• Title/Summary/Keyword: Fiber content

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Evaluation of Physiological Responses and Subjective Sensation in Different Sock Materials (양말 소재별 인체생리적 반응 및 주관적 감각평가)

  • 김칠순;정명희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.8
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    • pp.1475-1483
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    • 2001
  • The purpose of this study was to determine the physiological responses and subjective sensation according to fiber content of socks. Six female students participated in the wear trial test which was conducted in controled environmental chamber with 26${\pm}$1$^{\circ}C$ and 60${\times}$3%. R.H.SAS program was used for statistical analysis. The results of this study were as follows. Mean skin temperature was significantly different among three different socks. AWNP socks had the highest mean skin temperature and instep temperature. Also relative humidity in the microclimate of socks as well as heart rate were influenced by fiber content of socks, However, test of subjective sensation such as thermal, humid, comfort sensation showed that there was no significant difference among three different socks thermal sensation during the exercise and recovery period.

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A Modified Method for the Determination of the Carboxyl Groups in Fibers by Headspace Gas Chromatography

  • Hou, Qingxi;Chai, Xin-Sheng;Zhu, Junyong
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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    • pp.265-270
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    • 2006
  • This paper reports an improved headspace gas chromatographic method for the determination of carboxyl group content in wood fibers. Pretreatment of wood fibers was applied using dilute HCl to convert carboxyl groups to carboxylic acid groups and then using deionized water to wash fiber samples thoroughly. The samples were finally air dried. Sodium bicarbonate solution was used to react with carboxylic acid groups of the pretreated fibers in a closed testing vial to release carbon dioxide. The content of carboxyl groups in fibers was accurately quantified by determining the amount of carbon dioxide released by a headspace gas chromatograph equipped with a thermal conductivity detector. The modified process for fiber sample pretreatment increased the reliability and accuracy in measuring carboxylic acid groups. The present method is simple, accurate.

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Numerical simulation of elastic-plastic stress concentration in fibrous composites

  • Polatov, Askhad M.
    • Coupled systems mechanics
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    • v.2 no.3
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    • pp.271-288
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    • 2013
  • In the present study an elastic-plastic strain analysis is carried out for fibrous composites by using numerical modeling. Application of homogeneous transversely-isotropic model was chosen based on problem solution of a square plate with a circular hole under uniaxial tension. The results obtained in this study correspond to the solution of fiber model trial problem, as well as to analytical solution. Further, numerical algorithm and software has been developed, based on simplified theory of small elastic strains for transversely-isotropic bodies, and FEM. The influence of holes and cracks on stress state of complicated configuration transversely-isotropic bodies has been studied. Strain curves and plasticity zones that are formed in vicinity of the concentrators has been provided. Numerical values of effective mechanical parameters calculated for unidirectional composites at different ratios of fiber volume content and matrix. Content volume proportions of fibers and matrix defined for fibrous composite material that enables to behave as elastic-plastic body or as a brittle material. The influences of the fibrous structure on stress concentration in vicinity of holes on boron/aluminum D16, used as an example.

Effects of Dietary Fiber and Fat Sources on Lipid Contents of Serum and Tissues in Rats Fed Cholesterol Diet (식이섬유와 지방의 종류가 고콜레스테롤식을 섭취한 흰쥐의 혈청과 조직의 지질성분에 미치는 영향)

  • Park, Yaung-Ja;Kwon, Kee-Hwa
    • Journal of the East Asian Society of Dietary Life
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    • v.7 no.4
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    • pp.411-418
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    • 1997
  • The purpose of this research was to investigate the effects of 10%(w/w) of various dietary fiber, pectin(P), lignin(L), cellulose(C) and fiber-free (F) on lipid content of serum, liver and intestinal tissues in rats fed 10% coix oil (C)-or lard(L)-1% cholesterol diets for four weeks. The lard pectin(LP) group was the lowest In body weight gain and feed intake. Liver weight was not affected by dietary fiber and fat sources, and intestinal weight was higher in pectin(CP, LP) groups than in the other groups. Serum cholesterol was significantly lower in pectin(CP, LP) groups than in fiber-free(CF, LF) groups, and was higher in lard fiber-free(LF) than In the other groups(p<0.05). Serum triglycerides was significantly lower in coix oil pectin(CP) and lignin(CL, LL) than in fiber-free(CF, LF) groups. Liver total lipid and cholesterol content was significantly lower In pectin than In lard fiber-free group, and liver triglycerides was lower in coix oil pectin(CP) than in fiber-free groups (p<0.05). Lipid content of intestinal tissue was not affected by dietary fiber source. But total lipid and triglyceride content of intestinal tissues was significantly lower, and cholesterol content was higher in coix oil than in lard group(p<0.05). These results indicate that pectin and lignin reduced serum cholesterol. Pectin also decreased total lipid, cholesterol and triglyceride contents of liver in rats fed either coix oil-or lard-cholesterol diets whereas lignin did not affect liver lipid content.

