• Journal of the Korean Wood Science and Technology
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• v.52 no.2
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• pp.191-203
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• 2024

Persimmon wood (Diospyros kaki) is a seasonal fruit-producing plant with a beautiful dark pattern in its wood that is suitable for high-quality furniture, sculptures and musical instruments. The utilization of persimmon wood can be improved by determining its anatomical characteristics, such as juvenile and mature wood. This study aimed to determine the boundaries between juvenile and mature wood and observe the anatomical properties of juvenile and mature wood and their variations in the axial direction. Three 30-year-old persimmon (D. kaki) trees grown in Karo, North Sumatra, Indonesia, were used in this study. The boundary between juvenile and mature wood was determined by measuring the fiber length and vessel element length from near the pith to near the bark. Anatomical observations were conducted in the juvenile and mature wood areas. The results showed that the average boundaries between juvenile and mature wood were 44.11 mm from the pith and were not significantly different in the axial direction of the trees. Furthermore, the wood anatomy categories of juvenile and mature wood differed significantly in terms of fiber diameter, fiber proportion, vessel proportion, and axial parenchyma proportion. In the axial direction, vessel diameter, ray parenchyma frequency, and ray parenchyma proportion at the base, middle, and top of the tree were significantly different.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.679-684
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• 2002

MODIS LAI has been one of key products for analyzing the quantitative aspects ofterrestrial ecology. This study was designed to validate MODIS LAS product by using the reference LAI map that was derived from both ground measurements and ETM＋ surface reflectance. The study area, the Kwangneung Experiment Forest in Korea, covers mixed species of deciduous and conifers of temperate forest. Throughout the growing season of 2002, we have measured LAS at the 30 sample plots using an optical device. Ground measured LAS data were then correlated to the ETM＋ reflectance to produce a continuous map of LAS over the study area. Preliminary comparison between MODIS LAI and the reference LAI map showed the lower LAI values from the MODIS product.

• Journal of Forest and Environmental Science
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• v.36 no.2
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• pp.163-172
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• 2020

The objective of this study was to develop evaluation criteria for forest education using the Context, Input, Process, and Product (CIPP) model. To this end, we designed a survey based on expert advice and content analysis of previous studies on the CIPP model and forest education. The survey was conducted on 393 forest education specialists, and Cronbach's α coefficient was set as 0.6 or higher to verify reliability and validity, and to determine reliability by factor. Eventually, 52 out of 57 evaluation items were extracted, and the evaluation indexes were selected through factor analysis as follows: four evaluation indexes for the context dimension, namely "Clarity of goal setting," "Developing conditions for education," "Meeting of requirements," and "Institutional drive"; three evaluation indexes for the input dimension, namely "Acquisition of education infrastructure," "Establishment of operational support," and "Adequacy of assigned manpower"; four evaluation indexes for the process dimension, which were "Adequacy of budget allocation," "Expertise of forest education instructors," "Diversity of programs," and "Public-private academic partnership"; and five evaluation indexes for the product dimension, namely "Effectiveness of perception change," "Influence over the society," "Continuity of improvement in evaluation," "Continuity of education," and "Verification of the effects of education."

• Journal of Forest and Environmental Science
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• v.30 no.2
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• pp.189-200
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• 2014

The tropical wet evergreen, tropical semi evergreen and moist deciduous forest types are projected to be impacted by climate change. In the Western Ghats region, a biodiversity hotspot, evergreen forests including semi evergreen account for 30% of the forest area and according to climate change impact model projections, nearly a third of these forest types are likely to undergo vegetation type change. Similarly, tropical moist deciduous forests which account for about 28% of the forest area are likely to experience change in about 20% of the area. Thus climate change could adversely impact forest biodiversity and product flow to the forest dependent households and communities in Uttara Kannada district of the Western Ghats. This study analyses the distribution of non-timber forest product yielding tree species through a network of twelve 1-ha permanent plots established in the district. Further, the extent of dependence of communities on forests is ascertained through questionnaire surveys. On an average 21% and 28% of the tree species in evergreen and deciduous forest types, respectively are, non-timber forest product yielding tree species, indicating potential high levels of supply of products to communities. Community dependence on non-timber forest products is significant, and it contributes to Rs. 1199 and Rs. 3561/household in the evergreen and deciduous zones, respectively. Given that the bulk of the forest grids in Uttara Kannada district are projected to undergo change, bulk of the species which provide multiple forest products are projected to experience die back and even mortality. Incorporation of climate change projections and impacts in forest planning and management is necessary to enable forest ecosystems to enhance resilience.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.303-314
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• 2020

