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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Wood Science and Technology
Journal Basic Information
Journal DOI :
The Korean Society of Wood Science Technology
Editor in Chief :
Volume & Issues
Volume 43, Issue 6 - Nov 2015
Volume 43, Issue 5 - Sep 2015
Volume 43, Issue 4 - Jul 2015
Volume 43, Issue 3 - May 2015
Volume 43, Issue 2 - Mar 2015
Volume 43, Issue 1 - Jan 2015
Selecting the target year
Seasonal Change of Cambium Activity of Pine Trees at Different Growth Sites
Park, So-Yeon ; Eom, Chang-Deuk ; Seo, Jeong-Wook ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 411~420
DOI : 10.5658/WOOD.2015.43.4.411
Despite of the same species there is a difference in the tree shape and its wood property due to quantitatiVe and qualitatiVe differences in wood cells by the intra-annual cambial actiVity. The purpose of this study was to proVide the fundamental database of intra-annual cambial seasonal actiVity for red pine in Sokwang-ri and Anmyondo for the determination of their wood qualities. As the results of intra-annual cambial actiVity, the initiation of cambial actiVity of red pine in the plots with Age Class V in Sokwang-ri was in the middle of April and it was at the beginning of April in all plots in Anmyondo. Only the plots with Age Class IX in Sokwang-ri showed relatiVely late initiation of cambial actiVity as between middle of May and middle of June. Except one plot with Age Class IX in Sokwang-ri all plots in both sites showed the same cessation of cambial actiVity as between middle and end of October. According to intra-annual cambial actiVity, the duration of cambial actiVity in Sokwang-ri is shorter than that of Anmyondo. On the other hand, the number of cell diVision of cambial actiVity in Sokwang-ri was more than those of Anmyondo. We could establish the database for intra-annual cambial actiVity for Sokwang-ri and Anmyondo to estimate their wood quality.
Studies on Wood Quality and Growth of Quercus rubra in Korea - Anatomical Properties -
Han, Mu-Seok ; Lee, Jin-Ri ; Kim, Ji-Su ; Shin, Soo-Jeong ; Kim, Byung-Ro ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 421~428
DOI : 10.5658/WOOD.2015.43.4.421
This study was carried out to investigate the relationship between anatomical characteristics and growth rate of Quercus rubra from different origins of seed. Anatomical characteristics showed that all Quercus rubra species were ring-porous woods with 1~3 layers of large pores in earlywood, but the latewood had small pores oriented in radial direction. There were slight differences in libriform fiber length and vessel element diameter in the earlywood among different provenance origins of seeds. In growth rate, the libriform fiber length and vessel element diameter was negative correlation in the earlywood, but not correlative in the latewood, and vessel element length was not correlative in the early and latewood, Volumetric composition of libriform fiber and ray in latewood was higher than those in ear lywood, and a higher composition of vessel element was observed in earlywood. Ray height was the range of from 11 to 15 cells.
Investigation on the Physical Properties of Acetylated Domestic Softwoods
Lee, Won-Hee ; Hong, Seung-Hyun ; Kang, Ho-Yang ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 429~437
DOI : 10.5658/WOOD.2015.43.4.429
It has been known that acetylation improves the dimensional stability of wood. Liquid phase acetylation is more popular than gas-phase acetylation for the effectiveness of weight gain of wood. In this study domestic red and Korean pine specimens were liquid phase acetylated and their physical properties, such as density, bending strength, dimensional stability etc., were investigated. Acetylation increased the average weights of red and Korean pine specimens by 10.4% and 9.2%, respectively, and their average oven-dry densities were increased by 6.9% and 4.6%, respectively. Acetylation did not influence on modulus of rupture (MOR), modulus of elasticity (MOE) and dynamic MOE (DMOE). The average percentage reduction in hygroscopicity (PRH) of red and Korean pine specimens were respectively 20.6% and 13.8%, while the average percentage reduction in water soaking (PRW) were respectively 20.0% and 8.5%. Thus it can be concluded that the liquid acetylation improved the dimensional stability of red pine specimens more than that of Korean pine specimens.
The Color Change of Korean Pine Specimens Oil-Heat-Treated at 180 and 200℃
Lee, Won-Hee ; Lim, Ho-Mook ; Kang, Ho-Yang ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 438~445
DOI : 10.5658/WOOD.2015.43.4.438
Among several thermal wood modification methods German oil heating technology was applied to Korean pine specimens by heat treatment at
. In addition the matched specimens were heat-treated by Thermowood method. The heat-treated specimens were planed and their colors were measured with a colorimeter at 1 mm and 4 mm below the surfaces. The average lightness index (L*) of Oil-180 specimens was the largest followed by Oil-200 and Tmo-200 specimens. The average redness indexes (a*) of all specimens were increased by heat treatment, while the average yellowness indexes (b*) were variable. The average color differences (
) of Oil-200 and Tmo-200 specimens were above 30.0, while that of Oil-180 specimens was only 18.4. It can be concluded that the colors of the heat-teated specimens were uniformly changed because their average color difference indexes (
) between the inner layers were below 6.0.
