• 한국초등과학교육학회지:초등과학교육
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• 제35권4호
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• pp.426-441
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• 2016

The purpose of this study was getting the information for successful application to the national curriculum and students' core competencies enhancement, through investigation about competencies discussed in 2015 revised national curriculum development process and analysis about perception of 150 elementary school teachers in study. The results were as follows : Communication skill is considered to be the most important. Thinking ability what has been important traditionally is the middle of the rankings. Elementary school teachers think that a competency is specific to a subject. From this point of view, Creative/Scientific Problem-Solving Ability is the most important in science. They think that the enhancing of the ability of inquiry performance is highlighted in current science class. On elementary school teachers' awareness, inquiry model is the most effective in enhancing of scientific thinking and the ability of inquiry performance. And STS instruction model is in the other. PBL learning model and experimental inquiry model is the most effective in enhancing a competency has the highest feasibility like scientific thinking or the ability of inquiry performance.

• Nuclear Engineering and Technology
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• 제49권1호
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• pp.1-5
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• 2017

The heavy water zero power reactor (HWZPR), which is a critical assembly with a maximum power of 100 W, can be used in different lattice pitches. The last change of core configuration was from a lattice pitch of 18-20 cm. Based on regulations, prior to the first operation of the reactor, a new core was simulated with MCNP (Monte Carlo N-Particle)-4C and WIMS (Winfrith Improved Multigroup Scheme)-CITATON codes. To investigate the criticality of this core, the effective multiplication factor ($K_{eff}$) versus heavy water level, and the critical water level were calculated. Then, for safety considerations, the reactivity worth of $D_2O$, the reactivity worth of safety and control rods, and temperature reactivity coefficients for the fuel and the moderator, were calculated. The results show that the relevant criteria in the safety analysis report were satisfied in the new core. Therefore, with the permission of the reactor safety committee, the first criticality operation was conducted, and important physical parameters were measured experimentally. The results were compared with the corresponding values in the original core.

• Nuclear Engineering and Technology
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• 제53권12호
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• pp.3902-3909
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• 2021

SACOS series of subchannel analysis codes have been developed by XJTU-NuTheL for many years and are being used for the thermal-hydraulic safety analysis of various reactor cores. To achieve fine whole core pin-level analysis, the input preprocessing and parallel capabilities of the code have been developed in this study. Preprocessing is suitable for modeling rectangular and hexagonal assemblies with less error-prone input; parallelization is established based on the domain decomposition method with the hybrid of MPI and OpenMP. For domain decomposition, a more flexible method has been proposed which can determine the appropriate task division of the core domain according to the number of processors of the server. By performing the calculation time evaluation for the several PWR assembly problems, the code parallelization has been successfully verified with different number of processors. Subsequent analysis results for rectangular- and hexagonal-assembly core imply that the code can be used to model and perform pin-level core safety analysis with acceptable computational efficiency.

• Molecules and Cells
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• 제24권2호
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• pp.276-282
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• 2007

Protein phosphorylation is one of the major mechanisms by which eukaryotic cells transduce extracellular signals into intracellular responses. Calcium/calmodulin ($Ca^{2+}/CaM$)-dependent protein phosphorylation has been implicated in various cellular processes, yet little is known about $Ca^{2+}/CaM$-dependent protein kinases (CaMKs) in plants. From an Arabidopsis expression library screen using a horseradish peroxidase-conjugated soybean calmodulin isoform (SCaM-1) as a probe, we isolated a full-length cDNA clone that encodes AtCK (Arabidopsis thaliana calcium/calmodulin-dependent protein kinase). The predicted structure of AtCK contains a serine/threonine protein kinase catalytic domain followed by a putative calmodulin-binding domain and a putative $Ca^{2+}$-binding domain. Recombinant AtCK was expressed in E. coli and bound to calmodulin in a $Ca^{2+}$-dependent manner. The ability of CaM to bind to AtCK was confirmed by gel mobility shift and competition assays. AtCK exhibited its highest levels of autophosphorylation in the presence of 3 mM $Mn^{2+}$. The phosphorylation of myelin basic protein (MBP) by AtCK was enhanced when AtCK was under the control of calcium-bound CaM, as previously observed for other $Ca^{2+}/CaM$-dependent protein kinases. In contrast to maize and tobacco CCaMKs (calcium and $Ca^{2+}/CaM$-dependent protein kinase), increasing the concentration of calmodulin to more than $3{\mu}M$ suppressed the phosphorylation activity of AtCK. Taken together our results indicate that AtCK is a novel Arabidopsis $Ca^{2+}/CaM$-dependent protein kinase which is presumably involved in CaM-mediated signaling.

