[en] In case the power of KALIMER is increased by the large size, the structural concept of in-vessel fuel transfer equipment was suggested and reviewed. The core size is expanded due to increasing of the electric power 150 MWe to 600 MWe. The size of rotating plug and the method of the fuel transfer were evaluated by assuming the increased core size. Also, among the various evaluated concepts two concepts were selected and the marginal length of the arm for the pantograph type IVTM was analysed. The model configuration of IVTM is fully extended condition of the pantograph arm. In this condition, the loads considered are the weight of the core assembly, self weight and reaction force for the withdrawal of the core assembly. The structural analysis of IVTM was carried out by the finite element analysis using ANSYS code. The stress and deformation were calculated to the the refueling and seismic loads for the section variation of the components considered as the design parameters of IVTM

[en] Sodium is usually used as a coolant in LMR(Liquid Metal Reactor) and it caused the problems due to the fabrication defects and residual stresses for the welds of the structural material in long time operation under high temperature. It is necessary to evaluate the influence of the residual stress and distortion in the design and fabrication of welded structure and the sound welded structure can be maintained by such consideration. In this study, two test pipes including the multipass weld with the 316 L stainless steel which is the pipe material of LMR were fabricated and the experiment and analysis of the multipass weld were carried out, so the characteristics of the residual stress distribution after welding were estimated. The HRPD(High Resolution Powder Diffractometer) instrumented in HANARO was used for the residual stress measurement. The residual stresses of the weld were calculated by finite element method using ANSYS code and the experimental and calculated results were compared and the characteristics of the distribution for the residual stress were discussed

[en] We present the N=2 supersymmetric formulation for the classical and quantum dynamics of a nonrelativistic charged particle on a curved surface in the presence of a perpendicular magnetic field. For a particle moving on a constant-curvature surface in a constant magnetic field, our Hamiltonian possesses the shape-invariance property in addition. On the surface of a sphere and also on the hyperbolic plane, we exploit the supersymmetry and shape-invariance properties to obtain complete solutions to the corresponding quantum mechanical problems

[en] The effect of stress state on the fracture behavior of SA508 Gr.3 steel in the transition temperature region has been investigated using notched round tensile specimens of various notch root radii. The test results showed that the fracture stress and fracture strain are strongly dependent on the stress triaxiality ; the fracture stress increases with the stress triaxiality, while the fracture strain decreases with the stress triaxiality. The fracture stress is nearly independent of the test temperature. However, the fracture strain reveals typical ductile-to-brittle transition with lower and upper shelf. The transition behaviors of the fracture strain, such as the ductile-to-brittle transition temperature(DBTT) and upper shelf value, are strongly affected by the stress state. Also, a model for evaluating the fracture toughness(K_c) from the tensile test results is proposed and applied. The fracture toughness values calculated with the model are statistically analysed according to the ASTM E1921 method and the results are compared with the results from three-point bend(TPB) specimens

[en] This paper discusses salient aspects of severe accident related phenomenological considerations, scoping studies, and mitigative design features being studied for incorporation into a high-power research reactor plant. Key results of scoping studies on steam explosions, recriticality, core-concrete interactions, and containment transport are highlighted. Evolving design features of the containment are described. Containment response calculations for a site-suitability basis transient are presented that demonstrate acceptable source term values and superior containment performance. Oak Ridge National Laboratory's (ORNL) Advanced Neutron Source (ANS) will be a new user facility for all kinds of neutron research, centered around a research reactor of unprecedented neutron beam flux. A defense-in-depth philosophy has been adopted. In response to this commitment, ANS Project management initiated severe accident analysis and related technology development early-on in the design phase itself. This was done to aid in designing a sufficiently robust containment for retention and controlled release of radionuclides in the event of such an accident. It also provides a means for satisfying on- and off-site regulatory requirements, accident-related dose exposures, and containment response and source-term best-estimate analyses for level-2 and -3 Probabilistic Risk Analysis (PRAs) that will be produced. Moreover, it will provide the best possible understanding of the ANS under severe accident conditions and consequently provide insights for the development of strategies and design philosophies for accident mitigation, management, and emergency preparedness efforts

[en] This book is about superconductivity engineering which introduces superconductivity history, basic element of superconductor such as measurement of critical current, characteristic critical temperature and characteristic critical magnet, Quench, including mechanism of Quench, Adiabatic stability, minimum propagating zone and minimum Quench Energy, stability about measurement and fundamental, AC loss, superconductive wire material such as NbTi, Nb3Sn, MgB₂, BSCCO and YBCO, application of superconductivity like SMES, MHD, NMR, MRI and superconducting fault current limiter, necessary technology for application of superconducting.

