Multiphase Medium Research Articles

On the impact of runaway stars on dwarf galaxies with resolved interstellar medium

ABSTRACT ‘Runaway stars’ might play a role in driving galactic outflows and enriching the circumgalactic medium with metals. To study this effect, we carry out high-resolution dwarf galaxy simulations that include velocity ‘kicks’ to massive stars above eigth solar masses. We consider two scenarios, one that adopts a power law velocity distribution for kick velocities, resulting in more stars with high-velocity kicks, and a more moderate scenario with a Maxwellian velocity distribution. We explicitly resolve the multiphase interstellar medium (ISM) and include non-equilibrium cooling and chemistry. We sample individual massive stars from an IMF and follow their radiation input and SN feedback (core-collapse) channel at the end of their lifetime. In the simulations with runaway stars, we add additional (natal) velocity kicks that mimic two- and three-body interactions that cannot be fully resolved in our simulations. We find that including runaway or ‘walkaway’ star scenarios impacts mass, metal, momentum, and energy outflows as well as the corresponding loading factors. The effect on the mass loading factor is small, but we find an increase in the metal loading by a factor of 1.5 to 2. The momentum loading increases by a factor of 1.5–2. The energy loading increases by roughly a factor of 5 when runaway stars are included. Additionally, we find that the overall level of star formation is increased in the models that include runaway stars. We conclude that the inclusion of runaway stars could have an impact on the global star formation and subsequent outflow properties of dwarf galaxies.

Passive damping of the beam elements of antenna systems

Beams are one of the most common elements of antennas - they can be used both as elements for receiving and transmitting radio signals, and as design solutions for various purposes. The paper considers a hinged-supported composite beam consisting of symmetrical layers reinforced with fiber with a viscoelastic coating. The representative element forming the beam layer consists of a fiber, a viscoelastic layer and a matrix. To assess the effect of the volumetric content of reinforcing fiber with a viscoelastic coating on the loss coefficient of a layered composite beam, the viscoelastic analogy method is used, within which the properties of a viscoelastic material are specified by complex quantities. And to evaluate the effect of the volumetric content of reinforcing fiber with a viscoelastic coating on the loss modulus of the composite material, the three-phase method extended to a multiphase medium and the viscoelastic analogy method are used. A study is also carried out to study the influence of the ratio of the real parameter of the loss modulus of the viscoelastic layer to the shear modulus of the reinforcing fiber on the effective transverse loss modulus of the composite material and on the loss coefficient of the laminated composite beam. Numerical values of the effective transverse loss moduli for the composite material under study and the loss coefficients of a simply supported beam are given depending on the thickness of the viscoelastic layer. For the parameters under study, the nature of the peak values is analyzed and ways of influencing their position and shape are discussed. It is assumed that such beams can find wide application in antenna technology, since they will significantly reduce mechanical resonant vibrations of antenna system structures, while maintaining their rigidity and strength.

Illuminating the Black Box: A Perspective on Zeolite Crystallization in Inorganic Media.

