• 한국가구학회지
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• 제16권1호
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• pp.9-16
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• 2005

This study was carried out to displace traditional virgin wood fiber by exploded MDF-waste fiber for the manufacture of medium density fiberboard. MDF waste was exploded in condition of $215^{\circ}C,20$ minutes. The higher the mixing ratio of exploded MDF-waste fiber, the lower the MOR and IB of MDF. There was no difference of formaldehyde emission by desiccator method between virgin wood fiber and exploded MDF-waste fiber. Adding $25^{\circ}C$ of exploded MDF-waste fiber met the KS of MDF 15 type.

• Journal of the Korean Wood Science and Technology
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• 제20권3호
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• pp.11-20
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• 1992

Steam explosion is one of the most effective pretreatment for fractionating wood. This leads to the total utilization of wood basic components; cellulose, hemicellulose and lignin. The amount of sugar and lignin extracted with the hot water method was very low. The lignin content of residues after extraction with using a sodium hydroxide treatment, increased delignification of carbohydrate as the concentration of alkali was increased. Oak, pretreated with steam exploded at 25kg/$cm^2$ for 6 min. then 1% alkali for 2hrs. showed a delignification rate up to 95%. A sodium chlorite treatment of steam exploded pine and oak also afforded a high deligninfication effect. Pine, treated 10% sodium chlorite for 2hrs. showed high delignification. However, by using a sodium hydroxide treatment, a 2% retreatment for Ihr. after a 2% for 2hrs. afforded remarkable delignification effect on exploded wood at 30kg/$cm^2$ for 9min. and at 35kg/$cm^2$ for 3-6min. In oak, an initial 2hrs. treatment of 2% sodium chlorite was followed by a second 2hrs. treatment at 10%. This showed a delignification rate of 96%.

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.20-25
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• 1996

Wood chips of oak(Quercus mongolica) and larch(Larix leptolepis) were exploded with the optimum condition. Main components of exploded wood were separated with hot hot water and methanol. The hemicelluloses were purified from hot water extracts and alditol complexs were prepared from purified hemicellulose. And also, cellulose nitrate was prepared from extractive residue and characterized. The results can be summarized as follows. 1. Amounts of carbohydrate(72~79%) in the crude hemicellulose of larch wood was more than those of oak wood(55~66%). 2. The crude hemicelluloses were mainly composed of oligosaccharides in oak wood but those in larch wood contained about 50% monosaccharides. 3. Decolorization of hemicellulose was successful with activated charcoal and ion-exchange resin treatment. The alditol yields were 56.3~82.9%. 4. The degree of substitution(D.S.) of cellulose nitrate was 1.95~2.87 and it showed a good acetone solubility.

• Journal of the Korean Wood Science and Technology
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• 제24권3호
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• pp.45-50
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• 1996

Wood chips of oak(Quercus mongolica) and larch(Larix leptolepis) were treated with low pressure steaming explosion. Main components of exploded wood were separated with hot water and methanol extraction. Crude lignin separated from those extractives were purified and those chemical characteristics were investigated. And also, lignin adhesive was prepared from crude lignin and studied those chemical characteristics. The results can be summarized as follows ; 1. The purified lignin by Bj$\ddot{o}$kman's method from crude lignin is about 30% in exploded oak wood and is about 11% in exploded larch wood as a low amount. 2. The phenolic hydroxyl groups in the purified lignins are little higher than those of MWL and molecular weight distributions of the purified lignins are some lower than that of MWL. 3. Alkaline nitrobenzene oxidation products are very low in the clude lignin but those are increased in the purified lignin 4. The gravity of lignin resins(1.15 and 1.13) are a little lower than that of phenol resin(1.16) and the compressive shearing strength of lignin resins are higher than those of phenol resin.

• Journal of the Korean Wood Science and Technology
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• 제17권2호
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• pp.65-73
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• 1989

Steam explosion process is an efficient pretreatment method for sparating and utilizing wood main components has attracted attention in utilization of ligno-cellulosic biomass. In order to obtain the effective pretreatment condition. this study was made explosion apparatus. examined the composition. extraction of exploded wood. Wood chips of pine(Pinus densiflora oak (Quercus serrata) and birch wood (Belula platyphylla var. japonica) were treated with a high pressure steam(20-30 kg/$cm^2$, 2-6 minutes). The results can be summarized as follow; In analysis of exploded wood(EXW). It was found arabinose residues rapidly decreased with increasing of steaming time and pressure. Extractives of EXW with sodium hydroxide increased with increasing of steaming-time and- pressure especially extractives 1% sodium hydroxide has higher than other extracted method extractives of hard wood(oak, birch) has higher than pine wood. In EXW extracted with sodium hydroxide and methanol lignin was partially delignified alkali extraction was more delignified than methanol extraction hardwood than pine wood.

