• Journal of Korea Foresty Energy
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• v.20 no.1
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• pp.62-72
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• 2001

To elucidate the behaviors of alkali swelllng of woods. the dimensional change in cross section of cell elements of four major Korean woods during alkali swelling were examined by an optical microscory, an imaging analysis method and an X-ray diffrartion During alkali swelling, tracheid diameter of Larix kaempferi wood showed greater swelling property than that of Pinus koraiensis wood, and the cell wall swelled highly over 10% sodium hydroxide solution treatment. The radial diameter of vessel elements in earlywood shrunk, but it swelled slightly in tangential direction. When treated with 5% NaOH, the wall thickness of wood fiber increased about three times over the original one. The thickness of cell wall in all elements and the diameter of wood fiber and tracheid showed almost isotropic shrinkage. The diameter of cell elements during the mercerization process decreased, but cell wall thickness Increased. Crystal transformation of cellulose in wood was not occurred by alkali treatments. but relative crystallinity and crystallite width of the woods increased slightly. Consequently, it was demonstrated that the swelling properties of woods were dependant on wood species, cell elements and alkali concentration.

• Journal of Korea Foresty Energy
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• v.21 no.2
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• pp.34-42
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• 2002

This research was carried out to investigate water repellent effectiveness of natural oil treated wood. Linseed oil, castor oil, olive oil, bean oil, perilla oil and sunflower oil were used in this test. For evaluation of water repellent of natural oil treated wood, moisture absorption test, water-drop contact angle test and color difference test of accelerated decomposition by UV and water were used. The moisture absorption amount of natural oil treated wood was less than untreated wood until 3 hours, but it was increased with time, there was no big difference with oil treated wood and untreated wood after 48hours. Oil treated wood and untreated wood showed big difference on contact angle test. It was no big difference by kind and oil concentration. Natural oil treated wood did not showed stability on the weather aging test. Contact angle test could be used on evaluation of wood surface status treated with natural oil.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.66-73
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• 2006

The effects of operation conditions, such as bed temperature, temperature rising rate, particle size, moisture content and so on, on thermo-chemical conversion of waste wood have been determined in a micro fixed bed gasifier. The samples were waste wood-chips such as pine, oak, acacia and ginkgo. The thinning timbers used as reactants in the experiments had $35wt\%$ moisture content, $0.5wt\%$ ash content and 4,550 kcal/kg heating value on a dry basis. A typical product distribution was a $40wt\%$ liquid, $20wt\%$ solid, and $40wt\%$ dry syngas. The syngas concentration was affected by operation conditions and average syngas concentration was $H_2:40vol\%,\;CO:30vol\%,\;CH_4:10vol\%$.

• Environmental engineer
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• s.323
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• pp.22-27
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• 2013

종이 펄프 공장의 폐수는 다른 공업에 비해서 폐수량이 많고 오염도가 높다. 목재로부터 종이를 제조하는 경우에 수율은 종이의 종류와 제법에 의해 큰 차이가 있어서 한마디로 말하기는 어렵지만 평균 50~70%로 보는 경우, 목재 성분의 30~50%는 용해 또는 SS의 상태로 폐수중에 존재하기 때문에, 이들이 직접 하천이나 바다에 방류되면 오염의 원인이 된다. 그 때문에 각 공장에서는 목재자원의 종합적인 이용의 입장으로서 제품의 수율을 좋게 하고 동시에 폐수의 양을 감소시키고 폐수에서 유용한 자원을 회수하거나 증해약품의 회수 등을 위하여 연구 및 노력을 계속하고 있는 것이 현 상태이다. 우리 나라의 거의 모든 제지회사에서는 물리적, 화학적 처리법과 생물학적 처리법 중 호기성 처리방법이 주 처리방법으로 사용되고 있으며 탈묵 폐수나 리그닌을 다량 함유하는 폐수의 경우에는 혐기성 처리방법을 이용하기도 한다. 본 실험에서는 우유팩을 재생하여 화장지 제조의 원료로 이용하는 G제지공장의 폐수를 이용하였고, 공장의 원폐수를 부상법으로 1차 처리한 처리수를 실험실로 운반하여 활성슬러지법으로 실험하였다. 처리효율의 영향인자인 HRT를 G제지공장에 맞추어 12시간으로 조정하고 적절한 F/M비(0.23)를 위해 COD와 MLSS가 유지된 후부터 실험을 시작했다. $20^{\circ}C{\sim}560^{\circ}C$까지 $10^{\circ}C$간격으로 온도를 변화시키면서 미생물의 상태변화를 관찰하고, 또한 각 용도에서의 처리수질을 비교해 보았다. 실험조건은 pH는 중성상태(6.5~7.5), DO는 $2{\sim}4mg/{\ell}$, 영양원은 BOD : N : P = 100 : 5 : 1로 맞추고 BOD, COD, SS, SVI를 측정하였으며, 현미경을 통하여 미생물과 Floc를 관찰하였다. $20^{\circ}C$부터 종균제를 초기 운전시 $200mg/{\ell}$ (분말상)을 폭기조에 투여하고 매일 $200mg/{\ell}$를 정기적으로 투입하여 온도변화에 따른 미생물의 상태 및 처리수질을 비교해보았다. 특히 종균제로는 기존의 G제G지공장에서 사용하는 신일 미생물(Bio sound S)종균제와 청림C&C의 종균제(Cell bio P)를 비교 관찰하였다. 고온성 종균제를 두배 투입하여 투입량에 대한 처리효율을 비교하였으며 종균제를 사용하지 않고 운용함으로써 그 차이도 비교할 수 있었다.

