Mode Particles Research Articles

Validation of the current and pressure coupling schemes with nonlinear simulations of TAE and analysis on the linear stability of tearing mode in the presence of energetic particles

Both current and pressure coupling schemes have been adopted in the hybrid kinetic–magnetohydrodynamic code CLT-K recently. Numerical equivalences between these two coupling schemes are strictly verified under different approximations. First, when considering only the perturbed distribution function of energetic particles (EPs), the equivalence can be proved analytically. Second, when both the variations of the magnetic field and the EP distribution function are included, the current and pressure coupling schemes numerically produce the same result in the nonlinear simulations. On this basis, the influences of co-/counter-passing and trapped EPs on the linear stabilities of the m/n = 2/1 tearing mode (TM) have been investigated (where m and n represent the poloidal and toroidal mode numbers, respectively). The results of scanning of EPs show that the co-passing and trapped EPs are found to stabilize the TM, while the counter-passing EPs tend to destabilize the TM. The behind (de)stabilization mechanisms of the TM by EPs are carefully analyzed. Furthermore, after exceeding critical EP betas, the same branch of the high-frequency mode is excited by co-/counter-passing and trapped EPs, which is identified as the m/n = 2/1 energetic particle mode.

Chitosan particle-emulsion complex adjuvants: The effect of particle distribution on the immune intensity and response type

Particle-emulsion complex adjuvants as a new trend in the research of vaccine formulation, can improve the immune strength and balance the immune type. However, the location of the particle in the formulation is a key factor that has not been investigated extensively and its type of immunity. In order to investigate the effect of different combining modes of emulsion and particle on the immune response, three types of particle-emulsion complex adjuvant formulations were designed with the combination of chitosan nanoparticles (CNP) and an o/w emulsion with squalene as the oil phase. The complex adjuvants included the CNP-I group (particle inside the emulsion droplet), CNP-S group (particle on the surface of emulsion droplet) and CNP-O group (particle outside the emulsion droplet), respectively. The formulations with different particle locations behaved with different immunoprotective effects and immune-enhancing mechanisms. Compared with CNP-O, CNP-I and CNP-S significantly improve humoral and cellular immunity. CNP-O was more like two independent systems for immune enhancement. As a result, CNP-S triggered a Th1-type immune bias and CNP-I had more of a Th2-type of the immune response. These data highlight the key influence of the subtle difference of particle location in the droplets for immune response.

Size-resolved gas-particle partitioning characteristics of typical semi-volatile organic compounds in urban atmosphere

Understanding particle size distribution and size-resolved gas-particle partitioning of semi-volatile organic compounds (SVOCs) is important for characterizing their fate in atmosphere. However, the size-resolved gas-particle partitioning characteristics of SVOCs has not been adequately considered. To address this issue, the present study collected gaseous and size-fractioned particulate samples both in and outside of schools, offices, and residences in three districts of different urbanization levels in a megacity, Guangzhou, South China during two seasons. Typical SVOCs, including 15 polycyclic aromatic hydrocarbons (PAHs), six organophosphate esters and seven phthalic acid esters were measured. Emission sources, physicochemical properties, and environmental conditions at the sampling sites considerably impacted the spatiotemporal distribution patterns and particle size distribution of target SVOCs. Not all observed gas-particle partition coefficients (Kp) of target SVOCs were negatively correlated with subcooled liquid-vapor pressures (PL0), probably because certain factors, such as the non-exchangeable part of the particle-bound SVOCs, were not considered in traditional gas-particle partition theories. Particle size was an important factor affecting gas-particle partitioning. Adsorption was the dominant mechanism for PAHs with high molecular weight in different particle modes. A new model was established to predict size-resolved Kp of PAHs with high molecular weight based on PL0 and particle size.

Hybrid simulations of m/n = 1/1 instability driven by energetic counter-passing particles in tokamak plasmas

A systematic simulation study of the $n/m=1/1$ instability driven by energetic counter-passing particles in tokamak plasmas has been carried out using the kinetic-MHD (Magnetohydrodynamics) hybrid code M3D-K. The safety factor's radial profile is monotonically increasing with central value $q_0$ less than unity. The linear simulation results show that the instability is either a $m/n=1/1$ energetic particle mode or a $m/n=1/1$ global Alfvén eigenmode depending on the value of the central safety factor. The mode frequencies are close to the tip of Alfvén continuum spectrum at the magnetic axis. The excited modes are radially localized near the magnetic axis well within the safety factor $q=1$ surface. The main wave particle resonance is found to be $\omega _\phi +2\omega _\theta =\omega$ , where ω is the mode frequency. The nonlinear simulation results show that there is a long period of quasi-steady-state saturation phase with frequency chirping up after initial saturation. Correspondingly, the energetic particle distribution with low energies is flattened in the core of the plasma. After this quasi-steady phase, the mode amplitude grows again and frequency jumps down to a low value corresponding to a new mode similar to the energetic co-passing particle-driven low-frequency fishbone while the energetic particle distribution is flattened for higher energies in the core of plasma.

