Synthesis of a magnetoactive compound based on iron(II) sulfate

The effect of synthesis parameters on properties of a magnetoactive compound (MAC) prepared via condensation of iron(II) sulfate in the presence of sodium nitrite is investigated. It is found that nitrite ions almost completely coprecipitate with the solid phase during the formation of a magnetoactive compound and subsequently participate in the redox conversions to yield magnetite. In order to obtain a magnetoactive compound with high relative magnetic susceptibility, condensation from the initial solutions is to be carried out at least 15 min after it is prepared; sodium nitrite consumption is to be at least 0.12 mol/mol FeSO₄.     

Mechanochemical preparation and pharmacological activities of water-soluble intermolecular complexes of arabinogalactan with medicinal agents

A possibility of mechanochemical preparation of water-soluble complexes of a plant polysaccharide arabinogalactan and poorly soluble medicinal agents (Sibazon(=Diazepam), Mezapam(=Medazepam), Indometacin, and Azaleptin(=Clozapine)) has been investigated. Their molecular dynamics (NMR relaxation method in solution) and some pharmacological properties have been studied in comparison with the original pharmaceutical drugs.     

Observation of higher order facets on 3He crystals

Faceting has been observed on 3He crystals investigated with a low-temperature Fabry-Pérot interferometer. Nine types of facets were clearly identified during growth of a bcc- 3He single crystal at a temperature of 0.55 mK, while previously only three types of facets have been seen. Because of the weak coupling between the liquid-solid interface and the solid lattice in 3He the facets are apparently too small to be observed in equilibrium. The number of facets observed in our experimental conditions is consistent with the theory of dynamic roughening.     

Anisotropic magnetocaloric effect in thin magnetic films

We consider the magnetocaloric effect in thin magnetic films. The experimental method is based on heat transfer in a layered structure containing a magnetic film and a film of material with a metal-dielectric phase transition. The anisotropy of the magnetocaloric effect is studied.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 40–43, November, 1989.The authors thank G. A. Petrakovskii and V. G. Pyn'ko for useful discussions.     

Electric properties of single-crystalline nickel films deposited by the method of chemical transport reactions

The conditions for obtaining single-crystalline nickel films with a high resistivity ratio at room temperature and at 4.2 K (up to 1000) are described. The thicknesses of the films studied fall in the range 0.7–10 m. The meanfree path length of the carriers (6–7 m) and the specularity parameter (0.05) are determined using the Fuks-Sondheimer method.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 12–15, April, 1986.     

Mechanical and physicochemical properties of matrices for fiber reinforced plastics based on low-melting phthalonitrile monomers

The mechanical properties of cured phthalonitrile matrices for fiber reinforced plastics (FRP) based on low-melting phenylmethylsilanediyl-bis[oxymethylene(1,4-phenylene-4’-oxyphthalodinitrile)] (1) or its mixture with 1,3-phenylene-bis(oxy-4-phthalodinitrile) (2, comonomer) were studied. The flexural strength, Young’s modulus, fracture toughness, and some other characteristics of the cured resins based on monomer 1 (PN-1) and the mixture of monomers 1 and 2 (PN-1m) were determined. It is noted that the PN-1 resin can be processed by vacuum infusion and the PN-1m resin can be processed by compression injection molding. The developed resins are promising as materials for high-tech aerospace applications.