V.N. Reutsky1, V.S. Shatsky1,2 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State University, Novosibirsk, Russia
Keywords: Diamond, olivine, mineral inclusions, melt inclusions, mantle metasomatism, kimberlite magma evolution, alkali-carbonate melts, metal-carbon melts, subduction, fluoride melts, placer deposits of diamond, Siberian craton, carbon isotopes, spectroscopy, Y-centers, high-pressure experiment, sulfur, fluid, U-Pb dating, plate tectonics
This special issue of the journal Russian Geology and Geophysics comprises studies presented in the wake of the scientific conference “Processes of mineral formation at high pressures: the origin of diamond and mantle magmas”, dedicated to the 90th anniversary of the birth of the outstanding researcher of diamond formation processes, Academician Nikolai Vladimirovich Sobolev. The conference was held on June 17-19, 2025, at the V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, in Novosibirsk Akademgorodok. The range of topics addressed, from detailed studies of crystal lattice defects in individual diamond crystals and their inclusions to the regimes and timing of the plate tectonics on the early Earth, fully reflects N.V. Sobolev’s contribution to the formation of our modern understanding of the evolution of the Earth’s mantle composition and the formation settings of kimberlites and diamonds.
A.V. Sobolev1, S.V. Sobolev2,3 1Institut de Sciences de la Terre, Grenoble, France 2Helmholtz Center for Geosciences, Potsdam, Germany 3University of Potsdam, Institute of Geosciences, Potsdam, Germany
Keywords: Hadean, Archean, subduction, plate tectonics, mantle plumes, impurity elements, isotopes, quantitive models
The main process that changes Earth’s silicate composition after core segregation is the formation and recycling of continental crust. These processes are closely related to the tectonic regimes that operated at different times during Earth’s history. This review combines recent geochemical data and geodynamic models of how continental crust formed throughout Earth’s history, especially during the Hadean and Archean eons. Continental crust cannot form by direct melting of the dry ultramafic mantle. It requires water, mafic protolith, and minerals compatible with high-field-strength elements (Ti, Nb, Ta, Zr, Hf), such as amphibole, rutile, ilmenite, or jadeite pyroxene. For the early Earth, the most likely model involves two stages: first, basaltic or picritic (oceanic) crust is extracted from the mantle, leaving behind a refractory harzburgitic residue. Then, after hydration, the oceanic crust subducts, melts or releases water to flux melting in the mantle, creating continental-crust magmas. Meanwhile, the remaining refractory residue mixes with refractory mantle material, producing a depleted mantle reservoir. Canonical Nb/U and Ce/Pb ratios are unaffected by mantle melting under dry conditions but change during melt generation when amphibole and high-Ti phases are present. Therefore, these ratios are useful indicators of continental crust formation. Geochemical tracers such as: 1) Sr isotope compositions of komatiite melts and plagioclase in anorthosites; 2) element ratios in komatiite melts; 3) trace element contents and Hf isotopic compositions of zircon, and 4) decay products of short-lived Sm and Hf isotopes in rocks either support or do not contradict the operation of active continental crust formation and mantle depletion during the Hadean. Production and recycling of continental crust in this period likely involved episodic, short-lived subduction triggered by plumes. Overall, these findings suggest that tectonic regimes in the Hadean (4.4-4.0 Ga after magma-ocean solidification) and in the Eoarchean (4.0-3.6 Ga) were more dynamic and varied in time and space than previously thought. However, the development of global plate tectonics requiring a connected network of subduction zones, mid-ocean ridges, and transform faults could only start later, during the Archean. The causes of the onset of plate tectonics throughout Earth’s history are still debated, and new ideas (such as those involving surface processes, such as the erosion of continents) are being proposed and require further testing.
V.S. Shatsky1,2,3, A.L. Ragozin1, V.V. Kalinina1 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State University, Novosibirsk, Russia 3A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
Keywords: Inclusions in diamonds, fluoride melts, diamond formation, mantle, subduction zone, Siberian craton
This paper presents new evidence for the fluorine enrichment of the diamond-bearing mantle of the Siberian craton. For the first time, we have discovered inclusions containing calcium and aluminum fluorides in placer diamonds from the northeastern Siberian craton. In contrast to microinclusions in fibrous diamonds and coated diamonds, the studied inclusions can be interpreted as fluoride melts. In diamond ISTD-119, inclusions are oriented parallel to the octahedron faces and can be considered syngenetic, whereas in diamond ISTD-124, an elongated inclusion is oriented parallel to slip lines. This suggests that the formation of the inclusion was synchronous with the stage of diamond deformation. In variety V diamonds XLS-147 and ISTD-193, the morphology of inclusions located in the central parts of the crystals allows them to be interpreted as healed cracks. Fluorine is present in the inclusions, as calcium compounds with stoichiometry close to fluorite. The inclusions comprise zones consisting of calcium fluorides and zones consisting of carbonates and/or iron oxides. In variety V diamond XLS-147, aluminosilicate and aluminosilicate-fluoride inclusions have been identified. In contrast to the inclusions in diamonds ISTD-119, ISTD-193, and ISTD-124, the fluoride component of these inclusions is aluminum fluoride. There is evidence for the growth of variety V diamonds in subduction zone. The compositional variations of the studied inclusions indicate immiscibility of fluoride, aluminosilicate, and carbonatite melts. These inclusions testify to the fluorine-enriched diamond-forming mantle of the Siberian craton at the time of the diamond formation.
