• Steel and Composite Structures
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• v.33 no.3
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• pp.375-388
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• 2019

This paper aims to investigate the axial load behavior and stability strength of square tubed steel-reinforced concrete (TSRC) columns. Unlike concrete filled steel tubular (CFST) column, the outer steel tube of a TSRC column is mainly used to provide confinement to the core concrete. Ten specimens were tested under axial compression, and the main test variables included length-to-width ratio (L/B) of the specimens, width-to-thickness ratio (B/t) of the steel tubes, and with or without stud shear connectors on the steel sections. The failure mode, ultimate strength and load-tube stress response of each specimen were summarized and analyzed. The test results indicated that the axial load carried by square tube due to friction and bond of the interface increased with the increase of L/B ratio, while the confinement effect of tube was just the opposite. Parametric studies were performed through ABAQUS based on the test results, and the feasibility of current design codes has also been examined. Finally, a method for calculating the ultimate strength of this composite column was proposed, in which the slenderness effect on the tube confinement was considered.

• Corrosion Science and Technology
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• v.20 no.3
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• pp.118-128
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• 2021

The oxide layer in samples taken from an irradiated Zr-2.5Nb pressure tube from a CANDU-PHWR reactor was analyzed using electron probe microanalysis (EPMA). The examined tube had been exposed to temperatures ranging from 264 to 306 ℃ and a neutron fluence of 8.9 × 10²¹ n/cm² (E > 1 MeV) for the maximum 10 effective full-power years in a nuclear power plant. Measuring oxide layer thickness generally employs optical microscopy. However, in this study, analysis of the oxide layer from the irradiated pressure tube components was undertaken through X-ray image mapping obtained using EPMA. The oxide layer characteristics were analyzed by X-ray image mapping with 256 × 256 pixels using EPMA. In addition, the slope of the oxide layer was measured for each location. A particular advantage of this study was that backscattered electrons and X-ray image mapping were obtained at a magnification of 9,000 when 20 kV volts and 30 uA of current were applied to radiation-shielded EPMA. The results of this study should usefully contribute to the study of the oxide layer properties of various types of metallic materials irradiated by high radiation in nuclear power plants.

• Steel and Composite Structures
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• v.44 no.3
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• pp.339-351
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• 2022

A mortar-filled rectangular hollow structural section (RHS) can increase a structural section property as well as a compressive buckling capacity of a RHS member. In this study, the tensile performance of newly developed mortar-filled RHS members was experimentally evaluated with various connection details. The major test parameters were the type of end connections, the thickness of cap plates and shear plates, the use of stud bolts, and penetrating bars. The test results showed that the welded T-end connection experienced a brittle weld fracture at the welded connection, whereas the tensile performance of the T-end connection was improved by additional stud bolts inserted into the mortar within the RHS tube. For the end connection using shear plates and penetrating stud bolts, ductile behavior of the RHS tube was achieved after yielding. The penetrating bars increased load carrying capacity of the RHS. Based on the analysis of the load transfer mechanism, the current design code and test results were compared to evaluate the tensile capacity of the RHS tube according to the connection details. Design considerations for the connections of the mortar-filled RHS tubes were also recommended.

• Nuclear Engineering and Technology
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• v.27 no.5
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• pp.775-783
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• 1995

This study is to assess the effects of increasing wall thickness on the safety margin of pressure tube in operating and of lowering initial hydrogen concentration on the DHC growth in respect to the improvement of the reliability of pressure tube in CANDU reactors. The pressure tube with thicker wall of 5.2 mm shows much higher safety margin for flaw tolerance by 25％ than the current 4.2mmm tube. The thicker pressure tubes have a great benefit in LBB assessment including the initial crack depth at which DHC occurs, the crack length at onset of leaking and the available time for action. The resistance for the pressure tube ballooning at LOCA accident is also increased with the thicker tube. The calculations for Heq concentration after 20 years of operation as a function of wall thickness and initial hydrogen concentration show that the 5.2 mm nil thickness tube with 5 ppm initial hydrogen concentration is the most resistant to DHC. with the lower initial hydrogen concentration, TSS temperature for the precipitation or hydride decreases and the crack growth during cooldown reduces.