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Mechanical behavior and chloride resistance of cementitious composites with PE and steel fiber

  • Liao, Qiao;Guo, Zhen-wen;Duan, Xin-zhi;Yu, Jiang-tao;Liu, Ke-ke;Dong, Fang-yuan
    • 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.

Spatting and Fire Enduring Properties of High Strength RC Column Subjected to Axial Load Depending on Fiber Contents (중심 축하중을 받는 고강도 RC기둥의 섬유 혼입량에 따른 폭열 및 내화 성상)

  • Han, Cheon-Goo;Hwang, Yin-Seong;Lee, Jae-Sam;Kim, Kyoung-Min
    • Journal of the Korea Concrete Institute
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    • v.18 no.1 s.91
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    • pp.83-90
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    • 2006
  • This paper investigates experimentally the fire resistance performance and spatting resistance of high performance reinforced concrete column member subjected to fire containing polypropylene fiber(PP fiber) and cellulose fiber(CL fiber). An increase in PP fiber and CL fiber contents, respectively resulted in a reduction of fluidity due to fiber ball effect. Air content is constant with m increase in fiber content. Compressive strength reached beyond 50 MPa. Based on fire resistance test, severe failure occurred with control concrete specimen, which caused exposure of reinforcing bar. No spall occurred with specimen containing PP fiber. This is due to the discharge of internal vapour pressure. Use of CL fiber superior to control concrete in the side of spatting resistance, localized failure at comer of specimen was observed. Corner of specimen had deeper neutralization than surface of specimen. Specimen containing PP fiber had the least damaged area due to spatting. Neutralization depth ranged between 6 and 8 mm Residual compressive strength of specimen containing PP fiber maintained 40%, which is larger than control concrete with 20% of residual strength. Specimen containing CL fiber had 25% or residual strength.

Analysis of Dietary Fiber Content in Korean Vegetable Foods (국내산 식물성 식품중 식이섬유 함량의 분석)

  • Lee, Kyung-Sook;Lee, Su-Rae
    • Korean Journal of Food Science and Technology
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    • v.25 no.3
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    • pp.225-231
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    • 1993
  • Total dietary fiber and crude fiber contents were analyzed for 54 different kinds of Korean vegetable foods by AOAC method. On the fresh matter basis, total dietary fiber and crude fiber contents of tested food samples ranged from $1.19{\sim}10.35%,\;0.19{\sim}1.28%$ in cereals, $1.12{\sim}1.81%,\;0.29{\sim}0.64%$ in potatoes, $2.05{\sim}18.14%,\;0.38{\sim}4.42%$, in pulses, $0.99{\sim}7.42%,\;0.35{\sim}2.61%$ in fresh vegetables, $2.28{\sim}41.14%,\;0.97{\sim}20.96%$ in processed vegetables, $0.19{\sim}2.91%,\;0.10{\sim}0.79%$ in fruits, $4.27{\sim}10.83%,\;0.96{\sim}4.62%$ in nuts and seeds, $1.62{\sim}3.94%,\;0.79{\sim}0.89%$ in mushrooms, $28.70{\sim}38.19%,\;2.17{\sim}6.41%$ in seaweeds, and $4.65{\sim}6.67%,\;2.49{\sim}3.44%$ in seasonings, respectively. The ratio of total dietary fiber/crude fiber contents ranged from 2 to 13, showing a wide variation among food commodities, necessitating the analysis of total dietary fiber content for individual food items.

