm, low preservative contents, praraben-free system, and even preservative-free systems can be expected in the near future.

• KCID journal
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• v.5 no.1
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• pp.83-96
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• 1998

• Food Industry And Nutrition
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• v.4 no.2
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• pp.5-16
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• 1999

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.122-127
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• 1997

Chitin and chitosan have been almost neglected until 1960's although they second largest biomass on earth. Chitosan is a partially deacetylated chitin and belongs to the class of cationic biopolymers. We investigated the antimicrobial activity of chitosan as natural preservatives in cosmetic products. Antimicrobial activity of chitosan against some microorganisms was investigated. The results indicated that chitosan had an effectiveness against some bacteria. We found that chitosan had minimum inhibitory concentataions as low as 100 ppm to S. aureus ATCC 6538, E. coli ATCC 1634 and P. aeruginosa KCTC 2004. But there was not effects to Asp. Niger ATCC 1374 at 1,000 ppm. Also, formuias preserved with chitosan have been subjected to preservative efficacy tests to some microorganisms. Formla preserved with 0.5% chitosan had an effective antimicrobial activity against the Gram (+) and Gram (-) bacteria but not fungi. It is possible to dertermine the formulas with chitosan, which would be effective to reduce the artificial preservatives.

• Journal of Korean Society of Forest Science
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• v.2 no.1
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• pp.37-40
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• 1962

1) The greater parts of rail road cross tie wood in Korea have been supplied by the imported woods from foreign countries such as Formosa (Taiwan) and Japan. However on account of anatomical properties on these imported woods are not known when newly imported, identification and preservative treatment are apt to fail. Accordingly this expriment was accomplished by the need of application of anatomical properties for the preservative treatment and identification of several imported woods. 2) In this study macroscopical and microscopical properties were inspected and briefly described about four species (Cyclobalanopsis gilva Blume, Castanopsis longicaudata K. et H., Machilus longiflora Hay and Schima superba Gard et Champ) from Formosa and one (Fagus crenata, Blume) from Japan. With several native species these are important as the rail road tie wood in Korea. 3) According to the results measured values of the vessels and fibers of each tested species are as following table.

• Journal of the Korea Furniture Society
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• v.19 no.2
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• pp.124-129
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• 2008

Moisture content of Larix kapempferi was maintained at 28% after air drying. 5% CCFZ solution penetration depth was observed through longitudinal tracheid and axial resin canal. Penetration depth was increased significantly from heartwood to sapwood and the penetration depth was found 1.3 times higher for sapwood measured at 15.0 second of penetration. On the other hand, liquid flow in sapwood and heartwood involved most liquid first entering the resin canals. Overall resin canal conducted 1.4 times more than tracheid. Latewood was found more permeable than in earlywood. At the beginning of penetration, the speed was high and then decreased in the course of time.