Phenolcarboxylic acids of Organum vulgare

Irkutsk Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, Vol. 6, pp. 850–851, November–December, 1989.     

Sedimentation of Kaolin Suspension in the Presence of Praestol Anionic Flocculant and Aluminum Polyoxychloride and Sulfate Coagulants

The kinetics of sedimentation of kaolin suspension in the presence of coagulants (aluminum polyoxychloride and sulfate) and Praestol anionic flocculant was studied, as influenced by the concentrations of coagulants and flocculant, mode and time of their addition into the suspension, composition of the coagulant mixture, and chemical structure and conformation of flocculant macromolecules.     

Structural and transport characteristics of substituted bismuth niobates

The results of studying solid solutions with the composition of Bi₃Nb_{1 ? y} Zr _y O_{7 ± δ}, Bi_2.95Y_0.05Nb_{1 ? y} Zr _y O_{7 ± δ} (y = 0–0.5; Δy = 0.1), and Bi_6.95Y_0.05Nb_{2 ? y} Zr _y O_15.5 (y = 0.1–1; Δy = 0.1) are presented. XRD and electron microscopy with X-ray microanalysis are used to determine the homogeneity regions of solid solutions; crystallochemical parameters are calculated. It is shown that irrespective of the ratio of Bi: Nb, two cubic phases are formed at an increase in the dopant amount. One of these represents a solid solution based on Bi₃NbO₇ (δ-phase) and the second one is a solid solution based on δ-Bi₂O₃ (δ′-phase). Conductivity of sintered samples is studied using the impedance spectroscopy technique. Introduction of yttrium into the bismuth sublattice results in no increase in conductivity of solid solutions, while in the case of the ratio of Bi: Nb = 3: 1, overall conductivity of solid solutions is somewhat higher at similar dopant concentrations.     

Structural and thermal stability of BIMEVOX oxygen semiconductors

The results on the structural and thermal stability of different modifications of solid solutions Bi₄V_{2 − x} Fe _x O_{11 − δ} (BIFEVOX), where x = 0.05–0.6, and Bi₄V_{2 − x} Cu _x/2Ti _x/2O_{11 − δ} (BICUTIVOX), where x = 0.025–0.50, are shown. The stability is assessed by varying the thermodynamic parameters of the medium and also the time parameters with the use of modern methods, namely, the high-temperature X-ray diffraction analysis, the differential scanning calorimetry, and the dilatometry. The γ-modification of BIFEVOX is shown to be stable in a wide range of temperatures and oxygen partial pressures.