• Title/Summary/Keyword: Fiber volume

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Evaluation of Structural Performance for Filament Wound Composite Ablative Tubes (필라멘트와인딩된 복합재 내열튜브의 구조 성능 평가)

  • 윤성호;황태경;윤남균;문순일
    • Composites Research
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    • v.15 no.1
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    • pp.53-60
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    • 2002
  • Composite ablative tubes required capabilities of ablative and structural characteristics were fabricated through filament winding technique and several experiments were conducted to evaluate the structural performance of composite ablative tubes. For this purpose, manufacturing procedures were briefly described and then resin digestion method was applied to measure the fiber volume fraction and the void content of composite ablative tubes. The configuration of tensile specimen fur composite ablative tubes with not losing the continuity of reinforced fibers was suggested by evaluating mechanical properties of several types of the specimen with different widths. Also, suitable processing variables for composite ablative tubes were determined by evaluating mechanical properties of several types of the specimen with different processing variables. In addition, acoustic emission signals were obtained during the proof test and could be applicable to study the crack initiation and the damage mode of composite ablative tubes. Finally, the structural reliability of composite ablative tubes could be verified to satisfy design requirements through the proof and burst tests.

Evaluation of Sampling and Analytical Methods for the Determination of Polycyclic Aromatic Hydrocarbons in the Ambient Atmosphere (환경대기중 다환방향족탄화수소의 포집과 분석방법에 관한 연구)

  • 백성옥
    • Journal of Korean Society for Atmospheric Environment
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    • v.7 no.1
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    • pp.1-16
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    • 1991
  • In this study, sampling and analytical procedures were evaluated for the determination of ambient levels of atmospheric PAH, both in gaseous and particulate phase. The method involves low-volume sampling and Soxhlet extraction of the filters and Tenax absorbent, followed by a clean-up stage using a silica column prior to analysis by reversed-phase HPLC with wavelength programmable fluorescence and UV detection. A total of 18 PAH were identified and quantified, all of which have been of environmental concern. In order to validate the methodology and to ensure compatibility of the results, the analytical method used for the determination of PAH was evaluated with respect to the efficiencies of extraction and clean-up procedure, HPLC separation, and lower limits of detection. In addition, substrate dependency of PAH recovery was investigated for the two types of fiters, i.e. glass fiber and PTFE filters.

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A Study of the normativeness on the Influence of the Memphis on the Comtemporary Fashion Design - Focused on the End of the 20th Century - (멤피스(Memphis)디자인이 현대 패션에 미친 조형적 특징에 관한 연구 -20세기말을 중심으로-)

  • 임영자;한윤숙
    • Journal of the Korean Society of Costume
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    • v.51 no.1
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    • pp.5-20
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    • 2001
  • The purpose of this study suggest the fashion of communication for 21th century fashion. Especially, Memphis fashion have the possibility of communicating through objects. The results of this study are as follows : First, Memphis idea is to make design into a sophisticated, conscious instrument of communication. As the Memphis fashion points out : design is an extraordinary tool for communicating because its intrinsic characteristic is the fact that it is used and distributed anyway, even without communicating anything. The Memphis fashion is trying to connect design and industry to the broader culture within which fashion moves. Second, Using different materials provides not only new structural Possibilities. but - above all - new semantic and metaphoric possibilities, order modes of communication, another language, and even a change of direction, broadening of perspective, appropriation and digestion of new values and the concomitant rejection of traditional structures that renewal always Involves. The memphis fashion works on the fabric of contemporaneity (lurex yarn, latex, chrome metal and steel) and contemporaneity means computers, electronics, a new awareness of the body. mass exercise and tourism. Third, color in Memphis has never been an ideological vehicle. As with decoration it is born tilth the design, forming an integral part of the structure. It alters the objects molecules. It works as a mass, as an intrinsic feature of a certain form and volume. The Memphis fashion was realized the introduction of ultramodern science into such experimental and creative implementation as optical motive, brilliancy of colour of electronic medium in audition to metallic fabric and high technical synthetic fiber. A color tilth pop culture connotations that weaver between technological allusions and Mcdonald's.

