• Korean Journal of Organic Agriculture
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• v.12 no.4
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• pp.399-409
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• 2004

This study was conducted to investigate the effect of different concentrations of microbial products on growth of chinese cabbage and microorganisms in soil. Two different levels of microbial products, such as 50 times and 100 times diluted solutions of chitosan, wood vinegar and EM activity liquid, were treated for foliar application. the results were summarized as follows : Among foliar applications of microbial products, 100 times diluted solution of chitosan was effective on growth of chinese cabbage comparing to other levels of dilutions and untreated control plot. The number of microorganism in the soil tended to increase under the treatment of microbial products compared to control plot. Especially, the numbers of the bacteria and actinomycetes were estimated $73.67{\times}10^3$ CFU/g and $34.00{\times}10^3$ CFU/g, respectively, under the treatment of 100 times diluted solution of chitosan.

• Journal of the Korea Institute of Building Construction
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• v.8 no.6
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• pp.117-122
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• 2008

This study targets to improve and complement the problem of existing flame resistant processing with flame resistant performance the same as existing flame resistant agents or better, keeping wooden surface & feel as they are, and to attempt to raise flame resistant performance and economic efficiency by applying phosphorous flame resistant agents, a colorlessness, odorless new product to woods for an improvement of flame resistant performance for wooden nature and to offer a basic data for an uniform high-performance for flame resistant woods by reinforcing wooden durability and usability.

• Journal of the Korean Wood Science and Technology
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• v.19 no.2
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• pp.22-29
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• 1991

The endo-1,4-${\beta}$-xylanase was extracted and purified from the extracellular xylanolytic systems of Trichoderma viride. The crude enzyme was chromatographed with ion-exchange reins of DEAE Sepharose CL-6B, Sepharose, S-Sepharose CL-6B and the resulting xylanase was turned out to be a single protein as 20KD hy SDS-polyacrylamide gel electrophoresis. The xylooligomers were obtained from xylan by incubation with the purified xylanase up to 50%. The ${\beta}$-xylosidase lost its activity completely by incubation of crude enzyme for 24hr with buffer solution of pH 2.8 at $27^{\circ}C$. And also, the xylooligomers were obtained from xylan as a main product by incubation with the crude enzyme treated with acidic buffer.

• KSBB Journal
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• v.13 no.3
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• pp.312-319
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• 1998

The dilute-acid pretreatment/hydrolysis of hemicellulose in oak wood using a percolation reactor was investigated. The experimental conditions ranged 160∼180$^{\circ}C$ and 0.05∼0.2 wt.% sulfuric acid. XMG(xylan+mannan+galactan) recovery was higher when sulfuric acid was used as leaching solvent than water. Also it was important for high XMG recovery to keep leaching temperature higher after reaction. XMG recovery was decreased as the size of wood chips was increased. At an optimum condition (reaction condition= 170$^{\circ}C$, 0.1% sulfuric acid, 1ml/min, 10min, leaching condition=0.1% sulfuric acid, 2mL/min, 20 min), the product yield and the sugar concentration were about 92% and 2.7%, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.30-36
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• 2016

This study was conducted to investigate the influence of the changes in handsheet structure by beating, wet pressing and the addition of wood flour spacer on the water absorption and the moisture absorption properties. The higher beating treatment of BKP resulted in the denser structure of handsheet samples, which leaded to the lower water and moisture absorption. The wet pressing showed the similar effects by reducing the bulk of handsheets. In case of the handsheet samples with similar bulk structure made of different beaten pulps, the severer beating treatment increased the water absorption and the moisture absorption. The addition of the wood flour spacer resulted in the higher bulk following the higher water and moisture adsorption. Since the water and the moisture absorption properties of paper products could greatly affect on not only the product quality but also the process runnability, the control of the water response of paper product has been considered as very important technology. The results of this study might be useful for control of water and moisture absorption properties of paper products.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.80-84
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• 1991

Lignocellulosic biomass including acetosolv ricestraw and spruce lignin were liquefied and converted into liquid hydrocarbons by catalytic hydroliquefaction reaction. These experimental works were carried out in 1-liter-capacity autoclave using 50% tetralin and m-cresol solution respectively as soluble solvent and Ni. Pd. Fe and red mud as catalyst. $H_2$ gas was supplied into the reactor for escaltion of deoxhydroenolysis reaction. Catalyst concentrations were 1 % of raw material based on weight. The ratio between raw materials and soluble solvent are 1g and 10cc. The reaction conditions are 400-$700^{\circ}C$ of reaction temperature, 10-50 atms of reaction pressure. The highest yield of hydrocarbon, so called "product oil" showed 32% and 5.5% of lowest char formation when red mud was used as catalyst. The product oil yields from those of other catalysts were in the range of 20-29%. The influence of different initial hydrogen pressures was examined in the range d 30-50 atms. A minimum pressure of 35 atms was necessary to obtain a complete recovery of souble solvent for recycling.