Handling multi-objective optimization problems with a comprehensive indicator and layered particle swarm optimizer.

The multi-objective particle swarm optimization algorithm has several drawbacks, such as premature convergence, inadequate convergence, and inadequate diversity. This is particularly true for complex, high-dimensional, multi-objective problems, where it is easy to fall into a local optimum. To address these issues, this paper proposes a novel algorithm called IMOPSOCE. The innovations for the proposed algorithm mainly contain three crucial factors: 1) an external archive maintenance strategy based on the inflection point distance and distribution coefficient is designed, and the comprehensive indicator (CM) is used to remove the non-dominated solutions with poor comprehensive performance to improve the convergence of the algorithm and diversity of the swarm; 2) using the random inertia weight strategy to efficiently control the movement of particles, balance the exploration and exploitation capabilities of the swarm, and avoid excessive local and global searches; and 3) offering different flight modes for particles at different levels after each update to further enhance the optimization capacity. Finally, the algorithm is tested on 22 typical test functions and compared with 10 other algorithms, demonstrating its competitiveness and outperformance on the majority of test functions.

Analysis of the ECH effect on EPM/AE stability in Heliotron J plasma using a Landau closure model

The aim of the present study is to analyze the effect of the electron cyclotron heating (ECH) on the linear stability of Alfvén eigenmodes (AEs) and energetic particle modes (EPMs) triggered by energetic ions in Heliotron J plasma. The analysis is performed using the FAR3d code that solves a reduced MHD model to describe the thermal plasma coupled with a gyrofluid model for the energetic particle (EP) species. The simulations reproduce the AE/EPM stability trends observed in the experiments as the electron temperature (T e ) increases, modifying the thermal plasma β, EP β and EP slowing-down time. Particularly, the EPM and Global AE are stabilized in the low-bumpiness (LB) configuration due to an enhancement of the continuum, finite Larmor radius and e-i Landau damping effects as the thermal β increases. On the other hand, a larger ECH injection power cannot stabilize the AE/EPM in medium-bumpiness and high-bumpiness (HB) configurations because the damping effects are weaker compared to the LB case, unable to balance the further destabilization induced by an enhanced EP resonance as the EP slowing-down time and EP β increases with T e .

Migration of silver nanoparticles from plastic materials, with antimicrobial action, destined for food contact.

Five materials with antimicrobial function, by adding silver, were investigated to evaluate total silver concentration in the polymers and migration of silver nanoparticles from the materials in contact with food. The migration test was carried out by contacting plastic material with food simulant. Migration concentrations and average silver particle sizes were determined by mass spectrometry with inductively coupled plasma, performed in single particle mode (spICP-MS). Additionally, silver particles size and shape were characterized by scanning electron microscopy (SEM) with chemical identification by energy-dispersive X-ray spectroscopy (EDS). Most of samples showed detectable total silver concentrations and all samples showed migration of silver nanoparticles, with concentrations found between 0.00433 and 1.35ngkg-1. Indeed, the migration study indicated the presence of silver nanoparticles in all food simulants, with sizes bellow 95nm. The average particle size determined for acetic acid was greater than that observed in the other simulants. In the images obtained by SEM/EDS also confirmed the presence of spherical silver nanoparticles, between 17 and 80nm. The findings reported herein will aid the health area concerning of human health risk assessments, aiming at regulating this type of material from a food safety point of view.