Determination of Grades and Design Strengths of Machine Graded Lumber in Korea
Hong, Jung-Pyo ; Lee, Jun-Jae ; Park, Moon-Jae ; Yeo, Hwanmyeong ; Pang, Sung-Jun ; Kim, Chul-Ki ; Oh, Jung-Kwon ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 446~455
DOI : 10.5658/WOOD.2015.43.4.446
Based on comparative studies on standards and grading procedures of machine graded lumber in Korea and other countries, this study proposed a procedure of determining the grade classification and design strengths of domestic machine graded lumber. Differences between machine stress rated lumber and E-rated laminations were detailed in order to clarify the need for the procedure improvement. To this improvement the use of average MOE requirement for grading was introduced instead of the fixed minimum MOE requirement which is currently used in the Korean standards. It was found that the fixed minimum MOE requirement method was easier for an inspector to grade but, less efficient as a strength predictor than the average MOE requirement method. The advantage of average MOE requirement method is statistically MOR-MOE regression-based MOR prediction and highly efficient in quality control though it requires a computer-aided operation system in an initial setup. A major weakness of the current Korean grading system was found that different strength characteristics depending on wood species were not reflected on the grade classification and the tabulated allowable design stress. The proposed procedures were developed taking advantages of respective merits of both methods and based on MOR-MOE regression analysis. Through this procedure, the grades of machine stress rated lumber should be revised to become interchangeable with E-rated lamination, which would be beneficial to the cost competitiveness of domestic machine graded lumber and glued laminated timber industry.
Analysis of Allowable Stresses of Machine Graded Lumber in Korea
Hong, Jung-Pyo ; Oh, Jung-Kwon ; Park, Joo-Saeng ; Han, Yeon Jung ; Pang, Sung-Jun ; Kim, Chul-Ki ; Lee, Jun-Jae ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 456~462
DOI : 10.5658/WOOD.2015.43.4.456
365 pieces of domestic
Red pine structural lumber were machine graded conforming to a softwood structural lumber standard (KS F 3020). The allowable bending stresses calculated for each grade were compared with the values currently tabulated in the standard. Four calculation methods for lower
percentile bending stress were non-parametric estimation with 75% confidence level, 2-parameter and 3-parameter Weibull distribution fit, and bending modulus of rupture (MOR)-modulus of elasticity (MOE) regression based method. Only the data set of Grades E8, E9, and E10 were statistically eligible for the
percentile calculation. The MOR-MOE regression based method only was able to estimate the lower
percentile values theoretically for the full range of grades. The results showed that all allowable bending stresses calculated were lower than the design values tabulated in the standard. This implies that the current machine grading system has the pitfall of structural safety. Improvement in current machine grading system could be achieved by introducing the bending strength and stiffness combination grade system.
Performance Evaluation of Bending Strength of Curved Composite Glulams Made of Korean White Pine
Song, Yo-Jin ; Jung, Hong-Ju ; Lee, In-Hwan ; Hong, Soon-Il ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 463~469
DOI : 10.5658/WOOD.2015.43.4.463
In this study, to improve bending strength performance of Korean white pine, we made the curved composite glulam that was reinforced with glass fiber materials and larch lamina. Five types of Korean white pine curved glulams were made depending on whether they had been reinforced or not and how they had been reinforced. Type-A, reference specimen, was produced only with Korean white pine lamina, and Type-B was with larch lamina in the same thickness. Type-C was made by inserting a glass fiber cloth of textile shape between the each layer. Type-D was reinforced with two glass fiber cloths, which were placed inside and outside of the outermost lamina. Type-E was reinforced with GFRP sheet in the same way as Type-D. As a result of this bending strength test, the modulus of rupture (MOR) of Type-B, Type-C and Type-E were increased by 29%, 6%, and 48% in comparison with Type-A. However, MOR of Type-D was decreased by 2% in comparison with Type-A. In the failure modes, Type-A, Type-B and Type-C were totally fractured at the maximum load. However, load values of Type-D and Type-E decreased slowly because of reinforcement of fracture suppression, and the GFRP sheet (Type-E) had better reinforcing effect on compressive stress and tensile stress than the glass fiber cloth (Type-D).