ConspectusSince the discovery of synthetic zeolites in the 1940s and their implementation in major industrial processes involving adsorption, catalytic conversion, and ion exchange, material scientists have targeted the rational design of zeolites: controlling synthesis to crystallize zeolites with predetermined properties. Decades later, the fundamentals of zeolite synthesis remain largely obscured in a black box, rendering rational design elusive. A major prerequisite to rational zeolite design is to fully understand, and control, the elementary processes governing zeolite nucleation, growth, and stability. The molecular-level investigation of these processes has been severely hindered by the complex multiphasic media in which aluminosilicate zeolites are typically synthesized. This Account documents our recent progress in crystallizing zeolites from synthesis media based on hydrated silicate ionic liquids (HSIL), a synthesis approach facilitating the evaluation of the individual impacts of synthesis parameters such as cation type, water content, and alkalinity on zeolite nucleation, growth, and phase selection. HSIL-based synthesis allows straightforward elucidation of the relationship between the characteristics of the synthesis medium and the properties and structure of the crystalline product. This assists in deriving new insights in zeolite crystallization in an inorganic aluminosilicate system, thus improving the conceptual understanding of nucleation and growth in the context of inorganic zeolite synthesis in general. This Account describes in detail what hydrated silicate ionic liquids are, how they form, and how they assist in improving our understanding of zeolite genesis on a molecular level. It describes the development of ternary phase diagrams for inorganic aluminosilicate zeolites via a systematic screening of synthesis compositions. By evaluating obtained crystal structure properties such as framework composition, topology, and extraframework cation distributions, critical questions are dealt with: Which synthesis variables govern the aluminum content of crystallizing zeolites? How does the aluminum content in the framework determine the expression of different topologies? The crucial role of the alkali cation, taking center stage in all aspects of crystallization, phase selection, and, by extension, transformation is also discussed. New criteria and models for phase selection are proposed, assisting in overcoming the need for excessive trial and error in the development of future synthesis protocols.Recent progress in the development of a toolbox enabling liquid-state characterization of these precursor media has been outlined, setting the stage for the routine monitoring of zeolite crystallization in real time. Current endeavors on and future needs for the in situ investigation of zeolite crystallization are highlighted. Finally, experimentally accessible parameters providing opportunities for modeling zeolite nucleation and growth are identified. Overall, this work provides a perspective toward future developments, identifying research areas ripe for investigation and discovery.

Multiphase fragmentation: Molecular shattering

Abstract Recent observations suggest galaxies may ubiquitously host a molecular component to their multiphase circumgalactic medium (CGM). However, the structure and kinematics of the molecular CGM remains understudied theoretically and largely unconstrained observationally. Recent work suggests molecular gas clouds with efficient cooling survive acceleration in hot winds similar to atomic clouds. Yet the fragmentation of molecular clouds into a large number of fragments (‘shattering’) when subjected to external shocks or undergoing rapid cooling remains unstudied. We perform radiative, inviscid hydrodynamics simulations of clouds perturbed out of pressure equilibrium to explore the process of shattering to molecular temperatures. We find molecular clouds larger than a critical size can shatter into a mist of tiny droplets, with the critical size deviating significantly from the atomic case. We find that cold clouds shatter only if the sound crossing time exceeds the local maximum of the cooling time ∼8000 K. Moreover, we find evidence for a universal mechanism to ‘shatter’ cold clouds into a ‘mist’ of tiny droplets as a result of rotational fragmentation – a process we dub ‘splintering.’ Our results have implications for resolving the molecular phase of the CGM in observations and cosmological simulations.

Transmission/Reflection Dual-Mode Ultrasonic Tomography Using Weighted Least Square-Lagrange Joint Reconstruction

Industrial Ultrasonic Tomography (UT) possesses unique advantages in multiphase medium imaging and has received broad attention. In this work, a novel transmission/reflection dual-mode image reconstruction algorithm based on information fusion is proposed. The transmissive attenuation and reflective time-delay information are both integrated into an improved Lagrange framework with the weighted least square transformation of objective function, which is then solved by a pair of coupled preconditioned gradient approaches. Experiment results show that the proposed algorithm performs better than existing image fusion strategies in terms of accuracy (average relative error 0.456, average correlation coefficient 0.870) and robustness (average standard derivation of relative error and correlation coefficient 0.056 and 0.041). Accordingly, the dual-mode UT approach is proved feasible to provide more accurate image of biphasic medium distribution.