A.V. Golovin, A.A. Tarasov
N.V. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Kimberlites, olivine, xenoliths, sheared peridotites, morphology of olivine, variations in olivine composition, Udachnaya-East pipe, Siberian craton
Olivine is the main rock-forming mineral in kimberlites, and the results of numerous studies of kimberlitic olivine are widely used in most models of kimberlite petrogenesis. Kimberlitic olivine investigations also provide constraints for models of the composition, structure, and evolution of the lithospheric mantle beneath ancient cratons. However, a persistent problem is the identification of magmatic olivine in kimberlites and olivine derived from disaggregated mantle xenoliths, as both may display very similar morphologies. In this study, we demonstrate that although the morphology of these olivines can be similar, they can be distinguished using compositional and internal structural criteria. The study is based on an extensive analytical dataset (more than 500 olivine grains up to 5 mm in size were analyzed from a single volcaniclastic kimberlite phase of the Udachnaya-East pipe, Siberian craton) and on a summary of the previously obtained data on the compositions of olivine from 158 xenoliths of sheared peridotites from the same kimberlite pipe. New data on the composition of olivine from 20 sheared peridotite microxenoliths (≤0.5 cm) are also presented in this work. Microxenoliths of sheared peridotites can be divided into two groups according to the Mg# of their olivine: 89.5-92.5 (50% of the samples) and 84.5-87.5 (45% of the samples). In contrast, olivine from sheared peridotite xenoliths (≥5 cm) shows a unimodal Mg# distribution, with most olivine compositions (80% of the samples) falling within the Mg# range 89.5-92.5. The paper presents a series of well-documented examples where olivine neoblasts derived from disaggregated sheared peridotite xenoliths acted as nuclei for the growth of magmatic olivine. In addition, a unique example of the disaggregation of a microxenolith of sheared peridotite in situ during kimberlite emplacement is provided. This example is the compact occurrence of nonresorbed and unzoned euhedral neoblasts within a 1 mm field of view in the kimberlite rock. The largest portion of true magmatic kimberlitic olivine occurs in the groundmass size fraction (<0.25 mm) of unaltered rocks; however, olivine of this size fraction in kimberlites worldwide remains de facto unstudied.
Studying the composition and crystallization conditions of olivine in kimberlites is crucial for understanding their petrogenesis and assessing their diamond potential. Our investigation focuses on the origin of the least studied generation of this mineral: late high-Mg olivine. The research material comprises samples of unaltered kimberlites from the Udachnaya-East pipe, where all olivine generations are fully preserved. Scanning electron microscopy and microprobe analysis reveal that high-Mg olivine exhibits the following compositional variations: Mg# (Mg/(Mg+Fe2+)×100, mol.%) 93.3-98.7, 0.01-0.05 wt.% NiO, 0.12-1.88 wt.% CaO, and 0.18-0.94 wt.% MnO. This olivine forms a paragenetic association with late magmatic minerals of kimberlites: magnetite, perovskite, apatite, monticellite, sodalite, phlogopite, djerfisherite, and calcite. High-Mg olivine occurs as individual grains (the first such finding in kimberlites), rinds, daughter phases within melt inclusions, phases in embayments and fractures within earlier olivine generations, and phases in the interstices of microxenoliths. Its crystallization is interpreted to have occurred from alkaline-carbonate-chloride melts. The temperatures and oxygen fugacity values for the crystallization of high-Mg olivine are semi-quantitatively estimated at 670-780 °C and +3.6 to +7.4 lg units ΔQFM. These findings indicate that such olivine crystallized from evolved kimberlitic melts, which contradicts earlier models proposing its formation from fluids or during kimberlite serpentinization.
Yu.N. Palyanov1,2, Yu.M. Borzdov1, I.N. Kupriyanov1, A.F. Khokhryakov1,2, Yu.V. Bataleva1 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State University, Novosibirsk, Russia
Keywords: Diamond, experiment, high pressures, metal-carbon melts, mantle, fluids, diamond genesis
Natural diamonds are polygenic and form over a very wide range of P-T parameters, crystallization medium compositions, and oxygen fugacity. As has been demonstrated in recent years, the genesis of some diamonds is directly related to their crystallization from metal-carbon melts. Since natural mineral formation is assumed to include various components typical of the mantle media, we consider it relevant to analyze the experimental results of the effect of C-O-H-N-S fluids on the crystallization features and indicator properties of diamond. The experimental data presented in this review show that increasing the concentration of fluid components (N, O, S, H2O, CH4-H2) at constant P-T parameters inhibits diamond crystallization in metal-carbon melts and eventually leads to the formation of metastable graphite instead of diamond. Increasing P and T decreases the inhibitory effect of impurities and expands the diamond crystallization region. We have revealed the basic patterns of specific changes in the morphology, defect-impurity composition, and internal structure of diamond crystals, depending on the type and concentration of impurity in the crystallization medium. We have established that impurity-induced specific changes in diamond morphology and trends in nitrogen concentration in diamond are indicative of crystallization conditions and provide a basis for reconstructing diamond formation under reducing conditions in the metal-bearing mantle.
A.G. Sokol, O.A. Koz’menko, A.N. Kruk
V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Subduction, mantle, marine sediment, fluid, melt, trace element, arc magma, metasomatism
Experiments are conducted on pelite doped with 3 wt.% CaCO3 over a pressure range of 3.0-7.8 GPa and temperatures of 750-1090 °C. The goal is that the total carbonate content in initial samples should reach 7 wt.%, consistent with that of the global subducting sediment model (GLOSS). Dehydration and decarbonation of the pelite under the thermal regimes of subduction zones produce a residue composed of garnet, clinopyroxene, phengite, coesite, ± Mg-Fe carbonate, and kyanite, along with accessory rutile, monazite, and zircon. In addition, a mobile phase forms that evolves significantly with increasing P-T conditions along the average subduction geotherm. At 3.0 GPa and 750 °C, a melt with a granite-like composition forms. This melt is enriched in SiO2 and Al2O3, has a K2O/Na2O ratio of 1.2, and contains up to 19 wt.% H2O + CO2. At 5.5-7.8 GPa and 850-940 °C, a supercritical fluid-melt forms (H2O + CO2 ≈ 40 wt.%) that is enriched in SiO2 and K2O, poor in Al2O3, and has a K2O/Na2O ratio reaching 9.5. The supercritical fluid-melt generated in carbonate-bearing pelite can efficiently transport large-ion lithophile elements (LILE) and light rare earth elements (LREE), including trace element markers of both dilute aqueous fluids (Ba and U) and granite-like melts (Sr, LREE, and Th). Host minerals play an important role in trace element fractionation: phengite (LILE), monazite (LREE), and rutile (high field strength elements, HFSE). An increase in carbonate concentration in the pelite leads to a slight decrease in the partition coefficients of the most incompatible elements due to a higher proportion of the mobile phase and an increased CO2 concentration within it. The supercritical fluid-melt equilibrated with rutile-bearing residue retains the negative Nb anomaly characteristic of marine sediments and can transfer this anomaly to arc magmas if it participates in their generation.