Gambir is a non-wood forest product with a potential of being used as wood adhesive, due to about 33% catechin in it. Meanwhile, catechins and sucrose have not been studied as adhesives. Therefore, basic characteristics of gambir-sucrose adhesives were investigated. In this research, adhesives were prepared by dissolving gambir and sucrose in distilled water, at different blending ratios of the gambir/sucrose such as 100/0, 75/25, 50/50, and 25/75 wt%. Furthermore, gas chromatography-mass spectrometry (GC-MS) was employed to determine the gambir chemical compositions, and Fourier transform-infrared (FTIR) spectroscopy was carried out to identify chemical bonds. Particleboards with a target density of 0.8 g/㎤ were then manufactured by hot-pressing for 10 min at 200℃. The internal bond (IB) strength of particleboard was subsequently measured. Based on the GC-MS analysis, 31.11% of catechin was identified. In addition, the viscosity, density, solid content, and gelation time of the adhesives, and insoluble matter content (IMC) in boiling water were 7.30~33.24 mPa.s, 1.2~1.3 g/㎤, 25.56~28.44%, 73~420 min, and 29.75~62.10%, respectively. Adding sucrose to the adhesive was observed to raise the IMC from 49.05 to 62.10%, at 180℃ and 200℃. FT-IR analysis showed that the gambir absorption peaks occurred at approximately 1620 cm^-1, assigned to the C=O stretching of 5-hydroxymethylfurfural, which tended to increase with the addition of sucrose. The reaction between gambir and sucrose was observed in the form of the dimethylene ether bridge. The 25/75 wt% gambir-sucrose adhesives and 200℃ hot-pressed temperature resulted in the highest IB strength (0.89 MPa), and met the requirement of JIS A5908-2003 type 18. Consequently, the gambir-sucrose adhesive could be used as a particleboard adhesive.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.21-22
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• 2019

In order to prevent global warming according to fossil fuel use, countries around the world are making efforts through the Kyoto Protocol and the Paris Climate Change Convention. In addition, in order to prepare for high oil prices, researches such as the development of various renewable energy are being conducted. At present, the domestic production rate of energy sources in Korea is low at 18.1%, and power plants using forest biomass are being constructed to meet the domestic situation where 63% of the land is a forest. In 2015, the global production of wood pellets, a raw material for wood-based biomass power generation, was 28 million tons, up 7.7% from 2014, and has increased tenfold over the last decade. This is a result of increased demand for biomass. Korea is also increasing every year. However, biomass fly ash, an industrial by-product generated by biomass energy generation, is now being disposed of entirely, and there is little research to utilize it. Therefore, this paper will use biomass fly ash, an industrial by-product, which is currently being discarded due to a lack of separate treatment methods, as an admixture concept to contribute to solving environmental problems, developing new admixtures, improving quality, and seeking recycling plans.

• International Journal of Reliability and Applications
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• v.3 no.4
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• pp.155-164
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• 2002

This paper focuses on how modem data mining can be integrated with real-time relational databases and commercial data warehouses to improve reliability in real-time. An important Issue for many manufacturers is the development of relational databases that link key product attributes with real-time process parameters. Helpful data for key product attributes in manufacturing may be derived from destructive reliability testing. Destructive samples are taken at periodic time intervals during manufacturing, which might create a long time-gap between key product attributes and real-time process data. A case study is briefly summarized for the medium density fiberboard (MDF) industry. MDF is a wood composite that is used extensively by the home building and furniture manufacturing industries around the world. The cost of unacceptable MDF was as large as 5% to 10% of total manufacturing costs. Prevention can result In millions of US dollars saved by using better Information systems.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.458-471
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• 2020

Effect of pre-treatment and compression ratio on specific gravity (SG) and dimensional stability improvement of three lesser-used wood species from natural forest area of North Kalimantan Province, Indonesia had been investigated. Hot soaking at 80℃ for 3 hours within 2 and 5% of boron solution was applied as pre-treatment, while compression ratio applied was 20 and 40% from the initial thickness. Densification was conducted using hot pressing machine at 30 kg/㎠ of pressure and 160℃ of temperature for 15 minutes. Specific gravity was measured gravimetrically, while dimensional stability was evaluated through thickness swelling and water absorption as the indicator. Results show that SG of densified wood was influenced by wood species and compression ratio, but not by pre-treatment applied; while dimensional stability was influenced by wood species, compression ratio, and pre-treatment. Specific gravity and water absorption of densified wood was improved significantly. Specific gravity increased 28.86-63.03%, while water absorption decreased 12.80-15.89%. Thickness swelling of 20% densified wood was lower than that of 40% densified wood.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.68.1-68.1
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• 2005

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.71-71
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• 2000

Recycled fibers usually give slow drainage in the paper forming zone on papermachine, which limit the application of more refining to the fibers for improving paper strength and formation. To use recycled fibers, especially, OCC, more effectively, developing very efficient handling technique of short fibers and fines is inevitable. We tried to make hard flocs of fractionated short fibers and fines, which were the main cause of slow drainage, by adding excessive amount of retention aid on them. This technique was proved to increase drainage with no difference in strength properties, compared to the conventional technique of adding the same amount of polymers to the whole furnish in the lab test. The bonding capability of short fibers and fines in Korean OCC were very poor to be considered as ´fillers´in paper products. Various chemical treatment on the short fibers and fines of the Korean OCC did not improve their bonding and optical properties. One of the reasons of no improvement in their properties was thought to be their high amount of ashes (over 30% in the fractionated samples).