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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 28, Issue 4 - Dec 2000
Volume 28, Issue 3 - Sep 2000
Volume 28, Issue 2 - Jun 2000
Volume 28, Issue 1 - Mar 2000
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A Study on Mechanical Properties of Strand/Particle Composites(I) - Effect of Layer Constructions -
Kim, Yu-Jung ; Shibusawa, Tatsuya ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 1~8
To develop the technology of producing structural board from low grade materials, an attempt was made to produce strand/particle composites from split wood strand(S) and particle(P) of (Cryptomeria japonica D. Don), which changed the layer construction and the ratio of S/P. The influence of layer construction on board properties was determined, focusing on the number and alignment of the S layers. The effect of weight ratio of S/P (3:7, 1:1, 7:3) on mechanical properties was also discussed on seven layered panel. Mechanical properties were determined from static bending tests to give parallel and perpendicular modulus of rupture (MOR) and modulus of elasticity (MOE), and the internal bond (IB) strength. In general, the surface strand layers contributed to the MOR and MOE. The parallel MOR and MOE values were the largest for the single layered S panel (only Slayers: S1), but the perpendicular MOR and MOE was the smallest. Perpendicular MOR and MOE were the largest for seven layered composite that had two cross oriented strand layers (SPSPSPS: SP7). Specimens retained more than half of their MOE and MOR after two hours in boiling water and one hour soaking. IB was the largest for the panel having only P layers, however, differences in IB strength were not identified among the other multi-layered composite panels thus the effect of layer construction on IB strength was small. Thickness swelling (TS) and surface roughness were smaller for the composite having P layers on the surface than for those having S layers. The addition of strands did not enhance the mechanical properties (MOR, MOE, IB). TS values for the panels, with which the S/P ratio was over than 1:1, was the similar to the value for the single layered S panels.
Study on the Optimum Pre-treatment Condition for Manufacture of Rice Hull Board
Lee, Hwa-Hyoung ; Han, Kie-Sun ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 9~13
Wood demand is increasing more and more, but world has been confronted with decreasing forest resources. Korea has to depend upon foreign wood and wood-based products for more than 95 percent of total domestic demand per year. In order to heighten self-sufficiency for wood supply and demand, we have to develop wood substitutes. Rice hull is the cheapest agricultural by-product we can get in Korea, more over the production of rice hull amounts to 1 million tons per year. This study was carried out to utilize rice hull and to decide the optimum condition of rice hull pretreatment for manufacture of rice hull board. Steam explosion method gave the best result, and the next boiling treatment of 1 hour, the last 1 hour treatment with 1% NaOH solution. Optimum conditions of explosion method were 20kgf/
minute and 25kgf/
minute. Rice hull board made with exploded rice hull met the KS standard(KS F 3104, 1997) and showed the same strength as a control, PB. And also the 1 hour boiling treatment was more effective than the 1 hour treatment with 1% NaOH solution.
Performance Evaluation of Softwood Plywood as Structural and Concrete-Form Panels
Lee, Jun-Jae ; Kim, Gwang-Chul ; Lee, Guk-Sik ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 14~24
In present research, the plywoods made of radiata pine or Japanese larch, the potential softwood species in mass supply, were discussed to examine their feasibility as the structural and concrete form panels through the basic properties test. First, plywood qualities and its nail performance were tested. The performance test for concrete form or structural panel by concentrated and uniformly distributed load were conducted to investigate the possibility as structural material for light frame and concrete constructions. Test results of basic quality such as specific gravity, cupping, bowing, and twisting appeared to satisfy the criteria for structural use. Also, nail performance test results, for roof and wall sheathing panels, nail lateral resistance, nail withdrawal resistance, and nail push head resistance proved to meet the required standard for structural use. The test results on performance as structural panel by concentrated and uniformly distributed load and as concrete form panel showed that these two species could be used for structural sheathing, subfloor, and concrete form panels.
