• Nuclear Engineering and Technology
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• v.31 no.2
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• pp.139-150
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• 1999

The swelling pressure of a potential buffer material was measured and the effect of dry density, bentonite content and initial water content on the swelling pressure was investigated to provide the information for the selection of buffer material in a high-level waste repository. Swelling tests were carried out according to Box-Behnken's experimental design. Measured swelling pressures were in the wide range of 0.7 Kg/$\textrm{cm}^2$ to 190.2 Kg/$\textrm{cm}^2$ under given experimental conditions. Based upon the experimental data, a 3-factor polynomial swelling model was suggested to analyze the effect of dry density, bentonite content and initial water content on the swelling pressure The swelling pressure increased with an increase in the dry density and bentonite content, while it decreased with increasing the initial water content and, beyond about 12 wt.% of the initial water content, levelled off to nearly constant value.

• Textile Coloration and Finishing
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• v.23 no.2
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• pp.118-130
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• 2011

In this study, hydrophilic polyurethane (PU) was synthesized by one shot process to get good non-swelling effect and to keep high breathability using reactive silicone oil of mono terminal and bi-terminal types. We also blended non reactive silicone oil with pure hydrophilic PU to compare non-swelling effect and breathability with hydrophilic PU synthesized by the two types of reactive silicone oils. The hydrophilic films were analyzed by nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photo electron (XPS) spectroscopy, energy dispersive spectrometry (EDS), breathability, waterproofness, tensile strength, contact angle and swelling effect. The results showed that the film made by hydrophilic PU which was synthesized with mono terminal type silicone oil provided good non-swelling effect and acceptable moisture permeability due to the modified surface properties.

• Journal of Biomedical Engineering Research
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• v.18 no.2
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• pp.167-172
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• 1997

Novel measurement method has been performed for the noninvasive study of the swelling effect detected in hydrophilic polymers using Magnetic Resonance Microscopy. iN NMR images were acquired to measure geometric changes due to the swelling effect occurred in the polymer specimens. In addition to the geometric changes, the water ingress process was visualized noninvgsively. The measurement method performed .in the present study utilized some of NMR's valuable properties, both noninvasiveness and parameter selectivity. It is believed that the method used in the present study may be applicable to the study of biopolymers in which noninvasiveness is particularly important.

• Geomechanics and Engineering
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• v.29 no.1
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• pp.91-97
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• 2022

The cohesive non-swelling soil (CNS) cushion technology has been widely applied in the subgrade and slope improvement at expansive soil regions. However, the mechanism of the inhibition effect of the CNS layer on expansive soil (ES) has not been fully understood. We performed four outdoor model tests to further understand the inhibition effect, including different kinds of upper layer and thickness, under the unidirectional seepage condition. The swelling deformation, soil pressure, and electrical resistivity were constantly monitored during the saturation process. It is found that when a CNS layer covered the ES layer, the swelling deformation and electrical resistivity of the ES layer decreased significantly, especially the upper part. The inhibition effect of the CNS layer increases with the increase of CNS thickness. The distribution of vertical and lateral soil pressure also changed with the covering of a CNS layer. The electrical resistivity can be an effective index to describe the swelling deformation of ES layer and analyze the inhibition effect of the CNS layer. Overall, the CNS deadweight and the ion migration are the major factors that inhibit the swelling deformation of expansive soil.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1996.12a
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• pp.70-70
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• 1996

The cytotoxicological effect of Bt 1-endotoxin, well-known as a bioinsecticide, was investigated on ion channel of insect cell lines. This study attempted to evaluted the specificity by simple experiment to measure the cell swelling using lepidopteran cell lines in isotonic solution containing only one cation. Cell swelling was stimulated in KCI-sucrose isotonic solution as well as TC-100 media containg in solubilized crystal 5-endotoxin. It suggested that the cell swelling by Bt toxin have a relation to K+ channel. The cell swelling may be due to the stimulation K+ influx and simultaneously the penetration of H2O induced by Bt toxin, because the stimulation of swelling was observed with the solubilized toxin in KCI-sucrose isotonic solution, but not in sucrose isotonic solution. Moreover the specific K+ channel blocker, such as 4-arnjnopyrimidine(4-AP) and ouabain, showed the significant effect on the cell swelling induced by Bt toxin. The increasement of the cell swelling induced by 4-AP suggested to be caused by the block of K+ efflux through K+ leak channels. The inhibition of cell swelling by ouabain, which is the well-known inhibitor of Na+, K+-ATPase, suggested to be due to decreasement of K+ influx following diminishment of Na+, K+-ATPase activities.

