Initial Particle Size Distribution Research Articles

Effect of the Particle Size Distribution of the Ballast on the Lateral Resistance of Continuously Welded Rail Tracks

While the effect of ballast degradation on lateral resistance is noteworthy, limited research has delved into the specific aspect of ballast breakage in this context. This study is dedicated to assessing the influence of breakage on sleeper lateral resistance. For simplicity, it is assumed that ballast breakage has already occurred. Accordingly, nine granularity variations finer than No. 24 were chosen for simulation, with No. 24 as the assumed initial particle size distribution. Initially, a DEM model was validated for this purpose using experimental outcomes. Subsequently, employing this model, the lateral resistance of different particle size distributions was examined for a 3.5 mm displacement. The track was replaced by a reinforced concrete sleeper in the models, and no rails or rail fasteners were considered. The sleeper had a simplified model with clumps, the type of which was the so-called B70 and was applied in Western Europe. The sleeper was taken into consideration as a rigid body. The crushed stone ballast was considered as spherical grains with the addition that they were divided into fractions (sieves) in weight proportions (based on the particle distribution curve) and randomly generated in the 3D model. The complete 3D model was a 4.84 × 0.6 × 0.57 m trapezoidal prism with the sleeper at the longitudinal axis centered and at the top of the model. Compaction was performed with gravity and slope walls, with the latter being deleted before running the simulation. During the simulation, the sleeper was moved horizontally parallel to its longitudinal axis and laterally up to 3.5 mm in static load in the compacted ballast. The study successfully established a relationship between lateral resistance and ballast breakage. The current study’s findings indicate that lateral resistance decreases as ballast breakage increases. Moreover, it was observed that the rate of lateral resistance decrease becomes zero when the ballast breakage index reaches 0.6.

Gas and particle emissions from rifle and pistol firing

Emissions were sampled from firing an M4 carbine rifle and a M9 (military issue of Beretta 75 FS 9 mm pistol) to develop sampling methods and assess potential exposures and range contamination issues. Breech and muzzle emissions were sampled from the rifle when firing M855A1 ammunition (lead (Pb)-free slugs) in single- and triple-shot burst mode and from single pistol shots when firing 9 mm XM1152 ammunition (not Pb-free). Emissions were sampled for carbon monoxide (CO), carbon dioxide (CO2), methane, hydrogen cyanide, ammonia, particulate matter by size, polycylic aromatic hydrocarbons, and volatile organics. Analyses on the particles included elemental composition, size distribution, carbon composition (black, total, organic, and elemental carbon), and particle composition and morphology. Emission concentrations from both the rifle and pistol were characterized by CO/CO2 ratios between, approximately, 1/1 and 2/1, respectfully, indicating incomplete carbon oxidation. The initial particle size distribution was dominated in number by particles smaller than 40 nm but the high particle concentrations led to rapid agglomeration. The abundance of CO and metals of inhalable particle size are noteworthy and indicate that further assessment of exposure would determine potential inhalation health hazards, particularly in indoor firing ranges.

Study on size effect and crushing characteristics of gangue-filling material under the confined compression

ABSTRACT The diameter, particle size distribution, and diameter-height ratio of coal gangue backfill material directly affect its mechanical behavior. This study investigated the influence of different particle sizes on the bearing characteristics and particle breakage of coal gangue backfill material under constrained compression through orthogonal experiments. A numerical model of randomly geometrically filled stones under compression was developed to reveal the micro-damage mechanism of coal gangue backfill material under different particle size effects. The results indicate that the diameter Rd of coal gangue backfill material has the greatest impact on its mechanical behavior, followed by the particle size distribution Rg, with the diameter-height ratio Rd-h having the least impact. The diameter significantly affects the compressive strength of the samples, with larger diameters leading to poorer initial force chain stability and lower compressive strength. The particle size distribution has a significant impact on sample breakage, with the breakage rate and fractal dimension increment being negatively correlated with the initial particle size distribution. Particle breakage in the samples gradually progresses from the periphery towards the center, with tensile failure being the primary mode of damage.

