Computer software CURVES

To quantitate proteins from staining, a densitometer aided by computer software is used to evaluate band areas of samples compared to band areas of a standard curve. Amido black, Coomassie Brilliant Blue, and silver stains are all appHcable for use in quantification of proteins. 

The parameters are easily determined by using computer software. In Microsoft Excel, the data are put into columns A and B and the graph is created as for a linear curve fit. This time, though, when adding the trendline, choose the polynomial icon and use 2 (which gives powers up to and including x ). The result is... 

An ideal calibration curve (Figure 2.7) is a straight line with a slope of about 45 degrees. It is prepared by making a sequence of measurements on reference materials which have been prepared with known analyte contents. The curve is fundamental to the accuracy of the method. It is thus vitally important that it represents the best fit for the calibration data. Many computer software packages, supplied routinely with various analytical instruments, provide this facility. It is, however, useful to review briefly the principles on which they are based. 

COMPUTER ALGORITHMS SOFTWARE CURVE FITTING Gurvilinear rate behavior,... 

In the preceding sections, several potential energy curves associated with electrode reactions have been presented. Their purpose is heuristic and they are therefore schematic in nature. Nevertheless, they resemble carefully calculated curves in which molecular dynamics and computer software have been used to obtain the potential energy curves at the various displacements from equilibrium (Rose and Benjamin, 1996 Xia and Berkowitz, 1997) (Fig. 9.16). 

Kinetic analysis of tyrosinase and calculation of constants will be described using graphical analysis by the Michaelis-Menten equation, Lineweaver-Burk equation, or the direct linear curve. Procedures for preparing these graphs are described below. Alternatively, students may use available computer software to graph data and calculate kinetic constants. Recommended enzyme kinetic computer software packages include Enzyme... 

The indirect method can be employed by extrapolating the rheologic models or the shear stress-shear rate data to zero shear rate. The computer software Table Curve 1.12 was used to fit the shear stress-shear rate data to the different rheologic models. This software uses the Simplex method for a nonlinear regression curve fit. 

Microtiter plate readers were developed for ELISA techniques and this is reflected in the computer software available. The Molecular Devices reader is recommended since the software (Softmax ) was developed for diverse applications and contains a curve fitting facility that is ideal for analysis of survival curves. 

S. A. Sande and J. Karlsen, Curve fitting of stability data by personal computer. Software in pharmaceutics II, Int. J. Pharm. 73, 147-156 (1991). 

Calculating the slope of the tangent to a curve at a particular point is undoubtedly easier using computer software. However, this should not be taken to imply that the result is free from uncertainty. 

EnPlot software ASM s analytical engineering graphics software that is used to transform raw data into meaningful, presentation-ready plots and curves. It offers users a wide array of mathematical functions that are used to fit data to known curves and includes quadratic Bezier spline, straight-line polynomial, Legendre polynomial, nth order, and exponential splines. See computer software mathematics. 

If one wishes to attain high conversion at constant composition, the more reactive monomer must be added in a programmed manner. The procedure is as follows from the copolymerization diagram (or from the reactivity ratios) one obtains the monomer composition that will lead, at low conversion, to the desired copolymer composition. A conversion/time curve is drawn up for this system and the composition of the copolymer determined from time to time. From this, one can find how much of the more reactive monomer is to be added at given times during the polymerization in order to maintain an approximately constant composition (see Example 3.39). Special computer software has already been developed for this. 

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