• Journal of Environmental Science International
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• 제8권4호
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• pp.473-477
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• 1999

The purpose of this study was to investigate the characteristics of removal efficiency for aromatic hydrocarbons using a high-temperature fiber filter on a laboratory scale. The main elemental compositions of a high-temperaure fiber filter are aluminium and silica, which can act as the catalysts. Benzene, toluene and o-xylene among aromatic hydrocarbons were used in this experiment. For 3cm thickness of fiber filter, these compounds were removed more than 90% at the face velocities of 3cm/sec and 5cm/sec above 45$0^{\circ}C$. For 4cm thickness of it, the removal efficiencies of these compounds were almost 90% from 40$0^{\circ}C$ at the same face velocities, suggesting that it may be due to increasing the contact time between the fiber filter and aromatic hydrocarbons. The pressure droop ranged from 22 to 48mmH2O for 3cm thickness of fiber filter. However, for 4cm thickness of it, it was about two times(41~89mm$H_2O$) higher than that for 3cm fiber thickness.

• Journal of the Korea institute for structural maintenance and inspection
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• 제8권3호
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• pp.141-148
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• 2004

This paper 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 workability of high strength steel fiber reinforced cementitious composites. As for the test results, it was found that the workability of high strength steel 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 steel fiber improved the workability of fiber reinforced cementitious composites. And the steel fiber reinforced cementitious composites with better workability showed the enhanced compressive strength and flexural strength.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.573-576
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• 2004

High performance SFRC composed of mira-sized ultra fine particles is characterized by high strength, high ductility and excellent durability. therefore many researches about materials based on new composition like this are performed recently. many researchers have reported that adding steel fiber to concrete improved its tensile and flexural strength significantly. the main objective of this research is to examine the effect of adding steel fiber on the tensile strength of high performance SFRC. variables considered in this study are w/c ratio and fiber volume fraction.

• Computers and Concrete
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• 제9권2호
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• pp.153-169
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• 2012

The contribution of steel fibers on the 28-day compressive strength of high-performance steel fiber reinforced concrete was investigated, is presented. An extensive experimentation was carried out over water-cementitious materials (w/cm) ratios ranging from 0.25 to 0.40, with silica fume-cementitious materials ratios from 0.05 to 0.15, and fiber volume fractions ($V_f$= 0.0, 0.5, 1.0 and 1.5%) with the aspect ratios of 80 and 53. Based on the test results of 44 concrete mixes, mathematical model was developed using statistical methods to quantify the effect of fiber content on compressive strength of HPSFRC in terms of fiber reinforcing index. The expression, being developed with strength ratios and not with absolute values of strengths, is independent of specimen parameters and is applicable to wide range of w/cm ratios, and used in the mix design of steel fiber reinforced concrete. The estimated strengths are within ${\pm}3.2%$ of the actual values. The model was tested for the strength results of 14 mixes having fiber aspect ratio of 53. On examining the validity of the proposed model, there exists a good correlation between the predicted values and the experimental values of different researchers. Equation is also proposed for the size effect of the concrete specimens.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제16권6호
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• pp.75-80
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• 2017

The use of optical fiber makes it possible to transfer a large amount of data, thereby enabling a high-speed image transmission with a high response speed and a large number of frames. The need for an optical fiber HDMI System has grown in importance due to the rapid development of displays with large sizes and high-resolution images. In this paper, we have studied the structural design and FEM analysis of a 4C fiber guide for hybrid interconnection implementation. According to the structural analysis of the fiber guide, we have confirmed the safety of the design and we will make additional design changes to minimize the optical loss and fabricate a fiber guide for photoelectric composite HDMI in the future.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.377-380
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• 2008

The material and mechanical properties in the high temperature area of 40 to 100 MPa high strength concrete structural member was identified based on mixing of fiber cocktail and the structural element fire behavior simulation through the finite element analysis method (ABAQUS) was interpreted. The results are as follows. First, it was interpreted that the test specimen with concrete fiber cocktail mixed was more controllable in the maximum shrinkage than the one with concrete fiber cocktail not mixed the controllable range was about 25% to 55%. This means that shrinkage is controllable through mixing of fiber cocktail for the high strength concrete columns. Second, this study didn't consider the explosive spalling by the pore pressure within high strength concrete. If the properties for the pore pressure within high strength concrete is considered and database by strength and by inner temperature of various high strength concrete and steel materials are established in the future, it is interpreted that the technical foundation will be laid for performance based design of fire resistant construction.

• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 2002년도 제10회 하계 Workshop
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• pp.59-101
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• 2002

PVDF is good material for a hollow fiber membrane with high porosity and excellent hydrophobicity. Asymmetric PVDF hollow fiber membranes were prepared by the Loeb-Sourirajan phase inversion method. Asymmetric PVDF hollow fiber membranes could be controlled in pore size and porosity using various additives(LiCl, ZnCl$_2$) and internal coagulants (water, EtOH/water, and DMAc/water mixture). $CO_2$removal efficiency of asymmetric PVDF hollow fiber membranes was 1.2 times high than that of commercialized PP hollow fiber membranes at MEA 5wt% solution. $CO_2$flux of asymmetric PVDF hollow fiber membranes was 2.5 times higher than that of commercialized PP hollow fiber membranes. $CO_2$removal efficiency and absorption rate of asymmetric PVDF hollow fiber membranes were 30 times higher than those of packed column at absorbent $H_2O$. $CO_2$flux of asymmetric PVDF hollow fiber membranes at MEA 5wt% solution was 48 times higher than that of pure water. In the case of MEA 5wt% solution used as an absorbent, the $CO_2$absorption rate and removal efficiency of PVDF hollow fiber membrane were 2.3 times higher than that of a packed column.

• Transactions of the Korean Society of Mechanical Engineers
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• 제16권2호
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• pp.200-206
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• 1992

The effect of fiber diameter and gauge length on pull-out test for the interfacial properties in fiber reinforced resin composites have been investigated and these results have been arranged as statistical analysis. The fiber and matrix resins used for this study were stainless steel fiber (SUS316) and carbon fiber (high strength type), epoxy and high density polyethylene resin. From this study, it has been found that shear strength are constant regardless of gauge length of pull-out test and coefficient of variation depend on fiber diameter. In addition, it has been found that the interfacial shear strength decreased with the increasing fiber diameter, and in all case, Weibull parameter (m) has approximately 1.2/C.O.V.

• Journal of the Korea institute for structural maintenance and inspection
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• 제12권3호
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• pp.101-109
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• 2008

Many researchers have reported that adding steel fiber to concrete improved its tensile and flexural strength significantly, but relatively few studies have been made on the compressive behavior of steel fiber-reinforced concrete. It is still less in case of high strength steel fiber-reinforced cementitious composites(SFRC). The main objective of this research is to examine the effect of adding steel fiber on the compressive strength of high strength SFRC using fiber reinforcing index(RI, $V_f(I_f/d_f)$). It was found from the study that compressive strength was noticeably increased in proportion to RI. In conclusion, the relationship between Reinforcing Index(RI) and compressive strength in case of high strength steel fiber-reinforced cementitious composites was suggested.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.75-80
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• 1997

This research has been examined to measure the degree of the fiber damage of ozonenation high yield pulp in the beating process. Ozone treated the TMP(Thermomechanical Pulp) and CTMP(Chemithermomechanical Pulp) of spruce and the CTMP of birch has been beaten to be reached 200ml(freeness) of its content. It had been studied the forming of fiber distribution by treatment for long fiber, short fiber, fine with the above method. As ozone treatment time gets longer, the pulp has showed the tendency of increasing the fiber content of 28, 48mesh. Ozone treated fiber has been increased long fiber content by being added softness. By given longer ozone treatment time, the TMP and CTMP of spruce has showed the decreasing of fiber content. On the contrary, CTMP of birch has showed the increasing its fiber content. It had proved that the results of difference are rather closer to the species of tree than closer to the kinds of pulp. The fiber content of over 200mesh which has created in beating process demonstrates the decreasing of its fiber content by getting longer ozone treatment time. The softness of fiber can be extracted by the lignin of fiber surface that had been formed by ozone treatment. Thus we assume that the fiber in the process of beating obtains less physical damage.