Synthesis of 1-substituted 2-azaspiro[4.5]deca-6,9-dien-8-ones and 2-azaspiro[4.5]deca-1,6,9-trien-8-ones by condensation of 2,6-dimethylphenol with isobutyraldehyde and nitriles

1-Substituted 3,3,7,9-tetramethyl-2-azaspiro[4.5]deca-6,9-dien-8-ones and 3,3,7,9-tetramethyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones were synthesized by three-component condensation of 2,6-dimethylphenol with isobutyraldehyde and nitriles in concentrated sulfuric acid.     

On solutions of the problem in stresses with the use of Maxwell stress functions

The spatial problems of elasticity are mainly solved in displacements [1, 2], i.e., the Lamé equations are taken as the initial equations. This is related to the lack of general solutions for the system of basic equations of elasticity expressed in stresses. In this connection, a new variational statement of the problem in stresses was developed in [3, 4]; this statement consists in solving six generalized equations of compatibility for six independent components of the stress tensor, while the three equilibrium equations are transferred to the set of boundary conditions. This method is more convenient for the numerical solution of problems in stresses and has been tested when solving various boundary value problems. In the present paper, analyzing the completeness of the Saint-Venant identities and using the Maxwell stress functions, we obtain a new resolving system of three differential equations of strain compatibility for the three desired stress functions φ, ξ, and ψ. This system is an alternative to the three Lamé equilibrium equations for three desired displacement components u, v, w and is simpler in structure. Moreover, both of these systems of resolving equations can be solved by the new recursive-operator method [5, 6]. In contrast to well-known methods for constructing general solutions of linear differential equations and their systems, the solutions obtained by the recursive-operator method are constructed as operator-power series acting on arbitrary analytic functions of real variables (not necessarily harmonic), and the series coefficients are determined from recursive relations (matrix in the case of systems of equations). The arbitrary functions contained in the general solution can be determined directly either from the boundary conditions (the obtained system of inhomogeneous equations with a right-hand side can also be solved by the recursive-operator method [6]) or by choosing them from various classes of analytic functions (elementary, special); a complete set of particular solutions can be obtained in the same function classes, and the coefficients of linear combinations of particular solutions can be determined by the Trefftz method, the least-squares method, and the collocation method.     

Some transformations of 2-(2-hydroxy-3-chloropropylthio)benzothiazole

The reaction of phenyl isocyanate and acetic anhydride with 2-(2-hydroxo-3-chloropropylthio) benzothiazole was studied. At 140 °C, this benzothiazole cyclizes with the formation of quaternary salt which readily reacts with hydrazine and alkali.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1483–1484, November, 1983.     

A sol-gel method for synthesizing porous iron-aluminum oxide substances and regulating their physicochemical characteristics

Mixed oxides of iron and aluminum have been prepared by a sol-gel method. Measurements have been made on the texture, phase composition, and rate of reaction with hydrogen. There are substantial differences in the iron-aluminum ratio between the surface and the bulk. Hydrothermal treatment of the hydrogel favors a more uniform element distribution on the surface. Pisarzhevskii Physical Chemistry Institute, Ukrainian National Academy of Sciences, 252039 Kiev, Prospekt Nauki 31. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 2, pp. 120–123, March–April, 1997.     

Separation of C1–C4 hydrocarbon gases on impregnated liquid membranes

Diffusion plays an important role along with complexation in the separation of C₁–C₄ hydrocarbon gases on copper-containing impregnated liquid membranes. The partition factor changes as the process goes from nonsteady-state to steady-state. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 34, No. 3, pp. 191–195, May–June, 1998.     

Effect of the conditions of structure formation on the physicochemical properties of ozonated shungites

It was investigated the influence of ozone on the physicochemical properties of shungites (type 1) (75–98% C) from Nigozero and Chebolaksha deposits (Karelia) formed by hydrothermal (Nigozero) and high-temperature (Chebolaksha) processes. Ozonation was found to affect the specific surface and the total pore volume of shungites considerably. The pore size distribution pattern depends on the volume morphology (texture) of the sample. An increase in the temperature and pressure during the structure formation of shungite (Chebolaksha) led to a shift of the maximum on the distribution pattern towards the formation of mesopores. The size distribution of pores with the dominant contents of micro- and submesopores for both shungites correlated with the basic structural nanoelements of shungite carbon. The peculiarities of the ozonation of shungite nanocarbon found previously (the non-steady state vibrational kinetics of ozonation and the absence of carbon(II) oxide among the reaction products) were confirmed.     

Simultaneous separation of actinides and technetium from large volumes of natural water for their determination

Journal of Radioanalytical and Nuclear Chemistry - Monitoring of radionuclide concentration in natural samples is important for assessing environmental safety. The low concentration of long-lived...     

Viscosity of Cellulose Ether Solutions as Influenced by Mechanical Impact Intensity

Structuring and viscosity of solutions of cellulose derivatives as influenced by mechanical treatment under high shear stresses were studied.