• Title/Summary/Keyword: Fiber exposure

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A Study on the Formativeness of Materials of Man′Fashion in 1990′s (1990년대 남성복 소재에 나타난 조형성에 관한 연구)

  • 이효진;류근영
    • The Research Journal of the Costume Culture
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    • v.8 no.6
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    • pp.806-821
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    • 2000
  • Each and everything named fashion together with clothes were limited in the boundary of women and men's wear has been slow and narrow in changing speed compared to women's, even there are some differences in accordance time. But maintaining the basic features, men's wear in the latter 20th century has undergone diverse change in the part of materials such as various synthetic fiber, glass, metal, artificial leather and the see-through fabric able to seeing the body wearing the clothes. Therefore, the aim and definition of this study is to present the systematic framework giving help to develop men's wear design newer and more various by considering moulding of materials which existing men's wear could not show up and by grasping material trend of men's clothes in 1990s. The results of the study were summarized as follows : (1) Material containing lustering is categorized as Velvet, Silk, Lustering materials by synthetic fiber and Lustering materials by additional substance. The Velvet generally acknowledged having something to feel womanly image shows the bisexual character coexisting feature of men and women after grafting with men'fashion. The Silk was endowed the role as means of pleasure to express beyond boundary of sex breaking the existing consciousness which men should wear male clothes, not considering differences between men and women. The lustering made by synthetic fiber expressed modern sensitivity aesthetically to the suit. The lustering materials made by additional substance is seen mixed masculine character with womanly character. (2) See-through materials are acknowledged as decadence beauty caused by expanding subjective awareness in beauty. (3) Materials by the sorts of Net is categorized as Lace, Knit The Lace expression seemed to emphases the human liberation of men and women and the humanity from liberation of subjecthood. The Knit can be felt both woman's image and man's image as bisexual image, not raising only one side sex. (4) Elastic materials offered the opportunity to approve exposure in a time when exposure of men's body was not granted ethically. (5) Leather was shown as indication of social status and inferiority and expression of collective resistance against sexual stagnation of men and women.

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A Risk Assessment of Asbestos Fiber Leaks to Environment during Asbestos Removal Activity in Buildings (건물 내 석면제거 작업과 공기 중 석면의 외부누출 위험성 평가)

  • Paik, Namwon;Lee, Soungcheoul;Byeon, Jaecheol;Lee, Donghee
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.30 no.4
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    • pp.405-411
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    • 2020
  • Objectives: The objectives of this study were to investigate whether airborne fibers were released to the outside air from the asbestos removal area in buildings, and to confirm the existence of asbestos fibers in samples using transmission electron microscopy(TEM). Methods: A total of 1,295 samples was collected from inside and outside 155 asbestos removal areas. To investigate the release of asbestos fibers from the removal area, samples were collected at three locations, such as an entrance to change room, an exit of negative pressure unit(NPU) and perimeter areas. Samples were also collected in the removal area prior to and after removal activity. All samples were analyzed by phase contrast microscopy(PCM) and one-tenth of the samples was analyzed using TEM to discriminate asbestos fibers. Results: During the asbestos removal activity, 27(4.1%) of 662 samples collected outside the removal area showed airborne fiber concentrations equal to or in excess of 0.01 f/cc, the permissible emission standard of the Korean Ministry of Environment. Further, 111 samples were analyzed using TEM. The distribution of asbestos fiber concentrations was log-normal. It was found that 51 of 111 samples(46%) contained asbestos fibers. Conclusions: There is a potential risk of asbestos exposure among neighbors and the public outside the asbestos removal areas. It is recommended that the asbestos removal work be conducted strictly following the specifications required by government and/or professional organizations.

Effect of Chronic Exposure of PFOS (Perfluorooctane Sulfonate) on Survival, Activity, Growth, and Organ Structure of the Melania Snail, Semisulcospira gottschei (Gastropoda: Pleuroceridae) (PFOS에 만성노출된 곳체다슬기, Semisulcospira gottschei의 생존, 운동성, 성장 및 기관계 구조)

