• Korean Journal of Environment and Ecology
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• v.12 no.4
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• pp.345-360
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• 1999

The purpose of this study was to suggest vegetation management Planning and plant community structure of Camellia Japonica forest at Hakdong, Kojedo, Hallyo-Haesang National Park. Forty-six plots(l00$\m^2$/plot) were established in Camellia japonica forest and surveyed. By DCA ordination technique and mean importance value analysis, the plant communities were classified into four community types, which were Camellia japonica community, Camellia japonica-Eurya japonica community, Camellia japonica-Neolitsea sericea community, Chumaecyparis obtusa-Camellia japonica community. It was supposed that Camellia japonica-Neolitsea sericeu community succeeded to Neolitsea sericea community. The others would not be replaced by another woody species. The vegetation management for successional controls in long-term basis were suggested; for the short-term basis, the species of Chamaecyparis obtusa, Neolitsea sericea and Eurya japonica should be removed. The species of Quercus serrata, Prunus sargentii, Meliosma myriantha, Machilus thunbergii and Litsea japonica. must be controlled under the long-term management of vegetation.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.271-278
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• 2002

Methanol extracts from 420 samples of 173 plant species in 58 families were tested at 5000 ppm for their insecticidal and acaricidal activities against five economically important arthropod pests by spray method. The responses varied with arthropod pest species, plant species and plant tissue sampled. In a test with Nilaparvata lugens Stal, extracts from Zanthoxylum piperitum barks, Chamaecyparis obtusa leaf and Quercus salicina leaf showed potent insecticidal activity. With Plutella xylostella L., potent larvicidal activity was observed from extracts of Platycarya strobilacea wood, Meliosma myriantha barks, Sophora japonica leaf, Zanthoxylum piperitum barks, and Pinus thunbergii wood. Methanol extracts of Sophora japonica leaf and Zanthoxylum piperitum barks showed high insecticidal activity against Spodoptera litura. In a test with Tetranychus urticae Koch, extract from Carpinus coreana leaf, Firmiana simplex barks, Elaeagnus macrophylla leaf, Aralia elata leaf, Comus controversa barks and Chamaecyparis obtusa leaf exhibited strong acaricidal activity. As a naturally occurring pest control agent, Zanthoxylum piperitum barks could be useful as new insecticidal and acaricidal products against various arthropod pests.

• Fire Science and Engineering
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• v.32 no.2
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• pp.1-6
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• 2018

The combustion characteristics of cypress wood coated with boric acid (BA) and ammonium pentaborate (APB) were examined using a cone calorimeter according to the ISO 5660-1 standard. As a result, the combined specimens of boric acid and ammonium pentaborate (BA/APB) led to an improved fire performance index due to their synergistic effect. In addition, the total heat release values of the specimen coated with the boron compounds were 6.1~14.1% lower than that of the base specimen. The total smoke release rate (TSR) of the specimens coated with the boron compound decreased throughout the combustion process, except for BA/APB. The maximum concentration of carbon monoxide was reduced by 15.8~25.5%. In general, wood treated with flame retardants has a lower fire hazard.

• Fashion & Textile Research Journal
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• v.19 no.3
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• pp.331-336
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• 2017

Bacteria exist everywhere and continuously come into contact with daily surroundings and humans. Super bacterium methicillin-resistant Staphylococcus aureus, resistant to methicillin, has recently appeared. The morbidity and rate of death associated with super bacteria infection has increased. This study investigated the antibacterial activity of fabrics naturally dyed with Chamaecyparis obtusa leaves extract against methicillin-resistant Staphylococcus aureus. Fabrics were left for 15 min in a natural dyeing solution prepared by extraction from C. obtusa leaves using 11.3% (o.w.f) with a fixed liquor ratio of 1:22 at $40^{\circ}C$. The dyeing process was conducted using three different mordants; subsequently, the K/S value of the dyed fabrics increased in the order of None < Cu < Fe < Al. The color fastness property of the fabrics to washing, dry-cleaning, and rubbing was found to be excellent and ranked in the 4-5 grade. The color fastness to light of natural dyeing is low in most cases and has the problem that the dye color soon becomes bleached. Yet, in most cases cloth dyed with retinispora leaves, the color fastnezz to light was good with a third to fourth grade. Non-mordant fabrics, aluminum mordants, and copper mordants also showed better antibacterial properties (99.9% reduction) against methicillin-resistant Staphylococcus aureus, compared to the control fabrics. The dyed fabrics showed the same antibacterial activity even after three washes. The results highlight the strong potential of fabrics naturally dyed with C. obtusa-extract as a medicinal material with excellent antibacterial function against methicillin-resistant Staphylococcus aureus.

• Journal of Forest and Environmental Science
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• v.18 no.1
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• pp.53-60
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• 2001

2kg of the dried leaves of chamaecyparis obtusa Endlicher were ground, extracted with acetone-$H_2O$(7:3, v/v), concentrated, and fractionated with a series of hexane, $CH_2Cl_2$, EtOAc and water on a separatory funnel. Each fraction was freeze dried to give dark-brown powder and a EtOAc soluble portion of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Spectrometric analyses such as NMR and FAB-MS including TLC were performed to characterize the structures of the isolated compounds. The leaves of chamaecyparis obtusa Endlicher contained a large amount of taxifolin-3-O-${\beta}$-D-xylopyranoside and (+)-catechin in addition to a small amount of quercetin-3-O-${\alpha}$-L-rhamnopyranoside.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.305-308
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• 2012

