• Journal of the Korea Institute of Building Construction
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• v.11 no.4
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• pp.379-386
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• 2011

Durability of concrete is an important issue, and one of the most critical aspects affecting durability is chloride diffusivity. Factors such as water.cement ratio, degree of hydration, volume of the aggregates and their particle size distribution have a significant effect on chloride diffusivity in concrete. The use of polypropylene fibers(particularly very fine and well dispersed micro fibers) or mineral additives has been shown to cause a reduction in concrete's permeability. The main objective of this study is to evaluate the manner in which the inclusion of fiber(in terms of volume and size) and blast furnace slag(BFS) (in terms of volume replacement of cement) influence the chloride diffusivity in concrete by applying 3D computer modeling for the composite structure and performing a simulation of the chloride penetration. The modeled parameters, i.e. chloride diffusivity in concrete, are compared to the experimental data obtained in a parallel chloride migration test experiment with the same concrete mixtures. A good agreement of the same order is found between multi.scale microstructure model, and through this chloride diffusivity in concrete was predicted with results similar to those experimentally measured.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.1
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• pp.60-77
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• 2000

Experimental studies were done to research effects of Leejungtang and Leejungtanggamibang on the anti-allergic effects. We studied the vacular permeability response induced by histamine and serotonin, homologous PCA provoked by IgE-like antibody against EWA, contact dermatitis induced by picryl chloride and delayed type hypersensitivity response to SRBC. The results were obtained as follows: 1. In effects of the Leejungtang and Leejungtanggamibang on the vascular permeability responses to intradermal serotonin, the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect. 2, In effects of the Leejungtang and Leejungtanggamibang on the vascular permeability responses to intradermal histamine, the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect. 3. In the homologous PCA provoked by IgE-like antibody against white albumin, the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect. 4. In the delayed type hypersensitivity responses to picryl chloride, the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect. 5. In the delayed type hypersensitivity responses to sheep red blood cell the Leejungtang revealed insignificant effect and Leejungtanggamibang revealed significantly inhibitory effect.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.259-262
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• 1999

In underground reinforced concrete structures, such as drainage structure, water and chloride ion penetrated into concrete through the cracks of concrete and its permeable property, cause the corrosion of reinforcing steel bar, which accelerates the expansive cracks and deterioration of concrete. It is necessary to control those deterioration of underground structure by improving its permeability and durability through the reasonable solutions in design, construction and materials. In the present study, fly ash concrete, which has good material properties in long-term period, was compared and studied with plain concrete using ordinary portland cement in terms of fundamental mechanical properties, permeability, drying shrinkage and durability. Also, the mix design and field test of low permeable concrete using fly ash were performed. From this study, fly ash concrete can control the penetration of water and chloride ion effectively by forming dense micro-structure of concrete. Therefore, fly ash concrete may increase the long-term function, performance and serviceability of underground structures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.81-84
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• 2002

Recently Bentonite mat is applied various structure : External waterproofing for underground structure, A reclaimed land, Artificial lake, Large-scaled civil structure, etc. With these various structure environment, water quality for application of Bentonite Mat affects watertightness. Specially spot with a large quantity of Chloride ion like salt water, degree of watertightness revelation is evaluated and applied. In this study, it is a main goal to investigate watertightness of Bentonite Mat with distilled water and salt water dissolved chloride ion Contents 0.88%. The result of this paper is as follows. 1) Water permeability coefficient of Bentonite Mat : distilled water(1.21$\times$10$^{-9}$cm/sec), salt water(3.12$\times$10$^{-7}$cm/sec). 2) Variation of thickness : distilled water(187%), salt water(108%). 3) Swelling ratio : distilled water(1500%), salt water(350%).

• The Journal of Pediatrics of Korean Medicine
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• v.4 no.1
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• pp.1-17
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• 1990

?In order to investigate effects of Zanthoxyli Fructus (Sample-A) and Fagarae mandshuricae Fructus (Sample-B), experimental study was performed through observation on isolated - ileum analgesic, hypothermal, anti-pyretic, anti-inflammatory, capillary permeability, blood flow rate, blood pressure and respiratory works. The results were as follows; 1. In spontaneous movement of mice isolated-ileum, both samples were noted to have strong inhibitory action after temporary contraction, and to show antagonism against acetylcholine chloride and barium chloride. 2. Both samples were showed to have antihistamin work on guinea pig isolated-ileum 3. In analgesic work by the acetic acid method, only Fagarae mandshuricae Fructus was proved to have significant analgesic effect in mice. 4. Both sample groups indicated anti-pyretic and anti-inflammatory effect. 5. Both samples were noted to have inhibitory effect against capillary permeability ?rise in mice. ?6. Both samples were noted to have dose-dependent falling effect on blood pressure in rabbits.