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Dynamic Behaviors of Metal Matrix Composites in Low Velocity Impact (저속 충격하에서의 금속복합재료의 동적 특성)

  • ;Gamal A. Aggag;K.Takahashi
    • Composites Research
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    • v.12 no.1
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    • pp.68-75
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    • 1999
  • This study has observed that the dynamic behavior of Metal Matrix Composites (MMCs) in low velocity impact varies with impact velocity. MMCs with 15 fiber volume percent were fabricated by using the squeeze casting method. The AC8A was used as the matrix, and the alumina and the carbon were used as reinforcements. The tensile and vibration tests conducted yielded the yielded the tensile stress and elastic modulus of MMCs The low pass filter and instrumented impact test machine was adopted to study dynamic behaviors of MMCs corresponding to impact velocity. Stable impact signals were obtained by using the low pass filter. Impact corresponding to impact velocity. Stable impact signals were obtained by using the low pass filter. Impact energy of unreinforced alloy and MM s increased as the impact velocity increased. The increase of crack propagation energy was especially prominent, but the dynamic toughness of each material did not change much. To show the relation between crack initiation energy and dynamic fracture toughness, a simple model was proposed by using the strain energy and stress distribution at notch. The model revealed that crack initiation energy is proportional to the square of dynamic fracture toughness and inversely proportional to elastic modulus.

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Micromechanical Model for the Consolidation Behavior in SiC-Ti Metal Matrix Composites (SiC-Ti금속기 복합재료의 강화거동에 관한 미시역학적 모델)

  • 김준완;김태원
    • Composites Research
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    • v.16 no.3
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    • pp.1-8
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    • 2003
  • Densification occurs by the inelastic flow of the matrix materials during the consolidation processes at high temperature for MMCs, and the results depend on many process conditions such as applied pressure, temperature and volume fraction of fiber and matrix materials. This is particularly important in titanium matrix composites since material failure may occur by either the applied conditions or microstructural parameters through the processes, and thus a generic model based on micro-mechanical approaches enabling the evolution of density over time to be predicted has been developed. The mode developed is then implemented into FEM so that practical process simulation has been carried out. Further the experimental investigation of the consolidation behavior of SiC/Ti-6Al-4V composites using vacuum hot pressing has been performed, and the results obtained are compared with the model predictions.

Intake and performance of lambs finished in feedlot with wet brewer's grains

  • Frasson, Monica Feksa;Carvalho, Sergio;Jaurena, Gustavo;Menegon, Aliei Maria;Severo, Marcelo Machado;da Motta, Juliano Henriques;Teixeira, William Soares
    • Journal of Animal Science and Technology
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    • v.60 no.5
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    • pp.12.1-12.5
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    • 2018
  • Background: The use of agroindustrial by-products in ruminant nutrition to be an interesting alternative in order to reduce production costs and environmental impacts arising from the inadequate destination of residues. The initial step of beer production yields a large volume of wet brewer's grains all year around, which is available at a low cost and has a high nutritional quality, and hence a big potential for animal production. Methods: Twenty-four Suffolk non-castrated male lambs, from simple parturition were kept in individual spots and allocated to four treatments constituted by four levels of substitution of sorghum silage by WBG (i.e.0; 33.5; 66.5 and 100% of substitution). It was used roughage: concentrate rate of 50:50, based on dry matter. Results: The ether extract intake increased while the acid detergent fiber intake decreased linearly ($P{\leq}0.05$). Substituion of sorghum silage by WBG did not change lambs' feed DMI, daily weight gain and feed conversion. Conclusion: The substitution of sorghum silage by WBG as roughage showed to be a viable alternative from the productive and economic point of view for finishing of feedlot lambs.

Potentials of the Fermented Food Wastes as the Animal Feed (발효된 음식폐기물의 사료화 잠재력에 관한 연구)

  • Kim, Nam Cheon;Chung, Jae Chun
    • Journal of the Korea Organic Resources Recycling Association
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    • v.3 no.1
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    • pp.13-20
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    • 1995
  • The purpose of this study was to evaluate the potentials of food wastes as an animal feed. The food wastes from the Inha University and Hanyang University Hospitals were used for this fermentation study. As the additive, approximately 40~50% of dry bean curd dregs and sawdust was mixed for moisture adjustment, certain amount(l/300 of the total content) of inoculum was added into the 140L volume fermenter and fermented for 40~48 hours with the temperature of $46{\sim}52^{\circ}C$ maintained. Fermentation product with the dry bean curd dregs had the lower content of crude protein, crude ash, calcium and phosphorus than the commercial pig feed. Fermentation product with sawdust had the lower content in most components than the commercial pig feed except crude fiber content. Based upon these findings, it was considered that only the fermentation product with dry bean curd dregs as the additive could be used for the animal feed aid.

