• International Journal of Highway Engineering
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• v.19 no.2
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• pp.17-24
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• 2017

PURPOSES : This study aims to develop a sealant for use in the installation of Weigh-In-Motion (WIM) sensor for asphalt concrete or cement concrete pavements. METHODS : In order to investigate the properties of various sealants that were mixed with latex and carbon fiber, various test methods were adopted, such as bituminous bond strength test, softening point test, and cone penetration test. To evaluate moisture susceptibility, the BBS test was conducted under moist condition. The bond strength ratio (BSR) was calculated based on tensile strength ratio method. RESULTS : The sealant's properties significantly varied according to the amount of latex or carbon fiber. The usage of latex marginally enhanced the cone penetration test result, notwithstanding reduced asphalt content. This implies that the sealant will be proper cold temperature reason. Moreover, the addition of latex and carbon fiber evidently increased the softening point. This indicates that the tendency of the material to flow at elevated temperatures is encountered during service. With the addition of latex and carbon fiber, the moisture susceptibility measured with BSR improved marginally, while the bond strength under dry condition decreased marginally. Sealant F displays the highest bond strength and BSR under limited test conditions. CONCLUSIONS : According to the proportion of latex and carbon fiber mixed, properties of sealant, such as softening point, cone penetration, and BSR varied marginally. This indicates that the sealant has to be applied considering the environmental condition, to improve service life.

• Journal of the Korea Institute of Building Construction
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• v.10 no.6
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• pp.67-75
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• 2010

In this paper, by using steel fiber, polypropylene fiber and these two hybrid fibers, the fire resistance performance and explosive properties of High Strength Concrete (HSC) with specified compressive strength of 40MPa are discussed. The paper also examines the bending resistance of the beam and the shearing resistance properties of non-reinforced HSC beam. This research helps to clarify the fire resistance of fiber HSC and its anti-explosion methods. The test results show that crack generation, explosion and carbonization can be effectively restrained when HSC is mixed with hybrid fibers under high temperature; furthermore, the maximum internal force and ductility are increased and the initial cracking can be restrained in the mechanical test.

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.31-39
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• 2018

Purpose: The aim of study was to determine the effects of carbohydrate, fat, protein, and fiber contents on glycemic responses in a single food item or meal. Methods: Glycemic responses were measured in 30 healthy young adults (17 males and 13 females) with various test foods, including rice, egg whites, bean sprouts, olive oil, noodles, prune, broccoli, Korean dishes, Western dishes, and salad dishes, etc. Test foods were designed to contain various carbohydrate, fat, protein, and fiber contents in single or mixed foods or dishes. After 12 hours of fasting, participants consumed test foods, and the glycemic response was measured for a subsequent 120 min (0, 15, 30, 60, 90, and 120 min). Three hundred and fifty three glycemic responses from 62 foods were collected. The incremental area under the curve (AUC) was calculated for each test food for each subject to examine glycemic responses. Statistical analysis was conducted to identify which macronutrient (carbohydrate, fat, protein and fiber) affected the AUC using a mixed model. Results: Carbohydrates (${\beta}=37.18$, p < 0.0001) significantly increased while fat (${\beta}=-32.70$, p = 0.0054) and fiber (${\beta}=-32.01$, p = 0.0486) significantly reduced the glycemic response. Conclusion: It can be concluded that the glycemic response of a meal can be modified depending on the fat and fiber contents of ingredient foods, even though carbohydrate content is maintained.

• Membrane Journal
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• v.30 no.4
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• pp.269-275
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• 2020

In this study, CO₂ separation experiment was performed on a CH₄/CO₂ mixed gas using a ceramic hollow fiber membrane contactor (HFMC). In order to fabricate high-performance HFMC, experiments were conducted to manufacture high-permeability hollow fiber membranes, and the prepared hollow fiber membranes were evaluated through N₂ gas permeation experiments. HFMC for CH₄/CO₂ mixed gas separation was manufactured using the manufactured high-permeability hollow fiber membrane. In the experiment, mixed gas of CH₄/CO₂ (34.5% CO₂, CH₄ balance) and monoetanolamine (MEA) was used, and the effect of CO₂ removal efficiency on the flow rate of the absorbent was evaluated. The CO₂ removal efficiency increased as the liquid flow rate increased, and the CO₂ absorption flux also increased with the liquid flow rate.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.5
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• pp.27-33
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• 2011

Hemp bast pulp cooked at temperature below $100^{\circ}C$ followed by defibration by the knife and the valley beater, respectively was mixed with softwood pulp varying the amount of hemp pulp in order to find the optimum condition for making hemp-wood paper. Both the knife and the valley beaters contributed to the dispersion of pulp fiber well. Lots of shives were found when the knife beater was applied exclusively, but the fibers were dispersed well when freeness dropped to 600 mL CSF and 500 mL CSF by the valley beater. Air resistance decreased drastically below 500 mL CSF where rapid disrupture of pulp fiber occurred. As the values for freeness and hemp fiber content increased, so did roughness and bulk. It was apparent that the tear strength of hemp-wood paper was on the rise drastically as hemp fiber content increased. Nevertheless the optimum hemp fiber content of hemp-wood paper would be 20% considering the decrease in both tensile and burst strengths as well as sheet formation.

