• Korean Journal of Plant Resources
• /
• v.23 no.4
• /
• pp.368-373
• /
• 2010

Juniperus chinensis var. sargentii Henry is a short and creeping evergreen shrub which reaches about 60 cm in height and only occurs in the northeast Asia and in the top of high mountains over the Korea. The Korea Forest Service protects it strictly by law since J. chinensis var. sargentii is an eccentric plant and possibly may be exterminated soon in Korea. This study was carried out to develop the propagation technique by cutting for conservation of genetic resources of J. chinensis var. sargentii. The rooting responses of branch cuttings, obtained from hard(May) and semi-hard wood shoots (August) to four growth regulators, namely, IAA, IBA, NAA and Rooton(exceptionally powder method) applied at various concentrations(0, 100, 200, 500, 1000 and 2000 $mgL^{-1}$) were examined in mixed soil media. Rooting rate showed significant difference between cutting times, among kinds and among concentrations of growth regulators. The optimum cutting time was April to May in hardwood cutting. The application of IBA 1000 $mgL^{-1}$(rooting rate : 36.4%) was most effective in callus formation and rooting of cutting. Relatively, rooting of cutting of the control taken in May was 30.4%. Root characteristics such as number, length and diameter of root were not significantly affected by kinds and concentrations of growth regulators in hardwood cutting.

• Korean Chemical Engineering Research
• /
• v.51 no.5
• /
• pp.561-567
• /
• 2013

Mixed hardwood chips were pre-pulping extracted with green liquor prior to kraft pulping in order to recover hemicelluloses for use as biofuels. This green liquor solution containing mainly sodium sulfide and sodium carbonate was applied at different alkali charges (expressed as $Na_2O$) of 0, 1, 3, and 5% on dry wood weight. The extractions were performed at $160^{\circ}C$ for residence times ranging from about 1-2 h to determine the effect of extraction severity on composition of the pre-pulping extract. The severity of hemicellulose extraction time and green liquor charge controls the concentration of acetic acid and monosaccharide sugars available for downstream processing, the accumulation of degradation products such as organic acids and furans in the extract. As the alkali charge was increased, the amount of acetate side chains on the hemicelluloses and the dissolved lignin in the extract increased but the carbohydrate and sugars in the extract decreased appreciably. Hot water extraction (0% alkali addition) released the greatest amount of carbohydrates, up to 29.80 g/L measured as component sugars, but resulted in the greatest decrease in pulp yield. Meanwhile, pre-pulping extraction with 3% green liquor increased the pulp yield while greatly reducing the component sugars to 7.08 g/L. Fundamental data obtained in this study will allow selection of optimum hemicellulose extraction conditions for integrating the extraction operation into the Kraft pulping process.

• Journal of the Korean Wood Science and Technology
• /
• v.45 no.5
• /
• pp.559-571
• /
• 2017

This study was conducted to determine the adhesive performances of plywoods affected by layering direction and the amounts of thermoplastic films. The face and back layers of veneer were hardwood species (Mixed light hardwood) and core layer veneer was radiata pine (Pinus radiata D. Don). Thermoplastic film used as adhesive were polypropylene (PP) film and polyethylene (PE) film. Thermal analysis and tensile strength were investigated on each films. As a result, the melting temperature of PP and PE films were $163.4^{\circ}C$ and $109.7^{\circ}C$, respectively, and the crystallization temperature were $98.9^{\circ}C$ and $93.6^{\circ}C$, respectively. Tensile strength and elongation of each films appeared higher on the width direction than length direction. Considering the characteristics of the thermoplastic films, the test for the amount of film used was carried out by layering film to the target thickness on veneer. The effecting of layering direction of film on plywood manufacturing was conducted by laminating in the length and width directions of the film according to the grain direction of veneer. Tensile-shear strength of plywood in wet condition was satisfied with the quality standard (0.7 MPa) of KS F 3101 when the film was used over 0.05 mm of PP film and over 0.10 mm of PE film. Tensile-shear strength of plywood after cyclic boiling exceeded the KS standard when PP film was used 0.20 mm thickness. Furthermore, higher bonding strength was observed on a plywood made with width direction of film according to grain direction of veneer than that of length direction of film. Based on microscopic analysis of the surface and bonding line of plywood, interlocking between veneers by penetration of a thermoplastic film into inner and cracks were observed.