Abnormal grain growth of tetragonal tungsten bronze structured ferroelectric ceramics

Microstructures of tetragonal tungsten bronze-structured ferroelectric ceramics vary owing to abnormal grain growth. Control of the grain microstructure stability is a critical aspect in the electrical properties. In this study, the grain growth behavior was meticulously explored through a combination of experiments and numerical simulations. Effects of the liquid phase and initial particle-size distribution on the microstructural evolution were investigated under different grain boundary energy anisotropy conditions. The grain area and edge number were calculated to investigate the grain growth kinetics and shape variation. The results revealed that the presence of a large amount of the liquid phase contributed to rapid grain growth and a duplex structure formation. The grain-size inhomogeneity can be eliminated by using initial particles with a bimodal particle-size distribution. The grain shape was mainly determined by the degree of anisotropy of the grain boundary energy and was nearly unaffected by the process parameters. The findings of this study afford theoretical guidance for microstructure regulation and stable preparation of high-performance ferroelectric ceramics.

Exploring the Effects of Process Parameters during W/O/W Emulsion Preparation and Supercritical Fluid Extraction on the Protein Encapsulation and Release Properties of PLGA Microspheres.

In this study, protein-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared via supercritical fluid extraction of emulsion (SFEE) technology. To understand the correlation between process parameters and the main quality characteristics of PLGA microspheres, a comprehensive prior study on the influence of process variables on encapsulation efficiency (EE), initial drug burst release (IBR), morphology, surface property, and particle size distribution (PSD) was conducted within a wide process condition range of each unit process step, from the double-emulsion preparation step to the extraction step. Bovine serum albumin (BSA), a high-molecular weight-protein that is difficult to control the IBR and EE of PLGA microspheres with, was used as a model material. As double-emulsion manufacturing process parameters, the primary (W/O) and secondary emulsion (W/O/W) homogenization speed and secondary emulsification time were evaluated. In addition, the effect of the SFEE process parameters, including the pressure (70-160 bar), temperature (35-65 °C), stirring rate (50-1000 rpm), and flow rate of supercritical carbon dioxide, SC-CO2 (1-40 mL/min), on PLGA microsphere quality properties were also evaluated. An increase in the homogenization speed of the primary emulsion resulted in an increase in EE and a decrease in IBR. In contrast, increasing the secondary emulsification speed resulted in a decrease in EE and an increase in IBR along with a decrease in microsphere size. The insufficient secondary emulsification time resulted in excessive increases in particle size, and excessive durations resulted in decreased EE and increased IBR. Increasing the temperature and pressure of SFEE resulted in an overall increase in particle size, a decrease in EE, and an increase in IBR. It was observed that, at low stirring rates or SC-CO2 flow rates, there was an increase in particle size and SPAN value, while the EE decreased. Overall, when the EE of the prepared microspheres is low, a higher proportion of drugs is distributed on the external surface of the microspheres, resulting in a larger IBR. In conclusion, this study contributes to the scientific understanding of the influence of SFEE process variables on PLGA microspheres.

Induction heating-based pulsed spray drier for dewatering of alkali metal halide salts: Numerical model and its experimental validation

Dewatering of alkali metal halide salts in conventional co-current or counter-current spray driers to obtain low moisture content and agglomeration in resultant dried powders is difficult owing to their hygroscopic nature. Co-current spray driers offer the advantage of good heat transport characteristics in spray zone while counter-current spray driers offer better thermal utilization throughout the drying chamber. In the present work, modified prototype of a conventional counter-current spray drier is developed to obtain both these advantages in the drying chamber by employing induction heating and mechanical pulsation techniques. After carrying out several experiments in this prototype viz. Induction heating-based pulsed spray drier (IH-PSD), the optimal process parameters are obtained which maximize thermal utilization throughout the drying chamber and minimize both moisture content and agglomeration in resultant dried powders of sodium and potassium halide salts. The initial droplet and final particle size distributions are obtained using laser diffraction analyzer and sieve shaker experiments respectively. An experimentally validated numerical model implemented using open-source computational solvers is utilized to obtain average drying rates in IH-PSD. It is observed that the average drying rate lies between 0.03 and 0.18 mg/s and 0.04 and 0.14 mg/s for sodium and potassium metal halide salts respectively.

