• Journal of the Korean Wood Science and Technology
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• v.50 no.6
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• pp.427-435
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• 2022

For effective applicability of reinforced cork, cork composites reinforced with metal, glass fiber, and carbon fiber were developed, and the effects of the reinforcing materials on the mechanical properties of cork composites were investigated. The bending moduli of elasticity (MOE) of cork composites were in the 32.7-35.9 MPa range, while the bending strength values were in the 1.62-1.73 MPa range. The strength performance decreased in the order cork-metal > cork-carbon fiber > cork-glass fiber. The bending MOEs were improved by 29%-41% compared with simple cork boards, while the bending strengths of reinforced cork were 35%-45% higher. The strength performance significantly improved following the incorporation of thin mesh materials into the middle layer of the studied cork composites. The bending strains of the cork composites were remarkably higher compared with oak wood, making them promising for applications that require bending processing, such as curved jointing. The internal bond strengths of the cork composites were 0.26-0.44 MPa, approximately 0.36-0.60 times lower compared with medium-density fiber boards.

• Carbon letters
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• v.28
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• pp.9-15
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• 2018

In the aerospace field, Carbon/Cork composites have been used for rocket propulsion systems as a light weight structural component with a high bending stiffness and high thermal insulation properties. For the fabrication of a carbon composite with a heat insulation cork part, the bonding properties between them are very important to determine the service life of the Carbon/Cork composite structure. In this study, the changes in the interfacial adhesion and mechanical properties of Carbon/Cork composites under accelerated aging conditions were investigated. The accelerated aging experiments were performed with different temperatures and humidity conditions. The properties of the aged Carbon/Cork composites were evaluated mainly with the interfacial strength. Finally, the lifetime prediction of the Carbon/Cork composites was performed with the long-term property data under accelerated conditions.

• Korean Journal of Pharmacognosy
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• v.42 no.2
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• pp.169-174
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• 2011

In this study, we investigated on antioxidative activity, antibacterial activity and tyrosinase inhibitory activity in 75% ethanol extracts of bark and cork layer from Prunus sargentii. The total polyphenol content of cork and bark extract was found to be 217.4 mg/g and 184.3 mg/g. And flavonoid content was found to be 31.9 mg/g and 58.6 mg/g respectively. In DPPH radical scavenging ability, cork extract was exhibited stronger scavenging ability than bark extract. Moreover, cork extract was showed higher inhibitory activity than bark extract in tyrosinase inhibitory activity. In antibacterial activity, bark extract was showed higher growth inhibition effect than cork extract against tested bacterial strains. In measurement of cytotoxicity by MTT assay, bark and cork extract showed fine cell viabilities(95.7~120.9%) against RAW 264.7 cell.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.6
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• pp.868-876
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• 2005

Silk fabrics were dyed with yellow natural materials. Gardenia, turmeric, amur cork tree, safflower, Japanese pagoda tree, and onion were used as natural materials. Color image of natural dyed silk fabrics was classified by 4 factors(Cheerfulness, Comfortness, Pastrol, Revealation). Cheerfulness factor affected significantly with color image. Amur cork tree or turmeric dyed fabrics were shown as light and cute, safflower or gardenia dyed fabric shown as comfort, and onion dyed fabrics shown as mature and simple. Color image with specialty was significant difference in Preference and Revelation factor. Preference was appeared as amur cork tree>turmeric>gardenia>safflower>Japanese pagoda tree>onion.

• Journal of Environmental Science International
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• v.11 no.12
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• pp.1327-1331
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• 2002

The cork have been preferred over the conventional materials, zeolite, ceramics, and lignite as a biofilter medium. During the 6 months of operation, the performance of the cork biofilter was considered good with 150ppm of mixture BTX vapor efficiencies greater than 90% at 60 second of EBCT. It was observed 56 % of removal efficiency under transition conditions at first stage, and then the removal efficiency was increased to above 90 %, and the sustainability of removal efficiency was maintained. At second stage, the performance of cork biofilter was not decreased 90 % efficiency with 150 ppm BTX at 30 sec. EBCT. The production of $CO_2$ due to microbial respiration was increased to the 40 % on the operation of cork biofilter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.362-369
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• 1996

Seven different drying methods were tested in peony roots of Euisung cultivar, harvested in February, in three year's old plant. The roots were selected in length and diameter and half of the samples were removed cork-layers to compare the effects of cork-layer in processing of drying. The 3$0^{\circ}C$ heat drying without cork-layer reduced in days to drying by five days compared to those of the with cork-layers at the same temperature. The 5$0^{\circ}C$ heat drying after cork-layers removed was the most effective in days to drying. In quality of skin color of the 5$0^{\circ}C$ heating was worse to compare with the lower drying temperature. In the drying at room temperature and the heat drying at lower temperature, the paeoniflorin content in drying after cork-layers removed were higher than that of the drying with cork-layers. However, in the boiling water treatment, the paeoniflorin contents in drying after cork-layers removed were lower than those of with cork-layers. In heat drying, paeoniflorin content showed a decreasing tendency to increase of drying temperature. Total sugars in the peony roots showed a decreasing tendency according to the drying temperature increasing, but starch concentration showed a increasing tendency at the same condition. Concentrations of crude protein, crude fiber and crude ash were showed no differences in various drying methods and the materials with or without cork-layers. Relationships between the paeoniflorin and total sugars, and the paeoniflorin and starch were different significantly by the materials of cork-layers removed or not. The 30~4$0^{\circ}C$ heat drying without cork-layers was the most advisable condition for drying in paeoniflorin concentration, days to drying and skin color after drying.

