Absorption coefficient calculation

Effective wavelengths have been included in Table 3-1 to show the changes that occur in this important variable when one gas is substituted for another. These wavelengths correspond to mass absorption coefficients calculated from Equation 3-14 and were obtained by interpolation from tabulated values of absorption coefficients for different wavelengths.15... 

In Fig. 46 the absorption coefficient, calculated for ice in this band, is expressed in cm-1. The frequency dependences, found for spatial (a) and planar (b) schemes, are compared. In the planar variant the maximum absorption is less than in the spatial variant. This defect of the theory could be reduced by increasing the dipole moment of the reorienting molecules. 

Log arithmic-Mean Driving Force. As noted eadier, linear operating lines occur if all concentrations involved stay low. Where it is possible to assume that the equiUbrium line is linear, it can be shown that use of the logarithmic mean of the terminal driving forces is theoretically correct. When the overall gas-film coefficient is used to express the rate of absorption, the calculation reduces to solution of the equation... 

Units. The unit of sound absorption is the metric sabin, which is equivalent to one square meter of "perfect" absorption, eg, one square meter of a material with a = 1.0. The Knglish unit of sound absorption is the sabin, which is equivalent to one square foot of perfect absorption. In order to avoid confusion, the designation metric should always be used when referring to metric sabins. The number of metric sabins of absorption provided by an area of material is calculated by multiplying its area by its sound-absorption coefficient. For example, 10 m of material having a sound-absorption coefficient of 0.75 provides 7.5 metric sabins of absorption. 

ASTM E1050-90 also makes use of a tube with a test specimen at one end and a loudspeaker at the other end, but iastead of a single movable microphone there are two microphones at fixed locations ia the tube. The signals from these microphones are processed by a digital frequency analysis system which calculates the standing wave pattern and the normal iacidence sound-absorption coefficients. 

The capacity factors of SN-SiO, for metal ions were determined under a range of different conditions of pH, metal ions concentrations and time of interaction. Preconcentration of Cd ", Pb ", Zn " and CvS were used for their preliminary determination by flame atomic absorption spectroscopy. The optimum pH values for quantitative soi ption ai e 5.8, 6.2, 6.5, 7.0 for Pb, Cu, Cd and Zn, respectively. The sorption ability of SN-SiO, to metal ions decrease in line Pb>Cu> >Zn>Cd. The soi ption capacity of the sorbent is 2.7,7.19,11.12,28.49 mg-g Hor Cd, Zn, Pb, andCu, respectively. The sorbent distribution coefficient calculated from soi ption isotherms was 10 ml-g for studied cations. All these metal ions can be desorbed with 5 ml of O.lmole-k HCl (sorbent recovery average out 96-100%). 

For good spectra to be obtained, the difference between the ln(I /lQ) before and after the absorption edge, the edge jump, should be between 0.1 and 1. This may be calculated from the mass absorption coefficient of a sample ... 

From the optical absorption of two different hexaphenyl films, one with its chains predominantly standing upright on the substrate, the other with the chains randomly distributed in all orientations, similar structure property relations can be concluded [139]. By comparing the calculated absorption coefficient [139J perpendicular to the chains with the observed optical absorption spectra of both films we see that the optical absorption, plotted in Figure 9-9, in the visible and... 

Figure 9-9. Calculated absorption coefficient perpendicular to /nnu-licxaplienyl chains (c) computed to the experimentally determined ubsurplion perpendicular (b) and parallel (a) to the chains - taken Iront Ref. I39. ...

The basic principle of most colorimetric measurements consists in comparing under well-defined conditions the colour produced by the substance in unknown amount with the same colour produced by a known amount of the material being determined. The quantitative comparison of these two solutions may, in general, be carried out by one or more of six methods. It is not essential to prepare a series of standards with the spectrophotometer the molar absorption coefficient can be calculated from one measurement of the absorbance or... 

The values of the molar absorption coefficients and e2 can be deduced from measurements of the absorbances of pure solutions of substances 1 and 2. By measuring the absorbance of the mixture at wavelengths Xl and X2, the concentrations of the two components can be calculated. 

Figure 1-8 shows log-log curves calculated from Barkla s absorption-coefficient data. (A log-log plot shows most clearly what Barkla discovered.) For carbon, the wavelength distribution is virtually unchanged from that of the incident polychromatic beam, mainly scattered x-rays being detected the situation is reminiscent of Figure 1-5. The curve for calcium, on the other hand, begins with a straight line that shows the presence in the scattered beam of a relatively intense component for which k is large and sensibly constant. The curve for tin shows two such components. Barkla realized that these components are emitted, and he eventually called them K and L spectra.22 He...

It is obvious that Figure 3-6 serves as a calibration curve with the help of which the chlorine content of unknown, similar materials could be readily determined. It will now be shown that the solid line agrees closely with kf values calculated from the mass absorption coefficients of benzene, hydrogen, and chlorine small variations in effective wavelength will be disregarded. 

Values calculated from Equation 3-13 have been plotted in Figure 3-6 (circles and broken line). Comparison of the two sets of data shows with what precision the polymer could have been analyzed by the x-ray method, had only one sample been available, for none of the data underlying Equation 3-13 was obtained on the polymer itself. (Even better agreement could probably have been obtained by making certain that all the absorption coefficients involved were for the same effective wavelength.)... 

The alternating component of the applied voltage causes a continuous variation in the efficiency of the x-ray excitation (Step II) during each cycle of operation. A polychromatic x-ray beam has a different total absorption coefficient and a different ratio of photoelectric to scattering absorption coefficient for each wavelength (Step V). It is very difficult to take account of these factors exactly. Fortunately, reasonable estimates will suffice in the making of the calculations for Table 4-4 and Figure 4-15. The efficiency has been taken as that for the root-mean-... 

The n t effect of the presence of other elements is conveniently assessed by comparing the intensity of the analytical line in their presence with the intensity calculated from Equation 7-1. The net effect may be to increase the intensity over that calculated (positive), or to decrease it (negative). Individual effects may result from the following causes (1) Presence of an element with absorption coefficient smaller than that of E positive absorption effect). (2) The reverse of this situation negative absorption effect). (3) Presence of an element a characteristic line... 

The change in the absorption effect with chemical composition can be calculated in simple cases by properly adjusting a (Equation 7-5) to allow for the change in mass absorption coefficient. The mass absorption coefficient of the sample for a given wavelength is given by... 

The absolute values of the solubilities of gases are not at present calculable from any general law, although W. M. Tate (1906) finds in the case of aqueous solutions a relation with the viscosities of the solution (/x ), and water (/x0), the critical temperatures of the gas (T0), and of water (T. ), and the absorption coefficients ... 

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