Deformation behaviors and microstructure evolution of a novel multiphase medium Mn high Al lightweight steels with excellent strength-ductility combinations

The effects of phase constituents on the deformation behavior and the correlated mechanical properties at different solution temperatures were investigated in medium Mn high Al lightweight steels with different Al contents (Fe-12Mn-(6,8)-Al-1C). This study indicates that the mechanical properties of medium Mn high Al lightweight steels can be significantly enhanced though changing the content of Al and solution treatment. 6Al steel shows lower yield strength (YS) and tensile elongation (TEL) values than those of 8Al steel at the same temperature due to the unitary austenite phase. When Al is added to 8 wt%, both the precipitation of intergranular and intragranular κ-carbide are promoted and the constituents of multiple phases (austenite + ferrite +κ-carbide) result in ultra-high strengthening. The apparent strain partitioning causes by the different characteristics between different phases leads to the high initial strain hardening. During the deformation process, the sufficient formation of slip bands in austenite grains keeps the high strain hardening exponent and postponed the plastic stability, which also contribute to a pronounced ductility. The existence of multiple phases owing to the addition of Al is the key feature of excellent properties in the investigated lightweight steel.

Investigation of the load sustaining micro mechanisms of cemented sand using the mesoscale FEM approach

While the mechanics of cemented granular material have already been approached by means of constitutive modeling, the capacity of introducing the precise internal structure of multiphase media in numerical simulations offers an alternative perspective of investigation. In specific, means of X-ray computed tomography are able to quantify the internal irregular geometry of the composite material in the form of three-dimensional images. Image analysis can be applied in order to distinguish the topology of each material phase and advanced meshing techniques are able to form a twin meshed domain. The current paper deals with the quantitative description of the morphology of small cemented sand samples, the application of developed image analysis algorithms to treat imaging artefacts (mainly due to beam hardening), the equivalent mesh generation via the image adapted meshing technique and the numerical testing using the Finite Element Method. Four samples are imaged, meshed and numerically tested in uniaxial compression; the mesoscale finite element simulations are able to display the intergranular stress transmission chains. A statistical analysis of the load carried by the granular skeleton provides evidence of the influence of the cementation degree and the compaction of the aggregates on the uniformity of the stress distribution.

Possible observation of Leggett-like modes in a coherent two-phase medium

Spontaneous symmetry breaking is a ubiquitous phenomenon in physics responsible for various collective modes. Collective excitations predicted by Leggett in 1966 are specific for multiband superfluids and reflect oscillations of the relative phase of different band components. In this work, we argue that such modes should exist also in a multiphase medium with a coherent Josephson-like coupling between the different superconducting components. Point-contact experiments on superconducting ceramics formed by grains of two bismuth-based superconducting oxides with transition temperatures of about 70 and 100 K made it possible to reveal multiple periodic conductance peaks, which we have attributed to elastic scatterings by a Leggett-like mode inherent in the studied two-phase samples. We believe there should be a large group of superconducting materials where such modes could exist and assert that point-contact spectroscopy is one of the best ways to identify and characterize them.

Enhanced electromagnetic wave absorption performance of multiphase (TiC/TiO2/C)/SiOC composites with unique microstructures

Incorporating multiphases can not only increase the attenuation capacity but also partially alleviate impedance mismatch. In this work, (TiC/TiO2/C)/SiOC composites were prepared from polymer-derived ceramics (PDCs) using a TiC nanoparticle modified polysiloxane (PSO) precursor at 900 °C under an Ar flow. The addition of TiC serves a dual purpose of enhancing conductivity loss and acting as a source of Ti for the generation of TiO2 particles. The combination of these particles with the carbon layer in amorphous SiOC creates a multiphase loss medium that significantly improves not only conductive loss and dipole polarization loss but also interface polarization loss, resulting in excellent impedance matching characteristics and EM wave absorption. Accordingly, the (TiC/TiO2/C)/SiOC with a TiC fraction of 20 wt% indicated a significant minimum reflection loss (RLmin) of −54.2 dB (over 99.999% absorption), and the effective absorption bandwidth (EAB) covered 4.2 GHz with a thickness ranging from 2.5 to 3.3 mm in the X band. A maximum radar cross section (RCS) reduction of 24.6 dBm2 was achieved at a scattering angle of 75°. Thus, the (TiC/TiO2/C)/SiOC composites have the potential to be utilized in radar stealth technology and reduce EM pollution, offering a novel approach to address these challenges.

