Water content particle

Infiltration rate Water content Particle size distribution Frozen soil Bulk density Clay mineralogy Macro porosity... 

Apart from simple in-process controls (visual observations, recording pH-values, weights, counting, etc.) it is also possible to perform analyses. For this, large scale production utilises the term Process Analytical Technology (PAT). PAT utilises a diverse array of analytical in-process controls such as near-infrared spectroscopy (NIR, see Fig. 17.3) to quantify water content, particle size, and homogeneity of mixtures. 

Several aqueous systems should be considered in a similar manner. For example, in the selective removal of divalent cations from a saturated salt solution, the hydrated resin gives up a portion of its normal water content as it contacts the salt stream. In so doing, the particles shrink, and the inner pathways for ion migration become smaller. 

Moisture and Water Content. Resins are thoroughly washed with water upon completion of manufacture and conversion (if necessary) to another ionic form. Excess water is removed by vacuum draining or filtration. Nevertheless, a significant quantity of water associated with the functional groups and adhering to the outer surface of the resin particles remains with the resin as it is discharged into shipping containers. No effort is made to dry the resin, except in a few appHcation areas, since the resins are used in aqueous processes in most installations. 

Mathai (21) summarized the specialty conference on atmospheric visibility. With the exception of water content of particles and the measurement of organic species, analytical laboratory techniques are readily available for particle analysis. Regulatory approaches to mitigate existing visibility impairment and to prevent further impairment are being formulated. A... 

Okubo et al. [87] used AIBN and poly(acrylic acid) (Mw = 2 X 10 ) as the initiator and the stabilizer, respectively, for the dispersion polymerization of styrene conducted within the ethyl alcohol/water medium. The ethyl alcohol-water volumetric ratio (ml ml) was changed between (100 0) and (60 40). The uniform particles were obtained in the range of 100 0 and 70 30 while the polydisperse particles were produced with 35 65 and especially 60 40 ethyl alcohol-water ratios. The average particle size decreased form 3.8 to 1.9 /xm by the increasing water content of the dispersion medium. 

Clay, in one particle classification system, consists of inorganic particles less than 0.005 mm in size. In another system, clay is a fine-grained inorganic. soil that can be made plastic by adjusting the water content. When dried, clay exhibits considerable strength (i.e., clay loses its plasticity when dried and its strength when wetted). Also, it will shrink when dried and expand when moisture is added. 

The pore space of a soil may contain either water or a gaseous atmosphere. Thus the aeration of a soil is directly related to the amount of pore space present and to the water content. Soils of fine texture due to a high clay content contain more closely packed particles and have less pore capacity for gaseous diffusion than an open-type soil such as sand. 

Recently Romanov and Sten gach (Ref 89) found that discharge energies for 50% explns of PETN Increased with PETN particle size, packing density, water content, circuit inductance, and a decrease in ambient temp. The discharge energy-interelect rode distance curve... 

Scanning electron microscopy shows the cement to consist of zinc oxide particles embedded in an amorphous matrix (Smith, 1982a). As with the zinc phosphate cement, a separate globular water phase exists since the cement becomes uniformly porous on dehydration. Porosity diminishes as the water content is decreased. Wilson, Paddon Crisp (1979) distinguish between two types of water in dental cements non-evaporable (tightly bound) and evaporable (loosely bound). They found, in the example they examined, that the ratio of tightly bound to loosely bound water was 0-22 1-0, the lowest for all dental cements. They considered that loosely bound water acted as a plasticizer and weakened the cement. 

Increase in concentration of aluminium and phosphoric acid in the liquid serves to slow the reaction. This observation is in line with the above reaction scheme. Increase in the aluminium content will serve to increase the thickness of the coating formed around zinc oxide particles. Increase in phosphoric acid content implies a decrease in water content and an impairment of the hydration reaction. 

Pt/MWNT) [20,21], fine and homogeneous Pt nanoparticles deposited on MWNTs were obtained when pure EG was used as the solvent or less water (<5vol.%) was introduced. With the increase in water content, aggregation of the metal nanoparticles occurred, the average particle size increased and the particle size distribution became wider. 

Table 2. Effect of water content in EG on the particle size of Pt nanoparticles deposited on MWNTs.

Water content (%, volume ratio) Average size of Pt particles (nm) Size distribution of Pt particles (nm)... 

Matrix properties (nature, particle size, pore structure, water content, adsorptive strength)... 

The spectra are characterised by high signals of lithium, sodium, magnesium, aluminium, calcium and iron and their oxides. A high signal from hydroxyl ions was observed, which indicates a high water content of the particle. 

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