• Title/Summary/Keyword: Fiber Fractions

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Flexural Performance Evaluation of HPFRCC Using Hybrid PVA Fibers (하이브리드 PVA 섬유를 이용한 HPFRCC의 휨 성능 평가)

  • Kim, Young-Woo;Min, Kyung-Hwan;Yang, Jun-Mo;Yoon, Young-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.753-756
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    • 2008
  • HPFRCC (High-Performance Fiber Reinforced Cementitious Composites), which is relatively more ductile and has the characteristic of high toughness with high fiber volume fractions, can be used in structures subjected to extreme loads and exposed to durability problems. In the case of using PVA(polyvinyl alcohol) fibers, it is noted by former studies that around 2% fiber volume fractions contributes to the most effective performance at HPFRCC. In this study, therefore, compressive and flexural tests were implemented to evaluate the compressive and flexural capacities of HPFRCC while the total fiber volume fractions was fixed at 2% and two different PVA fibers were used with variable fiber volume fractions to control the micro-crack and macro-crack with short and long fibers, respectively. Moreover, specimens reinforced with steel and PVA fiber simultaneously were also tested to estimate their behavior and finally find out the optimized mixture. In the result of these experiments, the specimen consists of 1.6% short fibers (REC 15) and 0.4% long fiber (RF4000) outperformed other specimens. When a little steel fibers added to the mixture with 2% PVA fibers, the flexural capacity was increased, however, when high steel fiber volume fractions applied, the flexural capacity was decreased.

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NUTRITIONAL EVALUATION OF MAIZE FODDER AT TWO DIFFERENT VEGETATIVE STAGES

  • Azim, A.;Naseer, Z.;Ali, A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.2 no.1
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    • pp.27-34
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    • 1989
  • Different fractions of maize plant and whole mixed fodder were analysed for their chemical composition and dry matter digestibility (DMD). Highest crude protein (CP) values were found in leaves as compared to the other portions. Younger plants contained more CP as compared to the matured ones. The crude fiber (CF) content of various fractions of the plant ranged between 19.12 to 35.60% with maximum values in the bottom portion of the stem. Matured plants contained more CF. The analysis of cell wall constituents indicated that the maximum values for neutral detergent fiber (NDF) were found in the bottom portion and in the whole mixed plant. The highest levels of acid detergent fiber (ADF) were observed in bottom fraction followed by whole mixed plant, whereas the other plant fractions did not show any differences. Variation in acid detergent lignin (ADL) values existed in different fractions of the plant and the lowest were in the top portion of the stem. Although there existed a variation in the mineral composition of different fractions of the plants, the results were non significant. Maximum DMD was found in leaves followed by the whole mixed plant, middle and bottom portion of the stem. The values of DMD were higher in younger plants as compared to the matured ones. It may be concluded that younger plants and the upper portion of the plants have a higher nutritive value as compared to the matured plants and lower portion of the plants.

AMINO ACID DIGESTIBILITY AS AFFECTED BY VARIOUS FIBER SOURCES AND LEVELS 2. THE RELATIONSHIP BETWEEN FIBER LEVELS AND AMINO ACIDS DIGESTIBILITY

  • Nongyao, A.;Han, In K.;Choi, Yun J.;Lee, N.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.3 no.4
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    • pp.353-361
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    • 1990
  • A number of correlation and regression analyses were performed on data from apparent and true digestibility of amino acids at ileal and fecal level with finishing pigs, in order to investigate whether these amino acid digestibilities could be predicted with certainly degree on their fiber fractions content (chemical analysis). The data comprised 16 diets varying in 4 levels of crude fiber and from 4 fiber sources. The relationships between fiber fractions including crude fiber (CF), NDF, ADF lignin and cellulose contents on apparent and true digestibility of almost all amino acids in both ileal and fecal level were negative, except glutamine at fecal level. In apparent digestibility at ileal level, the correlations of fiber fractions were moderate (r of NDF = 0.53 to 0.63; ADF, 0.50 to 0.77; cellulose, 0.50 to 0.75), with an exception of CF content was relatively high (r of 0.58 to 0.81). The correlations to true digestibility of amino acids were weaker. In case of at fecal level, the higher correlation (negative) was found with NDF than CF content. Estimations of amino acids digestibility were performed using regression equation. The data showed that apparent digestibility of amino acids could be estimated for almost amino acids except arginine, threonine, valine and tyrosine at fecal level and phenylalaine, valine and glycine at ileal level. The best prediction at ileal and fecal level ($r^2=0.55-0.77$ and 0.52-0.76), respectively was obtained with NDF content. Prediction for true digestibility of amino acids, none of fiber fractions could be estimated for arginine, leucine and valine at all collection levels. At ileal level, CF could be used for most of amino acids except phenylalanine, glycine and praline; cellulose, only for lysine and methionine and NDF, only for proline. At fecal level, glutamine digestibility could be estimated only from CF and ADF content. The best predictor at ileal level was ADF content whereas at fecal level was NDF content. These results indicate that lignin content could not be used as predictor for all amino acids at both levels neither in apparent nor true digestibility.