[en] We synthesized graphene nanosheets (GNs)/cobalt aluminum (CoAl) double hydroxide composites through a layer-by-layer deposition process while varying the concentration of the graphene precursor used. The CoAl layered double hydroxide particles were uniformly distributed on the surfaces of the graphene layers and effectively prevented the agglomeration of the GNs, resulting in a higher reactive surface area and easier ion transport. We employed X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, field-emission scanning electron microscopy, and field-emission transmission electron microscopy to investigate the microstructures and morphologies of the composites. In addition, cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge measurements were performed to analyze the electrochemical behaviors of the composites. The as-prepared composites showed desirable electrochemical characteristics, including high specific capacitances, low resistances, and high cycling stabilities. In particular, the composite formed by optimizing the GNs/CoAl ratio (the electrolyte used was a 6 M aqueous KOH solution) exhibited the maximum specific capacitance, which was 974 F g"−"1

[en] Highlights: • Reduced graphene oxide surface was modified by introduction of ionic liquids. • Microstructure and capacitance of modified electrode were dependent on the ionic liquids contents. • Modification gives electrode better charge transport and higher specific capacitance. • Modified electrode showed the better capacitive performance such as rate capability and cycle stability. - Abstract: In this work, reduced graphene oxide (rGO)/ionic liquids (IL) composites with different weight ratios of IL to rGO were synthesized by a simple method. In these composites, IL contributed to the exfoliation of rGO sheets and to the improvement of the electrochemical properties of the resulting composites by enhancing the ion diffusion and charge transport. The structure of the composites was examined by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The TEM images showed that IL was coated on the surface of rGO in a translucent manner. The electrochemical analysis of the prepared composites was carried out by performing cyclic voltammetry (CV), galvanostatic charge–discharge, and electrochemical impedance spectroscopy (EIS). Among the prepared composites, the one with a weight ratio of rGO to IL of 1:7 showed the highest specific capacitance of 147.5 F g⁻¹ at a scan rate of 10 mV s⁻¹. In addition, the rate capability and cycle performance of the composites were enhanced compared to pristine rGO. These enhanced properties make the composites suitable as electrode materials for the better performance supercapacitors

[en] In this study, graphene nanosheets (GNS) were modified by 1-Butyl-3-methylimidazolium hexafluorophosphate, which is one of Ionic Liquid (IL). Owing to the modification of graphene with ionic liquids, graphene can not only be structurally stabilized, but also showed the higher charge transfer that is favor to exhibit an enhanced electrochemical performance. Also, a graphene aggregation by the intersheet van der Waals interaction can be prevented because ionic liquids act as an effective agent for the exfoliation of graphene sheets. The structural analysis of prepared composites was confirmed by transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and X-ray diffractometer (XRD). The electrochemical properties are studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The GNS/IL composites show a high specific capacitance (114 Fg⁻¹) compared to pristine graphene (99 Fg⁻¹) at 10 mVs⁻¹ in 6 M KOH electrolyte. Also, the prepared composites showed the enhanced electrochemical performance such as high rate capability and excellent cycle performance. Therefore, the prepared composites could be a candidate of electrode materials for supercapacitors

[en] Novel porous NdGaO₃ (NGO) thin film was fabricated as a new seed layer for liquid phase epitaxy growth of YBa₂Cu₃O_7-δ. The microstructure and crystallization mechanism of NGO new seed layer due to post-annealing temperature were revealed by high resolution SEM. Amorphous NGO layers on LaAlO₃ single crystalline substrate obtained by pulsed laser deposition method at room temperature and this layer shows the very porous and columnar structure. And this amorphous NGO layers were annealed at wide temperature range below 1300 deg. C in air. Amorphous NGO layer begins to crystallize by post-annealed at 750 deg. C and its orientation gets better with increased annealing temperature. The thickness of NGO layers decrease with increased annealing temperature above 500 deg. C and the well-oriented NGO layers were obtained between 900 and 1300 deg. C. The NGO layers annealed at above 1100 deg. C show very dense film