• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.563-568
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• 2002

This paper is a fundamental study on the mechanical properties of the high performance concrete confined with metal lath, glass and carbon fiber laterally. According to the results, it shows that the compressive strength increases by 9%, 8% and 6% in metal lath carbon fiber and glass fiber in case of W/B 30% respectively. In case of W/B 30% and 40%, flecxural strength shows largely in order of carbon fiber, metal lath, glass fiber. In strain-stress curve with the kinds of material for lateral confinement, while brittleness failure occurs in plain concrete just after maximum load, it is improved in some degree in confined concrete due to increase of the strain by increase of toughness. But, elastic modulus shows the similar tendency between confined concrete and plain concrete. Length change ratio by drying shrinkage shows little a bit in order of carbon fiber, glass fiber and metal lath due to confinement.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.393-396
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• 2006

This study present the experimental research investigating the influence of material factors such as a type or amount of superplasticizer, velocity agent, mineral admixture and steel fiber on the construction performance of fiber reinforced cementitious composites. As for the test results, it was found that the workability of fiber reinforced cementitious composites can be improved when the material factors were matched properly in amount and composition. Furthermore, it was shown that the smaller value of the aspect ratio of fiber improved the workability of fiber reinforced cementitious composites. And the fiber reinforced cementitious composites with better workability showed the enhanced compressive strength and flexural strength.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.625-633
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• 2000

The mechanical and curing properties of short nylon66 fiber reinforced Chloroprene rubber have been investigated as functions of interphase conditions and fiber content. The tensile strength exhibits a dilution effect at a low fiber content in each interphase. It is found that the interphase conditions have an important affect on the dilution ratio and critical fiber content. Double coatings of bonding agent 402 and rubber solution become the best interphase model in this study. The yield strength, tensile modulus, tear strength and fracture toughness at rupture, Jr are significantly improved due to fiber concentration.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1740-1750
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• 1993

The aluminar short fiber reinforced composite materials for hot extrusion were fabricated by semi-solid stirring method, and extruded at extrusion temperature $400^{\circ}C$ with various extrusion ratio. The hot extrusion load of volume fraction 15% metal matrix composites and base alloy Al7075 has been compared. The fiber length distribution, fiber breakage and fiber orientation are investiged to know the fiber behaviour in before and after hot extrusion. The tensile strength of the hot extruded billet are experimentally determined for different of extrusion ratios, and compared with theorically calculated strength.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.4
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• pp.35-41
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• 2001

A newly developed functional fiber for textile, Tencel, which is known to have some advantages over wood fiber such as fibrillation, absorbency and so on, was examined to see the possibility of a raw material for hanji. Hanji was manufactured by the conventional handmade method using Tencel of three different fiber lengths with three different levels of mixing ratio of Tencel and paper mullberry fiber, and their physical and calligraphic properties were evaluated and compared with one another. It was needed to develop more efficient beating methods than conventional one such as valley beating for Tencel to be used effectively as a raw material for hanji. It was found out by image analysis that the calligraphic properties of hanji could be improved by mixing of 10 to 20% of Tencel of relatively short-length fiber with paper mulberry.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.82-83
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• 2015

Recently, the research on steel fiber reinforced concrete has been actively conducted to compensate the defect of brittle fracture of concrete and to enhance toughness. Therefore, the effect of the mixture rate of straight steel fiber on flexural behavior of high strength steel fiber reinforced concrete was evaluated in this research. As a result, when 2% of steel fiber was mixed with concrete volume ratio, it showed the best flexural capacity.

• Journal of the Optical Society of Korea
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• v.11 no.3
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• pp.97-100
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• 2007

We have investigated properties of a plastic photonic crystal fiber guiding terahertz radiations, THz photonic crystal fiber. The single-mode condition and dispersion of a plastic triangular THz photonic crystal fiber are investigated by using the plane wave expansion method and the beam propagation method. The THz photonic crystal fiber can perform as a single-mode fiber below 2.5 THz when the ratio of diameter (d) and period (${\Lambda}$) of air holes is less than 0.475. The THz photonic crystal fiber with ${\Lambda}=500{\mu}m$ and $d/{\Lambda}=0.4$ shows almost zero flattened dispersion behavior, $-0.03{\pm}0.02 ps/THz{\cdot}cm$, in the THz frequency range from 0.8 to 2.0 THz.

• Advances in concrete construction
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• v.12 no.6
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• pp.451-459
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• 2021

The mechanical behaviors and chloride resistance performance of fiber reinforced cementitious composites (FRCC) with hybrid polyethylene (PE) and steel fiber (in total 2% by volume) were investigated. Based on micro-mechanics and fracture mechanics, the reason why the tensile strain capacity of FRCC changed obviously was obtained. Besides, the effects of the total surface area of fiber in FRCC on compressive strength and chloride content were clarified. It is found that the improvement of the tensile strain capacity of FRCC with hybrid fiber is attributed to the growth of strain-hardening performance index (the ratio of complementary energy to crack tip toughness). As the total surface area of fiber related with the interfacial transition zone (ITZ) between fiber and matrix increases, compressive strength decreases obviously. Since the total surface area of fiber is small, the chloride resistance performance of FRCC with hybrid PE and steel fiber is better than that of FRCC containing only PE fiber.

