• Journal of IKEEE
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• v.27 no.1
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• pp.85-92
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• 2023

Recently, as the era of the 4th Industrial Revolution approaches, IoT devices that emphasize portability are increasing. At the same time, battery usage is also increasing rapidly. With the rapid increase in battery usage, issues related to battery safety have become inevitable problems and many studies have been conducted. This paper deals with explosion issues caused by swelling among various battery issues, and includes research and development of a system that detects battery swelling by identifying resistance changes. The core technology of this study is to develop a system that frequently detects changes in the resistance of wires drawn on the battery through changes in volume that occur when the battery swelling, and uses the resistance changes to prevent battery explosion. In addition, through pattern analysis, it was analyzed how the wire should be constructed to cause a lot of resistance changes.

• 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 the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.215-222
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• 2020

Metformin is a recommended first-line therapy drug for type 2 diabetes patients. However, compared to other oral antidiabetic drugs (OAD), metformin has a large unit dosage, with bioavailability of 40-60%. This limiting bioavailability is because metformin is absorbed only in the upper gastrointestinal tract as a BCS class 3 drug. Hence, we propose that applying the Gastroretentive Drug Delivery System (GRDDS) and extending drug release time in the stomach will result in improved bioavailability. We selected the swelling type delivery system, as it is considered the most stable gastroretention technology compared to other GRDDSs. We modified the swelling excipient by using a natural swelling excipient to form a swelling tablet made of carrageenan and hydroxypropyl methylcellulose (HPMC). Our results indicate that the swelling complex tablet made of carrageenan and HPMC has a good swelling ability and shows required sustained release in a dissolution pattern. In addition, the carrageenan complex has a better swelling ability than the marketed metformin tablet, as determined by the ratio, (swelling ability)/(excipient weight). Taken together, our results indicate that the carrageenan complex can be developed as a good swelling excipient. Further optimizations are required for the commercialization of the carrageenan complex.

• Textile Coloration and Finishing
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• v.24 no.1
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• pp.1-7
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• 2012

Dyeing and fastness characteristics of 100% meta-aramid fiber were investigated with cationic dyes and swelling agents under various dyeing conditions such as dyeing temperature and pH of dye bath. Dye exhaustion started at around $80^{\circ}C$ and settled down at $130^{\circ}C$. Among swelling agents used, N-methyl formanilide showed comparatively higher K/S values comparing to 1-phenoxypropan-2-ol. Under weak acidic conditions in the range pH 5 to 7, the exhaustion of cationic dyes could be enhanced leading to higher adsorption and stability of colorimetric property. Wash and rubbing fastness were generally good but low light fastness found can be attributable to the poor photo-stability of the cationic dyes.

• Polymer(Korea)
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• v.32 no.3
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• pp.219-229
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• 2008

A pH sensitive ternary copolymer gel was synthesized in the presence of ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent through radical polymerization of vinyl acetate (VA), acrylic acid (AA) and methyl acrylate(MA) with a weight ratio of 1 : 1.3 : 1. A number of experiments were carried out to determine the swelling behavior of the gel under a variety of pH conditions of the swelling medium. As the pH of the swelling medium was changed from 1.0 to 8.0 at $37^{\circ}C$, the gel showed a shift in the pH-dependent swelling behavior from Fickian (n=0.3447) to non-Fickian (n=0.9125). The resulting swelling parameters were analyzed using graphical and statistical methods. The results showed that the swelling of the gel was controlled by the pH of the medium, i.e. $n=n_o{\exp}(S_{C}pH)$, where n is the diffusion exponent, $n_o(=28.9645{\times}10^{-2})$ is the pre-exponential factor and $S_C$(=0.1417) is pH sensitivity coefficient. The swelling behavior of the gel was also examined in aliphatic alcohols. The results showed that the rate of swelling increased with increasing number of carbon atoms in the alcoholic molecular chain.

