• 제목/요약/키워드: Fiber Type

검색결과 2,107건 처리시간 0.028초

강섬유보강 초속경시멘트 콘크리트의 휨인성 및 피로거동 (Flexural Toughness and Fatigue Behavior of Steel Fiber Reinforced Rapid-set Cement Concrete)

  • 이봉학;홍창우;김동호
    • 산업기술연구
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    • 제19권
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    • pp.163-172
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    • 1999
  • This study is conducted on the flexural toughness and flexural fatigue test to fine the mechanical properties of steel fiber reinforced rapid-set cement concrete. Experimental investigation is examined according to fiber contents(0, 0.4, 0.7, 1.0, 1.5%), fiber aspect ratio(58, 60, 83), fiber type (hooked, crimped fiber), and cement type (normal portland & rapid-set cement). The principal results obtained through this study are as follows; toughness and fatigue resistance tend to considerably increase with fiber contents, fiber aspect ration. And hooked fiber is improved better than crimped fiber. Concrete using rapid set cement is increased strength properties compared with concrete using normal portland cement, but relative strength properties behavior and fatigue resistance show a tendency to decrease a little.

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Fiber post의 Relining 방법과 시멘트 유형에 따른 Push-out Bond Strength의 비교 (Comparison of Push-out Bond Strengths According to Relining Procedure and Cement Type on Fiber Post)

  • 강현영;조소연;유미경;이광원;김경아
    • 구강회복응용과학지
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    • 제27권3호
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    • pp.253-265
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    • 2011
  • 근관치료된 치아의 수복에서 fiber post 크기와 포스트 공간의 직경이 일치하지 않은 경우, 포스트 공간은 두꺼운 레진 시멘트로 채워지게 된다. 레진 시멘트가 두꺼워지면 시멘트 내에 기포가 형성되어 포스트 분리가 발생되기 쉽다. 이런 문제점을 해결하기 위한 방법은 composite resin을 이용하여 fiber post를 relining하는 것이다. 이렇게 형성된 해부학적 포스트는 포스트 공간에 잘 적합하고 시멘트의 두께를 감소시킨다. 이 연구의 목적은 relining 과정과 임상 과정의 간소화를 위해 사용되고 있는 luting agents 종류에 따른 fiber post의 push-out 결합 강도를 평가하는 것이다. 42개의 발치된 치아는 6개의 그룹(n=7)으로 나누어졌다. (A1: relined fiber post를 Luxacore/all-bond 2로 합착, A2: non-relined fiber post를 Luxacore/all-bond 2로 합착. B1: relined fiber post를 Calibra/XP-bond로 합착. B2: non-relined fiber post를 Calibra/XP-bond로 합착. C1: relined fiber post를 RelyX Unicem으로 합착. C2: non-relined fiber post를 RelyX Unicem으로 합착.) Push-out 결합 강도는 relining procedure와 cement type의 상호작용에 의해 영향을 받는 것으로 나타났다. relined fiber post 그룹이 non-relined fiber post 그룹보다 더 높은 결합 강도를 가지며 fiber post relining 과정은 결합강도에 유의한 영향을 가진다.(p<0.05) Luting agent에 따라 모든 그룹에서 RelyX Unicem의 결합강도가 Luxacore/All-bond 2와 Calibra/XP bond에 의한 것보다 유의하게 더 높았다(p<0.05).

원형 톱날의 형태와 마모가 유리 탄소섬유 하이브리드 복합재료의 절단 품질에 미치는 영향 (Effect of the Circular Saw-Blade Type and Wear on the Cutting Quality of a Glass Carbon-Fiber Hybrid Composite)

  • 백종현;주창민;김수진;박윤옥
    • 한국기계가공학회지
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    • 제20권10호
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    • pp.72-79
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    • 2021
  • A circular saw is an effective tool for cutting glass and carbon-fiber hybrid composites. This study investigated tool wear and cut quality when reusing saw blades. The carbide saws wear four times faster than the new ones, and polycrystalline diamond (PCD) is very resistant to tool wear, except at the end of its lifespan. The cut cross-section quality is affected by the blade type, tool wear, and spindle speed. Alternate top bevel (ATB)-type blades are suitable for cutting fiber-reinforced plastics, but triple-chip grind (TCG)-type blades are unsuitable because they cause fiber-pullout defects. Tool wear and low spindle speeds increase the occurrence of arc scratches, due to the rear saw blade. A microscopic examination showed that the burr, which is a mixture of fiber chips and epoxy matrix, was bonded on top, and glass-fiber delamination occurred on the bottom glass-fiber-reinforced polymer (GFRP) surface.

Streptozotocin 유발 당뇨백서에서의 골격근의 GLUT-4와 근섬유의 변화 (The change GLUT-4 and muscle fiber type in Streptozotocin-diabetic rats)

  • 허명;김계엽;오명화;박승규
    • 대한임상전기생리학회지
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    • 제1권1호
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    • pp.73-85
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    • 2003
  • The purpose of this study is to discuss and analyze the change of GLUT-4 and muscle fiber type of streptozotocin(STZ)-diabetic rats over a period of 6 weeks. We divided into four groups; I(aquatic exercise and feeding of Cordyceps militaris; n=6), test group II(feeding of Cordyceps miliaris; n=6), test group III(aquatic exercise; n=6), control group IV(non-treatment; n=6). After experimenting we measured the blood glucose, body weight, muscle fiber type and GLUT-4 protein content. The change of glucose levels decreased greater in group I than the other group. The body weight gain was lower in the all groups. The change femoris muscle fiber type, the size of muscle fiber TypeII lessened more than the one of Type I in group IV. Decrease of muscle fiber size more diminishment in group I than the other group. GLUT-4 protein quantity decrease in group IV compared to normal group. It was significantly increased in group. I, III compared to group IV. But there was more increase in group I (p<.001). These results suggest that GLUT-4 and muscle fiber type II decrease in STZ-diabetic rats and that when we apply aquatic exercise and feeding of Cordyceps militaris in diabetic rats over a period 6 weeks, it is increase GLUT-4 and the increase of insulin sensitivity of peripheral tissue. So it is considered to be helpful in improvement of glucose homeostasis and in prevent from muscle atrophy resulted from complication.

