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A compact absorption spectrometer with a narrowband continuous tunable diode laser providing sensitivity in terms of the absorption coefficient on the order of 1 × 10^-6 cm^-1 is developed. The design of the spectrometer, the measurement technique, the scheme of ozone generation and maintenance are described. The spectrometer is used to record the absorption spectrum of the ozone molecule for a system of Wulf bands in the near infrared range 11900-12800 cm^-1 corresponding to the rovibronic transitions from the ground to the excited triplet electronic states above the main dissociation threshold of the molecule. The magnitude of the predissociation broadening is estimated from the simulation of the absorption coefficient in the measured spectral range. Ozone absorption cross sections in the considered range are recommended for atmospheric applications; they have been obtained using statistically weighted averaging of the new measurements and experimental laboratory data published in the literature.

Carbon dioxide absorption broadened by argon is studied on the basis of the asymptotic line wing theory. The line shape parameters concerned with the classical potential governing the center-of-mass motion and the quantum intermolecular interaction potential are found. The temperature dependence of the CO₂-Ar absorption beyond the 4.3 mm band edge is explained through changes in the classical potential describing the temperature behavior of the second virial coefficient in the temperature region under study.

The results of hyperspectral sounding of the atmosphere at the Ural Atmospheric Station in Kourovka from 2012-2022 are presented. It is shown that the average rate of CO₂ growth in the atmosphere of this region is about 2.5 ppm per year. The amount of carbon dioxide absorbed from the atmosphere by the forest ecosystem per unit area during the growing season (April-September) in the vicinity of the carbon landfill in Kourovka is estimated using two independent methods. One method is based on the data on the CO₂ total column obtained from sounding the atmosphere with a ground-based high-resolution infrared Fourier spectrometer. The second method is based on the use of an artificial neural network with data from spectral channels of the MODIS satellite sensor as injnit. The results obtained by both methods demonstrate good agreement. The estimates made show that the amount of CO₂ absorbed from the atmosphere by the forest ecosystem in the vicinity of the carbon landfill site during the growing season of 2022 is about 1.5 t/ha (the first method) and about 1.3 t/ha (the second method).

In order to develop the technology of eudialyte concentrate processing based on the use of sorption conversion, the patterns of metal extraction from sulphocationites saturated in the process and the regeneration of sulphocationite and solutions used for desorption for reuse are investigated. The compositions of saturated sorbents containing alkaline metals (sodium, potassium), alkaline earth and rare earth metals, titanium, zirconium (hafnium), niobium (tantalum), aluminium, iron, manganese, natural radionuclides are presented. Desorption with various solutions is investigated. It is found that niobium (tantalum) is most difficult to desorb. It is recommended to carry out two-stage desorption at a temperature of 20 ^oC: at first, desorption with a 5 M NaCl solution, in which the majority of metals contained in the sorbent are converted into solution, and then desorption of zirconium and niobium with a 1 M Н₂С₂О₄ solution. The issues of further processing of the obtained desorbates are considered. In accordance with previous studies, the impurity cake containing thorium, iron, aluminium, titanium is precipitated and separated from desorbates based on a 5 M NaCl solution through fractional neutralization, initially to pH 4, then the concentrate of rare earth elements is separated by neutralization to pH 7.5, and, finally, at pH ≥ 10, alkaline earth metals and manganese. Zirconium (hafnium) - niobium concentrate is precipitated from desorbates based on 1 M Н₂С₂О₄ solution through neutralization with NaOH to pH 10, and then zirconium (hafnium) is leached from it using Na₂CO₃ solution. It is stressed that the sorbent in the H⁺-form is formed after desorption with a 1 M Н₂С₂О₄ solution, which allows using it repeatedly to decompose eudialyte concentrate by sorption conversion. It is shown that the 1 M Н₂С₂О₄ solution can be regenerated by electrodialysis from the Na₂С₂О₄ solution obtained by precipitation of the collective zirconium (hafnium) - niobium concentrate.

The results of studies on the development of technologies for the utilisation of silica sols formed during eudialyte concentrate processing by means of sorption conversion are presented. As promising areas, the following directions have been proposed and studied: additional extraction of valuable metals from silica sols by sorption with sulphocationite; silica sol separation into silica-enriched silica gel and silica-depleted acid solution by successive freezing and thawing of the initial silica sol; the use of silica contained in silica sols to obtain wollastonite. The percentage of rare metals that can be absorbed by sulphocationite from silica sols obtained at a temperature of 80°C - the optimum temperature for the decomposition of eudialyte concentrate by sorption conversion - is found to be (%) 58.6-70.3 Ti, 46-50 Zr, 24.7-29.9 Hf, 23.5-34.7 Nb, while sodium remains in silica sol. The low degree of filling of the sorption exchange capacity of the sulphonic cation exchanger allows it to be additionally saturated in the process of sorption conversion. It is shown that the concentration of SiO₂ reached 33.0 g/L in silica gels obtained by successive freezing and thawing of silica sols. The specific effective radioactivity of silica gels is low, which allows them to be used in the production of civil building materials. Acid solutions depleted in silica, the volume of which was 72.5-81.2 % of the volume of the initial silica sols, contain up to (%) 78.3 Ti, 56 Zr, 45.1 Hf, 76.4 Nb, 92.2 Na, 100 Th, 100 U, and only 1.1-3.6 SiO₂. Such solutions after additional strengthening are suitable for reuse for the decomposition of eudialyte concentrate. The possibility of obtaining wollastonite from silica sol based on nitric acid solution without the use of autoclave equipment has been experimentally proven. The ways of regeneration of the mother liquor obtained after precipitation of the wollastonite precursor are discussed.