Modeling of Particle Size Distribution in the Presence of Flocculant

This study presents a mathematical description of the solid fraction aggregation process in the presence of a flocculant and its result. The basis is a population balance equation. The model is realized in Python language. Verification was carried out using red mud from the investigated enterprise; Flomin AL P 99 VHM was used as a flocculant. The mean square deviation for the parameter “mean aggregate diameter” is equal to 19.88 μm. The time required for the model calculation is about 3 min. The time spent on modeling depends on the number of calculation channels. In this study, 40 channels (20 with PSD source data, and 20 with empty values required for the calculation) were used for the calculation. The time spent on the model calculation is much shorter than the inertia via each of the communication channels for the studied symmetric radial type thickener. A user interface is developed, where the input parameters are the initial pulp particle size distribution, viscosity and density of pulp in the thickener, particle surface area, concentration and flow rate of flocculant, concentration of solid particles, inner diameter and height of the feed well, and simulation time. The result of the simulation is particle size distribution in the feed well of the washer and the mean flocculus diameter.

Discrete pore and particle size distributions during pore blocking and cake filtration

Modeling membrane filtration is important for plenty industrial applications. The understanding of the phenomena and related mechanisms aims at the improvement of techniques in different areas. Therefore, different authors have proposed models to describe the mechanisms related to the filtration process involving either cake build-up or blocking processes, a few of them however have proposed both concepts simultaneously, although none considered pore and particle size distribution during the process, which is the proposal brought up in this paper. Transient solutions for filtrate volume and filter cake thickness as a function of initial pore and particle size distributions are obtained. Good matching between the studied experimental data and the proposed model was observed. In general, the results showed that permeability reduction and filtrate volume are strongly influenced by the initial pore and particle size distributions. In addition, the cake build-up rate depends on both the particle size distribution and the residual flow through blocked pores. It was observed that, after all the largest particles have blocked the smaller pores, effective permeability and flow rate vary only due to cake build-up. Finally, because the proposed empirical parameters do not depend on the pore size distribution, this model can be applied for predicting permeability decline for any feed concentration.

Peculiarities of particle splicing at interlayer boundaries of hot-formed powder materials

Modern production of machine-building parts and building structures is directly related to the production of high-quality hot-formed powder materials. Powder metallurgy as a modern innovative technology, creating materials with unique physical properties, has such a significant advantage as environmental safety. The absence of aggressive and environmentally hazardous components in the technology makes the process of manufacturing powder steels harmless to the environment. The present scientific study deals with the given microstructures of hot-pressure treated powder materials. Residual porosity, which significantly affects the functional properties (mechanical and physical), is considered to be a fundamental factor influencing the areas of powder steel use. The mechanism of mutual diffusion of the introduced components and peculiarities of modeling the structure of powder blanks under conditions of sintering and subsequent deformation were studied. The influence of initial powder particle size on the formation of powder alloys structure under the characteristic features of homogenization under sintering conditions was analyzed. The conducted works allow to study the character of influence of technological parameters in the process of processing on the quality of powder materials splicing, formation of features of their structure and functional properties and qualities. The structure of almost porosity-free steel obtained during the tests of hot-pressure treatment is characterized by complete coverage of the entire number of particles by plastic deformation, which indicates its homogeneity, inherent in the initial particle size distribution of iron powder. The conducted scientific studies of physical processes during hot pressure deformation prove the decisive influence of the choice of technological parameters on improving the quality of splicing, as well as on the formation of microstructure and properties of powder steels.

Analysis of homogeneity and rheological properties of filling slurry during the mixing process through electrical resistance tomography

Mixing is a key process in the paste filling technology. This study utilized electrical resistance tomography and rheological experiments to examine the particle distribution and rheological properties of filling slurry at different shearing speeds, concentrations, and initial particle size distributions. The results indicated that filling slurry flow could be categorized into three states under different shearing speeds: insufficient mixing, full mixing, and excessive mixing. In combination with the rheological characteristics, the radial index and the filling slurry index could be used to measure homogenization. As the shearing speed increases, the homogeneity of the filling slurry improves, and the dynamic yield stress also changes. Increasing shearing speed has a negative impact on particle distribution as homogeneity is reached. The homogenization of the filling slurry is related to particle migration. Additionally, the mechanical response to shearing is discussed. Material and shearing conditions determine the interaction between particles.

