Intraparticle porosity

Porosity can be primary or secondary. Primary porosity develops as the sediment is deposited and includes inter- and intraparticle porosity (Figure 3.1). Secondary porosity develops after deposition or rock formation and is referred to as diagenesis (Figure 3.2). 

Intraparticle porosity refers to the fraction of the particle volume which is occupied by internal pores most manufactured food particles are porous. However, it is important to distinguish this quantity from bed voidage. The interparticle voidage e is the fraction of the packed bed occupied by the void spaces between particles and is defined as... 

The dimensionless constant K is known as Kozeny s constant and has a value of approximately 5.0 although strictly it is a function of both intraparticle porosity and particle shape. Assuming now that the bed... 

Brusseau, M. L., The influence of solute size, pore water velocity, and intraparticle porosity on solute dispersion and transport in soil , Water Resour. Res., 29,1071-1080 (1993). 

The bed void volume available for flow and for gas and liquid holdup is determined by the particle size distribution and shape, the particle porosity, and the packing effectiveness. The total voidage and the total liquid holdup can be divided into external and internal terms corresponding to interparticle (bed) and intraparticle (porosity) voidage. The external liquid holdup is further subdivided into static holdup eLs (holdup remaining after bed draining due to surface tension forces) and dynamic holdup eLrf. Additional expressions for the liquid holdup are the pore fillup Ft and the liquid saturation SL ... 

Hence at around 1 pm the detected pore volume arises almost entirely from spaces within the pellets. In contrast around 0.1 pm, the pore volume due to inter-pellet spaces is dominant. The integral values of pore volume per gm are then 0.140 cm for intraparticle porosity, with values of 0.086 cm and 0.045 cm for intra-pellet and inter-pellet spaces respectively. 

This leads to a group of electrodes in which porous carbonaceous material itself provides the active materials. The carbon aerogels [18, 398, 399] are representative of this phenomenon. Storck have developed a mathematical model for the potential distribution in an activated-carbon packed-bed electrode [450]. An intraparticle porosity as well as an interparticle macroporosity are treated. It is a general problem... 

A comparison of true particle density, apparent particle density, and bulk density can provide information on total porosity, interparticle porosity, and intraparticle porosity. Methods include true particle density measurements via helium pycnometry, mercury intrusion porosimetry, and poured and tapped bulk density. 

Internal or intraparticle porosity, Fraction of the column volume contained inside the particles. Also called the fractional pore volume. Fraction occupied by the stagnant mobile phase. 

The first case can be implemented in two versions the component that is precipitated first is thermosensitive or, on the contrary, thermostable. In the first version, hydrogel particles are encapsulated by the thermostable compound. As a result, in calcination of such a globule, its inner part decreases substantially, while the outer shell remains almost unchanged. This leads to formation of intraparticle porosity and, shown by the experimental results, increase in the sorption capacity of the compounds after they were calcinated at the temperature of intense sintering of the component contained inside the globule. 

Alkaline treatment causes lignocellulosic materials to swell increased swelling leads to higher susceptibihty of cellulose to saccharification. In the presence of alkaline chemicals (e.g., NaOH or NHj), cellulose, hemicellulose, and hgnin bonds can be disrupted. This permits cellulose to swell beyond normal water-swollen stages. Consequently, the pore size, the intraparticle porosity, and the capillary size are increased. There is also a phase change in the cellulose crystal-hne structure [33]. 

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