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Purpose. The identification and hygienic assessment of main sources of natural exposure of the population of the city of Moscow. Ranking areas of the territory of the city according to the potential radon hazard. The elaboration of criteria for the radon hazard of the territory. Material and Methods. There are provided data of the radiation control of the territory of the city (g-spectrometry, the determination of the activity of natural radioactive substances, including samples of the soil and in lithological layers, the density of radon flux (DRF) from the soil), surveys of residential and public buildings for different purposes according to the content of the equivalent equilibrium volumetric activity of radon (EEVAR). Results. There is presented the analysis of materials concerning the evaluation of results of radiation control (the of 226Ra activity in different types of soils, the levels of the DRF from the soil, the concentration of radon in newly constructed and operated buildings, various premises) in administrative districts of Moscow. There was executed the comparison of the spatial distribution of the fields of DRF and EEVAR values in basements and premises of buildings exceeding 200 Bq/m3. There was performed the analysis of criteria of radon-dangerous of areas. Conclusion. There were substantiated criteria and zones of the aggravated radon danger within the city according to following indices: 226Ra content in soils, DRF on soil surfaces, EEVAR in premises, annual dose of the radiation. Performed long-term studies allowed to rank the territory of Moscow into various zones of the radon danger and allocate most dangerous areas (South-Eastern Administrative District, South Administrative District, South-Western Administrative District). There was obtained a map of the interrelationship of the spatial distribution of anomalous DRFs from the soil surface and elevated EEVA values in premises. Ranging of areas for the radon danger permits to significantly optimize the system of radiation control and measures for radiation protection of the population.

Materials on the work of interdepartmental expert councils for 2011-2014 are presented. The results of the analysis of the conditions and methodological approaches of the establishment by the expert councils of the causal connection of diseases, disability and death of citizens exposed to radiation factors due to the Chernobyl disaster are shown. Data on the number and structure of the taken measures are presented, and the place of the expertise in the system of post-emergency sanitary and hygienic measures is shown.

Two algorithms for the automatic determination of flaw parameters during ultrasonic testing of welded joints with a high level of structural background noises are considered. The experimental data collected in the course of automated ultrasonic testing (AUT) using Avgur series with coherent processing of data (Avgur 4.2 and Avgur 5 systems) and the results of the assessment of nondestructive testing data are used. The first algorithm is used to identify zones where flaws may be located. This algorithm is applied after running AUT in the “search” mode. If the parameters of the algorithm application are selected properly, this algorithm makes it possible to determine the coordinates and the conventional length of the identified flaws. The second processing algorithm is intended to determine the flaw’s actual length and height. For its operations the algorithm uses the images obtained from coherent data processing. Results of testing methods for automatic (computer) determination of flaw parameters are cited. These results are obtained by the Avgur system during testing of austenite welded joints in stainless-steel pipes with a diameter of 325 mm and in perlite-steel pipes of various diameters.

The main properties of infrared stimulated electronic Raman scattering (SERS) at the 62 S 1/2-72 S 1/2, 3/2 transitions in cesium atoms are studied theoretically and experimentally as functions of the atomic concentration, which was varied from 1011 to 1016 cm−3. It is found that the efficiency of generation of Stokes radiation strongly depends on one-photon absorption of the pump radiation tuned near frequencies of the 62 S 1/2-72 P 1/2, 3/2 transitions. By using the equation for the density matrix, which describes the evolution of a three-level system, the theory of resonance excitation of IR radiation upon one-photon absorption at an adjacent transition is developed. The theory describes well the main features of IR SERS in alkali-metal vapors.

Solar wind plasma and magnetic field observations from multiple spacecraft can be used to separate temporal and spatial variations and to determine the accuracy of predictions of solar wind conditions near Earth based on distant-spacecraft measurements. The study of correlations between the ion fluxes measured by three spatially separated spacecraft (IMP 8, WIND and INTERBALL-1) was one of the first steps in this direction. This paper describes a complex multifactor analysis of different physical, geometrical, and statistical parameters that control such correlations (considered separately and in combination). A linear-regression and an artificial neural network techniques are used for this analysis. The analysis is applied to an extensive array of correlation coefficients for the ion flux in the solar wind and provides estimates of the relative significance of the factors that control these correlation coefficients. The study shows that the most influential parameters are the solar wind density and the standard deviations of solar wind density, solar wind velocity and interplanetary magnetic field. This set of parameters permits us to develop a sufficiently accurate (with a relative error of less than a few per cent) quantitative model for the correlation between the ion fluxes measured on two spatially separated spacecraft.

Experimental data concerning superradiant emission from the LaF3 medium doped with impurity praseodymium ions are presented in the cases of a free medium and when the medium is placed into an optical resonator. The spike structure of superradiance is registered and studied. When the medium is placed inside a cavity, a new channel of energy removal by superradiance related to the cavity mode appears; the old noncavity channels are preserved. The duration of superradiance in the cavity channel is decreased, and regular modulation arises. These peculiarities of superradiance induced by the presence of an optical resonator are explained.

The causes of widely met diagnostic errors in pregnancy determination are considered. Several clinical cases of wrong diagnosis connected with pathologically changed female organism organs are described, as well as a case of false (suggestive) pregnancy is presented. The cause and effect relations of the origin of the pathologic symptomcomplex of false pregnancy are analyzed. The causes of diagnostic errors in pregnancy differentiation are explained, and the conditions are emphasized when such errors are excluded.