Coherent Flow Structures Near Tongue Region in a Centrifugal Fan With Forward-Curved Blades

Abstract The unsteady characteristics of the velocity field around the tongue of the volute in a centrifugal fan with forward-curved blades were investigated by time-resolved particle image velocimetry and mode decomposition analysis, i.e., proper orthogonal decomposition (POD) and spectral proper orthogonal decomposition (SPOD). Both POD and SPOD analysis reveal the existence of two types of unsteadiness in the flow field in the volute, one is the large-scale fluctuations at rotation frequency and its high-order harmonics in the main outlet flow, the other is due to the jet–wake structures at blade passing frequency in the cutoff clearance region. Additionally, SPOD analysis reveals a third type of disturbance, which is characterized as strip-like velocity structures at the intermediate frequency. The geometric and dynamic features of these coherent flow structures are inspected by the eigenfunction and their reduced-order reconstruction. In comparison with the POD analysis, the SPOD analysis enables the examination of the spatial pattern of each frequency component due to its dual-orthogonality nature. These structures direct impact the tongue, and thus might be responsible for the generation of strong wall-pressure fluctuation on the nose of the tongue. Due to the frequency mixing limitation of POD analysis, they cannot be easily identified from the leading-order POD modes. Furthermore, the frequency range of these three groups of disturbances, as well as their spatial extension, are determined via SPOD analysis and reduced-order reconstruction.

Effect of channel width on the sedimentation modes of a cold elliptical particle in hot narrow channels

Many natural and industrial processes involve transport of solid particles. This research reports sedimentation modes of a single cold elliptical particle with an aspect ratio of 2 in narrow hot channels. Prior research on settling of non-isothermal elliptical particles was limited to wide vertical channels. A cold particle with constant non-dimensional temperature of T p ∗ = 0 and an initial orientation of θ 0 = π / 3 between its major axis and horizontal axis is released in a hot fluid. Fluid Prandtl number is 7, and its initial temperature is T f , 0 ∗ = 1 . Simulations are based on an in-house lattice-Boltzmann solver with two distribution functions for fluid flow and heat transfer and using Boussinesq approximation in low density variations. In total, 120 simulations in five channel widths have been run, with enough time for the particle to reach a distinct sedimentation/rising pattern. Effects of channel width ( L = 12 A / 13 − 38 A / 13 ), where A is ellipse major diameter, the Grashof number ( Gr = 100 − 1000 ), and particle-to-fluid density ratio ( ρ r = 1 . 0003 − 1 . 3 ) have been studied. Channel width, gravity and heat transfer have been discovered to cause the particle to travel up or down. Seven sedimentation modes have been observed including i) horizontal at centerline, ii) inclined off-center, iii) vertical at center, iv) oscillatory motion around centerline, v) tumbling off-center, vi) horizontal fluttering at centerline, and vii) inclined off-center with oscillations. Three of these patterns (iii, iv, vii) are peculiar to narrow channels, and have not previously been observed for cold elliptic particles in wide channels ( L = 52 A / 13 ). Moreover, the particle has been seen to move upward rather downward in the narrowest channel for small particle-to-fluid density ratios. • Sedimentation modes of a cold elliptical particle in hot narrow channels are studied. • In total seven settling modes are observed; three of them are new and unique to narrow channels. • Grashof and Archimedes number and channel width have significant influence on the sedimentation pattern. • In narrow channels, wall and heat transfer effect are stronger than in wide channels and can even push the particle upward by overcoming the gravity. • Sedimentation velocity of the particle has been seen to be lower in narrow channels compared to wider ones.

Enhanced comprehensive properties of stereolithography 3D printed alumina ceramic cores with high porosities by a powder gradation design

• A novel powder gradation design strategy greatly enhances comprehensive properties in ceramic cores by SLA 3D printing. • Particle sizes importantly determine sintering degrees in SLA 3D printed ceramic cores. • The fracture mode of coarse powders varies with changing particle size gradation. • A "non-skeleton" microstructure model is established for SLA 3D printed ceramic cores. • Porosity presents more effect on high-temperature deflection of ceramic cores than particle size. Ceramic cores with complex structures and optimized properties are critical for hollow turbine blades applied in aeroengines. Compared to traditional methods, additive manufacturing (AM) presents great advantages in forming complex ceramic cores, but how to balance the porosity and strength is an enormous challenge. In this work, alumina ceramic cores with high porosity, moderate strength, and low high-temperature deflection were prepared using stereolithography (SLA) 3D printing by a novel powder gradation design strategy. The contradiction between porosity and flexural strength is well adjusted when the mass ratio of the coarse, medium, and fine particles is 2:1:1 and the sintering temperature is 1600 °C. The fracture mode of coarse particles in sintered SLA 3D printing ceramic transforms from intergranular fracture to transgranular fracture with the increase of sintering temperature and the proportion of fine powders in powder system. The sintered porosity has a greater influence on the high-temperature deflection of SLA 3D printed ceramic cores than grain size. On this basis, a "non-skeleton" microstructure model of SLA 3D printed alumina ceramic cores is created to explain the relationship between the sintering process and properties. As a result, high porosity (36.4%), appropriate strength (50.1 MPa), and low high-temperature deflection (2.27 mm) were achieved by optimizing particle size gradation and sintering process, which provides an insight into the important enhancement of the comprehensive properties of SLA 3D printed ceramic cores.

