• Journal of the Society of Disaster Information
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• v.10 no.3
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• pp.432-441
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• 2014

The purpose of this research is to investigate characteristics of lathe scrap for manufacturing fiber reinforced cementitious composites(FRCCs) to use lathe scrap as a alternative materials of steel fiber. It should be noted that the use of the lathe scrap for making FRCCs raised friendly environmental effect as well as economy because the lathe scrap was a by-product of steel manufactures. For this purpose, various steel scraps were collected from processing plants of metal and then their physical properties were evaluated. Also, steel scraps were classified and analyzed according to the KS D 2101 and then of these scraps, lathe scrap as a alternative materials of steel fiber was suggested. In addition, FRCCs containing lathe scraps were made according to their total volume fractions of 0.0, 0.5, 1.0, 1.5, and 2.0% for water-binder ratios of 30%, 40%, respectively, and then characteristics, such as the workability, compressive strength, and flexural strength of those were evaluated. It was observed from the test result that the compressive strengths at 7 and 28 days of FRCCs containing lathe scrap were slightly small but the flexural strengths at 28 days of those increased by 10% compared with plain concrete.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.2
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• pp.81-93
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• 2020

The fatigue characteristics of glass fiber reinforced plastic (GFRP) composites were studied under repeated loads using the finite element method (FEM). To realize the material characteristics of GFRP composites, Digimat, a mean-field homogenization tool, was employed. Additionally, the micro-structures and material models of GFRP composites were defined with it to predict the fatigue behavior of composites more realistically. Specifically, the fatigue characteristics of polybutylene terephthalate with short fiber fractions of 30wt% were investigated with respect to fiber orientation, stress ratio, and thickness. The injection analysis was conducted using Moldflow software to obtain the information on fiber orientations. It was mapped over FEM concerned with fatigue specimens. LS-DYNA, a typical finite element commercial software, was used in the coupled analysis of Digimat to calculate the stress amplitude of composites. FEMFAT software consisting of various numerical material models was used to predict the fatigue life. The results of coupled analysis of linear and nonlinear material models of Digimat were analyzed to identify the fatigue characteristics of GFRP composites using FEMFAT. Neuber's rule was applied to the linear material model to analyze the fatigue behavior in LCF regimen. Additionally, to evaluate the morphological and mechanical structure of GFRP composites, the coupled and fatigue analysis were conducted in terms of thickness.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.28-41
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• 2014

The distinctive physiological effect of dietary fiber in the body were studied according to contents and characteristics of each fiber component. In the present study, the composition of fiber in vegetables was investigated, and the effect of heat treatments on fiber content was studied. Contents of total pectin were 0.89~2.75 g/100 g on dry weight basis, with most contents from 1~2 g/100 g. The hot water soluble pectin (HWSP) content of vegetables ranged from 0.33~0.98 g/100 g, sodium hexametaphosphate soluble pectin (HXSP), from 0.29~0.81 g/100 g and HCl soluble pectin(HCLSP), from 0.30~1.40 g/100 g. HCLSP showed the greatest variation according to the type of vegetables. Every vegetable types showed similar contents of these three pectic fractions. Fiber contents of vegetables ranged from 8.8~23.8% for cellulose, 0.6~10.6% for hemicellulose, 1.0~5.2% for lignin, 10.9~25.4% for acid detergent fiber (ADF) and 11.8~31.9% for neutral detergent fiber (NDF) on dry weight basis. Especially, peppers showed higher contents of NDF than the other vegetables. It was found that a great portion of NDF, which is total insoluble dietary fiber, was composed of cellulose since cellulose constituted 63% of NDF. Heat treatment reduced total pectin content in all vegetables regardless of the heating methods and the greatest reduction was observed upon boiling. HWSP content increased, whereas HXSP and HCLSP contents decreased. Heat treatment increased the NDF, ADF and cellulose contents, and most changes were due to changes in cellulose content. The values of hemicellulose and lignin showed irregular pattern upon heating. Contents of total dietary fiber (TDF) were 1.20~7.11% on fresh weight basis. Garlic, edible burdock and pepper leaf showed higher contents of TDF than other vegetables. It was found that a great portion of TDF was composed of insoluble dietary fiber.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.73-76
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• 2002

This study developed SiC/Al composites for electronic packaging to which reinforcements were added with the volume fractions of 49%, 56% and 63% by the squeeze casting method. 0.8 wt.% of the inorganic binder as well as the $Al_2O_3$ fiber and SiC particles with the volume fraction of 1:10 were added to the SiC/Al composites For the produced SiC/Al composites, the CTEs (coefficients of thermal expansion) were measured from 30 to $300^{\circ}C$ and compared with the FEM numerical simulation to analyze the temperature dependent properties. The experiment showed the CTEs of SiC/Al composites that were intermediate values of those of Rule of Mixture and Turner's Model. The CTEs were close to Turner's Model in the room temperature and approached the Rule of Mixture as the temperature increases. These properties analyzed from the difference of the average stress acting between the matrix and the reinforcements proposed in this study

• Food Science and Preservation
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• v.4 no.3
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• pp.311-315
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• 1997

Proximate compositions of black rice and antioxidative effects of its methanol extract on refined perilla oil were investigated. Black rice seeds were composed of water 12.4%, crude protein 7.9%, crude fat 2.2%, crude fiber 1.0%, ash 1.4% and N-free extract 75.1%. The hexane and 80% methanol fractions in yields were higher than 80% ethanol and chloroform. In AOM(active oxygen method) test, antioxidative effects of black rice added to the refined perilla oil was increased with dose-dependent fashion in concentration of the black rice extracts. Among several extracts tested, 80% aqueous methanol extract showed the highest antioxidative activity, followed by hexane, chloroform, in that order. The peroxide value and TBA value for their antioxidation stability were also lower than that of control. This result was similar to that of AOM test.