Many real-life problems require discovering temporal correlations between behavior of a complex object and relatively rare events initiated by this behavior, or correlating with it. It is supposed that an event is preceded by some combination of the values describing the object in a known range of delays. In this paper, a neural network-based method for analyzing such objects is proposed with the view of revealing the morphological and dynamic features that initiate an event or precede its occurrence.

Ultrasonic scanning with coherent data treatment is a very promising method for nondestructive inspection of welded pipeline joints. This method requires processing of high-dimensional raw data obtained from ultrasonic probes. In practice, the raw data have a substantial noise level. Besides, acoustic contact between scanning probe and inspected pipe is sometimes lost, which may cause gaps in data, resulting in performance degradation during further analysis. This paper describes a neural network system providing noise removal and gaps filling in ultrasonic data.

The paper presents the experimental results on temporal characteristics of coherent stimulated emission on the 3PO-3H6 transition of Pr3+ doped into the LaF3 matrix while turning the pumping frequency in the vicinity of 3H4-3PO transition. The stimulated emission was generated in the modes both with and without an external resonator. It was found that the emission duration could be up to 2 μs and consisted of train of spikes. Simultaneously the fluorescence emission was observed on the 3PO-3H4, 3H5j, 3H6, 3F2 transitions Pr3+, which also had a complicated temporal form.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Many practical tasks require discovering interconnections between the behavior of a complex object and events initiated by this behavior or correlating with it. In such cases it is supposed that emergence of an event is preceded by some phenomenon - a combination of values of the features describing the object, in a known range of time delays. Recently the authors suggested a neural network based method of analysis of such objects. In this paper, the results of experiments on real-world data are presented. The method aims at revealing morphological and dynamical features causing the event or preceding its emergence.

The paper reports the experimental results on the temporal characteristics of coherent stimulated emission on the 3P 0-3H 6 transition of Pr3+ ion dopped into the LaF3 matrix while tuning of pumping frequency in the vicinity of the 3H 4-3P 0 transition. The generation pulse duration was found to be about 10 ns, and it was delayed by 3-4 ns relative to the beginning of the pumping pulse at the exact resonance. It was observed that as the detuning increased, the shape of the coherent stimulated emission pulse changed and its delay increased up to 10ns. A theoretical interpretation of the experimental results observed is proposed.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Radiation and environmental safety concerning the handling of nuclear submarine reactor compartments is the most important problem and requires steady attention and thorough investigation among the common list of unsolved problems, related to decommissioning, storage and utilization of Russian nuclear submarines, since the reactor compartments are the potential sources of radiation incidents. Total radioactivity, accumulated in the reactor compartment (with spent nuclear fuel) discharged is estimated as around 80,000 Ci for a nuclear submarine of the first generation 5 years after reactor shutdown. Spent fuel discharge removes completely the problem of reactor compartment nuclear hazard, but not the risk of radiation impacts on region ecology. After discharging the spent fuel, in each reactor compartment there is around 300 tonnes of radioactive materials of different radiation levels and types, which constitute the above radioactivity. Accordingly, the process of transfering the reactor compartments to environmentally safe state should allow to reduce (or eliminate at all) environmental risk for the region, where the nuclear submarines to be utilized are transported, or planned to be stored for long time, to the level as low as possible.

A novel algorithm for creation of a hierarchical structure of neural network classifiers for classification of large databases is suggested. Each node of the hierarchical tree is a multilayer perceptron trained by the algorithm combining self-organization with supervised learning. Thus, the problems of clustering and classification for a given node are solved in concord. Also, it allows the a priori information on similarity of grouped patterns to be naturally taken into account. The algorithm performance has been tested on model data and on real-world problems.

The major issues to be dealt with when decommissioning nuclear submarines (NSs) are the choice of the concept and, later, the development of a process for handling reactor compartments (RCs). RCs feature extremely compact arrangement of large-sized power equipment and systems, limited free space for dismantling work, high radiation background in some RC rooms. The afore-named conditions in RCs pose the problem of finding the optimal procedure for RC recycling, which, on the one hand, would provide the maximum possible efficiency and, on the other hand, the maximum possible safety, i.e., would lead to minimum radiation exposure to personnel and have a negligibly small effect upon the population and the environment. The principal radiation factors that determine the radiation safety when handling RCs at all stages of NS decommissioning are as follows: total amount of the activity accumulated in the reactor facility (RF); the activity distribution over RF equipment and structures; the forms in which the accumulated activity exists; the radionuclide composition and decay of the activity accumulated in RF; the radiation situation at the nuclear submarine and dose commitments associated with the work to be performed; possible radioactive waste; impact of the chosen handling technology upon population and environment.

Mass decommissioning of domestic nuclear submarines (NSs) and the start of recycling have given rise to a number of complicated scientific engineering and economic problems. Among the most urgent ones causing ever increasing concern of the population are the issues related to handling radioactive equipment from the reactor compartments (RCs). Without a solution of this problem the process of nuclear submarine recycling cannot be completed. This is due to potential risk to the environment due to NSs in the state of “decay storage” (temporary waterborne storage) with unloaded spent nuclear fuel (SNF) and cut-out reactor compartments, which are SNF-free, but contain high-level equipment and materials.

A single-transducer fast-neutron spectrometer was used to measure the spectra of fast pile neutrons after passing through polyethylene layers of different thicknesses. The results of measurements at En>3 MeV show excellent agreement with data computed by the method of moments. At En