• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.378-383
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• 2013

Continuous fiber-reinforced ceramic matrix composites (CFCCs) have a complex distribution of porosity, consisting of interfiber micro pores and interbundle/interply macro pores. Owing to the complex geometry of the pores and fiber architecture, it is difficult to obtain representative microstructural features throughout the specimen volume with conventional, destructive ceramographic approaches. In this study, we introduce X-ray computed microtomography (X-ray ${\mu}CT$) to nondestructively analyze the microstructures of disk shaped and tubular $SiC_f$/SiC composites fabricated by the chemical vapor infiltration (CVI) method. The disk specimen made by stacking plain-woven SiC fabrics exhibited periodic, large fluctuation of porosity in the stacking direction but much less variation of porosity perpendicular to the fabric planes. The X-ray ${\mu}CT$ evaluation of the microstructure was also effectively utilized to improve the fabrication process of the triple-layered tubular SiC composite.

• Journal of the Korean Society of Costume
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• v.58 no.9
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• pp.129-141
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• 2008

Jikgeum(woven with supplementary golden wefts) hyungbae(rank badge) of danryung(official uniform) excavated from Im Backryung'tomb($1498{\sim}1546$) of the Joseon dynasty($1392{\sim}1910$) at Goyang, Gyunggi-Do in 2007, was in a critical condition because of serious collapse of substrate in metal thread. For conservation of hyungbae, metal thread was examined by different scientific methods(Light Microscope, Scanning Electron Microscope and Energy Dispersive X-Rray Spectrometry(SEM-EDS), Fourier Transform Infrared Spectroscopy(FT-IR)). Analytical data showed that metal thread was gilt membrane strip composed of gold leaves and proteinaceous substrate which was probably parchment. To protect collapse of substrate, 1% solution of Paraloid B-72 was infilterated into substrate for consolidation of substrate and it was adhered to warp of fabric in hyungbae, before wet cleaning. After wet cleaning, the most of the gold leaves were restored, which was confirmed by both the examination with the naked eye and the microscopic examination.

• Fashion & Textile Research Journal
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• v.11 no.1
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• pp.121-129
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• 2009

Nowadays, global interest is being placed on research and development of smart clothing which is expected to create a high added-value industry in the future. The purpose of this research is to develop smart pants with vibrating massage functions that have excellent outer appearances and provide comfort to wearers and assess outer appearance, comfort, and massaging effects of smart pants. As the results of this research, smart pants where vibrating devices which are mainly composed of vibrating motor, controller, and switch are attached were completed. Vibrating motors were fixed on a thin and light non-woven fabric material, covered with a mesh material, and attached by snaps to the experiment pants. Switch was attached to the inside of a pocket, and batteries were positioned inside of pockets. Ten subjects marked their satisfaction of wearing smart pants on a 5-point scale. Noticeable changes in outer appearance when vibrating motors operate turned out to be low. Wearer's comfort in back waist and front thigh parts where vibrating motors were attached turned out to be high-satisfied. Massaging effects of smart pants turned out to be high. Attaching and detaching vibrating devices turned out to be convenient. Lining materials used for smart paints were effective in blocking electromagnetic waves generated from vibrating devices.

• Advanced Composite Materials
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• v.17 no.4
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• pp.359-372
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• 2008

The moisture absorption behavior of carbon fiber-reinforced plastic (CFRP) and its effect on dimensional stability were examined. Moisture diffusivity in CFRP was determined by measuring a specimen's weight during the moisture absorption test. Three types of CFRP specimens were prepared: a unidirectionally reinforced laminate, a quasi-isotropic laminate and woven fabric. Each CFRP was processed into two geometries - a thin plate for determination of diffusivity and a rod with a square cross-section for the discussion of two-dimensional diffusion behavior. By solving Fick's law expanded to 3 dimensions, the diffusivities in the three orthogonal directions were obtained and analyzed in terms of the anisotropy of CFRP moisture diffusion. Coefficients of moisture expansion (CMEs) were also obtained from specimen deformation caused by moisture absorption. During moisture absorption, the specimen surfaces showed larger deformation near the edges due to the distribution of moisture contents. This deformation was reasonably predicted by the finite element analysis using experimentally determined diffusivities and CMEs. For unidirectional CFRP, the effect of the fiber alignment on CME was analyzed by micromechanical finite element analysis (FEA) and discussed.

• Elastomers and Composites
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• v.54 no.4
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• pp.294-298
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• 2019

A three-layered PVC sheet consisting of polyvinyl chloride (PVC) and woven polyester fabric was prepared by extrusion and calendering. The flexibility and durability of the PVC were tuned by adding plasticizers, additives, and surface coatings. The tensile and tear strengths of the three-layered PVC sheet were higher than those of commercial two-layered sheet, while exhibiting low weight. The concentrations of the total volatile organic compounds (TVOCs) and formaldehyde (HCHO) emitted from the sheet were also lowered. The PVC sheet remained stable after prolonged exposure to UV light, signifying that the PVC sheet is suitable for cargo screen applications.