G.G. Shemin1, P.A. Glazyrin1,2, O.A. Smirnov3, E.V. Deev1,2, L.G. Vakulenko1, V.V. Sapyanik4, P.S. Lapin1 1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
3LLC “Ingeoservice”, Tyumen, Russia
4All-Russian Research Geological Oil Institute, Moscow, Russia
Keywords: Regional stratigraphic stages, Lower-Middle Jurassic deposits, lithological area, paleogeographic area, facies zoning, Siberian Arctic
The Lower Jurassic and Middle Jurassic deposits of the Siberian Arctic, which hold promise for oil and gas exploration, are characterized by a complex structure and a low, uneven level of exploration by drilling. A separate facies zoning of these deposits has not yet been developed. The initial information for this zoning was lithological and paleogeographic maps previously compiled by the authors of this article at the regional stratigraphic stage levels. Nine such maps were prepared, five of which covered the Lower Jurassic and four covered the Middle Jurassic. Lithological and paleogeographic regions were identified on each map. Map analysis allowed us to compile lithological and paleogeographic maps of the Lower Jurassic and Middle Jurassic deposits as a whole. These maps formed the basis for the development of a new version of separate facies zoning schemes for the Lower Jurassic and Middle Jurassic deposits in the study region, as presented in this article.
A.A. Primakova1, A.M. Petrov1, K.V. Sukhorukova1, S.V. Ananyev1, 2 1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
Keywords: Electrical well logging, numerical inversion, regularization, lateral logging sounding, geoelectrical model, petrophysical model, saturation
A multilayer approach to resistivity well log inversion has been developed to estimate the true formation resistivity of oil and gas reservoirs in cases where the application of conventional layer-by-layer interpretation techniques is difficult or impossible. Provided the available initial data are sufficient, the approach enables the assessment of formation properties under conditions of significant vertical heterogeneity. However, an increase in the number of parameters of the geoelectrical model inevitably leads to increased equivalence of the inversion results. This paper proposes an approach to improving the stability of multilayer inversion in presence of strong parameter equivalence. The approach is based on a solution regularization mechanism and a method for incorporating a priori petrophysical information. The proposed regularization mechanism allows for the selection of a model characterized by the most gradual vertical variation of reservoir resistivity from a variety of equivalent solutions. The mechanism does not impose constraints on the surrounding non-reservoir formations, which ensures its applicability to high-contrast geological sections. The method for incorporating a priori petrophysical information allows the equivalent solutions space to be narrowed by restricting the admissible ranges of variation of the geoelectrical model parameters based on petrophysical data. The results of numerical experiments using resistivity well logs typical for terrigenous formations in Western Siberia demonstrate the effectiveness of the proposed approach under conditions of both significant vertical heterogeneity and high reservoir clay content.
V.V. Marusin1,2 1Trofimuk Institute of Petroleum Geology and Geophysics of SB RAS, Novosibirsk, Russia 2Novosibirsk State University, Novosibirsk,Russia
Keywords: patch reefs, skeletal fossils, Cambrian, Tommotian Stage, Cambrian Explosion
Since the origin of the first metazoan reef-builders in the Tommotian, reefs have played an important role in marine ecosystems throughout the Phanerozoic, stimulating ecological diversity, regulating the shoreface hydrodynamic regime, and acting as a locus of skeletal carbonate production. In contrast, pre-archaeocyathan calcimicrobial buildups are comparatively primitive in composition and have barely affected the distribution of benthic organisms in the Nemakit-Daldynian and early Tommotian. This work studies a vast package of biogenic carbonates (Suordakh Member) in the upper Kessyusa Group of the Olenek Uplift and spatiotemporal distribution of associated diverse macroscopic fossils. The Suordakh Member comprises a patch reef, composed of grouped low-relief calcimicrobial buildups surrounded by peloidal and ooidal shoals. The study demonstrates that macroscopic molluscs, anabaritids, hyoliths, and conulariids inhabited granular shoals between the calcimicrobial patch reefs by ~530 Ma, but they neither took part in the reef construction nor inhabited the bioherms.
Trofimuk Institute of Petroleum Geology and Geophysics, Novosibirsk, Russia
Keywords: organic matter, kerogen, elemental composition, carbon isotope composition, pyrolysis, Jurassic deposits, southern-eastern and central regions of Western Siberia
For the first time, the geochemical features of the kerogen composition of the Jurassic deposits in the central and southeastern regions of Western Siberia have been studied in detail. The patterns of changes in the pyrolytic, isotopic, and elemental characteristics of organic matter (OM) have been established, and information has been obtained about its genetic type, maturity level, and oil and gas generation potential. The main oil-producing complexes of the Jurassic deposits are considered: the Bazhenov Formation, the Togur Formation in the Tomsk Region, the Danilovskaya Formation, the Verkhnemaryanovskaya Formation, and the Nizhnetutleymskaya Subformation in the Khanty-Mansi Autonomous Okrug (KhMAO), as well as the Georgievskaya Formation in the Tomsk Region and the KhMAO, which have the elemental and isotopic compositions of kerogens characteristic of mature aquagenic organic matter and have a relatively high oil-generating potential. The moderately transformed Jurassic strata of the central and southeastern regions of Western Siberia are located in the main oil-forming zone, while the higher-temperature Salym section is located in the gas-forming zone. A decrease in the values of the main geochemical parameters of kerogens (H/Cat and HI) is observed from Upper Jurassic to Lower Jurassic deposits: with increasing maturity, kerogen, like coal, becomes enriched in carbon. The use of schematic maps of Jurassic deposit catagenesis and the geochemical properties of kerogen will significantly enhance our understanding of the oil and gas potential for the southern regions of Western Siberia.
