Mass Exchange Processes Research Articles

Construction of the technological process and design development of a multifunctional unit for processing vital soybeans with ultrasound. Feasibility of water-crude suspension

Cereals and legumes have a porous structure, being an inert carrier during mass exchange processes; they contain voids in the form of pores and stomata, on the surface of which there are foreign extractable substances in a solid state, in particular, trypsin and urease inhibitor proteins. These substances, due to their harmful effect on the final product, are subject to removal by extraction. One of the methods for inactivating anti-nutritional substances is ultrasonic treatment of soybeans.The article discusses the technology of inactivating inhibitors that worsen food and protein value of vital soybeans. The developed technology was aimed at dissolving a solid substance - soybean inhibitor protein in a liquid, carried out due to molecular diffusion, intensifying the processes of mass transfer and mass return. When creating a suspension by mixing the solid (crushed soybean grain) and liquid (water) phases, water molecules, which are a solvent, penetrate under the action of capillary forces into the pores and stomata of the treated body, begin to penetrate. On this basis, technological directions of research have been established, a sequence has been built and the physical essence of operations has been substantiated, consisting of four main ones - grinding soybean grain, creating a “water-soybean” suspension, ultrasonic (US) treatment of soybeans, drying. As a result of the conducted research, optimal technological parameters have been established for intensifying the process of inactivation of anti-nutritional substances contained in native soybeans: the degree of grinding of soybean grains is 0.5-1.0 mm; the ratio of water-soy suspension (1:1). The efficiency of the developed technological process will be factors affecting the quality of the resulting products, the duration and energy intensity of the process, resource conservation, simplicity of design and low cost of manufacture, the possibility of automation.

Production of dry extracts from sea buckthorn raw materials: Research results

Production of soluble dry extracts from sea buckthorn raw materials is relevant and promising for enterprises of the Republic of Buryatia. The authors have selected technological equipment for obtaining dry extracts: extractor, concentrator, dryer. The possibility of using vacuum-pulse action and the influence of technological factors on the yield of water-soluble substances from sea buckthorn leaves and shoots has been studied. The operating parameters of the technological process have been determined experimentally under production conditions: temperature 45–50 °C, total duration of extraction, concentration and drying 79–111 minutes. The process of obtaining dry extracts is carried out in three stages: water extraction; filtration and concentration; drying in a vacuum pulse dryer. The resulting experimental sample of dry extract from sea buckthorn leaves and shoots is a free-flowing crystalline powder with a moisture content of 4–6 %, highly soluble in water, having high organoleptic characteristics – a natural, well-defined aroma characteristic of sea buckthorn, light brown color. The use of low temperatures and vacuum-pulse modes at the stages of the technological process predicts high safety of thermolabile biologically active substances in the product. The process of obtaining dry extracts from sea buckthorn leaves and shoots has been studied. The results of the studies prove the possibility of producing a dry extract with high organoleptic characteristics using the developed by the authors' technology by equipment whose vacuum-pulse operating modes have a positive effect on the yield of extractives and help reduce time costs along with the intensification of heat and mass exchange processes in sea buckthorn raw materials.

Fast, accurate and accessible calculations of leaf temperature and its physiological consequences with NicheMapR