• Journal of the Mineralogical Society of Korea
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• v.30 no.2
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• pp.71-81
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• 2017

Rock properties and the effects of chemicals that were used for conservation were studied for effective conservation treatment of Seated Buddha rock carving, which is composed of grayish white tuff, at Golguram Hermitage, Gyeongju. The rocks contain 3-5% montmorillonite, a swelling mineral and reacting with water, the d spacing of swelling minerals was increased (1.54-2.69%). On the one hand, the physical properties of the rock samples, such as surface hardness, water absorption rate, and porosity improved after the application of ethyl silicate-based stone strengthener. On the other, the interlayer of swelling minerals decreased and greater the of swelling mineral content, the greater is the extent of swelling (4.23-12.12%). When the ethyl silicate-based stone strengthener was applied after pretreatment with a swelling inhibitor, the physical properties were similar to those of the stone strengthener alone. There was no interlayer spacing change of swelling minerals due to swelling inhibition treatment; however, when the stone strengthener was applied after the swelling inhibitor, interlayer changes were similar to those when only the stone strengthener was treated (4.10-11.85%). Though the peak intensity of swelling minerals in X-ray diffraction pattern decreased, the effect of the swelling inhibitor was almost negligible. Therefore, it is not appropriate to use ethyl silicate-based stone strengthener for Golgulam rock containing swelling minerals and supplementing them with a swelling inhibition system is not effective. Because weathering rapidly progresses when swelling minerals contact moisture, for now, measures to prevent water contact, such as expansion of the canopy, are needed in the lower and side parts of the carving.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.220-223
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• 2006

To investigate the effect of solution pH and particle size of Na-bentonite on swelling characteristics and relative hydraulic conductivity, four kinds of acids and two alkali were selected. The results showed that the swelling was decreased to half of the original Na-bentonite's swelling index. Also the decrease in SI was most distinctive in pH 3.5 of HCl. But changes of swelling index between initial and stabilized were minimal in alkali treatment, compared to the change by acid treatment. No flux was detected under atmospheric pressure although there was drastic decrease in swelling. However, leaching started after application of 1.5 bars of air-pressure equivalent to 15 m of water head.

• Journal of Korean Foot and Ankle Society
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• v.24 no.1
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• pp.31-36
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• 2020

Purpose: Leg elevation is known as an effective method for reducing leg swelling, and it has been routinely used in medical practice. However, the effect of swelling reduction in relation to the degree of elevation height is not known. This study evaluated the swelling of the leg after acute ankle fracture operations at two different elevation heights and the elevated leg heights were compared. Materials and Methods: A total of 66 patients with postoperative acute ankle fractures were classified into two groups depending on the presence of different leg elevation heights: high-elevated (HE, case) and low-elevated groups (LE, control). We checked leg swelling, pain, subjective satisfaction for the elevation device, and the American Orthopedic Foot and Ankle Society (AOFAS) score, and we retrospectively compared them between both the groups. Results: Leg swelling and pain were reduced in both groups. However, they did not show any significant differences between both the groups (p>0.05). Nineteen patients in the HE group replied with uncomfortable, while no patients in LE group did so. The AOFAS score at 1 year postoperatively did not show any significant differences between both the groups (p=0.46). Conclusion: High elevation of the leg after ankle fractures did not show a significant difference from low elevation in regard to leg swelling, pain, and function. Furthermore, high leg elevation resulted in discomfort during the postoperative period. Thus, low elevation with a pillow is enough for acute ankle fracture patients with little discomfort and satisfactory swelling reduction.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.256-262
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• 2012

Hyaluronic acid(HA) hydrogels were synthesized by immersing HA microbeads in phosphate buffered saline solutions having different pH levels to assess the effect of pH on the swelling ratio of HA hydrogels for smart drug delivery systems. No beads were formed when the HA solution(below pH 9) was crosslinked with divinyl sulfone(DVS) because DVS is a basic solution. The variation regarding the size of the microbead was not significant, suggesting that the bead size is not a function of pH(10 ~ 14). However, the pore size of the microbeads decreased with increasing pH from 10 to 14, leading to the surface smoothness and dense network as a result of higher crosslinking. The swelling ratio of hydrogels increased when the pH rose from 2(acidic) to 6(neutral). Afterwards, it decreased with further increasing pH(basic). The lower swelling ratio may be due to the lack of ionization of the carboxyl groups. On the other hand, a higher swelling ratio is likely due to the increased electrostatic repulsions between negatively charged carboxyl groups on different chains. Experimental results suggested that pH-responsive HA hydrogels can be applicable to the controlled drug delivery systems.

• Macromolecular Research
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• v.13 no.6
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• pp.483-490
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• 2005

A novel, polysaccharide-based, superabsorbent hydrogel was synthesized through crosslinking graft copolymerization of methacrylic acid (MAA) onto kappa-carrageenan ($_{k}C$), using ammonium persulfate (APS) as a free radical initiator in the presence of methylenebisacrylamide (MBA) as a crosslinker. A proposed mechanism for $_{k}C$­g-polymethacrylic acid ($_{k}C$-g-PMAA) formation was suggested and the hydrogel structure was confirmed using FTIR spectroscopy. The effect of grafting variables, including MBA, MAA, and APS concentration, was systematically optimized to achieve a hydrogel with the maximum possible swelling capacity. The swelling kinetics in distilled water and various salt solutions were preliminarily investigated. Absorbency in aqueous salt solutions of lithium chloride, sodium chloride, potassium chloride, calcium chloride, and aluminum chloride indicated that the swelling capacity decreased with increased ionic strength of the swelling medium. This behavior can be attributed to the charge screening effect for monovalent cations, as well as ionic crosslinking for multivalent cations. The swelling of super absorbing hydrogels was measured in solutions with pH ranging from 1 to 13. In addition, the pH reversibility and on-off switching behavior, at pH levels of 3.0 and 8.0, give the synthesized hydrogels great potential as an excellent candidate for the controlled delivery of bioactive agents.