Long-lived light mediators from Higgs boson decay at HL-LHC and FCC-hh, and a proposal of dedicated long-lived particle detectors for FCC-hh

We study the pair production of the long-lived mediator particles from the decay of the SM Higgs boson and their subsequent decay into standard model particles. We compute the projected sensitivity, both model-independently and with a minimal model, of using the muon spectrometer of the CMS detector at the HL-LHC experiment for ggF, VBF, and Vh production modes of the Higgs boson and various decay modes of the mediator particle, along with dedicated detectors for LLP searches like CODEX-b and MATHUSLA. Subsequently, we study the improvement with the FCC-hh detector at the 100\,TeV collider experiment for such long-lived mediators, again focusing on the muon spectrometer. We propose dedicated LLP detector designs for the 100\,TeV collider experiment, DELIGHT (\textbf{De}tector for \textbf{l}ong-l\textbf{i}ved particles at hi\textbf{gh} energy of 100\,\textbf{T}eV), and study their sensitivities.

Pressure-dependent microstructure evolution of Fe-based amorphous alloy powders via high-pressure gas atomization

The pressure-dependent microstructure evolution of the gas-atomized Fe-based amorphous alloy powders at gas pressures in the range from 5 MPa to 8 MPa has been studied experimentally and theoretically. The results showed that the amorphous fraction and nucleation mode of particles were sensitive to the gas pressure. Specifically, at 7 MPa, the particles presented a fully amorphous structure with the maximal size class of 45–75 µm, and preferred to nucleate heterogeneously within the sphere rather than on the surface. These interesting phenomena were associated with the difference of cooling rate within droplets, reflected by the gas-liquid relative velocity at the cooling and solidification stage in the atomization process. It was also indicated that the amorphous phase underwent three stages of reactions upon devitrification with the precipitations of {Fe, Ni} and Fe 2 P, α-Fe and M 23 B 6 , respectively. Finally, glass-forming features of powders at different pressures have been elucidated based upon a kinetics analysis of the cooling rates of droplets and the phase selection competition. This work provides beneficial guidance for the devisal of metallic glass powder with different microstructures via gas atomization. • The amorphous fraction and nucleation mode of particles were sensitive to the gas pressure. • The cooling histories of droplets with typical diameters were simulated in the atomization process. • At 7 MPa, the largest gas-liquid relative velocity resulted in the largest cooling rate for droplets. • The microstructure evolution and transition depend on the calculation of R c and cooling histories of droplets.

Chemical fractionation of particulate-bound metal(loid)s to evaluate their bioavailability, sources and associated cancer risk in India

Eleven potentially toxic metal(loid)s (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), proven source markers of mineral based coal-fired industrial emissions and vehicular exhausts, were analysed using the four steps sequential extraction method to evaluate metal(loid)s concentration, in total and fractions of bioavailable and non-bioavailable for fine (PM2.5) and coarse (PM10–2.5) particulate modes. A total of 26-day-wise samples with three replications (total number of samples = 78) were collected in January–December 2019 for each PM10 and PM2.5 at an urban-residential site in India. In both the coarse and fine particulate modes, Pb and Cr have respectively shown the highest and lowest total concentrations of the measured metal(loid)s, indicating the presence of coal-fired power plants and heavy vehicular activities near to study area. In addition, Mn has shown highest bioavailable fraction for both coarse and fine particulate modes. More than 50 % of metal(loid)s concentration, in total to a bioavailable fraction (BAF) were observed in case of As, Cd, Cr, Co, Mn, Ni, and Pb of PM2.5. Mn and Zn have shown similar behaviour in the case of coarse particulate mode. Source apportionment of metal(loid)s bioavailable fractions using positive matrix factorization (PMF 5.0) has found three significant sources: crustal and natural dust (30.04 and 39 %), road traffic (49.57 and 20 %), and industrial emission (20.39 and 41 %) for coarse and fine particulate mode, respectively. Cancer risk through the inhalation pathway was high in total concentration but lower in BAF concentration in both age groups (children and adults).