• Journal of the Korean Wood Science and Technology
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• v.6 no.1
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• pp.3-7
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• 1978

Quercus serrata degraded by Leminus edodes(berk) Singer was investigated. In order to evaluate on affect of the fungi on the sound logs, and the logs attacted for 2 years and five years were used as a sample tree. Large portions of carbohydrate mainly was decomposed by the fungy. It is supported by the increasing of alkaline extractives and the breaking up of crystallinity. Lignin is transformed considerably as shown the results of the determination of Klason lignin, gel filtration and nitrobezene oxidation. On the other hand, the decreasing of methoxyl group and the increasing of carboxyl group in parallel with demethlation and acidification are presented. Syringyl nuclei unit is decomposed easier than guaiacyl unit. It is also illustrated that the more decreasing of carboxyl group compared with aldehyde group was acidified biodegradation.

• Journal of the Korean Wood Science and Technology
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• v.49 no.2
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• pp.154-168
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• 2021

Various types of wooden relics are being unearthed following the full-scale excavation in Wolseong palace site, Gyeongju in Korea. In particular, a large number of relics were found in the moat surrounding the Wolseong Fortress. This study attempted to secure basic data on the shields of the Silla era through species identification, radiocarbon dating, and shape analysis of the two wooden shields excavated from the Wolseong moat. As a result of the radiocarbon dating, it was confirmed that the shields were made of wood procured in the period between the mid-4th century and the early 5th century. The species identification confirmed that the body of the relic was made with Pinus soft pine group and the handle with Zelkova serrata. It was also confirmed that the excavated wooden shield was made by first marking a thin line on a flat grain board, then marking double concentric circles and perforating small holes. The distance between the division lines is constant at about 6cm, and spaces between them are colored in red and black. The shape analysis estimated that two artifacts were more than 50cm and 36cm in width, respectively.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.38-43
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• 2003

This is the second in a series of reports on the evaluation of weathering durability of waterborne preservative treated wood by accelerated weathering. The leaching of copper from ACQ-, CCA-, and CuAz-treated samples during weathering was increased by UV irradiation, when compared between full weathering and water-only weathering. The FTIR spectra of the weathered ACQ-, CCA, CuAz-treated samples at 1731 cm^-1, 1625 cm^-1, 1510 cm^-1, which are related to the fixation of copper, were different from those of unweathered controls. This result means that UV irradiation can weaken the chemical bond between lignin and copper and/or extraction of lignin-copper complex can be occured when lignin erode away by weathering.

• Journal of the Korean Wood Science and Technology
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• v.31 no.2
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• pp.52-57
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• 2003

This research is to collect, classify and identify the insects boring tunnels into wood or damaging wooden frame structure. Intensive insect collections have been carried at the historical local schools annexed to the confucian shrine from March to September 2001. Ten species of Coleoptera, 15 species of Hymenoptera, 6 species of Hemiptera, 4 species of Ditera and 1 species of Demaptera were recorded. Most species of Coleoptera and Hymenoptera have the manducatory apparatus in the mouth-part that cause severe damage in wood, and showed the highest population among the genera recorded. Further research should be considered on the identification of wood demage insects at the species level among present collection and their mechanism of wood demage in the wood.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.12-18
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• 2013

Existing wood decks brings out negligent accident because fastener can be pulled-out by cyclic load of pedestrians. When deck and joist are connected, it also causes the problems, which are cracking of wood decks and rapid decay by material of fastener. In this study, strength property of deck unit using reinforced plastic connector made by domestic A company was evaluated. Southern yellow pine (Pinus palustris Miller) were used for deck material. Bending strength of deck units were implemented for fastener type and joist spacing (400, 600 mm). In the result, carbon steel screw into reinforced plastic connector was the best in average bending strength(Joist spacing : 400, 600 mm). In the result of bending strength for joist-width (40, 50, 70, 80 mm), the average maximum bending strength was measured when the joist spacing was 40 mm.

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.122-130
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• 2013

One of recent methods to protect wooden cultural assets from fire, there is the flame retardation which is applied directly to wood and it is to prevent fire through securing flame resistance for the material and delaying combustion when failed fire in advance and then to gain time for people in the room to evacuate and it has same goal with the Korean Fire Service Act by protecting life and property. However, in case of spraying flame retardant on the colored surface of the wooden cultural assets, there are continuous problems of decoloration, efflorescence and water absorbtion after sometime and accordingly there increases danger of damages of cultural assets. So when treating with flame retardant on wooden cultural assets, there has to be no problems on dancheong after sometime and securing sustainable methods for flmae retardation should be preceded. Accordingly, this study aims to provide basic sources for selecting proper flame retardation methods by evaluating and analyzing flame retardation capabilities according to types of flame retardants which are frequently used nowadays and spraying them on the dancheong-painted surface and confirming if there is no problem on the dancheong and wood after sometime and if flame retardation effect is sustainable with its quality and capability through precise analysis.