• Journal of the Korean Wood Science and Technology
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• v.43 no.2
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• pp.206-213
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• 2015

This study was carried out to use carbonized medium density fiberboard (MDF) for the replacement of sound absorbing material. Carbonization treatment was performed to improve sound absorption property for MDF at carbonizing temperatures of $500^{\circ}C$, $700^{\circ}C$, $900^{\circ}C$ and $1100^{\circ}C$. As the carbonization temperature increased, the results of the observation by scanning electron microscope (SEM) demonstrated that the fibers exhibited a more compressed morphology within the surface section of the MDF than those within the middle section of MDF. As the carbonizing temperature increased, the cavity increased. The sound absorption coefficient increased between the temperatures of $500^{\circ}C$ and $900^{\circ}C$, but decreased at a temperature of $1100^{\circ}C$. The sound absorption properties of the carbonized MDF and the non-carbonized MDF were compared. The maximum sound absorption coefficient of the carbonized MDF was 12.38%. This was almost double of the value of the non-carbonized MDF.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.885-891
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• 2003

Effects of each acoustic property on absorption characteristics of polyester fiber materials has been studied in this paper. It would be impossible for us to measure effects of each acoustic property by experimental method since we cannot make sound-absorbing materials in which only one of the properties is changed. We have adopted a numerical prediction method to carry out parameter studies for each acoustic property. And to get a general behavior of acoustic performance of the materials, the numerical simulation has been repeated to several cases of different bulk density. Finally we have obtained frequency-dependent control factors in the absorption performance which gives us design capability of acoustic absorbing materials.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.236-237
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• 2014

Recently, it changes to the frame construction in the wall type structure for the life span improvement of the apartment house of our country. The execution of the light panel increased while the execution of the frame construction increased. Therefore, the density and absorption ratio of the magnesium oxide matrix according to the wood flour amount of addition ratio property try to be analyze for the lightweight of the surface material of the light panel. The test result, the density has been declined as the addition ratio increase of the wood flour. In the case of the water absorption ratio, water absorption ratio has been increased as addition ratio increase of wood flour. However, wood flour addition ratio 15% determined the most appropriate when considering the density and water absorption ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.208-211
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• 2003

In this paper, mechanical property of electric epoxy with water aging was discussed. We studied mechanical property of elastic resin after absorption in water from 0 to 484 hour. As a result, diffusion factor of elastic epoxy showed $20-21{\times}10^{-4}mm^2/s$ and general epoxy showed $9.5{\times}10^{-4}mm^2/s$. Elastic property increased linearly according to amount of addictives and decreased elastic property according to amount of water absorption. Tensile strength was reduced to add to addictives. It was effected by water absorption of micro-void of elastic epoxy. Hardness inclined to decrease after increasing according to absorbed time.

• Journal of the Korea Furniture Society
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• v.19 no.6
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• pp.420-427
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• 2008

To study the suitability of chestnut as a cask for ripening traditional liquors, the absorption property for pure water, liquor with 30% alcohol content and ethanol with 95% alcohol content were investigated for five species. Oriental oak had the greatest amount of liquid absorption while chestnut had the smallest amount. The absorption amount linearly increased with increasing soaking time. The absorption amounts for each section were greatest in RT plane, and the difference between LR plane and LT plane was very small for all soaking conditions. The anisotropy of absorption amount for five species was greatest in Japanese cedar and was smallest in white mulberry on the whole. And the change of absorption amounts according to soaking conditions tended to decrease in softwoods and increase in hardwoods, and the difference among wood species was not clear. From this result, it was found that chestnut with a small absorption amount, regarding of soaking behavior, was a good material as a cask for ripening traditional liquors, whereas small diameter oriental oak with a great absorption amount was not suitable in this purpose.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.429-434
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• 2005

In this paper, we investigated EM wave absorption property of EM wave absorbers prepared with sendust. The EM wave absorbers have good EM wave absorption properties in 1 GHz ${\sim}$ 3 GHz. On the other hand, the absorption band of the EM wave absorber coated with $Al(OH)_3$ larger than non-coated one. Pulverization effect of sendust on EM wave absorption properties was also investigated.

