• Title/Summary/Keyword: Caps

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PVC and POM gripping mechanisms for tension testing of FRP bars

  • Basaran, Bogachan;Yaka, Harun;Kalkan, Ilker
    • Structural Engineering and Mechanics
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    • v.77 no.1
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    • pp.75-87
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    • 2021
  • The present study pertains to the introduction of two new types of grip adaptor for universal testing machines, namely Polyvinyl Chloride (PVC) and Polyoxymethylene (POM) grip adaptors, and their application to tension testing of FRP bars with different fiber and surface finish types. The tabs are connected to the FRP bar sample with the help of mechanical anchors, i.e. bolts. These new adaptors offer vital superiorities over the existing end tab designs (anchors with filling material or mechanical anchorage), including the reduction in the time and labor for production, reusability and the mild nature, i.e. low hardness of the tab material, which retards and even prevents peeling and crushing in the gripping regions of an FRP sample. The methods were successfully applied to FRP bars with different types of fiber (CFRP, GFRP and BFRP) and different types of surface texture (ribbed, wrapped, sand-coated and wound). The test results indicated that the both types of end caps prevented slip of the bar, crushing and peeling in the gripping zone. The mechanical properties from the material tests with the new caps were in perfect agreement with the ones from the material tests with steel tubular caps.

Survey of genetic structure of geese using novel microsatellite markers

  • Lai, Fang-Yu;Tu, Po-An;Ding, Shih-Torng;Lin, Min-Jung;Chang, Shen-Chang;Lin, En-Chung;Lo, Ling-Ling;Wang, Pei-Hwa
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.2
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    • pp.167-179
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    • 2018
  • Objective: The aim of this study was to create a set of microsatellite markers with high polymorphism for the genetic monitoring and genetic structure analysis of local goose populations. Methods: Novel microsatellite markers were isolated from the genomic DNA of white Roman geese using short tandem repeated probes. The DNA segments, including short tandem repeats, were tested for their variability among four populations of geese from the Changhua Animal Propagation Station (CAPS). The selected microsatellite markers could then be used to monitor genetic variability and study the genetic structures of geese from local geese farms. Results: 14 novel microsatellite loci were isolated. In addition to seven known loci, two multiplex sets were constructed for the detection of genetic variations in geese populations. The average of allele number, the effective number of alleles, the observed heterozygosity, the expected heterozygosity, and the polymorphism information content were 11.09, 5.145, 0.499, 0.745, and 0.705, respectively. The results of analysis of molecular variance and principal component analysis indicated a contracting white Roman cluster and a spreading Chinese cluster. In white Roman populations, the CAPS populations were depleted to roughly two clusters when K was set equal to 6 in the Bayesian cluster analysis. The founders of private farm populations had a similar genetic structure. Among the Chinese geese populations, the CAPS populations and private populations represented different clads of the phylogenetic tree and individuals from the private populations had uneven genetic characteristics according to various analyses. Conclusion: Based on this study's analyses, we suggest that the CAPS should institute a proper breeding strategy for white Roman geese to avoid further clustering. In addition, for preservation and stable quality, the Chinese geese in the CAPS and the aforementioned proper breeding scheme should be introduced to geese breeders.

Development of a CAPS Marker Derived from the Pg-Actin Gene Sequences and RAPD Markers in Platycodon grandiflorum (도라지에서의 RAPD 마커 분석과 Actin 유전자 염기서열에서 유래한 CAPS 분자표지 개발)

