• Journal of Electrochemical Science and Technology
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• v.5 no.2
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• pp.37-44
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• 2014

The $Li-O_2$ battery has been attracting much attention recently, due to its very high theoretical capacity compared with Li-ion chemistries. Nevertheless, several studies within the last few years revealed that Li-ion derived electrolytes based on alkyl carbonate solvents, which have been commonly used in the last 27 years, are irreversibly consumed at the $O_2$ electrode. Accordingly, more stable electrolytes are required capable to operate with both the Li metal anode and the $O_2$ cathode. Thus, due to their favorable properties such as non volatility, chemical inertia, and favorable behavior toward the Li metal electrode, ionic liquid-based electrolytes have gathered increasing attention from the scientific community for its application in $Li-O_2$ batteries. However, the scale-up of Li-$O_2$ technology to real application requires solving the mass transport limitation, especially for supplying oxygen to the cathode. Hence, the 'LABOHR' project proposes the introduction of a flooded cathode configuration and the circulation of the electrolyte, which is then used as an oxygen carrier from an external $O_2$ harvesting device to the cathode for freeing the system from diffusion limitation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.4
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• pp.499-509
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• 1998

In the absorption process of water vapor in a liquid film, the composition of the gas phase, in which a non-absorbable gas is combined with the absorbate influences the transport characteristics remarkably. In the present study, the absorption processes of water vapor into aqueous solution of lithium bromide in the presence of non-absorbable gases were investigated analytically. The continuity, momentum, energy and diffusion equations for the solution film and gas phase were formulated in integral forms and solved numerically. It was found that the mass transfer resistance in gas phase increased with the concentration of non-absorbable gas. However the primary resistance to mass transfer was in the liquid phase. As the concentration of non-absorbable gas in the absorbate increased, the liquid-vapor interfacial temperature and concentration of absorbate in solution decreased, which resulted in the reduction of absorption rate. The reduction of mass transfer rate was found to be significant for the addition of a small amount of non-absorbable gas to the pure vapor, especially at the outlet of an absorber where non-absorbable gases accumulated. At higher non-absorbable gas concentration, the decrease of absorption flux was almost linear to the volumetric concentration of non-absorbable gas.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.597-597
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• 2012

A simple solution-based method is developed to deposit crystalline ultrathin (2 nm) nickel hydroxide on vertically grown ZnO nanowires to achieve high specific capacitance and long-term life for flexible and wearable energy storage devices. Ultrathin crystalline $Ni(OH)_2$ enables fast and reversible redox reaction to improve the specific capacitance by utilizing maximum number of active sites for the redox reaction while vertically grown ZnO nanowires on wearable textile fiber effectively transport electrolytes and shorten the ion diffusion path. Under the highly flexible state $Ni(OH)_2$ coated ZnO nanowires electrode shows a high specific capacitance of 2150 F/g (based on pristine $Ni(OH)_2$ in 1 M LiOH aqueous solution with negligible decrease in specific capacitance after 1000 cycles. The synthesized energy-storage electrodes are easy-to-assemble which can provide unprecedented design ingenuity for a variety of wearable and flexible electronic devices.

• Journal of Pharmaceutical Investigation
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• v.37 no.5
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• pp.311-314
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• 2007

Paclitaxel (PTX) is an antineoplastic agent approved for the treatment of ovarian and breast carcinomas. However, the use of paclitaxel as an anticancer drug is limited by its extremely poor water solubility (below $0.3\;{\mu}g/mL$). Furthermore, it has very low bioavailability when administered orally because paclitaxel is a substrate of P-glycoprotein (P-gp) efflux pump. In this study, buccal delivery of PTX was investigated as one of the alternatives for PTX delivery. Ethanol and glyceryl monooleate (GMO) were selected as permeation enhancing agents to increase solubility and permeation across buccal mucosa of PTX. At the different concentrations of ethanol solution ($30{\sim}70\;w/w\;%$), PTX permeation was studied, followed effects of GMO in the concentration range of $2.5{\sim}25%$ with ethanol vesicle. The transbuccal ability of PTX was evaluated in vitro using Franz diffusion cells mounted with rabbit buccal mucosa. As a result, incorporation of PTX into ethanol vesicle with GMO significantly enhanced the PTX permeation in rabbit buccal mucosa. Particularly, the mixtures of ethanol:water:GMO at the ratio of 50:47.5:2.5 showed the most excellent enhancing ability. The results showed a promising possibility for buccal delivery of PTX.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.2
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• pp.245-252
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• 2002

Numerical analysis was conducted to characterize particle deposition on a horizontal rotating disk with thermophorectic effect under laminar flow field. The particle transport mechanisms considered were convection, Brownian diffusion, gravitational settling and thermophoresis. The averaged particle deposition velocities and their radial distributions for the upper surface of the disk were calculated from the particle concentration equation in a Eulerian frame of reference for rotating speeds of 0∼1000rpm and temperature differences of 0∼5K. It was observed from the numerical results that the rotation effect of disk increased the averaged deposition velocities, and enhanced the uniformity of local deposition velocities on the upper surface compared with those of the disk at rest. It was also shown that the heating of the disk with ΔT=5K decreased deposition velocity over a fairly broad range of particle sizes. Finally, an approximate deposition velocity model for the rotating disk was suggested. The comparison of the present numerical results with the results of the approximate model and the available experimental results showed relatively good agreement between them.

