• Elastomers and Composites
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• v.44 no.4
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• pp.401-407
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• 2009

Commercial grades of solution styrene-butadiene rubbers extended with high aromatic oils having high polycyclic aromatic compounds (PCA) and low PCA oils were used to study the effect of the processing oil particularly on the crack propagation resistance and frictional wear resistance of the vulcanizates. The aromatic oil based vulcanizates exhibited superior fracture behavior over the low PCA oil extended vulcanizates based on tensile and trouser tear tests. Compounds with aromatic oil showed superior crack propagation resistance compared with those containing low PCA oil, especially at the lower ranges of tearing energy. In terms of frictional wear resistance, the aromatic oil extended compounds showed superior performance particularly in the lower frictional work ($W_f$) range but in the higher $W_f$ range the low PCA oil extended vulcanizates performed better.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.4
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• pp.69-78
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• 2012

This paper study on the physical property of naturally vulcanizing waterproofing synthetic rubber sheet for the underground concrete wall. In order to finding the naturally vulcanizing time, the relation of vulcanizing time and tensile strength is analysed from non-vulcanizing to naturally vulcanizing time. Physical tests such as tensile strength, tear strength: etc., under the thermal environment temperature at $-20^{\circ}C$, $-10^{\circ}C$, $20^{\circ}C$, $60^{\circ}C$. The result of experiment show that the developed rubber sheet has the delay time about 85 days and the curing time about 35 days. The tensile strength increased by about 692% and coefficient of expansion decreased by about 10% which value can be sufficiently compensate the demerit of vulcanized rubber sheet. Also, all of the physical properties of the naturally rubber sheet satisfy the KS standard and compare to the vulcanized rubber sheet, the developed naturally rubber sheet have excellent durability.

• Elastomers and Composites
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• v.47 no.2
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• pp.141-147
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• 2012

Silicone resin has no water-absorbing function because it is a strong hydrophobic polymer. However, addition of super absorbent polymer gives much better absorbency than that of conventional silicone resin. In this study, we developed novel silicone materials with water-absorbing function by choosing three types of amorphous acrylic super absorbent polymers with different particle sizes, determining the mixing ratio of the three polymers and applying the mixtures into two-component type silicone material for medical purpose. The change in the mechanical properties such as tensile strength, tear strength, compressive strength and hardness was investigated by varying the particle size and content ratio of the added super absorbent polymers while preparing the silicone resins. The absorbency of the silicone resins was measured over time. Additionally, the particle shape of the super absorbent polymers as well as the distribution within the silicone resin was observed using an optical microscope.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.470-477
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• 2018

With a highly functional methyl vinyl silicone rubber (VMQ) matrix and filler materials of $B_4C$, PbO, and benzophenone (BP) and through powder surface modification, silicone rubber mixing, and vulcanized molding, a flexible radiation shielding and resistant composite was prepared in the study. The dispersion property of the powder in the matrix filler was improved by powder surface modification. BP was added into the matrix to enhance the radiation resistance performance of the composites. After irradiation, the tensile strength, elongation, and tear strength of the composites decreased, while the Shore hardness of the composites and the crosslinking density of the VMQ matrix increased. Moreover, the composites with BP showed better mechanical properties and smaller crosslinking density than those without BP after irradiation. The initial degradation temperatures of the composites containing BP before and after irradiation were $323.6^{\circ}C$ and $335.3^{\circ}C$, respectively. The transmission of neutrons for a 2-mm thick sample was only 0.12 for an Am-Be neutron source. The transmission of ${\gamma}$-rays with energies of 0.662, 1.173, and 1.332 MeV for 2-cm thick samples were 0.7, 0.782, and 0.795, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.366-373
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• 2019

Combat uniforms require higher tensile and tear strength than civilian products, and applied infrared reflectance from the recently developed nighttime fluoroscopy equipment to ensure combatant survival at night. Unlike other uniforms for civilian use, combat uniforms require durability against laundering because they may not be supplied again, once originally provided. Therefore, this study examined the changes in strength and changes in infrared reflectance after multiple washing of combat uniforms. The experiment confirmed that the strength change after the washing of combat uniforms 15 times was maintained in the same manner as the result after washing five times. In the case of infrared reflectance, the difference in reflectance after multiple washing treatments was greater than that in the case where washing was not performed. Therefore, although the durability in the case of combat uniforms is strong, it is necessary to maintain a reflectance higher than a certain level through the development of materials and the development of dyes.

• Elastomers and Composites
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• v.41 no.4
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• pp.245-251
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• 2006

Thermoplastic elastomer was prepared from dynamical vulcanization of isotactic polypropylene(iPP)/nitrile rubber blend (NBR/iPP=70/30 wt/wt) in an internal mixer using dicumyl peroxide (DCP) as a curing agent and zinc dimethacrylate (ZDMA) as a coagent. There was a great improvement in tensile and tear strength, elongation-at-break and lower tension set when ZDMA was incorporated into the blend, which is supposed to be due to the increase in crosslink density or the rubber phase and the reduction in size of the rubber particles. It was revealed that the dynamically vulcanized blend exhibited good reprocessibility, indicating its thermoplastic nature.

