• Title/Summary/Keyword: integral bases

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The Effect of Water in Four Adenine-Thymine and Three Guanine-Cytosine Pairs: Combining Quantum and Statistical Mechanics

  • Lee, Jinkeong;Ham, Sihyun
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.151-155
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    • 2015
  • The molecular interactions between the nucleic acid bases and water molecules are important in organism. Despite Adenine-Thymine Hoogsteen base pair and Guanine-Cytosine Watson-Crick base pair have been demonstrated to be most stable in a gas phase, the effect of water on the stability of these base pairs remains elusive. Here we report the structural and thermodynamic characteristics on possible Adenine-Thymine and Guanine-Cytosine base pairs in a gas phase as well as in an aqueous phase by using quantum mechanical method and statistical mechanical calculations. First, we optimized the direct base-pair interaction energies of four Adenine-Thymine base pairs (Hoogsteen base pair, reverse Hoogsteen base pair, Watson-Crick base pair, and reverse Watson-Crick base pair) and three Guanine-Cytosine base pairs (GC1 base pair, GC2 base pair, and Watson Crick base pair) in a gas phase at the $B3LYP/6-31+G^{**}$ level. Then, the effect of solvent was quantified by the electronic reorganization energy and the solvation free energy by statistical mechanical calculations. Thereby, we discuss the effect of water on the stability of Adenine-Thymine and Guanine-Cytosine base pairs, and argue why Adenine-Thymine Watson-Crick base pair and Guanine-Cytosine Watson-Crick base pair are most stable in an aqueous environment.

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Uncertainty and sensitivity analysis in reactivity-initiated accident fuel modeling: synthesis of organisation for economic co-operation and development (OECD)/nuclear energy agency (NEA) benchmark on reactivity-initiated accident codes phase-II

  • Marchand, Olivier;Zhang, Jinzhao;Cherubini, Marco
    • Nuclear Engineering and Technology
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    • v.50 no.2
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    • pp.280-291
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    • 2018
  • In the framework of OECD/NEA Working Group on Fuel Safety, a RIA fuel-rod-code Benchmark Phase I was organized in 2010-2013. It consisted of four experiments on highly irradiated fuel rodlets tested under different experimental conditions. This benchmark revealed the need to better understand the basic models incorporated in each code for realistic simulation of the complicated integral RIA tests with high burnup fuel rods. A second phase of the benchmark (Phase II) was thus launched early in 2014, which has been organized in two complementary activities: (1) comparison of the results of different simulations on simplified cases in order to provide additional bases for understanding the differences in modelling of the concerned phenomena; (2) assessment of the uncertainty of the results. The present paper provides a summary and conclusions of the second activity of the Benchmark Phase II, which is based on the input uncertainty propagation methodology. The main conclusion is that uncertainties cannot fully explain the difference between the code predictions. Finally, based on the RIA benchmark Phase-I and Phase-II conclusions, some recommendations are made.

Rethinking Immigration, Remaking Identities: Exploration of Ethnic Identity among the Immigrant Adolescents and the Adolescents Born in Marital-Immigrant Families in Korea (결혼 이주 가정 및 중도 입국 청소년들의 민족 정체성 탐색과 형성)

  • Kim, Kihyun;Yi, Jaehee;Hong, Hyemi
    • Korean Journal of Social Welfare Studies
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    • v.44 no.1
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    • pp.165-192
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    • 2013
  • Though identity formation is a major developmental task during adolescence and ethnic identity is an integral part of one's identity formation, little is known about ethnic identity exploration and formation among the immigrant adolescents as well as the adolescents born in marital-immigrant families living in Korea. Seventeen adolescents aged 13 to 17 having immigration experiences participated in the study and shared their experiences related to ethnic identity. Results of analyzing in-depth interview data indicated that the concept of ethnic identity was a multidimensional construct: self-identification, bases of identification, emotional reactions, and process of identity formation were important components consisting of the participants' ethnic identities. The youths also reported a variety of socio-cultural experiences related to one's ethnic identities. Based on the findings, the study discussed theoretical implications of the findings and suggestions for providing services for these youths.