Abstract Mechanistic predictions of ecological niches are fundamentally based on energy and mass exchange processes that, to be realistic, must be linked to microclimate and incorporate behaviour and physiology. Estimates of leaf temperature and associated transpiration and net photosynthesis rates are fundamental in ecology, agriculture and global change biology. Equations for calculating leaf energy budgets have been available for over 60 years and complex models of stomatal behaviour have been developed. However, user‐friendly ways of estimating leaf temperature under realistic microclimatic regimes, including soil moisture effects, remain limited. Here we show that the integrated microclimate and ectotherm functions of the NicheMapR package for the R programming environment can be used to make fast and effective estimates of leaf temperature and associated rates of water loss and photosynthesis for a wide range of leaf functional types, root depths and microhabitats. Stomatal conductance may be constant or simulated to change dynamically (a) as a function of vapour pressure deficit and CO2 concentration, (b) as a function of soil water potential and (c) as a thermoregulatory mechanism to avoid heat stress. We tested the approach against hourly leaf temperature observations in summer from an arid shrubland in Australia, a temperate woodland in Montana USA, along an elevational gradient in Colorado USA, and at a botanical garden in Florida, USA. National or global gridded data sets can provide the required forcing data but local observational data or some combination of local and gridded data can be used. The global ERA5 and NCEP datasets allow historical leaf energy budget calculations to be made anywhere in the world and a Shiny app has been developed to facilitate use of the model with these datasets. Situated leaf energy budget calculations can be used to design informative field programs to collect much needed detailed temporal data on leaf temperature under natural settings, enabling better predictions and interpretations of how plants respond to environmental change.

Про фундаментальну підготовку фахівців авіаційної та аерокосмічної галузей

The subject of the study is the state of the fundamental training of specialists in aviation, rocket, and space technology. Recently, the processes of expanding and deepening the fundamental training of specialists in the specialized areas of specific higher education institutions have been intensified. Unfortunately, experience of recent years has shown, the priorities rightfully belong to the aviation and aerospace industries, both in the scientific/creative and design/production spheres. Training of the specialists in the field of aerohydrodynamics of aircraft and their components; gas dynamics of the modern aircraft engines of various types, is currently the priority. In addition, both – the problems in aeroelasticity and research in the field of aerodynamic acoustics related to the environmental safety of the operation of aviation equipment are important for the design of the modern aircraft. Moreover, the design of aircraft that overcomes trans- and supersonic flight speed, requires in-depth study of the processes of heat and mass exchange determining physico-chemical transformations, which are also present in the internal gas-dynamic processes of gas-turbodynamic and rocket engines of aircraft. Structure and comparative analysis study of programs and courses for fundamental training of specialists in the aerospace industry at the universities of USA, Canada, Germany, China, as well as in KhAI, Ukraine, are presented. This study provides comparative information about scientific and experimental bases of aerodynamic complexes available in Ukraine and in leading organizations of North America and Western Europe. This study demonstrates the real unification of deep fundamental theoretical knowledge and practical skills with experimental research based on existing modern research laboratories. Conclusion. Analysis and comparative indicators presented in paper allow us to state that based on today’s needs, the National Aerospace University "Kharkiv Aviation Institute" is capable of significant increase of the quality of training for specialists of all levels for the developed aviation and rocket-space industries of Ukraine.

Developing novel ensemble models for predicting soil hydraulic properties in China’s arid region

Accurately quantifying the mass (water, nutrients, and carbon) and energy exchange processes between the Earth’s atmosphere, biosphere, and lithosphere requires the accurate parameterization of soil hydraulic properties (SHPs) and their spatial heterogeneity. Because direct measurements of SHPs are difficult, time-consuming, and impossible at larger spatial scales, various pedotransfer functions (PTFs) have been developed in the last few decades, providing divergent estimates of SHPs from readily measurable variables. However, existing PTFs are mostly developed for specific regions and may not be suitable for other pedoclimatic conditions. Here, PTFs were developed using multiple machine-learning algorithms to estimate SHPs and examined the weaknesses and strengths of each method in estimating the average and variability of SHPs across China’s arid region. The optimal PTFs were applied to a 1 × 1 km2 regional map of texture and bulk density, thus producing maps of the saturated hydraulic conductivity (Ks), the parameters of the van Genuchten (VG) formulation, field capacity (θfc), wilting point (θwp), plant available water (θpa), and soil macroporosity (ϕm) in the 0–2 m soil profile throughout the region. The results indicate that the ensemble model with the averaging method (EMA) is the most robust for estimating all SHPs. The EMA-PTFs for Ks yielded the best performance for sand textures, followed by sandy loam, loam, silty loam, silty clay loam, loamy sand, and clay loam textures. There were no significant differences in estimating soil water retention curve parameters among the different soil texture classes. Using the same observed data set, we demonstrated that the new EMA-PTFs outperformed those of existing PTFs, such as Rosetta and HYPRES, with RMSE values decreasing by 25–83 % depending on the SHPs. Furthermore, our SHP datasets exhibited significantly deeper soil profiles and higher accuracy than other available regional and global SHP products. The VG retention parameter α shows the greatest variation vertically throughout the 0–2 m soil profile, followed by ln(Ks), θr, θpa, θfc, θwp, ϕm, θs and n. All SHPs exhibit much lower variability in the desert than in other areas, likely due to the homogeneous particle size distribution of desert areas. This study provides more accurate SHP estimates in China’s arid region than the existing SHP products by developing advanced PTFs and highlights the inconsistency in SHPs among different global or regional products; the uncertainties induced by PTFs should thus be considered in future terrestrial biosphere modeling.

