• 제목/요약/키워드: kinds

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섬유의 종류, 형상 및 치환율에 따른 HPFRCC의 공학적 특성에 관한 실험적 연구 (An Experimental Study on the Engineering Properties of HPFRCC According to Kinds, Shapes and Volume Fraction of Fibers)

  • 김영덕;조봉석;김재환;김규용;최경렬;김무한
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2003년도 학술.기술논문 발표회
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    • pp.59-62
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    • 2003
  • Kinds, shapes and fraction ratios of fibers have influence on properties of HPFRCC(High-Performance Fiver Reinforced Cementitious Concrete) like bending strength, strain capacity and fracture toughness. For example, hydrophilic fibers have different chemical bond strength from hydrophobic fibers, fiber shapes influence on fiber pull-out and rupture, and fiber volume fraction influence on bending strength. In this study, to estimate influences of kinds, shapes and fraction ratios of fibers, we make HFRCC with 3 kind of fiber in various volume fraction of fiber and compare cracking, bending strength and fracture toughness. As the results, bending strength of HPFRCC was increased as fiber volume fraction was increase and fiber tensile strength was increase, and strain capacity and fracture toughness of HFRCC was higher in fiber pull-out fracture than in fiber rupture fracture. And HFRCC showing pseudo strain hardening has higher fiber reinforce efficiency than others.

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DETECTION AND CLASSIFICATION OF DEFECTS ON APPLE USING MACHINE VISION

  • Suh, Sang-Ryong;Sung, Je-Hoon
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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    • pp.852-862
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    • 1996
  • This study was carried out to develop tools to detect defects of apple using machine vision. For the purpose, 6 kinds of frame for color images, R, G, B, h, S, and I frame, and a frame for near infra-red images (NIR frame) were tested first to select one which is useful to segment defect areas from apple images. After then, several methods to classify kind of defect for the segmented defect areas were developed and tested. Five kinds of apple defect -bruise , decay ,fleck worm hole and scar were investigated . The results are as follows: NIR frame was selected as the best one among the 7 kinds of image frame, and R, G and I frames showed favourable result to segment areas of apple defect. Various features of the segmented defect areas were measured to classify the defect areas. Eight kids of feature of the areas-size, roundness, axes length ratio, mean and variance of pixel values, variance of real part of spectrum, mean and variance of power spectrum resulted from spacial ourier transform were observed for the segmented defect areas in the selected 4 frames. then procedures to classify defects using the features were developed for the 4 frames and tested with 75-113 defects on apples. The test resulted that NIR and I frames showed high accuracies to classify the kind of defect as 77% and 76% , respectively.

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Diacylglycerol Acyltransferase에 대한 생약자원의 저해활성 검색 (Inhibitory Effects of Medicinal Herbs on Diacylglycerol Acyltransferase Activity)

  • 이승웅;고정숙;권오억;이상명;김영호;노문철;김영국;이현선
    • 생약학회지
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    • 제32권3호통권126호
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    • pp.193-199
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    • 2001
  • The inhibitory effects of methanol extracts of 135 medicinal herbs on diacylglycerol acyltransferase (DGAT) activity were investigated. DGAT was partially purified from rat liver. Eleven kinds of methanol extracts of medicinal herbs including Evodiae Fructus showed a mild inhibitory effect with the concentration of $125\;{\mu}g/ml$ (above 40% inhibition). Six kinds of methanol extracts including Ephedrae Herba exhibited a weak inhibition. Among them, three kinds of butanol extracts (Sophorae Radix, Arecae Semen, Caesalpiniae Lignum) and the chloroform extracts of Evodiae Fructus showed significant inhibitory activities (above 60% inhibition) at the same concentration.