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Quality Characteristics of Sponge Cakes Containing Various Levels of Millet Flour (조 분말의 첨가가 sponge cake의 품질특성에 미치는 영향)

  • Chang, Hak-Gil
    • Korean Journal of Food Science and Technology
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    • v.36 no.6
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    • pp.952-958
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    • 2004
  • Effects of normal (non-waxy) and waxy millet flours on properties of sponge cake were examined. Total dietary fiber contents of normal and waxy millets were 5.04 and 5.12%, respectively, while that of soft wheat flour was 2.23%. Alkaline water retention capacity value generally increased with addition of normal and waxy millet flours, whereas peak, minimum, and final viscosities decreased. Mixing time and mixing height decreased with addition of millet flour. Lightness of cake crust increased with addition of normal millet flour, whereas it decreased with addition of waxy millet flour, tightness of cake crumb decreased as the amount of normal and waxy millet flours increased. Increasing proportions of normal and waxy millet flours resulted in significantly decreased loaf volume. Replacement of 10% wheat flour by both normal and waxy millet flours did not significantly affect characteristics of sponge cake, but addition of more than 20% millet flour resulted in significant differences in quality characteristics.

Fishing power estimation of biodegradable traps in the East Sea (동해 생분해성 통발의 어획성능 평가)

  • Bae, Bong-Seong;An, Heui-Chun;Jeong, Eui-Cheol;Park, Hae-Hoon;Park, Seong-Wook;Park, Chang-Doo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.4
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    • pp.292-301
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    • 2010
  • For an effective management of fisheries resources, it is very important that to make clean inhabitation environment and to preserve fisheries resources. The material which is mainly used as fishing gear in modern times, is polyethylene, polypropylene, polyamide, etc., chemical fiber. And lost fishing gears which are make of these, occur ghost fishing and ocean pollution. To solve these problem, we development biodegradable fishing trap using the polybutylene succinate (PBS). Developed traps are for red snow crab (Chionoecetes japonicus) and shrimp, major traps in the East Sea, and we carried out fishing research using two kind traps in the coastal sea of Ayajin-port (Goseong) to analysis fishing efficiency of PE trap and PBS trap. As a result for fishing experiment (year 2005-2006) of red snow crab trap, two kind traps were almost the same in catches and length composition. During a experiment, parts of meshes, used for over 1 year, were cut by biodegradation. As a result for fishing experiment (year 2007) of shrimp trap, northern shrimp (Pandalus eous), coonstripe shrimp (Pandalus hypsinotus) and morotoge shrimp (Pandalopsis japonica) were catched, and the almost is northern shrimp. Two kind traps were almost the same in catches and length composition. In accordance with these result, it is recommended that the developed traps are have to commercialized because the fishing powers of PE traps and PBS traps were same. But biodegradation speed is have to controled in consideration of ocean microorganism volume and traps life.

Quality characteristics of the bread with sprouted brown rice flour (발아현미분을 첨가한 식빵의 품질 특성)

  • 최지호
    • Korean journal of food and cookery science
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    • v.17 no.4
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    • pp.323-328
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    • 2001
  • Breads were prepared with the addition of sprouted brown rice flour(SBRF) as a funtional ingredient up to 50%, and their quality characteristics were evaluated through analyses of proximate composition amino acid by HPLC, fatty acid by GC, and sensory evaluation. The optimum amount of SBRF for bread preparation was 30%(w/w). The more SBRF was added, the greater the proximate components such as ash, crude protein, crude fat, fiber and amino acid content were, although the baking quality such as volume decreased. The results of sensory evaluation for bread showed that the more SBRF was added, the lower the scores of color, appearance. texture and the feelings in the mouth were, but the higher the score of taste.

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