• Title/Summary/Keyword: fiber analysis

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FPF(Fibrillated Polypropylene Fiber) Reinforcement Method for Slope Repair (사면보수보강을 위한 FPF 보강공법개발)

  • 김낙경;박동원
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.257-264
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    • 2001
  • This study presents the slope stability analysis results for the model slope test. The model slope was made of the soil reinforced by FPF(Fibrillated Polyprophylene Fiber). The shear strength properties of the soil reinforced by FPF fibers were evaluated through the direct shear tests. The model slope 1:1 and 1:1.5 were made and the load tests were performed. Back analysis using limit equilibrium method was carried out to evaluate the shear strength increase on the FPF reinforced slope. The factor of safety of the FPF reinforce slope increased about 23% over unreinforced slope.

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Nonlinear Failure Analysis of Reinforced Concrete Structures using Fiber Model (파이버모델에 의한 철근콘크리트 구조물의 비선형 파괴해석)

  • 송하원;김일철;변근주
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.127-134
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    • 1998
  • The objectives of this paper is to analyze the reinforced concrete structures by using fiber model. In this study, the fiber modeling techniques including modeling of support conditions are studied. In order to verify the modeling techniques, analysis results obtained for reinforced concrete cantilever beam and reinforced concrete T-girder bridge under cyclic loading are compared with experimental results from full scale test. From the comparison, it is shown that the modeling techniques in this study can be well applied to the nonlinear failure analysis of reinforced concrete structures with porper modifications.

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Physicochemical Characteristics of Silk Fibroin Degummed by Protease in Bacillus licheniformis I. Physicochemical Characteristics of Degummed Silk Fiber (Bacillus licheniformis 단백질 분해 효소에 의한 정연 견사의 특성 I. 정연 견사의 이화학적 특성)

  • 김영대;남중희
    • Journal of Sericultural and Entomological Science
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    • v.34 no.2
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    • pp.41-51
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    • 1992
  • In this thesis, both soap and enzymatic degumming method were adopted and the optimum degumming conditions were obtained. Difference between the two degumming methods in silk fiber state was investigated and analyzed on the basis of the results of physical testings, polarizing microscopy, scanning electron microscopy, viscosity measurement, (${\alpha}$$\varepsilon$) amino group contents measurement, birefringence measurement, amino acid analysis, thermal analysis, infrared spectroscopy and x-ray diffraction analysis. The results obtained were summarized as follows; Physical test results of the degummed silk fiber showed that the tenacity and the elongation of enzymatic degummed silk fiber were lower than those of soap degummed fiber. But SEM observation and amino acid analysis showed almost the same tendency in the two degumming methods. The viscosity of enzymatic degummed silk fiber was lower than that of soap degummed fiber, but (${\alpha}$$\varepsilon$) amino group contents was higher in the enzymatic degummed fiber. It can be suggested that the enzymatic degummed silk fibroin was more degraded than the soap degummed fibroin. The birefringence, endothermic temperature of DSC spectrum, IR crystallinity and X-ray lateral order factor of enzymatic degummed silk fiber were higher than those of soap degummed fiber. It seems that the enzymatic degummed silk fiber has the higher crystallinity than that of soap degummed one according to the above results. However, it can be inferred that these differences between soap and enzymatic degummed fiber would be lessened if pretreatment and aftertreatment were included in the enzymatic degumming process.

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A Study on the Comfort Properties of Carbon Heated Socks (I) - A Study on the Subjective Sensitivity and Emotional Sensibility of Chitosan/SUS Fiber Socks Fabrics- (탄소섬유를 사용한 발열양말의 쾌적성 연구(제1보) - 키토산섬유와 SUS섬유의 양말 소재의 주관적 감각 및 감성에 관한 연구 -)

  • Lee, Ji-Eun;Kwon, Young-Ah
    • Fashion & Textile Research Journal
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    • v.12 no.1
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    • pp.103-108
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    • 2010
  • The purpose of this study was to analyze the effect of fiber contents of socks fabric on the subjective sensitivity and emotional sensibility of consumers. We investigated the relationship of subjective sensitivity and sensibility according to fiber contents and color value of socks. We made five plain knit fabrics as specimens, with a combination of chitosan/SUS fiber contents and three value levels of grayish color. The subjects were 15 males and 54 females in the twenties. The data analysis was conducted with Pearson's correlation analysis, ANOVA, Duncan multiple range test, and regression analysis. The major finds were as follows: A factor analysis showed that subjective sensitivity was classified into five factors (bulky, surface-rough, elastic, attention, and variety) and emotional sensibility was into four factors (salience, stability, luxury, and activity). There were significant correlation between the subjective sensitivity and emotional sensibility. The subjective sensitivities of 'surface-rough' and 'elastic' were significantly influenced by fiber contents. The sensibilities of 'salience' and 'luxury' were significantly influenced by fiber contents. Where as the 'salience' and 'roughness' were significant influenced by color value level. According to sex, there were significantly difference in 'bulky', 'elastic' and 'salience'. As a result of the regression analysis, preference, consuming desire and satisfaction appears to be closely related with all subjective sensitivity and sensibility.

