On self-adjoint operators connected by inequalities and on their applications to problems of mathematical physics

Translated from Matematicheskie Zametki, Vol. 55, No. 6, pp. 3–12, June, 1994.     

Isolation and purification of lignoperoxidase from the mushroom <Emphasis Type="Italic">Pleurotus ostreatus</Emphasis>

The accumulation dynamics of lignolytic enzymes in culture media of the basidiomycetes Panus tigrinus, Pleurotus ostreatus, Fomes fomentarus, and the micromycete Aspergillus terreus were studied during the incubation period. It was found that Pleurotus ostreatus is the most active producer of lignoperoxidase enzymes among the studied fungi. Gel filtration and ion-exchange chromatography were used to isolate a homogeneous enzyme with lignoperoxidase activity. The maximum activity was found at pH 2.7 and 29°C. Gel electrophoresis determined the molecular weight (44 kDa). __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 564–566, November–December, 2007.     

Condensation of acetanilide and N-phenylbutyrolacatam with γ-butyrolactone

1,2,3,4-Tetrahydro-2-quinolone and -6-(1,2,3,4-tetrahydro-2-quinolonyl)butyric acid were obtained by condensation of acetanilide with -butyrolactone in the presence of aluminum chloride. -n-(N-phenylbutyrolactamyl)butyric acid was obtained by carboxyalkylation of N-phenylbutyrolactam with -butyrolactone.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 77–79, January, 1973.     

Experimental Vapor Pressures and Derived Thermodynamic Properties of Aqueous Solutions of Lithium Nitrate from 423 to 623 K

Vapor pressures of six aqueous lithium nitrate solutions with molalities of (0.181, 0.526, 0.963, 1.730, 2.990, and 5.250) mol-kg^–1 have been measured in the temperature range 423.15–623.15 K with a constant-volume piezometer immersed in a precision liquid thermostat. The static method was used to measure the vapor pressure. The total uncertainty of the temperature, pressure and composition measurements were estimated to be less than 15 mK, 0.2%, and 0.014%, respectively. The vapor pressures of pure water were measured with the same apparatus and procedure to confirm the accuracy of the method used for aqueous lithium nitrate solutions. The results for pure water were compared with high-accuracy P_S–T_S data calculated from the IAPWS standard equation of state. Important thermodynamic functions (activities of water and lithium nitrate, partial molar volumes, osmotic coefficient, excess relative partial molar entropy, and relative partial molar enthalpy values of the solvent) were derived using the measured values of vapor pressure for the solution and pure water. The measured and derived thermodynamic properties for solutions were compared with data reported in the literature. The present results are consistent with most previous reported thermodynamic data for the pure water and H₂O + LiNO₃ solutions at low temperatures.     

On finite rank perturbations of definitizable operators

It was shown by P. Jonas and H. Langer that a selfadjoint definitizable operator A in a Krein space remains definitizable after a finite rank perturbation in resolvent sense if the perturbed operator B is selfadjoint and the resolvent set ρ(B) is nonempty. It is the aim of this note to prove a more general variant of this perturbation result where the assumption on ρ(B) is dropped. As an application a class of singular ordinary differential operators with indefinite weight functions is studied.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-[2-hydroxy-4(5)-methyl- and -5-(methylcyclohexyl)benzyl]morpholines as antioxidants for transformer oils

Aminomethylation of m- and p-cresols and of p-(1-methylcyclohexyl)phenol with formaldehyde and morpholine was studied. The products obtained were tested as antioxidant additives to T-1500 transformer oil.