Average absorption

This method [18] is well suited to handling the details of a complicated problem, yet utilizing the concept of average absorption and stripping factors. It also allows for the presence of solute components in the solvent and the loss of lean oil into the off gas. Reference 18 presents more details than are included here. Reference 18 is Edmister s original publication of the basic method for absorbers and strippers. Reference 18 also generates the... 

From Eq. (3.28), one finds that the oscillator strength is proportional to the square of the soliton-anlisolilon separation R. Using this, Eq. (3.33) reduces to the following form for the average absorption coefficient at low photon eneigy ... 

The average absorption rate increases with the gas holdup in the vessel. This may be caused by a change in the gas flow rate or the agitation intensity. The effect is augmented as k increases. 

An increase in bubble diameter will generally depress the total average absorption rate. This effect diminishes as the chemical reaction rate is decreased. 

Although there are many cases of human overexposure to carbon tetrachloride vapor, there are few quantitative studies of pulmonary absorption of carbon tetrachloride in humans. Based on the difference in carbon tetrachloride concentration in inhaled and exhaled air, absorption across the lung was estimated to be about 60% in humans (Lehmann and Schmidt-Kehl 1936). In animals, monkeys exposed to 50 ppm absorbed an average of 30.4% of the total amount of carbon tetrachloride inhaled, at an average absorption rate of 0.022 mg carbon tetrachloride/kg/minute (McCollister et al. 1951). The concentration of carbon tetrachloride in the blood increased steadily, but did not reach a steady-state within 344 minutes of exposure. 

The UV spectra of 1,2-thiazetidinone oxides have been recorded by Beeken and Korte. Measured in cyclohexane or chloroform, the N-substituted cyclohexyl- (35), phenyl-, and aryl-substituted 4,4-bisphenyl-l,2-thiazetidin-3-one 1,1-oxides showed an average absorption band at = 240 nm... 

TABLE 4.7 Averaged Absorption Cross Sections (Base e) from 202 to 274 nm for NOz at 298 K ... 

The average absorption cross section of a randomly oriented collection of identical homogeneous ellipsoids (12.30) may be written... 

A total of seven injections of o-nitroanisole in 0.0082-mole increments into a similar solution containing 0.1 mole of NaOH resulted in an average absorption of 496 ml. of H2 per injection. 

The average absorption coefficient of an isolated molecule can be expressed in the form5... 

Analysis of Defined Fractions. Quantitative infrared analysis was used for those fractional groups that have definitive bands average absorptivities were estimated using model compounds (12, 16, 17). Table I lists the infrared bands and the apparent integrated absorption intensities (B) used. Quantitative IR spectra were measured in methylene chloride with 0.05 cm sodium chloride cells, using a Perkin-Elmer 521 infrared spectrophotometer. Peak area was measured by planimetry. Molecular weights were determined by vapor-pressure osmometry in benzene. 

For a dilute gas, and when the equilibrium curve can be approximated by a linear relationship passing through the origin, Eq. (25) is applicable, and an average absorption factor A can be applied to describe the contactor. Under these conditions, an analytical solution of the material balance equation and the equilibrium relationship is possible, giving the Kremser equation ... 

For concentrated gases, the absorption factor varies from stage to stage. In many cases Eq. (27) can be used with an effective average absorption factor and the mole ratio concentration y ... 

Horton and Franklin (1940) used the average absorption factor approach in analyzing a number of absorbers in the petroleum industry. Edmister (1943) extended the Horton and Franklin concept, retaining the Kremser equation form and making use of several empirical factors. He used an effective absorption factor Ae and a modified absorption factor A, given by... 

Spatial resolution was limited by the 2 mm laser beam diameter. Average absorption measurements were obtained by using a 4.0 s time constant on the lock-in detector. 

Patients with exocrine pancreatic dysfunction may malabsorb vitamin B12 because a considerable part of the dietary vitamin may bind to R-proteins in the stomach. The R-proteins are normally broken down by pancreatic enzymes. The vitamin is released and binding to intrinsic factor then takes place. If the R-proteins are not degraded, then the vitamin B12 will remain bound to these proteins and will not be absorbed (M10). Harms and his colleagues (H27) measured vitamin B12 absorption in 19 children with exocrine pancreatic insufficiency and found the average absorption to be 8.0% compared to 59.2% in a control group. Adding pancreatin to the test dose of radiolabeled vitamin B12 increased absorption of the vitamin to an average of 61%. 

The difference spectrum of the DNPH-treated sample versus the acid-treated control is determined and the results can be expressed as nmol DNPH incorporated/mg of protein, based on average absorptivity of 21.0 mM-1 cm-1 in the region of 365-375 nm for most aliphatic hydrazones (Jones et al., 1956). 

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