• Corrosion Science and Technology
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• v.21 no.2
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• pp.100-110
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• 2022

Corrosion of steel reinforcement is the most important mode of concrete structures damages. It strongly depends on the composition and physicochemical properties of the cementitious medium. The use of waste materials as lightweight aggregates in concrete is environmentally recommended in polluted environments such as marine and/or industrial atmospheres in order to reduce its porosity and ensure the requested protection of reinforcing steel. The present study investigated the effect of waste cork addition on corrosion resistance of steel rebar in mortar specimen prepared in the laboratory. The main objective of this study was to improve the corrosion resistance of reinforcing steel. Another objective of this study was to valorize this ecological product and preserve the environment. Results obtained from various electrochemical tests indicated that the presence of a fine cork powder substantially improved the corrosion resistance of steel in the mortar contaminated by chloride ions. This improvement was reflected by a notable decrease in corrosion current density and a shift of corrosion potential of the steel towards more noble values. Moreover, the presence of a fine cork powder in the mortar had no adverse effect on its mechanical properties.

• Journal of Gastric Cancer
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• v.18 no.3
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• pp.242-252
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• 2018

Purpose: Surgical resection for gastric adenocarcinoma is associated with significant post-operative morbidity and mortality. The aim of this study was to assess the prognostic significance of sarcopenia in patients undergoing resection for gastric adenocarcinoma with respect to post-operative morbidity and survival. Materials and Methods: A retrospective analysis was conducted on a cohort of consecutive patients who underwent surgical resection for gastric adenocarcinoma between 2008 and 2014. Patient demographics, radiological parameters, and pathological data were collected. OsiriX software (Pixmeo) was used to measure skeletal muscle area, which was normalized for height to calculate skeletal muscle index. Results: A total of 56 patients (41 male, 15 female; mean age, $68.4{\pm}11.9years$) met the inclusion criteria. Of these, 36% (20 of 56) of the patients were sarcopenic pre-operatively. Both sarcopenic and non-sarcopenic patient groups were equally matched with the exception of weight and body mass index (P=0.036 and 0.001, respectively). Sarcopenia was associated with a decreased overall survival (log-rank P=0.003) and was an adverse prognostic predictor of overall survival in multivariate analysis (hazard ratio, 10.915; P=0.001). Sarcopenia was a predictor of serious in-hospital complications in multivariate analysis (odds ratio, 3.508; P=0.042). Conclusions: In patients undergoing curative resection for gastric cancer, there was a statistically significant association between sarcopenia and both decreased overall survival and serious post-operative complications. The measurement and reporting of skeletal muscle index on pre-operative computed tomography should be considered.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.148-149
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• 2020

Currently, the most commonly used EPS insulation material has been mainly used because its ease of adhesion with concrete. However, due to poor adhesion with wallpaper, separate adhesion needs to be strengthened and there are cases of breakage or grooves in the process of dismantling the mold. The biggest problem is that when a fire breaks out, various harmful substances are present and highly flammable. Cork used in this study is a truly eco-friendly building material that is taken from between the outer and inner bark of cork trees and does not damage the wood. Also, it is a porous material that is made up of countless cells and contains an air gap between the cells. It is very light in weight between 0.06 and 0.07 and has excellent insulation with a heat conductivity of 0.04W/mK. In addition, it has high stability in the topic of conversation because it does not produce harmful gas when burned and has self-sustaining properties. However, research on cork, an eco-friendly building material with excellent performance to date, is scarce Therefore, we encourage existing scholars to raise interest in new eco-friendly building materials through this study. It also aims to manufacture insulation boards with new inorganic properties using the low weight and heat conductivity held by the cork.

• Textile Coloration and Finishing
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• v.29 no.4
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• pp.276-283
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• 2017

The aim of this study is to develop an effective dyeing process for black color on the silk fabrics, using natural Indigo, Madder, Amur cork tree, Alder, Logwood, and Gallnut. All natural dye materials were water-extracted, concentrated, and freeze-dried. Seven different processes were carried out and the color differences(${\Delta}E$) of black color with each process from the chemical black dyed fabric were compared. The light, washing, and rubbing fastness were evaluated. The black dyeing of the silk fabrics was well carried and excellent black color was obtained in every methods. The profound black color could be obtained by the subtractive mixture of the three primary colors of red, yellow, and blue in the order of indigo(blue) - amur cork tree(yellow) - madder or lac(red). Black color was efficiently obtained by iron mordant when logwood or alder fruit was used. The color difference(${\Delta}E$) from the black color with chemical dyestuff was the lowest in the indigo - amur cork tree - lac - iron method. Light fastness and washing fastness were excellent in all dyeing processes, showing grade 5. The fastness to rubbing was excellent as shown grade 5 in the dry samples of logwood - iron process and alder fruit - iron process.