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수지 혼합비가 FRMLs의 피로균열전파거동과 기계적 성질에 미치는 영향에 관한 연구 (Study on the Effect of Resin Mixture Ratios on the Fatigue Crack Propagation Behavior and Mechanical Property in a FRMLs)

  • 김철웅;손세원
    • 한국정밀공학회지
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    • 제16권8호
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    • pp.149-154
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    • 1999
  • FRMLs(Fiber Reinforced Metal Laminates) is a new type of hybrid materials. FRMLs consists of high strength metal and fiber which are laminated using a structural adhesive bond(epoxy resin). The effect of resin mixture ratios on the fatigue crack propagation behavior and mechanical property of Aramid fiber reinforced aluminum composites was investigated. The epoxy, diglycidylether of bisphenol A(DGEBA) was cured with methylene dianiline(MDA) with or without accelerator(K-54). Eight kinds of resin mixture ratio were tested for the experiment ; five kinds of FRMLs(1))epoxy & curing agent) and three kinds of FRMLs(2)(epoxy & curing agent & accelerator). FRMLs(2) have a more effective characteristics on the fatigue crack propagation behavior and mechanical property than FRMLs(1)

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FRP에 의한 무인잠수정의 설계와 구조해석 (Structural Design and Analysis of Autonomous Underwater Vehicle by Fiber Reinforced Plastics)

  • 김윤해;배성열;조영대;문경만
    • 대한기계학회논문집A
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    • 제32권11호
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    • pp.937-942
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    • 2008
  • This research investigated to find out the possibilities of applying FRPs to the AUVs. In this study, two kinds of metal materials, which is one of the popularly used materials for manufacturing AUVs, and 6 kinds of FRP materials were considered. Material properties of FRPs were derived by tensile tests and chemical analysis. Moreover, various types of AUVs were designed by 8 kinds of materials. From structural analysis, we can find out that the weights of AUV by CFRP-Autoclave could be reduced by 60% in comparison with the weights of AUV by Al 7075-T6. Also, 40% weight reduction could be expected compared to the AUV by Ti-6Al-4V. In this result, we could conclude that the material of CFRP-Autoclave have various merits and potentialities as one of the AUV materials.

산지별 녹용(鹿茸)류의 성분분석 연구(II) -Ganglioside 및 유리 아미노산의 분석- (Studies on the Analysis of Constituents of Deer Horn(II) -Analysis of gangliosides and free amino acids-)

  • 홍남두;원도희;김남재;장승엽;윤황금;김혜수
    • 생약학회지
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    • 제24권1호
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    • pp.38-46
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    • 1993
  • Two kinds of gangliosides contained in deer horns were determined by integrating the peaks of TLC densitometry. Japanese deer horn originated from China showed the highest gangliosides among tested samples and the upper parts in deer horns showed higher gangliosides than the lower parts. In the case of graded samples, the best grade A showed the highest content and the worst grade E did the lowest content. Sixteen kinds of free amino acids were analyzed by auto amino acid analyzer. The lower region the deer horn was, the more the total content of free amino acids was and several kinds of amino acids were contained quite regularly.

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음장제어용 막재료의 음향 및 단열특성 (Sound Absorption and Thermal Insulation Characteristics of Membrane Used for Sound Field Control)

  • 정정호;김정욱;정재군;조병욱
    • 한국소음진동공학회논문집
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    • 제22권2호
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    • pp.103-114
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    • 2012
  • Nowadays membrane material is widely used for large indoor spaces and long spaces such as traditional market. Thermal insulation and sound field control performance is considered as a main properties for design of such buildings. In this paper sound absorption and thermal insulation properties of membrane material was investigated. Firstly, normal incidence sound absorption coefficient of 10 kinds of glass wool textiles showed that sound absorption coefficient was increased in proportion of thickness and surface density of textile. Sound absorption coefficient of 4 kinds of sound absorptive inner membrane with outer membrane was tested in the reverberation chamber. Sound absorption coefficient of mid frequency range was about 0.4 ~ 0.6. Also, sound absorption coefficient was changed by the air space behind the membrane material. Secondly, sound field control performance was investigated using mock-up space. By the installation of sound absorption membrane material, reverberation time was decreased and speech intelligibility was increased. Finally, thermal resistance and room temperature in two kinds of mock-up rooms were tested, simultaneously. Results of thermal properties showed thermal insulation properties ware increased by adding inner membrane material underneath the outer membrane.

