• Fibers and Polymers
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• v.3 no.2
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• pp.60-67
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• 2002

In the present study, the fluorescence behavior ova phenylethynyl-terminated imide (LaRC PETI-5) resin, a bismaleimide (BMI) resin, and various LaRC PETI-5/BMI blends with different blend compositions has been characterized as a function of heat-treatment temperature, using a steady-state fluorescence technique with a front-face illumination method far solid-state films. It is observed that there are distinguishable changes in the spectral shape, size, and position of fluorescence with varying heat-treatment temperature in the pure and blend samples. The result is qualitatively explained in terms of charge transfer complex formation as well as microenvironmental change with local mobility and viscosity occurring in the LaRC PETI-5, BMI, and their blends during the cure process. The result also implies that a steady-state fluorescence technique may be a useful tool to understand the processing conditions of polyimides and their blends in the film form on the basis of their thermo-photophysical responses.

• Fire Science and Engineering
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• v.16 no.2
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• pp.59-69
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• 2002

The conventional fire extinguishing gas-agent system has a configuration in which the gas-agent comes out of a cylindrical container having vertically settled shape. However, in this study a horizontally installed container of a piping shape having a cylinder of the same shape with a cylinder valve and a discharge nozzle was used, and the relationship between orifice size of nozzle and discharge rate of gas-agent was investigated through various experiments including the measurement of discharge rate under different ambient-temperature conditions. In such experiments, HCFC Blend A was used without super-pressurization by nitrogen. From this research, it was observed that statutory discharge duration of 10 seconds can be met if the relatively large size of the valve and the nozzle orifice were properly selected.

• Journal of Korea Multimedia Society
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• v.22 no.4
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• pp.491-501
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• 2019

Variational methods, which cast deformation as an energy-minimization problem, are known to provide a good trade-off between practicality and speed. However, the time required to deform a fully detailed shape means that these methods are largely unsuitable for real-time applications. We simplify a 2D shape into a curve skeleton, which can be deformed much more rapidly than the original shape. The curve skeleton also provides a simplified control for the user, utilizing a small number of control handles. Our system deforms the curve skeleton using an energy-minimization method and then applies the resulting deformation to the original shape using linear blend skinning. This approach effectively reduces the size of the variational optimization problem while producing deformations of a similar quality to those obtained from full-scale nonlinear variational methods.

• Korean Journal of Radiology
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• v.25 no.2
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• pp.166-178
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• 2024

Objective: This study aimed to determine the predictive performance of non-contrast CT (NCCT) signs for hemorrhagic growth after intracerebral hemorrhage (ICH) when stratified by onset-to-imaging time (OIT). Materials and Methods: 1488 supratentorial ICH within 6 h of onset were consecutively recruited from six centers between January 2018 and August 2022. NCCT signs were classified according to density (hypodensities, swirl sign, black hole sign, blend sign, fluid level, and heterogeneous density) and shape (island sign, satellite sign, and irregular shape) features. Multivariable logistic regression was used to evaluate the association between NCCT signs and three types of hemorrhagic growth: hematoma expansion (HE), intraventricular hemorrhage growth (IVHG), and revised HE (RHE). The performance of the NCCT signs was evaluated using the positive predictive value (PPV) stratified by OIT. Results: Multivariable analysis showed that hypodensities were an independent predictor of HE (adjusted odds ratio [95% confidence interval] of 7.99 [4.87-13.40]), IVHG (3.64 [2.15-6.24]), and RHE (7.90 [4.93-12.90]). Similarly, OIT (for a 1-h increase) was an independent inverse predictor of HE (0.59 [0.52-0.66]), IVHG (0.72 [0.64-0.81]), and RHE (0.61 [0.54-0.67]). Blend and island signs were independently associated with HE and RHE (10.60 [7.36-15.30] and 10.10 [7.10-14.60], respectively, for the blend sign and 2.75 [1.64-4.67] and 2.62 [1.60-4.30], respectively, for the island sign). Hypodensities demonstrated low PPVs of 0.41 (110/269) or lower for IVHG when stratified by OIT. When OIT was ≤ 2 h, the PPVs of hypodensities, blend sign, and island sign for RHE were 0.80 (215/269), 0.90 (142/157), and 0.83 (103/124), respectively. Conclusion: Hypodensities, blend sign, and island sign were the best NCCT predictors of RHE when OIT was ≤ 2 h. NCCT signs may assist in earlier recognition of the risk of hemorrhagic growth and guide early intervention to prevent neurological deterioration resulting from hemorrhagic growth.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.3
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• pp.458-467
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• 2017