Yu.V. Rostovtseva1, S.V. Tomasenko2, V.D. Nemova2,3 1Geophysical Centre of the Russian Academy of Sciences (GC RAS), Moscow, Russia 2LUKOIL-Engineering, Moscow, Russia
3Gubkin University, Leninsky Prospekt, Russia
Keywords: Acidic volcanics, secondary porosity, characteristics of hydrothermal fluids, leaching, chloritization, top of the pre-Jurassic complex, Elizarovsky trough, West Siberian plate.
Volcanics of dacite-rhyolite composition from the Permian-Triassic top of the oil-bearing pre-Jurassic complex in the Elizarovsky Trough of the West Siberian Platform were studied using a set of methods. It was established that, alongside fracturing, two main typesofsecondary porosity are distinguished in these rocks, formed on the felsitic (main) mass of the rocks and phenocrystals of feldspars. The alteration of rocks by weakly acidic-neutral chloride fluids led to the dissolution of the felsitic (main) mass of the volcanics, leaching of silica, and the precipitation of chlorite and idiomorphic crystals of albite at temperatures ranging from approximately 300–350°C down to about 175°C. The formation of chlorite occurred on average at around 291–310°C. As a result of acid leaching, porosity was developed along phenocrystals of feldspars, which usually contain abundant microscopic residual TiO₂ inclusions. The chemical composition of volcanics with secondary porosity shows differences in SiO₂, Al₂O₃, TiO₂, P₂O₅, Cl, and Ba compared to other studied rock types. Volcanics with perlite structure exhibit the highest filtration-capacitive properties. The study revealed the heterogeneous action of hydrothermal fluids, manifesting differently in the near-vent zone of the paleovolcano and in its distal parts.
V.D. Efremenko, P.G. Borodin, I.N. Kosenko
Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Jehol Biota, freshwater fishes, taphonomy, paleoenvironments
Based on the differences of the fishes taphonomic states and the orictocenoses Turga paleolake burial features that led to the lagerstatten formation were reconstructed. The main factors that led to a high preservation state of the fossil fishes and invertebrates were the absence of hydrodynamic influence, oxygen deficiency, and water alkalinity. Important factor of the preservation was absence of prolonged postmortem flotation. Low water temperatures prevented postmortem floatation during the cold season, while elevated pH prevented it during warm season when temperatures was favorable for this. Bedding planes with shell pavements of clam shrimps Eosestheriamiddendorfii deposited during summer time and contained small-sized fishes. Larger fishes were buried during autumn and winter seasons.
I.S. Karputin1, A.G. Sokol1, O.A. Kozmenko1, A.L. Ragozin1 1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: supercritical fluid-melt, subduction, high-pressure high-temperature experiments, distribution coefficient, rutile, pelite, schist, mantle metasomatism
Previously, in experiments at pressures of 5.5–7.8 GPa and temperatures of 850–1090°C, it was established that dehydration of naturally doped quartz-muscovite-chlorite schist results in the formation of a supercritical fluid-melt (SiO2>Al2O3≥K2O>Na2O, >30 wt.% H2O and ~10 wt.% CO2) and a restite (garnet, phengite, clinopyroxene, coesite, kyanite, and accessory rutile, zircon, monazite). In this work, the compositions of rutile and the supercritical fluid-melt were determined by LA-ICP-MS, and based on the obtained data, the fractionation patterns of HFSE and REE between them were reconstructed. It is shown that at pressures of 5.5–7.8 GPa, with increasing temperature, the distribution coefficient of Nb between rutile and the supercritical fluid-melt decreases from 400–800 (850–940°C) to 70–80 (1030–1090°C), and the distribution coefficient of Ta decreases from 100–200 to ~10. The ratio of the distribution coefficients we established, D(Nb/Ta), is 2–10, which is significantly higher than the values for rutile–silicate melt or rutile–carbonatite melt pairs. It is concluded that the separation of volatile-rich supercritical fluid-melts during the dehydration of rutile-bearing metasediments at depths >170 km may lead to the formation of eclogitic restite with increased Nb/Ta ratio. Analysis of the obtained data demonstrated the possibility of using the Zr-in-rutile thermometer for rutile- and zircon-bearing metasediments in the pressure range of 5.5–7.8 GPa. However, a systematic underestimation of 22–30% was found for the values calculated using the thermometer (calibrated up to 3.0 GPa) relative to the experimental temperatures.
T.M. Parfenova, A.E. Kontorovich, D.S. Melnik
Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: dispersed organic matter, bitumens, hydrocarbons, catagenesis, primary migration, hypergenesis, Kuonamka formation, Cambrian, Siberian Platform.
The article presents ideas about the migration of dispersed bitumen and the formation of oil accumulations in black shale deposits, to the development of which Russian researchers have made a major contribution. New results are presented from a study of organic matter in the Lower and Middle Cambrian Kuonamka Formation using a comprehensive methodology developed for the analysis of high-carbon rocks. Features of its composition were revealed in Cambrian deposits distributed on the Munsky arch of the eastern slope of the Anabar anteclise. It is shown that a number of samples exhibit similar compositions, ratios, and distributions of hydrocarbon isomers and homologues, and a genetic relationship is observed between open-pore bitumen and residual autochthonous closed-pore bitumen. It is established that potentially oil-producing and oil-saturated rocks have undergone intense postsedimentation and postdiagenetic changes during their geological history. Furthermore, the residual organic matter of some crushed and uncrushed samples poorly preserved the composition and distribution of hydrocarbons, which originated from Cambrian biological communities. Low contents of open-pore bitumen and significant changes in their group composition, as well as the contents and ratios of individual hydrocarbons, are the result of primary migration within the Kuonamka Formation, emigration into the underlying and overlying sediments, and active destructive weathering processes. In the hypergenesis zone, light petroleum components were dispersed from paraautochthonous and allochthonous rock bitumen throughout their open-pore system, along with bacterial and nonbacterial oxidation of organic matter components.
