Absorption void fraction

X-ray absorption method This method is similar to void fraction measurement by radiation attenuation. 

E] Compared napthalene sublimination to aqueous absorption to obtain kc, a, and ki separately. Raschig rings and Berl saddles, = diameter of sphere with same surface area as packing piece. lo - operating void space = e - (f)Li, where e = void fraction w/o liquid, and dri = liquid holdup. Same definition as 5-28-A and B. Onda et al. correlation (5-28-D) is preferred. G = peUsuper gas... 

Porosity (void fraction)

Average rate of absorption... 

This data set also illustrates the problems in making reproducible measurements on mixtures of particles. The largest source of variation is probably the void fraction. The effect of void fraction on absorption is profound in close-packed mixtures, but the changes tend to occur at all wavelengths... 

You have isolated a protein to be used as a vaccine by absorption from a buffer on a packed bed of a custom-synthesized ion-exchange resin. The resin consists of 0.011 cm spheres, with a void fraction of 0.37. It is packed in a 100 cm column, 83 cm in diameter, fed at a velocity of 0.052 cm/sec. Under these conditions, the protein is adsorbed with a mass transfer coefficient of 6 X 10 cm/sec and an adsorption equilibrium constant of 27. After this bed is completely loaded, you plan to elute it with a more acidic buffer. This new buffer has an adsorption constant of 0.22, but all other conditions are unchanged. How long must you elute until the concentration is 10% of the maximum Answer 40 min. 

By relating the endpoint of crushed DBF absorption to the void space within and between equivalent spheres of aggregates, and assuming the spheres to be packed at random, Wang et al. obtained the following equation for the effective volume fraction of carbon black ... 

The elution profile of cytochrome P-448 (absorption at 418 nm) and epoxide hydratase activity from a sodium cholate-solubi-lized hepatic microsomal preparation (from DBA-treated male skates) applied to a DEAE-cellulose column and eluted with Buffer II is shown in Fig. 3. The void volume of the column contained significant amounts of epoxide hydratase activity. Fractions 40-70 (Fig. 3) were combined, and concentrated. The carbon monoxide difference spectrum, which had an absorption maximum at 448 nm in the induced state, is shown in Fig. 4. This form of the cytochrome (i.e.,... 

Zinc-binding components of urine were examined using modified gel chromatography (15). Urine (3 ml) was chromatographed on Sephadex G-25 columns (2.5 x 40 cm) equilibrated with a buffer containing 10 ppm Zn as Zn(N03)2 and 10 mM Tris buffer, pH 7.4. Fractions of 3 ml were analyzed by atomic absorption spectroscopy. Void volume of the column was determined with blue dextran. 

Gas adsorption (N2, Kr) can be used to estimate the relative quantity of zeolite deposited on the support (BET- or Langmuir equation). When a dense substrate is used, ellipsometry gives the film thickness and void volume fraction. Absorption spectroscopies such as FTIR, are adapted to study the membrane material short range structure. 

The coolant void reactivity coefficient was first analyzed for a core with a 10% coolant fraction, a 10% enrichment, and fuel fractions ranging from 10% to 50%. The results (Fig. 3.2) show that for fuel fractions less than 30%, complete voiding of the Flibe coolant from the core could result in a positive reactivity addition. As the fuel concentration is increased to provide more realistic excess reactivity values and longer core bumup times, the relative importance of the absorption and moderation in the Flibe is reversed, and the overall void coefficient is then negative as the uranium-to-carbon atom ratio exceeds approximately 0.05. For an NaZrFs salt, the void coefficient is positive for fuel fractions less than 60%. 

The contribution of a particle type to absorption is proportional to the volume fraction (including voids) of the particle type and to the absorption coefficient of the material making up the particle. 

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