• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.372-373
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• 2004

• Steel and Composite Structures
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• v.32 no.1
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• pp.59-66
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• 2019

Hollow steel-reinforced concrete-filled GFRP tubular member is a new kind of composite members. Firstly set the mold in the GFRP tube (non-bearing component), then set the longitudinal reinforcements with stirrups (steel reinforcement cage) between the GFRP tube and the mold, and filled the concrete between them. Through the axial compression test of the hollow steel-reinforced concrete-filled GFRP tubular member, the working mechanism and failure modes of composite members were obtained. Based on the experiment, when the load reached the ranges of $55-70%P_u$ ($P_u-ultimate$ load), white cracks appeared on the surface of the GFRP tubes of specimens. At that time, the confinement effects of the GFRP tubes on core concrete were obvious. Keep loading, the ranges of white cracks were expanding, and the confinement effects increased proportionally. In addition, the damages of specimens, which were accompanied with great noise, were marked by fiber breaking and resin cracking on the surface of GFRP tubes, also accompanied with concrete crushing. The bearing capacity of the axially compressed components increased with the increase of reinforcement ratio, and decreased with the increase of hollow ratio. When the reinforcement ratio was increased from 0 to 4.30%, the bearing capacity was increased by about 23%. When the diameter of hollow part was decreased from 55mm to 0, the bearing capacity was increased by about 32%.

• Steel and Composite Structures
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• v.52 no.4
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• pp.451-460
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• 2024

Hollow reinforced concrete columns confined with GFRP tubes (GRCH) are composite members composed of the outer GFRP tube, the PVC or other plastic tube as the inner tube, and the reinforced concrete between two tubes. Because of their high ductility, light weight, corrosion resistance and convenient construction, many researchers pay attention to the composite members. However, there are few studies on GRCH members under eccentric compression compared with those under axial compression. Eight hollow columns were tested under eccentric compression, including one axial compression column and seven eccentric compression columns. The failure modes and force mechanisms of GRCH members were analyzed, considering the varying in hollow ratio, reinforcement ratio and eccentricity. The test results showed that configuring steel bars can greatly increase the bearing capacity and ductility of the members. Each component (GFRP tube, concrete, steel bar) had good deformation coordination and the strength of each material could be fully utilized. But for specimens with larger eccentricity ratio (e_r=0.4) and larger hollow ratio (χ=0.55), the restraining effect of GFRP tube on concrete was significantly decreased.

• Structural Engineering and Mechanics
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• v.66 no.4
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• pp.439-444
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• 2018

This paper presents a numerical study on the behavior of continuous hollow steel beam strengthened using carbon fiber reinforced polymers (CFRP). Most previous studies on the CFRP strengthening of steel beams have been carried out on the steel beams with simple boundary conditions. No independent study, to the researcher's knowledge, has studied on the CFRP strengthening of square hollow section (SHS) continuous steel beam. However, this study explored the effect of the use of adhesively bonded CFRP flexible sheets on the behavior of the continuous SHS steel beams. Finite Element Method (FEM) has been employed for modeling. Eleven specimens, ten of which were strengthened using CFRP sheets, were analyzed under different coverage length, the number of layers, and the location of CFRP composite. ANSYS software was used to analyze the SHS steel beams. The results showed that the coverage length, the number of layers, and the location of CFRP composite are effective in increasing the ultimate load capacity of the continuous SHS steel beams. Application of CFRP composite also caused the ductility increase some strengthened specimens.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.69-70
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• 2010

This paper presents the flexural capacities of one-way hollow slab with materials. To verify the flexural capacities of this hollow slab, flexural tests were performed on the one-way hollow slabs. The test parameters included two different materials of plastic balls. The material parameters were general plastic and glass fiber plastic.

• Structural Monitoring and Maintenance
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• v.6 no.4
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• pp.269-289
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• 2019

This study investigated experimentally the response of thick reinforced concrete specimens having hollow cores with critical parameters. The investigation includes testing of twelve specimens that are solid and hollow-core slab models. Each specimen consists of two pieces, the piece dimensions are (1.2 m) length, (0.3 m) width and (20 cm) thickness tested under both monotonic and repeated loading. The test program is carried out to study the effects of load type, core diameters, core shape, number of cores, and steel fiber existence. Load versus deflection at mid span, failure modes, and crack patterns were obtained during the test. The test results showed that core shape and core number has remarkable influenced on cracking pattern, ultimate load, and failure mode. Also, when considering repeated loading protocol, the ultimate load capacity, load at yielding, and ductility is reduced.

