Complex criteria for ecological assessment of the efficiency of intra-water-body processes

Modern ecological control methods of the state of hydro-ecosystems of river basins have been developed for ensuring their sustainable development, assessment of self-recovery properties of aquatic ecosystems that are a reflection of intra-water-body processes. For the first time ever the index of hydro-ecosystem development was proposed for conducting the ecological control of such systems.     

Estimating the efficiency of two algorithms for segmentation of digital radiation images of test objects

A mathematical model that describes digital radiation images of test objects is presented. Two algorithms are given for automatic segmentation of digital images distorted by additive noises. The efficiency of the algorithms is estimated based on mathematical modeling.     

A mathematical model of multichannel continuously scanning systems for digital X-ray analysis

A mathematical model of continuously scanning systems for digital X-ray analysis is developed. The systems contain a linear array of detectors that can be used not only in systems of radiation sources with an anisotropic angular distribution and a nonuniform distribution of the quantum yield over the focal spot but also in systems of detectors with nonuniform spatial sensitivity to incident radiation. The systems also make it possible to normalize the records of the radiation image of a tested object and perform digital filtering of the results.     

The Upper Resolution Threshold of Digital Radiographic Scanning Systems

The upper resolution threshold in the scanning direction has been determined for scanning digital radiographic systems containing a line of detectors with a nonuniform spatial sensitivity to radiation incident along the scanning direction.     

Comparative Analysis of Various Definitions of the Concept of Effective Atomic Number of Material of a Multicomponent Object

Comparative analysis is provided for various definitions of the concept of effective atomic number as applied to the material of a multicomponent object. Definitions in which radiation is and is not taken into account explicitly have been considered. Results of calculating the effective atomic numbers of various substances are presented on the basis of the definitions considered. New formal definitions are proposed for this concept when X-raying a multicomponent object with polychromatic radiation.     

Identification of materials in X-Ray inspections of objects by the dual-energy method

The state-of-the-art, application experience, and trends in further perfection of the dualenergy method as used in digital-radiography and X-ray computed-tomography systems intended for nondestructive testing and screening of objects are reviewed.     

Electronic transition,ferroelectric and thermoelectric properties of bismuth pyrostannate Bi2(Sn0.85Cr0.15)2O7

The ferroelectric properties of bismuth pyrostannate Bi₂(Sn_0.85Cr_0.15)₂O₇ in the high-temperature region are established. The linear thermal expansion coefficient, electrical resistance, impedance, I?V characteristics, capacitance, loss-angle tangent, charge, and thermopower of the investigated material are measured in the temperature range of 300?700 K at frequencies of 10²?10⁶ Hz. Anomalies of the thermal expansion coefficient and hodograph spectrum variation in the region of polymorphic phase transitions are observed. The high resistance and change of the hopping conductivity for the tunnel-emission are found. The hysteresis in the electric field dependence of polarization is established. The change in the thermopower sign with temperature is revealed. The obtained experimental data are explained in the framework of the model of migration polarization by charged chromium ions.