• Journal of Radiation Industry
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• v.5 no.1
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• pp.87-93
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• 2011

A laboratory experiment using a radioisotope was performed to analyze the characteristics of transport and diffusion of a pollutant released from industrial plants. A wave hydraulic model based on the similarity theory was constructed and used to reappear the tidal wave in the laboratory. Two-dimensional numerical models were used to reproduce the results of a wave hydraulic model. The measured and calculated concentrations were compared with the same conditions. As a result of the comparative study, the time of maximum concentration showed slight difference between them, but the values of maximum concentration were relatively well agreed.

• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.2
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• pp.51-60
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• 2003

In the nuclear power plant, emergency core coolant system (ECCS) is furnished at reactor coolant system (RCS) in order to cool down high temperature water in case of emergency. However, in this coolant system, thermal stratification phenomenon can occur due to coolant leaking in the check valve. The thermal stratification produces excessive thermal stresses at the pipe wall so as to yield thermal fatigue crack (TFC) accident. In the present study, effects of turbulence penetration on the thermal stratification into T-branches with square cross-section in the modeled ECCS are analysed numerically. Standard k-$\varepsilon$ model is employed to calculate the Reynolds stresses in momentum equations. Results show that the length and strength of thermal stratification are primarily affected by the leak flow rate of coolant and the Reynolds number of duct. Turbulence penetration into the T-branch of ECCS shows two counteracting effects on the thermal stratification. Heat transport by turbulence penetration from main duct to leaking flow region may enhance thermal stratification while the turbulent diffusion may weaken it.

• Journal of Pharmaceutical Investigation
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• v.2 no.1
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• pp.18-30
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• 1972

Renal pathways for excretion of sulfadiazine has been studied by standard clearance technique in the rabbit. 1. Large part of sulfadiazine filtered in the glomeruli is reabsorbed in the tubules, as visualized from the fact that Csd (clearance of sulfadiazine) amounts only a fraction of simultaneously measured Ccr (GFR). 2. Csd changed linearly with the rate of urine flow, whether it is increased by the duir etics or decreased by clamping u reter. 3. Csd remained unchanged until the plasma level of the Csdremained unchanged drug reached 10.0 mg%, and the amount transported in the tubules increased linearly with the increase in the load, exhibiting No maximum capacity for transport. 4. Csd was increased by 2,4-dinitrophenol which is an uncoupling agent of oxidative phosphorylation and decreased by probenecid which is on uricosuric agent. 5. During sodium bicarbonate infusion net secretion of sulfadiazine by tubules observed. All the evidences obtained in the rabbit indicated that sulfadiazine was reabsorbed by active, energy-requiring, or passive, simple diffusion, process, and secreted simultaneously by a probenecid-sensitive, active procss.

• Membrane Journal
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• v.27 no.4
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• pp.291-312
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• 2017

Seawater desalination is currently considered to be one of the primary technologies to resolve the global water scarcity problem. A basic understanding of membrane filtration phenomena is significant not only for further technological development but also for integrated design, optimal control, and long-term maintenance. In this vein, the present work reviews the major transport and filtration models, specifically related to reverse osmosis phenomena, provides theoretical insights based on statistical mechanics, and discusses model-based physical meanings as related to their practical implications.

• Journal of Electrochemical Science and Technology
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• v.5 no.2
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• pp.58-64
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• 2014

The surface of an ordered mesoporous silica (OMS) was functionalized using 1H,1H,2H,2H-perfluorooctyltrimethoxysilane at $20^{\circ}C$ and $60^{\circ}C$. It was shown that only elevated temperature allows lyophobic properties on the walls of OMS, eventually preventing pore flooding with nonaqueous electrolytes. The functionalized OMSs (OMS-F) were characterized with various techniques: wettability test, $N_2$ sorption measurement, high-resolution transmission electron microscopy (HR-TEM). Cathodes of $10mg/cm^2$ loading were prepared with a commercial Pt/C catalyst and polyvinylidene fluoride (PVDF, 2.5 wt.%) binder using a typical doctor blade method on a commercial gas diffusion layer (GDL) in the presence or in the absence of OMS-F additives. Subsequent discharge-charge curves were taken in a 1M LiTFSI-TEGDME electrolyte at 60oC in pure oxygen atmosphere. It was found that the discharge capacity was significantly affected by OMS-F: 5 wt.% of additive extended discharge capacity by a factor 1.5. On the other hand, a similar OMS material but synthesized at $20^{\circ}C$ did not show lyophobic properties and deteriorated cathode capacity.