Home – Home – Jornals – Chemistry for Sustainable Development 2022 number 6

The calculated line intensities of the 1-0, 2-0 and 3-0 absorption bands of the radioactive hydrogen chloride isotopologue H³⁶Cl are presented. The line positions were calculated using the Dunham coefficients obtained with the help of the isotopic independent spectroscopic constants. The line intensities of these bands were calculated using the effective dipole moment parameters obtained with the help of the isotopic substitution equations based on the effective dipole moment parameters of the H³⁵Cl isotopologue. The latter were fitted to the line intensities presented in the HITRAN2020 database.

The methane spectrum is studied near R (3) and R (4) multiplets of the first vibrational overtone in the 298-720 K temperature range with a tuning diode laser. We have developed the technique for laser radiation measurement and frequency calibration with the use of a high-stability plain-mirror interferometer. The coefficients of collisional broadening by nitrogen are calculated at different temperatures.

The results of experimental studies of absorption spectra of pure NH₃ at room temperature in the ranges 6604.3-6606.3 and 6611.6-6613.5 cm^-1 and pressure of up to 0.04 atm are presented. The measurements were carried out at the Department of Diode Laser Spectroscopy of the Institute of General Physics at a high-sensitivity high-resolution diode laser spectrometer with a signal-to-noise ratio of ~ 1400. The spectra were analyzed using a Voigt contour. The results of retrieving the parameters of spectral absorption lines are presented: the positions of centers, intensities, and coefficients of collisional self-broadening and shifts. A comparison was made with the parameters from HITRAN database. A two-fold difference between the measured intensities of a number of lines and the HITRAN values was found.

The absorption spectrum of stable dimers in the long-wave wing of the rotation H₂O band is estimated proceeding from available experimental data on the H₂O continuum absorption in this region and calculations on the basis of the asymptotic line wing theory. The spectral line contour of the rotational band describing the spectral and temperature behavior of the H₂O continuum absorption in the 8-12 mm range was used in the calculations. The spectrum derived does not conflict with computations with the dimer model of the continuum absorption.

Nitric acid plays an important role in atmospheric chemistry; therefore, it is currently monitored by various methods and instruments. Ground-based FTIR method based on spectral measurements of solar radiation by Bruker Optics IFS 125HR spectrometers allows to retrieve not only the total column HNO₃, but also its content in several atmospheric layers. We analyze time series of HNO₃ measurements at St. Petersburg NDACC site between 2009 and 2021. We demonstrate that FTIR measurements can provide information on HNO₃ content in at least two atmospheric layers; the degrees of freedom for signal in average totals 3.1. The mean random error of HNO₃ measurements amount to 3.9, 14 and 1.6% for total atmospheric, tropospheric (up to 15 km), and stratospheric (above 15 km) content, respectively. Thus, the FTIR-method considered is more sensitive to changes in the stratospheric HNO₃ content. The absorption of solar radiation by nitric acid in the measured spectra overlaps with the absorption by water vapor; therefore, the information content and accuracy of HNO₃ measurements are maximal in winter and minimal in summer: in winter, measurements are carried out mainly at low sun and low humidity, and in summer, vice versa.

The results of a comparison of the time series of the turbulent mixing layer height, which is determined from the height-time distributions of the kinetic energy dissipation rate of turbulence and from the height-time distributions of the gradient Richardson number are presented. It is found that only under conditions of atmospheric boundary layer instability due to convection, estimation of the height of the turbulent mixing layer from the height-time distributions of the Richardson number gives results close to those obtained from the distributions of the kinetic energy dissipation rate of turbulence. In other cases, the height of the mixing layer found from the Richardson number can be significantly underestimated.

The phenomenon of reflection of light radiation from crystalline particles oriented in the atmosphere, as well as the physical laws and possible conditions contributing to its occurrence, are considered. A variant of registration of mirror layers using a panoramic optical station (AllSky system) is described.

The time and space derivatives of the air temperature and its products with the wind vector components are analyzed for the cases where the temperature and wind fields are resolved into the deterministic, meso-gamma scale, and turbulent parts. Ultrasonic thermoanemometer measurements in the surface air layer are used for the analysis. The variability ranges of the derivatives are estimated including meso-gamma scale variations in the temperature and wind fields. The variability ranges of these derivatives are compared with those of the “classical” derivatives (when only deterministic and turbulent parts are considered). The derivatives of the components which contain meso-gamma scales are shown to be comparable with the components which include only turbulent parts.

