• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.293-305
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• 2015

In this paper, we suggest the conceptual design of a water-cooled reactor system for a low-pressure inherent heat sink nuclear desalination plant (LIND) that applies the safety-related design concepts of high temperature gas-cooled reactors to a water-cooled reactor for inherent and passive safety features. Through a scoping analysis, we found that the current LIND design satisfied several essential thermal-hydraulic and neutronic design requirements. In a thermal-hydraulic analysis using an analytical method based on the Wooton-Epstein correlation, we checked the possibility of safely removing decay heat through the steel containment even if all the active safety systems failed. In a neutronic analysis using the Monte Carlo N-particle transport code, we estimated a cycle length of approximately 6 years under 200 $MW_{th}$ and 4.5% enrichment. The very long cycle length and simple safety features minimize the burdens from the operation, maintenance, and spent-fuel management, with a positive impact on the economic feasibility. Finally, because a nuclear reactor should not be directly coupled to a desalination system to prevent the leakage of radioactive material into the desalinated water, three types of intermediate systems were studied: a steam producing system, a hot water system, and an organic Rankine cycle system.

• International Journal of Stem Cells
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• v.17 no.2
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• pp.113-119
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• 2024

This report presents guidelines for the systematic management of packaging, storage, transportation, and traceability of source cells used for organoid research. Given the important role of source cells in organoid studies, it is important to ensure the preservation of their quality and integrity throughout transportation and distribution processes. The proposed guidelines, therefore, call for a cohesive strategy through these stages to minimize the risks of contamination, deterioration, and loss-threats that significantly compromise the safety, efficacy, and efficiency of source cells. Central to these guidelines is the quality control measures that include roles and responsibilities across the entire supply chain, with recommendations specific to packaging materials, transportation facilities, and storage management. Furthermore, the need for an integrated management system is emphasized, spanning from source cell collection to the final application. This system is crucial for maintaining the traceability and accountability of source cells, facilitating the sharing, distribution, and utilization on a global scale, and supporting to advance organoid research and development.

• ETRI Journal
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• v.32 no.1
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• pp.68-72
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• 2010

The coupling between the transverse and longitudinal components of the channel electron motion in NMOS devices leads to a reduction in the barrier height. Therefore, this study theoretically investigates the effects of the in-plane velocity of channel electrons on the capacitance-voltage characteristics of nano NMOS devices under inversion bias. Numerical calculation via a self-consistent solution to the coupled Schrodinger equation and Poisson equation is used in the investigation. The results demonstrate that such a coupling largely affects capacitance-voltage characteristic when the in-plane velocity of channel electrons is high. The ballistic transport ensures a high in-plane momentum. It suggests that such a coupling should be considered in the quantum capacitance-voltage modeling in ballistic transport devices.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.2
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• pp.130-133
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• 2010

This paper presents a study of the influence of variation of counter doping thickness on short channel effect in symmetric double-gate (DG) nano MOSFETs. Short channel effects are estimated from the computed values of current-voltage (I-V) characteristics. Two dimensional Quantum transport equations and Poisson equations are used to compute DG MOSFET characteristics. We found that the transconductance ($g_m$) and the drain conductance ($g_d$) increase with an increase in p-type counter-doping thickness ($T_c$). Very high value of transconductance ($g_m=38\;mS/{\mu}m$) is observed at 2.2 nm channel thickness. We have established that the threshold voltage of DG MOSFETs can be tuned by selecting the thickness of counter-doping in such device.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.106-106
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• 2012

Strategies to facilitate carrier transfer/transport while preserving confined characteristics of isolated nanocrystal quantum dots (NQDs) will be discussed. Specifically, synthesis and characterizations of 1) the fabrication of neat NQD solids (assembled NQD films) with modified surfaces by attaching ligands or by applying physical processes such as heat annealing [J. Phys. Chem. C (2011), 115(3), 607] and 2) coupling NQDs to one-dimensional nanostructures such as single-walled carbon nanotubes (SWNTs) [ACS Nano, (2010) 4(1), 324] will be presented. Further, recent achievement ours of fabricating NQDs assemblies into photovoltaic devices for elucidating transfer mechanism witll be discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.454-454
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• 2011

Graphene shows unusual electronic properties, such as carrier mobility as high as 10,000 $cm^2$/Vs at room temperature and quantum electronic transport, due to its electronic structure. Carrier mobility of graphene is ten times higher than that of Silicon device. On the one hand, quantum mechanical studies have continued on graphene. One of them is quantum Hall effect which is observed in graphene when high magnetic field is applied under low temperature. This is why two dimension electron gases can be formed on Graphene surface. Moreover, quantum Hall effect can be observed in room temperature under high magnetic field and shows fractional quantization values. Quantum Hall effect is important because quantized Hall resistances always have fundamental value of h/$e^2$ ~ 25,812 Ohm and it can confirm the quantum mechanical behaviors. The value of the quantized Hall resistance is extremely stable and reproducible. Therefore, it can be used for SI unit. We study to measure quantum Hall effect in CVD graphene. Graphene devices are made by using conventional E-beam lithography and RIE. We measure quantum Hall effect under high magnetic field at low temperature by using He4 gas closed loop cryostat.

• Proceedings of the Korean Vacuum Society Conference
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• 2001.02a
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• pp.40-41
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• 2001

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.32-32
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2006.08a
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• pp.179-179
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• 2006

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.1
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• pp.93-97
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• 2022

We report highly efficient quantum dot light-emitting diodes (QLEDs) with TiO₂ nanoparticles (NPs) as an alternative electron transport layer (ETL) and poly (methyl methacrylate) (PMMA) as an insulating layer. TiO₂ NPs were applied as ETLs of inverted structured QLEDs and the effect of the addition of PMMA between ETL and emission layer (EML) on device characteristics was studied in detail. A thin PMMA layer supported to make the charge balance in the EML of QLEDs due to its insulating property, which limits electron injection effectively. Green QLEDs with a PMMA layer produced the maximum luminance of 112,488 cd/m² and a current efficiency of 25.92 cd/A. We expect the extended application of TiO₂ NPs as the electron transport layer in inverted structured QLEDs device in the near future.