Fluorescence of substituted aromatic derivatives crystalline materials for optical nonlinear applications
Our fluorescence study gave information on the presence of chemical defects and irregularities in crystal structure, offering a good tool for quality evaluation of organic crystalline materials. We have analyzed the correlation between the bulk or thin film samples' quality determined by experimental parameters (thermal gradient, moving speed of the growth interface, crucible configuration, slow or fast solidification rates) and the fluorescence characteristics for pure meta-dinitrobenzene and meta-dinitrobenzene doped with 8 hydroxyquinoline or 1.3 dihydroxybenzene. The comparative study of the position and shape of the fluorescence emissions for pure and controlled doped materials gave us information on the chemical defects.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The aim of this study was to determine the basic rheological parameters of dispersed highly concentrated lignite aqueous suspensions. Typical dilatant behavior was observed, where critical parameters of dilatancy were determined for different size fractions and concentrations. To modify the non-Newtonian behavior of the lignite highly concentrated suspensions, the effect of surfactant addition on the flow parameters of the suspensions was determined.