Total absorbance

Beer s law can be extended to samples containing several absorbing components provided that there are no interactions between the components. Individual absorbances, A , are additive. For a two-component mixture of X and Y, the total absorbance, Atot, is... 

If, as is usually the case, it is a TT-electron that is raised in energy by the quantum or photon from the Sq state to the state, the electron is said to undergo a tt — tt transition. Because the quantum is totally absorbed, the TT-electron is raised in energy by exactly the same amount as the energy of the quantum. 

The use of an integral video screen in instruments presents very great advantages, both in the ease of operation and in the ability to develop and understand analytical methods. Complete analytical records can be stored in the instrument and a visual display of good calibration curves can be stored in memory and recalled at will. It is most useful to have a graphical display of atomisation peaks when using a furnace where a distinction can be made of the total absorbance peak and that due to the analyte absorbance. 

As previously described (Chapter 2), the area under short-term stress-strain curves provides a guide to a material s toughness and impact performance (Fig. 7-6). The ability of a TP to absorb energy is a function of its strength and its ductility that tends to be inversely related. The total absorbable energy is proportional to the area within the lines drawn to the appropriate point on the curve from the axis. The material in area A is... 

In this change there will be in general a finite amount of heat withdrawn by the system from its environment, which may be absorbed in various parts. The total absorbed heat we shall denote by YQ. At the same time the parts of the system, exerting forces on external bodies, may perform mechanical work. The total mechanical work done by the system on external bodies we shall denote by 2A. 

Fig. 6-2 Comparison of infrared absorbance of a vertical column of atmospheric CO2 and H2O vapor. The nearly total absorbance by H2O between 5 and 7 /

In all countries with developed medical care, X-ray contrast media can be expected to be present at appreciable quantities in sewage water. Clara et al [13] detected iopromide at a mean concentration of 3.84 pg in the influent of a WWTP receiving hospital wastewater, while in WWTPs without a hospital within their drainage area this contrast media was not present. lodinated X-ray contrast media are proved to contribute significantly to total absorbable organic iodine in clinical wastewaters up to 130 pg of iodine in the influent of municipal WWTP in Berlin and 10 mg in hospital sewage was detected [23]. 

Griseofulvin is adminisfered orally in the form of tablets. It is not totally absorbed when given orally, and one method of increasing absorption is to reduce the particle size of the drug. Griseofulvin is deposited in the deeper layers of the skin and in hair keratin, and is therefore employed in chemotherapy of fungal infections of these areas caused by susceptible organisms. 

If we express the effective thickness t for the resonant absorption in terms of the total absorber thickness t in g cm, a nuclear absorption coefficient can be defined in cm g such that = t. The signal amplitude is then given by ... 

With this actinometer reasonable exposure periods and solution volumes result with total absorbed intensities on the order of 1017 photons. 

Comparison of exposure levels — total absorbed dose of chlorpyrifos (passive dosimetry vs. urinary monitoring)... 

Table 7 Comparison of Exposure Estimated Levels (Total Absorbed Dose of Chlorpyrifos) Dosimetry vs. Urine Monitoring...

The described method of simultaneously measuring the total absorbed dose by passive dosimetry and biomonitoring shows excellent reproducibility over a range of four states, six worker types, and a range of 84 test replicates (one replicate = one volunteer). 

At the end of an additional time T2 the total quantity of absorbed water is measured. This term Suction Amount is defined as the total absorbing capacity of the introduced load. Through this, a large amount of absorbed water corresponds to a large load, a small amount of water to a small load. The results of the experiments show that the type and size of a washing load is related to the Suction Speed and the Suction Amount . Apart from this recognized tendency (Fig. 5.67), the results are somewhat fuzzy and thus justify the use of FUZZY CONTROL . 

Compound impurities can lead to biased results when plate readers are used for detection since the total absorbance at a particular wavelength is employed for the determinations. The yt/PLC system employed in these determinations can easily compensate for this problem since only the value for the peak area due to the compound (at the corresponding retention time) is considered for the calculations. For example, in the case of a nifedipine sample, purity was determined to be... 

Substitute the given data into two equations for the total absorbance at 632 and 447 nm to get... 

A quantum yield was determined for acid generation based on the total absorbance of the film and the reflectivity from single crystal silicon at 254 nm. Total film absorbance at 254 nm is 0.185 which corresponds to 35% absorption by the film. Reflectivity at 254 nm is 0.66 (17) and so an additional 15% of the incident light is absorbed after reflection. Total absorption was taken to be 50% of incident dose. It should be noted that the resin absorption without sulfonium salt is 0.155 and thus constitutes about 84% of the total film absorbance with sulfonium salt. 

Table I lists the proportions of the non-planar conformers of TIN and TINS that are present in various solvents and the contribution to the total absorbance made by the non-planar conformer, %A (X), at the excitation wavelength, X, calculated using Equation 1, together with relevant solvent parameters.

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