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 electro-physical process in the discharge circuit of a copper vapor laser (CVL) with an LT-10Cu industrial gas-discharge tube has been studied. It is shown that the pumping of the active medium of the CVL is carried out in two stages. During the first (preparatory) stage, the capacitive components of the laser discharge circuit are charged from the storage capacitor, and during the second stage, the active medium is directly pumped. The transition from the preparatory stage to the pumping stage is carried out as a result of “breakdown”. It is shown that under these conditions it is possible to achieve a practical CVL efficiency of ~ 1% in pump circuits with magnetic compression units and ~ 2.5-3% when the energy input is cut off after the generation pulse. The conditions for implementing the mode of cutting off the energy input after the generation pulse are considered.

A new algorithm is proposed for obtaining stability domains of multistep numerical schemes. The algorithm is based on Bernoulli's algorithm for computing the greatest in magnitude root of a polynomial with complex coefficients and the ndelin-Lobachevsky-Graeffe method for squaring the roots. Numerical results on the construction of stability domains of Ams-Bashforth methods of order 3-11 are given.

An experimental study of the efficiency of 3D bounry value problem solvers on the regular subgrids of quasi-structured parallelepipel grids has been carried out. Five solvers are considered: three iterative: the successive over-relaxation method, the implicit alternating direction method, the implicit incomplete factorization method with acceleration by conjugate gradients, as well as two direct methods: PARDISO and HEMHOLTZ - both from the Intel MKL library. The characteristic features of the conducted research are the following: 1) the subgrids contain a small number of nodes; 2) the efficiency is estimated not only for single calculations, but also mainly for a series of calculations, in each of which a large number of repetitions of solving the problem with different bounry conditions on the same same subgrid. On the basis of numerical experiments, the fastest solver under the given conditions was revealed, which turned out to be the method of successive over-relaxation method.

M.M. Lavrentiev's linear integral equation arises as a result of a special transformation of a nonlinear coefficient inverse wave sensing problem. The completeness of the set of products of regular harmonic functions and Newtonian potentials supported by a segment is proved. As a corollary, we establish the uniqueness of the solution to M.M. Lavrentiev's equation and a related inverse problem of wave sensing. We present results of an approximate solution of this equation by using parallelization of calculations.

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.

Description of formation of a manmade backfill made of frozen briquettes using the cryoresource of the permafrost zone involves the phase transfer theory. The seasonal dynamics of the regional temperature is included in the closed life cycle of a solid substance as the main component of the geotechnology. A Stefan problem is adapted to heat processes in formation of a manmade frozen rockmass in the permafrost by filling a mined-out void with briquettes frozen on ground surface, with further injection of processing slurries having a positive temperature in remaining cavities. The numerical implementation program is developed for the set problem in 3D formulation. The freezing time of the artificial rockmass made of the frozen briquettes is related with the size of the briquettes, and with the temperature of the permafrost and the slurries. The frozen backfill in underground mined-out voids is a favorable decision in terms of ecology in mineral mining in the permafrost zone.

The authors implement a new model of calculating temperature field and stresses in frozen rock mass at all successive stages of sinking: rock freezing, shafting, concrete lining and thawing. The model allows assessing dynamics of temperatures and stresses in rock mass, in frozen wall and in concrete lining at the freeze and thaw stages with regard to the thermophysical and mechanical properties of the materials. It is found that functioning of the freezing pipes in the same mode in depth is nonoptimal and leads to excessive energy consumption.

In this study, combustion properties such as thermogravimetric analysis and differential thermogravimetric analysis, combustion profile, ignition temperature and peak temperature were analyzed for 3 lignite samples obtained from different regions of Konya in Turkey. In the kinetic analysis, activation energies were calculated separately for four different reaction sequences using the Coats-Redfern method. As a result, when the calculated activation energies, thermal and kinetic properties of the coal samples are evaluated together, it is seen that Beyşehir coal is more prone to combustion than other coals.

The article describes the studies into the current flow charts available for processing diamond-bearing kimberlites of complex material constitution. The theoretical and experimental substantiation is given for the methods to modify properties of the mineral components to enhance selectivity of their separation. Efficiency of luminophore-containing compositions is proved for weakly and abnormally luminescent diamond. Luminophores modify the spectral and kinetic properties of diamond crystals to the values at which diamonds become recordable and recoverable in the current flow charts of X-ray luminescence separation. Efficiency of integration of ultrasonic, thermal and electrochemical methods in removal of hydrophilic impurities from diamond surface toward enhanced recovery of diamonds by grease technology and froth separation is demonstrated. The method is developed to increase the corrosion resistance of ferrosilicon by means of its nitride coating which unsupports interaction with corrosive components of the water environment. Experiments justify that magnetic separation improves the quality of preconcentrates of float-and-sink separation owing to removal of up to 95.8% of magnetic minerals from the diamond-bearing material.