Effect of morphological properties on the particle size distribution measurements and modelling of porous and nonspherical aerosol behaviour

Estimating the time evolution of the suspended aerosol concentration in nuclear reactor containment is critical in assessing the environmental source term during severe accident conditions. Morphological properties of porous and non-spherical aerosol particles are necessary to convert the measured equivalent size distributions to actual size distributions and modelling the aerosol processes. Towards this, the dynamics of liquid PAO (Poly Alpha Olefin) and metal aerosol (non-radioactive fission product equivalent SrO2; and structural steel) are studied individually in a 1 m3 closed chamber. The effect of initial particle size distributions (PSDs) based on different equivalent diameters and the morphological properties on realistic modeling of experimental results is analysed. Electrical Low-Pressure Impactor (ELPI) and Scanning Mobility Particle Sizer (SMPS) are used to measure concentration decay and size growth. The aerosol dynamics model is validated with PAO aerosol data and applied to metal aerosol. Modelled dynamics using both the aerodynamic and effective density (ρe) corrected mobility equivalent PSDs of ELPI (APSD and MEPSD) agree with the measured values within 10% deviation for PAO aerosol, which are spherical with ρe (0.82 g cm−3) slightly differed from 1 g cm−3. Modelled dynamics using APSD significantly deviate around 77.5–137% for the porous and non-spherical/fractal metal aerosols, irrespective of the morphological properties explicitly used to model the aerosol processes with marginal effect. As ρe of SrO2 and steel aerosols (3.16 and 3.34 g cm−3) are >1 g cm−3, aerodynamic distribution underestimates the coagulation phenomenon, the primary aerosol dynamics process to a larger extent. The mobility equivalent size distributions of ELPI model the aerosol dynamics within 6–23% deviation, as supported by SMPS measurements. This study can be extended to ascertain the input parameters required for improved estimations of sodium combustion aerosol dynamics, which has added complexity of hygroscopic growth and time-varying chemical speciation.

Effect of grain size distribution on the shear properties of sand

In this study, we investigated the effect of particle size distribution on the shear properties of sand. Direct shear tests were conducted using four types of sand samples with different particle size distributions obtained from standard sand produced by Xiamen ISO Co. Ltd. The results show that the influence of particle size distribution on the internal friction angle was significant. Typically, the internal friction angle increases with increasing the coefficient of non-uniformity (Cu) and decreasing the curvature coefficient (Cc). The discrete element results show that the initial particle size distribution significantly affects the porosity, coordination number, and particle slide fraction. In addition, the grey relation analysis revealed that the sliding fraction and coordination number have the greatest correlation with the internal friction angle. The research results of this study help to understand the changes in particle contact, internal stress, and particle sliding during the shear failure process of sand.

Accelerated reactive dissolution model of drug release from long-acting injectable formulations

Long-acting injectable formulations represent a rapidly emerging category of drug delivery systems that offer several advantages compared to orally administered medicines. Rather than having to frequently swallow tablets, the medication is administered to the patient by intramuscular or subcutaneous injection of a nanoparticle suspension that forms a local depot from which the drug is steadily released over a period of several weeks or months. The benefits of this approach include improved medication compliance, reduced fluctuations of drug plasma level, or the suppression of gastrointestinal tract irritation. The mechanism of drug release from injectable depot systems is complex, and there is a lack of models that would enable quantitative parametrisation of the process. In this work, an experimental and computational study of drug release from a long-acting injectable depot system is reported. A population balance model of prodrug dissolution from asuspension with specific particle size distribution has been coupled with the kinetics of prodrug hydrolysis to its parent drug and validated using in vitro experimental data obtained from an accelerated reactive dissolution test. Using the developed model, it is possible to predict the sensitivity of drug release profiles to the initial concentration and particle size distribution of the prodrug suspension, and subsequently simulate various drug dosing scenarios. Parametric analysis of the system has identified the boundaries of reaction- and dissolution-limited drug release regimes, and the conditions for the existence of a quasi-steady state. This knowledge is crucial for the rational design of drug formulations in terms of particle size distribution, concentration and intended duration of drug release.

Influences of double-sided molding method and initial particle size on fragmentation characteristics of reconstituted coal briquette

Using the reconstituted coal briquette to replace tectonic coal is a forced choice for many experimental studies on the mechanism of coal and gas outbursts. The molding method and initial particle size are two important factors affecting the properties of the soil-like coal briquette. In this study, tectonic coal particles with five different initial sizes were compressed into coal briquettes using three different molding methods. Each coal briquette was evenly divided into five parts along the vertical direction and each subunit was fragmented by a drop hammer to test the firmness. The results show that the briquette density first increases and then decreases with the rise of initial particle size. Briquettes obtained by the traditional one-sided molding method possess the lowest density. The fragment size distributions of the briquettes and the original tectonic coal have segmented and non-segmented fractal characteristics, respectively, which are mainly related to the initial particle size distribution of the coal powder used for making briquettes. Combining the vertical distribution laws of the surface work, Protodyakonov coefficients, and fractal dimension of the briquettes, it is determined that the coal briquettes obtained by the double-sided molding method are soft in the middle and possess a relatively symmetric structure. The surface work and Protodyakonov coefficients of the briquettes (9.03 ± 2.27 J/m2 and 0.10 ± 0.02, respectively) are comparable to those of the in-situ tectonic coal with the highest outburst risk.