The SATIN project – I. Turbulent multiphase ISM in Milky Way simulations with SNe feedback from stellar clusters

ABSTRACT We introduce the star formation and supernova (SN) feedback model of the satin (Simulating AGNs Through ISM with Non-Equilibrium Effects) project to simulate the evolution of the star forming multiphase interstellar medium (ISM) of entire disc galaxies. This galaxy-wide implementation of a successful ISM feedback model tested in small box simulations naturally covers an order of magnitude in gas surface density, shear and radial motions. It is implemented in the adaptive mesh refinement code ramses at a peak resolution of 9 pc. New stars are represented by star cluster (sink) particles with individual SN delay times for massive stars. With SN feedback, cooling, and gravity, the galactic ISM develops a three-phase structure. The star formation rates naturally follow observed scaling relations for the local Milky Way gas surface density. SNe drive additional turbulence in the warm (300 < T < 104 K) gas and increase the kinetic energy of the cold gas, cooling out of the warm phase. The majority of the gas leaving the galactic ISM is warm and hot with mass loading factors of 3 ≤ η ≤ 10 up to h = 5 kpc away from the galaxy. While the hot gas is leaving the system, the warm and cold gas falls back onto the disc in a galactic fountain flow. The inclusion of other stellar feedback processes from massive stars seems to be needed to reduce the rate at which stars form at higher surface densities and to increase/decrease the amount of warm/cold gas.

Dynamic hydraulic fracturing in partially saturated porous media

The well-known phase-field approach applied to fracturing solids has recently been embedded in the Theory of Porous Media for the description of dynamic hydraulic fracturing scenarios based on fully saturated porous media. This method has further been enhanced by the introduction of a crack-opening indicator to distinguish between open and closed cracks accompanied by a switch between Darcy-type and Navier–Stokes-type flow situations in the unbroken porous domain and in fully broken areas. Based on these achievements, the present article extends the challenging matter of fully saturated media by the introduction of partially saturated scenarios, where the pore space contains both a liquid, such as water or oil, and a pore gas, such as air or natural gas. Proceeding from the Theory of Porous Media, the setup of the model is based on first principles of continuum mechanics, while the numerical study proceeds from the Finite-Element Method, where coupled problems of fracturing multi-component and multi-phasic media are treated by a monolithic solution strategy provided by a solver for coupled problems. By use of this procedure, it can be shown by comparison of fully and partially saturated porous media that the existence of pore gas slows down the fracture evolution. It is furthermore pointed out that the existence of closed precracks combined with external loads does not only lead to opening and evolving fractures, but also to fractures that do not open as a result of compressive boundary conditions.

Mechanisms of propeller jet-induced migration, release, and distribution of perfluoroalkyl acids in sediment–water systems

Perfluoroalkyl acids (PFAAs) are continuously accumulated in surface sediments due to extensive and long-term application. However, the mechanisms through which disturbances induced by ship propeller jets at the riverbed cause secondary release of PFAAs from sediments remain unclear. In this study, the effects of different propeller rotational speeds on PFAA migration, release, and distribution in multiphase media were investigated by performing indoor flume experiments combined with particle tracking velocimetry. Moreover, key factors influencing PFAA migration and distribution were identified, and partial least squares regression (PLS) method was applied to develop quantitative prediction models of relationships among hydrodynamics, physicochemical parameters, and PFAA distribution coefficients. The total PFAA concentrations (ΣPFAAs) in overlying water under propeller jet action exhibited transient characteristics and hysteresis with time after the disturbance. In contrast, the ΣPFAAs in suspended particulate matter (SPM) exhibited an upward trend throughout the process with consistent characteristics. The spatial distribution trends of PFAAs in overlying water and SPM at different propeller rotational speeds featured vertical variability and axial consistency. Furthermore, PFAA release from sediments was driven by axial flow velocity (Vx) and Reynolds normal stress Ryy, while PFAA release from porewater was inextricably linked to Reynolds stresses Rxx, Rxy, and Rzz (p < 0.05). PLS regression models showed that variations in Vorticity, dissolved organic carbon, and pH influenced the decreases in PFAA distribution coefficients between SPM and overlying water (KD-SW) as propeller rotational speed increased, except for very long-chain PFAAs (C > 10). The increases in PFAA distribution coefficients between sediment and porewater (KD-SP) were mainly determined by physicochemical parameters of sediments, and the direct effect of hydrodynamics was relatively weak. Our study provides valuable information regarding the migration and distribution of PFAAs in multiphase media under propeller jet disturbance (both during and after disturbance).

