[en] In the spring of 1992 a survey of the contamination of cesium 137 in several links of the aquatic food chain started for the area just outside the 30 km zone of the electric power plant in Chernobyl. Samples were collected from the Kiev reservoir and in an old arm of the river Pripyat. Samples of 7 types of fish, macrofauna, zooplankton and water have been analyzed. Attention is paid to the relation between the weight of the fishes and the ¹³⁷Cs concentration in the fish. The highest concentration was found in fish of prey (perch and pike)

[en] A method for the production of high-quality radiation-resistant silicon-on-sapphire structures through the fabrication of a layer of nanopores in sapphire by helium ion implantation, i.e., by creating charge-carrier recombination centers, is proposed. In this case, the quality of the silicon layer is simultaneously improved. The problem of the thermal stability of the pores is discussed with the aim of analyzing the possibility of producing a microcircuit on the resultant modified silicon-on-sapphire sample. The layer of pores possesses a large total surface area and, hence, decreases the lifetime of charge carriers generated during irradiation of the operating microcircuit. This effect reduces the charge at the silicon-sapphire interface and improves radiation resistance

[en] A database of TFs for ⁹⁰Sr and ¹³⁷Cs for crops from different Russia soils was developed. Among the key factors influencing TFs, soil properties and biological properties of crops were important. The differences of ¹³⁷Cs TFs for different soil types are up to 28.1 times for barley and 5.2 times for cabbage. The differences between barley and cabbage in the accumulation of radionuclide are from 1.1 to 7.0 times. Differences in means of TFs ⁹⁰Sr were 6.4 times for barley and 5.5 times for cabbage. The differences between barley and cabbage in the accumulation of radionuclide varied from 1.1-2.0 times. The accumulation of ⁹⁰Sr by crops was higher 2.6-14.3 times than that of ¹³⁷Cs for barley and 8.1-32.0 times for cabbage. Soil characteristics that largely influence the accumulation of radionuclides by plants were identified. Transfer factors were used for radioecological classification of soils. On the basis of the statistical processing of experimental data two schemes of soil classification have been developed based on ¹³⁷Cs transfer factors in barley and three schemes of soil classification based on the rate of ⁹⁰Sr uptake by plants. (author)

[en] The effect of He⁺ ion implantation and subsequent annealing on the silicon-on-sapphire microstructure is studied by transmission electron microscopy and X-ray diffraction analysis. It is established that He⁺ ion implantation leads to the formation of defects in the Si layer and α-Al₂O₃, while subsequent annealing causes dissociation of radiation defects in Si and formation of nanopores in α-Al₂O₃. The effect of implanted-ion dose and annealing temperature on the parameters of the porous α-Al₂O₃ layer and structural quality of the Si layer is investigated.

[en] The Gibbs energies of solvation of 2,2'-dipyridyl (2,2'-Dipy) in methanol (MeOH), acetonitrile (AN), dimethylsulfoxide (DMSO), and N,N-dimethylformamide (DMF) are calculated via quantum chemical modeling. Estimates are made for the contributions from universal and specific types of interaction between the molecules of 2,2'-Dipy and the solvent to the change in the Gibbs energies of solvation of the amine when MeOH is replaced with AN, DMSO, and DMF.

[en] The enthalpies of solvation of piperidine (Ppd) in methanol (MeOH), ethanol (EtOH), N,N‑dimethylformamide (DMF), and dimethylsulfoxide (DMSO) are calculated by means of quantum-chemical modeling. The enthalpies of solvation of Ppd in EtOH and DMF are determined calorimetrically. The energies of Ppd solvation in aprotic solvents is found to be generally governed by universal types of interactions between amine and solvent molecules. The energy contributions from both universal and specific types of interactions to the overall enthalpy of Ppd solvation are determined in amphoteric MeOH and EtOH.