• 영재교육연구
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• 제25권6호
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• pp.971-987
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• 2015

본 연구에서는 학교정보공시를 활용하여 과학중점 고등학교에서의 SW동아리 활동 실태를 분석하였다. 전국의 103개 과학중점 고등학교를 대상으로 SW동아리에 영향을 주는 요인을 분석하였으며, 학교교육계획서, 학교특색사업계획서, 과학중점학교 운영보고서를 통해 SW동아리 활동 실태를 분석하였다. 동아리 참여율에 가장 많은 영향을 미치는 것은 정보교과의 편성이므로 교육과정 개편이 가장 시급한 것으로 판단된다. 또한 SW관련 비교과활동 및 예산지원은 정(+)적 영향을 미치고 있었고, 고등학교가 소재한 지역의 사회 경제적 배경을 반영하기 위해 사용한 학비지원율은 부(-)적 영향을 미치고 있었다. 그러나 고등학교의 전반적인 학력 수준을 파악하기 위한 학업성취도는 유의한 영향을 미치지 않았다. 따라서 가능한 많은 학생들이 SW관련 비교과활동을 할 수 있도록 지원하되, 이를 위해서는 지역 및 학교의 특성을 반영한 프로그램 개발 및 예산지원이 필요할 것으로 판단된다.

• Nuclear Engineering and Technology
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• 제40권2호
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• pp.117-126
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• 2008

In this paper, a new reactor core design is proposed on the basis of a mixed core concept consisting of a thermal zone and a fast zone. The geometric structure of the fuel assembly of the thermal zone is similar to that of a conventional thermal supercritical water-cooled reactor(SCWR) core with two fuel pin rows between the moderator channels. In spite of the counter-current flow mode, the co-current flow mode is used to simplify the design of the reactor core and the fuel assembly. The water temperature at the exit of the thermal zone is much lower than the water temperature at the outlet of the pressure vessel. This lower temperature reduces the maximum cladding temperature of the thermal zone. Furthermore, due to the high velocity of the fast zone, a wider lattice can be used in the fuel assembly and the nonuniformity of the local heat transfer can be minimized. This mixed core, which combines the merits of some existing thermal SCWR cores and fast SCWR cores, is proposed for further detailed analysis.

• 한국과학교육학회지
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• 제43권6호
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• pp.583-594
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• 2023

본 연구는 코로나19 관련 데이터를 활용한 고등학생을 위한 e-PBL 프로그램을 개발하고 개발된 프로그램이 학생들의 과학과 핵심역량에 미치는 영향을 알아보고자 하였다. 이를 위해 학습자와 e-PBL의 특성을 고려한 e-PBL 프로그램과 과학과 핵심역량 분석틀을 개발하여, 일반고 생명과학동아리 학생 26명에게 적용했다. 질문지를 통한 과학과 핵심역량 검사가 수업 전·후로 실시되었고, 수업 중 담화 데이터를 수집하여 분석틀로 분석하였다. 연구 결과, 개발된 프로그램은 다섯가지 과학과 핵심역량 향상에 효과가 있었다. 과학과 핵심역량 설문지 분석 결과에서는 과학적 사고력, 과학적 탐구능력, 과학적 문제해결능력에서만 유의한 영향이 있는 것으로 나타났고, 과학적 의사소통 능력과 과학적 참여 및 평생학습 능력은 질문지에서는 유의미한 결과를 나타내지 않았지만, 담화 분석 결과에서는 유의미한 결과를 나타내었다. 특히, 과학적 의사소통 능력과 과학적 참여 및 평생 학습 능력은 프로그램 단계를 통해 가장 고르게 나타났다. 본 연구를 통해 개발한 코로나19 관련 데이터를 활용한 고등학생용 e-PBL 프로그램은 학생들의 과학과 핵심역량 향상에 효과적임을 확인했으므로 과학교육 현장에서 유용하게 사용될 것으로 기대한다.

