• Journal of the Korean Wood Science and Technology
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• v.40 no.4
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• pp.244-256
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• 2012

The anatomical characteristics of the ten Indonesian wood species (Gmelina, Jeunjing, Mangium, Durian, Gandaria, Jengkol, Kupa, Mangga, Nanaka and Rambutan) were investigated by optical microscopy. All the species were diffuse-porous with solitary and radial pore multiple. In Mangium, however, tangential pore multiple was observed as well. Tangential diameter of pore was larger than that of radial one except for Jeunjing and Nangka. Nangka showed the largest tangential diameter of pore among the species. Vessel number per $mm^2$ of Mangium, Gandaria and Kupa was higher than that of the other species. Especially Kupa showed highest vessel number. The tangential width of axial parenchyma cell in Gmelina, Mangium, Kupa and Mangga was larger than that of wood fiber, while the other species showed the opposite trend. Mangium was the largest in tangential width of axial parenchyma cell. Rays were homocellular composed only of procumbent cell in Gmelina, Jeunjing and Rambutan. Heterocellular rays composed of procumbent cells in the body and one row of upright and/or square in the margin are observed in Gandaria. Mangium, Durian, Jengkol, Kupa, Mangga and Nangkabody showed heterocellular rays composed of procumbent cells in the body and mostly 1~2 rows of upright and/or square cells in the margin. Crystals occurred in Durian, Gandaria, Jengkol, Jeunjing, Mangga and Rambutan and silica in Jeunjing and Mangga.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.719-725
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• 2004

Mesquite or Vilayati babul (Prosopis juliflora) is a drought resistant, evergreen, spiny tree with drooping branches and a deep laterally spreading root system. It grows in semi-arid and arid tracts of tropical and sub-tropical regions of the world and is spreading because the leaves are unpalatable and animals do not digest its seed. The mesquite has become a major nuisance; cutting or pruning its branches to form a canopy would provide shade for travelers, aid harvesting of pods, as well as make available wood for fuel. An average plant starts fruiting by 3-4 years of age and yields annually 10-50 kg pods/ tree, which can be collected from May-June and September-October. Availability of pods worldwide is estimated to be about 2-4 million metric tonnes. Ripe pods are highly palatable; on dry matter basis they contain 12% crude protein, 15% free sugar, a moderate level of digestible crude protein (7% DCP) with a high level of energy (75% TDN). The pods contain low tannin levels below those toxic to animals. Seeds contain 31-37% protein; pods should be finely ground before feeding to facilitate utilization of the seeds. Mesquite pods could replace costlier feed ingredients such as grain and bran contributing 10-50% of the diet. Phosphorus supplements need to be added when mesquite pod, exceeds 20% of animals' diet.

• Wind and Structures
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• v.37 no.2
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• pp.95-104
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• 2023

The latest revision of AS/NZS 1170.2 incorporates some new research and knowledge on strong winds, climate change, and shape factors for new structures of interest such as solar panels. Unlike most other jurisdictions, Australia and New Zealand covers a vast area of land, a latitude range from 11° to 47°S climatic zones from tropical to cold temperate, and virtually every type of extreme wind event. The latter includes gales from synoptic-scale depressions, severe convectively-driven downdrafts from thunderstorms, tropical cyclones, downslope winds, and tornadoes. All except tornadoes are now covered within AS/NZS 1170.2. The paper describes the main features of the 2021 edition with emphasis on the new content, including the changes in the regional boundaries, regional wind speeds, terrain-height, topographic and direction multipliers. A new 'climate change multiplier' has been included, and the gust and turbulence profiles for over-water winds have been revised. Amongst the changes to the provisions for shape factors, values are provided for ground-mounted solar panels, and new data are provided for curved roofs. New methods have been given for dynamic response factors for poles and masts, and advice given for acceleration calculations for high-rise buildings and other dynamically wind-sensitive structures.

• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.218-224
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• 2021

This study was conducted to determine the mass-loss rates and the changes in carbon/nitrogen (C/N) ratio of dead woods, which were of following species: Dryobalanops aromatic, D. rappa, and Cratoxylum arborescens. These were dominant tree species in mixed Dipterocarp forests (MDF) and peat swamp forests (PSF) in Brunei Darussalam. In May, 2019, 48 dead wood samples (15 cm×4.8 cm×5 cm) were placed in MDF and PSF sites, and all the samples were collected after 16 months. The effects of species on mass loss were statistically significant (p<0.05); however, no difference was observed in the mass loss obtained from the two forest types (p>0.05). The initial density (g·cm^-3) of the dead woods D. aromatic, D. rappa, and C. arborescens, was 0.64±0.02, 0.60±0.00, and 0.44±0.01, respectively. Also the annual mass loss rate (%) was estimated to be 6.37, 8.17, and 18.53 for D. aromatic, D. rappa, and C. arborescens, respectively. The proportion of dead woods in decay class III was only 25% of C. arborescens samples, which were attacked by wood-feeding invertebrates, such as termites. The C/N ratio decreased significantly in D. aromatic and D. rappa, but the decreasing trend of C/N ratio was not statistically significant in C. arborescens. The results indicate that physical traits of dead woods, such as density, could be one of the main factors causing the decomposition of dead woods initially, as invertebrates such as termites are one of the key decomposers of dead wood in tropical rainforests. In the samples of C. arborescens, which was attacked by invertebrates, nitrogen immobilization occurred to lesser extent as compared to that observed in D. aromatic and D. rappa.

• Journal of the Korean Wood Science and Technology
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• v.34 no.2
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• pp.68-77
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• 2006

The heartwood of cengal (Neobalanocarpus heimii) is known to have a high degree of decay resistance by virtue of its high extractive content. After 30 years in ground contact an utility pole of this tropical hardwood was found to be degraded only in the surface layers by cavity-forming soft rot fungi. The present work was undertaken 1) to characterize the degradation of cengal heartwood from the aspect of ultrastructure and chemistry and 2) to investigate the correlation between soft rot decay and its extractive microdistribution in wood tissues. The chemical analysis of cengal heartwood revealed the presence of a high amount of extractives as well as lignin. The wood contained a relatively high amount of condensed lignin and the guaiacyl units. Microscopic observations revealed that vessels, fibers and parenchyma cells (both ray and axial parenchyma) all contained extractives in their lumina, but in variable amounts. The lumina of fibers and most axial parenchyma were completely or almost completely filled with the extractives. TEM micrographs showed that cell walls were also impregnated with extractives and that pit membranes connecting parenchyma cells were well coated and impregnated with extractives. However, fungal hyphae were present in the extractive masses localized in cell lumina, and indications were that the extractives did not completely inhibit fungal growth. The extent of cell wall degradation varied with tissue types. The fibers appeared to be more susceptible to decay than vessels and parenchyma. Middle lamella was the only cell wall region which remained intact in all cell types which were severely degraded. The microscopic observations suggested a close correlation between extractive microdistribution and the pattern and extent of cell wall degradation. In addition to the toxicity to fungi, the physical constraint of the extractive material present in cengal heartwood cells is likely to have a profound effect on the growth and path of invasion of colonizing fungi, thus conferring protection to wood by restricting fungal entry into cell walls. The presence of relatively high amount of condensed lignin is also likely to be a factor in the resistance of cengal heartwood to soft rot decay.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.42-50
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• 2013

Since 1990's, a plywood for flooring base has gotten customers' demand. Costs of raw material and production increased because of changed environment of industry. Tropical timber such as Red Meranti (Shorea acuminate) used for raw material of the floor has been depleting beside countries in South Eastern Asia changed species of afforestation. As a result, it gets hard to secure good quality of raw material for plywood. Moreover plywood price is increased suddenly after earthquake in Japan. Eucalyptus (Eucalyptus globulus) in china has been using for raw material as a countermeasure of changed environment of industry. In this study, possibility of using flooring consisted of Eucalyptus veneer as crossband layers was checked by deflection experiments. Flooring consisted of Red Meranti was used for comparison. Two factors which impact on deflection are a type of density gradient and density difference between Long-grain veneer and Short-grain veneer. Red Meranti samples are M type of density gradient on the other hand Eucalyptus samples are W type of density gradient. The more samples have high density difference, the more deformation was checked. A sample which has big density difference between core and cross bands layer warp more also deform. Flooring was deformed smaller than plywood and samples which have big density difference was deformed more.

