A catalytic technique to enhance graphite formation in nongraphitizing carbons was adapted to work with three-dimensional wood-derived scaffolds. Unlike many synthetic graphite precursors, wood and other cellulosic carbons remain largely disordered after high temperature pyrolysis. Using a nickel nitrate liquid catalyst and controlled pyrolysis conditions, wood-derived scaffolds were produced s...

This study demonstrates a facile, mild and environmentally-friendly sustainable (soft processing) approach for the efficient electrochemical exfoliation of graphite using a sodium hydroxide/hydrogen peroxide/water (NaOH/H2O2/H2O) system that can produce high-quality, anodic few-layer graphene nanosheets in 95% yield at ambient reaction conditions. The control experiment conducted using NaOH/H2O...

The MCNP5 Monte Carlo code has been frequently used to model HTGRs with explicit geometric representation of fuel compacts or pebbles, including the microscopic fuel kernels within them. The random locations of fuel kernels within each fuel compact or pebble, and of pebbles within the core, however, present difficulties. A new, on-the-fly, stochastic geometry model for MCNP5 has been developed ...

Today, high resolution electron microscopy is seriously limited by the noise which results from the irregularity of the substrates used. For example, this limitation is of particular significance in recent attempts (1) to elucidate by electron microscopy the nucleotide sequence of D N A by chemical at tachment of base-specific, heavy metal markers. The following technique was originally develop...

14C is one of the limiting radionuclides used in the categorization of radioactive graphite waste; this categorization is crucial in selecting the appropriate graphite treatment/disposal method. We propose a rapid analysis method for 14C specific activity determination in small graphite samples in the 1-100 μg range. The method applies an oxidation procedure to the sample, which extracts 14C fr...

The firstand second-order Raman spectral features of graphite and related sp2 carbon materials were examined with laser wavelengths ranging from 293 to 1064 nm. A wide range of carbon materials was considered, including highly ordered pyrolytic graphite (HOPG), powdered and randomly oriented graphite, and glassy carbon prepared at different heat-treatment temperatures. Of particular interest is...

Five spheroidal graphite cast irons were investigated, a usual ferritic grade and four pearlitic alloys containing Cu and doped with Sb, Sn and Ti. These alloys were remelted in a graphite crucible, leading to volatilization of the magnesium added for spheroidization and to carbon saturation of the liquid. The alloys were then cooled down and maintained at a temperature above the eutectic tempe...

The potential applications of new graphitic materials, including carbon nanotubes and carbonized spheres, is limited by both the cost of production and the difficulties of organizing them into final geometries. We have developed a simple, low temperature (ca. 500 C) novel technology based on our discovery that in certain lean burn combustion environments graphite will grow rapidly (>1 graphene ...

Graphite basal surface is inert, and decomposition of n-alkanes on the graphite surface has not been discovered. We here report the evidence of decomposition of n-octanes on highly oriented pyrolytic graphite (HOPG) surface, heat-treated up to 1200 °C under high vacuum (10(-7) Pa), at near room temperatures. Using a temperature programmed desorption apparatus equipped with a quadrupole mass spe...

Density functional theory calculations are used to elucidate the interactions of platinum clusters with graphite; the results are analyzed in terms of geometry, and energetic and electronic properties. Adsorption of platinum clusters from 1 to 38 atoms is evaluated on a 3-layer graphite model structure. The approach includes van der Waals interactions, which have proved to be essential to descr...