The characteristics of mineral floatability, namely, the wetting angle and the induction time, are examined. The agreement between the predicted floatability using these characteristics and the theoretical and experimental data is accessed. It is found that hydrophobicity defined by the wetting angle is not always a quantitative characteristic of floatation. The floatability predicted using the time of induction and mechanism of physisorption of collecting agents agrees with the tests and actual practice. The successive change in floatability of sulfhydryl and oxyhydryl collectors in transition between different reagents disagrees with the estimate of the collector force determined from the binding energy between the functional group of a collector and the cation of mineral surface. The force estimated as the effect of a physisorbed collector on the water interlayer between bubble and particle adequately describes floatability of minerals. The mechanism of physisorption of a collector is universal relative to different reagents, is applicable to the description of particle-bubble interaction and enables selecting the structure and composition of radical on an effective collecting agent.

The article describes the method of potentiometry in determination of characteristic diameters of air bubbles. The authors discuss feasibility of the Sauer diameter measurement of air bubbles using the difference of electrode potentials at different depths in flotation machine and with further evaluation of aeration intensity. The studies involved a two-phase system at different consumptions of air and frother. The highest aeration intensity is found from the checking tests of a three-phase system. It is found that the rate of increase in the difference between the electrode potentials linearly correlates with the Sauter diameter of air bubbles.

The article discusses hydrochemical modification of properties of zeolite-bearing rocks in East Transbaikalia. It is found that acid-based modification enhances adsorbability of natural zeolites. The technology of processing with chemical modification is developed for zeolite-bearing rocks with regard to the earlier research findings on mineral treatment by ultrasound, accelerated electrons and high-power magnetic impulses. The rate of dealumination and the silicon module of natural zeolites from East Transbaikalia are correlated with the sulfuric acid concentration. The implemented computer-aided modeling of zeolite minerals is based on the quantum-chemical interaction of particles. The authors depict the range of use of the high-quality zeolite products in the technologies of mining waste management.

In this study, the thermal decomposition of zircon magnetic tailing has been conducted to remove phosphate using a roasting process with Na₂CO₃ and water leaching. The research on zircon magnetic tailing processing, which contained monazite, xenotime, zircon, anatase, rutile and cerianite, aimed to test the effectiveness of roasting techniques for phosphate decomposition so that REE can be easily extracted. The optimal conditions to ensure phosphate recovery up to 93.27% were determined. In this condition, zircon and xenotime minerals are still confirmed in the roasting products using Na₂CO₃.

The authors have developed a procedure for estimating recovery dynamics of natural ecosystems damaged by mineral mining using the satellite observation data. The procedure uses the vegetation index of phytocenosis and the temperature of underlying terrain. The case-study of apatite-bearing ore processing waste revealed the time series of the vegetation index and the underlying terrain temperature of the incipient phytocenosis as compared with the phytocenosis of the surrounding natural landscape. It is found that the recovery of the natural ecosystems by generation of a biologically active medium activate the test factors to reach the values of phytocenosis of the surrounding natural landscape. The justification is provided for usability of the retrospective earth remote sensing data on ground surface in the objective estimation of recovery dynamics of natural ecosystems damaged by mineral mining in the Arctic conditions without undertaking land exploration.

The article presents a case study of dust emissions from the preparatory works for the opening of the mine "Cukaru Peki" near Bor, Republic of Serbia, including an analysis of the total deposited materials, which illustrates the practical application of the proposed methodology. The monitoring was conducted one year before the start and from January to September 2018 during the preparatory mining works. The analysis of existing data predicts the creation of deposited substances from the atmosphere. This paper evaluates the validity of the Gaussian model for predicting the potential impact of dust deposits generated during preparatory mining works.

The authors propose and analyze the method of soft rock reinforcement by injection of bicomponent organomineral resin with compressed-air blowing of reagents deeper in rocks. The bench tester structure, the polymeric formula, the composition and resin properties, as well as the treatment procedure are presented. The tests are described. The scope of the discussion encompasses the results of the permeation tests, strength tests and the analysis of structure of voids in sand samples after their stabilization using the proposed approach and the standard single-component resin injection. The advantages of the successive injection include the chemical treatment coverage, specific consumption of agents and the increased strength.

The authors discuss the known methods of shaft lining monitoring and put forward a new technique of real-time measurement of displacements on inner surface of concrete lining by laser scanning. The results of the preliminary filtering and subsequent processing of the specific monitoring measurements implemented in two mine shafts of Uralkali are presented as the estimates of the change in the shaft diameter, circumferencial strains and ellipticity. The monitoring data are effectively applicable in verification of mathematical models of strains and strength of concrete lining in shafts, including their junctions with horizontal tunnels.