There is increased interest in clothes dryers and garments made of spandex-blend woven fabrics; however, there is limited information available for the laundering and drying these clothes. This study investigates the effects of washing and drying on shrinkage, skewness, and wrinkle for woven fabrics with and without spandex. When spandex with good elastic recovery was blended, the deformed shape from washing and drying improved skewness and wrinkle by easily returning to its original shape. However, these properties had a negative effect on shrinkage in terms of length and area change. When the influence of clothes maintenance was classified, the drying process had the biggest influence of 58%, followed by spinning-rinsingwashing. Tumble drying, in which the fabric is exposed to mechanical force and heat for a long period, had more negative effects on the dimensional stability than line drying. The spandex blend had the effect of preventing skewness and wrinkle in garments, but it was also shown to accelerate shrinkage by garment maintenance cycles. It was important to control drying in order to reduce shrinkage during the maintenance process; consequently, this had the greatest influence on the dimensional stability of fabrics. Therefore, line drying was more advantageous for spandex-blend fabrics than tumble drying in terms of management for shrinkage, skewness, and wrinkle.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.65-70
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• 2012

Structural changing materials which can induce the physical deformation of materials are interesting research topics with various potential applications. Particularly, light among many driving mechanisms is a non-contact energy source, hence the light-responsive system can be used where non-destructive, local irradiation, and remote control is needed. Here, a mainchain azobenzene polymer is synthesized and its physical and optical properties are observed and compared to that of a polymer having a light-responsive azobenzene moiety on its side chain. Further dispersion onto polyvinylalcohol hydrogel is made and its dual stability and actuation are observed upon UV-visible light irradiation. Extended azobenzene polymer blend films show an anisotropic light-actuation with non-polarized UV light at room temperature. This physical shape change is quite reversible and occurs at lower temperature than that of any other reported systems including liquid crystalline elastomers. It is successfully demonstrated that the simple physical azobenzene/polymer blending has a very good actuation compared to that of LCEs which need an elaborate chemical design and it can be further used in the areas requiring a dimensional shape change.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.8
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• pp.1032-1042
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• 1998

The purpose of this study is to measure, compare, and investigate the physical properties of rayon/cotton blend fabrics treated with cellulase and cellulase & specific degeneration silicon and to present basic data which is in development a value-added fabric. The results are as follows. The condition for the treatment of cellulase was at 55$^{\circ}C$, pH 4 and the weight loss increased as the concentration of cellulase and the treated time increased. On treatment with cellulase, the crossectional view & longitudinal view of fiber noticed remarkable crack as weight loss increased and tensile strength and elongation decreased, and pilling was enhanced remarkably. KOSHI was increased, NUMERI and FUKURAMI were decreased as weight loss increased. In the basic characteristic value of clothing wearning, shape stability and drapability were decreased, but air content was improved. On treatment with cellulase & silicon, the degree of damage in the crossectional view & longitudinal view of the fiber reduced. Tensile strength, elongation, moisture regain improved. KOSHI and FUKURAMI were reduced, NUMERI was improved rather than when it was treated with cellulase. Therefore handle was improved. In the basic characteristic value of the clothing wearing, shape stability, air content, drapability were improved.

