• Proceedings of the KSEEG Conference
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• 2002.04a
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• pp.224-226
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• 2002

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.4
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• pp.343-353
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• 2017

Processing and equipment were tailored for engineering scale fabrication of $UO_2$ porous pellets, a feed material for the electrolytic reduction process in the PRIDE (PyRoprocessing Integrated DEmonstration) facility at KAERI (Korea Atomic Energy Research Institute). The starting materials, $UO_2$ powder and pre-milled surrogate oxide powders, were proportioned to simulate the chemical composition of spent fuel (so-called Simfuel). The Simfuel powders were homogenized by mixing, compacted into a pellet shape, and finally heat treated using a tumbling mixer, rotary press, and sintering furnace. After sintering at $1450^{\circ}C$ for 24 h in $4%\;H_2-Ar$, the average bulk density of the $UO_2$ Simfuel pellets was $6.89g{\cdot}cm^{-3}$, which meets the standard of the following electrolytic reduction process. In addition, the results of a microstructural analysis demonstrated that the sintered Simfuel $UO_2$ porous pellets accurately simulate the properties of spent fuel in terms of the formation of second phases. These results provide essential information for the massive fabrication of $UO_2$ porous pellets for engineering scale pyroprocessing research.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.587-592
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• 2013

In this study, we prepared pelletized porous carbon adsorbent (PCA) according to the different pyrolysis temperature using activated carbon and polyvinyl alcohol (PVA) as a binder for the removal of toluene, which is one of the representative volatile organic compounds (VOCs). We investigated physical characteristics of PCA using FE-SEM, BET, TGA and evaluated their adsorption capacity for toluene using GC. It was confirmed that the formability of pellets composed of the activated carbon, PVA and solvent of mass mixing ratio was 1 : 0.2 : 0.8 was the most outstanding. Toluene adsorption capacity was evaluated by measuring the maximum time when more than 99% of toluene adsorbed on the pellet. The specific surface area of the adsorbent pyrolyzed at $300^{\circ}C$ was measured as 4.7 times in $941.9m^2/g$ compared to that of the unpyrolyzed pellet. Micropore volume and toluene adsorption capacity of PCA increased fivefold to be 0.30 cc/g and thirteenfold to be 26 hours compared to that of the unpyrolyzed pellet, respectively. These results were attributed to the change of pore size and specific surface area due to the PVA content and the different pyrolysis temperature.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2012.10a
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• pp.89-90
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• 2012

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.21-26
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• 2003

Diesel particulate trap is a core technology for the reduction of PM from diesel vehicles This study presents the features and the characteristics of DPF system when using pellet type filters. In comparison with wall-flow filter, the pellet filter has the advantages of cracking free during regeneration and shape flexibility. Experiments are conducted in a test bench simulated as diesel engine exhaust condition. Pressure drop and particle loading rate was compared by using two pellet filters having the porosity of 70% and 0%. Also its regeneration was tested.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2012.10a
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• pp.91-92
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• 2012

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2012.10a
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• pp.93-94
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• 2012

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.2
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• pp.97-104
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• 2012

A porous $TiO_2$ pellet was electrochemically converted to the metallic titanium by using a $CaCl_2$ molten salt system at $850^{\circ}C$. Ni-$TiO_2$ and graphite electrodes were used as cathode and anode, respectively. The electrochemical behaviour of $TiO_2$ pellet was determined by a constant voltage control electrolysis. Various reaction intermediates such as $CaTiO_3$, $Ti_2O$ and $Ti_6O$ were observed by XRD analysis during electrolysis of the pellet. Once $TiO_2$ pellet was converted to a porous metallic structure, the porous structure disappeared by sintering and shrinking with increasing the reaction time at high temperature.

• Polymer(Korea)
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• v.32 no.4
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• pp.328-333
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• 2008

The osmotic delivery systems are based on osmosis. The transverse diffusion of water through a porous membrane from a medium with a low osmotic pressure to a medium with a high osmotic pressure. Nifedipine tablet dosage forms of Procardia $XL^{(R)}$(Pfizer) and $Adalat^{(R)}$(Bayer) are commercialized systems of this type that push-pull osmotic tablet operates successfully in delivering water-insoluble drugs. We prepared osmotic pellet system by fluidized bed coating method, and model-drug used nifedipine. The osmotic pellet system was composed of the core material. the swelling and osmotic pressure layer, the drug coating layer, and the porous membrane. This work is performed to investigate the effect of different factors, such as composition and thickness of membrane. The osmotic pellet has been successfully prepared by fluidized bed coating technology. The drug release behavior depended on the increase of CA ratio and thickness in porous membrane. The morphology of the osmotic pellet before and after the dissolution test were observed by SEM. In conclusion, we found that the drug release of osmotic pellet depended on the composition and coating thickness of porous membrane.

• Polymer(Korea)
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• v.32 no.4
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• pp.322-327
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• 2008

In this study, a multi-layered pellet was composed of a seed layer including a water-swellable agent and a drug layer containing doxazosin as a model drug, a porous membrane and a castor oil layer to control drug release. The pellet is prepared by a fluidized bed coating method. To confirm drug release from polymer blending in multi-layered pellet system, it is prepared by containing different ratio such as hydroxypropylmethylcellulose (HPMC) : ethyl cellulose (EC) in drug layer and cellulose acetate(CA) : Eudragit RS in membrane. Also, to confirm the effect of oil in drug release, castor oil is coated. As a result, we observed regularly spherical pellet with diameter of $1500{\mu}m$. Release pattern of drug is confirmed by dissolution tester in aqueous media. The more the ratio of EC in drug layer, CA in membrane, and castor oil layer in pellet, the less the drug release is observed. Formation and the amount of pores in membrane is observed by SEM.