• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.8
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• pp.547-555
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• 2008

The effects of paper properties such as density, air permeability, water vapor transmission rate on the thermal performance of plate-type enthalpy exchanger were experimentally investigated. Papers having different properties were made from the same pulp by calendering or refining. Enthalpy exchanger samples were made from the papers, and were tested according to the standard test procedure (KS B 6879). Effective efficiencies were obtained, which accounted for the air leakage between supply and exhaust streams. Results showed that paper density affected the sensible heat transfer of the samples. Sensible heat transfer increased with density of the paper. It was also shown that effective efficiency of latent heat transfer was approximately the same independent of the samples, which suggests that papers made of the same pulp show similar water vapor transmission characteristics independent of the degree of calendering or refining. Best performance was obtained for the sample having highest paper density and moderate water vapor transmission ratio.

• Proceedings of the Korean Fiber Society Conference
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• 2001.04a
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• pp.197-200
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• 2001

• Membrane Journal
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• v.16 no.2
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• pp.115-122
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• 2006

In this study the membrane preparation and water vapor permeation of the hydrophilic polymer materials, polyaminosiloxane and polyhydroxylsiloxane, used as the coating materials for the preparation of asymmetric flat and hollow fiber membranes were investigated. And the water vapor permeation towards air permeation and their permselectivity were intensively studied for the resulting Resin A/Resin C (coupling agent) and Resin B/Resin C membranes. The water vapor permeability for 3 wt% Resin C introduced into Resin A (Resin A/Resin C) membrane was higher than for 1 and 5 wt% membranes and also water vapor permeability increased with increasing operating temperatures. In addition, at this content of 3 wt% Resin C, the absorption capability became maximum through dynamic equilibrium absorption experiment. Water vapor permeability, 43578 Barrer (1 Barrer = $10^{-10}cm^3(STP){\cdot}cm/cm^2{\cdot}s{\cdot}cmHg$) and 53000 Barrer, and the selectivity of $P(H_2O)P(Air)$, 101.3 and 102.6 were shown at 25 and $35^{\circ}C$, respectively.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.247-252
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• 2001

The need to determine the permeability of organic vapors to polymeric films such as aromas, flavors, etc. has significantly increased in the food industry because of preservation and safety issues along with migration problems. However, due to the complex nature of the permeation process, there have been few investigations compared to nonorganic compounds. In this paper, we review the history of permeability studies and typical methods of permeability measurement such as the isostatic method and quasi-isostatic method for organic vapors. New instrumental developments and significant findings are also introduced and discussed.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.1
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• pp.72-79
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• 1998

Journal of the Korean Society of Clothing and Textiles Vol. 22, No. 1 (1998) p. 72∼79 The purpose of this study was to investigate the effects of geometrical structure and fiber type on the water vapor transport properties of nonwoven batting materials. Two types of fiber were used such as polyester and wool. Correlation between physical properties of nonwovens and water vapor transport rate was analyzed by Pearson Correlation. Steady and dynamic state water vapor transport properties were measured by absorption, evaporation and cobaltots chloride method respectively. The results were as follows: 1) In geometrical structure, thickness of nonwovens was effected on absorption and evaporation rate and air permeability was more influencing factor on water vapor transport rate than porosity. There were no decreasing of water vapor transport rate in hydrophilic fiber at high relative humudity. 2) The hydrophilicity of fiber affected steady and dynamic state water vapor permeabilities and wool nonwoven showed higher water vapor transport rate than polyester at high relative humidity. 3) Thickness showed higher correlation coefficient with water vapor transport rate than other physical properties of nonwovens.

• Textile Coloration and Finishing
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• v.25 no.1
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• pp.30-36
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• 2013

Swelling and subsequent deformation of membranes by water wetting are regarded as a prime drawback of hydrophilic polyurethane breathable film. Fluoroalkylated surface was prepared by reacting the film with hexamethylene diisocyanate(HDI) and 2-perfluorohexyl ethanol. IR spectra and XPS results showed that the fluoroalkyl group was successfully introduced to the film surface with hexamethylene linkage. Water contact angle was increased from $68.7^{\circ}$ up to $144.2^{\circ}$ with the degree of fluoroalkylation. Decrease in water-vapor permeability was minimized even for the film of highest fluoroalkylation.

• Journal of the Korean Society for Railway
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• v.3 no.3
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• pp.101-108
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• 2000

In this study, we tested hybrid pilot system combined with soil vapor extraction and bioventing methods on the contaminated railroad soil. So, we found out the remediability and operating conditions. Air permeability(k) and gas phase(O$_2$/CO$_2$/VOCs) level trend are very important to determine the remediation rate of the contaminated sites. Throughout hybrid pilot test on different conditions, the range of air permeability(k) was 1985∼1194 darcy. The tests results in hybrid system was appropriate on this test sites, and the suitable injection air flow rate was 3.5㎥/hr. So, we suggested a basic data for the remediation and management of contaminated railroad soil.

• Textile Coloration and Finishing
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• v.26 no.4
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• pp.322-330
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• 2014

The phospholipid-based MPCE(2-Methacryloxyethyl Phosphoryl Chlorine) copolymer was mixed with wet polyurethane for coating of nylon fabrics. The substitution rate of water in coagulation bath with DMF was changed under control of the size of formed hydrophilic microporous cell enable to manufacture excellent breathable, anti-bacterial and moisture control fabrics. Biocompatible property, vapor permeability, hydrostatic pressure, moisture management and anti-bacterial property were investigated for treated nylon fabrics. In result, increased moisture transmission rates, decreased water resistance and outstanding moisture control property could be confirmed by enhanced hydrophilicity of wet-coated nylon fabric with MPCE copolymer.

• Carbon letters
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• v.15 no.1
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• pp.50-56
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• 2014

We prepared ethylene vinyl alcohol (EVOH)/graphene oxide (GO) membranes by solution casting method. X-ray diffraction analysis showed that GOs were fully exfoliated in the EVOH/GO membrane. The glass transition temperatures of EVOH were increased by adding GOs into EVOH. The melting temperatures of EVOH/GO composites were decreased by adding GOs into EVOH, indicating that GOs may inhibit the crystallization of EVOH during non-isothermal crystallization. However, the equilibrium melting temperatures of EVOH were not changed by adding GOs into EVOH. The oxygen permeability of the EVOH/GO (0.3 wt%) film was reduced to 63% of that of pure EVOH film, with 84% light transmittance at 550 nm. The EVOH/GO membranes exhibited 100 times better (water vapor)/(oxygen) selectivity performance than pure EVOH membrane.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.303.1-303.1
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• 2016

Polymer-like amorphous carbon films were deposited on polyethylene naphthalate (PEN) substrate by plasma-enhanced chemical vapor deposition (PECVD) and their water vapor transmission rates (WVTR) were tested. propane was used as precursors. To make a polymer-like amorphous carbon film the deposition rate, surface roughness, light transmittance, and WVTR of the films were characterized as a function of the precursor feed ratio and plasma power. The water vapor transmission rates of bare PEN film and single layer PAC on PEN substrate were 6.95 g/m2/day and 0.3 g/m2/day, respectively. The superior property the water vapor permeability of thin layers of PAC was attributed to uniform coverage and good adhesion between PAC film and PEN substrate.