Absorbance higher order

The neglect of higher-order terms in S2, etc. means that the changes in concentration or in instrument reading are small. In some cases, if a protonation equilibrium occurs, it has proved useful to add a pH indicator to provide a large absorbance change. 

As was shown in previous section, the many-body forces play a crucial role in metal cluster stability. So, a model potential must include many-body terms, at least 3- and, sometimes, 4-body ones. For clusters of larger size, the fitted parameters in these terms will include ( absorb ) many-body effects of higher orders. 

In these circumstances, the feasibihty of quantum Hthography depends on the possibihty of obtaining absorbers with large cross-sections for the entangled photon TPA, or higher order absorption processes. In fact, the munerical value of ae should approach that of Oab ... 

Both Hong and Noolandi [72] and Rice et al. [73] inverted Laplace transforms of order s 1/2 for small s to get the term in f 1/2. The nature of higher-order time dependence was not discussed. For the totally absorbing boundary condition (47), with Rice et al. showed... 

The stringent condition (2.2) can be relaxed. First it is clear that one may allow an arbitrary (positive) factor /(Q), since it can always be absorbed in the time scale. It merely means that large systems may evolve more slowly than small systems. Secondly, as we are going to expand in Q1, it does no harm when higher orders of Q1 occur in addition to (2.2). Thus the final form of our assumption is, rather than (2.2),... 

In derivative Spectrophotometry the absorbance (AJ of a sample is differentiated with respect to wavelength (A) to generate the first, second, or higher order derivatives... 

If some of the reactant or product species are present in excessive quantities, then the fractional changes in their concentrations over the entire duration of the reaction may be immeasurably small. In such cases the concentrations of the reactants present in excess remain approximately constant and may be absorbed into the rate constant fe. A measurement of the order of the reaction from concentration-time plots then does not reveal the dependence of the rate on the concentrations of the overabundant species the measurement yields the pseudo molecularity of the reaction, that is, the sum of the orders with respect to the species that are not present in excess. Thus a number of higher-order reactions are found to be pseudounimolecular under certain conditions. This observation provides the basis for the isolation method of determining the order of a complex reaction with respect to a particular reactant in this method, the apparent overall order (pseudo-molecularity) of the reaction is measured under conditions in which all of the reactants except the one of interest are present in excess. 

Spinach absorbed higher amounts of U than other vegetables and crops did, in spite of the fact that the U availability in the soil was low. The uptake of U by spinach from soil can be accompanied by the uptake of other elements that are also insoluble in soils. In order to compare U and other trace elements taken up by spinach tissues, concentrations of Mg, Al, Ca, Fe, Cu and Zn in acid digests of spinach samples were analysed by inductively coupled plasma optical emission spectrometry (VistaPro, Varian). 

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