• Journal of Radiation Protection and Research
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• v.46 no.3
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• pp.106-111
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• 2021

Background: Crookes tube is utilized in junior high and high schools in Japan to study the character of electrons and current, and not for radiological education. There is no official guideline or regulation for these radiation source to the public. Therefore, most teachers have no information about the leakage of X-rays from Crookes tube. The peak energy of X-rays is approximately 20 keV, and it is impossible to measure using conventional survey meters. Materials and Methods: Each leakage dose of low energy X-rays from 38 Crookes tube in the education field, such as junior and senior high schools in Japan, was explored by the teachers in the school using radio-photoluminescence (RPL) dosimeters. Before and after the measurements, the dosimeters were sent by postal mails. Results and Discussion: At the exploration in this study, it was estimated that the 70 ㎛ dose equivalent, H_p(0.07) of X-rays from 31 Crookes tubes were smaller than 100 µSv in 10 minutes, at the distance of 1 m, where the Crookes tube was usually observed. However, the highest dose was estimated as 0.69 mSv by an equipment with the full power. Furthermore, one Crookes tube exhibited 0.62 mSv with minimum output power of the induction coil. This relatively large dose was reduced by the shorter distance of discharge electrodes of the induction coil. Conclusion: The leakage dose of low energy X-rays from 38 Crookes tube was explored using RPL dosimeters. It was estimated that the H_p(0.07) of X-rays from 31 Crookes tubes were smaller than 100 µSv in 10 minutes at the distance of 1 m, while some equipment radiated a higher dose. With this study, the provisional guideline for the safety operation of Crookes tube is established.

• Fashion & Textile Research Journal
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• v.26 no.3
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• pp.279-288
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• 2024

Fingernail-related content on YouTube is gaining popularity. This study aimed to present a new direction for nail content marketing and video production by identifying the current status of nail-related content on YouTube and factors affecting views. As for the research method, the study used the YouTube website, and the elements under analysis were classified into YouTuber characteristics (verbal characteristics, age group, gender, professional status, and celebrity status) and content characteristics (nail field, editing elements, and content). The results showed that standard language and terminology were generally used, and the proportion of YouTubers in their 30s was high. All nail-related content creators on YouTube were women, and they were found to be experts who worked as nail artists and nail content creators. As for the content characteristics, the proportion of art videos was high, and the video length was found mostly to be between 10 and 20 minutes. The editing elements included images, videos, and subtitles, and sound effects and background music were used frequently. Finally, it was found that the proportion of videos providing nail tips and know-how, product information, and procedures was high. This study identified factors that influence the number of views for nail videos. As a result, the study was able to present video production ideas for newcomers starting a nail-content YouTube channel, and this will be helpful in the development of nail content.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.6
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• pp.579-585
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• 2009

The multifrequency eddy current testing(ECT) have been proposed various frequency mixing algorithms. In this study, we compare these approaches to frequency mixing of ECT signals from steam generator tubes; time-domain optimization, discrete cosine transform-domain optimization. Specifically, in this study, two different frequency mixing algorithms, a time-domain optimization method and a discrete cosine transform(DCT) optimization method, are investigated using the experimental signals captured from the ASME standard tube. The DCT domain optimization method is computationally fast but produces larger amount of residue.

• Progress in Superconductivity and Cryogenics
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• v.5 no.1
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• pp.81-86
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• 2003

This paper presents a numerical analysis of transient magnetic diffusion in a melt-cast-processed BSCCO-2212 tube subjected to sinusoidal applied fields. The nonlinear f-$\lrcorner$ relation obtained by experiments in liquefied $N_2$ is used to find the magnetic diffusion coefficient. The magnetic flux density, shield current density and p-J$^2$ loss are considered. According to the result of this study, the shielding current density is varied with external applied field and coordinate in the superconductor tube. The result of analysis can be used to explain the response of a Supercon -ductor-Shield-Core-Reactor subjected to sinusoidal applied fields.

• Journal of Institute of Convergence Technology
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• v.3 no.1
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• pp.19-23
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• 2013

This study is concerned with air-conditioning system in use of thermoelectric device. It is introduced that the well designed structures for better cooling & heating performance with high efficiency. And also it is performed that the system performance test of four types trial products for the use of hybrid commercial vehicle. System performance is affected by many component parts, especially heat sink design & power control method. It is applied that dual extrusive fin tube with buffer zone for the effective radiating of circulating liquid in tube. And also it is applied that power supply method with constant-current system. It is attained that system cooling capacity is 1.2kW, COP is 0.95.

• BMB Reports
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• v.44 no.7
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• pp.435-445
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• 2011

Serous ovarian cancer is one of the most lethal gynecological malignancies. Progress on effective diagnostics and therapeutics for this disease are hampered by ambiguity as to the cellular origins of this histotype of ovarian cancer, as well as limited suitable animal models to analyze early stages of disease. In this report, we will review current animal models with respect to the two proposed progenitor cells for serous ovarian cancer, the ovarian surface epithelium and the fallopian tube epithelium.