• Journal of the Korea Furniture Society
• /
• v.18 no.4
• /
• pp.261-267
• /
• 2007

This report describes the wood anatomy and 1% safranine solution penetration depth in radial and longitudinal directions of Anthocephalus chinensis belonging to the family Rubiaceae native to Bangladesh. The wood of this species was mostly characterized by diffuse porous, vessel with simple perforation plate, vestured alternate intervessel pittings, relatively medium vessel elements and fiber, and nonseptate fiber with distinctly bordered pits at radial wall. The body ray cell was procumbent with 2 to over 4 rows of upright and square marginal cells. Sometimes, the rays with procumbent, square and upright cells were mixed. Latewood fiber was thin to thick walled while it was very thin walled in earlywood. Axial parenchyma was diffuse, vasicentric, 5-8 cells per parenchyma strand dominantly present. Liquid penetration depth was observed in radial and longitudinal directions at moisture level of 7.42%. Longitudinal penetration was found 6.3 times higher than radial penetration. The initial penetration rate of safranine solution was high, but gradually decreased during the course of time. Different anatomical features were found to be responsible for the variation of safranine solution penetration depth compared to Gmelina arborea.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.576-579
• /
• 2007

Timber inventory is a good starting point for developing strategies to effectively manage the timberland. In the sale of timberland, pricing is mostly based on this inventory. For a small timberland, inventory by conventional ground survey could be possible. In the case of large and nationwide business transactions, swift and inexpensive inventory is worth to be considered as the conventional methods require more experienced man power, money and time. In the present study, it was aimed to identify the chronicle of timberland such as changes that has occurred owing to silvicultural activities and by other means using the historical aerial photography and satellite data. Historical aerial photos from National Aerial Photography Program (NAPP), National High Altitude Photography (NHAP), Survey Photography and Landsat satellite data were used. Orthophotos were constructed using the DOQQ and DEM from USGS. Simple photo interpretation technique was employed to classify the orthophoto and satellite data. The plantation area was classified into softwood, mixed and hardwood. The timber age and the corresponding acreage details and the changes were also estimated. The result of this study could be more useful to the timberland buyers to better understand the chronicle of timberland of their interest prior to transactions.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.2
• /
• pp.172-182
• /
• 2014

Extraction is a necessary element in the bioconversion of lignocellulosics to fuels and chemicals. Although various forms of chemical pretreatment of cellulosic materials have been proposed, their effectiveness varies depending on the treatment conditions and substrate. In this study, mixed hardwood (MH) and loblolly pine (LP) were pretreated with dilute acid in a 100 mL accelerated solvent extraction (ASE) at the predetermined optimal conditions: temperature: $170^{\circ}C$, acid concentration: 0.5% (w/v), and reaction time: 2~64 min. This method was highly effective for extracting the hemicellulose fraction. Total xmg (defined as the sum of xylose, mannose, and galactose) can be extracted from milled MH and LP through pressurized dilute acid treatment in maximum yields of 12.6 g/L and 15.3 g/L, respectively, representing 60.5% and 70.4% of the maximum possible yields, respectively. The crystallinity index increased upon pretreatment, reflecting the removal of the amorphous portion of biomass. The crystalline structure of the cellulose in the biomass, however, was not changed by the ASE extraction process.

• Journal of the Korean Wood Science and Technology
• /
• v.48 no.5
• /
• pp.581-590
• /
• 2020

Pulp refining is the major way to alter the properties of fibers and formed paper. Different combinations of the bar profile of the rotor and stator during low consistency refining processes directly affect the properties of the paper. In this study, a mixture of softwood and hardwood pulp was refined by varying the bar angle of the stator while that of the rotor is fixed at 0º. The pulp samples were collected at different refining times. Then, the pulp and paper properties, such as beating degree, fiber external fibrillation, and tensile and tear indexes were measured to explore the effects of the combined refining plates at different bar angles on paper properties. The results of the experiment show that the combined refining plate of 0º and 5º recorded the most significant improvement in the pulp beating degree and fiber external fibrillation. This consequently increased the fiber bonding area, which in turn, improved both the tensile and the tear indexes of the paper. Also, the influence of the combined refining plates with a larger bar angle on the paper properties was weaker compared to that of smaller angles. This study not only provides ideas for the bar profile design but also improves the optimal selection of refining plates.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06b
• /
• pp.311-316
• /
• 2006