• Fashion & Textile Research Journal
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• v.20 no.4
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• pp.457-463
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• 2018

This study examined the water absorption and drying properties of the thirteen types of the knitted fabrics for sports wear. These physical properties were analysed with relation to the constituent fiber cross-sectional shape and structure parameters of the knitted fabrics by regression analysis. Absorption and drying properties of the knitted fabric specimens were increased with increasing the porosity of the constituent yarns, which was attributed to the capillary channels in the yarns. The water absorption and drying properties were increased and decreased with increasing tightness factor and stitch density of the knitted fabric. The absorption property of the knitted fabric for perspiration absorption and fast dry sport-wear clothing was mostly influenced mostly by fiber cross-sectional shape and its characteristics, whereas, drying property was dependent on the structural parameters of the knitted fabric such as tightness factor and stitch density. Therefore, superior perspiration absorption and fast drying knitted fabric could be obtained in the fabric structure with optimum tightness factor and stitch density, and constituent yarn structure with non-circular fiber crosssection and high porosity. GATS method and MMT method are used to measure sweating fast drying properties and it is necessary to carry out studies using these measurement methods in order to compare with the results of this study.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.33-37
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• 2004

Recently, Growing tendency for structure surface to use water repellent agent has increased steadily. But investigation of it's protection and durability property is not sufficient. Therefore, this paper shows the investigation about repellent property and micro structure's change in surface layer of mortar that is applied by water repellent agent. Water repellent property, absorption coefficient, air permeability, porosity and observation of micro construct was investigated according to water repellent agent type. The test results indicated that mortar applied water repellent agent appears tiny absorption coefficient, but air permeability is maintained. The reason is because silane solution is coating at capillary surface of a wall and minute pore structure is changeless.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.1
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• pp.29-34
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• 2008

The charcoal has been used not only as fuel but also as human health care material since it was used. Charcoal's performances were generally investigated in aspects of energy efficiency and caloric values. This study was conducted in order to increase charcoal's application area and to develop functional paper. Five types of charcoal were used on a basis of gas absorption properties from previous study. Handsheets were made by two methods by internal loading and surface spray on interlayer. Strength properties of internal loading and interlayer spray handsheets were decreased as the charcoal loading increased. Ethylene gas absorption property was higher in both of oak's black charcoal and white charcoal than others. In terms of strength, 5-10% charcoal loading was efficient. Above 10% loading, a rate of strength decrease was higher than that of ethylene gas absorption rate. Formaldehyde absorption property was higher at both of oak's black charcoal and mixed charcoal than others. However, to guarantee enough charcoal loading should be higher than 95 $g/m^2$ for sufficient formaldehyde absorption.

• Textile Coloration and Finishing
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• v.16 no.3
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• pp.22-30
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• 2004

The polyester fabrics were treated with the chitosan with various solubility in optimized treatment condition. The treatment method was discussed to be a high functional finishing for the polyester fabric to obtain the high moisture absorption and anti-microorganism property by evaluating the effect of the chitosan purification method on the yield and anti-microorganism property of the chitosan. On the other hand, soluble polyurethane was added to the chitosan treatment solution and/or plasma pretreatment was done. The addition of soluble polyurethane give a high add-on ratio as well as a linen like effect of treated polyester fabric. The results were as follows: 1. In the treatment of polyester fabric by the chitosan solution, a soluble PU resin and low temperature plasma treatment were done to obtain high binding force between the fabrics and the chitosan. The add-on rate and the moisture absorption ratio of the fabrics treated with the chitosan-PU after treated with the plasma slightly increased more than those of the fabrics treated with the chitosan only. 2. Anti-static property of the fabrics treated with the chitosan decreased rapidly with increasing of the chitosan concentration. The washing fastness of the fabrics treated with the chitosan-PU after treated with the plasma was better than those of the fabrics treated with chitosan only. The wrinkle resistance of the treated fabrics decreased constantly with the concentration of the chitosan. The bending rigidity of the treated fabrics increased greatly. On the treatment of polyester fabric under optimum condition, the microorganism reduction rate kept above 90％ after 10times launderings. 3. As the polyester fabrics which has flat yam was used as a weft yams were treated with the chitosan-PU as give a functional finishing effects such as durability, moisture absorption, anti-static and anti- microorganism property. Treated polyester fabric showed a good functional finishing effect and a linen like property.