Flow Exchange In Vegetated Environments: Integrating Experimental Insights Into Practical Engineering

Vegetation provides practical protective tools for estuarine and coastal regions. The roots, stems, and canopy systems of mangroves can divert and retard the flow field within and surrounding vegetation regions (Truong et al., 2019) and also absorb external forces from waves (Phan et al., 2015). The area within the vegetation is usually calmer compared to the unprotected region outside. Consequently, sediment tends to be deposited inside the vegetation region (Vargas Luna et al., 2015). The sediment deposited then may have feedback on the wave and flow field and the growth conditions of the vegetation (Truong et al., 2017). These mutual interactions between ecological area (vegetation), hydrodynamic conditsions (wave and flow field), and morphological conditions (sediment transport) are the crux of any proposed nature-based solutions (NbS). From a hydraulic engineering perspective, these dynamic interactions can translate into the momentum and mass exchange processes between vegetation and nearby areas. By observing the evolution of mangrove forests and associated with the rate of erosion/accretion of the shoreline, Phan, 2015 and Truong., 2017 proposed a hypothesis of “squeezed mangrove forest”, in which “the mangrove width” is considered a crucial length-scales that is related to the sustainable development of the mangroves. This length scale was physically interpreted and connected to the penetration of the mixing layer into the vegetation region (Truong., 2017; Truong et al., 2019). It is noted that whereas the characteristic of the incoming waves mainly controls the penetration of the mixing layer into the coastal mangroves, that of the estuarine mangroves is mainly governed by the characteristic of lateral flow. The latter is the primary focus of this study. Large vortex structures caused by the Kelvin-Helmholtz instability at the vegetation’s edge play an essential role in the transverse exchange of mass and momentum (White & Nepf, 2007; Truong et al., 2019). These structures are usually large compared to the water depths and are termed large horizontal coherent structures (LHCSs). The Reynolds Shear stresses (RSs) induced by LHCSs contribute more than 90% to the total turbulent shear stress at the edge of the floodplain vegetated region (Truong & Uijttewaal 2019). Nevertheless, our understanding of this topic often stems from small-scale laboratory experiments. Whether the presence and characteristic of vortex structures at the interface of the low flow and fast flow region obtained from small-scale physical models remain true for estuaries and coasts has not yet been determined. In order to obtain more insight into the physics of the exchange processes occurring at the vegetation interface at different scales, two unique physical models of vegetated channels have been conducted. One small-scale and another large-scale experiment, both with and without vegetation, were conducted at TU Delft Water Lab and the Korea Institute of Civil Engineering and Building Technology - River Experiment Center (KICT-REC), respectively. Two digital twin models of this flume were subsequently constructed using Delft3D, which were calibrated and validated using the collected datasets. In this study, recent findings pertaining to these experiments are presented