• Journal of the Korean Society for Railway
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• v.10 no.1 s.38
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• pp.39-44
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• 2007

This rafer explains a durability test of a large train car body made of carbon/epoxy composite material. The composite car body with the length of 23m was manufactured as a sandwich structure composed of an aluminum honeycomb core and CF1263 woven fabric carbon/epoxy faces. In order to evaluate durability of the composite car body, it was excited by two 500kN capacity hydraulic actuators installed underneath the body bolster. The natural frequency of the composite car body under full weight condition was found to be 4.33Hz. Based on this result, the excitation frequency and displacement of 5Hz and ${\pm}1.0mm$, respectively, were used as inputs for the durability test. The test was conducted for $2{\times}10^6$ cycles. During the test, the nondestructive tests using X-ray radiography and dye penetration method was performed to determine the presence of the cracks. Upon completion of the test, no cracks were found.

• Carbon letters
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• v.5 no.1
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• pp.1-5
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• 2004

The effects of fiber surface-treatment and sizing on the dynamic mechanical properties of unidirectional and 2-directional carbon fiber/nylon 6 composites by means of dynamic mechanical analysis have been investigated in the present study. The interlaminar shear strengths of 2-directional carbon/nylon 6 composites sized with various thermosetting and thermoplastic resins are also measured using a short-beam shear test method. The result suggests that different surface-treatment levels onto carbon fibers may influence the storage modulus and tan ${\delta}$ behavior of carbon/nylon 6 composites, reflecting somewhat change of the stiffness and the interfacial adhesion of the composites. Dynamic mechanical analysis and short-beam shear test results indicate that appropriate use of a sizing material upon carbon fiber composite processing may contribute to enhancing the interfacial and/or interlaminar properties of woven carbon fabric/nylon 6 composites, depending on their resin characteristics and processing temperature.

• Journal of the Korean Society of Clothing and Textiles
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• v.6 no.2
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• pp.9-15
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• 1982

This study was conducted to examine the relation between the clothing materials and the garment's ease under wearing condition. Wearing test of slacks in the same pattern which were made of 3 woven fabrics and 1 knitted fabric have teen carried out. Subjects were 5 female students. Some physical properties of these fabrics were investigated. The following results were obtained. 1, By analysis variance with the results of sensory test which was tested by paired com-parison method, it was obtained that the effect of materials on the garment's ease were significant at the $1\%$ level on every part of stacks and posture of subject. It indicates that there is a difference of materials from materials in garment's ease. 2. Significant at the $5\%$ level among the materials. Jersey and Jean were looser than the other two materials. Clothing materials have considerable effect on the garment's ease of slacks, therefore it was noticed that the ease of slacks must have considered the clothing materials. It is more necessary in working dress. 3. Elastic recovery of width was more contributive to garment's ease of slacks than any other physical properties.

• Journal of Fashion Business
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• v.7 no.5
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• pp.17-31
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• 2003

$Premi\grave{e}re$ Vision is a leading textile collection held since 1973. In this study, textiles for 2004/05 F/W season in $Premi\grave{e}re$ Vision were analyzed at the various point of view, such as general trend, sub-theme, fiber content, color trend, structure, yarn trend, pattern, texture, decoration, finishing and other technical treatment, and functionality. There were three general trends; natural/ecology, geometry, and combination. Natural color and texture were widely used over the fabric exhibited, and irregularities expressed the natural trend of textiles. Geometric patterns were used for knit as well as for woven. Geometry expressed by various methods such as weaving, knitting, printing, shearing, embossing, and etc. However, geometry shown in this season was not a clear form expressed by weaving, but a blurry, irregular form expressed by various other methods such as knitting. The combination among heterogeneous fibers, yarns, colors, images, and textures was usual, however, the harmony among them was accomplished.

• Earthquakes and Structures
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• v.16 no.3
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• pp.369-373
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• 2019

Construction industry is one of the largest markets for composite materials. Composite materials are mostly utilized as surface coatings or concrete reinforcements, and they can hardly be found as a load bearing member in buildings. The three-dimensional composite structures with considerable bending, compressive and shear strengths are capable to be used as construction load bearing members. However, these composites cannot compete with other materials due to higher manufacturing costs. If the cost issue is resolved or their excellent performance is taken into consideration to overcome disadvantages related to economic-competitive challenges, these 3D composites can significantly reduce the construction time and result in lighter and safer buildings. Sandwich composite panels reinforced with 3D woven glass fabrics are amongst composites with highest bending strength. The current study investigates the possibility of utilizing these composite materials to construct ceilings and their application as slabs. One-to-one scale experimental loading of these composite panels shows a remarkable bending strength. Simulation results using ABAQUS software, also indicate that theoretical predictions of bending behavior of these panels are in good agreement with the observed experimental results.