Current research has identified Duplex pellets as an effective strategy for decreasing the centerline temperature of the fuel. However, before this design can be widely utilized several areas, including fission gas release, need to be better characterized. Therefore, this paper seeks to ascertain the relative difference in fission gas release between a standard solid UO2 reference design and a ...

The temperature dependence of the irreversible phase transition from a two-dimensional gas to an ordered zero-dimensional solid on the Si(111)-7 × 7 surface was studied using photoemission spectroscopy. With increasing Na coverage, the two-dimensional Na gas, which is a state of highly mobile Na atoms, undergoes a phase transition into ordered zero-dimensional magic nanoclusters at room tempera...

The numerical simulation of solid-gas two-phase flow is an important tool in the prediction of its flow behavior. Predicting the axial pressure profile is one of the major difficulties in modeling of solid-gas two-phase flow. A model using a Particle Based Approach (PBA) is developed to accurately predict the axial pressure profile in a vertical annular tube. The simulation model accounts for t...

objectives : because of poor bond between resin cement and zirconia ceramics, laser surface treatments have been suggested to improve adhesion. the present study evaluated the effect of co 2 and nd:yag lasers on the shear bond strength (sbs) of resin cement to zirconia ceramic. materials and methods : ninety zirconia disks (6×2 mm) were randomly divided into six groups of 15. in the control gro...

a fiber coating from polyaniline (pani) was electrochemically prepared and employed for solid phase micreoextraction (spme). the pani film was directly electrodeposited on the platinum wire surface using cyclic voltametry (cv) technique. the same method was applied for the preparation of spme fiber coated by polyaniline multiwalled carbon nanotubes (pani/mwcnts) composite. the concentration of ...

The direct link between microstructure and material properties is the core principle underpinning modern material science and engineering. Phase transformations in solids and solidification of melts have been extensively studied to the point where the key elementary processes, process steps and process variables are well understood. Less well investigated and less well understood are the change...

We report a computational fluid dynamics-discrete element method (CFD-DEM) simulation study on the interplay between mass transfer and a heterogeneous catalyzed chemical reaction in cocurrent gas-particle flows as encountered in risers. Slip velocity, axial gas dispersion, gas bypassing, and particle mixing phenomena have been evaluated under riser flow conditions to study the complex system be...