  • Lee, Jae-Woo;Park, Jung-Jun;Jin, Young-Guk;Jung, Ae-Jin;Cho, Hyeon-Seo;Lee, Jung-Sick
    • Environmental Analysis Health and Toxicology
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    • v.22 no.2 s.57
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    • pp.119-128
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    • 2007
  • The present study was conducted to find out effect of PFOS on survival, activity, growth and organ structure of the melania snail, Semisulcospira gottschei. Experimental groups were composed of one control condition and four PFOS exposure condition (0.1, 0.5, 1.0 and 5.0 mg/L). After 16 week exposure, survival rate and activity were not significantly influenced at the two lower exposure groups, 0.1 and 0.5 mg/L, but they were significantly reduced in 1.0 and 5.0 mg/L groups. Total weight and meat weight rate (MWR) were reduced in PFOS exposure group in comparison to control group. Also, histological degenerations such as acidification of mucous, necrosis and split of muscular fiber bundle, atrophy of anterior pedal gland were recognized in the foot. Hepatopancreas showed the atrophy and degeneration of the digestive cell, vacuolation of digestive gland and closure of lumen in digestive gland.

Critical Temperature for Inter-Laminar Shear Strength and Effect of Exposure Time of FRP Rebars (FRP 보강근의 계면전단강도에 대한 임계온도와 노출시간의 영향)

  • Moon, Do-Young
    • Journal of the Korea Concrete Institute
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    • v.25 no.1
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    • pp.45-51
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    • 2013
  • Short beam tests of GFRP and CFRP specimens exposed to high temperature were conducted to measure the inter-laminar shear strength. For the phase I test, the exposure time and temperature were varied to measure reduction in the strength due to the applied conditions. As a results, the critical temperature was found to $270^{\circ}C$ for the both FRP reinforcements. The high temperature, which causes 50% loss of inter-laminar shear strength, is defined as the critical temperature in this study. It should be noted that the critical temperature for the inter-laminar shear strength is mainly dependent on resin properties not on fiber type. In the phase II test, the effect of exposure time was investigated at intervals of 0.25hour for the critical temperature. All test results demonstrate that the exposure time effect is not significant compared to the maximum exposure temperature, but it is not negligible and, moreover, is significant at the critical temperature.

High Total Dose Radiation Effects on Fiber Bragg Grating Sensors (광섬유 브래그 격자 센서의 고선량 방사선 효과)

  • Kim, Jong-Yeol;Lee, Nam-Ho;Jung, Hyun-Kyu;Kim, Youngwoong;Han, Won-Taek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.6
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    • pp.1425-1431
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    • 2013
  • We have measured the radiation-induced Bragg wavelength shift (BWS) of fiber Bragg grating (FBG) which was inscribed in Ge-doped core silica using a phase mask during irradiation up to a dose of 23 kGy and annealing effects after the gamma-exposure. For packaged FBG sensors, we observed the maximum radiation-induced BWS of about 91 pm during irradiation. Packaged FBG sensors also show higher radiation sensitivity above nearly a factor of two than non-packaged type sensor in the same condition.

Study on the Mechanical Properties of Lightweight Mortar for Fire Protection Covering Material in High Strength Concrete (고강도콘크리트용 내화피복재로 활용하기 위한 경량모르타르의 역학적 성상)

  • Lim, Seo-Hyung;Yoo, Suk-Hyung;Moon, Jong-Woog
    • Fire Science and Engineering
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    • v.25 no.5
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    • pp.8-13
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    • 2011
  • High strength concrete is the occurrence of explosive spalling associated with high temperature such as a fire. The spalling causes the sever reduction of the cross sectional area with the exposure of the reinforcing steel, which originates a problem in the structural behaviour. The purpose of this study is to investigate the mechanical properties of lightweight mortar using perlite and polypropylene fiber for fire protection covering material. For this purpose, selected test variables were the ratio of water to cement, the ratio of cement to perlite, contents of polypropylene fiber. As a result of this study, it has been found that addition of perlite and polypropylene fiber to mortar modifies its pore structure and reduces its density. And it has been found that a new lightweight mortar can be used in the fire protection covering material.

Effect of Recycled PET Fiber Reinforced Concrete on Chemical Environment (화학적 환경하에서 재생 PET섬유보강 콘크리트의 성능)

  • Jang, Chang-Il;Lee, Sang-Woo;Choi, Min-Jung;Kim, Joon-Mo;Won, Jong-Pil;Kim, Wan-Young
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.709-712
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    • 2008
  • This study evaluated a mechanical performance of recycled polyethylene terephthalate(PET) fiber reinforced concrete on chemical environment. This study applied to three types of environmental condition including alkaline, salt, $CaCl_2$ in water solution and measured a reduction of mechanical performance of recycled PET fiber reinforced concrete for 30, 60, 90 days under chemical solutions. The mechanical performance of recycled PET fiber reinforced concrete evaluated to carried out a compressive strength test. As the result of test, it was found that the mechanical performance decreased as the exposure time to alkaline environment and indicated a excellence performance under salt, $CaCl_2$ environment conditions.