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연속섬유강화 플라스틱 복합재료의 컵형 압축성형성에 관한 연구 (A Study on the Cup-Type Compression Molding for Continuous Fiber-Reinforced Poymeric Composites)

  • 오영준;김형철;조선형;김이곤
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1997년도 추계학술대회논문집
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    • pp.176-181
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    • 1997
  • During a compression molding of continuous fiber reinforced composites, the separation of matrix and fiber is caused by the flow of the molding process. As the characteristics of the products are greatly dependent on the separation, it is very important to clarify the separation in relation to molding condition, degree of needle punching number on the degree of nonhomogeneity are studied.

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보강재의 형태와 종류가 금속복합재료의 기계적 물성에 미치는 영향 연구 (Effects of Reinforcements Type on Mechanical Properties of Metal Matrix Composites)

  • 남현욱;조종인;한경섭
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 추계학술발표대회 논문집
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    • pp.79-82
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    • 2001
  • In this research, tile effects of reinforcements type on mechanical properties of MMCs were studied. Six kinds preform were fabricated by using Saffil short fiber, HTZ short fiber, $Al_2O_3$ particle, and SiC particle. MMCs were fabricated by using squeeze casting methods. Various tests were conducted to show the effects of reinforcements type on mechanical properties of MMCs. Tensile and compressive properties of MMCs depend on short fiber, however wear properties depend on particle reinforcement. Generally, properties of fiber/particle hybrid MMCs were excellent than those of MMCs with short fiber.

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강섬유와 탄소섬유를 사용한 고인성 시멘트 복합체의 비빔 및 휨강도 특성 (Mixing and Flexural Strength Characteristics of HPFRCCs using Steel Cord and Carbon Fiber)

  • 이원석;변장배;윤현도;김선우;전에스더
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.377-380
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    • 2006
  • HPFRCCs(High performance fiber reinforced cementitious composites) is a class of FRCCs(Fiber reinforced cementitious composites) exhibit multiple crack. Multiple crack lead to improvement in ductility, toughness, and deformation capacity under compressive and tensile stress. These properties of HPFRCCs are affected by type of fiber, water cement ratio, type of admixture and rate of substitution. Furthermore these influence dispersion of fiber, mixing performance and fluidity of mixture. In this paper, HPFRCCs made of steel cord and carbon fiber were tested with water cement ratio, type of admixture and rate of substitution to evaluate characteristics of mixing and flexural strength.

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Dyeing Properties of Bi-functional Reactive Dyes on a Novel Regenerated Cellulosic Fiber

  • Koh, Joonseok;Kim, Ik Soo;Kim, Sung Soo;Shim, Woo Sub;Kim, Jae Pil
    • Fibers and Polymers
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    • 제5권1호
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    • pp.44-51
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    • 2004
  • Three bi-functional reactive dyes such as Bis(vinylsulphone) type, Bis(monochlorotriazine) type and Bis(mononicotinotriazine) type were applied to regular viscose rayon and new regenerated cellulosic fiber ($enVix^ⓡ$) which was prepared from cellulose acetate fiber by the hydrolysis of acetyl groups, and their dyeing properties and fastness properties were compared. enVix exhibited better dyeability and fastness than regular viscose rayon and these results were also explained by the differences in the supramolecular structure of these two fibers.

스펙클 패턴을 이용한 반사형 광섬유 센서에 대한 연구 (A Study of the Reflection Type Optical Fiber Sensor Based on Speckle Detection)

  • 정은주;박재희
    • 센서학회지
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    • 제13권2호
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    • pp.121-127
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    • 2004
  • A reflection type optical fiber line sensor based on the speckle detection has been developed using the optical fiber mirror with the reflectance of 72 %. Some experiments were carried on with the automobile and the 500 m length multimod fiber. When the automobile passed on the fiber sensor, two abrupt changes of the output waveform occured like the transmission type sensor based on the speckle variations. The signal to noise ratio of this sensor was about 40 dB.

섬유혼합 보강토의 전단강도특성 및 마찰특성 연구 (A Study on Shear strength and Friction Properties of Fiber-Mixed Soil as Backfill Material in Reinforced Earth Wall)

  • 조삼덕;김진만;안주환
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 가을 학술발표회 논문집
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    • pp.651-658
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    • 2002
  • A series of experimental study are performed to evaluate the shear strength and friction properties of fiber-mixed soil as backfill material in reinforced earth wall. In order to evaluate the properties of shear strength the big-size direct shear tests are carried out and on the friction properties, the shear friction tests and the pull-out tests are performed. In the results, when the mixed ratio of the net type fiber is 0.2%, the reinforcement effect was better than the others. Also the reinforcement effect of the net type fiber was larger than that of the line type fiber.

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