N.D. Tolstykh1, M.O. Shapovalova1, N.S. Bortnikov2 1VS Sobolev Institute of Geology and Mineralogy of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, Russian Academy of Sciences, Moscow, Russia
Keywords: sulfosalt-acanthite-chalcopyrite, gold-hessite-galena associations, Se-acanthite, S-naumannite, tennantite-(Zn), (Ag,Bi,Se)-galena, matildite, porphyry-epithermal systems, Lazurnoe ore occurrence, Kamchatka
The Lazurnoe ore occurrence, associated with the diorite-andesite volcano-plutonic association of the Khim-Kirganik ore field located in the Bystrinsky district of Kamchatka Region, is characterized by two ore associations (stages): sulfosalt-acanthite-chalcopyrite and gold-hessite-galena. The first of them, with a predominance of chalcopyrite, includes a silver sulfoselenides of the acanthite and naumannite series Ag2(S,Sе)–Ag2(Se,S); Ag,Bi,Se-bearing galena, forming partial solid solutions with matildite AgBiS2; Bi-enriched tennantite-(Zn); chalcocite Cu2S, co-crystallizing with acanthite Ag2S to form finely dispersed mixtures of them, as well as other Cu-enriched minerals: cupropearceite [Cu6As2S7][Ag9CuS4], jalpaite Ag3CuS2, stromeyerite CuAgS, and mackinstryite Ag6Cu3S4. The second gold-hessite-galena association is composed of galena PbS, sphalerite ZnS, hessite Ag2Te, native gold and silver. The geochemical specialization of the sulfosalt-acanthite-chalcopyrite association is described by the combination of elements Cu-Ag-S-Se-As-Bi, while that of the gold-hessite-galena association is described by Au-Ag-Pb(Zn)-Te-S. Each of these associations has its own mineralogical and geochemical features due to individual hydrothermal events of the ore-forming system of the Lazurnoe ore occurrence. Based on known criteria: the association of ores with subvolcanic intrusions and dikes of quartz diorite-porphyrites; the formation sequence of the identified associations (stages), the typomorphism of the identified parageneses, and the spatial relationship with the copper-porphyry ore occurrences of the Kirganik Complex – it is suggested that the Lazurnoe ore occurrence belongs to the low-temperature facies of the porphyry-epithermal system.
M.I. Epov, E.A. Melnik, A.S. Salnikov
Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Natural hydrogen, lithospheric plates, Siberian platform and its folded framing, faults, migration paths, deep traps, multiscale geological and geophysical data, seismic modeling, gas geochemical survey, modern computational technologies.
The use of hydrogen as an environmentally friendly energy carrier is recognized by many countries, including Russia. For these reasons, the problem of searching for natural hydrogen accumulations formed as a result of natural processes in the Earth's interior is extremely urgent and scientifically significant. The current lack of a coherent classification of diagnostic features for hydrogen potential, considering the specifics of generation and accumulation in various geological and tectonic settings, prioritizes the development of new exploration approaches. These approaches include the integration of geological, geophysical, and geochemical methods together with modern technologies for processing the entire data array. Such diverse materials have been obtained over the past 20 years through regional geological and geophysical reference profiles carried out by the Federal Agency for Mineral Resources, which cross heterogeneous blocks of Northeastern Eurasia. One of these is the 3-DV reference profile (Skovorodino village – Shelikhov Gulf), stretching approximately 2,900 km across the structural elements that define the modern geodynamics of Central Asia: the Eurasian, Amur, and Okhotsk Sea lithospheric plates. This article analyzes the distribution of hydrogen and other deep-seated gases accumulated in the subsoil layer along the Southern section of the 3-DV reference profile. The aim of this work is to identify areas with their anomalous concentrations and to study the features of the deep structure (down to the upper mantle) of such zones to form a set of diagnostic criteria for assessing the hydrogen potential of various territories.
Y.A. Kalinin1, E.D. Greku1, V.P. Petrochenko2, A.A. Tomilenko1, V.A. Yakovlev1, S.S. Nikitin1, F.I. Zhimulev1, K.I. Zatolokina1, A.Sh. Shavekina1, R.A. Shelepaev1, M.L. Kuibida1, A.A. Milskaya3, M.O. Shapovalova1, I.V. Vikentiev4 1 V.S. Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russia
2 JSC Bystrinskaya Mining Company 683001, Petropavlovsk-Kamchatsky, Russia
3 Lomonosov Moscow State University, Faculty of Geology, Moscow, Russia
4 Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry of the Russian Academy of Sciences, Moscow, Russia
Keywords: Kumroch ore field; mineralogical and geochemical features of ores; fluid inclusions; porphyry and epithermal types of mineralization.
The Kumroch deposit, located in the middle part of the East Kamchatka tectonic zone, is one of the most significant gold mining sites in Kamchatka. It is characterized by a combination of signs of Au-Cu-porphyry and Au-Ag vein ore genesis. The hydrothermal ore-magmatic system is represented by intrusions of dioritic porphyrites containing interspersed quark copper mineralization, as well as zones of volumetric hydrothermal mining of host volcanites with large gold ore polysulfide quartz veins. The spatial and genetic relationship between the gold-copper-porphyry and vein subepithermal stages of the ore-bearing system activity in the Miocene-Pliocene time is shown. Lateral zonation was revealed, expressed in a change from the southwest to the northeast of mineral associations: chalcopyrite-magnetite and pyrite-chalcopyrite (early), manifested in the centers of Cu-Au porphyry mineralization, gold-polysulfide and gold-pale ore-telluride (transitional), forming an intermediate part with Au-polymetallic subepithermal tools, and As-pyrite-antimonite (late) epithermal, in the peripheral part. The coexistence of two types of hydrothermal fluids has been established: 1) high-temperature (Thom
= 515–330 °C) and highly salted (>50 wt. % NaCl-eq.), responsible for the formation of Au-Cu porphyry mineralization, and 2) medium-temperature (Thom
= 350–160 ° C), with increased salinity (up to 11 wt. % NaCl-eq.), with signs of boiling and heterogenization of mineral-forming solutions, which deposited vein Au mineralization.
