• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2887-2900
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• 2020

Cladding failure in a fuel rod during operation in a BWR is analyzed using a FALCON code-based model. Comparative calculation with a neighbouring, intact rod is presented, as well. A considerable 'hot spot' effect in cladding temperature is predicted with the SLICE-DO model due to a thermal barrier caused by the localized crud deposition. Particularly significant overheating is expected to occur on the affected side of the cladding of the failed rod, in agreement with signs of significant localized crud deposition as revealed by Post Irradiation Examination. Different possibilities (criteria) are checked, and Pellet-Cladding Mechanical Interaction (PCMI) is shown to be one of the plausible potential threats. It is shown that PCMI could lead to discernible concentrated inelastic deformation in the overheated part of the cladding. None of the specific mechanisms considered can be experimentally or analytically identified as an only cause of the rod failure. However, according to the current calculation, a possibility of cladding failure by PCMI cannot be excluded if the crud thickness exceeded 300 ㎛.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.302-309
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• 2009

The effectiveness of Building Information Modeling (BIM) tools and processes has been recognized by the industry and owners are beginning to adopt Triple Bottom Line accounting practices, to enhance economic performance and environmental and social performance. However, the widespread and practical application of Green BIM remains largely unrealized. The authors identify that lack of understanding of the applicability of sustainability metrics to BIM design process is a significant barrier to this adoption. Through literature review this paper outlines the various sustainability metrics available to construction and elaborates on the potential of BIM for sustainable design. The paper maps and correlates applicable concepts of sustainability evaluation systems to BIM and describes the constraints in current BIM tools.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.172-177
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• 2023

This study explores the feasibility and potential of using virtual reality (VR) technology to enhance the museum viewing experience through digital media. In an increasingly digital world, museums face the challenge of adapting to changing visitor expectations. This study explores the integration of virtual reality and digital media as a means to engage, educate, and attract museum visitors in a novel, immersive way. By analyzing its advantages, challenges, and practical implications, this study aims to elucidate the feasibility of this transformative approach.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.195-200
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• 2011

Construction materials usually constitute a major portion of the total cost in a building construction project. Despite the potential benefit of ICT, convincing construction organisations to embrace its use and implementation has proved a difficult task. This study seeks to identify the implementation of ICT for materials management processes in construction projects. The findings from the interviews reveal that the implementation of ICT in the materials management processes for construction projects in Malaysia is at early stage. Microsoft Excel Spreadsheet and handheld devices are found to be the common ICT tools adopted in the materials management processes. The main barrier is found to be the cost involvement at the initial stage or overall implementation of ICT in the materials management processes. Finally, this paper concludes the finding from interviews towards the ICT implementation of materials management in the construction projects.

• Korean Circulation Journal
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• v.54 no.5
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• pp.223-232
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• 2024

Trigger and functional substrate are related to the tone of autonomic nervous system, and the role of the autonomic nerve is more significant in paroxysmal atrial fibrillation (AF) compared to non-paroxysmal AF. We have several options for neuromodulation to help to manage patients with AF. Neuromodulation targets can be divided into efferent and afferent pathways. On the efferent side, block would be an intuitive approach. However, permanent block is hard to achieve due to completeness of the procedure and reinnervation issues. Temporary block such as botulinum toxin injection into ganglionated plexi would be a possible option for post-cardiac surgery AF. Low-level subthreshold stimulation could also prevent AF, but the invasiveness of the procedure is the barrier for the general use. On the afferent side, block is also an option. Various renal denervation approaches are currently under investigation. Auditory vagus nerve stimulation is one of the representative low-level afferent stimulation methods. This technique is noninvasive and easy to apply, so it has the potential to be widely utilized if its efficacy is confirmed.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.495-501
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• 2005

Al is a active metal that owes its resistance to a thin, protective, barrier oxide surface layer, which is stable in air and neutral aqueous solution. Thus Al alloys are widely used in architectural trim. cold & hot-water storage vessels and piping. However Al and most of its alloy may corrode with some forms such as pitting corrosion, intergranular corrosion and galvanic corrosion in the case of exposure to various industrial and marine atmosphere. Therefore a correct evaluation of corrosion resistance for their Al and Al alloys may be more important in a economical point of view. In this study. a relative evaluation of corrosion resistance for three kinds of Al alloys such as ALDC2, ALDC3, and ALDC8 series was carried out with electrochemical method. There is a tendency that corrosion potential is shifted to positive or negative direction by alloying components regardless of corrosion resistance. Moreover the data of corrosion properties obtained from cathodic Polarization curve, cyclic voltammogram and AC. DC impedance respectively showed a good correspondence each other against the corrosion resistance but variation of corrosion potential. passivity current density of anodic polarization curve and corrosion current density by Tafel extrapolation and Stern-Geary method didn't correspond with not only each other but also considerably the data of corrosion properties discussed above. Therefore it is suggested that an optimum electrochemical evaluation for corrosion resistance of Al alloy is to calculate the diffusion limiting current density of cathodic polarization curve, impedance of AC or DC and polarization resistance of cyclic voltammogram.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.32-32
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• 2009

