Determination of U,Ra and Th in waters from the Danube Delta area

The methods applied for natural uranium, radium and thorium determinations in water samples are shortly presented together with some preliminary results. The measurements will be continued as part of an extended program of ecological study of the Danube Delta area.     

Investigation of the reaction order for nucleophilic substitution of dialkyl methylphosphonates by alkoxides

The rate of nucleophilic substitution at the phosphorus centre of dialkyl methylphosphonates by methoxide and ethoxide has been studied to investigate the possible involvement of hexacoordinated phosphorus species in this reaction. For alkoxide concentrations less than ca. 1.5 M the rate increases with the square of alkoxide concentration. However, consideration of the activity of the alkoxides, represented by an appropriate acidity function, reveals that only one equivalent of alkoxide is involved in the rate-determining step. Thus, there is no requirement to invoke the intermediacy of a hexacoordinated species in the reaction pathway. © John Wiley & Sons, Inc.     

Scattering of scalar fields by rough surfaces. Accounting for multiple scattered waves

Physical Engineering Institute, Moscow. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 5, pp. 565–574, May, 1991.     

Electron Energy Distribution Functions in CO2 Laser Mixture: The Effects of Second Kind Collisions from Metastable Electronic States

Electron energy distribution functions (eedf) in CO₂ laser discharge (He—CO₂—N₂—CO mixture) have been calculated by solving the Boltzmann equation in the presence of given concentrations of excited (vibrational and electronic) states. The results show a well structured eedf as a result of second kind collisions coming from metastable electronic states of N₂ and He as well as a strong dependence of rate coefficients for CO₂ dissociation and for the ionization of the different species.     

On integration of constraints imposed on a system of conservation laws by the second law of thermodynamics

In this paper the explicit form of such systems of conservation laws, which imply an additional conservation law, is determined. It is shown that there are many classes of such systems besides the symmetric conservative ones. From the point of view of phenomenological thermodynamics, this result can be interpreted as a sort of integration of the constraints imposed by the second law of thermodynamics.     

Efficacy of the accent method of voice therapy

The management of voice disorders may follow one of four approaches: surgical, pharmacological, technical aid, and/or voice therapy. The latter approach offers a wide variety of techniques, each based on certain theoretical beliefs. One of these techniques is the Smith Accent Method. The principles and goals of the Accent Method are presented. The results of its application are discussed. This technique proved effective for cases of functional voice disorders, vocal nodules, and some degrees of vocal fold paralysis.     

Supersymmetric nonlinear graviton

Branch of Theoretical Problems, USSR Academy of Sciences, Translated from Funktsional'nyi Analiz i Ego Prilozheniya, Vol. 26, No. 1, pp. 89–90, January–March, 1992.