• Journal of the Korean Wood Science and Technology
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• v.40 no.2
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• pp.123-132
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• 2012

Pre-pulping extracts were found to contain a dilute amount of xylo-oligosaccharides and acetic acid as the major components, and many minor components including other organic acids, lignin-derived phenolics, and sugar degradation products. Once separated from the pulp, a secondary hydrolysis step was required to hydrolyze oligomeric hemicellulose sugars into monomeric sugars before fermentation. The following study detailed the extent of hemicellulose recovery by pre-pulping using hot water extraction and characterized the hydrolysis of the extract with respect to comparing acid and enzymatic hydrolysis. The secondaryhydrolysis of hot water extracts made at an H-Factor of 800 was tested for a variety of acid and enzyme loading levels using the sulfuric acid and xylanases. The maximum fermentable sugar yield from acid and enzyme hydrolysis of the extract was 18.7 g/${\ell}$ and 17.7 g/${\ell}$ representing 84.6% and 80.1% of the maximum possible yield, respectively.

• Journal of Korea Foresty Energy
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• v.18 no.2
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• pp.70-77
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• 1999

The behaviors of alkali swelling in four major Korean woods were examined as a function of concentration cf alkali solution. Density of alkali-treated woods increased highly with increasing alkali concentration in both softwoods and hardwoods. Wood samples swelled in dimension during alkali swelling, and thereafter they shrank highly by water washing and air drying. The air-dried wood samples after alkali treatment showed almost isotropic shrinkage in tangential and radial direction.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.432-436
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• 1995

Perforated ray cells are recorded for the first time in the Korean hardwoods of Rosa multiflora, Rosa multiflora var. platyphylla, Rosa rugosa, Spiraea cantoniensis, and Stephanandra incisa belonging to the family Rosaceae. The perforated ray cells have simple perforations, which are identical with the types of perforation plates in the vessel elements of same wood.

• Journal of the Korea Furniture Society
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• v.10 no.1
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• pp.23-32
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• 1999

The ultrastructural characteristics of shear fracture surfaces of laminated wood prepared from major four Korea wood specimens were examined. Commercial urea and urethan resin were used as adhesives for laminated woods of both homospecies and heterospecies. The morphology of fracture surface was observed using an optical microscopy and scanning electron microscopy. Three anatomical failure types were recognized : intercell failure, intrawall failure and transwall failure. In dry specimen, failure occurred mainly in woods. Laminated woods of softwoods showed mostly intrawall failure and transwall failure of tracheids, and them of hardwoods indicated mainly intrawall failure and interwall failure. Laminated woods prepared with urethan resin showed coarse fracture surface, on the other hand, those prepared with an urea formaldehyde resin had clean surface. In wet specimen, failure occurred dominantly in glue line. Intrawall failure and flags were characterized in laminated wood prepared with urethan resin. In heterospecies laminated woods, failure was occurred mainly in softwood. Consequently, fracture morphology of laminated wood may be influenced by adhesives, moisture content, species and anatomical characteristics.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.221-224
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• 2008

We made densified wood pellet by hemp woody core as replacing wood resource. Hemp was separated into the bast fiber and the woody core by hot steaming treatment. The hemp woody core had a similar lignin content and carbohydrate composition with hardwood. Also, the hemp had a low ash content, which resulted in a low ash formation in pellet burning. Heating value of the hemp pellet had a very similar to the pellet made by hardwoods. The hemp woody core can replace hardwood for densified wood pelletmaking.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.196-196
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• 1982

There is a heavy stocked wood volume in the forest of Kang-Won Province compared with the other forests of Korean Provinces. It mainly, however, consists of non-productive and inferior hardwoods and shrubs which grows naturally. -This naturally grown hardwood forest should be cut and reforested with more economical confierous and diciduous tree species by artificial and natural regeneration under the positive government support. This study was carried out to survey the reasonable and economical utilization measures on harvesting wood products when existing hardwood forest should be cut primarily. This is the rust report on the resources and the classification of tree species by the uses of wood growing in the hardwood forest of Kang-Won Province. According to the investigation, 321 hardwood species are growing in this forest, and 141 species of them are extremely not suitable for wood production. The usable species as fuel wood was 180, and these are able to classify into the 22 groups by the uses of wood.