Перспективные конструкторские решения для сушки жидких пищевых систем

An assessment of promising alternative design solutions for drying liquid food systems is given. Drying technology and techniques for removing moisture from liquid materials in a dispersed state have found widespread use in the food industry. The almost instantaneous drying of the sprayed particles in the coolant flow causes the formation of a developed phase interaction surface and acceleration of heat and mass transfer procedures, as well as the exclusion of overheating of the material due to intensive volumetric evaporation of moisture. A number of dryer designs have been developed to eliminate disadvantages (such as the large size of the dryers and their relatively high energy consumption and complexity of structural elements) or to reduce their impact on the course of the dehydration operation. The design specifics of devices for dewatering in the atomized state are due to the methods of supplying thermal energy, technological conditions and limitations, parameters of the dried product and the final powder substance, as well as its specific yield, peculiarities of the spraying operation, etc. The justification of the method of spray drying of liquid food material and the constructive use of the apparatus should be based on the study of a set of parameters and characteristics of the dehydration object, as well as on the construction and solution of a mathematical model of heat and mass transfer and exchange processes at the boundary of the phase section, as well as their mechanism in the development of a rational method of moisture removal to ensure the quality of finished products and energy- and resource saving. The proposed plant designs are recommended for organizing the drying process of liquid products, in particular for drying broths in fish production technologies.

The Thermophysical Aspects of the Transformation of Porous Structures in Versatile Nanostructured Materials

The technology of obtaining porous nanostructures is based on ecological organosilicon materials and their uses in some spheres of human life, for example, for medical preparations, for thermal insulation of building structures and industrial equipment, and for cleaning. The purpose of this study was to establish correlations between various experimental parameters (shear stress, speed pulsations, temperature, viscosity, and processing time) and the rheological characteristics of suspensions obtained by the method of liquid-phase dispersion; it was a study of hydrodynamic effects and the processes of heat and mass exchange in liquid systems during the liquid-phase dispersion of hydrogel monoliths by means of discrete-pulse activation in a special rotary apparatus. The dehydration of hydrogels was carried out by two methods: convective drying in a layer and spraying in the coolant flow. Experiments have shown that the key parameters for obtaining stable homogeneous suspensions are a synergistic combination of concentration factors and processing time. To obtain adsorbents in the form of pastes with specified adsorption properties and a monolith size of up to 300 μm, the optimal parameters were a hydrogel concentration of 70% and a processing time in the double-recirculation mode. Xerogels obtained by convective drying are a polydisperse mixture of strong monoliths and fragile aggregates. In contrast, xerogel monoliths obtained by spray drying show great homogeneity in terms of dispersion and strength characteristics. The rheological parameters of the hydrogel dispersions, which depend on the concentration and hydrodynamic treatment modes, are the dominant factors affecting the moisture extraction during drying. This study marks the first investigation into the resilience of porous organosilicon structures against the influence of intense turbulence fields and mechanical stresses experienced within the rotor apparatus during suspension production.

Exploring pore-scale production characteristics of oil shale after CO2 huff ‘n’ puff in fractured shale with varied permeability

Recent studies have indicated that the injection of carbon dioxide (CO2) can lead to increased oil recovery in fractured shale reservoirs following natural depletion. Despite advancements in understanding mass exchange processes in subsurface formations, there remains a knowledge gap concerning the disparities in these processes between the matrix and fractures at the pore scale in formations with varying permeability. This study aims to experimentally investigate the CO2 diffusion behaviors and in situ oil recovery through a CO2 huff ‘n’ puff process in the Jimsar shale oil reservoir. To achieve this, we designed three matrix-fracture models with different permeabilities (0.074 mD, 0.170 mD, and 0.466 mD) and experimented at 30 MPa and 91 °C. The oil concentration in both the matrix and fracture was monitored using a low-field nuclear magnetic resonance (LF-NMR) technique to quantify in situ oil recovery and elucidate mass-exchange behaviors. The results showed that after three cycles of CO2 huff ‘n’ puff, the total recovery degree increased from 30.28% to 34.95% as the matrix permeability of the core samples increased from 0.074 to 0.466 mD, indicating a positive correlation between CO2 extraction efficiency and matrix permeability. Under similar fracture conditions, the increase in matrix permeability further promoted CO2 extraction efficiency during CO2 huff ‘n’ puff. Specifically, the increase in matrix permeability of the core had the greatest effect on the extraction of the first-cycle injection in large pores, which increased from 16.42% to 36.64%. The findings from our research provide valuable insights into the CO2 huff ‘n’ puff effects in different pore sizes following fracturing under varying permeability conditions, shedding light on the mechanisms of CO2-enhanced oil recovery in fractured shale oil reservoirs.