• Journal of the Korean Wood Science and Technology
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• v.46 no.6
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• pp.656-669
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• 2018

Tropical bamboo species, which have a very rapid growth rate, are considered as a promising non-timber forest product capable of exhibiting new functionality by carbonization technology. This study was conducted to compare the characteristics of carbonized bamboos from Andong (G. pseuudoarundinacea (Steudel) Widjaja), Hitam (G. atrovialacea), Tali (G. apus), Kuning (B. vulgaris Var. striata (Lodd. Ex Lindl)), and Ampel (B. vulgaris Scharad. ex Wendland), and Betung (D. asper). Each bamboo was carbonized at 200, 400, 600, 800, and $1,000^{\circ}C$, respectively, and their physical and anatomical characteristics were investigated. The result showed that the volume and weight of carbonized bamboo decreased with increasing carbonization temperature and showed the substantial changes of volume and weight between 200 and $400^{\circ}C$. The highest and the lowest density of carbonized samples were found in Ampel bamboo and Betung bamboo, respectively. The density of all carbonized bamboos tended to decrease after carbonization at 200 and $400^{\circ}C$ and relatively become constant afterwards. The carbonized bamboo prepared at 800 and $1,000^{\circ}C$ showed better refining degree. The results of the anatomical observation showed that the vascular diameter of carbonized bamboo decreased with increasing carbonization temperature, and the shrinkage in radial and tangential direction showed similar tendency. Statistical analysis showed that there was significant correlation between physical contraction and anatomical contraction. Based on the results of this study, comprehensive data about Indonesian bamboo charcoals could be obtained and it will be useful for future application studies.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.327-336
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• 2013

Anatomical characteristics of White Jabon (Arthocephalus cadamba) and Red Jabon (Arthocephalus macrophyllus) were investigated by IAWA hardwood feature list. Both species were diffuse-porous, and radial multiple pore with 2~3 rows was mostly observed. Tangential diameter of vessel lumina was 100 to $200{\mu}m$, and vessels per square millimeter were 5 to 20. White Jabon has more vessels than Red Jabon. The number of solitary pore per square millimeter in both species was similar, but more pore multiple was observed in White Jabon. Axial parenchyma diffuse was observed in both species, but axial parenchyma of White Jabon was hardly identified on the cross section. Rays were classified into "body ray cells procumbent with over 4 rows of upright/square marginal cells" type and partly "all ray cells upright and/or square" type on radial section. Ray width 1 to 3 cells and 1 to 2 cells observed in White Jabon and Red Jabon, respectively. Ray height of White Jabon was $420{\mu}m$ and Red Jabon $474{\mu}m$. Fiber length was the range of 900 to $1,600{\mu}m$ in both species, and it showed a tendency to increase from pith to bark. Consequently, it is considered that pore multiple, ray width and axial parenchyma are to be suggested the keys for identification of both species.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.1
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• pp.52-58
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• 2013

The effets of the pretreatments of tropical kapok fibers were evaluated in this study in terms of water sorption capacity and oil sorption capacity. The alkali treatments with NaOH resulted in the reduction of lignin, oil and hemicellulose, which were detected with FT-IR spectrum. The reduction of the lyphophilic components such as fat on kapok fiber by the ozone treatments were also measured with FT-IR spectrum. The oil sorption capacity of kapok fiber was decreased by the alkali treatments and the ozone treatments, while the water sorption capacity was increased. The liquid sorption capacity were greatly affected by the mechanical cutting of kapok fiber which exposed the big lumen of kapok fiber. The hydrophilic property of kapok fiber could be controlled by the pretreatments, which would increase the applicability of kapok fiber for preparation of various functional paper products.

• 보존과학연구
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• s.22
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• pp.41-52
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• 2001

The wooden building is mainly damaged by the termite which have an effect of the structure by making emptied inner part of wood. One class, Japanese termite, inhabits throughout Korea and is often detected. So the deterioration by termite attacking the wooden building needs to be controlled. Termites are over 2,800 species in the world, usually they inhabit in the tropical or subtropical region and don’t over winter in dormant condition. So their activity and distribution are chiefly restricted by temperature and humidity. The termite inhabiting in Korea is Reticulitermes speratus kyushuensis Morimoto, which known to have an optimal temperature range at $12~30^{\circ}C$ and minimum temperature at $6^{\circ}C$ for activation. These temperatures correspond to the mean temperature($5.6^{\circ}C$~$25.8^{\circ}C$) from March to November and the activity time of termitein Seoul. In addition, as a result of environmental pollution by industrial development, the climate of Korea is getting warm. The increase of mean temperature in Korea has been $1.1^{\circ}C$ for the past seventy five years, so it is expected that the damage of wooden building by termite will increase gradually. Therefore, in order to protect wooden building from damages by termite, it needs not only development of new pest control methods, but also studies on the control of environmental factors having an effect on the activity and growth of termite. For the conservation of the large cultural properties such as the wooden building in the open air, it would be effective to use the methods of fumigation, insecticidal and antiseptic chemical treatment of wood materials, soil termiticideinjection treatment, and termite colony elimination system.