• Journal of the Korean Wood Science and Technology
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• v.12 no.1
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• pp.11-30
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• 1984

This study was executed to offer the basical data needed to the plywood industry as examining on the wood characteristics of veneer species that grow in Korea. According to the aggravation of log import from foreign countries caused by the gradual exhaustion of wood resources in recent years, the study on wood characteristics of veneer species growing in Korea should be carried out preferentially in promotion of the domestic timber utilization and development of it's processing technique for plywood industry. 50 commercial veneer species in this study were selected from 33 genuses, and general macroseopical wood characteristics for them were examined and described by the species. And also keys for the identification based on gross features were briefly prepared and presented by gymnosperm and angiosperm respectively.

• Journal of the Korea Furniture Society
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• v.18 no.1
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• pp.39-46
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• 2007

This study was carried out to investigate the wood properties for efficient utilization of warm temperate tree species of Quercus acuta Thunb. grown in Korea. Fundamental wood properties in the anatomical, physical, mechanical and chemical characteristics were examined. Quercus acuta Thunb. is a radial-porous, straight grained and fine textured wood. The heartwood is not clearly distinguished from the sapwood. In physical properties, it has a high oven-dry specific gravity of $0.85{\pm}0.02$, and high shrinkage from green to air-dried condition of $7.05{\pm}0.52%$ in radial and $11.13{\pm}0.48%$ in tangential direction. Mechanical properties determined are strong with the MOR of $1,065{\pm}90kgf/cm^2$, and tensile strength parallel to grain of $1,490{\pm}258kgf/cm^2$ and shear strength of $175{\pm}13kgf/cm^2$. Also, this wood has high extractive contents: 11.11% for cold and 13.51% for hot water.

• Journal of the Korean Wood Science and Technology
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• v.51 no.2
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• pp.81-97
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• 2023

The aim of this study were to evaluate tannin resorcinol formaldehyde (TRF) for the preparation of cross-laminated timbers (CLTs) made from fast-growing tree species and to analyze the physical and mechanical properties of CLTs. TRF copolymer resin was prepared by using the bark extracts of Swietenia mahagoni (L.) Jacq. It was observed that the TRF adhesive possessed less solid content (23.59%), high viscosity (11.35 poise), and high pH values (10.0) compared to the standard phenol resorcinol formaldehyde. The TRF adhesive was applied to produce CLTs with the addition of 15% tapioca and flour as an extender. The six-layered CLTs were produced from sengon (Falcataria moluccana Miq.), jabon [Anthocephalus cadamba (Roxb) Miq.], coconut (Cocos nucifera L.), and the combination of coconut-jabon and coconut-sengon wood. The analysis of variance revealed that the layer composition of CLT significantly affected the physical and mechanical properties of the beam. While the modulus of rupture met the standard, the moisture content and modulus of elasticity values did not fulfill JAS 1152-2007. All of the CLTs produced in this study demonstrated low formaldehyde emission, ranging from 0.001 mg/L to 0.003 mg/L, thereby satisfying the JAS 1152 for structural glue laminated timber.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.190-193
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• 1982

Conclusion: The results of this study are encouraging for the development of a set of interpretable diagnostic criteria for a reasonably reliable identification of some species. The present study has been limited in the characteristics studied and was made on relatively poor photography. Further study on high quality photography, over wider areas and including such additional characteristics as crown texture and shadow intensity should prove useful. A preliminary examination has been made of some photo-image characteristics of a number of important tree species on large scale (1:9,000) contact prints of panchromatic mm. The characteristics studied were crown image tone, and shape. Image tone was estimated against a standard grey-scale and shows within-species consistency and a range between species. Crown shapes were subjectively assessed but there appears to be a within-species consistency and interpretable between-species differences. The results of this trial suggest that it should be practicable to make a number of important species distinctions by photo-interpretation with a useful degree of reliability. Other characteristics beside those studied might be usefully examined. Photography: Hand-printed glossy contact prints of vertical 1:9,000 scale panchromatic photography of Kwangnung Experimental Forest flown May 1964. The filter used is unknown (probably minus-blue). The camera is unknown but was probably a military type K-17 or K-22 with 6"(apostfophy) lens. The photography shows notably poor resolution. Species: 143 individual trees ranging through 11 species (7 softwood, 4 hardwood) were included in the study. A range of size classes were included for each species.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.293-302
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• 2013

The present study summarizes the occurrence, distribution and autecology of 12 taxa of the class Cyanophyceae collected from several swamps, reservoir and highland wetlands in South Korea from 2009 to 2012. A new species, Anabaena koreana sp. nov. and 11 taxa of blue-green algae newly recorded are described and illustrated. Anabaena koreana is similar to A. oumiana, A. spiroides and A. crassa in that the trichomes form regular coils. However, A. koreana is distinguished from these three species by the morphological characteristics of the vegetative cell, heterocyst, and akinet shape and size. This study considers 12 blue-green algal species, including a new species, Anabaena koreana sp. nov. and 11 species that are recorded for the first time in the Korean freshwater algal flora. Among them, the genus Nostochopsis Wood ex Bornet et Flahault 1886 had not previously been recorded in Korea.