Formation and Evolution of a Dust Cloud as a Result of TNT Detonation in a Borehole: Numerical Simulation

Here, we present a numerical model for simulating the formation and evolution of the gas and dust cloud that forms after the detonation of high explosive charges in boreholes. This model provides a possible method for converting a substance ejected from an explosion funnel into discrete particles (smaller particles and stones) and calculating the movement of these condensed particles and their interaction with the air–gas flow; this method uses the framework of equations for multiphase media motion. For modeling of borehole explosion, we focused on the parameters of commercial blasting that are carried out at the Lebedinsky open pit. The results of simulating the initial stage of a borehole explosion with a mass of 1000 kg are presented in this paper. These results demonstrate the evolution of a gas and dust cloud, the change in the mass of particles of different sizes in the air over time, and their spatial distribution.

3D Modelling of double elbow pipeline erosion in methane – water – sand multiphase medium

Introduction. In gas industry, predicting sand erosion damage of pipelines by sand particles is a difficult task because this process is strongly influenced by many factors. Particulate matter carried away by the multiphase product during production can seriously compromise the integrity of fluid handling structures such as pipelines and elbows.&#x0D; Materials and methods. A three-dimensional numerical modelling approach in three-phase gas – liquid – solid flows was used to analyze erosion processes in pipe elbows. A key advantage of using CFD is that it can provide a wealth of information such as the effect of various parameters on erosion, maximum erosion rate, and erosion-prone areas. A variation of the Euler method for multiphase fluids was used to simulate three-dimensional unsteady gas-water annular flows with the presence of sand particles.&#x0D; Results. The results showed that a vertical pipe with two elbows is more prone to erosion at the second elbow than atthe first elbow. However, in a horizontal pipe with two elbows, it can be concluded that the first elbow is more proneto erosion. On the other hand, erosion at L/D = 0 showed the maximum erosion rate among all the geometries studied.&#x0D; Conclusions. In a vertical pipe, the second elbow of the pipeline is more susceptible to erosion. In addition, the erosion rate at the second elbow of vertical and horizontal pipes is the same for all studied geometries. The pipeline with L/D = 10 showed the optimal layout choice for vertical and horizontal pipe with an average erosion rate of 57.9 mm/year, which representsthe lowest erosion rate among the options studied.

Numerical Investigation of the Mass Transfer of Dispersed Particles during the Passage of a Shockwave in a Mono and Polydisperse Gas Suspension

The paper numerically simulates the propagation of a shock wave through a gas suspension. The carrier medium was described as a viscous, compressible, heat-conducting gas. The mathematical model implemented a continuum method for the dynamics of multiphase media, taking into account the interaction of the carrier medium and the dispersed phase. The mass transfer of disperse inclusions suspended in the gas, caused by the interaction of the shock wave with monodisperse gas suspensions and with gas suspensions having a multi-fractional composition, was modeled. Differences in the mass transfer of particles depending on the particle size are revealed. It was also found that the process of mass transfer of dispersed inclusions in a monodisperse gas suspension differs from a similar process for a fraction of a polydisperse gas suspension having the same particle size and the same volume content.