Change of Dimensional Stability of Thermally Compressed Korean Pine (Pinus koraiensis Sieb. et Zucc.) Wood by Heat Treatment
Cho, Beom-Geun ; Hwang, Sung-Wook ; Kang, Ho-Yang ; Lee, Won-Hee ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 470~477
DOI : 10.5658/WOOD.2015.43.4.470
This study was carried out to investigate the change of dimensional stability of thermally compressed Korean pine (Pinus koraiensis Sieb. et Zucc.) wood by post heat treatment. Specific gravity of compressed wood was notably increased with thermal compression. In the compression set 50%, compressed Korean pine showed a specific gravity of 0.84. The amount of water absorption and swelling of thermally compressed Korean pine decreased with increasing temperature and time of the heat treatment. Set recovery also decreased with increasing temperature and time of heat treatment. Thermally compressed Korean pine that heat-treated in
for 24 hours showed a set recovery of 3.8%, whereas non-treated group showed 11.5%. Therefore, it was confirmed that the thermal treatment was a very effective method for the dimensional stability of the heat compressed wood.
Combustion Properties of Woods for Indoor Use (II)
Seo, Hyun Jeong ; Kang, Mee Ran ; Son, Dong Won ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 478~485
DOI : 10.5658/WOOD.2015.43.4.478
The aim of this study is to analyze the combustion and thermal properties in order to establish baseline data for the fire safety evaluation of domestic timbers. The combustion properties such as heat release rate, total heat release, gas yield, and mass loss were analyzed by the method of cone calorimeter test and thermogravimetry (TGA). Thermal decomposition temperatures of the specimens by TGA were recorded as
for White pine,
for Red-Leaved Hornbeam,
for Carolina poplar,
for Konara oak, and
Sargent cherry. Red-Leaved Hornbeam showed the highest value of heat release rate, but, Carolina poplar wood showed the lowest value. In case of the total heat release, Red-Leaved Hornbeam wood showed the highest value and Carolina poplar wood showed the lowest one. The gas analysis results showed that Sargent cherry wood had the lowest value of 0.021, and Konara oak had the highest at 0.031 in the
. The minimum value of mass reduction was recorded as 87.57% for Sargent cherry, but, on the other hand, it was 95.03% for Konara oak. There was a correlation between the gas generation of CO and
, and combustion behavior of woods. These results are expected to be usful for providing a fundamental guideline with the fire safety of wood use in interior applications.
Ultrasonic Nondestructive On-Site Evaluation of Decks in-Service
Oh, Sei-Chang ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 486~493
DOI : 10.5658/WOOD.2015.43.4.486
The ultrasonic nondestructive test (NDT) was applied to deck in-service to inspect and evaluate the performance of decking materials using ultrasonic pulse velocity. First, the measuring method between direct and indirect method according to transducer arrangement was studied. Second, the ultrasonic pulse velocity of decks in-service was compared with the passage of time. Finally, the change of ultrasonic pulse velocity was evaluated to expect service life of decking materials. The results of comparison between direct and indirect method was statistically insignificant and the ratio of direct to indirect method was 1.02. 1.05 respectively. The ultrasonic pulse velocity of decks in-service was decreased as the passage of time and the linear relationship in the ultrasonic pulse velocity to passage of time was found. From the results, The ultrasonic NDT will be helpful as an efficient method of on-site management of decks in-service.
Comparative Study on The Composition of Essential Oil by Supercritical Carbon Dioxide Extraction and Hydro-distillation from Chamaecyparis obtusa Leaves
Kim, Jae-Woo ; Choi, Won-Sil ; Lee, Sung-Suk ; Park, Mi-Jin ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 494~503
DOI : 10.5658/WOOD.2015.43.4.494
This study was focused on the comparison of the variations in the yield and chemical composition of Chamaecyparis obtusa leaf oil obtained under different pressure conditions of the supercritical carbon dioxide extraction (SCE), and by hydro-distillation. SCE was carried out varying the pressure in the range of 100~400 bar at
. The chemical composition of C. obtusa leaf oils was determined by gas chromatography-mass spectroscopy (GC-MS) analysis. The maximum yield of 4.4% (relative to the initial mass of oven dry mass) was obtained in the extraction under 300 bar pressure, which was higher than that of the hydro-distillation method (1.9%). The contents of sesquiterpenes in the extracts obtained by the SCE were higher than those of the essential oils of C. obtusa by the hydro-distillation. The sesquiterpenes in the SCE extracts made up approximately 39%~46% of the total, followed by monoterpenes, diterpene, and lignan. The contents of each constituent in the supercritical carbon dioxide extracts were varied on the extraction pressure. Therefore, these results showed that the extraction condition of SCE had significant effect on the yield of C. obtusa oils and its chemical composition.
