• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.106-112
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• 2011

The effects of alkaline treatment on the WRV, crystalline structure and sheet structure of softwood and hardwood bleached kraft pulp were investigated. Sodium hydroxide and sodium carbonate were used as chemicals for alkaline treatment and two levels of alkali dosage (5%, 10%) were applied respectively. Alkali treated and untreated pulp were refined to three levels (550, 450 and 350 mL CSF). WRV of the alkali treated pulps depended on the alkaline type and concentration. It was found that the crystalline structures of softwood and hardwood pulp were not changed by refining. Sodium carbonate and lower concentration of sodium hydroxide treatment did not caused any modification of cellulose crystalline structure, while higher concentration of sodium hydroxide treatment caused the partial modification of cellulose crystalline structure. Alkaline treatment of hardwood bleached kraft pulp led to the shrinkage of fiber diameter and bulky structure of sheet. Alkaline treatment of softwood bleached kraft pulp did not cause the significant change in fiber shrinkage and bulk of sheet.

• The Korean Journal of Ecology
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• v.18 no.1
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• pp.99-108
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• 1995

Deciduous hardwood communities were ecologically analyzed in order to determine their distributional characteristics. The quadrats were sampled in Mt. Chiri, Mt. Deokyu, Mt. Kyeryong, Mt. Sokri, and Mt. Jungwang, and their environmental factors including topographical features as well as soil properties were investigated. The computer program TWINSPAN and CANOCO were used to elucidate the relationship between environmental factors and species composition. In the relations of communities and environmental factors, the optimal ecological habitats of Carpinus tschonoskii community could be the sites at low latitudes such as the regions of southern part of Korea in which total nitrogen and organic matters are rich, while those of Fraxinus mandshurica community, Acer mono community, and Betula costata community could be the sites which are wet and have high total nitrogen and organic matters in soil. The quercus mongolica community is distributed widely throughout Korea, and its ecological habitats could be the sites which have high soil nutrient and moderate soil moisture in central and northern parts of Korea, while those of Quercus variabilis community could be the sites which is dry and have high Mg and C.E.C. value.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.111-122
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• 2013

The steam explosion-chemical pretreatment is a more effective wood pretreatment technique than the conventional physical pretreatment by accelerating reactions during the pretreatment process. In this paper, two-stage pretreatment processes of hardwood were investigated for its enzymatic hydrolysis and the succinic acid yield from the pretreated solid. The first stage pretreatment was performed under conditions of low severity to optimize the amount of solid recovery. In the second stage pretreatment washed solid material from the first stage pretreatment step was impregnated again with chemical (alkaline or chlorine-based chemicals) to remove a portion of the lignin, and to make the cellulose more accessible to enzymatic attack. The effects of pretreatment were assessed by enzymatic hydrolysis and fermentation, after the two stage pretreatments. Maximum succinic acid yield (16.1 g $L^{-1}$ and 77.5%) was obtained when the two stage pretreatments were performed at steam explosion -3% KOH.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.405-413
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• 2015

We classified the streamside plant community by phyto-sociological method and analyzed the relationship between environment factors and vegetation structure by using the classification and ordination method. We found that twenty one plant communities were classified according to dominant species at the natural streamside valley forest with surveying the 65 quadrats (10 m × 10 m). From the survey results, the hardwood plant communities were classified as streamside valley forest and the softwood plant communities as riparian forest according to the degree of flooding. The valley forest had a distribution of 17 plant communities which was 65% (42 quadrats) of 65 quadrats: Maackia amurensis community, Betula davurica community, Quercus variabilis community, Pinus densiflora community, Q. serrata community, Prunus sargentii community, and Meliosma oldhamii community etc. The riparian forest had a distribution of four plant communities which was 35% (23 quadrats) of 65 quadrats: Salix koreensis community, S. rorida community, S. purpurea var. japonica community, and S. glandulosa community, etc. From the two-way indicator species analysis (TWINSPAN) analysis, we found indicator species Oplismenus undulatifolius and Lindera obtusiloba for the streamside valley forest and Humulus japonicus, Phragmites japonica, and S. koreensis for the riparian forest. From the results of the canonical correspondence analysis (CCA), coordinates, altitude, and stream structure showed low correlation to the distribution of the plant community. Therefore, it seemed that valley forest and riparian forest were distinguished by the stream gradient and waterway width which determined by the stream water level.

• Journal of the Korean Wood Science and Technology
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• v.20 no.3
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• pp.67-78
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• 1992

The application of white-rot fungi to pulping and bleaching processes has been studied at the Wood Chemistry Laboratory in Kyushu University, cooperatively with the Biotechnology Laboratory of Kobe Steel, Ltd. Some successful results of the studies for a biomechanical pulping process, biobleaching of hardwood and softwood kraft pulp, as well as chlorine free biobleaching of oxygen-prebleached hardwood kraft pulp are dealt with. Biological treatment of the pulp bleaching effluent is also described.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.541-554
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• 1999