V.A. Kashirtsev, B.L .Nikitenko, E.B. Peshchevitskaya
Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Siberian platform, Upper Jurassic, organic geochemistry, hydrocarbon biomarkers, deep chlorophyll maximum (DCM).
In the north of the Siberian Platform, deep chlorophyll maximum (DCM) regions have been reconstructed in Upper Jurassic and Berriasian sedimentary formation based on geological and geochemical features of organic matter composition. These reconstructions are based on the results of chromatograph mass-spectrometry studies of the individual composition of chloroform extraction bitumen, primarily the exceptionally high concentrations of isoprenoid hydrocarbons (pristane and phytane), the content of which is several times higher than that of adjacent (nearly eluting) normal alkanes. In the aromatic fractions of bitumen, DCM is identified by the unusually high contents of chromanes with an "isoprenoid tail," which arose as a result of diagenetic condensation reaction between chlorophyll and phenols. The spatial location of the DCM regions is determined by the coastline of the Anabar-Lena Sea and the Siberian paleocontinent.
V. A. Aksenov, S. I. Orlov, O. I. Potaturkin, S. B. Uzilov
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: classification accuracy, natural and anthropogenic objects, multispectral images, spectral channels, feature systems, image processing
It is proposed to use spectral channels with a width of 30 nm as feature systems for classifying natural and anthropogenic objects in the field of observation. The effectiveness of using algorithms that select and process a small number of narrow-band multispectral images of real scenes formed in the most informative intervals of the visible and near-infrared ranges has been experimentally demonstrated. A system of three features is defined that ensures high accuracy in classifying objects in real scenes. The possibility of switching from systems of three features to systems of two features in the classification of combined classes of test regions of interest is shown.
A. V. Lapko1,2, V. A. Lapko1,2, S. T. Im1,3, Yu. P. Yuronen1 1Reshetnev Siberian State University of Science and Technology, Krasnoyarsk, Russia 2Institute of Computational Modelling SB RAS, Krasnoyarsk, Russia 3Sukachev Institute of Forest SB RAS, Krasnoyarsk, Russia
Keywords: structural analysis of spectral data, automatic classification, correlation coefficient, NDVI method, NDII method, kernel probability density function, statistical data decomposition, remote sensing data, forest area, damaged stands
A method for structural analysis of remote sensing data is proposed, based on a two-level decision-making system. At the first level of the system's structure, remote sensing data is decomposed using the signs of the components that make up the estimated correlation coefficient between spectral features. Based on this, four classes of spectral data are identified. At the second level of the system structure, each identified first-level class undergoes further decomposition according to the Euclidean distance values for the components of the correlation coefficient estimate between spectral features. The developed system was used in the structural analysis of remote sensing data of a dark coniferous forest damaged by the Siberian silkmoth. The obtained results were compared with those obtained using the NDVI and NDII spectral indices of remote sensing. Nonparametric probability density estimates were used to analyze the spectral indices of remote sensing data and the developed decomposition system methodology. A procedure for optimizing kernel probability density estimation is considered. Schematic diagrams of the obtained results are provided.
S.V. Savelyev1,2, V.P. Kosykh1 1Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State University, Novosibirsk, Russia
Keywords: multi-object tracking, tracking-by-detection, neural network, ByteTrack
This paper explores the integration of computationally efficient neural networks into a multi-object tracking algorithm in video sequences to reliably predict subsequent trajectories. Several well-known neural network models are tested, and a new one is proposed. The models examined demonstrate improved trajectory prediction performance compared to the baseline ByteTrack algorithm, without significantly impacting performance.
K. I. Budnikov1, A. S. Potapova1, A. N. Savostyanov2,3, A. G. Karpova4 1Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Scientific and Research Institute of Neurosciences and Medicine, Novosibirsk, Russia 3Federal Research Center, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia 4M.K. Ammosov North-Eastern Federal University, Yakutsk, Russia
Keywords: South-to-North relocation, motor reflex control, stop-signal paradigm, machine learning
The article examines variations in the psychophysiological state of migrants who have moved from regions with a southern climate to permanent residence in the Far North, using international students studying in Russia's northern region as an example. This type of move is accompanied by a stress response, which arises from a negative perception of the new environment. Therefore, monitoring changes in the psychophysiological state of migrants is necessary. For this purpose, it is proposed to assess subjects' motor control abilities using a stop-signal paradigm, electroencephalogram monitoring, and machine learning methods for processing the collected data. A comprehensive method for analyzing the obtained information is proposed to determine anxiety using biophysical markers.
R. E. Shcherbakov1, I. V. Matveev2 1Nedra Digital, St. Petersburg, Russia 2National Research Tomsk Polytechnic University, Tomsk, Russia
Keywords: machine learning, anomaly detection, time series processing, managed pressure drilling, reservoir fluid inflow
The proposed data processing technique is designed to detect formation fluid influx during managed pressure drilling. The approach is based on multi-stage enrichment of time series with context-dependent features, which enables anomaly detection based on the dynamics of process parameters within the context of the ongoing technological operation. The method remains robust to variations in drilling operations and conditions. Experimental results demonstrate a statistically significant 13% relative increase in balanced accuracy achieved with the developed features.
S. V. Mantsurova1,2, N. L. Shwartz1,2 1Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State Technical University, Novosibirsk, Russia
Keywords: planar nanowires, GaAs, silicon, simulation, Monte-Carlo
This work is devoted to the search for conditions of stable unidirectional planar GaAs nanowires growth on Si(111) substrates using Monte Carlo simulation. The effect of temperature on the stability of the planar growth on a structured surface in form of trenchesis investigated. The influence of the nanowire growth front geometry on the probability of stable planar growth in trenches oriented along the [211 ] and [011 ]directions is demonstrated. The growth kinetics of planar and non-planar GaAs nanowires at different temperatures is analyzed. An increase in the probability of planar nanowirestable growth with increasing temperature is revealed. It is shown that the reason for the transition from planar to non-planar growth for any trench orientation is wetting of the upper part of the planar nanowire with a gallium droplet.