The role of short fibre pulp - Mixed Harwood, Eucalyptus, Aspen, Birch, etc for the manufacture of different grades of paper is very well recognized. At the same time, lots of efforts are in progress to maximize the advantages while preserving their own special property. Bleached Acacia Kraft Pulp (BAKP) is comparatively new entry but gained quick recognition. BAKP was introduced to the world market by South East Asian suppliers in the late 1990's. This paper discusses in detail the role and opportunities of use of short fibre pulps. A logical technical comparison has been made between BAKP and another short fibre grades. BAKP being a short, thin-walled fibre shows several similarities with Eucalyptus pulp in terms of good bulk and stiffness. Refining energy and strength properties are very similar, but the shorter fibres and thinner cell walls give an outstanding opacity and formation compared to other commercial short fibre pulps. The collapsed and band-shaped nature gives a matchless smoothness, enabling less calendaring and exceptional printing properties. BAKP is shown to give several advantages to fine paper manufactures, compared with a number of established short fibre pulps such as Brazilian and Chilean Eucalyptus, Canadian Aspen and Indonesian Mixed Hardwood. It is important to consider refining and calendaring conditions to achieve optimum performance. For outer layers of multiply board, Acacia gives excellent coverage due to its high opacity and uniform fibre distribution. Its low roughness property gives improved printability. For tissue products, Acacia gives unique property of superior softness both in terms of hand feel and bulk softness. The high fibre population gives an impression of much higher quality due to the higher opacity and good formation.

• Journal of Korean Society of Forest Science
• /
• v.95 no.4
• /
• pp.393-397
• /
• 2006

Thuja koraiensis Nak. is a short and creeping evergreen shrub which reaches about 3 m in height and only occurs in the northeast China and in high mountains over the Korea. It's designated as a rare and endangered tree species in Korea and DD (data deficient) in Red List Category & Criteria of IUCN. This study was carried out to develop the propagation technique by cutting for conservation of genetic resources of T. koraiensis. The rooting responses of branch cuttings, obtained from hard (May) and semi-hard wood shots (August) to three plant growth regulators (PGRs), namely, IAA, IBA, and NAA applied at various concentrations (0, 100, 500, 1000, 2000, and 3000 mg/l) were examined in sand and mixed soil media. Percentage of rooting showed significant difference between cutting time, among kinds and among concentration of PGRs. The optimum cutting time was April to May in hardwood cutting. The application of IAA 1000 mg/l and NAA 500mg/l were effective in callus formation and rooting of cutting. Relatively, rooting of cutting of the control taken in May was above 93%.

• Journal of Mushroom
• /
• v.2 no.2
• /
• pp.88-96
• /
• 2004

This study was executed to decide the physiological characteristics of Ferule mushroom. Four strains of Ferule mushroom were tested to select a superior strain in its mycelial growth. The pertinent substrates, temperature and pH ranges for the growth of selected strain were determined. And then, the wood rotting ability and type of the Ferule mushroom were determined. The superior strain F-2 among four strains was selected, on the basis of its vegetative mycelial growth and density on agar media. Mycelial growth of F-2 was the best on MYPA among other tested synthetic or semi-synthetic media. The temperature range for pertinent mycelial growth was about $25{\sim}34^{\circ}C$ and best at $30^{\circ}C$. The optimum pH range on MYPA was 5.0~6.0. The mycelial growth was mostly stimulated by soluble starch at cont. 1% (w/w) and secondly, maltose among several carabon sources and by mixed solution of YE(0.25%) and ME(0.25%) but not by ME alone. Cell thining and erosion of Pinus rigida wood by the mycelia of Ferule mushroom were found only on a few cell but largely at wood block test, indicating that the softwood rotting ability of Ferule mushroom mycelia was not so good. The result of polarized light microscopy appeared that cellulose of some tracheides showing the S3 layer lost brifringence was degraded by Ferule mushroom. But only part of cellulose of P. rigida wood was degraded by Ferule mushroom, because most of wood cells continued to showing briefingence. A largely degraded ray parenchyma and longitudinal parenchyma cell and partly thinning and erosion of hardwood(Quercus serrata) cell was found and it indicates that the rotting ability of Ferule mushroom mycelia on hardwood was higher than on softwood. It could be concluded that the difference in the wood rot by Ferule mushroom between the hardwood and softwood was made by the difference of chemical constitutions between them, especially in the contents and the types of lignin. Ferule mushroom was considered as white rotter as a result of bavendam test, although more research should be required.