• Title/Summary/Keyword: reference materials

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Analysis of Phylogenetic Relationship of 30 Cultivars of Korean Mulberry (Rosales: Moraceae) in Korea

  • Kwon, O-Chul;Kim, Hyun-Bok;Sung, Gyoo-Byung;Kim, Yong-Soon;Ju, Wan-Taek
    • International Journal of Industrial Entomology and Biomaterials
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    • v.37 no.2
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    • pp.82-89
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    • 2018
  • This study was carried out to understand phylogenetic relationships of the 30 mulberry cultivars converved in Korea based on the ITS rDNA region, and they were compared to 40 reference sequences from GenBank. The size and the G+C content of the ITS rDNA gene regions from the 30 Korean mulberry cultivars and 40 reference sequences varied from 612-630 bp and 58.19-61.62%, respectively. Based on the results of the comparative phylogenetic analysis of the ITS rDNA regions of the 30 Korean mulberry cultivars and 40 reference sequences, they were divided into three groups (Group 1, 2, and 3) and two subgroups (Group 1A and 1B within Group 1). The sequence lengths of the Korean mulberry cultivar numbers 1-26 and 27-30 were 615 bp and 616 bp, respectively. At 205 bp location of ITS1 rDNA region, the cultivar numbers 1-26 contain the nucleotide thymine but the cultivar numbers 27-30 contain the nucleotide adenine. In addition, the insertion of the nucleotide adenine at 206 bp location was found only in the four Korean mulberry cultivars (numbers 27-30). Based on these sequence information and phylogenetic result, the 30 Korean mulberry cultivars were identified as M. alba and M. australis. This study will contribute to the construction of genetic database constructions and accurate variety identifications for unidentified mulberry varieties in Korea.

Homogeneity Test on Bio-Matrix Reference Material for Chemical Analysis of Environmental Pollutants (환경 오염물질 분석용 생물 표준물질 균질성 시험평가 연구)

  • Lee, Jangho;Chung, David;Choi, Jeong-Heui;Lee, Jongchun;Lee, Soo Yong
    • Journal of Environmental Science International
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    • v.27 no.12
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    • pp.1271-1277
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    • 2018
  • The National Environmental Specimen Bank (NESB) has been sampling and cryogenically preserving various wildlife specimens to monitor bio-accumulations of chemical pollutants since 2010. Recently, the NESB set up a plan to develop reference materials at their facility to assure the analytical quality of and validate the analytical methods for their monitoring samples. One of the crucial characteristics of reference materials is intra- and inter-bottle homogeneity. In this study, we used ANOVA for total mercury concentrations in some samples to validate their homogeneities after milling and homogenization. We examined the intra- and inter-bottle homogeneities of two cryogenically-milled samples (Korean mussel (Mytilus coruscus) and black-tailed gull's egg (Larus crassirostris). The variations in the total mercury concentrations were not significantly different intra- and inter-bottle (mussel: F=0.74, p=0.67; gull egg: F=1.96, p=0.10). Additionally, the relative standard deviations of the total mercury concentrations showed low values (mussel: 2.02%, gull egg: 1.78%). Therefore, the cryogenic-milling process statistically proves the homogeneity of the materials of mussels and sea gull eggs for chemical analysis for total mercury.

Study on the Inspection of Repairing Materials and Methods for Concrete Structures (콘크리트 보수 재료 효과 분석 및 공법기준관련 연구)

  • Kim, Do-Gyum;Oh, Kwang-Chin;Ahn, Sang-Ku;Park, Jung-Jun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.317-320
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    • 2006
  • In this paper, in order to inspect effect of marketed repair materials, it inspected first the repair material through laboratory work by repair method. After we carry out laboratory work and choice the construction with ongoing deterioration to inspect performance of repair materials, we apply the repair materials there. This results will be make use of reference whenever selection of repair materials and repair method. Also which will be used basic data for repair construction code.

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Structure of Ni and NiO Nanoparticles Observed by X-ray Coherent Diffraction Imaging

  • Kim, Chan;Kim, Yoon-Hee;Hamh, Sun-Young;Son, Jun-Gon;Khakurel, Krishna Prasad;Iqbal, Mazhar;Noh, Do-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.542-543
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    • 2012
  • Coherent diffraction imaging (CDI) method using hard x-ray at 5.46 keV was applied to study assembly of Ni and Ni oxide nano structures formed on a Si3N4 membrane. Density distribution of Ni nano-particles was obtained quantitatively with about 15 nm lateral resolution by reconstructing images from the speckle diffraction pattern. In addition, reconstructed images of nickel oxide particles indicated that Ni atoms diffuse out during the oxidation process leaving pores inside the nickel oxide crust. Furthermore, we recognize that really weak phase object, less than 5 nm thickness of Ni residues, can be reconstructed due to the reference particles. We achieved quantitative information of nanometer sized materials and demonstrate the effect of reference particles by using hard x-ray coherent diffractive imaging method.

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An adaptive approach for the chloride diffusivity of cement-based materials

  • Tran, Bao-Viet;Pham, Duc-Chinh;Loc, Mai-Dinh;Le, Minh-Cuong
    • Computers and Concrete
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    • v.23 no.2
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    • pp.145-153
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    • 2019
  • Adaptive schemes are constructed in this paper for modeling the effective chloride diffusion coefficient of cement-based materials (paste and concrete). Based on the polarization approximations for the effective conductivity of isotropic multicomponent materials, we develop some fitting procedures to include more information about the materials, to improve the accuracy of the scheme. The variable reference parameter of the approximation involves a few free scalars, which are determined through the available numerical or experimental values of the macroscopic chloride diffusion coefficient of cement paste or concrete at some volume proportions of the component materials. The various factors that affect the chloride diffusivity of cement-based material (porous material structure, uncertainty of value of the chloride diffusion coefficient in water-saturated pore spaces, etc.) may be accounted to make the predictions more accurate. Illustrations of applications are provided in a number of examples to show the usefulness of the approach.

Deviation of landmarks in accordance with methods of establishing reference planes in three-dimensional facial CT evaluation

  • Yoon, Kaeng Won;Yoon, Suk-Ja;Kang, Byung-Cheol;Kim, Young-Hee;Kook, Min Suk;Lee, Jae-Seo;Palomo, Juan Martin
    • Imaging Science in Dentistry
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    • v.44 no.3
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    • pp.207-212
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    • 2014
  • Purpose: This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. Materials and Methods: Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. Results: The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. Conclusion: In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

Engineering J-Integral Estimation for Internal Axial Surface Cracks in Cylinders (II) -Optimised Reference Stress Based Estimation- (실린더에 존재하는 축방향 표면균열에 대한 공학적 J-적분식 (II) - 최적참조응력에 기초한 방법-)

  • Kim, Jin-Su;Kim, Yun-Jae;Kim, Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.11
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    • pp.2442-2449
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    • 2002
  • This paper provides an reference stress based J estimation equation fur cylinders with finite internal axial surface cracks under internal pressure. In part 1, the J estimation equation based on deformation plasticity using Ramberg-Osgood (R-0) materials is proposed. In this paper, the developed CE/EPRI -type solutions ale then re-formulated based on the reference stress concept. Such a re-formulation provides a simpler equation for J. estimation are then further extended to combined internal pressure and bending. The proposed reference stress based J estimation equation is compared with elastic-plastic 3-D FE results using actual stress-strain data for a Type 304 stainless steel. Good agreement between the FE results and the proposed reference stress based J estimations provides confidence in the use of the proposed method to elastic -plastic fracture mechanics of pressurised piping.