V. S. Tsarev, G. K. Alagashev, A. G. Okhrimchuk
Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
Keywords: direct laser writing, birefringence, optical memory
We investigate a method for forming birefringent microstructures in fused silica using a burst of ultrashort linearly polarized laser pulses separated by sub-nanosecond equidistant intervals. The method utilizes a tensile deformation wave induced by a pressure jump in the region of electron-hole plasma formation. This tensile deformation reduces the laser pulse energy required to reach the modification threshold of glass and to inscribe a birefringent structure. It is established that a sub-nanosecond burst of ultrashort laser pulses, comprising a first pulse with an energy no more than twice the glass modification threshold energy and followed by several subsequent pulses with energies an order of magnitude lower than the first, enables the creation of a submicron-sized birefringent structure. It is suggested that the mechanism of birefringence formation is based on the anisotropy of the deformation wave excited by the first pulse. This new approach to generating a sub-nanosecond burst is promising for increasing the writing speed of birefringent structures in fused silica, which can be used for fabricating various elements in photonics.
N.E. Dultsev, E.N. Chesnokov, P.V. Koshlyakov
Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: IR spectroscopy, DFB laser, methane
The paper considers the possibility of creating an automated device for detecting methane (CH4) in the atmosphere based on tunable diode infrared absorption spectroscopy using stepwise frequency modulation of laser radiation. A feedback diode laser (DFB) operating at a wavelength of 1653 nm was used as the radiation source. The optimal value of the modulation amplitude has been determined. The possibility of detecting methane in concentrations from 6 ppm for an optical path of 60 cm is demonstrated.
V. O. Zuev, S. V. Dvoynishnikov, V. G. Meledin, G. V. Bakakin
Kutateladze Institute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: phase triangulation, phase images decoding, receiving-transmitting function
A phase triangulation method, invariant to receiving-transmitting function nonlinearity nature, is proposed for objects geometric parameters precision control in the optical light source and receiver limited dynamic range conditions. The method is based on the algorithm of the closed area shape minimization, formed by the values for given phase shifts of recorded intensity and generated by the source brightness. It was shown in the work that the proposed method provides a similar error level when the receiving-transmitting function is linear and high metrological characteristics when it has nonlinearities and frequency response of the measurement complex source and receiving optical systems is not ideal.
C. G. Baev1, T. N. Khatsevich2, E. V. Druzhkin3 1Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Siberian State University of Geosystems and Technologies, Novosibirsk, Russia 3PC LUGGAR LLC, Novosibirsk, Russia
Keywords: F-Theta lens, telecentric trace, scanning spot scan path, the width of the lines on the optical scales
The results of the development of a high-aperture telecentric F-Theta lens for a laser workstation using a femtosecond laser as a radiation source and designed for the production of optical grids and scales on elements of optical and mechanical industry products are presented. The features of lens alignment are discussed. The results of experimental studies confirming the possibility of recording optical scales with a minimum line width of 0.003 (for field is 6x6 mm) to 0.002 mm (for field is 3x3 mm) are presented.
A. A. Krivonosov, A. Yu. Tkachenko, N. R. Poddubrovskii, S. I. Kablukov
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: nonlinear frequency conversion, sum-frequency generation, self-sweeping laser, tunable radiation
This work demonstrates for the first time sum-frequency generation (SFG) based on a continuous-wave Yb-doped self-sweeping fiber laser. The use of a self-sweeping laser in the SFG process enables the development of frequency-tunable radiation sources. Synchronization of the self-sweeping laser radiation with that of a microchip laser is demonstrated. SFG near 532 nm with a tuning range of up to 50 pm is achieved. The peak power obtained is 11 mW, corresponding to a quantum conversion efficiency of approximately 2 % for the self-sweeping laser radiation. The demonstrated approach can be adapted for difference-frequency generation (including terahertz radiation) and is promising for spectroscopic applications.
E. F. Pen, V.N. Zatolokin
Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: input/output gratings, waveguide, spectral characteristics, diffraction efficiency, reflection hologram, photopolymer
Spectral and diffraction characteristics of color monochrome single-layer (R, G and B) reflection holograms, as well as a three-layer RGB structure in the form of their superposition on each other (stacks), intended for use as gratings of input/output radiation of color LED devices in AR displays, were obtained and analyzed. An experimentally established mismatch between the spectral characteristic contour widths of the obtained holograms and the KY-016 LED diode used in the experiments. Because of this reason fractions of useful intensities of the R, G, and B components of this device are only 64 %, 32 %, and 34 %, respectively, of their potential values. Based on the well-known CIE RGB color specification model, the actual intensity ratios were found for mixing the emissions of the color components of an LED diode in interaction with reflection holographic gratings in order to synthesize white color. When assessing the energy efficiency of input/output of radiation using reflection holograms and color LED devices, the main criterion is the maximum brightness of the total illumination for a given set of color components and white balance conditions, and not the maximum intensities of individual components of R, G, and B radiation.
I.S. Sadkin, E.P. Kopyev
Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: burner, fuel atomization, superheated steam, primary air, gasification chamber, operating parameters, NOₓ and CO emissions
A study was conducted on the thermal and environmental characteristics of liquid hydrocarbon fuel combustion in a steam-atomizing burner with a gasification chamber under limited air supply to the chamber at various power parameters. It was shown for the first time that limiting the primary air supply to the gasification chamber during steam atomization leads to a narrowing of the device's operating zone and a shift in carbon monoxide emission characteristics compared to a device with free air supply. At the same time, a key advantage is a significant reduction (up to 70%) in nitrogen oxide emissions due to lower peak temperatures in the combustion zone. A comparison of the performance of a device with a forced-air controlled air supply revealed that, with the same amount of air in the gasification chamber, the different supply methods exhibit differences in the distribution of combustion products in the flame, such as CO, H₂, and CH₄, due to the higher temperatures achieved with forced air supply. Consequently, it was established that modifying an atmospheric steam-atomizing burner by limiting the air supply to the gasification chamber allows for a reduction in NOₓ production over a wide power range while maintaining high combustion efficiency.