• Computers and Concrete
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• v.30 no.5
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• pp.323-337
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• 2022

This paper proposes a numerical model to simulate the rotational behavior of steel fiber in fresh cement-based materials in the presence of a magnetic field. The results indicate that as the aspect ratio of fiber increases, the required minimum magnetic field intensity to make fiber rotate in viscous fluid increases. The optimal magnetic field intensity is 0.03 T for aligning steel fiber in fresh cement-based materials to ensure that the applying time of the magnetic field can be conducted concurrently with the vibrating process to increase the aligning efficiency. The orientation factor of steel fiber in cement mortar can exceed 0.85 after aligning by 0.03 T of the uniform magnetic field. When the initial angle of the fiber to the magnetic field direction is less than 10°, the magnetic field less than 0.03 T cannot make the fiber overcome the yield stress of fluid to rotate. The coarse aggregate in steel fiber-reinforced concrete is detrimental to the rotation and alignment of the steel fiber. But the orientation factor of ASFRC under the 0.03T of the magnetic field can also exceed 0.8, while the orientation factor of SFRC without magnetic field application is around 0.6.

• Journal of Nutrition and Health
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• v.30 no.5
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• pp.465-477
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• 1997

The purpose of this article is to know the effects on bowel function of the kind of fiber and the amount of fiber in SD-rats. To do this experiment, we select of $\alpha$-cellulose as n insoluble cellulose source and alginic acid and pectin as soluble cellulose source. The rats diets contained callolose camcentrations of 1.0%, 3.6%, 6.0% and 10.0%. After that, we raised the SD-rats for 4weeks and measured the amount of food intake, body weight, the food effciency ratio, the length of liver and stomach the weight of the intestines, the transit time through the intestines, pH in feces, and the amount of bile acid and Ca, Mg, pp. 1) The amount of food intake was 15.75-31.00g/day. It was highest in the 10.0% cellulose group and the lowest in the 3.6% and 6.0% alginic acid group (p<0.05). The body weights of rats were 277.50-349.809. It was highest in the 1.0% pectin group and lowest in the 3.6% alginic acid group, 6.0% cellulose group, and 10.0% pectin group. It had differences according to the content fiber and the kind of dietary(p<0.01). The food efficiency ratio was (p<0.01). The higher the content of dietary fiber, the lower the calory and the food efficiency ratio. 2) Transit time was 446.0-775.0 minutes and it showed signidicant ifferences according to the content and kind of dietary fiber(p<0.01). It was long in the 1.0% cellulose group and 1.0% pectin group but short in the 10.0% alginic acid group. As the content of dietary fiber increased, the transit time through the intestines was shortened. The length of small intestine was 101.03-120.40cm and there were no difference cegardloss of the content and kind of fiber. The length of the large intestine was 20.92-25.42cm and there were significant differences according to the content and kind of the fiber. High-fiber diets resulted in increases in the length of the large intestine. 3) The weight of the liver was 8.68-10.96g and there were no differences according to the content and kind of fiber. The weight of stomach was 1.28-1.74g and there were no differences resulting from the kind of dietary fiber, but it was highest in the 10.0% alginic acid group. The weight of the small intestine was 5.52-8.04g with no difference resulting from to the kind of fiber. It was highest in the 10.0% the alginic acid group and lowest in the 1.0% alginic acid group(p<0.05). The weight of large intestine was 2.50-3.30g with no differences related to the kind of dietary fiber. It was heaviest in the 6.0% and 10.0% alginic acid groups and in the 10.0% pectin group with differences related to the content of fiber(p<0.05). 4) The pH of the feces was 5.82-6.86 according to the kind of dietary fiber, alginic acid group was high at 6.66, the cellulose group was 6.26. but the pectin group was low at 6.30. There were difference according to the content of fiber, but no consistency. The content of bile acid was 6.25-34.77umol per 1g of dry feces. According to the kind of dietary fiber, the alginic acid group was low at 12.91umol, cellulose group was 18.64umol and, the pectin group was the highest at 27.78umol(p<0.001). Based on the content of dietary fiber, alginic acid group was low at 1.0%, but high at 3.6% pectin group(p<0.001). 5) The amount of feces was 1.00-5.10g/day. The weight of rat feces was 2.23g/day in the alginic acid goup, 2.75g/day in the cellulose group, and 1.82g/day in the pectin group. According to the content of fiber, cellulose group was high at 10.0% but alginic acid group was 1.0%, and there were significant difference according to the dietary fiber. The more the content of fiber, the more increase the content of feces in alginic acid, cellulose and pectin group. The content of Ca in the feces was 80.10-207.82mg/1g of dry feces. In the dietary fiber, alginic acid group was 193.08mg, cellulose group was 87.5mg, pectin group was 138.16mg. In the content of fiber, alginic acid group was high at 1.0% and 3.6% but low at 10.0% of Pectin group. The content of Mg was 19.15-44.72mg/1g of dry feces. According to the kind of dietary fiber, alginic acid group was 35.33mg, cellulose group was 23.60mg, and pectin was 36.93mg. According to the content of fiber, pectin group was high at 1.0% and low at 10.0% of cellulose group. The content of P was 1.65-4.65mg/1g of dry feces. According to the kind of dietary fiber, alginic acid group 2.23mg/g dry feces, cellulose group was 2.29mg/g, pectin group wa 4.08mg/g dry feces. In the content of fiber, pectin group was high at 6.0% and low at 6.0% alginic acid group, but there were significant difference among the analysis value. The conetnt of Ca and MG was higher in soluble alginic acid group and pectin group than in insoluble cellulose group. The high the content of the dietary fiber, the lower the food efficiency ratio and the short the transit time through intestine with the increase of the length of large intestin as well as the higher level of the stomach, the small intestine and the large intestine. According to the content of the dietary fiber, the amount of the feces, Ca, Mg and P was increased but the length the small intestin, the weight of liver, pH of the feces and the amount of bile acid showed no differences and consistency.