Home – Home – Jornals – Journal of Mining Sciences 2013 number 3

Large array of simultaneous measurements of spectral aerosol extinction coefficients b(l) (surface layer) and the aerosol optical thickness t ^а(l) of the atmosphere in the range l = 0,45¸3,9 μm is analyzed. In many cases, situations revealed, where the height of the homogeneous aerosol atmosphere Н ₀(l) = t ^а(l)/b(l) increases with increasing wavelength in the infrared region of the spectrum. It is suggested that such anomalous spectral dependence of the H ₀(l) is associated with the presence in the boundary layer of clear atmosphere of the visually indistinguishable coarse aerosol of different nature (soil or liquid-drop). It is shown that for detection of such aerosol in the cloud-free atmosphere it is necessary to perform simultaneous measurement of b(l) and t ^а(l) at wavelength l > 2 μm.

Transient response in the near-field scattering of a laser pulse on a micron-sized spherical dielectric particle is considered. The spatial area constituting the photonic jet is theoretically investigated and the analysis of the temporal dynamics of jet dimensions as well as of its peak intensity is presented. The jet evolution scenario is shown to include generally the non-resonant and resonant temporal phases; during each phase the photonic jet can change its spatial form and intensity.

The results of experimenatl study of drop movement and breakdown in a skirling viscous flow at small Reynolds numbers are presented. For the first time it is shown that at small Reynolds numbers the drop breakdown is observed at some critical Bond number values. The dependence of the critical Bond number value corresponding to drop shape instability by Rayleigh–Teylor mechanism from drop movement regime at Reynolds numbers Re = 0.03 ¸ 0.84 is experimentally found.

We derive the Mueller matrix for the molecular scattering of light. Conclusion is based on the concept of independence of the density and anisotropy fluctuations in gases at low pressures and averaging over equiprobable orientations of molecules. A comparison with some of the published matrices is made.

Light scattering matrices of truncated plate-like ice droxtals are calculated within the framework of geometric optics for the case of quasi-horizontal orientations. New halos appear because of truncated facets of ice crystal. The main quantitative properties of the brightest halos are obtained. All 16 elements of the scattering matrix are analyzed in terms of modified scattering matrix. A comparison of the matrices for the truncated droxtals and the hexagonal plates is carried out.

The analysis of vertical distribution of greenhouse gases is carried out according to measurements of authors and to references. Comparison of the received results with most frequently used models is carried out. It is shown, that models are substantially outdated and require a new development.

Using aerosol optical depth (AOD) and active fire (FIRMS) data obtained with the help of MODIS instruments (both Aqua and Terra satellites) and the upper-air network data we present an analysis of spatial-temporal evolution of smoke plume during the period of the mass wildfires over the territory of European Russia (ER) in summer 2010. The relationship between the structural features of the plume with the large-scale dynamics is established. The smoke plume evolution in the metropolitan area is described in detail. Various statistical characteristics of AOD spatial and temporal variations are calculated. An estimation of the mass of smoke is presented. The radiation effects of smoke aerosols are evaluated. The time evolution of the regionally averaged aerosol radiative forcing on the top and the bottom of the atmosphere is described. Spatial distribution of radiative effects over the territory of ER in the period of extreme smoke pollution is presented. A statistically significant correlation between the active fire data and the wind is found. During wildfires period the validation of the AOT obtained by MODIS instrument with the AOD obtained by the CIMEL sun photometer, operated at the AERONET station Zvenigorod, was performed.

Results of the analysis of spatial-temporal distribution of atmospheric total moisture ( W ) and total ozone over Western Siberia, Eastern Siberia, Primorye, and Japanese sea are presented. The evaluation of total moisture was made, using data of radiosonde and satellite measurements. Satellite measurements agree satisfactorily in summer; in winter they disagree more then by two orders of magnitude.

The factors influencing on rainfall production in the Selenge River basin are investigated, using observational data about atmospheric precipitation, surface air temperature, and NCEP/NCAR Reanalysis 1 data about vertical velocity and precipitable water vapor. The contribution of each of rainfall forming factors and relationships between them are defined. Combinations of the most favorable and unfavorable factors for precipitation in the investigated region are revealed. The long-time variations of the total rainfall and rainfall forming factors are investigated for period 1948–2010 in the Selenge River basin. The intervals with different rainfall forming conditions are showed. It was found that the main reason of precipitation decrease observed in recent decades is the atmospheric moisture content decrease caused by reduction in East Asian of the summer monsoon moisture transport.

Results of joint ground-based measurements of vertical structures of ozone and temperatures with the use microwave and lidar technical equipment are presented. The importance of similar observations in the studying of the influence of various disturbances on ozone layer is discussed. The comparative analysis of the received results with satellite MLS/AURA data and with model profiles are given.