Automated Stereology and Uncertainty Quantification Considering Spherical Non-Penetrating Dispersions

Automated stereological methods are presented for approximating the 3D size distribution of unimodal or bimodal precipitate dispersions considering 2D and 1D measurements taken from polydisperse spherical non-penetrating particle dispersions. A method to quantify the uncertainty of the approximation as a function of the number of sampled particles is presented and demonstrated to experimental data. The derivation and verification of the analytical stereological expressions used are included. Two procedures are presented for estimating the 3D size distribution of bimodal particle populations depending upon the relative size of the two particle populations. If the particles can be characterised using micrographs of the same magnification, it is possible to estimate the volume fraction of each particle population. For cases where micrographs have been taken at different magnification, an estimate of the area fractions of the particle populations is needed to combine the datasets and allow for the approximation of the 3D size distribution. These methods are useful for use in determining the initial particle size distribution for use in modelling and determining the appropriate number of micrographs and particles to measure when characterising a precipitate dispersion.

Quantifying Particle Breakage and Its Evolution Using Breakage Indices and Grading Entropy Coordinates

Particle breakage in soils is a well-recognised behaviour. Conventional methods for quantifying the breakage process rely on calculating the area between the particle size distribution (PSD) curves produced before and after crushing. A key aspect of breakage is understanding the process across the different size/sieve fractions. Grading entropy coordinates allow for the representation of any PSD to be shown as a single point on a Cartesian plane and are able to track grading evolution with relative ease. In this study, grading entropy coordinates are compared to three commonly used breakage indices (Br, Br* and IG). It is shown that grading entropy coordinates are advantageous over the traditional indices in quantifying subtle changes in the PSD evolution and directly provide further insight with regards to the individual fraction sizes. It is also discussed that conventional breakage indices rely on relative measures and are dependent on assumptions of an initial and/or final PSD. In contrast, grading entropy coordinates depend only on the characteristics of the (current) PSD curve. It was also observed that the breakage evolution captured by the entropy coordinates is able to determine the rate at which differently sized particles break as differently sized particles take on stress. Moreover, it is suggested that entropy coordinates may also stress path dependency, a feature not present in conventional indices.

Modeling coarse and giant desert dust particles

Abstract. Dust particles larger than 20 µm in diameter have been regularly observed to remain airborne during long-range transport. In this work, we modify the parameterization of the mineral dust cycle in the GOCART-AFWA dust scheme of WRFV4.2.1 to also include such coarse and giant particles, and we further discuss the underlying misrepresented physical mechanisms which hamper the model in reproducing adequately the transport of the coarse and giant mineral particles. The initial particle size distribution is constrained by observations over desert dust sources. Furthermore, the Stokes drag coefficient has been updated to account for realistic dust particle sizes (Re < 105). The new code was applied to simulate dust transport over Cabo Verde in August 2015 (AER-D campaign). Model results are evaluated against airborne dust measurements and the CALIPSO-LIVAS pure dust product. The results show that the modeled lifetimes of the coarser particles are shorter than those observed. Several sensitivity runs are performed by reducing artificially the particles' settling velocities in order to compensate underrepresented mechanisms, such as the non-spherical aerodynamics, in the relevant parameterization schemes. Our simulations reveal that particles with diameters of 5.5–17 and 40–100 µm are better represented under the assumption of an 80 % reduction in the settling velocity (UR80), while particles with sizes ranging between 17 and 40 µm are better represented in a 60 % reduction in settling velocity (UR60) scenario. The overall statistical analysis indicates that the best agreement with airborne in situ measurements downwind (Cabo Verde) is achieved with a 40 % reduction in settling velocity (UR40). Moreover, the UR80 experiment improves the representation of the vertical structure of the dust layers as those are captured by the CALIPSO-LIVAS vertically resolved pure dust observations. The current study highlights the necessity of upgrading the existing model parameterization schemes of the dust life-cycle components towards improving the assessment of the dust-related impacts within the Earth–atmosphere system.

