• 제목/요약/키워드: Material Resistance

검색결과 4,713건 처리시간 0.033초

한국 소방대원 방수피복의 소재특성에 관한 비교 연구 (A Study on the Textile for Protective Clothing of Fire Fighters)

  • 정정숙;이연순
    • 대한가정학회지
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    • 제40권5호
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    • pp.15-24
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    • 2002
  • The following research conclusions were made, relative to the experiments of the textiles of fire fighters Protective Clothing. 1. When the body protection efficiency such as the thickness, the strength and heat resistance are considered, Nomex(N) is tuned out the best outer shelf, Gore-tex(KG) the best moisture barrier, and Wool-felt(WC) the best thermal barrier. 2. In the hygienic and sanitary efficiency also, N is turned out the best outer shelf, KG the best moisture barrier, and WC the best thermal barrier in its degree of water resistance, water vapour permeability, and air permeability. 3. In the washing and maintenance efficiency, too. N is turned out the best outer shell, KG the best moisture barrier, and WC the best thermal barrier, being considered the material's rate of contraction, the changing rate of frame resistance, water resistance, and water vapour permeability. 4. When considered the frame resistance against the reflection tape and reflection efficiency, O is the best material for it marks the highest score in the frame resistance and reflective effect.

미끄럼 접촉을 하는 탄소강의 경도차 조합에 따른 마모특성변화 연구 (The Change of Sliding wear properties of Carbon Steel against several hardened steels)

  • 이한영;김근영
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2003년도 학술대회지
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    • pp.85-90
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    • 2003
  • Although wear resistance of material improves with increasing its hardness, it is known that the wear resistance of steel is varied with hardness of counter material. In this context, wear properties of steel must be depended on the difference of hardness between the testpiece and the counter material. In this study, using the pin-on-disc type wear machine, annealed carbon steels were tested against ahoy tool steels with various levels of hardness. Then the changes of wear properties of carbon steel according to the hardness of counter material were investigated and the morphology of worn surface after test were evaluated. The results indicate that if there are no remarkable difference of hardness between them, wear resistance of carbon steel in running-in wear decreases with increasing the hardness of counter material. However, its wear properties at the range of high sliding speed have no relation with hardness of counter material. It is clear that wear properties is influenced by the formation of oxide of steel on their worn surface during wear.

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랩퍼(Rapper) 패션에 나타난 저항성(抵抗性) 연구(硏究) (A Study on Resistance in Rapper Fashion)

  • 권혁주;양숙희
    • 패션비즈니스
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    • 제5권1호
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    • pp.53-71
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    • 2001
  • The purpose of this study how 'Afro-American resistance' is showed up in the fashion trough the study of rapper's fashion present in singing rap music. Rap music produced by the influence of black music. It have been the tool of expression of pain and sorrow of their lives and included their resistant spirit. So rapper's fashion expressed resistance. at this point I categorized the resistant feature of rapper's fashion at two types in terms of the extent of expression. Their are active resistance fashion and passive resistance fashion. Also each fashion types was classified in terms of style, material, color, accessories and so forth. Active fashion is possible to classify these three styles as follows. The first one is Afrocentic style that was raised from longing for Africa. The second one is Military style which contains an ling-time enduring spirit of resistance against the society. The last one is Hiphop style that violated the typical rule of dressing under the hiphop style culture. these kinds of active resistance are also classified as material like blue Jean showing black workers' resistance, color like black showing off superiority of 'black' and red, gold and green color expressing black people's resistance, and other accessories like chains, cross and so on. Passive resistance fashion has several variations according to the style. There are Jazz style, Uniform style and Hiphop style. It is also categorized as high-tech materials, white color which is the expression of desire for white and luxurious accessories showing off wealth.

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지중 배전케이블용 자켓 컴파운드의 특성평가 (Evaluation of Jacket Compounds for Underground Distribution Power Cables)

  • 한재홍;송일근;김동명;이재봉;정창수
    • 한국전기전자재료학회논문지
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    • 제15권8호
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    • pp.687-694
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    • 2002
  • In order to replace the jacket material for URD power cables, the 6 kinds of polyethylene compounds were manufactured and evaluated. The characteristics of the compounds were investigated by water vapor transmission (WVT) test, thermal and mechanical test. In WVT test, all the polyethylene compounds showed the superior water resistance to conventional PVC. The molecular structure and density of polyethylene play an important role in WVT. Also, the polyethylene compounds showed the suitable characteristics in thermal and mechanical test. Especially, the linear polyethylene compounds showed the superior characteristics to LDPE ones. Due to the fillers in compounds, the abrasion resistance was decreased and the cut-through resistance was increased. From this study, it can be considered that the polyethylene compounds may be suitable to jacket material for URD power cables.

