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The pyrolysis behavior of wheat straw and mallee residue and resulting gases, liquids, and chars were examined. The specific heat and thermal conductivity of both species were measured using computer-aided thermal analysis at heating rates of 10 and 100 °C/min to a temperature of 1000 °C. The sample decomposition was also measured by thermogravimetry. Gas chromatography detected evolved gases, and the bio-oils were characterized using GC-MS. Chars were examined using FTIR, proximate, and ultimate analysis. Both species initially displayed endothermic behavior, followed by rapid decomposition and fluctuating specific heat and thermal conductivity between 250 and 500 °C. Oxides of carbon were the primary gases evolved, with small amounts of hydrocarbons and hydrogen. The bio-oils predominantly contained oxygenated aromatics and organic acids, and the chars had high fixed carbon and low sulfur. In all instances approximately half of the product output was liquid. Straw produced 14% gas and 32% solid at 500 °C, whereas mallee produced 13% gas and 36% solid. At 1000 °C the proportions of solid decreased and gas increased. The efficiency of pyrolysis to 500 °C, assuming no losses, was around 96% for both species. At 1000 °C the efficiency decreased, with pyrolysis of mallee slightly more efficient than for straw.

An experimental study of initial solidification of 304 stainless steel melts in direct contact with copper substrates under conditions approximating the meniscus region of a strip caster has highlighted the importance of interfacial heat transfer during the first 30 ms of contact. The mechanisms governing initial heat transfer are strongly influenced by dynamic wetting phenomena. This has been illustrated experimentally by the effects of the buildup and melting of oxide films such as manganese silicates at the interface during successive immersions, by the role of surface active agents such as tellurium in the melt, and by the use of specially designed substrate textures to control contact areas.

A modified levitated drop technique and an immersion technique were used to study the wetting and nucleation behavior of steel melts on a metallic substrate. Thermal histories of the solidifying shell and the substrate were recorded and used to elucidate the mechanisms of interfacial heat transfer and nucleation. The melt/substrate wetting behavior was shown to be controlled by the melt surface tension. The interfacial heat transfer resistance was controlled by the degree of melt/substrate wetting consequently affecting the heat flux across the interface. According to the classical heterogeneous nucleation theory, improved wetting is expected to reduce the energy barrier for nucleation while increasing the cooling rate of the liquid. Because the overall nucleation rate is controlled by both the rate of cluster formation and the rate of atom transfer to the nucleus, increasing the cooling rate above a critical level is expected to reduce the nucleation rate. The measured experimental data allowed the melt undercooling and the time for nucleation of the first solid phase to be determined and compared to the theoretical predictions. The implications of the mechanisms of nucleation on early shell growth are also considered.

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