• Elastomers and Composites
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• v.55 no.2
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• pp.108-113
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• 2020

Wear particles of the model tread compounds for bus and truck tires were made using a laboratory abrasion tester and characterized based on their size distributions, shapes, and crosslink densities. The influence of the carbon black contents and rubber compositions (NR= 100 and NR/BR= 80/20) on the production of wear particles was investigated. The wear particles were separated according to size using a sieve shaker. The shape properties of the wear particles were analyzed using an image analyzer and scanning electron microscopy (SEM). Their shapes were observed as tiny stick cookies or sausages with bumpy surfaces. The particle size distribution tended to be smaller with increasing carbon black content. Moreover, the particle size distributions of the NR = 100 samples were larger than that of the NR/BR blend samples. There were different filaments in the wear particles. The filament diameters tended to be thinner with increasing carbon black content. The crosslink density increased with increasing carbon black content, and the crosslink densities of the NR= 100 samples were lower than those of the NR/BR blend ones. The particle size distribution tended to be smaller with increasing crosslink density. Based on the experimental results, the wear particles can be produced by detaching debris from the main body through repetitive strain and recovery.

• Journal of the Korean Home Economics Association
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• v.19 no.2
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• pp.143-149
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• 1981

Consumer consider the purpose for which they plan to use clothes when they purchase it, and the socks in textile products is evaluated in the same way. serviceability is judged by the extent to which the socks will be useful for its intended purpose. It should retain its original shape and size, good air permeability, good absorbency, good abrasion resistance, high fastness etc. Owing to importance of serviceability in socks, in this paper, these end-use requirement characteristics were tested. The results obtained were as follows: 1. Blend ratios were different between the indicated fiber contents on labels and the testing ones. 2. Air permeability was higher in the samples which contain less stitch density, and hydroscopicity was higher in those which contain natural fibers such as cotton and wool. 3. Shrinkage depended on the blend ratios of cotton and wool, and elastic recovery was better in the course direction than in the wale direction. 4. Pilling was conspicuous in the synthetic fibers such as polyester and nylon, and fastness of laundering and perspiration was higher in the fading grade than in the staining grade.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.69-82
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• 2005

These studies were carried out (1) to investigate the growth characteristics of Sedum album L. in the field, (2) to propose a suitable shallow peen roof system for this plant, and (3) to evaluate plant growth in the proposed system over the long term. The growth characteristics, such as morphological properties, growth habit, shade tolerance, and flowering, were surveyed. In experimental shallow green-roof systems, the effects of drainage type, substrate type, and soil depth on plant growth were investigated. Then drought tolerance was investigated. After planting Sedum album L. in the proposed system survival rate, cover, and resistance to insects, heal and cold were evaluated for about 2 years. The results of these studies are summarized below. 1. In the field, the aboveground part of Sedum album L. did not die back during the winter. Plant height was 4$\sim$7 cm. Roots were distributed to a depth of 5$\sim$7 cm. Sedum album L. is a compact ground-cover plant that spreads vigorously. Shading condition of less than $30\%$ of full sunlight didn't cause any trouble, but shading conditions above $87\%$ made the shape of the shoots and leaves abnormal. The plant bloomed from June to August and had a rather large compound umbel of white, star-shaped flowers. 2. Two systems, a drainage-blend-10 cm soil depth and a reservoir$\cdot$drainage-blend-15 cm soil depth, performed best in terms of cover, fresh weight, and dry weight. The first has an advantage for green roofs because it is lighter than the latter. 3. In drainage-blend-10 m soil depth and modified reservoir · drainage-blend-10 cm soil depth system no plants died for about 4 months after stopping the irrigation. The visual quality of the latter system was above 5 for 4 months and that of the former was under 5 after 2 months. In the field, however, the drought tolerance of Sedum album L. grown in the former would be enough to withstand the dry season. Considering the urban ecosystem and the importance of healthy growth the modified reservoir $\cdot$ drainage-blend-10 cm soil depth system was finally recommended. This system was composed of a 4 cm thick drainage layer and drain outlets placed at a height of 2.5 cm. 4. In the proposed system, the survival rate was $100\%$, and there was no injury induced by insects and heat. The leaf density decreased a little in winter. Cover increased throughout the year. Sedum album L. was planted with a cover of 72$cm^{2}$ on 3 April 2003; on 16 June 2003 and 15 June 2004, cover was $132.66\pm$5.87 $cm^{2}$(1.8 times) and $886.98\pm$63.51 $cm^{2}$(12.3 times), respectively.