• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.30-37
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• 2001

The effects of enzymatic treatment of recycled fiber were investigated to obtain the basic informations which can be used to improve the papermaking properties of recycled fiber. The recycled fibers were prepared by the repeated handsheet making and disintegrating of hardwood of hardwood and softwood kraft pulp. Novozym 342, Dinimax and Pulpzyme HC were used for enzymatic treatment. The change of fiber length distribution, freeness, contact angle and crystallinity of pulp were measured. The brightness, opacity, breaking and tear index of paper were also measured. The enzymatic treatment decreased long fiber fraction of recycled hardwood fiber, but increased long fiber fraction of recycled softwood fiber. Freeness was decreased with 0.1% enzyme and then increased again with the increase of th enzyme dosage. The improvement of flexibility of recycled fiber was obtained through the decrease of contact angle that is resulted from the decrease of crystallinity of fiber. Brightness and opacity were affected by the type of pulp and enzyme, and dosage of enzyme. Breaking length of recycled hardwood fiber was improved with enzyme treatment, but breaking length of recycled softwood fiber was decreased except for 0.01% Pulpzyme treatment. Tear index was decreased with enzymatic treatment and the lowest decrease was observed with the treatment to Pulpzyme.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.5
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• pp.20-25
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• 2009

Residual extractives had a noticeable impact on the brightness of unbleached hardwood kraft pulps (trembling aspen). The brightness-impacting extractives were effectively removed by oxygen delignification. In addition, oxygen delignification was more effective in removing chromophores in hardwood unbleached kraft pulps than in those of softwood (loblolly pine). The residual extractives in unbleached hardwood kraft pulps also affected the pulp color, primarily redness and the L value. These redness-related extractives in unbleached hardwood kraft pulps were also effectively removed by oxygen delignification. There were no significant color differences between untreated and solvent-extracted oxygen-delignified aspen kraft pulps. The residual extractives in unbleached and oxygen-delignified softwood (loblolly pine) kraft pulps did not have a significant impact on either brightness or pulp color.

• Korean Journal of Medicinal Crop Science
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• v.6 no.4
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• pp.251-257
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• 1998

This experiment was carried out to establish cutting propagation method of dendropanax morbifera $L_{EV}\$. at Wando in Chonnam, native area. The hardwood cutting and the greenwood cutting were able to be used as propagation method, but callus formation and rooting ratio in the greenwood cutting were higher than in hardwood cutting. The optimum cutting time was February to middle of March in hardwood cutting and July to August in greenwood cutting. The earthen-ball cutting method was better than normal cutting method in callus formation and rooting ratio. The rooting in different bed soils was the best at sand-loam soil. The application of IBA 100ppm promoted rooting.

• Journal of Korea Foresty Energy
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• v.21 no.2
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• pp.69-76
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• 2002

To collect the basic data for the use of major softwood and hardwood vinegar, the chemical compositions were analized. In softwood vinegar the phenolic compounds derieved from lignin and extractives are vanillin, guaiacol, 3-methylphenol, acetoguaiacone, 1,2-benzenediol, ethylguaiacol, pyrocatechol. The compound derived from carbohydrates is 2-hydroxy-3-methyl-2-cyclopenten-1-one. The isolated compounds are the most in the phenolic fraction, and in the vinegar of Pinus koraiensis. In hardwood vingar 2-methoxyphenol, 2,6-djmethoxyphenol, 1-(4-hydroxy-3-methoxyphenyl) -ethanone, 3-methoxy-4-hydroxybenzylalcohol, 1-(4-hydroxy-3,5-dimethoxy-phenyl)-ethanone are the compounds derived from lignin and extractives. 2-hydroxy-3-methyl-2,4-cyclopen-1-one, methyl-4-t-butyl-2-furoate are the major compounds derived from the decomposition of carbohydrates. Many different kinds of compounds are analized in the neutral, phenolic and acidic fraction of hardwood vinegar The amount and kinds of compounds in hardwood vinegar are more higher than those of softwood than in softwood.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.57-69
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• 2022

This study analyzes the fuel conditions and environmental effects of converting heating in rural villages that rely on fossil fuels into wood fuel. In particular, we tried to derive the most important considerations when using wooden chips as fuel in aging agricultural villages where various variables such as weather, facility characteristics, fuel quality, and maintenance capabilities work. Above all, an experiment was conducted by comparing it with oak trees to determine whether Italian poplar, a representative attribute water created to supply fuel wood in Korea, is suitable for heating fuel. Through experiments, 1) Even though the supply of poplar wood chips during 10 hours of operation was 60.74 kg less than that of hardwood chips, the production of hot water was 140 kWh higher. 2) The higher the exhaust gas temperature, the proportional (increase) oxygen concentration and inversely (decrease) PM and CO emissions. 3) Poplar has twice as much ash content as hardwood and three times more fine dust has been detected, but it meets all the standards for wood quality at the Korea Forest Science Institute. 4) Under the condition that there is a difference in water content (7.7%), hardwood cost 1.13 times more wood chips per 1 MWh than poplar, and even if the water content is corrected equally, hardwood cost 1.05 times more per 1 MWh than poplar. 5) In conclusion, it was proved that the fuel possibility, economic possibility, and environmental possibility of poplar wood chips are sufficient.

