• Journal of agriculture & life science
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• v.45 no.4
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• pp.73-80
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• 2011

This study was conducted to elucidate the best cutting condition in propagation of Juniperus chinensis var. sargentii in respect of survival rate, rooting rate, and early growth after cutting via process of cutting time, cutting media, cutting type and growth regulators. As for cutting time, rooting rate was 68.3% on April, which was higher than 39.5% on May and 32.5% on June. The best cutting media was stream sand of rooting rate 72.7%. Those of mixed soil and decomposition were 40.1% and 27.5% each. The effect of growth regulators was different according to the kind of cutting media. There was no effect on stream sand media which showed the highest rooting rate, while it was very effective on the media of decomposition of granite, which rooting rate showed the lowest. Hardwood as cutting materials showed somewhat higher survival and rooting rate compared to semi-hardwood. The cutting with hardwood condition to stream sand on April, it is regarded to be the most effective condition for Juniperus chinensis var. sargentii to increase survival and rooting rate. Therefore in this experiment it is considered that the best season cutting is April, and the most useful media and plant materials stream sand, and hardwood respectively.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.388-397
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• 1990

This study was conducted to investigate the changes of land use and stand volume around Mt. Kuem-O by B/W aerial photographs in 1979 and B/W Infrared aerial photographs in 1988. The results obtained in this study were as follow : 1. In classification of forest type on aerial photographs, coniferous stand was dark tone and hardwood stand was light tone and irregularly rounded crowns. 2. In classification of coniferous stand, Pinus densiflora was narraw cone and rounded tip of crowns and rough texture, Pinus rigida was irregulary rounded and broadly conical crowns. 3. To refer to changes of forest land area, mixed forest was changed into P. desiflora (687ha), P. rigida (130ha) and hardwood stand (219ha). 4. The regression equations between crown diameter and DBH were significant at 1% level by F-test in all stands. So the equation, D=a+bCD was used to estimate DBH. 5. The tree height curve equations were significant at 1% level by F-test in all stands. To estimate tree height the equation, logH=loga+blogD was adopted in P. densiflora and L. leptolepis and $H=a-bD+cD^2$ was adopted in P. rigida, hardwood stand and mixed forest. 6. The highest volume per hectare was observed in L. leptolepis and mixed forest showed the greatest growth percentage, while the lowest volume per hectare and growth percentage were observed in hardwood stand.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.231-237
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• 2006

Grease barrier food containers are commonly used for packaging of fast food, cooked food, and food in general. Greaseproofing is also used for certificate paper and label paper etc. Different pulp raw materials, due to their different fiber morphology and chemical compositions, produce papers of varying characteristics. We used optical photomicroscopy and fiber analysis data to evaluate fiber morphology and traits under various beating conditions in order to understand which pulp raw materials produced superior greaseproofing property when a fluorinated greaseproofing agent was added internally. The experiment studied 9 species of pulps, including 2 softwood (northern pine and radiata pine) bleached kraft pulps which were beaten to 550 and 350 mL CSF, respectively; 3 hardwoods (eucalypts, acacia, mixed Indonesian hardwoods) bleached kraft pulps which were beaten to 450 and 250 mL CSF, respectively; and nonwood fibers of reed, bagasse, and abaca. A fluorinated greaseproofing chemical at 0.12% dosage with respect to dry pulp was added to each pulp preparation and formed handsheets. A total of 67 sets of handsheets were prepared, and their basis weights, thickness, bulks, opacities, wet opacities, air resistance, water absorption and degrees of greaseproofing were measured for an overall evaluation of pulp and freeness on greaseproofing papers. The experimental fiber length, coarseness and distribution characteristics and the greaseproofing results suggest that softwood pulps (radiate pine > northern pine) were superior to hardwood pulps (eucalypts > acacia > mixed Indonesian hardwoods). The unbeaten pulps gave papers with high porosities and nearly devoid of greaseproofing property. Greaseproofing is proportional to air resistance. Among the nonwood fibers, bagasse had the best greaseproofing property, followed by reed and abaca was the poorest. With regards to waterproofing property, hardwood pulps (mixed Indonesian hardwoods > acacia > eucalypts) were better than softwood pulps (northern pine > radiate pine). Among the Nonwood fibers, reed had the highest waterproofing property, and it was followed by abaca, while bagasse had the poorest waterproofing characteristic. In summary, bleached kraft northern pine, eucalypts and reed pulps were best suited for making greaseproofing papers, Freeness of the pulps should be kept at $200{\sim}280mL$ CSF for optimal performance.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.3
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• pp.31-39
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• 2013

Some researcher started studies of natural capital from 1980's. But many researches are going along with the theme lately. Most assessment of ecosystem services are approaching a general assessment using a land-cover map. Therefore they have some problems such as overestimate, underestimate, and double counting, and so on. This study suggested a detailed typology for quantitative assessment about ecosystem services. It compared land-cover map and forest type map to select a based map and made criteria with reference to the literature and field survey. It subdivided a forest typology using ecological feature (natural forest, artifical forest), forest type (coniferous forest, mixed forest, hardwood forest) and age of stand in forest type map. Each forest type is widely distributed 21~40 ages of forests and biggest area is 21~40 ages of mixed forest in all forest typology. Further researches have to progress consistently assessment using detailed typology and function of forest ecosystem services.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.3
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• pp.81-87
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• 2014

Conditions of paper manufacturing process should be changed depending on the end use and paper properties. Most of the case, mixed pulps with long softwood fibers and short hardwood fibers are used to achieve proper qualities of product with reasonable production cost. For specialty paper manufacture the wood pulp and cotton linter pulp are usually mixed together. The objectives of this study is to analyze physical, mechanical and fracture mechanical properties of paper depending on SwBKP, HwBKP and cotton linter pulp(CLP) mixing. When the mixing ratio of SwBKP was increased, strength properties, such as tensile, tear, and folding endurance, were also increased. When the mixing ratio of SwBKP and HwBKP was increased, stress concentration index was decreased and fracture toughness was increased.