A 12-year-long (2010–2021) hydrological and biogeochemical dataset in the Sicily Channel (Mediterranean Sea)

Abstract. The dataset presented here consists of 273 conductivity–temperature–depth (CTD) stations, as well as 2034 sampled data points in the water column, where dissolved inorganic nutrients have been measured, that were collected during 12 summer oceanographic cruises (BANSIC series) in the Sicily Channel (central Mediterranean Sea) between 2010 and 2021. The quality of the CTD dataset is ensured by regular sensor calibrations and an accurate control process adopted during the acquisition, processing, and post-processing phases. The quality of the biogeochemical dataset is ensured by the adoption of best-practice analytical and sampling methods. This data collection fills a gap of information in the Sicily Channel, i.e., a key area where complex water mass exchange processes involve the transfer of physical and biogeochemical properties between the eastern and western Mediterranean. The available dataset will be useful to evaluate the long-term variability on a wide spatial scale, supporting studies on the evolution of the Mediterranean circulation and its peculiar biogeochemistry, as well as on the physical and biogeochemical modeling of this area. The data are available in Zenodo (https://doi.org/10.5281/zenodo.8125006, Placenti et al., 2023).

Impact of inlet steam state on ejector internal flow and performance considering non-equilibrium condensation

Most of the numerical studies adopted dry gas model to predict transonic and supersonic flow in steam ejectors, but it cannot accurately reflect flow characteristics in ejectors, since the condensation and evaporation of wet steam is ignored. The current work develops and validates a CFD model describing spontaneous condensation to simulate complicated flow behaviors and phase transition inside an ejector, and illustrates the impact of initial state of primary fluid including wet, saturated and superheated state on flow characteristics, mass and heat exchange and ejector performance. It is found that the initial steam wetness obviously impacts the average liquid fraction in the ejector. Both the superheated and wet initial primary steam suppress the process of mass and heat exchange during nucleation, and the position and intensity of nucleation are influenced by the inlet steam state. Compared with the case of dry saturated inlet steam, the superheated inlet steam improves entrainment ratio by 3.7%, and decreases compression ratio by 2.5%.

INTENSIFICATION OF HEAT AND MASS EXCHANGE PROCESSES OF PROCESSING OLD SLUDGE

At sewage treatment plants, in addition to filtered water, sludge is formed during wastewater treatment. They are dumped on mud sites, which occupy large areas and are almost completely overflowing. The content of a large amount of minerals and toxic substances in sediments leads to the deterioration of the condition of groundwater and soil, which in turn leads to the deterioration of ecology and life. An urgent task in Ukraine is the creation of complex processing of sludge, which includes economic, technological, social and ecological aspects. The purpose of the research is to intensify the heat and mass exchange processes of processing old sludge deposits with the subsequent creation of a technology for obtaining composite fuel based on them. The study of drying kinetics of composite granules was carried out on an experimental convective stand with automatic data collection. A comparison of the drying time of composite granules depending on the granulation method was carried out, which showed the expediency of carrying out the process for granules formed on a screw mechanical device. Adsorption studies were carried out, which made it possible to determine the equilibrium moisture content. It was established that the specific heat of combustion of composite granules exceeds the heat of combustion of peat by 1.2 times, which allows them to be used as an alternative fuel.