Manufactures of Functional Materials by Using Xylan from Agricultural ＆ Forest Residues(I) - The Isolation and Purification of Xylan -
Byun, Ji-Hye ; Lim, Bu-Kug ; Yang, Jae-Kyung ; Chang, Jun-Pok ; Lee, Jong-Yoon ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 25~33
This study was carried out to find the optimal isolation conditions of xylan from steam-exploded materials, such as rice straw(Oryza sativa), barley straw(Hordeum vulgare) and oak wood(Quercus mongolica), In the chemical composition, we found that the contents of water-extractives and ash of rice straw and barley straw were more than those of oak wood. Rice straw, barley straw and oak wood were steam-exploded at 20kgf/
for 3 minutes or 6 minutes. The content of lignin in three different steam-exploded materials was higher than that of non-treated materials. The crude xylan was extracted with hot water and 0.5% KOH solution from steam-exploded materials. In the sugar type of crude xylan extracted with hot water and 0.5% KOH solution, the oligomer content of crude xylan extracted with hot water was much more than that of crude xylan extracted with 0.5% KOH solution. The crude xylan was purified with 5% barium hydroxide Solution and ethanol precipitation procedure. The content of xylose of purified xylan was over 85%, but other sugar residues(arabinose, mannose, galactose and glucose) were not removed completely.
Manufacture of Biodegradable Polymer with Wastepaper(I) - Pretreatment and Analysis of Chemical Components On Wastepaper -
Kwon, Ki-Hun ; Lim, Bu-Kug ; Yang, Jae-Kyung ; Chang, Jun-Pok ; Lee, Jong-Yoon ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 34~41
Recently many scientists have tried to synthesize biodegradable polymers due to durable and non-biodegradable products of conventional synthetic plastics when these were wasted in nature. So to reuse the wastepapers for biodegradable polymer resources, ONP (old newsprint), OCC (old corrugated containerbpard) were carried out by the pretreatment of chlorinite, hypochlorite and oxygen-alkali treatment conditions. For manufacturing of biodegradable polymer with wastepaper, this study performed to investigate change of chemical components and optimal pretreatment condition. The summarized results in this study were as follows: Lignin content in ONP and OCC was was higher than in MOW and ash content was the highest in MOW. More amount of ash components were reduced by wet defiberation than by dry defiberation. Wet defiberation fiber are better than dry defiberated fiber in chemical pretreatment condition for wastepapers, and the best result was obtained in the condition of sodium chlorite at
, because it has high delignification ratio,
-cellulose contents and degree of polymerization in this treatment condition. Oxygen-alkali treatment condition is the worst method because of low yield, low degree of polymerization in this pretreatments.
Antimicrobial Activity and Antioxidative Activity in the Extractives of Quercus dentata Thunberg
Kim, Min-Young ; Kim, Yun-Geun ; Kim, Tae-Hong ; Jo, Jong-Soo ; Yang, Jae-Kyung ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 42~51
Antimicrobial activity and antioxidative activity of the organosoluble extractives from the leaves, bark and xylem of Quercus dentata were investigated. Antimicrobial activity was tested by paper disk method and bioautography methods, The most pronounced antimicrobial activities of leaves parts were ethyl acetate solubles fraction against the Klebsiella pneumoniae by the paper disk method. The strongest activities of bark parts were ethyl acetate solubles fraction against Bacillus subtilis, Klebsiella pneumoniae. Ethanol extractives from xylem parts showed high activities against Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae and Vibrio parahaemolyticus. These antimicrobial activities of ethanol extractives from Quercus dentata were in order to xylem > bark > leaves. The strong inhibition zones of the ethanol extractives and its fractions of xylem showed Rf values in 0.41~0.63. In leaves extractives, the petroleum ether solubles showed lower antioxidative activity and ethyl acetate insolubles showed higher antioxidative activity of 70% compared with the
values of the control. Antioxidative activity of bark and xylem extractives showed higher approximately 2 times than the control except the petroleum ether solubles.