In this study, we evaluated antifungal and antioxidant activities of condensed liquid of volatile organic compounds generated during the drying process of Chamaecyparis obtuse. Condensed liquid of volatile organic compounds were extracted with hexane and ethyl acetate, respectively. The extracts were used for antifungal activity at range from 100 to 500 mg/L Antifungal activity of extracts increased as the extracts concentration increased, the activity against tested dermatophytes was high at 500 mg/L. Among extract solvents, antifungal activity was higher at hexane extract than the ethyl acetate. Especially, the antifungal activity against Trichophyton rubrum was higher than other tested dermatophytes. Antioxidant activity was 90% above 25 mg/L regardless of the extractive solvents, while the hexane extract showed high antioxidant activity below 25 mg/L. Major compounds of hexane extract were torreyol, alpha-cadinol, and tau-cadinol. However, major compounds of ethyl acetate extract were alpha-amorphene, alpha-cadinol, and gamma-cadinene.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.1
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• pp.1-10
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• 2004

The climate of Minamiakikawa forest in Japan is similar to that of Mt. Jiri in South Korea. There is a large development plan for Minamiakikawa forest, and a change in the species composition is expected. This study was initiated to compare forest transition caused by artificial perturbations in Korea and Japan. Long-term field observations on species composition are reported. We found 98 families, 231 genera, 315 species, 29 varieties, and 8 races, making a total of 352 classification groups of higher plants in the Minamiakikawa forest area. Among them, 11 families, 12 species and 2 varieties are rare or endangered. The study area is dominated by Cryptomerica japonica and Chamaecyparis obtusa. The time and restoration effects on secondary and latent forestation consider the development of the Quercus mongolica community, the Quercus serrata community, and deciduous-broadleaved tree ascension. This indicates that the forest has been restored to Abies firma, Pinus densiflora or Cryptomeria japonica and Fagus japonica, which is considered latent natural forestation of the area in a natural transfer.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.205-213
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• 2012

In this study, the stability of cream containing the ethyl acetate fraction of C. obtusa leaf extract was evaluated. The pH, viscosity, and absorbance were measured under the 4 different temperatures (4, 25, 37 and $45^{\circ}C$) and under the sun light during the 12 weeks. The control cream without containing the extract did not show pH change under the different temperatures mentioned above. However, the pH of the cream with the extract was decreased 0.11 at $4^{\circ}C$ and $25^{\circ}C$. Under the $37^{\circ}C$, $45^{\circ}C$ and sun light condition, the pH was decreased 0.55, 0.84 and 0.59, respectively. After treating the cream for 12 weeks under the different temperatures, the viscosity was measured for the cream containing the extract and control cream. The values were decreased by 2,404 cPs in average compared to the initial value for the former and control cream were decreased by 1,296 cPs in average for the latter. On the other hand, the viscosity of control cream treated under the $45^{\circ}C$ for 12 weeks was decreased (1,915 cPs) relative to the cream containing the extract, which showed 3,810 cPs decrease in viscosity. The cream containing the extract did not show absorbance change at $4^{\circ}C{\sim}37^{\circ}C$ for 12 weeks. Instead, the absorbance of the cream treated under $45^{\circ}C$ and sun light condition was decreased 32.5 % and 35.2 %, respectively. This decrease in absorbance is relatively small compared to the 54.8 % decrease of the extract sampled from the cream using ethanol solution. This indicates that the extract is stabilized in the cream. In addition, any change in color or smell was not observed through 12 weeks of the experimental time period. Also physical changes as creaming and cohesion were not shown. The results show that the cream containing C. obtusa leaf extract was relatively stable. However, it is concluded that it is still not clear in the stability of the cream containing the extract when it is stored for a long time. Accordingly, it is suggested that further study is needed for the application of the extract to cosmetics.

• Resources Recycling
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• v.19 no.2
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• pp.19-27
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• 2010

The purpose of this research was to see thermal and breaking type characteristics of waste wood for construction materials using high temperature and pressure equipment. In TG/DTA graph weight of waste wood was steeply decreased at $250^{\circ}C$, it has to be treated below $250^{\circ}C$ for construction materials. In popping test the needle-leaved tree was more broken in texture than the broad-leaved tree, especially, Chamaecyparis obtusa(W-7) was the best. The optimum result was obtained at temp. $200^{\circ}C$, pressure 3MPa among the experimental condition.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.551-558
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• 2011

This present study was performed to analyze the efficiency and volatility of a porous film containing $Chamaecyparis$ $obtusa$ extract as a method to effectively package food compounds. Phytoncide was contacted the state of gas and showed effective antimicrobial properties. Limonene can be distilled without decomposition as a relatively stable terpene and was one of the extract components. $Chamaecyparis$ $obtusa$ essential oil. The optimal solvent composition was a ratio 5:20:0.3 of T-500:ethanol:hardener to effectively manufacture film containing phytoncide essential oil and the minimum antibacterial concentration was 2%. The films were made under different conditions(A-50LF1, A-25SF2, B-50SF1, C-50LF1, C-25SF2 and D-50SF1) containing phytoncide and the amounts of limonene inside the 1-L reaction chamber depending on storage were measured by gas chromatography-mass selective detention. The results showed that the 25SF2(width, 25 mm; length, 20 cm) revealed more amount of limonene compared with 50LF1(width 50 mm, length 20 cm). We confirmed that the gas emission amount showed a better layer on the film side than on the internal film. An effect of film thickness on phytoncide emissions was observed in that the amounts was less than the expectation for a thicker film at the beginning time, but the emitting amounts increased with increasing storage periods. In the storage testing of various films at $35^{\circ}C$ and 70% humidity for 14 days, 25SF2 showed longer preservation compared with that of 50LF in the case of bread. $C.$ $obtusa$ essential oil is a useful fresh ingredients, hence, analysis of limonene emission kinetics from various film was helpful to develop films with an optimal antimicrobial effect, and will allow application of such films in food packaging systems.