• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.482-488
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• 2017

The measurement based on reliable standard operating procedures (SOPs) is important for consistent information. The objective of this study is to investigate reliable SOPs of soil physical methods, including core method for bulk density, Yamanaka hardness, and air permeameter method for air permeability. The coefficients of variation in bulk density (core method), Yamanaka hardness, and air permeability were ranged of 1~6%, 8~13%, and 10~84%, respectively. The variation in situ measurement such as bulk density, hardness, and air permeability due to spatial variability at measuring site was larger due to the number of replicates, organic matter content, and soil texture. Nevertheless, air permeability had different values as different number of replicates, and thus, it is thought that more replicates can result in higher reliability. It suggested that investigation of soil physical properties for the target sites should required to consider about soil texture, organic matter content, and number of replications before measurement. In conclusion, core sampling for bulk density measurement in upland soil recommended to perform in 3 repetitions with 2 inch core, and 3 inch core sampling for higher organic matter content.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.400-406
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• 2023

In this study, the relationship between the material properties and air permeability characteristics was examined, an experimental method to analyze the air permeability characteristics was presented, and experimental results were derived. The effects of compressive strength and apparent density of hardened concrete on air permeability characteristics were evaluated experimentally. Focusing on the mix proportions used in nuclear power plant concrete structures, concrete test specimens were manufactured and air permeability characteristics were measured according to changes in binder, maximum aggregate size, and water-binder ratio. The apparent density was over 2,400 kg/m³ for the OPC mix and the FA-35 mix, and the air permeability for both mixes were low, in the range of 0.1-0.2 L/min. On the other hand, in the case of the combination of FA-40, FA-45, and FA-M, the apparent density was measured to be less than 2,400 kg/m³ and the air permeability was measured to be more than 0.3 L/min, experimentally verifying that the apparent density is an important factor in air permeability characteristics.

• Journal of the Korean Wood Science and Technology
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• v.46 no.2
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• pp.149-154
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• 2018

The changes in sound absorption capability and air permeability of Malas wood after high temperature heat treatment were investigated. The average air permeability of Malas in longitudinal direction after heated under the temperature of $190^{\circ}C$ during 3 hours was about 23.48 darcys and that of control was about 3.11 darcys. The noise reduction coefficients of Malas specimens were 17% for treatment and 10% for control. The means of sound absorption coefficient of specimens in the frequency range of 50~6,400 Hz were 42% for treatment and 17% for control, respectively.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.293-296
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• 2004

The objective of this study was to decide the designing factor for remediaton of the contaminated site. The soil and ground-water samples were analyzed and hydro- geological characteristics was assayed for the survey of pollution level. Also air-permeability test and MPN(most probable number) test were conducted for selecting the designing factor. The contaminants were mainly found in north-west part of the site and were expected to move toward the south. Ex-situ technology was expected more useful than in-situ one with the results of air-permeability test saying that air permeability was relatively low. Additional microbes were expected for remediation efficiency because residual microbes were loosely populated. The choosing of the designing factor was requisite for remediation of contaminated site.

• The Research Journal of the Costume Culture
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• v.11 no.3
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• pp.423-430
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• 2003

Cotton fabric md nylon fabric were chosen as base fabric specimens for dyeing using Japanese pagoda tree colorants through chitosan, treatment. With the chitosan treatment, the dye-uptake of the treated fabric increased. This treatment is also expected to be effective in terms of environment-friendliness. The effect of the dyeing methods, mordanting or non-mordanting, and chitosan treatment on the dye-uptake and air permeability of the treated fabrics was investigated. In case of cotton fabric, Al mordanted dyeing resulted in higher dye-uptake through the chitosan treatment. Therefore, the chitosan treatment is effective in this case. Japanese pagoda tree seems to have direct affinity for nylon fabric without the mordanting treatment. In case of cotton fabric, it seems that the cellulose molecules, colorants, and the chitosan make a complex, thereby reducing the air permeability. In case of nylon fabric, due to the fact the Japanese pagoda tree colorant molecules form direct physical bonding with the nylon molecules, it seems that there is not much of air permeability reduction.

• The Research Journal of the Costume Culture
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• v.11 no.3
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• pp.431-440
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• 2003

The purpose of this study is to investigate the feasibility of applying the chitosan for a natural mordant. The chitosan, a natural chelate macromolecule, is acquired from the crustacean. Investigation was focused on the change of the dyeability according to the chitosan treatment based on the Caesalpinia sappan and the color change of the dyed fabric according to the application of heavy metal mordant. The change of air permeability of the fabric with the dyeing condition was also investigated systematically. The effect of dyeing with/without mordant on the air permeability of the fabric after the chitosan treatment. It seems that the increase in the dye-uptake is attributable to the fact that chitosan forms a complex with the Caesalpinia sappan and Al during mordant dyeing of cotton fabric. For nylon fabric, the darkest color was achieved on the occasion of non-mordant dyeing of the fabric. The mordant treatment or chitosan treatment, however, reduced the dyeability. While the dyed nylon fabric could maintain the same air permeability as the grey nylon fabric, the cotton fabric lowered the air permeability after dyeing.