Technology of applying a multifunctional homogenizer assembly for carbamide-ammonium mixture preparation

This paper considers the technological process of preparing carbamide-ammonium mixture using a multifunctional homogenizer assembly. The study object is the work process in the flow part of the multifunctional homogenizer assembly. Carbamide-ammonium mixture is used to feed plants with nitrogen, which is one of the main macro elements necessary for their growth and development. Nitrogen contributes to the formation of proteins, enzymes, and other important organic compounds, which are necessary for healthy plant growth and crop formation. Production of carbamide-ammonium mixture includes several stages, such as mechanical, hydromechanical, thermal, mass exchange, and chemical processes. To optimize these processes, a multifunctional homogenizer assembly of the rotary-dynamic principle of action was designed, which is capable of simultaneously performing all stages of carbamide-ammonium mixture preparation. A test bench was constructed to study the process of preparing carbamide-ammonium mixture and the sample was analyzed for nutrient content. The designed unit is capable of preparing about 30 liters of ready-made KAS-32 mixture in 10 minutes. The energy indicators obtained as a result of parametric tests are: head H=22.1 m, power N=27 kW, with productivity Q=5 m3/h. The use of such technology makes it possible to implement the principles of precision agriculture under the conditions of small-scale production, thereby increasing the efficiency of land cultivation. There is also the possibility of using equipment of this type for other needs, for example, for the preparation of liquid complex fertilizers and growth stimulants based on humates. Further development based on this assembly includes the construction of an automatic component supply line and the formation of a closed production cycle system

Digitalization of the thermoplastic beryllium oxide slurry forming process using ultrasonic activation

This paper presents the results of the digitalization of the thermoplastic beryllium oxide slurry forming process using ultrasonic activation. Ceramics made from beryllium oxide (BeO) using ultrasound-assisted forming exhibit more intense sintering and, in comparison to ceramics formed without ultrasound, have reduced shrinkage (by 2.4-4.3%) and sintering temperature (by 50-180°C). The forming processes occurring during ultrasonic treatment resulted in the homogenization of the thermoplastic suspension and dense packing of BeO powders in the casting. Ultrasound activation alters the rheology of the thermoplastic slurries. These changes are attributed to processes of slurry mass dispersion and mass exchange at the phase boundary of the suspension. Ultrasound activation also enhances casting properties. During the cooling-solidification process under the influence of ultrasound, the density and strength of the castings increase due to the effective compensation of shrinkage. Shrinkage compensation is carried out according to the classical scheme by supplying a liquid suspension. For hot casting with ultrasound of thermoplastic beryllium oxide slurries, it is advisable to use compositions with a binder content of 11.0-11.7% by weight since these compositions provide better shrinkage compensation and, consequently, a denser casting.

RESEARCH OF THE SIDE VENTILATION SYSTEM IN THE POULTRY HOUSE USING CFD

Maintaining a standardized microclimate in the poultry house is one of the main factors. The quality of the output ultimately depends on the quality indicators of the air parameters. Keeping a bird requires great efforts and technological solutions. In connection with this study, there is an improvement of the microclimate system in the air environment of the poultry house due to the inclusion of exhaust fans on the rear end wall in an unconventional way. Computational Fluid Dynamics (CFD) using ANSYS Fluent is a powerful tool for predicting the microclimate system in the poultry house as an alternative to experimental studies. The CFD model was performed on the Navier-Stokes equations for convective flows. The calculations use the Discrete Ordinates radiation model and the Spalart-Allmaras turbulence model.
 The calculations were made with an air consumption of 21.5 kg/s. The temperature of the outside air is assumed equal to +3 ºС and the thermal radiation parameter is entered. For air removal, Munters EM50 1.5 HP exhaust fans are used in a total number of 4 pcs. Inflow valves Wlotpowietrza 3000-VFG with a total number of 80 pcs., which are placed at a height of 0.21 m from the ceiling (1-8 valves) and 0.81 m for 9-40 valves.
 According to the results of CFD modeling of hydrodynamics and heat and mass exchange processes, it was concluded that changing the angle of the spoiler by 73o allows air to be supplied to the center of the poultry house. The upper air layers near the ceiling and near the side wall have a slightly higher temperature. This is accompanied by radiation from the sun and ranges from +21.5 to +24.5 ℃. Since the bird is a source of heat, and in combination with radiation, the air in the room is partially heated. In the center of the room along the entire height, the temperature reaches +15-16 ℃. At the same time, the pressure drop of the inlet valves is 70 Pa, which allows the exhaust fan to be fully supplied. The air velocity at the inlet of the inflow valves is 11.54 m/s. The average air speed at a height of 0.7 m from the floor level is 0.5 m/s, the temperature is 16.55 ℃.
 Thus, the presented scientific research can be used in the future to develop new ventilation systems for poultry houses.

