Subparticle

In a particle having a bidispersed pore structure comprising spherical adsorptive subparticles of radius forming a macroporous aggregate, separate flux equations can be written for the macroporous network in terms of Eq. (16-64) and for the subparticles themselves in terms of Eq. (16-70) if solid diffusion occurs. 

Bidispersed Particles For particles of radius Cp comprising adsorptive subparticles of radius r, that define a macropore network, conservation equations are needed to describe transport both within the macropores and within the subparticles and are given in Table 16-11, item D. Detailed equations and solutions for a hnear isotherm are given in Ruthven (gen. refs., p. 183) and Ruckenstein et al. [Chem. Eng. Sci., 26, 1306 (1971)]. The solution for a linear isotherm with no external resistance and an infinite fluid volume is ... 

In these equations, D, is the diffusivity in the subparticles, and Dp is the diffusivity in the pore network formed by the subparticles. 

Mechanism parameter for combined resistances (Fig. 16-12) p Subparticle radial coordinate, m... 

For large K, values, the uptake curve depends only upon the value of the parameter (1 representing the ratio of characteristic time constants for diffusion in the pores and in the subparticles. For small (1 values, diffusion in the subparticles is controlling and the solution coincides with Eq. (16-96) with r, replacing rp. For large (3 values, pore diffusion is controlling, and the solution coincides with Eq. (16-96) with ZpDp/iZp + pplQ replacing D . 

Asymptotic Solution Rate equations for the various mass-transfer mechanisms are written in dimensionless form in Table 16-13 in terms of a number of transfer units, N = L/HTU, for particle-scale mass-transfer resistances, a number of reaction units for the reaction kinetics mechanism, and a number of dispersion units, Npe, for axial dispersion. For pore and solid diffusion, = r/rp is a dimensionless radial coordinate, where rp is the radius of the particle. If a particle is bidis-perse, then rp can be replaced by rs, the radius of a subparticle. For preliminary calculations, Fig. 16-13 can be used to estimate N for use with the LDF approximation when more than one resistance is important. 

Second, nucleation and growth of Stober silica particles is modeled by a controlled aggregation mechanism of subparticles, a few nanometers in size, as for example presented by Bogush and Zukoski (19). Colloidal stability, nuclei size, surface charge, and diffusion and aggregation characteristics are the important parameters in this model. 

During uncoating several different rhinovirus subparticles are observed. These are thought to be intermediates in the uncoating process [32-33]. The fully infectious 149S particle becomes an 125S A-particle, which has lost VP4 but still maintains viral RNA. This A-particle is no longer infectious. The A-particle then releases RNA to become an 80S empty shell. 

The spectrum of functionality modification can be substantially enlarged by the coprocessing or particle engineering of two or more existing excipients. Coprocessing involves interaction of two or more excipients at the subparticle level, aimed at... 

These subparticle simulations also allow in-depth understanding of the applicability of their closure laws for higher scale simulations. For example, Ma et al. (2009) found that the typical "drafting-kissing-... 

OgenkoV.M., LysyukL.S., Volkov S.V., ShpakA.P. (2004) Novel Carbon Nanostructures Obtained by Electrochemical Method. I. Geometrical Structure of Subparticles. Nanosystems, Nanomaterials, Nanotechnologies (in Russian), Kyiv Akademperiodyka 1, 1, 157-164. 

But today, scientists relate to the atoms subparticles such as quarks, leptons, neutrinos, muons, photons, mezons,... 

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