A is the area of contact area between soil particles. J is the moment of inertia of soil particles. The bond is broken when the normal and tangential shear stresses exceed some predefined value, ... and conducted an in-depth analysis of the overall changes in Bond between agglomerate particles during the simulated shear process, as shown in Fig ...
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Total and regional deposition, as well as agglomerate break-up and aerosolisation, is dependent upon three factors: (1) impact velocity and inelastic component of momentum (agglomerate fracture/compressive forces), (2) forces imparted by the airstream (to detach/reentrain particles), and (3) the elastic component of the particles …
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The emission of engineered nanoparticles (ENPs) into the environment in increasing quantity and variety raises a general concern regarding potential effects on human health. Compared with soluble substances, ENPs exhibit additional dimensions of complexity, that is, they exist not only in various sizes, shapes and chemical …
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Agglomeration is when particles are joined loosely together which can be simply broken by mechanical forces but aggregation is a definite pattern of moleclues which may be in any physical state ...
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The conventional sintering of a porous green body consisting of coarse polycrystalline particles is a process of grain-growth-induced densification facilitated …
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Typically, the structure of these agglomerates is characterized with the fractal dimension, Df, and pre-exponential factor, kn, of simulated agglomerates of …
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Kafui and Thornton [2] expressed the extent of damage as the fraction of initial primary particle contacts that were broken as a result of impact. The number of interparticle bonds in agglomerate may be expected to reflect the bulk impact strength of the agglomerate and therefore the damage ratio would quantify the deterioration in the …
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Composition Migration and Grading Rules of Agglomerate in Reclaimed Asphalt Pavement. ... the RAPs were sieved into a single particle size from 13.2 to 0.075 mm, and hot-mix and extraction tests were carried out on the RAPs with single particle sizes. ... can be divided into strongly bound agglomerates and weakly bound agglomerates according …
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The paper focuses on identifying the physical processes that lead to fracture. It is shown that fracture is the result of the manner in which strong interparticle forces …
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The breakage energy efficiency η 1 when the agglomerate is broken in the hammer crusher is, therefore, ... by DEM simulation is the percent of the number of broken bonds after breakage over the number of bonds between particles forming the agglomerate before breakage, it indicates a really-broken degree with the particle size …
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Purification of mRNA with oligo(dT)-functionalized magnetic particles involves a series of magnetic separations for buffer exchange and washing. Magnetic particles interact and agglomerate with each other when a magnetic field is applied, which can result in a decreased total surface area and thus a …
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A simple mechanistic model is presented here which relates the number of broken contacts in agglomerate due to impact velocity, interparticle adhesion energy and the particle properties of the ...
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Conventional sintering is a time- and energy-consuming process used for the densification of consolidated particles facilitated by atomic diffusion at high temperatures. Nanoparticles, with their ...
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Figure 3 provides more detail on the collision and agglomerate formation distribution across the channel height, and the locations where these events are occurring (with the floor of the channel being at x + = 0). Results are shown for 16 equally spaced regions in the wall-normal direction for both particle sizes at time t + = 1000, although …
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Upon analyzing the outcomes after the destruction of the agglomerate samples, the following results were obtained. During compressive deformation, the content fine particles with sizes smaller than 5.0 mm was 15.0–20.5% (with an average of 17.2%). The fraction of particles smaller than −10.0 mm was 26.9–34.9% (with an average of …
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The agglomerate-particle has a diameter of d A = 60 μ m, a free surface energy of Δ γ = 72 × 1 0-4 J / m 2, and a relative velocity of 5 m / s. The dimensionless numbers are similar to the first test, although there are somewhat more small child particles. The mass fraction of broken off small particles is 0.1101.
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Agglomerate particles exhibit fracture strengths much less than their monolithic analogs as a consequence of two distinctive structural features: large …
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Fig. 1 shows a polydisperse cuboidal agglomerate consisting of 10,000 autoadhesive elastic primary particles of five different sizes in the range 16 to 24 μm. The interface energy is 1.0 J m −2.In order to create the agglomerate, the primary particles were initially randomly generated within a defined cuboidal region with no interparticle …
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where was the average projected area of the broken-up fragments of an agglomerate excluding the single primary particles and A the total area of all the fragments, that is the area of the intact particle. The area-equivalent GMDs 269 nm and 143 nm were then used to evaluate the areas of the intact and deposited particles, …
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In order to understand particle agglomeration, it is important to understand the surface forces at the interface of the particle and aqueous portion of the colloid. Particles with …
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The tensile strength of an agglomerate is calculated by [18]: (5) σ t = 1 3 σ i i = 1 3 V ∑ i N r i ∑ j = 1 z i n i j ⋅ f v, i j where V is the volume of the agglomerate, N the total number of particles, r i the particle radius, z i the coordination number and n ij the unit vector connecting the centres of particles i and j.
