• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 1996년도 춘계 총회 및 학술발표회
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• pp.55-56
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• 1996

Heterophase polymer system has been attractive for a potential applicability to gas separation membrane material. It has been known that there is a trade-off between gas permeability and its selectivity in common polymers. Therefore, the heterophase polymer can be an alternative for a gas separation membrane material because its transport properties can be readily controlled by blending of two different polymers. The transport properties of immiscible polymer blends strongly depend upon the intrinsic transport properties of corresponding polymers. Another important factor to determine the transport properties is their morphology: volume fraction, size and shape of dispersed phase. Although the effect of the volume fraction of the dispersed phase on the transport properties has been widely investigated, the size and shape effects have been paid attention very much. In an immiscible polymer blend of two polymers, its morphology is primarily controlled by its volume fraction of dispersed phase. Therefore, the effect of the size of the dispersed phase can be hardly seen. Therefore, a block copolymer has been commonly employed to control their morphology when each block is miscible with one or the other phase. In this work, gas transport properties will be measured by varying the morphology of the heterophase polymer membrane. The transport properties will be interpreted in terms of their morphology. The effect of the volume fraction of the PI phase and, in particular, its size effect will be investigated experimentally and theoretically.

• Journal of the Korean Society of Clothing and Textiles
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• 제22권1호
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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.

• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3766-3777
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• 2022

It is essential to ensure the safety of spent nuclear fuel (SNF) transport cask in drop situation that is included in transport accident scenarios. The safety of the drop situation is affected by the impact absorption performance of impact limiters. Therefore, when designing an impact limiter, the uncertainty in the material properties that affect the impact absorption performance must be considered. In this study, the material properties of the wood inside the impact limiter were selected as the variables for a parametric study. The sensitivity analysis of the drop response of the SNF transport cask with impact limiter was performed. The minimum wood strength required to prevent a direct collision between the cask and floor was derived from the analysis results. In addition, the plastic strain response was analyzed and strain-based evaluation was performed. Based on this result, the critical values of wood properties that change the impact dynamic characteristics were investigated. Finally, the optimal material properties of wood were obtained to secure the structural safety of the SNF transport cask. The results of this study can contribute to the development of SNF transport cask, thereby ensuring safety in transport accident conditions.

• Polymer(Korea)
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• 제25권5호
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• pp.719-727
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• 2001

Recently it was found that the charge carrier transport properties are significantly enhanced due to effective intermolecular $\pi$-orbital overlapping and low disorder of hopping sites caused by self-organization of liquid crystal molecules. In this study, the xerographic properties of a double-layer photoconductor doped with nematic liquid crystal, 4-pentyl-4'-cyanoterphenyl (5CT), as a charge-carrier transport material to enhance the charge-tarrier mobility were investigated. From the results of measured surface voltage properties for the photoconductor doped with various concentrations of liquid crystal, 5CT, the initial voltage was found to increase with the concentration of 5CT and the dark decay decreased with the concentration of 5CT. The highest sensitivity was obtained at a specific concentration, 40wt% 5CT. The fluorescence behavior of the carrier transport layer (CTL) was also investigated. It was found that the charge-carrier transport properties of the organic photoconductor depend on the charge-carrier transport properties of the complex. The TNF : 5CT (40 wt%) and OXD : 5CT (40 wt%)samples showed the highest sensitivity because the greatest charge transport complex was termed between the charge-carrier transport materials in these samples.

• Journal of the Korean Ceramic Society
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• 제53권3호
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• pp.273-281
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• 2016

This review examines computational simulations of thermoelectric properties, such as electrical conductivity, Seebeck coefficient, and thermal conductivity. With increasing computing power and the development of several efficient simulation codes for electronic structure and transport properties calculations, we can evaluate all the thermoelectric properties within the first-principles calculations with the relaxation time approximation. This review presents the basic principles of electrical and thermal transport equations and how they evaluate properties from the first-principles calculations. As a model case, this review presents results on $Bi_2Te_3$ and Si. Even though there is still an unsolved parameter such as the relaxation time, the effectiveness of the computational simulations on the transport properties will provide much help to experimental scientist researching novel thermoelectric materials.

• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 1996년도 춘계 총회 및 학술발표회
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• pp.30-32
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• 1996

Although the transport of small molecules through polymer membranes has been extensively studied for a long time, understanding of the transport mechanism is still far from satisfactory. This in turn makes difflcult the search for new membrane materials with the desired transport characteristics. Therefore it is of the utmost interest to study the correlations between a polymer's structure and morphology and its transport properties. Generally, polyurethanes serve as excellent polymer materials for such studies since their physical and chemical properties can be widely and systematically modified by varying the length, composition and chemical structure of the hard and soft segments. In this paper liquid crystalline polyurethanes are presented as new membrane materials for liquld separation and their transport properties with respect to molecular and supermolecular-structure are discussed.

• Bulletin of the Korean Chemical Society
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• 제35권5호
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• pp.1559-1561
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• 2014

• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.418-422
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• 2009

We synthesized new electroluminescence materials [(1,10-phenanthroline)(8-hydroxyquinoline)] Zn(phen)q and investigated their electron transport properties. We used Zn(phen)q and $Alq_3$ for the conductive materials and measured their electron transport properties as a function of the organic layer thickness. The difference between Zn(phen)q and $Alq_3$ as electron transporting materials suggests that the electrical properties depends on the carrier injection.

• BMB Reports
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• 제32권5호
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• pp.429-435
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• 1999

Unlike the mammalian glucose transporter GLUT1, little is known about the nature of the endogenous sugar transporter(s) in insect cells. In order to establish the transport characteristics and other properties of the sugar transport proteins of Sf9 cells, a series of kinetic analyses was performed. A saturable transport system for hexose uptake has been revealed in the insect cells. The apparent affinity of this transport system(s) for 2-deoxy-D-glucose was relatively high, the $K_m$ for uptake being <0.5 mM. To further investigate the substrate and inhibitor recognition properties of the insect cell transporter, the ability of other sugars or drugs to inhibit 2-deoxy-D-glucose transport was examined by measuring inhibition constants ($K_j$). Transport was inhibited by D-mannose, D-glucose, and D-fructose. However, the apparent affinity of the C-4 epimer, D-galactose, for the Spodoptera transporter was relatively low, implying that the hydroxyl group at the C-4 position may play a role in the strong binding of glucose and mannose to the transporter. The results also showed that transport was stereoselective, being inhibited by D-glucose but not by L-glucose. It is therefore concluded that insect cells contain an endogenous glucose transport activity that in several aspects resembles the human erythrocyte glucose transporter. However, the mammalian and insect transporters were different in some of their kinetic properties, namely, their affinities for fructose and for cytochalasin B.

• International Journal of Contents
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• 제13권1호
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• pp.45-52
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• 2017

Carbon Capture and Storage (CCS) technologies involve three major stages, i.e., capture, transport, and storage. The transportation stage of CCS technologies has received relatively little attention because the requirements for $CO_2$ transport differ based on the industry-related conditions, geological, and demographical characteristics of each country. In this study, we analyzed the properties of $CO_2$ transport using a pipeline. This study has important implications for ensuring the stability of a long-term CCS as well as the large cost savings, as compared to the small cost ratio as a percentage of the entire CCS system. The state of $CO_2$, network topologies, and node distribution are among the major factors that influence $CO_2$ transport via pipelines. For the analysis of the properties of $CO_2$ transport using a pipeline, the $CO_2$ pipeline connections were visualized by the simulator developed by Lee [11] based on the network topologies in $CO_2$ transport. The case of Korean CCS technologies was applied to the simulation.