Density functional theory was used to study the effects of different types of oxygen-containing functional groups on the adsorption of oxygen molecules and single active oxygen atoms on carbonaceous materials. During gasification or combustion reactions of carbonaceous materials, oxygen-containing functional groups such as hydroxyl(-OH), carbonyl(-CO), quinone(-O), and carboxyl(-COOH) are often...

The nature and composition of the surface of pyrolytic graphite and the consequent possible effects, when the material is used as an electrode. are considered on the basis of the structure of the graphite and of the handling and/or treatment to which the electrodes may have been exposed. Because of the relatively limited studies on pyrolytic graphite, certain aspects of the behavior of other ty...

In this present work effect of temperature and graphite contents on the microstructural and mechanical properties of iron based powder metallurgy freeform was studied. The different graphite contents (0%, 2%, 5% and 10%) were mixed in iron powder and compact them in 100 KN. These specimens were sintered at 7000 C, 8500 C and 10000 C in muffle furnaces. Microstructural properties were evaluated ...

We report simulations of the elastic scattering of atomic hydrogen isotopes and helium beams from graphite (0001) surfaces in an energy range of 1-4 eV. To this aim, we numerically solve a time-dependent Schrödinger equation using a split-step Fourier method. The hydrogen- and helium-graphite potentials are derived from density functional theory calculations using a cluster model for the graphi...

The UK nuclear power industry is predominantly based on gas-cooled, graphite moderated reactors with their being 20 operating and 6 shutdown Magnox reactors. The radioactive graphite issues associated with the Magnox reactors relate mainly to the reactor core graphite but, at two of the stations, there is also another graphite waste stream which results from the handling of their particular des...

Differential scanning calorimetry (DSC) is a powerful technique that measures the heat evolution from a sample under a controlled condition and studies the phase transformation, precipitation, and dissolution activities. In this work, we investigated the influence of admixed silicon and silicon carbide and the effect of different atmospheres on the heat flow properties and microstructure of ato...