Research of gas exchange and air purification processes by plants of the common privet (Ligustrum vulgare L.) species

Growing urbanization creates air pollution problems, which is becoming dangerous for human health and unsuitable for indoor ventilation. An effective solution is the combination of green structures with engineering systems, which requires the development of new methods and quantitative laboratory studies of gas and mass exchange processes of plants. The purpose of the study was to quantify the ability of plants of the common privet (Ligustrum vulgare L.) to release and absorb oxygen and СО2, as well as to study the effectiveness of air purification from particulate matter in order to properly take into account the impact of plants in the process of their selection for greening urban landscapes. The research was carried out according to the methodology developed by the authors in a gas exchange chamber, which was upgraded to model external conditions and study plants with small leaf area and developed stems. The results of the experiment showed that Ligustrum vulgare L. bushes with a small total photosynthetic leaf surface area are inefficient for carbon dioxide absorption in an urbanized environment, so plants with a significant proportion of photosynthetically active biomass and fast-growing plants should be preferred. It was determined that at maximum illumination, the degree of absorption of PM2.5 and PM10 by Ligustrum vulgare L. bushes was 8.84‧10-5...1.5‧10-4 μg/s, which confirms the effective absorption of particulate matter with a diameter of up to 2.5 and up to 10 μm from the air by the studied plants. The results obtained indicate an increase in the concentration of total volatile organic compounds in the outlet compartment, which indicates the active release of volatile phyto-organic substances by plants in the amount of 2.442...2.973 μg/s. The results of the study can be used for effective taxonomic selection of woody plants during the design and creation of urban green spaces that are resistant to the conditions of the urban environment

CONFIRMATION OF THE NEW EVOLUTIONARY STATUS OF UU CAS

We present results of a new spectroscopic study of a close binary system with massive components UU Cas based on the spectra obtained with the echelle spectrometer on the 1.2m telescope of the UrFU Kourovka Astronomical Observatory from 2017 to 2022. The results of this study confirm the new evolutionary status of UU Cas previously determined by the author with the spectrophotometry of this system in 2017 and confirmed in a number of works by other researchers. According to these studies, the system is in the final stage of the mass exchange process, but not at its beginning, as previously thought. The components of UU Cas are not very massive, and the ratio of their masses is opposite to a ratio determined earlier from the results of photometry. The parameters of the binary system were obtained on the more extensive observational material. This new parameters differ only slightly from those obtained earlier by the author. The half-amplitudes of the radial velocities are \({{K}_{1}} = 195.6\) km s–1, \({{K}_{2}} = 106.5\) km s–1. The masses of the components are \({{M}_{1}} = 9.6\;{{M}_{ \odot }}\), \({{M}_{2}} = 17.6\;{{M}_{ \odot }}\) for the orbital inclination i = 74.5°. The orbital radius of this close binary is \(A = 54.2\;{{R}_{ \odot }}\). The paper is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars”, dedicated to the 90th anniversary of Professor M.A. Svechnikov.