D.A. Buntin, O.I. Vishnyakov
Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: constant resistance thermometer, amplitude-frequency characteristics, hot-wire anemometer sensor, pulsation spectrum
This paper continues a series of studies devoted to a method for determining the amplitude-frequency response (AFR) of a constant-resistance hot-wire anemometer based on the direct application of a short-duration pulse to the sensor's sensitive element, simulating the effect as a delta function. The pulse is generated by laser radiation. This method is used to study the influence of parameters such as different settings of the constant-resistance hot-wire anemometer and changes in flow velocity on the AFR. Practical recommendations for selecting the laser radiation intensity/power for accurate frequency response assessment have been developed. A practical application of the method for comparing boundary layer pulsation spectra is demonstrated.
This article is devoted to the numerical modeling of the co-combustion of diesel fuel and micro-ground coal dust in a small-scale furnace with a steam-oil burner. A comprehensive mathematical model describing heat and mass transfer processes in burner and furnace devices is presented: diesel fuel evaporation under the influence of a steam jet, turbulent combustion of evaporated diesel fuel, and burnout of coal particles. The simulations demonstrated that the existing combustion chamber with a steam-oil burner allows for the combustion of micro-ground coal dust and operates stably over a wide range of coal dust flow rates. The obtained numerical modeling results can be used in the design of new compact combustion devices for flare combustion of coal dust.
A video recording of the boiling process on biphilic copper surface with arrays of hydrophobic cavities of about 100 μm in size and a pitch of 780 μm was conducted. The departure diameters and frequencies for bubbles were determined depending on the heat flux, and their ascent rates were established depending on the diameter. The dependence of the diameters on the heat flux was compared with theoretical dependencies and with data from other authors. It was shown that common dependencies do not take into account the parameters important for boiling on biphilic surfaces with inhomogeneities in the form of depressions/caverns and are poorly suited for describing the bubble dynamics on them.
D.V. Kuznetsov1,2, I.A. I.A. Kosovskikh1,2, O.A. Volodin1, I.M. Serdyuk3, V.S. Serdyukov1,2,3 1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 2Novosibirsk State University, Novosibirsk, Russia 3Chinakal Institute of Mining SB RAS, Novosibirsk, Russia
Keywords: boiling, heat transfer, vaporization, active methods of heat transfer intensification, vibration exposure
The article presents the results of an experimental study of the effect of mechanical vibration on heat transfer and vaporization dynamics during nucleate boiling of saturated water in the pressure range of 10-101.3 kPa. The relevance of the study is determined by the need to improve heat transfer efficiency in power and thermal engineering systems operating under reduced pressure and subject to external mechanical influences. Despite the existence of numerous studies devoted to boiling at atmospheric pressure, the effect of vibrations at reduced pressures remains insufficiently studied. This study demonstrates that applying vibration to a liquid leads to an earlier onset of boiling, a reduction in heating surface superheat, and an increase in heat flux at a fixed superheat. The most pronounced effect is observed at lower pressures, whereas at atmospheric pressure, the influence of vibration is weakened and manifests itself primarily in the region of initial nucleate boiling. Analysis of video data revealed that vibration exposure leads to a decrease in the bubble separation diameter, an increase in the frequency of bubble separation, and an increase in the density of active vaporization sites, especially at low pressures. The obtained results confirm that mechanical vibration is an effective active method for controlling boiling processes and can be used in the development and optimization of thermal engineering systems operating over a wide pressure range.
This work presents an experimental investigation of a water film thickness driven by a turbulent gas flow in a flat minichannel. It was found that the transition from macro- to minichannels can lead to a significant reduction in film thickness at comparable flow parameters. An existing model has been modified to estimate the average thickness of a liquid film under conditions of turbulent gas-driven film flow in a minichannel.
S.V. Rykov1, I.V. Kudryavtseva2, V.A. Rykov2 1Saint Petersburg State University of Industrial Technologies and Design, Saint-Petersburg, Russia 2ITMO University, Saint-Petersburg Russia
Keywords: ethanol, pressure, density, average diameter, phase equilibrium line, Clapeyron-Clausius equation
For ethanol, equations have been developed for vapor pressure line, the vapor and liquid density lines, and the "apparent" heat of vaporization, r *, which describe the phase equilibrium line in the temperature range from the triple point and to the critical point. All four equations are consistent in terms of critical parameters, as well as critical indices and exponents of all components of the equations, calculated within the framework of the renormalization group and scaling theory. The coefficients of saturation line, which determine the behavior of the average diameter and the order parameter in a wide vicinity of the critical point, are established based on the correlation between the critical amplitude and the critical index of the saturation line, as well as the renormalization group. The proposed phase equilibrium line model describes the experimental data of the pressure and density of saturated vapor, and the density of saturated liquid of ethanol with less uncertainty than the equations of Bazaev et al (2007), Polikhronidia et al (2007), Ustyuzhanin et al (2013), Schroeder et al (2014).
D.A. Suslov, S.G. Skripkin, S.I. Shtork
Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: vortex core precession, laser Doppler anemometer (LDA), diffusers, swirl parameter
The influence of the diffuser aperture angle and the flow swirl degree on the characteristics of a turbulent flow and the precessing vortex core forming within it was experimentally studied. Laser Doppler anemometry was used to analyze the flow. It was shown that the effects associated with changes in the diffuser aperture angle depend significantly on swirl. With strong swirl, nonmonotonic behavior of the integral swirl parameter in the far wake was observed, which is interpreted as a change in flow regimes. Increasing the aperture angle enhances velocity fluctuations associated with vortex precession. The results form the basis for validating computational models and optimizing diffusers in power plants.
Measurements of the liquidus temperature in the NaCl - KCl system were carried out in the range of compositions from 0 to 100% mol. KCl on 14 samples using the oscillation method of phase analysis (VFA). The melting temperatures of the components and the minimum composition of this system have been clarified.
