• Title/Summary/Keyword: co-transformation

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Effect of Co substitution on NiSi and $NiSi_2$: ab initio calculation (NiSi와 $NiSi_2$에 대한 Co 치환의 영향: ab initio 계산)

  • Kim, Yeong-Cheol;Seo, Hwa-Il
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.3
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    • pp.13-17
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    • 2007
  • Effect of Co substitution on crystal structures of two nickel silicides, NiSi and $NiSi_2$, is investigated by using an ab initio calculation. Relaxed NiSi and $NiSi_2$ structures are calculated and the calculated lattice parameters are in good agreement with experimentally determined lattice parameters within about 2%. A Co atom substitutes a Ni and Si site, respectively, to evaluate the preferable site between them. Co prefers Ni site to Si site in both NiSi and $NiSi_2$. The calculated total energy also indicates that the Co substitution to Ni site stabilizes both the NiSi and $NiSi_2$ structures. Co also prefers Ni site in $NiSi_2$ to that in NiSi, indicating that $NiSi_2$ becomes more stable than NiSi with Co substitution. As Co addition to NiSi improves its thermal stability experimentally, this indicates that the energy barrier between the two phases is high enough to prevent the phase transformation from NiSi to $NiSi_2$ up to high temperature.

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Factors Affecting the Agrobacterium Mediated Transformation of 'Gala' Apple (사과 갈라 품종의 Agrobacterium이용 형질전환에 영향하는 요인)

  • 송관정;성은수;황정환;제갈성;차지은;김정희;신용억
    • Korean Journal of Plant Tissue Culture
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    • v.28 no.4
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    • pp.221-225
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    • 2001
  • Some factors of wounding methods, solidifying agents, origin of leaf explants, cone. of acetosyring-one, and MES affecting regeneration and transformation by Agrobacterium tumefaciens were investigated to establish an efficient transformation system of apple. Wounding by cutting the leaves merely showed the tendency of regeneration and transformation with higher efficiency compared with that of wounding by non-traumatic forcep when carrying out co-cultivation for three days after bacterial inoculation. While examining the solidifying agents of medium with the combination of agar (A)+Gelrit $e^{ }$ (G) in g. $L^{-1}$ , the higher concentration of Gelrit $e^{ }$ increased the efficiency of regeneration. However, there was no difference in the efficiency of transformation from the treatments of 2.5 G, 3.5 A+1.2 G, and 7.0 G. The origin of leaf explants showed no difference statistically in the efficiency of regeneration and transformation, but that from the shoots of proliferation medium showed the tendency with higher efficiency. The concentration of above 0.1 mM acetosyringon had an increase in the efficiency of regeneration and transformation and the concentration of 0.15 mM had the highest efficiency of transformation in the treatment of acetosyringone with different concentration. There was no effect of MES on regeneration and transformation.ion.

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Evience that a Plasmid Endoces Genes for Metabolism of Malonte in Pseudomonas fluorescens (Pseudomonas fluorescens에 있는 하나의 Plasmid가 말론산 대사에 관련된 유전자를 가지고 있다는 증거)

  • Kim, Yu-Sam;Kim, Eun-Joo
    • Korean Journal of Microbiology
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    • v.32 no.3
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    • pp.192-197
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    • 1994
  • Pseudomonas fluorescens which is able to utilize malonate as a sole carbon source was found to contain a novel 60 kb plasmid, which encodes the genes for the proteins to assimilate malonate, including malonate decarboxylase and acetyl-CoA synthetase. The evidence is as follows: The Pseudomonas cured with mitomycin C was unable to grow on malonate-medium as well as it lost plasmid. The plasmid isolated from the Pseudomonas could be introduced into E. coli strain JM103 and DH1 by transformation. The transformed E. coli was able to grow on malonate-medium and could transmit its plasmid back to the cured P. fluorescens by conjugation. The existence of the plasmid in the transformed E. coli was confirmed by hybridization with a labeled probe prepared from 12 kb segment of the plasmid. Dot hybridization showed that the copy number of the plasmid in the transformed E. coli is at least 13 times higher than in the wild type P. fluorescens. The two key enzymes, malonate decarboxylase and acetyl-CoA synthetase, were inducible by malonate in the transformed E. coli.

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Curve Estimation among Citation and Centrality Measures in Article-level Citation Networks (문헌 단위 인용 네트워크 내 인용과 중심성 지수 간 관계 추정에 관한 연구)

  • Yu, So-Young
    • Journal of the Korean Society for information Management
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    • v.29 no.2
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    • pp.193-204
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    • 2012
  • The characteristics of citation and centrality measures in citation networks can be identified using multiple linear regression analyses. In this study, we examine the relationships between bibliometric indices and centrality measures in an article-level co-citation network to determine whether the linear model is the best fitting model and to suggest the necessity of data transformation in the analysis. 703 highly cited articles in Physics published in 2004 were sampled, and four indicators were developed as variables in this study: citation counts, degree centrality, closeness centrality, and betweenness centrality in the co-citation network. As a result, the relationship pattern between citation counts and degree centrality in a co-citation network fits a non-linear rather than linear model. Also, the relationship between degree and closeness centrality measures, or that between degree and betweenness centrality measures, can be better explained by non-linear models than by a linear model. It may be controversial, however, to choose non-linear models as the best-fitting for the relationship between closeness and betweenness centrality measures, as this result implies that data transformation may be a necessary step for inferential statistics.

