Synthesis and study of the phosphate Cs<Subscript>2</Subscript>Mn<Subscript>0.5</Subscript>Zr<Subscript>1.5</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript>

The new phosphate Cs₂Mn_0.5Zr_1.5(PO₄)₃ was synthesized for the first time and characterized by X-ray diffraction. Its crystal structure was refined in space group P2₁3, Z = 4 at 25°C (a = 10.3163(1) Å, V = 1097.93(1) ų), by the Rietveld method using the powder X-ray diffraction data. The structure is built of an octahedral-tetrahedral framework {[Mn_0.5Zr_1.5(PO₄)₃]^2?}_3∞ with cesium atoms being located in large cavities. The hydrolytic stability of the powdered phosphate containing ¹³⁷Cs radionuclide was studied. The minimum achieved ¹³⁷Cs leaching rate was 4 × 10^?8 g/cm₂ day.     

Drying and Impregnation of Wood with Propiconazole Using Supercritical Carbon Dioxide

The process of wood drying is studied in supercritical (SC) CO₂ and SC-CO₂ containing 5 vol % ethanol at temperatures of 323, 343, and 353 K and pressures of 10, 20, and 30 MPa. It is established that 40–87% of moisture is removed from wood in the first cycle of drying. An increase in the duration of the decompression stage of the drying process decreases the number of cracks in the wood samples. The solubility of propiconazole is studied in SC-CO₂ at 323, 343, and 353 K in the pressure range of 10–30 MPa using a dynamic method. Rather high saturation concentrations of (3–5) × 10^–3 mol/mol CO₂ are obtained, which indicates the potential benefits of using SC-CO₂ as a solvent in wood impregnation with propiconazole. Continuous impregnation is achieved when impregnating wood with propiconazole from SC-CO₂. The impregnation efficiency increases with increasing pressure and duration of the process.     

Some Thermodynamic Characteristics of Paracetamol Dispersing with the SEDS Method

The solubility of paracetamol in supercritical carbon dioxide and its mixtures with acetone is experientially studied. The isobaric heat capacity of paracetamol and the systems “paracetamol–CO₂” and “paracetamol–acetone–CO₂” is measured under pressures 7–29 MPa and temperatures 303–523 K. The results of paracetamol dispersing using the SEDS method (Solution Enhanced Dispersion by Supercritical Fluids) are presented.     

Maxwell-Gouy potential in statistical mechanics

The probabilistic-statistical justification for the equilibrium-thermodynamic Maxwell-Gouy potential is given. The relationship between the change in the potential and the information about the structure of the system, expressed by Kul'bak's measure, is established.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 29–33, July, 1987.