• Journal of the Korean Wood Science and Technology
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• 제47권2호
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• pp.189-199
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• 2019

This study addresses the biorefinery feedstock from Pinus densiflora. This raw material is a major tree species in the Republic of Korea; it is renewable, has cost-effective, and is readily available. In this study, steam explosion of P. densiflora was performed in a reactor at $225^{\circ}C$ and with 1 to 13 min reaction times with or without previous water impregnation. The combined severity factor (Ro), which is an expression relating the reaction temperature and reaction time used in the steam explosion treatment, ranged from 3.68 to 4.79. The influence of both impregnation and steam explosion conditions were investigated by examining color variations, chemical composition, and mass balance on the pretreated solids. The results showed that steam-exploded P. densiflora that was not impregnated with water exhibited significantly darker color (chroma 28.8-41.4) than water-impregnated and steam-exploded P. densiflora (chroma 18.8-37.3). The increased ${\alpha}$-cellulose and lignin contents were detected as the severity factor increased. Furthermore, the ${\alpha}$-cellulose and lignin contents in the non-impregnated/steam-exploded P. densiflora were higher than those in the water-impregnated/steam-exploded P. densiflora. However, the decreased holocellulose content was detected as the severity factor increased. In mass balance, the holocellulose yield from water-impregnated/steam-exploded P. densiflora was higher than that from the non-impregnated P. densiflora.

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.598-606
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• 2001

A mathematical model is proposed that can depict the kinetics of simultaneous saccharification and fermentation (SSF) using steam-exploded wood(SEW) with a glucose- and cellobiose-fermenting yeast strain. Brettanomyces custersii. An expression to describe the reduction of the relative digestibility during the hydrolysis of the SEW is introduced in the hydrolysis model. The fermentation model also takes two new factors into account, that is, the effects of the inhibitory compounds present in the SEW hydrolysates on the microorganism and the fermenting ability of Brettanomyces custersii, which can use both glucose and cellobiose as carbon sources. The model equations were used to simulate the hydrolysis of the SEW, the fermentation of the SEW hydrolysates, and a batch SSF, and the results were compared with the experimental data. The model was found to be capable of representing ethanol production over a range of substrate concentrations. Accordingly, the limiting factors in ethanol production by SSF under the high concentration of the SEW were identified as the effect of inhibitory compounds present in the SEW, the enzyme deactivation, and a limitation in the digestibility based on the physical condition of the substrate.

• Journal of the Korean Wood Science and Technology
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• 제28권3호
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• pp.25-33
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• 2000

본 연구는 농산 및 임산폐자원을 폭쇄처리한 후 xylan을 단리하기 위한 최적의 방법과 조건을 확립하기 위해 수행하였다. 농산 및 임산폐자원으로는 볏짚, 보릿짚 및 신갈나무를 시료로 하였다. 농산 및 임산폐자원의 화학 조성을 살펴보면, 볏짚 및 보릿짚에서의 추출물 함량과 무기물 함량은 신갈나무보다 약 10~20% 정도 높게 나타났다. 폭쇄전처리는 20kgf/$cm^2$의 압력에서 3, 6분처리 하였다. 폭쇄처리된 시료의 리그닌 함량은 폭쇄처리 전보다 약 3~22% 정도 높게 났다. 열수 및 0.5% 수산화칼륨 용액 추출에 의한 xylan 단리를 시도하였다. 열수 및 0.5% 수산화칼륨 용액 추출에 의해서 단리된 xylan의 형태를 살펴보면, 열수추출로 단리된 xylan은 소당류 형태로 존재하고 있음을 확인할 수 있었다. 1차적으로 열수 및 0.5% 수산화칼륨 용액으로 단리된 xylan을 5% 수산화바륨 용액과 에탄올 적하법으로 정제를 시도하였다. 최종적으로 정제된 xylan의 xylose 함량은 약 85% 이상이었지만, 기타의 당류들이 존재하였다.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1355-1361
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• 2006

The simultaneous saccharification and fermentation (SSF) process consists of concurrent enzymatic saccharification and fermentation. In the present cybernetic model, the saccharification process, which is based on the modified Michaelis-Menten kinetics and enzyme inhibition kinetics, was combined with the fermentation process, which is based on the Monod equation. The cybernetic modeling approach postulates that cells adapt to utilize the limited resources available to them in an optimal way. The cybernetic modeling was suitable for describing sequential growth on multiple substrates by Brettanomyces custersii, which is a glucose- and cellobiose-fermenting yeast. The proposed model was able to elucidate the SSF process in a systematic manner, and the performance was verified by previously published data.

• Journal of the Korean Wood Science and Technology
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• 제43권2호
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• pp.224-237
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• 2015

We hypothesized that the extract from steam exploded Q. variabilis might be cytoprotective for tenofibroblasts cells during oxidative stress. In the present study, the extracts obtained from steam exploded (severity log Ro 4.68) Q. variabilis contained high quantities of phenolics and flavonoids contents. Also, the extracts appear to have, on these tenofibroblasts, a protective effect against oxidative stress. Tenofibroblasts cells incubated with the extracts and stressed with $H_2O_2$ showed an increase in cell viability by MTT assay. The extracts is found to inhibit $H_2O_2$-induced apoptosis in tenofibroblasts cells, as shown by Annexin V/PI double staining analysis. Western blot data showed that in the extracts/$H_2O_2$-treated cells, the extracts inhibited the $H_2O_2$-dependent phosphorylation of ERK and p38. From these results, it is suggested that the extracts showed the protective effect on $H_2O_2$-mediated oxidative stress. The main chemical compounds of the extract was identified as 1,8-cineole by GC-MS analysis. The anti-apoptosis activity is accordingly believed to be attributable to the 1,8-cineole.