Extractives of the Wood of Black Locust and the Bark of Poplar as Decay-Resistant Hardwood Tree Species
Bae, Young-Soo ; Ham, Yeon-Ho ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 52~61
Black locust(Robinia pseudoacacia) and poplar(Populus alba
glandulosa) trees were collected, extracted with acetone-
(7:3, v/v) after drying, fractionated with hexane, chloroform and ethylacetate, and freeze dried to get some brown powder. Each fraction of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluting solvents. The wood extractives of black locust contained (+)-leucorobinetinidin as flavan, robtin as flavanone and dihydrorobinetin as flavanonol, and robinetin as flavonol. The poplar bark extractives contained various kinds of phenolic compounds : (+)-catechin as flavan, naringeoin, eriodictyol, sakuranetin, aromadendrin and taxifolin as flavanonol, salireposide as salicin derivative, and minor compounds such as aesculin and p-coumaric acid. However, aesculin has not been reported as a constituent of the poplar bark in Korea yet. NMR and FAB-MS analyses were done to elucidate the structures of isolated phenolic constituents.
Extractives of the Bark of Ash and Elm as Medicinal Hardwood Tree Species
Bae, Young-Soo ; Kim, Jin-Kyu ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 62~69
The bark of ash(Fraxinus rhynchophylla) and elm(Ulmus davidiana var. japonica) trees were collected, extracted with acetone-
(7:3, v/v), fractionated with hexane, chloroform and ethylacetate, and freeze dried to give some dark brown powder. Each fraction of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The ash bark contained a large amount of coumarin derivatives such as aesculetin and aesculin in addition to trace amount of ligstroside and oleuropein. Most of the elm bark extractive were (+)-catechin and its glycosides such as (+)-catechin-7-O-xylopyranose and (+)-catechin-7-O-apiofuranose in addition to a small amount of procyanidin B-3, a dimeric (+)-catechin. NMR and FAB-MS spectrometric analyses were performed to characterize the structures of isolated phenolic compounds.
Studies on Biological Activity of Wood Extractives(IV) - Antimicrobial and Antioxidative Activities of Extractives from the Heartwood of Morns bombycis and Synthesized Congeneric Stilbenoids -
Lee, Sung-Suk ; Lee, Hak-Ju ; Choi, Don-Ha ; Hishiyama, Shojiro ; Kato, Atsushi ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 70~77
Among four compounds such as oxyresveratrol, resveratrol, morin and afzelechin isolated from the heartwood of Morns bombycis, oxyresveratrol and resveratrol which belong to stilbenoid indicated high antioxidative and antimicrobial activity, respectively. Based on this result, this experiment was carried out to elucidate the relationship between biological activities of stilbenoids and their chemical structures using two isolated and six synthesized ones prepared by Wittig reaction. Antimicrobial activity of 3,5-dihydroxystilbene(pinosylvin) devoid of hydroxyl group of B-ring was the best among the tested stilbenoids. Antimicrobial activities of the stilbenoids showed negative dependency on the number of hydroxyl groups of B-ring, that is, the fewer number of hydroxyl groups of B-ring, the higher antimicrobial activity. On the other hand, antioxidative activities of the stilbenoids indicated a positive relationship with the number of hydroxyl groups of B-ring. In tetrahydroxystilbenoids, antioxidative activities of the compounds possessing ortho-diphenol structure, 2',3,3',5- and 3,3',4',5-tetrahydroxystilbene, were superior to the others. As a result, it was concluded that resveratrol and oxyresveratrol isolated from the heartwood of M. bombycis had antimicrobial and high antioxidative activities, and these activities of stilbenoids were also dependent on the number and position of hydroxyl groups of B-ring.
Studies on Biological Activity of Wood Extractives(V) - Identification of Flavonoids from the Heartwood of Larix leptolepis and Their Antioxidative Activities -
Yoon, Sun-Young ; Lee, Hak-Ju ; Lee, Sung-Suk ; Choi, Don-Ha ; Paik, Ki-Hyon ;
Journal of the Korean Wood Science and Technology, volume 28, issue 3, 2000, Pages 78~84
Two flavanones and one flavone were isolated from the diethylether soluble fraction of ethanol extract of Larix leptolepis heartwood. These compounds were identified 3,3',4',5,7-pentahydroxyflavanone(taxifolin), 3,4',5,7-tetrahydroxyflavanone(aromadendrin) and 3,3',4',5,7-pentahydroxyflavone(quercetin) by instrumental analyses using UV, IR, MS and NMR spectrometries. Antioxidative activies of these compounds were investigated by 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging activity. Quercetin and taxifolin indicated high free radical scavenging activities compared to
-tocopherol and BHT(butylated hydroxytoluene).