Concentrations of Heavy Metals in the Upper Volga Bottom Deposits

The distribution of heavy metals in the Volga bottom deposits is studied. According to the degree of pollution with heavy metals, three stretches are singled out within the river reach under consideration. A drastic increase in Cu and Cd concentrations in bottom deposits is established. A close statistical correlation between Cu and Pb accumulation and the organic matter content of bottom deposits is revealed.     

Effective energy loss per electron-ion pair in proton aurora

Effective energy loss per electron-ion pair produced, <xi>(E ₀), as a function of a particle’s initial energy has been obtained for proton transport in the atmosphere. The influence of some transport parameters on the shape of <xi>(E ₀) has been studied. Comparisons with the case of electron transport and with other results were made. It has been shown that: 1. for E ₀>1 keV, <xi>(E ₀) varies within the range 30–36 eV; 2. as E ₀ increases the value of <xi>(E ₀) tries to attain an asymptotic value that is the same as for electrons (\approx35 eV); 3. <xi>(E ₀) strongly depends on the average energy of secondary electrons, but the energy distribution of secondary electrons is not as important. The range of possible changes in <xi>(E ₀) associated with discrepancies in cross sections has been obtained.     

On correlation between seismic velocity anisotropy and stressesin situ

Seismic velocity anisotropies measured in underground mines are compared within situ stress measurements in these mines. These underground data are also compared with seismic velocity anisotropies observed by large scale seismic sounding conducted from the earth's surface, The velocity anisotropies are about 10% and the data obtained by different methods on different scales and frequencies agree with each other. The directions of largest and smallest velocities coincide with the largest and smallest horizontal stresses, respectively. These results suggest that the direction and magnitude of stresses in potential mining areas could be estimated from velocity anisotropies observed in seismic prospecting of the area.     

Heterogeneous loss of OH on NaCl and NH4 NO 3 at tropospheric temperatures

The uptake coefficients () for OH radicals on some dry salts of tropospheric interest (NaCl and NH₄NO₃) have been investigated as a function of temperature using the flow tube technique combined with an EPR spectrometer as a detection method. The temperature dependence of -values measured over the temperature range 245–340 K can be expressed in Arrhenius form: ^OH_NaCl=(1.2±0.7)×10⁻⁵exp[(1750±200)/T] and ^OH_NH4NO3=(1.4±0.5)×10⁻⁴exp[(1000±100)/T]. These Arrhenius expressions lead to very similar -values (\approx4×10⁻³) for both salts studied at 300 K. It is shown that the heterogeneous OH sinks on solids aerosol play a very minor role in tropospheric chemistry in comparison with the homogeneous sinks.     

Upper Cretaceous deposits in the northwest of Saratov region, Part 2: Problems of chronostratigraphy and regional geological history

Problems of geochronological correlation are considered for the formations established in the study region with due account for data on the Mezino-Lapshinovka, Lokh and Teplovka sections studied earlier on the northwest of the Saratov region. New paleontological data are used to define more precisely stratigraphic ranges of some stratigraphic subdivisions, to consider correlation between standard and local zones established for different groups of fossils, and to suggest how the Upper Cretaceous regional scale of the East European platform can be improved. Considered in addition are paleogeographic environments in the study region during the Late Cretaceous epoch and principal stages of the regional geological evolution.     

An algorithm for on-the-fly K shortest paths finding in multi-storey buildings using a hierarchical topology model

This article presents an approach to computing K shortest paths in large buildings with complex horizontal and vertical connectivity. The building topology is obtained from Building Information Model (BIM) and implemented using directed multigraphs. Hierarchical design allows the calculation of feasible paths without the need to load into memory the topology of the entire building. It is possible to expand the graph with new connectivity on-the-fly. The paths calculated may be composed of traversable building components that are located inside the buildings or those that are both inside and outside buildings. The performance (computational time and heap size used) is optimized by using the appropriate collections (maps, lists and sets). The proposed algorithm is evaluated in several use-case scenarios – complete graphs and real building environments. In all test scenarios, the proposed path finding algorithm is faster and uses less memory when compared to the fast version of the Yen’s KSP algorithm. The proposed approach can be successfully used as a first level of coarse-to-fine path finding algorithms.     

Simulation of Formation and Melting of Ice in the Kerch Strait

The optimized (all iterative procedures are excluded) local one-dimensional thermody-namic model of the formation and melting of ice is proposed. The numerical computation of ice cover evolution in the Kerch Strait under the influence of thermodynamic factors for the period of 5 months is carried out for the real conditions of winter of 2011/12. Thec results agree well with the available obser-vational data on the timing of ice formation and on ice thickness in the southern part of the Sea of Azov and in the Taman Bay. In combination with the full three-dimensional hydrodynamic model and taking into account diurnal variations in external factors, the model simulates the spatial distribution of ice cover formation.