The objectives of this study were to examine the amount of nutrient input by throughfall and stemflow, and the nutrient dynamics by throughfall, stemflow and soil solution among Piuns koraiensis, Larix leptolepis and hardwood forests including oaks at Kwangju-Gun, Kyonggi-Do. A total amount of rainfall during the study period was 1410.1mm. Of the total rainfall, 85% was from throughfall at the L. leptolepis stand, 84.5% at the thinned P. koraiensis stand, 83.2% at the unthinned P. koraiensu stand and 81.2% at the hardwood stand, showing greater throughfall at the conifer stand than at the hardwood stand. Stemflow showed 2.7% of rainfall at the hardwood stand, 1.3% at the unthinned P. koraiensis stand, 1.2% at the thinned P. koraiensis stand and 0.8% at the L. leptolepis stand, showing greater stemflow at the hardwood stand than at the conifer stand. Ion concentration of stemflow was greater than those of rainfall and throughfall. The conifer stand showed higher ion concentration than the hardwood stand both for cation and anion. The ion concentrations of throughfall and stemflow were higher in the descending order : $NH{_4}^+$-N > $K^+$ > $K^+$ > $Na^+$ > $Mg^{2+}$ for cations and $SO{_4}^{2-}$ > $NO{_3}^-$-N > $Cl^-$-N for anions. After the precipitation passed through the canopy, $K^+$ increased most at the hardwood stand, whereas $NH{_4}^+$-N did most at the P. koraiensis and L. leptolepis stands. The ion concentration of soil solution was higher in the descending order : $Ca^{2+}$ > $Mg^{2+}$ > $Na^+$ for cations and $NO{_3}^-$-N > $Cl^-$ > $SO{_4}^{2-}$ for anions. $NH{_4}^+$-N and $K^+$ seemed to be supplied primarily from atmospheric deposition while $Ca^{2+}$, $Mg^{2+}$ and $Na^+$ from weathering.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.343-356
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• 2010

Plant micropropagation techniques include bud cultures using apical or axillary buds, organogenesis through callus culture or adventitious bud induction, and somatic embryogenesis. In Korea Forest Research Institute (KFRI), the first tissue culture trial in woody plant was initiated from the bud culture of hybrid poplars (Populus alba x P. glandulosa) in 1978. Since then several mass propagation techniques have developed from conifer and hardwood species, resulting in allowing practical application to Poplars, Birches and some oak species. In addition, useful micropropagation and genetic resources conservation techniques were established in some rare and endangered tree species including Abeliophyllum distichum. Among various in vitro propagation techniques, somatic embryogenesis is known to be the most efficient plant regeneration system. Since the first somatic embryo induction was reported in Tilia amurensis by KFRI in 1986, various protocols for direct or indirect somatic embryogenesis systems have developed in conifer and hardwood species including Larix leptolepis, Pinus rigida x P. taeda F1, Kalopanax septemlobus and Liliodendron tulipifera, etc. However, most of these technologies have been developed using juvenile tissues, i.e. immature zygotic embryos or mature embryos. Therefore it has been difficult to directly application to tree breeding program due to their unproven genetic background. Recently remarkable progresses and new approaches have been achieved in mature tree somatic embryogenesis. In this article we reviewed several micropropagation techniques, which have been mainly developed by KFRI and recent international progresses.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.4
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• pp.64-70
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• 2010

In this study, hemicelluloses were pre-extracted from mixed hardwood chips using sodium hydroxide solution and then they were isolated from pre-extractives by using various solvents. Isolation was conducted by precipitating hemicelluloses with isopropanol, ethanol, 1,4-dioxane, dimethylsulfoxide (DMSO) and potassium hydroxide (KOH), respectively. The precipitate yield on alkali pre-extractives was the highest when hemicelluloses were isolated by DMSO and then precipitated with ethanol. Most precipitates were yellow colored. The efficiency of isolation was evaluated by analysing the characteristics of isolated hemicelluloses. Isolation using DMSO, KOH and 1,4-dioxane ($80^{\circ}C$) showed rather high efficiency. The highest total separation efficiency was about 77% when alkali pre-extractives were reacted with KOH and precipitated with ethanol. The quantity and purity of isolated hemicelluloses were affected by the solvent type.

• Journal of the Korean Wood Science and Technology
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• v.38 no.5
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• pp.391-398
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• 2010

In this study, the figure of domestic hardwood was observed using the naked eye and the possibility of substituting imported wood with domestic one in the making woodcraft or furniture was investigated. It was known from the investigation on 8 different hardwoods that there were various figures such as cloud-shaped figure, blister figure, crotch figure, bird's eye figure, etc. in Zelkova serrata wood and the beautiful pigment figure in Diospyros Kaki wood. There were the unusual figures such as wavy grain figure, fiddle back figure, etc. in Cedrela sinensis wood and was clear ray-fleck figure in Quercus variabilis wood. There were also various figures such as wavy grain figure, blister figure, pigment figure, etc. in Sophra japonica, Tilia amurensis, Castanea crenata, Kalopanax septemlobus wood, etc. It is thus that distinguished figures appeared in each kind of wood can be used for craft, sculpture, furniture, and interior material. These kinds of figures can also be used for instrument, toy, stationery, life article material and souvenir, etc. And it can be expected that they will replace the imported wood has been mainly used to make the woodcraft or furniture until now.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2005.09a
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• pp.41-44
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• 2005