• Journal of Pharmaceutical Investigation
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• v.31 no.1
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• pp.13-18
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• 2001

This study was to investigate the relationship between the gel layer thickness and swelling boundary via strength measurements using texture analysis. The novel texture analysis approach was used to examine the dynamics of swelling behavior in a ternary polymeric matrix tablet. The method permitted the characterization of the changes occurring at the peripheral as well as within interior boundary of the swelling during water ingress. The increase in gel strength for pectin, HPMC, and a ternary mixture with gelatin was found to depend on polymer concentration. Therefore, this method is further applicable to characterize the swelling behavior and provide opportunity to differentiate the gel-layer from that of swelling boundary.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2616-2628
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• 2021

The results of effective irradiation swelling in a wide range of burnup levels are numerically obtained for an inert matrix fuel, which are verified with DART model. The fission gas swelling of fuel particles is calculated with a mechanistic model, which depends on the external hydrostatic pressure. Additionally, irradiation and thermal creep effects are included in the inert matrix. The effects of matrix creep strains, external hydrostatic pressure and temperature on the effective irradiation swelling are investigated. The research results indicate that (1) the above effects are coupled with each other; (2) the matrix creep effects at high temperatures should be involved; and (3) ranged from 0 to 300 MPa, a remarkable dependence of external hydrostatic pressure can be found. Furthermore, an explicit multi-variable mathematic model is established for the effective irradiation swelling, as a function of particle volume fraction, temperature, external hydrostatic pressure and fuel particle fission density, which can well reproduce the finite element results. The mathematic model for the current volume fraction of fuel particles can help establish other effective performance models.

• Korean Membrane Journal
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• v.6 no.1
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• pp.37-43
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• 2004

Comb-type graft hydrogels composed of alginate and poly(N-isopropylacrylamide) (PNIPAAm) were prepared to manifest rapid temperature and pH sensitivity. To appear the electro-sensitivity, the polyaniline, conducting polymer, was added into the matrix. The swelling kinetics and ratios were compared under the various compositions of polyaniline. The swelling behaviors revealed that conducting polymer/hydrogel composites could control the swelling ratio and kinetics. The addition of polyaniline in the matrix improved the thermal stability in comparison with that of the hydrogel without polyaniline. In temperature sensitivity, the adding the polyaniline into the matrix decreased the degree of change in the swelling ratio. The swelling ratios continuously increased with increasing pH values. The drug release rate from the hydrogel increased with the adding the polyaniline and the applying the direct voltage to the hydrogels.

• Nuclear Engineering and Technology
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• v.44 no.1
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• pp.89-102
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• 2012

The buffer and backfill are important components of the engineered barrier system in a high-level waste repository, which should be constructed in a hard rock formation at a depth of several hundred meters below the ground surface. The primary function of the buffer and backfill is to seal the underground excavation as a preferred flow path for radionuclide migration from the deposited high-level waste. This study investigates the hydraulic conductivity and swelling pressure of Kyungju Ca-bentonite, which is the candidate material for the buffer and backfill in the Korean reference high-level waste disposal system. The factors that influence the hydraulic conductivity and swelling pressure of the buffer and backfill are analyzed. The factors considered are the dry density, the temperature, the sand content, the salinity and the organic carbon content. The possibility of deterioration in the sealing performance of the buffer and backfill is also assessed.

• Textile Coloration and Finishing
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• v.30 no.1
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• pp.20-28
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• 2018

The near infrared ray camouflage fabric has a near infrared ray reluctance similar to the surrounding environment and has a camouflage effect on the surrounding environment. Synthetic fibers used in military uniforms are difficult to have gastrointestinal function as general commercial dyes, unlike cellulose fibers, which use some commercial vat dyes to impart infrared gastrointestinal function. In this study, we optimized the adsorption pH, temperature and time for NIR dye application for polyester fabrics, and established the optimum concentration for the evaluation of adsorption build-up characteristics. In addition, it is difficult to adsorb it since the polyester material has a dense crystal structure and the NIR dye is bulky. Therefore, a swelling agent used for dyeing meta-aramid fibers with high Tg and high crystallinity was introduced as a separate preparation to increase the affinity to polyester, which is a hydrophobic fiber, to thereby obtain an excellent adsorption rate. As a result of comparing before and after using swelling agent, the adsorption rate difference was 10 times or more when compared with before.