• Textile Coloration and Finishing
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• v.6 no.2
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• pp.63-70
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• 1994

최근, Courtaulds Fiber Ltd.사에 의해 개발된, 새로운 용제방사(瑢劑紡絲) cellulose fiber인 Tencel에 대한 관심이 고조되고 있다. 이 글에서는, 먼저 Tencel의 고기능 특성을 cellulose섬유의 구조적 성질과 관련지어 언급코져 한다. 다음으로, 중공섬유막(hollow fiber membranes), sponge, 부직포와 bacterial cellulose, 그리고, 그 들 cellulose로부터 유래된 새로운 상품과 그 응용의 광범위한 분야를 서술하고져 한다. 그 외에, cellulose fibers와 fabric에 대한 가능성 후처리기술들의 최근의 동향도 기술하고져 한다. 끝으로, 생분해성 plastic과 super섬유로서의 cellulose의 특성, 그리고 장래 그들의 기술적 전망도 부언하고져 한다.

• Current Optics and Photonics
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• v.3 no.4
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• pp.298-303
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• 2019

We propose a photonic quasi-crystal fiber (PQF) for supporting up to 14 orbital angular momentum (OAM) modes with low and ultra-flat dispersion characteristics over the C+L bands. The designed PQF which consists of a large hollow center and quasi structural small air holes in the clad region exhibits low confinement losses and a large effective index separation (>$10^{-4}$) between the vector modes. This proposed fiber could potentially be exploited for mode division multiplexing and other OAM mode applications in fibers.

• Membrane Journal
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• v.1 no.1
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• pp.65-77
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• 1991

The perstraction of ethanol and acetic acid were performed for three systems of xylene-acetic acid-water, MIBK-ethanol-water, and TBP-ethanol-water, The operating variables were pressure difference between aqueous and organic phase, and superfial velocities of aqueous and organic phases. The tortuosities of PP hollow fiber membrane of Celgard X10-400 and PTFE hollow fober membrane of Tex TA001 were found to be 1.82 and 1.43 respectively, They were obtained from mass tranfer coeffidents in membrane phase for xylene-acetic acid-water systems. The permeation flux and overall mass transfer coefficient for MIBK-ethanol-water system are larger than those for TBP-ethanol-water system. This tendency is magnified with increasing the superficial velocity of organic phase. Overall mass transfer coefficient($K_o$) increases nonlinearly with the increase of superficial velocity of organic phase($V_{or}$), and the relationship between $K_o$ and $V_{or}$ is that $K_o {\propto} V_{or}^{-0.35}$. For ethanol perstraetion using the hollow fiber membrane of Gore Tex TA001, the mass transfer in membrane phase is the rate-limiting step.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.501-507
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• 2009

Ordered single-walled hollow aluminogermanate (ALGE) nano-balls(NBs) and nano-tubes(NTs) have been self-assembled from the ALGE precursors having an Al/Ge ratio of 1.33 using simple pH-control. The hollow ALGE NBs with average monodisperse diameters of 5 nm and chemistry of Al/Ge=1.5~1.6 were formed through structural assembly in the ALGE solution (Al/Ge=1.33) highly basified to pH=13(Na/Al=28~30) and followed by immediate acidification to pH=9. When the basified solution(pH=13) were acidified to pH=4, ALGE S-NTs (Short-fiber nano-tubes) with diameters of 3.3 nm, 15~20 nm in length, and chemistry of Al/Ge=2.6~2.8 were successfully synthesized. Whereas the solution was basified to pH=9, and subsequently acidified to pH=4, L-NTs(Long-fiber nano-tubes) with >100 nm in length were synthesized for the first time. The self-assembly of the hollow NBs, S-NTs, and L-NTs form the ALGE precursors can be explained by the degree of $H^+$-dissociation of the -Ge-OH inner surfaces, which was controlled by amount of $Na^+$ and pH conditions of ALGE precursor solutions. This results indicate that target forms of ALGE nanomaterials can be synthesized by simple pH controls.