고속충격을 받는 Ti/Al 적층재의 파괴거동에 관한 연구 (A study on the fracture behavior of Ti/Al laminates under high velocity impact)

  • 손세원;이두성;홍성희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.267-272
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    • 2003
  • In order to investigate the effect of face material on Ti/Al alloy laminates under high velocity impact, a ballistic testing was conducted. Ballistic resistance of these materials was measured by protection ballistic limit($V_{50}$), a statistical velocity with 50% probability penetration. Fracture behaviors and ballistic tolerance, described by penetration modes, were respectfully observed, by $V_{50}$ test and Projectile Through Plates (PTP) test at velocities greater than $V_{50}$. PTP tests were conducted with $0^{\circ}$obliquity at room temperature using 5.56mm ball projectile. $V_{50}$ tests with $0^{\circ}$obliquity were also done with projectiles that were able to achieve near or complete penetration during PTP tests. Resistance to penetration, and penetration modes which face material was Titanium alloy, were compared to those which face material was anodized Al alloy after cold-rolling.

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산화물 초전도체의 자기적 특성 (Magnetic Properties of Oxide Superconducting Material)

  • 이상헌
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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    • pp.115-118
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    • 2003
  • The sensor at liquid nitrogen temperature showed the increase of electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor was changed from zero to a value more than $100\;{\mu}V$ by the applied magnetic field. The change of electrical resistance depended on magnetic field. The sensitivity of this sensor was $2.9\;{\Omega}/T$. The sensing limit was about $1.5{\times}10^{-5}\;T$. The increase of electrical resistance by the magnetic field was ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material. Considering the observed properties of the superconductor with trapped magnetic flux, a magnetic sensor was fabricated to detect simultaneously both the intensity and the direction of the magnetic field.

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4차 염화 가교화된 4-vinylpyridine 공중합체들을 사용한 습도센서의 감습 특성 (Humidity Sensitive Properties of Humidity Sensor Using Quaternized Cross-linked Copolymers of 4-Vinylpyridine)

  • 공명선;이성수;이임렬
    • 한국전기전자재료학회논문지
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    • 제14권4호
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    • pp.302-308
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    • 2001
  • The polymers with various composition of 4-vinylpyridine (4-VP) with n-butyl acrylate (n-BA) and 2-hydroxypropyl methacrylate (HPMA) were synthesized as a humidity sensitive material and quaternized with 1.5-dibromopentane. Resistance versus relative humidity decreased with increase in the content of n-BA in the copolymer. The introduction of HPMA increased the resistance of the humidity sensor as well as enhanced the adherence to the alumina substrate. In the case of 4-VP/n-BA/HPMA=80/10.10, the hysteresis and temperature coefficient were $\pm$2%RH and -0.42∼0.46%RH/$\^{C}$. The average resistance at 30%RH, 60%RH and 90%RH are 3.1㏁, 155 ㏀ and 7.9 ㏀, respectively.

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Effect of Aging Time on the Resistance to Localized Corrosion of the Hyper Duplex Stainless Steel

  • Jeon, Soon-Hyeok;Kim, Soon-Tae;Lee, In-Sung;Kim, Ji-Soo;Kim, Kwang-Tae;Park, Yong-Soo
    • Corrosion Science and Technology
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    • 제9권5호
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    • pp.209-215
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    • 2010
  • To elucidate the effect of aging time on resistance to localized corrosion of hyper duplex stainless steel, a double-loop electrochemical potentiokinetic reactivation test a potentiodynamic anodic polarization test, a scanning electron microscope-energy dispersive spectroscope analysis, and a thermodynamic calculation were conducted. With an increase in aging time, sigma phases are precipitated much more than chi phases due to the meta-stable chi phase acting as a transition phase. As aging time at $850^{\circ}C$ increases, the corrosion resistance decreases owing to an increase in Cr, Mo and W depleted areas adjacent to the intermetallic phases such as sigma phases and chi phases.

침수조건에 따른 방탄재료의 성능변화와 파괴거동 분석 (Failure Mechanism Analysis and Performance Change of Ballistic Resistance Material on Wet Condition)

  • 태원석;김건인
    • 한국군사과학기술학회지
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    • 제16권6호
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    • pp.803-810
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    • 2013
  • In this paper, we have verified the performance of ballistic resistance material on wet condition. Considering Korea terrain, soldiers may face many rivers and streams. However, bullet-proof jacket has no waterproofing and there's no water-proof standard in Military. Wearing wet bullet-proof jacket, soldiers can't be protected properly because of the decrement of jacket. Thus, we measure the performance of existing material on wet condition and analyze failure mechanism in order to indicate factors to improve bullet-proof jacket.

이중절연 자기융착테이프 제조기술 (Manufacturing technology of two-layer self bonding insulating tape)

  • 조용석;이철호;심대섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.890-893
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    • 2001
  • Two-layer self bonding insulating tape consists of butyl rubber(IIR ; Isobutylene-isoprene rubber) adhesive layer and polyethylene protective film. Butyl rubber have inherent characteristics such as resistance to corrosion and water, low temperature flexibility, excellent electrical insulating properties also resistance to environmental effect such as ozone and ultraviolet. Polyethylene film was used for the purpose of good insulating properties and resistance to ozone and ultraviolet. The tape was manufactured using extrusion and calender method.

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