• Corrosion Science and Technology
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• v.15 no.1
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• pp.28-37
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• 2016

Due to the increased construction of offshore concrete structures and the use of de-icing salts for the purpose of snow removal, the needs for the development of anti-corrosive concrete are increasing. To solve these problems, an evaluation of the mechanical and durability properties for concrete were conducted by mixing modified-sulfur as 0 %, 5 %, 10 %, 15 % cement weight ratio. Both strengths and the properties affecting durability such as water absorption coefficient, chloride ion permeability, accelerated carbonation resistance, rapid freezing and thawing, and chemical resistance were evaluated. All evaluations performed were according to the test specifications associated KS. The results indicate that mixing of modified-sulfur lowed chloride ion permeability and improved chemical resistance.

• Geomechanics and Engineering
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• v.10 no.6
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• pp.807-826
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• 2016

In this study, aiming to investigate the effects of sulfate attack on cement stabilized highly plastic clay; an experimental study was carried out considering the effects of cement type, sulfate type and its concentration, cement content and curing period. Unconfined compressive strength and chloride-ion penetration tests were performed to obtain strength and permeability characteristics of specimens cured under different conditions. Test results were evaluated along with microstructural investigations including SEM and EDS analyses. Results revealed that use of sulfate resistance cement instead of normal portland cement is more plausible for soils under the threat of sulfate attack. Besides, it was verified that sulfate concentration is responsible for strength loss and permeability increase in cement stabilized montmorillonite. Finally, empirical equations were proposed to estimate the unconfined compressive strength of cement stabilized montmorillonite, which was exposed to sulfate attack for 28 days.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1651-1655
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• 2013

Anion exchange membranes for a vanadium redox flow battery (VRB) were prepared by pore-filling on a PE substrate with the copolymerization of vinylbenzyl chloride (VBC) and glycidyl methacrylate (GMA). The ion exchange capacity, water uptake and weight gain ratio were increased with a similar tendency up to 65% of GMA content, indicating that the monomer improved the pore-filling degree and membrane properties. The vanadium ion permeability and open-circuit voltage were also investigated. The permeability of the VG65 membrane was only $1.23{\times}10^{-7}\;cm^2\;min^{-1}$ compared to $17.9{\times}10^{-7}\;cm^2\;min^{-1}$ for Nafion 117 and $1.8{\times}10^{-7}\;cm^2\;min^{-1}$ for AMV. Consequently, a VRB single cell using the prepared membrane showed higher energy efficiency (over 80%) of up to 100 cycles compared to the commercial membranes, Nafion 117 (ca. 58%) and AMV (ca. 70%).

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.2
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• pp.165-181
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• 2000

Sinichengpaeum has been widely used in the oriental medical treatment of nasal diseases. These studies were performed done to investigate the effect of Sinicheng- paeum on the anti-allergic action We studied the vascular permeability response induced by the histamine and serotonin injection(allergy Ⅰ type), homologous PCA provoked by the IgE-like antibody against EWA(allergy Ⅳ type), contact dermatitis induced by picryl chloride(allergy Ⅳ type), delayed type hypersensitivity response to SRBC (allergy Ⅳ type), and the amount of eosinophil and IgE. The results were as follows: 1. The effect of Sinichengpaeum on vascular permeability responses to intradermal histamine and serotonin were significant. 2. In the homologous PCA provoked by the IgE-like antibody against white egg albumin, Sinichengpaeum showed a significant effect. 3. In the delayed type hypersensitivity responses to picryl chloride, Sini-chengpaeum provoked a significant effect. 4. After reaction provoked by picryl chloride, Sinichengpaeum showed an insignficant effect on amount of eosinophil, but a significant effect in IgE amount. 5. In the delayed type hypersensitivity responses to SRBC, Sinichengpaeum provoked a significant effect. 6. After reaction provoked by SRBC, Sinichengpaeum showed a significant effect on amount of cosinophil, but an insignificant effect in IgE amount.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.207-212
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• 2002

Reportedly, the use of mineral admixtures make concrete more durable and tighten against water. But, it is needed to study more about the relationship between the admixtures and the chloride ion diffusion. When concrete is mixed with fly-ash, pozzolanic reaction occur to time. So we should consider the factors that can evaluate inner structure of concrete in order to evaluate the chloride diffusion of the concrete more accurately. Therefore, in this study, we analyzed the correlation between chloride ion diffusion and physical properties such as compressive strength, void ratio, air permeability of the concrete, and tried to use them as fundamental data for analyzing chloride ion diffusion mechanism of the concrete mixed with fly-ash.