Relationship Between Co-operative Society Governance And Members Satisfaction: A Case Study of the Ambrose Alli University Workers/Farmers Multi-Purpose Cooperative Society, Edo State, Nigeria

  • Ekhorutomwen, Asemota Abel;Peters, Ojeakeri Benson
    • International Journal of Knowledge Content Development & Technology
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    • v.11 no.4
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    • pp.87-99
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    • 2021
  • The study examines the relationship between co-operative society governance and members' satisfaction. Co-operative societies face problems of how to keep balance between efficiency and governance because those in charge of operations of co-operative; the board and the staff must meet two demands i.e. good business practice and the social responsibility which involves the satisfaction of members. The objective of this study is to examine the relationship between co-operative governance and members' satisfaction using Ambrose Alli University Workers/Farmers Multi -Purpose the Co-operative Society as a case study. The data collected in this study were obtained through structured questionnaire. Data analyzed were subjected to descriptive statistics and graphs. The data analyzed indicated that the challenges facing the co-operative society include theft /fraud and mismanagement. Members agitated for transformation of the co-operative society to operate in line with the guidelines of the Central Bank of Nigeria. It was recommended that for efficiency and high productivity, staff should be trained. Also there is need for innovative technology and the necessity for the cooperative society in question to network with other organizations.

Magnetic Properties and the Order-disorder Phase Transformation of (Fe1-XCoX) Pt Magnetic Thin Films

  • Na, K.H.;Park, C.H.;Na, J.G.;Jang, P.W.;Kim, C.S.;Lee, S.R.
    • Journal of Magnetics
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    • v.4 no.4
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    • pp.119-122
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    • 1999
  • Magnetic properties and crystal structures of (Fe1-XCoX) Pt (X = 0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1.0) ternary thin films were investigated. The order-disorder phase transformation of FePt thin films during annealing was also studied by x-ray diffraction and M ssbauer spectroscopy. The magnetic thin films were deposited on glass substrates using a dc sputtering method and were subsequently annealed at 400~$700^{\circ}C$ in a high vacuum. The as-deposited films exhibited a high degree of the <111> preferred orientation and the preferred orientation was not destroyed even after the subsequent post annealing. The coercivity of the ($Fe_xCo_{1-x}$) Pt thin films annealed at $700^{\circ}C$ showed a minimum value at the equiatomic composition of the Fe and Co atoms. The ordered structure of the FePt alloy was thought to have formed from the disordered structure by an inhomogeneous process, which was confirmed by the asymmetric peak shapes and M ssbauer spectra.

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ACRYLAMIDE-INDUCED NEOPLASTIC TRANSFORMATION OF HUMAN EPITHELIAL CELLS IN CULTURE (Acrylamide가 인체상피세포의 발암화에 미치는 영향)

  • Kim, Sang-Kyu;Kim, Jin-Wook;Kim, Chin-Soo
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.6
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    • pp.602-610
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    • 2008
  • Purpose Acrylamide is present in significant quantities in a wide range of commonly consumed human foods. Carcinogenic risk of acrylamide through the consumption of food is a great public concern and in controversy, but it is not properly addressed due to the lack of evidence in humans. While a plenty of data is available on the carcinogenicity in animal models, the studies in humans are limited. Thus, the present study attempted to examine the carcinogenic potentials of acrylamide on the human epithelial cell, which is the target cell origin of the most cancers. Material and method & Result 1. Acrylamide was not cytotoxic up to $100{\mu}M$ as measured by MTT and LDH assays, indicating a relatively low toxicity of this substance in human epithelial cells. 2. The parameters of neoplastic cellular transformation such as cell saturation density, soft-agar colony formation and cell aggregation were analyzed to examine the carcinogenic potential of acrylamide. 3. The neoplastic transformation was further increased with the co-treatment of TPA 4. Antioxidants blocked the generation of Reactive Oxygen Species(ROS) and the GSH depleting agent dramatically increased the ROS production. 5. mRNA levels of fibronectin following acrylamide exposure was increased in a dose-dependent manner, indicating a possible biomarker of acrylamide-induced cellular transformation. Conclusion The present study will provide a valuable basis to compare the interspecies differences in response to carcinogenic potentials of acrylamide. The data on the interspecies differences are essential element in human risk assessment. Thus, our results obtained from the human epithelial cells will contribute to improving the risk assessment of human neoplasm including oral cancer.

Phase Transformation and Work-hardening Behavior of Ti-based Bulk Metallic Glass Composite

  • Hong, Sung Hwan;Kim, Jeong Tae;Park, Hae Jin;Kim, Young Seok;Park, Jin Man;Suh, Jin Yoo;Na, Young Sang;Lim, Ka Ram;Kim, Ki Buem
    • Applied Microscopy
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    • v.45 no.2
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    • pp.37-43
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    • 2015
  • In present work, work-hardening behavior of TiCu-based bulk metallic glass composite with B2 particles has been studied by systemic structural and mechanical investigations. After yield, pronounced work-hardening of the alloy was clearly exhibited, which was mainly related to the martensitic transformation as well as the deformation twinning in B2 particles during deformation. At the early plastic deformation stage (work-hardening stage), the stress-induced martensitic transformation from B2 phase to B19' phase and deformation-induced twinning of B19' phase was preferentially occurred in the around interface areas between B2 phase and amorphous matrix by stress concentration. The higher hardness value was observed in vicinity of interface within the B2 particles which are probably connected with martensitic transformation and deformation twinning. This reveals that the work-hardening phenomenon of this bulk metallic glass composite is a result of the hardening of B2 particles embedded in amorphous matrix.