• Structural Engineering and Mechanics
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• v.74 no.4
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• pp.515-520
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• 2020

In the modern era, the world is facing unprecedented challenges in form of environmental pollution and international agencies are forcing scientists and materialists to look for green materials and structures to counter this problem. Composites based on renewable sources like plant based fibres, vegetable fibres are finding increasing use in interior components of automobile vehicles, aircraft, and building construction. In the present study, jute and flax fibre based composites were developed and tested for assessing their suitability for possible applications in interior cabin and parts of automobile and aerospace vehicles. Matrix system involves epoxy as resin and fibre weight fractions used were 45% and 55% respectively. Composites samples were prepared as per American society for testing and materials (ASTM) standard and were tested for individual fiber tensile strength, composite tensile strength, and flexural strength to analyse its behavior under various loading conditions. The results revealed that the Jute fibre composites possess enhanced mechanical properties over Flax fibre composites.

• Computers and Concrete
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• v.18 no.1
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• pp.113-137
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• 2016

Extensive experimental studies on remarkable mechanical properties Polypropylene Fibre Reinforced Self-compacting Concrete (PFRSCC) have been executed, including different fibre volume fractions of Polypropylene fibers (0.25%, 0.5%, 0.75%, and 1%) and different water to cement ratios (0.21, 0.34, 0.38, and 0.41). The experimental program was carried out by using two hundred and sixteen specimens to obtain the impact resistance and mechanical properties of PFRSCC materials, considering compressive strength, splitting tensile strength, and flexural strength. Statistical and analytical studies have been mainly focused on experimental data to correlate of mechanical properties of PFRSCC materials. Statistical results revealed that compressive, splitting tensile, and flexural strengths as well as impact resistance follow the normal distribution. Moreover, to correlate mechanical properties based on acquired test results, linear and nonlinear equations were developed among mechanical properties and impact resistance of PFRSCC materials.

• Smart Structures and Systems
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• v.13 no.1
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• pp.111-135
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• 2014

Based on the Reissner mixed variational theorem (RMVT), finite rectangular layer methods (FRLMs) are developed for the three-dimensional (3D) linear buckling analysis of simply-supported, fiber-reinforced composite material (FRCM) and functionally graded material (FGM) sandwich plates subjected to bi-axial compressive loads. In this work, the material properties of the FGM layers are assumed to obey the power-law distributions of the volume fractions of the constituents through the thickness, and the plate is divided into a number of finite rectangular layers, in which the trigonometric functions and Lagrange polynomials are used to interpolate the in- and out-of-plane variations of the field variables of each individual layer, respectively, and an h-refinement process is adopted to yield the convergent solutions. The accuracy and convergence of the RMVT-based FRLMs with various orders used for expansions of each field variables through the thickness are assessed by comparing their solutions with the exact 3D and accurate two-dimensional ones available in the literature.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.110-112
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• 1998

1. 서론 : 분석화학의 중요한 과제중 하나 고효율(high efficiency)과 고해상도(high resolution)를 가지고서 혼합물에서 분자나 입자의 분리능을 개선하는 것과 낮은 수준의 농도에서 이런 분획들(fractions)을 정량화 하는 것이다. 현재의 추세는 분리하고자 하는 분자의 상한선을 증가시키는 것이 순수과학과 산업에서 중요하게 되었다. 이런 분리 기술의 응용은 거대분자(macromolecules)와 입자들(particles)인 cell fragments, plasmides, chromosomes, liposomes, synthetic polymers 등에 적용되고 있는데, 고전적인 분석방법으로는 한외여과, 원심분리, 크기배제 크로마토그래피 등이 있지만 시간이 걸리고 해상도와 효율에 제한이 있다.

• Journal of Forest and Environmental Science
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• v.27 no.3
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• pp.183-194
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• 2011

This study reviewed on the research trend of sources and utilization of the byproducts(Lignin) from bioethanol production process with lignocellulosic biomass such as wood, agri-processing by-products(corn fiber, sugarcane bagasse etc.) and energy crops(switch grass, poplar, Miscanthus etc.). During biochemical conversion process, only Cellulose and hemicellulosic fractions are converted into fermentable sugar, but lignin which represents the third largest fraction of lignocellulosic biomass is not convertible into fermentable sugars. It is therefore extremely important to recover and convert biomass-derived Lignin into high-value products to maintain economic competitiveness of cellulosic ethanol processes. It was introduced that lignin types and characteristics were different from various isolation methods and biomass sources. Also utilization and potentiality for market of those were discussed.