Effects of emission sources on the particle number size distribution of ambient air in the residential area

Particle size distribution is a major factor in the health and climate effects of ambient aerosols, and it shows a large variation depending on the prevailing atmospheric emission sources. In this work, the particle number size distributions of ambient air were investigated at a suburban detached housing area in northern Helsinki, Finland, during a half-year period from winter to summer of 2020. The measurements were conducted with a scanning mobility particle sizer (SMPS) with a particle size range of 16–698 nm (mobility diameter), and the events with a dominant particle source were identified systematically from the data based on the time of the day and different particle physical and chemical properties. During the measurement period, four different types of events with a dominant contribution from either wood-burning (WB), traffic (TRA), secondary biogenic (BIO), or long-range transported (LRT) aerosol were observed. The particle size was the largest for the LRT events followed by BIO, WB, and TRA events with the geometric mean diameters of 72, 62, 57, and 41 nm, respectively. BIO and LRT produced the largest particle mode sizes followed by WB, and TRA with the modes of 69, 69, 46, and 25 nm, respectively. Each event type had also a noticeably different shape of the average number size distribution (NSD). In addition to the evaluation of NSDs representing different particle sources, also the effects of COVID-19 lockdown on specific aerosol properties were studied as during the measurement period the COVID-19 restrictions took place greatly reducing the traffic volumes in the Helsinki area in the spring of 2020. These restrictions had a significant contribution to reducing the concentrations of NOx and black carbon originating from fossil fuel combustion concentration, but insignificant effects on other studied variables such as number concentration and size distribution or particle mass concentrations (PM1, PM2.5, or PM10).

Effects of Moisture on the Ignition and Combustion Characteristics of Lignite Particles: Modeling and Experimental Study.

The influence of the moisture content on the ignition and combustion characteristics of lignite single particles was studied using an ignition model of single coal particles with moisture and experimental investigations in a visual drop tube furnace under the temperature of 1300 K. The moisture content and the lignite particle size were varied within the ranges of 0–20% and 75–250 μm, respectively. The images of the combustion process illustrated that higher moisture content caused a significant ignition delay. The probability of homogeneous ignition was greatest when the particle size was 125–150 μm and the moisture content was 5%. An ignition model was employed to explain the mechanism of the influence of moisture content on the ignition and combustion characteristics, which embedded the chemical percolation devolatilization model to increase the accuracy of predictions. The predicted results show that there was an overlap in the release of moisture and volatile matter from the lignite particle during the combustion at a high heating rate. The devolatilization rate increases with the increase of moisture, which explains the increase in the probability of homogeneous ignition and fragmentation. Both particle size and moisture content have two-sided effects on the ignition mode, which causes the complexity and irregularity of the ignition mode of particles with moisture.

Microstructural evolution of amorphous nano carbon reinforced TiB2–SiC–B4C composite ceramics derived from absorbent cotton

In this study, amorphous nanocarbon particles were added by the vacuum deposition of absorbent cotton, and TiB 2 –SiC–B 4 C composite ceramics were prepared via vacuum filtration, cold isostatic pressing, and pressureless sintering. X-ray diffractometry (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to determine the phase transformation and microstructural evolution of the nanocarbon-reinforced TiB 2 –SiC–B 4 C composites. Based on the high-resolution TEM results, the formation processing of lamellar grains, induced by the presence of parallel nanocarbon particles, was discussed in detail. Furthermore, owing to the optimization of the fracture mode and reinforcement of the nanocarbon particles, the mechanical properties of the composites were found to be significantly improved, that is, the flexural strength and fracture toughness were 585.6 MPa (almost a 39% increase to blank TiB 2 –SiC–B 4 C composite ceramics) and 5.9 MPa m 1/2 (almost a 55% increase), respectively. The introduction of nanocarbon particles via cotton pyrolysis not only reduced the production cost but also solved the problem of nanophase dispersion, providing a novel strategy for the low-cost preparation and improved performance of structural ceramics.

Micromagnetic Modes of Anisotropy of Magnetic Susceptibility in Natural Magnetite Particles

AbstractAnisotropy of magnetic susceptibility (AMS) is commonly used to assess sedimentation, deformation, tectonics, rock fabric, and texture. Using focused‐ion beam nanotomography, we develop a micromagnetic method to investigate the AMS of individual magnetite inclusions in silicates across the transition between single‐domain (SD) to multidomain behavior. We calculate individual AMS tensors by modeling the magnetization response of a particle to weak applied fields in three orthogonal directions. The main AMS mode of elongated SD particles is not a homogeneous magnetization rotation, but focused alignment of spins at their edges and tips. In single‐vortex particles, vortex displacement is the dominant AMS mode, which focuses the largest magnetization changes in a planar region containing the vortex core, and perpendicular to the direction of vortex motion. In multi‐vortex structures a combined motion of all vortex centers can lead to high degrees of anisotropy when some motion patterns are energetically much easier to achieve than others.

