No abstract

The low-temperature ([similar or less than]4 K) dependence of the photoconductance in n-type silicon on the conduction electron and bound donor electron spin state serves as the basis of a high-precision, wide-range magnetic field measuring probe, which by virtue of its very small dimensions is well suited for spatial mapping of highly inhomogeneous fields produced by superconducting magnets. The probe may also be adapted to power and frequency measurement of microwave sources operating at approximately mW power levels and frequencies up to approximately 500 GHz.

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Besides the widely applied hydropower, wind farms and solar energy, biomass and municipal and industrial waste are increasingly becoming important sources of renewable energy. Nevertheless, fouling, slagging and corrosion associated with the combustion processes of these renewable sources are costly and threaten the long-term operation of power plants. During a high-temperature biomass combustion, alkali metals in the biomass fuel and the ash fusion behavior are the two major contributors to slagging. Ash deposits on superheater tubes that reduce thermal efficiency are often composed of complex combinations of sulfates and chlorides of Ca, Mg, Na, and K. However, thermodynamic databases involving all the sulfates and chlorides that would favor a better understanding and control of the problems in combustion processes related to fouling, slagging and corrosion are not complete. In the present work, thermodynamic properties including solubility limits of some phases and phase mixtures in the K2SO4-(Mg,Ca)SO4 system were reviewed and experimentally investigated. Based on the new and revised thermochemical data, binary phase diagrams of the K2SO4-CaSO4 and K2SO4-MgSO4 systems above 400 °C, which are of interest in the combustion processes of renewable-energy power plants, were optimized.