폴리우레탄 코팅포의 봉제성능 (The Sewability of polyurethane coated fabrics)

  • 신혜원;이정순
    • 한국의류학회지
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    • 제25권2호
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    • pp.350-357
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    • 2001
  • In this study, seam strength, seam elongation and seam efficiency of polyurethane coated fabrics were examined under various sewing conditions using three kinds of fabrics, four kinds of sewing threads and three kinds of stitch lengths. And the sewability of polyurethane coated fabrics were evaluated by FAST system. The results were as follows: 1. Seam strength decreased with the increase of stitch length. The loop strength of sewing thread and the type of base fabric than the type of coated surface had an effect on seam strength. 2. Seam elongation also decreased with the increase of stitch length and was affected by the type of base fabric. The tensile elongation of polyurethans coated fabric had an effect on seam elongation. 3. Sean efficiency also was related to stitch length, the type of base fabric, and seam strength. The suitable seam efficiency was within 50%∼65% in which polyurethane coated fabric and sewing thread broke at the same time. Therefore PS thin and PPC thin sewing threads and 3mm stitch length were suitable to polyurethane coated fabrics. 4. The relaxation shrinkage(RS) of polyurethane coated fabric was smaller than the smallest value of control chart in FAST system. And the extensibility(E) and the shear rigidity(G) were larger than the largest value.

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한국산 작은 말거머리 (Whitemenia edentula)의 상피조직과 선세포의 구조적 특성 (Structure of Epithelium and Gland cells in a Korean leech, Whitemenia edentula)

  • 장남섭
    • Applied Microscopy
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    • 제27권1호
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    • pp.1-12
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    • 1997
  • Dorsal and ventral epithelium of leech, Whitemenia edentula, were observed, using both light and electron-microscope. Results are as follows. Epithelia are composed of simple columnar or irregularly-shaped epithelium, the transveral folds were seen in the cross-sectioned dorsal and ventral epithelia, but only longitudinal folds(depth $500{\mu}m$, width $350{\mu}m$) were discovered in the ventral epithelium. As to muscular tissue under the dorsal epithelium of Whitemenia edentula, that of longitudinal muscle layer is thicker and more developed than that of circular muscle layer. Seven gland cells (type-A, B, C, D, E, F and H cells) and one pigment cell (type-G cell) were discovered in the whitemenia edentula. Those were identified as three kinds of the neutral mucopolysaccharide granoles (type-A, B and F cells), two kinds of acidic mucopolysaccharide granules (type-C and D cells), and two kinds of non-reactive granules respectively (type-E and F cells). The glanules of the type-A and type-B gland cells ae electronly high-dense, and surrounded by the muscular tissue. As to the distribution of gland cells, the type-A, type-B, type-C, type-D, type-I and type-H gland cells were discovered only between the connective tissue and the circular muscle layer, while type-F gland cells were discovered only between tile circular muscle layer and the longitudinal muscle layer.

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Comparative Study on Volatile Flavor Compounds of Traditional Chinese-type Soy Sauces Prepared with Soybean and Defatted Soy Meal

  • Gao, Xian-Li;Zhao, Hai-Feng;Zhao, Mou-Ming;Cui, Chun;Ren, Jiao-Yan
    • Food Science and Biotechnology
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    • 제18권6호
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    • pp.1447-1458
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    • 2009
  • Volatile extracts obtained from traditional Chinese-type soy sauces prepared with soybean (SSSB) and defatted soy meal (SSDSM) by solid phase microextraction (SPME) and direct solvent extraction (DSE) were analyzed by gas chromatography-mass spectrometry (GC-MS). The volatile flavor compounds and relative contents of different chemical classes detected in SSSB and SSDSM were compared for their differences. Results showed that significant differences in both constituents of volatile flavor compounds and relative contents of different chemical classes were observed for both kinds of soy sauces. A total of 152 and 131 compounds were identified in SSSB and SSDSM, respectively, and 102 volatile flavor compounds were common in both kinds of soy sauces. Moreover, relative contents of acids, aldehydes, esters, furan(one)s, miscellaneous compounds, phenols, pyrazines, pyrrol(idinon)es, and sulfur-containing compounds in both kinds of soy sauces were all significantly different.