• Journal of the Korean Wood Science and Technology
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• v.20 no.3
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• pp.61-66
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• 1992

It is well known that polymer chemistry started by the study on cellulose. However, the study on cellulose has not made a significant progress after the 2nd World War, because the interest of researchers has directed to the newly developed synthetic polymer science. Recently the situation has been changing as suggested by the creation of a word "Cellulose Renaissance". This change is due to the recognition that cellulose is a renewable resource and a biodegradable, environmentally friendly material. In this lecture I'd like to introduce you some recent topics in cellulose chemistry which were reported by Japanese researchers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.1
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• pp.24-30
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• 2012

This study was carried out in order to analyze a repletion possibility about color change of base paper after elevated heat exposure when wooden fillers were added. Fillers may reduce production cost because its price is usually inexpensive than pulp with higher bulkiness. Wooden fillers have lower density than inorganic fillers, so they may increase bulk more than inorganic fillers. Never the less wooden fillers have disadvantage of yellow color by heat exposure, so the addition level should be carefully controlled. Brightness and whiteness changes after elevated heat exposure depending on coating weight were analyzed. With wooden fillers addition, breaking length and surface strength decreased but bulkiness increased. As the exposure time of elevated heat increased the coating paper with wooden fillers addition had higher brightness and whiteness values than those of inorganic fillers.

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.622-628
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• 2017

In order to develop value-added utilization technology of domestic oaks the processing yield rate from the standing tree to the flooring material for the Quercus variabilis and Quercus mongolica were investigated. Also, to reduce drying time, improved drying schedule was applied and the physical properties were measured. The drying time was 173 hours in total, and the final moisture content was 5.39% (Quercus variabilis) and 4.17% (Quercus mongolica). The color difference of oak lumber before and after drying showed a significant change as ${\Delta}E$ value from 7 to 11. The shrinkage rates of Quercus variabilis and Quercus mongolica during drying were 8.1% and 8.5% in the tangential direction and 5.0% and 6.2% in the radial direction, respectively. The lumber manufacturing yield rate of sawn lumber was 30 to 40% and that of the final product was 8 to 15%. It is expected that the processing characteristics of the Quercus species investigated in this research could contribute to formulate an efficient production plan of domestic hardwoods that are still under utilization.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.108-115
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• 2012

Archaeological waterlogged woods found under the sea, in lakes, or in swamp environments are generally weak and fragile. If waterlogged wood materials were taken out of the water and left without modification, they would collapse and lose their original dimensions completely. Conservation is performed to replace the water with chemical agents and to give dimensional stabilization and durability. EDTA and PEG are the most commonly used in the preservation of wood. pH control-precipitation method is used for recovery of EDTA from waste fluid of archeological waterlogged wood conservation treatment. The black substance is eliminated from wood as Fe-EDTA complex are formed and EDTA is separated and precipitated from Fe-EDTA complexes at pH 2.68 or less. The result of analysis of the precipitated products and the commercial EDTA by FT-IR and FE-SEM showed that precipitated product by pH adjusted was not a type of Fe-EDTA complex, but pure EDTA. Waste fluid produced in PEG treatment shows the black color and has an offensive odor by organic matter extracted from wood. Color of waste fluid is decolored with oxidation reaction by peroxy hydrate. In FT-IR and SEM-EDX of PEG after freeze-drying process, no significant change of functional groups induced from oxidation is observed, and any metal ion does not exist in the solid PEG specimen. The molecular weight of PEG is measured using GPC and viscometry. Properties of PEG before and after preservation treatment, and after oxidation with $H_2O_2$ were not changed. Consequently, the peroxidation with $H_2O_2$ is a reasonable and simple method to decolor the used PEG solution.