• Journal of the Korean Wood Science and Technology
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• v.27 no.1
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• pp.79-87
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• 1999

To use the agricultural residues as the raw material of molded packaging material, the packaging trays were manufactured from rice-straw pulp. The physical properties were measured to compare non-treated trays with the addition trays, such as the addition of starch, rosin size, carboxymethyl cellulose(CMC), polyethylene glycol(PEG), alkylketene dimer(AKD), polyacryl amide(PAM). The results were as follows : 1. In the addition of starch, air permeability at addition of 5% was highest. Bursting strength and tensile strength were smaller than non-treated trays. 2. In the addition of rosin size, air permeability, bursting strength and tensile strength were smaller than non-treated trays. 3. In the addition of CMC, air permeability was higher than non-treated trays. Bursting strength and tensile strength were similar to non-treated trays. 4. In the addition of PEG, air permeability was higher than non-treated trays. Bursting strength at addition of 3% was the highest and tensile strength was smaller than non-treated trays. 5. In the addition of AKD, air permeability at addition of 1% and 5% was higher than non-treated trays. Bursting strength and tensile strength were smaller than non-treated trays. 6. In the addition of PAM, air permeability at addition of 0.01% was the highest. Tensile strength at addition of 0.01% were higher than non-treated trays. 7. The water absorption of the trays decreased with increasing adding of natural additives.

• The Research Journal of the Costume Culture
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• v.13 no.4 s.57
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• pp.540-549
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• 2005

It was the purpose of this study to investigate the effect of chitosan treatment and mordanting on the air-permeability, fastness of the dyestuff to washing, fastness of the dyestuff to light, and antimicrobial effect of cotton and nylon fabrics dyed using Rhusjara ica. In the dyeing experiment, examinations were made on the difference between the chitosan treated fabrics and chitosan untreated fabrics, and on the difference according to the type of mordanting agents and the mordanting methods. Dyeing was carried out for the chitosan treated and untreated fabrics under the conditions of non-mordanting and Al, Sn, Fe mordanting. As a result, due to the dye-uptake of the dyestuff component of the Rhusjara ica, the air-permeability values decreased considerably. And due to the action of the mordanting agents, the air-permeability decreased also. The air-permeability decreased more conspicuously in the case of the dyestuffs uptake to the chitosan components than in the case of the dyestuffs uptake to the cotton fibers or nylon fibers. Nylon dyed fabric exhibited better wash fastness than the cotton dyed fabric. As the number of washing increased, the color of the cotton fabric specimens and nylon fabric specimens, dyed using Rhusjara ica, shifted toward yellowish. The light fastness values were in the range of grade 1${\~}$2, which were very inferior. The light fastness values did not improve according to the mordanting or to the chitosan treatment. In the case of chitosan untreated fabrics dyed using Rhusjara ica, the growth rate of the bacteria promoted, on the contrary, compared to that of the control white fabric.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.59-67
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• 2015

PURPOSES : In this study, an image analysis method is used to evaluate the pore structure characteristics and permeability of hybrid concrete. METHODS : The binder weight of hybrid concrete is set to $400kg/m^3$, $370kg/m^3$, and $350kg/m^3$, and for each value of binder weight, the pore structure and permeability of concrete mixture is evaluated. The permeability of hybrid concrete is evaluated using a rapid chloride penetration test(RCPT). RESULTS : The concrete pore structure characteristics of hybrid concrete reveals that as the binder weight is reduced, the entrained air is reduced and the entrapped air is increased. The permeability of the hybrid concrete for all values was measured to be below 1000 C, which indicates a "Very Low" level of permeability relative to the evaluation standard of KS F 2711. Additionally, as the binder weight is decreased, there is a significant increase in the permeability of chloride ions. CONCLUSIONS : In this study, the pore structure characteristics of hybrid concrete at different binder weights shows that as the binder weight is reduced, the entrained air is reduced and the entrapped air is increased. Consequently, chloride ion penetration resistance of the hybrid concrete is diminished. As a result, it is expected that this will reduce the concrete's durability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.645-648
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• 2005

The grounds of multipurpose practical use degree are built much holding world cup 2002 but material that is used in this building most external membrane ceiling is accomplishing PTEE A master and servant. Therefore, this research analyzed assessment about sound absorption special quality that measure ventilation quantitys of 10 act material and analyze correlation with Air Permeability and the sound absorption rate, and follow in change of layer of air of inside facts material. Result is as following. When Air Permeability good dimension is 5$\sim$15 cc/cm$^2$/sec and acoustic absorptivity is the best as Air Permeability result that measure acoustic absorptivity of inside facts material particularly firstly, could know 8$\sim$9 cc/cm$^2$/sec love. When establish sound absorption inside facts in external membrane as result that measure acoustic absorptivity of inside (acts material secondly, could know that acoustic absorptivity is good though become about minimum back layer of air 900mm.