  • Kim, Munhwi;Jeong, Eunah;Jeong, Jeongsu;Kwon, Soontae;Jeon, Ikjo;Jeong, Jeong Hag;Lee, Je Min;Yeam, Inhwa
    • Korean Journal of Plant Resources
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    • v.28 no.5
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    • pp.648-655
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    • 2015
  • Balloon flower (Platycodon grandiflorum A. DC.) is a perennial plant of mainly Campanulaceae family, which have been widely used as a food ingredient and herbal medicine in East Asia. Although demands on related products and yearly cultivation area for balloon flower are increasing, diverse fundamental technologies and molecular breeding studies are not very well supported in Platycodons. In this study, 30 random amplification of polymorphic DNA (RAPD) primers were test in an attempt to explore genetic diversities. In addition, sequences information of the actin gene, a well conserved gene encoding a globular protein that forms microfilaments, was retrieved and analyzed. Two actin homologs were recovered; 3.4 kb fragment is a Pg-actin and 1.4 kb fragment is a Pg-actin homolog with 28.6% similarity. We have confirmed that the Pg-actin gene is configured into 4 exons and 3 introns. A single nucleotide polymorphism (SNP), G↔A, was detected on the intron 3, which served as a target for the CAPS marker development. The marker Pg-Actin-Int3 was applied to 32 balloon flower accessions. Balloon flower DNA sequence information generated in this study is expected to contribute to the analysis and molecular breeding and genetic diversity analysis of balloon flowers.

Soil Arching in Embarikments Suppoyed by Piles with Geosynthethics (말뚝과 토목섬유로 지지된 성토지반의 아칭효과)

  • Hong, Won-Pyo;Lee, Jae-Ho
    • Journal of the Korean Geotechnical Society
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    • v.23 no.6
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    • pp.53-66
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    • 2007
  • A series of model tests were performed to investigate the soil arching effect in embankments supported by piles with geosynthetics. In the model tests, model piles with isolated cap were inserted through the holes in a steel plate, which could be operated up and down. Then geosynthetics was laid on the pile caps below sand fills. The settlement of soft ground was simulated by lowering the plate. As the plate was lowered, the soil arching was mobilized in the embankments. The deformation of both the sand fills and geosynthetics were captured by camera. Also the loads acting on pile cap and the tensile strain of geosynthetics were monitored by data logging system. Model tests showed that the embankment loads transferred on pile cap by soil arching Increased rapidly with settlement of the soft ground. In case of the absence of geosynthetics, the loads acting on pile caps dropped to residual value after peak value, whereas loads on pile caps gradually increased until constant value in case of geosynthetic-reinforced. This illustrated that reinforcing with the geosynthetics has a good effect to restrain the settlement of embankments. Also, the deformation shape of geosynthetics between pile caps was circular. The embankment loads transferred on pile caps can be estimated by considering both soil arching and tensile strain of geosynthetics in embankments supported by piles with geosynthetics.

Vibrations and thermal stability of functionally graded spherical caps

  • Prakash, T.;Singh, M.K.;Ganapathi, M.
    • Structural Engineering and Mechanics
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    • v.24 no.4
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    • pp.447-461
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    • 2006
  • Here, the axisymmetric free flexural vibrations and thermal stability behaviors of functionally graded spherical caps are investigated employing a three-noded axisymmetric curved shell element based on field consistency approach. The formulation is based on first-order shear deformation theory and it includes the in-plane and rotary inertia effects. The material properties are graded in the thickness direction according to the power-law distribution in terms of volume fractions of the constituents of the material. The effective material properties are evaluated using homogenization method. A detailed numerical study is carried out to bring out the effects of shell geometries, power law index of functionally graded material and base radius-to-thickness on the vibrations and buckling characteristics of spherical shells.

Structural Performance Evaluation for the Precast Shell type Pier Cap (PC Shell 형식 피어캡의 구조성능 평가)

  • Shin, Sung-Jin;Hwang, Do-Kyu;Lee, Jae-Hoon;Son, Je-Kuk;Park, Dong-Kyu;Yoo, Dong-Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.81-82
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    • 2010
  • As a part of rapid construction technology of bridge pier caps, controversial issues for design and construction of precast pier caps were discussed. Three kinds of approaches of rapid bridge pier cap construction were proposed and discussed. Especially for an approach of precast shell type structures, experimental studies were performed to evaluate structural performance and compared with conventionally constructed reinforced concrete pier cap.

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