• Structural Engineering and Mechanics
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• v.90 no.2
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• pp.107-116
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• 2024

This study examined the changes in the mechanical properties of coral concrete under different coconut fiber admixtures. To accomplish this goal, the compressive strength, splitting tensile strength, flexural strength and elastic modulus properties of coral concrete blocks reinforced with coconut fibers were measured. The results showed that the addition of coconut fiber had little effect on the cube and axial compressive strengths. With increasing coconut fiber content, the flexural strength and splitting tensile strength of the concrete changed substantially, first by increasing and then by decreasing, with maximum increases of 36.0% and 12.8%, respectively; additionally, the addition of coconut fibers resulted in a failure type with some ductility. When the coconut fiber-reinforced coral concrete was 7 days old, it reached approximately 74% of its maximum strength. The addition of coconut fiber did not affect the early strength of the coral concrete mixed with seawater. When the amount of coconut fiber was no more than 3 kg/m3, the resulting concrete elastic modulus decreased only slightly from that of a similar concrete without coconut fiber, and the maximum decrease was 5.4%. The optimal dose of coconut fiber was 3 kg/m3 in this study.

• Journal of the Korean Wood Science and Technology
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• v.27 no.2
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• pp.31-37
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• 1999

This study was carried out to develop the Korean paper(Hanji) sludge-wood fiber composite boards utilizing the relinquished sludges occurring from the making process of Korean classic paper Hanji. The bark of paper mulberry(Broussonetia kazinoki Sieb.) has been used as a raw material since past hundreds and thousands years. Korean paper(Hanji) sludge was divided into two kinds, the one was the white sludge from the first stage and the other was the black sludge occurring from the final stage of Korean paper(Hanji) making. Four levels of the mixed ratio of each white or black sludge to wood fiber(10:90, 20:80, 30:70 and 40:60), three levels of the resin adhesives(PMDI, urea and phenol resin) and three levels of the density(0.60, 0.75 and 0.90) were designed to investigate the mechanical properties of Korean paper(Hanji) sludge-wood fiber composite boards. From the results and discussion, it could be concluded as follows : 1. In the white and black sludge-wood fiber composite boards, bending modulus of rupture showed the clear decreasing tendency according to the increase of sludge additive, but it was clearly increased with the increase of specific gravity. Modulus of elasticity showed the same tendency as in the modulus of rupture, and also tensile and internal bonding strength had the same tendencies as in these bending properties. 2. Among the resin adhesives, PMDI or urea resin showed great values in MOR of white sludge-wood fiber composite board, but urea resin was greater than PMDI in MOR and MOE of black sludge-wood fiber composite board. Tensile and internal bonding strength showed the same tendencies as in white sludge-wood fiber composite board. 3. It is suggested that the white sludge-wood fiber composite boards bonded with PMDI or black sludge-wood fiber composite boards bonded with urea resin were able to made similar boards to general fiberboard by the mixed ratio 20:80 of sludge to wood fiber.

• Magazine of the Korean Society of Agricultural Engineers
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• v.27 no.2
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• pp.47-56
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• 1985

Wasting fiberous residues from the cutting processes of steel materials at an iron-Works were mixed with concrete. The strength and toughness of steel fiber concrete with different steel contents were tested in a laboratory. The test results showed that the steel fiber residues can be used for the reinforcement of concrete. The potential applications of such product include floor constructions for facilities like dairy barns, grain storages, and machinery shops. The test results are as follows. 1. The compressive strengths of steel fiber concrete with one percent steel content by volume were 20 percent greater than that of plain concrete. The treatments also increased the concrete toughness by 96 percent. 2. When applied to tensile forces, the steel fiber concrete showed the increased strengths by 20 percent, and the toughness by 48 percent. 3. The steel content levels greater than or equal to 1.5 percent by volume resulted in the decreases of the compressive and tensile strengths of steel fiber concrete by 10 percent as compared to plain concrete. The concrete toughness increased with the steel contents. 4. The reinforcement effects of steel fiber depend on the quality of fiber material being used. Good steel fiber for concrete reinforcement appears to be uniform in shape and component, fine and long, and round-shaped.

• Journal of Nutrition and Health
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• v.28 no.1
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• pp.23-32
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• 1995

This study was performed to investigate the influence of dietary fibers from the whole foods on the serum lipid level and bowel function in rats. The fiber sources of experimental diets were prepared by drying and milling of cereal(rice bran), vegetables(Korean cabbage, radish), fruit(apple), and sea weeds(laver, sea tangle). Each of fiber sources was mixed into the diet to make the 5% level of total dietary fiber. Male rats of Sprague-Dawley strain were blocked into 8 groups : FF, CC, CE, V1, V2, ER, S1, and S2. The animals were fed ad libitum each of experimental diets for 4 weeks. Serum triglyceride level was not significantly different among groups. The laver group showed the lowest level in the serum total cholesterol. The Korean cabbage group showed the highest level in the serum HDL cholesterol. The longest transit time was observed in the fiber free group and the shortest transit time was observed in the sea tangle group. Absorption rates of calcium were especially lower in the Korean cabbage and the sea tangle groups than the other groups. Magnesium and phosphorus absorption rates were influenced by SDF(Soluble Dietary Fiber) intake and TDF(Total Dietary Fiber) intake, respectively. Mucosa weight in the small intestine showed the tendency to increase by increasing of IDF (Insoluble Dietary Fiber) intake. especially the Korean cabbage group was the heaviest. The activity of maltase in the mucosa of small intestine was the lowest in the radish group.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.2
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• pp.44-50
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• 2012

When the fiber Bragg gratings are embedded in a fiber-optic Sagnac loop for measuring temperature or strain, it is difficult to separate the Bragg wavelengths. The transmitted light is mixed with the reflected Bragg wavelengths in the photo-detector, working as noises. To suppress the noises, we placed the FBG sensors and a fiber-optic attenuator at asymmetric positions in the loop. With the arrangement the reflected light became much bigger than the transmitted light, enabling the separation of the reflected Bragg wavelengths with almost the same signal-to-noise ratio of the FBG sensors outside the loop.