Application of X-Ray Diffraction to Study Mineralogical Dependence of Reduction: Disintegration Indices RDI of Blast Furnace Sinters

The aim of this research was to continue an examination of influence of mineral components of blast furnace sinters on their quality. Two of reduction-disintegration indices RDI were taken into account: static resistance to degradation RDI-1+6.3 and static susceptibility to degradation RDI-1-3.15. X-ray diffraction was used for phase identification and the Rietveld method was applied to study quantitative dependence. Static susceptibility to degradation RDI-1-3.15 showed clearly dependence on quantitative mineral composition, namely on quantities of magnetite, silicates and slag phases. Static resistance to degradation RDI-1+6.3 was also dependent on fractions of magnetite and silicates.

Extension of the Working Temperature Range of Magnetic Fluid Susceptibility Measurements

Tests have been carried out to measure the temperature dependence of static susceptibility of a magnetic fluid stabilized with polypropylene glycol (PPG) in propanol, ethyl ether and propylene oxide. The use of propylene oxide provides the widest temperature range for measurements of fluid susceptibility. The coagulation stability of the PPG-stabilized magnetic fluid against ethylene glycol and 1,4-butylene glycol is investigated. It has been shown that ethylene glycol can be used to separate PPG magnetic fluid into fractions. The fluid separation begins as soon as the volumetric fraction of ethylene glycol exceeds 30%. Butylene glycol is unsuitable for fractionation but can be used to remove excess surfactant - PPG.

DIELECTRIC RELAXATION IN RELAXOR FERROELECTRICS

In this review the dielectric properties of relaxor ferroelectrics are discussed and compared with the properties of normal dielectrics and ferroelectrics. We try to draw a general picture of dielectric relaxation starting from a textbook review of the underlying concepts and pay attention to common behavior of relaxors rather than to the features observed in specific materials. We hope that this general approach is beneficial to those physicists, chemists, material scientists and device engineers who deal with relaxors. Based on the analysis of dielectric properties, a comprehensive definition of relaxors is proposed: relaxors are defined as ferroelectrics in which the maximum in the temperature dependence of static susceptibility occurs within the temperature range of dielectric relaxation, but does not coincide with the temperature of singularity of relaxation time or soft mode frequency.