The results of bimorph deformable mirror DM2-100-31 testing in AOS at BSVT are described. It is shown that the tip – tilt range of the controllable mirror is not enough for image stabilization in condition of strong wind swinging of telescope construction components. Slow response and insufficient range of controllable mirror surface deformation within clear aperture 60 mm does not allow a high performance of wave front correction.

The results of the laboratory experiments on compensation of the laser beam initial wave front aberrations by the stochastic parallel gradient descent algorithm (SPGDA) are presented. It is shown that for wave front aberration, considered in the experiment, optimal choice of the initial and iteration algorithm steps, as well as the optimal coefficient of noise threshold provides for the compensation of the main part of aberrations, using 150–200 iterations of SPGDA.

Low frequency lasing mode of CuBr laser operation (50 Hz) is made, using double-discharge excitation. Dissociating and main pumping pulses are applied to the active medium. The main feature of the utilized excitation circuit is application of thyristor–based pulser for dissociating pulse forming. Dependences of lasing energy on the dissociative and pumping pulse parameters are studied.

The SP-9 and SPM multiwavelength sun photometers are described and briefly characterized. The SP-9 sun photometer is designed for year-round monitoring of the spectral atmospheric transparency in the wavelength range 0.3–2.2 mm in the regional network of stations. To implement the automatic measurement mode (unattended by operators), the instrument includes solar sensor, automatic sun pointing/tracking system, built-in GPS receiver and flash drive, and sensors of meteorological parameters. The SPМ portable photometer is a simplified version of SP-9 and is designed for the atmospheric transparency measurements under mobile conditions.

200 probability density values ​​of the received radiation of diverging laser beam from the He–Ne laser (l = 0,63 mm), extending to a length of routes of 260 and 520 m at three receiver diameters (0,1, 0,8, and 3,1 mm) are analyzed. Measurements were carried out during the snowfall. It was found that the most commonly measured distributions are approximated by gamma-distribution for all diameters of the receiver. The increase of the receiver’s diameter by 30 times causes the decrease of fluctuations and a change of symmetry when varying the optical thickness along the path.

The results of atmospheric experiments on propagation of femtosecond IR-pulses with complex initial transverse profile of intensity under self-focusing and filamentation conditions are presented. The effect of initial geometric divergence of radiation on transverse structure of light energy of a beam at the end of the path is studied. Numerical simulation of the problem is carried out and parameters of the generated filaments and plasma channel are determined. It is shown that geometric focusing or defocusing of radiation allow the transfer of the nonlinear focus and filamentation region connected with it along the path in sufficiently wide range.

The influence of the coherence degree of the transmitting beam on the bit error rate (BER) for free space optics (FSO) communication systems is investigated. It is found that for all types of propagation paths (horizontal, vertical or inclined), and various degrees of the turbulence strength there are the optimal value of the output power and the optimal degree of coherence of the optical transmitter beam defined by the Fried parameter. The optimal coherence degree can be determined by the minimum of BER.

The intensity of broadband optical pulses propagating in the free space is calculated in the approximation of the envelope of narrowband signal and based on the complex analytic signal. It is shown that the narrowband-signal envelope approximation can be used to calculate the diffraction of pulsed optical beams regardless of the pulse duration and its coherence in space and time.

A modified spectral-phase algorithm for computer generation of time-evolving random processes and fields has been developed. Use is made of a combined autoregressive moving-average model, described by a discrete difference equation. The implementation of the algorithm is shown to be simple and efficient in simulations of dynamic problems of atmospheric and adaptive optics.

This paper considers the results of 12-year long investigations of dependencies of the aerosol scattering coefficient on relative humidity at its controlled growth (hygrograms). It is revealed that this function cannot be always represented in single-parameter form in the entire range of variations of the relative humidity. The well-pronounced phase transition is sometimes observed at its certain value. The frequency of occurrence of hygrograms with phase transition in different seasons and in various air masses is analyzed. The substances are determined, the presence of which in aerosol particles can cause the appearance of the phase transition.

We consider specific features in the spatial distribution and seasonal variations of the atmospheric aerosol optical depth (AOD) in a wavelength region of 0.55 mm on the territory of Povolzhye, Urals, and Western Siberia according to many-year data of satellite (MODIS/TERRA and AQUA) observations. The satellite values of AOD for particular regions of the Middle Urals are compared with AERONET observations in the region of Kourovka Astronomical Observatory. It is shown that the annual AOD variations from April to December are similar in all regions: with turbidity maxima, observed in spring and summer (August), and with minima in June and fall. On the average, the AOD values are larger in the south of the Western Siberia and Povolzhye and minimal in the Northern Urals. A high interrelation in the monthly AOD variations between individual regions is noted.