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Influence Evaluation of Fiber on the Bond Behavior of GFRP Bars Embedded in Fiber Reinforced Concrete (섬유보강 콘크리트에 묻힌 GFRP 보강근의 부착거동에 대한 섬유영향 평가)

  • Kang, Ji-Eun;Kim, Byoung-Ill;Park, Ji-Sun;Lee, Jung-Yoon
    • Journal of the Korea Concrete Institute
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    • v.24 no.1
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    • pp.79-86
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    • 2012
  • Though steel reinforcing bars are the most widely used tensile reinforcement, corrosion problems are encountered due to the exposure to aggressive environments. As an alternative material to steel, the fiber reinforced polymers have been used as reinforcement in concrete structures. However, bond strength of FRP rebar is relatively low compared to steel rebar. It has been reported that fibers in matrix can resist crack growth, propagation and finally result in an increase of toughness. In this study, high-strength concrete reinforced with structural fibers was produced to enhance interfacial bond behavior between FRP rebar and concrete matrix. The interfacial bond-behaviors were investigated from a direct pullout test. The test variables were surface conditions of GFRP bars and fiber types. Total of 54 pullout specimens with three different types of bars were cast for bond strength tests. The bond strength-slip responses and resistance of the bond failure were evaluated. The test results showed that the bond strength and toughness increased according to the increased fiber volume.

Performance of Hybrid Fiber Reinforced Concrete at Elevated High Temperature (고온에서 하이브리드 섬유보강 콘크리트의 성능)

  • Won, Jong-Pil;Park, Kyung-Hoon;Park, Chan-Gi
    • Journal of the Korea Concrete Institute
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    • v.20 no.3
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    • pp.325-333
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    • 2008
  • This study evaluated the mechanical performance, shrinkage crack and fire resistance of hybrid fiber (blended steel and polypropylene fiber with different diameter and length) reinforced concrete at elevated temperature. The compressive, splitting tensile, flexural, plastic shrinkage test were conducted to the evaluate the mechanical properties and the resistance of shrinkage crack. Also, the surface investigation, reduction rate of mass and residual compressive test were performed to evaluate the physical and mechanical properties after 400$^{\circ}C$, 600$^{\circ}C$, 800$^{\circ}C$ and 1,200$^{\circ}C$ exposure. Test results showed that the hybrid fiber reinforced concrete improved the mechanical performance, shrinkage crack and fire resistance. The reduction of performance with a temperature change were high at the temperature of $600\sim800^{\circ}C$.

Mechanical Behavior of Directionally Solicified (Y2O3)ZrO2/Al2O3 Eurtctic Fibers

  • Park, Deok-Yong;Yang, Jenn-Ming
    • Journal of the Korean Ceramic Society
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    • v.41 no.1
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    • pp.1-8
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    • 2004
  • The microstructural features and mechanical behavior of directionally solidified $(Y_2O_3)ZrO_2/Al_2O_3$ eutectic fibers after extended beat treatment in oxidizing environment were investigated. The fiber was grown continuously by an Edge-defined Film-fed Growth (EFG) technique. The microstructure was characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscopy(SEM). The microstructure of the fiber in the as-fabricated state consists of highly oriented colonv and fine lamellar microstructure along the fiber axis. Tensile strength of the $(Y_2O_3)ZrO_2/Al_2O_3$ eutectic fiber remained unchanged with heat treatment at temperatures between $1200^{\circ}C$ and $1500^{\circ}C$ up to 300h. The weibulls modulus remained fairly constant after extended thermal exposure. The fracture toughness and crack propagation behavior were investigated. The fracture toughness ($K_{1C}$) of the $(Y_2O_3)ZrO_2/Al_2O_3$ eutectic fiber in the as-fabricated state were measured to be 3.6 ${\pm}$ 0.5 MPa${\cdot}m^{1/2}$ by an indentation technique and 2.2 ${\pm}$ 0.2 MPa${\cdot}m^{1/2}$ by assuming elliptical flaw of a semi-infinite solid, respectively. The $(Y_2O_3)ZrO_2/Al_2O_3$ eutectic fiber showed a radial (Palmqvist) crack type and exhibited an orthotropic crack growth behavior under 100 g load.