• Journal of the Korean Wood Science and Technology
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• v.19 no.1
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• pp.6-13
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• 1991

Tests of notched specimens of ten hardwood species in the LR and LT systems were conducted to investigate fracture toughness($K_{IC}$) and effective moduli of elasticity(MOE). $K_{IC}$ values were examined in relation to MOR, MOE, specific gravity of clear wood specimens. It was found in both systems that there were significant relationship between $K_{IC}$ and MOR, $K_{IC}$ and specific gravity. To predict the effective MOE of notched specimen from MOE of clear wood, it was analyzed by using equvalent cross-section method. In LR system, the observed values were similar to the predicted values, but in LT system, both were not agreed as the ovserved values were smaller. However. the results were shown that this method was avaliable to predict the effective MOE of notched specimens.

• Journal of the Korean Wood Science and Technology
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• v.15 no.4
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• pp.1-11
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• 1987

한국산(韓國産) 활엽수재(潤葉樹材) 27과(科) 45속(屬) 82종(種)을 선정(選定)하여 이들 목부(木部)에 존재(存在)하는 결정(結晶)의 형태(形態) 및 분포(分布)를 조사(調査)함으로써 얻은 결과(結果)를 간단히 요약(要約)하면 다음과 같다. 1. 다면체형(多面體形)의 결정(結晶)이 가장 많이 관찰(觀察)되었으며 집정(集晶)도 종종 관찰(觀察)되었으나 주정(柱晶)은 극히 일부 수종(樹種)에서만 나타났다. 2. 이러한 결정(結晶)은 주로 축방향유조직(軸方向柔組織) 및 방사조직(放射組織)에 존재(存在)하였으며 수(髓), 타일로시스, 진정목섬유(眞正木纖維) 및 수반점(髓斑點)에서도 그 존재(存在)가 확인(確認)되었다. 3. 대부분의 결정세포(結晶細布)는 재분제(再分製) 및 확대(擴大)를 통하여 변형(變形)되므로써 결정(結晶)을 지니지 않은 세포(細胞)와 그 형태적(形態的)인 차이를 나타내었다.

• Journal of the Korean Wood Science and Technology
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• v.22 no.1
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• pp.66-71
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• 1994

To increase drying rate and reduce drying degradation, pretreatments such as prefreezing and presteaming have been widely used in wood industries. Presteaming lumbers prior to kiln drying is known positively to improve its permeability, to increase diffusion coefficient and to reduce discoloration, but negatively to increase collapse. Prefreezing lumbers prior to kiln drying is also known to reduce significantly its drying defects and its shrinkages. Thus it is no doubt that the pretreated lumbers shrink diversely from the untreated. In this study the shrinkage behaviors of the pretreated specimens are investigated by drying two tropical hardwoods (Apitong and Taun) in three different dying conditions: high temperature and slow drying rate (drying in a closed cylinder), high temperature and rapid drying rate (drying in an oven) and low temperature and slow drying rate(drying at room temperature). The prefrozen specimens show the least volumetric shrinkages in most drying conditions. The specimens dried in cylinders shrink most among all drying conditions. In general the pretreated specimens reached the 30 % moisture content faster than the untreated by about 30 %.

• Journal of the Korean Wood Science and Technology
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• v.26 no.2
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• pp.24-28
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• 1998

Ray cells with perforations are recorded for the first time in the Korean Celastraceae species of Euonymus sieboldiana and Tripterygium regelii and the Oleaceae species of Abeliophyllum distichum, Forsythia ovata, Ligustrum japonicum, and Osmanthus heterophylla, All these anomalous ray cells have simple perforations, and the vessel elements of all these species have simple perforation plates, Thus, in the Korean Celastraceae and Oleaceae, the perforations of ray cells appear to be identical with the types of perforation plates in the vessel elements of the same wood, The diagnostic value of the perforated ray cells is also discussed.