• Journal of the Korean Wood Science and Technology
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• v.50 no.5
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• pp.365-374
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• 2022

Today, commercialized Hinoki cypress cubes are used for fragrance, humidification, and pillows in Korea. In this study, the sound absorption ability of Hinoki cypress (Chamaecyparis obtusa) cubes was examined. The three groups of Hinoki cypress cubes were prepared depending on their dimension (L: 9 × 9 × 9, M: 7 × 7 × 7, S: 4 × 4 × 4 mm). Their sound absorption coefficient was examined after filling 6, 8, 10, and 12 cm height in impedance tubes, respectively. Overall, the sound absorption ability depending on dimension was superior in the M group compared to the L and S groups. Also, as the filling height increased, the sound absorption capacity increased. In sum, noise reduction coefficients (NRC) of all Hinoki cypress cubes were 0.41-0.59. Thus, this research found that Hinoki cypress cubes have a sound-absorbing function.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.1-13
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• 2019

In this study, eco-friendly functional leather was developed by recycling wastes such as eel skin, marigold(Tagetas erecta l.), hinoki cypress(Chamaecyparis obtusa). The hot water extracts of marigold and hinoki cypress leaves were freeze-dried at $-80^{\circ}C$ to prepare colorant powder. The dyeing of eel leather with marigold was carried out to investigate the effects of dyeing conditions, mordanting on dye uptake, color, morphological change, and color fastness. Considering shrinkage of eel leather caused by dyeing, the optimum dyeing conditions were $60^{\circ}C$ of dyeing temperature and 60 min of dyeing time at 1:100 of bath ratio, and color of the dyed eel leather was Y to YR Munsell series. In order to prevent the degradation of leather from microbe, we conducted combination dyeing with marigold and hinoki cypress leave colorants. In this case, the combination dyed eel leathers showed excellent antimicrobial activity with above 99% bacterial reduction rate against S. aurieus and K. pneumoniae. It was confirmed that all of the dyed eel leathers were sufficient to meet the Korean Standard for color fastness of leather products. It can be applied practically for the development of eco-friendly functional leather by utilizing some useful active components extracted from plant resources and by recycling food wastes.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.747-757
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• 2014

Since the air contamination by air pollutants from indoor construction materials and daily supplies has been increased in recent decades, the public interest of using environmentally friendly products and improving indoor air quality also attracted much attention. As known as effects of phytoncide, it has been used in construction materials and daily supplies with various method. In this study, hinoki cypress (Chamaecyparis obtusa) was used because of its high contents of phytoncide. The leaves of hinoki cypress (C. obtusa), which generated by pruning, were extracted by steam distillation, and then used as humidification water source. Volatile organic compound (VOC) from C. obtusa were characterized by GC-MS (Gas chromatograph-Mass spectrophotometry) in order to evaluate effects and risks of using C. obtusa extracts. Total 86 types and 116 types of VOC were detected from distilled water (DI water) and C. obtusa extracts, respectively. Aromatic compounds (DI water: 13 types, 53%; C. obtusa extracts: 13 types, 38%) and terpenoids (DI water: 16 types, 23%; C. obtusa extracts: 23 types, 33%) were detected more diverse types and higher amount than other compound categories. No additional aromatic compounds were found from C. obtusa extracts, so C. obtusa extracts did not affect on aromatic compounds emission. However, in terpenoids, total amount of emission from C. obtusa extracts increased to 33% from 23% (DI water) and 7 more types of compounds were found from C. obtusa extracts. Especially, from C. obtusa extracts, terpinen-4-ol was emitted 71 times higher than DI water. During the humidification with C. obtusa extracts, emitted terpenoid compounds were well known for higher anti-bacterial, anti-insect, and anti-septic functions, but also these had anti-hypertensive and anti-cancer activities. Therefore, terpenoids from C. obtusa extracts can help to improve public health by using humidifier.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.236-245
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• 2012

This research was performed to analyze growth performance and pattern of eighteen families of hinoki cypress (Chamaecyparis obtusa), which were imported in Jeju region. The growths of 'Yako-7', 'Muei-1', and 'Sangsong-9' families were superior to other families whereas those of 'Sanguen-3', 'Yago-6', and 'Hyena-2' families were poor. The height growth between age 9-year to 15-year was superior to those between other ages. No specific growth pattern was observed in the diameter at breast height (DBH) by ages. Family heritability of height, DBH, and volume were estimated at 0.68, 0.75, and 0.75, respectively. Pearson's correlation analysis showed that there was little juvenile-mature correlation in the growth of C. obtusa.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.155-155
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• 2005

• Korean Journal of Veterinary Service
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• v.32 no.1
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• pp.87-92
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• 2009

The avoidance of the allergen of the house dust mite is one of the challenges to reduce and treat the symptoms of allergic diseases. Accordingly, various acaricidal agents are being used to kill the mite, but just killing it leaves the remains of it, which still act as the allergen. Therefore expelling the mite is thought as best policy to avoid the mite allergen. For this, some materials have been applied to repellent agents against the mite. Among them, a material with natural origin, known as the phytoncide, is being used for its repellent activity, as well as for its benefits for health. In this experiment, essential oils extracted from Korean white pine (Pinus koreaiensis S. et Z.) and hinoki cypress (Chamaecyparis obtusa), which are widely used as the source of phytoncide products, are studied for demonstration of the repellent effect against the house dust mites, Dermatophagoides farinae and D. pteronyssinus. Direct contact method was used to evaluate the repellent effect (%). And the results suggest the oils have a significant effect enough to be used as a source of repellent agent. For the repellent effect, the most effective concentration was $0.5{\mu}l/cm^2$ at 45 minutes both in the white pine and the hinoki oil.