[en] During post Chernobyl radiation monitoring of water ecosystems made by the Complex Radioecological Expedition of the Russian Academy of Sciences in 1992, a lake with abnormal high ¹³⁷Cs contents in fish muscles was discovered in the Bryansk area. The concentration of ¹³⁷Cs in fish muscles from this lake is about a hundred times higher than in fish from other lakes in this area and even higher than in fish from the Cooling Pond of the Chernobyl NPP. This lake is called Kojanovskoe. It was suggested to investigate this phenomenon in the frame of the ECP 3 project. During 1993-1995 the ichthyofauna of the lake, the fish feeding specificity and the ¹³⁷Cs contents in fish muscles in comparison with fish from other water bodies was investigated. Some suggestions about reasons for the phenomenon are made. An idea to organize an international radioecological reserve on the lake Kojanovskoe is put forward

[en] A quantum chemical study of the structure of different molecular configurations of 18-crown-6 ether (18C6) in the free state, as well as in methanol, ethanol, dimethylsulfoxide, dimethylformamide, and acetonitrile media is performed using the GAUSSIAN 03 software package in the B3LYP version of the electron density functional theory using the cc-pVTZ basis set. The structure of molecules in the solvated state is studied by means of a self-consistent reaction field in the polarizable continuum model (PCM). Based on the calculation results, it is concluded that the configuration of the macrocycle of the C_i symmetry is in all cases the one most stable. The geometrical parameters and the charges on the atoms in the free and solvated states are calculated for this configuration of 18C6. To provide details of the intermolecular interactions between the solvent and solute molecules in the studied solvents, enthalpies of solvation ∆_solvH⁰(18C6) are calculated via quantum-chemical simulations using the PCM model. It is established that the solvation energy of 18C6 in alcohols is mostly determined by the universal interactions between the crown-ether and solvent molecules, and the contributions from the universal and specific interactions to the solvation enthalpy of the macrocycle are virtually equal in aprotic solvents.

[en] Discrete model (local chains approach) reveals the influence of heterogeneity of structure on the movement of a helium atom in the form of a soliton Frenkel-Kontorova. The transition to the field form of this equation - to the Klein-Fock-Gordon equation or, simply, to the sine-Gordon equation, allows us to calculate the diffusion coefficient of such a soliton, taking into account the collective nature of the movement of the atom and the accompanying reversible displacements of the atoms of the environment through the medium in the form of a soliton and taking into account the details of the structure of nanostructures. (paper)

[en] Targets made of ITER-grade 316L(N)-IG stainless steel and Russian-grade 12Cr18Ni10Ti stainless steel with a close composition were exposed at the QSPA-T plasma gun to plasma photonic radiation pulses simulating conditions of disruption mitigation in ITER. After a large number of pulses, modification of the stainless-steel surface was observed, such as the formation of a wavy structure, irregular roughness, and cracks on the target surface. X-ray and optic microscopic analyses of targets revealed changes in the orientation and dimensions of crystallites (grains) over a depth of up to 20 μm for 316L(N)-IG stainless steel after 200 pulses and up to 40 μm for 12Cr18Ni10Ti stainless steel after 50 pulses, which is significantly larger than the depth of the layer melted in one pulse (∼10 μm). In a series of 200 tests of ITER-grade 316L(N)-IG ITER stainless steel, a linear increase in the height of irregularity (roughness) with increasing number of pulses at a rate of up to ∼1 μm per pulse was observed. No alteration in the chemical composition of the stainless-steel surface in the series of tests was revealed. A model is developed that describes the formation of wavy irregularities on the melted metal surface with allowance for the nonlinear stage of instability of the melted layer with a vapor/plasma flow above it. A decisive factor in this case is the viscous flow of the melted metal from the troughs to tops of the wavy structure. The model predicts saturation of the growth of the wavy structure when its amplitude becomes comparable with its wavelength. Approaches to describing the observed stochastic relief and roughness of the stainless-steel surface formed in the series of tests are considered. The recurrence of the melting-solidification process in which mechanisms of the hill growth compete with the spreading of the material from the hills can result in the formation of a stochastic relief