Silicon carbide (SiC) is a wide-bandgap semiconductor that has materials properties necessary for the high-power, high-frequency, high-temperature, and radiation-hard condition applications, where silicon devices cannot perform. SiC is also the only compound semiconductor material. on which a silicon oxide layer can be thermally grown, and therefore may fabrication processes used in Si-based technology can be adapted to SiC. So far, atomic force microscopy (AFM) has been extensively used to study the surface charges, dielectric constants and electrical potential distribution as well as topography in silicon-based device structures, whereas it has rarely been applied to SiC-based structures. In this work, we investigated that the local oxide growth on SiC under various conditions and demonstrated that an increased (up to ~100 nN) tip loading force (LF) on highly-doped SiC can lead a direct oxide growth (up to few tens of nm) on 4H-SiC. In addition, the surface potential and topography distributions of nano-scale patterned structures on SiC were measured at a nanometer-scale resolution using a scanning kelvin probe force microscopy (SKPM) with a non-contact mode AFM. The measured results were calibrated using a Pt-coated tip. It is assumed that the atomically resolved surface potential difference does not originate from the intrinsic work function of the materials but reflects the local electron density on the surface. It was found that the work function of the nano-scale patterned on SiC was higher than that of original SiC surface. The results confirm the concept of the work function and the barrier heights of oxide structures/SiC structures.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.199-199
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• 2013

The distinctive cellular and mitochondrial dysfunctions of a human epithelial lung cancer cell line (H460) from a human lung fibroblastic normal cell line (MRC5) have been studied by dielectric barrier discharge (DBD) plasma treatment. The DBD plasma device have generated large amount of H2O2 and NOx in culture media which is dependent on plasma exposure time. It is found that the cell number of lung cancer cell H460 has been reduced more than the lung normal cell MRC5 as being increased exposure and incubation time. Also these both cell lines have showed mitochondria fragmentation under 5 minutes' plasma exposure, which is a clue of apoptosis. It is noted in this study that AnnexinV staining has showed not only early apoptosis, but also late apoptosis in lung cancer cell H460. Mitochondria enzyme activity and ATP generation have been also much reduced in lung cancer cell H460. Their mitochondrial membrane potential (${\Delta}{\psi}m$) has been found to be reduced in magnitude and shifted to the induced-potential level of cccp, while MRC5 mitochondrial membrane potential has been shifted slightly to that. These distinctively selective responses of lung cancer cell H460 from lung normal cell MRC5 gives us possibility of applying plasma to cancer therapy.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.2
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• pp.105-112
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• 2004

A waste container, one of the key components of a multi-barrier system in a potential high level radioactive waste (HLW) repository in Korea ensures the mechanical stability against the lithostatic pressure of a deep geologic medium and the swelling pressure of the bentonite buffer. Also, it delays potential release of radionuclides for a certain period of time, before it is corroded by intruding impurities. Even though the material of a waste container is carefully chosen and its manufacturing processes are under quality assurance processes, there is a possibility of initial defects in a waste container during manufacturing. Also, during the deposition of a waste container in a repository, there is a chance of an incident affecting the integrity of a waste container. In this study, the appropriate Features, Events, and Processes(FEP's) to describe these incidents and the associated scenario on radionuclide release from a container to the biosphere are developed. Then the total system performance assessment on the Initial waste Container Failure (ICF) scenario was carried out by the MASCOT-K, one of the probabilistic safety assessment tools KAERI has developed. Results show that for the data set used in this paper, the annual individual dose for the ICF scenario meets the Korean regulation on the post closure radiological safety of a repository.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.34.2-34.2
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• 2011

The demand for Ru has been increasing in the electronic, chemical and semiconductor industry. Chemical mechanical planarization (CMP) is one of the fabrication processes for electrode formation and barrier layer removal. The abrasive particles can be easily contaminated on the top surface during the CMP process. This can induce adverse effects on subsequent patterning and film deposition processes. In this study, a post Ru CMP cleaning solution was formulated by using sodium periodate as an etchant and citric acid to modify the zeta potential of alumina particles and Ru surfaces. Ru film (150 nm thickness) was deposited on tetraethylorthosilicate (TEOS) films by the atomic layer deposition method. Ru wafers were cut into $2.0{\times}2.0$ cm pieces for the surface analysis and used for estimating PRE. A laser zeta potential analyzer (LEZA-600, Otsuka Electronics Co., Japan) was used to obtain the zeta potentials of alumina particles and the Ru surface. A contact angle analyzer (Phoenix 300, SEO, Korea) was used to measure the contact angle of the Ru surface. The adhesion force between an alumina particle and Ru wafer surface was measured by an atomic force microscope (AFM, XE-100, Park Systems, Korea). In a solution with citric acid, the zeta potential of the alumina surface was changed to a negative value due to the adsorption of negative citrate ions. However, the hydrous Ru oxide, which has positive surface charge, could be formed on Ru surface in citric acid solution at pH 6 and 8. At pH 6 and 8, relatively low particle removal efficiency was observed in citric acid solution due to the attractive force between the Ru surface and particles. At pH 10, the lowest adhesion force and highest cleaning efficiency were measured due to the repulsive force between the contaminated alumina particle and the Ru surface. The highest PRE was achieved in citric acid solution with NaIO4 below 0.01 M at pH 10.