Measurements of the atmospheric aerosol microphysical characteristics were carried out in April–December, 2009 and January–December, 2011 at the Vostok continental station in the framework of the 54th and 56th Russian Antarctic Expeditions. The instrumentation complex consisted of a modified nephelometer FAN, AZ-10 photoelectric counter and the aethalometer, designed at Institute of Atmospheric Optics. The aerosol number and mass concentrations N _a (cm ^–3) and M _a (mg × m ^–3), aerosol disperse composition in the particle size range d = 0.3–10 mm and the mass concentration of black carbon M _BC (mg × m ^–3) were recorded with the period of 1–2 hours. Temporal variability of the measured aerosol parameters is determined. Seasonal variations of the aerosol parameters are revealed as maximal in the period from November to April and minimal from June to August. It is shown that seasonal differences in the disperse composition of Antarctic aerosol are observed mainly in submicrometer size range. The results obtained are compared with the data of other researchers for high-latitude regions of the Antarctic.

This work contains results connected with boundary layer structure and dynamics in Far East ocean–continent zone in summertime by means of aerosol lidar. Mean values of PBL height, top of the convective layer and mean height of the nocturnal layer are presented. As the example of several summer days, specific features of the PBL structure and dynamics are identified, presented and analyzed. Maximal values of breeze circulation heights are also presented.

The paper analyzes experimental data on variations of vertical-temporal structure of aerosol, which were obtained using lidar complex of the small station of high-altitude atmospheric sensing (SSHAS) IAO SB RAS for the period 2010–2011. A characteristic feature of this period was almost no volcanic activity with emissions to the stratosphere. This made it possible to study the behavior of the vertical structure of the background aerosol in the stratosphere on a monthly basis for certain nights during two years. The analysis of the results revealed differences in the vertical stratification of aerosol between 2010 and 2011. For 2010, the aerosol loading was maximal in January up to heights of 30 km, it diminished starting from February until almost no decrease in March–August, and showed a steady growth since September. In 2011, the aerosol loading of the stratosphere was more intense and longer-term. For instance, the height of the extension of the aerosol component reached 40 km in January–March, and the aerosol was absent in the stratosphere within three months (May–July).

The results of experimental researches of fluctuations of the laser beam intensity extending through a supersonic flooded jet are presented. The work is executed at the stand of Institute of applied and theoretical mechanics of the Siberian Branch of the Russian Academy of Science. The laser beam passed across a jet on various distances from Vitochinskogo nozzle. The experiment was spent at pressure in Ejfelja chamber from 1,7 up to 7 at two modes of the expiration of a jet: with the use of chevrons on the day off nozzle and without chevrons. Dependences of a dispersion and spectra of fluctuations on pressure and distances from the nozzle are found. The internal optical scale of the turbulence is estimated.

The equation for light intensity in maximum, analogous to the equations of strong theory and Kirchhoff formula, is obtained on a basis of experimentally determined existence of deflection of light beams in the range of screen edge and regularity determining it and formation of diffraction fringes by a slit owing to interference of the beams propagating from the ranges near opposite edges of the slit.

In order to show that the presence of nonresonant optical fields near the surface of the agglomerates of nanoparticles may lead to decrease of lasing dye energy threshold of superluminescence and increase its efficiency. The superluminescence was studied experimentally in a thin layer of laser dye R6G with nanoparticles of Ag, Al, Ni, without manifestations of random laser medium and the effect of the plasmon resonance.

The paper presents the results of experimental study of middle scale CuBr laser performance with longitudinal capacitive discharge excitation. Lasing power dependences on various operating conditions were investigated including the influence of equivalent electrode capacitance value. Maximum average output power of 12 W with ~0,5% efficiency was reached in CuBr laser excited by longitudinal capacitive discharge. These results were obtained with total calculated electrode capacitance of 1190 pF on the each side of a gas discharge active region. Linear growing of lasing power with increasing of input power is observed at all values of electrode capacitances and indicates the perspective of further increasing of output power of capacitively excited CuBr lasers.

The experimental measurements of CO ₂ and H ₂O in disc tree-rings of some coniferous from regions with different climates have been obtained, the results were compared with the tree-ring widths, some conclusions were made about climatic response of annual CO ₂ and H ₂O distributions. The hypothesis was put forward that the appearance of long-period cyclicities in annual CO ₂ tree-ring distribution is a tree's response to the environmental change.

A stimulating effect of sunlight transformed by a photoluminescent polymer films on the abundance dynamics, fermentation and respiration of indigenous microflora in oil-contaminated soils was investigated. The extents of biodegradation of petroleum hydrocarbons within 60 days were up to 60–70% and 26% of the overall background pollution level for the experimental and control site, respectively. Residual hydrocarbons extracted from samples of the contaminated soils were analyzed by infrared spectroscopy to show the appearance of additional absorption bands at 3350, 1600, and 1710 cm ^–1, thus indicating the formation of metabolites during enzymatic oxidation of oil. Chromatographic data corroborated the occurrence of intense oxidation.