• Journal of Oral Medicine and Pain
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• v.35 no.1
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• pp.19-29
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• 2010

Phytoncide, essential oil of trees, has microbicidal, insecticidal, acaricidal, and deodorizing effect. The present study was performed to examine the effect of phytoncide on Candida albicans, which is a commensal colonizer of the mucous membranes but has become an opportunistic pathogen. C. albicans was incubated with or without phytoncide extracted from Hinoki (Chamaecyparis obtusa Sieb. et Zucc.; Japanese cypress) and then changes were observed in its optical density, cell viability and morphology. As concentrations of phytoncide added to the culture medium increased, optical density and cell viability of C. albicans decreased. Minimum inhibitory concentration of phytoncide for C. albicans was observed to be 0.25%, and minimum fungicidal concentration was 0.5%. Numbers of morphologically atypical cells with electron-dense cytoplasm and granules and increased with increasing concentration of the phytoncide. At higher concentrations of phytoncide, compartments and organelles in the cytoplasm became indistinguishable. The overall results indicate that the phytoncide used for this study has a strong antimicrobial activity against C. albicans. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral candidiasis.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.349-356
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• 2019

This study examines the effect of thinning in terms of changes in the growth characteristics of Chamaecyparis obtusa stands after they were thinned with varying intensity in Gochang, North Jeolla Province, Korea. Thinning was carried out in 2000 on Chamaecyparis obtusa stands (22 years old), and the stands were categorized in terms of the thinning intensity in the experiment: very heavy, heavy, medium, light, and control. The results of monitoring up to 2018 revealed that the diameter at breast height and the growth rate of individual trees after thinning had a positive correlation with the thinning intensity, whereas the stand volume showed a negative correlation. The height to diameter (H/D) ratio decreased by up to 70-80 due to the increased diameter at breast height after thinning and thereby resulted in better quality. The relative yield index right after the first thinning was between 0.75 and 0.95, which suggests the best timing for the first thinning had been missed. This study's findings are expected to serve as a basic reference in establishing the thinning system for Chamaecyparis obtusa forests.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.321-328
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• 2012

The purpose of this study was to examine the toothbrushing behavior of the citizens, their use of dentifrice, awareness of the importance of dentifrice purchase and consciousness of dentifrice containing the extract of Chamaecyparis obtusa in the city of Gwangju. It's basically meant to provide some informations on the development of oral health supplies involving dentifrice containing the extract of Chamaecyparis obtusa in that city in an effort to help the city serve as a hub of the dental industry. The subjects in this study were the selected citizens in the city of Gwangju. As a result of analyzing their awareness of the importance of the considerations for the purchase and use of dentifrice, they gave 68.2% overall. They gave the highest marks of 83.3% to the importance of effect. As for the importance of each item, they gave the highest marks of 85.1% to the importance of the prevention of dental caries. Concerning differences in awareness of the importance of the external purchase factors according to age, every age group placed the most importance on inspection by the certification authorities except for those who were in their 40s and 60s, and the respondents who were in their 40s and 60s attached more importance to price than the other items. Regarding differences in awareness of the importance of effectiveness according to age, those who were under the age of 20 gave the highest marks of 79.8% to the importance of dental-caries prevention and whitening effects. As a result of asking them whether they had an intention to use dentifrice containing the extract of Chamaecyparis obtusa if this dentifrice would be developed, 54.6% replied they had the intention. When they were asked another question whether they thought this dentifrice would have an effect on oral health, 55.1% answered they thought so. 33.8% expected this dentifrice to have a primary effect on the prevention of dental caries. Given the findings of the study, full-scale R&D efforts should be directed into the development of dentifrice containing the extract of chamaecyparis obtusa in the future.

• Journal of Korean Society of Forest Science
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• v.77 no.4
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• pp.429-444
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• 1988

Considering the recent trent toward the development of multiple-use of forest trees, investigations for comprehensive information on these young stands of Hinoki cypress are necessary for rational forest management. From this point of view, 83 sample trees were selected and cut down from 23-ear old stands of Hinoki cypress at Changsung-gun, Chonnam-do. Various stem growth factors of felled trees were measured and canonical correlaton analysis, principal component analysis and factor analysis were applied to investigate the stem growth characteristics, relationships among stem growth factors, and to get potential information and comprehensive information. The results are as follows ; Canonical correlation coefficient between stem volume and quality growth factor was 0.9877. Coefficient of canonical variates showed that DBH among diameter growth factors and height among height growth factors had important effects on stem volume. From the analysis of relationship between stem-volume and canonical variates, which were linearly combined DBH with height as one set, DBH had greater influence on volume growth than height. The 1st-2nd principal components here adopted to fit the effective value of 85% from the pincipal component analysis for 12 stem growth factors. The result showed that the 1st-2nd principal component had cumulative contribution rate of 88.10%. The 1st and the 2nd principal components were interpreted as "size factor" and "shape factor", respectively. From summed proportion of the efficient principal component fur each variate, information of variates except crown diameter, clear length and form height explained more than 87%. Two common factors were set by the eigen value obtained from SMC (squared multiple correlation) of diagonal elements of canonical matrix. There were 2 latent factors, $f_1$ and $f_2$. The former way interpreted as nature of diameter growth system. In inherent phenomenon of 12 growth factor, communalities except clear length and crown diameter had great explanatory poorer of 78.62-98.30%. Eighty three sample trees could he classified into 5 stem types as follows ; medium type within a radius of ${\pm}1$ standard deviation of factor scores, uniformity type in diameter and height growth in the 1st quadrant, slim type in the 2nd quadrant, dwarfish type in the 3rd quadrant, and fall-holed type in the 4 th quadrant.