• Journal of the Korea Fashion and Costume Design Association
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• v.26 no.3
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• pp.13-33
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• 2024

This study aims to analyze the potential and limitations of using traditional men's suits as upcycled materials by examining case studies of deconstructed and reassembled designs. The research explores the potential of upcycled suit design and proposes data to guide future directions in upcycling. A literature review was conducted, revealing that upcycled designs are often created through deconstruction, within the framework of Jacques Derrida's deconstructionist philosophy. The study examined 10 brands that focused on suit-based upcycled designs across two or more seasons, resulting in 202 upcycled suit products for analysis to identify key design characteristics. Upcycle suits have been shown to be disordered decentralized properties through deformation, discontinuity through deformation, and damage through reconstruction of existing suits. First, deformation was expressed in the design of a typical dressing, asymmetry, overlap, distortion, and repetition. Second, deformation mainly appeared as a method of omission, heterogeneous insertion, material conversion, and separation. Third, damage appeared as a doodle, tear, and incomplete up-cycle design method. Using these methods, three decentralized upcycle suit designs were developed, and a new direction of upcycle design was suggested. The study concludes that upcycled suit design can contribute to sustainable fashion by achieving zero waste, developing refined sewing techniques, pursuing diverse design methods, and promoting transparency in production. This research offers insights into innovative and diverse product development through the reinterpretation of discarded suits.

• Journal of Forest and Environmental Science
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• v.9 no.1
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• pp.67-80
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• 1993

There are a lot of serious problums associated with conventional pulping processes, such as kraft and sulfite. In order to tackle these difficulties, organic acid pulping of Populus tomentiglandulosa T. Lee and Pinus densiflora S. et Z. have been investigated as on alternative method. The acetic acid cooking of Populus tomentiglandulosa T. Lee achieved good delignification with pulp yields of 55-65% under almost all cooking conditions. In the acetic acid cooking of Pinus densiflora S. et Z., it was not cooked at a low temperature. The strength properties of the acetic acid pulps from Pinus tomentiglandulosa T. Lee showed the optimum with 95% acetic acid concentration at $185^{\circ}C$ maximum cooking temperature for 0.5hr cooking time. The strength properties of the acetic acid pulps from Pinus densiflora S. et Z. displayed excellent tear strength in comparison with those of the other softwoods. In the process of acetic acid cooking, glucose has been removed a little, but other sugars have been eliminated. The elemental compositions and $C_9$ formulas of acetosolv lignins from Populus tomentiglandulosa T. Lee were 63.88% carbon, 5.45% hydrogen and 30.67% oxygen and $C_9H_{9.15}O_{3.24}$ The elemental compositions and $C_9$ formulas of acetosolv lignins from Pinus densiflora S. et Z. were 61.85% carbon, 6.14% hydrogen and 32.01% oxygen and $C_9H_{9.15}O_{3.50}$ The Wt. av. MWT's of the acetosolv lignins from Pinus tomentiglandulosa T. Lee and Pinus densiflora S. et Z. were 731 and 725.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.315-320
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• 1996

In this paper, we investigated the retention amounts(ash contents) according to the addition amounts of retention aid and calcium carbonate and compared the mechanical and optical properties of sheets under the same ash content. As the addition amounts of retention aid increase, the retention of calcium carbonate, that is, ash contents of sheets increase in all retention system. In this case, the sheets included ash content as already expected is produced by adjusting the addition amounts of retention aid and calcium carbonate. Tensile index, burst index, tear index, internal bonding strength of sheets straightly decrease as the ash content of sheets increases. Especially, in the same ash content, all sorts of strength are high in compozil system, low in dual polymer system. Opacity increases along with according to the increase of ash content, and is high in hydrocol system, the worst in dual polymer system. In equal opacity, the strength of paper decreases compozil, hydrocol, and dual polymer system in order. But to judge she superiority or inferiority of retention aids, it should consider the various factors such as the optimum production and process conditions besides the retention amounts of filler and the sheet strength.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.457-463
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• 2013

To determine the impact of artificial tears which include carboxymethyl cellulose on a hydrogel contact lenses. Methods: A contact lenses made of the cross-linking agent, EGDMA (ethylene glycol dimethacrylate) and HEMA (2-hydroxyethyl methacrylate) and with added NVP (n-vinyl-2-pyrrolidone) and MMA (methyl methacrylate) was evaluated for water content, refractive index, spectral transmittance and contact angle of produced contact lens. Results: The physical properties of the sampled copolymerized polymers showed that water content, refractive index, visible ray transmittance and contact angle were in the range of 26.61%~48.58%, 1.422~1.455, 80.8%~91.4% and $33.93^{\circ}{\sim}65.70^{\circ}$, respectively. In addition, after soaking with artificial tears, the water content, refractive index and contact angle were in the range of 24.46%~48.25%, 1.422~1.457, 77.0%~91.0% and $37.25^{\circ}{\sim}77.33^{\circ}$, respectively. The changes of the physical property depending on hydration time and showed an increase of refractive index and contact angle, decrease of water content and visible ray transmittance. Conclusions: Artificial tears which include carboxymethyl cellulose sodium which is used as a wetting agent influenced water content, refractive index, contact angle and spectral transmittance of a hydrogel contact lenses.