An economically viable and environmentally friendly method is proposed for recycling the wastes from electrical discharge cutting of the blanks obtained by the spark plasma sintering of a powdered composition based on zirconium diboride with the addition of silicon carbide, lanthanum and yttrium oxides. The wastes are ground in a flow-type centrifugal mill TsEM-7-1, and the product of milling is further consolidated by spark plasma sintering. The microstructure and phase composition of the sintered materials made from initial powder composition and the powder obtained by grinding the ceramic wastes from final machining of finished products are investigated. It is shown that the largest pieces in the wastes that cannot be ground in the mill are to be crushed preliminarily to enhance the yield of ground powder. The absence of differences in the phase composition of initial and processed powder mixtures and blanks made of them has been revealed, which demonstrates the possibility of repeated use of the wastes for spark plasma sintering of the materials formed from ceramic powders based on zirconium diboride, for the purpose of decreasing the consumption of initial components.

The features of the molecular and supramolecular structure of brown and bituminous coals at different metamorphisms stages have been determined using a complex of methods: IR spectroscopy, X-ray diffraction, the kinetics of swelling in solvents, and sorption of molecular iodine. The relations of the supramolecular structure of coals with the indicators of molecular composition are established, the evolution of coal structure in the series of metamorphism, the mechanisms of transport of solvent molecules into the volume of the organic mass of various coals are considered.

The published data are considered, and the technological aspects of a promising industrial process for the chlorine-free production of alkoxysilanes from silicon dioxide are analysed. Particular attention is paid to key issues that have not yet been considered in the literature. It is shown that the raw material base for the synthesis of alkoxysilanes can be expanded at the expense of microsilica, waste from the production of silicon and ferrosilicon. It has been experimentally confirmed that potassium hydroxide used as a catalyst for the synthesis of alkoxysilanes can be recovered and returned to the process. It has been established that the products of tetramethoxysilane (Si(OMe)₄) synthesis from silicon dioxide and dimethyl carbonate contain 55 components (among them, 45 high-boiling ones have not been identified). The main impurities in the reaction products are MeOH, CH₂O, MeOMe, and (MeO)₃SiOSi(OMe)₃. Technological prospects for the process of obtaining Si(OMe)₄ from industrial wastes are considered.

The regularities of ethoxylation of benzoic acid derivatives during interaction with polyethylene glycol through mechanochemical solid-phase synthesis in a vibrating apparatus have been studied. The conditions for carrying out mechanochemical reactions to increase the conversion degree of initial reagents into reaction products are analysed. The products of ethoxylation are characterized by IR spectroscopy, acid-base potentiometric titration, tensiometry, and dilatational rheology. It has been established that the degree of starting reagents conversion into ethoxylation products depends on the nature of the substituent and its position in the benzene ring. The degree of conversion into reaction products is higher for ortho-substituted derivatives of benzoic acid. It is shown that the salts of ethoxylated derivatives of benzoic acid exhibit pronounced surfactant properties at the air - solution interface.

The distribution of the 1^st hazard class substances and trace elements in the natural waters of the Novosibirsk urban agglomeration is investigated. A substantial role in water pollution is played in the study area not only by a large number of vehicles but also industrial enterprises. The composition of natural waters is determined as mainly hydrocarbonate calcium and hydrocarbonate calcium-magnesium, with total dissolved solids varying from 127 to 910 mg/dm³, and silicon concentration 0.14-11.61 mg/dm³. The geochemical setting changes from reducing (Eh -164.3 mV) to oxidizing (Eh 442.1 mV), pH 6.9-8.8 with O₂(sol.) content 0.48-20.28 mg/dm³. Within the city of Novosibirsk, excesses of background values for 33 elements were revealed; the concentrations of the first hazard class substances are, mg/dm³: Be (6.4·10^-6)-(1.4·10^-4), As 0.0003-0.26, Hg (8.33·10^-7)-(2.3·10^-4), Tl (6.2·10^-7)-(8.2·10^-5), U (1.3·10^-5)-0.21. The activity of radon, established in the natural waters of the city of Novosibirsk, varies from 1 to 1570 Bq/dm³. The waters under active anthropogenic load are mainly the river waters of the Inya, the Eltsovka the 2^nd, the Plyushchikha, the Eltsovka, the Kamyshenka, and the Ob. In groundwater samples, excesses over the actual normative documents and maximum permissible levels were revealed in the well in Kirov settlement (Mn - by a factor of 14, Fe - 10, As - 5), and in the Topol Gardeners Non-Commercial Partnership (Mn - by a factor of 59, Fe - 94, and As - 27).