摘要:
The present disclosure relates to a pellet containing an oxide additive to improve a nuclear-fission-gas-adsorption ability of a uranium-dioxide pellet used as nuclear fuel and increase the grain size thereof, and to a method of manufacturing the same. A La2O3—Al2O3—SiO2 sintering additive is added to uranium dioxide so that mass movement is accelerated due to the liquid phase generated during sintering of the uranium-dioxide pellet, which promotes the growth of grains thereof. Further, since less volatilization occurs during sintering due to the low vapor pressure of the liquid phase, efficient additive performance is exhibited, so the liquid phase surrounding the grain boundary effectively adsorbs cesium, which is a nuclear fission gas.
摘要:
Proposed are nuclear fuel pellets showing high oxidation resistance in a steam atmosphere and a method for manufacturing same. The method includes: preparing a powder mixture by mixing a sintering additive powder including Cr2O3, MnO, and SiO2 with a uranium dioxide powder; forming a molded body by subjecting the powder mixture to compression molding; and sintering the molded body in a weak oxidative atmosphere in which an oxygen potential is −581.9 kJ/mol to −218.2 kJ/mol. The nuclear fuel pellets contain 0.05% to 0.16% by weight of the sintering additive composed of Cr2O3, MnO, and SiO2. A liquid phase generated during the sintering accelerates grain growth and inhibits reaction between uranium dioxide with steam by forming a film at the grain boundary of the uranium dioxide. This reduces leakage of a fission material by improving high-temperature water vapor oxidation resistance at around 1204° C. in a loss-of-coolant accident condition.
摘要:
The present disclosure relates to a pellet containing an oxide additive to improve a nuclear-fission-gas-adsorption ability of a uranium-dioxide pellet used as nuclear fuel and increase the grain size thereof, and to a method of manufacturing the same. A La2O3—Al2O3—SiO2 sintering additive is added to uranium dioxide so that mass movement is accelerated due to the liquid phase generated during sintering of the uranium-dioxide pellet, which promotes the growth of grains thereof. Further, since less volatilization occurs during sintering due to the low vapor pressure of the liquid phase, efficient additive performance is exhibited, so the liquid phase surrounding the grain boundary effectively adsorbs cesium, which is a nuclear fission gas.
摘要:
A catalyst coated electrolyte membrane including an anode catalyst layer and a cathode catalyst layer at opposite sides thereof, respectively, wherein micro cracks of the anode catalyst layer or cathode catalyst layer occupy 0.01-1 area % of the total area of the respective anode catalyst layer or cathode catalyst layer, a fuel cell including the same, and a method of preparing the catalyst coated electrolyte membrane. In the catalyst coated electrolyte membrane, micro cracks of the cathode catalyst layer or the anode catalyst layer can be minimized and thus the resistance between the electrode catalyst layer and an electrolyte membrane can be minimized, and crossover of a fuel, such as methanol, ethanol, other alcohols, methane, etc., to a cathode electrode can be minimized, and thus the catalyst coated electrolyte membrane has improved performance and durability.
摘要:
A method of estimating a lifespan of a fuel cell including a cathode and an anode which contain catalysts and an electrolyte membrane interposed between the anode and the cathode. A cyclic potential with a voltage ranging from a low voltage to a voltage greater than oxidation voltages of the catalysts is applied between the anode and the cathode and fuel cell performance is measured initially and after a predetermined number of cycles. The lifespan of the fuel cell may estimated based on degradation of cell performance after the predetermined number of cycles, based on CV curves obtained during the cycling of the potential and/or a change in particle size of the catalysts after the predetermined number of cycles.
摘要:
Provided are a method of forming a device isolation layer and a method of fabricating a semiconductor device. The method includes: forming a first trench and a second trench in a substrate, wherein the second trench is connected to the first trench and has a width smaller than the first trench; forming a liner insulation layer in the second trench such that the liner insulation layer is buried in the second trench; and forming a gap fill insulation layer on the liner insulation layer such that the gap fill insulation layer is buried in the first trench.
摘要:
A method of estimating a lifespan of a fuel cell including a cathode and an anode which contain catalysts and an electrolyte membrane interposed between the anode and the cathode. A cyclic potential with a voltage ranging from a low voltage to a voltage greater than oxidation voltages of the catalysts is applied between the anode and the cathode and fuel cell performance is measured initially and after a predetermined number of cycles. The lifespan of the fuel cell may estimated based on degradation of cell performance after the predetermined number of cycles, based on CV curves obtained during the cycling of the potential and/or a change in particle size of the catalysts after the predetermined number of cycles.
摘要:
A paper guide used in an ink-jet printer. The paper guide for the ink-jet printer includes a plurality of first guide ribs which protrude on the paper guide to face a front-half swath of a printhead and forms a predetermined interval therebetween, and a plurality of second guide ribs which protrude on the paper guide to face a rear half-swath of the printhead and forms an interval therebetween to be wider than the interval between the first guide ribs.
摘要:
A fuel cell includes a cathode, an anode, an electrolyte membrane interposed between the cathode and the anode, and a porous layer containing a moisture retentive material. The anode includes an anode catalyst layer adjacent to the electrolyte membrane and an anode diffusion layer adjacent to the anode catalyst layer, and the porous layer is disposed between the anode catalyst layer and the electrolyte membrane. The performance of the fuel cell can be stably maintained even when a fuel supply is temporarily interrupted due to a malfunction of a pump or clogging of a fuel channel.
摘要:
A direct liquid feed fuel cell includes a membrane electrode assembly (MEA) including an anode electrode and a cathode electrode respectively disposed on either side of an electrolyte membrane. A conductive anode plate and a conductive cathode plate which respectively face the anode electrode and the cathode electrode, and have flow channels therein. Stripe-shaped hydrophilic members are formed on the cathode electrode, cross the flow channels of the conductive cathode plate, and transfer water from the flow channels to the conductive cathode plate. The conductive cathode plate is hydrophilic.