Radionuclide contamination of the LIRA faciliticies territory

Radiation situation at the LIRA site has been investigated. It served as a test site for 6 underground nuclear explosions. In comparison with background in the region the explosions caused a slight increase of the level of radionuclide contamination in the territory of the site. It was found that the release of ¹³⁷Xe and ⁹⁰Kr onto the surface is the main reason for formation of additional contamination with ¹³⁷Cs and ⁹⁰Sr. The peculiarities of the distribution and migration of the radionuclides in dependence on the relief and soil conditions are taken into consideration.     

Supramolecular systems based on 1-alkyl-4-aza-1-azoniabicyclo[2.2.2]octane bromides

The aggregation in aqueous solutions of alkylated 1,4-diazabicyclo[2.2.2]octanes of various hydrophobicity and their adsorption at the water-air interface were studied by tensiometry, conductometry, potentiometry, viscosimetry, and ESR spectroscopy. The parameters of adsorption, critical micelle concentrations, concentrations of free counterions (bromide ions), and degree of binding of the counterions with micelles were determined. The intensification of the micelle formation ability of the surfactants with an elongation of the alkyl fragment was shown. The effective radii of ensembles of the hexadecyl and octadecyl derivatives were determined by the dynamic light scattering method. A relationship between the concentration dependences of the size of micelles and their shape was established.     

Complex formation and self-association in the alkylated polyethyleneimine-calix[4]resorcinarene-chloroform system

Complex formation and self-association in the system alkylated polyethyleneimine-calix[4]resorcinarene-chloroform were studied by UV spectrophotometry, dilecometry, and light scattering. The constant of complex formation of polyethyleneimine with calixarene was found to depend on the hydrophobicity of the components of the system and presence of surfactants.     

Some peculiarities of the contamination with radionuclides and toxic elements of the Syrdarya river basin, Kazakhstan

Investigation of radionuclide and element composition of environmental objects such as soil, bottom sediments, water, vegetation sampled at the Syrdarya river basin in Kazakhstan is presented. Distribution and season variations of radionuclide content for various objects were studied. Main sources of Syrdarya river contamination were revealed: the tributaries Keles and Badam, Shieli uranium field. This revised version was published online in August 2006 with corrections to the Cover Date.     

Multiphoton transitions between energy levels in a current-biased Josephson tunnel junction

The escape of a current-biased Josephson tunnel junction from the zero-voltage state in the presence of weak microwave radiation is investigated experimentally at low temperatures. The measurements of the junction switching current distribution indicate the macroscopic quantum tunneling of the phase below a crossover temperature of T small star, filled approximately 280 mK. At temperatures below T small star, filled we observe both single-photon and multiphoton transitions between the junction energy levels by applying microwave radiation in the frequency range between 10 and 38 GHz to the junction. These observations reflect the anharmonicity of the junction potential containing only a small number of levels.     

Complexes of 1-alkyl-4-aza-1-azoniabicyclo[2.2.2]octane bromides with lanthanum nitrate. Micelle-forming and adsorption properties

Novel organometallic surfactants were synthesized from monoquaternized 1,4-diazabicyclo[2.2.2]-octanes of varied hydrophobicity [Alk = C _n H_2n+1, n = 14, 18] and lanthanum nitrates. The spectral, micelleforming, and adsorption properties of the synthesized compounds were studied by IR, ¹Н NMR and electronic spectroscopy, tensiometry, conductometry, and potentiometry. The critical micelle concentrations, counterionic micellar binding constants, and adsorption parameters at the water–air interface were determined and compared with the respective characteristics of the ligands and conventional amphiphiles.     

Aggregation Capacity and Complexation Properties of a System Based on an Imidazole-Containing Amphiphile and Bovine Serum Albumin

A complex of physicochemical methods was used to study the aggregation characteristics of an imidazolium-containing amphiphile and its ability for complex formation with bovine serum albumin (BSA). Tensiometry showed that adding BSA to the surfactant decreases the aggregation threshold of the system by a factor of 50. Dynamic light scattering established, that the size of the surfactant–BSA complexes depends on the size of the polypeptide (6–10 nm) and is independent on the concentrations of the surfactant and BSA. The Stern?Volmer constants and surfactant?protein binding constants were calculated from fluorescence spectroscopy data.     

Analogs of the Kolmogorov-Seliverstov-Plessner theorem for nonorthogonal function systems

For arbitrary function systems, the growth of partial sums is estimated depending on the growth of the corresponding Lebesgue functions. We prove analogs of the Kolmogorov-Seliverstov-Plessner convergence theorem for trigonometric series and the Kaczmarz convergence theorem for orthogonal series for arbitrary (nonorthogonal) function systems as well as for orthogonal-like and generalized orthogonal-like systems. Translated fromMatematicheskie Zametki, Vol. 67, No. 1, pp. 87–101, January, 2000.