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Effect of Dietary Protein and Fiber on Ethanol-induced Hepatotoxicity in Rats (흰쥐의 에탄올성 간장해에 미치는 식이 단백질과 섬유소의 영향)

  • 조수열;박은미;이미경;장주연;김명주
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.4
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    • pp.675-681
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    • 1997
  • This study was conducted to investigate the effect of dietary protein and fiber levels on the activities of ethanol metabolizing enzymes of liver in ethanol-treated rats. Sprague-Dawley male rats were fed on diets containing two levels of protein(7, 20%/kg diet) and pectin(5, 10%/kg diet). In ethanol experiments, ethanol(25% v/v) was administered by oral intubation(5g/kg body weight) at the same time once a day Control animals received an isocaloric dose of sucrose. The rats were sacrificed after 5 weeks of feeding periods. Alcohol dehydrogenase and microsomal ethanol oxidizing system activities of hepatic tissue were increased more in ethanol-treated groups than in control groups. Increment of activities predominated in normal protein normal fiber group. Aldehyde dehydrogenase activity was decreased in ethanol-treated groups and significantly decreased in normal Protein normal fiber group. Cytochrome P-450 content was significantly increased in ethanol-treated groups and Predominated in normal protein groups. Xanthine oxidase activity was increased in ethanol-treated groups, but not significantly except normal protein normal fiber group. Glutathione content tended to increase in proportion to level of dietary protein and was higher in normal fiber groups than in high fiber groups, whereas it was decreased by ethanol treatment. Lipid Peroxide content was significantly increased in low Protein normal fiber groups.

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Effect of Heat Treatment on In Vitro Hydrolysis Index of Commercial Saengshik (시판 표준 생식의 전분 가수분해지수에 열처리가 미치는 영향)

  • Han, Sung-Hee;Han, Sang-Yoon;Rhee, Chul
    • The Korean Journal of Food And Nutrition
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    • v.21 no.4
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    • pp.470-476
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    • 2008
  • In this study, we assessed the effects of heat treatment on the in vitro hydrolysis indices of commercial Saengshik. Thermal treatment on grain flour and commercial Saengshik increased soluble dietary finer(SDF) and insoluble fiber(IDF), while total dietary fiber(TDF) content remained nearly constant regardless of thermal treatment. Among the samples, COS(Commercial Ohaeng Saengshik) showed the highest TDF and IDF content in raw and heated samples. Additionally, the resistant starch(RS) contents in unheated samples were shown to be high. After heating, the RS levels of all the samples were reduced significantly, by over 12%. The degree of gelatinization in the unheated samples was lower than that of the heated samples, whereas the degree of retrogradation in the unheated samples was higher than that of the heated samples. The hydrolysis indices(HI) of the unheated samples were relatively low, whereas the heated group evidenced high levels. The HI must be affected by content of RS and IDF in samples.

Interfacial Properties and Microfailure Mechanisms of Electrodeposited Carbon Fiber/epoxy-PEI Composites by Microdroplet and Surface Wettability Tests (Microdroplet 시험법과 Surface Wettability 측정을 이용한 전기증착된 탄소섬유 강화 Epoxy-PEI 복합재료의 계면물성과 미세파괴 메카니즘)

  • Kim, Dae-Sik;Kong, Jin-Woo;Park, Joung-Man;Kim, Minyoung;Kim, Wonho;Park, In-Seo
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.153-157
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    • 2001
  • Interfacial properties and microfailure modes of electrodeposition (ED) treated carbon fiber reinforced polyetherimide (PEI) toughened epoxy composite were investigated using microdroplet test and the measurement of surface wettability. As PEI content increased, Interfacial shear strength (IFSS) increased due to enhanced toughness and plastic deformation of PEI. In the untreated case, IFSS increased with adding PEI content, and IFSS of pure PEI matrix showed the highest. On the other hand, for ED-treated case IFSS increased with PEI content with rather low improvement rate. The work of adhesion between fiber and matrix was not directly proportional to IFSS for both the untreated and ED-treated cases. The matrix toughness might contribute to IFSS more likely than the surface wettability. Interfacial properties of epoxy-PEI composite can be affected efficiently by both the control of matrix toughness and ED treatment.

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