Limited impact of jet-induced feedback in the multi-phase nuclear interstellar medium of 4C12.50

Context. 4C12.50 (IRAS 13451+1232) at z = 0.122 is an ultraluminous infared radio galaxy that has often been proposed as a prime candidate for the link between ultraluminous infared galaxies and young radio galaxies. It is also an interesting target to investigate whether and how radio-induced feedback affects the evolution of galaxies in the early phases of radio activity. Aims. We study, in detail for the first time, the hot (≥1500 K) molecular gas in 4C12.50. The potential impact of the radio jet on this gas phase, as well as on the star formation activity, are investigated. We also study the ionised (including coronal) gas as traced by the near-infrared lines. Methods. Using near-infrared long slit spectroscopy obtained with EMIR on GTC and X-shooter on VLT, we analyse the emission line spectrum of the ionised, coronal, and, specially, the hot molecular gas in the western nucleus hosting the compact radio jet. Based on high spatial resolution ALMA CO(2–1) data, we also revise the location of 4C12.50 in the Kennicutt-Schmidt diagram in order to investigate whether star formation is suppressed. Results. 4C12.50 hosts (2.1 ± 0.4) × 104 M⊙ of hot molecular gas. An unusually high rotational temperature Trot = 3020 ± 160 K is inferred. The molecular gas mass obeys a power-law temperature distribution, dMH2/dT ∝ T−5, from T ∼ 300 K and up to ∼3000 K. Both results support the idea that shocks (probably induced by the radio jet) contribute to the heating and excitation of the hot molecular gas. A molecular outflow is not detected. The coupling of the outflowing ionised and neutral outflows with the hot molecular gas is poor. Contrary to other studies, we claim that there is no evidence for star formation suppression in this object. Conclusions. If radio-induced feedback can regulate the star formation activity in galaxies, 4C12.50 is a promising candidate to reveal this phenomenon in action. However, we find no solid evidence for a current or past impact of this mechanism on the evolution of this system, neither by clearing out the dusty central cocoon efficiently, nor by suppressing the star formation activity.

Phase Distribution Measurement of Liquid–Solid Media Using Multimode Ultrasound

Ultrasound tomography (UT) is an emerging technique for phase distribution measurement in industrial multiphase flow monitoring. A multimode UT combining the ultrasound transmission and reflection modes is proposed to measure stratified phase distribution and sound speed of liquid–solid mixtures in the horizontal pipe. First, the acoustic attenuation is used to reconstruct the phase distribution with a modified matrix regularization algorithm, and the time-of-flight (TOF) of ultrasound is used to extract the boundary of multiphase layers with the weight Akaike information criterion algorithm. Second, a wavelet fusion method based on the principal component averaging is proposed to fuse the reconstruction images of UT transmission and reflection. Third, numerical investigations are carried out to validate the feasibility of the proposed method. According to the quantitative indexes, the proposed method can effectively reconstruct the phase distribution of multiphase media. Finally, an experimental test pipeline Section is established, and sand–water and oil–water–sand liquid–solid media are investigated. The minimum relative error (RE) and the maximum correlation coefficient (CC) of experimental fusion results can reach 0.33 and 0.94, respectively, and the average measurement error (ME) of the layer height is 3.80%.