Characterization of Insoluble Fibers Prepared from the Peel of Ripe Soft Persimmon (Diospyros kaki L. cv. Daebong)

  • Akter, Mst. Sorifa;Eun, Jong-Bang
    • Food Science and Biotechnology
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    • v.18 no.6
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    • pp.1545-1547
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    • 2009
  • The fiber-rich fractions including enzyme treated insoluble dietary fiber, alcohol insoluble solid, and water insoluble solid were prepared from the peel of soft ripe persimmon, and to evaluate and compare the yields, proximate compositions, monosaccharide profiles, and functional properties. The results showed that uronic acid was the main sugar followed by glucose, which indicated that all insoluble fibers were mainly composed of pectic substances and cellulose. The presence of xylose and fucose indicated the occurrence of hemicellulose. All fiber-rich fractions were exhibited high yield and functional properties. Thus, the peel of ripe persimmon could be used as fiber supplements.

Assessment of the Nutritive Value of Whole Corn Stover and Its Morphological Fractions

  • Li, H.Y.;Xu, L.;Liu, W.J.;Fang, M.Q.;Wang, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.2
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    • pp.194-200
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    • 2014
  • This study investigated the chemical composition and ruminal degradability of corn stover in three maize-planting regions in Qiqihaer, Heilongjiang Province, China. The whole stover was separated into seven morphological fractions, i.e., leaf blade, leaf sheath, stem rind, stem pith, stem node, ear husk, and corn tassel. The assessment of nutritive value of corn stover and its fractions was performed based on laboratory assays of the morphological proportions, chemical composition, and in situ degradability of dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF). The chemical composition of corn stover was significantly different from plant top to bottom (p<0.05). Among the whole corn stover and seven morphological fractions, leaf blade had the highest crude protein (CP) content and the lowest NDF and ADF contents (p<0.05), whereas stem rind had the lowest CP content and the highest ADF and acid detergent lignin (ADL) contents (p<0.05). Ear husk had significantly higher NDF content and relatively lower ADL content than other corn stover fractions. Overall, the effective degradability of DM, NDF, and ADF in rumen was the highest in leaf blade and stem pith, followed by ear husk. The results indicate that leaf blade, ear husk, and stem pith potentially have higher nutritive values than the other fractions of corn stover. This study provides reference data for high-efficiency use of corn stover in feeding ruminants.

A Study about Mechanical Properties of GFRP Laminates depending on Fiber Volume Fraction (섬유체적함유율의 영향에 따른 GFRP적층판의 기계적 특성에 관한 연구)

  • 국중석
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.10a
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    • pp.225-230
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    • 2003
  • Domestic small and medium ship companies have lack of leisure boat technologies and especially they have a problem about its low performance because of the overweight of boat hull. So it is necessary to have alternative manufacturing process to improve the mechanical properties of composite material. In this study, a vacuum curing system was developed as an alternative manufacturing process and then changed the fiber volume fractions of GFRP laminates. The properties of GFRP laminates such as void contents, Young's modulus and fracture toughness were determined for various fiber volume fractions.