Evaluation of Soil Contamination by Copper Depleted from ACQ-Treated Wood
Ra, Jong-Bum ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 504~510
DOI : 10.5658/WOOD.2015.43.4.504
This research was performed to evaluate soil contamination caused by copper depleted from ACQ-treated wood. Three years after the exposure of ACQ-treated wood in the field test sites, soil samples around the treated wood were collected and analyzed for the copper amount and distribution through soil. Soils around the deck posts installed in five different neighborhood parks located in Chonnam and Gyeongnam were investigated for copper contents. The results of the field test showed that the amount of copper leached from the end surface of treated wood buried under soil was more than 1.5 times the copper amount leached from the lateral surfaces, and the mobility of copper was very restricted in soil. The copper contents of soil within 10 cm from the treated deck posts installed in the parks showed to be less than 500 mg/kg, which are the limit values of the 2nd region set up by enforcement regulation of soil environment conservation act. The distribution ranges of copper in soil from the treated wood set up in the field test sites seemed to be much wider than those from deck posts, which may explained by the fact that the retentions of the treated samples used in the field test sites were much higher than those of the deck posts.
Effect of Flame Resistant Treatment on The Sound Absorption Capability of Sawdust-mandarin Peel Composite Particleboard
Kang, Chunwon ; Jin, Taiquan ; Kang, Ho-Yang ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 511~517
DOI : 10.5658/WOOD.2015.43.4.511
Sound absorption capability of the flame resistant treated sawdust-mandarin peel composite particleboard was were estimated by two microphone transfer function methods. The weight of flame resistant treated board slightly increased by the treatment. The treatment improved fire retardant performance by decreasing the charred area of flame resistant treated board. Sound absorption capabilities of flame resistant treated sawdust-mandarin peel composite particleboard, in the entire estimated frequency range of 500-6,400 Hz was slightly lower than those of the control specimen. Sound absorption capability of both the control and flame resistant treated sawdust-mandarin peel composite particleboards were higher than that of commercial gypsum boards, being widely used as a sound absorber for ceiling at the estimated frequency.
Fundamental Properties of Electrospun Polylactic Acid/Cellulose Nanocrystal Composite Mats
Jo, Yu-Jeong ; Lee, Sun-Young ; Chun, Sang-Jin ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 518~527
DOI : 10.5658/WOOD.2015.43.4.518
In this study, nanocomposite mats consisting of cellulose nanocrystals (CNCs) and poly(lactic acide) (PLA) were electrospun from a suspension mixture consisting of tetrahydrofuran at room temperature. Morphology study showed that fibers of electrospun composite mats were aligned in three dimensional surface along the fiber long-axis. Average diameter of the electrospun fibers decreased with an increase in the CNC loading level. Tensile strength of the electrospun fibers mat decreased with an increase in the CNC loading level because of bead formation in the formed fibers and low interfacial bond strength between PLA and CNC. Meanwhile, thermal stability of the electrospun nanocomposite mats was effectively improved as the amount of CNC increased.
Utilization of Waste Bone Powders as Adhesive Fillers for Plywood
Ko, Jae Ho ; Roh, JeongKwan ;
Journal of the Korean Wood Science and Technology, volume 43, issue 4, 2015, Pages 528~537
DOI : 10.5658/WOOD.2015.43.4.528
To reuse the waste bone from restaurants or butcher houses, the possibility of using waste bone powder after cooking as a filler for wood adhesives used in manufacturing plywood was investigated. Radiata pine (Pinus radiata D. Don) plywoods were manufactured by using commonly used wood adhesives such as urea-melamine formaldehyde (UMF) resin, urea-formaldehyde (UF) resin, and phenol-formaldehyde (PF) resin and the prepared fillers from cattle bone powder, pig bone powder, and seashell powder. Plywood fabricated by using cattle bone powder, pig bone powder, and seashell powder showed weaker performance in dry and wet glue-joint shear strength and wood failure than those of the plywood with wheat flour. The result showed that it was hard to use only bone powder for the replacement of wheat flour. However, the filler mixed with wheat flour and bone powders showed equivalent dry bonding strength and better water resistance than the wheat flour, indicating that bone powders mixed with wheat flour might be used for the manufacture of plywood. When bone powders were mixed with wheat flour as adhesive fillers the shell powder showed the lowest bonding properties and there was no big difference between the cattle bone powder and the pig bone powder.