Method for Determining Fiber Volume Fraction in Carbon/Epoxy Composites Considering Oxidation of Carbon Fiber (탄소섬유 산화 현상을 고려한 탄소복합재료의 섬유체적비 측정법)

  • Kim, YunHo;Kumar, Sathish;Choi, Chunghyeon;Kim, Chun-Gon;Kim, Sun-Won;Lim, Jae Hyuk
    • Composites Research
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    • v.28 no.5
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    • pp.311-315
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    • 2015
  • Measuring fiber volume fraction properly is very important in designing composite materials because the fiber volume fraction mainly determines mechanical and thermal properties. Conventional Ignition methods are effective for ceramic fiber reinforcing composite materials. However, these methods are not proper for applying to carbon fiber reinforcing composites because of the venerable characteristic against oxidation of carbon fiber. In the research, fiber volume fraction of carbon fiber composites was obtained by a thermogravimetric analysis considering oxidation characteristic of the carbon fiber and the method was compared and verified with the results from microscopic cross section images.

Extraction of dietary fibers from cassava pulp and cassava distiller's dried grains and assessment of their components using Fourier transform infrared spectroscopy to determine their further use as a functional feed in animal diets

  • Okrathok, Supattra;Thumanu, Kanjana;Pukkung, Chayanan;Molee, Wittawat;Khempaka, Sutisa
    • Animal Bioscience
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    • v.35 no.7
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    • pp.1048-1058
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    • 2022
  • Objective: The present study was to investigate the extraction conditions of dietary fiber from dried cassava pulp (DCP) and cassava distiller's dried grains (CDG) under different NaOH concentrations, and the Fourier transform infrared (FTIR) was used to determine the dietary fiber components. Methods: The dried samples (DCP and CDG) were treated with various concentrations of NaOH at levels of 2%, 4%, 6%, and 8% using a completely randomized design with 4 replications of each. After extraction, the residual DCP and CDG dietary fiber were dried in a hot air oven at 55℃ to 60℃. Finally, the oven dried extracted dietary fiber was powdered to a particle size of 1 mm. Both extracted dietary fibers were analyzed for their chemical composition and determined by FTIR. Results: The DCP and CDG treated with NaOH linearly or quadratically or cubically (p<0.05) increased the total dietary fiber (TDF) and insoluble fiber (IDF). The optimal conditions for extracting dietary fiber from DCP and CDG were under treatment with 6% and 4% NaOH, respectively, as these conditions yielded the highest TDF and IDF contents. These results were associated with the FTIR spectra integration for a semi-quantitative analysis, which obtained the highest cellulose content in dietary fiber extracted from DCP and CDG with 6% and 4% NaOH solution, respectively. The principal component analysis illustrated clear separation of spectral distribution in cassava pulp extracted dietary fiber (DFCP) and cassava distiller's dried grains extracted dietary fiber (DFCDG) when treated with 6% and 4% NaOH, respectively. Conclusion: The optimal conditions for the extraction of dietary fiber from DCP and CDG were treatment with 6% and 4% NaOH solution, respectively. In addition, FTIR spectroscopy proved itself to be a powerful tool for fiber identification.

Post-peak response analysis of SFRC columns including spalling and buckling

  • Dhakal, Rajesh P.
    • Structural Engineering and Mechanics
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    • v.22 no.3
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    • pp.311-330
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    • 2006
  • Standard compression tests of steel fiber reinforced concrete (SFRC) cylinders are conducted to formulate compressive stress versus compressive strain relationship of SFRC. Axial pullout tests of SFRC specimens are also conducted to explore its tensile stress strain relationship. Cover concrete spalling and reinforcement buckling models developed originally for normal reinforced concrete are modified to extend their application to SFRC. Thus obtained monotonic material models of concrete and reinforcing bars in SFRC members are combined with unloading/reloading loops used in the cyclic models of concrete and reinforcing bars in normal reinforced concrete. The resulting path-dependent cyclic material models are then incorporated in a finite-element based fiber analysis program. The applicability of these models at member level is verified by simulating cyclic lateral loading tests of SFRC columns under constant axial compression. The analysis using the proposed SFRC models yield results that are much closer to the experimental results than the analytical results obtained using the normal reinforced concrete models are.