The chromatographic behavior of a number of human blood plasma metabolites in HPLC-MS/MS analysis using a monolithic chromatographic column with a 1-vinyl-1,2,4-triazole-based sorbent was studied. Acetonitrile and a buffer based on ammonium carbonate and ammonia (pH 9.8) were used as the mobile phase. The experiment was carried out in two chromatographic modes: reversed-phase and hydrophilic. The metabolites selected for analysis allow for an unambiguous demonstration of the behaviour of both polar molecules and hydrophobic or amphiphilic lipid molecules in both of the chromatographic modes used. It was discovered that the change of chromatographic regime was accompanied by an inversion of the order of elution of metabolite groups having differences in chemical structure and hydrophilicity. It was shown that this 1-vinyl-1,2,4-triazole-based monolithic column can be used to screen metabolites in both reverse-phase and hydrophilic chromatography modes, and the use of two chromatography modes in metabolome screening using this column is mutually complementary and can help to increase the coverage of metabolites from different metabolic pathways.

In view of the 2^nd type diabetes mellitus "epidemic" developing over the world, and the absence of any efficient and safe drug therapy, the search for new hypoglycemic agents is a highly relevant task. Usnic acid produced by lichens, in addition to its diverse biological effects, also exhibits hypoglycemic action, though only in high doses. To decrease the effective hypoglycemic dose and reduce the risk of side effects, in the present work usnic acid was modified through reactions with the amino acid β-alanine and its derivatives. The hypoglycemic effect of the synthesized enamine derivatives of usnic acid was investigated in mice with alloxan-induced diabetes mellitus. It was determined that the derivative containing the amide fragment in the substituent exhibited a clearly pronounced hypoglycemic effect at the dose of 50 mg/kg. Neither of the studied compounds exhibited activity in the oral glucose-tolerance test in mice without any carbohydrate metabolism disorders.

Results of the multidisciplinary investigation of unique cult objects of the Ob Ugrians are reported. These objects were discovered during field work in the Berezovsky district of Khanty-Mansi Autonomous Territory - Yugra. The first item is a head scarf, which is a sacrificial gift to the Mansi deity Mis-Ne (Forest Woman); the second is a fragment of clothing of an ittarma figure (the Khanty family spirit). The third item (a head scarf) had no embroidery, but part of it was made of handmade fabric. The artefacts were used in the ritual practice of the northern groups of the Ob Ugrians and were probably imported, since the art of embroidery and the skills of hand-weaving existed in the 18^th-19^th centuries only among the southern groups of the Khanty and Mansi. The analysis of fibres and identification of embroidery dyes for hand-woven products of the turn of the 18^th-19^th centuries were carried out. The samples were studied by IR spectroscopy, scanning electron microscopy, and high-performance liquid chromatography with diode array detection. As a result, the plant structure of the fabric of products (presumably nettle fabric) and the composition of decoration dyes and pigments were determined.

The applicability of N,N -substituted bispidines as ligands of metal complex catalysts for the ethynylation reaction was demonstrated on the addition of phenylacetylene to 4-fluorobenzaldehyde. It was shown that the N,N -myrtenyl-substituted bispidinone led to a slight enantioselectivity in the formation of the corresponding propargyl alcohols.

The paper presents the generalizing results of a long-term study (1994-2020) of the behaviour of persistent organic pollutants (POPs) in the unique Baikal-Selenga lake-river ecosystem in Russia and Mongolia. The research started in 1993 on the initiative of V. A. Koptyug by the staff of the Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS and the Baikal Institute of Nature Management SB RAS within the framework of Russian and international field work missions. As a result of the analysis of the data obtained by means of gas chromatography-mass spectrometry, some regularities of the entry, distribution and accumulation of POPs in various regions of the Baikal-Selenga aquatic ecosystem, which is the largest lake-river system in Inner Asia, were revealed. Detailed data on the content, distribution and profiles of organochlorine pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons in surface waters, bottom sediments and biota have been obtained. The studies were carried out over the entire territory of the Baikal-Selenga ecosystem: Lake Baikal, the Selenga River delta, the Selenga River basin at the territories of Russia and Mongolia, including industrial areas and specially protected natural areas. The data obtained are an assessment of the current ecological state of the Baikal-Selenga region and can serve as a basis for identifying anthropogenic impact on the environment and public health with an assessment of environmental risk. These data can be used to develop approaches for environmental quality management and rational use of natural resources, conservation of unique biodiversity and sustainable development of the Baikal region territory and can be considered as an element of the implementation of the Stockholm Convention on POPs.