• Nuclear Engineering and Technology
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• 제51권2호
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• pp.377-383
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• 2019

Targeting at simulating the application of thorium-uranium (TU) fuel in the CANDU-6 reactor, this paper analyzes the process using the code DRAGON/DONJON where the discrete TU fuel pins are applied in the CANDU-6 reactor under the time-average equilibrium refueling. The results show that the coolant void reactivity of the assembly analyzed in this paper is lower than that of 37-element bundle cell with natural uranium and 37-element bundle cell with mixed TU fuel pins; that the max time-average channel/bundle power of the core meets the limits - less than 6700kW/860 kW; that the fuel conversion ratio is higher than that of the CANDU-6 reactor with natural uranium; and that the exit burnup increases to 13400 MWd/tU. Thus, the simulation in this paper with the fuel in the 37-element bundle cell using discrete TU fuel pins can be considered to be applied in CANDU-6 reactor with adequate modifications of the core structure and operating modes.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1813-1824
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• 2022

This paper shows the verification work of SARAX code system in the reactor core transient calculation based on the simplified EBR-II Benchmark. The SARAX code system is an analysis package developed by Xi'an Jiaotong University and aims at the advanced reactor R&D. In this work, a neutron-photon coupled power calculation model and a spatial-dependent reactivity feedback model were introduced. To verify the models used in SARAX, the EBR-II SHRT-45R test was simplified to an ULOF transient with an input flowrate change curve by fitting from reference. With the neutron-photon coupled power calculation model, SARAX gave close results in both power fraction and peak power prediction to the reference results. The location of the hottest assembly from SARAX and reference are the same and the relative power deviation of the hottest assembly is 2.6%. As for transient analysis, compared with experimental results and other calculated results, SARAX presents coincident results both in trend and absolute value. The minimum value of core net reactivity during the transient agreed well with the reported results, which ranged from -0.3$ to -0.35$. The results verify the models in SARAX, which are correct and able to simulate the in-core transient with reliable accuracy.

• Applied Microscopy
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• 제47권1호
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• pp.29-35
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• 2017

Transverse magnetic field annealing (TFA) was carried out on $Fe_{73.5}Cu_1Nb_3Si_{15.5}B_7$ nano-crystalline magnetic core with the aim at decreasing coercivity ($H_c$) while keeping high inductance ($L_s$). The magnetic field generated by direct current (DC) was applied on the magnetic core during different selected annealing stages and it was proved that the nanocrystalline magnetic core achieved lowest $H_c$ when applying transverse field during the whole annealing process (TFA1). Although the microstructure and crystallization degree of the nanocrystalline magnetic core exhibited no obvious difference after TFA1 compared to no field annealing, the TFA1 sample showed a more uniform nanostructure with a smaller mean square deviation of grain size distribution. $H_c$ of the nanocrystalline magnetic core annealed under TFA1 decreased along with the increasing magnetic field. As a result, the certain size nanocrystalline magnetic core with low $H_c$ of 0.6 A/m, low core loss (W at 20 kHz) of 1.6 W/kg under flux density of 0.2 T and high $L_s$ of $13.8{\mu}H$ were obtained after TFA1 with the DC intensity of 140 A. The combination of high $L_s$ with excellent magnetic properties promised this nanocrystalline alloy an outstanding economical application in high frequency transformers.