Formation of multiphase plasma in galactic haloes and an analogy to solar plasma

Thermal instability (TI) potentially explains the origin of cold gas in the intracluster medium (ICM), which is heated sufficiently by AGN feedback. The Hαfilaments seen in cluster cores provide strong motivation for TI. The hot (∼107K) ICM coronae allow the growth of isobaric TI. The multiphase medium (cold-dense—hot-diffuse) forms once TI saturates. However, gravitational stratification can spatially constrain TI, and thermal conduction is known to stabilize all scales below the field length (λF). In addition, the transport of energy is anisotropic along magnetic fields. Thermal conduction may further trigger gyroscale instabilities and effective reduction ofλF. However, cold gas at small scales(&lt;λF)needs to be verified in observations. The virial temperature in galactic haloes is lower (∼106K) and opens the regime of isochoric TI. In this regime, the cooling time is typically shorter than the sound-crossing time, and large-scale isochoric clouds are rendered unstable. The linear and non-linear isochoric clouds have interesting differences which potentially lead to either fragmentation of the cloud or not. On saturation, TI produces a turbulent medium that helps mix phases and thermalize kinetic energy and thus completes a cycle of condensation and heating. Various aspects of condensation, stratified turbulence, and magnetized transport are physically identical in solar coronae but scaled down to lower luminosity (similar temperatures). We will discuss the recent progress in TI, its connection to observations, and the analogy to solar prominences.

Ways of increasing the economic efficiency of the seed preparation process

Implementing the method considered allows to improvement the economic efficiency of the process by reducing the cost of production and improving the purity of the main fraction. With the increase in the gross production of grain crops, as one of the primary sources of human nutrition, the intensification of post-harvest grain processing becomes relevant. It is necessary to use biologically active seed material (SM) to obtain a high yield of grain crops without reducing quality and nutritional characteristics. Separating machines that separate by seed density have the highest efficiency of separating seed material by selecting highly productive and biologically active seeds. The aspect of reducing the economic efficiency of the process during long-term storage is considered, which is the effect of self-heating. This effect occurs when wet material is placed in storage, which begins to release heat and moisture actively during long-term interaction with the environment (high external temperatures). The process of damaging healthy grain can last for weeks. However, in poorly cleaned material with cracks and injuries, the self-heating process occurs slowly and lasts several hours. In a short period, the grain temperature can reach 85 degrees. This process is irreversible and affects large batches of grain. Repeated mechanical interaction of working bodies of machines and equipment implementing the process with SM particles causes micro- and macroinjury of seeds. Macrotraumas may include the reflection of a part of the embryo and a partially or destroyed shell. Microtraumas are internal cracks and injuries from interaction with pests. The number of injured seeds can reach 90%, depending on the culture. The article lists the factors that are decisive for an efficient and economical process of separating seed material by seed density: The frequency of oscillations of the working surface; The amplitude of oscillations of the working surface; Airflow speed, tray angles, and seed density. The hydrodynamics method of multiphase media is optimal for mechano-mathematical modeling of the seed layer. The SM layer was modeled as a multiphase medium consisting of two phases: "discrete" - the SM layer and "continuous" - airflow. This approach effectively links the kinematic and structural parameters of the separating machine with the physical and mechanical properties of the raw material. One of the critical indicators of SM's quality is its main fraction's purity, which has been adopted as a criterion for the efficiency of the separation process using a pneumatic sorting table. The purity of the main fraction of SM is understood as the content of the primary culture in it, expressed as a percentage of the weight. The method makes it possible to predict the process's quality indicators depending on the material's properties that get processed and to reduce the time for setting up the pneumatic sorting table for a specific culture. Keywords: economic efficiency, seed material, biological potential, separation, vibro-pneumatic fluidized bed, multiphase environment, pneumatic sorting table, seed injury, germination.

DEVELOPMENT OF A MODEL OF HYBRID DETONATION IN A MIXTURE OF OXYGEN-HYDROGEN-ARGON WITH ALUMINUM PARTICLES

A simple mathematical model of hybrid detonation in oxygen-hydrogen-argon mixtures with suspended aluminum particles is suggested. The model is based on the approaches of the mechanics of multiphase media and equations of reduced chemical kinetics to describe gaseous and heterogeneous reactions. Production of alumina in the form of nanoparticles is considered. The problem of initiation and propagation of cellular detonation in a planar channel is analyzed. The results of calculations show that addition of small amount of combustible particles leads to increase in the detonation velocity and transformation of the cellular structure.