Influence of particle size distribution on fractal characteristics of waste rock backfill materials under compression

Broken waste rock as backfill materials is filled into the underground goaf and will encounter particle breakage under the overburden pressure. The damage degree of the crushed waste rock materials directly affects the compression properties of the backfill body and the control effect of strata movement and surface subsidence. Fractal theory can be used to quantify the breakage degree of waste rock particles. In this study, compression tests are carried out on the broken waste rock materials with different particle size distributions to investigate the influence of the particle size distribution on the fractal characteristics of waste rock backfill materials under compression. The results show that the waste rock specimens with discontinuous size grading and containing more coarse particles have higher stress when entering the stable deformation stage, larger strain if at the same stress level and larger breakage ratio after compression. The particle size distribution of the crushed waste rock specimens after compressive loading has superior fractal characteristics and the fractal dimension increases with the content of fine particles and decreases significantly under discontinuous size grading. The fractal dimension has significant negative exponential function regression relationship with the strain and the breakage ratio. The strain and the breakage ratio decline with the growing fractal dimension. If the waste rock specimens have continuous particle size gradation and higher content of fine particles, the fractal dimension, the strain and the breakage ratio of the waste rock backfill materials tend to be optimal and stable, proving a desirable initial particle size distribution of the waste rock backfill materials.

Packing, compressibility, and crushability of rockfill materials with polydisperse particle size distributions and implications for dam engineering

In rockfill dam engineering, particle breakage of rockfill materials is one of the major factors resulting in dam settlement. In this study, one-dimensional compression tests on a series of coarse granular materials with artificially-graded particle size distributions (PSDs) were carried out. The tests focused on understanding the role of initial PSDs in the dense packing density, compressibility and crushability of coarse granular materials. The effects of fractal dimension (D) and size polydispersity (θ) of PSDs were quantitatively analyzed. Two different loading stages were identified from the logarithms of the stress–strain relationships, with the turning point marked as the yield stress. A similar effect of initial PSDs was observed on the packing density and low-pressure modulus of coarse granular materials. The packing density and low-pressure modulus increased monotonically with θ, and their peak values were attained at a D value of approximately 2.2. However, there was no unique correspondence between the dense packing density and low-pressure modulus. The particle breakage was influenced differently by the initial PSDs, and it decreased with the values of D and θ. The emergence of the unique ultimate state was also identified from both the compression curves and PSDs of the samples after the tests. The potential implications of the test results in the design of both low and high rockfill dams were also demonstrated.

Revisiting transient coarsening kinetics: a new framework in the Lifshitz-Slyozov-Wagner space

Phase coarsening in multiphase materials is a fundamental and crucial process in the study of microstructure evolution, for which a thorough understanding of kinetics can make a significant contribution to material processing and performance design. In this work, a new framework in the dimensionless Lifshitz-Slyozov-Wagner space is developed to study the kinetics of transient coarsening co-controlled by interface and matrix diffusion. The dynamic equations for individual particles are derived from the thermodynamic extremal principle, in consideration of energy dissipations by matrix diffusion, interface migration/reaction, and trans-interface diffusion. The effects of initial particle size distribution and finite volume fractions are clarified. Different from the conventional viewpoints, the time for transient coarsening is found to change non-monotonically with the width and tail length of the initial distribution. The ultralong transient coarsening with ‘quasi-steady’ distributions can occur for systems initiated from both the ‘wide & long tail’ and ‘narrow & short tail’ distributions. Furthermore, this work proves the existence of a unique attractor state for the steady stage and reveals the numerical origin of ‘quasi-steady’ distributions, which answers Brown's unsolved puzzle for years [LC Brown. Acta Metall 1989;37:71]. Finally, an increase in volume fraction is shown to directly shorten the transient stage dominated by single mechanism (matrix diffusion or interface), but indirectly delay the transition from the interface-dominated state to the diffusion-controlled stage. These findings not only offer new insights into the previous observations in microgravity experiments [VA Snyder, J Alkemper, PW Voorhees, Acta Mater 2001;23:699], but also theoretically describe the limiting coarsening behaviors at ultrahigh volume fractions [H Yan, KG Wang, ME Glicksman. Acta Mater 2022;117964].