Confirmation of the New Evolutionary Status of UU Cas

A new spectral study of the close binary system (CBS) UU Cas with massive components was carried out, based on spectra obtained on the echelle spectrometer of the 1.2-m telescope of Kourovka Astronomical Observatory of UFU from 2017 to 2022. The results of this study confirm the new evolutionary status of UU Cas, previously determined by the author based on spectrophotometry of this system in 2017 and confirmed in a number of works by other researchers, according to which the system is in the final stage of the mass exchange process, and not at its beginning, as previously thought. Its components are not very massive, and the value of their mass ratio is the opposite of what was previously determined from photometry results. The values of the half-amplitudes of the radial velocities \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{K}_{1}} = 195.6$$\\end{document} km/s, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{K}_{2}} = 106.5$$\\end{document} km/s and the masses of both components \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{M}_{1}} = 9.6\\;{{M}_{ \\odot }}$$\\end{document}, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{M}_{2}} = 17.6\\;{{M}_{ \\odot }}$$\\end{document} obtained on a much more extensive observational material, for the orbital inclination angle i = 74.5°, given recently in the literature, as well as the orbital radius \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$A = 54\\;{{R}_{ \\odot }}$$\\end{document} of this close binary system are comparable with the values previously found by the author. The article is based on a talk presented at the astrophysical memorial seminar “Novelties in Understanding the Evolution of Binary Stars,” dedicated to the 90th anniversary of Professor M.A. Svechnikov.

Estimation of soil thermal properties using conduction and conduction–convection heat transfer equations in the Brazilian Pampa biome

Soil temperature, composition, and structure directly affect the heat transfer mechanisms in soil. Understanding the thermal behavior of soil is fundamental for describing the processes of mass and energy exchange in the soil-plant-atmosphere system. In addition, estimating thermal property values is necessary to determine the amount of heat transferred, stored, or transmitted by conduction and convection between the soil surface and deeper layers. This study used two soil heat transfer models (the conduction and conduction-convection methods) to estimate soil thermal properties. Soil data were collected in a natural pasture area in the Pampa biome in southern Brazil over 1.5 years. The results showed that soil thermal diffusivity (k) has an inverse seasonal variation with soil temperature (Ts). The k and soil thermal conductivity (λ) values are higher as the soil depth and soil moisture (θ) increase, confirming the vertical variation of thermal properties. The liquid water flux density (W) represents the vertical movement of water in the soil and decreases in periods of higher Ts. Increasing values of W led to an increase in the variability of k with depth. The conduction–convection method provides the best estimates for Ts with R2 = 0.99 for deeper layers compared to the conduction method. However, we found that both models gave similar results for near-surface layers since, in this case, the conduction process was responsible for most of the heat transfer from the surface to the ground. The results obtained here allowed us to evaluate heat transfer at different depths and estimate thermal properties as a function of soil moisture in a natural pasture area in the Brazilian Pampa biome. Furthermore, the results can be integrated into global land surface models intended to represent the behavior of the energy exchange between soil, surface, and atmosphere.

Improvement of sintering conversion technology of bauxite processing using solid fuel additives

In order to increase the technical and economic parameters of the process of sintering bauxite charges in a rotary furnace, it is the use of additives of finely divided solid fuel in them, which, without significantly deteriorating the value of the initial components, make it possible to intensify the development of internal crystal chemical transformations in the resulting specks due to changing the intensity of heat and mass exchange processes. Laboratory studies of thermal transformations in bauxite charge sinter showed that the use of solid fuel additives intensifies the development of internal heat and mass exchange processes, reducing the temperature difference in the cross section of samples. Increasing the addition of solid fuel to the bauxite charge contributes to shifting the compaction processes to the region of elevated heat treatment temperatures. Increasing the conditions for the development of internal crystal chemical transformations using an internal heat source in the form of solid fuel additives up to 1 % contributes to an increase in the yield of aluminum oxide and sodium into the solution after leaching the resulting cake. Ill. 3. Ref. 12.