• Journal of Institute of Convergence Technology
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• v.2 no.2
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• pp.59-65
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• 2012

This paper presents the study on applications of a surplus heat source. The heat is generated while hardwood charcoals are produced. We measure the temperature of the generated heat and analyze whether it can heat water or not. The analytic results show that the generated heat is useful as one of heat sources. In agricultural methods using a vinyl house, heating expenses will be saved by 10~20% when the surplus heat source is used.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.37-42
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• 2003

Physical properties of paper can be explained in terms of the changes in fiber's morphological properties. As the paper machine speed increases, the basis weight decreases and the mixing ratio of inferior recycled fibers increases, paper break becomes important than ever before. One of the objectives of this study is to analyze paper's physical, mechanical and fracture mechanical properties depending on softwood(SW) and hardwood(HW) mixing ratios and recycling. Fibers were refined by Valley beater to 450 mL CSF. Handsheets of 30 g/$\textrm{m}^2$ were prepared at different mixing ratios. Fracture toughness was measured as the amount of energy applied to cracked sample before total failure. Fracture toughness showed different trend to other strength properties. At the mixing ratio of SW 80: HW 20, papers showed the maximum fracture toughness. At this mixing ratio, flexible softwood fibers were mostly broken and stiff hardwood fibers were mostly pulled out.

• The Korean Journal of Ecology
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• v.26 no.6
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• pp.335-340
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• 2003

Patterns of mass loss and nutrient release from decomposing oak (Quercus mongolica) and mixed litters (Q. mongolica, Betula schmidtii, Acer pseudo-sieboldianum, Kalopanx pictus and Tilia amurensis) in a natural hardwood forest in Gyebangsan (Mt.) were examined using litterbags placed on the forest floor for 869 days. Mass loss rates from decomposing litter were consistently higher in mixed litter (59%) than in oak litter types (52%) during the study period. Nutrient concentrations such as nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg) from decomposing litter were also higher in mixed litter than in oak litter types. Nutrient concentrations (N, P, Ca, and Mg) increased compared with initial concentration of litter, while K concentrations dropped rapidly at the first 5 months and then stabilized. The results suggest that mas loss and nutrient release obtained from decomposing litter of single species in mixed hardwood forest ecosystem should be applied with caution because of the potential differences of mass loss and nutrient release between single litter and mixed litter types.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.203-208
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• 2006

This study compared the roundwood demand prediction accuracy of econometric and time-series models using Korean data. The roundwood was divided into softwood and hardwood by species. The econometric model of roundwood demand was specified with four explanatory variables; own price, substitute price, gross domestic product, dummy. The time-series model was specified with lagged endogenous variable. The dummy variable reflected the abrupt decrease in roundwood demand in the late 1990's in the case of softwood roundwood, and the boom of plywood export in the late 1970's in the case of hardwood roundwood. On the other hand, the prediction accuracy was estimated on the basis of Residual Mean Square Errors(RMSE). The results showed that the softwood roundwood demand prediction can be performed more accurately by econometric model than by time-series model. However, the hardwood roundwood demand prediction accuracy was similar in the case of using econometric and time-series model.

• Korean Journal of Plant Resources
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• v.21 no.3
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• pp.222-225
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• 2008

Chemical composition and enzymatic saccharification characteristics of hemp woody core were investigated by their chemical composition analysis and enzymatic saccharification with commercially available cellulases (Celluclast 1.5L and Novozym 342). Hemp woody core have higher xylan and lower lignin contents than its bast fiber. Based on hemicelluloses and lignin composition, hemp woody core is similar with hardwood biomass. However, cellulose was more easily converted to glucose than xylan to xylose and this trend was confirmed both hemp woody core and yellow poplar. Hemp woody core biomass shows higher saccharification than yellow poplar (hardwood biomass) based on cellulose and xylan hydrolysis. With easier enzymatic saccharification in cellulose and xylan, and similar chemical composition, hemp woody core have better biorefinery feedstock characteristics than hardwood biomass.