Alkali emissions characterization in chemical looping combustion of wood, wood char, and straw fuels

Chemical looping combustion of wood pellets (WP), wood char (WC), and straw pellets (SP) was conducted in a 60 kW CLC pilot with ilmenite and braunite oxygen carriers (OCs). Alkali emissions were investigated with impactor-based and surface ionization detector (SID) measurements. Particle size distributions for WP and WC fuels were dominated by coarse particles formed by refractory species. For SP fuel, the distribution was bimodal with a distinct fine particle mode formed by nucleation of volatile ash species. Thermodynamic modelling of stable alkali species at 800 °C predicted that high KOH(g) and lower concentrations of KCl(g) are stable for WP and WC fuels. For SP fuel, equilibrium K species were dominated by condensed-phase K species, followed by KCl(g), and KOH(g). Modelling of fuel-OC interactions showed that ilmenite decreases equilibrium levels of KOH(g) and KCl(g). Braunite impacted only KOH(g) levels. Impactor sample leachate analysis showed that for WP-braunite operation, the leachate contained KCl, NaCl, KOH, and NaOH, in decreasing order. For WC-ilmenite operation, the samples contained KOH and KCl. For SP fuel, most detected alkalis were KCl. For most cases, speciation of impactor samples qualitatively agreed with modelling predictions. Impactor and SID alkali measurements showed reasonable agreement for WC-braunite and SP-braunite tests.

Tunable multiband metamaterial coherent perfect absorber based on graphene and vanadium dioxide

In this paper, we propose a tunable multiband metamaterial coherent perfect absorber, where vanadium dioxide (VO2) square particles are periodically arranged on the two sides of polysilicon–silica–graphene–silica–polysilicon​ structure. The absorption spectrum of our absorber exhibits three peaks with high absorptivity which are originated from the plasmon resonance modes of graphene and VO2 particle. Benefitting from the tunable conductivity of graphene, the adjustment range of the absorption peak based on the first-order plasmon resonance mode of graphene is as much as 7.88μm when the Fermi level of graphene is increased from 0.3 to 1 eV. As VO2 is changed from metal phase to insulating phase, the absorption peak stemming from the plasmon resonance mode of VO2 particle disappears. The modulation depth of absorption peak can achieve up to 98.85% by tuning the relative phase of two coherent light beams. The resonance wavelengths and intensities of absorption peaks are also dependent on the array period, side length of VO2 particle and the thickness of silica layer. In addition, the change of surrounding refractive index causes a shift of the absorption peak corresponding to VO2 particle. Our findings are helpful for the engineering of actively tunable nano plasmonic devices and metamaterials.

Thermophysical processes in dry granulation of metallurgical slags

Mathematical model for theoretical analysis of thermophysical processes of melt drops solidification is examined during their motion inside cooling gas, applying to granulation task. The heat exchange equations during granulation, taking into account convection, heat conductivity in solid phase and Stefan conditions on the boundary of phase transition, are presented. The relationships characterizing correlation of the power exchange parameters in dispersed medium are obtained in the conditions of phase transition in melt drops inside gas phase flow. Analytical relationships allow to consider correlation of the parameters which characterize granulation process, to provide directions of efficient conduction of the processes for achieving the preset aims and to reveal the conditions for optimal technological parameters of the process. Speed of the power exchange processes determines the size of an installation and allows to make preliminary assessment during designing. Different motion modes for particles and gas are investigated. The variants for calculation of gas dynamic parameters of straight flying trajectory for a slag melt particle are suggested; they are based on solving the problem of particle motion in the gas medium, taking into account particle size, medium resistance, initial particle speed. Used relationships allow to assess the particle flying time, which is corresponded to the required time of particle cooling during its flying, and to choose programming conditions for motion of dispersed jet of slag melt. These conditions guarantee forming of solid crust on the cooled particle and possibility of size determination for a granulation system. Possible scheme of slag heat realization, allowing to utilize maximally the exergy of secondary power resources, is considered. The obtained results can be used for improvement of the existing installations fir dry granulation and for designing of the new ones, as well as for optimization of operating modes of granulators, for their efficiency rise and increase of power saving possibilities for a granulation system.  The research was conducted within the framework of the State assignment, project No. FSWF-2020-0019.