The composition of the fatty acids of green algae Ulva intestinalis living in the small rivers of the pool of the lake Elton was investigated. It is established that the basic fatty acids are acids with a long chain of 16 and 18 carbon atoms. The variability of the structure of fatty acids of lipids of U. instenstinalis depending on the factors of environment - level of mineralization, temperature, saturation by oxygen, acidity of environment - was investigated. It was revealed that unsaturation of fatty acids increases with an increase in water mineralization. Participation ω6 and ω3 desaturases in the adaptation of U. intestinalis to this factor is assumed.

Flower opening time and duration of blooming, the time of the anther opening and the type of pollination of five species of Hemerocallis genus were studied under different weather conditions. We found that weather conditions do not affect the flowering of mesophytic species. Under adverse weather conditions, the xerophytic species start to bloom later, and their blossom time increases. The main type of pollination is xenogamy, which is combined with geytonogamy. The pollen collected in a sunny weather at 65 % air humidity is characterized by high viability.

Continuously growing callus cultures of three species of Silene genus – S. linicola, S. aprica and S. frivaldszkyana were obtained. It was shown that the genotype and type of explant influence the processes of callus. The highest growth indexes had calluses from hypocotyl – 10,1 ± 1,4, 11,6 ± 3,4 and 7,4 ± 1,1 ( S. linicola, S. aprica and S. frivaldszkyana respectively).

The authors present energy estimations of mechanical-and-electromagnetic transformation of rock specimens during failure that can be of use to diagnosing rockburst hazard rate in underground mines.

The zonal disintegration is studied from a viewpoint of the spatial strain localization, a prospective idea to tackle the problem. The three-dimensional loading and unloading models are modeled numerically based on a strain-softening heterogeneous constitutive model. In the loading model, after a cylindrical tunnel is excavated, the displacement-controlled loading is conducted in the direction of the tunnel axis. However, in the unloading model, after the model has reached a static equilibrium state, a cylindrical tunnel is excavated step by step. In loading and unloading conditions, numerical results reveal that the zonal disintegration phenomenon that annular regions with high shear strains are isolated or divided by those with lower shear strains is existent. Compared with results in the loading model, results in the unloading model are even consistent with the field observations. At a plane orthogonal to the tunnel axis, the regions with higher shear strains, far away from the tunnel surface, are formed by propagation of shear bands that do not originate from the plan.

The deep rock masses are considered as granular materials containing uniform distribution of defects. Defects in the deep rock masses are characterized by the damage variable. The damage variable of the deep rock masses is determined using Mori–Tanaka’s method and Sidoroff’s method, which consider the interaction among microcracks. Effect of the pre-existing microcracks and secondary microcracks on scalar curvature and the free energy density is investigated. A new non-Euclidean mode is established, considering effect of the pre-existing microcracks and secondary microcracks. Contributions of pre-existing microcracks and secondary microcracks to the self-equilibrated stresses are derived from the free energy and the deformation incompatibilty condition. The stress fields of the surrounding rock masses around a deep circular tunnel are determined from a new non-Euclidean model.

The article describes procedure of solving inverse problems on identification of flat specimen failure by tension using in situ displacements and acoustic emission. Weak coherence area is defined by concentration of pores and modeled by a mathematical cut with lengthwise averaged normal tensile stresses. In places with high concentration of pores, Young’s modulus is “degraded,” i.e. deformation intensifies here and causes shear stresses. The latter are calculated by successive approximations of solutions of direct problems on specimen contour displacements and concentrated acoustic emission. In principle, under consideration are primal inverse problems of the continuum mechanics coupled with the new class of inverse problems on failure.

The authors discuss experimental nano-indentation results obtained on carnallite, spathic salt and sylvinite grains on Dimension ICON scanning probe microscope, as well as comparative assessments of elasticity modulus and hardness of the minerals.

The options of electrical tomography in studying complex-structure geological profiles in coal deposits are examined using mathematical modeling of electrical fields in nonuniform media. The modeling results show regular patterns of electrical fields distribution, which are used to interpret in situ data to build background models aimed at defining shape, size, occurrence conditions and physical properties of mineral deposits in weak-differentiated media. The study is illustrated by experimental research conducted on a lignite coal field.

The article discusses and extends the known concept on block structure of geomedium by Peive–Sadovsky. It is shown that interaction of structural geoblocks generates force moment. This allowed construction of rotation model of geomedium, assumption of the existence of “rotation” waves and explanation of rheidity properties of geomedium. It appears that representative values of “rotation” waves are close to the velocity values of pendulum waves (µ-waves by Oparin).