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The influence of physical parameters, which describe the St. Petersburg surface properties in the WRF-ARW model, on the forecast of surface meteorological elements is studied. The results are estimated for the cases June 14-22, 2015, when intense positive temperature anomaly occurred in St. Petersburg in comparison with the surroundings. The parameters were chosen from the analysis of similar studies for several cities of the world. Experiments with serial variations in the parameters selected showed that decrease in the surface albedo, soil moisture content, and surface emissivity and an increase in the roughness length improved the forecast quality for the city in comparison with a control experiment. In final experiment, the concurrent variations in the urban surface physical parameters, in accordance with the results of serial experiments, significantly improved the simulation of the city’s thermal anomaly in the model. In the time periods corresponding to the intense urban heat island occurrence, the difference in the surface temperatures between the control and final forecasts could attain 2 °C for the St. Petersburg model area. Under certain synoptic conditions, the variations in the urban surface parameters in the model affect the forecast of meteorological fields within a radius of 150 km from the center of the metropolis.

The conditions for applicability of the Bouguer-Lambert-Beer law for aerosol clouds with particles much larger than the photon wavelength are derived in the form of an analytical formula. The corrections to this law due to diffraction scattering and the geometry of a measuring device are estimated. The resulting formula is useful for processing single experiments that cannot be repeated for some reason.

The limiting sensitivity of a method for detecting vapors of nitrocompounds in the atmosphere based on laser fragmentation/laser-induced fluorescence is estimated in calculations with the developed kinetic model of the LF/LIF process. The calculations take into account the influence of atmospheric nitrogen dioxide as a limiter of the sensitivity of the method when operating in a real atmosphere. It is shown that if the concentration of nitrogen dioxide in the atmosphere does not exceed 10 ppb, the maximum detectable concentrations of nitrobenzene and o -nitrotoluene vapors are ppb-level. It was also shown that the one-color excitation method usually used for the detection of nitrocompounds does not allow attaining the maximum efficiency of the LF/LIF process.

The paper describes the results related to variations in precipitable water vapor at the peak Terskol site. Applying MPM Liebe model and MOLIERE model and using JPL and HITRAN configurations, we estimated optical thickness of the atmospheric column above peak Terskol for 100, 150 and 225 GHz.

The authors propose a new approach to processing multichannel data on surface waves to enhance interference immunity of dispersion curves of the Rayleigh wave phase velocities determined from the analysis of motion paths of particles in the time-and-frequency domains based on the S-transform applied to the two-component seismic records. Efficiency of the approach is demonstrated as a case-study of processing of the synthetic and field data of shallow seismic investigations.

Rock testing data are used to determine proper bases of tensors where strains along the unit vectors are only governed by stresses along them. The obtained curves along the unit vectors-one curve is proportional and the other curve is nonlinear, and both are independent of loading history and mechanism-are used to solve geomechanical problems. In planar post-limit deformation, these curves lead to a hyperbolic system of differential equations with four real functions and four relations to find four unknown functions: average stress, maximum shear stress, rotation angle and angle of directions of principal stress tensor axes. For finding their boundary values, the Cauchy stress vector and the displacement vector are assigned simultaneously at one and the same boundary. The authors propose an algorithm of finding these four functions within the post-limit deformation domain.

Chagan Aobao Iron-Zinc Mine is taken as the research case, and the characteristic angles of overlying strata collapse caused by underground mining are recommended. The research results can provide guidance for disaster prevention and control of rock collapse.

The authors have developed a regression model of coal freezing adhesive strength in transportation on equipment made of steel and rubber. The model uses the response surface methodology and the coal freezing adhesive strength tests. The influence exerted on the adhesive strength by the external conditions, as well as by the coal and transportation surface properties is analyzed.

The authors describe numerical investigations of hydraulic fractures in boreholes with branches (intersecting boreholes). The directions of growing fractures were determined in the static problem solution by the criterion of maximum tangential stresses and in the quasi-static three-dimensional formulation with the analysis of fracture of an elastic uniform medium using the cohesive failure mode and the extended finite element method. It is found that some geometrical parameters of the starter fracture and the stress state nonuniformity have influence on the growth direction and shape of the created fractures. The X-shaped starter fracture, which simulates branching and intersections of boreholes, is preferable over the disc-shaped starter fracture in local control of hydraulic fracture orientation in rock mass under nonuniform compression.

The spotlight is on the stress patterns in oil and gas reservoirs and in enclosing rock mass containing displaced fractures (disjunctive cleavages). The mathematical modeling finds out that with the decreasing reservoir pressure in rock mass subject to elastic deformation, the shearing stress raisers arise on the surfaces of displaced fractures and can make an initially impermeable fracture to become fluid-conductive. Creeping widens the fractures, which also contributes to hydrodynamic connection between a pay zone and the upper- and low-lying permeable strata. This process of formation of the permeable channels in rock mass can be an explanation for the mechanism of oil and gas reservoir infeed with fluid flows from the lower-lying fluid-bearing strata.