• 한국자원식물학회지
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• 제2권2호
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• pp.291-297
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• 1989

It was indicated that natural fiber crops Ln Korea have been major crops, such as cotton, flax, ramie and Kenaf. The major varieties andagronomic characterics are summarized as follows. Cotton variety, Mokpo 6 is long fiber length and, is high lint yield, flax variety, Wiera is hiTh amount of dry stem and grains weiTht. On the other hand, kenaf variety, Suweon 2 is high dry fiber weight and fiher ratio.

• 수산해양기술연구
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• 제35권4호
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• pp.421-427
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• 1999

The critical fracture energy and failure mechanisms of GF/PP composites are investigated in the temperatures range of the ambient temperature to $-50^{\circ}C$ The critical fracture energy increase as fiber volume fraction ratio increased The critical fracture energy shows a maximum at ambient temperature and it tends to decrease as temperature goes up. Major failure mechanisms can be classfied such as fiber matrix debonding, fiber pull-out and/or delamination and matrix deformation.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.579-584
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• 2001

A method is described for predicting crack with and spacing in Steel Fiber Reinforced Concrete (SFRC). The crack behavior of SFRC influenced by longitudinal reinforcement ratio, volume and type of steel fiber, strength of concrete. It can be observed from experimental results that addition of steel fiber to reinforced concrete beam reduces crack width in serviceability limit states. The proposed method predicts crack widths in cracking stage of the beam. Calculated crack widths obtained for reinforced concrete beams and different volume and type of steel fiber, strength of concrete showed good agreement with experimental results.

• 한국철도학회논문집
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• 제8권4호
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• pp.293-298
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• 2005

A method is described for predicting crack with and spacing in Steel Fiber Reinforced Concrete (SFRC). The crack behavior of SFRC influenced by longitudinal reinforcement ratio, volume and type of sleet fiber, strength of concrete. It can be observed from experimental results that addition of steel fiber to reinforced concrete beam reduces crack width in serviceability limit stales. The proposed method predicts crack widths in cracking stage of the beam. Calculated crack widths obtained for reinforced concrete beams and different volume and type of steel fiber, strength of concrete showed good agreement with experimental results.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 춘계학술발표회 논문집
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• pp.328-332
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• 1997

Hot stretching focused on the improvement of properties of poly(L-lactic acid) fiber. Some aliphatic polyesters are biodegradable under microbial attack and the new unique applications are expected. Generally, these materials have a somewhat low melting temperature and low mechanical properties compared with the aromatic polyesters. In this study, melt-spinning of poly(L-lactic acid) was conducted. We investigated effects of the stretching and the molecular orientation of aliphatic polyester fibers on the change of fine-structure. Glass transition temperature, molecular orientation and crystallinity increased according to the increase of stretching ratio.

• Composites Research
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• 제12권5호
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• pp.23-30
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• 1999

Fiber reinforced composite materials are widely used in automotive industry to produce parts that are large, thin, lightweight, strong and stiff. It is very important to know a charge shape in order to have good products in the compression molding. In particular, the product such as a bumper beam is composed of the random and unidirectional fiber mats. The characteristics of flow fronts such as a bulging phenomenon for random mat and unidirectional fiber mat and slip parameters are studied numerically. And the effects of viscosity ratio and stack type on mold filling parameters are also discussed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.857-860
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• 2000

An experimental study on the behavior of Steel Fiber Reinforced Concrete Columns under eccentric compression are presented. Forth-one columns were tested; the variables were column type, eccentricity of load, fiber contents, and longitudinal reinforcement ratio. The column size was $250\times160$ mm in cross section with an effective length of 1150 mm. Eccentricity of load was varied in the range from 1/6 to 1/2 times the column depth. This paper is to provides a framework for basic understanding of the steel fiber concrete columns.

• 한국농공학회논문집
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• 제56권4호
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• pp.21-28
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• 2014

In this study, evaluated ware the strength and durability of the vegetated water purification channel concrete to which recycled aggregates, hawang-toh and jute were applied. Box-Behnken method of response surface analysis in statistics was applied to the experimental design. Experimental variables are as follows, recycled coarse aggregates, hawang-toh, blast-furnace slag and jute fiber. In the experiment, conducted were the tests of compressive strength, chloride ion penetration, abrasion resistance and impact resistance the replacement rate effects of the recycled aggregates, blast-furnace slag and hwang-toh on the performance of vegetated water purification channel concrete were analyzed by using the response surface analysis method on the basis of the experimental results. In addition, an optimum mixing ratio of vegetated water purification channel concrete was determined by using the experimental results. The optimum mixing ratio was determined to be in 10.0% recycled coarse aggregates, 60.0% blast-furnace slag, 10.1% hwang-toh and 0.16% jute fiber. The compressive strength, chloride ion penetration, abrasion rate, and impact number of fracture test results of the optimum mixing ratio were 24.1 MPa, 999 coulombs, 10.30 g/mm3, and 20 number, respectively.

• Journal of the Korean Wood Science and Technology
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• 제24권1호
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• pp.1-10
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• 1996

The frequency distribution diagrams of Korean diffuse-porous woods, 36 families, 75 genera, 145 species, 215 specimens in relation to habit and phenology were analyzed. As the habit character changes from shrub to tree, such quantitative features as vessel frequency, percentage of solitary vessels, length/diameter(L/D) ratio of vessel element decreased but tangential vessel diameter, fiber length/vessel element length(F/V) ratio increased. Qualitative features such as helical vessel wall thickening, diffuse distribution of longitudinal parenchyma, heterogeneous ray composition decreased, while alternate intervessel pits, libriform wood fiber, simple perforations increase. As the phenology character changes from evergreen to deciduous species, such quantitative features as percentage of solitary vessels, vessel element length and L/D ratio decreased but tangential vessel diameter, F/V ratio increased. Diffuse distribution of longitudinal parenchyma, heterogeneous ray composition, and crystals in qualitative features decreased, while alternate intervessel pits, libriform wood fiber, simple perforation of vessel element, ray width and ray height increased.

• 한국의류산업학회지
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• 제17권2호
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• pp.287-294
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• 2015

This study investigates the physical properties of Murata Vortex Spinning (MVS) blended yarn with yarn count(20's, 30's, 40's) and blend ratio(Polyester 100, Polyester70:Cotton30, Polyester50:Cotton50, Polyester30:Cotton70, and Polyester50:Tencel40:Cotton10). This study evaluated tenacity, elongation, bending rigidity, bending hysteresis, hairiness coefficient, irregularity and twist number. The structure of MVS blended yarn influenced stress, strain, bending rigidity, bending hysteresis and the hairiness coefficient of MVS blended yarn decreased as the yarn count increased. MVS blended yarn consists of core and sheath. The core of MVS blended yarn is composed of a parallel fiber with a wrapping fiber that covers thecore fiber. This special structure of the MVS blended yarn effects the physical properties of the yarn; in addition, the mechanical properties of the component fibers influenced the stress, strain, bending rigidity, bending hysteresis and hairiness coefficient of MVS blended yarn with the blend ratio. Polyester decreases and cotton increases resulted in decreased physical properties. A similar polyester content increased the tencel and physical properties. Appropriate physical properties and a variety of touch expression can be realized through a correct blend ratio.