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Optimal fiber volume fraction prediction of layered composite using frequency constraints- A hybrid FEM approach

  • Anil, K. Lalepalli;Panda, Subrata K.;Sharma, Nitin;Hirwani, Chetan K.;Topal, Umut
    • Computers and Concrete
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    • v.25 no.4
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    • pp.303-310
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    • 2020
  • In this research, a hybrid mathematical model is derived using the higher-order polynomial kinematic model in association with soft computing technique for the prediction of best fiber volume fractions and the minimal mass of the layered composite structure. The optimal values are predicted further by taking the frequency parameter as the constraint and the projected values utilized for the computation of the eigenvalue and deflections. The optimal mass of the total layered composite and the corresponding optimal volume fractions are evaluated using the particle swarm optimization by constraining the arbitrary frequency value as mass/volume minimization functions. The degree of accuracy of the optimal model has been proven through the comparison study with published well-known research data. Further, the predicted values of volume fractions are incurred for the evaluation of the eigenvalue and the deflection data of the composite structure. To obtain the structural responses i.e. vibrational frequency and the central deflections the proposed higher-order polynomial FE model adopted. Finally, a series of numerical experimentations are carried out using the optimal fibre volume fraction for the prediction of the optimal frequencies and deflections including associated structural parameter.

Effect of Apple Dietary Fiber on the in vitro Growth of Intestinal Bacteria (사과의 식이섬유질이 장내세균의 in vitro 생육에 미치는 영향)

  • Lee, Hyeon-Ah;Lee, Sang-Sun;Shin, Hyun-Kyung
    • Korean Journal of Food Science and Technology
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    • v.29 no.1
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    • pp.107-114
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    • 1997
  • Various fractions of apple fibers such as crude pulp, total dietary fiber, soluble dietary fiber, and insoluble dietary fiber were prepared and added to the proteose peptone-yeast extract-fildes (PYF) media to see their effects on the growth of type cultures of intestinal bacteria. Most microbes tested in this experiment grew well in PYF media with the soluble dietary fiber of apple than with the insoluble dietary fiber. Especially Bifidobacterium species such as B. adolescentis, B. animalis, B. infantis, B. longum, B. thermophilum showed higher growth in PYF media containing the soluble dietary fiber than other fiber fractions. However, pectin-added media didn't promote the growth of most microbes used in the experiment. In the in vitro mixed culture using rat feces as starter, the addition of the soluble dietary fiber or pectin to the basal medium showed larger proportion of Bifidobacterium species in total bacteria than that of glucose.

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Spalling and Internal Temperature Distribution of High Strength Column Member with Polypropylene Fiber Volume Fractions (폴리프로필렌섬유 혼입률에 따른 고강도콘크리트 기둥부재의 폭렬 및 내부온도 분포특성)

  • Won, Jong-Pil;Jang, Chang-Il;Lee, Sang-Woo;Kim, Heung-Youl;Kim, Wan-Young
    • Journal of the Korea Concrete Institute
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    • v.20 no.6
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    • pp.821-826
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    • 2008
  • This study evaluated spalling and internal temperature distribution after elevated temperatures test for high strength concrete ($f_{ck}=60\;MPa$) column member with various polypropylene fiber volume fractions. The ISO-834 time-temperature curve was used for measurement of fire resistance properties. As the result of test, average internal temperature results indicated to low temperature in increased polypropylene fiber volume fraction. But, the highest internal temperature results show that does not difference in proportion of polypropylene fiber volume fractions.

Characteristics and Application of Soybean Hull Fractions Obtained by Microparticulation/Air-Classification (초미세분쇄/공기분급을 이용한 대두피 분획물의 특성과 응용)

  • Ku, Kyung-Hyung;Park, Dong-June;Kim, Seung-Ho
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.506-513
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    • 1996
  • Soybean hull was microparticulated at cut-off wheel speed of 9,000 rpm and air-classified into fine and coarse fraction at air classifying wheel speeds (ACWS) of 10.000, 15,000 and 20,000 rpm. respectively. Proximate analysis of the coarse and fine fractions of the microparticulated/air-classified soybean hull showed that ash, protein and lipid were enriched in the coarse fractions and carbohydrates in the fine fraction. Dietary fiber were enriched in coarse fractions and dietary fiber and dietary fiber content increased with decreasing ACWS. Mean particle size of fine fractions ranged from $3.1{\mu}m\;to\;5.5{\mu}m$ that of coarse fractions ranged from $9.9{\mu}m\;to\;20.0{\mu}m$ and both increased with decreasing ACWS. The particles were mostly oval-shaped regardless of the fractions. Generally the fraction of low ACWS showed higher viscosity. In water holding capacity, oil absorption and emulsion capacity, there was significant difference between coarse and fine fractions while there was no significant difference as a function of different ACWS. Oil absorption of flying batter was decreased significantly in the fraction of ACWS 15,000. when cakes and cooking were prepared partially substituted with soybean hull fraction, there was no significant changes on their physical and sensory properties up to 10% substitution.

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