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.27-35
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• 2001

Four different sources of wood-fibers from Eucalyptus, Italian poplar, hemlock, and mixed species fibers were used to study the influence of their fiber characteristics on the performance of medium density fiberboard (MDF) panels bonded with both urea-formaldehyde (UF) and phenol-formaldehyde (PF) adhesives. Included fiber characteristics were fiber length, size distribution, bulk density, and acidity. Physical and mechanical properties of MDF panels manufactured by dry process using these different fibers were determined for the comparison of board performance. Two hardwood species had a large fraction of short fibers resulting in a higher bulk density while very long hemlock fibers had lower bulk density. Fiber acidity was revealed to strongly affect the internal bond (IB) strength of MDF panels bonded with UF resins. MDF panels made from mixed species fibers showed highest IB strength of all panels prepared. UF-bonded MDF panels showed poor dimensional stability. In conclusion, the present study showed that wood-fiber characteristics such as fiber length, bulk density, and acidity affect the performance of MDF boards, and also suggested that fiber characteristics be considered for MDF panel manufacture.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.83-91
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• 2011

Hemicelluloses are useful materials for papermaking and other biotechnological applications. To recover and further utilize the hemicelluloses, this study carried out the pre-extraction of the hemicelluloses from Korean mixed hardwoods chips using hot water and sodium hydroxide solution at various temperature and time conditions. Through the hot water pre-extraction, the wood components of 22% was extracted and the 35% of the hemicelluloses which were contained in the original wood chips were dissolved into the pre-extractives. The yield of the pre-extractives was more significantly influenced by the pre-extraction temperature than the time. The pre-extractives with the yield of 30% could be obtained by alkali pre-extraction and alkali concentration was the most important factor. It had lower hemicellulose content but high molecular weight, compared with the hot water pre-extractives.

• Journal of Korea Foresty Energy
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• v.23 no.1
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• pp.26-37
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• 2004

This study was to investigate the rational propagation of the Vitex rotundifolia, which is distributed as a community naturally at coastal area in Korea. The germination rate of ordinary temperature stored fruits was the highest with 67%. In the matter of the number of seedlings per fruit, 1 seed germinated fruit was the most with 40.3 % and the mean was 1.4 seedlings per fruit. The best rooting rate of both greenwood and hardwood cutting was 96.7% in the case of cuttings soaked in IBA 2500ppm for 1 minute on the Compost+Sand bed-soils. Generally the root development of cuttings was higher in the high IBA concentration with soaking in a moment than in the low IBA concentration with soaking in long time, and bed-soils mixed with sands and composts. And in the rooting rate, greenwood cutting was better about 10% than hardwood cutting of Vitex rotundifolia.

• Journal of the Korean Wood Science and Technology
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• v.51 no.1
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• pp.38-48
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• 2023

Two important steps in utilizing technical kraft lignin (KL) from black liquor to synthesize lignin-phenol-formaldehyde (LPF) resin are its extraction via precipitation and fractionation. However, the effects of precipitation pH and acetone fractionation on the characteristics of hardwood KL have not been studied for LPF resins. Therefore, this paper reports the effects of the precipitation pH of black liquor and acetone fractionation on the characteristics of KL from mixed hardwood species for LPF resins. The precipitation was conducted at various pH levels from 3 to 9 of black liquor to obtain crude KL (C-KL), which was used in acetone fractionation to produce acetone-soluble KL (AS-KL) and acetone-insoluble KL (AI-KL). Precipitation at pH 3 and 9 produced the highest and lowest yields of C-KL, respectively. As expected, the C-KL infrared spectra were similar regardless of the precipitation pH levels. As the pH increased, the molecular weight of C-KL increased. However, the molecular weight of AS-KL and AI-KL after acetone fractionation increased to a maximum of 4,170 and 47,190 g/mol at pH 7, then decreased to 3,210 and 19,970 g/mol at pH 9, respectively. The smallest molecular weights of AS-KL and AI-KL were 3,210 and 15,480 g/mol and were found at pH 9 and 3, respectively. These results suggest that both AS-KL at pH 9 and AI-KL at pH 3 have good potential as starting lignins for synthesizing LPF resins that require cross-linking for polymerization.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.4
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• pp.93-97
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• 1999

Tobacco stalks are greatly produced as annual agricultural wastes. These residues are available approximately 70,000 tons per year. This study was performed to evaluate the potentials of tobacco stalks as a new resource for reconstituent tobacco sheet. Tobacco stalk was more lignified than cereal straws, and had similar chemical constituents to hardwood. Pulping yields by cooling at 170$^{\circ}C$ of dry and green tobacco stalks were 56.7% and 66.3% , respectively. Around 50$^{\circ}$SR freeness level of mixed pulp was adjusted by mixing more than 10% chemical pulp9CP) in the case of dry tobacco stalk and more than 15% CP with wet one. By immersing this handsheet in extracted cooking liquors, reconsitutent sheet contained about 0.28% of nicotines could be prepared. This sheet had enough strength properties for cigarette paper making . In conclusion, it was proved that tobacco stalk could be used to produce the reconstituent tobacco sheet.