• Journal of the Korean Wood Science and Technology
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• v.50 no.6
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• pp.414-426
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• 2022

The Lauraceae family has commercial uses, such as in the food, pharmaceutical, and perfume industries. This study was conducted to investigate anti-asthmatic activity of essential oils from the seven species in the Lauraceae family. The essential oils were extracted from the leaves of seven species, and the chemical composition was investigated by gas chromatography-mass spectrometry. The major constituents of essential oils differed depending on the species, even if they belonged to the same family. The main constituents were camphor (89.09%) in Cinnamomum camphora, linalool (26.91%) in Cinnamomum cassia, 1,8-cineole (23.90%) in Cinnamomum japonicum, d-limonene (10.27%) and β-eudesmol (10.03%) in Lindera obtusiloba, δ-cadinene (13.85%) and α-phellandrene (11.57%) in Machilus japonica, cis-,trans-β-ocimene (13.80% and 12.06%) and elemol (11.46%) in Neolitsea aciculata, and cis-β-ocimene (37.94%) and sabinene (24.91%) in Neolitsea sericea. The anti-asthmatic activity of essential oils was investigated using the lipopolysaccharide-induced NCI-H292 cells. The relative expression levels of the pro-inflammatory cytokines [interleukin (IL)-1β and IL-6] and mucus gene (MUC5AC and MUC5B) were significantly reduced by essential oils from seven species in the Lauraceae family. Among the seven essential oils, the essential oil from L. obtusiloba had the most superior anti-asthmatic activity. These results suggest that the essential oil of L. obtusiloba leaves could be used as an agent to suppress mucus hypersecretion.

• Journal of the Korean Society of Safety
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• v.22 no.6
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• pp.46-54
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• 2007

The purpose of this study was to examines the burning rate of fire retardant treated wood in the cone heater with a one-dimensional integral model. The wood samples used in this study were four species. The species of woods are Redwood, White oak, Douglas fir and Maple. Each sample was nominally 50mm thick and 100mm square. Samples were exposed to a range of incident heat fluxes 10 to $35kW/m^2$ using the cone heater. A one-dimension integral model has been used to predict burning rate, heat of gasification, flame heat fluxes, charring rate and char depth of samples. As a result measurement of mass loss rate, softwoods(Redwood and Douglas fir) has relatively low value than those for hardwoods(White oak and Maple). Average charring rate of woods in case of fire retardant treatment showed reduction effect of 41.29%, 50.00%, 48.18% and 60.82% for Redwood, Douglas fir, White fir and Maple, respectively. Almost all the predictions from integral model showed faster charring than those measured. Average difference between predictions and experimental data was 16%, 9.5% and 11.8% for N, F1 and F2 respectively. Water-soluble fire retardant used in this study find out more effect in hardwood than softwood from the result of measurement of mass loss rate and average charring rate.

• Journal of the Korean Wood Science and Technology
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• v.33 no.4 s.132
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• pp.1-8
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• 2005

The initiation and cessation of cambial activities were investigated to find out the growth characteristics of the major species growing in Chuncheon, Korea. The division of cambial zone in Pinus densiflora and Pinus koraiensis began from the middle of March through the end of March. The activity of cambial zone in P. densiflora and P. koraiensis was vigorous from the end of May through the middle of July. During this period the number of cells increased rapidly in radial direction. However, the number of cells in P. densiflora was gradually increased. The division of cambial zone in ring-porous wood, such as Quercus mongolica and Robinia pseudoacacia began in the middle of March, before the formation of vessel. The division of cambial zone in diffuse-porous wood, such as Cornus controversa and Prunus sargentii, began in early April, and then the formation of vessels began after one to three weeks. It was considered that the cambial zone in softwood was ceased from the beginning of November, whereas cambial activities in hardwood ceased in the middle of October. Consequently, the formation of growth ring was different among the species, even though the trees were grown under the same conditions.

• Journal of the Korea Furniture Society
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• v.16 no.2 s.30
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• pp.1-11
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• 2005

본 실험은 한국산 주요 침엽수인 소나무, 잣나무, 리기다소나무, 낙엽송의 safranine의 침투도를 실험하였다. 진공, 압력 및 safranine의 침투시간을 각각 다르게 하여 수종별 침투도를 측정하였다. 실험 결과 진공조건의 변화에 따른 침투도 변이는 크게 나타나지 않았고, 압력조건의 차이에 의한 침투도는 다르게 나타났다. 목재의 방향별 침투도를 고찰한 길과 축방향, 방사방향, 접선 방향의 순서로 침투도가 높았다. 변재와 심재의 사이의 침투성을 고찰 한 결과 변재가 심재보다 쉽게 침투 되었다. 수종별 침투성을 고찰한 결과 소나무가 가장 우수했다.

• Journal of the Korean Wood Science and Technology
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• v.36 no.5
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• pp.11-23
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• 2008

The mechanical and physical properties of zinc borate (ZB)-modified oriented strandboard (OSB) from southern wood species were investigated in this study. OSB panels treated with ZB were not significantly weaker than the untreated samples in terms of specific modulus of elasticity (SMOE) and specific modulus of rupture (SMOR). ZB showed the negative effect on specific internal bond (SIB) strength, since some of ZB would persist as a powder state on the flake surfaces, thereby reducing the bonding efficiency of the adhesive. The ZB level did not show significant effect on thickness swelling (TS). ZB-modified OSB showed the suitable mechanical and physical properties for the structural wood composites.