• Journal of Sensor Science and Technology
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• v.32 no.6
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• pp.455-461
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• 2023

We investigated the electrical characteristics of ZnO nanoparticles (NPs) with air exposure that is a widely used electron transport layer for quantum dot light-emitting diodes (QLEDs). Upon air exposure, we observed changes in the density of states (DOS) of the trap levels of ZnO NPs. In particular, with air exposure, the concentration of deep trap energy levels in ZnO NPs decreased and electron mobility significantly improved. Consequently, the air-exposed ZnO reduced leakage current by approximately one order of magnitude and enhanced the external quantum efficiency at the low driving voltage region of the QLED. In addition, based on the excellent conductivity properties, high-brightness QLEDs could be achieved.

• International Journal of Aerospace System Engineering
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• v.11 no.1
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• pp.1-3
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• 2024

Around the world, fossil fuel energy is being replaced with renewable energy due to environmental problems and sharp price increases. Many countries are making a change in the direction of moving toward eco-friendliness by reducing carbon emissions. Among renewable energies, the wind energy is eco-friendly because it produces electricity by wind power without carbon emissions, and it attracts attention worldwide as a great alternative to the exhausted fuel energy. To improve the efficiency of wind turbines, large and extra-large wind turbines have been developed all over the world by increasing install and diameter. These wind turbines have difficulty in transport after manufacture because of their size and height. Since the height of wind turbine blades is higher than the existing tunnel height, it is impossible to transport them. In this study, therefore, a 5 MW class large blade was separated for transport easiness as wind power generators became larger globally. Aerodynamic design and analysis was carried out for the blade. After performing structural design and analysis with the model designed, the stress concentration of the analyzed model and the various factors for consideration when separating were considered to conduct the study of selecting the optimal blade separation positions.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.182-183
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• 2004

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.05a
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• pp.88-89
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• 2018

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.4
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• pp.42-50
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• 2001

In this paper, the reduction of CO₂ gas emission and exhaust gas emission by using the shift of coastal transport from land transport for import-export container cargo was proposed. At first, the domestic CO₂ gas emission, exhaust gas emission and the transportation of import-export container cargo are investigated. And also, we investigated the reduction of CO₂ gas emission and exhaust gas emission by the shift of coastal transport from land transport for the transportation of import-export container cargo between Kyongin area and Pusan Port. Finally, the change of NOx gas emission due to the change of the share of coastal transportation and using the 320TEU container ship are investigated. The research results show that the shift of coastal transport from land transport was effective to reduce the CO₂ gas emission and exhaust gas emission.

• Advances in Energy Research
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• v.1 no.1
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• pp.35-52
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• 2013

A model for DMFC anode performance is developed. The model takes into account potential--independent methanol adsorption on the catalyst surface, finite rate of proton transport through the anode catalyst layer (ACL), and a potential loss due to methanol transport in the anode backing layer. An approximate analytical half--cell polarization curve is derived and equations for the anode limiting current density are obtained. The polarization curve is fitted to the curves measured by Nordlund and Lindbergh and parameters resulted from the fitting are discussed.

• Advances in nano research
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• v.1 no.1
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• pp.29-34
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• 2013

The conversion of mechanical energy into electrical energy at nanoscale using piezoelectric nanowire arrays has been in detail shown by deflection of nanowires. Recently it has performed an analytical model, both at classical and at quantum level, for describing the most important quantities concerning transport phenomena; the model predicts interesting peculiarities, as high initial charge diffusion in nanodevices constituting by nanowires and permits also in particular to deduce interesting informations about the devices sensitivity, focusing on the correlation between sensitivity and high initial diffusivity of these materials at nanometric level.

• Archives of Pharmacal Research
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• v.6 no.2
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• pp.109-114
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• 1983

A mechanism of taurine transfer across the rat small intestine was elucidated by using the in situ recirculation perfusion or loop method. Taurine uptake was saturable, Km= 39.9 mM, and energy dependent, and required sodium. The close structural analogues, aminomethane sulfonic acid, .gamma.-amino-butyric acid, hypotaurine, and .betha.-alanine, reduced significantly taurine uptake when present in 10-fold excess. The .alpha.-amino acid, glycine, did not inhibit uptake. Hence, all of these findings lead to a conclusion that a carrier-mediated transport system for taurine exists in the small intestine.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.2
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• pp.168-172
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• 2003

The electron transport coefficients in Air is analysed in range of E/Nvalues from 100~1000(Td) by a MCS and BE method. This paper have calculated W, ND$\sub$L/, ND$\sub$T/, Mean energy mixtures by N$_2$+O$_2$. The results gained that the values of the electron swarm parameters such as the electron drift velocity, longitudinal and transverse diffusion coefficients.

• BMB Reports
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• v.39 no.4
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• pp.394-399
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• 2006

The transport of putrescine into a moderately salt tolerant cyanobacterium Synechocystis sp. PCC 6803 was characterized by measuring the uptake of radioactively-labeled putrescine. Putrescine transport showed saturation kinetics with an apparent $K_m$ of $92{\pm}10\;{\mu}M$ and $V_{max}$ of $0.33{\pm}0.05\;nmol/min/mg$ protein. The transport of putrescine was pH-dependent with highest activity at pH 7.0. Strong inhibition of putrescine transport was caused by spermine and spermidine whereas only slight inhibition was observed by the addition of various amino acids. These results suggest that the transport system in Synechocystis sp. PCC 6803 is highly specific for polyamines. Putrescine transport is energy-dependent as evidenced by the inhibition by various metabolic inhibitors and ionophores. Slow growth was observed in cells grown under salt stress. Addition of low concentration of putrescine could restore growth almost to the level observed in the absence of salt stress. Upshift of the external osmolality generated by either NaCl or sorbitol caused an increased putrescine transport with an optimum 2-fold increase at 20 mosmol/kg. The stimulation of putrescine transport mediated by osmotic upshift was abolished in chloramphenicol-treated cells, suggesting possible involvement of an inducible transport system.