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The current paper describes discrete element model (DEM) computer simulations of the impact of cohesive arrays of particles ( i.e. agglomerates) of different sizes and with different properties against other agglomerates and against walls.
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We study the erosion dynamics of wet particle agglomerates inside a simple shear flow of noncohesive granular materials by relying on the three-dimensional …
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Agglomerate (particle system) at the end of the simulation (V=0.2 m s −1) large fragments in three shades of grey (lighter for larger fragments) ... (grey) and broken bonds (black) and (b) particle configuration showing debris particles (black) and large fragments (grey). Download : Download full-size image; Fig. 9.
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As a wet agglomerate falls down and impacts on a rigid plane at a high speed, the capillary bond between particles may be broken when the separation distance between particles exceeds their rupture distance, the liquid is then immediately shared proportional to the particle size due to the lubrication effects of the liquid, and this liquid ...
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Surface tension and particle solubility in wash solvent affects the formation of agglomerates. ... was placed onto the sample holder and lumps were broken and spread evenly to avoid uneven heating. ... the increase in agglomerate strength is likely to be attributed to the compression of filter cake when subjected to pressurized conditions (1 ...
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Total number-based primary particle size distribution as function of the primary particle and agglomerate size at (a) t = 0.001, (b) 0.01, (c) 0.1 and (d) 0.5 s for TiCl4 oxidation with O2 . The white line is the limit of full coalescence where primary and agglomerate particle sizes are identical: coalescence line (Xiong & Pratsinis, 1993).
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The detailed evolution of primary and agglomerate particle growth during flame spray synthesis of 30 g/h of zirconia nanoparticles is monitored online by a differential mobility analyzer (DMA), an aerosol particle mass (APM) analyzer and a condensation particle counter (CPC) as well as thermophoretic sampling/microscopy.The differences …
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As described previously, the particles which have their bonds with the agglomerate broken spread and reduce the level of stress on the rest of the assembly. Consequently, a residual cluster always survives, irrespective of velocity in the range tested. The pattern of breakage is affected by the method of preparation.
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Discrete element method (DEM) simulations have access to particle scale information on the coordinates and velocities of all the constituted primary particles …
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According to the number distribution q 0 the overwhelming part of the agglomerates is broken up into primary particles. Only about 17.5% of larger agglomerates are found, whereat these are predominantly two- and three-particles agglomerates and the largest remaining agglomerate comprises solely 6 primary particles (one exception …
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Typical time evolutions of the force generated at the agglomerate-wall interface, the kinetic energy of the system of primary particles composing the agglomerate and the proportion of initial interparticle bonds broken during the impact are shown in Fig. 4 (the impact velocity of the particle system is 2 m/s, the interface energy between the ...
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(18) relates the number of broken contacts in the agglomerate with the primary particle properties (particle density, ρ; particle diameter, D; and particle elastic modulus, E), the interparticle interaction, the agglomerate properties (the number of particles in the agglomerate, N) and the characteristics of the test (i.e., impact velocity, …
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Although a rigorous link between the fragmentability of agglomerate particles in the airborne state and their behavior in liquid suspension (such as cellular or other body fluids) remains to be established, these findings suggest that the smallest units to which diesel particles can be broken down are probably on the order of the size of ...
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The average number of broken bonds per agglomerate was calculated in the following manner. The geometric mean diameter of the de-agglomerated and intact particles and the size-dependent effective density were used to estimate the average mass of the agglomerates before and after impaction. ... The number of primary particles per …
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This leads to Eq. (18), in which the number of broken contacts is related to the primary particles properties (elastic modulus, Poisson's ratio, particle density, particle diameter and bond strength), agglomerate properties (number of particles in the agglomerate and coordination number) and external parameters (impact velocity). …
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The particle friction, f, (a) and collision frequency, β, (b) as a function of gas (Kn = λ gas /r) and diffusional Knudsen number (Kn D = λ p /r), respectively. The f goes through a transition (0.01 < Kn < 30) from the Epstein (solid line, f ∼ r 2) to the Stokes drag (broken line, f ∼ r) with increasing r (decreasing Kn). The Cunningham ...
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Again, cells with core-shell particles have a higher lithiation compared to cells with agglomerate particles due to shorter diffusion paths. Figure 5d shows that for low C-rates of 0.5, 1 and 2C cells with agglomerate particles achieve higher energy densities than with core-shell particles at 0.5, 1 and 2C. This is due to the sufficient time ...
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